This document provides information on the Cochran and Lancashire boiler. It describes the Cochran boiler as a vertical, multi-tube, fire-tube boiler that is internally fired with natural circulation and low pressure. It has increased heating surface area through multiple fire tubes. The Lancashire boiler is described as a horizontal, fire-tube, multi-tube boiler that is internally fired with natural circulation and low pressure. Both boilers are commonly used in industries for steam generation and heating. Their construction, working principles, advantages, and disadvantages are summarized.

1. Presentation
on
Cochran and Lancashire
Boiler
In partial fulfillment of the subject
Elements of Mechanical Engineering
(2110006)
Submitted by:
Agarwal Ritika (130120116001) /IT / C-1
Akabari Nirali (130120116002) /IT/ C-1
Akanksha Sharma (130120116003) /IT/C-1
GANDHINAGAR INSTITUTE OF
TECHNOLOGY

2. What is Boiler?
 It is a closed vessel in which steam is
produced from water by supplying heat from
combustion of fuels.
The steam produced is used for:
 For generating power in steam engines or
steam turbines.
 Heating the residential and
industrial buildings.
 Performing certain processes in the sugar
mills, chemical and textile industries.

3. Classification of Boiler
 According to geometric orientation:
Horizontal, Vertical, Inclined
 According to position of water and gases:
Fire tube, Water tube
 According to location of furnace:
Externally fired, Internally fired
 According to method of water circulation:
Natural circulation, Forced circulation

4. According to working pressure:
High pressure, Medium pressure, Low
pressure
According to mobility:
Stationary, Mobile
According to numbers of tube:
Single tube, Multi tube

5. Cochran Boiler
Characteristics:
 This boiler is a vertical, multi tube, fire
tube, internally fired, natural circulated
,stationary and a low pressure boiler.
 This kind of boilers are used for a
variety of steam powered vehicles and
other mobile machines, including
early steam locomotives.

6.  It is modification of simple vertical boiler
where heating surface has been increased
by increasing number of fire tubes.
 Improvement over the simple vertical boiler
as it provides greater heating surface.
 It is used for steam generation at low rate.
 Ranges from 1m dia.*2m high, evaporation
20kg/hr to 3m dia *6m high, evaporation
3000kg/hr.

8. Construction
 It is one of the best types of vertical multi-tubular
boiler, and has a number of horizontal
fire tubes.
 Cochran boiler consist of a cylindrical shell
with a dome shaped top where the space is
provided for steam.
 The furnace is one piece construction
 Its crown has a hemispherical shape and
thus provides maximum volume of space

9. Working
 The water is supplied to the boiler through feed
check valve. The coal is introduced to the great
through the fire door. The hot gases produced
from furnace enters combustion chamber
through fuel pipe. This hot gases enters into
horizontal fire tubes. Convection heat transfer
take place from fuel gases passing inside the
tubes to water surrounded the tubes.

10.  The fuel gases coming from of fire tubes
enter into smoke box. Finally they
discharge to atmosphere through a
chimney. The ash formed is collected in ash
pit. The steam is collected through
antipriming pipe on top of the shell.

11. Mounting and accessories
used:
 A man-hole is provided near the top of the
crown of shell for cleaning.
 Pressure gauge used to indicate pressure
of steam inside the boiler
 Water gauge indicates water level inside
the boiler to the observer
 Feed check valve controls the water from
pump to the boiler
 Steam stop valve used to control the
passage of steam from boiler to the steam
pipe.

12.  Blow off cock used to discharge sediments
 Dead weight safety valve used to maintain
safe pressure inside the boiler.
 Feed water heater, economizer, super
heater, air preheated ,steam separator are
some of essential accessories of boiler

13. Advantages :
 Initial cost of boiler is less.
 Quick and easy installation.
 Any type of fuel can be used.
 It can be moved and set up readily in different
locations.
Disadvantages:
 Steam raising capacity is less due to vertical
design.
 Efficiency is poor in smaller sizes.
 Water along with steam may enter the steam pipe
under heavy loads due to small steam spaces.

14. Lancashire Boiler
Characteristics:
 It is horizontal ,fire tube, internally fired,
naturally circulated, low pressure ,stationary
,multi tube boiler.
 It is simple in design, easy to operate and less
operating and maintenance cost.
 It is one of the most commonly used stationary
boilers.
 It is normally used in sugar mills, textile
industries where power generation as well as
process heating is required.

15. Lancashire Boiler

16. Working:
 The coal is introduced to the grate through
fire holes. The combustion of coal takes
place in presence of air which is regulated
by damper. The combustion will produce
hot gases.

17. Mounting and accessories
used:
 The mountings used in this boiler is same
as the previous boiler like man-hole, safety
valve, pressure gauge, and water level
indicator and blow off cock
 The fusible plugs are mounted on the top of
main flues.
 Accessories are added to the boiler as per
the requirement of steam generation.

18. Advantages:
 Large rate of steam generation per square metre of
heating surface. To some extent this is due to the
vibration caused by the motion.
 It is free from brickwork, special foundation and
chimney. This reduces the cost of installation.
 Easy operation, low maintenance costs, easy to
clean and inspect.
Disadvantages:
 Maximum working pressure is limited to 16 bars.
 Due to brick work, more floor area is required.
 Response of pressure build up is less.
 The furnace is inside the tubes therefore the grate
area is restricted.

19. References:
 Elements of mechanical engineering by
NM Bhatt.
 www.wikipedia.com
 www.mosi.org.uk/media/33871781/lancashi
reboiler.pdf
 www.cochran.co.uk

20. Thank you...