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, 2003
Filed:
Aug. 16, 2000
Lothar Hofmann, Altenkunstadt, DE;
Wieland Mathes, Michelau, DE;
Siemens Aktiengesellscahft, Munich, DE;
Abstract
A metering system in a combustion unit having an exhaust-gas chamber and a reducing agent reservoir includes an electrically controllable valve for introducing the reducing agent into the exhaust-gas chamber without using compressed air. The valve has an outlet opening that opens directly into the exhaust-gas chamber. The outlet opening is fluidically connected to the reservoir through the valve. The metering system can be produced with only little technical outlay. The metering system includes a recirculating circuit, and the valve has a holding chamber for the reducing agent. The holding chamber is disposed downstream of the outlet opening in a reducing agent flow direction, and is fluidically connected into the recirculating circuit. The metering system includes a coolant circuit for cooling the valve. The valve and its outlet opening is disposed in the exhaust-gas chamber to position the principal axis of the valve at an angle of less than 90° with respect to a principal direction of flow of exhaust gas in the exhaust-gas chamber. The metering system includes a baffle disposed in the exhaust-gas chamber to cause a change in direction of reducing agent introduced therein. The combustion unit can be a diesel engine, and the reducing agent can be a urea solution.