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:
Jul. 31, 2001
Filed:
Sep. 17, 1999
Applicant:
Inventor:
Thomas Tsoi-Hei Ma, Essex, GB;
Assignee:
Ford Global Technologies, Inc., Dearborn, MI (US);
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
B01D 5/392 ; B01D 5/394 ; B01D 5/396 ;
U.S. Cl.
CPC ...
B01D 5/392 ; B01D 5/394 ; B01D 5/396 ;
Abstract
A lean NOx trap in an exhaust system of a spark ignition internal combustion engine having a three-way catalyst upstream of the lean NOx trap, and the lean NOx trap connected in series along the exhaust system is heated by modulating the air to fuel ratio (AFR) of the engine cyclically at various frequencies such as 0.5 Hz, 1 Hz, 1.5 Hz, and 2 Hz, so that different portions of the lean NOx trap are heated at different times so as to completely remove sulfur from the lean NOx trap.