Working Principle of Cabinet-Type Centrifugal Exhaust Fans

Working Principle of Cabinet-Type Centrifugal Exhaust Fans

Cabinet-type centrifugal exhaust fans exhibit minimal pressure variation, typically eliminating the need to account for changes in gas specific volume. In other words, the gas is treated as an incompressible fluid. Operating on the principle of converting kinetic energy into potential energy, these fans accelerate gas through a high-speed rotating impeller. The gas is then decelerated and redirected, transforming kinetic energy into potential energy (pressure). In the cabinet-type centrifugal exhaust fan, gas enters the impeller axially, transitions to a radial flow direction as it passes through the impeller, and then enters the diffuser. Within the diffuser, the change in flow direction causes deceleration, converting kinetic energy into pressure energy. The primary pressure increase occurs in the impeller, followed by the continuation of the diffusion process. In cabinet-type centrifugal exhaust fans, a counterflow device directs air into the next impeller to generate higher pressure. The blades of cabinet-type centrifugal exhaust fans can be categorized into three types based on their outlet installation angle: backward-curved, forward-curved, and radial-curved. Backward-curved blades bend in the opposite direction of the impeller's rotation, with an outlet installation angle less than 90 degrees. Radial blades have a radial outlet direction, with an outlet installation angle reaching 90 degrees. Forward-curved blades bend in the same direction as the impeller's rotation, with an outlet installation angle exceeding 90 degrees.