Enhancements in pulping with dissolved solids control
CA 2197312 C · Owner: Laakso, Richard O. · Inventors: Luhrmann, Carl L.; Marcoccia, Bruno S.; Prough, J. Robert
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
The sulfide ion concentration and sulfidity of kraft cooking liquor during kraft cooking of cellulose pulp is selectively increased. After treatment in a first, treatment zone in which impregnation or kraft cooking takes place using a kraft, cooking liquor having a first sulfide ion concentration and sulfidity black , liquor, is extracted from the material liquid is withdrawn from the material and dilution, liquid is added to the withdrawn liquid and the withdrawn liquid with dilution liquid is reintroduced. In a second treatment zone after the first zone a second, kraft cooking liquor is introduced having a second sulfide ion concentration and, sulfidity greater than the first sulfide …
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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 1, 1995 and granted September 10, 2002. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended June 1, 2015.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by June 1, 2017.
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Everything on this page comes from the CIPO record linked above. Contains information licensed under the Open Government Licence – Canada.