Mixing device for mixing reaction medium into gas stream, exhaust gas line and internal combustion engine having such mixing device

Abstract

The invention relates to a mixing device (1) for mixing a reaction medium into a gas flow, the mixing device (1) having a flow housing (3) with a longitudinal axis (L) and an inlet wall (5) with an inlet opening (7) for the gas flow, the inlet opening (7) being arranged with respect to the longitudinal axis (L) such that the inlet wall (5) has an inlet opening (7) for the gas flow. The inlet opening (7) is arranged in the flow housing (3) such that an inflow direction (SR) of the gas flow encloses a first limited angle (alpha) with the longitudinal axis (L), and wherein a vortex element (9) is arranged in the flow housing (3) opposite the inlet opening (7) in the inflow direction (SR).

Description

Technical Field

[0001] The present invention relates to a mixing device for mixing a reaction medium into a gas stream, an exhaust gas line for an internal combustion engine having such a mixing device, and an internal combustion engine having such a mixing device or such an exhaust gas line. Background Technology

[0002] When mixing a reaction medium into a gas stream using a mixing device, there is a requirement to achieve the most homogeneous mixing possible with the smallest possible structural space, especially with the shortest possible mixing path. If additional requirements must be met, such as evaporating the liquid reaction medium or involving the chemically active reaction medium in the reaction, for example by introducing a precursor of the reactant that is converted into a reactant upon contact with the gas stream, then the goal is also to achieve the most complete possible treatment in the sense of evaporation and / or reaction. Furthermore, sedimentation of the reaction medium at the walls of such a mixing device should be avoided at least to a large extent. Moreover, known mixing devices typically have undesirable high flow resistance and the resulting back pressure, and / or are improveable in terms of their manufacturing cost. Summary of the Invention

[0003] Therefore, the present invention is based on the objective of providing a mixing device for mixing a reaction medium into a gas stream, an exhaust gas line for an internal combustion engine having such a mixing device, and an internal combustion engine having such a mixing device or such an exhaust gas line, wherein at least the aforementioned disadvantages are reduced, and preferably they are eliminated.

[0004] The task is accomplished by providing current technical teachings, particularly teachings in the independent claims and in the preferred embodiments disclosed in the dependent claims and the specification.

[0005] In a first aspect, the task is addressed in particular by providing a mixing apparatus for incorporating a reaction medium into a gas stream, wherein... - The mixing device has a flow housing having a longitudinal axis and an inlet wall with an inlet opening for gas flow, wherein, - The inlet opening is arranged relative to the longitudinal axis such that the inflow direction of the gas flow together with the longitudinal axis encloses a first finite angle, wherein, - In the flow housing, vortex elements are arranged opposite the inlet opening along the inflow direction, wherein, - The vortex element is arranged such that a first flow path for gas flow is formed on the side of the vortex element facing the inlet opening in the flow housing, wherein a second flow path for gas flow is formed on the side of the vortex element away from the inlet opening in the flow housing, wherein... - The mixing device has at least one dispensing device for dispensing the reaction medium into the flow shell, and wherein, - The at least one dispensing device is arranged and configured to dispense the reaction medium along a dispensing direction that is inclined to the inflow direction and to the longitudinal axis.

[0006] Advantageously, by reversing the gas flow from the inflow direction to a main flow direction oriented along the longitudinal axis (wherein the gas flow generates vortices through vortex elements) and by introducing the reaction medium at an angle to both the inflow direction and the longitudinal axis, the proposed mixing device can achieve a particularly small structural space and a particularly short mixing path while simultaneously and effectively mixing and processing the reaction medium. Furthermore, by providing a second flow path on the back side of the vortex element, the vortex element can be efficiently and rapidly heated by a typical hot gas flow on its back side, thereby effectively preventing the precipitation of the reaction medium on the vortex element. The orientation of the introduction direction at an angle to the longitudinal axis is particularly effective: it shifts at least the hypothetical collision point of the reaction medium onto the wall of the mixing device in the direction toward the vortex element, so that any possible droplets of the reaction medium collide with the vortex element and evaporate there, because the vortex element is advantageously heated by the portion of the gas flow that passes through on the back side along the second flow path. Simultaneously, the gas flow flowing in along the inflow direction flows through at least one dispensing device and carries away the droplets formed there. Furthermore, the mixing device can be manufactured from a simple housing part and, in particular, plates at a reasonable cost.

[0007] Preferably, the feeding direction is oriented at least partially opposite to the inflow direction, that is, it begins or is oriented, in particular, obliquely, along the direction of the inflowing gas flow.

[0008] The longitudinal axis is, in particular, the imaginary longitudinal axis of the flow shell. The longitudinal axis is especially the axis of the longest extension of the flow shell, and / or preferably the axis of symmetry and / or central axis of the flow shell, which is at least substantially cylindrical. The longitudinal axis also defines the main flow direction of the gas through the shell.

[0009] In one embodiment, the flow housing has an outlet wall with an outlet opening. In one design, the outlet wall can be perpendicular to the longitudinal axis, or in other words, the outlet normal vector of the outlet wall is oriented parallel to the longitudinal axis. In this case, the outflow direction of the gas flow through the outlet opening is preferably the same as the main flow direction along the longitudinal axis. In another design, the flow housing can have an additional flow reversing section, wherein the outlet wall and thus the outlet normal vector of the outlet opening are oriented inclined to the longitudinal axis.

[0010] The gas flow is directed in the direction along which the gas flows into the flow housing through the inlet opening; this is in particular the direction of the inlet normal vector of the imaginary inlet face defined by the inlet opening.

[0011] The eddy current element is preferably constructed as an eddy current plate.

[0012] The first flow path is preferably the main flow path for the gas flow, while the second flow path is a secondary flow path for the gas flow. This specifically means that a larger portion (i.e., the main part of the gas flow) flows along the first flow path, while a smaller portion flows along the second flow path. Here, the second flow path is primarily used for heating the back side of the vortex element and is therefore advantageously sized to satisfy the function of effectively avoiding sedimentation on the vortex element, wherein, advantageously, a larger portion of the gas flow than necessary to satisfy this function is not directed along the second flow path. In contrast, the first flow path is used for processing and homogenizing the reaction medium, thereby directing the largest possible portion of the gas flow along the first flow path (without compromising the function of effectively heating the vortex element). However, it is important that the gas flows particularly parallel to the two flow paths during operation of the mixing device.

[0013] By means of heating the vortex element through a second flow path, unlike known measuring devices, the mixing apparatus proposed herein no longer primarily attempts to avoid contact between the reaction medium and the wall of the flow shell according to a feasible scheme; instead, wall contact is controlled by shifting the collision position while simultaneously heating the vortex element to at least largely prevent precipitation. Advantageously, this results in the mixing apparatus being able to have an advantageously small structural space and a short mixing path while simultaneously and effectively mixing and processing the reaction medium.

[0014] Without being bound by theory, heating the eddy current element causes the Leidenfrost-Effekt effect to occur when the reaction medium comes into contact with the eddy current element. In this effect, colliding droplets bounce off and break into smaller droplets, which are then further transported and evaporated by the flow.

[0015] In the context of current art teachings, the reaction medium specifically refers to a precursor or reactant used as a reactant, which is brought into the reaction, particularly downstream of the mixing device, along with at least one component of the gas stream, preferably in a catalyst provided for this purpose. The catalyst can specifically relate to an oxidation catalyst or a catalyst for the selective catalytic reduction of nitrogen oxides (SCR catalyst). Correspondingly, an oxidizing medium, or a medium itself oxidized while reducing a component of the gas stream, or a reducing medium, is preferably used as the reaction medium. In one design, ammonia or a solution containing ammonia, or an ammonia precursor or a solution thereof, preferably urea or a solution containing urea, especially an aqueous urea solution, is added to the mixing device by means of a dispensing device as the reaction medium.

[0016] In the preferred design, the gas flow is the exhaust gas flow, especially the exhaust gas flow of an internal combustion engine.

[0017] In one embodiment, at least one dispensing device is configured as a dispensing nozzle or a dispensing valve.

[0018] Preferably, the vortex element is arranged eccentrically off-center relative to the imaginary centerline of the inlet opening along the longitudinal axis. Specifically, when viewed along the main flow direction, it does not extend to a first reference point on the inlet side relative to the end of the inlet opening, but on the outlet side it extends beyond a second reference point on the outlet side relative to the end of the inlet opening. In this way, a portion of the gas flow can reach the second flow path, particularly below or behind the vortex element, and is technically parallel to the first flow path.

[0019] According to an improved embodiment of the invention, the vortex element is arranged such that the second flow path is technically constructed parallel to the first flow path, thereby distributing the gas flow from the inlet opening onto the first and second flow paths. That is, the gas flow does not flow sequentially through the first flow path first and then through the second flow path, but is instead distributed from the inlet opening into a first branch flowing along the first flow path and a second branch flowing along the second flow path, wherein the first and second branches flow parallel to each other through the flow paths. Here, viewed from the inlet opening, the first flow path is arranged before (or above) the vortex element, and viewed from the inlet opening, the second flow path is arranged after (or below) the vortex element. The gas flow can reach the vortex element particularly proportionally because the vortex element, as previously explained, is arranged eccentrically along the longitudinal axis relative to the imaginary centerline of the inlet opening, wherein, viewed along the main flow direction, it does not extend to the first reference point at the inlet-side end of the inlet opening, thus preserving free space through which the gas can flow past the vortex element.

[0020] Advantageously, the design also facilitates efficient heating of the eddy current element and contributes to low flow resistance and thus low back pressure.

[0021] In one embodiment, the first flow path and the second flow path converge upstream of the outlet opening of the flow housing. In other words, the first and second streams converge into a single flow before the outlet opening and flow together as a single stream through the outlet opening.

[0022] The first position or first element is arranged "upstream" of the second position or second element, which, in the context of current art teachings, means that the volumetric component of the gas flow first flows through the first position or first element and then flows through the second position or second element.

[0023] Accordingly, the first position or the first element is arranged "downstream" of the second position or the second element, which is understood as: the volumetric component of the gas flow first flows through the second position or the second element and then flows through the first position or the first element.

[0024] According to an improved embodiment of the invention, the first angle is set to be between 20° and 110°, preferably 90°. In particular, within this angle range, it is advantageous to achieve an effective vortex flow of gas upon impacting and contacting the vortex element.

[0025] According to an improved embodiment of the invention, the dispensing direction, together with the inflow direction, surrounds a second angle of 95° to 115°, preferably 100° to 110°, preferably 102° to 106°, and preferably 105°. Advantageously, the dispensing is carried out only partially opposite to the inflow direction, and particularly so that droplets of the reaction medium formed at the dispensing device are stripped away and carried or transported away by the gas flow.

[0026] Alternatively or additionally, the flow direction is configured to align with the longitudinal axis and thus surround the main flow direction at a third angle, which is 5° to 25°, preferably 10° to 20°, and most preferably 15°. Advantageously, within this angle range, the collision area of ​​the reaction medium with the vortex element shifts, so that the reaction medium at least does not first collide with the cooler wall of the flow housing, but rather with the vortex element heated by the second flow path coming from its back side.

[0027] According to the improved embodiment of the invention, the vortex elements are arranged and configured to generate a double vortex of convection in the gas flow along the longitudinal axis and thus along the main flow direction. In this way, particularly effective mixing of the reaction medium and the gas flow can be achieved. Advantageously, any concentration difference that may also exist in the reaction medium is equalized by the contact between the two vortex flows and each other in the imaginary central plane of the double vortex.

[0028] In one embodiment, the vortex element is designed such that the radius of each individual vortex flow in the dual vortex is 35% to 60% of the width dimension measured perpendicular to the longitudinal axis, particularly the radius of the flow housing, preferably 40% to 50%, preferably 42% to 48%, preferably 43% to 47%, particularly recommended 44% to 46%, and preferably 45%. In one design, the radii of the two vortex flows are the same, especially equivalent.

[0029] Alternatively or additionally, the vortex element has an integrally curved portion. That is, it is curved not only locally (e.g., in different regions of the forming or deepening portions), but overall. The vortex element particularly has integrally curved walls, or is constructed as an integrally curved plate. The curvature radius of the vortex element can vary locally or remain constant overall. Preferably, the curvature radius (in the case of local variation, optionally at each part of the vortex element) is 20% to 80% of the width dimension measured perpendicular to the longitudinal axis, particularly the radius of the flow shell, preferably 30% to 70%, preferably 35% to 60%, preferably 40% to 50%, preferably 42% to 48%, preferably 43% to 47%, particularly recommended 44% to 46%, preferably 45%.

[0030] Alternatively or additionally, the vortex axis of the vortex flow, that is, the axis of rotation or revolution, extends at least approximately parallel, preferably parallel to, the longitudinal axis of the flow shell.

[0031] In the context of current technical teachings, a double vortex convection is particularly understood as a flow pattern in which two vortex flows, placed parallel to each other (each rotating about a rotation axis arranged parallel to the longitudinal axis), are constructed adjacent to each other, wherein the rotation axes of the vortex flows extend in the direction of the longitudinal axis relative to each other, which are placed parallel to the longitudinal axis, and wherein the rotation directions of the vortex flows are opposite to each other, that is, the rotation direction of one vortex flow (in the direction of observation along the longitudinal axis, i.e., along the main flow direction) is mathematically negative, and the other rotation direction of the other vortex flow is mathematically positive.

[0032] The vortex element is arranged and configured such that it divides the interior of the flow housing into volumetric regions for each of the two vortex flows.

[0033] Preferably, the two vortex flows of the dual vortex are directed from the inside out. This means that the gas flow collides with the vortex element in the middle inside the flow housing, and through the vortex element, the two vortex flows are reversed radially outward and laterally flow towards the inlet opening at the wall of the flow housing, essentially flowing upwards, thereby constructing the corresponding vortices. In particular, viewed along the longitudinal axis, i.e., along the main flow direction, the rotation direction of the left vortex flow is mathematically negative, and the rotation direction of the right vortex flow is mathematically positive. This vortex flow design is particularly suitable for the back pressure of the mixing device, that is, the mixing device designed in this way has particularly low back pressure.

[0034] In one embodiment, the vortex elements are arranged and configured to generate the convection in a double vortex with a proportionally homogeneous distribution of the gas flow. Advantageously, in this way, particularly good homogenization of the reaction medium and the gas flow can be achieved. Here, proportionally homogeneous distribution of the gas flow is understood in particular, within the context of the present art teachings, as the two vortex flows guiding at least substantially equal, preferably equal, proportions of the total mass flow of the gas flow.

[0035] According to an improved embodiment of the invention, the vortex element is configured such that it has a rounded V-shaped shape in the cross-sectional plane (the longitudinal axis, and thus the main flow direction, is perpendicular to it), i.e., a V-shaped shape with curved, particularly inwardly bulging, i.e., a recessed foot or arm when viewed from outside the V-shape. This presents a particularly suitable geometry for the vortex element to generate double vortices. In particular, the rounded V-shape is open along the continuous imaginary flow direction; in other words, the preferred rounded or particularly roof-shaped apex of the V-shape points toward the inlet opening, while the arm of the V-shape extends away from the inlet opening. That is, if viewed along the longitudinal axis in the main flow direction of the gas flow and the inlet opening is arranged above, the vortex element has an inverted, rounded V-shaped shape in the cross-sectional plane, wherein the apex points upward, or in other words, a rounded Λ shape, especially with a particularly recessed arm that terminates gently to the side, like a child's line drawing of a bird; therefore, the vortex element is also called a "bird-shaped plate". Preferably, the eddy current element further has the following geometry, wherein the cross-sectional shape is extruded in a direction perpendicular to the cross-sectional plane along the longitudinal axis.

[0036] Alternatively, the vortex element is configured such that it has a rounded W-shaped shape in the cross-sectional plane (the longitudinal axis, and thus the main flow direction, is perpendicular to it), i.e., a W-shaped shape with curved, particularly outwardly bulging, or rather, protruding feet when viewed from outside the W-shape. This also presents a particularly suitable geometry for vortex elements that generate double vortices. In particular, the rounded W is open opposite to the inflow direction; in other words, the apex of the preferably rounded or particularly roof-like sloping interior of the W-shape points in the direction toward the inlet opening, wherein the feet of the W-shape also extend in the direction toward the inlet opening. That is, if viewed along the longitudinal axis in the main flow direction of the gas flow and the inlet opening is arranged above, the vortex element has an upright, rounded W-shaped shape in the cross-sectional plane, wherein the apex and particularly concave feet point upward. Preferably, the vortex element further has a geometry in which the cross-sectional shape is extruded in a direction perpendicular to the cross-sectional plane along the longitudinal axis.

[0037] According to the improved embodiment of the invention, the flow housing is configured such that it has at least one guide vane in the region of the inlet opening. Advantageously, the gas flow in the region of the inlet opening can thus be guided in a suitable manner into the interior of the flow housing, wherein it can be oriented, in particular, toward the vortex element for generating a double vortex.

[0038] In one embodiment, the flow housing has two guide vanes in the region of the inlet opening that are perpendicular to the longitudinal axis and thus perpendicular to the main flow direction. In this way, the incoming gas flow can be guided, in particular, to the vortex element in the middle, thereby enabling the formation of the double vortex rotating from the inside out as described above.

[0039] In one embodiment, at least one guide plate is constructed in one piece, preferably in the same material as the eddy current element. Preferably, the two guide plates are constructed in one piece, preferably in the same material as the connecting element. Particularly preferably, the rounded, W-shaped, elongated legs of the eddy current element form the two guide plates, wherein they are constructed, particularly towards the center, that is, partially curved back along the longitudinal axis.

[0040] In one embodiment, the eddy current element, together with its one-piece constructed guide plate, is constructed as a curved plate.

[0041] In another embodiment, at least one guide plate is constructed in multiple parts with the vortex element and is arranged separately from it in the flow housing.

[0042] In one embodiment, at least one guide vane is arranged such that its effective inlet cross-section for the gas flow is constant along the longitudinal axis. Preferably, the two guide vanes are arranged such that their effective inlet cross-section for the gas flow is constant along the longitudinal axis. This is particularly advantageous compared to designs where the guide vanes narrow the effective inlet cross-section along the longitudinal axis, thereby achieving a higher gas flow velocity and thus further improved mixing. Furthermore, the higher flow velocity helps prevent the formation of a fixed membrane.

[0043] In one design, the two guide vanes are arranged and configured to incrementally narrow the effective inlet cross-section for the gas flow along the longitudinal axis and thus along the main flow direction. This specifically means that the guide vanes are brought closer together along the longitudinal axis (viewed along the main flow direction), or in other words, the spacing between the guide vanes relative to each other, measured perpendicular to the longitudinal axis, decreases along the longitudinal axis. Advantageously, in this way, sufficient space is reserved for the gas flow while maintaining optimal orientation towards the vortex element, thus advantageously reducing the back pressure of the mixing device, particularly compared to a design where the guide vanes keep the effective inlet cross-section constant. Furthermore, the inflowing gas flow is advantageously accelerated by this narrowing when the inflow is less pronounced than in embodiments where the inlet cross-section is kept constant along the longitudinal axis, at least in the aforementioned design.

[0044] By specifically designing the spacing between the guide vanes, and optionally, especially the radius and / or profile of the guide vanes, the flow velocity of the gas flow can be affected, and the intensity of the vortex flow can be particularly advantageously affected.

[0045] Alternatively, or additionally, to the two guide vanes, the flow housing has at least one guide vane, specifically one arranged in the middle, in the region of the inlet opening. This guide vane is particularly configured as a distribution vane, which preferably divides the inflowing gas flow in half, that is, in equal proportions, into two streams. In this design, convective double vortices can be generated, wherein, however, the direction of rotation is from the outside to the inside, and wherein the inflowing gas flow flows along the wall of the flow housing to the outer end (Ausläufern) of the vortex element, so that from there it flows back upward in the middle in the direction toward the inlet opening.

[0046] In one embodiment, the flow housing has at least one impacting element laterally relative to the longitudinal axis, that is, laterally relative to the main flow direction, arranged such that droplets of the reaction medium reaching the edge region of the flow housing are stopped at the at least one impacting element. Advantageously, the droplets can be broken into smaller droplets at the at least one impacting element, which can evaporate more easily and quickly.

[0047] In one embodiment, at least one impact element is arranged at the height of the vortex element along the longitudinal axis, that is, along the main flow direction.

[0048] In one embodiment, at least one impact element is configured as two annular segments perpendicular to the longitudinal axis, that is, perpendicular to the main flow direction, extending radially into the flow region of the gas flow. This presents a particularly advantageous and efficient design for at least one impact element. Here, the corresponding two opposing annular segments specifically form the impact element.

[0049] Alternatively or additionally, the flow housing may have two impact elements arranged sequentially along the longitudinal axis, that is, along the main flow direction. Here, droplets of the reaction medium that are not intercepted by the first impact element in front can be intercepted by the second impact element behind.

[0050] In one design, each of the two impact elements arranged sequentially along the longitudinal axis is formed by two opposing annular segments, that is, pairs of annular segments.

[0051] In one embodiment, the rear (i.e., the second) impact element in the main flow direction, particularly the two rear annular segments of the two annular segments, extends further radially into the flow region than the front impact element. In this way, droplets of the reaction medium that are not intercepted by the front first impact element can be intercepted particularly effectively by the rear second impact element.

[0052] Here, the radial direction is understood, in the context of current technical teachings, specifically as the direction perpendicular to the longitudinal axis.

[0053] It can also be provided with exactly one impact element, or with more than two impact elements, especially with five impact elements. In addition, the impact element can have only one annular segment or have more than two annular segments.

[0054] At least one impact element can also be constructed as a single piece with the peripheral wall portion, especially as a partially formed portion or part of the peripheral wall portion, for example, as a bellows, as in a compensator.

[0055] In one embodiment, the flow housing has a peripheral wall portion.

[0056] In one embodiment, the peripheral wall is constructed in a columnar shape, particularly as the circumference of a cylinder. However, it is also possible for the peripheral wall to be implemented by a plurality of planar wall segments that are angled relative to each other.

[0057] According to an improved embodiment of the invention, the flow housing has at least one spacer element arranged and configured to keep the vortex element spaced apart from the peripheral wall of the flow housing.

[0058] In one embodiment, the flow housing has a plurality of spacer elements, which are preferably arranged in a peripheral direction about the longitudinal axis and / or along the longitudinal axis, that is, spaced apart from each other.

[0059] At least one spacer element connects the vortex element and, preferably, at least one guide plate to the peripheral wall. In particular, the vortex element and, preferably, at least one guide plate, are fixed to the peripheral wall by at least one spacer element.

[0060] Advantageously, based on the spacing between the vortex element (especially at least one guide plate) and the peripheral wall on the other side, caused by at least one spacer element, it is possible to ensure that the vortex element is effectively circulated by the hot gas flow, and thereby ensure particularly effective heating of the vortex element (and preferably at least one guide plate). Further advantageously, the at least one spacer element defines the distance between the peripheral wall and the vortex element, wherein the distribution of gas flow to the first and second flow paths can be adjusted by the length of the at least one spacer element and the selection of this distance, and simultaneously the intensity of heating behind the vortex element can be preset.

[0061] According to an improved embodiment of the invention, at least one spacer element is configured as a spacer pin. Alternatively or additionally, at least one spacer element has a columnar or pillar-like shape. Further alternatively or additionally, at least one spacer element is configured as a spacer pin.

[0062] In one design, at least one spacer element is connected to the peripheral wall and to the eddy current element material, for example by fusion welding or welding.

[0063] In particular, the vortex element, constructed as a single piece with at least one guide plate, has a radial spacing, preferably defined by at least one spacer element, relative to the peripheral wall at each location. Thus, advantageously, it can be circulated by a portion of the gas flow along its entire peripheral extension and also along its longitudinal extension, and can be heated particularly effectively by the gas flow.

[0064] According to an improved embodiment of the invention, the flow housing has a peripheral wall and a first end side, wherein an inlet opening, which serves as an inlet wall, is arranged at the peripheral wall, and at least one dispensing device is arranged at the first end side.

[0065] The interior of the flow shell is confined, in particular, by the peripheral wall and by the first end side.

[0066] Preferably, the first end side has an end-side normal vector oriented inclined to the longitudinal axis. Here, the insertion direction preferably points along the direction of the end-side normal vector. In particular, the end-side normal vector and the longitudinal axis together enclose the third angle.

[0067] The eddy current element is preferably arranged, and particularly fixed, at the peripheral wall. Alternatively or additionally, at least one impact element is arranged, and particularly fixed, at the peripheral wall.

[0068] In one embodiment, the flow housing has a second end side with an outlet opening thereon. The second end side is in particular the outlet wall portion described above.

[0069] In one embodiment, the second end side is opposite to the first end side along the longitudinal axis, that is, along the main flow direction.

[0070] According to the improved embodiment of the invention, the mixing device is configured to have two dispensing devices. Advantageously, in this way, on the one hand, even with a large gas mass flow, a higher reaction medium flow can be dispensed by means of, for example, a smaller dispensing device from the LKW field, wherein, however, at the same time, the smaller reaction medium flow can be dispensed with particular accuracy, especially by disconnecting one of the dispensing devices.

[0071] In one embodiment, the two dispensing devices are arranged adjacent to each other at the same height on the first end side.

[0072] In one embodiment, the two dispensing devices are arranged relative to the vortex element such that each dispensing device dispenses the reaction medium into the volume region of the vortex flow associated with it in each of the two vortex flows of the twin vortex. In other words, each of the two vortex flows is respectively assigned to one of the dispensing devices for dispensing the reaction medium into the corresponding vortex flow.

[0073] In another embodiment, the mixing device is configured to have three dispensing devices. Advantageously, in this way, on the one hand, even with a large gas mass flow, a larger reaction medium flow can still be dispensed again by means of a smaller dispensing device, such as those from the LKW field, wherein, however, the smaller reaction medium flow can be dispensed particularly accurately, especially by disconnecting one or two of the dispensing devices.

[0074] In one embodiment, three dispensing devices are arranged symmetrically on the first end side in the form of, in particular, an isosceles triangle.

[0075] According to an improved embodiment of the invention, the flow housing has at least one flow orientation element in the region of the inlet opening. Advantageously, non-uniform, especially vortex-like, gas flow can be homogenized, or in other words, uniformized, by at least one flow orientation element. Gas flow from the turbine of the exhaust gas turbocharger can be oriented by at least one flow orientation element, particularly becoming parallel, especially before it subsequently re-passes through the vortex element to obtain a defined vortex.

[0076] In one embodiment, the flow housing has at least two flow guide plates as at least one flow orientation element.

[0077] In one design, at least two flow guide plates are arranged parallel to each other in a cross-sectional plane perpendicular to the inflow direction. Alternatively or additionally, at least two flow guide plates are arranged obliquely, and particularly orthogonally to each other, in a cross-sectional plane perpendicular to the inflow direction.

[0078] In the second aspect, the task is also addressed by providing an exhaust gas path for an internal combustion engine having at least one mixing device according to the invention, or one or more mixing devices according to the embodiments described above. In particular, the advantages previously explained regarding the mixing device are realized with regard to the exhaust gas path.

[0079] Preferably, the exhaust gas line has a catalyst downstream of the mixing device, particularly an oxidation catalyst or a catalyst for selective catalytic reduction of nitrogen oxides (SCR catalyst).

[0080] In one embodiment, the exhaust gas line has an exhaust gas turbocharger upstream of the mixing device, particularly at least one turbine of the exhaust gas turbocharger.

[0081] In a third aspect, the task is further addressed by providing an internal combustion engine having a mixing device according to the invention or one or more of the mixing devices described above, or having an exhaust gas line according to the invention or one or more of the exhaust gas lines described above. In particular, the advantages already explained above regarding the mixing device or exhaust gas line are evident with regard to this internal combustion engine.

[0082] Preferably, the internal combustion engine can be configured as a stationary internal combustion engine, particularly for driving generators or delivery pumps. Alternatively, the internal combustion engine can be configured to drive motor vehicles, particularly commercial vehicles, such as trucks, engineering or construction machinery, defensive vehicles, marine vehicles, or air vehicles. Attached Figure Description

[0083] The invention will now be explained in more detail with reference to the accompanying drawings. Figure 1 A first view showing a first embodiment of the mixing device; Figure 2 Showing according to Figure 1 A second view of a first embodiment of the mixing device; Figure 3 The first embodiment of the mixing device is shown along Figure 1 A sectional view of line A–A in the diagram; Figure 4 The first embodiment of the mixing device is shown along Figure 2 A cross-sectional view of line B–B in the diagram; Figure 5 Shown from Figure 4 Detailed view of D; Figure 6 The first embodiment of the mixing device is shown along Figure 1 A cross-sectional view of line C–C in the middle; Figure 7 A first view showing a second embodiment of the mixing device; Figure 8 A schematic side view showing a second embodiment of the mixing device; Figure 9 The second embodiment of the mixing device is shown along Figure 7 A cross-sectional view of line C–C in the middle; Figure 10 An illustration showing a third embodiment of the mixing device, and Figure 11 A schematic illustration of a fourth embodiment of the mixing device is shown. Detailed Implementation

[0084] Figure 1 A first view showing a first embodiment of the mixing device 1.

[0085] The mixing device 1 is configured to mix a reaction medium into a gas stream and has a flow housing 3 having a longitudinal axis L and an inlet wall 5 with an inlet opening 7 for the gas stream. The longitudinal axis L defines the main flow direction through the flow housing 3. The inlet opening 7 is arranged relative to the longitudinal axis L such that the inflow direction SR of the gas stream and the longitudinal axis L enclose a first finite angle α, see [reference needed]. Figure 3 In the flow housing 3, a vortex element 9, preferably configured as a vortex vane, is arranged opposite the inlet opening along the inflow direction SR. The vortex element 9 is arranged such that a first flow path S1 for gas flow is formed on the side of the vortex element 9 facing the inlet opening 7 in the flow housing 3 (see [link to relevant documentation]). Figure 3), wherein, in the flow housing 3, a second flow path S2 for gas flow is formed on the side of the vortex element 9 opposite to the inlet opening 7. Figure 3 The mixing device 1 further includes at least one dispensing device 11 for dispensing the reaction medium into the flow housing 3, wherein the at least one dispensing device 11 is arranged and configured to dispense the reaction medium along the dispensing direction DR, which is inclined to the inflow direction SR and inclined to the longitudinal axis L. Figure 3 ).

[0086] Preferably, the mixing device is part of the exhaust gas line 13 of the internal combustion engine 15 and is arranged upstream of the catalyst in the exhaust gas flow of the internal combustion engine 15, especially upstream of the catalyst for selective catalytic reduction of nitrogen oxides (SCR catalyst), wherein, as a reaction medium, urea or a solution containing urea, especially a urea-water solution, is preferably mixed into the mixing device 11 by means of the batching device 11.

[0087] Preferably, the flow housing 3 has a peripheral wall 17, which, in the first embodiment shown here, is columnar in construction, particularly constructed as the circumference of a cylinder, and the peripheral wall forms the inlet wall 5. Furthermore, the flow housing 3 has a first end side 19, wherein at least one dispensing device 11 is arranged at the first end side 19.

[0088] The eddy current element 9 is preferably arranged, especially fixed, for example, welded or fused to the peripheral wall 17.

[0089] Preferably, the flow housing 3 has a second end side 21, which is particularly the outlet wall, where an outlet opening 23 is preferably arranged. Here, the second end side 21 can be opposite to the first end side 19 in the direction of the longitudinal axis L.

[0090] In the first embodiment shown here, the mixing device 1 has two dispensing devices 11, particularly configured as dispensing valves, arranged adjacent to each other at the same height on the first end side 19.

[0091] Preferably, the flow housing 3 has at least one guide plate 25 in the region of the inlet opening 7, and more particularly, two guide plates 25 opposite each other perpendicular to the longitudinal axis L. Thus, the incoming gas flow can be guided in the middle to the vortex element 9, thereby enabling the following... Figure 6 The described double vortex rotating from the inside out.

[0092] The two guide vanes 25 are arranged and configured such that they narrow the effective inlet cross-section for the gas flow along the longitudinal axis L. In particular, the guide vanes 25 are close to each other along the longitudinal axis L; in other words, the spacing between the guide vanes 25 relative to each other decreases along the longitudinal axis L.

[0093] The guide plate 25 in the first embodiment is constructed in multiple parts with the vortex element 9 and is arranged separately from it in the flow housing 3.

[0094] Figure 2 Showing according to Figure 1 A second view of the first embodiment of the mixing device 1.

[0095] Elements shown multiple times in the figures are labeled only once for clarity. Furthermore, identical and functionally identical elements are labeled with the same reference numerals in all figures, and thus refer to the preceding description accordingly.

[0096] Here, a first end side 19, which is inclined relative to a position perpendicular to the longitudinal axis L, can be particularly identified. At the first end side, dispensing devices 11 are arranged adjacent to each other at the same height.

[0097] Figure 3 The mixing device 1 is shown along Figure 1 A sectional view of line A–A in the diagram.

[0098] The first angle α shown here is 90° in the first embodiment.

[0099] The inlet direction DR and the inflow direction SR together surround the second angle β, which is preferably 95° to 115°, preferably 100° to 110°, preferably 102° to 106°, and preferably 105°.

[0100] The insertion direction DR, together with the longitudinal axis L, surrounds a third angle γ, which is 5° to 25°, preferably 10° to 20°, and most preferably 15°. The insertion direction DR points in particular along the direction of the end-side normal vector of the end side 19. In particular, the end-side normal vector and the longitudinal axis L surround the third angle γ.

[0101] The first flow path S1 is primarily used for the gas flow, while the second flow path S2 is a secondary flow path for the gas flow. Thus, a larger portion of the gas flow (i.e., the main part) flows along the first flow path S1, while a smaller portion flows along the second flow path S2. The second flow path S2 is primarily used for heating the back side of the vortex element 9, and thereby effectively preventing the reaction medium from settling on the vortex element 9, while the first flow path S1 is used for processing and mixing the reaction medium with the gas flow.

[0102] The vortex element 9 is arranged eccentrically relative to the imaginary centerline of the inlet opening 7 along the longitudinal axis L; viewed along the main flow direction, the vortex element does not extend to the first reference point at the end of the inlet opening 7 on the inflow side, but extends beyond the second reference point at the end of the inlet opening 7 on the outflow side. In this way, a portion of the gas flow can reach the second flow path S2 below the vortex element 9 (or to the right of the connecting element 9 in the figure).

[0103] Preferably, the flow housing 3 has at least one impact element 27 arranged along the longitudinal axis L in the height region of the vortex element 9 in the direction of the longitudinal axis L. Here, there are two impact elements 27.1 and 27.2 arranged sequentially along the longitudinal axis L, such that droplets of the reaction medium reaching the edge region of the flow housing 3 are stopped at the impact element 27. Advantageously, these droplets can be broken into smaller droplets there, which can evaporate more easily and quickly.

[0104] The impact element 27 is preferably arranged at the peripheral wall portion 17, and is particularly fixed thereon.

[0105] The vortex element 9 is arranged such that the second flow path S2 is technically constructed parallel to the first flow path S1. Thus, the gas flow originating from the inlet opening 7 is distributed onto the first flow path S1 and the second flow path S2. Preferably, the first flow path S1 and the second flow path S2 converge upstream of the outlet opening 23.

[0106] Figure 4 The mixing device 1 is shown along Figure 2 A cross-sectional view of line B–B in the diagram.

[0107] The impact elements 27 are each constructed as annular segments 29 that are opposite each other perpendicular to the longitudinal axis L and extend radially into the flow region of the gas flow.

[0108] Figure 5 Shown from Figure 4 Detailed view of D.

[0109] In one embodiment, the rear (i.e., second along the main flow direction) impact element 27.2 extends radially further into the flow region than the front (i.e., first along the main flow direction) impact element 27.1.

[0110] Figure 6 The mixing device 1 is shown along Figure 1 A cross-sectional view of line C–C in the diagram.

[0111] Eddy current element 9, especially in Figure 6The cross-sectional plane shown (with the longitudinal axis L perpendicular to it) has a flipped, rounded V-shaped shape, that is, a V-shaped shape with a curved, particularly inwardly bulging, i.e., a concave foot or arm when viewed from outside the V-shape. Here, the rounded V is open along the continuous imaginary inflow direction SR, that is, the rounded apex of the V-shape points towards the inlet opening 7 and thus opposite to the inflow direction SR, while the arm of the V-shape extends away from the inlet opening 7. Furthermore, the vortex element 9 as a whole has a geometry that is, arguably, perpendicular to the... Figure 6 The cross-sectional plane shown is extruded along the longitudinal axis L.

[0112] In this way, the vortex element 9 is specifically arranged and configured to generate a double vortex of convection along the longitudinal axis L in the gas flow. This enables particularly effective mixing of the reaction medium and the gas flow.

[0113] Here, two parallel vortex flows, DSL and DSR, are constructed adjacent to each other, with their rotation axes extending parallel to each other along the longitudinal axis L, and their rotation directions pointing in opposite directions. Along the longitudinal axis, i.e., along the main flow direction—that is, in the direction of observation in the attached drawing plane—the first rotation direction of the vortex flow DSL on the left side of the figure is mathematically negative, while the second rotation direction of the vortex flow DSR on the right side of the figure is mathematically positive.

[0114] Preferably, the two vortex flows DSL and DSR are directed from the inside out. That is, the gas flow inside the flow housing 3 collides with the vortex element 9 in the middle, and is radially reversed outward by the vortex element to form the two vortex flows DSL and DSR. It then flows laterally along the wall of the flow housing 3 (here, the outer wall 17) towards the inlet opening 7, which can be said to be an upward return flow, thereby constructing the corresponding vortex.

[0115] Preferably, the vortex element 9 is arranged and configured to generate a double vortex of convection by distributing the gas flow in a proportionally homogeneous manner.

[0116] The two dispensing devices 11 are arranged, in particular, relative to the vortex element 9, such that each dispensing device 11 dispenses the reaction medium into its corresponding vortex flow DSL, DSR. In other words, each of the two vortex flows DSL, DSR is respectively assigned one of the dispensing devices 11 for dispensing the reaction medium into the corresponding vortex flow DSL, DSR.

[0117] The eddy element 9 is preferably designed such that the radius of the corresponding eddy flow DSL, DSR is 35% to 60% of the width dimension measured perpendicular to the longitudinal axis, especially the radius of the flow housing 3, preferably 40% to 50%, preferably 42% to 48%, preferably 43% to 47%, particularly recommended 44% to 46%, preferably 45%.

[0118] Preferably, the vortex element 9 has an integral bend. The bending radius of the vortex element 9 can vary locally or can be constant overall. Preferably, the bending radius (in the case of local variation, optionally at each location of the vortex element 9) is 20% to 80% of the width dimension measured perpendicular to the longitudinal axis, particularly the radius of the flow housing 3, preferably 30% to 70%, preferably 35% to 60%, preferably 40% to 50%, preferably 42% to 48%, preferably 43% to 47%, particularly recommended 44% to 46%, preferably 45%.

[0119] Alternatively or additionally, the rotation axis of the vortex flow DSL, DSR extends at least approximately parallel, preferably parallel to the longitudinal axis L of the flow housing 3.

[0120] Figure 7 The first view showing a second embodiment of the mixing device 1 can be described as having a peripheral wall portion 17 that is shown for perspective purposes only.

[0121] In the second embodiment, the guide plate 25 is arranged such that its effective inlet cross-section for the gas flow is constant along the longitudinal axis L. Here, the guide plate specifically forms an inlet slot with parallel edges, as shown here by the thick dashed line 26.

[0122] Figure 8 A schematic side view of a second embodiment of the mixing device 1 is shown, which also has a peripheral wall portion 17 that is shown for perspective purposes only.

[0123] In the second embodiment, the guide plate 25 and the connecting element 9 are constructed as a single piece, preferably of the same material, and in particular, are constructed as a curved plate.

[0124] Preferably, the flow housing 3 has at least one spacer element 31, which is arranged and configured to keep the vortex element 9 spaced apart from the peripheral wall of the flow housing 3. The flow housing 3 particularly has a plurality of spacer elements 31, which are arranged here distributed along the periphery about the longitudinal axis L and along the longitudinal axis L, that is, spaced apart from each other. For clarity, only two of the spacer elements 31 are given reference numerals. The spacer elements 31 connect the vortex element 9 (along with the guide plate 25) to the peripheral wall 17. The vortex element 9, which is integrally constructed with the guide plate 25, is fixed to the peripheral wall 17, particularly by means of the spacer elements 31.

[0125] The spacer element 31 is configured here as a spacer pin or spacer needle, which in particular has a columnar or pillar-shaped form. The spacer element can be connected to the peripheral wall portion 17 and the eddy current element 9 by means of materials such as fusion welding or welding.

[0126] The vortex element 9, which is constructed as a single piece with the guide plate 25, has a radial spacing defined by the spacer element 31 at various locations relative to the peripheral wall portion 17.

[0127] Figure 9 The mixing device 1 is shown along Figure 7 A cross-sectional view of the second embodiment with line C–C in the middle.

[0128] In the second embodiment, the vortex element 9 has a rounded W-shaped shape in its cross-sectional plane (perpendicular to the longitudinal axis L), i.e., a curved, particularly outwardly bulging, W-shaped shape with protruding feet when viewed from outside the W-shape. In particular, the rounded W-shape is open opposite to the inflow direction SR; in other words, the central apex of the preferably rounded or particularly roof-shaped interior of the W-shape points towards the inlet opening 7, wherein the feet of the W-shape also extend towards the inlet opening 7. That is, if as in Figure 9 When observed along the longitudinal axis L in the main flow direction of the gas flow and positioned above the inlet opening 7, the vortex element 9 has an upright, rounded W-shaped shape in the cross-sectional plane, wherein the apex and, in particular, the concave foot point upwards. Preferably, the vortex element 9 further has a geometry in which the cross-sectional shape is extruded, approximately perpendicular to the cross-sectional plane, along the longitudinal axis L.

[0129] Particularly preferably, the rounded W-shaped, elongated legs of the vortex element 9 form the two guide plates 25, which are constructed particularly toward the center, that is, partially curved back along the longitudinal axis L.

[0130] Preferably, the flow housing 1 in the second embodiment does not have an impact element, or in other words, has no impact element.

[0131] Figure 10 The illustration shows a third embodiment of the mixing device 1, which also has a peripheral wall portion 17 that is shown in a) for perspective purposes only.

[0132] In the third embodiment, corresponding to the second embodiment, the flow housing 1 has at least one flow orientation element 33 in the region of the inlet opening 7. Therefore, it is advantageous to homogenize non-uniform, especially vortex-like, gas flows.

[0133] As shown in a), the flow housing 3 has two flow orientation elements 33, namely, two flow guide plates 35 that are oriented parallel to each other in a cross-sectional plane perpendicular to the flow direction.

[0134] As shown in b), the two flow guide plates 35 can also be arranged perpendicular to each other in a cross-sectional plane perpendicular to the inflow direction.

[0135] In c), four flow guide plates 35 are shown, which are arranged in pairs parallel to each other and perpendicular to each other in the form of a grid.

[0136] Figure 11 A schematic illustration of a fourth embodiment of the mixing device 1 is shown.

[0137] In the fourth embodiment, the mixing device 1 has three dispensing devices 11. The three dispensing devices 11 are preferably arranged symmetrically at the first end side 19 in the form of an isosceles triangle.

Claims

1. A mixing device (1) for mixing a reaction medium into a gas stream, wherein, - The mixing device (1) has a flow housing (3) having a longitudinal axis (L) and an inlet wall (5) with an inlet opening (7) for the gas flow, wherein, - The inlet opening (7) is arranged relative to the longitudinal axis (L) such that the inflow direction (SR) of the gas flow and the longitudinal axis (L) enclose a first finite angle (α), wherein, - In the flow housing (3), vortex elements (9) are arranged opposite to the inlet opening (7) along the inflow direction (SR), wherein, - The vortex element (9) is arranged such that a first flow path (S1) for the gas flow is formed in the flow housing (3) on the side of the vortex element (9) facing the inlet opening (7), wherein a second flow path (S2) for the gas flow is formed in the flow housing (3) on the side of the vortex element (9) away from the inlet opening (7), wherein, - The mixing device (1) has at least one dispensing device (11) for dispensing the reaction medium into the flow housing (3), and wherein, - The at least one dispensing device (11) is arranged and configured to dispense the reaction medium along the dispensing direction (DR), which is inclined to the inflow direction (SR) and to the longitudinal axis (L).

2. The mixing device (1) according to claim 1, wherein, The vortex element (9) is arranged such that the second flow path (S2) is constructed to flow parallel to the first flow path (S1), so that the gas flow originating from the inlet opening (7) is distributed to the first flow path (S1) and the second flow path (S2), wherein, optionally, the first flow path (S1) and the second flow path (S2) converge upstream of the outlet opening (23) of the flow housing (3).

3. The mixing apparatus (1) according to any one of the preceding claims, wherein, The first angle (α) is 20° to 110°, preferably 90°.

4. The mixing apparatus (1) according to any one of the preceding claims, wherein, The insertion direction (DR) - Enclosing a second angle (β) together with the inflow direction (SR), the second angle being 95° to 115°, preferably 100° to 110°, preferably 102° to 106°, preferably 105°, and / or - Together with the longitudinal axis (L), it surrounds a third angle (γ), which is 5° to 25°, preferably 10° to 20°, and preferably 15°.

5. The mixing apparatus (1) according to any one of the preceding claims, wherein, The vortex element (9) is arranged and configured to generate a double vortex of convection along the longitudinal axis (L) in the gas flow, preferably with a proportionate homogeneous distribution of the gas flow.

6. The mixing apparatus (1) according to any one of the preceding claims, wherein, The eddy current element (9) has a V-shaped or W-shaped shape that is particularly rounded in the cross-sectional plane, and the longitudinal axis (L) is perpendicular to the cross-sectional plane.

7. The mixing apparatus (1) according to any one of the preceding claims, wherein, The flow housing (3) has at least one guide plate (25) in the region of the inlet opening (7), and in particular two guide plates (25) opposite each other perpendicular to the longitudinal axis (L), wherein, optionally, the at least one guide plate (25) ‒ Constructed as a single piece with the eddy current element (9), or ‒ Constructed in a multi-piece configuration with the eddy current element (9), and / or ‒ It is configured such that the effective inlet cross section for the gas flow remains constant or narrows along the longitudinal axis (L).

8. The mixing apparatus (1) according to any one of the preceding claims, wherein, The flow housing (3) has at least one spacer element (31) arranged and configured to keep the vortex element (9) spaced from the peripheral wall (17) of the flow housing (3), and preferably has a plurality of spacer elements (31).

9. The mixing apparatus (1) according to claim 8, wherein, The at least one spacer element (31) is configured as a spacer pin or spacer needle.

10. The mixing apparatus (1) according to any one of the preceding claims, wherein, The flow shell (3) - It has a peripheral wall portion (17) and a first end side (19), wherein, - The inlet opening (7) is arranged at the peripheral wall (17) as an inlet wall (5), and the at least one dispensing device (11) is arranged at the first end side (19).

11. The mixing apparatus (1) according to any one of the preceding claims, wherein, The mixing device (1) has two dispensing devices (11) or three dispensing devices (11).

12. The mixing apparatus (1) according to any one of the preceding claims, wherein, The flow housing (3) has at least one flow orientation element (33) in the region of the inlet opening (7), and preferably at least two flow guide plates (35), which are optionally arranged parallel to or orthogonal to each other in a cross-sectional plane perpendicular to the flow direction (SR).

13. An exhaust gas line (13) for an internal combustion engine (15) having at least one mixing device (1) according to any one of claims 1 to 12.

14. An internal combustion engine (15) having a mixing device (1) according to any one of claims 1 to 12 or having an exhaust gas line (13) according to claim 13.

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