"Inflatable Air Blower" formed of rotating stall: fan impeller structure, dimensions are in accordance with the rated air flow (CFM) designed, when the normal air flow (CFM) working gas into the direction of the air flow impeller blade inlet Mounting Angle consistent, smooth gas may enter the impeller when entering "Inflatable Air Blower" gas flow impeller is less than the rated flow, the radial velocity of the gas into the impeller is reduced, the gas flow into the direction of the relative angular velocity of the impeller is reduced, Thus the blade inlet angle is not consistent with the installation. "Inflatable Air Blower" in the processing and leaves the installation process, the blade due to various reasons can not have exactly the same shape and the mounting angle. When changes in the operating conditions deviate leaving the flow direction in each blade angle of attack can not be imported identical.