The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Apr. 01, 2008
Filed:
Jul. 29, 2003
Friedemann Rohr, Hanau, DE;
Peter Kattwinkel, Marienheide, DE;
Stefan D. Peter, Eggenstein-Leopoldshafen, DE;
Thomas Kreuzer, Karben, DE;
Egbert Lox, Hochwaldhausen, DE;
Friedemann Rohr, Hanau, DE;
Peter Kattwinkel, Marienheide, DE;
Stefan D. Peter, Eggenstein-Leopoldshafen, DE;
Thomas Kreuzer, Karben, DE;
Egbert Lox, Hochwaldhausen, DE;
Umicore AG & Co. KG, Hanau, DE;
Abstract
The present invention provides a process and a device for regeneration of a nitrogen oxide storage catalyst in the exhaust system of a diesel engine. The process comprises a first and a second regeneration strategy. The first regeneration strategy is applied when the exhaust gas temperature is above a threshold value and comprises changing the air/fuel-ratio from a lean to a rich value during a first regeneration period. The second regeneration strategy is applied when the exhaust gas temperature is below a threshold value and comprises switching the air/fuel-ratio back and forth between lean and rich air/fuel-ratios, forming a sequence of between 2 and 10 rich pulses and between 2 and 10 lean pulses during a second regeneration period.