A mixer assembly for mixing an injected reductant with an exhaust gas comprises a tubular housing including a reductant inlet, an exhaust gas inlet and an exhaust gas outlet. The reductant inlet is positioned on a first side of the tubular housing and oriented to direct injected reductant along an injection access that extends transversely to a longitudinal axis. A first flow guide element is shaped as a sheet including a first aperture extending therethrough as well as a surface facing upstream. Exhaust gas flowing through the first aperture is impinged by the injected redundant. A second flow guide element is shaped as a sheet, positioned downstream from the first flow guide element and fixed to the first flow guide element to define a mixing chamber between the first flow guide element and the second flow guide element in which the injected redundant and the exhaust gas mix.

A method is disclosed for cleaning a component of an exhaust aftertreatment system located downstream of a combustion engine in an exhaust flow path delimited by an outer wall. The exhaust aftertreatment system includes a first device releasably mounted in the outer wall upstream of the component and a second device releasably mounted in the outer wall downstream of the component, each of the devices being a sensor or an injector. The method includes sealing the exhaust flow path upstream of the first device and downstream of the second device, removing at least the first and second devices, thereby providing at least two openings in the outer wall, so that a cleaning flow path is provided, and introducing cleaning fluid into at least one of the openings, so that the cleaning fluid flows across the component via the cleaning flow path.

An exhaust gas purification system for an internal combustion engine is provided with a filter including a selective catalytic reduction NOx catalyst carried thereon. Further, a post-catalyst is provided for an exhaust gas passage disposed on a downstream side from the filter. The post-catalyst has an oxidizing function, and the post-catalyst has such a function that the production of N.sub.2 based on the oxidation of ammonia is facilitated in a predetermined first temperature area. A filter regeneration process execution unit is programmed to control the temperature of the post-catalyst to be in the first temperature area while adjusting the temperature of the filter to be in a predetermined second temperature area lower than a filter regeneration temperature during a certain period of time.

An exhaust gas treatment system for an internal combustion engine includes an exhaust gas pathway configured to receive exhaust gas from the internal combustion engine, a first treatment element positioned within the exhaust gas pathway, a first injector configured to introduce a first reductant into the exhaust gas pathway upstream of the first treatment element, a second injector configured to introduce a second reductant into the exhaust gas pathway downstream of the first treatment element, a second treatment element positioned within the exhaust gas pathway downstream of the second injector, the second treatment element including a SCR element, and a controller configured to periodically initiate a desulfuring regeneration cycle by increasing a concentration of hydrocarbons in the exhaust gas and increasing the flow of the first reductant through the first injector to oxidize sulfur contamination in the first treatment element at temperatures between 400 and 500 degrees Celsius.

A method is provided for determining exhaust mass flow through a diesel particulate filter (DPF) in an engine arrangement including an engine and an exhaust after treatment system (EATS) comprising the DPF. The method comprises determining soot loading and soot distribution in the DPF, measuring pressure drop over the DPF, measuring pressure in the DPF, measuring temperature in the DPF, and determining exhaust mass flow through the DPF as a function of the measured pressure drop, the measured pressure, the measured temperature, and the soot loading and soot distribution. An arrangement is also provided for determining exhaust mass flow through a diesel particulate filter. A method for controlling one or more engine components, and an engine, are also provided.

An exhaust gas treatment system for an internal combustion engine includes an exhaust gas pathway configured to receive exhaust gas from the internal combustion engine, a first treatment element positioned within the exhaust gas pathway, a first injector configured to introduce a first reductant into the exhaust gas pathway upstream of the first treatment element, a second injector configured to introduce a second reductant into the exhaust gas pathway downstream of the first treatment element, a second treatment element positioned within the exhaust gas pathway downstream of the second injector, the second treatment element including a SCR element, and a controller configured to periodically initiate a desulfuring regeneration cycle by increasing a concentration of hydrocarbons in the exhaust gas and increasing the flow of the first reductant through the first injector to oxidize sulfur contamination in the first treatment element at temperatures between 400 and 500 degrees Celsius.

A method is disclosed for cleaning a component of an exhaust aftertreatment system located downstream of a combustion engine in an exhaust flow path delimited by an outer wall. The exhaust aftertreatment system includes a first device releasably mounted in the outer wall upstream of the component and a second device releasably mounted in the outer wall downstream of the component, each of the devices being a sensor or an injector. The method includes sealing the exhaust flow path upstream of the first device and downstream of the second device, removing at least the first and second devices, thereby providing at least two openings in the outer wall, so that a cleaning flow path is provided, and introducing cleaning fluid into at least one of the openings, so that the cleaning fluid flows across the component via the cleaning flow path.

A gas turbine system includes an exhaust processing system that may process exhaust gas generated by a gas turbine engine, the exhaust processing system includes an exhaust diffuser that may receive the exhaust gas from a turbine of the gas turbine engine and having an annular passage disposed between an inner annular wall and an outer annular wall, and an air injection assembly disposed within the exhaust diffuser. The air injection assembly includes one or more air injection conduits disposed within the annular passage of the exhaust diffuser and including fluid injection holes that may direct a cooling fluid into a first mixing region of the exhaust diffuser.

A reductant insertion system for an after treatment system configured to decompose constituents of an exhaust gas, includes: a dry reductant tank configured to contain a dry reductant; a reductant delivery line configured to operatively couple the dry reductant tank to the after treatment system for delivery of the dry reductant to the after treatment system; and a pressurized gas source configured to communicate the dry reductant to the after treatment system through the reductant delivery line using pressurized gas.

A gas turbine engine system is equipped with a tempering system for a selective catalyst reduction system. The subject tempering system for a selective catalyst reduction system comprises a tempering compartment equipped with a plurality of relatively high temperature environment self-supporting pipes, and optionally, a plurality of flow vanes.