摘要:
A carrier body includes an overall surface having at least one coating portion with a catalytically active coating including at least one type of catalyst elements disposed in dispersed form at a surface of the carrier body. The catalyst elements have a mean spacing along the surface of at least 3 micrometers. The surface has a mean roughness depth Rz of 2 to 10 micrometers. The carrier body has a maximum increase in pressure loss compared to a carrier body with a smooth and uncoated surface of 25%. A process for producing a carrier body and an exhaust gas treatment unit and a vehicle having a carrier body, are also provided.
摘要:
An apparatus for treating exhaust gas of an internal combustion engine, includes a feed conduit feeding aqueous solution, a hydrolysis catalytic converter connected to the feed conduit and an SCR catalytic converter through which exhaust gas flows. A rod-shaped heating element heats at least parts of the feed conduit and/or hydrolysis catalytic converter. The apparatus provides a compact structure of a feed conduit heated by a rod-shaped element and a corresponding hydrolysis catalytic converter, with which an aqueous solution containing urea can be evaporated and then hydrolyzed to a gas stream containing ammonia. This gas stream serves as a reducing agent in the SCR process. The compact configuration allows installation in very confined space conditions. The hydrolysis catalytic converter, through which exhaust gas does not flow, permits the volume of the hydrolysis catalytic converter to be decisively reduced, since significantly smaller mass flows of gas need to be hydrolyzed therein.
摘要:
A method for removing particulates from a gas stream includes providing a gas-permeable filter layer having subregions with a parameter of differing magnitudes in the direction of the layer thickness. This parameter relates at least to the porosity, the fiber diameter of fibers or the fiber type content of the filter layer. The gas stream is divided into partial gas streams which are each passed through different subregions of the filter layer. Fiber layers, particulate filters, exhaust systems and vehicles based on this method are also provided.
摘要:
A device and method for providing a gaseous substance mixture which includes at least one reducing agent and/or at least one reducing agent precursor, includes a reservoir for an aqueous solution which includes at least one reducing agent precursor that can be flow connected to an evaporator chamber, and a device for dosing the aqueous solution in the evaporator chamber. A device can heat the evaporator chamber to a temperature higher than or equal to a critical temperature, in which the aqueous solution is at least partially evaporated. The device and method enable reducing agent to be provided for selective catalytic reduction of nitrogen oxides in the exhaust of an internal combustion engine. Preferably, an evaporator unit is configured as the evaporator chamber and a hydrolysis catalytic converter is disposed outside the exhaust system. As a result, the size of the hydrolysis catalytic converter is reduced, allowing compact construction.
摘要:
A process for producing a body for exhaust gas treatment having a plurality of metallic layers, includes bringing the layers into contact with each other in a connection region. A connection is made by a roller seam welding process in such a way that the layers form passages through which a gas stream can flow. A corresponding body for exhaust gas treatment can especially be used as a filter or catalyst carrier body in the automobile industry.
摘要:
A particle filter includes a casing and at least one body disposed in the casing and having at least one metallic fiber layer. The at least one metallic fiber layer forms a multiplicity of spatially separate flow paths through the body. The flow paths each have a flow restrictor at least at one location. The at least one metallic fiber layer has an area-related thermal capacity in a range of from 400-1200 Joule per Kelvin and square meter [J/Km2]. The particle filter therefore has an especially high particle storage capacity and regeneration capacity.
摘要翻译:颗粒过滤器包括壳体和设置在壳体中并具有至少一个金属纤维层的至少一个主体。 所述至少一个金属纤维层形成通过所述主体的多个空间上分离的流动路径。 每个流动路径至少在一个位置具有限流器。 所述至少一个金属纤维层具有400-1200焦耳/开尔文和平方米[J / Km <2>]范围内的面积相关热容量。 因此,颗粒过滤器具有特别高的颗粒储存能力和再生能力。
摘要:
A method for providing a reducing agent-containing gas flow in the exhaust system of an internal combustion engine includes providing at least one reducing agent precursor, evaporating the precursor to provide a gas flow, at least partially heating the gas flow to temperatures of at least 250° C., at least partially converting the precursor in the gas flow to a reducing agent and adding the reducing agent-containing gas flow to the exhaust of the engine. The method and a device provide a reducing agent-containing gas flow in a quantity being easily controllable and adaptable to dynamic changes especially in exhaust systems of mobile applications such as automobiles. A temperature of a first zone is kept at 150° C. or just below while a temperature of a second zone is kept at more than 300° C. A hydrolysis catalytic converter is hardly cooled upon receiving the precursor as a vapor, positively affecting the method.
摘要:
A device for treating exhaust gas of an internal combustion engine includes a reducing agent solution evaporator, a hydrolysis catalytic converter connected thereto for hydrolysis of urea to form ammonia and an SCR catalytic converter for selective catalytic reduction of nitrogen oxides. The evaporator includes an evaporator unit providing a gaseous substance mixture including at least one reducing agent precursor and/or reducing agent. The evaporator unit evaporates an aqueous solution including at least one reducing agent precursor. The SCR catalytic converter is in an exhaust line, and the evaporator and the hydrolysis catalytic converter are outside of and can be connected to the exhaust line. A sufficiently large quantity of reducing agent for selective catalytic reduction of nitrogen oxides in the SCR catalytic converter can be provided, while permitting a smaller volume of the hydrolysis catalytic converter than in the prior art, since it is not traversed by exhaust gas.
摘要:
A device and a method for providing a gaseous substance mixture including at least one of a reducing agent and/or a reducing agent precursor, include a reservoir for an aqueous solution including at least one reducing agent precursor, from which the aqueous solution can be delivered into at least one metering line having a dispensing opening by a delivery device, and a device for heating the metering line above a critical temperature greater than the boiling temperature of water. Complete evaporation of an aqueous solution including urea and subsequent hydrolysis to form a substance mixture including ammonia, are carried out. The substance mixture is metered as a reducing agent into an SCR catalytic converter. Carrying out the evaporation outside the exhaust system uses considerably smaller hydrolysis catalytic converters, which is space-saving and cost-saving compared to conventional devices for providing a reducing agent for selective catalytic reduction of nitrogen oxides.
摘要:
A method for producing metal fibers includes a machining production method using at least one rotating tool. A device for producing metal fibers, a filter material having such fibers, a method for producing the material, a particle filter using such material, a motor vehicle equipped with the filter, and a fiber, are also provided.