Abstract: A metering device for introducing liquid reducing agent into an exhaust gas pipe. A metering valve is supplied with contents from a working tank by a delivery unit and dispenses the tank contents in a discharge direction. The delivery unit establishes a negative pressure between the delivery unit and the metering valve when the delivery direction is reversed. The negative pressure causes gas to be drawn off through the metering valve against the discharge direction. The delivery direction is reversed by either a feed pump with a reversible effective direction or a feed pump and a repolarization valve which communicates with the feed pump and transposes an inlet and an outlet of the feed pump.

Abstract: Methods and devices to monitor an exhaust gas after-treatment system of an internal combustion engine with a motor block and an exhaust gas duct. The engine has at least one catalytic converter, upstream from which a reagent substance necessary for the NOx reduction in the catalytic converter is introduced by means of an introduction device. The reduction agent rate is increased to such an extent at defined reference operating points until an ammonia breach is detected in direction of flow behind the catalytic converter by means of an ammonia sensitive sensor in the exhaust gas duct.

Abstract: A method for regenerating an exhaust aftertreatment system, in particular a particulate filter of an internal combustion engine, situated in a vehicle, having regeneration cycles controlled by a control device. An optimized regeneration of the exhaust aftertreatment system is achieved by supplying information relating to the travel route to the control device and controlling the regeneration cycles, taking the information into consideration.

Abstract: A procedure to operate a particle filter disposed in an exhaust gas area of an internal combustion engine and a device to implement the procedure are proposed. The particle filter is regenerated if required by the particles lodged in the filter, whereby the particle filter is heated for regeneration by manipulation of the exhaust gas temperature upstream in front of the particle filter. During the regeneration of the particle filter, the exhaust gas temperature is established to a specified exhaust gas temperature set point, which is dependent upon at least one parameter of the particle filter during the regeneration. The procedural approach according to the invention allows for a quick regeneration of the particle filter without endangering the particle filter with an inadmissibly high temperature.

Abstract: The invention relates to a procedure for purifying exhaust gas in the exhaust gas duct of a combustion engine with an exhaust gas purification system and a SCR-catalyzer that is arranged in the exhaust gas purification system for a selective catalytic reduction of nitrous gases (SCR), whereby reducing agents for the selective catalytic reduction of nitrous gases can be added to the exhaust gas in direction of the flow before the SCR-catalyzer. According to the invention it is provided that the exhaust gas is led through a catalyzer for converting nitrous gases with hydrocarbons and subsequently through the SCR-catalyzer and that the operating parameters are adjusted in a first operating phase in such a way, that nitrous gases are mostly converted at the catalyzer for converting nitrous gases with hydrocarbons and that the operating parameters are adjusted in a second operating phase in such a way, that nitrous gases are mostly converted at the SCR-catalyzer.

Abstract: A method for operating an internal combustion engine whose exhaust area has at least one SCR catalytic converter and a device for carrying out the method are described. The SCR catalytic converter receiving the reagent supports the conversion of the raw NOx emission of the internal combustion engine. At least a measure of the NOx concentration occurring downstream from the SCR catalytic converter is calculated and this value may be used to define a metering signal for the reagent and/or a heating measure for heating the SCR catalytic converter may be initiated. According to a refinement of this arrangement, a difference between the calculated NOx concentration and the sum of the measured NOx concentration and the measured reagent concentration downstream from the SCR catalytic converter is determined, and it is possible to intervene in the determination of the metering signal depending on the difference.

Abstract: A method for operating a catalytic converter used for purifying the exhaust gas of an internal combustion engine, and a device for implementing the method, which provide for an open-loop or closed-loop control of the reagent fill level in the catalytic converter to a predefined storage setpoint value. The targeted stipulation of the storage setpoint value ensures, on one hand, that in non-stationary states of the internal combustion engine, there is a sufficient quantity of reagent available for the completest possible removal of at least one unwanted exhaust-gas component, and on the other hand, a reagent slip is avoided.

Abstract: A procedure to operate a particle filter disposed in an exhaust gas area of an internal combustion engine and a device to implement the procedure are proposed. The particle filter is regenerated if required by the particles lodged in the filter, whereby the particle filter is heated for regeneration by manipulation of the exhaust gas temperature upstream in front of the particle filter. During the regeneration of the particle filter, the exhaust gas temperature is established to a specified exhaust gas temperature set point, which is dependent upon at least one parameter of the particle filter during the regeneration. The procedural approach according to the invention allows for a quick regeneration of the particle filter without endangering the particle filter with an inadmissibly high temperature.

Abstract: A procedure is introduced to operate a particle filter, which is disposed in the exhaust gas stream of an internal combustion engine and which collects particles from the exhaust gas and possesses the capability for selective catalytic reduction of nitrogen oxides, whereby the selective catalytic reduction is set off by the supply of a reducing agent. The procedure characterizes itself in such a manner, that the supply of the reducing agent is temporarily decreased during a thermal regeneration of the particle filter. Moreover a control unit is introduced, which controls the operation of the procedure.

Abstract: The invention concerns a procedure to monitor an exhaust gas after-treatment system of an internal combustion engine with a motor block and an exhaust gas duct, which has at least one catalytic converter, upstream from which a reagent substance necessary for the NOx reduction in the catalytic converter is introduced by means of an introduction device, whereby the reduction agent rate is increased to such an extent at defined reference operating points until an ammonia breach is detected in direction of flow behind the catalytic converter by means of an ammonia sensitive sensor in the exhaust gas duct.

Abstract: An exhaust gas purification system for purifying the exhaust gas of an internal combustion engine, especially an internal combustion engine featuring auto-ignition and/or direct fuel injection, is provided. The system includes at least one oxidation catalytic converter disposed in an exhaust gas duct of the internal combustion engine, at least one device for selective catalytic reduction of the exhaust gases which is installed downstream of the oxidation catalytic converter, and a feed device for feeding reducing agent into the exhaust gas stream upstream of, or in, the device for selective catalytic reduction. A switch-over device is provided for selectively feeding reducing agent into the exhaust gas stream upstream of, or inside, the at least one oxidation catalytic converter. A corresponding method for purifying the exhaust gas of an internal combustion engine is also provided.

Abstract: A method for operating an internal combustion engine whose exhaust area has at least one SCR catalytic converter and a device for carrying out the method are described. The SCR catalytic converter receiving the reagent supports the conversion of the raw NOx emission of the internal combustion engine. At least a measure of the NOx concentration occurring downstream from the SCR catalytic converter is calculated and this value may be used to define a metering signal for the reagent and/or a heating measure for heating the SCR catalytic converter may be initiated. According to a refinement of this arrangement, a difference between the calculated NOx concentration and the sum of the measured NOx concentration and the measured reagent concentration downstream from the SCR catalytic converter is determined, and it is possible to intervene in the determination of the metering signal depending on the difference.

Abstract: A method for operating a catalytic converter used for purifying the exhaust gas of an internal combustion engine, and a device for implementing the method, which provide for an open-loop or closed-loop control of the reagent fill level in the catalytic converter to a predefined storage setpoint value. The targeted stipulation of the storage setpoint value ensures, on one hand, that in non-stationary states of the internal combustion engine, there is a sufficient quantity of reagent available for the completest possible removal of at least one unwanted exhaust-gas component, and on the other hand, a reagent slip is avoided.

Abstract: A method for regenerating an exhaust aftertreatment system, in particular a particulate filter of an internal combustion engine, situated in a vehicle, having regeneration cycles controlled by a control device. An optimized regeneration of the exhaust aftertreatment system is achieved by supplying information relating to the travel route to the control device and controlling the regeneration cycles, taking the information into consideration.

Abstract: A method of reducing pollutants in an exhaust gas of an internal-combustion engine includes the following steps: producing, at a first location, a reactive gas component NO2 from at least one part of the NO content of the exhaust gas by reaction with the oxygen, contained in the exhaust gas, under an energy effect; and reactively converting the NO2 in a pollutant retaining system situated at a second location downstream of the first location as viewed in the flow direction.