Working principle of centrifugal fan

Centrifugal fan is a mechanical device that relies on input mechanical energy to increase gas pressure and discharge gas. It is a passive fluid machinery. Centrifugal fans are widely used for ventilation, dust removal, and cooling in factories, mines, tunnels, cooling towers, vehicles, ships, and buildings; Ventilation and induced draft for boilers and industrial furnaces; Cooling and ventilation in air conditioning equipment and household appliances; Drying and selection of grains; Wind tunnel wind source and inflation and propulsion of hovercraft.

Centrifugal fan is based on the principle of converting kinetic energy into potential energy, using a high-speed rotating impeller to accelerate gas, then decelerate and change the flow direction, converting kinetic energy into potential energy (pressure). In a single-stage centrifugal fan, gas enters the impeller from the axial direction, changes to the radial direction as it flows through the impeller, and then enters the diffuser. In a diffuser, the gas changes its flow direction causing deceleration, which converts kinetic energy into pressure energy. The increase in pressure mainly occurs in the impeller, followed by the expansion process. In multi-stage centrifugal fans, a reflux device is used to direct the airflow into the next impeller, generating higher pressure.