Abstract: A centrifugal blower apparatus suitable for industrial uses has a least a delivery outlet and at least two fluid inlets disposed on either side of a blower wheel suitable for being rotated by a drive system. Each inlet is associated with a respective control system for controlling the suction flow rte of fluid and is capable of establishing asymmetrical suction flow rates between the inlets. The inlets are fitted with control systems which differ in their mechanical structures and their characteristics concerning fineness of control.