Mine cooling power recovery system
CA 2002393 C · Owner: Hitachi, Ltd. · Inventors: Furutani, Naoshi; Saito, Makoto; Uchida, Kenji
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A mine cooling power recovery system is disclosed. A low-pressure slurry pump for charging the mud slurry produced in a mine into a pressure changeover feed chamber is arranged in parallel to a warm water charging low-pressure pump and each of outlets of the two pumps has a changeover valve so that a single power recovery system pumps up both the mud slurry and a warm water out of the mine. A second embodiment of the present invention employs a slurry sedimentation tank provided on the ground surface.
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 November 7, 1989 and granted June 4, 1996. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended November 7, 2009.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by November 7, 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.
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.