Fans The energy required for air flow in mechanical ventilation systems is supplied by fans.

Commonly used fans are centrifugal axial flow two kinds:

① centrifugal fan, fan pressure head is high, low noise, including the use of wing-shaped blades of the backward curved fan is a low-noise high-efficiency fan.

② axial fan, in the impeller diameter, speed of the same case, the wind pressure than centrifugal low noise than centrifugal high, mainly used for small system resistance ventilation system; the main advantage is the small size, easy to install, can be installed directly on the wall pipe. 　　

The fans used in the ventilation system are divided into dust-proof fans, explosion-proof fans corrosion-proof fans according to the conveying medium. 　　

Air filter In order to ensure human health meet certain industrial production processes (such as the food industry, etc.) on the requirements of air cleanliness, the air sent into the room must be purified to varying degrees. In the air supply system commonly used air filters to remove dust particles in the air, according to the different filtration efficiency, air filters are divided into coarse, medium high efficiency three categories. Usually metal wire mesh, glass wire, foam, synthetic fibers filter paper as filter material.