Apparatus for the Aftertreatment of the Exhaust Gases of Diesel Engines

摘要

An exhaust gas aftertreatment device, including a bent exhaust pipe, a mixing pipe having a closed end at the exhaust pipe bend and a bell-shaped widened portion in at least partial contact with the exhaust pipe at its opposite end, and a nozzle connected to a receptacle in the mixing pipe closed end for injecting an additive into the exhaust gases, with a mixing one in the exhaust pipe between the urea nozzle and the exhaust pipe outlet in which the exhaust gases flow around the mixing pipe symmetrically and form a double eddy in the mixing pipe.

主权项

1. A device for aftertreatment of exhaust gases, comprising:
an exhaust pipe (2) having an inlet end and an outlet end positioned in a downstream direction relative to the inlet end, the exhaust pipe including a continuously curved bend; a mixing pipe (20) including a first section having a substantially constant cross-sectional area extending between a first end adjacent the continuously curved bend and a second end downstream of the first end, and further including a second section having a conical or bell-shaped widened portion (23) extending outwardly from the second end and in contact with the exhaust pipe; a urea nozzle adjacent the first end of the first section of the mixing pipe for injecting an additive into the first section of the mixing pipe; and a mixing zone positioned downstream relative to the first end of the first section of the mixing pipe; wherein the first section of the mixing pipe includes a first plurality of perforations (22) permitting the flow of a first volume of exhaust gases therethrough to promote a homogenous mixture of the first volume of exhaust gases and the additive at the center of the exhaust pipe in the mixing zone; wherein the second section of the mixing pipe includes a second plurality of perforations (24) permitting the flow of a second volume of exhaust gases therethrough and forming a jacket flow around the homogenous mixture in the mixing zone.