A centrifugal blower is a mechanical device that uses input mechanical energy to increase gas pressure and discharge the gas; it is a type of driven fluid machinery.
Centrifugal fans operate on the principle of converting kinetic energy into potential energy. They utilize a high-speed rotating impeller to accelerate the gas, then decelerate and change the flow direction, converting kinetic energy into potential energy (pressure).
In a single-stage centrifugal fan, the gas enters the impeller axially, changes to a radial direction as it flows through the impeller, and then enters the diffuser.
In the diffuser, the gas changes its flow direction, causing deceleration. This deceleration converts kinetic energy into pressure energy. The pressure increase mainly occurs in the impeller, and secondarily in the diffusion process.
In a multi-stage centrifugal fan, a return channel is used to guide the airflow into the next impeller, generating even higher pressure.
