Mantelrohr mit thermisch isolierenden Sicken

摘要

The invention relates to a jacket tube, especially for a honeycomb element (12) used for exhaust gas treatment. The inventive jacket tube is provided with a first area (2) which is located close to a first front face (10) and a third area (4) which is located close to a second front face (11). The jacket tube (1) has a first inner diameter in the first (2) and third area (4) and is provided with a second area (3) which is disposed between the first (2) and third area (4). The second area (3) has a second inner diameter (9) which is larger than the first inner diameter (8). The invention is characterized in that the axial (19) length (5) of the first area (2) is less than 5 mm, preferably less than 3 mm. The relatively narrow first area (2) enables the honeycomb to be permanently fixed and ensures that only a small amount of heat is transmitted to the jacket tube (1). As a result, a significant improvement is achieved in the cold start performance of a catalytic converter.