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Expired Canadian patentCanada

Method and a device for screening and treating pulp

CA 1330731 C · Owner: Tamrock Oy · Inventors: Hautala, Jouko

CIPO record

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

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Abstract From the Canadian patent

The invention relates to a method and a device for screening and treating pulp. In the invention, the pulp is screened in a screen into an accepted fraction and a rejected fraction, the rejected fraction being treated after the screening by removing water from it. In order to reduce the energy consumption of the refining process, the rejected pulp fraction is screened by means of a means (13) rotating rapidly in a reject space (12) of a screen (1) in such a manner that the rapidly rotating means (13) effects a radial flow of the fine-grained material contained in the rejected fraction outwards through a perforated wall (14) surrounding the rotating means (13) into a space (15, 15a) from …

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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 July 19, 1994. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended July 19, 2011.
  • We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
FiledJuly 18, 1989
GrantedJuly 19, 1994
Term endedJuly 19, 2011
Patent numberCA 1330731 C
Classification (IPC)D21D5/02 +1 more

Timeline

Timeline From CIPO dates

19901993199619992002200520082011Application filedJuly 18, 1989Patent grantedJuly 19, 1994Term endedJuly 19, 2011

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