EL0002- M - 2- 0.3 - TYPES OF BOILER.

Types of Boiler

Boilers are classified based on the fuel use, handling. The fuels used are coal (utility boiler), natural gas and oil.

Based on Application and The various heat transfer sections of a boiler can be grouped as follows:A. Utility: Furnace, Superheater, Reheater, Economiser, Air HeaterB. Industrial: Furnace, Superheater, Boiler Bank, Economiser, Air Heater

Based on No. of Drums

1. Single Drum EL0002- M - 2- 0.3.a - SINGLE DRUM BOILER.2. Bi Drum EL0002- M - 2- 0.3.b - Bi- Drum Boiler., EL0002-M -2-0-3d - PFI BOILER.3. No Drum

Based on Construction

1. Vertical Package- VP EL0002-M -2-0-3c - THE FM.2. Vertical Recovery- V2R EL0002-M -2-0-12a - simple combined cycle system3. Heat Recover Steam Generator EL0002- M - 2- 0.12 - TYPES OF BOILER.4. EL0001-M -1-6-2 - HEAT RECOVERY STEAM GENERATOR.5. EL0002- M - 2- 0.13 - TYPES OF BOILER.

6. EL0002-M -2-0-13a - General Waste Heat Boiler.7. Vertical Unit 40- VU40 EL0002-M -2-0-3e - VU 40 Boiler.8. Vertical Unit 60- VU60 EL0002-M -2-0-3f - VU 60 Boiler.9. Modular Unit

10. Modular Boilers

Modular boilers are small hot water boilers rated at 58 kwh to 263 kwh input. These boilers are available with 85 percent or higher gross efficiency. These boilers are often used in tandem to provide hot water for space heating and/or domestic hot water. For example, if the design heating load were 58 kwh, four 176 kwh (input) modular boilers might be used. If the load were 25 percent or less on a particular day, only one boiler would fire and cycle on and off to supply the load. The other three boilers would remain off with no water flow. This reduces flue and jacket (covering of the boiler) heat losses.Some modular boilers have very small storage capacity and very rapid heat transfer so water flow must be proven before the burner is started.

11. Tower Type EL0002- M - 2- 0.6c - TOWER TYPE BOILER.

Based on Type of Firing EL0002- M - 2- 0.4 - TYPES OF BOILER.

A. Wall Firing

B. Tangential Firing

Tangential firing systemAlstom introduced tangential firing systems to the power generation industry. Today, our systems lead the market in reducing emissions.How does it work?A rotating flame envelope is formed within the furnace, directing heat to each wall, regardless of unit load of fuel input combinations. The furnace aerodynamic helps with heat absorption and achieves lower bulk gas temperatures compared to wall-fired boilers.

http://www.alstom.com/power/coal-oil/utility-boilers/firing-systems/C. Stoker

Stoker-fired boiler is typical of a medium pressure and temperature of some 15 to 20 years ago.

Stokers feed fuel onto a grate where it burns with undergrate air passing up through it, and overfire air passing over it. The grate is located within the lower furnace and removes the ash resiue after combustion. Evolving from the hand-fired boiler era, these type of boilers burn a wide range of fuels for industrial, small utility and cogeneration applications. Other than coal the fuels include sludge, wood waste and biomass (e.g. wood bark, straw, bagasse, rice hulls, peach pits, almond shells, orchard prunings, coffee grounds as well as residential, agricultural, industrial and commercial refuse.

Modern mechanical stokers firing system are composed of:

1. A stoker or fuel feeding system also referred as feeder, distributor or spoutThere are two types of systemsa. Underfeed stokers supply both the fuel

b. Overfeed stokers supply fuel from above grate and air from below the grate. These are further divided into two types: mass feed and spreaderIn the mass feed stoker, fuel is continuously fed to one end of grate surface and travels horizontally across the grate as it burns. The residual ash is discharged from the opposite end. Combustion air is introduced from below the grate and moves up through the burning bed of fuel. In spreader stoker, combustion air is again introduced primarily from below the grate but the fuel is thrown or spread uniformly across the grate area. The finer fraction of the fuel burns in suspension as it is lifted by the upward moving flue gas flow. The remaining heavier fraction of the fuel lands and burns on the grate surface with any residual ash removed from the discharge end of the grate.

Based on Tube Contenta. Fire Tube Boiler EL0002- M - 2- 0.6 - FIRETUBE BOILER.b. Water Tube Boiler EL0002- M - 2- 0.10 - TYPES OF BOILER.

Based on Fuel1. Oil Fired2. Oil & Coal Fired EL0002- M - 2- 0.6b - PULVERIZED FUEL BOILER.3. Black Liquor

The Recovery Boiler furnace was developed for combusting black liquor organic material while reducing the oxidized inorganic material in a pile, or bed, supported by the furnace floor. The molten inorganic chemical or smelt in the bed are discharged to a tank and dissolved to form green liquor. Green liquor active chemicals are Na2CO3 and Na2S. Green liquor contains unburned carbon and inorganic impurities from the smelt, mostly calcium and iron compounds, and this insoluble materials, or dregs, must be removed through clarification. This operation is basically settling of sediment and decantation of clear green liquor that can be pumped as slurry. Energy is released in the recovery furnace due to the combustion of black liquor. This energy produces steam from feedwater. The steam is introduced into a turbine generator . Steam is taken from the Turbine extractions at low pressure for process requirements such as cooking wood chips, evaporation, recovery furnace air heating and drying the pulp or paper production. Energy generated by turbine generator meets the energy demand of pulp and paper mill.

4. Baggas (Stoker) EL0002- M - 2- 0.14 - Multii fuel Plant.5. FBC EL0002- M - 2- 0.7 - FLUIDIZED BED BOILER.6. CFBC EL0001-M -1-5-10 - CIRCULATING FLUIDIZED BOILER.

Based on availability of Reheater

1. Reheat Type EL0002 - M - 2 -0.8 - REHEAT SYSTEM.2. Non-reheat Type EL0002 - M - 2 -0.8a - NON - REHEAT SYSTEM.

Based on Circulation EL0002- M - 2- 0.9 - TYPES OF BOILER.

1. Natural2. Forced Circulation3. Controlled Circulation EL0002- M - 2- 0.11 - FORCED CIRCULATION SYSTEM.4. Once Through

Boiler Parameter

A. Utility Boiler1. Main Steam Flow- T/Hr2. Main Steam Pressure- Kg/cm2

3. Main Steam Temperature- 0C4. Reheat Steam Flow- T/Hr5. Reheat Steam Pressure- Kg/cm2

6. Reheat Steam Temperature- 0C

B. Industrial Boiler1. Steam Flow- T/Hr

C. Heat Recovery Unit1. Fuel Used- T/Day

Pressure Parts

Based on Configuration

1. Headers2. Panels3. Coils4. Connections5. Supports

Based on Systems

1. Economizer System2. Circulation System3. Superheater System4. Reheater System

Pressure Parts

(With respect to arrangement)

Performance Parameters

1. Size (Diameter)2. Size (Thickness)3. Material (SS)4. Transverse Spacing5. Longitudinal Spacing6. Heating Surface Area7. No. of elements8. Inlet / Outlet Connection Requirements9. Furnace Width

10. Furnace Dia.11. Extended Pass12. Back Pass Path13. Hopper Angle14. Arch Configuration15. Coil / Bank Depth

Detail Design Requirement

IBR Requirements (Strength Calculation) Manufacture Heat Treatment Transport L

Stress Analysis Requirement

Guide, Supports & Suspensions Thermal Expansions Flexibility of Distance of Tube from roof Buck Stays Spacers

Arrangement Requirements

Interface free arrangement/ Routing of Risers / Pipes/ Links Wield Accessibility