Function, protection and structure of boiler forced draft blower

- Jan 23, 2019-

The boiler forced draft blower provides secondary air. After passing through the air preheater, a part of the blower provides peripheral air, sandwich wind, etc., which has an effect on the flame at the burner and can cool the burner. The other part provides the amount of oxygen required for boiler combustion. There is also a provision for SOFA and COFA winds to adjust combustion use.


Under normal circumstances, the working temperature, corrosion and friction of the forced blower of the boiler are not large. At this time, it is only necessary to use the normal temperature sealing paint for protection, which can play an excellent role in rust prevention and drag reduction. However, many power plants now increase the thermal efficiency in order to save energy. The secondary air is supplied by mixing the flue gas of the boiler with the cold air. At this time, the temperature, corrosion and wear of the forced blower of the boiler are increased. Wear-resistant anti-corrosion coatings, etc. to protect.


The boiler forced draft blower is mainly composed of an air box, a casing, a bearing box, a rotor and the like. Its air box is made of steel plate, and its function is to make the medium turn at the entrance of the fan to reduce the loss of resistance, the air box of the air box. One end is connected to the outer casing of the fan through an expansion joint, and the other end is connected to the air duct.


The boiler forced draft blower casing is made into a horizontal split structure, the impeller and the bearing are located in the fan casing, and the outer casing of the fan supports the impeller. The rotor is supported by bearings in the bearing housing, and there are three rows of bearings in the bearing housing, which respectively play different roles.