MIXER ASSEMBLY

Abstract

The invention relates to a mixing device (1) for integration into an exhaust pipe (4.1, 4.2) of an internal combustion engine and for mixing an exhaust gas stream (T), which device is formed from a housing (2) having a tubular wall (2.1) and a mid-axis (2.2) that can be aligned parallel to the exhaust pipe (4.1, 4.2) and from an intermediate wall (3) which is aligned transversely with respect to the mid-axis (2.2), wherein the intermediate wall (3) divides the housing (2) and has an inflow side (3.1) and an outflow side (3.2), wherein at least one inflow opening (E1) is provided in the intermediate wall (3), via which the exhaust gas stream (T) can at least partly flow from the inflow side (3.1) of the intermediate wall (3) to the opposite outflow side (3.2) of the intermediate wall (3), wherein the at least one inflow opening (E1) is placed eccentrically with respect to the mid-axis (2.2) and is brought close to a wall section (W1) of the tubular wall (2.1), wherein a flow guide element (S2) having a longitudinal axis (L2) is provided on the outflow side (3.2), which at least partly bounds a mixing chamber (2.3) with the intermediate wall (3) and by means of which an at least partial deflection of the exhaust gas stream (T) in a radial direction in relation to the mid-axis (2.2) can be effected, wherein the flow guide element (S2) has at least two outflow openings (A1, A2) and, by means of the flow guide element (S2), the exhaust gas stream (T) coming from the inflow opening (E1) can be guided to the at least two outflow openings (A1, A2), wherein the outflow openings (A1, A2) are placed eccentrically with respect to the mid-axis (2.2) and brought close to a common wall section (W2) of the tubular wall (2.1), wherein the wall section (W2) is arranged opposite to the wall section (W1) with respect to the mid-axis (2.2), and wherein the outflow openings (A1, A2) are arranged on opposite sides of the flow guide element (S2) with respect to the longitudinal axis (L1, L2), wherein, with respect to the mid-axis (2.2), the first partial stream (T3) can be can at least partly guided in the anticlockwise direction and a second partial stream (T4) can at least partly be guided in the clockwise direction out of the outflow openings (A1, A2).

Claims

1. A mixing device (1) for integration into an exhaust pipe (4.1, 4.2) of a combustion engine and for mixing an exhaust gas stream T, which is formed from a housing (2) with a tubular wall (2.1) and a mid-axis (2.2) that can be aligned parallel to the exhaust pipe (4.1, 4.2) and from an intermediate wall (3) which is aligned transversely to the mid-axis (2.2), wherein the intermediate wall (3) divides the housing (2) and features an inflow side (3.1) and an outflow side (3.2), wherein at least one inflow opening E1 is provided in the intermediate wall (3), through which the exhaust gas stream T can flow at least partially from the inflow side (3.1) of the intermediate wall (3) to an opposite outflow side (3.2) of the intermediate wall (3), wherein the at least one inflow opening E1 is positioned eccentrically with respect to the mid-axis (2.2) and is brought close to a wall section W1 of the tubular wall (2.1), characterized in that on the outflow side (3.2) a flow guide element S2 is provided with a longitudinal axis L2, which with the intermediate wall (3) at least partly bounds a mixing chamber (2.3), and by means of which an at least partial deflection of the exhaust gas stream T can be effected from its original flow direction into a radial direction in relation to the mid-axis (2.2), wherein the flow guide element S2 features at least two outflow openings A1, A2, and by means of the flow guide element S2, the exhaust gas flow T can be guided, starting from the inflow opening E1, to the at least two outflow openings A1, A2, wherein all outflow openings A1, A2 are positioned eccentrically with respect to the mid-axis (2.2) and are brought close to a wall section W2 of the tubular wall (2.1), wherein the wall section W2 is arranged opposite the wall section W1 with respect to the mid-axis (2.2), and the outflow openings A1, A2 are arranged on opposite sides of the flow guide element S2 with respect to the longitudinal axis L1, L2, wherein with respect to the mid-axis (2.2), a first partial stream T3 can be guided at least partially in the anticlockwise direction and a second partial stream T4 can be guided at least partially in the clockwise direction out of the outflow openings A1, A2.

2. The mixing device (1) according to claim 1, characterized in that on the intermediate wall (3), a first flow guide element S1 with a longitudinal axis L1 is provided, which protrudes upstream in the axial direction over the intermediate wall (3) and which with the intermediate wall (3) at least partly bounds the mixing chamber (2.3), wherein two inflow openings E1, E2 are provided in the intermediate wall (3), which are arranged opposite in relation to the longitudinal axis L1, wherein the flow guide element S1 effects a division of the exhaust gas stream T into two partial streams T1, T2, wherein with respect to the mid-axis (2.2), a first partial stream T1 can be guided in a clockwise direction and a second partial stream T2 can be guided in an anticlockwise direction around the flow guide element Si into the respective inflow opening E1, E2 and into the mixing chamber (2.3).

3. The mixing device (1) according to claim 1 or 2, characterized in that the flow guide elements S1, S2 are designed as a single piece, and/or at least one flow guide element S1, S2 is an integral part of the intermediate wall (3) or the tubular wall (2.1).

4. The mixing device (1) according to any one of the preceding claims, characterized in that the intermediate wall (3) and the mid-axis (2.2) enclose an angle α between 20° and 80°, or between 30° and 60°, or between 55° and 75°, or of 65°.

5. The mixing device (1) according to any one of the preceding claims, characterized in that the intermediate wall (3) has a single or multiple angled, contoured or curved form.

6. The mixing device (1) according to any one of the preceding claims, characterized in that in the mixing chamber (2.3) in the area before the outflow openings A1, A2, a corrugated base (7) and/or a flow guide element (8) is provided for the purpose of avoiding a steam bottleneck.

7. The mixing device (1) according to any one of the preceding claims, characterized in that the intermediate wall (3) is at least partially integrated into the housing (2) or at is at least partially formed from the housing (2).

8. A mixing device for connection to or integration into an exhaust pipe (4.1, 4.2) of a combustion engine and for mixing an exhaust gas flow T, which is formed from a housing (2) with a tubular wall (2.1) and with a mid-axis that can be arranged parallel to the exhaust pipe (4.1, 4.2) and with a first intermediate wall Z1 and with a second intermediate wall Z2 which are aligned transversely to the mid-axis (2.2), wherein both intermediate walls Z1, Z2 at least partly bound a mixing chamber (2.3), wherein the first intermediate wall Z1 features at least one inflow opening E1, through which the exhaust gas stream T can enter the mixing chamber (2.3), wherein the inflow opening E1 is positioned eccentrically with respect to the mid-axis (2.2) and is brought close to a wall section W1 of the tubular wall (2.1), and the second intermediate wall Z2 features at least one outflow opening A1, through which the exhaust gas stream T can exit from the mixing chamber (2.3), wherein the outflow opening A1 is positioned eccentrically with respect to the mid-axis (2.2) and is brought close to a wall section W2 of the tubular wall (2.1), characterized in that the wall section W2 is arranged opposite the wall section W1, so that an at least partial deflection of the exhaust gas stream T can be effected at least partially in a radial direction with respect to the mid-axis (2.2), and in the flow direction after the first intermediate wall Z1, at least one flow guide element S3 is provided, which protrudes in the radial direction over the tubular wall (2.1) and effects a division of the exhaust gas stream T into two partial streams T3, T4, wherein with respect to the mid-axis (2.2), a first partial stream T3 can be guided in an anticlockwise direction, and a second partial stream T4 can be guided in a clockwise direction around the flow guide element S3.

9. The mixing device (1) according to any one of the preceding claims, characterized in that a feed device (5) with a feed nozzle (5.1) is provided, through which an additive can be brought into the mixing chamber (2.3).

10. The mixing device (1) according to any one of the preceding claims, characterized in that the inflow opening E1 or the inflow openings E1, E2 form an inflow profile QE and the housing (2) features a profile surface QF that effects the stream, with 0.08 QF<=QE<=0.42 QF.

11. The mixing device (1) according to any one of the preceding claims, characterized in that the outflow opening A1 or the outflow openings A1, A2 form an outflow profile QA and the housing (2) features a profile surface QF that effects the stream, with 0.08 QF<=QA<=0.42 QF.

12. The mixing device (1) according to any one of the preceding claims, characterized in that the inflow opening E1 or the inflow openings E1, E2 form an inflow profile QE and at least one further inflow opening Ex is provided in the flow guide element S1 or in the intermediate wall Z1, through which a portion of the exhaust gas stream T can enter the mixing chamber (2.3), wherein the at least one inflow opening Ex forms an inflow profile Xe, with Xe<=0.1 QE.

13. The mixing device (1) according to any one of the preceding claims, characterized in that the outflow opening Al or the outflow openings Al, A2 form an outflow profile QA and at least one further outflow opening Ax is provided in the flow guide element S2 or in the intermediate wall Z2, through which a portion of the exhaust gas stream T can enter the mixing chamber (2.3), wherein the at least one outflow opening Ax forms an outflow profile Xa, with Xa<=0.1 QA.

14. The mixing device (1) according to one of claims 10 to 11, characterized in that on at least one inflow opening Ex and/or on at least one outflow opening Ax, a flow blade (9.1, 9.2) is provided. 15 The mixing device (1) according to any one of the preceding claims, characterized in that in the mixing chamber (2.3), at least one static mixer (6) and/or at least one baffle plate (2.5) is provided, wherein the baffle plate (2.5) is arranged parallel to the longitudinal axis L1, L2 of the flow guide element S1, S2.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Further advantages and details of the invention are explained in the patent claims and in the description and figures, in which:

[0038] FIG. 1a shows a profile view of the principle sketch of the mixing device from the front;

[0039] FIG. 1b shows the mixing device shown in FIG. 1a from the rear;

[0040] FIG. 2a, 2b show the respective profile view A-A or B-B according to FIG. 1a;

[0041] FIG. 3a shows the mixing device with exhaust pipe;

[0042] FIG. 3b shows the dividing wall with single-part flow guide element S1, S2;

[0043] FIG. 4 shows an alternative embodiment in a perspective view;

[0044] FIG. 5a shows the mixing device shown in FIG. 4 from the rear;

[0045] FIG. 5b shows the profile view C-C shown in FIG. 5a;

[0046] FIG. 6 shows a profile view of a schematic sketch without mixing pipe.

DETAILED DESCRIPTION OF THE INVENTION

[0047] The mixing device 1 shown in FIG. 1 a features a tubular housing 2 with a round profile Q. Within this housing 2, an intermediate wall 3 is provided which is set at an angle α. opposite a mid-axis 2.2 (see FIG. 2a, 2b). On the intermediate wall 3, a flow guide element S1 is provided which extends upstream with respect to the direction of the exhaust gas (to the left according to FIG. 2) from the intermediate wall 3. The flow guide element S1 features two inflow openings E1, E2, through which an exhaust gas flow T (see FIG. 3a) can flow from the inflow side 3.1 shown in FIG. 1a of the intermediate wall 3 to the rearward outflow side 3.2. The surface of the flow guide element S1 increases upwards, so that there is sufficient space for the inflow openings E1, E2 mentioned above. A bridge 2.6 is formed between the two inflow openings E1, E2. As a result of the bridge 2.6, said exhaust gas flow T is divided into two partial streams T1, T2. The partial stream T1 flows in a clockwise direction and the partial stream T2 flows in an anticlockwise direction into the respective inflow opening E1, E2. With respect to a symmetrical axis Sy, which according to FIG. 1a divides the housing 2 approximately in the middle and horizontally, the two inflow openings E1, E2 are moved towards the upper wall section W1, additionally the flow guide element S1 features a further inflow opening Ex, through which a small portion of the exhaust gas can flow from the inflow side 3.1 to the outflow side 3.2 of the intermediate wall 3.

[0048] The outflow side 3.2 of the intermediate wall 3 is according to FIG. 1b mirror symmetric to the symmetry axis Sy. There, the flow guide element S2 is located, which extends in the direction of the exhaust gas flow (to the right according to FIG. 2) over the intermediate wall 3. The flow guide element S2 features two outflow openings A1, A2, which are displaced downwards with respect to the symmetry axis S2 to a wall section W2. Both flow guide elements S1, S2 feature a longitudinal axis L1, L2, which according to the exemplary embodiment runs central to the pipe wall 2.1 or at right-angles to a mid-axis 2.2 of the pipe wall 2.1. Further outflow openings Ax are provided in the intermediate wall 3, which are positioned opposite the outflow openings A1, A2 with respect to the symmetry axis Sy. A bridge 2.4 is also formed between the two outflow openings A1, A2, so that the exhaust gas stream T exits in two partial streams T3, T4, wherein the partial stream T3 leaves the flow guide element S2 in an anticlockwise direction and partial stream T4 leaves in a clockwise direction. Additionally, the flow guide element S2 features further outflow openings Ax in the area of the bridge 2.4. A flow blade 9.2 is provided on the respective outflow opening Ax, through which the auxiliary stream that flows through the outflow opening Ax can be deflected in a radial direction.

[0049] Both flow guide elements S1, S2 bound a mixing chamber 2.3, which due to the opposite arrangement of the inflow openings E1, E2 on the one hand and the outflow openings A1, A2 on the other is predominantly flowed through by the exhaust gas stream T in the radial direction.

[0050] As can be seen in FIG. 3a, a feed device 5 with a feed nozzle 5.1 is located within the mixing chamber 2.3, through which an additive is introduced into the exhaust gas stream T.

[0051] In the profile view A-A shown in FIG. 2a, the flow guide element S1 and the flow guide element S2 can be seen in profile. The exhaust gas that flows in here from the left enters into the inflow opening E1 or into the additional opening Ex into the mixing chamber 2.3 and leaves said chamber via the outflow opening A1. Within the mixing chamber 2.3, a corrugated base 7 is arranged below the outflow opening A1 transversely to the main flow direction, which prevents the formation of a stream bottleneck in the area of the outflow opening A1. Additionally, within the mixing chamber 2.3, a baffle plate 2.5 is provided, which can be moistened with additive through the nozzle 5.1 not shown here.

[0052] In the profile view B-B according to FIG. 2b, only the intermediate wall 3 is profiled, while the two flow guide elements S1, S2 can be seen in a side view. The opposite inflow openings E1, E2 can be seen, as can the two outflow openings A1, A2. The intermediate wall 3 is set opposite the mid-axis 2.2 and the angle α. The exhaust gas stream that comes from the left here is largely deflected upwards in the radial direction towards the inflow openings E1, E2 and in turn flows through the mixing chamber 2.3 in the radial direction from the inflow openings E1, E2 downwards to the outflow openings A1, A2 and leaves the mixing chamber 2.3 to the right through the two outflow openings A1, A2 according to FIG. 2b.

[0053] According to FIG. 3a, the mixing device 1 is an integral part of an exhaust pipe 4.1, 4.2 as part of a particle filter or catalytic converter. Through the nozzle 5.1, additive is introduced into the mixing chamber 2.3, which is guided via the above exhaust gas stream T1 or T2, starting from the area of the inflow openings E1, E2 downwards in the radial direction to the outflow openings A1, A2, and leaves the mixing chamber 2.3 through both partial streams T3, T4, and again combines to form the total stream T. According to FIG. 3a, as an alternative to the corrugated base 7 shown in FIG. 2, a flow guide element in the form of a ramp 8 is provided in the area of the outflow opening A1 within the mixing chamber 2.3, so that stream bottlenecks are prevented in this area.

[0054] Decisive for the definition of the angle α is the straight line G, which connects the intersection points of the intermediate wall 3 and the pipe wall 2.1, wherein the two intersection points have the greatest distance from each other with respect to the exhaust gas stream or the direction of the mid-axis 2.2.

[0055] According to FIG. 3b, the intermediate wall 3 is shown with a single-part flow guide element S1, S2 arranged within it. The single-part flow guide element S1, S2 is designed as a cylindrical pipe, which is inserted into a corresponding recess in the oval intermediate wall 3 and which is tightly connected to the intermediate wall 3. The assembly thus created is then inserted into the housing 2, as shown in FIG. 3a, wherein the intermediate wall 3 is connected on the circumference side with the pipe wall 2.1.

[0056] FIG. 4 shows an alternative embodiment. Within the housing 2, two intermediate walls Z1, Z2 are provided at a distance with respect to the mid-axis 2.2, which extend respectively over approximately half the profile area QF of the housing 2. The two intermediate walls Z1, Z2 are also positioned opposite with respect to the two opposite wall sections W1, W2, so that the exhaust gas stream T, which enters into the mixing chamber 2.3 through an inflow opening E1, is deflected downwards in the radial direction to the outflow opening A1 and leaves the mixing chamber 2.3 through the outflow opening A1. The feed device 5 with the feed nozzle 5.1 for additive is also provided within the mixing chamber 2.3 or in the housing 2.

[0057] A wedge-shaped flow guide element S3 is provided in the area of the wall section W2, which divides the impinging exhaust gas stream T into two partial streams T3, T4. Due to the wedge-shaped design of the flow guide element S3, a partial stream T3 is created with respect to the flow direction, which is deflected in an anticlockwise direction, while the partial stream T4 is deflected in a clockwise direction.

[0058] According to FIG. 5a, the mixing device 1 is shown from the outflow side 3.1 (lee side). The mixing chamber 2.3 can only be seen within the scope of the outlet opening A1. In contrast to FIG. 4, within the upper part of the mixing chamber 2.3 an optional mixing pipe 6 with a perforation 6.1 is arranged, which is positioned coaxially to the feed device 5. The exhaust gas or exhaust gas stream T which flows in through the inflow opening, thereby initially flow through the mixing pipe 6 within which it then mixes with the sprayed in additive and is guided downwards towards the flow guide element S3, where the two partial streams T3, T4 are deflected in the circumferential direction in counter directions as described above.

[0059] Within the second intermediate wall Z2, further slit-shaped outflow openings Ax are provided, the outflow profile Xa of which is subordinate relative to the outflow opening A1. These then merely serve to prevent a stream bottleneck in the area of the upper wall section W1. Additionally, in the first intermediate wall Z1, further slit-shaped inflow openings Ex are provided, the inflow profile Xe of which is subordinate relative to the inflow profile QE of the inflow opening E1. These serve to prevent a stream bottleneck in front of the first intermediate wall Z1 in the area of the lower wall section W2. A flow blade 9.1 is provided on the respective inflow opening E1, through which the auxiliary stream that flows through the inflow opening Ex can be deflected in a radial direction.

[0060] FIG. 5b shows the profile view C-C shown in FIG. 5a The mixing pipe 6 is oval and therefore features an enlarged entrance and exit area facing towards the exhaust gas stream T. After it has flowed through the mixing pipe 6, the exhaust gas stream T is according to FIG. 5b deflected in the radial direction and leaves the mixing device 1 in a divided, counter-directional stream movement outwards in the circumferential direction.

[0061] In the exemplary embodiment shown in FIG. 6, the second intermediate wall Z2 is curved. A mixing chamber is not provided. The exhaust gas stream T that enters from the right is deflected downwards in the radial direction towards the flow guide element S3 after entering the mixing chamber 2.3, and leaves the mixing chamber 2.3 through the outflow opening A1. Here, the height of the flow guide element S3 increases in the direction of the first intermediate wall Z1, so that the two partial streams T3, T4 are formed at an early stage.

LIST OF REFERENCE NUMERALS

[0062] 1 Mixing device [0063] 2 Housing [0064] 2.1 Tubular wall [0065] 2.2 Mid-axis [0066] 2.3 Mixing chamber [0067] 2.4 Bridge between A1, A2 [0068] 2.5 Baffle plate [0069] 2.6 Bridge between E1, E2 [0070] 3 Intermediate wall [0071] 3.1 Inflow side, windward side [0072] 3.2 Off-flow side, lee side [0073] 4.1 Exhaust pipe [0074] 4.2 Exhaust pipe [0075] 5 Feed device [0076] 5.1 Feed nozzle [0077] 6 Mixer, mixer pipe [0078] 6.1 Perforation [0079] 7 Corrugated base [0080] 8 Cone, ramp, flow guide element [0081] 9.1 Blade of Ex [0082] 9.2 Blade of Ax [0083] A1 Outflow opening [0084] A2 Outflow opening [0085] Ax Outflow opening [0086] E1 Inflow opening [0087] E2 Inflow opening [0088] Ex Inflow opening

[0089] G Connection straight line, straight line [0090] LE Plane [0091] L1 Longitudinal axis of S1 [0092] L2 Longitudinal axis of S2 [0093] Q Profile of 2 [0094] QA Outflow profile [0095] QE Inflow profile [0096] QF Outflow area [0097] S1 Flow guide element [0098] S2 Flow guide element [0099] S3 Flow guide element [0100] Sy Symmetry axis [0101] T Exhaust gas stream [0102] T1 Partial stream of exhaust gas stream [0103] T2 Partial stream of exhaust gas stream [0104] T3 Partial stream of exhaust gas stream [0105] T4 Partial stream of exhaust gas stream [0106] W1 Wall section [0107] W2 Wall section [0108] Xa Outflow profile of total Ax [0109] Xe Inflow profile of total Ex [0110] Z1 Intermediate wall [0111] Z2 Intermediate wall [0112] α Angle