Batch cooking with black liquor pretreatment
CA 2278181 A1 · Owner: Kettunen, Auvo · Inventors: Henricson, Kaj; Ramark, Hannu; Kettunen, Auvo
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 a method and apparatus for cooking pulp. Especially, preferably, the invention relates to an alkaline batch cooking process, i.e. to a so-called Batch process. In the method and apparatus for cooking pulp by means of an alkaline batch process in accordance with the invention, the wood matter is supplied to the digester (10); the wood matter is pre-treated in the digester with a first liquor; the first liquor is displaced by a second liquor; said displaced first liquor is led to a further treatment; the wood matter is treated with the second liquor; and the cooked pulp is removed from the digester. The invention is characterized in that said second …
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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 January 22, 1998. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended January 22, 2018.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by January 22, 2020.
- 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.