Mixing device

Abstract

This utility model discloses a mixing device, which includes a housing, a flow guiding assembly, a perforated plate, and a flow guide. The housing has an air inlet chamber and a mixing chamber. The flow guiding assembly has a first end and a second end corresponding to the first end. The first end is used to communicate with a urea nozzle, and the second end is used to communicate with the mixing chamber. The flow guiding assembly has a hollow cavity and a first swirling orifice. The hollow cavity is located between the first end and the second end, and the first swirling orifice is closer to the first end than the second end. The first swirling orifice connects the cavity of the flow guiding assembly and the air inlet chamber. The perforated plate is provided with multiple connecting holes and is disposed in the mixing chamber, with a portion of the perforated plate connected to the housing. The flow guide is disposed in the air inlet chamber, corresponding to the first end, and connected to the housing. The flow guide is configured to reduce the countercurrent of airflow within the air inlet chamber. This mixing device can reduce the risk of urea crystallization on the walls of the mixing device.

Description

Technical Field

[0001] This utility model belongs to the field of engine aftertreatment technology, and specifically relates to a mixing device. Background Technology

[0002] This section provides only background information relevant to this disclosure and is not necessarily prior art.

[0003] Currently, the mixing device commonly used in engine aftertreatment systems has an air inlet for the exhaust gas to flow in, an exhaust outlet for the exhaust gas to be discharged, and a perforated plate installed on the exhaust outlet. The exhaust gas and urea droplets that have passed through the mixing device flow through the perforated plate at the exhaust outlet and are then discharged from the mixing device.

[0004] However, when existing mixing devices mix exhaust gas and urea droplets, large-diameter urea droplets adhere to the walls of the mixing device, posing a high risk of urea crystallization. Utility Model Content

[0005] This utility model aims to at least partially solve one of the technical problems in the related art.

[0006] This utility model provides a mixing device, comprising:

[0007] A housing having an air intake chamber and a mixing chamber spaced apart from the air intake chamber;

[0008] A flow guiding assembly has a first end and a second end opposite to the first end. The first end is used to connect to a urea nozzle, and the second end is located in the mixing chamber. The flow guiding assembly has a hollow cavity and a first swirling orifice. The hollow cavity is located between the first end and the second end. The first swirling orifice is closer to the first end than the second end. The first swirling orifice connects the cavity of the flow guiding assembly and the air intake chamber.

[0009] A porous plate, having multiple communicating holes, is disposed within the mixing chamber, and a portion of the porous plate is connected to the housing; and

[0010] A diverter is disposed in the air intake chamber and is correspondingly disposed to the first end. The diverter is connected to the housing and is configured to reduce the countercurrent of airflow in the air intake chamber.

[0011] In some embodiments, the drainage element includes a first sub-drainage element and a second sub-drainage element connected to the first sub-drainage element. The distance from the first sub-drainage element to the inner wall of the housing along the connection between the first sub-drainage element and the second sub-drainage element gradually decreases along the circumference of the housing.

[0012] In some embodiments, the flow guiding component includes:

[0013] A tapered tube, one end of which is the first end of the flow guiding assembly and is used to connect to the urea nozzle, the diameter of the tapered tube gradually increases in the direction away from the first end, and the tapered tube has the first swirl hole;

[0014] An outer tube, the outer tube being connected between the other end of the tapered tube and the mixing chamber; and

[0015] An inner tube is inserted into the outer tube and connected to the outer tube. The inner tube is provided with a strip-shaped hole.

[0016] In some embodiments, the end face of the outer tube away from the tapered tube forms a first angle with the axis of the outer tube, the first angle being between 30° and 60°, and the perforated plate forms a second angle with the axis of the outer tube, the second angle being between 30° and 60°.

[0017] In some embodiments, the end face of the inner tube away from the tapered tube forms a third angle with the axis of the outer tube, the third angle being between 30° and 60°.

[0018] In some embodiments, the tapered tube includes:

[0019] A first tube body, wherein the first swirl orifice is disposed circumferentially along the first tube body; and

[0020] The first swirl vane is connected to one side wall of the first swirl hole, and the first swirl vane is inclined.

[0021] In some embodiments, the outer tube includes:

[0022] A second tube body, wherein a second swirl hole is provided at one end of the second tube body near the tapered tube, and the second swirl hole is arranged circumferentially along the second tube body; and

[0023] The second swirl vane is connected to one side wall of the second swirl hole and is inclined.

[0024] In some embodiments, a first air hole is provided at the end of the second tube away from the tapered tube.

[0025] In some embodiments, the inner tube includes:

[0026] A third tube body, wherein the strip hole is disposed on the third tube body; and

[0027] At least two single arms, each single arm being connected to one end of the third tube near the tapered tube, and the single arm being connected to the outer tube.

[0028] In some embodiments, a separator is further included, through which the flow guiding assembly passes, the separator being connected to the flow guiding assembly and the housing, the housing, the flow guiding assembly, and the separator defining a cavity.

[0029] The mixing device provided by this utility model includes a housing, a flow guiding component, a perforated plate, and a flow guide. After the exhaust gas enters the intake chamber, the flow guide, which is disposed in the intake chamber and corresponds to the first end, prevents the exhaust gas in the intake chamber from generating convection, reduces the airflow collision in the intake chamber, prevents the generation of eddies, reduces the pressure, and increases the airflow velocity. Under the action of the flow guide, the airflow velocity is increased, improving the mixing effect of the exhaust gas and urea droplets. When the airflow passes through the flow guiding component, it can reduce the risk of urea crystallization on the flow guiding component. Attached Figure Description

[0030] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0031] Figure 1 This is a schematic diagram of the assembly structure of the mixing device provided in this embodiment of the utility model. Figure 1 ;

[0032] Figure 2 This is a schematic diagram of the assembly structure of the mixing device provided in this embodiment of the utility model. Figure 2 ;

[0033] Figure 3 This is an exploded schematic diagram of the mixing device provided in an embodiment of the present invention;

[0034] Figure 4 This is an assembly diagram of a portion of the structure of the mixing device provided in this embodiment of the utility model;

[0035] Figure 5 This is an exploded view of the flow guiding component provided in this embodiment of the utility model;

[0036] Figure 6 This is a schematic diagram of the drainage component provided in this embodiment of the utility model;

[0037] Figure 7 This is a top view of the drainage component provided in this embodiment of the utility model;

[0038] Figure 8 This is a top view of the perforated plate provided in this embodiment of the utility model.

[0039] Figure 9 This is a schematic diagram of the structure of the tapered tube provided in this embodiment of the utility model;

[0040] Figure 10 This is a schematic diagram of the structure of the outer tube provided in this embodiment of the utility model;

[0041] Figure 11 yes Figure 10 Enlarged view of section A;

[0042] Figure 12 This is a flow direction diagram of the airflow inside the air intake cavity provided in this embodiment of the utility model.

[0043] Figure label:

[0044] 10. Mixing device;

[0045] 1. Shell; 11. Air inlet; 111. Air inlet chamber; 112. Air inlet; 113. Urea inlet; 12. Mixing section; 121. Mixing chamber; 122. Air outlet;

[0046] 2. Flow guiding assembly; 21. Conical tube; 211. First tube body; 2111. First swirl orifice; 212. First swirl vane; 22. Outer tube; 221. Second tube body; 2211. Second swirl orifice; 2211. First air hole; 222. Second swirl vane; 23. Inner tube; 231. Third tube body; 2311. Strip-shaped hole; 2312. Second air hole; 232. Single arm;

[0047] 3. Perforated plate; 31. Connecting holes;

[0048] 4. Drainage component; 41. First sub-drainage component; 411. First arc-shaped surface; 412. Second arc-shaped surface; 42. Second sub-drainage component; 421. Third arc-shaped surface; 422. Fourth arc-shaped surface

[0049] 5. Separator; 51. Connecting plate; 511. First through hole; 52. First partition plate; 521. Second through hole; 53. Second partition plate; 54. Cavity;

[0050] θ1, the first included angle;

[0051] θ2, the second included angle;

[0052] θ3, the third included angle. Detailed Implementation

[0053] The present application will now be described in further detail with reference to the accompanying drawings and embodiments. It should be particularly noted that the following embodiments are for illustrative purposes only and do not limit the scope of the application. Similarly, the following embodiments are only some, not all, embodiments of the present application, and all other embodiments obtained by those skilled in the art without inventive effort are within the scope of protection of the present application.

[0054] The terms "first," "second," and "third" used in the embodiments of this application are for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, a feature defined as "first," "second," or "third" may explicitly or implicitly include at least one of that feature. In the description of this application, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified. All directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of this application are only used to explain the relative positional relationships and movement of components in a specific posture (as shown in the figures). If the specific posture changes, the directional indication will also change accordingly. The terms "comprising" and "having," and any variations thereof, in the embodiments of this application are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or device that includes a series of steps or units is not limited to the listed steps or units, but may optionally include steps or units not listed, or may optionally include other steps or components inherent to these processes, methods, products, or devices.

[0055] This embodiment provides a mixing device. The mixing device utilizes a urea injection unit installed on the exhaust pipe to spray a measured amount of urea aqueous solution into the exhaust pipe in a mist form. The urea droplets undergo hydrolysis and pyrolysis reactions under the action of high-temperature exhaust gas, generating the desired reducing agent, ammonia (NH3). Ammonia (NH3), under the action of a catalyst, selectively reduces nitrogen oxides (NOx) to nitrogen (N2), thus purifying the exhaust gas.

[0056] The mixing device includes a housing, a flow guiding assembly, a perforated plate, and a flow guide. The housing has an air inlet chamber and a mixing chamber separated from the air inlet chamber. The flow guiding assembly has a first end and a second end opposite to the first end. The first end is for connection to a urea nozzle, and the second end is located within the mixing chamber. The flow guiding assembly has a hollow cavity and a first swirling orifice. The hollow cavity is located between the first and second ends, and the first swirling orifice is closer to the first end than the second end. The first swirling orifice connects the cavity of the flow guiding assembly and the air inlet chamber. The perforated plate has multiple connecting holes and is disposed in the mixing chamber, connected to the housing. The flow guide is disposed in the air inlet chamber, corresponding to the first end, and connected to the housing. The flow guide is configured to reduce the countercurrent of airflow within the air inlet chamber.

[0057] After the exhaust gas enters the intake chamber, a guide component is installed in the intake chamber and corresponding to the first end to prevent the exhaust gas from generating convection in the intake chamber, reduce the airflow collision in the intake chamber, prevent the generation of eddies, reduce the pressure, and increase the airflow velocity. Under the action of the guide component, the airflow velocity is increased, which improves the mixing effect between the exhaust gas and urea droplets. When the airflow passes through the guide component, it can reduce the risk of urea crystal formation on the guide component.

[0058] Urea crystallization occurs when the urea solution becomes supersaturated due to water loss, causing urea to precipitate out. It is a product of a physical reaction process and can continue to decompose as the temperature rises. Because urea droplets are much larger than gas, crystals formed in areas where airflow is stagnant will continue to grow if they cannot be completely decomposed in time. Due to incomplete decomposition, urea crystal stones eventually form, which, if accumulated to a certain extent, may block the urea flow channels.

[0059] like Figure 1 and Figure 3 As shown, the mixing device 10 includes a housing 1, which has an air inlet chamber 111 and a mixing chamber 121. During operation, a mixed airflow of exhaust gas and urea droplets enters the housing 1 from the air inlet chamber 111. The mixed airflow of exhaust gas and urea droplets then flows from the air inlet chamber 111 to the mixing chamber 121 and is mixed within the mixing chamber 121 to ensure a sufficient reaction before being discharged from the mixing device 10.

[0060] Specifically, the mixing device 10 includes a housing 1, which includes an air inlet 11 and a mixing section 12. The air inlet 11 has an air inlet 112 and surrounds an air inlet chamber 111 facing the air inlet 112. The air inlet 112 communicates with the air inlet chamber 111. The mixing section 12 has an air outlet 122 and surrounds a mixing chamber 121 facing the air outlet 122. This housing 1 structure forms a gas flow channel for the mixing device 10 from air intake to exhaust.

[0061] like Figure 3As shown, in some embodiments, a urea inlet 113 is also provided at the end of the air intake 11 away from the mixing section 12. Urea can enter the air intake chamber 111 through the urea inlet 113. During operation, exhaust gas enters the air intake chamber 111 from the air intake port 112, and at the same time, urea enters the air intake chamber 111 from the urea inlet 113. After entering the air intake chamber 111, the urea begins to decompose and produce ammonia. During the gas flow, the exhaust gas carries urea droplets and flows from the air intake chamber 111 into the mixing chamber 121. The exhaust gas and urea are fully mixed in the mixing chamber 121 so that the ammonia reacts with the nitrogen oxides (NOx) in the exhaust gas to purify the nitrogen oxides (NOx) in the exhaust gas. Then, the purified exhaust gas is discharged from the air outlet 122.

[0062] In some embodiments, the mixing cavity 121 has a quasi-spherical structure, that is, the inner circumferential contour of the mixing section 12 is close to a sphere, so that the inner surface of the mixing section 12 is smooth, thereby reducing the flow resistance of the airflow in the mixing cavity 121, reducing eddies, and reducing back pressure.

[0063] In some embodiments, the air intake cavity 111 has a quasi-spherical structure, that is, the inner circumferential contour of the air intake cavity 111 is close to a sphere, so that the inner surface of the air intake part 11 is smooth, thereby reducing the flow resistance of the airflow in the air intake cavity 111, reducing turbulence, and reducing back pressure.

[0064] like Figures 2 to 4 As shown, in some embodiments, the mixing device 10 further includes a separator 5, through which the outer tube 22 passes. The separator 5 is connected to the outer tube 22 and the housing 1, and the housing 1, the outer tube 22, and the separator 5 define a cavity 54. By providing the separator 5, the housing 1, the outer tube 22, and the separator 5 form a cavity 54. The cavity 54 can provide insulation for the inside of the outer tube 22, which is beneficial to improving the mixing effect of urea and exhaust gas, improving the fullness of mixing of urea and exhaust gas, reducing the probability of urea droplets adhering to the wall surface of the mixing device 10, and reducing the risk of urea crystallization.

[0065] Specifically, the separator 5 includes a first separator plate 52, a second separator plate 53, and a connecting plate 51. The first separator plate 52 is connected to one end of the connecting plate 51, and the second separator plate 53 is connected to the other end of the connecting plate 51. The first separator plate 52 is provided with a first through hole 511. The second separator plate 53 is provided with a second through hole 521. The outer tube 22 passes through the first through hole 511 and the second through hole 521, so that the housing 1, the outer tube 22, and the separator 5 form a cavity 54. At the same time, the outer tube 22 passing through the first through hole 511 and the second through hole 521 makes the air intake cavity 111 and the mixing cavity 121 form independent chambers, avoiding the airflow mixing in the air intake cavity 111 and the mixing cavity 121 and causing circumferential flow, which is beneficial to improving the mixing effect of the mixing device 10.

[0066] In some embodiments, the housing 1 is welded to the partition 5. The outer tube 22 is also welded to the partition 5. The connection between the housing 1 and the partition 5, and the connection between the outer tube 22 and the partition 5, are achieved by welding. The connection is strong and the sealing at the connection point is good, making the cavity 54 a closed cavity.

[0067] In some embodiments, the first partition plate 52 is bent toward the air intake cavity 111, so that the first partition plate 52 and the air intake part 11 form a spherical structure, thereby reducing the flow resistance of the airflow in the air intake cavity 111.

[0068] In some embodiments, the second partition plate 53 is bent toward the mixing chamber 121, so that the second partition plate 53 and the mixing part 12 form a spherical structure, thereby reducing the flow resistance of the airflow in the mixing chamber 121.

[0069] In some embodiments, the mixing device 10 includes a flow guiding component 2. Now combined with Figure 3 and Figure 6 Details of the flow guiding component 2 are explained below.

[0070] like Figure 3 and Figure 5 As shown, the flow guiding assembly 2 has a first end and a second end corresponding to the first end. The first end is used to connect to the urea nozzle, and the second end is connected to the mixing chamber 121. The flow guiding assembly 2 has a first swirling hole 2111, which is close to the first end and connects the interior of the flow guiding assembly 2 and the air intake chamber 111. By setting the flow guiding assembly 2, the flow guiding assembly 2 guides the flow direction of exhaust gas and urea droplets between the air intake chamber 111 and the mixing chamber 121, so that the exhaust gas carries urea droplets into the mixing chamber 121 and is fully mixed in the mixing chamber 121.

[0071] like Figure 6 , Figure 7 and Figure 12 As shown, in some embodiments, the mixing device 10 further includes a guide member 4, which is disposed in the air intake chamber 111. The guide member 4 is disposed corresponding to the first end and is connected to the housing 1. The guide member 4 includes a first sub-guide member 41 and a second sub-guide member 42 connected to the first sub-guide member 41. The guide member 4 extends from the connection point of the first sub-guide member 41 to the inner wall of the housing 1. The distance from the first sub-guide member 41 to the inner wall of the housing 1 gradually decreases along the circumference of the housing 1, and the distance from the second sub-guide member 42 to the inner wall of the housing 1 gradually decreases along the circumference of the housing 1.

[0072] In some embodiments, the first drainage member 41 is bent in the direction of the drainage assembly 2. The first sub-drainage member 41 is an arc-shaped plate structure. The first sub-drainage member 41 has a first arc-shaped surface 411 and a second arc-shaped surface 412 opposite to the first arc-shaped surface 411. The first arc-shaped surface 411 is close to the inner wall of the housing 1 relative to the second arc-shaped surface 412. The first arc-shaped surface 411 matches the inner wall of the housing 1, and the second arc-shaped surface 412 matches the first arc-shaped surface 411.

[0073] In some embodiments, the second sub-drainage member 42 is bent in the direction of the drainage assembly 2. The second sub-drainage member 42 is an arc-shaped plate structure. The second sub-drainage member 42 has a third arc-shaped surface 421 and a fourth arc-shaped surface 422 opposite to the third arc-shaped surface 421. The third arc-shaped surface 421 is close to the inner wall of the housing 1 relative to the fourth arc-shaped surface 422. The third arc-shaped surface 421 matches the inner wall of the housing 1, and the fourth arc-shaped surface 422 matches the third arc-shaped surface 421.

[0074] After the exhaust gas enters the intake chamber 111, the guide member 4, which is set in the intake chamber 111 and corresponds to the first end, prevents the exhaust gas in the intake chamber 111 from generating convection, reduces the airflow collision in the intake chamber, prevents the generation of eddies, reduces the pressure, and increases the airflow velocity. Under the action of the guide member 4, the airflow velocity is increased, which improves the mixing effect of exhaust gas and urea droplets. When the airflow passes through the guide component 2, it can reduce the risk of urea crystal formation on the guide component 2.

[0075] Specifically, one end of the first sub-drainage member 41 is connected to one end of the second sub-drainage member 42. One end of the first sub-drainage member 41 is connected to one end of the second sub-drainage member 42 in an arc shape.

[0076] In some embodiments, such as Figure 9 As shown, the flow guiding assembly 2 includes a tapered tube 21. One end of the tapered tube 21 is the first end of the flow guiding assembly 2 and is used to connect to the urea nozzle, allowing urea droplets to directly enter the interior of the tapered tube 21. The tapered tube 21 has a first swirling hole 2111. After the exhaust gas enters the intake chamber 111 from the intake port 112, it can enter the interior of the tapered tube through the first swirling hole 2111, so that the exhaust gas and urea droplets are mixed and flow into the mixing chamber 121 inside the tapered tube 21.

[0077] Specifically, along the direction away from the first end, the diameter of the tapered tube 21 gradually increases. Compared with the cylindrical tube, the structural shape of the tapered tube 21 can provide the airflow with a direction of inclined flow towards the mixing chamber 121, which is beneficial to reduce the airflow resistance and make the air intake of the first swirl hole 2111 of the tapered tube 21 more uniform.

[0078] In some embodiments, the tapered tube 21 includes a first tube body 211 and a first swirl vane 212. A first swirl orifice 2111 is arranged circumferentially along the first tube body 211. The first swirl vane 212 is connected to one side wall of the first swirl orifice 2111 and is inclined. By providing the first swirl vane 212, which is inclined, the first swirl vane 212 located on the tube wall of the tapered tube 21 creates a rotational disturbance, causing the exhaust gas to collide violently with urea droplets after entering the tapered tube 21 from the first swirl orifice 2111, and to rotate and flow, increasing the flow distance and thus increasing the mixing distance between the exhaust gas and the urea droplets, which is beneficial for improving the mixing effect.

[0079] In some embodiments, the first swirl vane 212 is inclined inward toward the first tube 211, so that the exhaust gas entering the conical tube 21 can collide with the urea droplets injected into the conical tube 21, which is beneficial to improving the mixing effect of the exhaust gas and the urea droplets. At the same time, the inwardly inclined first swirl vane 212 can accommodate a larger diameter first tube 211 in the same space, which is beneficial to increasing the capacity.

[0080] Specifically, the first tube body 211 is provided with a plurality of first swirl holes 2111, which are evenly spaced along the circumference of the first tube body 211. Each first swirl hole 2111 is provided with a corresponding first swirl vane 212. On the one hand, this can reduce the countercurrent of airflow and lower the back pressure; on the other hand, the multiple first swirl vanes 212 make the swirl effect better, the swirl velocity along the radial direction of the conical tube is greater, the airflow velocity is increased and the airflow path is extended, the evaporation and decomposition of urea is accelerated, and the anti-crystallization ability is improved.

[0081] In some embodiments, the first swirl hole 2111 extends along the axial direction of the tapered tube 21.

[0082] Of course, in other embodiments, the first swirl vane 212 may also be tilted outward of the conical tube 21, which is beneficial to increase the swirl velocity of the exhaust gas entering the conical tube 21.

[0083] like Figure 9 and Figure 10 As shown, in some embodiments, the flow guiding assembly 2 further includes an outer tube 22, which is connected between the other end of the tapered tube 21 and the mixing chamber 121. After the exhaust gas enters the intake chamber 111 from the intake port 112, it can enter the interior of the outer tube 22 through the second swirl hole 2211 to mix the exhaust gas and urea droplets, and flow into the mixing chamber 121 inside the outer tube 22.

[0084] Specifically, the tapered tube 21 and the outer tube 22 are welded together.

[0085] In some embodiments, the outer tube 22 includes a second tube body 221 and a second swirl vane 222. A second swirl hole 2211 is provided at one end of the second tube body 221 near the tapered tube 21, and the second swirl hole 2211 is arranged circumferentially along the second tube body 221. The second swirl vane 222 is connected to one sidewall of the second swirl hole 2211, and the second swirl vane 222 is inclined. This arrangement allows the exhaust gas entering the outer tube 22 to collide with urea droplets, which is beneficial for improving the mixing effect of the exhaust gas and urea droplets. Simultaneously, the inwardly inclined second swirl vane 222 allows for a larger diameter second tube body 221 to be arranged in the same space, which is beneficial for increasing capacity.

[0086] Specifically, the second tube body 221 is provided with a plurality of second swirl holes 2211, which are evenly spaced along the circumference of the second tube body 221. Each second swirl hole 2211 is provided with a corresponding second swirl vane 222. On the one hand, this can reduce airflow countercurrent and lower back pressure; on the other hand, the multiple second swirl vanes 222 improve the swirl effect, increase the radial swirl velocity along the outer tube 22, enhance the airflow velocity and extend the airflow path, accelerate urea evaporation and decomposition, and improve anti-crystallization ability.

[0087] In some embodiments, the second swirl hole 2211 extends axially along the outer tube 22.

[0088] In some embodiments, a first vent 2211 is provided at the end of the second tube 221 away from the tapered tube 21. By providing the first vent 2211 at the end of the second tube 221 away from the tapered tube 21, the airflow distribution can be adjusted, and the uniformity of ammonia gas near the outlet 122 can be improved.

[0089] Meanwhile, the uniformity of ammonia distribution refers to the distribution uniformity index defined to evaluate the degree of uniformity of ammonia distribution, which is defined as U. vapor The formula is shown below:

[0090]

[0091] In the formula:

[0092] m″ i The ammonia mass fraction value for each grid cell on a certain plane;

[0093] m″ mean The average mass fraction of ammonia on a certain plane;

[0094] A i Let be the area of ​​each cell in a certain plane;

[0095] A represents the area of ​​a certain plane.

[0096] like Figure 1and Figure 8 As shown, in some embodiments, the mixing device 10 further includes a perforated plate 3. The perforated plate 3 is provided with a plurality of connecting holes 31, the perforated plate 3 is disposed in the mixing chamber 121, and a portion of the perforated plate 3 is connected to the housing 1.

[0097] like Figure 2 As shown, specifically, the end face of the outer tube 22 away from the conical tube 21 forms a first angle θ1 with the axis of the outer tube 22, which is between 30° and 60°. The perforated plate 3 forms a second angle θ2 with the axis of the outer tube 22, which is also between 30° and 60°. The end of the outer tube 22 away from the conical tube 21 cooperates with the perforated plate 3 to prevent the airflow from flowing rapidly towards the outlet 122, thus extending the mixing path of the exhaust gas and urea solution and enhancing the uniformity of mixing.

[0098] Optionally, the first included angle θ1 is 30°, 40°, 50°, 60°, or any range of two of the above values. The second included angle θ2 is 30°, 40°, 50°, 60°, or any range of two of the above values.

[0099] In some embodiments, multiple connecting holes 31 are provided, and the multiple connecting holes 31 are evenly distributed on the perforated plate 3. The structure is simple and easy to process.

[0100] In some embodiments, the perforated plate 3 has a semi-circular structure. This arrangement facilitates the connection between the perforated plate 3 and the housing 1.

[0101] like Figure 3 and Figure 5 As shown, in some embodiments, the mixing device 10 further includes an inner tube 23. The inner tube 23 passes through the outer tube 22 and is connected to the outer tube 22. The inner tube 23 is provided with a strip-shaped hole 2311. During the process of the exhaust gas carrying urea droplets into the mixing chamber 121, the urea droplets continuously collide with the inner tube 23. As they flow through the strip-shaped hole 2311, the urea droplets are fully broken down and decomposed, reducing the diameter of the urea droplets and preventing the urea droplets from depositing due to their large weight. This helps to reduce the risk of urea crystallization in the mixing device 10.

[0102] Specifically, the strip-shaped orifice 2311 extends along the axial direction of the inner tube 23, thereby allowing the rotating airflow to fully collide with the inner tube 23, which is beneficial to improving the breaking effect on urea droplets.

[0103] In some embodiments, the inner tube 23 includes a third tube body 231 and at least two single arms 232. A strip-shaped hole 2311 is provided on the third tube body 231. The single arms 232 are connected to one end of the third tube body 231 near the tapered tube, and are also connected to the outer tube 22. The connection between the outer tube 22 and the inner tube 23 is achieved by providing the single arms 232, resulting in a simple connection structure. The single arms 232 are connected to the outer tube 22 by welding.

[0104] Specifically, multiple strip-shaped holes 2311 are provided, and the multiple strip-shaped holes 2311 are distributed circumferentially along the third tube body 231, which is conducive to achieving full collision between the rotating airflow and the inner tube 23, and is conducive to improving the breaking effect of urea droplets.

[0105] In some embodiments, the third tube 231 is further provided with a second vent 2312, and the strip-shaped hole 2311 and the second vent 2312 are arranged sequentially along the direction away from the tapered tube 21. By providing the second vent 2312, the airflow distribution can be adjusted, and the uniformity of ammonia gas near the outlet 122 can be improved.

[0106] like Figure 2 As shown, in some embodiments, the end face of the inner tube 23 away from the tapered tube 21 forms a third angle θ3 with the axis of the outer tube 22, and the third angle θ3 is between 30° and 60°. The end of the inner tube 23 away from the tapered tube 21 cooperates with the perforated plate 3 to prevent the airflow from flowing rapidly to the outlet 122, prolonging the mixing path of the exhaust gas and urea solution, and enhancing the uniformity of mixing.

[0107] Optionally, the third included angle θ3 is 30°, 40°, 50°, 60° or a range consisting of any two of the above values.

[0108] In some embodiments, the first included angle θ1 is equal to the third included angle θ3.

[0109] In the description of this utility model, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this utility model and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model.

[0110] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this utility model, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0111] In this utility model, unless otherwise explicitly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a connection that allows communication between them; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0112] In this utility model, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0113] In this utility model, the terms "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of this utility model. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0114] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A mixing device, characterized in that, include: A housing having an air intake chamber and a mixing chamber spaced apart from the air intake chamber; A flow guiding assembly has a first end and a second end opposite to the first end. The first end is used to connect to a urea nozzle, and the second end is located in the mixing chamber. The flow guiding assembly has a hollow cavity and a first swirling orifice. The hollow cavity is located between the first end and the second end. The first swirling orifice is closer to the first end than the second end. The first swirling orifice connects the cavity of the flow guiding assembly and the air intake chamber. A porous plate having multiple connecting holes is disposed in the mixing chamber and connected to the housing. as well as A diverter is disposed in the air intake chamber, the diverter is disposed corresponding to the first end, the diverter is connected to the housing, and the diverter is configured to reduce the countercurrent of airflow in the air intake chamber.

2. The mixing device according to claim 1, characterized in that, The drainage component includes a first sub-drainage component and a second sub-drainage component connected to the first sub-drainage component. Along the connection point between the first sub-drainage component and the second sub-drainage component, the distance from the first sub-drainage component to the inner wall of the housing gradually decreases along the circumference of the housing, and the distance from the second sub-drainage component to the inner wall of the housing gradually decreases along the circumference of the housing.

3. The mixing device according to claim 1, characterized in that, The flow guiding component includes: A tapered tube, one end of which is the first end of the flow guiding assembly and is used to connect to the urea nozzle, the diameter of the tapered tube gradually increases in the direction away from the first end, and the tapered tube has the first swirl hole; An outer tube, the outer tube being connected between the other end of the tapered tube and the mixing chamber; and An inner tube is inserted into the outer tube and connected to the outer tube. The inner tube is provided with a strip-shaped hole.

4. The mixing apparatus according to claim 3, characterized in that, The end face of the outer tube away from the tapered tube forms a first angle with the axis of the outer tube, the first angle being between 30° and 60°. The perforated plate forms a second angle with the axis of the outer tube, the second angle being between 30° and 60°.

5. The mixing apparatus according to claim 4, characterized in that, The end face of the inner tube away from the tapered tube forms a third angle with the axis of the outer tube, and the third angle is between 30° and 60°.

6. The mixing apparatus according to claim 3, characterized in that, The tapered tube includes: A first tube body, wherein the first swirl orifice is disposed circumferentially along the first tube body; and The first swirl vane is connected to one side wall of the first swirl hole, and the first swirl vane is inclined.

7. The mixing apparatus according to claim 3, characterized in that, The outer tube includes: A second tube body, wherein a second swirl hole is provided at one end of the second tube body near the tapered tube, and the second swirl hole is arranged circumferentially along the second tube body; and The second swirl vane is connected to one side wall of the second swirl hole and is inclined.

8. The mixing apparatus according to claim 7, characterized in that, The second tube body has a first air hole at the end away from the tapered tube.

9. The mixing apparatus according to claim 3, characterized in that, The inner tube includes: A third tube body, wherein the strip hole is disposed on the third tube body; and At least two single arms, each single arm being connected to one end of the third tube near the tapered tube, and the single arm being connected to the outer tube.

10. The mixing apparatus according to any one of claims 1-9, characterized in that, It also includes a separator, through which the flow guiding assembly passes, the separator being connected to the flow guiding assembly and the housing, the housing, the flow guiding assembly and the separator defining a cavity.

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