Reducing nox emissions from an engine by temperature-controlled urea injection
CA 2572493 A1 · Owner: Hofmann, John E. · Inventors: Tarabulski, Theodore J.; Hofmann, John E.; Peter-Hoblyn, Jeremy D.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A safe, reliable SCR system for reducing NO x emissions from a lean-burn internal combustion engine utilizes urea in aqueous solution. Overheating and hydrolysis of the solution are prevented by maintaining the temperature of the urea solution sufficiently low that it is not permitted sufficient time at elevated, temperature to hydrolyze the urea to such an extent that solids precipitate. In a preferred embodiment an injector system similar to those used for fuel injection provides a constant feed to injectors and a return line. The feed and, injection can be controlled to provide sufficient urea for NO x reduction and sufficient cooling capacity for the feed and injection system to avoid …
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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 March 31, 1998. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended March 31, 2018.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by March 31, 2020.
- 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.