JP6114391B2 - Exhaust gas flow mixing method - Google Patents

Description

  The present invention relates to a method of using a mixer and the mixer itself.

  Some single-stage mixers are known from the most closely related prior art.

  Patent Document 1 describes a mixer provided with a wall structure for a flow guide surface. This wall structure basically occupies the profile of the housing and thus causes a relatively high dynamic pressure loss. This wall structure consists of several layers of undulating strips aligned parallel to the flow direction. The individual layers each extend in a direction transverse to the flow direction, are aligned in the direction across the flow direction, and are stacked one above the other. Here, the strip material of each layer is stacked so that a plurality of cells are formed between the strip materials of adjacent layers and each of these cells can be passed in the flow direction.

  In addition to the round undulations, it is also possible to design the undulations of the strip material in a rectangular or trapezoidal shape. As a result, individual cell profiles can be realized in a rectangular or hexagonal shape or in a honeycomb shape. The strip material forms a support, on which a plurality of flow guide surfaces are formed in pairs as mixing fins. For this purpose, the support comprises alternating areas with mixing fins and areas without mixing fins connected to it, so that one mixing fin enters each cell.

  Patent Document 2 describes an exhaust gas mixing device that causes exhaust gas to be mixed by a fin unit including a plurality of fins that are directly arranged on the front and rear sides. These fin units are arranged adjacent to each other in the direction crossing the flow direction and arranged in the front-rear direction in the flow direction. The plurality of fins are directly connected to each other without a support and are arranged in mirror symmetry with respect to the center plane.

  Patent Document 3 describes, in particular, an apparatus for mixing a fluid with a large amount of gas flowing into a gas flow path in order to add a reducing agent to exhaust gas containing nitrogen oxides. For this purpose, a nozzle lance with a nozzle for fluid delivery is used. The axis is inclined with respect to the flow direction of the mass gas flow. A flat mixer element is assigned to the nozzle, leaving space. The mixer element is inclined with respect to the flow direction of the large amount of gas flow. A plurality of flow vortices are formed on the mixer element and at least a portion of the fluid enters these flow vortices. In order to prevent the formation of a coating, when a liquid is used as the fluid, the nozzle lance is provided with at least two atomizer nozzles oriented in opposite directions, inclined with respect to the flow direction of the mass gas flow. Both atomizer nozzles are assigned to the disc-type mixer element so that vaporized gaseous parts and non-vaporized splash parts can be separated.

  Patent Document 4 describes an exhaust gas plant for a combustor having an exhaust gas line for inducing exhaust gas and an injection device for injecting liquid into the exhaust gas line. The exhaust gas line is provided with a vaporization unit provided with at least one tubular plate extending in the longitudinal direction of the exhaust gas line downstream of the injection device, thereby improving the vaporization of the injected liquid. Furthermore, a spring-type clamping device is provided for mounting the vaporizer in the exhaust gas line or for tensioning the vaporizer with respect to the exhaust gas line.

  Patent Document 5 describes an exhaust gas system having a reducing agent injection device as the most closely related conventional technique. In this exhaust gas system, a plate body having at least one wall extending in the longitudinal direction of the exhaust gas line is disposed downstream of the injection device. This wall is exposed to the exhaust gas stream on both sides. By injecting the reducing agent onto at least a part of the wall, the liquid reducing agent is converted into a vapor or gas state.

German Patent Application Publication No. 10 2006 024 778 (B3) German utility model No. 20 2006 017 848 (U1) German Patent Application Publication No. 10 2005 059 971 (A1) German Patent Application Publication No. 10 2006 043 225 (A1) German Patent Application Publication No. 10 2005 052 064 (A1)

  The concept of the present invention is to provide a method for increasing the degree of mixing of exhaust gas and fluid in accordance with the shape of the exhaust gas pipe.

The solution is a method of mixing the fluid injected into the exhaust gas pipe of the exhaust gas system by the injection device into the exhaust gas flow in the exhaust gas pipe. The method is characterized by the following method steps.
a) The exhaust gas flow is guided in the exhaust gas pipe in a flow direction parallel to the exhaust gas pipe in the region of the injection device.
b) The fluid is injected in a central injection direction deviating from the flow direction by an angle se and directly impinges on a deflection element arranged in the exhaust gas pipe.
c) Due to the at least one sheet metal member which is provided at the deflection element and rises at least partially at an angle sv with respect to the flow direction, a part of the exhaust gas flow is flow direction with respect to the flow direction. From the center to the center dispersion direction.
d) At least a part of the fluid is conveyed in the dispersion direction by the redirected exhaust gas flow part before and after impinging on the deflection element, and is redirected in the dispersion direction by the rising metal sheet member. What is essential here is that the exhaust gas flow is redirected by a sheet metal member in front of the mixer in a dispersion direction that deviates significantly from the flow direction. Here, the angle se in the direction in which the fluid can be injected is variable between 270 ° and 360 °.

  As a result, the fluid injected on one side is carried over the entire exhaust gas pipe profile in the direction of the center and thus impinges on the mixer over the entire mixer profile and can then be mixed into the exhaust gas stream. Due to the installation space, even when the exhaust gas pipe is curved rather than linear, the deflecting element can affect the moving direction of the fluid with respect to the traveling direction of the exhaust gas pipe.

  Another concept is that at least a part of the fluid impinges on a correction plate arranged with respect to the injection direction in front of the sheet metal member and is at least partially redirected in the flow direction, after which at least one mixing element Is further mixed by being redirected in several mixing directions by a static mixer having The correction plate is disposed above the thin metal plate member in parallel with the thin metal plate member, and is distributed on the fluid injection side of the thin metal plate member. Dispersion of the fluid in front of the mixer can be improved if the other parts of the fluid flow are already redirected from the injection direction to the flow direction by the correction plate before reaching the sheet metal member.

  Conveniently, the rise of the sheet metal member is realized by several fins which are provided on the sheet metal member and rise at the same or different angles sv. The angle sv is between 0 ° and 85 °. Due to the fact that each fin rises, the sheet metal member itself can be arranged parallel to the flow direction, and the necessary redirection of the exhaust gas flow and thus the fluid can be caused by the fin alone.

  It is further expedient if several holes are provided in the correction plate that extend in the drilling direction. This piercing direction is an angle bs between 45 ° and 135 ° with respect to the flow direction. As a result, a portion of the fluid can be further distributed over the mixer profile via one or more correction plates. Thus, some of the fluid can flow further through the infusion device and is partially redirected by the correction plate. The flow reservoir is further redirected and carried in the flow direction, while the non-storage portion of the flow through the perforated hole reaches the next correction plate in the injection direction or reaches the sheet metal member.

  The correction plate is arranged parallel to the flow direction and includes several correction fins that rise at an angle sk with respect to the flow direction. The angle sk is between 95 ° and 265 °. Since these correction fins are punched from the correction plate, the non-reserved fluid can pass through the correction plate through a plurality of openings formed by punching. At the same time, since the fluid is stabilized by each correction fin, unlike the flow state described above, it is redirected more slowly by the exhaust gas flow in the flow direction.

  Several mixing fins are provided on the mixing element. These mixing fins rise at an angle ms with respect to the flow direction, and rise at an angle mv with respect to the dispersion direction. The angle ms is a maximum of 70 ° and the angle mv is greater than 1 °. For the mixing process, it is advantageous that the fluid is further redirected by these mixing fins and is not further guided in the same direction determined by the fins or correction fins.

  For this method, it is convenient for the deflecting element arranged in the exhaust gas pipe of the exhaust gas system to guide the exhaust gas flow while retaining the fluid injected into the exhaust gas system by the injection device. In this case, the deflection element can be positioned in front of the static mixer with at least one mixing element in the flow direction and comprises at least one sheet metal member that can be positioned in the exhaust gas flow. The thin metal plate member rises at least partially in the dispersion direction at an angle sv with respect to the flow direction. As a result, at least part of the exhaust gas flow is diverted from the flow direction to the dispersion direction together with the fluid. A fin that rises at an angle sv is formed on the thin metal plate member. The sheet metal member is placed immediately in front of the mixer in the flow direction in order to achieve a symmetrical distribution of the fluid, part of which has already been converted into a gaseous state, over the exhaust gas pipe profile and thus over the mixer profile. The The smaller the gaseous part, the greater the influence of the deflection element on the mixing process by the mixer. The sheet metal member rises at least partially at an angle sv in the dispersion direction with respect to the flow direction by the fins. As a result of this, the exhaust gas flow, together with the fluid, is at least partially redirected from the flow direction to the dispersion direction. The influence on the direction change of the sheet metal member itself arranged parallel to the flow direction is negligible.

  Several fins rising at an angle sv are formed on the thin metal plate member. A number of fins provide a diversion of the fluid distributed over the exhaust gas pipe profile. By arranging several fins back and forth in the direction of flow, the direction change in the flow direction realized by these fins is partially accumulated, so that the direction change of the flow element is greater.

  The deflection element can be positioned in the exhaust gas pipe so that the majority of the fluid impacts significantly in the direction of the deflection element. As a result, the fluid velocity is initially reduced by the deflection element, so that the flow direction can be changed more easily as a result.

  Depending on the mass flow rate of the exhaust gas and the temperature of the exhaust gas, the penetration depth of the fluid into the exhaust gas pipe and the collision area of the fluid with the deflecting element vary.

  The deflection element comprises one or several correction panels arranged parallel to the flow direction or parallel to the sheet metal member. These correction plates decelerate the fluid and allow the fluid to be quickly redirected by the exhaust gas flow. These correction plates may have different lengths, or all may be designed with the same length.

  The correction plate is one or several correction fins rising at an angle sk between 95 ° and 265 °, several openings formed by these correction fins in a direction transverse to the flow direction, and / or the drilling direction A number of perforations extending into the surface. The drilling direction is an angle bs between 45 ° and 135 ° with respect to the flow direction. Alternatively, several drill holes are provided that extend in the drill direction at an angle bs between 45 ° and 135 ° with respect to the flow direction. As a result, a portion of the fluid can flow directly through the opening or perforation hole in its injection direction and is not decelerated. The correction plate provides flow correction and stabilization.

  The sheet metal member protrudes beyond all the correction plates with respect to the opposite direction of flow. The thin metal plate member is disposed behind the last correction plate with respect to the center injection direction. Due to the fact that the sheet metal member is thus arranged directly adjacent to the wall of the exhaust gas pipe facing the injection point, the sheet metal member can influence the total amount of fluid injected.

  The deflecting element is designed mirror-symmetrically with respect to a central plane oriented perpendicular to the flow direction. Alternatively, the plurality of fins and / or the plurality of correction fins are arranged in mirror symmetry with respect to the central plane. As a result of this symmetry, the central mixing element or flow element is in the same alignment so that the central region of the flow in the exhaust gas pipe into which the fluid is also injected can have a greater influence.

  A multi-stage disperser comprising a deflection element according to the above description and a static mixer attached to the deflection element or indirectly arranged behind the deflection element is advantageous. The static mixer has at least one mixing element comprising at least one support for one flow element or a plurality of mixing fins. By combining the deflection element and the mixer, a very effective mixing method is possible.

  The sheet metal member or the correction plate is arranged on a flow element or support that is parallel or oblique to the flow direction. As a result, the mixer and the deflecting element are at least partly or entirely designed as one piece and manufactured from the same material.

  Each mixing fin or each flow element rises at an angle ms of up to 70 ° with respect to the flow direction and rises at an angle mv greater than 1 ° with respect to the dispersion direction.

  The mixing element is designed to be mirror-symmetric with respect to a central plane arranged perpendicular to the flow direction. Alternatively, each mixing fin and / or each support is arranged mirror-symmetrically with respect to the central plane.

  Depending on the application, it may be advantageous for the mixing elements to be designed point-symmetrically with respect to the flow direction, or for the mixing fins and / or supports to be arranged point-symmetrically with respect to the flow direction. This arrangement creates a counter-rotating vortex behind the mixer in the exhaust gas pipe.

  For assembly or modification, there is further provided a housing parallel to the exhaust gas pipe and parallel to the exhaust gas flow direction, in which a support or flow element is arranged, the housing being in the exhaust gas pipe or It may be convenient to be able to position it inside. As a result, the mixing element or flow element of the mixer can be preassembled in the housing and then inserted into the exhaust gas pipe.

  The static mixer is advantageously provided with several mixing elements for the exhaust gas, which are arranged adjacent to each other in a direction transverse to the flow direction. In this case, each mixing element comprises several mixing fins, each mixing fin comprising one trailing edge region and two side edge regions with respect to the flow direction. Every mixing element comprises a support which is aligned parallel to the flow direction, in which a plurality of mixing fins are arranged via respective trailing edge regions and rise with respect to the support. Every support comprises two end regions through which each support is attached to the exhaust gas pipe. At least three mixing elements are provided. The supports of these mixing elements are arranged adjacent to each other at a distance of at least 5 mm from each other in a direction transverse to the flow direction in the region between the end regions. All the mixing fins are arranged such that all side edge areas and leading edge areas are spaced from the exhaust pipe. Preferably, adjacent supports are spaced apart by a distance of between 5 mm and 100 mm, preferably between 12 mm and 15.5 mm. As a result, the mixing element can be welded to the exhaust gas pipe or to a separate housing via a support, and the stability of the mixing element is determined by each support even while the exhaust gas flow and heat input are high. And each mixing fin placed there. By the insulating mounting of each mixing element and by the fact that each mixing fin is spaced apart and facing the tube wall and placed on the respective support, each fin improves the flow and thus the mixing. The

  A static mixer comprising several mixing elements, the mixing elements being arranged adjacent to each other in a direction transverse to the flow direction, each mixing element being aligned parallel to the flow direction and the support A static mixer or dispersion device may also be advantageous if it is equipped with several mixing fins that stand up against this support. Each support comprises two end regions and two connecting regions arranged between the two end regions and spaced from each end region and facing each other in the direction of the support. Since the first connection region and the end region of each support are connected to each other, the support subregion forms a closed cell, and the support subregion surrounding the cell has at least two mixing fins. Is placed. As a result, each cell is not closed by a partial region of the support where no mixing fins are provided, but is positioned in front of the mixing fins that enter the cell.

  For static mixers or dispersers it may be advantageous if the mixer comprises several exhaust gas flow elements, which are arranged adjacent to each other in a direction transverse to the flow direction. Each flow element is formed from a sheet metal having a corrugated cross-sectional profile. This cross-sectional profile comprises several channels that extend adjacent to each other in a direction parallel to the profile axis. The profile axis of each flow element is oriented at an angle ms of up to 70 ° relative to the flow direction, or at an angle ms of up to -70 °. These profile axes are aligned by at least two flow elements arranged adjacent to each other at equal angles ms in terms of direction and magnitude. As a result, the fluid flow that flows across the flow direction and reaches the center of the mixer is essentially trapped by the two central flow elements having the same alignment, so it can be redirected to another direction. it can. The cross-sectional profile preferably undulates regularly and all profile axes are arranged in parallel.

  A mixer for mixing fluid injected into an exhaust pipe into an exhaust stream includes a first mixing element including a base that interconnects a first side wall and a second side wall spaced from the first side wall. Including. The first and second side walls are sized and shaped to complement the inner surface of the exhaust pipe so that both side walls are adapted to be secured to the exhaust pipe. The first mixing element includes a deflection element positioned to impinge on the injected fluid and a mixing fin positioned downstream of the deflection element to mix the injected fluid with the exhaust gas. The second mixing element includes a base that interconnects the spaced first and second mounting flanges. The first and second mounting flanges are fixed to the inner surfaces of the first and second side walls. The second mixing element includes mixing fins for changing the direction of the exhaust flow.

  Another mixer for mixing the fluid injected into the exhaust pipe into the exhaust stream includes a tubular housing that includes a plurality of circumferentially spaced slots extending axially from the open end of the housing. . The first mixing element includes a central portion interconnecting the first peripheral portion and a second peripheral portion spaced from the first peripheral portion. The first peripheral portion is positioned inside one of the plurality of slots. The second peripheral portion is positioned inside another one of the plurality of slots. Each flange is fixed to the housing. The second mixing element includes a central portion that interconnects the third and fourth surrounding portions that are spaced apart. The third and fourth peripheral portions are positioned inside the other slots of the plurality of slots and are fixed to the housing. The second mixing element is spaced from the first mixing element.

  Further advantages and details of the invention are explained in the claims and in the description and shown in the drawings.

FIG. 2 shows a view of a part of an exhaust gas system with an exhaust gas pipe and an injection device in which a mixer is arranged with a deflection element rising in the flow direction. FIG. 2 shows the view according to FIG. 1 with a mixer and a deflection element with correction plate. FIG. 2 shows the view according to FIG. 1 with a mixer and a deflecting element designed in the same way as the mixer. A mirror-symmetric mixer is shown. 1 shows a point symmetric mixer with mixing elements with cells. Fig. 5 shows a mixer according to Fig. 4 in an exhaust gas pipe. Fig. 2 shows a point-symmetric mixer in which a plurality of supports are arranged at a distance. FIG. 4 shows a side view of a support having a plurality of mixing fins that rise alternately. FIG. 8 shows a side view of the mixer according to FIG. 7 with a deflection element with a modified fin. FIG. 8 shows a side view of the mixer according to FIG. 7 with a perforated deflection element. FIG. 4 shows a diagram of a mixer having a plurality of flow elements in contact with each other. Fig. 11 shows three flow elements for the mixer according to Fig. 10, with different arrangements for each profile axis. FIG. 11 shows a side view of the mixer according to FIG. 10 in the exhaust pipe with the deflection element pre-actuated. Figure 2 shows a diagram of the deflection element and the injection device. Figure 2 shows a square diagram for a mixing fin for a deflection element. It is a perspective view of an alternative mixer. It is another perspective view of the said alternative mixer. It is an end view of the alternative mixer. FIG. 18 is a cross-sectional view of the mixer taken along line 18-18 of FIG. FIG. 19 is a partial cross-sectional view taken along line 19-19 of FIG. It is a side view of the mixer. FIG. 6 is a perspective view of another alternative mixer. FIG. 6 is a perspective view of another alternative mixer. FIG. 6 is a partial perspective view of another alternative mixer. FIG. 24 is a partial end view of the mixer shown in FIG. 23. FIG. 6 is a perspective view of another alternative mixer. It is the perspective view which looked at the mixer shown by FIG. 25 from another angle. FIG. 27 is an exploded perspective view of the mixer shown in FIGS. 25 and 26. FIG. 6 is a partial cross-sectional view of a portion of an exhaust treatment system that includes another alternative mixer.

  FIG. 1 shows an exhaust pipe 40 as part of the exhaust gas system 4. A fluid as a reducing agent is injected into the exhaust pipe 40 in the injection direction E through the flange 50 disposed on the outer surface of the exhaust gas pipe 40 and the injection device 5 positioned on the flange 50. For the sake of clarity, each figure shows the center direction E of the injection, and in FIG. 3 shows the actual conical flow state indicated by the two dotted lines forming the v-shape. Not in.

  In the exhaust gas pipe 40, the exhaust gas basically flows in the flow direction S parallel to the exhaust gas pipe 40. With respect to the description of the invention, for the sake of simplicity, it is assumed that the flow direction S extends parallel to the entire cross section of the exhaust gas pipe 40 in front of the deflection element 6.

  The reducing agent flows into the exhaust gas pipe 40 in the injection direction E and is redirected by the exhaust gas flow. The degree to which the direction is changed depends on the mass flow rate of the reducing agent. After the injection device 5 in the flow direction S, a dispersion device comprising the mixer 1 with the deflection element 6 is provided. The dispersing device is positioned in the exhaust gas pipe 40 via the mixer 1 and the flange connecting portion 41.

  Since most of the reducing agent collides with the deflecting element 6, the impact of the reducing agent flow is mitigated. Since the deflection element 6 rises at an angle sv with respect to the flow direction S, the exhaust gas flow is redirected from the flow direction S to the dispersion direction V by the deflection element 6. With this redirected exhaust gas flow, the reducing agent is partially swept away along the dispersion direction V before being impinged on the deflection element 6, and in particular afterwards, and guided to the tube center of the exhaust gas tube 40. .

  FIG. 2 shows a part of the exhaust gas system 4 as described with reference to FIG. In this figure, however, the mixer 1 with the mixing fins 31 is incorporated as shown in detail in FIGS. The deflection element 6 for such a mixer 1 with mixing fins 31 is shown in detail in FIG. 9 and comprises a sheet metal member 60 arranged parallel to the flow direction and having fins 61 rising at an angle sv. A further correction plate 62 with correction fins 64 is provided as part of the deflection element 6.

  The mixer 1 according to FIGS. 4, 6 and 7 has three mixing elements 3 adjacent to each other and one or two further mixing elements 3a arranged in a direction transverse to the flow direction S. The mixing elements 3, 3a basically consist of a support 30, 30a and one or several mixing fins 31, 31a arranged there. The respective mixing fins 31 and 31a are attached to the supports 30 and 30a through the rear edge region hR with the flow direction S as a reference. The side edge region sR and the front edge region vR form a free flow edge with respect to the flow direction S, and are not connected to the other mixing fins 31 and 31a, the housing 2 or the exhaust pipe 40.

  The support 30 includes one end region 34 at each end thereof. The end region 34 does not comprise the mixing fins 31 and is inclined according to FIG. The support 30 is attached to the housing 2 via two end regions 34, as shown in the example of FIG. 7, or according to FIG. The support 30 is freely suspended between the two end regions 34 in the housing 2 or in the exhaust gas pipe 40. That is, it is not supported or held by another component, nor is it supported or held by another component. Furthermore, the supports 30 are arranged essentially parallel to each other in the region between the end regions 34. The distance 35 between them is about 13.5 mm.

  The housing 2 is a cylindrical tube member on which a plurality of mixing elements 3 and, in some exemplary embodiments, additional mixing elements 3a are attached to the sheath inner surface 20. As shown in FIG. 2, this type of mixer 1 is inserted into the exhaust gas pipe 40 of the exhaust gas system 4 together with the housing 2. The exhaust gas passes through the mixer 1 in the flow direction S parallel to the central axis 23 of the housing 2.

  The support 30 is made of a strip-shaped thin metal plate having a width 32 defined in FIG. 8, and is aligned parallel to the flow direction S. The flow direction S refers to the main direction of the exhaust gas flow in the mixer 1 and extends parallel to the central axis 12 of the mixer 1 and the central axis 23 of the housing 2. Due to the fact that the support 30 extends parallel to the flow direction S and thus parallel to the wall of the exhaust gas pipe 40, the mixer 1 can be easily mounted in a direction transverse to the flow direction in the exhaust gas pipe 40.

  In the exemplary embodiment according to FIG. 7, in which three mixing elements 3 are arranged essentially point-symmetrically in parallel and adjacent to each other, each mixing element 3 is formed by a support 30 and four mixing fins 31. The Therefore, the entire mixing element 3 is composed of the support 30 and the four mixing fins 31.

  The support 30 can be divided into three partial regions 36 to 38 between both end regions 34. The outer partial regions 37 and 38 are adjacent to both sides of the central partial region 36, respectively. Each of the outer partial regions 37 and 38 is inclined with respect to the central partial region 36. That is, the central partial region 36 forms an angle α with respect to each of the two outer partial regions 37 and 38. Accordingly, with reference to the first axis 11 extending parallel to the flow direction S, the outer two partial regions 37 and 38 intersect the central partial region 36 at an angle α of about 12 °. Since the outer partial regions 37 and 38 are inclined reversely with respect to the central partial region 36, the support 30 is designed to be point-symmetric with respect to the central axis 12 parallel to the flow direction S. That is, the support 30 and the mixing fins 31 are formed so as to be symmetrical with respect to each other.

  In addition to the three mixing elements 3, two further mixing elements 3 a are further provided in the region adjacent to the mixing element 3. The further mixing element 3a is formed by a support 30a and a mixing fin 31a. The further mixing element 3a is attached to the sheath inner surface 20 of the housing 2 via its two end regions 34a so as to be freely supported between the two end regions 34a.

  In the exemplary embodiment according to FIG. 4, the support 30 can be divided into three partial regions 36-38 according to the exemplary embodiment according to FIG. 7. The outer partial regions 37 and 38 are adjacent to both sides of the central partial region 36, respectively. Each of the outer partial regions 37 and 38 is inclined with respect to the central partial region 36. That is, the central partial region 36 forms an angle α with respect to each of the two outer partial regions 37 and 38. Accordingly, with reference to the first axis 11 extending in parallel to the flow direction S, the outer two partial regions 37 and 38 intersect the central partial region 36 at an angle γ of about 9 °. Since the outer partial regions 37 and 38 are inclined in the same direction with respect to the central partial region 36, the support 30 is designed to be mirror-symmetric with respect to the central plane 10 parallel to the flow direction S.

  As a result of point symmetry, the flow on one side of the central plane 10 is diverted upward and outward, while the flow on the other side of the central plane 10 is diverted in the direction transverse to the flow direction S. Is done. This flow is indicated by a plurality of arrows in FIG.

  In each exemplary embodiment according to FIGS. 4-9a, each mixing fin 31 forms an angle β with respect to the direction of the support 30 and an angle ms with respect to the flow direction S. Each mixing fin 31 is shown alternately. As shown in detail in FIGS. 8 and 9, the angle β is + 135 ° or −135 °, and the angle ms is + 45 ° or −45 °. Furthermore, the directly adjacent mixing fins 31 are partially separated from each other by a constant distance 33 of at least 1 mm, as shown in particular in FIG.

  In an exemplary embodiment not shown, adjacent end regions 34 are connected to each other by two supports 30 positioned adjacent to each other. Also, each one end region 34a of the further mixing element 3a is connected to one end region 34 of each adjacent mixing element 3. This is achieved by the fact that three mixing elements 3 and two further mixing elements 3a are made from a single sheet metal strip.

  As shown in FIGS. 7 and 9, a fastening element 24 is provided on the outer surface 21 of the housing 2. The fastening element 24 is designed as a hump and protrudes on the opposite side of the outer face 21. With the fastening element 24, the mixer 1 can be fastened in the exhaust gas pipe 40 to prevent rotation around the central axis 23. Furthermore, the fastening element 24 serves at the same time for the purpose of specifying the rotational attitude of the mixer 1 in the exhaust gas system 4 with respect to the central axis 23 when tightening. For this purpose, a corresponding holding device (not shown in detail) is provided at a specific position, in which the fastening element 24 is pushed in the direction of the central axis 23.

  According to FIG. 9, the mixer 1 together with the housing 2 is mounted between two exhaust gas pipes 40, 40 ′. For this purpose, two exhaust gas pipes 40, 40 ′ are mounted on both sides of the housing 2. A gap 42 is provided between the exhaust gas pipes 40, 40 ′ for welding the two exhaust gas pipes 40, 40 ′ and for welding the mixer 1 to the exhaust gas pipes 40, 40 ′. The formation of the gap 42 is the result of the exhaust gas pipes 40, 40 ′ being spaced apart from each other in the direction of the central axis 12 by the circumference of the plurality of dispersed adjusting elements 22. Each exhaust gas pipe 40, 40 ′ is adjacent to one side of the gap 42 in the direction of the central axis 12.

  The mixer 1 according to FIGS. 4 and 6 is designed mirror-symmetrically with respect to a central plane 10 oriented parallel to the flow direction S. That is, the support body 30 and the plurality of mixing fins 31 are formed so as to be mirror-symmetric with each other. Such a mixer 1 comprises three mixing elements 3 arranged adjacent to each other in parallel. Each mixing element 3 is formed by a support 30 and one or three mixing fins 31 arranged on the support 30.

  The support 30 can be divided into three partial regions 36-38 between the end regions 34. The outer partial regions 37 and 38 are adjacent to both sides of the central partial region 36, respectively. The outer partial regions 37 and 38 are inclined with respect to the central partial region 36. That is, the central partial region 36 forms an angle γ with respect to each of the two outer partial regions 37 and 38. Accordingly, the outer two partial regions 37 and 38 intersect the central partial region 36 at an angle γ of about 9 ° with respect to the first axis 11 extending parallel to the flow direction S. Since the outer partial regions 37 and 38 are inclined in the same direction with respect to the central partial region 36, the support 30 is designed to be mirror-symmetric with respect to the central axis 12 parallel to the flow direction S.

  The central mixing fin 31 includes a slit 39 at the center. The length LS of the slit 39 is between 50% and 80% of the length LM of the mixing fin 31. The slit 39 reduces the degree to which the flow in the central region is redirected, reducing vortex formation. Furthermore, the dynamic flow resistance of the mixer 1 is reduced in the very central region of the mixer 1 where the mass flow rate is maximum.

  In addition to the three mixing elements 3, further mixing elements 3 a are provided below the three mixing elements 3. The further mixing element 3a is formed by one support 30a and one mixing fin 31a. The mixing fin 31 a also includes a slit 39. The further mixing element 3a is attached to the sheath inner surface 20 of the housing 2 via its two end regions 34a so as to be freely supported between the two end regions 34a.

  FIG. 5 shows a point-symmetric mixer 1 having two identical mixing elements 3, 3 ′. Each mixing element 3, 3 ′ comprises two end regions 34, 340 and two connecting regions 370, 380 provided between these end regions 34, 340, respectively. Since the end region 34 and the first connection region 370 of each support 30 are connected to each other, the partial region 301 of the support 30 forms a closed cell 300. In the partial region 301 of the support 30 surrounding the cell 300, two mixing fins 31 are arranged on the support 30. The mixing element 3 is attached to the exhaust gas pipe 40 via the end region 340 and the second connection region 380.

  5 and 7 can also be combined with a deflecting element 6 in the same way as the mirror-symmetric mixer 1 according to the exemplary embodiment according to FIGS. 4 and 6. The deflection element 6 comprises a sheet metal member 60 having one or several fins 61 rising at an angle sv of about 20 °, as shown in FIGS. 9 and 9a. By these fins 61, the exhaust gas flow is turned upward in the dispersion direction V, and the reducing agent is also pushed upward. The sheet metal member 60 is placed directly on the surface of the support 30, 30a and, according to the illustrated exemplary embodiments, together with the mixing elements 3, 3a forms an integral component made of the same material.

  The deflection element 6 comprises several correction plates 62, 62 ', 62 "arranged parallel to the flow direction S and parallel to the sheet metal member 60. The correction plates 62, 62', 62" The reducing agent is dispersed just before the mixer 1. The correction plate 62 is arranged directly on the surface of the support 30, 30a and, according to each exemplary embodiment shown, together with the mixing elements 3, 3a forms an integral component made of the same material.

  The correction plates 62, 62 ′, 62 ″, according to FIG. 9, comprise several correction fins 64 that rise at an angle sk of 155 ° with respect to the flow direction S. These correction fins 64 are shown in detail in FIG. As shown in FIG. 4, the punching plate 62 is partially punched out and protrudes from the correction plate 62 in the direction of the adjacent correction plate 62 and / or in the direction of the thin metal plate member 60. As a result, from the correction plate 62 An opening 63 corresponding to the area of the protruding correction fin 64 is formed below the correction fin 64 of each correction plate 62. The correction fin 64 can protrude from one or both surfaces of the correction plate 62.

  Similarly, since the fin 61 of the metal thin plate member 60 is also punched out, the metal thin plate member 60 includes an opening 63 corresponding to the area of the fin 61 protruding from the metal thin plate member 60 below each fin 61. As shown in FIG. 14, the correction fins 64 protrude from both surfaces of the correction plate 62, and the fins 61 protrude from one surface of the thin metal plate member 60.

  The correction plates 62, 62 ′, 62 ″ according to FIG. 9a comprise several drill holes 65 directed in the drill direction B extending at an angle bs of 90 ° with respect to the flow direction S instead of the correct fins. Through the perforations, the exhaust gas stream can flow in the direction of the central axis 12 with the reducing agent, at least partially through the deflection element 6.

  FIG. 3 further shows a part of the exhaust gas system 4 as described in FIGS. 1 and 2. However, in this exemplary embodiment, the mixer 1 is combined with a deflecting element 6 configured in the same way as the mixer 1 itself. This kind of mixer 1 is formed according to FIG. 10 from several flow elements 7, 7 ′ which abut against each other.

  FIG. 11 shows in detail that the mixer 1 is made up of several flow elements 7, 7 ′, 7 ″ that abut against each other. The flow elements 7, 7 ′, 7 ″ have a corrugated cross-sectional profile. Each of them is formed by a thin metal plate 70 having 71. The cross-sectional profile 71 comprises a front surface 73 and a number of channels 72 that extend adjacent to each other in the direction of a plurality of parallel profile axes 74. The profile axes 74, 74 ′ of two adjacent flow elements 7, 7 ′ alternately rise with an angle ps of + 40 ° and −40 ° with respect to the flow direction S. As a result, the flow is simultaneously redirected upward and downward in the plurality of flow paths formed by the two flow elements 7, 7 '.

  However, according to the invention, the profile axes 74, 74 'of two adjacent central flow elements 7, 7' with respect to the central plane 10 are parallel, i.e. the same in terms of their direction and size -40. Since they extend at an angle ps of °, the flow elements 7, 7 'do not abut against each other. As a result, as can be seen from the arrows in FIG. 10, the flow in the flow path formed by the two flow elements 7, 7 'is redirected only upward, ie in the same direction. In each exemplary embodiment described above, the angle ps corresponds to the angle ms.

  Since the profile axes 74, 74 ′ of the two flow elements 7, 7 ′ arranged on both sides with respect to the center plane 10 and adjacent to each other at the same time are in the same alignment, the mirror-symmetric shape of the mixer 1 is centered This is realized with reference to the plane 10. The part of the exhaust gas stream and the reducing agent flowing in the center of the mixer 1 is thus redirected in one direction inside these two flow elements 7, 7 '.

  FIG. 12 shows a cross section of the mixer 1 in which the profile axes 74, 74 'rise at an angle of ± 30 °. In front of the mixer 1, a deflecting element 6 configured in the same way as the mixer 1 is arranged. Along with the deflection element 6, several sheet metal members 60 having a cross-sectional profile 66 are also arranged directly adjacent to each other. The profile axes 67 and 67 ′ of the deflection element 6 of the adjacent thin metal plate members 60 do not rise with respect to the flow direction S. That is, the profile axes 67 and 67 ′ extend in parallel to the flow direction S. Accordingly, the deflecting element 6 forms individual flow paths between the individual sheet metal members 60 corresponding to the two flow elements 7, 7 ′ in the center of the mixer 1. In these flow paths, the exhaust gas flow and the reducing agent are guided only in the direction parallel to the flow direction S.

  FIG. 13 shows a square diagram representing the angle and angle ratio of the correction fin 64 and the injection direction E together with the dispersion direction V and the flow direction S. FIG. 14 shows such an overview on the basis of the mixing fin 31 and the metal sheet 70 and on the basis of the dispersion direction V and the flow direction S.

  FIGS. 15-20 illustrate an alternative mixer identified by reference numeral 400. The mixer 400 includes a first mixing element 402, a second mixing element 404, a third mixing element 406, and a fourth mixing element 408. In order to provide the mixer 400 as a unitary assembly, the mixing elements 402, 404, 406, 408 are secured to each other. The first mixing element 402 functions as a holder or housing as well as a mixing element. To achieve this function, the first mixing element 402 includes a first arcuate sidewall 412 and a second arcuate sidewall 414 spaced therefrom. A generally planar base 416 interconnects the first side wall 412 and the second side wall 414 to define a “U” shape. As shown in each figure, the base 416 may be bent or a plurality of small bends may be included to provide inflection points 415, 417 that are bent. The first side wall 412 includes a distal end 418 spaced from the distal end 419 of the second side wall 414. The mixer 400 is positioned inside the exhaust gas pipe 40 such that the gap between the ends 418, 419 is aligned with the injection device 5. The reducing agent that can flow along the upper surface of the tube 40 is not limited by the presence of the mixer wall, but instead will flow downstream between the ends 418,419.

  The integrally formed deflection element 420 extends from the base 416 in the axial direction and substantially parallel to the flow direction S. The deflection element 420 includes a plurality of correction fins 422 that rise at an angle A of 30 ° with respect to the flow direction. The mixing fins 426 extend at an angle B of 45 ° with respect to the flow direction S. A slit 428 enters the mixing fin 426 and splits part of the fin.

  The second mixing element 404 includes a first flange 430 and a second flange 432 spaced therefrom. A base 434 interconnects the first flange 430 and the second flange 432. Base 434 extends away from base 416 substantially parallel to base 416. The first flange 430 includes an outer surface 438 positioned and engaged with the inner surface 440 of the first sidewall 412. The first flange 430 is secured to the first side wall 412 using a method such as welding, hammering, or some other mechanical fastening technique. Similarly, the second flange 432 includes an outer surface 442 positioned and engaged with the inner surface 444 of the second sidewall 414.

  The second flange 432 is fixed to the second side wall 414. The second mixing element 404 also includes one or more correction fins 450. The correction fins 450 extend at an angle C of 40 ° with respect to the flow direction S. In the opposite direction to the correction fins 450, the mixing fins 452 extend at an angle D of 40 °. In the embodiment shown in FIGS. 15-20, a single correction fin 450 is shown upstream from two laterally spaced mixing fins 452. Another mixing fin 454 that is partially bifurcated extends parallel to the fin 426. Outer mixing fins 456 and 458 extend at an angle E of 45 ° with respect to the flow direction S. It should be understood that angle E need not be equal to angle B, and it is often convenient for mixing fins 454 to extend non-parallel to fins 426. In order to optimally achieve uniform distribution of the reducing agent within a particular system, the mixer 400 may be “tuned” by changing both of the above angles.

  The third mixing element 406 is substantially similar to the second mixing element 404. The third mixing element 406 includes first and second flanges 464, 468. A base 470 interconnects the first flange 464 and the second flange 468. Base 470 is positioned to extend substantially parallel to flow direction S and base 434. First flange 464 and second flange 468 are shaped and positioned to be secured to inner surfaces 440, 444 of first mixing element 402. Similar to the second mixing element 404, the third mixing element 406 includes a modified fin 474, a pair of laterally spaced mixing fins 476, a bifurcated mixing fin 478, an outer mixing fin 480, 482. Each fin of the mixing element 406 extends substantially parallel to a similar fin of the second mixing element 404. It should be understood that this relationship is exemplary only and other angles may be defined.

  The fourth mixing element 408 is substantially similar to the second mixing element 404 and the third mixing element 406. The fourth mixing element 408 includes first and second flanges 486, 488. A base 490 interconnects the first flange 486 and the second flange 488. Base 490 is positioned to extend substantially parallel to flow direction S and base 470. First flange 486 and second flange 488 are shaped and positioned to be secured to inner surfaces 440, 444 of first mixing element 402. Similar to the second mixing element 404, the fourth mixing element 408 includes a modified fin 494, a pair of laterally spaced mixing fins 496, a bifurcated mixing fin 498, an outer mixing fin 500, 502.

  The fifth mixing element 610 includes ninth and tenth flanges 684, 686. Flanges 684, 686 are positioned in slots 688, 690 and are secured to seventh and eighth lips 692, 694.

  After each of the second mixing element 404, the third mixing element 406, and the fourth mixing element 408 are secured to the first mixing element 402, the mixer assembly 400 is connected to an exhaust conduit such as the exhaust gas pipe 40 described above. Can be positioned within. It should be understood that the first side wall 412 and the second side wall 414 have a size and shape that contact or are in close proximity to the inner surface of the exhaust gas pipe 40. The mixer 400 is placed in the exhaust gas pipe 40 at the desired axial position and in the desired angular orientation, and then connected to the exhaust gas pipe 40 by any number of processes including welding, mechanical fastening, pressing, etc. Fixed.

  FIG. 21 shows an alternative mixer identified by reference numeral 400a. The mixer 400a is substantially similar to the mixer 400 described above, except that the first side wall 412a includes a generally planar portion 413 positioned between the arcuate portions 415 and 417. The substantially planar portion 413 is separated from the inner surface of the exhaust gas pipe 40, whereas the portions 415 and 417 are fitted to the inner surface of the exhaust gas pipe 40 and are fixed to the inner surface of the exhaust gas pipe 40 by a method such as welding. The Similarly, the second side wall 414a includes a substantially planar central portion 419 positioned between the curved portion 421 and another curved portion 423. The substantially planar central portion 419 is separated from the inner surface of the exhaust gas pipe 40.

  22-24 show another alternative mixer identified by reference numeral 600. Mixer 600 includes a plurality of mixing elements 602, 604, 606, 608, and 610 spaced laterally. The mixer 600 includes a housing 612 that houses each of the mixing elements 602-610. The housing 612 may be a separate element and positioned inside the exhaust gas pipe, or the element 612 may represent the exhaust gas pipe itself.

  The housing 612 includes an open end 614 from which several pairs of slots extend axially. The first pair of slots 616, 618 extend a predetermined distance from the open end 614 parallel to each other in the axial direction and terminate in stop surfaces 617, 619. Slots 616, 618 may be formed as part of a stamping process. In this stamping process, a plurality of cuts extending through the housing 612 are created, and inwardly projecting lips, such as a first lip 620 and a second lip 622, are formed by the tool. The first lip 620 extends substantially parallel to the second lip 622.

  The first mixing element 602 includes a first peripheral portion or flange 624 and a spaced apart, generally parallel second peripheral portion or flange 626. A base 628 interconnects the first and second flanges 624, 626. The first flange 624 enters the slot 618 adjacent to the first lip 620. Similarly, the second flange 626 enters the slot 616 and is positioned adjacent to the second lip 622. The first and second flanges 624, 626 are fixed to the first and second lips 620, 622 by welding or brazing. The ends of the flanges 624, 626 are recessed below the cylindrical surface 632 defined by the majority of the housing 612. This allows the mixer 600 to be easily inserted into the exhaust conduit having a circular cross section. Base 628 is illustrated as including a pair of ribs 636 and 638 that are substantially planar and extend in the axial direction. The ribs 636, 638 provide inflection points that can bend the first mixing element 602 to accommodate an increase in element size based on the coefficient of thermal expansion. It should be understood that any number of geometric features may be included to achieve the desired flow and mixing characteristics. For example, any one of the mixing elements 602, 604, 606, 608, 610 may include one or more protruding tabs or bends similar to the modification fins 450 and / or the mixing fins 476, 478, or 480. It is possible.

  The second mixing element 604 is substantially similar to the first mixing element 602 and has third and fourth flanges 642, 644 extending in the axial direction. A second pair of slots 646, 648 extend through the housing 612 and accommodate third and fourth flanges 642, 644, respectively. Second mixing element 604 is secured to third and fourth lips 647, 649 of housing 612.

  A pair of opposing recesses 650, 652 are formed in the housing 612. Slots 654, 656 extend through housing 612 within recesses 650, 652. Inwardly extending lips such as lips 620, 622 are not formed from the housing 612 adjacent to the slots 654, 656. Instead, the slot 654 is positioned between the opposite end surfaces 657, 659 of the housing 612 that face each other. The third mixing element 606 includes fifth and sixth flanges 660 and 662 that extend substantially radially and enter the slots 654, 656.

  Third mixing element 606 includes a radially extending peripheral portion or base 664 away from flanges 660, 662. To ensure that the mixer 600 can withstand repeated heating and cooling events and cannot be structurally damaged by the coefficient of thermal expansion of each mixing element, the base 664 has radially extending flanges 660, 662. Are interconnected by inclined walls 668,670. Each mixing element includes a bend or some geometric shape positioned radially outward from the central planar base to provide a bending inflection point. During heating, as the width of the central, generally planar base increases, each mixing element bends, if necessary, to reduce stress and minimize the force applied to the housing 612. It is also conceivable that the central base and the surrounding part of one or more mixing elements are in the same plane. In this case, the housing will include a spring element for absorbing thermal expansion as part of the recess 650. In this configuration, no inflection point is provided on the mixing element.

  Returning to the embodiment of FIGS. 22-24, note that the peripheral portions or flanges 660, 662 are not facing upwards and extend generally parallel to the base 664. Thus, one surface of flange 660 is positioned adjacent to end surface 657 and the opposite surface of flange 660 is positioned adjacent to end surface 659. Similar arrangements exist on the flange 662 and on both ends defining the slot 656.

  The fourth mixing element 608 is a second mixing element except that its spaced seventh and eighth flanges 674, 676 extend outwardly in the opposite direction to the third and fourth flanges 642, 644. Substantially similar to element 604. To accommodate this arrangement, the fifth and sixth lips 678, 680 extend inward toward the third and fourth lips 647, 649.

  Each mixing element can be constructed using a stamping or forming process on sheet metal. The size and shape of each mixing element may be standardized or individually adjusted for a particular application. Also, although each figure shows a mixer having five mixing elements, it should be understood that a plurality of other mixers having more or fewer mixing elements than those shown are contemplated. For example, FIGS. 23 and 24 show a mixer 600a. The mixer 600a is almost the same as the mixer 600. Thus, similar elements are identified by similar reference signs with a lowercase “a” as a suffix. The mixer 600a includes a first mixing element 604a, a second mixing element 606a, and a third mixing element 608a. The housing 612a includes only the number of slots necessary to accommodate these mixing elements.

  FIGS. 25-27 illustrate an alternative mixer 700 that includes first to sixth mixing elements 702, 704, 706, 708, 710, and 712. Each mixing element of the mixer 700 is substantially the same as the mixing element of the mixer 400 and the mixing element 606 of the mixer 600, except that the main body portion of each mixing element is formed as a substantially flat plate, and is oblique to the plate. The difference is that it has a plurality of extending fins. Each mixing element 702-710 includes a plurality of upward mixing fins identified with the suffix "a". The mixing element 712 includes an outwardly extending deflection element 716 having a plurality of correction fins 712a oriented in a direction opposite to the mixing fins 702a-710a. Each mixing element 704-712 further includes a plurality of rear end mixing fins, identified with a suffix “b”, located in the central portion of each mixing element. Each element 704-710 further includes laterally spaced outer rear end mixing fins identified with a lowercase suffix “c”. In order to optimally disperse the injected reducing agent within a particular exhaust treatment system, the number of various mixing fins and the angle of each fin extending from the generally planar base can be adjusted exclusively. I want you to understand.

  Each mixing element includes a narrow tongue portion. This tongue portion is identified by adding the suffix “d” to the reference number of the mixing element and extends in the same plane as the full width body portion identified by the suffix “e”. The width of the tongue is reduced to pass through the generally cylindrical inner surface 718 of the ring 720.

  The ring 720 includes a plurality of recesses 724 that extend radially inward. Each recess includes a slot 726 extending therethrough. These recesses and slots are provided in pairs and are identified by the suffixes “a” to “l”. Each slot is also identified by a corresponding suffix depending on the paired position. The narrow tongue portion with the suffix “d” is first inserted into the ring 720. Peripheral portions of the wide body portion having the suffix “e” enter the corresponding pair of slots. For example, the peripheral portion of body portion 702e enters slots 726a and 726b in the lateral direction. As described above with respect to the third mixing element 606, the axial position of each mixing element 702-712 is identified by the corresponding slot length, tongue portion with the suffix "d" and the suffix "e". Defined by the axial position of the transition between the body part.

  A spring element 730 is positioned on one side of each slot 726 and another spring element 732 is positioned on the opposite side of slot 726. For clarity, only spring elements 730b and 732b are identified in FIGS. During a thermal event in which the temperature of the mixing element 702 increases and its width increases correspondingly with the linear thermal expansion coefficient, the spring elements 730, 732 bend radially outward. The other spring elements function in the same way when the dimensions of the mixing elements associated with each change as the temperature changes.

  In FIG. 28, an alternative mixer 800 is shown. Mixer 800 includes a mixer 802 that is substantially similar to one of the mixers described above, namely, mixer 1, mixer 400, mixer 600, or mixer 700. In order to improve the dispersion of the reducing agent in the exhaust pipe 40, a secondary mixer 804 is combined with the mixer 802 in the mixer 800.

  Mixer 802 includes a mixing fin 806 substantially similar to mixing fin 500 shown in FIG. 18 or mixing fin 31 as shown in FIG. In order to address the problem of the injected reducing agent flowing on or near the upper surface 810 of the exhaust pipe 40, the mixer 800 combines the secondary mixer 804 with the mixing features of the mixer 802. The upper surface 810 is defined as the portion of the inner surface of the exhaust pipe 40 that extends downstream, close to the angular position of the injection device 5. In order to improve the downstream dispersion of the reducing agent, the secondary mixer 804 changes the flow of the exhaust stream.

  Secondary mixer 804 is shown as a generally spherical protrusion 814 that protrudes radially inward from top surface 810. The protrusion 814 includes a point 816 at the maximum radial inward position that is recessed to about 10 percent of the diameter of the exhaust pipe 40. Secondary mixer 804 is positioned to affect the output from mixer 802. In particular, a configuration line 820 extending from a mixing fin 806 extending downstream is depicted. The configuration line 820 intersects the secondary mixer 804 at a position where the protrusion 814 continues to extend radially inward. In other words, the configuration line 820 intersects the protrusion 814 at a position upstream from the point 816. In the particular example shown in this figure, at the location where the configuration line 820 intersects the projection 814, 25 percent of the projection 814 is upstream of the intersection and 75 percent of the projection 814 is between Downstream from the intersection.

  Conveniently, the secondary mixer 804 contributes little or no back pressure due to its minimal inward projection. While the pumping rate dispersion remains approximately the same, the reducing agent uniformity shows a 7-12 percent improvement over the arrangement using only the mixer 802. Computer hydrodynamic modeling shows that the use of mixer 802 in combination with secondary mixer 804 increases the concentration of reducing agent as well as the dispersion gradient of the species. It is contemplated that the protrusion 814 may be axially positioned such that the location where the construction line 820 intersects the secondary mixer 804 is a position within the range of 10 percent to 50 percent of the axial length of the protrusion. This causes the exhaust and reducing agent moving along the upper surface 810 to be deflected radially inward, while the exhaust and reducing agent moving beyond the mixing fins 806 are directed radially outward.

  The above description is merely a disclosure and description of several exemplary embodiments of the present disclosure. Those skilled in the art will recognize from this description, and from the accompanying drawings and claims, various modifications, adaptations, without departing from the spirit and scope of the present disclosure as defined in the appended claims. And it will be readily appreciated that variations can be made.

Claims (18)

A mixer for mixing the fluid injected into the exhaust pipe into the exhaust stream,
A first mixing element including a base interconnecting a first side wall and a second side wall spaced from the first side wall, each of the first and second side walls being spaced apart from each other The first and second sidewall portions are sized to complement the interior surface of the exhaust pipe such that the first and second sidewall sections are adapted to be secured to the exhaust pipe. The base is spaced from the inner surface of the exhaust pipe, and the base mixes the deflected element positioned to collide with the injected fluid and the injected fluid into the exhaust gas. A first mixing element including a mixing fin positioned downstream of said deflection element to
A second mixing element including a base interconnected with spaced apart first and second mounting flanges secured to the inner surfaces of the first and second sidewalls for redirecting the exhaust flow A second mixing element comprising mixing fins;
With a mixer.   A third mixing element comprising a base interconnected with spaced apart third and fourth mounting flanges secured to the inner surfaces of the first and second side walls for redirecting the exhaust flow The mixer of claim 1, further comprising a third mixing element comprising mixing fins.   The mixer of claim 2, wherein the base of the second mixing element extends substantially parallel to the base of the third mixing element.   The mixer of claim 3, wherein the mixing fins of the second and third mixing elements extend substantially parallel to each other.   The mixer of claim 1, wherein the bases of the first and second mixing elements extend substantially parallel to each other.   The mixer of claim 1, wherein the distal ends of the first and second sidewalls are circumferentially spaced at an angle of less than 90 ° when measured from the center of the exhaust pipe.   2. The mixer according to claim 1, wherein the first and second side walls extend a certain length in an axial direction, and the deflection element extends in the axial direction and projects from the first and second side walls.   The plurality of mixing fins extend in the axial direction beyond the first and second sidewalls on opposite sides of the first and second sidewalls from the deflection element. Mixer.   The mixer of claim 1, wherein the deflection element includes a substantially planar portion extending substantially parallel to the direction of the exhaust flow and a correction fin extending obliquely with respect to the direction of the exhaust flow. .   The mixer of claim 1, wherein the first and second sidewall portions comprise an arcuate shape.   The mixer of claim 1, wherein the plurality of mixing fins extend at an angle in a range of approximately 40 degrees to 45 degrees with respect to a direction of exhaust flow upstream of the mixer.   The mixer of claim 11, wherein the deflection element extends at an angle of approximately 30 degrees with respect to the direction of exhaust flow upstream of the mixer. The mixer of claim 1, wherein a gap between the distal ends of the first and second sidewalls is aligned in a common angular orientation with an infusion device for injecting the fluid .   The first side wall includes a first curved portion and a second curved portion interconnected by a substantially planar portion, the planar portion being spaced apart from the inner surface of the exhaust pipe. The mixer according to claim 1.   The second sidewall includes a first curved portion and a second curved portion interconnected by a substantially planar portion, the planar portion of the second sidewall being the first sidewall. 15. The mixer of claim 14, wherein the mixer extends substantially parallel to the planar portion. A mixer for mixing the fluid injected into the exhaust pipe into the exhaust stream,
A housing including a first sidewall and a second sidewall spaced from the first sidewall, wherein each of the first and second sidewalls includes a spaced apart free distal end; A gap between the free distal end of the second side wall is aligned at a common angular orientation with an infusion device for injecting the fluid, and portions of the first and second side walls are secured to the exhaust pipe A housing that is adapted to,
A first mixing element including a generally planar deflection element positioned to impinge upon the injected fluid and a plurality of correction fins projecting obliquely from the deflection element;
A second mixing element interconnecting the first and second sidewalls and extending generally parallel to the first mixing element, the second mixing element including a mixing fin for redirecting the exhaust flow A mixed element of
A mixer equipped with.   The mixer according to claim 16, wherein the first and second side walls extend a certain length in the axial direction, and the deflection element extends in the axial direction and projects from the first and second side walls. The mixer of claim 17, wherein the deflection element extends substantially parallel to the direction of the exhaust flow upstream of the first and second sidewalls.

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