A method for controlling the operation of an exhaust aftertreatment system (EATS) in a vehicle is described. The EATS comprises a main SCR catalyst and a pre-SCR catalyst, a pre-injector arranged upstream the pre-SCR catalyst for providing reductant, a bypass channel fluidly connected to the fluid channel and arranged to bypass the pre-SCR-catalyst and the pre-injector, and a valve configured to control a split of exhaust gases between the pre-SCR catalyst and the bypass channel. The method includes determining the amount of ammonia stored in the pre-SCR catalyst; determining the temperature of the main SCR catalyst; when the ammonia storage in the pre-SCR catalyst is below an ammonia storage threshold and the temperature of the main SCR catalyst is above a temperature threshold, injecting reductant by the pre-injector and controlling the valve to allow a flow of exhaust gases to the pre-SCR catalyst sufficient for transporting the injected reductant to the pre-SCR catalyst for increasing the ammonia storage.

The honeycomb structure body has a dense part at a part in axial direction including a center region of the inflow end face, the dense part having a change ratio of porosity calculated by the following Expression (1) that is 2 to 8%, and has an outside-diameter increasing part, and the honeycomb structure body has a change ratio of average diameter calculated by the following Expression (2) that is 0.2 to 3%,

(1−Px/Py)×100, Expression (1): in Expression (1), Px denotes the porosity (%) at the center region of the inflow end face, and Py denotes the porosity (%) of a circumferential region of the inflow end face.

(1−Dx/Dy)×100,   Expression (2): in Expression (2), Dx denotes the average diameter (mm) of the inflow end face, and Dy denotes the average diameter (mm) of the outflow end face.

The honeycomb structure body has a dense part having a change ratio of porosity calculated by the following Expression (1) that is 1 to 5%. The honeycomb structure body also has an outside-diameter decreasing part in which the outside diameter decreases from the inflow end face to the outflow end face. The honeycomb structure body has a change ratio of average diameter calculated by the following Expression (2) that is 0.2 to 3%.

(1−P.sub.x/P.sub.y)×100,  Expression (1): in Expression (1), P.sub.x denotes the porosity (%) at the center region of the outflow end face, and Py denotes the porosity (%) of a circumferential region of the outflow end face other than the center region.

(1−D.sub.x/D.sub.y)×100,  Expression (2): in Expression (2), D.sub.x denotes the average diameter (mm) of the outflow end face, and D.sub.y denotes the average diameter (mm) of the inflow end face.

An exhaust gas aftertreatment system includes a housing assembly and a reductant delivery system. The housing assembly includes an upstream housing, a first inlet tube, a second inlet tube, and a mixing housing. The first inlet tube is coupled to the upstream housing and configured to receive a first portion of exhaust gas from the upstream housing. The second inlet tube is coupled to the upstream housing and configured to receive a second portion of the exhaust gas from the upstream housing. The mixing housing is coupled to the first inlet tube and the second inlet tube. The mixing housing is configured to receive the first portion of the exhaust gas from the first inlet tube and receive the second portion of the exhaust gas from the second inlet tube. The mixing housing is separated from the upstream housing by the first inlet tube and the second inlet tube.

An exhaust gas purification device (26) for a gas turbine engine (10) comprises a catalyst chamber (64, 96) defined in an exhaust gas passage (22), a reduction agent container (32) containing a solid material that releases a reduction agent gas effective for NOx reduction when heated, a heating device (36, 38) for heating the solid material contained in the reduction agent container, and a reduction agent gas supply passage (48) for supplying the reduction agent gas released from the solid material into the catalyst chamber.

Disclosed is a method for diagnosing a first exhaust treatment component for treatment of an exhaust gas stream comprising means for oxidizing nitric oxide into nitrogen dioxide. A first reduction catalytic converter is arranged upstream said means for oxidizing nitric oxide into nitrogen dioxide, and a second reduction catalytic converter is arranged downstream said means. A reagent is for reduction of nitrogen oxides in said first catalytic converter, and a first sensor measures an occurrence of nitrogen oxide downstream said means but upstream said second reduction catalytic converter. The method comprises: causing a supply of reagent upstream said first reduction catalytic converter to an extent exceeding the extent to which reagent is consumed by the first reduction catalytic converter, determining a first measure of the occurrence of reagent downstream said means for oxidizing, and diagnosing said means for oxidizing nitric oxide into nitrogen dioxide based on said first measure.

An exhaust-gas treatment module for an exhaust system of an internal combustion engine has a plurality of elements which follow one another in an exhaust-gas flow direction. The elements include a first mixing path with a first reactant dispensing arrangement in an upstream end region of the first mixing path and with a first mixing channel which is elongate in the direction of a first mixing path longitudinal axis. A first exhaust-gas treatment arrangement follows and is elongate in the direction of a first exhaust-gas treatment arrangement longitudinal axis and has an upstream end region connected to a downstream end region of the first mixing path, a second mixing path with a second reactant dispensing arrangement in an upstream end region which is connected to a downstream end region of the first exhaust-gas treatment arrangement.

An exhaust purification device includes an adding valve that adds an additive to exhaust gas. A first partition plate includes a first hole-formation region, which includes a main flow hole extending through a central portion and sub-flow holes surrounding the main flow hole, and a first hole-free region surrounding the first hole-formation region. A second partition plate located at a downstream side of the first partition plate includes a second hole-free region, which includes a portion overlapping the main flow hole, and a second hole-formation region surrounding the second hole-free region. An injector injects the additive in a circumferential direction of the first hole-free region from a position opposing the first hole-free region in the extending direction and opposing a projection of the first hole-formation region in a cross-sectional direction.

An exhaust aftertreatment system for an internal combustion engine includes an outer casing defining an exhaust flow path for exhaust gases from the internal combustion engine, a selective catalytic reduction unit provided in the exhaust flow path for reducing nitrogen oxides, a urea dosing device for adding urea to the exhaust flow upstream of the selective catalytic reduction unit, and a rotatable mixer device for mixing the urea with exhaust gases upstream of the selective catalytic reduction unit. The exhaust aftertreatment system further comprises an air inlet valve provided upstream of the mixer device for introducing air into the exhaust flow path, and an electric motor arranged for rotating the mixer device to create a suction of air into the exhaust flow path via the air inlet valve.

An aftertreatment system includes a first dosing module, a second dosing module, and a reductant tank assembly. The reductant tank assembly includes a reductant tank, a header coupled to the reductant tank, and a first splitting device that splits a first flow from the header into a first inlet flow and a second inlet flow. A first inlet line and a second inlet line direct the first inlet flow and the second inlet flow to the first dosing module and the second dosing module. A first outlet line and a second outlet line direct a first outlet flow and a second outlet flow from the first dosing module and the second dosing module to a second splitting device. The second splitting device merges the first outlet flow and the second outlet flow into a second flow and provides the second flow to the header.