Classification of Steam Boilers

Through there are many classifications of steam boilers, yet the following are important from the subject point of view:

1.     According to the contents in the tube

       (a) Fire tube or smoke tube boiler (Ex. Lancashire boiler, Scotch marine boiler)

       (b) Water tube boiler (Ex. La-Mont boiler, Babcock-Wilcox boiler)

2.     According to the position of the furnace

       (a) Internally Fired

       (b) Externally Fired

3.    According to the axis of the shell

       (a) Vertical 

       (b) Horizontal

4.    According to the number of tubes

       (a) Single tube (Ex. Cornish boiler)

       (b) Multibular

5.     According to the method of circulation of water and steam

       (a) Natural circulation

       (b) Forced Circulation

6.     According to the use

       (a) Stationary 

       (b) Mobile

7.    According to the source of the heat

The steam boilers may also be classified according to the source of the heat supplied for producing steam. These sources may be the combustion of solid, liquid or gaseous fuel, hot waste gases as by products of other chemical processes, electrical energy or nuclear energy.