Method of bleaching or delignification of cellulose pulp with oxygen
CA 1300322 C · Owner: Hornsey, Derek · Inventors: Perkins, Arthur S.; Lee, Robert; Hornsey, Derek
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A continuous method of bleaching or delignification of cellulose pulp with oxygen. The pulp in the form of an aqueous slurry is passed through a diffusing and mixing conduit at a velocity at which it behaves as a turbulent liquid and then through a holding vessel at a velocity at which it assumes plug flow. An oxygen-steam mixture is diffused through a microporous wall interfacing with the slurry in the conduit to form a mass of small oxygen bubbles from which the steam condenses imparting heat to the slurry and leaving the oxygen in the form of smaller bubbles dispersed throughout the slurry presenting a total, surface area markedly greater than bubbles resulting from the injection of …
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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 May 12, 1992. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended May 12, 2009.
- 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.