CLASSIFICATION OF BOILERS

Hello Readers,

Let us study classification of boilers.The boilers can be mainly classified on the bases mentioned below:

(1)According to the contents in the tube:

(a)Fire Tube Boilers:

In the fire tube boilers,the flames and hot gases,produced by combustion of fuel pass through the tubes which are surrounded by water. The heat is conducted through the walls of the tubes from the hot gases to the surrounding water.Example of fire tube boiler are>>Simple Vertical Boiler,Cochran Boiler,Lancashire Boiler,Cornish Boiler, and Velcox Boiler

(b) Water Tube Boiler:

In water tube boiler,the water is contained inside the tubes (Called water tube boilers) whichare surrounded by flames and hot gases on the outside.Example of water tube boilers are>>Bobcox & WIlcox Boiler,Sterling Boiler,Benson Boiler,Lamont Boiler,Yerrow Boiler and Loaffler Boiler

(2)According to the axis of the shell:

(a)Vertical Boilers (b)Horizontal Boilers

(3)According to number of tubes:

(a)Single Tube Boilers:

In a single tube boilers,there is only one fire tube or water tube .Simple vertical boiler and cornish boiler are single tube boilers.

(b)Multi Tube Boilers:

There are two or more fire or watertubes inside it.

(4)According to the method of circulation of water and steam:

(a)Natural Circulation Boilers:

In Natural Circulation Boilers the circulation of water is by natural convection currents produced due to density difference of water-steam mixture which are set up during the heating of water. In most of the steam boilers there is natural circulation of water.

(b)Forced Circulation Boilers:

In forced Circulation Boilers, There is force circulation of water by centrifugal pump driven by some external power. Use of forced circulation is made in high pressure boilers such as La-mont Boiler,Benson Boiler

(5)According to the Position Of Furnace:

(a)Internally Fired Boilers:

In Internally Fired Boilers the furnace is located inside the boiler shell.Most of the fire tube boilers are internally fired

(b)Externally Fired Boilers:

In Externally Fired Boilers the furnace is arranged undermeath the shell in brick setting.Water tube boilers are generally externally fired

(6)According To the Source Of Heat Of type Of Fuel:

The used boilers may be classified on the basis of fuel i.e. Coal Fired,Oil Fired or Gas Fired. Depending upon fuel used

(7)According to the Use :

(a) Stationary Boilers:

The stationary boilers are used in power plant and industries for process work . These are called stationary because they are fixed on foundation and can not move from place to place

(b)Mobile Boilers:

The mobile boilers are those which move from place to place(e.g.Locomotive & Marine Boilers) during its working