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.

Date of Patent:
Feb. 13, 1979

Filed:

Sep. 12, 1977
Applicant:
Inventor:

Robert L Alldredge, Denver, CO (US);

Assignee:

Other;

Attorney:
Primary Examiner:
Int. Cl.
CPC ...
B01D / ;
U.S. Cl.
CPC ...
210279 ; 210290 ; 220 / ;
Abstract

An upwash, upflow, graded sand filter has a reusable imperforate diaphragm on the top of the graded filter media and an inlet for pressurized fluid above the diaphragm for inflating the diaphragm against the media during filter stage. The filter housing is flared upwardly and outwardly at selected portions to reduce the velocity of upflowing liquid during wash stage for improved grading of the filter media. A natural foraminous layer may be self-grading at the top of the filter media, allowing a circumferential outlet for filtrate. A layer of fine, dense filter media may also be used to increase the size range of media particles in the filter. Special diaphragms may be composed of individual leaflets that float above a dirty-liquid outlet during wash stage, but that sink due to a change in density when the filter is pressurized for filter stage.


Find Patent Forward Citations

Alldredge, Robert. (1979). Filter (U.S. Patent No. 4139473). U.S. Patent and Trademark Office. https://idiyas.com/patent/badge/4139473

Data source: USPTO (United States Patent and Trademark Office) public patent records. Weekly synchronization. How IDiyas builds this profile

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