Based on the direction of gas flow, corrosion-resistant fans are mainly classified into centrifugal corrosion-resistant fans and axial flow corrosion-resistant fans.
1. Centrifugal Corrosion-Resistant Fans When a centrifugal corrosion-resistant fan is working, the motor drives the impeller to rotate within a volute casing. Air is drawn in through the intake port from the center of the impeller. Due to the dynamic action of the blades on the gas, the gas pressure and velocity are increased, and under the action of centrifugal force, the gas is thrown along the impeller passage towards the casing and discharged from the exhaust port.
Centrifugal corrosion-resistant fans mainly consist of an impeller and a casing. In small fans, the impeller is directly mounted on the motor. Medium and large centrifugal corrosion-resistant fans are connected to the motor via a coupling or pulley. Centrifugal corrosion-resistant fans generally have single-sided air intake and use a single-stage impeller; those with large flow rates can have double-sided air intake, using two back-to-back impellers, also known as double-suction centrifugal corrosion-resistant fans.
2. Axial Flow Corrosion-Resistant Fans
When operating, axial flow corrosion-resistant fans are driven by a motor to rotate an impeller within a cylindrical casing. Gas enters from the collector, gains energy through the impeller, increasing its pressure and velocity, and is then discharged axially. Axial flow fans are available in vertical, horizontal, and inclined configurations. Small impellers have a diameter of only about 100 mm, while large ones can reach over 20 mm.
Small low-pressure axial flow corrosion-resistant fans consist of an impeller, casing, and collector, and are typically installed on building walls. Large high-pressure axial flow corrosion-resistant fans consist of a collector, impeller, streamlined body, casing, diffuser, and transmission components. Blades are evenly distributed on the hub, typically ranging from 2 to 24. More blades result in higher air pressure; the blade installation angle is generally 10° to 45°, with a larger angle resulting in greater airflow and pressure.
