Waste gas mixer with annular pore plate

Abstract

The utility model relates to a waste gas mixer which comprises an exhaust pipe used for guiding waste gas and provided with a longitudinal axis and defining a circulation cross section Q1; a mixing element placed in the exhaust pipe and having an outer diameter Mb and an outlet cross-section QM, the exhaust pipe wall together with the mixing element defining a gap of width Sb within which the exhaust gas can be guided. The orifice plate body downstream of the mixing element has an orifice plate edge arranged at least indirectly in the exhaust pipe and at least one orifice plate opening surrounded by the orifice plate edge, and wherein a) the at least one orifice plate opening has a total flow-through cross-section QB, where: 0.5 Q1 lt; = QBlt; the Q < 1 > is equal to 0.9 Q1 or 0.8 QMlt; = QBlt; = 1.2 QM, or b) the orifice plate body has an orifice plate wall downstream of the orifice plate opening, the orifice plate wall having perforations of a total flow-through cross-section QW, where: 0.5 Q1lt; = QWlt; the Q < 1 > is equal to 0.9 Q1, or 0.8 QMlt; = QWlt; the formula is as follows: 1.2 QM. The utility model solves the problem of how to design and arrange a waste gas mixer to realize sufficient mixing and favorable gas backpressure.

Description

Technical Field

[0001] This utility model relates to an exhaust gas mixer and a perforated plate body with a central shaft for use in the exhaust gas mixer. Background Technology

[0002] Patent document US 2011 / 0061374 A1 discloses an exhaust gas mixer with an orifice plate. The orifice plate is located downstream of the mixing pipe and has radially arranged annular shoulders, adjacent pipe sections, and centrally arranged baffles, wherein the pipe sections and baffles are provided with perforations. Utility Model Content

[0003] This utility model relates to an exhaust gas mixer, comprising: an exhaust pipe for guiding exhaust gas, which includes a longitudinal axis and defines a flow cross-section; and a mixing element disposed within the exhaust pipe and having an outlet with an outer diameter Mb and a cross-section QM. The exhaust pipe and the mixing element together define a gap with a width Sb in which exhaust gas can be guided. An orifice plate body is provided in the exhaust pipe downstream of the mixing element, wherein the orifice plate body includes an orifice plate edge at least indirectly disposed on the exhaust pipe, and at least one orifice plate opening surrounded or defined by the orifice plate edge. The exhaust pipe defines a flow cross-section Q1 for the exhaust gas. The mixing element may be tubular, wherein a plurality of exhaust gas inlets and one exhaust gas outlet are arranged opposite each other. The exhaust gas inlets may generate an exhaust gas flow entering in a radial or circumferential direction. The exhaust gas outlet may generate an exhaust gas flow exiting in an axial direction.

[0004] This utility model also relates to a perforated plate body with a central axis for an exhaust gas mixer, the perforated plate body including a perforated plate opening defined by the perforated plate edge and the perforated plate edge, the perforated plate body spanning a plane.

[0005] This invention solves the problem of how to design and arrange an exhaust gas mixer to achieve thorough mixing and favorable gas back pressure.

[0006] According to this utility model, the problem is solved by the following means:

[0007] a) At least one orifice plate body includes a total flow cross-section QB, wherein,

[0008] 0.5 Q1 <= QB <= 0.9 Q1, or 0.8 QM <= QB <= 1.2 QM, or

[0009] b) The orifice plate body downstream of the orifice plate opening includes an orifice plate wall, the orifice plate wall including perforations having a total flow cross-section of QW, wherein:

[0010] 0.5 Q1<= QW <= 0.9 Q1, or 0.8 QM <= QW <= 1.2 QM.

[0011] This ensures that the exhaust gas can still be fully mixed even under low back pressure. The orifice plate edge includes a projected surface Fr relative to the central axis, and at least one orifice plate opening includes a projected surface Fo, wherein the flow cross-section Q1 corresponds to the sum of the projected surfaces Fr and Fo. The projected surfaces are perpendicularly aligned or perpendicularly aligned to the central axis.

[0012] According to this utility model, the following problems can also be solved:

[0013] a) The angle between the edge of the orifice plate and the plane is β, where 0° <= β < 80°; or

[0014] b) The orifice plate edge comprises a blade structure or a sheet structure consisting of multiple blades or sheets. In each case, the angle β is the minimum angle between the side of the orifice plate edge facing the exhaust gas flow or the side of the orifice plate edge facing away from the exhaust gas flow and the clamping plane.

[0015] Preferably, the orifice plate edge may include perforations having a total flow cross-section QR, wherein 0.1QB <= QR <= 0.2QB, or 0.1QW <= QR <= 0.2QW. The perforations on the orifice plate edge prevent stagnant flow downstream of the orifice plate edge in the exhaust pipe wall region.

[0016] More preferably, the edge of the orifice plate forms an angle α with the exhaust pipe wall, where 70° <= α < 90°. By setting the angle α, the deflection direction of the exhaust gas flow entering through the gap can be adjusted accordingly. By applying a corresponding positive or negative angle α, the deflection can be carried out in the flow direction or the opposite direction.

[0017] Furthermore, advantageously, there is an axial distance (d) between the edge of the orifice plate and the mixing element, wherein:

[0018] a) 5mm <= d <= 20 mm, or

[0019] b) 0.2 Sb <= d <= 3 Sb, or

[0020] c) 0.3 Mb <= d <= Mb.

[0021] The design of the distance between the edge of the orifice plate and the mixing element ensures, on the one hand, the optimal inflow of the exhaust gas flow entering through the gap, thereby achieving optimal mixing of the exhaust gas flow entering through the mixing element, and on the other hand, the optimal mixing of the added additives and the exhaust gas heat flow.

[0022] Preferably, the edge of the orifice plate may include blade or slab structures comprising multiple blades or slabs. Using multiple blades or slabs distributed circumferentially can further improve the mixing of the exhaust gas flow at the edge.

[0023] More preferably, each blade forms an angle α with the exhaust pipe wall, where 70° ≤ α ≤ 90°, and the angles of adjacent blades are different. This blade angle design has advantages similar to the orifice plate edge angle design described above. Because adjacent blades have different angles, the exhaust gas flow on one side of the gap is only partially deflected radially, thus providing greater advantages. The other portion is deflected in the opposite direction to the exhaust gas flow.

[0024] Of particular importance to this invention is that at least one blade includes a central axis perpendicular to the longitudinal axis of the exhaust pipe, wherein at least one blade has a helix, which is achieved by rotation or pivoting about the central axis. By using a twisting blade or fin, circumferential flow of the exhaust gas on the gap side can be achieved during mixing with the central exhaust gas flow. Due to this circumferential component, the mixing of the exhaust gas flow or additives is further improved. When the blade twists, the alignment directions of the blade base and the blade tip are different, while when the entire blade pivots, the alignment directions of the blade base and the blade tip are the same.

[0025] According to the design and arrangement of this invention, it is advantageous for adjacent blades to have the same or opposite helical directions. Opposite helical directions of adjacent blades or slabs can prevent the formation of vortices. However, during the mixing of the exhaust gas flow on the gap side, other flow components may be locally generated in the regions of their respective blade pairs or slab pairs, which has a positive impact on the mixing of the additives. Attached Figure Description

[0026] Further advantages and details of this utility model are described in the claims and description, and are shown in the accompanying drawings. Wherein:

[0027] Figure 1 This is a side view of the exhaust gas mixer;

[0028] Figure 2 is a side view of the end of the mixer;

[0029] Figure 2a is a schematic diagram of the projection plane;

[0030] Figure 3 is a side view of the end of the mixer;

[0031] Figure 3a is a schematic diagram of the total flow cross-section;

[0032] Figure 4 is a front view of the main body of the perforated plate;

[0033] Figure 5a is a side view of an alternative embodiment;

[0034] Figure 5b is a side view of an alternative embodiment;

[0035] Figure 5c This is a side view of an alternative embodiment;

[0036] Figure 6 This is a front view of the main body of the perforated plate;

[0037] Figure 7 This is a side view of the main body of the perforated plate. Detailed Implementation

[0038] The accompanying diagrams described below are mostly schematic diagrams illustrating the principles. Figure 1 The mixer 10 shown includes an exhaust pipe 1 with a longitudinal axis 1.1, and a mixing element 2 is installed inside the exhaust pipe 1. The mixing element 2 includes a blade region 2.1 through which the exhaust gas flow containing the additive flows into the mixing element 2. Furthermore, a gap 3 is provided between the mixing element 2 and the exhaust pipe 1, in which a portion of the exhaust gas flow that does not pass through the blade region 2.1 is guided. Downstream of the mixing element 2 is an orifice plate body 4 including a central shaft 4.5, which is fixed in the exhaust pipe 1 or on the exhaust pipe wall 1.2. The outer diameter or width of the mixing element 2 is Mb. The width of the gap is Sb. The axial distance between the orifice plate body 4 and the downstream end of the mixing element 2 is d.

[0039] According to the embodiment in Figure 2, the orifice plate body 4 is designed as a plate-shaped annular orifice plate. The orifice plate body 4 includes an orifice plate edge 4.1 and an orifice plate opening 4.2. According to Figure 2, the orifice plate opening 4.2 is designed as a notch. As mentioned above, the orifice plate edge 4.1 is designed as an annular orifice plate. The included angle α between it and the exhaust pipe wall 1.2 is 90°. Therefore, the projection planes Fr and Fo of the orifice plate edge 4.1 and the orifice plate opening 4.2 are shown in Figure 2a. As shown in Figure 3a, the projection plane Fo corresponds to the total flow cross-section QB of the orifice plate opening 4.2.

[0040] According to the embodiment in the upper half of Figure 3, the orifice plate edge 4.1 facing away from the exhaust gas of the orifice plate body 4 is further inclined relative to the exhaust pipe wall 1.2, and a minimum angle α of less than 90° is defined, approximately 76° in this example. According to the alternative embodiment in the lower half of Figure 3, the orifice plate edge 4.1 facing the exhaust gas is inclined in the opposite direction of the exhaust gas flow direction, with the same minimum blade angle α. According to the embodiment in Figure 3a, the total flow cross section Q1 of the exhaust pipe 1.2 is shown, as well as the total flow cross section QB of the orifice plate opening 4.2, which is part of it, and the total flow cross section QM of the mixing element 2, which is another part of it. The orifice plate edge 4.1 of the orifice plate body 4 has no perforations or exhaust gas flow openings 4.6.

[0041] According to the embodiment shown in Figure 4, the orifice plate body 4 includes an orifice plate edge 4.1, which is designed as a blade structure comprising multiple blades 4.3, 4.3'. Each blade 4.3, 4.3' is twisted about a radial central axis 4.4 and has a corresponding helix T relative to the central axis 4.4. In the upper half of Figure 4, adjacent blades 4.3, 4.3' have the same helical direction, while in the alternative embodiment in the lower half of Figure 4, adjacent blades 4.3, 4.3' have opposite helical Ts. The helix T of the blades 4.3 forms an exhaust gas flow opening 4.6, allowing exhaust gas to pass through the orifice plate edge 4.1. The orifice plate opening 4.2 remains open or is designed as a notch with a corresponding total flow cross-section QB. The orifice plate body 4 lies within a plane 9.

[0042] According to the embodiment in Figure 5a, adjacent blades 4.3 and 4.3' are tilted in opposite directions and each forms a minimum angle α with the exhaust pipe wall 1.2. This is equivalent to combining the two embodiments with included angle α in Figure 3. The angle α of blade 4.3 is approximately 75°, and the angle α of blade 4.3' is approximately -75°, both measured counterclockwise from the exhaust pipe wall 1.2 in each case.

[0043] Figure 5b is an AA side view of the lower blades 4.3 and 4.3' in Figure 4. Figure 5b depicts the other three blades 4.3'' up to the central axis 4.5 in a conventional manner. Blades 4.3 and 4.3' include a counter-rotating helix T with a twist angle δ of approximately 45°.

[0044] Figure 5c The image shows the individual orifice plate body 4, without the exhaust pipe wall. The adjacent blades 4.3 and 4.3' are also tilted in opposite directions. However, unlike Figure 5a, the values ​​of the angles (dem Betrag in German) also differ. The angle β of blade 4.3 is approximately 15°, and the angle β of blade 4.3' is approximately -25°; both angles are measured counterclockwise from plane 9.

[0045] according to Figure 6 In one embodiment, the orifice plate edge 4.1 of the orifice plate body 4 includes a perforation 4.6, the total flow cross-section QR of which is significantly smaller than the total flow cross-section QB of the orifice plate opening 4.2.

[0046] according to Figure 7In this embodiment, the orifice plate body 4 includes an orifice plate wall 4.8 extending downstream of the orifice plate opening. The orifice plate wall 4.8 includes perforations 4.7 having a total flow cross-section QW. The total flow cross-section QW approximately corresponds to the total flow cross-section QB of the orifice plate body 4. Therefore, the mixing effect produced by the orifice plate edge 4.1 is the same as in the embodiments without orifice walls shown in Figures 2 and 3. Unlike the embodiment of Figure 2, the orifice plate wall 4.8 has an additional mixing function due to the presence of the perforations 4.7. The exhaust gas is additionally agitated due to the presence of the perforations 4.7. Pressure loss can be offset by using a correspondingly large total flow cross-section QW.

[0047] List of reference numerals

[0048] 1: Exhaust pipe

[0049] 1.1: Longitudinal axis of exhaust pipe 1

[0050] 1.2: Exhaust pipe wall

[0051] 2: Hybrid Components

[0052] 2.1: Blade area

[0053] 3: Gap

[0054] 4: Perforated plate body

[0055] 4.1: Perforated plate edge

[0056] 4.2: Orifice Plate Opening

[0057] 4.3: Blades, Lamellae

[0058] 4.3': Blades, plates

[0059] 4.3'': Blades, flakes

[0060] 4.4: The central axis of blade 4.3

[0061] 4.5: Central axis of the perforated plate body 4

[0062] 4.6: Perforation, exhaust gas flow opening

[0063] 4.7: Perforation, exhaust gas flow opening

[0064] 4.8: Perforated plate wall

[0065] 9: Plane

[0066] 10: Exhaust gas mixer

[0067] d: distance

[0068] T: Spiral

[0069] α: Angle

[0070] β: Angle

[0071] δ: Angle of twist

[0072] Glossary

[0073] Mb: Width

[0074] Sb: Width

[0075] Fr: Projection plane

[0076] Fo: Projection surface

[0077] Q1: Total flow cross-section of exhaust pipe 1

[0078] QB: Total flow cross-section of orifice plate opening 4.2 mm.

[0079] QM: Total flow cross-section of hybrid element 2

[0080] QW: Total flow cross-section of the orifice plate wall is 4.8 mm.

[0081] QR: Total flow cross-section at the edge of the orifice plate (4.1).

Claims

1. An exhaust mixer, comprising: an exhaust pipe for directing exhaust gas, comprising a longitudinal axis and defining a flow cross section Q1; a mixing element disposed within the exhaust pipe, having an outer diameter Mb and an outlet with a cross section QM; a gap disposed between the exhaust pipe and the mixing element for directing exhaust gas; and an orifice plate body located in the exhaust pipe to direct exhaust gas radially out of the gap, the orifice plate body comprising at least one orifice opening extending therethrough, the at least one orifice opening comprising a total flow cross section QB, wherein 0.5Q1 < QB < 0.9Q1.

2. The exhaust mixer of claim 1, wherein, 0.8QM < QB < 1.2QM.

3. The exhaust mixer of claim 1, wherein, the orifice plate body comprises perforations, the perforations comprising a total flow cross section QR, wherein: 0.1QB < QR < 0.2QB, or 0.1QW < QR < 0.2QW.

4. The exhaust mixer of claim 1, wherein, the orifice plate body is plate-like and forms an included angle a with the wall of the exhaust pipe, wherein 70° <= a < 90°.

5. The exhaust mixer of claim 1, wherein, the orifice plate body is axially distanced from the mixing element by a distance d and the gap has a width Sb, wherein: a) 5mm < d < 20mm, or b) 0.2Sb < d < 3Sb, or c) 0.3Mb < d < Mb.

6. The exhaust mixer of claim 1, wherein, the orifice plate body comprises a vane structure or a lamella structure comprising a plurality of vanes or lamellas.

7. The exhaust mixer of claim 6, wherein, one of the plurality of vanes forms an included angle a with the wall of the exhaust pipe, wherein 70° <= a <= 90°, wherein adjacent vanes have different angles.

8. The exhaust mixer of claim 6, wherein, one of the plurality of vanes comprises a central axis perpendicular to the longitudinal axis of the exhaust pipe, the vane forming a spiral by rotating or pivoting around the central axis.

9. The exhaust mixer of claim 8, wherein, adjacent vanes comprise a spiral in the same or opposite direction as one of the plurality of vanes.

10. The exhaust gas mixer of claim 1, wherein, the orifice plate body is located downstream of the mixing element to direct exhaust gas radially inwards out of the gap at a location downstream of the outlet of the mixing element.

11. An exhaust mixer, comprising: an exhaust pipe for directing exhaust gas, comprising a longitudinal axis and defining a flow cross section Q1; a mixing element disposed within the exhaust pipe, having an outer diameter Mb and an outlet with a cross section QM; a gap disposed between the exhaust pipe and the mixing element for directing exhaust gas; and an orifice plate body located in the exhaust pipe to direct exhaust gas radially out of the gap, the orifice plate body comprising at least one orifice opening extending therethrough, the at least one orifice opening comprising a total flow cross section QB, wherein 0.8QM < QB < 1.2QM.

12. The exhaust gas mixer of claim 11, wherein, 0.5Q1 < QB < 0.9Q1.

13. An exhaust mixer, comprising: An exhaust pipe for guiding exhaust gases, comprising a longitudinal axis and delimiting a flow cross section Q1; a mixing element disposed within the exhaust pipe, having an outer diameter Mb and an outlet with a cross section QM; a gap disposed between the exhaust pipe and the mixing element for guiding exhaust gases; and an orifice plate body located in the exhaust pipe to direct exhaust gases radially away from the gap, the orifice plate body comprising at least one orifice plate opening extending therethrough, the at least one orifice plate opening comprising a total flow cross section QB, wherein, the orifice plate body comprises an orifice plate wall, the orifice plate wall comprising at least one perforation, the perforation comprising a total flow cross section QW, wherein 0.5Q1≤ QW≤ 0.9Q1, or 0.8QM≤ QW≤ 1.2QM.

14. The exhaust mixer of claim 13, wherein, an axial distance of the orifice plate body from the mixing element is d, and a width of the gap is Sb, wherein: a) 5 mm ≤ d ≤ 20 mm, or b) 0.2Sb≤ d ≤ 3Sb, or c) 0.3Mb≤ d ≤ Mb.

15. The exhaust gas mixer of claim 13, wherein, the orifice plate body is located within the exhaust pipe downstream of the mixing element to direct exhaust gases radially inward away from the gap at a location downstream of the outlet of the mixing element.

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