Product Brochure Gravimetric Belt Feeder ® Pfister G GBF BF
Highly accurate feeding of crushed coal for power plants Watch here how Pfister® dosing solutions work!
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Tradition & progress
FLSmidth Pfister has almost 120 years of experience in manufacturing of industrial weighing equipment. It has been member stock quoted FLSmidth Group/Denmark since 1998. The patented rotor weighfeeder was invented by Pfister in 1984 to feed pulverised fuels for the cement burning process. This state-of-the-art dosing device has proved its properties in more than 2,500 installations worldwide. FLSmidth Pfister additionally supplies know-how for equipment, related to the coal feeding process in order to ensure problem-free material handling and optimal pneumatic transport of the coal.
Pfister® weighfeeders are - engineered - designed - assembled - tested with the experience of almost 120 years.
Fuels have a wide variety of material characteristics. Thus, FLSmidth Pfister helps to design individual installation solutions.
German Ludwig Pfister founded the company in 1894 Above: Historic scale
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Customer benefits of gravimetric belt feeders Pfister® GBF Gravimetric belt feeders Pfister® GBF are advanced and highly developed systems. Their benefits are described in the following comparison of gravimetric and volumetric feeders. These benefits are essential for the firing of the boiler and a big step towards more economical and ecological operation of coal fired power plants.
Volumetric feeding vs. gravimetric feeding The main difference between gravimetric and volumetric feeders is the high accuracy of gravimetric feeders regarding the calorific (energy) troughput.
The accuracy of volumetric feeders is mainly influenced by the variations in the following coal characteristics: - Density - Calorific value - Displacement volume (lump size) Gravimetric feeders are able to reduce the influence of most of the variations as shown in the chart below. This results in a much higher accuracy in the feed rate of calorific (energy) value.
30 25 20 % Variation in Energy Feed
18
15 10 2,5
5 0
5
0,5 2,5
Volumetric Feeder
Gravimetric Feeder
Density Variation
18
0,5
Calorific Value Variation
2,5
2,5
5
0
Displacement Volume Variation
(Source: internal surv ey )
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Any efficient combustion process has three primary requirements: 1. Feeding of the right amount of fuel to meet demand for energy input. 2. Provide an exact amount of air to ensure complete combustion of the fuel. 3. Ensure a stable process in order to get the highest efficiency. For burners it is necessary to supply a sufficient excess-air cushion to avoid dangerous conditions due to a potentially incomplete combustion. A combustion with too much fuel (coal dust) and/or lack of combustion air creates carbon-monoxide (CO) which can react with oxygen (O2) in an explosion. On the other hand, too much excess-air wastes energy because the excess air is heated and lost in the atmosphere. Using less excess air is therefore significantly more economic. The amount of excess air is depending on the possible variations of the fuel-feed rate. Based on the gravimetric weighing principle Pfister® weighfeeders are doing exactly that: supplying high accuracy in fuel feed rate.
All assets result in: - overall increase of the power plant performance - increase of process efficiency
Further benefits: - Less slagging Reduced variation in the feed rate results in less variance in excess air between the burners. This results in consistent gas temperatures and less slagging of the burner environment. - Less corrosion of furnace walls Combustion of fossil fuels creates complex sulphur (H2S). Together with carbon-monoxide (CO), which itself results from an incomplete combustion, it causes corrosion of the furnace walls. - Less NOX formation To minimise NOX formation in the burning process when running with a low excessair cushion, accurate control of excess air is necessary. This can be accomplished when the amount of fed fuel is measured accurately. - Accurate energy accounting With using gravimetric feeders for feeding crushed coal to the coal mill, it is also possible to produce a highly accurate record of coal consumption (energy accounting) and to calculate the efficiency of all units and burners independently. - Fast and stable boiler load changes Gravimetric feeders have a high accuracy in the whole feed range of 1:10 of the maximum feed rate. Therefore, the feed rate is instantly and accurately adjustable which makes load changes of the boiler process very fast, stable and more efficient.
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Customer benefits of gravimetric belt feeders Pfister® GBF High flexibility - Modular design with a large variety in lengths and widths can be adapted optionally - Different types of inlet chutes guarantee excel lent silo extraction for a variety of material properties - Feed rate adjustment (t/h) in a range of up to a turn down ratio - 1:10 Easy maintenance - Lifetime lubricated idler - Easy calibration and adjustment of zero point High reliability - Belt and pulley strippers ensure no dirt is sticking to the rollers or to any side of the belt - Spherical v-grooved machined pulleys for optimal belt guidance
High accuracy - Advanced belt tensioning by tension roller which supports highest feeding accuracy - Digital tachometer (incremental encoder). This results in accurate values for the controller to calculate the needed speed of the motor - Impressive feed rate accuracy
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Functioning principle of gravimetric belt feeder Pfister® GBF The picture below displays a gravimetric belt feeder Pfister® GBF and its weighing and dosing principle: Crushed coal is extracted out of the material silo and fed into the infeed hoppers. The gravimetric belt feeder Pfister® GBF consists of a conveyor belt with integrally moulded side skirting which is equipped with moulded V guide at the bottom of the carrying side ensuring no swaying of the belt, thus maintaining accuracy. A belt scraper scrapes coal off the top surface of the conveyor belt. Its blade is kept pressed against the surface of the belt by a counterweight. The weighing zone of gravimetric belt feeder Pfister® GBF is defined by two rollers precisely located at a fixed distance. The weighing roller is at the center of these two rollers and suspended directly through load cells on both sides. The
load on the weighing zone is measured by dual load cells which are barometrically insensitive and environmentally sealed. These load cells yield a very high linearity. The signal from the load cell is fed to a microprocessorbased Pfister® gravimetric dosing controller. Thus, the speed of the belt is controlled inverse to the momentary load. From there the crushed coal is discharged into the further processes. Gravimetric belt feeder Pfister® GBF is auto calibrated by integrated calibration sensors. In case of load cell disrepancy an automatic change over switches to a volumetric weighing mode automatically. In the volumetric mode, the feeder runs based on historic density. It reverts automatically to gravimetric mode if load cell data show no more discrepany.
Technical drawing of a gravimetric belt feeder Pfister ® GBF:
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Structure of the dosing system: Pfister® Gravimetric Dosing Controller
Pfister® gravimetric dosing controller was especially developed to guarantee high dosing precision for gravimetric belt feeder Pfister® GBF The microprocessor-controlled Pfister® gravimetric dosing controller works with a 16 bit processor and offers the following main features: • •
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• •
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•
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configurable functionality of inputs & outputs. field-programmable logic controller can quickly implement features required on the field 7’’ touchscreen colour display HMI optional field interface module through CAN communication network for reduced cable cost variable frequency drive. integrated multiple microprocessors, which allow true parallel processing Memory on EEPROM basis and a battery backup RAM with inbuilt real time clock (RTC) 16 digital inputs and 16 digital outputs as well as 3 analog inputs and 3 analog outputs Support of Modbus and Profibus protocols
7’’ touchscreen colour display (left) and control cabinet (right) of Pfister ® gravimetric dosing controller
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Technical facts of gravimetric belt feeder Pfister® GBF Application fields:
Feeding to pulverizers and mills
Material:
Crushed coal, bituminous coal
Feeding capacity:
up to 150 t/h
Design example:
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Inlet collar Head and tail pulley Flat type idlers with mounting brackets Discharge hoppers with shut-off devices Gravimetric belt feeder Pfister® GBF Belt and scrapers Drive unit with shaft mounted gearbox Cleanout conveyor
Features:
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Stable material dosing Outstanding reliability High short- and longterm accuracy Compact, robust machinery Custom-made lengths and widths Large feeding range Easy to maintain through 4 inspection doors Pressure-proof design up to 3.5 bar as per NFPA 85
Dosing control:
- Gravimetric dosing control Pfister® GDC - VFD drive - User oriented interfaces
Certificates:
ISO 9001
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Applications with Pfister® GBF: Power station
In this application in a power station crushed coal is dosed with gravimetric belt feeders Pfister GBF® with a feed rate of up to 150 tph and an impressive accuracy. The bulk density varies between 0.8 – 1.2 t/m3. The belt of the gravimetric belt feeders Pfister GBF® is executed with integrally moulded side skirts.
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In this application the gravimetric belt feeders Pfister GBF® are built with a centre distance of more than 2.000 mm. The feeders are controlled by microprocessor-based dosing electronics located in the control cabinet.
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Applications with Pfister® GBF: Oversize solutions Gravimetric belt feeders Pfister GBF® can be built for extra sizes according to the customer’s needs. The drawing on the right side shows a solution for an oversize silo inlet with 3,500 x 1,000 mm in size. The picture below displays the belt feeders Pfister GBF® just before delivery to the client.
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Applications with Pfister® GBF: Inhouse accuracy testing facility As one of the first companies in India, FLSmidth Pfister is executing their accuracy tests for gravimetric belt feeder Pfister® GBF at their own test facilities on a complete feeder assembly. For these tests the feeder is connected with the remote and the integral cabinets and calibrated according to the feeder calibration procedure. The feeder is operated for 10 minutes with a quantity of test material for ten rotations. Thus, accuracy as well as functionality is controlled.
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State-of-the-art design & assembly of Pfister® weighfeeders
Based on the more than a century long experience of the German engineers at the FLSmidth Pfister headquarters in Germany, gravimetric belt feeders Pfister® GBF are engineered, designed and assembled at the brand new FLSmidth Pfister production facilities in Bawal / India.
FLSmidth Pfister production facilities in Bawal / India
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Engineering & design
FLSmidth Pfister® engineering services comprise: - Silo design - Installation of equipment - Calculation of pneumatic transport
FLSmidth Pfister does not only supply the single dosing machines. FLSmidth Pfister’s know-how includes the complete setup and surrounding of the installation like silo engineering, intermediate material transport and safety equipment. That ensures that customers get all engineering from one experienced partner and one single source.
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One-stop shop: FLSmidth Minerals Group Installation example - FLSmidth Wadgassen: Building, KochTM bin with extraction unit, KochTM screw conveyors - FLSmidth Pfister: 4 x rotor weighfeeders Pfister® TRW-D 4.14 with pre-hoppers; capacity 6 t/h, multifuel application - FLSmidth Hamburg: MöllerTM conveying transport
FLSmidth is the leading supplier of equipment and services to the global cement and minerals industries. For the power generation industry FLSmidth combines its know-how and expertise as a supplier for complete systems and components from the entire group - all in keeping our slogan: One Source.
FLSmidth brand names for the power industry: - Dorr-Oliver®, Eimco®, Krebs® world market leaders in machinery and equipment for liquid/solid separation, principal suppliers for gypsum dewatering systems in power stations - KochTM, MVTTM - material handling technology - MöllerTM - pneumatic conveying systems and silo technology - Pfister® - experts for continuous gravimetric weighing and dosing
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Pfister® customer service & after sales support Thousands of FLSmidth Pfister® systems are currently in operation worldwide and require global presence. Therefore FLSmidth Pfister operates sales and service offices in eight countries on four different continents. Experienced service technicians stand by your side and provide first-class service. A 24-hour hotline and online trouble-shooting provide worldwide support. Also available are telesupport packages. FLSmidth Pfister not only keeps a large number of spare parts in stock. Skilled spares specialists are looking forward to assist you in optimizing your own spare parts management. FLSmidth Pfister´s services are rounded up by service contracts, which can be adapted individually to the customer´s needs. Customer training on-site or at FLSmidth Pfister’s training center ensures the best possible knowledge transfer.
Pfister® after sales support: - 24-hour hotline - Telesupport - Modern maintenance management - Trainings and seminars - Service contracts
FLSmidth Pfister’s headquarters are located in Augsburg / Germany
Headquarters: FLSmidth Pfister GmbH Staetzlinger Str. 70 86165 Augsburg, Germany T. +49 821 7949 0 | F. +49 821 7949 524 Sales Department: sales@flsmidthpfister.com Technology Department: engineering@flsmidthpfister.com Service Department: service@flsmidthpfister.com
Branch offices: FLSmidth USA, Inc.
FLSmidth Pfister GmbH
Pfister Operations
6, Rue de Bretagne
3235 Schoenersville Rd., Bethlehem, PA 18017, USA
38070 St. Quentin Fallavier, France
p. +1 610 2645110 | f. +1 610 2645537
p. +33 4 74 95 55 44 | f. +33 4 74 94 50 75
pfister.usa@flsmidthpfister.com
pnl@flsmidthpfister.com
FLSmidth Pfister Ltda.
FLSmidth Private Ltd.
Rua José Dolles, 264 - Jardim Clarice II
i-Think Techno Campus, A-Wing, 6th Floor, Office No. 2
CEP 18116-710 - Votorantim, S.P. Brazil
Pokhran Road II, Thane West - 400 607, India
p. +55 15 3416 7438 | f. +55 15 3416 7599
p. +91 22 6117 2555 | f. +91 22 6117 2862
uwe.richter@flsmidthpfister.com
twsales-in@flsmidthpfister.com
FLSmidth Pfister GmbH Malaysian Branch
FLSmidth Pfister China
C-3A15, Centre Wing, Metropolitan Office Suite
No. 8, Taisu Road,
Metropolitan Square, Jalan PJU 8/1
Beiguan Industrial Park,
Damansara Perdana, 47820 Petaling Jaya
Jiaozhou City, Qingdao 266309, P.R. China
Selangor, Malaysia
p. +86 532 8526 6706 | f. +86 532 8526 6699
p. +60 3 7728 2039 | f. +60 3 7727 2039
24-hour-hotline: 400 612 3636
sales@flsmidthpfister.com
info-china@flsmidthpfister.com
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Copyright ©2014 FLSmidth A/S. ALL RIGHTS RESERVED. FLSmidth, Pfister, ProsCon and all other product names used herein are (registered) trademarks of FLSmidth A/S. This brochure makes no offers, representations or warranties (express or implied), and information and data contained in this brochure are for general reference only and may change at any time.
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