Method and apparatus for purifying a substance
CA 2203352 C · Owner: The Boc Group, Inc. · Inventors: Whitlock, Walter H.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A method and apparatus for purifying a substance in which the substance is rectified, within first and second distillation columns to produce a tower overhead in the second, distillation column, lean in both heavy and light impurities. The column bottoms produced, within the second distillation column is boiled to provide boil-up within the second distillation, column, thereby to initiate formation of an ascending vapor phase. A vapor stream is removed, from the second distillation and then fed into a bottom region of the first distillation column to, initiate formation of the ascending vapor phase therein. The vapor stream removed from the, second distillation column is formed from …
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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 April 22, 1997 and granted August 1, 2000. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended April 22, 2017.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by April 22, 2019.
- 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
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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.