| 摘要 |
PROBLEM TO BE SOLVED: To provide a Sirocco fan capable of achieving both of prevention of leak flow to a suction side of a fan rotor and prevention of degradation of fan performance.SOLUTION: A Sirocco fan 1 includes a fan rotor 3, a housing 2 and a backflow preventing plate 10. The backflow preventing plate 10 prevents air of an outer periphery of the fan rotor 3 from flowing back to a suction side of the fan rotor 3 through a clearance gap 21 between an end ring 17 disposed at an outer periphery of a blade 18 of the fan rotor 3, and an inner wall 20 of a housing body 2a. A length of the backflow preventing plate 10 is determined to a first length H1 which is a length equal to a length from the inner wall 20 of the housing body 2a to a far end 17a far from a suction opening 7 of the end ring 17 in a range excluding a prescribed range near a tongue portion 14 of the housing 2, and determined to a second length H2 longer than the first length H1 in the prescribed range near the tongue portion 14. |
