Static mixer for exhaust gas ducts of internal combustion engines, method of manufacturing thereof and exhaust unit incorporating the mixer

Abstract

Static mixer (11) for exhaust gas ducts of internal combustion engines, comprising an elongated hollow metal body (13) having a shape which, relative to a symmetry axis (S), substantially correspondsto a solid of revolution defining at its inside a cavity (15), in which opposite bases (17,19) are defined, at least one of which is provided with an axial opening, and a closed lateral wall (23) is defined connected to the opposite bases (17,19) and having at least one radial opening (25) over which a concave blade (27) is arranged extending radially outward of the lateral wall (23) of the mixerbody from a portion of the peripheral edge (29) of the radial opening (25) and surrounding a portion of the radial opening (25) so as to define, in a first angular direction relative to the symmetry axis, a corresponding concave screen or spoon (31) and, in a second, opposite direction, a mouth (33) intended for the passage of gases and located substantially in front of the concave screen or spoon(31).

Description

technical field [0001] The invention relates to a static mixer for an exhaust pipe of an internal combustion engine, and also to an exhaust unit comprising the mixer and a method of manufacturing the mixer. [0002] The mixer according to the invention can be applied to the exhaust duct of an internal combustion engine where it is necessary to promote the mixing of exhaust gases with substances or mixtures of substances capable of chemically interacting with said exhaust gases. A specific example of application of the mixer of the invention relates to an exhaust unit where selective catalytic reduction (SCR) of nitrogen oxides takes place. Background technique [0003] Static mixers are generally used to facilitate the mixing of exhaust gas with a reducing agent introduced in gaseous or liquid form into the exhaust system of an internal combustion engine. [0004] In this case, the main purpose of the static mixer is to promote the formation of a highly homogeneous mixture ...

AI Technical Summary

Problems solved by technology

[0016] Despite these efforts, however, prior art mixers do not fully address the problem of how to obtain optimum mixing while minimizing the aforementioned disadvantages

[0017] Furthermore, efforts to date have resulted in increasingly bulky, complex and expensive solutions

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