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. 27, 1991
Filed:
Apr. 30, 1990
Hans Erdmannsdoerfer, Ludwigsburg, DE;
Filterwerk Mann & Hummel GmbH, Ludwigsburg, DE;
Abstract
A soot filter has sets of three to five filter tubes disposed in a circle and axially parallel to one another, through which exhaust flows radially from the outside in during operation, composed of refractory ceramic yarn wound spool-wise to form hollow cylinders. To permit an electrical burn-off of the deposited soot with a relatively low expenditure of energy, the clearance A of all adjacent filter tubes 30 from one another amounts to 2 to 4% of the average filter tube diameter D. In each interstice 36 formed by at least three filter tubes 30 an elongated electrical heating element 37 is disposed which can be turned on if the exhaust gas stream is interrupted by shutting down the internal combustion engine or by diverting the exhaust gas stream away from a set of filter tubes.