Exhaust-gas treatment arrangement

An exhaust-gas treatment arrangement for an exhaust gas system of an internal combustion engine including a diesel internal combustion engine, the exhaust-gas treatment arrangement defining a flow path and comprising:

• a first exhaust-gas treatment unit;
• an exhaust-gas treatment assembly downstream of said first exhaust-gas treatment unit;
• said first exhaust-gas treatment unit and said exhaust-gas treatment assembly being arranged axially one after the other in a direction of a longitudinal axis (L2) of said flow path with said flow path including said first exhaust-gas treatment unit and said exhaust-gas treatment assembly;
• a hydrocarbon introduction assembly for introducing hydrocarbon into exhaust gas flowing through said exhaust-gas treatment arrangement;
• said hydrocarbon introduction assembly including a bypass flow channel having a flow-channel inlet region for receiving exhaust gas upstream of said first exhaust-gas treatment unit and a flow-channel outlet region for discharging at least one of the following:
• i) exhaust gas;
• and,
• ii) hydrocarbon
• into said flow path downstream of said first exhaust-gas treatment unit and upstream of said exhaust-gas treatment assembly;
• said hydrocarbon introduction assembly further including a hydrocarbon discharging unit for discharging hydrocarbon into said bypass flow channel;
• wherein said exhaust-gas treatment arrangement further comprises:
• at least one second exhaust-gas treatment unit arranged downstream of said exhaust-gas treatment assembly;
• an exhaust-gas/reactant mixing section having a mixing channel elongated substantially in a direction of a mixing-section longitudinal axis (L3);
• a reactant discharging unit for discharging reactant into said mixing channel, said reactant discharging unit being provided downstream of said exhaust-gas treatment assembly and upstream of said at least one second exhaust-gas treatment unit.

An exhaust gas system for an internal combustion engine including a diesel internal combustion engine, the exhaust gas system comprising:

• an exhaust-gas conduit conducting exhaust gas away from the combustion engine;
• and,
• an exhaust-gas treatment arrangement communicating with said exhaust-gas conduit and defining a flow path and including:
• an introduction housing for introducing exhaust gas into the exhaust-gas treatment arrangement, said flow path having an upstream end region adjoining said introduction housing;
• a first exhaust-gas treatment unit;
• an exhaust-gas treatment assembly downstream of said first exhaust-gas treatment unit;
• said first exhaust-gas treatment unit and said exhaust-gas treatment assembly being arranged axially one after the other in a direction of a longitudinal axis (L2) of said flow path with said flow path including said first exhaust-gas treatment unit and said exhaust-gas treatment assembly;
• a hydrocarbon introduction assembly for introducing hydrocarbon into exhaust gas flowing through said exhaust-gas treatment arrangement;
• said hydrocarbon introduction assembly including a bypass flow channel having a flow-channel inlet region for receiving exhaust gas upstream of said first exhaust-gas treatment unit and a flow-channel outlet region for discharging at least one of the following:
• i) exhaust gas;
• and,
• ii) hydrocarbon
• into said flow path downstream of said first exhaust-gas treatment unit and upstream of said exhaust-gas treatment assembly, so that the exhaust gas received in the bypass flow channel bypasses that first exhaust-gas treatment unit;
• said hydrocarbon introduction assembly further including a hydrocarbon discharging unit for discharging hydrocarbon into said bypass flow channel;
• and,
• wherein said flow-channel inlet region of said bypass flow channel adjoins at least one of:
• i) said introduction housing so as to permit receiving the exhaust gas from said introduction housing;
• and,
• ii) a portion of said flow path lying between said introduction housing and said
• first exhaust-gas treatment unit for receiving the exhaust gas from said flow path.

An exhaust gas system for an internal combustion engine including a diesel internal combustion engine, the exhaust gas system comprising:

• an exhaust-gas conduit conducting exhaust gas away from the combustion engine;
• and,
• an exhaust-gas treatment arrangement communicating with said exhaust-gas conduit and defining a flow path and including:
• a first exhaust-gas treatment unit;
• an exhaust-gas treatment assembly downstream of said first exhaust-gas treatment unit;
• said first exhaust-gas treatment unit and said exhaust-gas treatment assembly being arranged axially one after the other in a direction of a longitudinal axis (L2) of said flow path with said flow path including said first exhaust-gas treatment unit and said exhaust-gas treatment assembly;
• a hydrocarbon introduction assembly for introducing hydrocarbon into exhaust gas flowing through said exhaust-gas treatment arrangement;
• said hydrocarbon introduction assembly including a bypass flow channel having a flow-channel inlet region for receiving exhaust gas upstream of said first exhaust-gas treatment unit and a flow-channel outlet region for discharging at least one of the following:
• i) exhaust gas;
• and,
• ii) hydrocarbon
• into said flow path downstream of said first exhaust-gas treatment unit and upstream of said exhaust-gas treatment assembly;
• and,
• said hydrocarbon introduction assembly further including a hydrocarbon discharging unit for discharging hydrocarbon into said bypass flow channel;
• wherein said exhaust-gas treatment arrangement further comprises:
• at least one second exhaust-gas treatment unit arranged downstream of said exhaust-gas treatment assembly;
• an exhaust-gas/reactant mixing section having a mixing channel elongated substantially in a direction of a mixing-section longitudinal axis (L3);
• a reactant discharging unit for discharging reactant into said mixing channel, said reactant discharging unit being provided downstream of said exhaust-gas treatment assembly and upstream of said at least one second exhaust-gas treatment unit.

An exhaust-gas treatment arrangement for an exhaust gas system of an internal combustion engine including a diesel internal combustion engine, the exhaust-gas treatment arrangement defining a flow path and comprising:

• a first exhaust-gas treatment unit;
• an exhaust-gas treatment assembly downstream of said first exhaust-gas treatment unit;
• said first exhaust-gas treatment unit and said exhaust-gas treatment assembly being arranged axially one after the other in a direction of a longitudinal axis (L2) of said flow path with said flow path including said first exhaust-gas treatment unit and said exhaust-gas treatment assembly;
• a hydrocarbon introduction assembly for introducing hydrocarbon into exhaust gas flowing through said exhaust-gas treatment arrangement;
• said hydrocarbon introduction assembly including a bypass flow channel having a flow-channel inlet region for receiving exhaust gas upstream of said first exhaust-gas treatment unit and a flow-channel outlet region for discharging at least one of the following:
• i) exhaust gas;
• and,
• ii) hydrocarbon
• into said flow path downstream of said first exhaust-gas treatment unit and upstream of said exhaust-gas treatment assembly, so that the exhaust gas received in the bypass flow channel bypasses that first exhaust-gas treatment unit;
• said hydrocarbon introduction assembly further including a hydrocarbon discharging unit for discharging hydrocarbon into said bypass flow channel;
• and
• wherein said first exhaust-gas treatment unit includes an SCR catalytic converter unit and wherein said exhaust-gas treatment assembly includes an oxidation catalytic converter unit.

An exhaust gas system for an internal combustion engine including a diesel internal combustion engine, the exhaust gas system comprising:

• an exhaust-gas conduit conducting exhaust gas away from the combustion engine;
• and,
• an exhaust-gas treatment arrangement communicating with said exhaust-gas conduit and defining a flow path and including:
• a first exhaust-gas treatment unit;
• an exhaust-gas treatment assembly downstream of said first exhaust-gas treatment unit;
• said first exhaust-gas treatment unit and said exhaust-gas treatment assembly being arranged axially one after the other in a direction of a longitudinal axis (L2) of said flow path with said flow path including said first exhaust-gas treatment unit and said exhaust-gas treatment assembly;
• a hydrocarbon introduction assembly for introducing hydrocarbon into exhaust gas flowing through said exhaust-gas treatment arrangement;
• said hydrocarbon introduction assembly including a bypass flow channel having a flow-channel inlet region for receiving exhaust gas upstream of said first exhaust-gas treatment unit and a flow-channel outlet region for discharging at least one of the following:
• i) exhaust gas;
• and,
• ii) hydrocarbon
• into said flow path downstream of said first exhaust-gas treatment unit and upstream of said exhaust-gas treatment assembly, so that the exhaust gas received in the bypass flow channel bypasses that first exhaust-gas treatment unit;
• said hydrocarbon introduction assembly further including a hydrocarbon discharging unit for discharging hydrocarbon into said bypass flow channel;
• and
• wherein said first exhaust-gas treatment unit includes an SCR catalytic converter unit and wherein said exhaust-gas treatment assembly includes an oxidation catalytic converter unit.