METHOD FOR EMPTYING A REDUCING AGENT DELIVERY SYSTEM BELONGING TO AN SCR CATALYTIC CONVERTER

• Main Authors: Ringeisen, Marc, Hackert, Annabel, Reiter, Manuel Simon
• Format: Patent
• Language: English
• Published: 06.06.2019
• Subjects: BLASTING; ENGINE PLANTS IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNALCOMBUSTION ENGINES; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES ORENGINES IN GENERAL; HEATING; LIGHTING; MACHINES OR ENGINES IN GENERAL; MECHANICAL ENGINEERING; STEAM ENGINES; WEAPONS

The invention relates to a method for emptying a reducing agent delivery system belonging to an SCR catalytic converter, which comprises a delivery line and a return line, each line connecting a reducing agent tank to a delivery module, and which comprises a pressure line that connects the delivery module to a metering valve. The method comprises the following steps: closing (50) the metering valve, and switching the delivery module from a delivering function to a returning function, by switching (51) a switching valve from a first position to a second position. This enables a reducing agent solution to be returned (52) from the return line, the delivery line and the delivery module by means of the delivery module and the delivery line into the reducing agent tank. Subsequently, the metering valve is opened (53) and a reducing agent solution is returned (54) from the metering valve and the pressure line, and also from the return line, via the delivery line into the reducing agent tank. Additionally, the metering valve is closed again (55) in order to empty (56) the return line and the delivery module.