The working principle of the ventilator is basically the same as that of the turbo compressor, except that the gas flow rate is low and the pressure changes little. Generally, there is no need to consider the change of the gas specific volume, that is, the gas is treated as an incompressible fluid.

The relationship between fan and fan: fan is the abbreviation for gas compression and gas conveying machinery in our country. Generally speaking, fans include fans, blowers, compressors and Roots blowers, but do not include displacement blowers and piston compressors. compressor. Ventilator is a product type of fan, but people usually call ventilator barrel as fan, which means that ventilator is another name for fan.

It is basically the same as a centrifugal pump, mainly composed of a volute-shaped casing and an impeller. The difference between the high-pressure centrifugal blower is that the centrifugal fan is a multi-blade impeller, and because of the large volume (small density) of the conveying fluid, the impeller diameter is generally larger and the blades are shorter.

The blade has several forms: straight, forward and backward. Straight blades are generally used for low-pressure fans; fans with forward-curved blades have a large air supply but low efficiency; the blades of high-efficiency fans are usually backward-curved blades. The gas passage section of the volute is rectangular and circular. Generally, the low and medium pressure fans are mostly rectangular.

Wear resistance and wear-resistant treatment of the fan: Because a large number of fans are used for ventilation and dust exhaust in factories, mines, tunnels, etc., the impeller and casing of the fan have different degrees of wear, which directly affects in some places. The production goes on smoothly, so the wear resistance of the fan has high requirements. Commonly used wear-resistant treatments include surfacing, spraying, spray welding, coating with polymer wear-resistant materials, etc., which can relatively extend the service life of the fan. In recent years, my country has introduced a useful wear-resistant treatment method from abroad, which is to post or inlay wear-resistant ceramics on the surface of the impeller or volute. Because wear-resistant ceramics have outstanding wear resistance, they can greatly improve the performance of the extension. Wear resistance. Moreover, the ventilators with wear-resistant ceramic sheets are convenient for protection, so they have been widely promoted and applied in related occupations in my country.