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Expired Canadian patentCanada

Cryogenic air separation system with dual temperature feed turboexpansion

CA 2045740 C · Owner: Union Carbide Industrial Gases Technology Corp. · Inventors: Dray, James Robert; Parsnick, David Ross

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

A cryogenic air separation system comprising at least two columns wherein two portions of the feed air are turboexpanded at two different temperature levels to generate refrigeration, a third portion is condensed against vaporizing product from the air separation plant, and all three portions are fed into the same column to undergo separation.

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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 June 26, 1991 and granted May 17, 1994. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended June 26, 2011.
  • A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by June 26, 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.
FiledJune 26, 1991
GrantedMay 17, 1994
Term endedJune 26, 2011
Patent numberCA 2045740 C
Classification (IPC)F25J3/04

Timeline

Timeline From CIPO dates

1992199419961998200020022004200620082010Application filedJune 26, 1991Patent grantedMay 17, 1994Term endedJune 26, 2011

Sources & verification

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