The working principle of axial fan is that when the impeller rotates, the gas enters the impeller from the air inlet and is pushed by the vanes on the impeller to increase the energy of the gas and then flow into the guide vanes. The guide vane converts the deflection gas into an axial flow, and at the same time, the gas is introduced into the expansion tube, and the kinetic energy of the gas is further converted into the pressure energy, and finally the working pipeline is introduced. Axial fan blades can generally rotate angle, most of the axial flow fan is equipped with a set of blades hydraulic adjustment device. When the fan is running, the installation angle of the blade can be adjusted by the vane hydraulic regulating device, and the angle of the blade is kept at a certain angle, so that the fan still has high efficiency when the working condition is changed.
The jet fan is usually suspended at the top of the tunnel or installed on the side wall of the tunnel. The tunnel itself is used as an air duct. When the fan works, it can produce higher thrust from the given energy. A part of the air in the tunnel is sucked in by the fan and is ejected by the fan at the high speed after the impeller works. Based on the impact transmission principle, the high velocity air passes the energy to another part of the tunnel air, causing it to flow back together so that the air in the tunnel is pushed toward one end of the tunnel and the fresh air is sucked in from the inlet. When the air speed is attenuated to a certain value, the next set of fans continues to drive air flow in the same way, eliminating the pollution of the air in the tunnel.