... heat recovery boiler,,,,and various boilers. 2.Structure Centrifugal fan mainly consist of impeller,case,air inlet,adjusting door, ... the clockwise and counterclockwise with 0°,45°,90°,135°,180°,225°4. Product Characteristics-Optional Parts: flexible coupling, variable ... product performance requirement and operation environment for the Centrifugal Fan of you need,so that we can customize optimal ...