Treatment of sewage sludge
CA 2098134 A1 · Owner: Bezuidenhout, Frans Frederik · Inventors: Bezuidenhout, Frans Frederik; Terblanche, Johannes Stephanus
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Sewage sludge is mixed with organic material such as woodchips in a three screw mixer so that moving masses are created in the mixing compartment, there being a shearing action at the interfaces between the masses. The mixer includes the mixing compartment and a holding compartment into which dewatered sludge is continuously charged. There is a gate between the compartments which is opened when it is desired to convey sludge from the holding compartment to the mixing compartment. The shearing action results in the organic material being coated with a thin layer of sludge without the formation of dewatered sludge lumps which would rot instead of composting.
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 June 10, 1993. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended June 10, 2013.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by June 10, 2015.
- 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.