Exhaust gas purification apparatus for an internal combustion engine
US5402641A · kind A · utility
149Cited by
17References
25Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Jul 20, 1993 |
| Grant date | Apr 4, 1995 |
| Priority date | — |
| Expiry date | Jul 20, 2013 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02T10/12
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
An NOx absorbent is installed in an exhaust conduit of an internal combustion engine capable of fuel combustion at lean air-fuel ratios. An oxygen concentration is repeatedly or continuously decreased by, for example, switching the air-fuel from the lean air-fuel ratio to a stoichiometric or rich air fuel ratio when the exhaust gas temperature is higher than 550.degree. C. or when NOx absorbent temperature is higher than 500.degree. C. As a result, the SOx absorbed in the NOx absorbent during lean air-fuel ratio, low temperature operation is released from the NOx absorbent, and the SOx-poisoned NOx absorbent is recovered.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.