Abstract: A device for decreasing soot particles in exhaust gas, especially from an internal combustion engine, includes concentric outer and inner tubes forming an intermediate space through which the exhaust gas can flow. At least one annular electrode with a multiplicity of electrode tips protruding radially into the intermediate space is disposed on the inside of the outer tube. Terminals can connect the annular electrode and inner tube to a high voltage source forming an electric field in the intermediate space. At least two electrodes are preferably disposed axially at an electrode spacing of preferably 10 to 30 mm. The electrode tips can be approximately conical or pin-shaped with a radial length of 3 to 10 mm. The electrode tips of each electrode have a tip spacing in circumferential direction of 3 to 20 mm or 5 to 10 mm creating a very effective and uniform radial electric field for ionization.

Abstract: A high-temperature-resistant component for an exhaust-gas treatment unit, an exhaust-gas treatment unit and a method for producing such a unit, include providing the component or the exhaust-gas treatment unit with a surface layer intended to prevent the formation of chromium carbide bridges during a brazing process for producing the exhaust-gas treatment unit.

Abstract: An injection device for injecting a fluid into an exhaust-gas treatment device includes an injector positioned in an injector holder. The injector has a supply opening and a component of the injector holder extends into the supply opening. The injection device is suitable, in particular, for supplying a urea/water solution into an exhaust-gas treatment device of a motor vehicle. The component is preferably rigid in the longitudinal direction and can be compressed in the radial direction by way of a deformable rubber shell, in order to compensate for the volumetric expansion of the solution if it freezes. A motor vehicle having the injection device is also provided.

Abstract: A bypass flow filter includes a plurality of channels which are formed of at least one structured wall layer and a filter layer. Projecting guide vanes and passages, which are formed by the wall layer and lead to a different channel, are provided in at least a majority of the channels. The passages have a narrowing cross section and a narrowing part of the cross section is directed towards an adjacent guide vane. An exhaust system and a vehicle having a bypass flow filter, are also provided.

Abstract: A honeycomb body, especially a particulate filter, particularly for motor vehicle exhaust purification, includes inner walls defining passages with an entry and exit. Cavities free of walls in at least one subregion contain at least one spherical free space having a largest cross-sectional area at least 10 times a cross-sectional area of the passages in the subregion. The honeycomb body is wound, twisted or layered from at least one metal sheet having layers with a structuring forming the passages, at least in the subregion. The sheet-metal layers have holes with an area greater than 10 times the cross-sectional area of the passages in the subregion. The holes form cavities in at least 5 successive layers overlapping with an area at least 10 times the cross-sectional area of the passages in the subregion. The holes are double or more than triple the hydraulic diameter of the passages opening into the cavity.

Abstract: A honeycomb body for an exhaust system of an internal combustion engine has an axial length and channels which are substantially separated from each other and through which an exhaust gas can flow. The honeycomb body includes at least one first and one second subset of channels. At least the cross-sectional areas of one of the subsets of channels differs along the axial length of the honeycomb body, so that a transient time of the exhaust gas in the different subsets of channels is different. The difference in transient time of the exhaust gas between the different subsets of channels can be used for damping sound waves having one or more wavelengths, so that noise is reduced in the exhaust system in order to purify the exhaust gas without needing additional components in the exhaust system. An exhaust system and a method for muffling sound therein are also provided.

Abstract: A support body is described which has an adsorber material for adsorbing nitrogen oxides in an exhaust gas which is generated in at least one combustion chamber of an internal-combustion engine. A method is described for operating an internal-combustion engine having an exhaust system which has a support body of this type. All the combustion chambers of the internal-combustion engine together have an overall combustion chamber volume, and the support body has an adsorber volume. The adsorber volume is configured to be less than 75%, in particular less than 45%, and preferably even less than 5% of the combustion-chamber volume. A support body of this type ensures a good cold-starting performance of the exhaust system and prevents the emission of nitrogen oxides, in particular when using the proposed method of operating the exhaust system.

Abstract: A housing for a honeycomb body includes a jacket tube with an inner wall surface. The jacket tube has a passivation layer in at least one section of the inner wall surface in order to deliberately modify a connection to the honeycomb body by joining. A method for the production of a catalyst carrier body with a honeycomb body and a housing according to the invention are also indicated. A catalyst carrier body produced in this way reduces thermal stresses between the honeycomb body and the jacket tube and, in particular, ensures a reliable brazing process during production, even in a vacuum.

Abstract: The method and the novel device clean exhaust gas containing nitrogen oxide from an internal combustion engine. Liquid ammonia is preferably added as reducing agent from a reducing agent reservoir through a reducing agent line and a metering device through the use of open loop or closed loop control synchronously and/or phase-displaced in a relation to the corresponding output of exhaust gas from the combustion chamber and in portions adjusted to the quantities of NOx generated. The synchronized and quantitatively adjusted addition of ammonia allows for NOx and ammonium emissions to be kept low with a catalytic converter disposed downstream and having a small storage volume.

Abstract: A device is configured to catalytically reduce internal combustion engine exhaust gases which contain nitrogen oxides. The device has an exhaust pipe, one end of which can be connected to at least one exhaust outlet of the internal combustion engine. A reducing agent, in particular urea, is introduced into the exhaust pipe with a feed device. At least one mixer is arranged downstream of the reducing agent injection, as seen in the flow direction of the exhaust gas. The mixer has a multiplicity of passages through which the fluid can flow. At least one catalytic converter is arranged downstream of the mixer. At least one diffuser is located between the mixer and the converter. The diffuser which has a multiplicity of passages through which the exhaust gas can flow and which have a cross section which increases in the flow direction.

Abstract: A double-walled housing, in particular for exhaust gas catalytic converters of motor vehicles, includes an inner jacket and an outer jacket approximately concentrically surrounding and spaced apart from the inner jacket. The inner and outer jackets rest tightly against one another at both end surfaces. The inner jacket is kept under compressive strain at least at two end regions by constrictions of the outer jacket. The outer jacket has embossed features oriented toward the inner jacket. The housing is produced by deforming the inner jacket by rolling a metal sheet into cylindrical or conical form while maintaining a parting line. The outer jacket is deformed by rolling a metal sheet into cylindrical or conical form and by connecting mutually meeting edges by a joining technique. The inner jacket is disposed in the outer jacket and the outer jacket is plastically deformed inward over its entire circumference on both end surfaces in such a way that the inner jacket is kept under compressive strain.

Abstract: In a device for the catalytic conversion of exhaust gases in an exhaust system, in particular an exhaust system of a combustion engine, and a process for manufacturing the same, a catalyst carrier body is provided with a multiplicity of channels through which an exhaust gas can flow. At least a part of a free flow cross-section of the channels is closed in an exhaust gas flow direction by plastic deformation of channel walls in an outer annular region of the catalyst carrier body. The plastic deformation can be carried out with a tool. The tool has a disk rotatable about an axle. The disk is pressed with force against the catalyst carrier body and the jacket so that a plastic deformation of the jacket tube and the channel walls occurs. A circumferential bead directed towards the carrier body is produced. Other techniques for plastic deformation are possible.