Production of ultra-high purity oxygen from cryogenic air separation plants
CA 2037255 C · Owner: Woodward, Donald Winston · Inventors: Prentice, Alan Lindsay; Cormier, Thomas Edward Sr.; Agrawal, Rakesh
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
The present invention relates to an improvement for the production of ultra-high purity oxygen from cryogenic air separation processes which produce nitrogen and/or commmerical purity oxygen products. In particular, the improvement comprises removing or producing an oxygen-containing but heavy comtaminants-lean (free) stream from one of the distillation columns of a single or multiple column cryogenic air separation facility and further stripping the removed or produced oxygen-containing stream in a fractionator to produce ultra-high purity oxygen (i.e. contaiminants concentration <10 vppm).
Read the whole patent
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 February 27, 1991 and granted April 13, 1993. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended February 27, 2011.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by February 27, 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.