flat grate vs underfeed stoker design

  • An Introduction to Steam Boilers and Turbines for Power

    Underfeed stoker 75 60 Spreader stoker, traveling grate (with reinjection) 60 50 50 Spreader stoker, traveling grate (without reinjection) 60 50 50 Traveling grate (front gravity feed) 75 60 Solid waste 30 Table 1 Maximum velocities (ft/sec) in

  • MC Steam Boilers and Turbines for Power Plants R

    Stoker type Coal Wood Solid waste Coal Underfeed stoker 75 60 Spreader stoker, traveling grate (with reinjection) 60 50 50 Spreader stoker, traveling grate (without reinjection) 60 50 50 Traveling grate (front gravity feed) 75 60 Solid waste 30 Table 1 Maximum velocities (ft/sec) in convection sections

  • Solid-fuel firing - ScienceDirect

    Jan 01, 1982· The amount of grit and dust leaving the bed will vary with the design of stoker. But it may be assumed that a well operated chain-grate stoker, for example, will not have a carryover from the bed in excess of 1.5% of the fuel fired: equivalent to a concentration in the flue gas of about 1350 mg/m 3 (0.6 grains/ft 3 at NTP).

  • Wood Chip/pellet BoilerS - hargassner.ca

    1. Fully refractory-lined underfeed stoker 2. Boiler heat exchanger 3. Turbulators 4. Fly ash separation 5. Flue pipe top 6. Lambda sensor 7. Speed-controlled induced draught fan 8. Negative pressure control 9. Turbo concentration bricks 10. Drive motor for ash extraction and boiler cleaning 11. Fly ash and grate ash extraction auger 12. Ash box

  • Methods of Firing Steam Boiler | Electrical4U

    Feb 24, 2012· There are mainly two types of mechanical stoker firing systems. Under Feed Mechanical Stoker Firing. Here, combustion takes place on the grate. The primary air is fed below the grate. The secondary air is allowed at the top of the grate. When the coal is burnt, it is pushed down by fresh coal. The fresh coal is pushed on the grate using rams as ...

  • LIST OF STANDARD CLASSIFICATION CODES (SCC)

    2 ORGANIZATION OF SCCs The four levels of source descriptions for SCCs are associated with the first 1, 3, 6, and 8 digits of the codes, (for the point source codes used by AFS -

  • BOILERS | Energy-Models

    Stoker Fired Boiler: Stokers are classified according to the method of feeding fuel to the furnace and by the type of grate. The main classifications are: Chain-grate or traveling-grate stoker; Spreader stoker; Chain-Grate or Traveling-Grate Stoker Boiler. Coal is fed onto one end of a moving steel chain grate.

  • COST ESTIMATES FOR CAPITAL EXPENDITURE AND

    distribution has one design for an underfeed stoker where it pushes new fuel to the bottom of the combusting pile beneath the grate using a screw or ram process. This underfeed process requires fuels with lower moisture content, less than 45% (for which the prospective fuel supply meets this criteria).

  • Classification of Stoker Firing | Combustion | Coke (Fuel)

    Classification of stokers. Naresh B Asst.Professor, Dept. Of Mechanical Engg GITAM University - Hyderabad Automatic stokers are classified Overfeed stokers. Underfeed stokers. In case of overfeed stokers, the coal is fed into the grate above the point of air admission. In case of underfeed stokers, the coal is admitted into the furnace below the point of air admission.

  • Mechanical stoker - Wikipedia

    A mechanical stoker is a mechanical system that feeds solid fuel like coal, coke or anthracite into the furnace of a steam boiler.They are common on steam locomotives after 1900 and are also used on ships and power stations. Known now as a spreader stoker they remain in use today especially in furnaces fueled by wood pellets or refuse.. There are three types: the over feed, the under feed

  • Mechanical stoker - Wikipedia

    Mechanical stoker. A mechanical stoker is a mechanical system that feeds solid fuel like coal, coke or anthracite into the furnace of a steam boiler. They are common on steam locomotives after 1900 and are also used on ships and power stations. Known now as a spreader stoker they remain in use today especially in furnaces fueled by wood pellets ...

  • >>UTSk >>UTSP >>UTSR >>UTSW FULL OF ENERGY

    The UTSP underfeed stoker is an underfeed firing system variant that is perfectly ... Air-cooled flat-bed moving grate (flame flows counter to flow of fuel) 4. Under-grate de-ashing (automatic or manual) ... individual plates with variable design >> Good access to moving grate >> Automatic cleaning of the fire tubes Low-particle system:

  • Prill Combustion Air | Coal Stoker Boilers & Furnaces ...

    Nov 13, 2008· ambient air and it will combust, the high heat of the wood fire heats the air as it mixes with the gases. in the firebox and stays above the combustion temp of the gases so it burns freely,thats why the flue of. wood burning stove runs so hot,coal runs at about 1/2the temperature,so preheated air is needed. BigBarney.

  • 1.2 Anthracite Coal Combustion

    A second type of stoker boiler used to burn anthracite coal is the underfeed stoker. Various types of underfeed stokers are used in industrial boiler applications but the most common for anthracite coal firing is the single-retort side-dump stoker with stationary grates. In this unit, coal is fed intermittently to the fuel bed by a ram.

  • BR-1833 - A Comparison of Fluid-Bed Technologies for ...

    (BR-1802) compared stoker/grate to bubbling fluidized-bed technology. That paper evaluated a bubbling bed as the preferred technology over a stoker for typical moisture woody biomass fuels on the basis of lower O&M costs, lower capital cost and lower emissions. The following paper will evaluate a case study comparing

  • AP-42 Section 1.6 Wood Residue Combustion in Boilers

    The fuel accumulates in a cone-shaped pile on a flat or sloping grate. Combustion is accomplished in two stages: (1) drying and gasification, and (2) combustion of gaseous ... overall design and operating similarities, however, fuel cell and Dutch oven boilers have many ... overfeed and underfeed stokers are also utilized for smaller units.

  • Green heat with small-scale wood combustion

    Boiler type Characteristics of the biomass boiler Rated output Efficiency Underfeed stoker furnace 25 kW - 25 MW ± 90% Flat grate furnace 25 kW - 5 MW ± 90% Stepped grate furnace 150 kW 25 MW ± 90%

  • Top 100 Power Plant Engineering Objective Questions & Answers

    94. Where unpulverised coal has to be used and boiler capacity is large, the stoker which is used is (a) underfeed stoker (b) overfeed stoker (c) any. Ans: b. 95. TravelUng grate stoker can burn coals at the rates of (a) 5075 kg/m per hour (b) 75100 kg/m per hour (c)

  • Archimedean Screw - an overview | ScienceDirect Topics

    24.6.1. Underfeed stoker Mainly applied to sectional and small shell boilers, this principle is limited to doubles or singles coal. Simple in construction, it consists of a hopper normally mounted close to the appliance, which feeds via an Archimedean screw

  • A Comparison of European and U.S. Combustion Systems Using ...

    Jan 01, 1982· A Comparison of European and U.S. Combustion Systems Using Biomass. Author links open overlay panel Kalevi Leppa. Show more

  • PART TWO - Food and Agriculture Organization

    Figure 5.4 Refractory furnace and underfeed stoker. Figure 5.5 Above-fed cone grate. 5.3 Mechanical Flat Grates Figure 5.6 Dumping grate. The dumping grate stoker is usually applied in small or medium sized units. It is a stationary grate (see figure 5.6) made up of grate bars, mechanically linked so that they can be rotated 90 degrees to dump ash.

  • Flat Grate Vs. Underfeed Stoker Design | Stoker Coal ...

    Oct 27, 2007· Flat Grate Vs. Underfeed Stoker Design. 9 posts Page 1 of 1 . e.alleg Member Posts: 1285 Joined: Fri. Feb. 16, 2007 4:31 pm Location: western ny. Post by e.alleg » Sat. Oct. 27, 2007 1:37 am It seems that all the old school stokers were underfeed type that use a "bowl" to burn the coal, yet all the newer companies use a flat grate. Is ...

  • Coal Segregation as a Cause of Smoke and Its Correction

    let us analyze the case of the typical flat chute such as has often been used to feed stoker hoppers. If a flat Fig. 1. Fire on a chain grate stoker with segregated coal feed. Smoke and fine coal at quarter points; excess air and coarse coal along the sides and in the center. Fig. 2. Fire on a chain grate stoker with non-segregated coal feed.

  • INDUSTRIAL HEAT ENERGY

    introduced above the bed. Underfeed stokers are sometimes used for particulate biomass and are similar to grate burners. Various other systems with gas phase combustion are applicable for particulate biomass e.g. suspension, gasification or fluid bed burners. Flat grate traditional designs, involving hand-firing of fuelwood logs are still commonly

  • Boilers: 2011 Marketplace - Process Heating

    Jul 01, 2011· The reciprocating grate stoker with automated ash removal, the latest model in the biomass boiler series, offers an efficient multi-fuel design in various configurations. ... sawdust, shavings, sludge or agricultural biomass. The biomass boiler product lines options include flat-grate stokers, underfeed stokers and traveling-grate stokers to ...

  • Top 100 Power Plant Engineering Objective Questions & Answers

    94. Where unpulverised coal has to be used and boiler capacity is large, the stoker which is used is (a) underfeed stoker (b) overfeed stoker (c) any. Ans: b. 95. TravelUng grate stoker can burn coals at the rates of (a) 5075 kg/m per hour (b) 75100 kg/m per hour (c) 100150 kg/m per hour (d) 150200 kg/m2 per hour

  • Part II. Energy Efficiency by Sectors Energy Efficiency in ...

    Water- cooler vibrating- grate stokers 30- 60 Chain- grate and traveling- grate stokers 15- 50 Coal Underfeed stoker 20- 50 Fuel oil Oil burners, register type 15- 20 Multi -fuel burners and flat- flame 20- 30 Natural gas High pressure burner 5 7- Wood Dutch over (10- 23% through grates) and

  • EMISSION FACTOR DOCUMENTATION FOR AP-42

    A second type of stoker boiler used to burn anthracite coal is the underfeed stoker. Various types of underfeed stokers are used in industrial boiler applications but the most common for anthracite coal firing is the single-retort side-dump stoker with stationary grates (see Figure 2-3).

  • Power Engineer 3B1 Chapter 5,6 Flashcards | Quizlet

    Flat gauge glass. for pressure > 2800 kpa lined with sheet of mica. ... underfeed stoker. fresh coal enter from beneath the burning fuel bed between two tuyere ... air flow upward anthracite and bituminous coal are suitable for this type. crossfeed stoker. traveling grate stoker grate driben by sprockets and move slowly 5mm/s. YOU MIGHT ALSO ...

  • Chapter Combustion Technologies and Heating Systems

    The ash is removed manually or mechanically using a dumping grate. This feeding system allows very accurate feeding of pellets according to the current power demand and is thus often used in furnaces with very small nominal heat flows. 3.2.2. Underfeed Burners In underfeed burners (underfeed stoker or underfeed retort burners) the fuel

  • 5. Biomass Conversion Technologies

    Underfeed stokers supply both fuel and primary combustion air from beneath the grate so that the top of the fuel pile is not cooled by cold and moist fuel or cold air. The fuel is moved into a hopper and onto the grate by either a screw- or ram-driven mechanism. Underfeed stokers push the fuel into the

  • Steam power plant - SlideShare

    May 06, 2014· A stoker consists of a power operated coal feeding mechanism and grate. Mechanical stokers are of two types: 1.Overfeed stoker 2.Underfeed stoker 21. Overfeed stoker Overfeed stokers are used for large capacity boilers where coal is burnt as lumps (i.e., without pulverization).

  • t- 200 cover final:Layout 1

    comparisons of the new units available today vs. the existing biomass boilers in operation. Advancements such as a new over-fire air (OFA) design and state-of-the-art stoker technology with grate oscillation/vibration are used to increase

  • Stoker Fired Boiler types of stokers - Boilersinfo

    May 02, 2018· Stoker Fired Boiler types of stokers. May 2, 2018 Boiler articles, Water tube Boilers Leave a comment 19,281 Views. Stoker Fired Boiler are classified according to the method of feeding fuel to the furnace and by the type of grate. The main types of stokers are: Chain-grate or travelling-grate stoker. Spreader stoker boiler.

  • An Introduction to Steam Boilers and Turbines for Power Plants

    Underfeed stoker 75 60 Spreader stoker, traveling grate (with reinjection) 60 50 50 Spreader stoker, traveling grate (without reinjection) 60 50 50 Traveling grate (front gravity feed) 75 60 Solid waste 30 Table 1 Maximum velocities (ft/sec) in

  • SUCCESSFUL BIOENERGY INSTALLATIONS The tradeoff

    3.) Underfeed stoker, 1 pass, auger feed, automatic de-ashing 2.) Air cooled grate, 1 pass, auger feed, automatic grate de-ashing 1.) Water-cooled grate, 2 pass, ram stoker feed, automatic furnace and grate de-ashing Most expensive boiler design becomes cheapest option after 2.3 to 2.8 years 40 % heat plant utilisation 1 MW

  • POWER PLANT ENGINEERING (UNIT-1)

    Nov 16, 2018· Combustion: properties of coal overfeed and underfeed fuel beds, traveling grate stokers, spreader stokers, retort stokers, pulverized fuel burning system and its components, combustion needs and draught system, cyclone furnace, design and construction, dust collectors, cooling towers and heat rejection. corrosion and feed water treatment.

  • 2. BOILERS - Bureau of Energy Efficiency

    2. BOILERS Bureau of Energy Efficiency 27 Syllabus Boilers: Types, Combustion in boilers, Performances evaluation, Analysis of losses, Feed water treatment, Blow down, Energy conservation opportunities. 2.1 Introduction A boiler is an enclosed vessel that provides a means for combustion heat to be transferred into water until it becomes heated water or steam.

  • 1.6 Wood Waste Combustion In Boilers

    overall design and operating similarities, however, fuel cell and Dutch oven boilers have comparable emission characteristics. The firing method most commonly employed for wood-fired boilers with a steam generation rate larger than 100,000 lb/hr is the spreader stoker. In this boiler type, wood enters the furnace through a

  • (PDF) ENERGY EFFICIENCY ON BOILER

    Aug 02, 2010· The optimum excess air level varies with furnace design, type of burner, ... Chain-grate and traveling-grate stokers . 15-50. Coal . Underfeed stoker . 20-50. Fuel oil .

  • Boilers - Fink Machine for Viessmann and Schmid Biomass ...

    Underfeed Stoker Firing System Boiler 550 kW 900 kW ... The UTSR boiler unit is equipped with a flat feed grate and also suitable for fuel with a high ash content. The fuel is passed into the furnace from the rear of the furnace on the flat feed grate with high-alloy casting grate bars. ... Fink Machine Inc. can also design, build and ...

  • difference between overfeed and underfeed stoker ...

    Aug 02, 2018· Overfeed stoker is the type of stoker in which the coal is fed from the top and air is blown from below. No. 1867c THE DESIGN AND OPERATION OF UNDERFEED STOKERS 798 DESIGN AND OPERATION OP UNDERFEED STOKERS are removed. For wider furnaces, intermediate inclined movable grates or tuyeres are placed between the retorts and the dump