Patent ID: 8899022

Claim:
A device for aftertreating exhaust gases ( 1 ) of diesel engines, comprising: a supply of additive with a composition to chemically react with diesel engine exhaust gases across an SCR; an exhaust pipe ( 2 ) through which the exhaust gases ( 1 ) flow, said exhaust pipe defined by a pipe wall having a bend therein, wherein said exhaust pipe wall is substantially continuously curved along said bend; a urea nozzle for injecting the additive into the exhaust pipe ( 2 ) and/or into the exhaust gases ( 1 ) at said exhaust pipe bend, said urea nozzle being connected to the exhaust pipe; a mixing zone ( 3 ) downstream from the urea nozzle; and a substantially cylindrical mixing pipe ( 20 ) in the exhaust pipe ( 2 ), the mixing pipe having an axis and one end extending through the wall of the exhaust pipe ( 2 ) at the pipe bend, wherein the mixing pipe ( 20 ) includes: a first section comprising a substantially constant diameter, perforations ( 22 ), a closing cover ( 25 ) on said one end with a receptacle ( 26 ) in which the urea nozzle is inserted, said mixing pipe one end being in at least partial contact with the bend of the exhaust pipe ( 2 ), and a second section comprising a conical or bell-shaped widened portion ( 23 ) to contact with the exhaust pipe ( 2 ), wherein the exhaust pipe and mixing pipe are configured and relatively situated so that exhaust gases ( 1 ) flow around the mixing pipe ( 20 ) symmetrically and form a double eddy ( 1 ′) in the mixing pipe ( 20 ), and the gas flow directed against the exhaust pipe bend is progressively redirected by the continuously curved exhaust pipe bend from a path that is at a substantial angle to the mixing pipe axis to a path that is generally aligned with the mixing pipe axis.