Method for the periodically desulfating a nitrogen oxide or sulfur oxide accumulator of an exhaust gas cleaning system

US6637189B1 · kind B1 · utility

Assignee

• Daimlerchrysler AG · US

Inventors

• Walter Boegner · Waiblingen, DE
• Guenter Karl · Eßlingen, DE
• Bernd Krutzsch · Köngen, DE
• Stefan Renfftlen · Eislingen/Fils, DE
• Christof Schoen · Winnenden, DE
• Dirk Voigtlaender · Ditzingen, DE
• Guenter Wenninger · Stuttgart, DE

Key dates

• Filing date: Mar 20, 2001
• Grant date: Oct 28, 2003
• Expiry date: Mar 20, 2021

Classification

• Technology area (CPC F): Mechanical Engineering; Lighting; Heating
• CPC primary: F02D41/1408
• WIPO field: Chemical engineering
• WIPO sector: Chemistry

Abstract

In a method for the periodic desulphurization of a nitrogen-oxide or sulphur-oxide accumulator of an exhaust-gas cleaning system of an internal-combustion engine, during respective desulphurization periods, the accumulator is fed secondary air by secondary-air supply means, and is fed an engine exhaust gas which contains a reducing agent by setting a rich engine air ratio. At least during part of the desulphurization period, after a predeterminable desulphurization temperature has been reached, the accumulator air ratio is set, by suitably alternating the secondary air quantity supplied and/or the engine air ratio, between an oxidizing or stoichiometric atmosphere, and a reducing atmosphere.