Exhaust gas purification apparatus
US7673444B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Apr 27, 2007 |
| Grant date | Mar 9, 2010 |
| Priority date | — |
| Expiry date | Apr 24, 2028 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02T10/40
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
An exhaust gas purification apparatus includes an NOx reduction catalytic converter disposed in an engine exhaust passage to reductively purify NOx in exhaust gas using ammonia or its precursor as a reducing agent, a first concentration sensor which detects an ammonia concentration in an exhaust gas moving on a downstream side of the NOx reduction catalytic converter, and a control unit which incorporates therein a computer. The control unit conducts calculation to estimate an ammonia concentration in the exhaust gas moving on the downstream side of the NOx reduction catalytic converter, and when a difference between the ammonia concentration detected by the first concentration sensor and the estimated ammonia concentration by the calculation becomes larger than a first predetermined value, determines that the NOx reduction catalytic converter is deteriorated.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.