It is a high pressure water tube boiler which uses forced circulation method
Feed pump (FP) is used to pass the feed water through the economizer(E) from the hot-well
The flue gases heat the feed water in the economizer and this hot water is then fed to the evaporating drum (ED)
The circulating pump (CP) operating at 2 to 3 bar pressure higher than steam pressure draws the feed water from the evaporating drum and it supplies to the distribution header(DH)
The distributor header then distributes the water through the nozzles to radiant evaporating tubes(RET) where the water absorbs the radiant heat of the combustion chamber(CC) and then it is passed to the convective evaporating tubes(CET)
The mixture of water and steam from the evaporative tubes is passed to evaporating drum where the steam and water is separated and passed through the superheater for superheating of the steam.
The superheated steam is thus passed to steam turbine for developing mechanical work
The feed water drawn by the circulating pump to the evaporating tubes is 5 to 8 times to avoid any overheating of the tubes
The air drawn by the blower (B) is preheated in the air preheater by the flue gases before they are discharged through the chimney. The heated air from air preheater is supplied to the combustion chamber and it improves the combustion efficiency.
This boiler can generate steam upto a pressure of 150 bar and the generation rate of steam ranges from 30 to 50 tonnes per hour.