Process and apparatus for cleaning particulate filters
CA 1091164 A · Owner: Sterling Drug Inc. · Inventors: Ross, David S.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Method and corresponding apparatus for removing oil and grease film from the granular surfaces of particulate media for filtering waste water in waste water filter wherein the filter bed containing said particulate media is provided with an underdrain cavity, which comprises forcing a predetermined quantity of a chemical cleaning agent into the underdrain cavity, forcing a backwashing liquid into the underdrain cavity and up through the filter bed so as substantially to inundate the bed, stopping the flow of backwashing liquid for a predetermined period, hydraulically disturbing said bed of particulate material in contact with said liquid cleaning solution by forcing additional backwashing …
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Listed from its CIPO record in Patent Yard's archive of Canadian patents past their term. Its claims, description and drawings are in the CIPO record and on Google Patents, and the Claude kit works from them.
Why it's free to use
- Granted December 9, 1980. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended December 9, 1997.
- We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
Timeline
Timeline From CIPO dates
Sources & verification
Official CIPO records
Everything on this page comes from the CIPO record linked above. Contains information licensed under the Open Government Licence – Canada.