Continuous backwash filter and method of operation
CA 2068778 A1 · Owner: Baker Hughes Incorporated · Inventors: Johnson, Bruce R.; Kubosumi, David K.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A particulate media filter employing a continuous media backwash, designed to promote mass or plug flow of the filter media within a filtration vessel and to eliminate areas of stationary media particles. The filter vessel contains a filter bed moving downwardly countercurrent to, an upwardly-moving solids-contaminated influent or feed stream. The contaminated liquid is cleaned by its passage through the filter bed, and is removed as filtrate from a location in the vessel above the top of the filter bed. The downwardly-moving filter bed media becomes progressively more contaminated, and is removed from the filtration stream near the bottom of the filter vessel for cleaning and recycling …
Read the whole patent
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
- Filed May 15, 1992. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended May 15, 2012.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by May 15, 2014.
- 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.