Exhaust aftertreatment mixing device

Abstract

An exhaust gas post-treatment mixing device, comprising a shell with an internal space, a baffle located in the shell, and a mixing plate located in the shell and downstream of the baffle, wherein the baffle and the mixing plate divide the internal space into an air inlet chamber and an air outlet chamber, and a mixing chamber connecting the air inlet chamber and the air outlet chamber is formed between the baffle and the mixing plate, and the mixing chamber is used to mix atomized urea droplets with the exhaust gas of the engine; the baffle comprises an air inlet connecting the air inlet chamber and the mixing chamber, and the mixing plate comprises a curved surface protruding toward the mixing chamber, and the curved surface is provided with a plurality of through holes connecting the mixing chamber and the air outlet chamber. Compared with the prior art, the curved surface of the present invention can improve the distribution of airflow on the surface of the curved surface, thereby improving the uniformity of mixing.

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] Therefore, it is necessary to provide a novel exhaust gas aftertreatment mixing device to solve the above technical problems. Summary of the invention

[0004] The object of the present invention is to provide an exhaust gas post-treatment mixing device with strong mixing ability.

[0005] To achieve the above-mentioned purpose, the present invention adopts the following technical scheme: an exhaust gas after-treatment mixing device, which includes a shell with an internal space, a baffle located in the shell, and a mixing plate located in the shell and downstream of the baffle, the baffle and the mixing plate divide the internal space into an air inlet chamber and an air outlet chamber, a mixing chamber connecting the air inlet chamber and the air outlet chamber is formed between the baffle and the mixing plate, and the mixing chamber is used to mix atomized urea droplets with the exhaust gas of the engine; the baffle includes an air inlet connecting the air inlet chamber and the mixing chamber, the mixing plate includes a curved surface protruding toward the mixing chamber, and the curved surface is provided with a plurality of through holes connecting the mixing chamber and the air outlet chamber.

[0006] As a further improved technical solution of the present invention, the outer edge of the mixing plate is sealed and fixed on the inner wall of the shell, and the baffle is at least partially fixed on the mixing plate, so that most of the exhaust gas can only enter the mixing chamber from the air inlet, and enter the air outlet chamber from the through hole after mixing.

[0007] As a further improved technical solution of the present invention, the curved surface portion extends obliquely toward the mixing chamber.

[0008] As a further improved technical solution of the present invention, the curved surface portion includes a first ridge portion located in the middle, and a first curved surface portion and a second curved surface portion extending to both sides from the first ridge portion.

[0009] As a further improved technical solution of the present invention, the baffle includes a blocking portion fixed on the inner wall of the shell and a first enclosing portion and a second enclosing portion extending from both sides of the bottom of the blocking portion toward the mixing plate, wherein the outer edges of the first enclosing portion and the second enclosing portion are respectively fixed on the first curved surface portion and the second curved surface portion, and the through holes include a plurality of first through holes located on the first curved surface portion and a plurality of second through holes located on the second curved surface portion.

[0010] As a further improved technical solution of the present invention, the air inlet includes a first air inlet and a second air inlet located on both sides of the top of the blocking portion; the first surrounding portion and the second surrounding portion are respectively provided with an airflow guide portion extending inward and used to guide the exhaust gas to the first air inlet and the second air inlet.

[0011] As a further improved technical solution of the present invention, the exhaust gas post-treatment mixing device further includes a porous plate fixed on the back side of the mixing plate and located in the air outlet cavity.

[0012] As a further improved technical solution of the present invention, the porous plate includes a third curved surface portion and a fourth curved surface portion, wherein the third curved surface portion is fixed on the back side of the first curved surface portion, the fourth curved surface portion is fixed on the back side of the second curved surface portion, the third curved surface portion is provided with a plurality of third through holes, and the fourth curved surface portion is provided with a plurality of fourth through holes.

[0013] As a further improved technical solution of the present invention, the porous plate includes a second ridge portion located in the middle, and the third curved surface portion and the fourth curved surface portion are respectively extended from two sides of the second ridge portion.

[0014] As a further improved technical solution of the present invention, the housing includes a mounting seat for mounting a urea nozzle, and the urea nozzle is used to spray atomized urea droplets into the mixing chamber.

[0015] Compared with the prior art, the mixing plate of the present invention is provided with a curved surface portion protruding toward the mixing chamber, which can improve the distribution of the airflow on the surface of the curved surface portion, thereby improving the uniformity of mixing. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a three-dimensional schematic diagram of the exhaust gas aftertreatment mixing device of the present invention.

[0017] Figure 2 yes Figure 1 A three-dimensional diagram from another angle.

[0018] Figure 3 yes Figure 1 Left view of .

[0019] Figure 4 yes Figure 1 Right view of .

[0020] Figure 5 Yes Figure 1 A three-dimensional schematic diagram of the middle shell.

[0021] Figure 6 yes Figure 5 A three-dimensional diagram from another angle.

[0022] Figure 7 yes Figure 5 A three-dimensional schematic diagram from another angle.

[0023] Figure 8 is along Figure 3 Schematic diagram of the cross section along line AA.

[0024] Fig. 9 yes Figure 1 3D exploded view of .

[0025] Fig.10 yes Fig. 9 Front view of the mixing board.

[0026] Fig.11 yes Fig.10 Top view of the .

[0027] Fig.12 yes Fig.10 Bottom view of .

[0028] Fig.13 yes Fig.10 Side view of.

[0029] Fig.14 yes Fig. 9 Front view of the center panel.

[0030] Fig.15 yes Fig.14 Top view of the .

[0031] Fig.16 yes Fig.14 Bottom view of .

[0032] Fig.17 yes Fig.14 Side view of.

[0033] Fig.18 yes Fig. 9 Front view of the medium-well plate.

[0034] Fig.19 yes Fig.18 Top view of the .

[0035] Fig. 20 yes Fig.18 Bottom view of .

[0036] Fig.21 yes Fig.18 Side view of. DETAILED DESCRIPTION

[0037] Please refer to Figures 1 to 21 As shown, the present invention discloses an exhaust gas post-treatment mixing device 100 for treating exhaust gas of an engine. The exhaust gas post-treatment mixing device 100 comprises a housing 1 having an internal space 10, a baffle 2 located in the housing 1, a mixing plate 3 located in the housing 1 and downstream of the baffle 2, and a porous plate 4 fixed on the back of the mixing plate 3.

[0038] The baffle plate 2 and the mixing plate 3 divide the internal space 10 into an air inlet chamber 101 and an air outlet chamber 102. A mixing chamber 103 connecting the air inlet chamber 101 and the air outlet chamber 102 is formed between the baffle plate 2 and the mixing plate 3. The mixing chamber 103 is used to mix the atomized urea droplets with the exhaust gas of the engine. In one embodiment of the present invention, the air inlet chamber 101 is used to be connected to a first post-processing device (such as a diesel particulate filter and an oxidation catalytic converter, not shown in the figure), and the air outlet chamber 102 is used to be connected to a second post-processing device (such as a selective catalytic reducer, not shown in the figure).

[0039] The housing 1 includes a mounting seat 11 for mounting a urea nozzle, and the urea nozzle is used to spray atomized urea droplets into the mixing chamber 103 .

[0040] The baffle plate 2 includes an air inlet connecting the air inlet chamber 101 and the mixing chamber 103. Specifically, in the illustrated embodiment of the present invention, the baffle plate 2 includes a blocking portion 21 fixed to the inner wall of the housing 1 and a first surrounding portion 22 and a second surrounding portion 23 extending from both sides of the bottom of the blocking portion 21 to the mixing plate 3. The air inlet includes a first air inlet 211 and a second air inlet 212 located on both sides of the top of the blocking portion 21. The first surrounding portion 22 and the second surrounding portion 23 are respectively provided with an airflow guide portion 24 extending inwardly and used to guide the exhaust gas to the first air inlet 211 and the second air inlet 212.

[0041] The mixing plate 3 includes a curved surface portion 31 protruding toward the mixing chamber 103, and the curved surface portion 31 is provided with a plurality of through holes 32 connecting the mixing chamber 103 and the air outlet chamber 102. Figure 8As shown, the curved surface portion 31 extends obliquely toward the mixing chamber 103. Specifically, the curved surface portion 31 includes a first ridge portion 311 located in the middle, and a first curved surface portion 312 and a second curved surface portion 313 extending from the first ridge portion 311 to both sides. The through holes 32 include a plurality of first through holes 321 located on the first curved surface portion 312 and a plurality of second through holes 322 located on the second curved surface portion 313.

[0042] In the illustrated embodiment of the present invention, the outer edge of the mixing plate 3 is sealed and fixed to the inner wall of the housing 1. The outer edges of the first surrounding portion 22 and the second surrounding portion 23 are respectively fixed to the first curved surface portion 312 and the second curved surface portion 313. The baffle 2 is at least partially fixed to the mixing plate 3, so that most of the exhaust gas can only enter the mixing chamber 103 from the air inlet, and enter the outlet chamber 102 from the through hole 32 after mixing.

[0043] The porous plate 4 is generally butterfly-shaped, and includes a second ridge 41 in the middle, and a third curved surface 42 and a fourth curved surface 43 extending from both sides of the second ridge 41, wherein the third curved surface 42 is fixed to the back of the first curved surface 312, and the fourth curved surface 43 is fixed to the back of the second curved surface 313. The third curved surface 42 is provided with a plurality of third through holes 421, and the fourth curved surface 43 is provided with a plurality of fourth through holes 431. The third through holes 421 and the fourth through holes 431 can perform secondary crushing on the mixed airflow, thereby improving the uniformity of the mixing and reducing the risk of urea crystallization.

[0044] Compared with the prior art, the mixing plate 3 and the porous plate 4 of the present invention are both provided with curved surface parts, thereby forming a plurality of curved panels arranged in zones, and the angle of the curved panels in each zone is adjustable, and the distribution of the through holes is adjustable, so as to better control the airflow disturbance and ensure uniform mixing.

[0045] 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, characterized in that: The invention comprises a shell with an internal space, a baffle located in the shell, and a mixing plate located in the shell and downstream of the baffle, wherein the baffle and the mixing plate divide the internal space into an air inlet chamber and an air outlet chamber, and a mixing chamber connecting the air inlet chamber and the air outlet chamber is formed between the baffle and the mixing plate, and the mixing chamber is used to mix atomized urea droplets with exhaust gas of an engine; the baffle comprises an air inlet connecting the air inlet chamber and the mixing chamber, and the mixing plate comprises a curved surface portion protruding toward the mixing chamber, and the curved surface portion is provided with a curved surface portion connecting the mixing chamber and the mixing chamber. The mixing cavity and the air outlet cavity have several through holes; the curved surface portion includes a first ridge located in the middle and a first curved surface portion and a second curved surface portion extending from the first ridge to both sides; the baffle plate includes a blocking portion fixed on the inner wall of the shell and a first surrounding portion and a second surrounding portion extending from both sides of the bottom of the blocking portion to the mixing plate, the air inlet includes a first air inlet and a second air inlet located on both sides of the top of the blocking portion, and the through holes include a plurality of first through holes located on the first curved surface portion and a plurality of second through holes located on the second curved surface portion.

2. The exhaust gas post-treatment mixing device according to claim 1, characterized in that: The outer edge of the mixing plate is sealed and fixed on the inner wall of the shell, and the baffle is at least partially fixed on the mixing plate, so that most of the exhaust gas can only enter the mixing chamber from the air inlet and enter the outlet chamber from the through hole after mixing.

3. The exhaust gas post-treatment mixing device according to claim 1, characterized in that: The curved surface portion extends obliquely toward the mixing chamber.

4. The exhaust gas post-treatment mixing device according to claim 1, characterized in that: The outer edges of the first surrounding portion and the second surrounding portion are fixed on the first curved surface portion and the second curved surface portion respectively.

5. The exhaust gas post-treatment mixing device according to claim 1, characterized in that: The first surrounding portion and the second surrounding portion are respectively provided with airflow guide portions extending inwardly and used for guiding the exhaust gas to the first air inlet and the second air inlet.

6. The exhaust gas post-treatment mixing device according to claim 5, characterized in that: The exhaust gas post-treatment mixing device further comprises a porous plate fixed on the back side of the mixing plate and located in the gas outlet cavity.

7. The exhaust gas post-treatment mixing device according to claim 6, characterized in that: The porous plate includes a third curved surface portion and a fourth curved surface portion, wherein the third curved surface portion is fixed on the back of the first curved surface portion, the fourth curved surface portion is fixed on the back of the second curved surface portion, the third curved surface portion is provided with a plurality of third through holes, and the fourth curved surface portion is provided with a plurality of fourth through holes.

8. The exhaust gas post-treatment mixing device according to claim 7, characterized in that: The porous plate includes a second ridge portion located in the middle, and the third curved surface portion and the fourth curved surface portion are respectively extended from two sides of the second ridge portion.

9. The exhaust gas post-treatment mixing device according to claim 1, characterized in that: The housing comprises a mounting seat for mounting a urea nozzle, and the urea nozzle is used for spraying atomized urea droplets into the mixing chamber.

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