The working principle and core structure of centrifugal fans

A centrifugal fan is a fluid machine that achieves gas pressurization and transportation through centrifugal force. Its core principle is to convert mechanical energy into gas kinetic energy and then into pressure energy through the diffusion process. 1. Working principle: Gas enters the impeller axially, is accelerated by the blades, and then is flung out radially, forming a high-speed gas flow. In the volute diffuser, the gas flow velocity decreases, and the kinetic energy is converted into pressure energy and discharged through the outlet. 2. Core structure (1) Impeller: A key component that determines the performance of a fan. The shape of the blades (forward, backward, airfoil) directly affects efficiency and pressure characteristics. (2) Volute: It guides the airflow into the impeller evenly and reduces flow loss. Its helical design optimizes the pressure distribution. Collector: Ensures uniform airflow into the impeller inlet, reduces vortex losses, and enhances efficiency. (3) Classification and Selection: According to the rotation direction, they are divided into left-rotating and right-rotating fans. According to the pressure characteristics, they are classified as low-pressure, medium-pressure and high-pressure fans. The selection should take into account the air volume, pressure and working conditions.