Sewage sludge treatment with gas injection
CA 2033000 C · Owner: Long Enterprises, Inc. · Inventors: Grover, Philip M.; Cobb, William A.; Blythe, Robert D.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
This invention relates to a sewage sludge treatment system resulting in an oxygenated and/or ozonated treated sludge containing substantially no pathogens. The system includes apparatus (10) and a process for mascerating raw sludge, adjusting the pH to about 2.5 to about 3, adjusting the solids content to about 2.5% to about 4%, adjusting the temperature, if necessary, to about 20°C to about 40°C, mixing an oxygen-rich gas, such as oxygen and/or ozone with the sludge as the sludge is mixed or recirculated through a hyperbaric vessel (12) and simultaneously injecting the oxygen-rich gas into a combination gas and sludge mixing and dispersing assembly (30) in an upper portion (16) of the …
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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 21, 1990 and granted March 23, 1999. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended December 21, 2010.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by December 21, 2012.
- 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.