Working principle of axial fan

When the impeller rotates, the gas enters the impeller axially from the inlet, is pushed by the impeller blade and makes the energy of the gas rise, and then flows into the guide vane. The guide vane changes the deflected air flow into axial flow, at the same time, the gas is introduced into the diffuser, and the kinetic energy of the gas is further converted into pressure energy, and finally into the working line.

Axial fan blades work in a manner similar to the wings of an aircraft. The latter, however, acts lift upward on the wing and supports the weight of the aircraft, while the axial fan holds the air in place and moves it.

The cross section of axial fan is generally the wing section. Blades can be fixed or rotated about their vertical axis. The Angle of the blade to the flow or the blade spacing can be unadjustable or adjustable. Changing blade Angle or spacing is one of the main advantages of axial flow fans. Small blade spacing angles produce lower flow rates, while increasing the spacing produces higher flow rates.

Advanced axial-flow fans can vary blade spacing (much like helicopter rotors) while the fan is running, thereby changing the flow rate accordingly. This is called a moving-vane adjustable (VP) axial flow fan.