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Expired Canadian patentCanada

Direct delivery in-situ diffuser cleaning

CA 2109990 C · Owner: Winkler, William W. · Inventors: Winkler, William W.

CIPO record

Overview

Drawings and full text

Its claims, description and drawings are in the Canadian Patents Database.

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Abstract From the Canadian patent

This disclosure relates to aeration, especially biological treatment of wastewater with fine pore diffusers and in situ cleaning of these diffusers with liquid and/or gaseous cleaning fluids supplied to the diffusers through cleaning fluid channels that respectively have separate and direct connections to plural diffusers. Aeration and cleaning of fine pore diffusers is described in which cleaning fluid is conducted from a source of such fluid to a multiplicity of diffusers via a flow path which is separate from a flow path which conveys aeration gas to the diffusers. Methods of fabricating aeration gas distribution assemblies are also disclosed. One such method involves securing to an …

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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 November 25, 1993 and granted May 15, 2001. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended November 25, 2013.
  • A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by November 25, 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.
FiledNovember 25, 1993
GrantedMay 15, 2001
Term endedNovember 25, 2013
Patent numberCA 2109990 C
Classification (IPC)C02F3/20

Timeline

Timeline From CIPO dates

1994199619982000200220042006200820102012Application filedNov 25, 1993Patent grantedMay 15, 2001Term endedNov 25, 2013

Sources & verification

Everything on this page comes from the CIPO record linked above. Contains information licensed under the Open Government Licence – Canada.