DE112009001055T5 - Exhaust element comprising a static means for admixing an additive to exhaust gases - Google Patents

Abstract

Exhaust element (3; 4) which is part of an exhaust line (2) of a motor vehicle with internal combustion engine (1) and inside which a fluid flows which consists of exhaust gases and an additive to these gases, this exhaust element (3; 4) has an internally mounted static means (6) for adding this additive to these exhaust gases, characterized in that the static means (6) for adding the additive to the exhaust gases comprises at least one helical surface (helicoid) (61) which has an axis, which extends in a direction which forms a certain angle (α) with the flow direction (D) of the fluid in this exhaust gas element (3; 4).

Description

The present invention relates to an exhaust element which is part of an exhaust system of a motor vehicle with an internal combustion engine.

This invention relates to the automotive industry, and more particularly to the manufacture of equipment intended to ensure the outflow of gases resulting from the combustion of a fuel inside an internal combustion engine fitted to a motor vehicle.

Such a system is designed in the form of an exhaust line, which, viewed in the order according to the flow direction of the exhaust gases in this exhaust line, on the one hand connected to such an internal combustion engine, on the other hand has a succession of exhaust elements and finally into the atmosphere. empties.

In particular, the exhaust system of these exhaust elements at least one device for the physical and / or chemical treatment of the exhaust gases.

Such a device may consist of a catalyst which may be in the form of a catalyst (in particular of the SCR type) for reducing nitrogen oxides (NOx) and which has a means of treating the gases which are at least adapted for such reduction sure. Such a catalyst is of particular interest when it comes to purifying exhaust gases resulting from the combustion of a diesel fuel.

It. It has been found that the reduction of these exhaust gases inside such a catalyst is considerably improved if these exhaust gases have been mixed with an additive containing urea prior to their introduction into this catalyst. In fact, when introduced into hot exhaust gases (especially after evaporation of an aqueous urea solution), urea undergoes a chemical transformation in which it is converted to ammonia (NH3), which is a potent nitrogen oxides reductant. Thus, the exhaust gases are reduced in the interior of the catalyst and in the presence of this ammonia, so that at the output of this catalyst substantially water, hydrogen (H2) and nitrogen (N2) are released.

In this regard, it should be noted that the more homogeneous the mixture of the additive with the exhaust gases, the more efficient is the reduction of these nitrogen oxides.

In order to improve the homogeneity of this mixture, it is known to use a static mixer positioned inside an exhaust element (usually an exhaust pipe) and upstream of the means for treating the gases.

In the document WO 9300990 is described such a mixer which is formed in the form of a plurality of baffles, which are arranged on the one hand in several rows perpendicular to the axis of symmetry of the exhaust element and on the other hand aligned within one and the same row in one and the same direction and in two adjacent rows in an opposite direction ,

Furthermore, from the document EP-1514591 an exhaust element having internally a static mixer having a plurality of baffles formed in the shape of curved laminations extending from the periphery of this element towards its center. These baffles define wings of a helix that extends through the exhaust element.

Although these devices make it possible to improve the homogeneity of the mixture downstream of the mixer, they have the disadvantage of producing a considerable back pressure upstream of this mixer, which adversely affects the flow of the gases in the exhaust line as well as their treatment and their discharge ,

The present invention is capable of overcoming the disadvantages of the prior art devices.

To this end, the invention relates to an exhaust element which is part of an exhaust line of a motor vehicle with an internal combustion engine and in the interior of which flows a fluid consisting of exhaust gases and an additive to these gases, said exhaust element having an internally mounted static means for admixing it Has additional to these exhaust gases. This exhaust element is characterized in that the static means for admixing the additive to the exhaust gases comprises at least one helicoid having an axis extending in a direction which forms a certain angle with the flow direction of the fluid in that exhaust element ,

An additional feature relates to the fact that the direction of extension of the axis of a helical surface forms an angle in the range of 0 to 30 ° with the flow direction of the fluid in the exhaust gas element.

According to another feature, the mixer comprises a plurality of helical surfaces, each having an axis which extends on the one hand in a direction which forms with the direction of extension of the axis of another helical surface a certain angle, which is in particular in the range of 0 to 30 °, and on the other hand extends in a direction which forms a certain angle with the flow direction of the fluid in this exhaust element, which is in particular in the range of 0 to 30 °.

According to an additional feature, the two adjacent spiral surfaces have an identical or, and preferably, opposite direction of rotation.

An additional feature is that the mixer comprises a plurality of helical surfaces and that these helical surfaces are grouped within at least one set comprising at least two helical surfaces having a preferably identical rotational direction.

According to another feature, the mixer comprises at least one module having on one side a plate aligned parallel to the flow direction of the fluid in the exhaust element and on the other side at least one helical surface or set of at least two helical surfaces located in the downstream one Extension of this plate extends.

In fact, this mixer comprises a plurality of modules, each having a plate and a set of at least two helical surfaces on the one hand and connected in pairs, in particular in a vertical manner, by connecting means with which at least one plate of at least one such module is equipped.

Finally, such a module consists of a single, in particular metallic part, which is preferably produced by cutting, twisting, in particular supplemented by a bend.

In fact, this exhaust gas element consists either of an exhaust gas conduit internally provided with admixture of an additive to the flue gases, or of a device for physically and / or chemically treating the flue gases, internally the admixture of an additive to the flue gases and downstream thereof Mischers has a means for the physical and / or chemical treatment of this mixture.

The invention also relates to an exhaust system comprising such an exhaust element.

The advantages of the present invention are that the exhaust element comprises a static mixer for mixing the additive with the exhaust gases, such a mixer consisting of at least one helical surface positioned inside this exhaust element. Such a helical surface advantageously makes it possible to impart to the fluid a swirling motion which favors the homogenization of the mixture. Another advantage of such a helical surface is that the fluid downstream of this helical surface has such a flow that the back pressure created by the additive / exhaust mixture is substantially lower than that produced by the prior art devices becomes.

In addition, such a mixer may also have a plurality of helical surfaces, which are in fact arranged in a sophisticated manner inside the exhaust element, such that they adapt to the geometry and / or the dimensions of the exhaust element, which advantageously allows the flow of the fluid downstream of this mixing agent.

In addition, it is easily possible to adjust the number of helical surfaces, their positioning relative to each other and their properties (direction of rotation, length, pitch, diameter, orientation of the axis), which makes it possible to achieve advantageously good results, which the homogeneity of the mixture and the low level of back pressure (or even the trade-off between this back pressure and the pressure drop) downstream of the mixer.

In this connection, it should be noted that good results are achieved if this mixer has at least one pair of helical surfaces or even, and preferably, two pairs of helical surfaces.

An additional feature is that this mixer is positioned inside an exhaust element consisting of an exhaust pipe or a device for treating the gases, in particular a catalyst. Such an embodiment advantageously allows this mixer to be positioned in an optimized manner with respect to the means for introducing the additive and with respect to the means for treating the exhaust gases within the exhaust line.

Finally, this mixer can be made starting from at least one sheet, more particularly by cutting, twisting, in particular supplemented by a bend. This advantageously makes it possible to provide a particularly efficient static mixer with particularly low production costs.

Other objects and advantages of the present invention will become apparent in the course of the following description, which refers to embodiments given by way of example only, which are intended to be illustrative and not restrictive.

The understanding of this description will be facilitated by reference to the accompanying drawings in which:

1 is a schematic view of an exhaust line, comprising an exhaust element according to the invention;

2 a schematic view of an exhaust element in partial longitudinal section, which consists of an exhaust pipe and internally receives a means for mixing (mixer) of an additive to exhaust gases;

3 a schematic view and detailed view of such a mixer is;

the 4a and 4b schematic views and detailed views are each showing one of the two modules of which such a mixer is composed;

the 5a to 5d schematized views and detailed views are that of a first embodiment of the installation of such a mixer inside an exhaust element, which in 2 is shown correspond;

the 6a to 6c schematized views and detailed views are that of a second embodiment of the installation of such a mixer in the interior of an exhaust element, which in 2 is shown correspond.

The invention relates to the field of the automotive industry and more particularly to the manufacture of equipment designed to ensure the outflow of gases resulting from the combustion of a fuel inside an internal combustion engine 1 result, with which a motor vehicle is equipped.

Such a plant has the form of a Abgasstranges 2 on, on this engine 1 is connected and several exhaust elements ( 3 ; 4 ), which runs along this exhaust line 2 consecutive.

In particular, this exhaust system 2 , as in 1 seen, at least one exhaust element 3 comprising, means for ensuring the physical and / or chemical treatment of the combustion of a fuel inside the engine 1 originating exhaust gases.

Such a device for treatment 3 can be from a particle filter 31 (usually called "FAP"), the downstream of the engine 1 is positioned.

Such a device for treatment 3 can also be from a catalyst 32 which is also downstream of the engine 1 is positioned. According to a first embodiment, the in 1 is shown and a standard configuration of a Abgasstranges 2 corresponds, this catalyst can 32 downstream of an above-mentioned particulate filter 31 be positioned. However, according to another embodiment, not shown, such a catalyst 32 also in a more complex exhaust element 3 (usually called "cata-FAP"), which is such a catalyst 32 as well as a particle filter 31 of the type mentioned above.

In fact, there is such a catalyst 32 more specifically, and at least partially, a catalyst for treating the nitrogen oxides (NOx) contained in the exhaust gases.

Such a catalyst 32 for the treatment of nitrogen oxides can from a catalyst for trapping these nitrogen oxides (usually called "NOx trap" or NOx trap) or from a catalyst for the catalytic reduction of these nitrogen oxides, for example, a three-way catalyst type TWC or a catalyst type SCR (Selective Catalytic Reduction).

In the special case of a catalyst 32 for the reduction of nitrogen oxides, this catalyst 32 then inside a means (more specifically a ceramic or something analogous) for the treatment of the exhaust gases, which treatment agent is adapted to ensure the catalytic reduction of the nitrogen oxides contained in these gases.

In this regard, it should be noted that the catalytic reduction of the nitrogen oxides contained in the exhaust gases is favored when these gases contain a reducing agent.

The presence of such a reducing agent in these gases can be ensured by placing inside the exhaust line 2 and upstream of the catalyst 32 such a reducing agent is introduced, or the precursor of such a reducing agent, which in the interior of the exhaust line 2 and is converted into such a reducing agent upstream of the treating agent.

For this purpose, the exhaust system 2 by a means 5 completes, the downstream of the particulate filter 31 and upstream of the catalyst 32 is positioned and designed so that it enters the interior of this exhaust line 2 (In particular, by injection, more specifically after atomization or evaporation) introduces an additive which must be added to the exhaust gases for the production of a fluid by catalytic reduction in the interior of the catalyst 32 to treat.

This introduced additive consists of a reducing agent or a precursor of such a reducing agent.

In fact, and according to a preferred embodiment, this additive is made on the basis of urea and may consist of a (especially aqueous) solution with a low urea content, more specifically known under the name AdBlue (precursor of a reducing agent). This solution undergoes a chemical transformation (thermolysis, hydrolysis) inside the exhaust line 2 in that it is present within the fluid to be treated at least in the form of ammonia (NH3), which is the reducing agent admixed with the exhaust gases.

It should also be noted that the efficiency of the catalytic reduction of the nitrogen oxides contained in the exhaust gases increases with homogeneity of the catalyst 32 increased to be treated fluids.

To homogenize this fluid, the exhaust line points 2 also a static means 6 for mixing the additive with the exhaust gases, this agent 6 in the further course of the description for the sake of convenience "mixer 6 " is called.

Such a mixer 6 is then adapted to mix the waste gases with the additive, which, depending on the present case of the reducing agent (in the case of incorporation of an additive which consists of such a reducing agent, or after conversion of one into the strand 2 incorporated precursor of such a reducing agent into a reducing agent) and / or from the precursor of such a reducing agent (in the case of incorporation of an additive consisting of such a precursor of a reducing agent).

In fact, and as can be seen from the attached figures, this mixer is 6 , along the exhaust system 2 and within it 2 , between the mean 5 positioned for introduction of the additive and the means for treating this fluid.

For this purpose, and according to a first, not shown embodiment, such a mixer 6 inside an exhaust element 3 be arranged, which consists of a device 3 for the physical and / or chemical treatment of the exhaust gases, with which the exhaust system 2 Is provided.

This device 3 for treatment then has the agent inside 6 for admixing an additive to the exhaust gases, and downstream of this mixer 6 a means for physical and / or chemical treatment of the mixed fluid.

Preferably then there is this device 3 for treating the exhaust gases from a catalyst 32 for the catalytic reduction of the nitrogen oxides contained in the exhaust gases, or from a device 3 to the more complex treatment of the type mentioned above (cata-FAP), which is such a catalyst 32 includes.

However, according to a preferred embodiment of the invention, the means 6 for admixing an additive to the exhaust gases in the interior of an exhaust element 4 attached, that from an exhaust pipe 41 consists.

As can be seen from the attached figures, there is such an exhaust element 4 preferably from an exhaust pipe 41 for the connection of a particle filter 31 to a catalyst 32 ,

In fact, and how from the 5a to 5d and 6a to 6c it can be seen that such a line exists 41 preferably of two sections ( 411 ; 412 ) of the line 41 of which at least one 411 in the mixer 6 receives. This latter 6 then goes inside this section 411 the line 41 beyond its mouth and before (in particular, by making a strong connection, for example by welding) connecting this section 411 the line 41 to the other section 412 this line 41 introduced.

No matter which type of exhaust element. ( 3 . 4 ) is (treatment device 3 or lead 41 ) and / or which geometry it has, it also includes a means inside 7 for receiving the mixer 6 inside this exhaust element ( 3 . 4 ).

In fact, and how from the 5a to 5d and 6a to 6c there is such a means 7 for receiving preferably from a special embodiment of the exhaust element ( 3 . 4 ), in particular by deformation of this exhaust element ( 3 . 4 ), more precisely by deformation of a mouth end, which is a section 411 a line 41 has, from the such an exhaust element 4 consists.

According to the invention, the means exists 6 for admixing the additive to the exhaust gases from at least one helical surface (helicoid) 61 ,

Such a spiral surface 61 is characterized at least by a pitch, by a length, by a diameter, by a thickness, by a width, by an axis along which it extends, and by a direction of rotation.

In this regard, it should be noted that the width of such a helical surface 61 in the flow direction D of the fluid in the exhaust element ( 3 . 4 ) can be constant. Good results were, however, for a helical surface 61 achieved for which this width in the flow direction D of the fluid in the exhaust element ( 3 . 4 ) is increasing or and preferably decreasing.

In fact, and according to another feature of such a helical surface 61 , this has a width which corresponds to the configuration of the exhaust element ( 3 . 4 ) is adapted, the at least one such helical surface 61 receives. Such an embodiment advantageously allows the width of at least one such helical surface 61 to adapt to such a configuration (more particularly to the cross section of this exhaust element ( 3 . 4 ), in particular such that the total internal volume of this latter ( 3 . 4 ) is taken).

In addition, and according to another feature, has such a spiral surface 61 an axis extending in a direction coincident with the flow direction D of the fluid in this exhaust element ( 3 . 4 ) forms a certain angle α.

In this regard, it should be noted that the direction of extension of the axis of such a helical surface 61 with this flow direction D of the fluid in this exhaust element ( 3 . 4 ) forms an angle α in the range of 0 to 30 °.

According to a special embodiment of the invention, not shown, this mixer 6 from a single spiral surface 61 exist within an exhaust pipe 41 , is arranged and whose axis is at least parallel to the axis and in particular identical to the axis of this line 41 is.

According to a preferred embodiment of the invention, this mixer 6 but in reality several spiral surfaces 61 on.

• – zwei Wendelflächen 61 für ein Abgaselement (3, 4) mit einem im Wesentlichen rechteckigen Querschnitt;
• – drei Wendelflächen 61 für ein Abgaselement (3, 4) mit einem im Wesentlichen dreieckigen Querschnitt;
• – vier Wendelflächen 61 für ein Abgaselement (3, 4) mit einem im Wesentlichen quadratischen (6c) oder runden (5d) Querschnitt.

Such an embodiment advantageously allows the mixer 6 to the cross section of the exhaust element ( 3 . 4 ) equipped with it, and / or the quality of the homogenization of the fluid at the outlet of the mixer 6 For example, such a mixer 6 then include:

• - two spiral surfaces 61 for an exhaust element ( 3 . 4 ) having a substantially rectangular cross section;
• - three spiral surfaces 61 for an exhaust element ( 3 . 4 ) having a substantially triangular cross section;
• - four spiral surfaces 61 for an exhaust element ( 3 . 4 ) with a substantially square ( 6c ) or round ( 5d ) Cross-section.

Another feature of the invention is that these spiral surfaces 61 each having an axis which extends on the one hand in one direction, with the direction of extension of the axis of the other helical surface 61 or the other spiral surfaces 61 of the mixer 6 forms a certain angle α ', and on the other hand extends in a direction coinciding with the flow direction D of the fluid in this exhaust element ( 3 . 4 ) forms a certain angle α.

In this regard, it should be noted that the direction of extension of the axis of a helical surface 61 actually with the extension direction of the axis of another spiral surface 61 or the other spiral surfaces 61 forms an angle α 'in the range of 0 to 30 °.

In such a case, and as mentioned above, the extending direction of the axis of such a spiral surface 61 also with the flow direction D of the fluid in the exhaust gas element (FIG. 3 . 4 ) form an angle α in the range of 0 to 30 °.

A specific embodiment (shown in the accompanying figures) is that the angles α and α 'are equal to zero, so that the axis of a helical surface 61 parallel to the extension direction of the axis of the other helical surface 61 or the other spiral surfaces 61 of the mixer 6 and to the flow direction D of the fluid in this exhaust element ( 3 . 4 ).

In such a case, the extension axes of the helical surfaces 61 parallel to each other.

However, and according to another configuration, not shown, these helical surfaces can 61 be arranged so that their axes of extension in the flow direction D of the fluid in the exhaust element ( 3 . 4 ) diverge or, and preferably, converge.

As mentioned above, have these helical surfaces 61 in the flow direction D of the fluid in the exhaust element ( 3 . 4 ) a constant, increasing or decreasing and / or to the configuration of the exhaust element ( 3 . 4 ) adapted width.

This feature combines with that of the (in particular convergent or divergent) extension direction of the axes of these helical surfaces 61 , Advantageously, allows these spiral surfaces 61 to the configuration of the exhaust element ( 3 . 4 ) (more specifically to the cross section thereof), in particular such that the entire internal volume of this exhaust element ( 3 . 4 ) is taken.

According to an additional feature of the invention, the axes of these helical surfaces 61 in the form of a (rectangular, triangular, square, etc.) matrix, in particular a regular matrix, arranged according to the (rectangular, triangular, round or square, etc.) geometric shape of the cross section of this exhaust element ( 3 . 4 ). Such an embodiment advantageously enables the arrangement and distribution of these helical surfaces 61 inside the exhaust element ( 3 . 4 ) with respect to and depending on the design of the latter ( 3 . 4 ) to optimize.

As mentioned above, each helical surface has 61 one direction of rotation.

In this regard, it should be noted that, according to an additional feature of the invention, two helical surfaces located immediately adjacent to each other 61 or even all spiral surfaces 61 of the mixer 6 may have an identical direction of rotation.

Such an embodiment is particularly advantageous when the fluid is a longitudinal swirling motion (swirl) upstream of the mixer 6 performs.

According to a preferred embodiment of the invention ( 3 . 5d . 6c ) have such immediately adjacent spiral surfaces 61 but preferably an opposite direction of rotation on (opposite helical surfaces). Such an embodiment advantageously makes it possible to obtain a fluid to be treated which is optimally mixed.

Another feature of the invention is that the mixer 6 According to the invention several spiral surfaces 61 and that these spiral surfaces 61 within at least one sentence ( 611 ; 612 ) are grouped, the at least two spiral surfaces 61 includes.

In this regard, it should be noted that the spiral surfaces 61 one and the same sentence ( 611 ; 612 ) of helical surfaces 61 depending on the present case an opposite direction of rotation (opposite spiral surfaces) or (and preferably) have an identical direction of rotation ( 3 . 4a . 4b . 5d . 6c ).

A special, not shown embodiment can then be in a mixer 6 consist of a single set of at least two helical surfaces 61 having, in particular to an exhaust element 4 is adapted with rectangular or oblong cross-section.

According to a preferred embodiment of the invention, the mixer 6 but on the one hand at least one sentence 611 (or even multiple, preferably parallel sets) of at least two (or more) helical surfaces 61 on which are aligned in a certain first direction, and on the other hand at least one other sentence 612 (or even several other, preferably parallel sets) of at least two (or more) helical surfaces 61 aligned in a particular second direction forming a (preferably right) angle with the determined first direction.

In this regard, it should be noted that the number of these rates ( 611 ; 612 ), the number of spiral surfaces 61 from which such a sentence ( 611 ; 612 ), and the arrangement and orientation of these sentences ( 611 ; 612 ) as a function of the geometry of the exhaust element ( 3 . 4 ) that the mixer 6 be determined, in particular with the aim of filling the area, which is the cross section of the exhaust element ( 3 . 4 ) offers to optimize.

A preferred embodiment of the invention (in the 3 to 6c shown) is that the mixer 6 two sentences ( 611 ; 612 ) of helical surfaces 61 which are in particular mutually perpendicular and in each case a pair of helical surfaces 61 include. In this embodiment, the two helical surfaces 61 one and the same sentence ( 611 ; 612 ) an identical direction of rotation, while the two immediately adjacent Wendelflächen 61 two different sentences ( 611 ; 612 ) may have an identical direction of rotation, but preferably, as in the 3 to 6c shown, have an opposite direction of rotation.

Such a mixer 6 with four spiral surfaces 61 can be inside an exhaust element ( 3 . 4 ) arranged either from a device 3 to treat the gases as mentioned above or from an exhaust pipe 4 of conventional construction (and the most common) exists, and which has a round cross section ( 2 to 6c ).

In this latter case, the axes of these four spiral surfaces 61 preferably arranged in the form of a square matrix, the circular geometry of the cross section of the exhaust element 41 equivalent.

According to a first embodiment, which in the 5a to 5d are shown, these are four spiral surfaces 61 inside a section 411 with round cross-section of this exhaust pipe 41 arranged.

According to a preferred embodiment of the invention, which in the 6a to 6c are shown, these are four spiral surfaces 61 however, inside a special section 411 ' arranged with a square cross-section, in the region of this exhaust pipe 41 is defined with a round cross-section. Such an embodiment advantageously enables the effectiveness of the mixer 6 increase by the area of the cross-section of the pipe 41 that have little (or not at all) the effect of helical surfaces 61 is reduced proportionally with respect to a round cross-section.

Actually, this section can 411 ' with square cross section by deformation of the exhaust pipe 41 be defined with a round cross section, in particular by expansion.

According to another feature of the invention, these helical surfaces 61 a diameter of 25 to 40% (preferably about 35%) of the inside diameter (section 411 with round cross-section of the pipe 4 ) or the maximum cross-section (Section 411 ' with square cross section of the pipe 4 ) of the section ( 411 . 411 ' ) of the exhaust pipe 4 who has these spiral surfaces 61 picks up.

Above, a preferred embodiment has been described, which is a mixer 6 concerns the two sentences ( 611 . 612 ), each consisting of two spiral surfaces 61 consist. However, the present invention is by no means limited to such a configuration.

This mixer 6 can also, according to another, not shown embodiment, at least one sentence ( 611 ; 612 ) comprising more than two (in particular 3, 4 or more) helical surfaces 61 exists, which are aligned in one direction. Furthermore, another embodiment may be in a mixer 6 consisting of several sets, at least some of which have a different number of helical surfaces 61 exhibit.

Such is a mixer 6 conceivable, on the one hand at least one sentence 611 (or even several, preferably parallel sets) comprising 3, 4 or more helical surfaces 61 which are aligned in a certain first direction and on the other hand at least one other set 612 (or even several other, preferably parallel sets) of at least two (or more) helical surfaces 61 aligned in a particular second direction forming a (preferably right) angle with the determined first direction.

An additional feature is that these spiral surfaces 61 have a length in the range of 60 to 100 mm, preferably of about 80 mm, in particular of 82 mm.

According to another feature of the present invention, the static means comprises 6 for admixing the additive to the exhaust gases, at least one module 62 where each module is a plate ( 621 ; 622 ), which is aligned parallel to the flow direction D of the fluid in the exhaust element, and on the other hand, at least one helical surface 61 or a sentence ( 611 ; 612 ) of at least two helical surfaces 61 which is located in the downstream extension of this plate ( 621 ; 622 ).

In this regard, it should be noted that such a plate ( 621 ; 622 ) has two longitudinal sides, and in particular from one of these longitudinal sides (in particular from the downstream long side) and in its extension at least one helical surface 61 extends or the helical surfaces 61 a sentence ( 611 ; 612 ) of helical surfaces 61 extend which or which the module 62 having.

In fact, and according to a first, not shown embodiment, such a mixer 6 a single module 62 include a plate 621 and a helical surface 61 or a set of at least two helical surfaces 611 having.

According to a preferred embodiment, said mixer comprises 6 however, several modules 62 , on the one hand each a plate ( 621 ; 622 ) as well as a sentence ( 611 ; 612 ) of at least two helical surfaces 61 and on the other hand in pairs, in particular in a vertical manner, by connecting means 63 connected to at least one plate ( 621 ; 622 ) at least one such module 62 Is provided.

In this regard, it should be noted that these connecting means 63 on the one hand, from a joining agent 631 exist, with which a plate 621 and on the other hand from a complementary joining means 632 with which the other plate 622 is provided.

As in the 4a and 4b as can be seen, such a joining means exists 631 from a notch, in the upstream part of a plate 621 (Especially in the region of the upstream longitudinal side of this plate 621 ) while the complementary joining means 632 consists of another notch, which is in appropriate position in the downstream part of the other plate 622 (Especially in the region of the downstream longitudinal side of this plate 622 ) is trained.

As in the 3 . 5d and 6c can be seen, such a compound is made such that the helical surface 61 of a sentence 611 of helical surfaces preferably between two helical surfaces 61 another sentence 612 of helical surfaces 61 is inserted and simultaneously with respect to the alignment direction of the two helical surfaces 61 this other sentence 612 is shifted laterally.

Another feature is that a module 62 in the area of at least one of the side edges of a plate ( 621 ; 622 ) of this module 62 a thigh ( 641 ; 642 ) extending in the extension of this plate ( 621 ; 622 ) is located.

In the special case of a mixer 6 , which is a single module 62 includes, the two side edges of such a plate 621 through such a leg ( 641 ; 641 ' ), which is actually laterally with respect to such a plate 621 extends. These thighs ( 641 ; 641 ' ) then advantageously provide a means 8th for mounting the mixer 6 inside the exhaust element ( 3 . 4 ), in particular by being picked up by the receiving means 7 be received, with which this exhaust element ( 3 . 4 ) Is provided.

In the case of a mixer 6 that has several modules 62 includes, assigns each of these modules 62 in the area of at least one of the side edges of a plate ( 621 ; 622 ) of this module 62 a thigh ( 641 ; 642 ) extending in the extension of this plate ( 621 ; 622 ) and in the direction of another leg ( 642 ; 641 ), which the plate ( 622 ; 621 ) of another module 62 and with which of these legs ( 641 ; 642 ), in particular by welding.

A preferred embodiment, which in the 3 . 4a . 4b . 5d and 6c is that the plates ( 621 ; 622 ) of each module 62 in the area of its two margins one leg ( 641 . 641 '; 642 . 642 ' ) extending in the extension of such a plate ( 621 ; 622 ) and in the direction of another leg ( 642 . 642 '; 641 . 641 ' ), which the other plate ( 622 ; 621 ) and with which these legs ( 641 . 641 '; 642 . 642 ' ) are or can be firmly connected, in particular by welding.

In this regard, it should be noted that these legs ( 641 . 641 '; 642 . 642 ' ) actually and advantageously a means 8th for mounting the mixer 6 inside the exhaust element ( 3 . 4 ), in particular by being picked up by the receiving means 7 be received, with which this exhaust element ( 3 . 4 ) Is provided.

Another advantageous feature of the invention is that a module 62 of the type described above preferably consists of a single, in particular metallic part, which is preferably produced by cutting, twisting, in particular supplemented by a bend.

• – eine Platte (621; 622);
• – mindestens eine Wendelfläche 61 oder ein Satz (611; 612) von mindestens zwei Wendelflächen 61;
• – und, falls ein solches Modul 62 dies aufweist, ein Verbindungsmittel (63, 631, 632), mindestens ein Schenkel (641, 641'; 642, 642')

In particular, the following are defined as components of such a single part:

• - a plate ( 621 ; 622 );
• - At least one spiral surface 61 or a sentence ( 611 ; 612 ) of at least two helical surfaces 61 ;
• - and, if such a module 62 this has a connecting means ( 63 . 631 . 632 ), at least one leg ( 641 . 641 '; 642 . 642 ' )

As mentioned above, the exhaust element 3 that a mixer 6 comprising, having the above features, from a device 3 for the physical and / or chemical treatment of the exhaust gases, the inside the agent 6 for admixing an additive to the exhaust gases and downstream of this mixer 6 a means for physical and / or chemical treatment of this mixture.

• – entweder aus einem Katalysator 32 zur Behandlung der in den Abgasen enthaltenen Stickoxide (NOx), insbesondere zur katalytischen Reduktion dieser Stickoxide (NOx), zum Beispiel einem Dreiwegekatalysator vom Typ TWC oder auch einem Katalysator vom Typ SCR (Selective Catalytic Reduction); oder aus einem komplexeren Abgaselement 3 (gewöhnlich ”cata-FAP” genannt), das einen solchen Katalysator 32 sowie ein Partikelfilter 31 vom oben erwähnten Typ beinhaltet.

Such a device for treatment 3 can then exist:

• - either from a catalyst 32 for the treatment of the nitrogen oxides (NOx) contained in the exhaust gases, in particular for the catalytic reduction of these nitrogen oxides (NOx), for example a TWC three-way catalyst or also an SCR (Selective Catalytic Reduction) catalyst; or from a more complex exhaust element 3 (commonly called "cata-FAP") which is such a catalyst 32 as well as a particle filter 31 of the type mentioned above.

According to a preferred embodiment, the exhaust element 4 according to the invention, however, preferably from an exhaust pipe 41 , the in the center 6 for admixing an additive to the exhaust gases, having the above-mentioned features.

Finally, the invention also relates to an exhaust system 2 for a motor vehicle with an internal combustion engine 1 which, in order according to the flow direction of the gases in this exhaust line 2 considered, on the one hand, a means 5 for introducing an additive to be added to the exhaust gases in this exhaust gas line 2 and on the other hand a static means 6 for adding this additive to the exhaust gases and, on the other hand, a means for physical and / or chemical treatment of this mixture.

According to the invention, this exhaust system comprises 2 an exhaust element ( 3 . 4 ) having the above features and the agent 6 for admixing the additive to the exhaust gases. This mixer 6 is then between the mean 5 for introducing the additive into the exhaust gas line 2 and the means for treating the mixture (which in particular is an internal component of a device 3 for the physical and / or chemical treatment of this mixture, in the case of an exhaust element 3 that comes from such a device 3 exists) arranged.

This invention finds application in the field of production of the exhaust gas removal equipment used by the engine 1 a motor vehicle and from the combustion of a fuel, in particular a fuel of the type of diesel fuel, inside such an engine 1 result.

Embodiment:

• – zwei Paar Wendelflächen (611; 612);
• – zwei Wendelflächen ein und desselben Paares mit einer identischen Drehrichtung;
• – zwei Wendelflächen zweier verschiedener Paare mit einer entgegengesetzten Drehrichtung (gegenläufige Wendelflächen);
• – Ganghöhe und Länge der Wendelflächen: 82 mm
• – Durchmesser der Wendelflächen: 21 mm
• – Abgaselement: Leitung mit einem Innendurchmesser von 60 mm
• – stromabwärts des Mischers erzeugter Gegendruck: 33 mbar

Throughput of the engine at full load: 600 kg / h at 600 ° C mixer 6 :

• - two pairs of spiral surfaces ( 611 ; 612 );
• - Two spiral surfaces of the same pair with an identical direction of rotation;
• - Two helical surfaces of two different pairs with an opposite direction of rotation (opposite helical surfaces);
• - pitch and length of helical surfaces: 82 mm
• - Diameter of the helical surfaces: 21 mm
• - Exhaust element: pipe with an inner diameter of 60 mm
• - Backpressure generated downstream of the mixer: 33 mbar

Summary

The invention relates to an exhaust element ( 4 ), which is part of an exhaust line of a motor vehicle with an internal combustion engine and in the interior of which flows a fluid which consists of exhaust gases and of an additive to these gases, this exhaust element ( 4 ) an internally mounted static means ( 6 ) for admixing this additive to these exhaust gases. The static means ( 6 ) for admixing the additive to the exhaust gases comprises at least one helical surface (helicoid) ( 61 ) having an axis which extends in a direction which is at a certain angle with the flow direction (D) of the fluid in this exhaust element ( 4 ).

QUOTES INCLUDE IN THE DESCRIPTION

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Cited patent literature

• WO 9300990 [0009]
• EP 1514591 [0010]

Claims (17)

Exhaust element ( 3 ; 4 ), which is part of an exhaust system ( 2 ) of a motor vehicle with internal combustion engine ( 1 ) and in the interior of which flows a fluid which consists of exhaust gases and of an additive to these gases, this exhaust gas element ( 3 ; 4 ) an internally mounted static means ( 6 ) for admixing this additive to these exhaust gases, characterized in that the static agent ( 6 ) for admixing the additive to the exhaust gases, at least one helical surface (helicoid) ( 61 ) which has an axis extending in a direction which has a certain angle (α) with the flow direction (D) of the fluid in this exhaust element ( 3 ; 4 ). Exhaust element ( 3 ; 4 ) according to claim 1, characterized in that the helical surface or the helical surfaces ( 61 ) an increasing width in the flow direction (D) of the fluid in the exhaust element ( 3 ; 4 ). Exhaust element ( 3 ; 4 ) according to claim 1, characterized in that the helical surface or the helical surfaces ( 61 ) a decreasing width in the flow direction (D) of the fluid in the exhaust element ( 3 ; 4 ). Exhaust element ( 3 ; 4 ) according to one of the preceding claims, characterized in that the direction of extension of the axis of a helical surface with the flow direction (D) of the fluid in the exhaust element forms an angle (α) in the range of 0 to 30 °. Exhaust element ( 3 ; 4 ) according to one of the preceding claims, characterized in that the mixer ( 6 ) several spiral surfaces ( 61 ), each having an axis extending on the one hand in a direction coincident with the direction of extension of the axis of another helical surface ( 61 ) forms a certain angle (α '), which lies in particular in the range of 0 to 30 °, and on the other hand extends in a direction which corresponds to the flow direction (D) of the fluid in this exhaust element ( 3 ; 4 ) forms a certain angle (α), which lies in particular in the range of 0 to 30 °. Exhaust element ( 3 ; 4 ) according to claim 5, characterized in that the helical surfaces ( 61 ) are arranged such that their axes of extension in the flow direction of the fluid in the exhaust element ( 3 . 4 ) diverge. Exhaust element ( 3 ; 4 ) according to claim 5, characterized in that the helical surfaces ( 61 ) are arranged such that their axes of extension in the flow direction of the fluid in the exhaust element ( 3 . 4 ) converge. Exhaust element ( 3 ; 4 ) according to one of claims 5 to 7, characterized in that the axes of the helical surfaces ( 61 ) in the form of a matrix, in particular a regular matrix, corresponding to the geometric shape of the cross section of the exhaust element ( 3 . 4 ) are arranged. Exhaust element ( 3 ; 4 ) according to any one of claims 5 to 8, characterized in that two directly adjacent helical surfaces ( 61 ) have an identical direction of rotation. Exhaust element ( 3 ; 4 ) according to any one of claims 5 to 8, characterized in that two directly adjacent helical surfaces ( 61 ) have an opposite direction of rotation. Exhaust element ( 3 ; 4 ) according to one of the preceding claims, characterized in that the mixer ( 6 ) several spiral surfaces ( 61 ) and that these spiral surfaces ( 61 ) within at least one sentence ( 611 ; 612 ), which has at least two spiral surfaces ( 61 ), which have a preferably identical direction of rotation. Exhaust element ( 3 ; 4 ) according to one of the preceding claims, characterized in that the mixer ( 6 ) at least one module ( 62 ) comprising, on the one hand, a plate ( 621 ; 622 ) parallel to the flow direction (D) of the fluid in the exhaust element ( 3 ; 4 ) and at least one helical surface (FIG. 61 ) or a sentence ( 611 ; 612 ) of at least two helical surfaces ( 61 ) located in the downstream extension of this plate ( 621 ; 622 ). Exhaust element ( 3 ; 4 ) according to claim 12, characterized in that the mixer ( 6 ) several modules ( 62 ), which on the one hand in each case a plate ( 621 ; 622 ) as well as a sentence ( 611 ; 612 ) of at least two helical surfaces ( 61 ) and on the other hand in pairs, in particular in a vertical manner, by connecting means ( 63 ), with which at least one plate ( 621 ; 622 ) at least one such module ( 62 ) Is provided. Exhaust element ( 3 ; 4 ) according to claim 13, characterized in that a module ( 62 ) in the region of at least one of the side edges of a plate ( 621 ; 622 ) of this module ( 62 ) a thigh ( 641 . 641 '; 642 . 642 ' ) extending in the extension of this plate ( 621 ; 622 ) and in the direction of another leg ( 642 . 642 '; 641 . 641 ' ), which the plate ( 622 ; 621 ) of another module ( 62 ) and with which of these legs ( 641 . 641 '; 642 . 642 ' ), in particular by welding. Exhaust element ( 3 ; 4 ) according to one of claims 12 to 14, characterized in that the module ( 62 ) consists of a single, in particular metallic part, which is preferably made by cutting, twisting, in particular supplemented by a bend. Exhaust element ( 3 ; 4 ) according to one of the preceding claims, characterized in that the exhaust element ( 3 ; 4 ) a means ( 7 ) for receiving the mixer ( 6 ) having. Exhaust element ( 3 ; 4 ) according to one of the preceding claims, characterized in that the exhaust element ( 3 ; 4 ) either from an exhaust pipe ( 41 ) that inside the agent ( 6 ) for admixing an additive to the exhaust gases, or from a device ( 3 ) for the physical and / or chemical treatment of the exhaust gases, which internally the agent ( 6 ) for admixing an additive to the exhaust gases and downstream of this mixer ( 6 ) has a means for physical and / or chemical treatment of this mixture.

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