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Expired Canadian patentCanada

Ultra pure liquid oxygen cycle

CA 1280358 C · Owner: Cilen, Nellie · Inventors: Cilen, Nellie; Mcguinness, Roger M.

CIPO record

Overview

Drawings and full text

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 the production of 99.999+% pure oxygen. The process comprises a cryogenic distillation system which removes impurities from oxygen. The process can be operated independently of an air separation unit by using an external source to provide reboil and condensing duties for the distillation column.

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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 February 19, 1991. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended February 19, 2008.
  • We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
FiledMay 8, 1989
GrantedFebruary 19, 1991
Term endedFebruary 19, 2008
Patent numberCA 1280358 C
Classification (IPC)F25J3/04 +1 more

Timeline

Timeline From CIPO dates

1990199219941996199820002002200420062008Application filedMay 8, 1989Patent grantedFeb 19, 1991Term endedFeb 19, 2008

Sources & verification

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