Cleaning by cavitation in liquefied gas
CA 2101142 A1 · Owner: Stanford, Thomas B. · Inventors: Purer, Edna M.; Chao, Sidney C.; Townsend, Carl W.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Undesired material is removed from a chosen substrate (28) by a process comprising the steps of (a) placing the substrate containing the undesired material in a cleaning chamber (12) provided with cavitation-producing means (16 36, 52); (b) introducing a liquefied gas such as liquid, carbon dioxide, into the cleaning chamber and contacting the substrate containing the undesired material with the liquid carbon dioxide at a temperature below its critical temperature; and (c) exposing the liquid carbon dioxide to the cavitation-producing means for a period of time sufficient to remove the undesired material form the substrate. The substrate containing the undesired material may optionally be …
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 July 22, 1993. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended July 22, 2013.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by July 22, 2015.
- 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.