A mixer for a vehicle exhaust system includes an upstream baffle with at least one inlet opening configured to receive engine exhaust gas, a downstream baffle with at least one outlet opening configured to conduct engine exhaust gases to a downstream exhaust component, and an outer peripheral wall surrounding the upstream and downstream baffles and defining a mixer central axis. An intermediate plate is positioned between the upstream and downstream baffles to block direct flow from the inlet opening to the outlet opening. The intermediate plate initiates a rotational flow path that directs exhaust gases exiting the inlet opening through a rotation of more than 360 degrees about the mixer central axis before exiting the outlet opening.

One embodiment of the present disclosure describes an industrial system, which includes a control system with a predictive emissions monitoring system that facilitates determining a chemical level output from a selective catalytic reduction unit that reduces the chemical level in gaseous emissions produced by a combustion source using a selective catalytic reduction model. The control system tunes the selective catalytic reduction model by determining tuning parameters based at least in part on vendor information and tuning data determined via a tuning sequence. The tuning sequence includes operating the combustion source at a plurality of load levels, injecting a reactant into received gaseous emissions at each of the plurality of load levels in accordance with an injection rate provided in the vendor information; and determining an input chemical level to and an output chemical level from the selective catalytic reduction unit at each of the plurality of load levels.

A urea water solution injection system includes a urea water solution injection device for spraying a urea water solution into a portion of an exhaust passageway upstream of a selective catalytic reduction catalyst device, to reduce NOx in exhaust gas discharged from an internal combustion engine. Engine coolant is circulated through the urea water solution injection device to prevent freezing of the urea water solution. A crystal dissolution control unit performs crystal dissolution control on the urea water solution injection device by energizing at a preset amount of energization at a state where a urea water solution supply pump for supplying a urea water solution to the urea water solution injection device is kept stopped, and the crystal dissolution control unit performs the crystal dissolution control for a crystal dissolving energization time calculated in advance, after the engine is started but before a urea water solution is supplied.

An exhaust system for a diesel engine is provided. The exhaust system includes a component body with a surface, and a surface treatment disposed on some of the surface or all of the surface. The surface treatment is disposed so as to receive Diesel Exhaust Fluid (DEF) injected into the exhaust system during operation of the diesel engine. The surface treatment facilitates increased heat transfer to the received DEF to promote water evaporation and urea thermolysis of the received DEF.

Systems and methods of continuous operation of a urea-SCR system at low temperatures (200-350° C.) in the presence of high SOx containing flue gas are described. The methods comprise introducing a solution of urea and an NO.sub.2 forming compound, preferably an alkaline earth metal nitrate, into an exhaust stream before the exhaust stream contacts an SCR catalyst.

A plasma selective catalytic reduction (SCR) system according to an exemplary embodiment of the present invention includes: an exhaust pipe connected to an engine to communicate exhaust gas; a plasma burner installed in a first bypass line connected to the exhaust pipe, and configured to supply fuel to discharged plasma and form flame; a urea solution injector installed in the first bypass line at a rear side of the plasma burner, and configured to inject a urea solution to exhaust gas heated by the flame and generate ammonia; and an SCR catalyst installed in the exhaust pipe at a rear side of the urea solution injector, and configured to reduce a nitrogen oxide included in the exhaust gas with the ammonia.

A reducing agent injection device includes a honeycomb structure and a urea spraying device spraying a urea water solution in mist form. In addition, the reducing agent injection device includes a carrier gas inlet that introduces carrier gas f between the urea spraying device and the honeycomb structure. The exhaust gas treatment method of the present invention supplies the urea water solution from the urea spraying device into the cells from the first end face of the honeycomb structure body to generate the ammonia, while introducing the carrier gas f from the carrier gas inlet, and injecting the ammonia to the outside to treat exhaust gas containing NO.sub.X.

A reducing agent injection device includes a honeycomb structure and a urea spraying device spraying a urea water solution in mist form. A pair of electrode members is formed in the honeycomb structure. The honeycomb structure of the reducing agent injection device, the hydraulic diameter HD, defined as HD=4×S/C, when the area of the cross section of one of the cells in the cross section perpendicular to the cell extending direction is S, and the peripheral length of the cross section of one of the cells is C, is 0.8 to 2.0 mm. Also, the open frontal area OFA of the honeycomb structure in the cross section perpendicular to the cell extending direction is 45 to 80%.

A reducing agent injection device includes a first honeycomb structure and a urea spraying device spraying a urea water solution in mist form. A pair of electrode members is formed in the first honeycomb structure. The ratio L/D of length L in the cell extending direction of the honeycomb structure body to diameter D of the cross section perpendicular to the cell extending direction is 0.5 to 1.2. Also, it is preferable that a urea hydrolysis catalyzer is provided in the second end face side of the honeycomb structure body, with a gap from the second end face.

An emissions control substrate. The emissions control substrate includes a first end and a second end opposite to the first end. A plurality of channels extend between the first end and the second end, and are configured to direct exhaust from an engine through the substrate. The emissions control substrate is three-dimensionally printed