The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Mar. 16, 1999
Filed:
Sep. 04, 1997
John F Foss, Okemos, MI (US);
Scott C Morris, Okemos, MI (US);
Board of Trustees operating Michigan State University, East Lansing, MI (US);
Abstract
A shroud for an axial blade fan provides a circumferential, axially directed flow of air between the fan blade tips and the shroud to improve fan efficiency. The shroud preferably includes a smaller, centrally disposed fan which is driven by an auxiliary motor, a circumferentially extending generally toroidal plenum, a plurality of hollow spokes providing fluid communication between the fan and the plenum, a circular throat which directs air toward the annulus between the shroud and the fan blade tips and a throat adjacent, circumferential Coanda surface which controls and guides air exiting the throat. Air is provided to the shroud plenum at a pressure of between about 2 and 10 inches water gauge (4 to 20 Torr). The narrowest region of the circular throat has a width of between about 1 mm to 5 mm. Adjustment of the air pressure and throat dimension allows accurate control of the velocity profile of the air flow through the annulus.