Exhaust system for an internal combustion engine

An exhaust system, for an internal combustion engine, comprising:

• an exhaust line in which an exhaust treatment device is provided for treatment of the exhaust gases coming from the internal combustion engine,
• wherein upstream from the exhaust treatment device, a heating device is provided for heating the exhaust gases in the exhaust line, the heating device being connected to a fuel supply and to an air supply which produces primary air and secondary air, the heating device having a pre-oxidation zone and a post-oxidation zone situated downstream from the pre-oxidation zone, the pre-oxidation zone connected to the fuel supply to supply it with liquid fuel and connected to the air supply for its supply of primary air,
• the post-oxidation zone being connected to the air supply for its supply of secondary air,
• wherein the heating device further comprises a porous flow-through structure arranged between the pre-oxidation zone and the post-oxidation zone for retarding droplet breakthrough of fuel into the post-oxidation zone and homogenizing a mixture of fuel, primary air and oxidation products, and
• wherein a secondary air channel which surrounds the pre-oxidation zone and the porous structure in the form of a ring is provided in the area of a housing wall of the heating device.

An exhaust system for an internal combustion engine, comprising:

• an exhaust line in which an exhaust treatment device is provided for treatment of the exhaust gases coming from the internal combustion engine,
• wherein upstream from the exhaust treatment device, a heating device is provided for heating the exhaust gases in the exhaust line, the heating device being connected to a fuel supply and to an air supply which produces primary air and secondary air, the heating device having a pre-oxidation zone and a post-oxidation zone situated downstream from the pre-oxidation zone, the pre-oxidation zone connected to the fuel supply to supply it with liquid fuel and connected to the air supply for its supply of primary air,
• wherein the post-oxidation zone being connected to the air supply for its supply of secondary air,
• wherein at least one of the primary air and the secondary air enters the corresponding oxidation zone via flow openings that produce a turbulence,
• wherein metered addition of the primary air and fuel is coordinated with the flow openings, so that a homogeneous mixture of fuel and primary air is obtained in the pre-oxidation zone, the fuel-primary air mixture ignitable by an ignition device, whereupon it is oxidized at least partially, and
• wherein the heating device further comprises a porous flow-through structure configured to prevent droplet breakthrough of unoxidized fuel into the post-oxidation zone and to homogenize a mixture of fuel, primary air and oxidation products, wherein the secondary air feed is fed into the post-oxidation zone in such a way that at least one of complete combustion and post-oxidation takes place in the post-oxidation zone.