Boiler & It's Types

Boilers are most important part of Chemical Industry. 99 % boilers used in Pakistan Chemical Industries are water tube boilers because of their high efficiency and safety. So we should have clear understanding about the boilers.

1. “ Start with the name of Allah who is the
Most Beneficent and Most Merciful.”

2. In the respect of
Sir Kashif Hussain Mangi Sir Kashif Hussain Mangi
Ihsan Ali Wassan Ihsan Ali Wassan
(14ch18)
DISCIPLINE:
CHEMICAL ENGINEERINGCHEMICAL ENGINEERING
SUBJECT:
UNIT OPERATION-II UNIT OPERATION-II
QUAID-E-AWAM UNIVERSITY OF ENGINEERING,
SCIENCE & TECHNOLOGY NAWABSHAH, SINDH
PAKISTAN

3. Boiler & Its TypesBoiler & Its Types

4. PRESENTATION OUTLINESPRESENTATION OUTLINES
What is a Boiler?
What should characteristics of boiler?
Sources of heat in boiler?
Types of Boiler
Conclusion

5. What is a Boiler?What is a Boiler?
•A closed vessel made up of steel to transfer heat produced by
combustion of fuel to water and ultimately generate steam .
It may be defined as:
A steam generator or boiler is usually a closed vessel made of
steel. Its function is to transfer the heat produced by the
combustion of fuel to water and ultimately to generate steam.

6. What should characteristics of What should characteristics of
boiler?boiler?
 Generate maximum steam.
 Light in weight and not occupy large space.
 Proper safety regulations.
 Cheaper in cost.
 Easily accessible for inspection and repair.

7. Sources of heat in boiler?Sources of heat in boiler?
Wood
Coal
Diesel
Natural Gas
Nuclear Energy

8. Types of Boiler?Types of Boiler?
1.Water Tube Boiler
2.Fire Tube Boiler
3.Packaged Boiler
4.Stoker Fired Boiler
5.Pulverized Fuel Boiler
6.Waste Heat Boiler
7.Fluidized Bed (FBC) Boiler

9. Water Tube BoilerWater Tube Boiler
The water is contained inside the
tubes(called water tubes) which are
surrounded by flames and hot gases
from outside.
•Used for high steam demand and
pressure requirements
•Capacity range of 4,500 – 120,000
kg/hour
Examples:
Babcock and Wilcox boiler
Stirling boiler
La - Mont boiler
 Yarrow boiler and
Loeffler boiler

10. Water Tube BoilerWater Tube Boiler
•Used for high steam demand and pressure requirements
•Capacity range of 4,500 – 120,000 kg/hour

11. Fire Tube BoilerFire Tube Boiler
 In fire tube steam boilers, the flames and hot gases
produced by the combustion of fuel pass through the
tubes(called multi tubes) which are surrounded by water.
 The heat is conducted through the walls of the tube from
the hot gases through the surrounding water.

12. Fire Tube BoilerFire Tube Boiler
 Relatively small steam capacities (12,000 kg/hour).
 Operates with oil, gas or solid fuels.
Examples:
•Cochran boiler,
•Lancashire boiler,
•Cornish boiler
•Locomotive boiler
•Taper boiler
•Vertical fire tube boiler

13. Stoker Fired BoilerStoker Fired Boiler
A.Spreader stokers
•Coal is first burnt in suspension
then in coal bed
•Flexibility to meet load
fluctuations
•Favored in many industrial
applications
•Uses both suspension and grate
burning

14. Packaged BoilerPackaged Boiler
•Comes in complete package
•Features
•High heat transfer
•Faster evaporation
•Good convective heat transfer
•Good combustion efficiency
•High thermal efficiency
Oil
Burner
To Chimney

15. Stoker Fired BoilerStoker Fired Boiler
B. Chain-grate or traveling-grate stoker
•Coal is burnt on moving steel grate
•Coal gate controls coal feeding rate
•Uniform coal size for complete combustion

16. Pulverized Fuel BoilerPulverized Fuel Boiler
Generate thermal energy by burning pulverized coal
(powdered coal) or coal dust.
Its an other name is Utility Boiler.
Coal is pulverized to a fine powder, so that less than 2% is
+300 microns, and 70-75% is below 75 microns.
Pulverized coal powder blown with combustion air into
boiler through burner nozzles.
Combustion temperature at 1300 -1700 °C

17. Pulverized Fuel BoilerPulverized Fuel Boiler
Benefits:
varying coal quality coal, quick
response to load changes and high pre-
heat air temperatures.

18. Waste Heat BoilerWaste Heat Boiler
Used when waste heat available at
medium/high temp.
Auxiliary fuel burners used if steam
demand is more than the waste
heat can generate.
Used in heat recovery from exhaust
gases from gas turbines and diesel
engines.

19. Fluidized Bed (FBC) BoilerFluidized Bed (FBC) Boiler
•Particles (e.g. sand) are suspended in high velocity air
stream: bubbling fluidized bed
•Combustion at 840° – 950° C
Fuels:
•coal, rice husk, bagasse and agricultural wastes
Benefits:
•compactness,
• fuel flexibility,
•higher combustion efficiency

20. Fluidized Bed (FBC) BoilerFluidized Bed (FBC) Boiler
Fluidized Bed Boiler is categorized as:
•Atmospheric Fluidized Bed Combustion (AFBC) Boiler
•Atmospheric Circulating Fluidized Bed Combustion
(CFBC) Boiler

21. Atmospheric Fluidized Bed Combustion
(AFBC) Boiler
•Most common FBC boiler that uses preheated
atmospheric air as fluidization and combustion air

22. Atmospheric Circulating Fluidized Bed
Combustion (CFBC) Boiler
•Solids lifted from bed, rise,
return to bed
•Steam generation in
convection section
Benefits:
•more economical,
•better space utilization and
• efficient combustion

24. Conclusion:Conclusion:
Boilers are most important part of Chemical Industry. 99 %
boilers used in Pakistan Chemical Industries are water tube
boilers because of their high efficiency and safety. So we
should have clear understanding about the boilers.