A reductant injecting device, including: a honeycomb structure including: a pillar shaped honeycomb structure portion having partition wall that defines a plurality of cells each extending from a fluid inflow end face to a fluid outflow end face; and at least one pair of electrode portions arranged on a side surface of the honeycomb structure portion; an outer cylinder having an inlet side end portion and an outlet side end portion, the inlet side end portion comprising a carrier gas introduction port being configured to introduce a carrier gas, the outlet side end portion comprising an injection port being configured to inject ammonia; a urea sprayer arranged at one end of the outer cylinder; and a spray direction switcher configured to be able to switch a spray direction of the aqueous urea solution.

Methods and systems are provided for maintaining a temperature of exhaust gases of an engine within a temperature range at which catalytic conversion is most efficient. In one example, a method for controlling a temperature of exhaust gases entering a Selective Catalytic Reduction (SCR) system for an engine comprises delivering pressurized air into the exhaust gases upstream of the SCR system, the pressurized air cooled by an air cooler; and adjusting a degree of pressurization by adjusting operation of a turbocharger pressurizing the pressurized air. In one embodiment, the air cooler may be a charge air cooler of a primary turbocharger of the engine, which may flow pressurized air both to the engine and to the SCR system. In other embodiments, the air may be pressurized by an air pump or a secondary dilution turbocharger, and cooled by a secondary charge air cooler.

A vehicle exhaust system component, according to an exemplary aspect of the present disclosure includes, among other things, a housing defining an internal cavity to receive exhaust gases, at least one first catalyst received within the internal cavity, at least one filter positioned within the internal cavity downstream of the at least one first catalyst, and at least one second catalyst received within the internal cavity downstream of the at least one filter. A mixer has an inlet that receives exhaust gases exiting the at least one filter and an outlet that directs exhaust gases into the at least one second catalyst. One or more of the at least one first catalyst, the at least one second catalyst, and the at least one filter are serviceable.

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 method to reduce NOx breakthrough and NH3 slip is provided when the SCR system is increasing in temperature and/or increasing exhaust gas mass flow. The method includes the steps of monitoring states of parameters of the exhaust gas upstream of an SCR catalyst where the states of parameters include at least one of the inlet temperature or the exhaust gas mass flow; identifying one of a temperature increase or an increased exhaust gas mass flow at the SCR inlet; identifying a new lower ammonia set-point or storage concentration for the SCR; and identifying the rate of NH3 consumption. The method further includes the step of determining an “intervening phase” a small dosage of DEF is continued during the intervening phase.

A method of converting nitrogen oxides in a gas to nitrogen by contacting the nitrogen oxides with a nitrogenous reducing agent in the presence of a zeolite catalyst containing at least one transition metal, wherein the zeolite is a small pore zeolite containing a maximum ring size of eight tetrahedral atoms, wherein the at least one transition metal is selected from the group consisting of Cr, Mn, Fe, Co, Ce, Ni, Cu, Zn, Ga, Mo, Ru, Rh, Pd, Ag, In, Sn, Re, Jr and Pt.

A method for controlling a reductant generation device 100, the reductant generation device 100 including: a sprayer 10 capable of spraying a reductant precursor 50; and a heater 20 comprising a ceramic substrate 21, the heater 20 being arranged on a downstream side of the sprayer 10 and capable of heating the reductant precursor 50 to generate a reductant 60. The method includes: a permeation step of spraying the reductant precursor 50 from the sprayer 10 and permeating the ceramic substrate 21 with the reductant precursor 50 when the heater is not heated; and after the permeation step, a heating step A of heating the reductant precursor 50 by the heater 20 and generating the reductant 60 while spraying the reductant precursor 50 from the sprayer 10.

A controller for controlling regeneration of a selective catalytic reduction (SCR) catalyst of an aftertreatment system is configured to cause increase in a SCR catalyst temperature of the SCR catalyst to a first regeneration temperature, the first regeneration temperature being lower than a high regeneration temperature that is equal to or greater than 500 degrees Celsius. The controller is configured to determine an amount of ammonia slip downstream of the SCR catalyst; and cause an increase in the SCR catalyst temperature to a second regeneration temperature greater than the first regeneration temperature but lower than the high regeneration temperature based on the determined amount of ammonia slip.

An exhaust aftertreatment unit for cleaning exhaust gases includes an emission reducing module being a diesel particulate filter, DPF, and/or a diesel oxidation catalyst, DOC, a selective catalyst reduction, SCR, catalyst, an electrical heating element arranged upstream of the emission reducing module, a casing housing at least the emission reducing module and the electrical heating element, and a service lid removably arranged to cover a service opening of the casing through which the emission reducing module may be accessed. The electrical heating element is removably arranged relative the casing and is arranged accessible upon removal of the service lid and the emission reducing module.

An injector is provided to inject an aqueous urea solution into an exhaust line. The injector comprises a single fluid inlet, an injection passage, fluidly connecting the inlet to the injection port, and a shut-off device for the injection port. The shut-off device further comprises an actuator that is configured to selectively move a shutter between open and closed positions. A cooling passage is fluidly connected to the injection passage and is configured to cool the actuator. A fluid pressure regulator is interposed in the cooling passage.