Exhaust pipe with built-in exhaust gas catalyst - and outer insulation coating contg. evacuated cavity with chamber filled with better alloy

摘要

Exhaust pipe (I) has a built-in exhaust gas catalyst in the area of which is an outer insulation coating which surrounds (I) with the inclusion of a cavity. (a) The cavity is evacuated; (b) at least one chamber is provided in the cavity filled with a getter alloy; and (c) the desorption temp. of the getter alloy is less than the max. permissible operating temp. of the exhaust gas catalyst. Pref. the desorption temp. of the getter alloy is 350-400 deg.C. Pref. a vacuum of 10 power (-3) torr is produced in the cavity. ADVANTAGE - In the area of the insulating coating a high insulation effect is attained and, after attaining a desired operating temp. for the exhaust catalyst, a lower insulating effect is attained.