A prominent special case is our fluidized bed boiler, where independently produced steam is exchanged to a beneficiary (tank) on the train. It is fundamentally a shut vessel into which water is heated until the water is changed over into steam at required weight. This is most essential meaning of heater. The essential working rule of an evaporator is exceptionally straightforward. The provided fluidized bed boiler is basically a shut vessel inside which water is kept. Fuel is heated in a heater and hot gasses are delivered. These hot gasses interact with water vessel where the warmth of these hot gases exchange to the water and subsequently steam is delivered.