Method for removing alkaline sulfate scale
CA 2137007 C · Owner: Morris, Richard L. · Inventors: Morris, Richard L.; Paul, James M.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
The present invention relates to the use of low frequency sonic energy in the sonic frequency range for enhancing the dissolution of alkaline earth metal scales using a scale-removing solvent comprising an aqueous alkaline solution having a pH of about 8 to about 14 and containing EDTA or DTPA and a catalyst or synergist preferably an oxalate anion. When the scale-removing solvent is contacted with a surface containing a scale deposit while simultaneously transmitting low frequency sonic energy through the solvent, substantially more scale is dissolved at a faster rate than previously possible. The frequency of the sonic energy is within the range of 1.5 to 6.5 kHz and preferably 1.5 …
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 2, 1993 and granted September 16, 2003. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended June 2, 2013.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by June 2, 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.