|Water Tube Boilers|
A water tube boiler also spelled water-tube and water tube boiler may be a type of boiler in which water circulates in tubes heated outwardly by the hearth. Fuel is burned within the chamber, making hot gas that heats water within the steam generated tubes. In smaller boilers, further generating steam tubes are separate within the chamber, whereas larger utility boilers admit the water-filled tubes that structure the walls of the chamber to get steam.
The heated water then rises into the steam drum. Here, saturated steams are drawn off the high of the drum. In some services, the steam can re-enter the chamber through a superheater to become superheated. Superheated steam is outlined as steam that's heated on top of the boiling purpose at a given pressure. Superheated steam may be a dry gas and thus accustomed drive turbines since water droplets will severely harm rotary engine blades.
Cool water at the all-time low of the steam drum returns to the feed water drum via large-bore downcomer tubes wherever it pre-heats the feed water offer. (In massive utility boilers, the feed water is equipped with the steam drum and therefore the downcomers offer water to an all-time low of the water walls). to extend economy of the boiler, exhaust gases are accustomed pre-heat the air blown into the chamber and heat the feed water offer. Such water tube boilers in thermal power stations are known as steam generating units.