3. Introduction
Cochran boiler is modification of simple vertical boiler where
heating surface has been increased by increasing numbers of
fire tubes.
Improvement over the simple vertical boiler as it provides
greater heating surface.
It is used for steam generation at low rate.
It is a fire tube type boiler.
It is popular portable boiler.
It consist of very small floor area.
Cochran boiler is modification of simple vertical boiler where
heating surface has been increased by increasing numbers of
fire tubes.
Improvement over the simple vertical boiler as it provides
greater heating surface.
It is used for steam generation at low rate.
It is a fire tube type boiler.
It is popular portable boiler.
It consist of very small floor area.
Cochran boiler is modification of simple vertical boiler where
heating surface has been increased by increasing numbers of
fire tubes.
Improvement over the simple vertical boiler as it provides
greater heating surface.
It is used for steam generation at low rate.
It is a fire tube type boiler.
It is popular portable boiler.
It consist of very small floor area.
Cochran boiler is modification of simple vertical boiler where
heating surface has been increased by increasing numbers of
fire tubes.
Improvement over the simple vertical boiler as it provides
greater heating surface.
It is used for steam generation at low rate.
It is a fire tube type boiler.
It is popular portable boiler.
It consist of very small floor area.
6. Characteristics of Cochran boilerCharacteristics of Cochran boiler
It is vertical.
It is portable.
It is a fire tube boiler.
The number of tubes are more (multi-tube).
It is internally fired.
It has natural circulation.
Solid as well as liquid fuel can be burnt.
It’s low pressure boiler
It is vertical.
It is portable.
It is a fire tube boiler.
The number of tubes are more (multi-tube).
It is internally fired.
It has natural circulation.
Solid as well as liquid fuel can be burnt.
It’s low pressure boiler
8. Construction
The boiler consists of cylindrical shell, hemispherical fire box, fire
tubes and chimney.
The top of the shell having hemispherical shaped crown.
The hemispherical crown of boiler gives good strength to with
stand pressure of steam inside the boiler.
The hemispherical shape of furnace can withstand high heat and is
also useful to increase radiant heat transfer from the furnace to
hemispherical furnace wall.
The grate is placed at the bottom of the furnace and ash pit is
located below the grate.
The furnace and the combustion chamber are connected by
short flue pipe.
The wall of the combustion chamber is lined with the fire bricks.
The ash pit is located below the grate.
The boiler consists of cylindrical shell, hemispherical fire box, fire
tubes and chimney.
The top of the shell having hemispherical shaped crown.
The hemispherical crown of boiler gives good strength to with
stand pressure of steam inside the boiler.
The hemispherical shape of furnace can withstand high heat and is
also useful to increase radiant heat transfer from the furnace to
hemispherical furnace wall.
The grate is placed at the bottom of the furnace and ash pit is
located below the grate.
The furnace and the combustion chamber are connected by
short flue pipe.
The wall of the combustion chamber is lined with the fire bricks.
The ash pit is located below the grate.
9. Working principles of Cochran boilerWorking principles of Cochran boiler
The water is supplied to the boiler through feed check valve.
The coal is introduced to the grate trough the fire door.
The hot gases produced from furnace enters combustion
chamber through flue pipe.
This hot gases enters into horizontal fire tubes.
Convection heat transfer take place from flue gases passing inside
the tubes to water surrounded the tubes.
The flue gases coming from 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 anti-priming pipe on top of
the shell.
The water is supplied to the boiler through feed check valve.
The coal is introduced to the grate trough the fire door.
The hot gases produced from furnace enters combustion
chamber through flue pipe.
This hot gases enters into horizontal fire tubes.
Convection heat transfer take place from flue gases passing inside
the tubes to water surrounded the tubes.
The flue gases coming from 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 anti-priming pipe on top of
the shell.
10. Mounting and Accessories Used
Following mounting are required for the safety and proper
operation of Cochran boiler.
Steam pressure gauge
Water level indicator
Dead weight safety valve
Feed check valve
Blow off cock
Steam stop valve
Man-hole
Fusible plug
Anti priming pipe and dampers are the boiler mounting.
Following mounting are required for the safety and proper
operation of Cochran boiler.
Steam pressure gauge
Water level indicator
Dead weight safety valve
Feed check valve
Blow off cock
Steam stop valve
Man-hole
Fusible plug
Anti priming pipe and dampers are the boiler mounting.
Following mounting are required for the safety and proper
operation of Cochran boiler.
Steam pressure gauge
Water level indicator
Dead weight safety valve
Feed check valve
Blow off cock
Steam stop valve
Man-hole
Fusible plug
Anti priming pipe and dampers are the boiler mounting.
Following mounting are required for the safety and proper
operation of Cochran boiler.
Steam pressure gauge
Water level indicator
Dead weight safety valve
Feed check valve
Blow off cock
Steam stop valve
Man-hole
Fusible plug
Anti priming pipe and dampers are the boiler mounting.
11. Cont…Cont…
Fusible Plug:
If the water level in the boiler
falls below a predetermined
level, the boiler shell and
tubes will be overheated.
Fusible Plug:
If the water level in the boiler
falls below a predetermined
level, the boiler shell and
tubes will be overheated.
14. Cont…Cont…
Steam Stop Valve:
It regulates the flow of steam
supply outside.
The steam from the boiler first
enters into an anti-priming pipe
where most of the water
particles associated with steam
are removed.
Steam Stop Valve:
It regulates the flow of steam
supply outside.
The steam from the boiler first
enters into an anti-priming pipe
where most of the water
particles associated with steam
are removed.
Steam Stop Valve:
It regulates the flow of steam
supply outside.
The steam from the boiler first
enters into an anti-priming pipe
where most of the water
particles associated with steam
are removed.
Steam Stop Valve:
It regulates the flow of steam
supply outside.
The steam from the boiler first
enters into an anti-priming pipe
where most of the water
particles associated with steam
are removed.
15. Cont…Cont…
Safety Valve:
The function of the safety
valve is to prevent the
increase of steam
pressure in the holler
above its design pressure.
Safety Valve:
The function of the safety
valve is to prevent the
increase of steam
pressure in the holler
above its design pressure.
Safety Valve:
The function of the safety
valve is to prevent the
increase of steam
pressure in the holler
above its design pressure.
Safety Valve:
The function of the safety
valve is to prevent the
increase of steam
pressure in the holler
above its design pressure.
16. Cont…Cont…
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.
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.
17. Cont…Cont…
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.
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.
Man-hole: provided near the top of the crown of shell for cleaning.
18. Maintenance
Start up
most furnace explosions occur during start up and when
switching fuels, so always follow the manufacturer’s guidelines.
Operation
Requires proper training, equipment familiarity and routine
maintenance procedures.
Shutdown
If the boiler is to be placed out of service for an extended period
of time, proper lay-up procedures are required and must be
followed.
Maintaining the normal operating water level (NOWL) in the boiler
A low water condition is the most common cause of boiler
failure.
Start up
most furnace explosions occur during start up and when
switching fuels, so always follow the manufacturer’s guidelines.
Operation
Requires proper training, equipment familiarity and routine
maintenance procedures.
Shutdown
If the boiler is to be placed out of service for an extended period
of time, proper lay-up procedures are required and must be
followed.
Maintaining the normal operating water level (NOWL) in the boiler
A low water condition is the most common cause of boiler
failure.
Start up
most furnace explosions occur during start up and when
switching fuels, so always follow the manufacturer’s guidelines.
Operation
Requires proper training, equipment familiarity and routine
maintenance procedures.
Shutdown
If the boiler is to be placed out of service for an extended period
of time, proper lay-up procedures are required and must be
followed.
Maintaining the normal operating water level (NOWL) in the boiler
A low water condition is the most common cause of boiler
failure.
Start up
most furnace explosions occur during start up and when
switching fuels, so always follow the manufacturer’s guidelines.
Operation
Requires proper training, equipment familiarity and routine
maintenance procedures.
Shutdown
If the boiler is to be placed out of service for an extended period
of time, proper lay-up procedures are required and must be
followed.
Maintaining the normal operating water level (NOWL) in the boiler
A low water condition is the most common cause of boiler
failure.
19. Advantage
It is compact and portable boiler therefore minimum floor
area is required.
Initial cost of boiler is less.
It can be moved and set up readily in different location.
Quick and easy installation.
Any type of fuel can be used ( coal or oil).
It is compact and portable boiler therefore minimum floor
area is required.
Initial cost of boiler is less.
It can be moved and set up readily in different location.
Quick and easy installation.
Any type of fuel can be used ( coal or oil).
It is compact and portable boiler therefore minimum floor
area is required.
Initial cost of boiler is less.
It can be moved and set up readily in different location.
Quick and easy installation.
Any type of fuel can be used ( coal or oil).
It is compact and portable boiler therefore minimum floor
area is required.
Initial cost of boiler is less.
It can be moved and set up readily in different location.
Quick and easy installation.
Any type of fuel can be used ( coal or oil).
20. Disadvantage
Steam raising capacity is less due to vertical design.
Water along with steam may enter the steam pipe
under heavy loads due to small steam space.
Efficiency is poor in smaller sizes.
Difficult in cleaning and inspection due to vertical
design.
The boiler require high head room.
Steam raising capacity is less due to vertical design.
Water along with steam may enter the steam pipe
under heavy loads due to small steam space.
Efficiency is poor in smaller sizes.
Difficult in cleaning and inspection due to vertical
design.
The boiler require high head room.
Steam raising capacity is less due to vertical design.
Water along with steam may enter the steam pipe
under heavy loads due to small steam space.
Efficiency is poor in smaller sizes.
Difficult in cleaning and inspection due to vertical
design.
The boiler require high head room.
Steam raising capacity is less due to vertical design.
Water along with steam may enter the steam pipe
under heavy loads due to small steam space.
Efficiency is poor in smaller sizes.
Difficult in cleaning and inspection due to vertical
design.
The boiler require high head room.
