Treatment of a trickling-percolating filter
CA 2066231 A1 · Owner: Horsfall, Frank L. · Inventors: Horsfall, Frank L.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A method of treatment of a trickling-percolating filter to remove or inhibit blockages which consists in feeding electron acceptor substances (nitrates) with the filter medium in a distributed fashion. Perforated pipes (5) may be sunk into the filter medium (2) for the application of the substances in liquid form. The application of the electron acceptor solution may be followed by the application of a liquid suspension of bacteria capable of using the said solution.
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 July 26, 1991. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended July 26, 2011.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by July 26, 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.