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Expired Canadian patentCanada

Low pressure stripping process for the production of crude helium

CA 2034645 C · Owner: Gottier, Gerry Norman · Inventors: Gottier, Gerry Norman

CIPO record

Overview

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Its claims, description and drawings are in the Canadian Patents Database.

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Abstract From the Canadian patent

The present invention is a process for prefractionating a pressurized, helium-containing feed gas mixture (typically containing helium, natural gas and nitrogen) to produce a helium-enriched stream which comprises the following steps: (a) the pressurized helium-containing feed gas mixture is liquefied and subcooled by indirect heat exchange; (b) the liquefied, subcooled pressurized, helium-containing feed gas mixture is expanded whereby it is partially vaporized, thus producing a partially vaporized frationation feed stream; (c) the partially vaporized frationation feed stream is stripped in a cryogenic distillation column thereby producing as an overhead the, helium-enriched stream, 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 January 21, 1991 and granted April 19, 1994. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended January 21, 2011.
  • A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by January 21, 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.
FiledJanuary 21, 1991
GrantedApril 19, 1994
Term endedJanuary 21, 2011
Patent numberCA 2034645 C
Classification (IPC)F25J3/02 +1 more

Timeline

Timeline From CIPO dates

1992199419961998200020022004200620082010Application filedJan 21, 1991Patent grantedApril 19, 1994Term endedJan 21, 2011

Sources & verification

Everything on this page comes from the CIPO record linked above. Contains information licensed under the Open Government Licence – Canada.