Controlling mineral deposits in cooling systems
CA 2048059 A1 · Owner: Diversey Water Technologies Ltd./Technologies De L'Eau Diversey Ltee. · Inventors: Coughlin, Michael F.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
While chelants such as ethylenediaminetetraacetic acid (EDTA) have been used for preventing scale deposition in boiler water, because of the expense it has not been used in cooling water treatment. It has been found that a relatively small quantity of a chelant can be used in combination with a scale deposit control agent such as a phosphonate to prevent scale deposition in cooling water. A preferred composition including a 4.5:1 ratio by weight of hydroxyethylene diphosphonic acid (HEDP) to EDTA displays a synergistic effect when used for scale prevention.
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 29, 1991. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended July 29, 2011.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by July 29, 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.