摘要 |
The invention relates to a reducing agent dosing system for injecting a reducing agent into the exhaust-gas flow of an internal combustion engine for selective catalytic reduction, wherein the dosing system can be or is connected to a reducing agent tank (1) from which reducing agent is extracted and delivered by means of a reducing agent pump (2), wherein there is a compressed air supply (3) and at least one nozzle (4) is provided which is connected to the pressure line (11) of the reducing agent pump (2) and via which the reducing agent is introduced into the exhaust-gas flow and atomized by means of compressed air, wherein the pressure line (11) of the reducing agent pump (2) issues via an inlet (6) into a valve (5) which, when it is subjected to pressure by reducing agent delivered by the reducing agent pump (2), opens up the inlet (6) to the valve (5) and an overflow duct to an outlet (7) of the valve to a dosing line (12) to the nozzle (4). |