Reduction agent dosing system

Reductant dosing device comprises a reductant tank (3) and a supply line (5) connecting the tank with the exhaust gas pipe (8) of the engine using a dosing valve (6) arranged at a distance from the exhaust gas pipe in the supply line. The outlet of the valve opens into a mixing chamber (7) through which pressurized air flows. The reductant is mixed with an air stream in the chamber. Preferred Features: The diameter of the mixing chamber is larger than the diameter of the supply line pipe (5) located on the inlet side of the valve. The valve is arranged directly next to the engine. The mixing chamber is subjected to charging air of a turbocharger (10). One-way restricters (14, 16) are arranged in the pressurized air lines (13, 15). The reductant is an aqueous urea solution.