This document discusses high pressure boilers and their accessories. It begins by defining industrial boilers and their uses in steam generation. It then covers the classification of boilers based on orientation, firing method, and tube configuration. Specific boiler types are described in detail, including vertical, Cochran, Lancashire, locomotive, Babcock and Wilcox, and Stirling boilers. High pressure boilers like La-Mont, once-through, Ramzin, Loeffler, and Velox boilers are also summarized. The document concludes by comparing fire tube and water tube boilers, and describing important boiler mountings and accessories.

1. High Pressure Boilers &
Accessories
Prepared By
Prof. Jagdish S.Talpada
Assistant Professor,
Mechanical Engineering Department,
DJMIT, Mogar
151904 : POWER PLANT ENGINEERING

2. LECTURE - 1
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prepared by Prof. Jagdish S.
Talpada

3. Industrial Boilers

Steam generators

Closed vessels

made of steel and

used for generation of steam

vaporizing water

combustion of fuels

eg. coal,coke,oil,wood,saw dust and begesse etc.

Steam used for producing power,for industrial
process work or for heating proposes.
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prepared by Prof. Jagdish S.
Talpada

4. Requirements of a Perfect
Steam Boilers
 Should be absolutely reliable,capable of producing
maximum steam at required pressure for minimum of
fuel consumption,with minimum attention and minimum
initial cost and operating cost.
 Simple constructions
 Quick starting from cold
 Strong enough against temp. stress & strains
 Well design combustion chamber
 Less floor area, space & light weight
 Best gauges,safety valves and other mountings
 Easily accessible for inspection,cleaning and repairs
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Talpada

5. Classification of Steam
Boilers
 Vertical or Horizontal
 Stationary(Power plant,industrial,central heating and
combined power and heating
boilers.),Portable,Locomotive or Marine
 Internally Fired or Externally Fired (Lancashire and
Locomotive Boilers)
 Solid,Liquid or Gas Fired
 Fire(Smoke)Tube:Water is outside the tubes while the
hot gases are inside the tubes
eg.Vertical,Cochran,Lancashire,Cornish,Locomotives,etc
) or Water Tube: Contain a large number of small tubes
through which water circulates,the fire and hot gases
being outside of the tubes.eg.Babcock and Wilcox,
Stirling and High pressure Boilers etc.)
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prepared by Prof. Jagdish S.
Talpada

6. Vertical Boilers
 Used in small factories,small water supply
plants,cranes,excavators,winch engines in
mines and on sites of temporary nature such
as construction work etc.
 Required minimum floor space,not required
elaborate foundations,and is portable.
 Cheap,easy to start but inefficient due to large
wastage of fuel and less heating surface.
 Vertical Boilers are:Simple(having one to three
cross tubes), fire tubes and water tubes types.
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Talpada

7. Simple Cross tube vertical
boiler
 consists of a cylindrical shell surrounding a cylindrical fire box.
 heating surface is about 8-10 times the grate area.
 50% efficiency
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prepared by Prof. Jagdish S.
Talpada

8. Cochran Boiler
 It is well design of a Vertical multitubular fire tube boiler
 Improvement over the simple vertical boiler as it
provides greater heating surface.
 Total heating surface area is about 10-25 times the
grate area
 Efficiency 70-75%
 Ranges from 1m dia.X2m high,evaporation 20kg/hr to
3m dia X6m high,evaporation 3000kg/hr.
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prepared by Prof. Jagdish S.
Talpada

9. Cochran Boiler contd….
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Talpada

10. Lancashire Boiler
 Is horizontal smoke tube boiler size range
from a shell 2m diaX6m long to 3m diaX10m
long
 Working pressure range are up to 20kgf/cm2
 Ratio of heating surface to grate area is 24-30
 Efficiency is about 56% without economizer
and 75% with economizer.
 Similar to Cornish boiler,in Lancashire Boiler
two flue tubes but in Cornish boiler only one
flue tubes are there.
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Talpada

11. LECTURE - 2
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prepared by Prof. Jagdish S.
Talpada

12. Lancashire Boiler contd……
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prepared by Prof. Jagdish S.
Talpada

13. Lancashire Boiler contd……
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prepared by Prof. Jagdish S.
Talpada

14. Locomotive Boiler
 Is an internally fired multitubular fire tube boiler
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Talpada

15. Babcock and Wilcox water
tube Boiler
 Water tube boiler having lager pressure ranges and
larger sizes.
 Three main parts, steam and water drum,water tubes
and furnace.
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Talpada

16. Stirling Boiler
 Example of water tube boiler where bent tube are used
instead of straight tube which are used in Babcock and Wilcox
boiler
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Talpada

17. LECTURE - 3
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prepared by Prof. Jagdish S.
Talpada

18. High Pressure Boilers
 Two types- Natural circulation & Forced circulation
Boilers
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Talpada

19. High Pressure Boilers
contd………
 La-Mont Boiler( Forced circulation Boiler)
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Talpada

20. Once-Through Forced
Circulation Boiler
 Does not required a steam and water drum,saving in weight
 Supercritical Pressure Boiler
 Two types- Benson and Ramzin
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Talpada

21. Ramzin Boiler
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Talpada

22. Loeffler Boiler
 Indirect heating is combined with forced circulation
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prepared by Prof. Jagdish S.
Talpada

23. Velox boiler
 Fire tube forced circulation Boiler
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prepared by Prof. Jagdish S.
Talpada

24. LECTURE - 4
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prepared by Prof. Jagdish S.
Talpada

25. Fire tubes Vs water tubes
Boilers
 Fire tubes boilers has a large volume of water,therefore
more flexible and can meet the sudden demand of
steam without much drop of pressure.
 Fire tubes boiler is rigid and of simple mechanical
construction,so greater reliability and low in first cost.
 Fire tube boilers can be made in smallest sizes therefore
simple to fabricate and transport, occupies less floor
space but more height.
 Due to mostly externally fired water tubes boiler so
furnace can be altered considerably to meet the fuel
requirements.
 Water tubes boilers are more readily accessible for
cleaning,inspection and repairs,compared to the fire
tube boilers.
 Modern trend is in the favors of water tube boiler due to
continuous increase in capacities and steam pressures.25
prepared by Prof. Jagdish S.
Talpada

26. Boiler Mountings and
Accessories
 Fitting and devices which are necessary for the safety
and control are knows as boiler mountings
 Fitting or devices which are provided to increase the
efficiency of the boiler and help in the smooth working
of the plant are knows as boiler accessories.
 Fittings which are essential from the
safety point of view are as follows,
 Water level indicators
 Safety valves
 Combined high steam and low water safety valve
 Fusible plug
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Talpada

27. Boiler Mountings and
Accessories contd….
 Fittings which are essential from the
control point of view are as follows,
 Pressure gauge
 Junction or stop valve
 Feed check valve
 Blow-off cock
 Man hole and Mud Box
 The important accessories are
 Superheater
 Economiser
 Air-preheater
 Feed pump or injector
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prepared by Prof. Jagdish S.
Talpada