The document discusses steam boilers according to the Indian Boiler Regulation (IBR), defining them as closed vessels for generating steam under pressure. It describes characteristics of good boilers, factors affecting their selection, and various classifications and types of boilers, including fire tube and water tube designs. Additionally, it highlights specific examples of different boiler types, their features, steam generation capacities, and operating pressures.

1. Chapter 1:
Chapter 1:
Steam Boilers
Steam Boilers

2. Indian Boiler Regulation (IBR)
Indian Boiler Regulation (IBR)
As per IBR, any closed vessel
As per IBR, any closed vessel
exceeding 22.75 litres in capacity and
exceeding 22.75 litres in capacity and
which is used expressively for
which is used expressively for
generating steam under pressure is
generating steam under pressure is
termed as steam boiler.
termed as steam boiler.

3. Terms for Steam Boilers:
Terms for Steam Boilers:
Boiler Shell
Boiler Shell
Combustion Chamber
Combustion Chamber
Grate
Grate
Furnace
Furnace
Flue gases
Flue gases
Flue
Flue
Mountings
Mountings
Accessories
Accessories

4. Characteristics of Good Boiler
Characteristics of Good Boiler
1.
1. Maximum steam generation rate with minimum
Maximum steam generation rate with minimum
fuel consumption
fuel consumption
2.
2. Should accommodate load variation
Should accommodate load variation
3.
3. Can be started and stopped immediately
Can be started and stopped immediately
4.
4. Less erection time and detachable parts
Less erection time and detachable parts
5.
5. Tubes should not accommodate soot or scale.
Tubes should not accommodate soot or scale.
6.
6. Less frictional losses
Less frictional losses
7.
7. High heat transfer rate and good efficiency
High heat transfer rate and good efficiency

5. Characteristics of Good
Characteristics of Good
Boiler(cont.)
Boiler(cont.)
8.
8. Less initial, running and maintenance
Less initial, running and maintenance
cost
cost
9.
9. Occupy less floor area
Occupy less floor area
10.
10. Should be easily accessible for cleaning
Should be easily accessible for cleaning
and inspection
and inspection
11.
11. Should comply IBR acts
Should comply IBR acts

6. Factors affecting boiler selection:
Factors affecting boiler selection:
1.
1. Working pressure and power required
Working pressure and power required
2.
2. Steam generation rate at working pressure
Steam generation rate at working pressure
3.
3. Type of fuel used
Type of fuel used
4.
4. Availability of fuel and water
Availability of fuel and water
5.
5. Floor space occupied
Floor space occupied
6.
6. Type of load- steady or fluctuating
Type of load- steady or fluctuating
7.
7. Initial cost, running cost and maintenance cost
Initial cost, running cost and maintenance cost

7. Classification of Boilers:
Classification of Boilers:
According to Contents in the tube:
According to Contents in the tube:
(a) Fire Tube (b) Water tube
(a) Fire Tube (b) Water tube
According to Position of furnace:
According to Position of furnace:
(a) Internally fired (b) Externally fired
(a) Internally fired (b) Externally fired
According to Axis of shell:
According to Axis of shell:
(a) Vertical Boiler (b) Horizontal Boiler
(a) Vertical Boiler (b) Horizontal Boiler
According to number of tubes:
According to number of tubes:
(a) Single tube (b) Multi-tubular boiler
(a) Single tube (b) Multi-tubular boiler
According to method of water circulation:
According to method of water circulation:
(a) Natural Circulation (b) Forced circulation
(a) Natural Circulation (b) Forced circulation
According to Use:
According to Use:
(a) Stationary Boiler (b) Mobile Boiler
(a) Stationary Boiler (b) Mobile Boiler
According to source of heat:
According to source of heat:
(Solid, liquid, gas fuels, hot waste gas products, electricity etc
(Solid, liquid, gas fuels, hot waste gas products, electricity etc

8. Fire Tube Boilers
Fire Tube Boilers

9. Cochran Boiler
Cochran Boiler

10. Features:
Features:
Vertical fire tube boiler
Vertical fire tube boiler
Size: 1 to 3 m diameter, 2 to 6 m height
Size: 1 to 3 m diameter, 2 to 6 m height
Steam generation capacity: 3600 kg/hr
Steam generation capacity: 3600 kg/hr
Pressure limit : 11 bar
Pressure limit : 11 bar
Tube diameter: 62.5 mm
Tube diameter: 62.5 mm
No. of tubes: 165
No. of tubes: 165
Hemispherical shape of crown and fire box
Hemispherical shape of crown and fire box
requires least material and improves heat
requires least material and improves heat
radiation
radiation

11. Lanchasire Boiler:
Lanchasire Boiler:

13. Features:
Features:
Horizontal, stationary, fire tube boiler
Horizontal, stationary, fire tube boiler
Used for moderate operating pressure
Used for moderate operating pressure
Size: 2 to 3 m diameter, 7 to 9 m length
Size: 2 to 3 m diameter, 7 to 9 m length
Steam generation capacity: 8500 kg/ hr
Steam generation capacity: 8500 kg/ hr
Pressure limit: 14.7 bar
Pressure limit: 14.7 bar
Tube diameter: ¼ times drum diameter
Tube diameter: ¼ times drum diameter
Large heating surface area per unit
Large heating surface area per unit
volume
volume
Can handle load fluctuation easily
Can handle load fluctuation easily

14. Cornish Boiler
Cornish Boiler

15. Features:
Features:
Horizontal fire tube boiler
Horizontal fire tube boiler
Less capacity
Less capacity
Size: 1.25 to 1.75 m diameter, 4 to 7 m
Size: 1.25 to 1.75 m diameter, 4 to 7 m
length
length
Steam generation capacity: 6500 kg/hr
Steam generation capacity: 6500 kg/hr
Pressure limit: 10.5 bar
Pressure limit: 10.5 bar
Tube diameter: 0.6 times drum diameter
Tube diameter: 0.6 times drum diameter

16. Water Tube Boilers
Water Tube Boilers

17. Babcock and Wilcox Boiler
Babcock and Wilcox Boiler

19. Features:
Features:
Horizontal, stationary water tube boiler
Horizontal, stationary water tube boiler
Size: 1 to 2 m diameter, 6 to 9 m length
Size: 1 to 2 m diameter, 6 to 9 m length
Steam generation capacity: 20,000 to
Steam generation capacity: 20,000 to
40,000 kg/hr
40,000 kg/hr
Pressure limit: 11.5 to 17.5 bar
Pressure limit: 11.5 to 17.5 bar
Tube diameter: 100 mm (approx)
Tube diameter: 100 mm (approx)

20. High Pressure Boilers:
High Pressure Boilers:
Boiler operating with steam pressure
Boiler operating with steam pressure
above 80 bar is termed as high pressure
above 80 bar is termed as high pressure
boiler.
boiler.
Circulation of feed water is under pressure
Circulation of feed water is under pressure
hence increasing its saturation
hence increasing its saturation
temperature. Feed water is generally
temperature. Feed water is generally
heated up to saturation temperature in
heated up to saturation temperature in
economizer.
economizer.
Boiler supplies only latent heat.
Boiler supplies only latent heat.

21. Features of High Pressure Boilers:
Features of High Pressure Boilers:
High steam pressure and temperature
High steam pressure and temperature
Forced water circulation
Forced water circulation
Large number of small diameter tubes
Large number of small diameter tubes
(increases surface area to volume ratio)
(increases surface area to volume ratio)
Improved heat transfer (radiation)
Improved heat transfer (radiation)
Pressurised combustion (uses Pressurised air)
Pressurised combustion (uses Pressurised air)
Compactness
Compactness
High efficiency
High efficiency
Intensive heating
Intensive heating

22. High Pressure boilers:
High Pressure boilers:
La Mount Boiler
La Mount Boiler
Loeffler Boiler
Loeffler Boiler
Benson Boiler
Benson Boiler

23. La Mount Boiler:
La Mount Boiler:

24. Features:
Features:
Steam Generation rate: 50 tonnes/hr
Steam Generation rate: 50 tonnes/hr
Operating pressure and temperature: 130
Operating pressure and temperature: 130
bar, 300
bar, 3000
0
C
C

25. Loeffler Boiler
Loeffler Boiler

26. Features:
Features:
Uses oil as fuel
Uses oil as fuel
Steam generation capacity: 100 tonne/hr
Steam generation capacity: 100 tonne/hr
Pressure limit: 140 bar
Pressure limit: 140 bar
Use of superheated steam instead of flue
Use of superheated steam instead of flue
gases for evaporating feed water. Hence
gases for evaporating feed water. Hence
clean operation
clean operation
Responds rapidly to sudden load variation
Responds rapidly to sudden load variation

27. Benson Boiler
Benson Boiler

28. Features:
Features:
Super critical (operating above critical
Super critical (operating above critical
pressure), drum-less, once through boiler
pressure), drum-less, once through boiler
Steam generation capacity: 135 tonne/ hr
Steam generation capacity: 135 tonne/ hr
Pressure limit: 250 bar
Pressure limit: 250 bar
Can be started within 15 minutes
Can be started within 15 minutes
Drum-less, hence less weight
Drum-less, hence less weight
High pressure avoids bubble formation
High pressure avoids bubble formation
and improve heat transfer rate
and improve heat transfer rate