The backward curved fan impeller is mainly due to corrosion and stress corrosion directly caused by the corrosive gas contained in the fan's conveying medium. This is due to the difference in the conveying medium during the operation. The type of corrosion is also different.
The fan impeller bent backwards to a certain extent in order to prevent its corrosion and the occurrence of corrosion corrosion of the impeller, in the course of operation is usually an effective choice of its corrosion resistance stainless steel impeller material, painted on the impeller surface Plating or spray coating and improve impeller surface quality to solve corrosion wear problems.
The backward curved fan impeller has a low yield strength. During the operation, it is not suitable for manufacturing an impeller with a high rotation speed. In the process of operation, the general situation is applicable to general low-speed fan anti-corrosion impeller materials. In the case of a medium containing corrosive gases such as CO2 and smoke, Cr13 stainless steel is mainly used, but stress corrosion should be paid attention to, and a fan impeller with high corrosion resistance and high rotation speed is widely used for martensite precipitation stainless steel.
The surface of the backward curved fan impeller is sprayed with plasma spray to a certain degree. Nickel and nickel alloy spray coatings have good corrosion resistance to hydrogen sulfate, phosphoric acid, hydrogen cyanide, hydrofluoric acid, acetic acid, ferrous sulfate solution and dry gas, but to hydrochloric acid, nitric acid, potassium acetate, and sulfurous acid Other media, corrosion resistance is not good.