Abstract: An injection and mixing device comprises a casing having an exhaust inlet and an exhaust outlet, the casing internally defining a passage for exhaust gases from the exhaust inlet to the exhaust outlet. The exhaust inlet opens into an inlet region of the passage. The injection and mixing device further includes an injector of a liquid comprising a nitrogen oxide reducing agent or a precursor of such a reducing agent. A deflector is housed within the casing and defines in the passage a first passage connecting the inlet region to the exhaust outlet, in which the exhaust gases flow at a first average velocity, and a second passage connecting the inlet region to the exhaust outlet, in which the exhaust gases flow at a second average velocity lower than the first average velocity, The injector injects liquid into the second passage.

Abstract: A mixer mixes an exhaust gas and a reducer, the mixer comprising a box closed and sealed to the exclusion of an inlet and an outlet, and in which the exhaust gas flows from the inlet to the outlet. A reducer sprayer is arranged so that the reducer can be sprayed into an exhaust gas flow. The box has a substantially cylindrical shape with a bottom, a cover, an outer wall, and a deflector. The bottom and the cover are substantially flat, superimposed substantially parallel, and form faces of a cylinder. The outer wall joins perimeters of the bottom and the cover and forms a generator of the cylinder. The cover and the outer wall are made together in a single piece. The deflector is an inner wall that joins the bottom and the cover substantially perpendicularly, and the bottom and the deflector are made together in a single piece.