Method for regenerating soot filters in the exhaust gas system of a lean mix engine, and exhaust gas system therefor

US8327625B2 · kind B2 · utility

Assignee

• UMICORE AG & CO. KG · DE

Inventors

• Stephan Eckhoff · Alzenau, DE
• Ina Grisstede · Mannheim, DE
• Wilfried Mueller · Karben, DE
• Thomas Kreuzer · Karben, DE

Key dates

• Filing date: Jan 31, 2008
• Grant date: Dec 11, 2012
• Expiry date: Nov 8, 2028

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y02T10/40
• WIPO field: Environmental technology
• WIPO sector: Chemistry

Abstract

To adhere to legal exhaust-gas regulations, the exhaust gases of a lean-burn engine must be freed from soot particles and nitrogen oxides. It is proposed that the cylinders of the lean-burn engine be divided into two groups which discharge their exhaust gases into two associated exhaust lines which each comprise a soot filter and which are merged at an opening-in point into a common exhaust line. The common exhaust line comprises the catalytic converter for the removal of the nitrogen oxides. By regenerating the two soot filters at different times, the exhaust-gas temperature in the common exhaust line is limited to a mean temperature between the exhaust-gas temperature of normal operation and that of regeneration operation, and the catalytic converter for the removal of the nitrogen oxides is preserved.