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. 29, 2004
Filed:
Mar. 20, 2002
Peter H. Knappe, Santa Barbara, CA (US);
Seymour S. Kremen, Coronado, CA (US);
Hans A. Thomason, Lloret de Mar, ES;
Matthew B. Tanner, Ventura, CA (US);
TriSep Corporation, Goleta, CA (US);
Abstract
A spiral wound membrane filtration element capable of being back-flushed has a permeate carrier sheet; a permeable membrane filter layer sheet adhesively bonded to the permeate carrier sheet, and a feed spacer sheet. The membrane filter layer sheet folds over the feed spacer so that the feed spacer sheet is sandwiched between two layers of the membrane filter layer sheet. The sandwich positions over the permeate carrier sheet such that the adhesive seal bonds the membrane filter layer sheet to the permeate carrier sheet. The permeate carrier sheet, the membrane filter layer sheet, and the feed spacer sheet are wrapped around a permeate collection tube. The filter element is cleaned by pressurizing the feed solution or by creating a vacuum in the permeate collection tube, and periodically introducing a pressurized back flush fluid into the permeate collection tube of the filtration element to back-flush the membrane, under a pressure and for a time sufficient to dislodge a substantial portion of the retained solids on the surface of the membrane. The membrane filter layer sheet is made by placing a casting a casting solution of a certain thickness on a passing support substrate having a Frazier air permeability between 0.1 and 10 cfm/ft . The thickness of the casting solution on the support substrate is controlled through use of a mechanical device for dispersing the casting solution. The substrate with the casting solution is then immersed into a quench bath, to allow removal of casting solution, after an air quench time that allows formation of a thin membrane film on the support substrate.