Views: 0 Author: Site Editor Publish Time: 2022-03-25 Origin: Site
Fans can be divided into several categories according to the materials used, such as iron shell fans (ordinary fans), glass fiber reinforced plastic fans, plastic fans, aluminum fans, stainless steel fans and so on.
Fans can be classified into centrifugal, axial, oblique (mixed) and cross-flow types according to the direction of gas flow.
1. Centrifugal fan. After entering the impeller of the fan axially, the airflow mainly flows in the radial direction. This type of fan is made according to the principle of centrifugal action, and the products include centrifugal fans, centrifugal blowers and centrifugal compressors.
2. Axial flow fan. The airflow enters axially into the impeller of the fan and flows approximately axially on a cylindrical surface. Such fans include axial fans, axial blowers, and axial compressors.
3. Rotary fan. Use the rotor to rotate to change the volume of the air chamber to work. Common varieties are Roots blower, rotary compressor.
Fans are divided into axial flow fans, centrifugal fans and oblique flow (mixed flow) fans according to the flow direction of the airflow after entering the impeller.
Fans are divided into push-in local fans (hereinafter referred to as push-in fans) and flame-proof motors placed outside the flow channel or in the flow channels. ).
The fan can also be divided into single-stage, double-stage or multi-stage pressurized fan according to the form of pressurization. For example, 4-72 is a single-stage pressurized fan, and a high-end fan is a multi-stage pressurized fan.
Fans can be divided into: axial flow fans, mixed flow fans, roof fans, air conditioning fans, etc.
According to the pressure, fans can be divided into negative pressure fans, low pressure fans, medium pressure fans, and high pressure fans.
According to the outlet pressure (boost), it is divided into: ventilator (≤15,000 Pa), blower (15,000-350,000 Pa), and compressor (≥350,000 Pa).
There are many classification methods for ventilators, which can be roughly classified according to the following layers:
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, mixed flow and cross flow, jet type.
The fan generally refers to the turbine type, namely centrifugal, axial flow, mixed flow, cross flow and other forms.
Its main features are:
Centrifugal fans: higher pressure, but less air volume.
Axial fans: higher air volume but lower pressure.
Mixed flow fan: The air volume and pressure are between centrifugal and axial flow fans.
Cross-flow fan: It has a high dynamic pressure and can get a flat airflow.
2. According to the different materials used, it can be divided into: iron shell fan (ordinary fan), glass fiber reinforced plastic fan, plastic fan, aluminum fan, stainless steel fan, etc.
3. According to the direction of gas flow, it can be divided into centrifugal, axial flow, oblique flow (mixed flow) and cross flow.
4. According to the flow direction of the airflow after entering the impeller, it can be divided into: axial flow fan, centrifugal fan and oblique flow (mixed flow) fan.
5. According to the purpose, it can be divided into: push-in local fan and flameproof motor are placed outside the flow channel or in the flow channel, and the flameproof motor is placed in the extraction-type local fan in the explosion-proof sealed cavity.
6. According to the form of pressurization, it can also be divided into: single-stage, double-stage or multi-stage pressurized fan.
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 is also called air volume, which is expressed by the volume of gas flowing through the fan per unit time; pressure is also called wind pressure, which refers to the pressure rise of the gas in the fan, and can be divided into static pressure, dynamic pressure and total pressure; power refers to the fan The input power is the shaft power. The ratio of the effective power of the fan to the shaft power is called efficiency. The full pressure efficiency of the fan can reach 90%.
