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:
Jun. 14, 1994
Filed:
Dec. 07, 1992
Applicant:
Inventors:
Kenneth S Freund, Hendersonville, TN (US);
Elizabeth L Frisbie, Old Hickory, TN (US);
Robert E Wojcik, Hendersonville, TN (US);
Assignee:
E. I. Du Pont de Nemours and Company, Wilmington, DE (US);
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
B01D / ;
U.S. Cl.
CPC ...
210741 ; 28104 ; 28167 ; 137 14 ; 210 90 ; 340606 ; 364510 ;
Abstract
A method to determine differential filter pressure caused by filter pluggage in a high pressure liquid system operated by a computer-operated control valve without the need for a pressure sensor coupled to the filter by corerlating the percent the control valve is open with the differential pressure of the filter. A signal is provided when the percentage of time the control valve is open exceeds a predetermined time and the filter is replaced in response to the signal.