Forced circulation boiler
The forced circulation boiler is a steam generator of the type water tube boiler in which the flow of water / steam is forced through a circulation pump - in contrast to a natural circulation boiler , which works solely with the circulation as a result of natural convection .
Unlike the once-through boiler , the once-through boiler has a drum . The circulation pump sucks in boiler water from the drum and pushes it through the evaporator heating surfaces. The circulation rate indicates the ratio of the amount of water in circulation to the amount of steam in the boiler; it is typically between 5 and 40.
The steam is separated from the water in the drum . The evaporated water is replaced by feed water . The evaporator is divided into pipe systems connected in parallel, which reduces the frictional resistance of the overall system and the circulation pump has to generate less power.
A representative of this design is the La Mont boiler .