Filtering method and apparatus
CA 2055562 A1 · Owner: Process Developments Limited · Inventors: Kalman, Peter G.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Filtering apparatus includes two or more passages (2) acting in parallel, each having an extended filter (12) which passes through inlet and outlet ports (48 49), flowable preferably sealed by solidified plugs of the flowable substance such as a polymer being filtered. The flow of such substance to one passage can be terminated so as to permit filter advance under conditions of zero pressure drop, whilst flow through the other passage continues. Filter advance can be assisted by extrusion of a sealing plug in the outlet port under the pressure of such substance from the other passage which is still filtering. In additional or alternative mode, flow into a passage is terminated and a …
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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
- Filed November 14, 1991. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended November 14, 2011.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by November 14, 2013.
- 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.