This presentation is for chemical engineers to study what is boiler its types its efficiency its heat sources and the characteristics of a boiler

1. BOILER AND ITS TYPES
Presented by
Ahsan Iqbal-039
Nouman Ahmed-065

2. TABLE OF CONTENT
• What is boiler
• principle
• Types of boiler
• Source of heat in boiler
• What should be character of boiler
• Efficiency
• Conclusion reference

3. BOILER
‘’Boiler is a closed vessel in which water or other liquid is heated, steam or
vapor is generated, steam is super-heated, or any combination therefore
under pressure or vacuum, for use external to itself, by the direct
application of energy from the combustion of fuels, from electricity or
nuclear energy’’
Basically:
A closed vessel made up of steel to transfer heat produced by
combination of fuel to water and ultimately produced steam.

4. PRINCIPLES OF BOILER
• The basic working principle of boiler is very very simple and easy to
understand.
• The boiler is essentially a closed vessel inside which water is stored.
• Fuel (generally coal) is burnt in a furnace and hot gasses are produced.
• These hot gasses come in contact with water vessel where the heat of these hot
gases transfer to the water and consequently steam is produced in the boiler.
• Then this steam is piped to the turbine.

5. SOURCE OF HEAT IN BOILER
• Wood
• Coal
• Natural gas
• Diesel
• Nuclear energy
• Oil
• Electric steam boilers use resistance or immersion type heating elements.

6. CHARACTERISTICS
• The boiler should have maximum steam generation rate with minimum fuel
consumption.
• It can be started or stopped quickly.
• Its initial cost, running and maintenance cost should not be high.
• The boiler should have positive controls and safety apparatus.
• It should have a high rate of heat transfer and better combustion efficiency.
• It should be able to accommodate the load variation.
• It should be trouble free and require less attention and less maintenance.
• It should be free from manufacturing defects.
• All parts of the boiler should be accessible for cleaning and inspection

7. TYPES OF BOILER
• Water tube boiler
• Fire tube boiler
• Packaged tube boiler
• Stocked fire boiler
• Pulverized boiler
• Waster water boiler

8. WATER TUBE BOILER
• A water tube boiler can be defined as a
Steam boiler in which the flow of water in the
tubes, as well as hot gases.
• The internal structure of this boiler includes a
tiny steam drum, small width tubes.
• The hot gases will flow over the pipes in one
go only.
• boilers range from 4500 kg/h to 120, 000
kg/h.

9. FIRE TUBE BOILER
• In fire tube steam boiler, the flame and hot
gases produced by combustion of fuel pass
through the tubes(called multi tube) which
are surrounded by water.
• The heat is conducted through the wall of
tube from hot gases through the surrounded
water.
• Operate with oil gas and solid fuel.
• Relatively small heat capacity of
12,000kg/hr.

10. PACKAGED TUBE BOILER
• Come in complete package
• High heat transfer
• Faster evaporation
• Good combustion efficiency
• High thermal efficiency
• It is available in a range of standard
designs.
• Package boilers are used for heating and
act as a steam generator for small power
purposes such as self-powered industrial
plants.

11. STOCK TUBE BOILER
Spreader stokers:
• Coal is burnt in suspension then in coal bed
• Flexibility to meet load fluctuations
• Favored in many in industrial applications
• Use suspension and grate burring.
Chain grate or travelling-grate stocker:
• Coal is burnt in moving steel grate
• Coal grate control feeding rate
• Uniform coal size for complete
combustion

12. PULVERIZED BOILER
• Generate Thermal energy by burning
pulverized coal or coal dust.
• Its another 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

13. WASTE HEAT BOILER
• A boiler which uses the exhaust gas from an
engine to produce low pressure saturated
steam.
• 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 engine.
• Waste heat may be extracted from sources
such as hot flue gases from a diesel generator,
steam from cooling towers, or even waste water
from cooling processes such as in steel cooling.

14. EFFICIENCY
• “The percentage of the total absorption heating value of outlet steam in the total
supply heating value.”
• It is a rate how the boiler runs efficiently.
• Boiler Efficiency =
(𝑆𝑡𝑒𝑎𝑚 𝑣𝑎𝑙𝑢𝑒 𝑝𝑒𝑟 ℎ𝑜𝑢𝑟∶𝑘𝑔) × (ℎ2－ℎ1) × 100
(𝐹𝑢𝑒𝑙 𝑐𝑜𝑛𝑠𝑢𝑚𝑝𝑡𝑖𝑜𝑛 𝑝𝑒𝑟 ℎ𝑜𝑢𝑟∶𝑘𝑔) × (𝐹𝑢𝑒𝑙 𝑙𝑜𝑤 𝑐𝑎𝑙𝑜𝑟𝑖𝑓𝑖𝑐 ℎ𝑒𝑎𝑡𝑖𝑛𝑔 𝑣𝑎𝑙𝑢𝑒∶ 𝑘𝐽/𝑘𝑔)
%
• h2: The ratio enthalpy of feed water (kJ/kg)
• h1: The ratio enthalpy of steam (kJ/kg)

15. 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.