When the impeller rotates, the gas enters the impeller axially from the air inlet, is pushed by the blades on the impeller, and the energy of the gas rises, and then flows into the vane. The vanes change the deflected airflow into an axial flow, and at the same time introduce the gas into the diffuser tube, further convert the gas kinetic energy into pressure energy, and finally introduce the working line.
Axial fan blades work in a similar manner to the wing of an aircraft. However, the latter applies lift to the wing and supports the weight of the aircraft, while the axial fan fixes the position and moves the air.
The cross section of an axial fan is generally a wing profile. The blade can be fixed in position or rotated about its longitudinal axis. The angle of the blade to the airflow or the blade pitch may not be adjustable or adjustable. Changing the blade angle or spacing is one of the main advantages of axial fans. The small blade pitch angle produces a lower flow rate, while the increased spacing produces a higher flow rate.
Advanced axial fans can change the blade pitch while the fan is running (this is quite similar to a helicopter rotor), which in turn changes the flow. This is called a variable blade adjustable (VP) axial flow fan.