Process and apparatus for controlled addition of conditioning material to sewage sludge
CA 1257412 A · Owner: Her Majesty The Queen In Right Of Canada As Represented By The Minister Of The Environment · Inventors: Campbell, Herbert W.; Crescuolo, Phillip J.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
The invention provides processes and apparatus for the controlled addition of conditioning (polymer) material to sewage sludge to improve its dewaterability. These materials are expensive and overdosage is to be avoided while underdosage, causes difficulty in sludge handling. The principal problem has been the absence of a system capable of continuous determination of proper dosage. It has been found that shear stress tests with a viscometer result in characteristics that exhibit a unique peak when dosage is adequate or above. A control system controlling the rate of pumping of the polymer to mix with the sludge is operative by measuring the shear stress and increasing the dosage in 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
- Granted July 11, 1989. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended July 11, 2006.
- 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
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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.