| 摘要 |
A fan assembly provides for the compact and efficient movement of ambient air in areas requiring very low noise generation. In this new configuration, stationary turning vanes are placed at the air inlet followed by a sound cell, axial discharge fan and short axial (vaned) diffuser splitter sections. The stationary turning vanes induce a predetermined air rotation which provides a smooth rotating air flow into the rotating fan blades. The stationary turning vanes also block radiated noise from discharge through the air inlet and support the fan motor. The fan blades impart an opposite rotational momentum just sufficient to obtain an axial or nearly axial velocity discharge increment. The resulting axial fan discharge velocity is slowed in the short diffuser sections where diffuser vanes also block rear noise radiation. The slowed but pressurized air can now enter into an air distribution system with significantly reduced fan generated noise. Further noise reductions can be provided by inlet sound baffles, outlet acoustic diffuser splitters, and acoustic absorption materials in the inlet and short, rear axial diffuser short sections.
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