mixer assembly

Abstract

A mixer assembly comprises a housing, an air inlet baffle, an air outlet baffle and a deflector. The housing, the air inlet baffle, the air outlet baffle and the deflector jointly form a circular-arc-shaped mixing cavity. The housing is provided with a urea nozzle mounting seat for mounting a urea nozzle. The air inlet baffle is provided with a first air flow inlet and a second air flow inlet, both of which are in communication with the mixing cavity. The air outlet baffle is provided with an air flow outlet in communication with the mixing cavity. The tail gas flowing into the mixing cavity from the first air flow inlet and from the second air flow inlet at least partially collide with each other. In this way, the mixer assembly of the utility model has a lower back pressure. In addition, the collision of the air flow accelerates the breaking of the urea droplets, which is conducive to reducing the risk of urea crystallization and improving the conversion efficiency.

Description

Technical Field

[0001] This utility model relates to a mixer assembly, belonging to the field of engine exhaust aftertreatment technology. Background Technology

[0002] The mixer assembly in the related technology includes a housing, a first baffle, a second baffle, and a guide plate, with the guide plate located between the first and second baffles. The first baffle has an airflow inlet, and the second baffle has an airflow outlet. The housing, the first baffle, the second baffle, and the guide plate together form a mixing chamber, which is located between the airflow inlet and the airflow outlet. The exhaust gas flowing into the mixing chamber from the airflow inlet forms a swirling flow under the guidance of the guide plate.

[0003] However, the technology only has one airflow inlet, resulting in a large back pressure in the system; in addition, the mixing effect of exhaust gas and urea droplets needs further improvement. Utility Model Content

[0004] The purpose of this invention is to provide a mixer assembly with an improved structure.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: a mixer assembly for use in an engine exhaust aftertreatment system, the mixer assembly comprising a housing, an intake baffle fixed in the housing, an exhaust baffle fixed in the housing and spaced apart from the intake baffle, and a guide plate located between the intake baffle and the exhaust baffle; the housing is provided with an installation space, the intake baffle and the exhaust baffle are at least partially located in the installation space, the installation space includes an intermediate cavity located between the intake baffle and the exhaust baffle, and the guide plate is located in the intermediate cavity; wherein, the housing, the intake baffle, the exhaust baffle and the guide plate are... The guide plates together form an arc-shaped mixing chamber; the housing is provided with a urea nozzle mounting seat for mounting a urea nozzle, which is used to spray atomized urea droplets into the mixing chamber; the air inlet baffle is provided with a first airflow inlet and a second airflow inlet connected to the mixing chamber; the air outlet baffle is provided with an airflow outlet connected to the mixing chamber; the exhaust gas flowing into the mixing chamber from the first airflow inlet and the second airflow inlet at least partially opposes each other; the guide plate is provided with an arc-shaped guide section to form a swirling flow of the mixed airflow of the exhaust gas and the urea droplets, and exits from the airflow outlet.

[0006] As a further improvement of the present invention, the guide plate includes a blocking part connected to the guide portion. One side of the blocking part is fixed to the air inlet baffle, and the other side of the blocking part is fixed to the air outlet baffle. The blocking part is used to prevent the airflow entering the mixing chamber from passing directly through the blocking part and flowing to the airflow outlet.

[0007] As a further improvement of the present invention, an air outlet cavity is formed on the back side of the guide portion, and the air outlet cavity is connected between the mixing cavity and the airflow outlet.

[0008] As a further improvement of the present invention, the mixer assembly further includes a urea crushing plate located in the mixing chamber. The urea crushing plate is provided with a plurality of urea breakage holes, and the urea crushing plate is at least partially located within the spray range of the urea nozzle.

[0009] As a further improvement of this utility model, one side of the urea crushing plate is fixed to the air inlet baffle, and the other side of the urea crushing plate is fixed to the air outlet baffle.

[0010] As a further improvement of the present invention, the air intake baffle is provided with a side edge exposed in the second airflow inlet, and one side of the urea crushing plate is fixed to the side edge; the urea crushing plate and the housing together form an airflow inlet body that is connected to the second airflow inlet.

[0011] As a further improvement of this utility model, the urea crushing plate is perpendicular to the air inlet baffle and the air outlet baffle.

[0012] As a further improvement of this utility model, the urea crushing plate is fixed to the inner wall of the shell.

[0013] As a further improvement of this utility model, the air outlet baffle is circular, and the center of the airflow outlet is offset from the center of the air outlet baffle.

[0014] As a further improvement of this utility model, the air outlet baffle is further provided with several through holes that penetrate the air outlet baffle and are connected to the mixing cavity.

[0015] Compared to existing technologies, the mixer assembly of this invention features an inlet baffle with a first airflow inlet and a second airflow inlet connected to the mixing chamber. An outlet baffle has an airflow outlet connected to the mixing chamber. At least a portion of the exhaust gas flowing into the mixing chamber from the first and second airflow inlets opposes each other. An arc-shaped guide plate forms a swirling flow of the mixture of exhaust gas and urea droplets, which then exits through the airflow outlet. This configuration results in a lower back pressure for the mixer assembly. Furthermore, the opposing airflow accelerates the breakup of urea droplets, reducing the risk of urea crystallization and improving conversion efficiency. Attached Figure Description

[0016] Figure 1 This is a perspective view of the mixer assembly of this utility model in one embodiment; Figure 2 yes Figure 1 The left view shows the urea nozzle; Figure 3 yes Figure 1 The right view shows the urea nozzle; Figure 4 yes Figure 1 The main view shows the urea nozzle; Figure 5 It is along Figure 4 Schematic diagram of the cross section of line AA; Figure 6 yes Figure 1 Top view; Figure 7 It is along Figure 6 Schematic diagram of the cross section of the middle BB line; Figure 8 yes Figure 1 3D exploded view. Detailed Implementation

[0017] The specific embodiments of this utility model will now be described in detail with reference to the accompanying drawings. Where several specific embodiments exist, features in these embodiments can be combined with each other without conflict. When the description relates to the drawings, unless otherwise stated, the same numbers or symbols in different drawings represent the same or similar elements. The content described in the following exemplary embodiments does not represent all embodiments of this utility model; rather, they are merely examples of products consistent with this utility model and as described in the claims.

[0018] The terminology used in this invention is for the purpose of describing specific embodiments only and is not intended to limit the scope of protection of this invention. It should be understood that terms such as "first," "second," and similar words used in the specification and claims of this invention do not indicate any order, quantity, or importance, but are merely used to distinguish the features.

[0019] Please refer to Figures 1 to 8 As shown, this utility model discloses a mixer assembly 100 for use in an engine exhaust aftertreatment system. The mixer assembly 100 includes a housing 1, an intake baffle 2 fixed in the housing 1, an exhaust baffle 3 fixed in the housing 1 and spaced apart from the intake baffle 2, and a guide plate 4 located between the intake baffle 2 and the exhaust baffle 3.

[0020] In the embodiment illustrated in this utility model, the housing 1 is generally cylindrical and has an installation space 10. The air intake baffle 2 and the air outlet baffle 3 are both at least partially located within the installation space 10. In the embodiment illustrated in this utility model, the air intake baffle 2 and the air outlet baffle 3 are both welded and fixed to the inner wall of the housing 1. The installation space 10 includes an intermediate cavity 11 located between the air intake baffle 2 and the air outlet baffle 3, and the guide plate 4 is located within the intermediate cavity 11.

[0021] The housing 1, the air inlet baffle 2, the air outlet baffle 3, and the guide plate 4 together form an arc-shaped mixing cavity 12.

[0022] The housing 1 is provided with a urea nozzle mounting seat 13, which is used to mount a urea nozzle 14, and the urea nozzle 14 is used to spray atomized urea droplets into the mixing chamber 12.

[0023] The air intake baffle 2 is provided with a first airflow inlet 21 connected to the mixing chamber 12 and a second airflow inlet 22 connected to the mixing chamber 12.

[0024] The air outlet baffle 3 is provided with an airflow outlet 31 that communicates with the mixing chamber 12.

[0025] The exhaust gases flowing into the mixing chamber 12 from the first airflow inlet 21 and the second airflow inlet 22 at least partially oppose each other (please refer to...). Figure 5 As shown in the figure, the airflow counter-current accelerates the breakup of urea droplets, which helps reduce the risk of urea crystallization and improves conversion efficiency.

[0026] The guide plate 4 is provided with an arc-shaped guide portion 41 to form a swirling flow of the mixed airflow of the exhaust gas and the urea droplets, which then exits from the airflow outlet 31. In the embodiment illustrated in this utility model, the guide plate 4 further includes a blocking portion 42 connected to the guide portion 41. One side of the blocking portion 42 is fixed to the inlet baffle 2, and the other side of the blocking portion 42 is fixed to the outlet baffle 3. The blocking portion 42 is used to prevent the airflow entering the mixing chamber 12 from directly passing through the blocking portion 42 and flowing to the airflow outlet 31. In other words, the airflow in the mixing chamber 12 is forced to flow along the guide portion 41 in the mixing chamber 12 under the obstruction of the blocking portion 42 to form a swirling flow.

[0027] Furthermore, in the embodiment illustrated in this utility model, the mixer assembly 100 further includes a urea crushing plate 5 located in the mixing chamber 12. The urea crushing plate 5 is provided with a plurality of urea breakage holes 51, and the urea crushing plate 5 is at least partially located within the spray range of the urea nozzle 14. This configuration allows the urea crushing plate 5 to further break up the urea droplets sprayed onto it, thereby making the urea particles smaller. This helps reduce the risk of urea crystallization and improves conversion efficiency.

[0028] In the embodiment illustrated in this utility model, an air outlet cavity 40 is formed on the back side of the guide portion 41, and the air outlet cavity 40 is connected between the mixing cavity 12 and the airflow outlet 31.

[0029] In the embodiment illustrated in this utility model, one side of the urea crushing plate 5 is fixed to the air inlet baffle 2, and the other side of the urea crushing plate 5 is fixed to the air outlet baffle 3. The other two sides of the urea crushing plate 5 are fixed to the inner wall of the housing 1. The urea crushing plate 5 is perpendicular to the air inlet baffle 2 and the air outlet baffle 3.

[0030] The air intake baffle 2 has a side edge 23 exposed in the second airflow inlet 22, and one side of the urea crushing plate 5 is fixed to the side edge 23. The urea crushing plate 5 and the housing 1 together form an air inlet mouth body 15 that communicates with the second airflow inlet 22.

[0031] In the embodiment illustrated in this utility model, the air outlet baffle 3 is circular, and the center of the airflow outlet 31 is offset from the center of the air outlet baffle 3. The air outlet baffle 3 is also provided with a plurality of through holes 32 that penetrate the air outlet baffle 3 and communicate with the mixing chamber 12. The through holes 32 facilitate the adjustment of back pressure.

[0032] During operation, a portion of the exhaust gas flows in from the first airflow inlet 21, passes through the airflow inlet body 15, and enters the mixing chamber 12 through the urea breakage hole 51; another portion of the exhaust gas flows into the mixing chamber 12 from the second airflow inlet 22. The dual-inlet exhaust gas helps reduce back pressure. When injection conditions are met, the urea nozzle 14 sprays atomized urea droplets into the mixing chamber 12. Airflow counter-current accelerates the breakup of urea droplets, reducing the risk of urea crystallization and improving conversion efficiency. The airflow in the mixing chamber 12 is forced to flow along the guide section 41 under the obstruction of the blocking part 42, forming a swirling flow. The majority of the airflow flows through the outlet chamber 40 and exits from the airflow outlet 31. A small portion of the airflow exits through the perforation 32.

[0033] Compared to existing technologies, the exhaust gases flowing into the mixing chamber 12 from the first airflow inlet 21 and the second airflow inlet 22 can counteract each other, thereby accelerating the breakup of urea droplets. Furthermore, the urea droplets can be broken up by the urea breaking plate 5, and the mixed airflow of exhaust gas and urea droplets can form a swirling flow under the guidance of the guide section 41. The guide section 41 makes good use of the cross-sectional space of the shell 1, increases the flow channel length, improves conversion efficiency, and achieves a compact structure.

[0034] The above embodiments are only used to illustrate the present utility model and are not intended to limit the technical solutions described in the present utility model. The understanding of this specification should be based on those skilled in the art. Although the present utility model has been described in detail with reference to the above embodiments, those skilled in the art should understand that they can still make modifications or equivalent substitutions to the present utility model. All technical solutions and improvements that do not depart from the spirit and scope of the present utility model should be covered within the scope of the claims of the present utility model.

Claims

1. A mixer assembly for use in an engine exhaust aftertreatment system, characterized in that: The mixer assembly includes a housing, an intake baffle fixed within the housing, an outlet baffle fixed within the housing and spaced apart from the intake baffle, and a guide plate located between the intake baffle and the outlet baffle; the housing has an installation space, and both the intake baffle and the outlet baffle are at least partially located within the installation space, the installation space including an intermediate cavity located between the intake baffle and the outlet baffle, and the guide plate located within the intermediate cavity; wherein, the housing, the intake baffle, the outlet baffle, and the guide plate together form an arc-shaped mixing cavity; the housing The system includes a urea nozzle mounting base for mounting a urea nozzle, which sprays atomized urea droplets into the mixing chamber. An inlet baffle has a first airflow inlet and a second airflow inlet connected to the mixing chamber. An outlet baffle has an airflow outlet connected to the mixing chamber. Exhaust gases flowing into the mixing chamber from the first and second airflow inlets partially oppose each other. A guide plate has an arc-shaped guide section to form a swirling flow of the mixture of exhaust gases and urea droplets, which then exits from the airflow outlet.

2. The mixer assembly as claimed in claim 1, characterized in that: The guide plate includes a blocking part connected to the guide section. One side of the blocking part is fixed to the air inlet baffle, and the other side of the blocking part is fixed to the air outlet baffle. The blocking part is used to prevent the airflow entering the mixing chamber from passing directly through the blocking part and flowing to the airflow outlet.

3. The mixer assembly as claimed in claim 1, characterized in that: An air outlet cavity is formed on the back side of the guide section, and the air outlet cavity is connected between the mixing cavity and the airflow outlet.

4. The mixer assembly as claimed in claim 1, characterized in that: The mixer assembly also includes a urea crushing plate located in the mixing chamber, the urea crushing plate having a plurality of urea breakage holes, and the urea crushing plate being at least partially located within the spray range of the urea nozzle.

5. The mixer assembly as claimed in claim 4, characterized in that: One side of the urea crushing plate is fixed to the air inlet baffle, and the other side of the urea crushing plate is fixed to the air outlet baffle.

6. The mixer assembly as claimed in claim 5, characterized in that: The air intake baffle has a side edge exposed in the second airflow inlet, and one side of the urea crushing plate is fixed to the side edge; the urea crushing plate and the housing together form an airflow inlet body that communicates with the second airflow inlet.

7. The mixer assembly as claimed in claim 5, characterized in that: The urea crushing plate is perpendicular to the air inlet baffle and the air outlet baffle.

8. The mixer assembly as claimed in claim 5, characterized in that: The urea crushing plate is fixed to the inner wall of the shell.

9. The mixer assembly as claimed in claim 1, characterized in that: The air outlet baffle is circular, and the center of the air outlet is offset from the center of the air outlet baffle.

10. The mixer assembly of claim 1, characterized in that: The vent baffle is also provided with several through holes that penetrate the vent baffle and are connected to the mixing chamber.

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