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. 09, 2004
Filed:
Jun. 29, 2001
Hidayat Husain, Brampton, CA;
Henry Behmann, Puslinch, CA;
Pierre Côté, Dundas, CA;
Ian Pottinger, Ancaster, CA;
Ella Murphy, Hamilton, CA;
Zenon Environmental Inc., Oakville, CA;
Abstract
A filtration module has at least one nanofiltration or reverse osmosis membrane. The module is used to filter water and, when optionally fitted with at least one membrane adapted to selectively reject hardness causing salts, is used to remove hardness. Methods of cleaning using acidic solutions or gaseous carbon dioxide are discussed. Cleaning methods include the steps of periodically stopping permeation, injecting an acidic solution or gaseous carbon dioxide into the feed/retentate side of the module, holding the acidic solution or gaseous carbon dioxide in the module for a selected time, and flushing the acidic solution or gaseous carbon dioxide from the feed/retentate side of the module after expiration of the selected time.