The working principle of a centrifugal blower is similar to that of a centrifugal fan, except that the air compression process is usually carried out under the action of centrifugal force through several working impellers (or several stages). The blower has a high-speed rotating rotor. The blades on the rotor drive the air to move at a high speed. The centrifugal force causes the air to flow in the involute-shaped casing along the involute to the fan outlet. The high-speed airflow has a certain wind pressure. Fresh air enters and supplements from the center of the cabinet.
The working principle of a single-stage high-speed centrifugal fan is: the prime mover drives the impeller to rotate at high speed through the shaft, and the airflow enters the high-speed rotating impeller from the inlet axis and becomes a radial flow which is accelerated, and then enters the diffuser cavity, changing the flow direction and decelerating. This deceleration effect converts the kinetic energy in the high-speed rotating airflow into pressure energy (potential energy), so that the outlet of the fan maintains a stable pressure.
Theoretically speaking, the pressure-flow characteristic curve of a centrifugal blower is a straight line, but due to losses such as frictional resistance inside the fan, the actual pressure and flow characteristic curve decreases gently with the increase of the flow rate, and the corresponding centrifugal fan power- The flow curve rises as the flow rate increases. When the fan is running at a constant speed, the operating point of the fan will move along the pressure-flow characteristic curve. The operating point of the fan during operation depends not only on its own performance, but also on the characteristics of the system. When the resistance of the pipe network increases, the pipeline performance curve will become steeper. The basic principle of fan adjustment is to obtain the required working conditions by changing the performance curve of the fan itself or the characteristic curve of the external pipe network.