Process for bleaching cellulosic material and plant for carrying out the process
CA 2067844 A1 · Owner: Sinner, Michael · Inventors: Sinner, Michael; Schwarzl, Karl
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
There is disclosed a process and a plant for bleaching cellulosic materials using ozone. An ozonic gas is produced in an ozone generator by corona in air or oxygen. The ozonic gas is compressed and an aqueous solution enriched with oxygen (strong water) is recovered in an absorption vessel under pressure. The strong water is depressurized in a depressurizing zone thus releasing a gas having a high O3 content (strong gas. The strong gas is diluted with an ozone-free or oxygen-poor gas. The gas obtained is mixed with the cellulosic materials to be bleached and is reacted in a bleaching zone. The material suspension bleached is degassed, the solid material is washed and processed.
Read the whole patent
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 May 1, 1992. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended May 1, 2012.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by May 1, 2014.
- 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.