Fan classification method

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


According to the direction of gas flow


Fan classification can be divided into centrifugal, axial, diagonal (mixed flow) and cross flow according to the direction of gas flow.


(1) Centrifugal fan. The airflow mainly flows in the radial direction after entering the impeller of the fan axially. These fans are made according to the principle of centrifugal action, and the products include centrifugal fans, centrifugal blowers and centrifugal compressors.


(2) Axial fan. The airflow enters the impeller of the fan axially, flowing approximately in the axial direction on the cylindrical surface. Such fans include axial flow fans, axial flow blowers and axial compressors.


(3) Rotary fan. The rotor chamber is rotated to change the volume of the chamber to operate. Common varieties are Roots blowers and rotary compressors.


The fan is divided into an axial flow fan, a centrifugal fan and a diagonal flow (mixed flow) fan according to the flow direction of the airflow after entering the impeller.


The fan is divided into a push-in type local fan (hereinafter referred to as a press-in fan) and an explosion-proof motor placed outside the flow channel or in the flow channel according to the purpose, and the explosion-proof motor is placed in the explosion-proof sealed cavity of the extracting type local fan (hereinafter referred to as the extracting fan) ).


The fan can also be divided into single-stage, two-stage or multi-stage pressure fans according to the form of pressure. For example, 4-72 is a single-stage pressurization, and a high-end fan is a multi-stage pressurized fan. cnc machining


Fans can be divided into: axial flow fans, mixed flow fans, roof fans, air conditioning fans, etc. according to the purpose.


The fan can be divided into a negative pressure fan, a low pressure fan, a medium pressure fan and a high pressure fan according to the pressure.


According to the outlet pressure (boost), it is divided into: fan (≤ 15,000 Pa), blower (1.5 to 350,000 Pa), compressor (≥ 350,000 Pa).


Sort by layer


There are many classification methods for ventilators, which can be roughly classified by the following types:


(1) According to the level of pressure generated, it can be divided into: volumetric type: reciprocating type and rotary type; turbine type: centrifugal type, axial flow type, mixed flow type and cross flow type, and jet type.


Fans generally refer to turbine type, ie, centrifugal, axial, mixed flow, cross flow, and the like.


Its main features are:


Centrifugal fan: higher pressure, but less air.


Axial fan: Higher air volume, but lower pressure.


Mixed flow fan: The air volume and pressure are between the centrifugal and axial fans.


Cross-flow fan: It has a high dynamic pressure and can get a flat air flow.


(2) According to the different materials used, it can be divided into: iron shell fan (common fan), fiberglass fan, plastic fan, aluminum fan, stainless steel fan, etc.


(3) According to the direction of gas flow, it can be divided into centrifugal type, axial flow type, diagonal flow type (mixed flow type) and cross flow type.


(4) The flow direction after entering the impeller according to the airflow can be divided into: axial flow fan, centrifugal fan and diagonal flow (mixed flow) fan.


(5) According to the application, it can be divided into: the push-in partial fan and the explosion-proof motor are placed outside the flow channel or in the flow channel, and the explosion-proof motor is placed in the explosion-proof sealed cavity.


(6) It can also be divided according to the form of pressurization: single-stage, double-stage or multi-stage pressurized fan.


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 indicator. The flow rate is also called the air volume, which is expressed by the volume of gas flowing through the fan per unit time. The pressure is also called the wind pressure. It refers to the pressure rise of the gas in the fan, and there are static pressure, dynamic pressure and full pressure. The power refers to the fan. Input power, ie shaft power. The ratio of the effective power of the fan to the shaft power is called efficiency. The total pressure efficiency of the fan can reach 90%.