MULTI-BLADE CENTRIFUGAL FAN AND AIR CONDITIONER USING SAME

摘要

Provided are a multi-blade centrifugal fan wherein interference of swirl flow formed in expansion sections expanded in the direction of a rotating shaft of upper and lower end faces of a scroll casing and air flow discharged from an impeller is suppressed and noise reduction and high performance can be achieved, and an air conditioner using the same. There is disclosed a multi-blade centrifugal fan (1) having an impeller (16) rotatably set around a rotating shaft (15) in a scroll casing (2) with the flow path cross sectional area gradually increased in the rotation direction, wherein the scroll casing (2) has at least one of upper and lower end faces (9, 12) which is an inclined end face (12A) so expanded in the direction of the rotating shaft (15) that the expanded height is gradually increased from a scroll start side of the scroll casing (2) toward the rotation direction, and a step portion (23) comprising at least one step along the rotation direction is provided between the inclined end face (12A) and an inner peripheral side face (22A) of an expansion section (22).