Exhaust gas purifying system
US6276132A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 30, 2000 |
| Grant date | Aug 21, 2001 |
| Priority date | — |
| Expiry date | Jun 30, 2020 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB01J23/56
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
An exhaust gas purifying system for an internal combustion engine of an automotive vehicle. The exhaust gas purifying system comprises an exhaust gas composition regulating device for producing a low HC concentration reducing agent in a lean exhaust gas atmosphere where air-fuel ratio is leaner than a stoichiometric value. The exhaust gas composition regulating device is disposed in an exhaust gas passageway of the engine. The low HC concentration reducing agent is low in concentration of hydrocarbons to have an exhaust gas composition having a volume ratio of NOx/HC not less than 50 in the exhaust gas passageway immediately downstream of the exhaust gas composition regulating device. Additionally, a NOx treating catalyst is disposed in the exhaust gas passageway and located downstream of the exhaust gas composition regulating device. The NOx treating catalyst is arranged to reduce NOx in the presence of the low HC concentration reducing agent supplied from the exhaust gas composition regulating device. The exhaust gas composition of the low HC concentration reducing agent is obtained in the exhaust gas passageway immediately upstream of the NOx reducing catalyst.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.