Exhaust aftertreatment mixing device

Abstract

An exhaust gas post-treatment mixing device includes an inner shell, an outer shell, and a mixing tube located in the inner shell. The inner shell includes a first cavity, a second cavity, a first peripheral wall surrounding part of the first cavity, and a second peripheral wall surrounding part of the second cavity. An annular space is formed between the outer shell and the inner shell. The outer shell includes a third peripheral wall and a fourth peripheral wall. The exhaust gas post-treatment mixing device also includes a baffle assembly, which includes a first end cover having a first flange and fixed on the first peripheral wall, a second end cover having a second flange and fixed on the second peripheral wall, a first baffle connecting and fixing the first end cover and the third peripheral wall, and a second baffle connecting and fixing the second end cover and the fourth peripheral wall. The first baffle and the second baffle jointly enclose the annular space. The present invention reduces the difficulty of assembly by providing a segmented baffle assembly.

Description

Technical Field

[0001] The invention relates to an exhaust gas post-processing mixing device, belonging to the technical field of engine exhaust gas post-processing. Background Art

[0002] Studies have shown that the uniformity of ammonia distribution in the pipeline of the exhaust aftertreatment system (such as the selective catalytic reduction system, SCR system) has an important impact on the overall performance and durability of the system. If the ammonia distribution is uneven, it will lead to excessive ammonia in local areas, which is easy to cause ammonia leakage, and in other areas where the ammonia is thin, the nitrogen oxide (NOx) conversion efficiency will be too low. Long-term uneven distribution of ammonia will cause uneven aging of the catalyst, thereby affecting the overall performance of the catalyst. In addition, the uneven distribution of urea droplets will cause the temperature of the local pipe wall or mixing structure to be too low, forming crystals, which will block the exhaust pipe in severe cases and cause the engine power performance to decrease.

[0003] In order to improve thermal management, the prior art generally adopts a double-layer shell and fills the gap between the shells with thermal insulation cotton. The baffle matched with such a double-layer shell in the prior art is usually a one-piece structure, which is large in size and not conducive to assembly. Summary of the invention

[0004] The object of the present invention is to provide an exhaust gas post-treatment mixing device which is easy to assemble.

[0005] To achieve the above-mentioned purpose, the present invention adopts the following technical scheme: an exhaust gas after-treatment mixing device, which includes an inner shell, an outer shell and a mixing tube located in the inner shell, the inner shell includes a first cavity connected to a first after-treatment device, a second cavity connected to a second after-treatment device, a first peripheral wall surrounding part of the first cavity and a second peripheral wall surrounding part of the second cavity; an annular space is formed between the outer shell and the inner shell, the outer shell includes a third peripheral wall located on one side and a fourth peripheral wall located on the other side; the mixing tube includes a swirl plate located in the first cavity; the exhaust gas after-treatment mixing device also includes a baffle assembly matched with the inner shell and the outer shell, wherein the baffle assembly includes a first end cover having a first flange and fixed on the first peripheral wall, a second end cover having a second flange and fixed on the second peripheral wall, a first baffle connecting and fixing the first end cover and the third peripheral wall, and a second baffle connecting and fixing the second end cover and the fourth peripheral wall, the first baffle and the second baffle together close the annular space.

[0006] As a further improved technical solution of the present invention, the first peripheral wall has a first edge, and the second peripheral wall has a second edge; the first end cover has a first annular portion sleeved on the first edge, and the second end cover has a second annular portion sleeved on the second edge.

[0007] As a further improved technical solution of the present invention, the first annular portion is welded to the first edge, and the second annular portion is welded to the second edge.

[0008] As a further improved technical solution of the present invention, the third peripheral wall has a third edge, and the fourth peripheral wall has a fourth edge; the first baffle has a first socket portion socketed on the third edge, and the second baffle has a second socket portion socketed on the fourth edge.

[0009] As a further improved technical solution of the present invention, the first sleeve portion is welded to the third edge, and the second sleeve portion is welded to the fourth edge.

[0010] As a further improved technical solution of the present invention, the first flange is integrally formed from the first annular portion, and the first end cover also includes a first plate portion integrally extending from the first annular portion to the second end cover; the second flange is integrally formed from the second annular portion, and the second end cover also includes a second plate portion integrally extending from the second annular portion to the first end cover, and the first plate portion and the second plate portion are close to each other.

[0011] As a further improved technical solution of the present invention, the first baffle includes a first extension plate extending from the middle of the first sleeve portion to the second baffle; the second baffle includes a second extension plate extending from the middle of the second sleeve portion to the first baffle, and the first extension plate and the second extension plate are close to each other and press the first plate portion and the second plate portion inward.

[0012] As a further improved technical solution of the present invention, the first extension plate is provided with a first protrusion matched with the second extension plate, and the second extension plate is provided with a second protrusion matched with the first extension plate.

[0013] As a further improved technical solution of the present invention, the outer shell is provided with a positioning block formed by an inward depression, and the positioning block abuts against the inner shell; the positioning block is provided with a welding hole for fixing the inner shell and the outer shell together.

[0014] As a further improved technical solution of the present invention, the exhaust gas after-treatment mixing device is provided with a mounting seat located above the swirl plate and used to install a urea nozzle, and the urea nozzle is used to spray atomized urea droplets into the mixing tube; the exhaust gas after-treatment mixing device also includes an ω-shaped reflector located below the mixing tube.

[0015] Compared with the prior art, the present invention reduces the difficulty of assembly by providing a segmented baffle assembly. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a front view of the exhaust gas aftertreatment mixing device of the present invention.

[0017] Figure 2 yes Figure 1 Side view of.

[0018] Figure 3 is along Figure 1 Schematic diagram of the cross section along line AA.

[0019] Figure 4 yes Figure 1 Top view of the .

[0020] Figure 5 It is a three-dimensional exploded view of the exhaust gas aftertreatment mixing device of the present invention.

[0021] Figure 6 yes Figure 1 Partial exploded view of the .

[0022] Figure 7 yes Figure 3 A partial enlarged view of the circled part. DETAILED DESCRIPTION

[0023] Please refer to Figures 1 to 7 As shown, the present invention discloses an exhaust gas post-treatment mixing device 100 for treating the exhaust gas of an engine. The exhaust gas post-treatment mixing device 100 comprises an inner shell 1, an outer shell 2, a mixing pipe 3 located in the inner shell 1, and a baffle assembly 4 matched with the inner shell 1 and the outer shell 2. The inner shell 1 comprises a first cavity 11 for connecting to a first post-treatment device (such as a diesel particulate filter and an oxidation catalytic converter, not shown), a second cavity 12 for connecting to a second post-treatment device (such as a selective catalytic reducer, not shown), and a mounting seat 13 located at the top of the first cavity 11 and for mounting a urea nozzle (not shown). The urea nozzle is used to spray atomized urea droplets into the mixing pipe 3.

[0024] The inner housing 1 further comprises a first peripheral wall 14 surrounding part of the first cavity 11 and a second peripheral wall 15 surrounding part of the second cavity 12. The first peripheral wall 14 has a first edge 141 (upper edge), and the second peripheral wall 15 has a second edge 151 (lower edge).

[0025] An annular space 10 is formed between the outer shell 2 and the inner shell 1. Preferably, the annular space 10 is filled with heat insulation cotton. The outer shell 2 includes a third peripheral wall 21 located on one side and a fourth peripheral wall 22 located on the other side. The third peripheral wall 21 has a third edge 211 (left edge), and the fourth peripheral wall 22 has a fourth edge 221 (right edge).

[0026] The baffle assembly 4 includes a first end cover 41 having a first flange 411 and fixed on the first peripheral wall 14, a second end cover 42 having a second flange 421 and fixed on the second peripheral wall 15, a first baffle 43 connecting and fixing the first end cover 41 and the third peripheral wall 21, and a second baffle 44 connecting and fixing the second end cover 42 and the fourth peripheral wall 22. The first baffle 43 and the second baffle 44 jointly close the annular space 10.

[0027] Specifically, the first end cover 41 has a first annular portion 412 sleeved on the first edge 141 and a first plate portion 413 extending from the first annular portion 412 to the second end cover 42. The first flange 411 is integrally formed from the first annular portion 412. The width of the exhaust gas post-treatment mixing device 100 can be reduced by sleeve fitting, reducing the volume and saving space.

[0028] Similarly, the second end cover 42 has a second annular portion 422 sleeved on the second edge 151 and a second plate portion 423 extending from the second annular portion 422 to the first end cover 41. The second flange 421 is integrally formed from the second annular portion 422. After assembly, the first plate portion 413 and the second plate portion 423 are close to each other. The sleeve-fitting method can reduce the width of the exhaust gas post-treatment mixing device 100, reduce the volume, and save space.

[0029] In the illustrated embodiment of the present invention, the first annular portion 412 is welded to the first edge 141 , and the second annular portion 422 is welded to the second edge 151 .

[0030] The first baffle 43 has a first sleeve portion 431 sleeved on the third edge 211 and a first extension plate 432 extending from the middle of the first sleeve portion 431 to the second baffle 44. The sleeve fitting method can reduce the width of the exhaust gas post-treatment mixing device 100, reduce the volume, and save space.

[0031] The second baffle plate 44 has a second sleeve portion 441 sleeved on the fourth edge 221 and a second extension plate 442 extending from the middle of the second sleeve portion 441 to the first baffle plate 43. The first extension plate 432 and the second extension plate 442 are close to each other and press the first plate portion 413 and the second plate portion 423 inwardly. The sleeve-fitting method can reduce the width of the exhaust gas post-treatment mixing device 100, reduce the volume, and save space.

[0032] In the illustrated embodiment of the present invention, the first sleeve portion 431 is welded to the third edge 211 , and the second sleeve portion 441 is welded to the fourth edge 221 .

[0033] The first extension plate 432 is provided with a first protrusion 433 matched with the second extension plate 442 , and the second extension plate 442 is provided with a second protrusion 443 matched with the first extension plate 432 .

[0034] Please refer to Figure 3 As shown, the outer shell 2 is provided with a positioning block 23 formed inwardly concave, and the positioning block 23 abuts against the inner shell 1 to ensure that a predetermined assembly gap can be achieved. In the illustrated embodiment of the present invention, the positioning block 23 is provided with a welding hole 231, and the corresponding part of the inner shell 1 is exposed in the welding hole 231. By welding the welding hole 231, the inner shell 1 and the outer shell 2 can be fixed together.

[0035] The mixing tube 3 includes a swirl plate 31 located in the first cavity 11. When the exhaust gas of the engine enters the first cavity 11, the exhaust gas can rotate into the mixing tube 3 under the guidance of the swirl plate 31 to be evenly mixed with the urea droplets.

[0036] The exhaust gas post-treatment mixing device 100 further includes an ω-shaped reflector plate 5 located below the mixing tube 3 to achieve a double swirl effect and reduce the risk of urea crystallization.

[0037] The above embodiments are only used to illustrate the present invention but not to limit the technical solutions described in the present invention. The understanding of this specification should be based on the technicians in the relevant technical field. Although this specification has described the present invention in detail with reference to the above embodiments, ordinary technicians in the field should understand that technicians in the relevant technical field can still modify or replace the present invention with equivalents, and all technical solutions and improvements that do not depart from the spirit and scope of the present invention should be covered within the scope of the claims of the present invention.

Claims

1. An exhaust gas post-treatment mixing device, comprising an inner shell, an outer shell and a mixing tube located in the inner shell, wherein the inner shell comprises a first cavity connected to a first post-treatment device, a second cavity connected to a second post-treatment device, a first peripheral wall surrounding a portion of the first cavity and a second peripheral wall surrounding a portion of the second cavity; an annular space is formed between the outer shell and the inner shell, the outer shell comprises a third peripheral wall located on one side and a fourth peripheral wall located on the other side; the mixing tube comprises a swirl sheet located in the first cavity; characterized in that: The exhaust gas after-treatment mixing device also includes a baffle assembly that cooperates with the inner shell and the outer shell, wherein the baffle assembly includes a first end cover having a first flange and fixed to the first peripheral wall, a second end cover having a second flange and fixed to the second peripheral wall, a first baffle connecting and fixing the first end cover and the third peripheral wall, and a second baffle connecting and fixing the second end cover and the fourth peripheral wall, and the first baffle and the second baffle jointly enclose the annular space.

2. The exhaust gas post-treatment mixing device according to claim 1, characterized in that: The first peripheral wall has a first edge, and the second peripheral wall has a second edge; the first end cover has a first annular portion sleeved on the first edge, and the second end cover has a second annular portion sleeved on the second edge.

3. The exhaust gas post-treatment mixing device according to claim 2, characterized in that: The first annular portion is welded to the first edge, and the second annular portion is welded to the second edge.

4. The exhaust gas post-treatment mixing device according to claim 3, characterized in that: The third peripheral wall has a third edge, and the fourth peripheral wall has a fourth edge; the first baffle has a first sleeve portion sleeved on the third edge, and the second baffle has a second sleeve portion sleeved on the fourth edge.

5. The exhaust gas post-treatment mixing device according to claim 4, characterized in that: The first sleeve portion is welded to the third edge, and the second sleeve portion is welded to the fourth edge.

6. The exhaust gas post-treatment mixing device according to claim 5, characterized in that: The first flange is integrally formed from the first annular portion, and the first end cover also includes a first plate portion integrally extending from the first annular portion to the second end cover; the second flange is integrally formed from the second annular portion, and the second end cover also includes a second plate portion integrally extending from the second annular portion to the first end cover, and the first plate portion and the second plate portion are close to each other.

7. The exhaust gas post-treatment mixing device according to claim 6, characterized in that: The first baffle includes a first extension plate extending from the middle of the first sleeve portion to the second baffle; the second baffle includes a second extension plate extending from the middle of the second sleeve portion to the first baffle, the first extension plate and the second extension plate are close to each other and press the first plate portion and the second plate portion inwardly.

8. The exhaust gas post-treatment mixing device according to claim 7, characterized in that: The first extension plate is provided with a first protrusion matched with the second extension plate, and the second extension plate is provided with a second protrusion matched with the first extension plate.

9. The exhaust gas post-treatment mixing device according to claim 1, characterized in that: The outer shell is provided with a positioning block which is recessed inwards, and the positioning block abuts against the inner shell; the positioning block is provided with a welding hole for fixing the inner shell and the outer shell together.

10. The exhaust gas post-treatment mixing device according to claim 1, characterized in that: The exhaust gas post-treatment mixing device is provided with a mounting seat located above the swirl plate and used to mount a urea nozzle, and the urea nozzle is used to spray atomized urea droplets into the mixing tube; the exhaust gas post-treatment mixing device also includes an ω-shaped reflector located below the mixing tube.

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