Forced Draft Fan is a type of fan supplying pressurized air to a system. In the case of a Steam Boiler Assembly, this fan is very important. As we know, for a Steam Boiler to generate steam, combustion must occur, be it any fuel (wood/coal/rice husk/pet coke/LDO/Furnace oil), and for combustion to exist one of its three main requirements, is the air. A Forced Draft Fan compensates for this requirement.
This fan supplies air to the air preheater, where it captures the heat from the flue gases coming from the Boiler Outlet.
Nowadays, fluidized bed combustion is one of the promising ways of collecting more energy through combustion for solid fuels. But this wouldn’t have even been so famous if there wasn’t any Forced Draft Fan. Whether it is a Bubbling or Circulating fluidized bed combustion incorporated Boiler. This phenomenon of fluidization is achieved through a Forced Draft Fan only.
Let us consider Bubbling Fluidized Combustion, Proper designing of the Fan as per the weight of the sand placed on the bed is very essential. The pressurized air supplied by the Fan helps in providing enough draft equalizing the weight of the bed and the quantity to be supplied, hence creating fluidization of the sand in the furnace. The pressure head and the quantity of air supplied for combustion need to be calculated.
