MULTI-VANE CENTRIFUGAL FAN AND AIR CONDITIONING FACILITY USING SAME

摘要

In a multi-blade centrifugal fan including an impeller (7) rotatably disposed in a casing and composed of a disc-shaped hub (8), a plurality of blades (9), and an annular shroud (10), the blades (9) are curved in a concave shape on a pressure side in a cross-section perpendicular to a rotating shaft of the impeller (7) and have a curved shape that is backward-swept near a leading edge (9C) thereof and that is forward-swept near a trailing edge (9D) thereof, the inner diameter of the cascade of blades (9) increases gradually from the hub (8) toward the shroud (10), and the diameter of a maximum-curvature position (9B) where the curvature of the curved shape is maximized increases gradually from the hub (8) toward the shroud (10).