Working Principle Of Centrifugal Blower

The working principle of centrifugal blower is similar to that of centrifugal fan, but the air compression process is usually carried out under the action of centrifugal force through several working impellers (or stages). The blower has a high-speed rotating rotor. The blades on the rotor drive the air to move at high speed. The centrifugal force makes the air flow into the fan outlet along the involute in the involute shaped shell. The high-speed air flow has a certain wind pressure. The new air enters and replenishes from the center of the casing.

The working principle of the single-stage high-speed centrifugal fan is: the prime mover drives the impeller to rotate at a high speed through the shaft, and the air flow enters the impeller at a high speed from the inlet axial direction, and then becomes the radial flow to be accelerated, and then enters the diffuser to change the flow direction and decelerate. This decelerating effect transforms the kinetic energy in the high-speed rotating air flow into the pressure energy (potential energy), so as to maintain a stable pressure at the fan outlet 。

Theoretically, the pressure flow characteristic curve of the centrifugal blower is a straight line, but due to the friction resistance and other losses inside the blower, the actual pressure flow characteristic curve drops gently with the increase of the flow, and the corresponding power flow curve of the centrifugal blower rises with the increase of the flow. When the fan operates at a constant speed, the operating point of the fan will move along the pressure flow characteristic curve. The operating point of the fan depends not only on its own performance, but also on the characteristics of the system. When the resistance of the pipe network increases, the performance curve of the pipe will become steeper. The basic principle of fan regulation is to get the required working condition by changing the performance curve of the fan itself or the characteristic curve of the external pipe network.