Process for accelerating the response of an exhaust gas catalyst, and apparatus and electrically heatable carrier bodies for performing the method

US5146743A · kind A · utility

Assignee

• EMITEC Gesellschaft fuer Emissionstechnologie mbH · DE

Inventors

• Wolfgang Maus · Bensberg, DE
• Helmut Swars · Bensberg, DE
• Hans-Jurgen Breuer · Overath, DE
• Theodor Cyron · Bensberg, DE

Key dates

• Filing date: Oct 25, 1990
• Grant date: Sep 15, 1992
• Expiry date: Oct 25, 2010

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y10T428/24149
• WIPO field: Environmental technology
• WIPO sector: Chemistry

Abstract

A method of accelerating the response of an exhaust gas catalyst downstream of an internal combustion engine, the exhaust gas catalyst having at least one metal catalyst carrier body coated with ceramic and catalytically active material having a given response temperature, and the carrier body having at least one subzone, the method includes supplying electric power to the metal catalyst carrier body for direct heating at least in subzones thereof, switching on the current for a period of time at least as early as immediately after the onset of engine operation, and dimensioning the current such that at least subzones of the metal carrier body are heated to the given response temperature at least as early as the exhaust gas reaches the given response temperature. The apparatus for performing the above method includes a main catalyst and an electrically heatable precatalyst disposed upstream of the main catalyst as seen in the flow direction of the exhaust gas. The electrically heated precatalyst carrier body comprises layered metal sheets forming a stack with a plurality of channels through which a fluid can flow, the metal sheets having a thickness of substantially 0.03 to 0.06 mm…