Exhaust fan exhaust centrifugal fan

Role:

The working mechanism of centrifugal fan is basically the same as that of turbo compressor, because the gas flow rate is low and the pressure changes little, so it is generally unnecessary to consider the change of gas specific volume, that is, the gas is treated as incompressible fluid.

Centrifugal fans can be made into right-handed and left-handed types. From the motor side: the impeller rotates clockwise, which is called right rotating fan; The impeller rotates counterclockwise, which is called left rotating fan

Construction:

Centrifugal fan is composed of casing, main shaft, impeller, bearing transmission mechanism and motor. Enclosure: It is made of steel plate, which is firm and reliable. It can be divided into integral type and half-open type, and the half-open type is convenient for maintenance. Impeller: It consists of blades, curved front plate and flat rear plate. Rotor: static balance and dynamic balance should be done to ensure smooth rotation and good performance. Transmission part: it consists of main shaft, bearing box, rolling bearing and belt pulley (or coupling).

Centrifugal fan is essentially a variable flow and constant pressure device. When the rotating speed is constant, the theoretical curve of pressure-flow of centrifugal fan should be a straight line. The actual characteristic curve is curved due to internal loss. The pressure generated in centrifugal fan is greatly affected by the change of inlet air temperature or density. For a given intake air volume, the pressure generated when the intake air temperature is low. For a given pressure and flow characteristic curve, there is a power and flow characteristic curve. When the blower runs at a constant speed, for a given flow rate, the required power increases with the decrease of intake air temperature.

Centrifugal fans are widely used for ventilation, dust removal and cooling in factories, mines, tunnels, cooling towers, vehicles, ships and buildings.

Ventilation and induced draft of boilers and industrial furnaces;

Cooling and ventilation in air conditioning equipment and household appliances;

Drying and selecting grain;

Wind source in wind tunnel, inflation and propulsion of hovercraft, etc.