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:
Aug. 03, 2004
Filed:
Nov. 21, 2001
Shi-Wai S. Cheng, Troy, MI (US);
General Motors Corporation, Detroit, MI (US);
Abstract
A rolling regeneration diesel particulate filter and filtering process that utilizes NO produced in the process to generate additional amounts of NO than the NO produced by the diesel engine. The process includes the step of flowing diesel engine combustion exhaust through a filter system including a first section and a second section. The first section is positioned upstream of the second section with respect to the direction of the flow of the diesel engine exhaust through the filter. The first section includes a foam constructed and arranged to trap carbon-based particulates in the exhaust. A first catalyst is carried by the foam to promote the conversion of NO in the exhaust from the diesel engine to NO . The first catalyst also promotes the reaction of NO with at least a portion of the carbon-based particulates trapped by the foam to form CO and NO. The first catalyst carried by the foam also promotes the oxidation of CO to CO , and the oxidation of NO, generated by the reaction of NO with carbon, to generate additional amounts of NO . The additional amounts of NO are also utilized to oxidize the carbon-based particulates. The second section of the filter system includes a wall flow monolith having a plurality of through hole cells formed therein running the longitudinal length of the monolith. The monolith is constructed and arranged to trap particulates in the exhaust and to promote the reaction of NO and carbon to produce NO and CO. The ceramic foam may also be received in and surrounded by the wall flow filter.