IB01000dGBPfisterDRW

www.pfister.de

Product Brochure

Rotor Weighfeeder Pfister DRW

Highly accurate and reliable gravimetric feeding of

pulverised fuel

The Pfister DRW is especially designed for dosing pulverised fuels such as petrol coke, lignite or coal

dust in the cement burning process. It even allows in-line-blending of a number of fuels into one com-

mon fuel feeding line. Integration of material extraction, weighing, dosing and material transfer into

the pneumatic conveying line makes it a compact system that provides accuracy and constancy. Pow-

ered by the innovative dosing strategy ProsCon®, the mass flow is controlled in advance. Thus, high

short- and long-term accuracy and dosing stability are realised. Moreover, the outstanding constancy

of metering with Pfister DRW + ProsCon® makes it possible to achieve low levels of carbon monoxide in

the kiln exhaust gas.

Pfister DRW + ProsCon®: the innovative solution for metering pulverised fuels.

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History

FLSmidth Pfister has more than 110 years of

experience in manufacturing industrial weigh-

ing equipment and is part of the FLSmidth

group since 1998.

The Rotor Weighfeeder technology was devel-

oped by FLSmidth Pfister in 1984 and it is now

time tested and state of the art in the cement-

production industry. More than 1,700 systems

are in operation world-wide.

FLSmidth Pfister additionally supplies know-how

for equipment, related to the coal feeding proc-

ess. This is to ensure problem free material

handling and optimal pneumatic transport of

the coal.

Customised solution Since fuels have a wide variety of material

characteristics it is a necessity to have various

installation solutions. Each one gives the opti-

mal and most economic result form case to

case.

What solutions are there? Pages 4-5

How does the system work?

What are the benefits?

What are the dimensions?

What applications are there?

What are the technical facts?

Is there further information?

Pages 6-8

Pages 9-12

Page 13

Pages 14-21

Page 22

Page 23

All Pfister weighfeeders are

Engineered

Designed

Assembled

Tested

in Augsburg—Germany

1984—Start of the rotor weighfeeder technology

Historic Pfister scale. Ludwig Pfister,

founder of the company in 1894.

Content

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General Principle

The Pfister DRW is used to extract pulverised

coal out of a storage silo and feed it with high

accuracy and consistency to the burner to sup-

port a optimal flame for stable cement clinker

production.

The Pfister DRW is a breakthrough in continu-

ous, gravimetric dosing of pulverised fuels such

as hard-coal, lignite or petrolcoke to the kiln

and calciner burners. These fuels will be re-

ferred to as coal.

This mechatronic system uses an operation

principle similar to a horizontal rotary valve.

The gravimetric content is measured and the

speed of the motor is adjusted to compensate

variation in bulk material characteristics.

To achieve the accuracy of coal feeding it is

necessary to supply the rotor weighfeeder con-

stantly with coal and after dosing, transport the

coal pneumatically to the burner.

FLSmidth Pfister offers

Engineering for coal storage silo (1)

Intermediate coal transport system (2)

Engineering for intermediate silo (3)

Silo cone and cone aeration (4)

material activator Pfister SGA (5)

Calibration hopper (6)

Highly accurate rotor weighfeeder Pfister DRW (7)

Calculation of pneumatic transport pipe and blower

data (8)

Complete coal dosing and feeding system out of one hand

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2

3

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7

3

8

4

5

General Principle

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Downpipe Solution

The coal is extracted out of a coal silo (1), sup-

ported by an aeration system (2). The rotor

weighfeeder (4) reliably doses the coal and the

transport air (5) discharges the machine and

blows the coal directly to the burner. The high

feed accuracy of the rotor weighfeeder ensures

a steady air/coal mixture for the burner.

This installation is using a down-pipe (3) to con-

nect the silo outlet with the rotor weighfeeder

(4) . Silo cones provided by FLSmidth Pfister can

either be welded or flanged to the silo and are

available in different sizes. These cones are in

stainless steel, surface treated and have an

inclination of 75° for optimal material flow and

prevention of material bridging or tunnel flow.

Calibration-Hopper Solution

To provide safety in material flow and to give

the possibility for online-calibration, FLSmidth

Pfister offers a solution using an intermediate

buffer of coal in a calibration-hopper (5) . The

hopper cone is made in stainless steel and aer-

ated. The starfeeder (4) regulates the filling of

the calibration-hopper and provides an air seal-

ing back to the silo. Optional a agitator arm is

available to improve material flow.

1

2

5

4

3

Benefits of the Calibration-Hopper:

Online calibration of the rotor weighfeeder.

Backpressure and leakage elimination.

Therefore reduction of wear in the system.

Safety in coal supply even with extremely

fine and moist material.

Longer feed distances for pneumatic trans-

port.

How Online Calibration Works: During an online-calibration cycle, the upper

shut-off gate (3) stops the filling of the calibra-

tion-hopper (5). The bulk material content of

the calibration-hopper is measured by a

weight measurement unit at the bottom of the

system (8). After discharging a certain amount

of material in a certain time out of the calibra-

tion-hopper it is possible to compare the loss

of material in the hopper with the amount

calculated by the rotor weighfeeder (7). This

means comparing the static weighing of the

calibration-hopper with the dynamic weighing

of the rotor weighfeeder. The redundant prin-

ciple gives highest accuracy and optimal calcu-

lation of total coal consumption.

1

2

3

4

5

6

7

8

What solutions are there?

Downpipe solution. 1: silo, 2: silo cone aeration, 3: down-pipe, 4: Pfister DRW, 5: pneumatic transport system.

Calibration-hopper solution. 1: silo, 2: silo cone, 3/6: shut-off gates, 4: star feeder, 5: calibration hopper, 7: Pfister DRW, 8: weight measurement units.

Different Solutions

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Several Systems Under One Coal Silo

For more economic operation of the cement

burning process, Pfister provides a material

activator Pfister SGA. This makes it possible to

install up to four rotor weighfeeders DRW under

one coal silo.

Block-System Solution

A special and economic version of a coal silo

with an attached rotor weighfeeder is the so

called block-system. It can also be used for

online-calibration. The small size reduces coal

extraction problems.

This solution is useful if the burners are far

apart from the fine coal silo. It can easily be

placed near the front- or back-end firing of the

kilns.

It employs a intermediate silo with a volume of

up to 30m³. The silo is directly connected to the

rotor weighfeeder and both together are placed

on weight measurement units. The silo is also

explosion proof of up to 10 bar, therefore no

explosion flap necessary.

Block-System Solution 1: filter, 2: intermediate coal silo, 3: Pfister DRW.

1

2

3

7

4

6

1

2

3

5

6

7

1

2

3

Pfister SGA with down-pipes Pfister SGA with calibration hoppers 1: silo, 2: silo cone, 3: material activator Pfister SGA, 4: downpipe, 5: calibration hopper, 6: Pfister DRW, 7: pneumatic transport.

Different Solutions

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Functioning Principle of the

Rotor Weighfeeder The rotor wheel inside, is the heart of the sys-

tem and supplies highly accurate and constant

coal feeding.

The weighing axis (A-A) is eccentric to the rotor

shaft, but through the middle of inlet (1), outlet

(2) and blower pipe (3). The third point is sus-

pended at a load cell (4) which weighs the gra-

vimetric material content of the rotor. The pul-

verised coal is transported in the rotor cham-

bers from the inlet (1) to the outlet (2) . The coal

mass in the rotor wheel produces a force (F). The

transport air in the blower pipe (3) crosses the

rotor chambers at the outlet (2) and discharges

the coal.

The speed of the rotor wheel is controlled invers

to the measured force (F).

The measured gravimetric Force (F) provides

information on the bulk material mass in the

rotor weighfeeder before material discharge.

The loading of the rotor weighfeeder with the

related rotor position, is stored by the weighing

electronics. That means that the rotor weigh-

feeder measures real kilograms and is therefore

a true scale.

The weighing electronics

ProsCon® It calculates the required speed of the motor for

the time of the discharge. It uses the set

feedrate and the measured bulk material mass

to calculate the angular speed of the rotor (see

chart). Less material in the rotor results in a

higher angular speed, more material in a lower

speed.

With this pro-active principle, so-called prospec-

tive control ProsCon®, the rotor weighfeeder

achieves a highly accurate compensation of

variations in rotor loading and material density.

This results in an extremely accurate feedrate

for short- and long-term.

Rotor weighfeeder weighing and dosing principle 1: inlet, 2: outlet, 3: blow-out pipe, A-A: Eccentric Weighing Axis, F: material measuring force.

To achieve high accurate feeding, angular speed of rotor is controlled invers to rotor weighfeeder loading.

How does the system work?

1

2

3

4

Function Principle

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FLSmidth Pfister Rotor Weighfeeder

Controller

All Data are collected in the:

Pfister CPI—Can Process Interface, at the feeder (6)

and transferred via Can-Bus to the:

Pfister CSC—Can System Controller, in MCC (7)

The communication between the Pfister CSC

and the plant control system can either be

via:

Serial-Interface (ModBus RTU).

Network-Interface.

(Profi-Bus DP, Device Net)

Analog/Digital-Hardwired Interface.

5

7 Motor Control Center6 Local

2

3AC4

ACM T

1

CAN

aeration controller

feeder controller

CSC

process interface

CPI

weight transmitter

NWT1

Electronic control scheme for calibration-hopper solution. 1: Material storage silo, 2: silo cone and aeration, 3: shut-off gate, 4: star feeder, 5: calibration hopper, 6: rotor weighfeeder and Pfister CPI, 7: Pfister CSC.

Prospective Control ProsCon® (Forward looking / pro-active)

Reactive Control Compared to Pfis-

ter’s Proactive Control Strategy

Other feeders are based on a reactive control

(follow-up) rather then a proactive control.

Deviations in feedrate is measured and the pre-

feeding is adjusted. The measured deviation is

already sent to the process. This also requires a

very fine and sensitive pre-feeding device.

With the proactive Pfister rotor weighfeeder, the

material mass is measured before it leaves the

rotor weighfeeder. That means that the speed

of the rotor is adjusted before the coal gets

discharged into the system, not the other way

round. This eliminates CO peaks in the firing

process.

Reactive, Follow-up Control.

Pfister CSC controller

Volumetric feeding during refilling.

Function Principle

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Pneumatic Transport to the Burner

The pneumatic transport of the coal to the

burner is an essential part of the feeding sys-

tem. The rotor weighfeeder is directly con-

nected to a blower. Clean transport air is blown

with approximately 25m/s through the feeder

and transports the fuel the the burner. Pfister

supplies a calculation of the transport pipe and

blower, matching the individual installation.

From our experience we suggest strictly vertical

or horizontal pipes with either 0° or 90° inclina-

tion. It is also advisable to use a minimum

number of bends (min. 1.5m radius) and to

keep the pipe as short as possible.

Mixing of two different fuels into one feedpipe.

The amount of transport air depends on coal

feedrate and length of the pipe.

Pfister calculations provides optimal fuel trans-

port to rule out material segregation in the

pipes which would cause pulsations and CO

peaks.

If necessary it is possible to feed different

fuels into one feedpipe as shown in the figure.

Further on FLSmidth Pfister provides to possi-

bility to feed different fuels into one feedpipe,

as shown below.

Function Principle

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Service work at Pfister rotor weigh-feeder.

Long Service Life and High Availability

This is achieved by a slow rotation speed of the

rotor, only 6-8 rounds per minute.

The only moving part, the rotor itself, is made

in a certain cast steel to minimise wear of both,

sealing plates and rotor. The wear varies with

material abrasiveness but requires under nor-

mal conditions a rework of the sealing plates

only every 2 to 3 years of service time. The

plates can be reworked 2 to 3 times until a

spare part is necessary.

Simple & Intuitive Operator Interface

The rotor weighfeeder is an advanced mecha-

tronic system. However it is very simple to op-

erate the rotor weighfeeder. The communica-

tion to the local plant control system is flexible

and works reliable.

Minimal Air Back-Flow from pneu-matic transport system to material storage silo The rotor is designed with many small cham-

bers, each one representing an air seal between

the pneumatic transport and the material stor-

age silo

Optimal flame Control The rotor weighfeeder actively compensates

changes in material characteristics and supplies

a constant stream of coal to the burning proc-

ess.

It supplies high short and long-term accuracy in

deviation of set- and actual feedrate. The stable

feeding results out of the pro-active control

strategy and permanent gravimetric weighing

and dosing (ProsCon®, forward looking) .

Optional operation process display, RPD.

The rotor is the heart of the machine, small chambers prevent back pressure.

What are the benefits?

Optimal flame control with Pfister DRW.

Benefits

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4 3 2 1,7 1 0,6 0,250

0,5

1

1,5

CO %

O2 %

Rotor Weighfeeder DRW Continous Flow Measuring

Carbon monoxide (CO) development as a function of oxygen excess (O2) during metered feeding of pulverised coal. (source: Rotor weighfeeder plant test)

Feedrate of rotor weighfeeders are instantaneously adjustable to provide stable and reproducible feeding.

Eliminated CO-peaks Stable feeding without peaks of fed coal elimi-

nates CO-peaks and therefore prevents filter

shut-downs.

Reduced Excess-Air Cushion

Because of the above mentioned reasons it is

possible to reduce the over supply of air closer

to the optimum, while the generation of CO and

NOx is minimised (see chart).

Reliable Feeding

Pfister supplies know-how for the whole envi-

ronment of dosing and an integration of the

new system into the existing plant layout. Opti-

mised silo cones, material activators and cali-

bration-hoppers ensure reliable coal silo extrac-

tion. Accurate calculation of pneumatic trans-

port pipes ensure the transfer of the accurate

material stream from the rotor weighfeeder to

the burner flame.

Instantaneously Adjustable

Feedrate Because of its design, the rotor weighfeeder

supplies its high accuracy in a range from 10%

to 100% of the maximum feedrate. This accu-

racy is related to the actual feedrate.

The ProsCon® control strategy ensure virtually

no reaction time in changes of the feedrate.

This is especially necessary if the feedrate of

the primary fuel is adjusted to the insertion of

secondary fuels, which might change in quality

or is running out of supply.

Pfister DRW

Benefits

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FLSmidth Pfister Workshop in Augsburg—Germany.

Pfister DRW´s ready to ship.

Excellent Service & Support

Whether putting new systems in operation or

requiring maintenance for equipment which is

already in operation – FLSmidth Pfister service

technicians are trained and experienced in han-

dling all of our equipment. Thus FLSmidth Pfis-

ter may ensure that the production processes

will work smoothly from the beginning and fur-

Yearly maintenance work on Pfister DRW.

FLSmidth Pfister supports with the

following services:

Pfister Rotor weighfeeders are 100% tested in

the FLSmidth Pfister work-shop before delivery.

World-wide FLSmidth Pfister representation

through several subsidiaries and agencies.

Training for operators and maintenance per-

sonal at FLSmidth Pfister in Augsburg or on

customers site.

24 hours technical telephone hotline.

Short notice support with service specialists.

Fast support with emergency spare parts.

Modern maintenance management.

Technical assistance by Telesupport.

Service and Support

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Technical Assistance by Telesupport

With an optional modem, experienced Pfister

technicians have remote access to controller

parameters, control logic and sensoric inter-

face. This makes online help possible for trou-

ble shooting and interpreting events and sys-

tem messages.

Modern Maintenance Management

FLSmidth Pfister’s experience in maintenance

management has been helping cement plants to

make the cement production process more effi-

cient for many years.

Modern Maintenance Management reduces wear

Online trouble shooting with optional modem

The Benefits of MMM:

Cost saving pre-planning of kiln outages.

Regular check-up support; less overall

downtimes.

Support in spare parts management.

Replacement of crucial parts at the right

time.

All maintenance measures carried out by

experienced Pfister specialists.

Reduce overall service cost.

Maintenance contracts are available.

FLSmidth Pfister—Augsburg

WWW

Modem on site

Pfister CSC in MCC

Pfister CPI at feeder

Service and Support

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Rotor Weighfeeder Pfister DRW Series

Type Rotor Ø Feedrate*(max.) Weight (max.)

Pfister DRW 4.10 1000 mm 12 t/h 4.000 kg

PfisterDRW 4.12 1200mm 20 t/h 5.350 kg

PfisterDRW 4.14 1400 mm 40 t/h 8.800 kg

*depending on fuel characteristics

Rotor Weighfeeder Dimensions Here: Type Pfister DRW 4.10

Side view, Pfister DRW 4.10.

Top view, Pfister DRW 4.10.

What are the dimensions?

Dimensions

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Above: Silo cone and outlet Coal silo cone (1) with cone aeration (2). Material activator Pfister SGA (3)

with additional second/third/fourth outlet (4) and Pfister SGA aeration(5).

Pre-feeding devices shut-off gate (6)

and star feeder (7).

Below: Pfister DRW with calibration hopper. Calibration-hopper (1) with aeration (2). Pfister DRW 4.10 (3) with below calibration measure-ment units (4). Pneumatic transport pipe for coal transport to burner (5).

Application at a Cement Plant in Germany

What applications are there?

1

5

3 4

2

6

7

1

2

3

4

5

Applications

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Pfister DRW (1) with down-pipe (2), fresh air pipes from blower (3) and transport air pipes to burner (4).

Double coal silo.

Application at a Cement Plant in Pakistan

1

2

3

4

Applications

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Pfister DRW (9)

with calibration measurement units (10).

Local silo extraction unit (1) and new shut-off gate (2), star-feeder (3) and motor

for pre-hopper agitator arm (4).

Application at a Cement Plant in Germany

1

2

3

4

5

6

7

8

9

10

Pre-hopper top (5)

with service opening (6).

Pre-hopper cone (7)

with aeration (8).

Applications

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Application at a Cement Plant in the USA

1

2

3

4

5

6

7

8

9 Pfister DRW (8)

with calibration measurement units (9).

Star feeder (5) feeding into calibration-hopper (6) with agitator-arm motor and gear box(7).

Silo cone (1) with aeration (2), manual– (3) and pneumatic shut-off gate(4).

Applications

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Pfister SGA (1)

with shut-off gates (2) and star-feeders (3)

feeding into below calibration-hoppers (4).

Application at a Cement Plant in the USA

1

2

3

4

5

6

Pfister DRW (5)

with calibration-hoppers (6).

Applications

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Application at a Cement Plant in Great England

Aerated coal-silo cone (1) with material activa-tor Pfister SGA (2) and shut-off gates (3).

1 2

3

Calibration-hoppers (5) Pfister DRW (6) .

5

6

Star-feeders (4) feeding into calibration-hoppers (5).

4

5

Pfister DRW for oil-shale dosing (9).

9

Aerated silo cone (7) and star-feeder (8).

7

8

Coal Dosing Oil-shale Dosing

Applications

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Application at a Cement Plant in Lebanon

Aerated silo cone (1) and material activator Pfister SGA with three outlets (2). Shut-off gates (3) and star-feeders (4)

Calibration-hoppers (5)

and Pfister DRW (6).

Later on...

Pfister SGA exchanged to four outlets and four dosing systems below. Feeding three kilns, one with main burner and calciner burner.

1

2

3

4

5

6

Applications

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Four Pfister DRW (1) for dosing of pulverised fuel at a thermal power plant in Germany.

Pre-hopper with 20m³ (2), material activator (3).

The Drawing shows three Pfister DRW (1) installed to feed coal to ro-

tary kiln main burner, calciner burner and riser duct.

1

1

2

3

Applications

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Pfister DRW

Application: Highly accurate, gravimetric feed-

ing of pulverised fuel to the burners in the cement

production-process

Bulk material: Pulverised

Hardcoal

Lignite

Petrolcoke

Oil shale

Design:

Machine is engineered, designed, assembled and

tested in Germany

Certification:

DIN EN ISO 9001:2000

ATEX (94/9/EC) in categories II1/2D and II1/3D

Feedrate: 0.6 t/h to 40 t/h

Feedrange: 10% to 100%

Accuracy: ± 0.5%

over the complete feedrange related to

the actual value.

Electronic controller: Pfister CSC controller with proactive control

strategy ProsCon®.

Electronics Temperature Range:

Standard: 0°C to +40°C

With heater*: -20°C to +40°C

With cooler*: 0°C to +55°C *installed in local electric cabinet at feeder

Interface to Plant Control System:

Serial-Interface (ModBus-RTU).

Network-Interface.

(Profi-Bus DP, Device Net)

Analog/Digital-Hardwired Interface.

What are the technical facts?

Applications

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Pfister DRW Pulverized fuels

Pfister FRW Powdered products

Pfister TRW-K Crushed raw coal

Pfister TRW Coarse products

Pfister VRW Powdered products

Pfister TRW-S Alternative fuels

To see to the contend of your interest please click on the links below on our website:

Press articles http://www.flsmidth.com/Pfister/English/News/Pfister+news/Press+archive.htm

Special-interest articles http://www.flsmidth.com/Pfister/English/Special+interest+articles/Special-interest+articles.htm

Brochures http://www.flsmidth.com/Pfister/English/Downloads/Datasheets+and+Brochures/Brochures/Brochures.htm

Product datasheets http://www.flsmidth.com/Pfister/English/Downloads/Datasheets+and+Brochures/Datasheets/Datasheets.htm

Product animations http://www.flsmidth.com/Pfister/English/Downloads/Product+animations/Product+animations.htm

Applications

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Contacts

FLSmidth Pfister GmbH Staetzlinger Str. 70 86165 Augsburg Germany T. +49 821 7949 0 F. +49 821 7949 524 www.pfister.de Branches offices & joint ventures FLSmidth Pfister Inc. 2158 Avenue C, Suite 201 Bethlehem, PA18017-2148 U.S.A. T. +1 610 2645110 F. +1 610 2645537 [email protected] FLSmidth Pfister Ltda. Rua Vigário J.J. Rodrigues, 905 - c.j. 51 13.201 - 490 Jundiai S.P., Brazil T. +55 11 45266744 F. +55 11 45875711 [email protected] FLSmidth Pfister GmbH Malaysian Branch C-3A15, Centre Wing Metropolitan Office Suite Metropolitan Square, Jalan PJU 8/1 Damansara Perdana 47820 Petaling Jaya Selangor Malaysia T. +60 3 7728 2039 F. +60 3 7727 2039 [email protected] FLSmidth Pfister GmbH 6, Rue de Bretagne 38070 St. Quentin Fallavier France T. +33 474 955544 F. +33 474 945075 [email protected]

Sales Department: [email protected] Technology Department: [email protected] Service Department: [email protected] Transweigh India Ltd. 124, ABCD, Govt. Industrial Estate Kandivli (W) Mumbai - 400 067 India T. + 91 22 2868 2311 F. + 91 22 2868 2145 [email protected] FLSmidth Pfister GmbH China Western Part of Songshan Road Qingdao Airport Industrial Zone Chengyang District 266109 Qingdao P. R. China T. +86 532 877 60380 F. +86 532 877 56852 [email protected]

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IB01000dGBPfisterDRW