Abgas-Katalysator fuer eine Brennkraftmaschine

(A1) Ein Abgas-Katalysator fuer eine Brennkraftmaschine weist eine die Katalyse der Abgase bewirkenden Beschichtung auf einem vom Abgas durchstroemten Katalysatortraeger auf, der aus einem poroesen Material auf Metallbasis besteht. Um einen klein bauenden Katalysator mit hoher Reinigungsleistung, gutem Ansprechverhalten und guten Schalldaempfungseigenschaften auszubilden, ist vorgesehen, dass der Katalysatortraeger einen Traegerkoerper mit einer gesinterten Metallfaser-Struktur umfasst.

DE 19750980 A UPAB: 19990714 NOVELTY - The catalyst substrate (1) body (2) has a sintered metal fiber structure. DETAILED DESCRIPTION - Preferred features: The fibers have a maximum diameter of 50 mu m. The body is rolled and its wall thickness is up to 200 mu m. Its configuration is wavy. An iron- and/or nickel-based alloy is employed. The aluminum content is 5%-20%. Rare earths are incorporated. The body is encased by metal foil (3) with perforations (4). Its thickness is up to about 50 mu m. This sheet has a 5%-7% aluminum content and/or about 20% chromium. USE - To make a catalyst substrate for engine exhaust gases. ADVANTAGE - The catalyst achieves a particularly high surface area with low weight. A more compact unit becomes possible. Thermal inertia is reduced, for the important fast warm-up phase. Noise attenuation is enhanced and the structure can be designed to attenuate specific wavelengths. Catalytic efficiency is enhanced. The catalyst is suitable for location close to the engine, in the hottest gases at up to 1200 deg. C, further accelerating warm-up. The rolled material lends itself to simple structuring, e.g. wavy profiling. It forms thin, porous plates, permitting transverse flow (5). The open longitudinal construction presents little flow resistance to the exhaust gases. A large surface area is made available for catalytic coating. Foil casing perforation, assists transverse flow.