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Expired Canadian patentCanada

Rotating biological contactor

CA 1094237 A · Owner: Fmc Corporation · Inventors: Sako, Fumio; Pearson, Christopher C.

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

Apparatus for treating sewage by providing a plurality of uniquely designed thin discs that are mounted on a shaft so that the discs are immersed approximately 40% in a sewage tank. The shaft is rotated at peripheral speeds on the order of 35-75 feet per minute to alternately expose the discs to the atmosphere and the liquid containing wastewater in the tank to treat the wastewater in the tank by providing for the growth of biological slimes on the surfaces of the discs. The discs have a corrugated configuration with the corrugations of the alternate discs disposed at ninety degrees to each other to provide maximum usable surface area in a given rotating volume while having sufficient …

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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 January 20, 1981. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended January 20, 1998.
  • We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
FiledAugust 16, 1978
GrantedJanuary 20, 1981
Term endedJanuary 20, 1998
Patent numberCA 1094237 A
Classification (IPC)C02F3/08 +1 more

Timeline

Timeline From CIPO dates

1979198119831985198719891991199319951997Application filedAug 16, 1978Patent grantedJan 20, 1981Term endedJan 20, 1998

Sources & verification

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