DRAUGHT - Problem 4
Composed By:
R.Satheesh, M.E., Asso.Prof.,
E-Mail: rsatheeshemail@gmail.com
Problems - Boilers (Heat Balance Sheet)
Composed By:
R.Satheesh, M.E., Asso.Prof.,
E-Mail: rsatheeshemail@gmail.com
Classification of Boiler
Ø According to - The Contents in the
Tubes
Fire Tube Boiler-(Fire In
Tube)
In fire tube boiler the fire or hot gas are
present inside the tubes and water surrounds these fire tubes.
Ex:
Simple Vertical Boiler,
Lancashire Boiler,
Cochran Boiler,
Locomotive Boiler,
Cornish
Boiler,
Scotch Marine Boiler…
Water Tube Boiler-(Water In
Tube)
In water tube
boilers, the water is present inside the tubes and the fire or hot gases
surrounds these water tubes.
Ex:
Benson Boiler,
La-Mont Boiler,
Babcock and Wilcox Boiler,
Stirling
Boiler,
Loeffler Boiler,
Yarrow
Boiler…
Ø According to - The Number of Tubes
Single Tube Boilers
The boilers which
contain single water or fire tube are called as single tube boiler.
Ex:
Simple
Vertical Boiler
Cornish
Boiler…
Multitubular Boiler
The boilers which has
two or more water tubes or fire tubes are called multi tubular boilers.
Ex:
Locomotive
Boiler,
Cochran Boiler,
Lancashire Boiler,
Babcock
and Wilcox Boilers…
Ø According to - The Position of the
Furnace
Internally Fired Boilers
The boilers in which
the furnace is located inside the boiler shell are called internally fired
boilers. Among all the fire tube boilers, most of the boilers are internally
fired boilers.
Ex:
Cochran Boiler,
Lancashire
Boiler,
Locomotive
Boiler…
Externally Fired Boilers
In externally fired
boilers, the furnace is located outside the boiler shell. In this the furnace
is arranged underneath in brick work setting. Water tube boilers are always
externally fired boilers.
Ex:
Babcock and Wilcox Boiler,
Stirling
Boiler…
Ø According to - The Axis of the Shell
Vertical Boilers
The axis of the shell
in a boiler is found vertical.
Ex:
Simple Vertical
Boiler,
Cochran Boiler…
Horizontal Boilers
The axis of the shell
in a boiler is found horizontal.
Ex:
Babcock and Wilcox Boiler,
Locomotive Boiler…
Ø According to - The Methods of
Circulation of Water and Steam
Natural Circulation Boilers
The circulation of
water takes place naturally by the convection currents that set ups during the
heating of water. In most of the boilers there is a natural circulation of
water.
Ex:
Lancashire Boiler,
Cochran Boiler…
Forced Circulation Boilers
The water circulation
takes place with the help of a centrifugal pump driven by some external power. Forced
circulation is used in high pressure boilers.
Ex:
Benson Boiler,
La-Mont Boiler,
Loeffler Boiler, …
Ø According to - The usage
Stationary Boilers
These are the boilers
which are stationary and cannot be moved from one place to another. Once they
are installed, cannot be transported to other destination. These boilers are
used in power plants and in industrial process works.
Mobile Boilers
These are the steam
boilers which can be moved from one place to another.
Ex:
Locomotive
Boiler,
Marine
Boiler…
Ø According to - The working pressure
Low Pressure Boilers
It produces steam at
a pressure below 80 bar.
Ex:
Locomotive
Boiler,
Cochran
Boiler,
Lancashire
Boiler…
High Pressure Boilers
It produces steam at
a pressure above 80 bar.
Ex:
Babcock and Wilcox Boiler…
Ø According to - The nature of fuel
source used
Solid Fuel Fired Boilers
Oil Fired Boilers
Gas Fired Boilers
Ø According to - The Operating parameter
(Pressure & Temperature)
Super critical boiler
Operating above critical point (P=221.2
bar and T=373°C).
Sub critical boiler
Operating below
critical point.
Composed By:
R.Satheesh,
M.E.,
Asso.Prof.,