Three stage membrane gas separation process and system
CA 2057253 A1 · Owner: Praxair Technology, Inc. · Inventors: Prasad, Ravi
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Abstract of the Disclosure Very high purity nitrogen is produced by air separation in a three stage membrane system in which the third stage permeate is recycled to the second stage and the membrane surface area is distributed between the stages to achieve high product recovery and process performance. Other gas separations such, as argon from oxygen, can likewise be achieved by thus using a three stage membrane system. D-16497
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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 December 9, 1991. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended December 9, 2011.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by December 9, 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.