Cement shaft suspension furnace and process
CA 2034334 C · Owner: Gas Research Institute · Inventors: Zappa, Oswald L.; Woodroffe, Jaime W.; Tiwary, Rajiv
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Process and furnace for producing clinkered cement pellets from pellets of cement-forming batch materials without melting, fusion and agglomeration of said pellets. The furnace comprises an elongate vertical suspension shaft having top, intermediate and bottom portions. Pellets are fed at the top and heated to calcining temperatures before exiting the shaft into a pre-clinkering zone beyond the bottom. The pellets are heated to pre-clinkering temperatures and deposited on a porous pellet bed through which cooling air is forced to control the exothermic clinkering reaction and to regulate the speed at which the pellets migrate through the shaft.
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 January 17, 1991 and granted October 7, 1997. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended January 17, 2011.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by January 17, 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.