Centrifugal Ventilation Fans Composition and Principle

- Dec 23, 2017-

On the whole, in fact, the composition of centrifugal ventilation fans equipment is relatively simple, the main components include impeller, chassis, coupling and shaft and so on. Among them, the impeller is the main work component for generating wind pressure and transferring energy. The centrifugal ventilation fans casing is mainly used for introducing and exhausting gas, and at the same time, some kinetic energy of the gas can be changed into pressure energy.


The coupling is mainly to complete the centrifugal ventilation fans internal connection of the main components. When the centrifugal fan is running, the gas between the various blades will be subjected to centrifugal force, so as to obtain a certain kinetic energy. When it is discharged from the periphery of the impeller, it is guided by the volute casing and flows toward the outlet of the fan, so that a negative pressure is formed at the center of the impeller. As a result, the external gas source can be continuously replenished, and the gas discharge process has been completed.


In simple terms, in fact, centrifugal fan in normal operation, the first role of the shaft through the motor power to the fan impeller. At the same time, the impeller transfers the energy to the air during the rotation, and under the action of centrifugal force, the air will diffuse along the blades of the fan impeller. In general, the larger the impeller, the greater the air's ability to receive.


This means that the greater the wind pressure obtained by the centrifugal fan, the smaller the size of the impeller, the lower the air pressure. The device usually belongs to the single-side intake, with a single-stage impeller. Large flow can be bilateral intake, with two back to back impeller, also called double suction fan.


It should be noted that, for the centrifugal ventilation fans, the impeller is a very crucial part. Therefore, the geometry of the impeller itself, the size, the number of leaves and manufacturing accuracy will directly affect the performance of the machine. Only after the impeller is statically or dynamically calibrated, can the centrifugal fan ensure a smooth rotation.