FORCED DRAFT FAN
FD fan or forced draft fan, draws air from the atmosphere and
forces it into the furnace through a preheater. These fans are located at the inlet of the boiler to
push high pressure fresh air into combustion chamber, where it mixes with the fuel to produce positive
pressure. In power plants, where coal is used as fuel for combustion, FD fans are used as secondary air
fans to regulate proper combustion and maximize efficiency of the fuel. A typical FD fan arrangement
uses inlet and outlet dampers to control and maintain the required air pressure inside the system. These
fans have a wheel at the center that is hung on the shaft along with inlet boxes, silencer, filter and
rain hood.
A forced draft fan (FD fan) is a type of fan that is used to push air into a boiler or other
combustion chamber. It is located at the inlet of the boiler and creates a positive pressure in the
combustion chamber, which helps to ensure that the fuel burns properly . The working principle of a
forced draft fan is based on the Bernoulli principle, which states that the pressure of a fluid
decreases as its velocity increases. The fan blades rotate and impart momentum to the air, which causes
the air to accelerate. This acceleration of the air creates a lower pressure at the outlet of the fan,
which draws air in from the inlet. The amount of air that is pushed into the boiler by the FD fan is
determined by the fan’s capacity and the pressure differential between the inlet and outlet of the fan.
The FD fan is an essential component of any boiler system. It helps to ensure that the fuel burns
properly and that the boiler operates efficiently. Here are some of the benefits of using a forced draft
fan
- Improved combustion efficiency: The FD fan helps to ensure that the fuel burns completely, which results in improved combustion efficiency.
- Reduced emissions: The FD fan helps to reduce emissions by ensuring that the fuel burns completely.
- Increased boiler capacity: The FD fan can increase the capacity of the boiler by providing more air for combustion.
- Improved safety: The FD fan helps to improve safety by preventing the buildup of flammable gases in the boiler.
