Exhaust gas system with catalyst, for motor vehicles

摘要

A flow-calming chamber (16) is interposed between exhaust manifold (12) and catalyst (34). Exhaust enters this chamber as a quasi-freely expanding jet. Preferred features: At the inlet (17), the cross-section of the chamber increases abruptly, the diameter ratio exceeding 1:2.5. The chamber cross-section varies along its length to suit the surroundings, i.e. other vehicle components. Its length exceeds five times its inlet diameter. The chamber is located immediately ahead of the catalyst and immediately behind the manifold. The catalyst element may be located inside the chamber. An additional filter or static mixer filters combustibles and promotes mixing. This is located before, behind or inside the chamber (16). It is a porous ceramic body, especially a ceramic foam. The filter has channels, angled with respect to the through flow direction. A second set of channels is angled both with respect to the first set, and the flow direction. Channels are alternately parallel and adjacent in rows.