Exhaust gas purifying system
US6823662B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Oct 20, 2000 |
| Grant date | Nov 30, 2004 |
| Priority date | — |
| Expiry date | Oct 20, 2020 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF01N2610/08
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
An exhaust gas purifying system for an automotive internal combustion engine includes a NOx treating catalyst for reducing NOx disposed in an exhaust gas passageway of a combustion device, to reduce NOx in presence of reducing components in exhaust gas. Additionally, a hydrogen enriching device is disposed upstream of said NOx treating catalyst with respect to flow of exhaust gas from the combustion device and arranged to increase a ratio of hydrogen to total reducing components in at least one of combustion gas and exhaust gas so as to meet relations represented by following formulae (1) and (2), when reduction of NOx is carried out by the NOx treating catalyst:[H2/TR]d>[H2/TR]u  (1) [H2/TR]d≧0.3  (2) where [H2/TR]u is a ratio between a concentration [H2]u of hydrogen and a concentration [TR]u of total reducing components in at least one of exhaust gas in the exhaust gas passageway upstream of the hydrogen enriching device and combustion gas in a state before undergoing the hydrogen ratio increasing by said hydrogen enriching means; and [H2/TR]d is a ratio between a concentration [H2]d of hydrogen and a concentration [TR]d of total reducing components in…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.