Department of Chemical Engineering

CHEE 457: Design Project II

Production of Stainless Steel

Presented to:Prof. Dimitrios BerkMrs. Nadia RomaniDr. Roger Urquhart

Submitted by:Mohammed Abu Shark - 260376614Spencer John Brennan - 260315605

Saikat Chanda - 260372492Michael Garibaldi - 260353823

Friday April 11th, 2014

Design II

Acknowledgements

As a group we would like to sincerely thank Mrs. Romani and Dr.

Urquhart for all their guidance and support throughout the year. Their

engineering experience and knowledge were instrumental in our

learning process. We are grateful to have learned from such

professional instructors.

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Design II

1. INTRODUCTION....................................................................................................................................................1

1.1 PROJECT MANDATE...............................................................................................................................................................1

1.2 PROJECT SCOPE......................................................................................................................................................................1

1.3 DELIVERABLES.......................................................................................................................................................................3

2. PROCESS DESIGN..................................................................................................................................................4

2.1 PROCESS DESCRIPTION.........................................................................................................................................................4

2.1.1 Midrex Direct Iron Reduction................................................................................................................................. 4

Midrex Shaft Furnace......................................................................................................................................................................4

Steam Reformer.................................................................................................................................................................................6

Venturi Scrubber...............................................................................................................................................................................8

Boiler...................................................................................................................................................................................................... 9

2.1.2 Electric Arc Furnace................................................................................................................................................... 9

EAF Function.......................................................................................................................................................................................9

Process Overview..............................................................................................................................................................................9

Block Flow Diagram...................................................................................................................................................................... 10

Process Description.......................................................................................................................................................................10

Summary of EAF Reactions........................................................................................................................................................12

2.1.4 Continuous Casting.................................................................................................................................................. 13

2.2 DESIGN CRITERIA............................................................................................................................................................... 14

2.3 MATERIAL AND ENERGY BALANCE.................................................................................................................................15

2.3.1Midrex Direct Iron Reduction............................................................................................................................... 15

Midrex Shaft Furnace....................................................................................................................................................................15

Steam Reformer.............................................................................................................................................................................. 18

Boiler................................................................................................................................................................................................... 22

Energy Balance for Remaining Equipment.........................................................................................................................23

2.3.2 Electric Arc Furnace................................................................................................................................................ 24

2.3.4 Continuous Casting.................................................................................................................................................. 27

Water-Cooled Mould Methodology........................................................................................................................................28

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Design II

Water Spray Chamber..................................................................................................................................................................32

Blower Section.................................................................................................................................................................................35

3. OPERATING PHILOSOPHY..............................................................................................................................37

3.1 CONTROL THEORY..............................................................................................................................................................37

3.2 PROCESS AND INSTRUMENTATION DIAGRAM DEVELOPMENT....................................................................................37

3.2.1 Overall P&ID Development................................................................................................................................... 37

3.2.2 Common Unit Control Philosophy...................................................................................................................... 37

Pumps and Compressors............................................................................................................................................................ 37

Control Valves..................................................................................................................................................................................38

3.2.3 Midrex Direct Iron Reduction.............................................................................................................................. 40

Midrex Shaft Furnace and Conveyor Belts..........................................................................................................................40

Steam Reformer.............................................................................................................................................................................. 41

Boiler................................................................................................................................................................................................... 43

Venturi Scrubber............................................................................................................................................................................ 44

Heat Exchanger............................................................................................................................................................................... 45

3.2.4 Control Philosophy Electric Arc Furnace........................................................................................................46

Cooling water flow rate............................................................................................................................................................... 46

Hydraulic mechanisms.................................................................................................................................................................49

Bin weighing control.....................................................................................................................................................................54

Fan speed control...........................................................................................................................................................................55

3.2.6 Continuous Casting Section.................................................................................................................................. 56

Flux Transport Control................................................................................................................................................................56

Molten Stainless Steel Flow Control.......................................................................................................................................57

Cooling Water Flow Control......................................................................................................................................................58

Mist Flow Control...........................................................................................................................................................................59

4. PLANT DESIGN....................................................................................................................................................60

4.1 EQUIPMENT SIZING............................................................................................................................................................60

4.1.1 Midrex Direct Iron Reduction.............................................................................................................................. 60

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Design II

Shaft Furnace................................................................................................................................................................................... 60

Air blower.......................................................................................................................................................................................... 60

Air compressors..............................................................................................................................................................................61

Venturi Scrubber............................................................................................................................................................................ 63

Boiler................................................................................................................................................................................................... 64

Conveyor belts................................................................................................................................................................................. 65

Heat Exchanger............................................................................................................................................................................... 66

4.1.2 Electric Arc Furnace................................................................................................................................................ 67

Transformers................................................................................................................................................................................... 69

Axial Vane Fans............................................................................................................................................................................... 70

Ladles.................................................................................................................................................................................................. 70

Bins....................................................................................................................................................................................................... 71

Lime Pebble Silos........................................................................................................................................................................... 72

Cranes.................................................................................................................................................................................................. 72

Conveyors.......................................................................................................................................................................................... 73

Suspended Magnet.........................................................................................................................................................................74

Cooling Bed and Excavator........................................................................................................................................................ 74

4.1.4 Continuous Casting Section.................................................................................................................................. 75

Tundish............................................................................................................................................................................................... 75

Flux Silo and Hopper (SI-03-401 and HP-03-401 and HP-03-402)..........................................................................76

Oscillating Water-Cooled Mould (MD-03-401 and MD-03-402)...............................................................................77

Spray Chamber (SC-03-401 and SC-03-402)......................................................................................................................79

Pneumatic Conveying...................................................................................................................................................................80

Rotary Screw Air Compressor (CP-03-401 A/B)..............................................................................................................82

Membrane Air dryer (DR-03-401)..........................................................................................................................................82

Bottom Discharge Blow Tanks (TA-03-401 to 404).......................................................................................................82

Axial-Flow Compressor and Centrifugal Pump for Spray Chamber Mix (CP-03-402 A/B to 403 A/B and

PP-03-403 A/B to 404 A/B)......................................................................................................................................................83

Water-Cooled Mould Pump........................................................................................................................................................84

Power-Driven Roller Conveyors (RL-03-401 to 458)....................................................................................................85

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Design II

Roller Conveyor Slab Collection Rack (RA-03-401)........................................................................................................86

Blowers (BL-03-401 to 420).....................................................................................................................................................87

4.2 PLANT LAYOUT...................................................................................................................................................................88

5. ENVIRONMENTAL EVALUATION..................................................................................................................89

5.1 MIDREX PROCESS............................................................................................................................................................... 89

5.2 ELECTRIC ARC FURNACE...................................................................................................................................................89

5.4 CONTINUOUS CASTING.......................................................................................................................................................90

6. COST ANALYSIS.................................................................................................................................................91

6.1 CAPITAL EXPENDITURE (CAPEX)..................................................................................................................................91

Indirect Costs......................................................................................................................................................................... 95

6.2 OPERATING EXPENDITURES (OPEX).............................................................................................................................96

6.2.1 Net Present Value of Investment........................................................................................................................ 98

6.3 INTERNAL RATE OF RETURN............................................................................................................................................98

7. REFERENCES.....................................................................................................................................................100

APPENDIX A - MASS & ENERGY BALANCE.........................................................................................................I

A.2 ELECTRIC ARC FURNACE....................................................................................................................................................... I

A.4 CONTINUOUS CASTING......................................................................................................................................................VIII

APPENDIX B – EQUIPMENT SIZING..................................................................................................................XV

B.4 CONTINUOUS CASTING.......................................................................................................................................................XV

APPENDIX C – CAPEX & OPEX......................................................................................................................XXVII

C.1 CAPEX............................................................................................................................................................................... XXVII

C.2 - OPEX.............................................................................................................................................................................. XXXI

APPENDIX D – PROCESS FLOW DIAGRAMS...................................................................................................37

APPENDIX E – PROCESS & INSTRUMENTATION DIAGRAMS...................................................................44

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Design II

APPENDIX F – PLANT LAYOUT..........................................................................................................................51

APPENDIX F – EQUIPMENT LIST.......................................................................................................................56

List of Figures

Figure 1................................................................................................................................5

Figure 2................................................................................................................................7

Figure 3................................................................................................................................9

Figure 5..............................................................................................................................10

Figure 6..............................................................................................................................10

Figure 7..............................................................................................................................21

Figure 8..............................................................................................................................34

Figure 9..............................................................................................................................39

Figure 10............................................................................................................................40

Figure 11............................................................................................................................40

Figure 12............................................................................................................................42

Figure 13............................................................................................................................43

Figure 14............................................................................................................................44

Figure 15............................................................................................................................45

Figure 16............................................................................................................................46

Figure 17............................................................................................................................47

Figure 18............................................................................................................................48

Figure #9............................................................................................................................49

Figure 20............................................................................................................................49

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Design II

Figure #21..........................................................................................................................50

Figure 22............................................................................................................................51

Figure 23............................................................................................................................52

Figure 24............................................................................................................................53

Figure 25............................................................................................................................54

Figure 26............................................................................................................................55

Figure 27............................................................................................................................55

Figure 28............................................................................................................................56

Figure 29............................................................................................................................57

Figure 30............................................................................................................................58

Figure 31............................................................................................................................59

Figure 32............................................................................................................................60

Figure #33..........................................................................................................................63

Figure #34..........................................................................................................................64

Figure #35..........................................................................................................................65

List of Tables

Table 1...............................................................................................................................16

Table 2...............................................................................................................................20

Table 3...............................................................................................................................28

Table #4.............................................................................................................................65

Table 5...............................................................................................................................93

Table 6...............................................................................................................................96

Table 7...............................................................................................................................98

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Design II

Table 8..................................................................................................................................i

Table 9..................................................................................................................................i

Table 10...............................................................................................................................ii

Table 11..............................................................................................................................iii

Table 12............................................................................................................................viii

Table 13............................................................................................................................viii

Table 14..............................................................................................................................ix

Table 15.............................................................................................................................xii

Table 16............................................................................................................................xiii

Table 17............................................................................................................................xiii

Table 18............................................................................................................................xiv

Table 19.............................................................................................................................xv

Table #20..........................................................................................................................xvi

Table 21...........................................................................................................................xvii

Table 22..........................................................................................................................xviii

Table 23............................................................................................................................xix

Table #24...........................................................................................................................xx

Table #25..........................................................................................................................xxi

Table #26..........................................................................................................................xxi

Table #27.........................................................................................................................xxii

Table #28........................................................................................................................xxiii

Table #29........................................................................................................................xxiii

Table #29........................................................................................................................xxiv

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Design II

Table #30........................................................................................................................xxiv

Table #31.........................................................................................................................xxv

Table #32.........................................................................................................................xxv

Table #33........................................................................................................................xxvi

Table 34.........................................................................................................................xxvii

Table #35......................................................................................................................xxviii

Table #36......................................................................................................................xxviii

Table #37........................................................................................................................xxix

Table 39.............................................................................................................................34

Table 40.............................................................................................................................36

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Design II

1. Introduction

1.1 Project Mandate

Inox has selected three McGill consulting teams to design a complex in Quebec

for the production of stainless steel slabs by exploiting the chromite deposit from the

“Ring of Fire”. The project mandate of Group 3 is to produce 2 million tonnes of

stainless steel per annum. In order to satisfy the mandated tonnage, 1,400,550 tonnes per

annum of iron ore pellets, 150,000 tonnes per annum of steel scrap and 400,000 tonnes

per annum of ferronickel are procured, while, 600,000 tonnes of high carbon

ferrochromium (HCFeCr) is received from Groups 1 and 2.

1.2 Project Scope

Group 3 will design processes to produce the solidified stainless steel slabs with

dimensions 10 m x 0.25 m x 1 m at a composition of 18 % chromium, 0.08 % carbon and

8 % nickel. To produce such slabs, there are four main process steps required:

(1) Iron ore reduction in the Midrex Direct Iron Reduction Process

(2) Heating and further reduction of carbon in the Electric Arc Furnace (EAF)

(3) Oxidation and addition of chromium in the Argon Oxygen Decarburizer (AOD)

(4) Cooling of molten stainless steel for slab production by continuous casting

The aforementioned processes will be designed in full, from mass and energy

balance considerations and engineering drawings such as block flow diagrams (BFD),

process flow diagrams (PFD) and process and instrument diagrams (P&ID). Equipment

will be sized based on process flow calculations and the most suitable will be chosen and

recommended for implementation. A layout of the stainless steel production plant will be

provided – both top view and side view – indicating the preferred location of the process

equipment. A complete capital and operating economic evaluation (CAPEX and OPEX)

will be performed and the return on investment (ROI) based on the produced tonnage per

annum will be determined. To ensure the plant has the ability to meet future imposed

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Design II

environmental regulations, sustainable design aspects will be considered and a full

environmental evaluation completed.

Battery limits of the project define a process perimeter, limiting the scope of

group 3’s design responsibilities. Engineering design, sizing and costing of the processes

used to produce stainless steel are all within the battery limits of the outlined Inox

project. The specific aspects not within the battery limits of this project are:

The source and transportation of high carbon ferrochromium received in either

granulated or molten form Groups 1 and 2

The source and all aspects of pumping (including costing) of cooling water, which is

received from Group 2

All aspects of the process water treatment and return to the environment (although

pumping to the wastewater treatment plant is accounted for)

The distribution of slabs to their final market destination

The cost of all other raw materials (iron ore pellets, ferronickel (FeNi40) and steep scrap)

and utilities are accounted for during operation and procurement. Transportation costs

upon procurement are included in the price per unit quantity purchased.

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Design II

1.3 Deliverables

The following deliverables were included on the final report:

Executive Summary Overall Block Flow Diagram (BFD) Overall Process Flow Diagram (PFD) Process description Equipment description Overall Control strategy Engineering Drawings :

Individual Block Flow Diagram (BFD) Individual Process Flow Diagram (PFD) Individual Piping & Instrumentation Diagram (P&ID)

Plot Plan Economic evaluation (CAPEX, OPEX, ROI) Environmental Evaluation Mass and Energy balances Equipment Sizing Breakdown of Responsibilities

2. Process Design

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Design II

2.1 Process Description

2.1.1 Midrex Direct Iron Reduction

Midrex Shaft Furnace

The Midrex direct reduction system is a gas-based reduction process from which

the production of sponge iron can be achieved. The main difference between the sponge

iron, commonly referred to as direct reduced iron (DRI), and iron ore pellets feed is their

oxygen content. The iron ore contains approximately 30wt% oxygen while the direct

reduced iron has 3wt%. In order to reduce the oxygen content, the iron oxide (fe2O3;

96.8wt%) present in iron ore will undergo a series of consecutive oxidation-reduction

reactions, shown below, with a gas stream high in CO and H2 content, to form metallic

iron, carbon dioxide and steam:

(1) 3Fe2O3 + CO → 2Fe3O4 + CO2

(2) 3Fe2O3 + H2 → 2Fe3O4 + H2O (3) Fe3O4 + CO → 3FeO + CO2

(4) Fe3O4 + H2 → 3FeO + H2O (5) FeO + CO → Fe + CO2

(6) FeO + H2 → Fe + H2O

To a small extent, the metallic iron product is further reduced by carbon

monoxide and hydrogen by the following carburization reactions:

(7) 3Fe + 2CO → Fe3C + CO2

(8) 3Fe + CO + H2 → Fe3C + H2O

Traditionally, this process has been completed using blast furnaces, however since

they require high quality coke, auxiliary plants for raw material handling, higher

operating temperature and three times the CO2 emissions of direct iron reduction

methods, they are not favoured for iron ore reduction processes (Chatterjee, 1994). The

oxidation-reduction reactions are carried out in a shaft furnace where the iron ore pellets

are fed from the top through a charge hopper while the syngas stream flowing from the

bottom through tuyere. Feeding the reactants to the Midrex furnace in this counter-

current fashion allows for efficient heat transfer to occur between the solids and gases

(Anameric et al., 2007).

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Design II

Figure 1The Midrex unit is operated in a counter-current fashion to increase heat transfer between the gases and

solids (Anameric et al., 2007).

The incoming syngas enters the furnace at 894oC, heating the iron ores and leaves

as off-gas at 450 oC. The overall reduction process is endothermic (105 kJ/mol; 25 oC),

thus requiring an additional source of heating.

The sponge iron can be discharged in three different manners from the Midrex

furnace: cold DRI, hot DRI and hot briquetted DRI. Cold and briquetted DRI are

effective for storage and shipping, however since the reduced iron will be further

processed in the electric arc furnace (EAF), hot DRI is preferred since it is discharged at

a temperature of 650 oC, thus cutting down on the EAF’s energy consumption.

The chemical composition of the DRI is dependent on the quality of the iron ore

feed. A higher iron oxide percent in the pellets will give higher iron content in the

product and lower gangue amount (Anameric et al., 2007). Referring to the list of design

criteria in section X, the DRI composition has four criteria that need to be met: 3wt

%FeO, 1.6wt%C, 90% of FeS retained in the DRI and 100% of the remaining gangue

material retained in the DRI. The iron metallization percent is used to determine the

extent of iron reduction. For the given iron ore pellet composition and the DRI criteria

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Design II

needed, the sponge iron has a degree of metallization of 93.3%. This is within the

common metallization range of 90-94% for Midrex processes (Midrex Technologies,

2013).

Steam Reformer

The steam reformer is a catalytic process that converts natural gas and steam into

hydrogen and carbon monoxide gas. The reformer has two sets of reactions taking place:

the reforming reactions, which produced the syngas mixture (CO and H2) and the

combustion reactions which provides the heat input required for the endothermic

reforming reactions. The reforming reactions taking place depends on the composition of

the natural gas feed. For this case, methane, ethane, propane, butane and pentane react to

form syngas as follows:

(9) CH4 + H2O → CO + 3H2

(10) C2H6 + 2H2O → 2CO + 5H2

(11) C3H8 + 3H2O → 3CO + 7H2

(12) C4H10 + 4H2O → 4CO + 9H2

(13) C5H12 + 5H2O → 5CO + 11H2

The reforming reactions take place inside nickel catalyst-filled tubes that are vertically

mounted inside the combustion chamber. The burners and tubes can be arranged

according to either a top-fired or side-fired design. A top-fired design was used in this

process because of higher heat transfer efficiency compared to side-fired designs, using

twice as less burners (GBH Enterprises, 2013). The Midrex steam reformer recycles the

off-gas from the shaft furnace to generate more syngas, according to the following

reaction, thus lowering the natural gas demand:

(14) CH4 + CO2 → 2CO + 2H2

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Design II

Figure 2Top-fired steam reformer set-up (ThyssenKrupp, 2014).

The feed natural gas and steam are pre-heated to approximately 500oC using a

heat exchanger, thus cutting the reforming reactant heating requirement by more than

half. The off-gas from the electric arc furnace and argon oxygen decarburization

processes are sent to a gas scrubber and then recycled to the reformer, thus lowering the

natural gas amount needed for reforming reactions. The following combustion reactions

take place inside the combustion chamber:

(15) CH4 + 2O2 → CO2 + 2H2O (16) C2H6 + 7/2O2 → 2CO2 + 3H2O

(17) C3H8 + 5O2 → 3CO2 + 4H2O (18) C4H10 + 13/2O2 → 4CO2 + 5H2O

(19) C5H12 + 8O2 → 5CO2 + 6H2O

Air is used as the source of oxygen and is blown into the system using an air

blower. It is assumed that the syngas leaves the reformer furnace at approximately 900oC

and is heated entirely by the combustion of natural gas by reaction 15-19. The

combustion flue gas leaves the system through tunnels located at the bottom and is used

to pre-heat incoming reactants in the heat exchanger.

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Design II

Venturi Scrubber

A venturi scrubber is used to remove dust particles contained in the off-gasses of

the EAF and AOD process before recycling them into the Midrex reformer. Venturi’s are

classified as a wet scrubber method since water is used to remove the particles of interest.

The incoming gas stream’s speed is accelerated due to inertia when moving down the

throat section of the scrubber. This will cause, upon contact with water, the formation of

many small water droplets at the throat section of the scrubber. When the dust particles

enter the throat section of the venturi scrubber, they collide with the tiny water droplets

by impaction, illustrated below. The removal efficiency by impaction is proportional to

the dust particle diameter, but decreases exponentially for particle size less than 0.2μm

(EPA, 1991).

Figure 3Left: Impaction mechanism is used to trap the dust particles into the water droplets.

Right: venturi scrubber where the water is fed at the converging section (EPA, 2014).

The scrubber consists of three main parts: converging, throat and divergent

sections. The gas stream enters from the top of the venturi while the water stream is fed

from either the throat or converging section. Since the stream to be treated consists of hot

dry gas, the preferred region to feed the water is from the convergent section, because

this will prevent abrasion of the throat wall (EPA, 2014).

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Design II

Due to high gas velocity at the throat section of the venturi scrubber, some of the

water droplets are carried by the gas stream, creating entrainment droplets, thus venturi

scrubbers are commonly followed by a cyclone for mist elimination.

Boiler

The reforming reactions require steam in order to produce the syngas stream. This

will be provided by boiling process water and heating to 400oC by using a water boiler to

form super-heated steam. The boiler consists of a three-pass steam fire-tube. The boiler

transfers heat similar to a shell-and-tube heat exchanger, where the hot gases from

combustion flow through the tubes, while the water is contained in the shell. A large

capacity boiler was chosen (1300-2300 BHP) to meet the required power of 1800 boiler

horsepower (BHP). The heating will be provided by the combustion of natural gas instead

of oil, since natural gas is already used in other equipment of the Midrex process.

2.1.2 Electric Arc Furnace

EAF Function

An electric arc furnace (EAF) has three primary functions:

1. To contain the steel scrap and direct reduced iron;2. To heat and melt the steel scrap and direct reduced iron;3. To transfer the molten steel to the next processing stage.

Process Overview

Figure 4

Furnace charging Melting De-slagging Metal pouring

Furnace turn-aroundRoutine inspection of all furnace componentsLubrication

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Design II

Block Flow Diagram

Figure 5

Block flow diagram of EAF unit.

Process Description

Receive DRI

Direct reduced iron pellets arrive from the Midrex unit from the DRI conveyor

(CV-03-103). These pellets are directed into a chute which feeds into a bin (BN-03-

201/202). The bin is suspended from an overhead crane (CN-03-201) which measures the

change in weight of the bin. One-hundred and twenty-four tonnes of DRI are loaded into

this bin. Once the desired weight is reached, the DRI conveyor is stopped and the lime

pebble conveyor is activated.

Receive Lime

The lime pebbles are stored in three separate silos (SI-03-201). Only one of these

silos feeds the conveyor at a time. The silo hatch is opened and feeds lime onto the

conveyor (CV-03-201) as the conveyor moves below. Seven tonnes of lime are loaded

into the bin and then the silo hatch is closed and the conveyor is stopped. The bin is then

elevated and carried by the crane to the steel scrap transfer station.

Transfer of Steel Scrap

Steel scrap is purchased from an external vendor. CN Railways is under contract

with the company to deliver the steel scrap via rail car. A rail branches from the main CN

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Design II

line and enters the plant in the EAF section. The rail cars are detached from the

locomotive and rest inside the plant. The overhead crane (CN-03-201) binds the

suspended magnet (CN-03-204) and takes scrap from the rail car (BN-03-203), placing it

in the bin filled with DRI and lime. The crane measures 18 tonnes of scrap and then

detaches from the magnet, lifts the bin and carries it to the crane transfer station. Here the

bin is placed below another overhead crane (CN-03-202/203).

Charging EAF

The second crane in the process lifts the bin and positions it above the electric arc

furnace. With the roof of the EAF (RF-03-201/202) raised and to the side, the crane

charges the furnace by emptying the materials of the bin into the hearth (EAF-03-

201/202).

Moving of Roof, Turning on Fan, Switching on Current, Lowering Electrodes

The roof (RF-03-201) then moves into position above the furnace shell. Once the

roof is in place, the axial vane fan (FA-03-201) is turned on to begin venting. The control

valve for the cooling water (FCV-03-205) is opened to begin the flow of water to the

roof, bus bar (BB-03-201) and electrodes (EE-03-201). Pressure of the furnace is

measured to regulate the fan speed. The switch is then turned on to initiate the current

transfer from the transformer station, through the power cables and the bus bar and into

the three graphite electrodes. The height of the bus bar is then lowered, bringing the hot

electrodes into contact with the contents of the hearth.

Melting Charge

The initial melt takes fifteen minutes to achieve. To avoid fracturing the

electrodes, the height of the electrodes is initially above the mass of DRI, scrap and lime.

After fifteen minutes, the top layer of scrap and DRI is melted and the electrodes are

lowered further to bore into the material and expedite melting. The height of the

electrodes gradually decreases over the remaining forty-five minutes. After an hour, the

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Design II

current is switched off and the bus bar is raised to remove the electrodes from the bath of

slag and hot metal. During the melting period, temperatures inside the bath reach 1600°C.

Slag Removal

The slag forms a fluid layer on top of the molten metal. The slag door is located

above the top of the slag. It is opened using the hydraulic mechanism, creating a path for

slag to flow down the slag launder (LA-03-202) and into the slag pot (LC-03-201). The

furnace is tilted using the hydraulic mechanism and the slag pours out of the furnace. The

slag door is closed and the furnace is tilted upright once the slag ceases to flow.

The slag pot is positioned on a slag pot car, which moves automatically along a

rail to the outdoor cooling bed (CB-03-201). Upon reaching the cooling bed, the slag pot

is tipped on its side to pour out the molten slag. It is left to cool and solidify into grains.

An excavator (EX-03-201) removes the slag from the concrete bed and piles it on the slag

deposit (DP-03-201). It remains in the deposit until a disposal contractor moves it to

another remote location.

Hot Metal Tapping

The hot metal door is located above the hot metal launder (LA-03-201). It is

opened with the hydraulic mechanism and the furnace is tilted to allow the hot metal to

flow along the launder and into the hot metal ladle (LD-03-201).

Transfer of Hot Metal Ladle

The hot metal ladle is located beneath the overhead crane (CN-03-202). The crane

lifts the ladle and carries it to the Argon Oxygen Decarburization unit, where it undergoes

further processing.

Summary of EAF Reactions

Reaction1 : F e3C →3 Fe+CReaction2 : FeS+CaO→ FeO+CaS

Reaction3 : FeO+C →Fe+COxxii

Design II

2.1.4 Continuous Casting

Continuous strand casting is the process by which molten metal is solidified to a

strand of solid. Through the storage of molten stainless steel in the tundishes the stainless

steel production process is converted from batch to continuous. The restricting element

of the casting process is the heat removal rate. At the specified design capacity of 2

million t/a stainless steel production, there are two full gravity arc casting systems

employed. Cooling of the stainless steel from 1800 °C to room temperature occurs in

three main stages in continuous casting:

1. Primary cooling via the water-cooled copper mould

2. Secondary cooling via the spray chamber

3. tertiary cooling via numerous air blowers

Molten stainless steel tapped from the AOD in batches, is delivered to the

tundishes in crane-transported ladles. The stopper-controlled rod and nozzle allows for

the casting rate to be kept constant while the tundishes’ volumes vary. A CaF2 flux is

added to the tundish to minimise oxidation of the stainless steel, as well as provide vital

lubrication between the solidified stainless steel wall and oscillating water-cooled mould.

Molten steel is partially solidified in primary cooling, whereby the cooling water

runs counter-current to the stainless steel being cast. The mould removes approximately

20 % of the total required sensible and latent heat load, however, it provides integral

outer wall strength to the strand (solidifying 18 % of the steel) prior to reaching the spray

chamber.

Secondary cooling in the spray chamber, removes heat via evaporation of a water

mist created by mixing compressed air and water at an equal volumetric ratio. The spray

chamber introduces the water mist via nozzle spray directly onto the cast (and rollers),

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Design II

while the rollers provide directional guidance to the strand, ensure it is properly

supported as well as imposing its shape via compression. The spray chamber guides the

strand down the 12.2 m radius arc from upper plant floor to the ground floor. It also

extends for four meters beyond the arc in a straight section. This cooling process

solidifies the remainder of the strand and reduces the temperature at the outlet to 400 °C.

The strand is transported by individually power-driven stainless steel rollers upon

exit from the spray chamber. The strand is cut into individual slabs 10 m in length by an

oxyacetylene torch and eventually rolled to the slab collection rack. The slabs remain on

the collection rack for 4.21 hours, where tertiary heat removal occurs via forced air

convection with industrial scale blowers to 90 °C. From here slabs are lifted by a large

hoisting crane to inventory and subsequently to a flatbed truck or to a railcar for transport

to industry.

2.2 Design Criteria

xxiv

Design II

xxv

Parameter Value

Plant OperationPre-Production Span 3 yearsProduction Span 17 yearsOperation per Annum 351 daysRequired Tonnage of Stainless Steelper Annum 2,000,000 tonnes

Feed Specifications

Iron Ore Composition (Weight %)

Fe2O3 96.79SiO2 1.66CaO 0.57AlO3 0.41MgO 0.31TiO2 0.16MnO2 0.049Na2O 0.036P2O5 0.013FeS 0.006

Steel Scrap (Weight %)

Fe 96.85C 1.35

Mn 1.65Si 0.06P 0.04S 0.05

High Carbon Ferrochromium from Group 1 (Weight %)

Cr 60.00Fe 29.50Si 3.00C 7.50

High Carbon Ferrochromium from Group 2 (Weight %)

Cr 60.00Fe 30.20Si 1.20C 8.60

Ferronickel (Weight %)

S 0.05P 0.025Fe 59.32Si 0.6Cu 0.5C 0.1Ni 40

Product Specifications

Maximum Stainless Steel Compositions (Weight %)

C 0.08Cr 18.00Ni 8.00

UtilitiesCooling Water Supply 30 °CCooling Water Return 38.5 °CProcess Water Supply 30 °CAmbient Air Supply 25 °C

Design II

2.3 Material and Energy Balance

2.3.1Midrex Direct Iron Reduction

Midrex Shaft Furnace

Mass balance

The mass balance on the shaft furnace was started by first specifying the amount

of reactants and products needed for each reaction taking place in the system. The

reactions in the shaft furnace happen consecutively in group of two reactions, meaning a

group of two reactions can be written as one reaction for the purpose of calculating the

stoichiometric amount of reactants and products. Thus, the first two reactions take place

simultaneously and are followed by reaction 3-4 and so forth. The amount of reactants

and products are calculated based on stoichiometric amount of mol of the limiting

reactant in each group of reaction, while taking into consideration the conversion % for

each reaction. Table #1 below shows the limiting reactant and conversion % for each

group of reaction taking place together. Based on the design criteria provided by Inox

Inc, the 3wt% FeO in the DRI output is achieved by setting the conversion % to 97.5 in

reaction 5-6. This number was found using the excel solver function, where the

conversion rate of reaction 5-6 is iterated such that the FeO amount needed is achieved.

The same method was used to meet the design criteria of 1.6wt%C in the DRI output, by

setting the conversion% of reaction 7-8 to 24.5.

Table 1The limiting reactant and conversion % for each group of reactions taking place in the shaft furnace.

  Reaction Limiting Reactant Conversion %

1 3Fe2O3 + CO → 2Fe3O4 + CO2 Fe2O3 1002 3Fe2O3 + H2 → 2Fe3O4 + H2O

 3 Fe3O4 + CO → 3FeO + CO2 Fe3O4 1004 Fe3O4 + H2 → 3FeO + H2O

xxvi

Design II

 5 FeO + CO → Fe + CO2 FeO 97.506 FeO + H2 → Fe + H2O

 7 3Fe + 2CO → Fe3C + CO2 Fe 24.508 3Fe + CO + H2 → Fe3C + H2O

Due to strict CO emission requirements, the amount of CO and H2 provided for reactions

5 to 8 are not based on stoichiometric amount of the limiting reactant, but are calculated

based on how much is needed for the conversion % stated.

The DRI output needed is specified by the downstream EAF process and is used

to specify the first limiting reactant of the eight reactions (Fe2O3). This is done by taking

the ratio of the iron ore input to the DRI output, by taking a basis of calculation of Fe2O3

mass. Once the amount of first limiting reactant is computed, all stream flowrate except

the syngas can be known.

Once the amount of reactant and products are calculated by taking a basis of

calculation, the next step is to determine the stream composition and mass flowrate of

each stream of the system. The iron ore pellet composition is given by Inox Inc, which

contains the Fe2O3 reactant. It is assumed that it is the only species that react from the

iron ores. Thus, knowing the Fe2O3 needed allows us to specify the mass flowrate of the

iron ore stream. Similarly, the DRI flowrate is determined by adding the ferrous products

and reactant left from each of the eight reactions and adding them to the unreacted

species contained in the iron ore. The other two reactants (CO and H2) are coming from

the syngas produced from the steam reformer.

The syngas mass flowrate and composition is determined from the reformer’s

mass balance. The off-gas stream of the Midrex shaft furnace consists of the CO2 and

H2O generated from all eight reactions and any gas and solid that does not react from the

syngas stream.

The mass balance on the shaft furnace is:

msyngas+miron ore=mDRI+mflue gas

xxvii

Design II

Where m represents the mass flowrate of a stream.

Energy Balance

The eight reactions taking place in the furnace are either exothermic or

endothermic, but overall requiring a heat input. It was assumed that: the reactions start at

650oC, the system operates at steady state and the heating is provided by the hot syngas

stream and electric heating.

First, the temperature of the iron ore heated by the syngas is calculated according to the

following energy balance:

∑a

j

.n¿112 ,a C p ,a(T f −25)=∑a

j

. n¿ 110 ,a Cp ,a(900−T f )

Where,

a to j= species in the stream specifiedn¿ 122, a= molar flowrate of species a in iron ore stream (mol/hr)n¿ 110 ,a= molar flowrate of species a in syngas stream (mol/hr)C p ,a= average C p value of species a within temperature range (j/mol.k)

The final temperature, Tf, was found to be 575oC, however the off-gas

temperature of the Midrex shaft furnace, from various source, indicate that it is between

400-450oC. It was assumed that the final temperature of the off-gas and heated iron ore

temperature is 450oC. Thus, the iron ore pellet will need to be heated from 450oC to

650oC by electrical heating. The heat transfer efficiency for heating the iron ore is:

ε=450575

∗100=78 %

The ferrous product’s molar flowrate was used to compute the heat of reaction

released. For example, for the reaction 3Fe2O3 + CO → 2Fe3O4 + CO2, the molar flowrate

of Fe3O4 is used to compute the heat of reaction. Thus, the final energy balance used to

compute the energy requirement of the system is:

∑a

j

.n¿112 ,a ∫450

650

Cp dT +nFe3 O4 ,¿ 1¿H Rxn,¿1¿650+nFe3 O4 , ¿2¿ H Rxn ,¿2¿650+ nFeO ,¿ 3 H ¿Rxn ,¿3¿650+ nFeO ,¿ 4¿ HRxn, ¿4¿650+nFe, ¿5¿H Rxn ,¿5¿650+nFe, ¿6 ¿H Rxn ,¿ 6¿650+ nFe3C , ¿7¿ HRxn, ¿7 ¿650+nFe3 C , ¿8 ¿ HRxn ,¿ 8¿650=Qf

xxviii

Design II

Where,

n¿ 112 ,a= molar flowrate of species a in iron ore stream (mol/hr)nFe3 O4 ,¿1¿= molar flowrate of Fe3O4 for reaction #1 (mol/hr)H Rxn,¿1¿650= Heat of reaction at 650oC for reaction #1 listed in the process description (j/mol)

Steam Reformer

Mass Balance

The mass balance on the reformer is split into two parts: mass balance for

reforming reactions and mass balance for combustion reactions. Both mass balances

follow the same methodology of the Midrex’s mass balance for computing the reactants

and products mass based on stoichiometric amount, by taking a basis of reactant for each

reaction. However, unlike the shaft furnace’s mass balance, the reactions take place at the

same time instead of consecutively. For both the reforming and combustion reactions, all

reactions conversion is assumed to be 100% and the hydrocarbon reactants are provided

by a natural gas stream with a range for each species composition.

For the reforming reactions, both products (CO and H2) are the same for all

reactions. CO was taken as the basis of calculation for all reactants and products, since its

amount is calculated from the Midrex shaft furnace’s mass balance, but also because the

reforming reactions produce an excess amount of H2 than is needed for the shaft furnace.

In order to split how much CO is produced from each reforming reaction, the

composition of natural gas is used, since all the hydrocarbon reactants are provided only

from the natural gas feed. The natural gas composition was compared between Enbridge

and Union gas from their respective websites. Enbridge provides fixed natural gas

composition while union gas provides a range of composition. The Enbridge

compositions were first taken to provide a basis of calculation for the reforming

reactions.

The CO amount produced from the reforming reactions was first split based on

the Enbridge composition, however the presence of unreactive species in the stream

xxix

Design II

requires the percentage of CO generated from each reactions to be changed. For example,

the reactive species from the natural gas stream makes up 97.8mol% of the total stream,

therefore, when splitting how much CO is produced from each reaction, the remaining

2.2mol% were divided between each reaction. This method however would always

produce less CO than is needed by nearly 1-2%. To meet the CO flue gas emission

requirements, excess amount of CO was not added. This was fixed using the excel solver

function where the amount of CO produced from each reaction is iterated to meet the

required demand of the shaft furnace. This process alters the composition of the reactive

species from the natural gas stream but is within the range given from Union gas’s

website, as shown in table #2 below.

Table 2

Natural gas composition from Enbridge and Union gas supplier, compared to the iterated values from the reformer process.

The amount of steam required for the reforming reactions was not based on

stoichiometric amount of CO needed, but is instead based on steam to carbon ratio (S/C),

xxx

Species Enbridge (mol%) Union gas (mol%) Final (mol%)methane 95 87-97 95.40ethane 2.50 1.5-7 1.47propane 0.20 0.1-1.5 0.43butane 0.06 0.01-0.3 0.25pentane plus 0.02 trace-0.4 0.19nitrogen 1.60 0.2-5.5 1.60carbon dioxide 0.62 0.1-1 0.62

Design II

in order to reduce the risk of carbon deposition on the catalyst surface (Subramani et al,

2009), as illustrated in figure #7 below:

Figure 6Steam to carbon ratio with respect to operating temperature, pressure and conversion % (Subramani et al,

2009).

The operating temperature of 900oC was picked from the literature on the Midrex

process, thus in order to achieve a 100% conversion as is assumed for the reforming

reactions, a minimum S/C ratio of 1.4 would be needed.

The recycle stream from the Midrex shaft furnace is specified based on how much

CO2 reactant is needed from the reforming reactions. Thus, 39% of the shaft furnace’s

off-gasses are recycled back to the reformer, which includes any unreacted species

coming from the syngas stream of the reformer.

The following mass balance shows the final incoming and outgoing streams of the

system, for the reforming reactions:

mnatual gas+msteam+39 %∗mMidrex off gas=msyngas

For the combustions reaction of it was assumed that the air stream is the source of

oxygen and that the natural gas composition is the same from table #2 above. The natural

xxxi

Design II

gas flowrate is specified from the energy balance of the system. The mass balance for the

combustion reaction is:

mnatual gas+mair=mflue gas

Energy Balance

Incoming reforming feed enter the reformer at 494oC and will be heated to 900oC.

It is assumed that the reforming reactions start at 900oC and that all flue gas leave the

system at 900oC, thus heating was accounted for the air stream. This specified value is

lower than typical furnace outlet temperature of 1200oC (Song et al, 2004), however it is

enough to be used to pre-heat the reforming feed to near the target value of 500oC. With

the system at steady state, the heating requirement is:

∑a

j

.∫494

900

n¿122, aC p¿122 , a¿dT+∑a

j

.∫25

900

n¿ 103, aC p¿103 , a¿dT=Qheating

n¿ 122, a= molar flowrate of species a in reforming feed (mol/hr)n¿ 103, a= molar flow rate of species a in air stream (mol/hr)

When calculating the heat needed for each reforming reaction, the molar flowrate

of the hydrocarbon reactant was used. For example, for reaction 10, C2H6 + 2H2O → 2CO

+ 5H2, the molar flowrate of C2H6 was used to compute the heat required for the reaction.

For reaction 9 (CH4 + H2O → CO + 3H2) and 14 (CH4 + CO2 → 2CO + 2H2), the molar

flowrate of CH4 is shared between both reactions.

Thus the final energy requirement of the steam reformer is the sum of the heating

requirement Qheating and the heat needed for the reforming reactions:

Qheating+nCH 4 ,¿ 9¿ H Rxn ,¿ 9¿+ nCH 4 ,¿14¿ H Rxn ,¿14¿+ nC 2 H 6 H Rxn ,¿ 10¿900+nC 3 H 8 H Rxn ,¿11¿900+nC 4 H 10 H Rxn,¿ 12¿900+ nC 5H 12 H Rxn ,¿13¿900=Q f

xxxii

Design II

Boiler

Energy Balance

The water boiler is responsible to heat incoming process water to its boiling point

and further heat the steam produced to 400oC. It was assumed that the system operated at

steady state and that the heating requirement is met by the combustion of natural gas. The

heating required is calculated from the following energy balance:

n¿ 102∫25

100

C p , H 2O (L)dT+ n¿102∗H vap ,H 2 O+n¿102∫100

400

Cp , H 2 O (g)dT=Q

Where,

n¿ 102= molar flowrate of the process water stream (mol/hr)

Since the equipment has a percent efficiency, the final heat required is:

Qε

=Qf

Energy Balance for Remaining Equipment

The energy balance equation for the venturi scrubber, heat exchanger and when

calculating the outlet stream temperature of two streams that are combined, have the

same methodology. For the venturi scrubber and heat exchanger, the energy balance is

used to find an unknown outlet temperature by specifying the other outlet temperature to

a desired value. For example, for the heat exchanger used to heat the reforming feed, the

outlet reforming feed was specified, thus the energy balance is set up to calculate the

outlet temperature of the other outlet stream. It is assumed that the system is at steady and

no generation of heat occurs, thus for example, the heat exchanger energy balance can be

written as:

∑a

j

.ncold ,a Cp cold ,a(T desired , cold−T ¿ , cold)=∑a

j

. nhot , aC p hot ,a(T out−T f)

Where,

xxxiii

Design II

ncold ,a= molar flowrate of species a in the cold streamT desired= Specified temperature outletT f = temperature outlet to be calculatedThe Tdesired and Tf can be switched in the equation above depending on known and desired

values of the system.

The energy balance for calculating the outlet temperature of two streams that are

combined is similar, with the only difference is that the Tdesired is switch with Tf, as

follows:

∑a

j

.ncold ,a Cpcold ,a(T f −T¿ ,cold)=∑a

j

.nhot ,a Cp hot , a(T out−T f )

2.3.2 Electric Arc Furnace

An element balance is performed on a per annum basis to calculate the mass of

materials being processed by the EAF unit. The first important step in the balance is to

know the EAF output. This is determined from the AOD output, which is known to be

two megatons per year. From the reactions taking place in the AOD, the necessary input

is calculated and is used as the output for the EAF. This sets a basis for input

calculations. Next of importance is the composition of steel leaving the EAF and the

composition of steel scrap and direct reduced iron entering the EAF. The final

composition of the steel is given by the information provided by the client. The weight

percentages of the different components in direct reduced iron are known from the

Midrex stage calculations. Steel scrap is assumed to be comprised solely of plain steel,

the conformation of which can be found from various resources on the internet. With all

of the steel and DRI compositions known, only the slag make-up is unknown, but can be

calculated from the mass balance. User defined values for steel scrap input and lime input

are defined as a first approximation. With all of this information it is possible to construct

the element balance matrix in a spreadsheet.

xxxiv

Design II

In this system it is assumed that the mass entering the furnace is the same as the

mass leaving. There are five streams in total: the DRI feed, the steel scrap feed, the lime

input, the atmospheric air input, the steel outlet, the slag outlet and carbon-rich off-gas.

To begin calculations, an initial mass flow rate for steel scrap is assumed. Then,

an initial guess is made for the mass of DRI. This is followed by an element balance on

the iron component. In order to complete this balance without the actual conversion

known, it is assumed that 100% of the iron is extracted from the DRI and steel scrap.

Because the inflow is equal to the outflow, the sum of the moles of iron entering must

equal the sum of the moles leaving, or,

∑ M ¿−∑ M out=0

Where M=molar flow rate of Fe .

This is where the Solver Add-in is used in Microsoft Excel to optimize the mass

flow rate of DRI entering the EAF. Solver is commanded to satisfy the above equation by

changing the inflow of DRI. Now, with the mass flow rate of DRI entering the EAF

known, the slag mass flow rate is also known by the same property above, or,

∑ mi0−∑ mi=0

Where m=mass flow rate .

Once this has been completed, the element balance is performed for the remainder

of the species entering and leaving the reactor and the composition of the slag is found.

Note that the mass flow rates can be altered for all parameters in the case of

changing specifications. To account for changes, only the Solver Add-in must be used

again to find the new DRI input. For example, if the input changes from 30% DRI and

70% steel scrap to 100% DRI, Solver will find the new mass flow rate based on the same

elemental iron balance as mentioned above. The amount of lime needed is approximated

according to the final slag composition, which should contain in the range of 50 to 60 wt

% CaO.

xxxv

Design II

Other assumptions made in the mass balance calculation is that only Fe3C, FeO,

FeS and CaO react inside the heated bath. FeS reacts with CaO to form FeO and CaS.

Fe3C breaks down into three Fe atoms and C combines with 0.5O2 to form CO. It is

assumed that no CO2 is formed in the reaction. The oxygen is received from either FeO,

which breaks down to form one Fe atom and one O atom or from atmospheric oxygen.

Nitrogen does not participate in any reactions and leaves as the largest fraction of the off-

gas. No oxygen besides that bound in CO or other particles is assumed to leave in the off-

gas: all oxygen molecules that enter from the atmosphere are used to bind carbon to

decrease the steel’s C composition.

A very large assumption that has been made is that conversion of reactants, or inputs, is

100%. All Fe3C and FeO is broken down into iron and carbon monoxide. This is

typically not the case in reality and process conditions must be tuned according to

measurements of actual outputs.

Other important assumptions are that 99% of the input Fe leaves in the hot metal

and 0.5% in the slag as FeO and 0.5% in the off-gas as entrained FeO dust. Also included

is that 0.99% of the C input remains in the hot metal, while the rest leaves in the off-gas

as CO. For SiO2, 7.5% leaves with the hot metal, 91.5% leaves in the slag and the

remaining 1% is assumed to leave in the off-gas as entrained particles. Ninety-nine

percent of the Al2O3 leaves in the slag while 1% becomes entrained and leaves with the

off-gas. Lastly, it is assumed that 10% and 1% of P2O5 and elemental sulfur leave in the

steel, while the remainder of the P2O5 and sulfur leaches into the slag and is removed as

waste product.

All other components which enter the furnace, which are not Fe, C, SiO2, P2O5

or S are assumed to leave in the slag and off-gas. The amount of DRI input needed to

satisfy the conditions for the reactions taking place in the EAF is calculated from a mass

input-output balance. The overall mass balance is presented in the Appendix.

xxxvi

Design II

The energy balance for the EAF also requires a number of assumptions. The first

is that the temperature inside the hot bath is uniform, which realistically is not true until

after the entire charge has been melted, though a gradient between the electrode center

and the walls is always noticed. There is also a gradient between the top of the hearth and

the bottom of the hearth, where the bottom is typically cooler. It has also been

extrapolated from graphs of off-gas temperature versus bath temperature that the off-gas

temperature is 1200 degrees Celcius when the bath is 1600 degrees Celcius. One-

thousand six-hundred Celcius is also the assumed maximum temperature of the bath.

Last of the energy balance assumptions is that DRI enters the furnace at 650

degrees Celcius and that all other materials start at room temperature, 25 degrees Celcius.

Do to mixing of materials and variable temperatures within the plant, it may be found that

this is not the case in practice.

2.3.4 Continuous Casting

The mass of stainless steel lost in the caster itself is nil. Flux introduced into the

tundish via the pneumatic conveyor plays a significant role in decreasing oxidation and

therefore losses of stainless steel to slag. The amount of molten stainless steel, which

cools and solidifies in the tundish prior to casting is negligible. The flux also ensures

lubrication between the solidifying strand and the water-cooled mould, eliminated no

mass build-up. Therefore, without any accumulation of mass in the casting process, the

mass of molten stainless steel supplied to the mould is equivalent to that solidified and

cut into slabs. The mass balance, i.e. the water requirement, is directly governed by the

heat removal rate of the different cooling processes. Thus, the mass and energy balance

has been solved simultaneously. Although continuous cast cooling typically follows a

transient, two-dimensional differential equation, the following description and list of

assumptions indicates an original, reliable engineering approach to the calculation of

industry standard cooling rates.

The three major cooling processes are as follows:

xxxvii

Design II

(1) Cooling through a water-cooled mould(2) Cooling of the strand in the water spray chamber and (3) Forced-air convective cooling with multiple blowers

The overall underlying heat removal methodology is simple: there is a specified

amount of heat removed in the water-cooled mould (and a specified percentage of that

goes to solidification) and there is a specified strand temperature out of the spray

chamber. With these three specifications (including the parameter specifying the amount

of heat removed to solidification), the overall water duty may be calculated and yields

results in table #3. These values include overcapacity, which will be elaborated on

below. Only cooling water may be used in the mould (and recycled), where the water

never actually comes in contact with the stainless steel. In the spray chamber the water

sprayed directly on the strand and therefore must be sent to wastewater treatment before

being discarded back to the environment. A significant amount of compressed air is also

required to cool the steel and is utilised in both the spray chamber (to atomise the water

creating a spray mist) and in the blowers for forced convection. The air duty is also

outlined in table #3.

Table 3

Cooling Stage Cooling Process Fluid

Volumetric Requirement

(m3/hr)

Percentage of Required Heat Removed (%)

Primary Water-Cooled Mould Cooling Water 1173 17.24

Secondary Spray Chamber Process Water 3126 69Compressed Air 3126

Tertiary

Forced Convection on Slab Collection

Rack

Compressed Air 108000 13.78

The overall casting rate is specified similar to industry standards (Sengupta et al., 2004)

at a rate of 59.35 m/hr. Continuous casting may occur at rates much, however heat

removal limits final production rate. It is also unwise to solidify stainless steel too

quickly, causing significant strained zones within the slabs, which prove to be very brittle

and liable to fast fracture. In the calculations performed, casting at rates higher than

xxxviii

Design II

59.35 yielded insufficient heat removal in the mould, and therefore this speed was

specified as the operation rate.

Each caster solidifies 1 million tonnes of stainless steel (allowing for 14 days of

shutdown time) per annum. Therefore, to supply the required 2 million tonnes of

stainless steel as per the design criteria, there must be two continuous casting processes

running simultaneously, each for 351 days / annum. Industry standard also prompts a

water overcapacity of 81 %, and this number is used as well to ensure there is sufficient

water flow in both the spray chamber and the water-cooled mould.

Water-Cooled Mould Methodology

Primary cooling of the stainless steel is carried out in the oscillating water-cooled

mould. Through specification of the percentage of total heat removed in the water-cooled

mould (typically approximately 20% in an average steel casting process (Sengupta et

al.,2004) and the percentage of total molten stainless steel solidified (18%), a flowrate of

cooling water can be calculated, which extracts this amount of energy. With knowledge

of the average casting rate, limiting the outlet water temperature to 38.5 °C and assuming

there is no vaporisation of water in the mould at the surface (with water under pressure at

3.86 bar), the energy removed is simply by that sensible heat transfer:

Qremoved=t mCp ∆ T

Where t is the time spent in the mould, m is the mass flowrate of the water, Cp is the heat

capacity at constant pressure and ∆ T is the temperature change from the inlet to the

outlet of the mould.

This, however, is a very crude approximation and one much more accurate would be

through the modelling of the system as a heat exchanger with the following resistances.

Rtotal=RWater+RCopper Mold+RAir Gap+RSolidification of SS

xxxix

Design II

The energy must pass through each successive resistance to heat transfer adequately be

removed by the cooling water on the other side of the mould. The air gap resistance is

particularly large and arises from the gap formed between the mould wall and the strand

during thermal contraction upon stainless steel solidification. The flux layer decreases

this gap. Therefore the total resistance can be written as the inverse of the overall heat

transfer coefficient U in the following manner:

1UA

= 1hwater Amold

+Lcopper wall

k copper Amold+ 1

hair Amold+

L solidified SS avg

kstainless steel Amold

Where h is an individual heat transfer coefficient, L is the length, k is the thermal

conductivity and A is the area.

As seen previous equation, the average distance inward of solidified stainless steel

from the mould wall along the entire length of the mould is needed and therefore the final

width and height into the steel solidified on mould exit is required. These values are also

pertinent to the calculation of the mould outlet solidified temperature, which is significant

for the heat transfer calculations in the spray chamber to follow.

Through knowledge of the latent heat of fusion, the mass of solidified stainless

steel is calculated and the subsequent volume of solidification. Cooling is occurring from

all sides of the mould, and therefore solidification is proceeding from the mould wall

inwards (as heat flux moves in the opposite direction). The solidification process is

approximated as linear throughout the mould in two dimensions. Some molten stainless

steel is still present at the outlet of the mould though and it is required to know the cross-

sectional area of molten stainless steel at this point. For this, calculus was used and the

volume of molten stainless steel was calculated as a pyramid with the top cut off (initially

all molten at the base of the pyramid and moving to a smaller rectangle at the mould

outlet). The amount solidified is thus the total volume of the mould minus the amount

xl

Design II

still remaining molten. See Appendix A.4, for a description and Table 14 for the full

calculation.

Using the average width and height solidified, the average distance of solidified

stainless steel from the mould wall can be calculated for both the width and height. The

resistance due to conduction of heat through the stainless steel then takes on two different

equations: one for heat transfer through the width and one through the height. The

following equation outlines this:

Lsolidified SS avg

kstainless steel Amold=( w−wmolten

4 )( 1kSS lh )+( h−hmolten

4 )( 1kSS lw )

Therefore, overall heat transfer multiplied by the area is given in the following equation:

UA= 1hwater Amold

+Lcopper wall

kcopper Amold+ 1

hair Amold( w−wmolten

4 )( 1kSS lh )+( h−hmolten

4 )( 1kSS lw )

Finally, to model the system as a heat exchanger, the following standard equation for heat

rate is utilized:

Q=FUA ∆ T LM

In the water-cooled mould, however, there are four different ∆ T LM temperature gradients

due to both the sensible heat transfer in the molten stainless steel and the solidified

stainless steel as well as the latent heat transfer during solidification. The ∆ T LM

temperature gradients effectively create four heat transfer equations and can be seen as

follows:

Q=FUA (∆ T ¿¿ LM , molten¿ fusion¿+∆ T LM , fusion+∆ T LM , fusion¿ cooled solid¿+∆T LM , fusion¿cooled molten¿)¿

Where,

xli

Design II

∆ T LM=∆ T A−∆ T B

ln( ∆ T A

∆T B)

Here ∆ T A is the temperature gradient at the inlet between the hot steel and cold

water, while ∆ T B is the temperature gradient at the outlet. In fact this could be switched

to yield the same result.

The temperature of molten out of the mould is better approximated by a geometric

mean as opposed to a linear average due to diffusion of heat in the molten steel. The

general geometric mean formula follows:

Geometric Mean=(∏i−1

n

ai)1n

Imagining a cross sectional picture of the mould at the outlet, the temperature at

the middle of the molten portion is still T molten ,∈¿¿ and the temperature at the interface of

the solidified stainless steel is effectively T stainlesssteel fusion. Therefore the temperature of

molten at the outlet is the following:

T moltenout=√T molten∈¿T fusion¿

Knowledge of the final molten temperature at the mould outlet allows for all final ∆ T LM

to be solved and the overall model may now be employed. The heat exchanger model

specifies that 99% can be removed as an approximation, amounting to nearly all of the

specified 20% required removal. See Appendix A.4, Table 16 for full calculations.

The strand is particularly vulnerable to buldging at the exit of the water-cooled

mould when it hits the first curvature of the arc. To ensure buldging is not an issue,

significant calculation has gone into determining the ferrostatic pressure and to ensuring

xlii

Design II

that this value is far less than the reduced yield strength of the solidified stainless steel

strand wall. See Appendix A.4 for the description and Table 15 for full calculations.

Water Spray Chamber

Secondary cooling of the stainless steel occurs as the strand passes through the

spray chamber. The strand is cooled to a uniform temperature of 400 °C and is

completely solidified upon exit of the arced spray chamber. Heat is removed by spraying

a mixture of compressed air and water, which atomises the water creating a mist. The

mist is imparted onto the slab through specialized nozzles. The use of compressed air to

atomise the water is much more efficient than reducing the nozzle diameter as small

outlet nozzle diameters tend to block easily.

Assuming the nozzles are placed all around the slab - except only 25 % of the slab faces

are directly sprayed by the mist, while the entire strand side remains open to water flux -

the chamber’s heat transfer can be evaluated. The spray chamber’s length is the first

calculation and is evaluated through knowledge of the radius of casting (or the radius due

to the arc formed in the casting process). Industry standard radii are 12.2 m (Making,

Shaping and Treating of Steel, 1998) and therefore the length of the ¼ circle and the

subsequent straight portion can be calculated as follows:

lspray chamber=πrarc

2+l straight portion

The chamber removes heat in four ways:

1. Through evaporation of the mist falling onto the strand2. Through sensible heat removal from the mist within the film boiling regime3. Through conduction of heat through water cooled rollers (which are also being

sprayed by the mist)4. Through water running down the arc on the top surface of the strand

Since the water running down the strand both increases the effective water flux

for sensible heat transfer as it passes to the lower stages of the arc, but also decreases the

impinging mist, this will be neglected. In order to neglect this, it has to be ensured that

most of the water removed should be vaporized and discharging through the top of the

xliii

Design II

spray chamber instead of running down the strand. A sensible model has been developed

relating the water flux evaporated and the water flux sprayed.

Figure 7

The model of water evaporation, with water evaporated flux on the y-axis and total mist flux on the x-axis.

The maximum water flux evaporated is 0.0025 m3/m2s, which amounts to a 0.25 cm thick

film of water sprayed per second over a unitary area. This intuition is modeled by the

following equation:

W 'evaporated=

W '

400 W '+1

Where W ' is the mist flux reaching the strand surface.

Heat removal by evaporation therefore is given by the following equation:

Qevaporation=W 'evaporated Amist spray t ¿mold ρwater ∆ Hwater ,vaporisation

A majority of the heat removed is from the latent heat of vaporization of the water

(Sengupta et al., 2004) and therefore evaporation is much more significant than sensible

heat transfer from the strand to the mist. The calculated sensible heat removal is only

0.11 %. From Figure #8, therefore, it is ideal to keep the water flux in the vicinity of 0.01

m3/m2s as this is where there is significantly more evaporation per unit impinging water

flux. The calculated water flux is 0.0101 m3/m2s.

The heat removed by sensible heat transfer is modeled with an imperial formula for the

heat transfer coefficient h:

xliv

Design II

h=α W n

Where the constants α and n are empirically determined constants from industry,

typically between 0.45 – 0.75 and 0.5 – 1 respectively. For the calculation, the average

value has been taken (i.e. α = 0.6 and n = 0.75).

Separate from the strand surface mist requirement is the mist required to cool the

rollers of the spray chamber since the atmoising nozzles are located around the entire

system of strand-compressed rollers. The conduction of heat through the water-cooled

rollers does remove a significant amount of the heat from the strand and can be

approximated through the following conductive heat transfer equation:

Q=−kA dTdr

=−k Aroller touching strand(T strand−T roller)LM

rroller

Where k is the thermal conductivity of the copper roller, the area of the strand is

estimated as 5 % of the area of the top and bottom of the strand and a log mean

temperature difference is employed due to the fact that the strand is being cooled from

the inlet of the spray chamber to the outlet. The temperature of the roller has been

estimated as one half of the strand temperature at the inlet of the spray chamber. See

Appendix A.4, Table 17 for full calculations.

Blower Section

The rack section collects the cut slabs on a roller system where they are cooled by

large blower fans situated in staggered fashion on both sides of the rack. By specifying

the number of blowers employed to be 20 (10 per side of rack) and maximum allowable

outlet temperature of the strand (90 °C), only one parameter is needed to fully specify the

entire system. By solving for the spacing between blowers, all variables are calculated

including the length of the blower section (25 m), the time on slab spends on the rack

(calculated from the roll speed to be 4.21 hours)

xlv

Design II

Through estimation of the heat transfer coefficient for forced-convective mass

transfer of air over a flat plate, the overall transfer of heat from the strands to the cooling

air supplied by the blowers can be calculated. Through specification of one single

industry stand blower flowrate (1.5 m3/s) and the assumption 70 % of the air is

effectively cooling the entire surface of the slabs the entire way down the length of the

roller section, the velocity of air can be simply calculated:

v= VAcross section

η

Where V is the volumetric flowrate, the cross sectional area is assumed to be the

spacing between blowers times 1 m height above the strand and η is the efficiency of air

reaching the strand on average (i.e. 70% as previously stated due to staggering the blower

placement).

With the velocity the Reynolds number can be simply calculated:

ℜ= ρvLμ

Where ρ is the density of air, L is the characteristic length, which is the length of

the strand specified by the client (as the blower is blowing parallel to the direction of the

length) and μ is the dynamic viscosity of air.

The Prandlt number can also be calculated using properties of air at 40 °C:

Pr ¿Cp μ

k

Where C pis the heat capacity of air at 40 °C and k is the thermal conductivity of air at 40

°C.

Knowing these two values we can use a standard equation for calculating the

Nusselt number of the convective air flow over a flat plate under turbulent conditions.

xlvi

Design II

Since Nusselt number is directly proportional to the average heat transfer coefficient, this

equation can be rearranged to find the coefficient:

hx=0.0308 k

Lℜ

45 Pr

13

Now the heat rate of removed energy from the slabs can be estimated using the

convection equation with a log mean temperature difference expressing the difference

between the temperatures of the slab at the start of the blowing section to the final

temperature:

Q=ABlower section hx (T slab−Tair )LM

Therefore by knowing the average heat transfer rate across the blowing section, an

estimated time requirement can be calculated for the strand to remain within the influence

of the forced air currents. See Appendix A.4, Table 18 for full calculations.

3. Operating Philosophy

3.1 Control Theory

The following section outlines the control philosophy of the stainless steel plant,

including detailed control methodology of main operating units. An overall control

philosophy is first documented, followed by plant-wide control similarities such as pump

control and control valve control and finally the detailed control methodology of the main

operating units. All control functioning can be visualised in the P&IDs in Appendix D.

3.2 Process and Instrumentation Diagram Development

3.2.1 Overall P&ID Development

The Midrex, the EAF and the AOD units all operate in on a batch-to-batch basis.

The entire semi-batch process operates via tapping, until the ladle from the molten

xlvii

Design II

stainless steel is discharged into the tundish, where the process becomes continuous.

Fe… from Groups 1 and 2 are assumed to have fixed composition outside of the

responsibilities of Group 3. Control of the processes ensures production of 2 million

tonnes of stainless steel per annum safely from the batch to continuous process.

All vital, supporting operating units, which are required to ensure operation have

been designed with redundancies, where the operator may simply switch from one to

another at an instance of breakdown or if one requires maintenance. Controllers, for the

most part, are all wired to the central control room and indicate the measured value to the

main operating engineers. Alarms are installed at sensitive measurement sites to alarm

operators and the control room of operation at process range limits.

3.2.2 Common Unit Control Philosophy

Pumps and Compressors

The following is a typical illustration of a pump (where the control is identical to

a compressor although it is regulated by pressure control rather than flow control).

Figure 8

Figure #9 illustrates the enclosure of the pump by drain valves (with blind flanges)

directly on the lines surrounding the pump. The pump itself is drained to wastewater

treatment (WT) and is powered electrically, represented by the dashed line, by the motor

(M). A swing check valve is employed with the arrow to ensure no backflow in case of

downstream pipe blockage. The two outmost valves are for isolation purposes. The

suction side control valve is an on/off gate valve, which can be operated to restrict flow

xlviii

Design II

to the pump. This valve is not used for control purposes, but is especially usefully when

switching between the main pump and its redundant counterpart when maintenance is

being performed.

Control Valves

The following is a typical illustration of a control valve. A flow control valve is

shown, however the same control operation is used for a pressure control

valve.

Figure 9

Figure #10 illustrates the isolation of the control by gate valves on both the

upstream and downstream of the valve in case maintenance or replacement is required.

Drain valves with blind flanges provide the ability to drain the pipe prior to removal. A

control valve may either be fail opened (FO) or fail closed (FC), whereby on a loss of

actuated air pressure, the valve defaults to the specified position. The control conditions

downstream determine the fail selection.

A bypass line with a ball valve is connected in parallel to the control valve to

ensure processes are not halted while the valve is repaired or replaced. This valve is

closed during normal operation.

xlix

Design II

The following is a typical illustration of a level measurement and control system.

Figure 10

Figure #11 illustrates a typical level control system. Unlike other transmitters, a level

transmitter is typically isolated from the equipment with gate valves. It can be drained

via the drain valves with blind flanges upon replacement or if maintenance is required.

Notice the alarms indicating high and low levels of the measured vessel for any vital

system component.

3.2.3 Midrex Direct Iron Reduction

Midrex Shaft Furnace and Conveyor Belts

The conveyor belts make use of cascade control in order to reduce time lag. This

control mechanism is used since the amount of iron ores received from shipment will

fluctuated during the week, thus the need for a more fine-tuned control strategy. The

primary controller is a level controller located at the Midrex furnace. The level indicator

controller (LIC) will send a signal to the LIC of the charge hopper (HP) and will change

its set point value, such that immediate response take place to bring the level of iron ores

in the furnace to the desired level. The LIC of the charge hopper acts as a primary

controller to the speed signal converter (SY) set up for each conveyor belts. For each

conveyor belt, a speed transmitter (ST) sends an electrical signal to a speed indicator

controller (SIC) when the measured speed at one end the conveyor belt does not match

the set point value. The conveyor belts (including pan conveyor) contain at least four

hand stop switch (HSS) for manual control of the belt speed in the case of emergency

shutdown. The Midrex shaft furnace’s incoming syngas stream is regulated by the

l

Design II

cascade control mechanism described for the steam reformer section, however a simple

feedback loop system is set up to regulate its flowrate before entering the furnace. The

furnace’s level indicator also includes a high and low level alarm for iron ore level. The

flue gas leaving the system is regulated using a feedback loop system to regulate its

flowrate.

Figure 11

Conveyor belt and shaft furnace control are interconnected by cascade control mechanism.

Steam Reformer

It is desired to maintain the syngas temperature produced from the steam reformer

at 900oC when the Midrex process is operating. The two outlet streams of the reformer

can be used to control the upstream processes to maintain this desired temperature,

however it would be more difficult to find the appropriate set point value using the flue

gas stream. Thus, the syngas stream temperature is used to control upstream processes.

The feedback loop control mechanism was not chosen, since a temperature controller will

not respond to sudden change in flowrate due to pressure change of the inlet gas streams.

This is remedied by using a cascade control mechanism, where there is a primary

(temperature) and secondary (pressure) controller. The cascade control mechanism works

as follows:

li

Design II

A temperature transmitter (top right box in figure #13) sends an electrical signal

to a temperature indicator controller (TIC), where the measured value is compared to the

set point value of 900oC. When there is a difference, the TIC sends an electrical signal to

all three inlet stream’s pressure indicator controller (PIC) so that the set point value of the

PIC is changed, thus changing their flowrate according to the primary controller. Each

PIC is operated independently from the primary controller when their set point value is

not changed, by adjusting the inlet flowrate to the reformer to the desired value.

Figure 12

Cascade control mechanism is used to control syngas temperature.

A feedback loop system is used to control selected streams (2 more not shown in

figure #14) upstream of the reformer, since they do not feed directly into it. This would

suffice due the more thorough control mechanism set up for streams directly upstream of

the reformer. In this case, the TIC (top right box) sends a electrical signal to the pressure

signal converter to act on the control valve, when the measured syngas temperature is

different than the set point value. Since most gas streams contain flammable compounds,

drainvalves are installed to send the streams to flare, in case of emergency shutdown.

lii

Design II

Figure 13

Feedback loop mechanism is used for selected streams

Boiler

It is desired to maintain the outlet steam temperature of the boiler at 400oC. A

feedback loop mechanism suffices to accomplish this. The low time lag associated with

cascade control is not needed since the reformer feed contains enough steam for reformer

reactions to occur. The temperature transmitter (TT) sends an electrical signal to the TIC

when the outlet steam temperature deviates from 400oC. This in turn sends an electrical

signal to a pressure signal converter so that the control valve can modify the gas fuel

flowrate. It was chosen that the incoming gas fuel flowrate is adjusted instead of the

process water flowrate, since the gas fuel flowrate is proportional to the outlet steam

temperature. A pressure swing valve is installed downstream of the boiler to lower the

pressure of the stream before feeding into the reformer. In the case of emergency

shutdown, the drain valve installed sends the stream to waste water treatment.

liii

Design II

Figure 14

The boiler makes use of feedback loop control to adjust incoming gas fuel flowrate, to maintain target steam temperature.

Venturi Scrubber

Due to the high temperature of the off-gases from the EAF and AOD process

(800oC), it is important to monitor the outlet water temperature of the scrubber to make

sure boiling will not occur. It was set that the desired outlet temperature of the process

water to be the same as is given from the literature about the Midrex process: 80oC

(Fruehan et al ,1985). Referring to figure #16 below, this temperature will be maintained

using a cascade control mechanism to change the flowrate of the incoming off-gases to be

treated by both a temperature controller (primary) and pressure controller (secondary).

The feedback loop mechanism was not chosen due to its time lag, which may potentially

leave the water outlet to reach its boiling temperature. Incoming process water and off-

gas are regulated by a feedback loop mechanism to maintain flowrate at target value

(secondary control). In case of emergency shutdown, a vent to flare and drain valve to

waste water treatment is installed for the off-gas stream and process water respectively.

liv

Design II

Figure 15

Cascade control mechanism is used for the venturi scrubber to ensure process water outlet does not reach boiling temperature.

Heat Exchanger

The reforming reactants are heated from 356oC to 500oC using a heat exchanger

before feeding into the reformer. A feedback loop system is used to maintain the outlet

reforming feed at 500oC, by changing the flowrate of the incoming hot stream. Only the

incoming hot stream is changed, since the cold stream would need to be changed

inversely. A more rigorous control mechanism is not needed since the reforming feed is

pre-heated to a wide range of temperature. A temperature indicator controller (TIC)

located at the outlet reforming feed sends an electrical signal to the temperature signal

converter of the hot streams entering the heat exchanger, when there is deviation from the

desired outlet temperature.

lv

Design II

Figure 16

The heat exchanger maintains the outlet reforming feed temperature using feedback loop control mechanism.

3.2.4 Control Philosophy Electric Arc Furnace

Cooling water flow rate

Temperatures inside the electric arc furnace are above the melting point of typical

stainless steel. The furnace shell and roof and the electrodes and bus bar are all

susceptible to damage due to heating. The furnace shell is protected from overheating by

a refractory lining which decreases the heat flux into the steel shell. The roof and bus bar

are not protected by any refractory layer and a cooling system is implemented to mitigate

the occurrence of overheating.

The temperature of the water is desired at twenty-five degrees Centigrade. To

monitor this, a temperature reading is taken (TI-03-205) from the main cooling water line

and a signal is sent to the temperature transmit (TT-03-205). The measured temperature,

taken after the control valve, is sent to the flow controller (FIC-03-205), which turns the

valve position (FCV-03-205). The mass flow rate is adjusted according to the equation

for heat flux,

q=mA ∆ T

Where q is the heat flux, m is the mass flow rate of water and ΔT is the temperature

difference between the roof and the water. The area and delta T are constant, so the mass

lvi

Design II

flow rate must change if the water temperature increases or decreases. The heat flux, q, is

calculated from the following equation,

q= kx

∆ T

Note that each control valve also features a bypass stream with a manual globe

valve, two drain valves, and two manual on/off valves. The flow controller sends an

electrical signal to a flow relay transmitter (FY-03-205), which sends a pneumatic signal

to the control valve. There is also a flow alarm (FAL-03-205) for when the flow is too

low, which sends a signal to the control room, warning operators that manual control

action is necessary. This setup is used for each and every control valve in the EAF

process: FCV-03-201, FCV-03-202, FCV-03-203, FCV-03-204, FCV-03-205, FCV-03-

206, FCV-03-207, FCV-03-208, FCV-03-209 and FCV-03-210.

Figure 17

P&ID for Cooling Water Flow Valve FCV-03-205

A fraction of the water is diverted to the electrode bus bar and the electrodes, as

these too reach very high temperatures due to high currents of electricity. Two additional

control valves (FCV-03-201 and FCV-03-202) control the amount of water that is

diverted to the electrodes and to the bus bar. The flow rate through each line is controlled

lvii

Design II

through a feedback control loop and is adjusted according to the measured temperatures.

The relationship is the same as for the main line control loop, except here the temperature

of the electrode and bus bar determine the flow rate through each respective secondary

line. Deviation from a set value for electrode and bus bar temperature either increases or

decreases flow rate to achieve a desired amount of heat absorption.

Figure #18

P&ID of Cooling Water Flow Control for Electrode Bus Bar

Figure 19

P&ID of Cooling Water Flow Control for Electrodes (top), Temperature Measurement Instrumentation (bottom)

The last feedback control loop for temperature and flow rate control is located

after the first controller, and regulates the flow rate of cooling water into the roof. The

cooling water flows through cooling panels located on the underside of the roof. The

temperature of the roof is taken by TI-03-203 and transmitted via TT-03-203 to a flow

controller (FIC-03-203). The flow controller adjusts the control valve (FCV-03-203) to

lviii

Design II

increase flow rate in the case of roof temperature higher than the desired point or

decrease if the roof temperature becomes too cool (a low roof temperature can lower

energy efficiency in the furnace bath ).

Figure #20

P&ID for Flow of Cooling Water to Roof

All control valves for the cooling water are fail open, as an instability which

causes loss of control would not cause overheating to the furnace in this way.

Hydraulic mechanisms

All moving parts of the electric arc furnace – the roof, bus bar, furnace tilting,

slag door and hot metal door – are driven by hydraulic pressure, generated by a series of

pumps (PP-03-201). The pump sends pressurized water (up to 650 bar) into a main line.

There are five lines that branch from the main line. All lines are under high pressure and

therefore pipelines must have small diameter and large thickness to prevent rupture.

The flow rate of water into pump PP-03-201 is dictated by a control valve located

upstream from the pump. It is a globe valve and its position is controlled by a flow relay

(FY-03-207) which sends a pneumatic signal based on electrical input of the flow

indicator-controller (FIC-03-207). The FIC calculates its signal from the measured flow

rate of water in the pipe. This is to prevent too much or too little water from entering the

pump, which could damage the parts. After the control valve, there is a drain valve which

is turned on manually in the case of emergency or if the pump is undergoing repairs. The

pump is driven by an electric motor which consumes 1 MW of power to drive the

lix

Design II

movement of the furnace parts. There is also another drain valve connected to the pump

which opens when the pressure of the outlet water is too high. The water is sent to the

wastewater treatment unity. After the pump is a second drain valve for manual operation,

a one-way check valve and a manual on/off valve. The drain valve allows water being

pumped by the system to be redirected. The check valve assures that water doesn’t enter

the pump from the wrong side, thereby causing backflow. And the manual on/off valve is

used in the case of emergency to stop flow into the furnace hydraulic system.

Figure 21

Hydraulic Pumping System PP-03-201

The first hydraulic line is connected to the roof (RF-03-201) and provides force

for moving the roof into position. A position indicator (ZI-03-203) located on the bottom

of the roof sends a signal to the position transmit (ZT-03-203), telling the controller

whether the furnace is completely covered or uncovered. The position transmit sends a

signal to the flow controller (FIC-03-204), which opens or closes the valve (FCV-03-204)

to manipulate roof movement. This valve fails closed to lock the roof in place above the

furnace.

lx

Design II

Figure 22

P&ID of FCV-02-204: Roof Position Controller

Another line connects to the electrode bus bar (BB-03-201). This is to raise or

lower the bus bar and electrodes (EE-03-201). The bus bar height is measured and

transmitted by a level indicator-controller (LIC-03-201) which sends a signal to the flow

controller (FIC-03-210) for the hydraulic line, opening or closing the valve (FCV-03-

210) to change the height of the bus bar. This control valve fails open to lock the bus bar

at its maximum height above the furnace in the case of unstable control.

lxi

Design II

Figure 23

P&ID of FCV-03-210: Bus Bar Level Control

The tilting of the furnace for pouring material into the ladles also depends on

hydraulic force. The angle at which the furnace is tilted is measured by a level indicator-

controller (LIC-03-202). The controller sends a signal to the flow controller (FIC-03-208)

which moves the position of the control valve (FCV-03-208) to either increase or

decrease flow. To tilt the furnace in one direction, high-pressure water is pumped into the

hydraulic piston below the furnace shell. To tilt the furnace in the opposite direction, the

control valve is closed while the hydraulic pump is left on. This decreases the pressure of

the water in the piston, causing it to contract. In the case of failure, the control valve fails

open to prevent slippage of molten metal onto the factory floor.

lxii

Design II

Figure 24

P&ID of FCV-03-208: Furnace Tilt Control

The final two control valves monitor the level of the slag door (part of LA-03-

202) and the hot metal door (part of LA-03-201). Level indicator-controllers are in place

for each door. The doors have two levels: fully open or fully closed. The level indicator-

controller for the slag door and the hot metal door links to the respective flow controllers.

The position of valve, either fully open or fully closed, determines the level of the

respective doors. Both control valves fail closed to keep the doors shut.

lxiii

Design II

Figure 25

P&ID of FCV-03-206: Hot Metal Door Open/Close Control

Figure 26

P&ID of FCV-03-209: Slag Door Open/Close Control

Bin weighing control

One-hundred and fifty total tonnes are charged into the furnace prior to melting.

The DRI arrives on a conveyor (CV-03-102) from the Midrex unit. A bin (BN-03-201) is

located at the end of the conveyor below a chute. When the bin is empty and the control

is initiated, the conveyor turns on. When the conveyor turns on, DRI begins to flow into

the bin. As the bin is filled with DRI, it is suspended from an overhead crane (CN-03-

201). The crane is place on top of a scale, which measures the change in weight of the bin

through a level controller. When the weight of the bin reaches 100% of the required

weight of DRI, a high alarm sends a signal to the conveyor motor controller which stops

the conveyor. This alarm also sends a signal to the motor controller for the lime pebble

conveyor and lime pebble silo, after a slight time delay. First, the conveyor (CV-03-201)

is switched on. Then the hatch at the bottom of the silo (SI-03-201) is opened, emptying

lime pebbles onto the conveyor. The lime is transported to the bin, where the weight is

taken in the same way as previously mention. When the weight of lime reaches 85% of

lxiv

Design II

maximum, a high alarm sends a signal to the motor controller for the silo hatch, causing it

to close the hatch. This stops the flow of lime from the silo to the conveyor. When the

weight of lime is at 100%, a high-high alarm signals the conveyor motor controller to

stop.

The bin is transferred by the crane to the steel scrap weighing area. A suspended

magnet (CN-03-204), which carries about a single tonne of scrap from storage (BN-03-

203), loads the bin. As the magnet loads the bin, the weight of the bin is measured. When

the bin contents have reached the desired weight of one-hundred and fifty tonnes, the

magnet ceases its loading procedure and the bin is carried to the next transfer station

(CN-03-202 or CN-03-203).

Fan speed control

Atmospheric pressure in the furnace is desirable. The pressure increases above

this level however due to the formation of off-gas during melting. The change in pressure

is measured by an indicator-controller (PIC-03-201). The controller sends a signal to the

speed controller (SIC-03-201) for the axial vane fan (FA-03-201), which vents the off-

gas out of the furnace. This feedback control loop ensures that as pressure inside the

furnace increases, the fan speed increases to maintain a set point for pressure drop across

the fan blades. If pressure decreases, fan speed decreases.

Figure 27

P&ID of Fan Speed Control

lxv

Design II

3.2.6 Continuous Casting Section

Flux Transport Control

The following is an illustration of the flux control to the tundish:

Figure 28

Flux control highlighted.

Flux is critical to the heat transfer in the mould, to providing lubrication between

the strand and the oscillating mould wall and to minimising oxidation of the molten

stainless steel. Therefore, the level of flux powder in the hopper is constantly measured

to ensure there is a significant amount of flux entering the blow tank below, where it is

sent to the tundish. The level control, equipped with high level and low level alarms,

actuates the rotary control valve below the silo, which feeds the hopper.

lxvi

Design II

Flow control is used at the outlet of the bottom discharge blow tank to actuate

both rotary valves below the blow tank itself and below the hopper, thereby keeping a

constant flow of flux between these two units and that being transferred to the tundish via

the pneumatic conveyor. Knife on/off valves are used atop every rotary valve such that

operators may ensure the flux flow is ceased when they are to work underneath the silo,

hopper or blow tank.

A pressure transmitter in the blow tank signals the pressure controller to actuate

the pressure control valve on the recycle loop of the positive displacement screw

compressor thereby ensuring the pneumatic air is sufficiently pressurised downstream to

transport the flux to the tundish.

Molten Stainless Steel Flow Control

The following is an illustration of the rod-controlled stopper situated in the tundish.

Figure 29

Tundish level control highlighted.

The Level of molten stainless steel in the tundish is measured constantly to ensure the

following three situations do not occur:

1. Overflow – whereby there is a catastrophic discharge of molten stainless steel at 1800 °C due to the excessive addition from the AOD

2. Emptying – where the tundish becomes completely empty and casting is stopped indefinitely until the tundish is refilled with another ladle of molten stainless steel.

lxvii

Design II

3. Near empty – where the level in the tundish will be so low that the ferrostatic pressure of the molten stainless steel will not be sufficient to maintain the required casting speed.

For these reasons there are high level and low level alarms. At the level indicator must

inform the operator it is safe to dump a 150 t ladle of molten stainless steel into the

tundish, i.e. there is a sufficient empty volume. The level indicator also actuates the

stopper-controlled rod in the nozzle at the outlet of the tundish such that as the tundish

empties and the ferrostatic pressure decreases, a constant casting speed can be maintained

by increasingly lifting the stopper. The rod-controlled stopper defaults to fail-closed in

case of emergency, hindering the molten liquid from moving downstream.

Cooling Water Flow Control

The following is an illustration of the mould cooling water control strategy.

Figure 30

Cascade control of cooling water highlighted.

Cooling water used inside the copper mould for primary strand cooling is the first

of 3 essential cooling processes when casting the stainless steel. The flowrate must be

kept at a sufficient value to remove 20 % of the heat. The temperature is monitored at the

outlet and using cascade control this sets the setpoint for the flow rate of cooling water

lxviii

Design II

into the mould. The flowrate is also measured and the signal transmitted to this control

valve, which allows close regulation of the cooling water entering the mould. In this way

any upstream disturbances in the cooling water from Group 2 will be corrected at a much

shorter timescale, causing less variation in the essential primary cooling of the stainless

steel. There is a low flow rate alarm, which acts as a trip, signalling to the level indicator

of the tundish that a crucial water cooling supply has been reduced, which actuates the

stopper-controlled rod to close.

Mist Flow Control

The following is an illustration of the spray chamber mist control strategy.

Figure 31

Ratio of air to water control highlighted.

The mist applied directly onto the strand in the spray chamber is a mixture of air

and water, at an equal volumetric ratio. The ratio is maintained by measuring both the

flowrate of process water and of air pressure. The flow transmitter signals the flowrate of

process water and the ratio calculator sends a setpoint signal to the pressure controller,

lxix

Design II

which in turn actuates the pressure control valve to alter the flow or air. The process

water flow transmitter also sends a signal to control valve to regulate the amount of

process water entering the spray chamber. There is again a low flow rate alarm, which

signals that another critical water cooling supply has been reduced to the tundish level

controller, lowering the stopper-controlled rod via the actuator.

4. Plant Design

4.1 Equipment Sizing

4.1.1 Midrex Direct Iron Reduction

Shaft Furnace

Before sizing the shaft furnace, the residence time of the iron ores in the unit need to be

specified, since the volume of iron ores in the furnace affects the height and diameter to

be chosen. It is reported that for the largest capacity shaft furnaces in production, at about

275 tonnes per hour of DRI, require an average of 3 hours reduction in the furnace

(Hollar, 2013). However, the shaft furnace that is considered for this complex only

requires to output less than this amount. Therefore, it was chosen that the residence time,

for the capacity needed, would be 2 hours.

The inner diameter of the furnace is a parameter that is readily available in the literature.

Since the output of DRI needed for the process is close to 1 million, the recommended

inner diameter is 6.5, which is used for capacities up to 2 million tonnes DRI per annum

(Atsushi et al, 2010). The inner diameter will specify the reduction zone height of the

furnace, based on a length to diameter ratio calculated from a Midrex process.

Steam Reformer

lxx

Design II

Air blower

A centrifugal air blower with forward-curved blade was chosen to transport air

into the reformer, due to their capacity to discharge the gas at very high velocity

(Maloney, 2008; perry’s handbook). The required power was calculated from the

following equation, which is derived from the adiabatic compression equation (Burton,

2002):

Pw=Qair P1

17.4 εM ε B¿

Where,

Pw= Power (kW)Qair= Air flowrate at ambient conditionsP1=Inlet pressureP2=Outlet pressureε M=Motor efficiencyε B=Blower efficiency

The flowrate used to calculate the power is the design value, which for the air blower is

set at 20% overcapacity. The dimensions of the blower are retrieved from supplier

website, after calculating the power required.

Air compressors

Due to large output flowrate required from the compressors and based on the

figure below, an axial flow type compressor was chosen for the Midrex process. The

higher pressure ratios of centrifugal compressor are not needed, since the pressure ratio

provided by axial compressor would suffice.

lxxi

Design II

Figure #32

Performance characteristics for different compressor type (Maloney, 2008).

The isentropic adiabatic compression equation was used to calculate the power

requirement of the compressor:

Pw=R T ¿

ε¿

Pw= Power R= gas constantT ¿= inlet temperature P1=Inlet pressureP2=Outlet pressureε=Motor efficiency

As in the case for the air blower, the dimensions of the compressors are given by supplier

once power requirement is calculated.

lxxii

Design II

Venturi Scrubber

The majority of dust particles removed from the dirty gas stream comes from the

off-gas of the EAF process. Thus, as shown in the figure below, the average pressure

drop of 40 inches H2O across venturi scrubbers, used in common EAF processes, was

selected to design other parameters of the equipment.

Figure #33

Veturi scrubbers for EAF processes have typically a 30-50 inches H2O pressure drop.

The average size of particles to be removal from venturi scrubbers affects the

performance of the equipment and is the other parameter used to estimate the percent

removal of the scrubber. It was found that the median particle size of dust particles from

EAF process is 0.69μm (Hong-Xu et al, 2010). Thus, the percent removal can be

estimated from these parameters, as shown in the figure below, this would give a 98.5%

removal.

lxxiii

Design II

Figure #34

Venturi scrubber performance as a function of particles size to be removed and know pressure drop (EPA handbook, 1991).

The water flowrate needed was estimated from known liquid to gas ratio used for dust

particle scrubber. The energy requirement of the scrubber was estimated from the dirty

gas flowrate (EPA handbook, 1991). The dimensions of the scrubber are retrieved from

supplier specifications.

Boiler

The power requirement of the boiler is estimated from its energy balance

calculation. Both fire-tube and water-tube can be used for the process, however since

more information is readily available from suppliers on fire-tube boiler, it was chosen for

the process. The dimensions and fuel gas consumption is provided by the supplier.

Conveyor belts

2 conveyor belts and one pan conveyor are used in the Midrex process. The

values to be calculated will vary based on information that is set for each belt. Table #4

lxxiv

Design II

below shows the given information for each conveyor:

The specified and calculated parameters vary for the three belts in the Midrex process.

Table #4

Equipment Specified Parameter Calculated Parameter

CV-03-101 (port to plant site)

Length, speed and throughput Width

CV-03-102 (to Midrex shaft

furnace)

Width, speed, inclination and

throughputLength

CV-03-103 (pan conveyor, to EAF)

Length, speed and throughput Width

The only specified parameter that is shared by all three conveyors is the speed.

This value is set to the maximum working speed as given by the client: 1.2m/s. The

throughput is the same for the second and third conveyors, since they are responsible for

feeding and transporting the iron ores into and out of the shaft furnace. The first

conveyor’s throughput is set to the maximum working throughput, as specified by the

client: 900 tonnes per hour. This value was chosen because the amount of iron ore

received by boat shipment is not constant throughout the week and there is a minimum of

2 days of unloading to consider. This conveyor’s length has been set by the distance

between the port and plant site, while the pan conveyor’s length was chosen based on

plant layout geometry and by considering pan conveyor lengths used for Midrex

processes. The second conveyor, responsible for feeding the iron ores into the shaft

furnace has a maximum degree of inclination of 22o (Metso, 2011).

The calculation for the length or width of the conveyor will follow the same

methodology, as follows: First, the volumetric flowrate needed, based on the throughput

is calculated, as follows:

V= mρ

The width or length of the conveyor is then calculated by:

V=(w∗L)∗ν

lxxv

Design II

Where, ν is the specified conveyor belt speed.

Heat Exchanger

Both streams entering the heat exchanger are gas, thus this narrows the optimal

heat exchanger type to: shell-and-tube, double-pipe or compact (Hewitt & House, 1998).

Since the pressure of both inlet streams are above 1 atm, the compact design was not

chosen since it is not preferred for pressures above 1 atm. Both shell-and-tube and

double-pipe can operate to pressure up to 250 atm, making them both suitable. The

double-pipe design was not chosen, since for large scale applications they have a larger

space requirement, they are not designed for more than a single pass on tube side and

have a lower efficiency than the shell-and-tube design (Peyman, 2013). The two pass, u-

tube heat exchanger was chosen since they do not break easily when operating the heat

exchanger in conter-current flow compared to one-pass tube (Peyman, 2013).

The heat exchanger is sized from the total area of contact between the two streams:

A= QU∗LMTD∗F

Where,

Q= Heat requirement of the system (J/hr)U=Overall heat transfer coefficient (W/m2.K)LMTD= log mean temperature difference (K)F=correction factor (-)

The heat requirement is calculated from the energy balance discussed for heat

exchangers. The overall heat transfer coefficient was estimated from known values for

similar streams. The log mean temperature difference is calculated from:

LMTD=¿¿

And the correction factor is derived from graphical output, based on the two following factors:

R=¿¿

P=¿¿

lxxvi

Design II

The total length for heat transfer is then calculated from:

Atotal , tubes=2 πr Ltotal

Where the radius, r, is the inner radius of the tubes. 1 inches inner diameter was picked,

since it is common value used in industries. The lengths of tubes for heat exchangers

range from 8 to 20 feet (Hewitt et al, 1998). The length of the tubes, along with the shell

diameter is picked based on tabulated value of how many tubes to use for specific shell

diameter, taking into account that the tube length to shell diameter ratio should be

between 6 to 8.

4.1.2 Electric Arc Furnace

Note that all prices are in terms of 1996 $USD and are scaled up according to the

Marshall and Swift Index. The scaling factor is 1494.5 (2014) divided by 1061.9 (1996).

The costs given in the CAPEX section are representative of the costs below

multiplied by the scaling factor. The dollar values given in this section however are

relative to 1996 $USD.

The electric arc furnace (EAF-03-201) is responsible for containing the DRI,

lime, steel scrap and molten materials. It consists of a steel shell and a refractory lining.

The refractory lining absorbs the heat flux generated by the hot components inside the

bath. This is to prevent structural deformation to the shell of the furnace. The refractory

lining is composed of a single type of brick made from a mixture of magnesite-chromite.

The layering of these bricks creates a hearth. The thermal conductivity of magnesite

chromite is 2.668 W m-1 K-1. The dimensions of each brick are 0.34 m end-to-end. The

bottom of the hearth is termed the sub-hearth and is 0.55 m thick. From the top of the

sub-hearth, the bricks are layered five-deep along the perimeter. This conformation is

1.97 m high. Above this is a thinner layer, which is only two bricks-deep along the

perimeter. This conformation is 2.83 m to the top of the furnace. The overall diameter of

the bath is 3.43 m at the top and 1.94 m at the bottom. The bath is 4.8 m in height. The

hearth is 4.8 m in diameter from side to side and 5.4 m in height. The steel shell with

surrounds the hearth is made from stainless steel. It is 25 mm in thickness and covers the

sides and bottom of the furnace.

lxxvii

Design II

The overall dimensions for the furnace were used to calculate price. The volume

of steel required is 1.14 cubic meters. Taking the density to be 7,800 kg/cubic meter and

1,000 kg per tonne, it is found that 8.87 tonnes of steel is needed per furnace shell. At

$4,000 per tonne, a total of $35,470.15 per furnace shell is found. The volume of the sub-

hearth is 9.95 cubic meters. Using a density of magnesite-chromite equal to 2,620

kg/cubic meter, the weight of the sub-hearth is twenty-six tonnes. This is equivalent to

$104,302.89 if the value of magnesite-chromite brick is based upon $4,000 kg/cubic

meter. The roof (RF-03-201) is made of 25 mm thick steel with 50 mm thick cooling

panels covering the top surface. With diameter 4.8 m and depth 0.4 m, the total cost for

each roof is $26,758.83 including the steel plating and cooling panels. The bus bar (BB-

03-201) is taken to be a solid piece of steel 4.8 m in length, 1 m in width and 0.5 m in

depth for an equivalent price of $74,880 per bus bar. The launders (LA-03-201 and LA-

03-202) are made from magnesite-chromite brick. They are each 1 m in length and have

an area of 1 square meter. This results in an equivalent price of $10,480 per launder. Last

are the slag and hot metal doors and the hydraulic system. The doors are taken to be 30%

of the furnace shell price. The hydraulic system, not including the pump, but the

cylinders and pistons, is assumed to be 50% of the furnace price. The total price per EAF

is a sum of these individual prices and is calculated as $342,093.37.

The EAF supports three graphite electrodes (EE-03-201) for conducting current

from the bus bar (BB-03-201) into the charge. Each electrode is cylindrical, 0.6 m in

diameter and 6 m in length. Each electrode weighs 3.78 tonnes. At a price of $5064.89

per tonne, each electrode comes out to $19,161. Due to breakage and cave-ins of the

heavy material inside the furnace, electrodes are frequently replaced. Breakage of the

electrodes occurs at about one to two kilograms per heat. Sustained damage to the

electrodes lowers efficiency and can increase the time it takes for a single heat. At a

replacement rate of about one electrode per furnace for every two days, or one electrode

per day for the two furnaces, it is calculated that 298 electrodes are needed per year.

lxxviii

Design II

Both EAFs also need a single multiple-stage hydraulic reciprocating pump (PP-

03-201) to drive the positioning of various moving parts. The pump discharges water at

650 bar and requires 1 MW of power supply. It is constructed from stainless steel. Two

pumps are need and each is obtained at a purchase price of $1,000,000.00, for a total of

$4,600,000.00 with installation costs.

Transformers

Fifty-seven megawatt-hours are required to melt a single heat (150 tonnes) in the

EAF. The EAF runs with a power efficiency of 70%. About 0.39 MWh is required per

tonne of material to be melted (see Heat Balance). This corresponds to 57 MWh to melt a

single charge, ideally, and 81 MWh with consideration to efficiency. There are two EAFs

running simultaneously, hence a total of 162 MWh is needed. With the addition of all

auxiliary power demands, accounting for 15% of the power required for the EAFs, the

total power demand reaches 186 MWh. This power must be supplied by series of step-

down transformers. The electrical substation supplies 501 MVA for all plant operations.

The input from Hydro Quebec is 230 kV.

First in the series is a 501 MVA 3-phasetransformer which decreases the 230 kV

to 23 kV that feeds the furnaces. Following this transformer are two 81 MVA 3-phase

EAF transformers in parallel which decrease the voltage from 23 kV to 100-400 V. The

voltage is variable due to large fluctuations in current when the electrodes are initially

bore into the solid-phase charge. A second pair of step-down transformers in parallel is

required to drop the 23 kV to 11.5 kV for auxiliary power demands such as the hydraulic

pumps, conveyors, cranes, instrumentation and controllers. This is accomplished by 24

MVA 3-phase transformers.

The cost of capital for transformers is a function of MVA. For the 501 MVA 3-

phase transformers, the price is $8,350,000.00 and $110,000 for installation. Each 81

MVA transformer is $1,350,000.00 and $220,000 in combined cost for installation. The

last two 24 MVA transformers cost $400,000 each and $220,000 to install them together.

lxxix

Design II

Axial Vane Fans

Three tonnes of off-gas is generated in a single heat. This gas must be evacuated

from the furnace before it can escape into the plant where it can harm workers. An axial

vane fan is placed directly above a hole in the roof of the furnace (FA-03-201). The

power efficiency of the fan is 70% and it consumes 69.3 kW for continuous operation.

Gas entering one side of the fan is above atmospheric pressure and is accelerated across

the pressure gradient (0.16 bar) into the ductwork which leads to a gas scrubber, SC-03-

101.

The axial vane fans, two of which will be needed, are priced according to their

flow rate, which is rated at 3.03 cubic meters per second. This corresponds to a price of

$3,980.00 for each fan with an installation cost of $31,910.00 on each.

Ladles

Ladles were sized according to the volume of material to be contained. The hot

metal ladles (LD-03-201/202) have a design capacity of 200 tonnes of molten metal and

133 tonnes expected. Using the density of iron, this corresponds to a design capacity of

29 cubic meters. The inside of the ladles contains a refractory lining two bricks thick, or

0.68 m on all sides, to protect the ladle shell from heat flux generated by the 1600°C

metal. The shell therefore must be constructed to have a volume of 87 cubic meters. The

height to diameter aspect ratio is taken to be 1.5. Therefore, the hot metal ladles are given

a height of 5 m and a diameter of 3 m. The carbon steel shell is 0.05 m, or 50 mm. This

corresponds to 2.05 cubic meters of steel, or 16 tonnes, which gives a price equivalent to

$111,923.95 per hot metal ladle if the price of steel fabrication is $7,000/tonne. There are

four hot metal ladles, corresponding to a total price of $447,695.80 for all ladles plus a

total installation price of $8,000 (according to capital cost worksheet).

There are also four slag ladles, or pots (LC-03-201/202). The dimensions for these

pots are according to the volume of slag to be poured into them for each heat. The pots

have a design capacity of 30 tonnes, though are expected to hold 14 tonnes per heat. Slag

is at a temperature of 1600°C, necessitating a refractory lining of two-brick thickness

lxxx

Design II

across the entire inside surface of the pot. With an aspect ratio of 1.5, the diameter is 2.33

m for a height of 4 m. The shell thickness is 0.05 m and is constructed from carbon steel.

For the design of this slag pot, 0.75 cubic meters of steel are required, or 5.75 tonnes,

corresponding to a price of $40,116.80 each if the price is $7,000/tonne of fabricated

steel. For four pots, the purchase price is $160,467.21 with a $10,000 total installation

cost.

Bins

Four bins are being used to transport DRI, lime and steel scrap – BN-03-201/202.

These bins are sized according to the volume of material within them, with a design

capacity factor of 1.5. Each is to store 150 tonnes, which amounts to 225 tonnes by

design capacity. The density of materials is a weighted average of the densities of the

different components, being 7,000 kg/cubic meter, 3,350 kg/cubic meter and 7,700

kg/cubic meter for DRI, lime and steel scrap, respectively. There is also a porosity factor

of 0.5 for the steel scrap. This corresponds to an overall density of 6,335 kg/cubic m of

material, leading to a required volume of 36 cubic meters. The aspect ratio is 1.5, giving a

diameter of 3 m and a height of 5 m. The bin is cone shaped starting 4 m below its top.

The carbon steel shell is 0.05 m on average. The volume is found through the sum of the

volumes for the cylinder and the cone. The total volume of steel required to construct the

bin is 3 cubic meters, or 22 tonnes. This can be attained at a purchase price of $153,550

each or $614,200.00 for all, with a total installation price of $153,550.00.

Lime Pebble Silos

The silos (SI-03-201) are designed to hold a maximum of 3,000 tonnes of lime

pebbles and three silos are on site. This corresponds to a volume of 896 cubic meters. The

aspect ratio is 2.0, giving a diameter of 8.5 m for a 17 m height. The carbon steel shell is

0.05 m thick and priced at $7,000/tonne. Given these dimensions, the total weight of steel

needed to construct this silo is 192.77 tonnes (taken from the density of steel, 7,800

kg/cubic meter, and volume of steel 25 cubic meters). The price amounts to

lxxxi

Design II

$1,349,452.32 per silo, or $4,048,356.96 for all four. The installation price is

$2,833,849.87, or 70% of the purchase cost.

Cranes

There are a total of two overhead cranes in the plant, CN-03-201 and CN-03-202.

First to be sized and priced are the beams and supports. The cranes are designed to hold

15% more than the maximum tonnage which it will be carrying, which is 225 tonnes.

Hence they both have a design capacity of 265 tonnes. For the larger crane (CN-03-202),

a beam which is 94.5 m in length, 3.5 m in width and 2.5 m in depth with a porosity

factor of 0.75 is needed to support this weight. The porosity factor indicates how much of

the volume ascertained from the dimensions above is not filled by steel but presumably

air. The corresponding volume of such a beam is 207 cubic meters of stainless steel, or

1613 tonnes if density of steel is taken to be 7,800 kg/cubic meter. The second crane

(CN-03-201) requires a beam 44.1 m in length, 3 m in width and 2 m in depth also with a

porosity factor of 0.75. This gives a volume of 66.15 cubic meters of steel or 516 tonnes.

A total of twenty structural supports are needed to support the beams. These

supports are larger than the typical structural supports used to erect the building. Each

support is 2 m in width, 3 m in depth and 22 m in height. This gives a volume of 33 cubic

meters of stainless steel per support and a weight of 257 tonnes each.

To connect the supports to the main beams, twenty support beams are required.

Each beam connects a support to the main beam. The support beams are also stainless

steel and 1 m in width, 1 m in depth and 3.15 in length. The volume of each beam is

therefore 3.15 cubic meters, or 24.6 tonnes.

The price of these beams and supports is determined from the combined weight of

steel. The main beams are $6,449,625.00 for CN-03-202 and $2,063,880.00 for CN-03-

201. The total price for crane supports is $20,592,000 and the total price for support

beams is $39,312,000.00. These values are obtained using a steel fabrication price of

$7,000 per tonne.

lxxxii

Design II

The two cranes are equivalent sizes, as both are designed to carry up to 265

tonnes. The span (clearance space needed) is 12 m. The design capacity is set to 530

tonnes per hour, which includes the weight of materials for both furnaces plus a 15%

overdesign factor. The price of each crane is dependent on the lift capacity, or 265 tonnes

and includes motors, cables, span type, hooks and electrical controls. It does not include

the main beam and tracks or supports, which were calculated in the previous paragraphs.

The purchase cost for the two cranes comes to $1,084,402.00 and with installation cost

amounts to $1,624,436.00.

Conveyors

There is one belt conveyor for the EAF unit, CV-03-201. It is used to transport

lime pebbles from the silos (SI-03-201) to the charge bins (BN-03-201). The conveyor

must handle seven tonnes of lime per hour. With a design capacity factor of 1.2, the total

capacity is 8 tonnes per hour. The conveyor is 40 m in length and 2 m wide to support the

mass flow rate of lime. The price for this conveyor is based on its area and type (belt

conveyor). The purchase cost is found to be $165,000 with an installation cost that

increases the total to $330,000.000.

Suspended Magnet

The suspended magnet (CN-03-203) is designed to be picked up by CN-03-201

for the transport of steel scrap from the storage bins (BN-03-203) into the charge bins

(BN-03-201). The magnet has a capacity of 2 tonnes of scrap per lift, and 36 tonnes per

hour with a design capacity factor of 1.2 making the final capacity 45 tonnes of scrap per

hour. It is an electromagnet, therefore the magnetic properties are induced by a current

which can be switched on or off remotely by the operator. Turning the magnet on will lift

steel scrap approximately equal to 1-2 tonnes. The required dimensions for such a magnet

are 3 m by 3 m with 1 m depth. The price of such a magnet depends on two empirical

factors, the suspension height (distance from the magnet to the crane hook) and the area

lxxxiii

Design II

of the magnet. For one magnet with said area and a suspension height of 0.78 m, the

purchase cost is $37,841 and $61,454.00 with installation cost.

Cooling Bed and Excavator

The cooling bed (CB-03-201) is a shallow, sloped-pit in which molten slag is

dumped from the slag pots (LC-03-201). It is made by first digging a hole 5 m deep and

then filling it with 1 m of concrete. The dimensions of the cooling bed are 30 m length,

13 m width and 4 m in depth. The cost of the cooling bed is equivalent to the cost of 390

cubic meters of concrete, or $390,000.00.

The excavator, EX-03-201, is needed for the removal of slag from the cooling

bed. It has a bucket size of 0.75 cubic meters. It is designed to move 20 tonnes of slag per

hour from the cooling bed to the slag deposit (DP-03-201). It runs on diesel fuel, with an

efficiency of 0.185 cubic meters per hour. This amounts to 1,300 tonnes of fuel required

per year for a total operating expense of $461,456.00 per year.

4.1.4 Continuous Casting Section

Before sizing all equipment and unit operations, the throughput including losses

and shutdown time must be calculated. Additionally, a significant focus was specifically

placed upon the transformation of the batch production process (i.e. tapping batches of

molten stainless steel from the AOD) to the continuous casting process. The calculation

of the tonnage per day is shown in Appendix A.4, Table 12.

Tundish

The throughput is defined from the solidified casting rate, however the design

factor must be significant to ensure that the tundish never runs out of molten stainless

steel, such that the continuous casting operation stops. The design factor is specified as

2, such that two ladles can be received simultaneously by one tundish if necessary. The

lxxxiv

Design II

retention time is that of the throughput divided by the volume input per ladle, as that is

the target throughput of the entire system:

τ=˙V casting

V per ladle

Including the design factor, the volume of the tundish is then:

V design=2V ladle

The tundish is typically rectangular with a sloping bottom, for large continuous

casting systems and therefore the volume can be split up into two subsections, the

rectangle itself and the volume of a truncated pyramid. The volumes are calculated by

the following equations:

V rectangle=lwh V truncated pyramid=13

(l2+lb+b2 ) a

Where b is the length of the narrow end and a is the height of the truncated

pyramid. By setting the volume of the truncated portion and specifying the length and

width of the tundish, the height can be calculated knowing the required volume. The

density of the molten stainless steel density at 1800 °C as above, yielding 6799 kg/m3.

The nozzle is stopper-rod controlled and attached to the bottom of the tundish.

This allows a continuous flowrate of molten stainless steel through the shroud into the

mould, as would not be otherwise possible due to the diminishing hydrostatic pressure

atop the mould as the tundish empties. Stopper-rod head movement, either manually or

automatically, in relation to the nozzle opening dictates the discharge rate out of the

tundish through the nozzle. The nozzle is made of high purity, stabilized zirconia with a

radius of 0.15 m and a height of 0.5 m.

The shroud is submerged in the molten stainless steel in the mould, preventing

unwanted oxidation of the stainless steel between the nozzle and the mould as well as the

pick-up of suspended particles. Suspended particles may become trapped inside the

liquid steel and create unwanted inclusions in the shell and have the ability to create a

catastrophic break in the shell below the mould. It has two compounds of equal

lxxxv

Design II

thickness, 0.05 m: magnesite graphite and fused silica/zirconia. The length of the shroud

is 0.5 m in total with 0.1 m submerged and 0.4 m remaining above the mould. Full

information can be found in Appendix B.4, Tables 19 and 20.

Flux Silo and Hopper (SI-03-401 and HP-03-401 and HP-03-402)

Literature (Shin et al., 2006) states the flux powder consumption to casting ratio

as 1.45 kg

s

1.35 ms

, therefore defining the throughput of both the flux silo and the flux hopper,

prior to addition to the tundish. The silo and hopper are both cylindrical on top with a

slanted conical shape at the bottom for dispensing. Therefore the volume is split up into

two segments, the cylinder and the truncated cone as follows:

V cylinder=π D2

4h V truncated cone=

π3 (( D

2 )2

+ D~D4

+(~D2 )

2

)~h

Where D is the diameter and h is the height of the cylinder, ~D is the diameter of

the narrow exit and ~h is the height of the truncated cone. Specifying an average retention

time, the overall required volume required may be calculated:

V design=(1.10)˙M flux τ

ρaverage

Where τ is the retention time, 1.10 represents the overcapacity design factor at

10% and the average density is the weighted average of the individual components of the

flux given in Tables 21 and 22 of Appendix B.4.

lxxxvi

Design II

Specifying an optimum design ratio hD at 1.2, and the height and diameter of the

truncated cone, the height and diameter of the cylinder comprising a majority of the

volume can be calculated with the knowledge of the overall required volume using

solver. Full information can be found in Appendix XX, Table XX.

Oscillating Water-Cooled Mould (MD-03-401 and MD-03-402)

The water-cooled copper mould consists of two chambers: the inner chamber with

solidified stainless steel touching the walls and molten stainless steel inwards to the

middle and the surrounding water chamber, which covers the entire surface area of the

mould. The mould oscillates vertically so that the stainless steel doesn’t stick to the walls

and tear the casting skin: when the tensile forces are larger than the cohesive forces. This

is completed by a motor-driven cam and designed asymmetrically in velocity space in

such a way that the down stroke cycle moves faster than the mould (which helps to

solidify the shell) and the upstroke of the cycle is rapidly moved back to the starting

position. The heat is transferred from the latent and sensible heat of stainless steel to the

countercurrent flowing water, in a similar manner to a heat exchanger. The dimensions

of the mould are similar to industry standards (l=10 m , w=1m ,h=0.25¿, where the

mould length is situated in the vertical direction, perpendicular to the ground. The

throughput of the stainless steel is specified by the solidified casting rate, whereas the

water throughput is calculated as a required heat removal fluid with mCp ∆T assuming

there is no vaporization of the water locally at the interfacial surface:

mwater=γ ( Qremoved by mold

Cp ∆ T )

Where ∆ T is the change in water temperature, which is fed at a specified 30 °C and exits

the top of the mould at an industry standard 38.5 °C, to ensure the heated cooling water

does not exceed environmental limitations and γ is an industry standard water

overcapacity (81% overcapacity) (Making, Shaping and Treating of Steel, 1998) to

ensure there is significant water fed to all cooling components of the system.

lxxxvii

Design II

The internal wall thickness separating the water chamber to the stainless steel

mould, is a industry specified 0.04 m. The chamber width and height is a constant 0.02

m on all faces of the mould yielding a volume:

V water chamber=( w+2 w c) (h+2hc) l−lwh

Where w c and lc are the constant width and length of the water chamber, respectively.

The pressure of the water system is at 3.68 bar to ensure no surface boiling and

the average pressure in the water-cooled mould is defined by the height of molten

stainless steel above the mould plus half of the height of the mould itself creating the

ferrostatic pressure:

Pferrostatic=ρg(htundish+hshroud+hlength /2)

Where the density is the average density of molten stainless steel and solidified stainless

steel, weighted depending on their relative amounts in the mould, htundish is the height of

the tundish completely full, hshroud is the height of the shroud not submerged, and hlength /2 is

the average height of the mould.

The material of construction is the industry standard CuB-H alloy, with 99.9 %

Cu, a tensile strength of 245.09 Mpa (2 orders of magnitude larger than the average

ferrosatic pressure), a proof strength at 0.2 % elongation of 196.08 MPa and a hardness of

80 HB. Full information can be found in Appendix B.4, Table 23.

Spray Chamber (SC-03-401 and SC-03-402)

The throughput of the spray chamber is calculated as the mist required to cool the

slab to 400 °C through the direct impact of the impinging mist on the surface, which both

removes heat sensibly to the water and which also evaporates a significant layer of water

(creating a vapor layer) as well as through sensible heat transfer to the water-cooled

lxxxviii

Design II

rollers which cover 75 % of the top and bottom surface area of the strand. Roller sections

of varying sizes are spaced tightly, providing support to the strand to stop catastrophic

buldging failures in a process called compression casting. The rollers control the total

strain in the slab and maintain them below a critical level of cracking and serve to remove

a small amount of heat as well through conduction.

A mist cooling technique is often employed in the spray chambers as conventional

water spraying impact can initiate surface cracks due to uneven cooling, and a reduction

in nozzle size often leads to blockages. The introduction of compressed air to pressurised

water improves heat transfer, requires smaller water throughputs (as steam is constantly

removed by the compressed air) and creates cooling uniformity to hinder strand stresses.

The atomized water is ejected through standard 1PM.013.16.17 flat fan misting nozzles

with a 1 cm diameter, which produce a water flux that overlaps. The required water

pressure is 80 psig (Iron & Steel Society of AIME, 1983) and thus from “User Benefits of

Modern Air Mist Nozzle and Seconary Cooling System Technologies” (Frick, 2003), the

required volumetric water flowrate to air flowrate ratio is unity. The amount of water,

and air alike, ejected from the nozzles is 3126 m3/hr knowing the air throughput per

nozzle, the number of nozzles is 3127 per chamber. The mixture velocity can be

calculated as the following:

vmixture=V mixture

Anozzle

Where V mixture is the sum of V water and V air and Anozzle is the cross-sectional area of the

nozzle.

A simplified compression roller set-up has been adopted from Continuous Casting (Iron

& Steel Society of AIME, 1983), whereby there are 5 zones of different sized rollers

along the arc of the spray chamber from small to increasingly larger diameters, and a

final flat zone where the rollers are the largest. Full information can be found in

Appendix B.4, Table 24.

lxxxix

Design II

Pneumatic Conveying

Dense phase conveying systems use higher pressures than dilute phase conveying,

but require lower air flowrates (and thus lower compressor power consumption), cause

less corrosion and product degradation. Since the required flux flowrate is only 0.6 t/hr,

there is little rational in fully suspending the particles with a high air to flux ratio.

Furthermore, less air used for conveying infers less oxidation of the molten stainless steel

upon flux arrival in the tundish. Material-to-air ratios upwards of 14 (Pneumatic

Conveying Design Guide, 2004) define dense phase pneumatic flow systems. In the

calculation a value of 14 was chosen to determine the required air flowrate:

M air=M flux

14

Or in terms of volumetric air flowrate for compressor sizing:

V air=M flux

14 ρair

Setting a pressure on the discharge side of the compressor to 3 bar in order for the

downstream membrane dryer to function properly, the shaft work imparted by the

compressor required can be calculated via the Bernoulli’s equation, taking point 1 at

atmospheric conditions and point 2 to be in the line after the compressor.

H comp=Pgauge, conveyor

g ρair /flux mixture+

vconveyor2

2 g+H L

Where H comp is the shaft work imparted by the compressor, v is the velocity of the

air/flux slurry and H L are the head losses of the system due to fluid encountering

geometry changes, due to friction and to the air being pumped up to from the silo to the

second floor of the plant. The density of the air/flux mixture is simply a weighted

average of the components:

xc

Design II

ρair / fluxmixture=∑i

2

Pi ρi=Pair ρair+P flux ρflux=1

15 (1.184 kgm3 )+ 14

15 (3093 kgm3 )=2887 kg

m3

Note the velocity of the conveying fluid is just the velocity of the air carrier, which must

be that of the required flux velocity through the pipe (vconveyor=vair ¿v flux). The velocity

of the air transporting the flux is calculated by simply dividing the volumetric flowrate by

the air, which thus requires a pipe specification chosen to be a standard 4 inches.

The adiabatic discharge temperature is given by the following equation (Plant Design and

Economics for Chemical Engineers, 2002) for compressors and fans:

T out=T ¿( Pout

P¿)(k−1)

k

Where k is the ratio of heat capacity of the fluid (cleaned air) at constant pressure to the

heat capacity at constant volume.

Rotary Screw Air Compressor (CP-03-401 A/B)

A rotary screw, positive displacement compressor has been chosen due to its

high-pressure ratio from outlet to inlet (4:1 or higher), satisfying the need for high

pressure air (3 bar) passing through the membrane filter dryer prior to being used in

pneumatic conveying. Sizing information can be found in Appendix B.4, Table 25.

Membrane Air dryer (DR-03-401)

Membrane air dryers remove water from air through a dehumidification

membrane and are often employed transform ambient air conditions into suitable

pneumatic air for actuation and conveying. A membrane air dryer was chosen due to its

ability to remove not only water vapor, but also oils often particulates from the inlet as

well as the its ability to function without any use of refrigerants or desiccants. By

xci

Design II

specifying the process flowrate, an operating pressure and a dew point suppression, a

suitable filter can be chosen to remove water vapor from the air stream. Specifications

can be found in Appedix B.4, Table 26.

Bottom Discharge Blow Tanks (TA-03-401 to 404)

Specifying the pressure in the lines of the pneumatic conveyor automatically

specifies the pressure in the blow tanks, as the compressed air flowing in the lines is

exactly the same air being fed directly into the bottom discharge blow tanks (minus any

head losses encountered by air along the way, which is assumed to be negligible due to

the lack of viscosity of air). Knowledge of the volumetric flowrate, that of the air plus

the flux, and specification of a retention time of 30 minutes, allows for the volume to be

calculated in the tanks. The temperature of the slurry can estimated by assuming the flux

remains at 25 °C and taking a weighted average of the temperatures of the flux and the

air, similar to the weighted average of the slurry density. Full information can be found

in Appendix B.4, Table 27.

Axial-Flow Compressor and Centrifugal Pump for Spray Chamber Mix (CP-03-402 A/B to 403 A/B and PP-03-403 A/B to 404 A/B)

Atomising the water used in the spray chamber is realised by the introduction of

air to the water stream prior to fluid ejection through the nozzle onto the slab. With

knowledge of the pressure of the water (Iron & Steel Society of AIME, 1983), the

volumetric ratio of water to air can be appropriately selected, which is unity at 80 psig.

Therefore the air fan must supply the same volumetric flowrate as the water required in

the spray chamber (3126 m3/s). Assuming a head loss of 15 m in the system, due to

geometrical changes (especially at the nozzle head) and the friction, the required shaft

work of the fan and the pump must is determined by solving Bernoulli’s equation taking

point 1 to be at atmospheric conditions prior to blowing and point 2 at atmospheric

pressure after nozzle ejection:

xcii

Design II

H required=vdischarge

2

2g+HL

Where H requiredis the shaft work required (in m of head) by the air fan and the centrifugal

pump, v is the discharge velocity from the nozzle head, determined by the flowrate of air

divided by the sum of the nozzles cross sectional area.

The discharge pressure can be calculated by solving a Bernoulli’s equation about

the points (1) at atmosphere for air and from the process water storage tank and (2) after

the compressor and pump. By neglecting the pressure drop across the pump and the

head losses in the pipe prior to the pump (almost insignificantly small in the pressure

calculation), the outlet pressure can be estimated:

Pdischarge=Pambient +H s ρg−vdischarge

2

2 g

Where H s is the shaft work imparted by the compressor or pump.

Single stage centrifugal compressors with an open, shrouded, low-alloy steel (such as

AISI 4140) impeller will have the ability to achieve 56 m of head, however axial-flow

compressors are typically used for imparting large shaft work onto the gas with much

higher efficiency than that of a centrifugal compressor, especially at high throughput

volumes such as is required.

A multi-stage centrifugal pump was chosen for the transport of water, from the

required head at the flowrate due to its simplicity. Centrifugal pumps provide

continuous, non-pulsating flow, while keeping capital expenditure and maintenance costs

low. Closed impellers in centrifugal pumps are advantageous because they are highly

efficient in converting power to shaft work. However, efficiency is lost when pumping

“dirty” fluids as the wear ring clearance increases. As both the process and cooling water

have low suspended solid counts at 20 ppm, closed impellers can be employed without

significant efficiency reduction.

xciii

Design II

The adiabatic power required for a compressor follows the equation:

W ad=2.78 ×10−4 kk−1 F1 P1[( P2

P1 )( k−1)/ k

−1]Where k is the ratio of heat capacity of the fluid (cleaned air) at constant pressure to the

heat capacity at constant volume and F is the inlet volumetric flowrate. The required

pump power is calculated with the following equation:

W =H F ρ

3.670 ×105

Where H is the head required and F is the volumetric flowrate.

Sizing information can be found in Appendix B.4, Tables 28 and 29.

Water-Cooled Mould Pump

Cooling water used to remove heat from the steel in primary mould cooling, requires an

increase in pressure to overcome both the geometry of piping and friction, but includes

the 10 m of head required to pump the water from the bottom to the top of the mould

yielding approximately 20 m of head losses. The discharge temperature of the cooling

water is a specified 30 °C and the methodology of calculating the shaft work input

required is identical to above: choosing point in the water cooling tower and point 2

at the discharge in the cooling tower.

H required=vejection

2

2 g+H L

Here vejection is the velocity at discharge into the water cooling tower, which is simply the

volumetric flowrate divided by the cross sectional area of the transport pipe (a standard

4” pipe). The discharge pressure was calculated similarly to the spray chamber

centrifugal pump, where the initial pressure was the pressure of the cooling water tank

(1.5 bar). The required pump power is the same as above.

xciv

Design II

A single stage centrifugal pump has the ability to handle flowrates up to 2 x 104

m3/hr below 20 m of head imparted as shaft. However, at a head of 24 m the high

flowrates in conjunction with the gravity head causes the requirement of a multi-stage

impeller centrifugal pump. Efficiencies of centrifugal pumps at high flowrates approach

80%, which is significant. Standard 4 inch piping has again been used in these

calculations. Sizing information can be found in Appendix B.4, Table 30.

Power-Driven Roller Conveyors (RL-03-401 to 458)

Powered rollers are used in section 03-006 (only after the strands have been

cut into individual slabs) and 03-007 to ensure the strands are moved away from

the casting section and to the blower / inventory section. The rollers are

individually powered as apposed to line-driven as a safety measure to ensure that

the slabs are always moved away from the casting section even if there is a failure of

one roller. Line-driven rollers are less expensive, but if they experience a

mechanical or electrical failure, the entire system must be shut down. The steel

rollers are 0.4 m in diameter with 0.3 m spacing between them, having a width of

0.25 m. The overall length of the powered roller section is 20 m in parallel to the

direction of casting until the slabs are delivered to the slab collection rack. Roll

speed is an angular velocity calculated with knowledge of the linear velocity at the

end of the roller radius, which is perpendicular to the radius. This reduces the

angular velocity formula to:

ωrollers=r × vsolidified casting

¿ r∨¿2=¿ v∨ ¿¿ r∨¿ e z¿

¿¿

Where ez is the unit vector in the z direction, i.e. longitudinally out of the cylinder

along the axis.

xcv

Design II

With a spacing of 0.3 m between each roller the number of rollers required can be

approximated with the following relation:

Total Length of Roller Section=n Droller+(n−1 ) Lspacing

Where n can be solved for and calculated as:

n=Ltotal+Lspacing

D+Lspacing

Full information can be found in Appendix B.4, Table 31.

Roller Conveyor Slab Collection Rack (RA-03-401)

The collection rack rollers roll the slabs in a direction perpendicular to the

casting direction, with the length equivalent to the length of the slabs themselves.

Slab throughput – the number of slabs passing per hour - is calculated with

knowledge of the width of the collection rack, 25 m:

SlabThroughput=v solidified casting

L slab

The retention time of the slabs on the collection rack must at least equal to 4.21 hr - the

time needed to yield full heat removal by the blowers from 400 to 90 °C. It can be

calculated through the specification of the width of the rack:

τ=w rack

(w ¿¿ slab)× Slab Throughput ¿

The rack width is determined in this way to ensure adequate heat removal. The steel

roller diameter is 0.4 m and the spacing between rollers is 0.3 m as above and the

xcvi

Design II

supporting rack is made of steel as well. Full information can be found in Appendix B.4,

Table 32.

Blowers (BL-03-401 to 420)

Blowers are employed for the final cooling stage to cool the slabs from 400 to 90

°C, when the slabs are on the roller conveyor collection rack, prior to being

transferred to inventory. Through the specification of the air flowrate of blowers

and the width of the rack section, a heat removal estimate can be calculated as

above and the spacing between blowers can be determined. The discharge air

temperature is calculated as for the air fans above yielding a value of 25.56 °C.

Radial blades are used in centrifugal blowers. Forward-curved blades produce a

high discharge velocity, but a lower pressure. Since the required air velocity is large and

directly related to heat transfer, the forward-curved fan seems to be a good option.

However, backward-curved blade blowers operate at higher pressures, which will of

course allow a more evenly distributed heat removal across the slabs. The radial blade

blower is a compromise between the two and therefore has been selected.

Blowers have been selected for their ability to discharge high pressure, which is

ideal for creating effective forced convection in open blowing. Fans are typically used

for moving large volumes of air thorugh ducts or pipes, but would be less well suited to

remove the remaining sensible heat from the slabs on the cooling rack. Sizing

information can be found in Appendix B.4, Table 33.

4.2 Plant Layout

Construction of the plant requires a layout of equipment including equipment

spacing. With equipment sizing known, there are several tables of heuristics that are used

for determining distances between the equipment. Equipment is placed throughout the

plant according to each unit and in consequential order according to steps in the process.

The top-down layout provides a bird’s eye view of the plant, giving a relative perspective

xcvii

Design II

of equipment sizing and spacing, as well as relating the distance between separate units.

Additionally, there are side-view layouts of each unit, which provide a height perspective

of different elements of the plant. The top-down and side-view layouts each provide a

scale for distances in the plant, with 6.3 m between pillars in the top-down view, 20 m

height of the first floor and 10 m height of the second floor.

5. Environmental Evaluation

5.1 Midrex Process

The off-gas of the EAF and AOD process are completely recycled into the Midrex

process since they contain carbon monoxide that can be used for iron reduction the shaft

furnace. There are 4 main gaseous hazard chemicals that need to be checked before

emission to the atmosphere: carbon monoxide, sulphur dioxide, phosphorous pent oxide

and silicon dioxide. The carbon monoxide limit posed the most problem, if the off-gas of

xcviii

Design II

the EAF and AOD had not been recycled into the Midrex process. However, since the

Midrex process produces carbon monoxide from the reformer, it was important to

introduce only as much reactants for syngas production as is needed for the iron reduction

to prevent excess amount of CO in the flue gas stream. The other three particulate matter

were found to be emitted at concentrations below the limit.

An emission limit for the particulate matters is also set for flue gas emission to the

atmosphere. It was found that a secondary treatment process containing a baghouse with

a 70% removal performance needs to be used installed to meet the particulate matter

limit.

5.2 Electric Arc Furnace

The furnace produces 64,604 tonnes of off-gas per year. The entirety of this off-

gas is treated by the plant’s scrubber, as it is laden with oxides that are unsafe to enter the

atmosphere. Over 20% of the off-gas is carbon monoxide, which must be reduced by the

scrubber. The remainder is nitrogen gas, which comprises about 70% and is safe to eject

into the atmosphere.

There are also 112,125 tonnes of slag produced each year. This slag is stored on-

site in a deposit temporarily. A contractor will remove this slag on a monthly or bi-

monthly basis to transport it to permanent storage. This will occur at a cost to the plant,

which is considered under slag disposal in the operating expenses. Slag experiences no

off-gassing however and does not leach any harmful matter, making it safe to store

outdoors.

The amount of cooling water needed in the electric arc furnace is reduced due to

the use of a full refractory lining. As opposed to some designs which do not incorporate a

refractory lining throughout the entire hearth, the furnaces built for this operation will

xcix

Design II

feature magnesite-chromite brick from the bottom of the hearth to the roof. Cooling water

usage is drastically reduced for this reason, by over 100%.

One last consideration is the use of hot DRI pellets instead of cold DRI. The DRI

will enter the process at 650°C, which lowers heating requirements needed by the

electrodes.

5.4 Continuous Casting

Based on available information, acetylene released in air will simply partition to

the atmosphere due to its very low boiling point where it will biodegrade by

photodegredation. It is slightly soluble in water and would rapidly evaporate. There is

little aggregation in soil and bioaccumulation in organisms is negligible. Acute toxicity

levels of acetylene to aquatic organisms are such that it has virtually no negative effect

(Chevron Phillips, 2013).

Acetylene is not acutely toxic to humans, although it is an asphyxiant, therefore a

localised release of acetylene in enclosed vicinity may cause suffocation via the

displacement of oxygen. Exposure above 2500 ppm may cause adverse affects to central

nervous system to workers in the vicinity (Airgas, 2004). To ensure all operators are able

to work safely near the manifolded acetylene tanks, area monitors will be installed in this

vicinity, which will alarm the operators of a leak. Within a 10 m radius, the area

monitors will detect the acetylene concentration in air and sound the alarm prior to

reaching the critical 2500 ppm exposure limit. Beyond this radius, acetylene is

sufficiently volatile to disperse into the air to non-critical concentrations and will

partition into the atmosphere.

The process of solidifying and cooling stainless steel in the continuous casting

section is water intensive in both the water-cooled mold and the spray chamber. To

decrease the sustainable footprint of the plant and to promote sustainable engineering, the

c

Design II

mold-cooling water amounting to 19,765,432 m3 is recycled per annum and re-used for

other cooling water operations.

The spray chamber process water is sprayed directly onto the stainless steel strand

and therefore cannot be recycled and reused by other processes. To reduce the amount of

water required from the surrounding environment compressed air is introduced in the

spray chamber with the cooling water to create a mist. This is more efficient in removing

heat due to its ability to readily vaporise and more readily break through the vapour

boundary layer at the strand surface. More efficient cooling directly reduces the amount

of process water required and discharged into the environment after treatment.

6. Cost Analysis

6.1 Capital Expenditure (CAPEX)

CAPEX is the amount of money invested into production of the plant prior to any

return on incurred costs. This sum generally includes all direct costs of purchase to

acquire the materials and equipment to run the plant as well as indirect costs, such as

contractor fees and legal expenses required to make the plant fully operational. Delivery

costs are included within unit prices of purchased equipment, however installation costs

(often a significant portion of the total cost) are added to the procurement price. All

CAPEX values are in 2014 US dollars and are given for the size and throughput of the

equipment specified in Table XX (Eqpt table). The following table highlights the capital

costs to be incurred in pre-production and provides a breakdown of each component. It is

common practice to outline certain costs as a percentage of the mechanical equipment

costs for a rough estimate.

Further detail of the costing methodology can be found in Appendix C, however a

description of the different table expenditures follows.

Direct Costs

ci

Design II

The following list outlines the direct costs:

1. Piping is typically estimated as 25 % of the pump / compressor costs as the more

pumping of fluids required the more piping needed to transport said fluids. These

costs include not only pipes, but structural materials required for pipe support.

Also included in piping costs are the valves and fittings.

2. Instrumentation and process control costs include purchase of various process

instruments such as flow meters, their installation and subsequent calibration and

their software costs to run such instruments and interface them with the control

room.

3. Electrical costs include equipment switches, general building and instrumentation

wiring, electrical device grounding and electric motors to run large machinery.

4. Building costs amount to the cost of construction materials required to build and

structurally secure the site. Included in this cost is the price of administrative and

service buildings.

5. Yard improvements are often required once acquiring a piece of land prior to

commencing construction. This cost includes the price of completing (often

expensive) landscaping projects as well as the installation of railways, walkways

and parking lots.

6. The cost of land is the procurement of the land itself from the previous owner and

includes fees for geographical surveys of the site.

7. Service facilities include expenses occurred for the installation of utilities for the

creation of steam, the pumping of water and compressed air and fuel. This fee also

includes waste disposal, fire protection and medical facilities.

Table 5

Capital Expenditure

cii

Design II

ciii

Design II

Capital Expenditure

Items

Percentage of Mech.

Equip.

Purchase Cost ($)

Installation Cost ($)

Foundation Cost ($) Total Cost ($) Remarks

s

Direct Costs Mechanical Equipment 100 $195,578,459 $104,712,727 N/A $300,291,185 Piping N/A $4,273,732 N/A N/A $4,273,732 25% of pumpsInstrumentation & Control 26 $50,850,399.29 N/A N/A $50,850,399 Electrical 10 $19,557,846 N/A N/A $19,557,846 Buildings N/A $21,144,000 N/A $5,166,000 $26,310,000 Yard Improvements 12 $23,469,415 N/A N/A $23,469,415 Land N/A $34,233 N/A N/A $34,233 Service Facilities 55 $107,568,152 N/A N/A $107,568,152 Direct Costs Sub-Total $532,354,963

Indirect Costs % of Directs Engineering and Supervision 8 $42,588,397 N/A N/A $42,588,397 Construction Expenses 3 $15,970,649 N/A N/A $15,970,649 Legal Expenses 2 $10,647,099 N/A N/A $10,647,099 Contractor’s Fee 3 $15,970,649 N/A N/A $15,970,649 Working Capital 3 $15,970,649 N/A N/A $15,970,649 Contingency 30 $159,706,489 N/A N/A $159,706,489 Indirect Costs Sub-Total 49 $260,853,932

Decommissions Cost 5% of CAPEX $39,660,445

Total CAPEX per annum $832,869,339

Total CAPEX per tonne stainless steel $416.43

104

Design II

The direct costs as a percentage of mechanical equipment are as follows:

Instrumentation and process control costs: 26 % Electrical costs: 10 % Electrical costs: 10 % Yard improvements cost: 12 % Service facilities cost: 55 %

Indirect Costs

The following list outlines the indirect costs.

1. Engineering and supervision includes all the cost of all engineering fees, which

include both design and start-up of the plant.

2. Construction expenses include costs of tools used for construction and the cost of

erecting temporary construction facilities.

3. Legal expenses include the payment of lawyers to obtain licences and insurance on

the project, as well as the payment of any royalties to patents outstanding.

4. Contractor’s fees include the payment of the contractors such as a construction

group or a pluming group for a particular service.

5. Working capital includes liquid assets such as cash needed to pay for operational

expenses between the time, which the payment needs to be paid and the time at

which the money is received for stainless steel slab sale.

6. A contingency is always set up such that the project has enough money to deal with

unforeseen financial crises. This extra capital hinders delays in construction and

start up as well as providing significant reassurance of the project realisation

despite potential mishaps.

The indirect costs as a percentage of the total direct costs are estimated as the following:

Engineering and supervision costs: 8 %

Construction expenses: 3 %

Legal Expenses: 2 %

Contractor’s fee: 3 %

Cost of working capital: 3 %

105

Design II

Money for contingencies: 30 %

6.2 Operating Expenditures (OPEX)

Operating expenditures are incurred after pre-production of the plant, during

operation and production. This value represents the cost of production through the

procurement of raw materials needed, required utility usage, wages of labour required to

operate the plant, waste disposal and any other supplies required to function in an

efficient manner. Annual quantities required are tabulated and multiplied by the cost

per quantity to get a total operating cost. The addition of all operating expenses yields

the overall OPEX of the plant for one year. The following table outlines the operating

expenses incurred.

Table 6

Operating costs of stainless steel production without ferrochromium included as a raw material.

106

Design II

Operating Cost

ItemsUnit Cost

($/unit)Quantity (units/an)

Total Cost ($/annum) Sub-Total ($)

Raw Materials Quick Lime t 76.00 60,000 $4,560,000 Steel Scrap t 281.52 150,000 $42,228,000 Iron Ore t 150.00 1,400,550 $182,071,540 Ferronickel t 1280.00 2,000,000 $2,560,000,000 Oxygen Nm3 0.06 99,529,560 $5,971,774 Argon Nm3 1.24 222,764,256 $276,227,677 Calcium Oxide t 110.00 161,746 $17,792,060 Ferrosilicon t 1535.00 39,212 $60,190,420

$3,149,041,471Utilities Electricity MWh 40.59 1,394,835 $56,616,364 Fresh Water t 0.20 52,672,331 $10,534,466 Diesel Fuel m3 354.96 1,080 $383,451 Natural Gas GJ 4 12,738,012 $50,952,049

$118,486,330Wages & Salaries Staff no. 100,000 15 $1,500,000.00 Operating no. 100,000 134 $13,400,000.00 Maintenance no. 100,000 52 $5,200,000.00 $20,100,000.00Supplies Magnesite-Chromite Refractory Lining t 4,000.00 786 $3,144,000.00 Graphite Electrodes t 5,064.89 1,127 $5,708,131.03

$8,852,131.03Waste Products Slag Disposal t 10.00 112,125 $1,121,250.00

$1,121,250.00Total Direct Cost $3,297,601,183

Total Direct Cost15% of Direct

Costs $494,640,177

Total OPEX per annum $3,792,241,360

OPEX per tonne stainless steel $1,896

107

Design II

6.2.1 Net Present Value of Investment

Separate costing analyses has been performed by all three Hatch groups and the

accumulated expenditure values are tabulated in Table 7. This is required to determine

the net present value (NPV) of the plant through the calculation of cumulative cash flows.

Stainless steel slabs are the primary source of revenue, but slag sale from Group 3 and

chip sale from Group 1 augment the total revenue. The following table outlines the

economic breakdown per annum of expenditures and revenues for the entire stainless

steel plant.

Table 7

Table 39 in Appendix C outlines all expenses and revenues, takes into account

depreciation of fixed assets, taxation and the time value of money to calculate the NPV of

the overall stainless steel plant. All of the assumptions used and the methods used for

calculation are also listed in Appendix C. The NPV of the project is $3,362,288,181.

6.3 Internal Rate of Return

Internal rate of return (IRR), often used to measure the profitability of an

investment, refers to the annual effective rate of return of a project discounting any

external factors. Specifically, the IRR is the discount rate at which the NPV of the

project is equivalent to zero (i.e. the invested money is exactly equivalent to the profits

received in the future – taking into account the time value of money).

108

Group CAPEX OPEX RevenueHatch 1 $789,249,937 $172,889,473 $1,142,879Hatch 2 $509,002,228 $215,782,871 -Hatch 3 $832,869,339 $3,792,471,360 $5,262,511,350

Total $5,263,654,229

Design II

This can be visualised in Table 40 in Appendix C and is solved for using solver

targeting the discount rate to a specified value of where the NPV is equal to zero. The

internal rate of return of the project is 28.71 %.

109

Design II

7. References

1 Heat Capacity, <http://en.wikipedia.org/wiki/Heat_capacity> (2 Enthalpy of Vaporisation,

<http://en.wikipedia.org/wiki/Enthalpy_of_vaporization> (3 Thermal Conductivity of some common Materials and Gases,

<http://www.engineeringtoolbox.com/thermal-conductivity-d_429.html> (4 AISI Type 304 Stainless Steel Specifications,

<http://asm.matweb.com/search/SpecificMaterial.asp?bassnum=MQ304A> (

5 Stainless Steel - Grade 304 Properties, <http://www.azom.com/properties.aspx?ArticleID=965> (

6 Air - Absolute and Kinematic Viscosity, <http://www.engineeringtoolbox.com/air-absolute-kinematic-viscosity-d_601.html> (

7 Air Properties, <http://www.engineeringtoolbox.com/air-properties-d_156.html> (

8 AIME, I. S. S. o. Continuous Casting. (1983).9 Airgas. Material Saftey Data Sheet: Acetylene. (2014).10 Frick, W. User Benefits of Modern Air Mist Nozzle and Secondary Cooling

System Technology. (Germany, 2003).

11 Mills, D. Pneumatic Conveying Design Guide 2edn, (Elsevier Ltd., 2004).12 Mular, A. & Poulin, R. Capcosts. Vol. 47 (Canadian Mineral Processors Division

of Canadian Institute of Mining, Metalurgy and Petrolium, 1998).13 Peckner, D. & Bernstein, I. Handbook of Stainless Steels. (McGraw-Hill, 1977).14 Peters, M., Timmerhaus, K. & West, R. Plant Design and Economics for

Chemical Engineers. (McGraw-Hill Science Engineering, 2002).15 Phillips, C. Product Stewardship Summary: Acetylene. (2013).16 Sengupta, J., Thomas, B. & Wells, M. in Making, Shaping and Treating of Steel

2004 Conference (New Orleans, LA, 2004).17 Shin, H.-J. et al. Measurment and Prediction of Lubrication, Powder

Consumption, and Oscillation Mark Profiles in Ultra-low Carbon Steel Slabs. ISIJ International 46, 1635-1644 (2006).

18 Fruehan, R. J. The Making, Shaping, and Treating of Steel. Pittsburgh, PA: AISE

Steel Foundation, 1998. Print.

110

Design II

Appendix A - Mass & Energy Balance

A.2 Electric Arc Furnace

Table 8

EAF Reactions.

Table 9

Steel Slag Off-Gaswt% wt% wt%

Mass Rate Tonnes/year 1,094,550 112,125 64,604

Fe 98.93 0 0

FeO 0 6.27 10.89C 0.99 0 0

P2O5 0.005 0.41 0SiO2 0.08 20.41 0.39

Al2O3 0 5.44 0.10S 0.0002 0 0

CO 0 0 26.89MgO 0 4.49 0.41CaO 0 57.09 1.00O2 0 0 0N2 0 0 60.33

Na2O 0 0.45 0TiO2 0 1.99 0CaS 0 0.07 0

MnO2 0 3.37 0

I

REACTANTS PRODUCTS1 Fe3C 3 Fe, 1 C

1 FeS + 1 CaO 1 FeO + 1 CaS

1 FeO + 1 C 1 Fe + 1 CO

Design II

Table 10

Species

MW DRI Steel Scrap Lime Air Total

INSteel Slag Off-

GasTOTAL OUT

Kg/kmol

Kmol/a Kmol/a Kmol/

aKmol/

aKmol/a Kmol/a Kmol/

aKmol/

aKmol/a

Fe55.85 16977

449260116

4 4584 0195831

96193873

6497916 97916 195831

96

C12.01 13537

67 168609 0 0152237

7902252 0 62012

5152237

7

O16.00 17050

93 0 1103309

369759

2808402

891 2430974

746296

3178160

Si28.09 38732

3 3204 25766 0416293 31222 38090

84163 416293

Al26.98 11361

7 0 7179 0120796 0 11958

81208 120796

Ca40.08 14314

9 0 1011056 0

1154204

0 1142662

11542 1154204

Mg24.31 10842

6 0 23077 0131502 0 12492

76575 131502

Na 22.99 16395 0 0 0 16395 0 16395 0 16395

P 30.97 1432 1937 194 0 3563 356 3207 0 3563

Mn 54.94 8182 45049 0 0 53231 0 53231 0 53231

Ti 47.87 27990 0 0 0 27990 0 27990 0 27990

Cr 52.00 0 0 0 0 0 0 0 0 0

Ni 58.69 0 0 0 0 0 0 0 0 0

Cu 63.55 0 0 0 0 0 0 0 0 0

N

14.01

0 0 0

2781995

0 0 0 2781995

0

S 32.07 1156 2339 2900 0 6394 64 6331 0 6394

II

Design II

Table 11

ΔH (cal/mol)

ΔH (kJ/kmol

)

ΔH (kJ/tonne)

ΔH (MWh/tonne

)

M (tonnes/h

)

Power (MWh)

Fe3C 53552 224060 1247922 0.35 29.73 10.32

FeS -21064 -88133 -1002539 -0.28 0.01 0.00

Fe 17154 71772 1285094 0.36 103.10 36.83

FeO 9194 38466 535416 0.15 3.77 0.56

P2O5 89422 374140 1317905 0.37 0.03 0.01

SiO2 26012 108836 1811523 0.50 3.05 1.53

Al2O3 45753 191432 1877520 0.52 0.75 0.39

CO 12339 51625 1843093 0.51 2.05 1.05

MgO 18591 77783 1929899 0.54 0.53 0.29

CaO 19786 82787 1476293 0.41 7.91 3.25

N2 12262 51305 1830998 0.51 4.18 2.13

Na2O 19755 82656 1333622 0.37 0.06 0.02

TiO2 18039 75477 945044 0.26 0.27 0.07

MnO2 19713 82478 982626 0.27 0.39 0.11

Total (MW) 57Weighted Average

(MWh/tonne)

0.39

III

Design II

Sample Calculations

Electric Arc Furnace Shell Sizing

STEP 1: Define necessary bath volume

Weight of material∈bath=150 tonnes

Density of materials∈bath=( 124150

tonnes)∗(70 %∗7000 kgm3 +24 %∗7700 kg

m3 +2%∗2650 kgm3 +2 %∗5740 kg

m3 )+(50 % porosity∗18150

tonnes∗7700 kgm3 )+( 7

150tonnes)∗3350 kg

m3 =6335 kgm3

Mass per heat=150 tonnes∗1000 kgtonne

=150000 kg

Volume per heat=1500006335

=24 m3

Arbitrary Numbers :

Height :diamter ratio=1.4 ;

Basin :vertical wallratio=0.41(EAF is acylinder with a deeptorispheroidal basin)

Basindiameter :Top diameter ratio=0.405

Bathheight=4.8 m

Bathdiameter=3.43 m

Height of bath above basin=2.83

Height of basin=1.97

IV

Design II

Volume of Basin=π3∗(2 hR2−(2 a2+c2+2aR ) ( R−h )+3a2 csi n−1( R−h

R−a ))=π3∗(2 (1.97 m ) ( 4.80 m)2−(2 (0.0972m )2+(0.8505 m )2+2 (0.0972 m ) ( 4.80 m )) ( 4.80 m−1.97 m )+3 (0.0972m )2 (0.8505m ) si n−1( 4.80m−1.97 m

4.80 m−0.0972 m))=90 m3

Volume of top=π ( D2 )

2

h=π (3.43m )( 14 )(2.83m )=26 m3

Totalbath volume=116 m3

Volume of Hearth ( Bath+Refractory Lining )

Brick thickness=0.340 m ;

Brick layer∈top=2 bricks ;

Brick layer∈basin=5 bricks

Height of Subhearth=0.56 m

Diameter of Topwith Bricks=3.43 m+4∗0.34m=4.8m

Volume of top= π4

(4.8 m )2 (2.83 m)=51m3

Volumeof Basin

¿ π3∗(2 (1.97 m ) ( 4.80 m)2−(2 (0.0972m+2∗0.34 m )2+ (0.8505 m+2∗0.34 m )2+2 (0.0972m+2∗0.34 m ) ( 4.80 m) ) ( 4.80 m−(1.97 m ) )+3 (0.0972 m+2∗0.34 m )2 ( 0.8505m+2∗0.34 m ) si n−1( 4.80 m−(1.97 m )

4.80 m−(0.0972 m+2∗0.34 m ) ))=180 m3

Total hearthvolume=231 m3

V

Design II

Shell thickness=0.025 m;

Total Height with Subhearth=5.4 m;

Total Diameter=4.85 m

Total volume of steel=π4

( 4.85 m )2 (5.4 m )− π4

(4.80 m )2 (5.4 m )=2.04m3

Cost of steel shell=2.04 m3∗(7800 kgm3 )( 1tonne

1000 kg )( $7,000tonne )=$111,384

Total volumeof refractory lining=231m3−116 m3=115m3

Cost of refractory lining=115m3(2620 kgm3 )( 1 tonne

1000 kg )( $ 4000tonne )=$1,205,200

Transformer Pricing

Cost for 330 MVA 3−phase transformers=$500,000

Cost for 130 MVA 3−phase transformer=$ 500,0003

=$166,667

Cost for 1501 MVA 3−phase transformer=501 MVA30 MVA

($ 500,000 )=$ 8,350,000

Cementite (Fe3C) Energy Balance

∆ H =∆ H products−∆ H reactants=(3 ∆ H Fe+∆ H C )−∆ H Fe3 C

¿3 ¿

¿3( ∫873 K

1810 K

CPFedT +3670 cal

mol+ ∫

1810 K

1873 K

CPFedT )+ ∫

873 K

1873 K

CPCdT− ∫

873 K

1873 K

CP Fe3CdT

VI

Design II

¿53,522 calmol

=224,060 kJkmol

=1,247,922 kJt

=346.92 kWht

=0.35 MWht

tonnes per heat=23.92 % F e3 C∗82.87 % DRI∗150 tonnes=29.73 tonnes F e3 C per heat

total Power=0.35 MWht

∗29.73 t=10.32 MWh

A.4 Continuous Casting

Table 12

Calculation of tonnage per day, casting speed due to down time and accumulation.

Table 13

VII

Parameter Value

Speed of Liquid to Mould (m/s) 0.01940Speed of Solid Casting (m/s) 0.01649Strands Cast per Hour 5.94Process Yield (0% lost in tundish) 1Casting Rate (m3/s) 0.004850Casting Rate (m3/year) - 100% Operation 152947Casting Rate (kg/year) - 100% Operation 1039886076Casting Rate (tonne/year) - 100% Operation 1039886Casting Rate (tonne/day) - 100% Operation 2849Overcapacity Rate (tonne/year) - 100% Operation 39886Number of Permitted Days Without Operation 14Days of Operation 351Rate into Tundish (tonne/day) - Losses Inc. 2849Number of 150 Tonne Ladles per day 19Accumulation in Tundish (tonne/day) 0Accumulation Volume in Tundish (m3/day) 0

Parameter Value

Flux Powder Consumption Ratio to Casting Speed (kg/s/m/s) 1.074

Flux Powder Consumption (kg/s) 0.01771CaF2 Density (kg/m3) 3180SiO2 Density (kg/m3) 2648Al2O3 Density (kg/m3) 3950S Density (kg/m3) 1960CaCO3 Density (kg/m3) 2710Flux Density (kg/m3) 3092.64

Design II

Flux Specifications

Table 14

VIII

Design II

Solidified Volume Calculation

IX

Parameter Value Solving

Mould Height (m) 0.25Mould Length (m) 10.00Mould Width (m) 1.00Mould Water Chamber Thickness (m) 0.02Surface Area Water-Cooled Mould -Sides and Top (m2) 15.00Surface Area Water-Cooled Mould -Total (m2) 25.00Specify Percentage Heat Removal from total Slab (%) 0.20Percentage Solidified (%) 0.18Time From Beginning of Mould to End (s) 606.53Heat Removed (kJ) 3880000Total Volume Solidified (m3) 0.45Mass Solidified (kg) 3600Heat Removed to Solidification (kJ) 972000Volume Remaining Molten 2.05 TargetTotal Height of Pyramid (m) 51.99 Target VariableVolume of Molten 2.05 Change with SolverHeight Remaining Molten at center (m) 0.20Width Remaining Molten at center (m) 0.81Tmolten,in (°C) 1800Tmolten,out (°C) 1586.32ΔT molten in to out (°C) 213.68Heat Removed in Molten (kJ) 2475804Sensible heat removed to Solid (kJ) 432195ΔT molten in to solid out (°C) 240.11T solidified out (°C) 1157.89Twater,in (°C) 30.00Twater,out (°C) 38.50Mass Flowate Water (kg/s) 179.99Volumetric Flowate Water (m3/s) 0.18Volumetric Flowate Water + Overcapacity (m3/s) 0.33Volumetric Flowate Water + Overcapacity (tonnes/annum) 988272

Velocity of Water (m/s) 7.09

Design II

The following derivation was used to calculate of the volume of the molten stainless steel

remaining in the mould. Using similar triangles the following relations can be

determined:

Figure XX. A schematic of the similar tirangles used in the pyramid volume calculation.

(REF)http://tutorial.math.lamar.edu/Classes/CalcI/MoreVolume.aspx

The similar triangle relations for each side at some distance y up the pyramid:

sw

= yD , p

h= y

D

Where s and p are the length of the width and height respectively at y, w is the mould

with and h is the mould height and D is the total length of the pyramid (an arbitrary

variable only used for calculation).

Therefore the cross sectional area at some point y is:

A ( y )= y2 hwD2

Integration of this area over the mould length - from the outlet of the mould (D−l) to l -

yields:

∫D−l

D y2hwD2 = hw

3 D3 ( D3−(D−l)3 )

X

Design II

Varying the parameter D in excel and using solver to equate this volume with the volume

of molten remaining – which is known from energy removal – it is possible to find D.

Once D is solved for, s and p can be back calculated for at y=D−l.

Strength Check for Bulging

Bulging occurs when the ferrostatic pressure of the strand (i.e. the hydrostatic pressure

caused by the molten phase of the strand) overcomes the yield strength of the solidified

stainless steel at the endge of the strand. This phenomenon is particularly apparent at the

exit of the mould just at the onset of the casting arc. At this point the height above the

mould pressing downwards on the solidified section is the following:

h=hmolten∈tundish+hshroud+ lmold+habove arc point

Where the height above the arc point is defined as the height from the top of the arc to the

buldge point directly below it. Using simple trigonometry this can be evaluated as:

habovearc point=hmold

2sin ( π

4 )

The density of the molten at elevated temperature is taken as a weighted average of the

individual components as the average temperature of molten stainless steel (the log mean

average between the inlet molten temperature 1600 °C and the solidus temperature). The

following relations are given for the major components of the steel – where silicon and

phosphorus are neglected as they are in trace amounts and the density at elevated

temperature is unrecorded:

ρiron=8.3−(8.36 × 10−4 ) T

ρnickel=9.6−(12.00 ×10−4 ) T

ρcopper=9.11−(9.44 × 10−4 )T

XI

Design II

ρchromium=7.83−(7.23 ×10−4 ) T

Assuming an ideal mixture and taking a weight average – weighted by the individual

compositions of the stainless steel – an estimate of the density of the molten stainless

steel can be obtained.

One must ensure the ferrostatic pressure is less than the yield point of stainless steel at an

elevated temperature (the temperature of the solid exiting the mould). No force balance

is required as pressure acts equally in all directions at a certain height of the system. The

following mathematical relation must be satisfied in order to maintain there is no chance

of buldging.

Pferrostatic=ρgh<σ

Where gis the gravitational constant and σ is the yield strength of the steel at the

temperature of the solid exiting the mould. The ferrostatic pressure is in fact less than

one hundredth of the yield strength of steel at this temperature so there is no risk of

buldging at this point. See calculations in the following table.

Table 15

Strength check for buldging.

XII

Parameter Value

Max Height of Molten in Tundish (m) 3Height of Shroud (m) 0.5

Height Above Bulge Portion (m) 13.59Average Temperature of Molten Steel (°C) 1693

Density Calculation Values at Elevated T (g/cm3) * Percentage Density (kg/m3)Iron: 8.3 - 8.36 x 10-4 T 73.92 6884.52

Nickel: 9.6 - 12.00 x 10-4 T 8.00 7568.21Copper: 9.11 - 9.44 x 10-4 T 0.08 7511.66

Chromium: 7.83 - 7.23 x 10-4 T 18.00 6605.85Temperature of Roller 340.28

Density (assuming Ideality) (kg/m3) 6890Ferrostatic Pressure (Above Bulge Point) (MPa) 1.1398

Design II

*Neglecting Trace additions of S and P as all densities are on same order of magnitude.

Table 16

Heat exchanger model calculations.

Table 17

Spray chamber parameters and balances.

XIII

Parameter Value

h,water (kW/m2°C) 21.10Lcopper (m) 0.04Thermal Conductivity Copper (kW/mK) (575°C) 0.391/UA 0.87UA (kW/°C) 1.15ΔTLM, molten to fusion 1556.47ΔTLM, fusion to cooled solid 1240.09ΔTLM, fusion 1363.75ΔTLM, molten to cooled molten 1656.79F 0.95Heat Removed (kJ) 3850763Percent of Assumed Heat Removal Able to be Removed by Mould 0.99

Design II

Table 18

Blower section calculations.

XIV

Parameter Value Solving

Heat Removed by Spray Chamber 15520000 TargetSpray Chamber Length (m) 23.16Strand Width (m) 1.00Strand Height (m) 0.25Time in Chamber (s) 1404.94Spray Area (Top + Bottom at Percentage + Sides) m2 23.16ALPHA 0.60H(spray water) (kW/m2K) 0.003187LM Tavg (solid to cooled solid) 680.56Troller 340.28ΔTLM, solid to cooled solid - conduction (°C) 289.64Percentage of Copper Rollers touching SS Slab 0.05Percentage of Slab Blocked by Roller (%) 0.75Average Radius of Roller (m) 0.18Water Flux (m3/m2 s) 0.01010 Target VariableWater Flux Evaporated (m3/m2 s) 0.0008348Heat Removed from Evaporation (kJ) 15348757Heat Removed from Sensible Heat Transfer (kJ) 17647Heat Removed from Conduction Rollers (kJ) 153582Total Heat Removed (kJ) 15519986 Change with SolverWater Evaporated (m3/s) 0.01161Water Flowrate to Cool Rollers (m3/s) 0.4680Water Flowrate to Spray (m3/s) 0.4797Volumetric Flowate Water + Overcapacity (m3/s) 0.8684Volumetric Flowate Water + Overcapacity (tonnes/annum) 26336165

Design II

Appendix B – Equipment Sizing

B.4 Continuous Casting

Table 19

Tundish nozzle, shroud and lid specifications.

XV

Parameter Value Solving

Blower Flowrate (m3/s) 1.50Effective Percent Blowing Over Surface (%) 0.70Spacing Between Blowers (m) 1.32 Target VariableEffective Velocity of Air (m/s) 0.80L (cut section - length of cuts) (m) 10.00Reynolds Number (Turbulent Flow) 476325Prandlt Number 0.74Average Heat Transfer Coefficient (kW/m2K) 0.00263Heat Removal Required to 25 °C 3500000 TargetHeat Removed By Blowers (kj) 3500001 Change with SolverΔTLM, Cooled Solid to Room Temp 176.16Area (Blower Section) (m2) 250.05Length (Blower Section) (m) 25.01Number of Blowers Reqd. 20.00Time in Blower Section (s) 30204Time in Blower Section (hr) 4.21Slab Exiting Temperature (°C) 90.00

Design II

Table #20

Tundish sizing and specifications.

XVI

Parameter Value Unit

Nozzle PropertiesType Stopper-Rod Controlled

Materials of ConstructionHigh Purity Stabilised

ZirconiaDiameter 0.3 mHeight 0.5 m

Lid PropertiesMaterials of Construction SteelThickness 3 mWidth 42.38 mRemovalble Lid Yes

Shroud PropertiesInner Bore Radius 0.15 mLength 0.5 mLength Submerged 0.1 mMaterials of Construction(1) Magnesite graphiteThickness 0.05 m(2) Fused silica/zirconiaThickness 0.05 m

Design II

Table 21

Flux silo sizing and specifications.

XVII

Parameter Value Unit

Throughput 118.71 t/hrMass Added/Ladle 150 tRetention Time 76 minutesVolume 44.12 m3

Accumulation 0.00 t/dayAgitated noDesign Factor 100 %

Internal VolumesHeight Rectangle 2.83 mLength 5 mWidth 3 mVolume Rectange 42.38 m3

Hight of Slanted Portion 0.2 mWidth Tapered 0.20 mVolume of Slanted Portion 1.74 m3

Materials of Construction(1) Refractory LiningCarbon Block (x2) Thickness 0.4 m/per blockMgO Thickness 0.584 mSuprex 2000 Thickness 0.075 mTotal Thickness 1.459 mVolume of Refractory 42.06 m3

Density of Refractory 4450 kg/m3

Weight of Refractory 187.18 t(2) Carbon Steel ShellSteel Thickness 0.0254 mVolume of CS 0.85 m3

Density of CS 7850 kg/m3

Weight of CS 6.70 tMaterial Information

Material Stainless SteelAverage Density 0 kg/m3

Phase molten liquidPressure 1 barTemperature 1800 °C

Design II

Table 22

Flux hopper sizing and specifications.

XVIII

Parameter Value Unit

Throughput 0.1275 t/hrRetention Time 7 daysVolume 7.62 m3

Agitated noDesign Ratio 1.2Design Factor 10 %

Internal VolumesCylinder Height 2.30 mCylinder Diameter 1.91 mVolume Cylinder 6.61 m3

Height of Slanted Portion 1 mTapered Diameter 0.1 mVolume of Slanted Portion 1.01 m3

Material InformationMaterial Flux(1) CaF2 Composition 75.00 %(2) SiO2 Composition 3.00 %(3) Al2O3 Composition 1.00 %(4) S Composition 1.00 %(5) CaCO3 Composition 21.00 %Density 3092.64 kg/m3

Phase PowderPressure 1 barTemperature 25 °COff-Gas Produced noDensity of CS 7850 kg/m3

Weight of CS 6.70 tMaterials of Construction

Material Carbon SteelThickness 20 mm

Design II

Table 23

Oscillating water-cooled mould sizing and specifications.

XIX

Parameter Value Unit

Agitated noThroughput 0.0638 t/hrRetention Time 60 minutesVolume 22675 cm3

Ratio 1.2Design Factor 10 %Discharge Valve Rotary

Internal VolumesCylinder Height 33.06 cmCylinder Diameter 27.55 cmVolume Cylinder 19705.09 cm3

Height of Slanted Portion 10 cmTapered Diameter 10 cmVolume of Slanted Portion 2969.91 cm3

Material InformationMaterial Flux(1) CaF2 Composition 75.00 %(2) SiO2 Composition 3.00 %(3) Al2O3 Composition 1.00 %(4) S Composition 1.00 %(5) CaCO3 Composition 21.00 %Density 3092.64 kg/m3

Phase PowderPressure 1 barTemperature 25 °COff-Gas Produced noDensity of CS 7850 kg/m3

Weight of CS 6.70 tMaterials of Construction

Material Carbon SteelThickness 20 mm

Design II

Table #24

Spray Chamber sizing and specifications.

XX

Parameter Value Unit

 Mould

InteriorWater

ChamberVolumetric Throughput 43329 1173.16 m3/hrMass Throughput 118.71 117.32 t/hrRetention Time 607 1.41 secondsLength 10.00 10.00 mAgitated no noIndustry Standard Design Overcapacity - 81 %

Internal VolumesLength 10.00 10.00 mWidth 1.00 0.02 (x2) mHeight 0.25 0.02 (x2) mInternal Wall Thickness 0.04 m

Material Information

MaterialStainless

Steel Water

Average Density 7089 1000 kg/m3

Phase liquid/solid liquidAverage Pressure 52.68 1.2 bar

Temperature1800 ->

115830 -> 38.5 °C

Off-Gas Produced No NoFlow Direction Downwards UpwardsPhase PowderPressure 1 barTemperature 25 °COff-Gas Produced noDensity of CS 7850 kg/m3

Weight of CS 6.70 tMaterials of Construction

Materials CuB-HComposition Cu 99.9 %Tensile Strength 245.09 MPaProof Strength at 0.2% Elongation (MPa) 196.08 MPa

Hardness 80 HB

Design II

XXI

Parameter Value Unit

-

Water Throughput 3126.33 m3/hrWater Throughput 3126.33 t/hr

Nozzle Type

1PM.013.16.17 Flat Fan Misting

NozzleNozzle Diameter 0.005 mOverlapping Spray Area YesWater Throughput Per Nozzle 1 t/hrAir Throughput Per Nozzle 0.01124705 t/hrNumber of Nozzles 3126.325536Mixture Velocity 28.29421211 m/sIndustry Standard Design Factor 81 %

Arced Portion Zone ParametersZone 1 Zone 2 Zone 3 Zone 4 Unit

Percentage of Arc 10 10 60 20 %Length of Arc 1.92 1.92 11.50 19.36 mNozzle Spray Area Per Side 1.92 1.92 11.50 19.36 m2

Distance from Strand 17.8 17.8 58.4 58.4Rollers Diameter 220 290 350 425Number of Rollers Per Side 7 5 25 7

Straight Portion Zone ParametersZone 5 Unit

-

Percentage of Straight Portion 100 %

Length 4.00 mNozzle Spray Area Per Side 4.00 m2

Distance from Strand 58.4 cmRollers Diameter 700 mmNumber of Rollers Per Side 4

Material Information

MaterialWater / Air

Mixture

-Water Density 1000 kg/m3

Air Density 1.1839 kg/m3

Pressure (Gauge) 5.516 psigTemperature 30 °CPhase Liquid / Vapor

Design II

Table #25

Pneumatic conveyor air compressor sizing and specifications.

Table #26

Membrane air dryer specifications.

Table #27

Pneumatic conveyor blow tank sizing and specifications.

XXII

Parameter Value Unit

Air Throughput 0.003155 m3/hrPumping Height Required 30 mShaft Work Imparted 40.59 mCompressor Type Rotary-ScrewPower Required 0.1149 kW

Material InformationMaterial Cleaned AirDensity 1.1839 kg/m3

Molecular Weight 28.97 kg/kmolDischarge Temperature 361.36 °CDischarge Pressure (Gauge) 3 barPhase Vapour

Parameter Value Unit

Air Throughput 0.0032 m3/hrInlet Pressure 3 barDewpoint Suppression to -40 °C

Material InformationMaterial Ambient AirDensity 1.1839 kg/m3

Molecular Weight 28.97 kg/kmolPhase Vapor

Design II

Table #28

Air compressor for spray chamber mist sizing and specifications.

XXIII

Parameter Value Unit

Air Throughput 0.001578 m3/hrFlux Throughput 0.06 t/hrType Bottom DischargeRetention Time 30 minVolume 0.001132 m3

Agitated noDesign Ratio 1.2Design Factor 10 %

Material Information(1) Material Flux(1) CaF2 Composition 75.00 %(2) SiO2 Composition 3.00 %(3) Al2O3 Composition 1.00 %(4) S Composition 1.00 %(5) CaCO3 Composition 21.00 %Density 3092.64 kg/m3

Phase powder(2) Material Clean AirDensity 1.18 kg/m3

Phase Vapour(3) Material SlurryCoposition Flux 0.93 % (mass)Composition Air 0.07 % (mass)Phase vapor/solidPressure (Gauge) 0.2 barTemperature 47.42 °CDensity 2886.54 kg/m3

Design II

Table #29

Process water pump sizing and specifications.

Parameter Value Unit

Water Throughput 3126.33 m3/hrHead Losses Misting 15 mShaft Work Imparted 55.80 mPump Type CentrifugalNumber of Stages MulitpleImpeller Type ClosedPower 475.36 kW

Material InformationMaterial Process WaterDensity 1000 kg/m3

Pressure 1.2 barDischarge Temperature 30 °CDischarge Pressure 6.67 barPhase Liquid

XXIV

Parameter Value Unit

Air Throughput 3126.33 m3/hrHead Losses Misting 15 mShaft Work Imparted 55.80 mCompressor Type Axial-FlowPower Required 67.99 kW

Material InformationMaterial AirDensity 1.1839 kg/m3

Molecular Weight 28.97 kg/kmolPressure 1.0133 barDischarge Pressure 1.0140 barDischarge Temperature 25.16 °CPhase Vapor

Design II

Table #30

Cooling water pump sizing and specifications.

Table #31

Power-driven roller sizing and specifications.

XXV

Parameter Value Unit

Throughput 1173.16 m3/hrHead Losses 20 mShaft Work Imparted 24.0898749 mPump Type CentrifugalNumber of Stages MultipleImpeller Type ClosedPower 77.01 kW

Material InformationMaterial Cooling WaterDensity 1000 kg/m3

Discharge Temperature 30 °CFeed Tank Pressure 1.5 barDischarge Pressure 3.86 barPhase Liquid

Design II

Table #32

Slab collection rack sizing and specifications.

XXVI

Parameter Value Unit

Stainless Steel Throughput 118.71 t/hrSlab Speed 0.01649 m/sLength of Powered Roll Section 20 mNumber of Rollers 58Powered Individually

Material Information

MaterialStainless Steel

SlabsDensity 6799 kg/m3

Temperature 400.00 °CPhase Solid

Materials of Construction(1) Steel Frame(2) Steel RollersDiameter 0.40 mWidth 0.25 mRoll Speed 100 s-1

Power Required 100 kWSpacing Between Rollers 0.30 m

Parameter Value Unit

Slab Throughput 5.94 hr-1

Retention Time 4.21 hrPowered No

Material Information

MaterialStainless Steel

SlabsDensity 8000 kg/m3

Inlet Temperature 400.00 °COutlet Temperature 90.00 °CWidth 10.00 mHeight 1.00 mPhase Solid

Materials of Construction(1) Steel Frame(2) Steel RollersDiameter 0.4 mLength 10.00 mWidth 25.01 mSpacing Between Rollers 0.3 m

Design II

Table #33

Air blower sizing and specifications.

Table #34

Slab-hoisting crane sizing and specifications.

XXVII

Parameter Value Unit

Air Throughput 5400 m3/hrHead Losses Misting 1 mShaft Work Imparted 170.11 mBlower Type CentrifugalBlade Type RadialRequired Power 200.60 kW

Material InformationMaterial AirDensity 1.1839 kg/m3

Molecular Weight 28.97 kg/kmolPressure 1.01325 barDischarge Temperature 25.56 °CDischarge Pressure 1.016 barPhase Vapor

Parameter Value Unit

Number of Slabs Per Hoist 3Total Weight 60 tRatio of Total Weight to Design Weight 85 %Design Weight 70.59 tPowered Electrically

Material Information

MaterialStainless Steel

SlabsDensity 8000 kg/m3

Temperature 30.00 °CLength 10.00 mWidth 1.00 mHeight 0.25 mPhase Solid

Design SpecificationsSpacing Between Wheels 4.9 mWheels per Rack 2Vertical Clearance 18 mLength 25 mWidth 3 mHeight 1 m

Design II

Appendix C – Capex & Opex

C.1 Capex

Costs of individual pieces of equipment were collected from different sources and used as

references to extrapolate current prices. Two main references were used to find cost

estimates are the following:

(1) Capcosts (Capcosts 1998), a handbook for costing CAPEX purchases, which depends

on the particular capacity of the equipment being sized. The equation for costing is

as follows:

Cost (US 1998 $ )=a X b

Where a and b are empirical factors and the capacity unit and calculation X are all

dependant on the piece of equipment. The following table outlines the criteria for each

XXVIII

Design II

equipment sized with Capcosts.

Table 35

Equipment Capacity DescriptionCapacity

Unita b

Silo Volume capacity ft3 354 0.5372

Pneumatic Conveyor Diameter of pipe squared times length (carbon steel) ft3 31850 0.1506

Hopper Volume capacity ft3 392.8 0.46312-Stage Centrifugal Pump Volumetric flowrate capacity US GPM 5288 0.2474Axial-Flow Compressor Volumetric flowrate capacity ft3/min 4.818 0.9998Radial Centrifugal Blower Volumetric flowrate capacity ft3/min 1257 0.1636DRI, Lime and Steel Scrap Bins Bin capacity ft3 392.8 0.4631

Belt Conveyor for Lime Belt width squared multiplied by belt length ft3 1875 0.5225

Overhead Crane Lift capacity tonnes 240100 0.1504Rectangular Suspended Magnet

Product of belt width in feet times the suspension height in cubic inches ft x in3 251.6 0.4959

Lime Silos Silo capacity ft3 392.8 0.4631Air compressor; Stationay screw Volumetric flowrate cfm 384.4 0.8062

(2) A CAPEX costing example of a plant built in 1994, provided by the client.

If the capacity required was over that of the reference given, the price has been

approximated by the following equation:

Cost=Costreference [ capacitycapacityreference ]

n

Where n is the scaling up factor exponent, which varies for different pieces of equipment.

The following table outlines the exponents used for scaling up.

Table #36

XXIX

Design II

Type of Equipment Scaling Exponent nPump 0.33

If the equipment was scaled up and not present in the above table, a estimated scaling

exponent of 0.6 was assumed as is industry standard.

To bring cost to present day values, Marshall & Swift (M&S) indexes were used to take

into account inflation in prices. The following table lists the index values used at

different years to bring prices to 2014. The 2014 M&S index was extrapolated from the

second graph of page 304 of the Capcost document.

Table #37

Year Marshall & Swift Index1994 993.41998 1061.92014 1494.5

To correct costs to present day inflation values, the capital cost is multiplied by the ratio

of the current index to the year the price was obtained (the basis year). The following

equation highlights this:

Price2014=Pricebase( M ∧S index 2014

M∧S indexbase)

To account for substantial installation costs, a factor is always added to the purchase

price to more accurately estimate the price of capital expenditures.

The following table outlines the factor applied to the procurement cost used when

estimating the price of installation. These factors vary between different pieces of

equipment. The total CAPEX cost of each piece of equipment, therefore, is the cost of

procurement plus that of installation.

Table #38

XXX

Design II

Equipment Installation FactorHopper 0.254

Conveyor 0.761Continuous Caster 0.5

Pump 0.549Compressor 0.477

Blower 0.346Bins/Silos 0.254

Fan 0.392Reciprocating Pump 2.45

Overhead Crane 0.624

For capital budgeting, total plant costs are typically calculated as percentages of

equipment cost. Table XX lists these percentages and their respective weighted costs.

Building structural costs including foundation, structural steel, envelope, roof and

internal lighting are estimated to be $100/m3. With a plant volume of 211,440 m3, the

total cost is simply the product of the cost per cubic meter times the volume of the plant

($ 21,144,000).

Building costs consist of the following three sub-items:

(1) Cost of material ($100 / m3) multiplied by the total volume of the plant

(2) Cost of the crane support beam

There are a total of two overhead cranes in the plant, CN-03-201 and CN-03-202.

First to be sized and priced are the beams and supports. The cranes are designed to hold

15% more than the maximum tonnage which it will be carrying, which is 225 tonnes.

Hence they both have a design capacity of 265 tonnes. For the larger crane (CN-03-202),

a beam which is 94.5 m in length, 3.5 m in width and 2.5 m in depth with a porosity

factor of 0.75 is needed to support this weight. The porosity factor indicates how much of

the volume ascertained from the dimensions above is not filled by steel but presumably

air. The corresponding volume of such a beam is 207 cubic meters of stainless steel, or

1613 tonnes if density of steel is taken to be 7,800 kg/cubic meter. The second crane

XXXI

Design II

(CN-03-201) requires a beam 44.1 m in length, 3 m in width and 2 m in depth also with a

porosity factor of 0.75. This gives a volume of 66.15 cubic meters of steel or 516 tonnes.

A total of twenty structural supports are needed to support the beams. These

supports are larger than the typical structural supports used to erect the building. Each

support is 2 m in width, 3 m in depth and 22 m in height. This gives a volume of 33 cubic

meters of stainless steel per support and a weight of 257 tonnes each.

To connect the supports to the main beams, twenty support beams are required.

Each beam connects a support to the main beam. The support beams are also stainless

steel and 1 m in width, 1 m in depth and 3.15 in length. The volume of each beam is

therefore 3.15 cubic meters, or 24.6 tonnes.

The price of these beams and supports is determined from the combined weight of

steel. The main beams are $6,449,625.00 for CN-03-202 and $2,063,880.00 for CN-03-

201. The total price for crane supports is $20,592,000 and the total price for support

beams is $39,312,000.00. These values are obtained using a steel fabrication price of

$7,000 per tonne.

C.2 - OPEX

The operating expenses highlight the cost of raw materials, utilities, labour wages,

supplies and waste disposal for plant operation per annum. The quantity of units is

tabulated for the entire plant and multiplied by the cost per unit.

For example the cost of steel scrap used in the EAF is as follows:

Cost scrap=costunit

× no .unitsannum

=(200 $unit )(150,000 units

an )=$30,000,000

Labour wage costs were averaged over the wages of the administrative staff, the

operators and the maintenance workers (including benefits) to be $ 100,000 per annum

per unit. Since operation occurs 24 hours a day, 7 days a week, there are 4 shifts required

XXXII

Design II

for operation and maintenance (3 shifts on per day and one off). Therefore, if there are

an arbitrary 10 operators required at any given time, 40 must be employed in total. Only

administrative staff shift is required.

Net Present Value of Investment

All following return on investment calculations were performed under the following

assumptions:

The cost of depreciation rate of the fixed assets in the plant is 10% and the asset

pool follows declining balance depreciation

The corporate tax rate is 40%

The investment is 100% equity and therefore a high cost of capital rate is utilised

(10%)

A non-integrated taxation method where depreciation losses are not allowed was

selected, which yields the lowest NPV and IRR as the most conservative possible

estimate

The total capital investment of the plant is split equally over the first three years of

pre-production

The total project lifespan is 20 years

Annual revenue was calculated knowing the price of stainless steel sold to the market and

with knowledge of the average output volume of the plant per year, in addition to the slag

sold from Group 3 and the chips sold from Group 1.

Annual Revenue=(2million tannum )(2,650 $

t−20 $

t )+(251,135 tannum )(10 $

t )+(12,397 tannum)(92.19 $

t )=$ 5.26 billion

Where the stainless steel sells on the market for 2,650 $/t, but the shipping costs are

20$/t.

The annual expenses are simply the summation of the three groups annual OPEX and the

annual profits can be calculated with the following equation:

Annual Profit=Revenue−AnnualOPEX

XXXIII

Design II

Depreciation was calculated using a declining balance method, at 10% per annum. The

general formula for calculating the deductible depreciation at a given ith year is:

Deductable Depreciation=D (Investment−∑i

DD i)

Where D is the depreciation rate and DDi is depreciation cost of the ith year.

For example in the second year, the depreciation deduction from taxable income was the

following:

DD=0.1 ($ 2,131,121,504− ($213,112,150+$ 191,800,935 ) )=$ 172,620,842

The taxable profits are therefore the annual profits subtracted by the depreciation

deduction allowed by the government. The general equation for the net cash flow (NCF)

can be given by the following:

NCF=( Revenue−OPEX−Depreciation ) (1−corperate tax )+Depreciation

This equation simply removes the deductible depreciation from taxation and re-adds the

depreciation after the tax factor has been employed.

Converting the future values of projected earnings to its present day monetary value with

the discount rate:

PV = FV(1+i)n

Where PV is present value of money, FV is the future value at the n th year and i is the

discount rate.

For example, in the second year:

PV =−$ 710,373,835(1.15)2 =−$ 587,085,814

The sum of the cash flows at present value give yearly cumulative cash flow and at the

end of the 20 year project lifespan, the value of the cumulative cash flow is the NPV of

the project. Note in the last year the salvage value of all assets is included in the

cumulative cash flow via the following equation:

XXXIV

Design II

SV=(1−D ×TC

D+ i )(1+i)20

Where TC is the corporate tax factor at 40%.

See Table 39 for all figures.

Table 39

XXXV

Year Annual Revenue

Annual Expenses

Annual Profits Investment Depreciation Deduction

Taxable Profits

Taxes

0 $0 $0 $0 $710,373,835 $213,112,150 $01 $0 $0 $0 $710,373,835 $191,800,935 $02 $0 $0 $0 $710,373,835 $172,620,842 $03 $5,263,654,229 $4,180,913,704 $1,082,740,525 - $155,358,758 $927,381,768 $370,952,7074 $5,263,654,229 $4,180,913,704 $1,082,740,525 - $139,822,882 $942,917,644 $377,167,0575 $5,263,654,229 $4,180,913,704 $1,082,740,525 - $125,840,594 $956,899,932 $382,759,9736 $5,263,654,229 $4,180,913,704 $1,082,740,525 - $113,256,534 $969,483,991 $387,793,5967 $5,263,654,229 $4,180,913,704 $1,082,740,525 - $101,930,881 $980,809,645 $392,323,8588 $5,263,654,229 $4,180,913,704 $1,082,740,525 - $91,737,793 $991,002,733 $396,401,0939 $5,263,654,229 $4,180,913,704 $1,082,740,525 - $82,564,014 $1,000,176,512 $400,070,605

10 $5,263,654,229 $4,180,913,704 $1,082,740,525 - $74,307,612 $1,008,432,913 $403,373,16511 $5,263,654,229 $4,180,913,704 $1,082,740,525 - $66,876,851 $1,015,863,675 $406,345,47012 $5,263,654,229 $4,180,913,704 $1,082,740,525 - $60,189,166 $1,022,551,360 $409,020,54413 $5,263,654,229 $4,180,913,704 $1,082,740,525 - $54,170,249 $1,028,570,276 $411,428,11014 $5,263,654,229 $4,180,913,704 $1,082,740,525 - $48,753,224 $1,033,987,301 $413,594,92015 $5,263,654,229 $4,180,913,704 $1,082,740,525 - $43,877,902 $1,038,862,624 $415,545,04916 $5,263,654,229 $4,180,913,704 $1,082,740,525 - $39,490,112 $1,043,250,414 $417,300,16617 $5,263,654,229 $4,180,913,704 $1,082,740,525 - $35,541,101 $1,047,199,425 $418,879,77018 $5,263,654,229 $4,180,913,704 $1,082,740,525 - $31,986,990 $1,050,753,535 $420,301,41419 $5,263,654,229 $4,180,913,704 $1,082,740,525 - $28,788,291 $1,053,952,234 $421,580,89420 $5,263,654,229 $4,180,913,704 $1,082,740,525 - $25,909,462 $1,056,831,063 $422,732,425

Design II

Internal Rate of Return

The internal rate of return is calculated by using solver to calculate the value at which

NPV is equivalent to zero by altering the cost of capital (or the interest rate). Table 40

highlights this calculation.

Table 40

36

Year Annual Revenue

Annual Expenses

Annual Profits Investment Depreciation Deduction

Taxable Profits

0 $0 $0 $0 $710,373,835 $213,112,150 $01 $0 $0 $0 $710,373,835 $191,800,935 $02 $0 $0 $0 $710,373,835 $172,620,842 $03 $5,263,654,229 $4,180,913,704 $1,082,740,525 - $155,358,758 $927,381,768 $370,952,7074 $5,263,654,229 $4,180,913,704 $1,082,740,525 - $139,822,882 $942,917,644 $377,167,0575 $5,263,654,229 $4,180,913,704 $1,082,740,525 - $125,840,594 $956,899,932 $382,759,9736 $5,263,654,229 $4,180,913,704 $1,082,740,525 - $113,256,534 $969,483,991 $387,793,5967 $5,263,654,229 $4,180,913,704 $1,082,740,525 - $101,930,881 $980,809,645 $392,323,8588 $5,263,654,229 $4,180,913,704 $1,082,740,525 - $91,737,793 $991,002,733 $396,401,0939 $5,263,654,229 $4,180,913,704 $1,082,740,525 - $82,564,014 $1,000,176,512 $400,070,605

10 $5,263,654,229 $4,180,913,704 $1,082,740,525 - $74,307,612 $1,008,432,913 $403,373,16511 $5,263,654,229 $4,180,913,704 $1,082,740,525 - $66,876,851 $1,015,863,675 $406,345,47012 $5,263,654,229 $4,180,913,704 $1,082,740,525 - $60,189,166 $1,022,551,360 $409,020,54413 $5,263,654,229 $4,180,913,704 $1,082,740,525 - $54,170,249 $1,028,570,276 $411,428,11014 $5,263,654,229 $4,180,913,704 $1,082,740,525 - $48,753,224 $1,033,987,301 $413,594,92015 $5,263,654,229 $4,180,913,704 $1,082,740,525 - $43,877,902 $1,038,862,624 $415,545,04916 $5,263,654,229 $4,180,913,704 $1,082,740,525 - $39,490,112 $1,043,250,414 $417,300,16617 $5,263,654,229 $4,180,913,704 $1,082,740,525 - $35,541,101 $1,047,199,425 $418,879,77018 $5,263,654,229 $4,180,913,704 $1,082,740,525 - $31,986,990 $1,050,753,535 $420,301,41419 $5,263,654,229 $4,180,913,704 $1,082,740,525 - $28,788,291 $1,053,952,234 $421,580,89420 $5,263,654,229 $4,180,913,704 $1,082,740,525 - $25,909,462 $1,056,831,063 $422,732,425

Design II

Appendix D – Process Flow Diagrams

37

Design II

38

Design II

39

Design II

40

Design II

41

Design II

42

Design II

43

Design II

44

Design II

45

Design II

Appendix E – Process & Instrumentation Diagrams

46

Design II

47

Design II

48

Design II

49

Design II

50

Design II

Appendix F – Plant Layout

51

Design II

52

Design II

53

Design II

54

Design II

Appendix F – Equipment List

55

Design II

IDENTIFICATION TECHNICAL PROCUREMENT  DESIGN DATA POWE

RDIAGRAMS COST Supp. Information

Item

Area Tag No. Description Equip. Type Dimensions(l x w x h)

External Material

Operating Mode

Design Capacity

Installed

(kW)

PFD No. Unit Cost($)

Remarks

Internal Material

P&ID No.

  Argon Oxygen Decarburizers                 

AOD reactor AOD-03-301

Argon oxygen decarburizer AOD

Outer dia: 8 m; Bottom dia: 4 m;

Height: 11 m Carbon steel Intermittent 180 t/h N/A PFD-03-005 $10,062,788

2 AOD needed for 1 hour basis

Note: 1 AOD per batch

  Bins/Silos/Hoppers                  AOD feed

prepBN-03-301(2)

Storage bin for HCFeCr

(granules)Storage bin 7 m, 2 m, 7 m SS316 Carbon

steel 6 m3 N/A PFD-03-004 $8,281 3 + 1 spare

 AOD feed

prepBN-03-303

(2)Storage bin for

FeNi40 Storage bin 7 m, 2 m, 7 m Carbon steel Continuous 6 m3 N/A PFD-03-004 $7,611 3 +1 spare

 

AOD feed prep SI-03-301 Silo for flux Silo

Inside Dia: 7 m; Cone Dia: 20 m;

Height: 20 m Carbon steel Continuous 11 m3 N/A PFD-03-004 $18,901  

 AOD feed

prep HP-03-301 Hopper for flux Hopper 1 m, 4 m, 1 m Carbon steel Continuous 11 m3 N/A PFD-03-004 $10,965  

 AOD feed

prep BN-03-301 Receiving bin for flux

Receiving bin / Storage bin 1 m, 4 m, 1 m Carbon steel Continuous 11 m3 N/A PFD-03-004 $18,901  

 

AOD reactor BN-03-305 (3)

Storage bin for flux, FeNi40,

HCFeCrStorage bin

Flux: 7 m, 2 m, 6 m FeNi40: 7 m, 2 m, 7 m HCFeCr: 7

m, 2 m, 7 m

Carbon steel Intermittent

Flux: 5m3

FeNi40: 6m3

HCFeCr: 6m3

N/A PFD-03-005$7,611 / $8,281 / $8,281

3 bins total

 

Midrex furnace HP-03-101

Charge hopper for midrex furnace

Charge hopper 6 m, 6 m, 12 m SS316 Continuous 210 t/h   PFD-03-002    

 

EAF

BN-03-201(2),

BN-03-202 (2)

Charge bin for hot DRI, lime and

steel scrapBin

Height: 5 m; Dia: 3 m;

Cone height: 1 m; Opening Dia: 1.5 m

Carbon steel Intermittent 225 t/h N/A PFD-03-003 $153,550.00 Steel thickness: 0.05 m

 

EAF SI-03-201(3) Lime pebble silo Silo

Height: 27 m; Dia: 7 m;

Cone height: 5 m; Opening Dia: 0.6 m

Carbon steel Batch 24000 t/a N/A PFD-03-003 $1,349,452 Shell thickness: 0.05 m

  Continuous Casting SI-03-401 Flux Silo Silo Tank d-3.3m x h-2m Carbon Steel Continuous 25 t or 7

days N/A PFD-03-006 12953.89  

  Continuous Casting HP-03-401 Flux Hopper Hopper d-0.4m x h-0.5m Carbon Steel Continuous 0.1 t or 1

hour N/A PFD-03-006 625.18  

  Continuous Casting HP-03-402 Flux Hopper Hopper d-0.4m x h-0.5m Carbon Steel Continuous 0.1 t or 1

hour N/A PFD-03-006 625.18  

  Blowers                

  Reformer AB-03-101 Combustion air Air blower 0.51 m - 0.76 m   Continuous 240,000   PFD-03-001    

56

Design II

blower diameter blade wheels m3/h

 

Continuous Casting BL-03-401

Radial Centrifugal

BlowerBlower / / Continuous 5400 m3/h 201 PFD-03-007 8907.42

Minimum Required Head:

170 m Connection: 4" piping Blade Type: Radial

 

Continuous Casting BL-03-402

Radial Centrifugal

BlowerBlower / / Continuous 5400 m3/h 201 PFD-03-007 8907.42

Minimum Required Head:

170 m Connection: 4" piping Blade Type: Radial

 

Continuous Casting BL-03-403

Radial Centrifugal

BlowerBlower / / Continuous 5400 m3/h 201 PFD-03-007 8907.42

Minimum Required Head:

170 m Connection: 4" piping Blade Type: Radial

 

Continuous Casting BL-03-404

Radial Centrifugal

BlowerBlower / / Continuous 5400 m3/h 201 PFD-03-007 8907.42

Minimum Required Head:

170 m Connection: 4" piping Blade Type: Radial

 

Continuous Casting BL-03-405

Radial Centrifugal

BlowerBlower / / Continuous 5400 m3/h 201 PFD-03-007 8907.42

Minimum Required Head:

170 m Connection: 4" piping Blade Type: Radial

 

Continuous Casting BL-03-406

Radial Centrifugal

BlowerBlower / / Continuous 5400 m3/h 201 PFD-03-007 8907.42

Minimum Required Head:

170 m Connection: 4" piping Blade Type: Radial

 

Continuous Casting BL-03-407

Radial Centrifugal

BlowerBlower / / Continuous 5400 m3/h 201 PFD-03-007 8907.42

Minimum Required Head:

170 m Connection: 4" piping Blade Type: Radial

 

Continuous Casting BL-03-408

Radial Centrifugal

BlowerBlower / / Continuous 5400 m3/h 201 PFD-03-007 8907.42

Minimum Required Head:

170 m Connection: 4" piping Blade Type: Radial

 Continuous

Casting BL-03-409 Radial Centrifugal Blower / / Continuous 5400 m3/h 201 PFD-03-007 8907.42 Minimum

Required Head:

57

Design II

Blower

170 m Connection: 4" piping Blade Type: Radial

 

Continuous Casting BL-03-410

Radial Centrifugal

BlowerBlower / / Continuous 5400 m3/h 201 PFD-03-007 8907.42

Minimum Required Head:

170 m Connection: 4" piping Blade Type: Radial

 

Continuous Casting BL-03-411

Radial Centrifugal

BlowerBlower / / Continuous 5400 m3/h 201 PFD-03-007 8907.42

Minimum Required Head:

170 m Connection: 4" piping Blade Type: Radial

 

Continuous Casting BL-03-412

Radial Centrifugal

BlowerBlower / / Continuous 5400 m3/h 201 PFD-03-007 8907.42

Minimum Required Head:

170 m Connection: 4" piping Blade Type: Radial

 

Continuous Casting BL-03-413

Radial Centrifugal

BlowerBlower / / Continuous 5400 m3/h 201 PFD-03-007 8907.42

Minimum Required Head:

170 m Connection: 4" piping Blade Type: Radial

 

Continuous Casting BL-03-414

Radial Centrifugal

BlowerBlower / / Continuous 5400 m3/h 201 PFD-03-007 8907.42

Minimum Required Head:

170 m Connection: 4" piping Blade Type: Radial

 

Continuous Casting BL-03-415

Radial Centrifugal

BlowerBlower / / Continuous 5400 m3/h 201 PFD-03-007 8907.42

Minimum Required Head:

170 m Connection: 4" piping Blade Type: Radial

 

Continuous Casting BL-03-416

Radial Centrifugal

BlowerBlower / / Continuous 5400 m3/h 201 PFD-03-007 8907.42

Minimum Required Head:

170 m Connection: 4" piping Blade Type: Radial

 

Continuous Casting BL-03-417

Radial Centrifugal

BlowerBlower / / Continuous 5400 m3/h 201 PFD-03-007 8907.42

Minimum Required Head:

170 m Connection: 4" piping Blade Type: Radial

58

Design II

 

Continuous Casting BL-03-418

Radial Centrifugal

BlowerBlower / / Continuous 5400 m3/h 201 PFD-03-007 8907.42

Minimum Required Head:

170 m Connection: 4" piping Blade Type: Radial

 

Continuous Casting BL-03-419

Radial Centrifugal

BlowerBlower / / Continuous 5400 m3/h 201 PFD-03-007 8907.42

Minimum Required Head:

170 m Connection: 4" piping Blade Type: Radial

 

Continuous Casting BL-03-420

Radial Centrifugal

BlowerBlower / / Continuous 5400 m3/h 201 PFD-03-007 8907.42

Minimum Required Head:

170 m Connection: 4" piping Blade Type: Radial

  Boat Transfers                  River Dock BT-03-101 Iron ore transfer Boat transfer     Intermittent 210 t/h   PFD-03-002   1 boat/week  Boilers                

 AOD boiler B-03-101 Water boiler Boiler 5 m, 2.5 m, 2 m SS316 Continuous 24 million

BTU/hr   PFD-03-001   Water is heated to 400 °C

  Caster                

 Continuous

Casting Multiple Continuous Caster

Casting Apparatus / Carbon Steel Continuous / / PFD-03-006 $75,000,000.0

0  

 Continuous

Casting Multiple Continuous Caster

Casting Apparatus / Carbon Steel Continuous / / PFD-03-006 $75,000,000.0

0  

  Compressors                

 Scrubber CP-03-101 Centrifugal

compessor Air compessor 1.27 m, 0.64 m, 1.02 m SS316 Intermittent 55,000

m3/h   PFD-03-001    

 

Continuous Casting

CP-03-401 A

Rotary Screw Air Compressor

Rotary Screw Compressor / / Continuous 0.1 m3 air/h 0.2 PFD-03-006

cost under pneumatic conveyor

Minimum Required head:

41 m

 

Continuous Casting

CP-03-401 B

Rotary Screw Air Compressor

Rotary Screw Compressor / / Continuous 0.1 m3 air/h 0.2 PFD-03-006

cost under pneumatic conveyor

Minimum Required head:

41 m

 

Continuous Casting

CP-03-402 A

Axial-Flow Compressor Compressor / / Continuous 3150 m3/h 70 PFD-03-006 $18,540.25

Single Stage Minimum

Required head: 56 m

 

Continuous Casting

CP-03-402 B

Axial-Flow Compressor Compressor / / Continuous 3150 m3/h 70 PFD-03-006 $18,540.25

Single Stage Minimum

Required head: 56 m

 

Continuous Casting

CP-03-403 A

Axial-Flow Compressor Compressor / / Continuous 3150 m3/h 70 PFD-03-006 $18,540.25

Single Stage Minimum

Required head: 56 m

  Continuous CP-03-403 Axial-Flow Compressor / / Continuous 3150 m3/h 70 PFD-03-006 $18,540.25 Single Stage

59

Design II

Casting B CompressorMinimum

Required head: 56 m

  Conveyors                

 

AOD feed prep CV-03-301

Conveyor belt for transporting

granulesConveyor Length: 29 m;

Width: 7 mCarbon steel/

Rubber Continuous 800-900 t/h 25 kW PFD-03-004 $1,027,547 2 needed

 

AOD feed prep CV-03-302

Conveyor belt for transporting

FeNi40Conveyor Length: 29 m;

Width: 9 mCarbon steel/

Rubber Continuous 800-900 t/h 25 kW PFD-03-004 $1,027,547 2 needed

 

AOD feed prep CV-03-303 Conveyor belt for

transporting flux Conveyor Length: 29 m; Width: 2 m

Carbon steel / Rubber Continuous 800-900 t/h 25 kW PFD-03-004 $1,027,547 2 needed

 AOD reactor CV-03-304

Conveyor belt for transporting

powdersConveyor Length: 29 m;

Width: 3 mCarbon steel /

Rubber Continuous 800-900 t/h 25 kW PFD-03-005 $1,027,547.00  

 EAF CV-03-201 Lime pebble

conveyor Conveyor Length: 40 m; Width: 2 m

Carbon steel/ Rubber Continuous 17 t/h 25 kW PFD-03-003 $165,000.00  

  River Dock CV-03-101 Iron ore transfer Conveyor     Continuous 210 t/h   PFD-03-002    

 Midrex furnace CV-03-102 Hot charge of

DRI to EAF Conveyor 100 m, 2 m, 2 m   Intermittent 150 t/h   PFD-03-002    

 Continuous

Casting Multiple Flux Pneumatic Conveyor

Pneumatic Conveyor / Carbon Steel Continuous .01 m3 air/h

0.5 t/h / PFD-03-006 $101,267.17  

 Continuous

Casting Multiple Flux Pneumatic Conveyor

Pneumatic Conveyor / Carbon Steel Continuous .01 m3 air/h

0.5 t/h / PFD-03-006 $101,267.17  

  Cranes                

 

AOD feed prep CN-03-301 Crane for

handling Ladles Crane Clear span: 30m Length: 42m Height: 9m

Carbon Steel Intermittent 350 t/h 16.6kW PFD-03-004 $2,011,316  

 EAF CN-03-202

Suspended crane for handling EAF input and output

CraneClear span: 12 m; Length: 94.5 m;

Height: 9 mCarbon Steel Intermittent 530 t/h 16.6 kW PFD-03-003 $542,201  

 

EAF CN-03-201

Suspeded Crane for weighing and

transport feed bins

CraneClear span: 12 m; Length: 44.1 m;

Height: 9 mCarbon Steel Intermittent 530 t/h 16.6 kW PFD-03-003 $542,201  

 

EAF CN-03-204

Suspended magnet with

induced current for picking up steel scrap

Crane 3 m, 3 m, 1 m Carrbon steel Intermittent 45 t/h 16.6 kW PFD-03-003 $37,841  

 

Continuous Casting CN-03-401 Hoisting Crane Crane 25 m x 5 m x 1 m / Intermittent

Lift Capacity:

75 t16.6 PFD-03-007 $800,559.09

2 Wheels per rack with a 4.9 m

space Vertical

Clearance: 18 m Electrically Powered

60

Design II

  Cylinders                

 

Continuous Casting BT-03-401

Compressed Acetylene Cylinder

Manifolded in 2 Banks

Gas Cylinder / High Pressure Steel Intermittent 125 ft3 / PFD-03-006

cost under continuous

casting

Manifolded in Bank 1

 

Continuous Casting BT-03-402

Compressed Acetylene Cylinder

Manifolded in 2 Banks

Gas Cylinder / High Pressure Steel Intermittent 125 ft3 / PFD-03-006

cost under continuous

casting

Manifolded in Bank 1

 

Continuous Casting BT-03-403

Compressed Acetylene Cylinder

Manifolded in 2 Banks

Gas Cylinder / High Pressure Steel Intermittent 125 ft3 / PFD-03-006

cost under continuous

casting

Manifolded in Bank 1

 

Continuous Casting BT-03-404

Compressed Acetylene Cylinder

Manifolded in 2 Banks

Gas Cylinder / High Pressure Steel Intermittent 125 ft3 / PFD-03-006

cost under continuous

casting

Manifolded in Bank 1

 

Continuous Casting BT-03-405

Compressed Acetylene Cylinder

Manifolded in 2 Banks

Gas Cylinder / High Pressure Steel Intermittent 125 ft3 / PFD-03-006

cost under continuous

casting

Manifolded in Bank 1

 

Continuous Casting BT-03-406

Compressed Acetylene Cylinder

Manifolded in 2 Banks

Gas Cylinder / High Pressure Steel Intermittent 125 ft3 / PFD-03-006

cost under continuous

casting

Manifolded in Bank 1

 

Continuous Casting BT-03-407

Compressed Acetylene Cylinder

Manifolded in 2 Banks

Gas Cylinder / High Pressure Steel Intermittent 125 ft3 / PFD-03-006

cost under continuous

casting

Manifolded in Bank 2

 

Continuous Casting BT-03-408

Compressed Acetylene Cylinder

Manifolded in 2 Banks

Gas Cylinder / High Pressure Steel Intermittent 125 ft3 / PFD-03-006

cost under continuous

casting

Manifolded in Bank 2

 

Continuous Casting BT-03-409

Compressed Acetylene Cylinder

Manifolded in 2 Banks

Gas Cylinder / High Pressure Steel Intermittent 125 ft3 / PFD-03-006

cost under continuous

casting

Manifolded in Bank 2

 

Continuous Casting

BT-03-4010

Compressed Acetylene Cylinder

Manifolded in 2 Banks

Gas Cylinder / High Pressure Steel Intermittent 125 ft3 / PFD-03-006

cost under continuous

casting

Manifolded in Bank 2

  Continuous BT-03-411 Compressed Gas Cylinder / High Pressure Intermittent 125 ft3 / PFD-03-006 cost under Manifolded in

61

Design II

Casting

Acetylene Cylinder

Manifolded in 2 Banks

Steel continuous casting Bank 2

 

Continuous Casting BT-03-412

Compressed Acetylene Cylinder

Manifolded in 2 Banks

Gas Cylinder / High Pressure Steel Intermittent 125 ft3 / PFD-03-006

cost under continuous

casting

Manifolded in Bank 2

  Dryers                

 

Continuous Casting DR-03-401 Membrane Air

Dryer Dryer / / Continuous 0.01 m3

air/h / PFD-03-006cost under pneumatic conveyor

Inlet P = 3 bar Dewpoint

Supressed to -40 °C

  Electric Arc Furnaces                

 

EAFEAF-03-

201, EAF-03-202

Hearth, shell, cooling panels

Electric arc furnace

Height: 5.35 m; Dia: 4.8 m

Carbon steel / Magnesite-

chromite brickIntermittent 350 t/h N/A PFD-03-003 $171,046.69  

 EAF

RF-03-201 (2), RF-03-

202 (2)

Electric arc furnace roof EAF roof

Diameter: 4.8 m; Sidewall height: 0.4

m Carbon Steel Intermittent 350 t/h N/A PFD-03-003 included in

EAF price  

 EAF

EE-03-201 (3), EE-03-

202 (3)

Graphite electrodes

EAF Electrodes

Length: 6 m; Dia: 0.6 m Graphite Intermittent 350 t/h 57 MW PFD-03-003 $19,161 each  

  Excavators                

 EAF EX-03-201 325C slag

excavator Yard 0.75 m3 bucket Stainless steel Continuous 20 t/h N/A PFD-03-003 $461,456.00  

  Fans                

 EAF FA-03-201,

FA-03-202Axial vane fan for

EAF off-gas Fan Diameter: 1 m SS316 Intermittent 18 t/h 100 kW PFD-03-003 $3,890.00  

  Flue Stacks                

 Midrex Flue

Stack FS-03-101 Flue stack Flue stack Height: 65 m   Intermittent 365 t/h   PFD-03-001   75% air and steam

  Heat Exchangers                

 

Midrex furnace HX-03-101

Heat Exchanger for heating

reformer feed

Shell and tube heat

exchanger3 m, 1 m, 1.5 m SS316 Continuous 365 t/h   PFD-03-002    

  Ladles                

 

AOD feed prep LD-03-301 Ladle for HCFeCr Ladle 5 m, 2 m, 4 m Carbon Steel Continuous 6 m3 N/A PFD-03-004 $49,554 7 ladles needed

62

Design II

 

AOD feed prep

LD-03-301 (2)

Steel ladle for molten steel

transferLadle 7 m, 3 m, 7 m Carbon steel Continuous 18 m3 N/A PFD-03-004 $49,554 7 needed

 

AOD feed prep

LF-03-301 (2)

Ladle furnace for storing steel Ladle furnace 10 m, 3 m, 10 m Carbon steel Intermittent 17 m3 N/A PFD-03-004 $3,224,173 3 ladle furnaces

need + 1 spare

 

EAFLC-03-201 (2), LC-03-

202 (2)Slag car Ladle car Height: 4 m;

Dia: 2.33 m

Carbon steel / Magnesite-

chromite brickIntermittent 17 t/h N/A PFD-03-003 $40,116.80  

 

EAFLD-03-201 (2), LD-03-

202 (2)Hot metal ladle Ladle Height: 5 m; Dia: 3

m

Carbon steel/ magnesite-

chromite brickIntermittent 313 t/h N/A PFD-03-003 111923.95  

 AOD reactor SP-03-301 Slag pot Ladle 4 m, 2 m, 4 m Carbon steel Intermittent 4 m3 N/A PFD-03-005 $48,279 3 + 4 spares

 AOD reactor LD-03-301 Ladle for

stainless steel Ladle 9 m, 4 m, 8 m Carbon steel Intermittent 33 m3 N/A PFD-03-005 $49,554 4 + 4 spares

  Launders                

 AOD reactor LA-03-301 Metal launder for

hot metal Launder 1 m, 2 m Carbon steel Intermittent 33 t/h N/A PFD-03-005 $1,254  

 

EAF LA-03-203, LA-03-204 Slag launder Launder 1 m2 tap hole, 1 m

spoutMagnesite-

chromite brick Intermittent 17 t/h N/A PFD-03-003 included in EAF price  

 

EAF LA-03-201, LA-03-202

Hot metal launder Launder 1 m2 tap hole, 1 m

spoutMagnesite-

chromite brick Intermittent 160 t/h N/A PFD-03-003 included in EAF price  

  Midrex Shaft Furnaces                

 Midrex furnace S-03-102 Midrex shaft

furnaceMidrex shaft

furnace 6.5 m, 6.5 m, 20 m   Intermittent 55,000 m3/h   PFD-03-003    

  Molds                

 

Continuous Casting MD-03-401

Oscillating Water-Cooled

Mold

Double-Chamber Mold

10m x 1.04m x 0.29 m Copper Continuous

Stainless Steel: 120

t/h Water:

1200 m3/h

/ PFD-03-006cost under continuous

casting 

 

Continuous Casting MD-03-402

Oscillating Water-Cooled

Mold

Double-Chamber Mold

10m x 1.04m x 0.29 m Copper Continuous

Stainless Steel: 120

t/h Water:

1200 m3/h

/ PFD-03-006cost under continuous

casting 

  Nozzles                

63

Design II

 

Continuous Casting NZ-03-401 Rod-Controlled

Stopper NozzleNozzle and

Stopper d-0.3m x h-0.5mHigh Purity Stabilised Zirconia

/ / / PFD-03-006cost under continuous

casting 

 

Continuous Casting NZ-03-402 Rod-Controlled

Stopper NozzleNozzle and

Stopper d-0.3m x h-0.5mHigh Purity Stabilised Zirconia

/ / / PFD-03-006cost under continuous

casting 

  Pumps                

 EAF

PP-03-201, PP-03-202

Hydraulic compressors for

EAF mechanismsPump 2 m, 1 m, 1 m SS316 Intermittent 650 bar 1 MW P&ID No. 3 $1,000,000.00  

 Midrex boiler PP-03-101 Process water for

steam generation Pump 0.89 m, 0.51 m, 0.76 m SS316 Continuous 25 m3/h   PFD-03-001    

 Midrex furnace PP-03-102 Process water for

scrubber Pump 0.89 m, 0.51 m, 0.76 m SS316 Intermittent 35 m3/h   PFD-03-002    

 

Continuous Casting

PP-03-401 A

Cooling Water Centrifugal Pump Pump / / Continuous 1200 m3/h 80 PFD-03-006 111,253.19

Multiple Stage Minimum

Required head: 24 m Impeller:

Closed

 

Continuous Casting

PP-03-401 B

Cooling Water Centrifugal Pump Pump / / Continuous 1200 m3/h 80 PFD-03-006 111,253.19

Multiple Stage Minimum

Required head: 24 m Impeller:

Closed

 

Continuous Casting

PP-03-402 A

Cooling Water Centrifugal Pump Pump / / Continuous 1200 m3/h 80 PFD-03-006 111,253.19

Multiple Stage Minimum

Required head: 24 m Impeller:

Closed

 

Continuous Casting

PP-03-402 B

Cooling Water Centrifugal Pump Pump / / Continuous 1200 m3/h 80 PFD-03-006 111,253.19

Multiple Stage Minimum

Required head: 24 m Impeller:

Closed

 

Continuous Casting

PP-03-403 A

Process Water Centrifugal Pump Pump / / Continuous 3150 m3/h 500 PFD-03-006 238,697.74

Mulitple Stage Minimum

Required head: 56 m Impeller:

Closed

 

Continuous Casting

PP-03-403 B

Process Water Centrifugal Pump Pump / / Continuous 3150 m3/h 500 PFD-03-006 238,697.74

Mulitple Stage Minimum

Required head: 56 m Impeller:

Closed

 

Continuous Casting

PP-03-404 A

Process Water Centrifugal Pump Pump / / Continuous 3150 m3/h 500 PFD-03-006 238,697.74

Mulitple Stage Minimum

Required head: 56 m Impeller:

Closed

64

Design II

 

Continuous Casting

PP-03-404 B

Process Water Centrifugal Pump Pump / / Continuous 3150 m3/h 500 PFD-03-006 238,697.74

Mulitple Stage Minimum

Required head: 56 m Impeller:

Closed  Racks                

 Continuous

Casting RA-03-401 Slab Collection Rack Rack 25 m x 10 m x 1 m / Continuous 4.21

slabs/h / PFD-03-007 352,200.00  

  Rails                

 EAF NA

Steel tracks for various rail cars and ladle cars

Tracks Length: 1000 m; Width: 1.8 m SS316 Intermittent N/A N/A N/A $420,000.00  

  Reformer                

 Reformer R-03-101

Steam reformer for syngas production

Reformer Length: 12 m   Continuous 115 t/h   PFD:03-001    

  Rollers                

 

Continuous Casting RL-03-401 Power-Driven

Roller Roller d-0.4 m x l-0.25 m Carbon Steel Continuous / 100PFD-03-006 to PFD-03-

007

cost under continuous

castingRoll Speed 100 s-1

 

Continuous Casting RL-03-402 Power-Driven

Roller Roller d-0.4 m x l-0.25 m Carbon Steel Continuous / 100PFD-03-006 to PFD-03-

007

cost under continuous

castingRoll Speed 100 s-1

 

Continuous Casting RL-03-403 Power-Driven

Roller Roller d-0.4 m x l-0.25 m Carbon Steel Continuous / 100PFD-03-006 to PFD-03-

007

cost under continuous

castingRoll Speed 100 s-1

 

Continuous Casting RL-03-404 Power-Driven

Roller Roller d-0.4 m x l-0.25 m Carbon Steel Continuous / 100PFD-03-006 to PFD-03-

007

cost under continuous

castingRoll Speed 100 s-1

 

Continuous Casting RL-03-405 Power-Driven

Roller Roller d-0.4 m x l-0.25 m Carbon Steel Continuous / 100PFD-03-006 to PFD-03-

007

cost under continuous

castingRoll Speed 100 s-1

 

Continuous Casting RL-03-406 Power-Driven

Roller Roller d-0.4 m x l-0.25 m Carbon Steel Continuous / 100PFD-03-006 to PFD-03-

007

cost under continuous

castingRoll Speed 100 s-1

 

Continuous Casting RL-03-407 Power-Driven

Roller Roller d-0.4 m x l-0.25 m Carbon Steel Continuous / 100PFD-03-006 to PFD-03-

007

cost under continuous

castingRoll Speed 100 s-1

 

Continuous Casting RL-03-408 Power-Driven

Roller Roller d-0.4 m x l-0.25 m Carbon Steel Continuous / 100PFD-03-006 to PFD-03-

007

cost under continuous

castingRoll Speed 100 s-1

 

Continuous Casting RL-03-409 Power-Driven

Roller Roller d-0.4 m x l-0.25 m Carbon Steel Continuous / 100PFD-03-006 to PFD-03-

007

cost under continuous

castingRoll Speed 100 s-1

 

Continuous Casting RL-03-410 Power-Driven

Roller Roller d-0.4 m x l-0.25 m Carbon Steel Continuous / 100PFD-03-006 to PFD-03-

007

cost under continuous

castingRoll Speed 100 s-1

65

Design II

 

Continuous Casting RL-03-411 Power-Driven

Roller Roller d-0.4 m x l-0.25 m Carbon Steel Continuous / 100PFD-03-006 to PFD-03-

007

cost under continuous

castingRoll Speed 100 s-1

 

Continuous Casting RL-03-412 Power-Driven

Roller Roller d-0.4 m x l-0.25 m Carbon Steel Continuous / 100PFD-03-006 to PFD-03-

007

cost under continuous

castingRoll Speed 100 s-1

 

Continuous Casting RL-03-413 Power-Driven

Roller Roller d-0.4 m x l-0.25 m Carbon Steel Continuous / 100PFD-03-006 to PFD-03-

007

cost under continuous

castingRoll Speed 100 s-1

 

Continuous Casting RL-03-414 Power-Driven

Roller Roller d-0.4 m x l-0.25 m Carbon Steel Continuous / 100PFD-03-006 to PFD-03-

007

cost under continuous

castingRoll Speed 100 s-1

 

Continuous Casting RL-03-415 Power-Driven

Roller Roller d-0.4 m x l-0.25 m Carbon Steel Continuous / 100PFD-03-006 to PFD-03-

007

cost under continuous

castingRoll Speed 100 s-1

 

Continuous Casting RL-03-416 Power-Driven

Roller Roller d-0.4 m x l-0.25 m Carbon Steel Continuous / 100PFD-03-006 to PFD-03-

007

cost under continuous

castingRoll Speed 100 s-1

 

Continuous Casting RL-03-417 Power-Driven

Roller Roller d-0.4 m x l-0.25 m Carbon Steel Continuous / 100PFD-03-006 to PFD-03-

007

cost under continuous

castingRoll Speed 100 s-1

 

Continuous Casting RL-03-418 Power-Driven

Roller Roller d-0.4 m x l-0.25 m Carbon Steel Continuous / 100PFD-03-006 to PFD-03-

007

cost under continuous

castingRoll Speed 100 s-1

 

Continuous Casting RL-03-419 Power-Driven

Roller Roller d-0.4 m x l-0.25 m Carbon Steel Continuous / 100PFD-03-006 to PFD-03-

007

cost under continuous

castingRoll Speed 100 s-1

 

Continuous Casting RL-03-420 Power-Driven

Roller Roller d-0.4 m x l-0.25 m Carbon Steel Continuous / 100PFD-03-006 to PFD-03-

007

cost under continuous

castingRoll Speed 100 s-1

 

Continuous Casting RL-03-421 Power-Driven

Roller Roller d-0.4 m x l-0.25 m Carbon Steel Continuous / 100PFD-03-006 to PFD-03-

007

cost under continuous

castingRoll Speed 100 s-1

 

Continuous Casting RL-03-422 Power-Driven

Roller Roller d-0.4 m x l-0.25 m Carbon Steel Continuous / 100PFD-03-006 to PFD-03-

007

cost under continuous

castingRoll Speed 100 s-1

 

Continuous Casting RL-03-423 Power-Driven

Roller Roller d-0.4 m x l-0.25 m Carbon Steel Continuous / 100PFD-03-006 to PFD-03-

007

cost under continuous

castingRoll Speed 100 s-1

 

Continuous Casting RL-03-424 Power-Driven

Roller Roller d-0.4 m x l-0.25 m Carbon Steel Continuous / 100PFD-03-006 to PFD-03-

007

cost under continuous

castingRoll Speed 100 s-1

 

Continuous Casting RL-03-425 Power-Driven

Roller Roller d-0.4 m x l-0.25 m Carbon Steel Continuous / 100PFD-03-006 to PFD-03-

007

cost under continuous

castingRoll Speed 100 s-1

66

Design II

 

Continuous Casting RL-03-426 Power-Driven

Roller Roller d-0.4 m x l-0.25 m Carbon Steel Continuous / 100PFD-03-006 to PFD-03-

007

cost under continuous

castingRoll Speed 100 s-1

 

Continuous Casting RL-03-427 Power-Driven

Roller Roller d-0.4 m x l-0.25 m Carbon Steel Continuous / 100PFD-03-006 to PFD-03-

007

cost under continuous

castingRoll Speed 100 s-1

 

Continuous Casting RL-03-428 Power-Driven

Roller Roller d-0.4 m x l-0.25 m Carbon Steel Continuous / 100PFD-03-006 to PFD-03-

007

cost under continuous

castingRoll Speed 100 s-1

 

Continuous Casting RL-03-429 Power-Driven

Roller Roller d-0.4 m x l-0.25 m Carbon Steel Continuous / 100PFD-03-006 to PFD-03-

007

cost under continuous

castingRoll Speed 100 s-1

 

Continuous Casting RL-03-430 Power-Driven

Roller Roller d-0.4 m x l-0.25 m Carbon Steel Continuous / 100PFD-03-006 to PFD-03-

007

cost under continuous

castingRoll Speed 100 s-1

 

Continuous Casting RL-03-431 Power-Driven

Roller Roller d-0.4 m x l-0.25 m Carbon Steel Continuous / 100PFD-03-006 to PFD-03-

007

cost under continuous

castingRoll Speed 100 s-1

 

Continuous Casting RL-03-432 Power-Driven

Roller Roller d-0.4 m x l-0.25 m Carbon Steel Continuous / 100PFD-03-006 to PFD-03-

007

cost under continuous

castingRoll Speed 100 s-1

 

Continuous Casting RL-03-433 Power-Driven

Roller Roller d-0.4 m x l-0.25 m Carbon Steel Continuous / 100PFD-03-006 to PFD-03-

007

cost under continuous

castingRoll Speed 100 s-1

 

Continuous Casting RL-03-434 Power-Driven

Roller Roller d-0.4 m x l-0.25 m Carbon Steel Continuous / 100PFD-03-006 to PFD-03-

007

cost under continuous

castingRoll Speed 100 s-1

 

Continuous Casting RL-03-435 Power-Driven

Roller Roller d-0.4 m x l-0.25 m Carbon Steel Continuous / 100PFD-03-006 to PFD-03-

007

cost under continuous

castingRoll Speed 100 s-1

 

Continuous Casting RL-03-436 Power-Driven

Roller Roller d-0.4 m x l-0.25 m Carbon Steel Continuous / 100PFD-03-006 to PFD-03-

007

cost under continuous

castingRoll Speed 100 s-1

 

Continuous Casting RL-03-437 Power-Driven

Roller Roller d-0.4 m x l-0.25 m Carbon Steel Continuous / 100PFD-03-006 to PFD-03-

007

cost under continuous

castingRoll Speed 100 s-1

 

Continuous Casting RL-03-438 Power-Driven

Roller Roller d-0.4 m x l-0.25 m Carbon Steel Continuous / 100PFD-03-006 to PFD-03-

007

cost under continuous

castingRoll Speed 100 s-1

 

Continuous Casting RL-03-439 Power-Driven

Roller Roller d-0.4 m x l-0.25 m Carbon Steel Continuous / 100PFD-03-006 to PFD-03-

007

cost under continuous

castingRoll Speed 100 s-1

 

Continuous Casting RL-03-440 Power-Driven

Roller Roller d-0.4 m x l-0.25 m Carbon Steel Continuous / 100PFD-03-006 to PFD-03-

007

cost under continuous

castingRoll Speed 100 s-1

67

Design II

 

Continuous Casting RL-03-441 Power-Driven

Roller Roller d-0.4 m x l-0.25 m Carbon Steel Continuous / 100PFD-03-006 to PFD-03-

007

cost under continuous

castingRoll Speed 100 s-1

 

Continuous Casting RL-03-442 Power-Driven

Roller Roller d-0.4 m x l-0.25 m Carbon Steel Continuous / 100PFD-03-006 to PFD-03-

007

cost under continuous

castingRoll Speed 100 s-1

 

Continuous Casting RL-03-443 Power-Driven

Roller Roller d-0.4 m x l-0.25 m Carbon Steel Continuous / 100PFD-03-006 to PFD-03-

007

cost under continuous

castingRoll Speed 100 s-1

 

Continuous Casting RL-03-444 Power-Driven

Roller Roller d-0.4 m x l-0.25 m Carbon Steel Continuous / 100PFD-03-006 to PFD-03-

007

cost under continuous

castingRoll Speed 100 s-1

 

Continuous Casting RL-03-445 Power-Driven

Roller Roller d-0.4 m x l-0.25 m Carbon Steel Continuous / 100PFD-03-006 to PFD-03-

007

cost under continuous

castingRoll Speed 100 s-1

 

Continuous Casting RL-03-446 Power-Driven

Roller Roller d-0.4 m x l-0.25 m Carbon Steel Continuous / 100PFD-03-006 to PFD-03-

007

cost under continuous

castingRoll Speed 100 s-1

 

Continuous Casting RL-03-447 Power-Driven

Roller Roller d-0.4 m x l-0.25 m Carbon Steel Continuous / 100PFD-03-006 to PFD-03-

007

cost under continuous

castingRoll Speed 100 s-1

 

Continuous Casting RL-03-448 Power-Driven

Roller Roller d-0.4 m x l-0.25 m Carbon Steel Continuous / 100PFD-03-006 to PFD-03-

007

cost under continuous

castingRoll Speed 100 s-1

 

Continuous Casting RL-03-449 Power-Driven

Roller Roller d-0.4 m x l-0.25 m Carbon Steel Continuous / 100PFD-03-006 to PFD-03-

007

cost under continuous

castingRoll Speed 100 s-1

 

Continuous Casting RL-03-450 Power-Driven

Roller Roller d-0.4 m x l-0.25 m Carbon Steel Continuous / 100PFD-03-006 to PFD-03-

007

cost under continuous

castingRoll Speed 100 s-1

 

Continuous Casting RL-03-451 Power-Driven

Roller Roller d-0.4 m x l-0.25 m Carbon Steel Continuous / 100PFD-03-006 to PFD-03-

007

cost under continuous

castingRoll Speed 100 s-1

 

Continuous Casting RL-03-452 Power-Driven

Roller Roller d-0.4 m x l-0.25 m Carbon Steel Continuous / 100PFD-03-006 to PFD-03-

007

cost under continuous

castingRoll Speed 100 s-1

 

Continuous Casting RL-03-453 Power-Driven

Roller Roller d-0.4 m x l-0.25 m Carbon Steel Continuous / 100PFD-03-006 to PFD-03-

007

cost under continuous

castingRoll Speed 100 s-1

 

Continuous Casting RL-03-454 Power-Driven

Roller Roller d-0.4 m x l-0.25 m Carbon Steel Continuous / 100PFD-03-006 to PFD-03-

007

cost under continuous

castingRoll Speed 100 s-1

 

Continuous Casting RL-03-455 Power-Driven

Roller Roller d-0.4 m x l-0.25 m Carbon Steel Continuous / 100PFD-03-006 to PFD-03-

007

cost under continuous

castingRoll Speed 100 s-1

68

Design II

 

Continuous Casting RL-03-456 Power-Driven

Roller Roller d-0.4 m x l-0.25 m Carbon Steel Continuous / 100PFD-03-006 to PFD-03-

007

cost under continuous

castingRoll Speed 100 s-1

 

Continuous Casting RL-03-457 Power-Driven

Roller Roller d-0.4 m x l-0.25 m Carbon Steel Continuous / 100PFD-03-006 to PFD-03-

007

cost under continuous

castingRoll Speed 100 s-1

 

Continuous Casting RL-03-458 Power-Driven

Roller Roller d-0.4 m x l-0.25 m Carbon Steel Continuous / 100PFD-03-006 to PFD-03-

007

cost under continuous

castingRoll Speed 100 s-1

  Scrubber                

 Midrex furnace S-03-101 Scrubber for dust

particles removalVenturi

Scrubber 1.5 m, 1.5 m, 3 m   Intermittent 55,000 m3/h   PFD-03-002    

  Spray Chambers                

 

Continuous Casting SC-03-401 Arced Spray

ChamberMisting Spray

Chamber

Arc Length: 19.2 m Casting Radius:

12.2 m Straight Portion

Length: 4 m

Steel Continuous

Stainless Steel: 120

t/h Water:

3200 m3/h Air: 320

m3/h

/ PFD-03-006cost under continuous

casting

Number of Nozzles: 320 Nozzle Type:

1PM.013.16.17 Flat Fan Misting

Nozzle Nozzle Diameter: 0.005

m 4 Arced Roller

Zones 1 Flat Roller Zone

 

Continuous Casting SC-03-402 Arced Spray

ChamberMisting Spray

Chamber

Arc Length: 19.2 m Casting Radius:

12.2 m Straight Portion

Length: 4 m

Steel Continuous

Stainless Steel: 120

t/h Water:

3200 m3/h Air: 320

m3/h

/ PFD-03-006cost under continuous

casting

Number of Nozzles: 320 Nozzle Type:

1PM.013.16.17 Flat Fan Misting

Nozzle Nozzle Diameter: 0.005

m 4 Arced Roller

Zones 1 Flat Roller Zone

  Tanks                

 

Continuous Casting TA-03-401 Suspend Flux

Blow Tank

Bottom Discharge Blow Tank

d-0.2m x h-0.2m Carbon Steel Continuous .01 m3 air/h 0.5 t/h / PFD-03-006

cost under pneumatic conveyor

 

 

Continuous Casting TA-03-402 Suspend Flux

Blow Tank

Bottom Discharge Blow Tank

d-0.2m x h-0.2m Carbon Steel Continuous .01 m3 air/h 0.5 t/h / PFD-03-006

cost under pneumatic conveyor

 

 

Continuous Casting TA-03-403 Suspend Flux

Blow Tank

Bottom Discharge Blow Tank

d-0.2m x h-0.2m Carbon Steel Continuous .01 m3 air/h 0.5 t/h / PFD-03-006

cost under pneumatic conveyor

 

 

Continuous Casting TA-03-404 Suspend Flux

Blow Tank

Bottom Discharge Blow Tank

d-0.2m x h-0.2m Carbon Steel Continuous .01 m3 air/h 0.5 t/h / PFD-03-006

cost under pneumatic conveyor

 

  Torches                

69