Tumbling ozone reactor for paper pulp
CA 2044898 A1 · Owner: Jiang, Jian · Inventors: Dunn, Stephen J.; Funk, Erwin D.; Delcourt, Thomas R.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A method of delignifying comminuted cellulosic fibrous material (paper pulp) at a consistency of about 30-45% employing ozone as the active bleaching component, and capable of utilizing a variety of different reactor designs. In each case the paper pulp is fluffed and ozone gas is added to it and the, pulp is maintained in contact with the ozone containing gas while it is tumbled to keep it loose and homogenous, with a high surface area to volume ratio. The reactor may be just below a fluffer or, the pulp may be pneumatically conveyed to the reactor. The reactor may include a screw having lifters on the screw flights, or paddles extending radially outwardly from the screw shaft; or a short …
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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 18, 1991. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended June 18, 2011.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by June 18, 2013.
- 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.