| 摘要 |
PURPOSE:To reduce a pressure loss and to suppress the generation of noise by perpendicularly crossing a centrifugal fan with a diffusing direction of a diffused wind at its rotary shaft axis and so disposing it that its diffusing side is opposed to an air outlet. CONSTITUTION:An exhaust centrifugal fan 10 and an air supply centrifugal fan 11 are perpendicularly crossed at rotary shaft axes L with diffusing directions X, Y of diffused winds. Diffusing sides of the fans 10, 11 are so disposed as to be opposed to air outlets 7, 6. Accordingly, diffused winds in centrifugal directions of the fans 10, 11 are not bent perpendicularly as prior art, and hence pressure losses can be decreased. In order to supplement the losses, it is not necessary to increase, for example, numbers of revolutions of the fans 10, 11. As a result, generation of noise can be suppressed. Particularly, since the outlets 7, 6 of the centrifugal directions of the fans 10, 11 are opened within a duct joint 15, a silencing effect is provided to further reduce the generation of the noise. |
