Processes and systems for handling knots in a chemical pulping process
CA 2413386 A1 · Owner: Andritz Inc. · Inventors: Stromberg, C. Bertil
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Processes and systems are provided for cooking wood chips containing knots in a digester to produce a chemical pulp. Specifically a low, pressure slurry of comminuted cellulosic fibrous material is formed in a vessel operating at essentially atmospheric pressure by mixing therein a liquid and the comminuted cellulosic fibrous material. The low pressure slurry is thereafter supplied to a low pressure inlet of a high pressure transfer device while liquid is removed from the slurry through a low pressure outlet thereof. A high pressure liquid is supplied to the transfer device (e.g. via a slurry pump) so as to form a high pressure slurry of the comminuted cellulosic material which is then …
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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 December 3, 2002. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended December 3, 2022.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by December 3, 2024.
- 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.