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. 10, 1981
Filed:
Mar. 22, 1979
William R Phillips, Jr, Denver County, CO (US);
Ronald D Tate, Denver County, CO (US);
Dravo Corporation, Pittsburgh, PA (US);
Abstract
Two series connected fans driving a variable throat venturi are controlled by a single flow control feedback loop yet are decoupled by modifying the common flow control signal by separate but complementary piecewise linear characterizations of the flow characteristics of each fan. Both fans are protected from surging and overcurrent by their own differential pressure and current limiting control loops respectively which automatically assume control when conditions warrant. The venturi is controlled by its own differential pressure control loop which is operated to generate the maximum differential pressure allowed by the flow rate without surging the fans.