1. Fan body, muffler and support foot: the steel plate is automatically welded by numerical control and formed by mechanism. The surface is coated with coating technology to ensure that the jet fan has good strength and corrosion resistance.

2. Fan impeller: To meet the needs of tunnel ventilation, we can change the number of blades and change the Angle of fan blades. 

3. Muffler: The length of the muffler is related to the noise requirement, and its length is usually one time of the diameter of the fan. When the noise requirement is high, the length of the jet fan can be taken to be two times of the diameter of the jet fan. 

4. Supporting motor: The supporting motor of the fan is a fully enclosed squirrel cage, and the motor is equipped with a flange mounting plate. The leading cable of the motor can be connected to the junction box on the housing of the fan body. 

5. Reversible switching time of fan: Under emergency condition, the positive and negative switching time of jet fan is very important. SDS (R) fan has two switching methods: electronic and mechanical, which can be switched to the rated speed of fan in 30 seconds.