Fans can be divided into the following categories according to different categories:

1. Fans can be divided into several types according to the material used, such as iron shell fans (ordinary fans), fiberglass fans, plastic fans, aluminum fans, stainless steel fans and so on

2. The classification of fans can be divided into centrifugal, axial, oblique (mixed) and cross-flow types according to the direction of gas flow.

3. According to the flow direction after the air enters the impeller, the fan is divided into: axial fan, centrifugal fan and oblique flow (mixed flow) fan.

4. According to the purpose of the fan, it is divided into the pressure type local fan (hereinafter referred to as the pressure type fan) and the flameproof motor is placed outside the flow passage or in the flow passage, and the flameproof motor is placed in the explosion-proof sealed cavity of the extraction type local fan (hereinafter referred to as the extraction type fan).

5. The fan can also be divided into single stage, double stage or multiple stage pressure fans according to the form of pressure. If 4-72 is a single-stage pressurization, the Roots fan is a multi-stage pressurization fan.

6. Fans can be divided into axial flow fans, mixed flow fans, Roots fans, roof fans, air conditioning fans, etc.

7. Fans can be divided into low pressure fans, medium pressure fans, high pressure fans according to pressure.

Fan performance parameters:

The performance parameters of the fan mainly include flow, pressure, power, efficiency and speed. In addition, the size of noise and vibration is also the main fan design index. Flow rate, also known as air volume, is expressed by the volume of gas flowing through the fan in a unit time; Pressure, also known as wind pressure, refers to the pressure increase value of gas in the fan, which is divided into static pressure, dynamic pressure and total pressure.