A centrifugal fan (suction fan) is a device used to move, drain and transfer air from one place to another. Suction fans are designed and manufactured in different designs and sizes with different capacities depending on the place of use.
The operational mechanism of the fan is such that the incoming air, parallel to the axis of the impeller, enters the fan housing and, with the rotating motion towards the wings, the air will move towards the tip and wings. With this movement, kinetic energy mixes with the airflow, and as the motion slows down, the air velocity increases before entering the path of static pressure discharge.
Air entry into the device in a centrifugal fan takes place along the axis of the rotational motion of the impeller. During this process, both kinetic energy and static pressure of the air increase. The incoming air into the fan, to exit from it, undergoes rotational movement under the influence of the centrifugal force. An important point about the operation of the centrifugal fan is that the air velocity and volume in these fans are constant, but the mass of air changes based on its density. In simpler terms, ambient air enters the centrifugal fan through the inlet, rotates 90 degrees in the impeller section, and then accelerates due to the centrifugal force. Ultimately, it flows over the fan wings and exits the fan housing.
In addition to ventilation and air transfer, centrifugal fans are commonly used for drawing air through heat exchangers. The airflow generated by the wings of these fans has the ability to cope with and overcome the resistance present in the air. Centrifugal fans use the kinetic energy created by the wings for the movement of the air flow. This allows the generated airflow to have the ability to move against the resistance caused by ducts, dampers, and other components. Furthermore, the displacement of the airflow by the centrifugal fan is done radially, and the direction of the airflow also changes.