EXHAUST GAS PURIFYING DEVICE FOR VEHICLE

摘要

PURPOSE:To heat the catalyst of an exhaust gas purifying element to activation temp. within a short time by utilizing microwave heating at the start time of an engine. CONSTITUTION:A microwave supply means 20 supplies a microwave to the first exhaust gas purifying element 15 arranged in a heating chamber 14 at the start time of an engine. The first exhaust gas purifying element 15 is composed of a ceramic honeycomb 15a having a catalyst and a microwave absorbing exothermic material supported on the surface thereof and the microwave absorbing exothermic material absorbs a microwave to generate heat to heat the catalyst. The exhaust gas treatment at the start time of the engine is performed by the catalyst of the first exhaust gas purifying element 15. The honeycomb 16a of the second exhaust gas purifying element 16 arranged on the donwstream side of the heating chamber 14 is made of stainless steel and the surface on the upstream side thereof is provided as a microwave reflecting surface 16x. Since the microwave is reflected by the reflecting surface 16x, it is not supplied to the catalyst of the second exhaust gas purifying element 16.