Backwash method and apparatus
CA 2037799 A1 · Owner: Ryan, Leo · Inventors: Ryan, Leo
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A method and apparatus for cleaning filter elements that are vertically positioned within a filter vessel that has a tube sheet dividing the filter vessel into a lower filter compartment and an upper plenum compartment. A fixed volume of backwash liquid is rapidly directed from the plenum compartment above the tube sheet through the filter elements into the filter compartment that has been drained of liquid. The rapid movement of the backwash liquid is a result of a pressure differential between the plenum compartment and the filter compartment.
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 March 8, 1991. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended March 8, 2011.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by March 8, 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.