Air separation
CA 2004369 A1 · Owner: Owen, Robert · Inventors: Oakey, John D.; Owen, Robert; Kamrath, David J.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
In order to provide 'ultra high purity' nitrogen having diminished concentrations of light and heavy impurities in comparison with nitrogen produced by conventional cryogenic air separation the nitrogen product from, a conventional cryogenic air separation column is introduced into the bottom of a liquid-vapour contract column 2 fitted with a condenser 8 to provide reflux. A liquid nitrogen stream having a reduced concentration of heavy impurities is withdrawn from the column 2 through an outlet 22 situated at a level a few trays below the top tray in the column 2. The liquid nitrogen is then subjected to two stages of flash separation. In the first stage the liquid is passed through valve …
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 December 1, 1989. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended December 1, 2009.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by December 1, 2011.
- 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.