Exhaust treatment system, method for treatment of an exhaust stream and control system therefore

A method for treatment of an exhaust stream resulting from a combustion in a combustion engine, the method comprising:

• catching soot and ash created by the combustion by utilization of a particulate filter;
• controlling a supply of an additive into the exhaust stream by utilization of a dosing arrangement arranged downstream of the particulate filter;
• reduction of nitrogen oxides NOx in the exhaust stream by utilization of the supplied additive and a reduction catalyst arrangement arranged downstream of the dosing arrangement;
• and
• interaction of particles in the exhaust stream and at least one filter structure arranged downstream of the dosing arrangement, the particles being created by one or more of the supply of the additive into the exhaust stream and a transformation of the additive when flowing through the exhaust treatment system, wherein the at least one filter structure has a cross section area A in inches2 and a length L in inches resulting in an area to length ratio A/L having a value of at least 14 inches;
• A/L≥17 inches;
• and has an opening degree such that:
• the particles are caused to interact with the at least one filter structure, thereby being at least partly captured and removed by the at least one filter structure;
• and
• accumulation of soot and ash created by the combustion, which would affect the interaction of the at least one filter structure and the particles, is at least partly avoided.

A computer program A computer program product stored on a non-transitory computer-readable medium, said computer program product for treatment of an exhaust stream resulting from a combustion in a combustion engine, wherein said computer program product comprising computer instructions to cause one or more computer processors to perform the following operations:

• controlling a supply of an additive into the exhaust stream by utilization of a dosing arrangement arranged downstream of a particulate filter used to catch soot and ash created by the combustion;
• reduction of nitrogen oxides NOx in the exhaust stream by utilization of the supplied additive and a reduction catalyst arrangement arranged downstream of the dosing arrangement;
• and
• interaction of particles in the exhaust stream and at least one filter structure arranged downstream of the dosing arrangement, the particles being created by one or more of the supply of the additive into the exhaust stream and a transformation of the additive when flowing through the exhaust treatment system, wherein the at least one filter structure has a cross section area A in inches2 and a length L in inches resulting in an area to length ratio A/L having a value of at least 14 inches;
• A/L≥17 inches;
• and has an opening degree such that:
• the particles are caused to interact with the at least one filter structure, thereby being at least partly captured and removed by the at least one filter structure;
• and
• accumulation of soot and ash created by the combustion, which would affect the interaction of the at least one filter structure and the particles, is at least partly avoided.

A control system arranged for controlling an exhaust treatment system for treatment of an exhaust stream resulting from a combustion in a combustion engine, the treatment comprising:

• catching soot and ash created by the combustion by utilization of a particulate filter;
• controlling a supply of an additive into the exhaust stream by utilization of a dosing arrangement arranged downstream of the particulate filter;
• reduction of nitrogen oxides NOx in the exhaust stream by utilization of the supplied additive and a reduction catalyst arrangement arranged downstream of the dosing arrangement;
• and
• interaction of particles in the exhaust stream and at least one filter structure arranged downstream of the dosing arrangement, the particles being created by one or more of the supply of the additive into the exhaust stream and a transformation of the additive when flowing through the exhaust treatment system, wherein the at least one filter structure has a cross section area A in inches2 and a length L in inches resulting in an area to length ratio A/L having a value of at least 14 inches;
• A/L≥17 inches;
• and has an opening degree such that:
• the particles are caused to interact with the at least one filter structure, thereby being at least partly captured and removed by the at least one filter structure;
• and
• accumulation of soot and ash created by the combustion, which would affect the interaction of the at least one filter structure and the particles, is at least partly avoided.