Abstract: In an internal-combustion engine exhaust gas system, a storage tank stores the reducing agent, a supply pipe connects the storage tank to a metering unit which introduces the reducing agent into the exhaust gas system. A pump mechanism within the supply pipe conveys the reducing agent. A pressure sensor detects the pressure in the supply pipe downstream of the pump, and a pressure-releasing device has a return pipe connected to the storage tank and comes off the supply pipe. A first valve system is arranged in the supply pipe. A section of the return pipe is located at a higher level than the return pipe to form a storage volume for air present in the supply pipe. A second valve system is arranged in the supply pipe to create, when the second valve system is closed, a storage volume for pressurized reducing agent by way of this pipe branch.

Abstract: In a method for adapting the reducing agent feed in an exhaust gas aftertreatment system having an SCR catalyst for removing nitrogen oxides from the exhaust gas of an internal combustion engine and at least one reducing agent feed device, the minimum opening time of the reducing agent feed device is determined during operation and while suspending nitrogen emission, carrying out the following steps: a) the opening time of the reducing agent feed device is gradually prolonged until b) a reducing agent-sensitive sensor in the exhaust gas aftertreatment system detects a reducing agent signal. An exhaust gas aftertreatment system is designed accordingly for carrying out the method and a device is designed for controlling an exhaust gas aftertreatment system.

Abstract: A device (4) for introducing a liquid reducing agent (5) into an exhaust gas (6) of a combustion system (2) has a reservoir (20), a discharge element (23) for discharging the liquid reducing agent (5) into the exhaust gas (6), a feed line (22), interposed between the reservoir (20) and the discharge element (23), a delivery element (26) arranged in the feed line (22) for delivering the liquid reducing agent (5) in a direction of delivery (29) from the reservoir (20) to the discharge element (23). The feed line (22) is associated with a controllable venting element (34) upstream of the delivery element (26), the discharge element (23) is connected to the reservoir (20) via a return line (32) and a controllable shut-off element (36) is arranged in the return line (32).

Abstract: In an internal-combustion engine exhaust gas system, a storage tank stores the reducing agent, a supply pipe connects the storage tank to a metering unit which introduces the reducing agent into the exhaust gas system. A pump mechanism within the supply pipe conveys the reducing agent. A pressure sensor detects the pressure in the supply pipe downstream of the pump, and a pressure-releasing device has a return pipe connected to the storage tank and comes off the supply pipe. A first valve system is arranged in the supply pipe. A section of the return pipe is located at a higher level than the return pipe to form a storage volume for air present in the supply pipe. A second valve system is arranged in the supply pipe to create, when the second valve system is closed, a storage volume for pressurized reducing agent by way of this pipe branch.

Abstract: In a method for adapting the reducing agent feed in an exhaust gas aftertreatment system having an SCR catalyst for removing nitrogen oxides from the exhaust gas of an internal combustion engine and at least one reducing agent feed device, the minimum opening time of the reducing agent feed device is determined during operation and while suspending nitrogen emission, carrying out the following steps: a) the opening time of the reducing agent feed device is gradually prolonged until b) a reducing agent-sensitive sensor in the exhaust gas aftertreatment system detects a reducing agent signal. An exhaust gas aftertreatment system is designed accordingly for carrying out the method and a device is designed for controlling an exhaust gas aftertreatment system.

Abstract: A device (4) for introducing a liquid reducing agent (5) into an exhaust gas (6) of a combustion system (2) has a reservoir (20), a discharge element (23) for discharging the liquid reducing agent (5) into the exhaust gas (6), a feed line (22), interposed between the reservoir (20) and the discharge element (23), a delivery element (26) arranged in the feed line (22) for delivering the liquid reducing agent (5) in a direction of delivery (29) from the reservoir (20) to the discharge element (23). The feed line (22) is associated with a controllable venting element (34) upstream of the delivery element (26), the discharge element (23) is connected to the reservoir (20) via a return line (32) and a controllable shut-off element (36) is arranged in the return line (32).

Abstract: A heating device for heating a storage device (2) for a complex salt in a motor vehicle includes the storage device (2) for the complex salt and at least one mass-ducting hollow pipe (4). A mass flows through the mass-ducting hollow pipe (4) while the motor vehicle is operating and heats up while the motor vehicle is operating, and is thermally coupled to the storage device (2) for the complex salt in such a way that the heated mass in the mass-ducting hollow pipe (4) will heat the storage device (2) for the complex salt.