Low noise fan
First Claim
1. A low noise axial flow fan assembly for suppling fluid to a fluid distribution system which comprises:
- an external duct having fluid inlet and discharge means;
turning vane means within said duct adjacent to said inlet means for imparting a swirl velocity component to said fluid discharing from said turning vanes;
fan means spaced from said turning vane means for drawing said fluid through said inlet means and exiting said fluid out said exit means, said fan means having rotating blades configured to redirect said swirl velocity component of said fluid in a substantially axial direction through said discharge means;
an axial vaned discharge means comprising short vaned diffuser sections position within said duct intermediate said fan means and said fluid discharge means;
acoustical means, positioned intermediate the discharge of said turning vane means and a place prior to said short vaned diffuser section for attenuating sound produced by fluid exiting said vane means and said rotating fan blades;
means to support and rotate said fan wherein said inlet turning vanes, when projected on a plane perpendicular to the axis of said fan, substantially covers the fluid flow area projection thereby substantially preventing sound from discharging from the space between said turning vane means and fan through said turning vane means, wherein said external duct inlet and diffuser sections consist of modular detachable segments, one segment enclosing said turning vanes, a second segment forming a sound cell, closely enclosing said fan tips and a third segment enclosing said short diffuser.
0 Assignments
0 Petitions
Accused Products
Abstract
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.
122 Citations
16 Claims
-
1. A low noise axial flow fan assembly for suppling fluid to a fluid distribution system which comprises:
-
an external duct having fluid inlet and discharge means; turning vane means within said duct adjacent to said inlet means for imparting a swirl velocity component to said fluid discharing from said turning vanes; fan means spaced from said turning vane means for drawing said fluid through said inlet means and exiting said fluid out said exit means, said fan means having rotating blades configured to redirect said swirl velocity component of said fluid in a substantially axial direction through said discharge means;
an axial vaned discharge means comprising short vaned diffuser sections position within said duct intermediate said fan means and said fluid discharge means;acoustical means, positioned intermediate the discharge of said turning vane means and a place prior to said short vaned diffuser section for attenuating sound produced by fluid exiting said vane means and said rotating fan blades; means to support and rotate said fan wherein said inlet turning vanes, when projected on a plane perpendicular to the axis of said fan, substantially covers the fluid flow area projection thereby substantially preventing sound from discharging from the space between said turning vane means and fan through said turning vane means, wherein said external duct inlet and diffuser sections consist of modular detachable segments, one segment enclosing said turning vanes, a second segment forming a sound cell, closely enclosing said fan tips and a third segment enclosing said short diffuser. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16)
-
Specification