Method and arrangement for purifying exhaust gas in an internal combustion engine
US7621121B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jul 21, 2006 |
| Grant date | Nov 24, 2009 |
| Priority date | — |
| Expiry date | Oct 15, 2026 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF02D41/405
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
The invention relates to a method for purifying exhaust gas in an internal combustion engine provided with an LNT and a particulate matter filter arranged in an exhaust gas conduit of the engine. The method includes de-sulfurization of the LNT and regeneration of the particulate matter filter. The invention includes the following steps: initiating a heating phase wherein the engine is set to generate heat sufficient for the de-sulfurization and the regeneration; initiating a de-sulfurization phase during a first time period (t1), in which the engine is set to generate a rich exhaust gas in the exhaust gas conduit; keeping the first time period below a first maximum value so as to avoid release of emissions of H2S from the engine; initiating a regeneration phase during a second time period, in which the engine is set to generate a lean exhaust gas in the exhaust gas conduit; keeping the second time period below a second maximum value so as to avoid thermal damage to the particulate matter filter; and repeating the de-sulfurization phase and the regeneration phase in a periodical manner.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.