Internal heat exchange tubes for industrial furnaces
CA 2043935 C · Owner: Hoetzl, Max · Inventors: Hoetzl, Max; Lingle, Thomas M.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
An internal heat exchange tube for cooling work within an industrial furnace is positioned to extend within the furnace and is closed at its axial end which is inside the furnace. Within the tube is an open ended thin wall inner, tube formed in the shape of a helical coil. Water introduced into the inner tube distributes thermally induced circumferential stress gradients about both tubes to prevent tube bending while achieving fast cooling of the outer tube.
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 June 5, 1991 and granted December 14, 1993. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended June 5, 2011.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by June 5, 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.