| 摘要 |
A multi-blade fan (1) comprising: a first impeller (3a) provided inside a casing (2) having a suction inlet (6); and a second impeller (3b) provided in an internal space of the first impeller. The first impeller is a centrifugal fan having a plurality of first impeller blades (11). The second impeller is an axial flow-type fan having a plurality of second impeller blades (14) radially extending from a rotating axis (5). The second impeller blades have a smaller turning direction component in the slipstream in the outer circumference-side area of the internal space of the first impeller than the turning direction component of the slipstream in the inner circumference-side area of the internal space. |
