MULTIBLADE CENTRIFUGAL FAN

摘要

In a multiblade centrifugal fan (1) comprising a centrifugal fan (3) having a hub (5) rotary driven by a motor (2), and a large number of curved rectangular planar blades (6) arranged at a predetermined interval in the circumferential direction on the outer circumferential part of the hub (5) to form a tubular cage to which the front side of the hub (5) opens, and a scroll casing (4) having an air inlet (4a) and an air outlet (4b) and containing the centrifugal fan (3) to oppose the air inlet (4a), the blade length B<SUB>2</SUB> from the rear end of the blade (6) to the forward end of the blade outer edge (6b) is set shorter than the blade length B<SUB>1</SUB> to the forward end of the blade inner edge (6a), and the bellmouth (4x) of the air inlet (4a) is formed such that the distance from the forward end of the blade inner edge (6a) to the inner wall of the scroll casing (4) becomes shortest at the inner end P of the bellmouth (4x).