| 摘要 |
The extractor fan comprises a peripheral envelope 1, a hub 2 supported by a first flange 3 and comprising blades 4, an admission port 5 through a second flange 6, and an outlet 7 tangential to the envelope, and is characterised in that the geometry of at least one of the blades 4 is such that the distance between its end and the axis of the hub is less on the side nearest the flange 6 than on the side furthest from said flange. Advantageously, the ratio of the greatest distance from the axis to the least distance to the axis of said blade is between 1.1:1 and 2:1. Advantageously, the geometry of each blade 4 is such that the distance between its end and the axis of the hub is less on the side near the flange 6 than on the side furthest from said flange. <IMAGE> |
