Exhaust gas purification system for internal combustion engine
US6128899A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 8, 1999 |
| Grant date | Oct 10, 2000 |
| Priority date | — |
| Expiry date | Apr 8, 2019 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02T10/12
- WIPO fieldEngines, pumps, turbines
- WIPO sectorMechanical engineering
Abstract
A system for purifying exhaust gas of an internal combustion engine having a NOx reduction catalyst (NOx absorber) installed in the exhaust system of the engine which absorbs NOx in the exhaust gas generated by the engine in a lean environment where a lean fuel mixture is supplied and desorbs to reduce the absorbed NOx in a rich environment where a rich mixture is supplied. In the system, the rich fuel mixture is supplied for a period immediately before cutoff. With the arrangement, the NOx reduction catalyst desorbs the absorbed NOx and is regenerated to absorb NOx sufficiently. At the same time, the NOx reduction catalyst is regenerated from sulfur poisoning, thereby preventing the NOx purification efficiency from being degraded.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.