Steam-Calc-Medina 500 Bed - Rev2

7/23/2019 Steam-Calc-Medina 500 Bed - Rev2

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Steam Consumption Calculation for 500 Bed Madina Hospital

1.0 Steam Consumption for Domestic Hot Water Storage Calorifier

As per the Approved Sanitary Fixture Data (Data Sheet attached for reference), the Hot water

consumption can be calculated using the ASHRAE Tables for Hot Water Demand as detailedbelow:

Sanitary Fixture Qty. Demand rate per

Fixture

GPH

Total Demand Rate

GPH

Shower Tray 452 75 33900

Wash Basin 1226 6 7356

Janitor Sink 34 20 680

Bathtub 48 20 960

Scrub Sink 51 20 1020Kitchen Sink 196 20 3920

Lavatory (Wash Basin) 45 6 270

Dish Washer 2 150 300

Washing Machine 5

(Assumed)

400 2000

Total Demand 50,406 GPH

As per ASHRAE consider a Demand Factor of 0.25 for a Hospital Application

Therefore the Most Probable Hot Water Demand is 50,406 x 0.25= 12602GPH ~47704 LPH

Storage Capacity Factor is 0.6

Therefore the Storage Capacity of the Calorifier is 12600 x 0.6=7560 Gallons (29100 Liters)

Based on the above results we can select 3 Off Duty Storage Calorifiers with a storage

capacity of 10000 Liters to give a total of 30000 Liters of Hot Water Storage which is very

close to the above calculation based on ASHRAE.

STORAGE CALORIFIER SELECTION:

4 Off (3 Duty & 1 Standby) Copper Lined Storage Calorifier ( As per attached Technical

Submittal Approval ) each having 10000 Liters of Storage Capacity with a Flow Rate of 15900

L/Hr

We assume a temperature rise from 100C to 600C for domestic heating purpose

The Heating Capacity required is = 15900 x 4.186 x 50 / 3600 = 925 KW

Steam supply @ 6 bar(g) before the Control Valve will have a specific enthalpy of 2066 KJ/Kg

Therefore the Steam Consumption in Kgs/Hr would be = 925 x 3600 / 2066 = 1610 Kgs/Hr

Steam Consumption for 3 Duty storage calori fi erswould be = 4830 Kgs/Hr


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2.0 Steam Consumption for AHU Hot Water Heat Exchanger

As per the AHU Heating Load Schedule, HEs Duty (Heating Load=2692 MBH) is 790 KW

Hot Water Temperature inlet and outlet can be considered as 71.10C and 82.20C.

Steam required for the Heat Exchanger is = 790x 3600 / 2066 = 1377 Kgs/Hr

SELECTION OF HEAT EXCHANGERS:

We will select 2Off (1Duty & 1 Standby) Packaged Plate Heat Exchanger each having a

duty of 800 KW heating 17.22 lit/sec of Water for AHU from 71.1 to 82.2 Deg C.

Steam requir ed for the 1 Duty Heat Exchangers wil l be =800x 3600 / 2066=1394 Kgs/H r

3.0

Humidification

As per the AHU Humidification Schedule the Steam required for Humidification is 980 Kg/Hr

Steam required for humidifi cation = 980 Kgs/Hr

4.0 C.S.S.D

Due to non-availability of Equipment data, we will base our steam calculation on another 500

Bed MOH Hospital, the steam consumption can be considered as 600 Kg/Hr

Steam requir ed for Steril ization = 600 Kgs/H r

5.0

Laundry

Assumptions for the Laundry Equipment based on 500 Bed MOH Hospital:

Steam requir ed for Laundry is = 1005 Kgs/H r

Equipment QtySteam

Consumption

Total Steam

Load

Washer Extractor 3 50 Kg/Hr 150 Kg/Hr

Tumbler Dryers 4 75 Kg/Hr 300 Kg/Hr

Flat Work Ironer 1 255 Kg/Hr 255 Kg/Hr

Ironing Board 2 20 Kg/Hr 40 Kg/Hr

Presses 4 25 Kg/Hr 100 Kg/Hr

Dry Cleaning Machine 2 80 Kg/Hr 160 Kg/Hr

Total Steam Demand 1005 Kgs/Hr


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Calculation of Simultaneous Steam Consumption:

Case1 Night Time:Probable maximum consumption of steam during night time with the reduction in requirements

from Laundry, CSSD and domestic hot water production:

Domestic Hot Water Consumption 4830 x 30% = 1450 Kg/Hr.AHU Heating 1394 x100% = 1394 Kg/Hr.

Humidification 980 x 100% = 980 Kg/Hr.

CSSD 600 x 30% = 180 Kg/Hr.

Laundry 1005 x 30% = 302 Kg/Hr.

------------------------------------------------

Total Steam Demand 4306 Kg/Hr

Case2 Day Time:Probable maximum consumption of steam during day time with the reduction in requirements

from AHU Heating and Humidification:

Domestic Hot Water Consumption 4830 x 100% = 4830 Kg/Hr.

AHU Heating 1394 x 30% = 418 Kg/Hr.

Humidification 980 x 30% = 294Kg/Hr.

CSSD 600 x 100% = 600 Kg/Hr.

Laundry 1005 x 100% = 1005 Kg/Hr.

------------------------------------------------

Total Steam Demand 7147 Kg/Hr

Considering the maximum of the above two cases, the Max. Steam demand is 7147 Kg/Hr

Consider 10% Losses due to Feed Water Re-heating and Blowdown715 Kg/Hr

Hence Total Steam required shall be 7147 + 715 = 7862 Kg/Hr

SELECTION DATA

As per attached Technical Submittal Approval

Quantity: 3 Each (2 Duty and 1 Standby)

Boiler Capacity Selected 4000 Kgs/Hr F&A 100 Deg C.

Boiler Type: Conventional 3 Pass Wet Back Type

Boiler Working Pressure: 10.3 Bar(g)

Fuel Type: Diesel Oil

Electrical Rating: 380 V / 3 Ph / 60 Hz.


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Equipment Specifications:

1. Boiler:


Selection Criteria:

The detail selection procedure is provided in the steam consumption calculations.

Boilers Selected:

Qty: 3 Off (2 Duty and 1 Standby)

Model: Cochran Wee-Chieftain Packaged Steam Boiler

Capacity: 4000 Kg/Hr F&A 100 Deg C @ 10.3 bar(g)Overall Dimensions: Approx. 4896 long x 2690 wide x 3251 high (Dimensions in mm)

Boiler Specifications

The boilers should be Horizontal Three Pass Wet Back Conventional Type and shall be

designed and constructed to BS2790 latest revision.

Model: Cochran Wee-Chieftain

The boilers will be rated at 4000 kg/hr F&A 100 0C.

Working Pressure: 10.3 bar(g)

Electrical supply: 380 V / 3 Ph / 60 Hz; Control Circuit: 220 V / 1 Ph / 60 Hz.

Fuel: Diesel Oil

Accessories:

The boiler package shall consist of:

Pressure vessel (Shell)

Suitably sized Burner with all necessary controls and Control Panel,

Valves and fittings required as per relevant standards,

Water Level ControlsSelf Monitoring Probe Type Level Controls for Pump Controland Independent Level Control for First and Second Low Level Alarms and Lock Out.

Vertical Multi-Stage Feedwater pump wired to the control panel,

Automatic TDS Control System,

Sample Cooler System,

Automatic Timed Bottom Blowdown System

Rear Heat Shield,

Flue Gas Temperature Indicator,


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2. Feed Water Tank:


Selection Criteria:

Feed Water tank provides a reserve of water to cover the interruption of supply to the feed

pumps. Traditional practice is to have a feed water tank with sufficient capacity to allow one

hours steaming at maximum boiler evaporation.

As we have only 2 Duty boilers with each boiler providing 100% of total rated capacity during

peak load.

Feed Tank Capacity Selected:

Capacity: 8000 Liters

Approximate Dimensions: 2000 mm x 2000 mm x 2000m ( H x W x L)

Tank Specifications:

The tank will be fabricated in Saudi Arabia using Spirax Sarco design drawing and will be

constructed from 304 St. St. sheets of 5mm thickness and Size 2.0m x 2.0m x 2.0m complete

with 50mm Mineral Wool Insulation and Aluminum Cladding.

Accessories:

Spirax Sarco De-Aerator Head suitable sized as per attached sheet (Type DH) Spirax Sarco Type RFS Re-circulating Feed Water Spray System

Spirax Sarco Steam Injection System comprising of Temperature Control Valve,

Sensor Pocket, Steam Injector and Vacuum Breaker.

Spirax Sarco Water Level Controls (LP10-4) complete with LC1350 Controller

Spirax Sarco Water Level Gauge

Spirax Sarco Dial Thermometer

Spirax Sarco Cold Water Make Up Valve (WV1)

Vent Head (Type VH)


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3. Blowdown Vessel:


Selection Criteria:

The Selection of a blowdown vessel depends on the flowrate and the proportion of flash steam

released.

The following factors affect the selection:-

The Boiler Pressure

The Blowdown Line Size

The Length of the Blowdown line between the boiler and the blowdown vessel.

Blowdown Vessel Selected:

Spirax Sarco Blowdown Vessel Type: BDV60/4

Vessel Specifications:

The Vessel is designed, constructed and tested by Spirax Sarco to BS 5500 Category 3 with

Independent Third Party Verification and Inspection.

Accessories:

Spirax Sarco Blowdown Vessel System is supplied complete with all necessary manifolds,

valves and check valves required on the Bottom Blowdown connection and the TDS

Blowdown Connection from the three boilers. A cooling water system is provided to be

installed on the BDV for proper cooling of the boiler blow down water before being dumped to

the drain.


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4. Condensate Recovery Unit:


a. Main Hospital (Humidifiers, CSSD & Laundry)

Selection Criteria:Condensate return from all the steam consumers from the main hospital can be calculated

based on the maximum steam demand inside the hospital (Humidifiers, CSSD & Laundry -

Max. 2600 Kg/Hr) which amounts to 1550 Liters/Hr of condensate return (As only 30% of

condensate will return from Humidifiers, 90% from Sterilizers and 70% return from

Laundry).

We will size the Packaged Condensate Pump Unit based on the 1550 Kg/Hr Flow and 20m

head and as per attached Sizing chart we select Spirax Sarco DN50 x DN50 MFP14

Packaged Pump Unit

Condensate Pump Unit Capacity Selected:

1550 Liters/Hr @ a head of 20m

Model Selected: Spirax Sarco DN50 X DN50 MFP14 PPU

5. Storage Calorifier: (Domestic / Kitchen / Laundry Hot Water)

Selection Criteria:

The detail selection procedure is provided in the steam consumption calculations.

Storage Calorifiers Selected:

Qty: 4 Off (3 Duty + 1 Standby)

Model: Rycroft Copper Lined Storage CalorifiersMCZE 10000 (2640 Gallons)

Overall Dimensions: 4600 mm High x 1680 mm diameter

Capacity: 10000 Likters (2640 USG)

Duty: 15900 Lit/Hr (925 KW)Secondary Water: 10 to 60 deg C.

6. Heat Exchangers (for AHU):

Selection Criteria:The detail selection procedure is provided in the steam consumption calculations.

Heat Exchangers Selected:

Qty: 2 Off ( 1Duty + 1 Standby)

Model: Horizontal Mild Steel Shell and Tube Heat Exchanger

Capacity: 800 KWDuty: 17.22 Lit/Sec.


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List of Manufacturers submitted for the complete Boiler Package

BIB Cochran Boiler UK : Boilers Package

Rycroft Ltd.

UK : Storage Calorifiers

Spirax Sarco Ltd. UK : Feed Tank Accessories (Including Level Controls,

Recirculating Feed Water System, Steam Injection System etc.), Blowdown Vessel and all

related accessories, Automatic TDS Control System, Sample Cooler, Header Isolating Valves,

Condensate Recovery Unit, All steam and Condensate accessories like Valves, Strainers,

Separators, Steam Traps, Air Vents, Pressure Reducing Valves, Check Valves, Temperature

Control Valves & High Limit Control Valves and EASIHEAT PACKAGED PHE

Local Fabrication - KSA : Feed Water TankSt. St. material as per Spirax Sarco Design.

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Steam-Calc-Medina 500 Bed - Rev2