The document provides an overview of boilers, detailing their function to produce steam from thermal energy for various applications such as power generation and heating. It categorizes boilers based on properties like safety, efficiency, types (fire tube vs water tube), and features including mounting requirements and performance metrics. Key comparisons between fire tube and water tube boilers are outlined, highlighting differences in construction, operation, and efficiency.

1. BY:
Anuj Maurya
Roll. No- 13

2. Boiler is an apparatus to produce steam.
Thermal energy released by combustion of fuel issued to
make steam at the desired temperature and pressure.
The steam produced is used for:
1). For generating power in steam engines or steam
turbines.
2). Heating the residential and industrial buildings.
3). Performing certain processes in the sugar mills,
chemical and textile industries.

3. BOILER PROPERTIES
a). Safety: The boiler should be safe under the operating
conditions.
b). Accessibility: The various part of boiler should be accessible
for repair and maintenance.
c). Capacity: Should be capable of supplying Steam according
to the requirement.
d). Efficiency: Should be able to absorb a maximum amount of
heat produce due to burning of fuel in the furnace.
e). It should be simple in construction.
f). Its initial cost and maintenance cost is low.
g). It should be capable of quick starting and loading.

4. CLASSIFICATION OF BOILERS
The boiler may be classified as:
1. Horizontal, Vertical or Inclined.
2. Fire tube & Water tube.
3. Externally fired & Internally fired.
4. High pressure & Low pressure.
5. Forced circulation & Natural circulation.
6. Stationary & Portable.
7. Single tube & Multi tube boilers.

5. 1. Horizontal, Vertical or Inclined
If the axis of boiler is horizontal, the boiler is called
horizontal boiler.
If the axis is vertical then it is called vertical boiler.
If the axis is inclined then it is called inclined boiler.
Advantage of horizontal boiler:
a. it should be repair easily.
b. occupies less floor area.

6. 2. Fire tube & water tube boiler
In the fire tube boiler the hot gases are inside the tubes &
the water surrounds in the tube.
ex. Cochran, Locomotive etc.
In the water tube boiler the water is inside the tube & the
hot gases are surround them.
ex. Babcock & wilex, Lamont, Stirling boiler etc.

7. 3. Externally & Internally fired
The boiler is known as externally fired if the fire is
outside the shell.
ex. Babcok & wilcox.
In case of internally fired boilers, the furnace is located
inside the boiler shell.
ex. Cochran, Lancashire etc.

8. 4. Forced circulation & natural circulation
In forced circullation type of boillers the circullation of
water is done by forced pumps.
ex. Velox, Lamont etc.
In natural circullation type of boiller the circullation of
water in boiler take place due to natural convention.
ex. Lancashire, Babcock .

9. 5. High pressure & low pressure boilers
The boiler which produce steam at pressure of 80 bar and
above are called high pressure boiler.
ex. Velox .
The boiler which produce steam at pressure 80 bar are
called low pressure boiler.
ex. Cochran .

10. 6. Single-tube & multi-tube boilers
The fire tube boilers are classified as single tube & multi
tube boilers, depending upon the fire tube is one or more
than one .
Ex: Cornish boiler.

11. Boiler mainly classified as:
a. Fire tube boiler .
b. Water tube boiler .

12. a). FIRE TUBE BOILERS

14. b). WATER TUBE BOILERS

16. S
no.
Particulars Fire tube boilers Water tube
boilers
1. Mode of firing Internally fired Externally fired
2. Rate of steam
production
Lower Higher
3. Construction Difficult Simple
4. Transportation Difficult Simple
5. Treatment of water Not so necessary More necessary
6. Operating pressure Limited to 16 bar Under high
pressure as 100
bar
7. Floor area More floor area Less floor area
8. Shell diameter Large for same
power
Small same power
9. Explosion Less More
Comparison between Fire-tube & Water-tube boilers

17. TYPES OF FIRE TUBE BOILERS
• There are mainly five types of fire tube boilers.

20. 5). LOCOMOTIVE BOILERS

22. BOILER MOUNTING
Boiler Mounting are the part of boiler and are required for
proper functioning of boiler in accordance with Indian Boiler
Regulation Act. Boiler mounting is essential fitting for safe
working of boiler. These mounting are:
1). Fusible Plug
If the water level in the boiler falls
below a predetermined level,
the boiler shell and tubes will be
overheated.

23. 2). Water Level Indicator
This indicates the water
level in the boiler.
3). Pressure Gauge.
This indicates the pressure of
the steam in the boiler.

24. 4). Steam Stop Valve.
It regulates the flow of steam
supply outside. The steam from
the boiler first enters into an ant-
priming pipe where most of the
water particles associated with
steam are removed.
5). Safety Valve.
The function of the safety
valve is to prevent the
increase of steam pressure in
the holler above its design
pressure.

25. 6). Feed Check Valve.
The high pressure feed water
is supplied to the boiler
through this valve. This valve
opens towards the boiler only
and feeds the water to the
boiler.
7). Blow-off Cock.
The water supplied to the boiler always
contains impurities like mud, sand and,
salt Due to heating, these are deposited
at the bottom of the boiler, they have to
be removed using blow off cock.

26. Boiler performance
1) Evaporative capacity
can be expressed in terms of:
a) kg of steam/hr
b) kg of hour/hr/m2 of heating surface
c) kg of steam/kg of fuel fired
Boiler efficiency
Ratio of heat actually utilized in the generator to
the heat supplied by the fuel.
Efficiency= mw(h-hf)/C
Where C is the calorific value