CONSTRUCTION and WORKING:

The boiler barrel is cylindrical shell and consists of large number of flue tubes. The barrel comprise of a rectangular fire box at one end and a smoke box at the other end. The coal is introduced in fire box through fire hole and is made to burn on the grate. Water is filled into cylindrical boiler shell up to about ¾ level. Hot gases which are generated as a result of coal burning rise and get deflected by fixed fire brick lining. The hot flue gases heats water and then reach the smoke box at the other end. Finally flue gasses pass to atmosphere through short chimney. The steam produced is stored in steam space and steam dome. A throttle valve is provided in steam dome. The throttle valve is controlled by regulating rod from outside. For super heating, steam passes through throttle valve to the super heater.