Mixer with air outlet baffle and corresponding exhaust aftertreatment system

Abstract

The utility model relates to a mixer which comprises an outer shell, a sealing plate and a mixing pipe, a mixing cavity is defined by the outer shell and the sealing plate, a partition plate is arranged in the mixing cavity, an air outlet baffle is arranged between an air outlet of the sealing plate and the lower section of the mixing pipe, and the air outlet baffle seals one part of the air outlet. The gas outlet baffle is provided with a plurality of first holes, so that mixed gas is discharged through the area, which is not closed by the gas outlet baffle, in the gas outlet and the first holes of the gas outlet baffle. The utility model further relates to a corresponding exhaust aftertreatment system. The gas outlet baffle is additionally arranged between the gas outlet of the sealing plate and the lower section of the mixing pipe, gas flow uniformity and ammonia uniformity can be better adjusted, crystals can be effectively reduced and eliminated through the W-shaped arc plate, and the purposes of controlling overall back pressure, adjusting gas flow and ammonia gas distribution of the gas outlet and effectively improving the uniformity index of gas and ammonia gas before SCR are achieved. Further, the reduction reaction capacity with nitrogen oxides is improved.

Description

TECHNICAL FIELD

[0001] The utility model relates to exhaust treatment technical field, especially a kind of mixer with air outlet baffle and corresponding exhaust aftertreatment system. BACKGROUND

[0002] With the continuous upgrading of domestic diesel vehicle emission regulations, more stringent requirements are put forward for automobile exhaust aftertreatment system and its core component mixer. As a key component in the aftertreatment system, the performance of the mixer directly affects the emission of NOx.

[0003] The mixer needs to ensure that the exhaust gas and the reducing agent (such as urea solution) are fully mixed to improve the conversion efficiency of the SCR system. The mixer also needs to have good heat exchange performance to ensure that the urea solution is rapidly vaporized and fully mixed with the exhaust gas during the injection process, which helps to improve the conversion efficiency of the SCR system and reduce urea consumption. Due to the stricter emission limits of "China VI" standard under low temperature and low load conditions, and the increase of injection amount, the risk of crystallization of the mixer increases. The generation of a large amount of crystallization will block the aftertreatment channel, cause the back pressure of the aftertreatment system to rise, the vehicle power to be insufficient, and there is a risk of exceeding the regulatory limits of emissions.

[0004] Therefore, the existing aftertreatment system still has technical problems: high back pressure of the aftertreatment system, poor engine fuel economy, urea crystallization in the mixer, low mixing efficiency of urea and exhaust gas, and low De-NOx conversion efficiency. SUMMARY

[0005] In view of the deficiencies of the existing technology, the utility model provides a mixer with air outlet baffle and corresponding exhaust aftertreatment system, which can control the overall back pressure, effectively reduce or eliminate urea crystallization, and effectively improve the uniformity index of exhaust gas and ammonia before SCR.

[0006] To achieve the above object, the utility model discloses a first aspect provides a kind of mixer with air baffle, with the following technical solutions: the mixer includes outer shell, sealing plate, mixing pipe, the outer shell and sealing plate are enclosed and form mixing cavity, the mixing cavity is provided with partition, the partition separates the mixing cavity and forms upper cavity and lower cavity, the sealing plate is provided with the air inlet corresponding the upper cavity and the air outlet corresponding the lower cavity, the mixing pipe extends from the upper cavity and passes through the partition to the lower cavity, the upper section of the mixing pipe is provided with inlet, the lower section of the mixing pipe is provided with outlet, so that exhaust gas enters the upper cavity through the air inlet, enters the mixing pipe through the inlet, after mixing with reducing agent in the mixing pipe, mixed gas enters the lower cavity through the outlet, air baffle is arranged between the air outlet of the sealing plate and the lower section of the mixing pipe, the air baffle closes part of the air outlet, the air baffle is provided with a plurality of first openings, so that mixed gas is discharged through the area of the air outlet not closed by the air baffle and the first opening of the air baffle.

[0007] Preferably, the air baffle is a semicircular plate structure, and the semicircular plate structure matches the profile of the lower half of the air outlet.

[0008] Preferably, the middle region of the air baffle has an arc-shaped protrusion protruding towards the air outlet, the arc-shaped protrusion is arranged corresponding to the mixing pipe, and the arc-shaped protrusion extends in a direction parallel to the longitudinal axis of the mixing pipe.

[0009] Preferably, the first openings are distributed in the upper section of the air baffle and the lower section of the air baffle, the middle section of the air baffle is located between the upper section of the air baffle and the lower section of the air baffle, and the middle section of the air baffle is symmetrically provided with a pair of reinforcing ribs and a pair of second openings.

[0010] Preferably, the top end of the outer shell is provided with a reducing agent nozzle for spraying reducing agent to the top end of the mixing pipe.

[0011] The mixing pipe includes a mixing inner pipe, a cyclone pipe and a mixing outer pipe, the cyclone pipe is located above the mixing outer pipe, the cyclone pipe forms the inlet of the mixing pipe, the lower section of the mixing outer pipe is provided with a plurality of third openings, and the bottom end of the mixing inner pipe, the bottom end of the mixing outer pipe and the third openings on the lower section of the mixing outer pipe form the outlet of the mixing pipe.

[0012] Preferably, the peripheral edge of the cyclone tube is provided with a plurality of vane windows, the vane windows are formed at a preset angle with the tangential direction, so that the gas entering the mixing tube through the vane windows forms a rotating shape.

[0013] Preferably, the baffle is provided with at least one valve assembly, and the at least one valve assembly is arranged in a closed state when the exhaust gas is less than a preset pressure, and in an open state when the exhaust gas exceeds the preset pressure to form a bypass channel between the upper cavity and the lower cavity; when the at least one valve assembly is in the closed state, all the exhaust gas enters the upper cavity through the air inlet, and then enters the mixing tube through the inlet; when the at least one valve assembly is in the open state, part of the exhaust gas enters the upper cavity through the air inlet, and then enters the mixing tube through the inlet; the other part of the exhaust gas directly enters the lower cavity through the bypass channel formed after the valve assembly is opened.

[0014] Preferably, the bottom end of the mixing tube is provided with a W-shaped arc plate, and the mixed gas enters the lower cavity through the W-shaped arc plate.

[0015] Preferably, the bottom of the W-shaped arc plate is provided with a plurality of fourth openings, and both ends of the W-shaped arc plate have outward extending parts.

[0016] The second aspect of the utility model provides an exhaust gas aftertreatment system, its main feature is, including the mixer with the air baffle.

[0017] Preferably, the system comprises a DOC and an intake assembly, a DPF assembly, an SCR and an exhaust assembly, the DOC and the intake assembly, the DPF assembly and the air inlet of the mixer are in communication, the DPF assembly is located between the DOC and the intake assembly and the air inlet of the mixer, and the SCR and the exhaust assembly are in communication with the air outlet of the mixer.

[0018] The mixer with the air baffle and the corresponding exhaust gas aftertreatment system of the utility model increase the air baffle between the air outlet of the baffle and the lower section of the mixing tube, which is more conducive to adjusting the uniformity of the airflow and the uniformity of ammonia, and using the W-shaped arc plate can effectively reduce and eliminate crystallization, achieve the purpose of controlling the overall back pressure, adjusting the airflow and ammonia distribution of the air outlet, effectively improving the uniformity index of the gas and ammonia before SCR, and further improving the reduction reaction capacity with nitrogen oxides. BRIEF DESCRIPTION OF DRAWINGS

[0019] To more clearly illustrate the technical scheme in the embodiments of the utility model, the following briefly introduces the drawings needed to be used in the embodiments.

[0020] To more clearly illustrate the technical scheme in the embodiments of the utility model, the following briefly introduces the drawings needed to be used in the embodiments.Figure 1 It is a structural schematic view of the exhaust aftertreatment system of the utility model.

[0021] Figure 2 It is a principle simplified view of the exhaust aftertreatment system of the utility model.

[0022] Figure 3 It is a structural schematic view of the mixer of the utility model.

[0023] Figure 4 It is an explosion schematic view of the mixer of the utility model.

[0024] Figure 5 It is a working principle explanatory schematic view of the mixer of the utility model.

[0025] Figure 6 It is a structural schematic view of the valve assembly in the mixer of the utility model.

[0026] Figure 7A And Figure 7B It is a structural schematic view of the mixing pipe in the mixer of the utility model.

[0027] Reference signs

[0028] 1 DOC and intake subassembly;2 DPF subassembly;3 mixer;4 clamp;5 SCR and exhaust subassembly;6 bandage support;7 reducing agent nozzle;8 valve assembly;801 valve cover plate;802 valve seat;803 torsional spring;804 shaft rod;9 mixing pipe;901 cyclone pipe;902 mixing outer pipe;903 mixing inner pipe;10 heat shield;11 heat insulation cotton;12 outer shell;13 partition;14 W-shaped arc plate;15 sealing plate;151 air inlet;152 air outlet;16 nozzle mounting seat;17 exhaust baffle;1701 arc convex part;1702 first opening;1703 reinforcing rib;1704 second opening;18 nozzle seat fixing plate. DETAILED DESCRIPTION

[0029] In order to be able to more clearly describe the technical content of the utility model, the following is further described in combination with specific embodiments.

[0030] For example, Figures 1 to 2The figure shows a specific embodiment of the exhaust after-treatment system of the present invention. The exhaust after-treatment system includes the mixer 3, a DOC and an air intake subassembly 1, a DPF subassembly 2, an SCR and an air outlet subassembly 5. The DOC (Diesel Oxidation Catalyst) is a diesel oxidation catalyst, the DPF (Diesel Particulate Filter) is a diesel particulate filter, and the SCR (Selective Catalytic Reduction) is a selective catalytic reduction device. The DOC, DPF, and SCR subassemblies all contain catalyst carriers. The DOC and air intake subassembly 1 and the DPF subassembly 2 are connected to the air inlet of the mixer 3. The DPF subassembly 2 is located between the DOC and air intake subassembly 1 and the air inlet of the mixer 3. The SCR and air outlet subassembly 5 are connected to the air outlet of the mixer 3. The DOC and the air intake sub-assembly 1, the DPF sub-assembly 2, the mixer 3, the SCR and the air outlet sub-assembly 5 can be connected and fixed by flanges, clamps or welding.

[0031] In this embodiment, two clamps 4 are used, one clamp 4 is used to fix the connection between the mixer and the DPF sub-assembly, and the other clamp is used to fix the connection between the mixer and the SCR and the gas outlet sub-assembly 5, so as to achieve the function of connection fixation and sealing.

[0032] In this embodiment, a strap bracket 6 is used to achieve installation and fixation of the after-treatment system to the vehicle. On the one hand, it is fixed to the outer surface of the after-treatment system through a strap, and on the other hand, it is connected to the installation position of the vehicle through the mounting holes on the strap bracket.

[0033] like Figure 2 As shown, based on the connection relationship of the various components of the exhaust after-treatment system of the present invention, the engine's high-temperature exhaust gas (exhaust) passes through the internal cavity formed by the DOC and the intake sub-assembly 1, the DPF sub-assembly 2, the mixer 3, the SCR and the exhaust sub-assembly 5 in sequence, and the engine's high-temperature exhaust gas and the reducing agent are mixed inside the mixer 3, and the catalytic reduction reaction is carried out in the rear-stage SCR and the exhaust sub-assembly 5, and then the exhaust gas that meets the requirements is discharged.

[0034] like Figures 3 to 5 The figure shows an embodiment of a mixer 3 with an air outlet baffle according to the present invention. The mixer 3 comprises an outer shell 12, a sealing plate 15, and a mixing tube 9. The outer shell 12 and sealing plate 15 enclose a mixing chamber. In this embodiment, a heat insulating cotton 11 and a heat insulating cover 10 are sequentially arranged on the outside of the outer shell 12.

[0035] The mixing cavity is provided with a partition plate 13 which can be fixed to the inner surface of the outer shell 12. The partition plate 13 divides the mixing cavity into two cavities, an upper cavity and a lower cavity. The sealing plate 15 is provided with an air inlet 151 corresponding to the upper cavity and an air outlet 152 corresponding to the lower cavity. The mixing pipe 9 extends downward from the upper cavity and penetrates the partition plate 13 to the lower cavity, that is, the mixing pipe 9 penetrates between the upper cavity and the lower cavity. The upper section of the mixing pipe 9 is provided with an inlet, and the lower section of the mixing pipe 9 is provided with an outlet. Exhaust gas enters the upper cavity through the air inlet 151, enters the mixing pipe 9 through the inlet, mixes with the reducing agent in the mixing pipe 9, and then the mixed gas enters the lower cavity through the outlet. The air outlet 152 of the sealing plate 15 and the lower section of the mixing pipe 9 are provided with an air baffle 17. The air baffle 17 closes part of the air outlet 152. The air baffle 17 is provided with a plurality of first openings 1702, so that the mixed gas is discharged through the area of the air outlet which is not closed by the air baffle 17 and the first openings 1702 of the air baffle 17.

[0036] In the mixer with an air baffle according to the present application, the air baffle is additionally arranged between the air outlet of the sealing plate and the lower section of the mixing pipe, which can effectively adjust the gas uniformity index and ammonia uniformity index of the SCR end face, and can effectively prevent urea liquid or crystals from penetrating through the mixer components from the bottom to block the SCR catalyst of the SCR end face.

[0037] As shown in Figures 3 to 5 The air baffle 17 is a semicircular plate structure which matches the profile of the lower half of the air outlet 152 to close the bottom and lower half of the air outlet 152.

[0038] The middle region of the air baffle 17 has an arc-shaped protruding portion 1701 which protrudes towards the air outlet. The arc-shaped protruding portion 1701 corresponds to the mixing pipe 9 and extends along the longitudinal axis of the mixing pipe 9. The arc-shaped protruding portion can conform to the shape of the mixing pipe, which is beneficial to the adjustment of gas uniformity and ammonia uniformity.

[0039] The first opening 1702 is distributed on the upper section of the air outlet baffle 17 and the lower section of the air outlet baffle 17, the middle section of the air outlet baffle 17 is located between the upper section of the air outlet baffle 17 and the lower section of the air outlet baffle 17, and the middle section of the air outlet baffle 17 is symmetrically provided with a pair of reinforcing ribs 1703 and a pair of second openings 1704. In this embodiment, the reinforcing ribs are X-shaped, which can improve the structural strength of the part, and the shape can also be a cross or a diagonal line or other shapes. The second opening has a larger hole diameter than the first opening, which can adjust the operation of the gas and ammonia gas, and also serves as a production tool fixing hole.

[0040] As shown in Figure 4 The bottom end of the mixing pipe 9 is provided with a W-shaped arc plate 14, and the mixed gas enters the lower cavity through the W-shaped arc plate and is discharged through the air outlet 152. The arc plate is W-shaped, and the W-shaped body has a middle protruding structure and a bottom two-side circular arc structure, which can effectively prevent the deposition of urea and urea crystals; at the same time, the W-shaped body can effectively guide the airflow and urea droplets, reducing the risk of crystallization.

[0041] The bottom of the W-shaped arc plate 14 is provided with a plurality of fourth openings, through which high-temperature gas can enter the space formed by the W-shaped arc plate and the mixer shell to remove the crystals that may be formed in the space. At the same time, the high-temperature body can heat the W-shaped arc plate from the bottom space of the W-shaped arc plate, which is beneficial to the evaporation of urea and the removal of urea crystals.

[0042] Both ends of the W-shaped arc plate 14 have outward extensions, which can prevent urea from entering the lower part from both sides. The airflow on both sides is less than the middle, which is beneficial to the evaporation of urea. On the other hand, the outward extensions are fixed on the mixer shell.

[0043] The gas mixed in the mixing pipe 9 flows out through the W-shaped arc plate 14. In addition to the function of fixing and supporting the mixing pipe 9, the W-shaped arc plate 14 can effectively prevent the deposition of crystals and adjust the flow direction of the gas, thereby improving the uniformity index of the exhaust gas and ammonia gas before SCR.

[0044] As shown in Figures 3 to 6 The partition plate 13 is provided with a pair of valve assemblies 8, and the pair of valve assemblies 8 are symmetrically arranged on both sides of the mixing pipe 9. The valve assembly 8 is arranged in a closed state when the exhaust gas is less than a preset pressure, and in an open state when the exhaust gas exceeds the preset pressure to form a bypass channel between the upper cavity and the lower cavity.

[0045] Specifically, when the pressure value of the valve assembly 8 is less than the preset opening pressure of the valve assembly 8, the valve assembly 8 is in a closed state, and all gases enter the interior of the mixing tube 9 through the inlet of the upper section of the mixing tube 9, and are mixed with the reducing agent sprayed from the reducing agent nozzle 7 inside the mixing tube 9. The mixed gas flows out from the internal channel of the mixing tube 9 through the outlet into the lower cavity, enters the SCR and the gas outlet sub-assembly and is discharged.

[0046] When the pressure of the valve assembly 8 is greater than or equal to the preset opening pressure of the valve assembly 8, the valve assembly 8 is in the open state. Part of the gas enters the interior of the mixing tube 9 through the inlet of the upper section of the mixing tube 9, mixes with the reducing agent sprayed from the reducing agent nozzle 7 inside the mixing tube 9, and the mixed gas flows out from the internal channel of the mixing tube 9 through the outlet, enters the SCR and the gas outlet sub-assembly for discharge; the other part of the gas passes through the bypass channel formed by the open valve assembly 8, directly enters the lower cavity of the mixing chamber, enters the SCR and the gas outlet sub-assembly for discharge.

[0047] In the mixer embodiment of the present invention, the valve assembly is located outside the mixing tube 9, allowing direct bypass of the high-temperature exhaust gas. This means that the majority of the high-temperature exhaust gas remains mixed with the reducing agent within the mixing tube 9, while a small portion of the high-temperature exhaust gas bypasses the mixing tube and directly passes to the mixer's outlet without mixing. By controlling the bypass of the valve assembly, the mixer system's back pressure can be adjusted; the bypassed high-temperature gas can directly heat the outer wall of the mixing tube, reducing or eliminating the risk of urea crystallization; and the bypassed high-temperature gas can directly heat the outer wall of the mixing tube, increasing the urea evaporation rate and, consequently, improving nitrogen oxide removal efficiency. By controlling the valve assembly's opening, the SCR surface airflow and ammonia uniformity index can be adjusted.

[0048] The number of the valve assemblies 8 may be one or more, and the valve diameter of the valve assembly 8 may also vary, which is not limited in the present invention.

[0049] A reducing agent nozzle 7 is disposed at the top of the outer shell 12 for injecting a reducing agent, such as a urea-water solution, into the top of the mixing tube 9. The reducing agent nozzle 7 is fixedly mounted on a nozzle mounting bracket 16, which is mounted in an opening at the top of the outer shell 12 via a nozzle mounting bracket 18. The reducing agent nozzle 7 injects the reducing agent into the interior of the mixing tube 9.

[0050] like Figures 3 to 7B As shown, the mixing tube 9 includes an inner mixing tube 903, which is outer-mounted with a swirl tube 901 and an outer mixing tube 902. The swirl tube 901 is located above the outer mixing tube 902. That is, the swirl tube 901 is connected to the outer mixing tube 902 to form a gas and reducing agent mixing cavity, and the inner mixing tube 903 is located inside the mixing cavity formed by the outer mixing tube and the swirl tube.

[0051] The swirl tube 901 forms the inlet of the mixing tube 9. The gas enters the outer mixing tube 902 and the inner mixing tube 903 through the swirl tube 901 and is fully mixed with the reducing agent injected by the reducing agent nozzle 7. The lower wall of the outer mixing tube 902 is provided with several third openings. The bottom end of the inner mixing tube 903, the bottom end of the outer mixing tube 902, and the openings on the lower wall of the outer mixing tube 902 form the outlet of the mixing tube. In other words, the opening of the outer mixing tube 902 within the lower cavity serves as part of the outlet, and the bottom opening of the mixing tube 9 (the bottom end of the inner mixing tube 903 and the bottom end of the outer mixing tube 902) serves as another part of the outlet, that is, the mixed gas will flow out through the openings and the bottom channel.

[0052] The circumference of the swirl tube 901 is provided with a plurality of blade windows, and the blade windows form a preset angle with the tangent direction, so that the gas forms a rotating shape when passing through the blade windows and entering the mixing tube.

[0053] like Figure 7A As shown, the mixing inner tube 903 is provided with several blades facing inward or outward to enhance the swirl effect; at the same time, the mixing inner tube 903 is provided with several small holes for adjusting the airflow and back pressure.

[0054] like Figure 5 and Figure 6 As shown, the partition 13 is provided with a mounting hole. The valve assembly 8 includes a valve cover plate 801, a valve seat 802 having a through hole, and an elastic member 803. The through hole of the valve seat 802 is aligned with the mounting hole and mounted. The valve cover plate 801 is connected to the valve seat 802 in an openable and closable manner via the elastic member 803. The elastic force of the elastic member 803 controls the degree of opening and closing of the valve cover plate 801 under different exhaust pressures, and the opening and closing of the valve assembly 8 is controlled by the opening and closing of the valve cover plate 801. The opening angle of the valve cover plate 801 is related to the pressure difference between the upper and lower parts of the valve cover plate 801. The larger the opening angle, the greater the elastic force of the elastic member.

[0055] The valve assembly 8 can be directly and independently fixed on the baffle 13, or the baffle structure itself can be used as a valve seat, and the elastic member and valve cover plate are directly placed on the baffle, that is, the entire baffle acts as a bypass valve mechanism.

[0056] In this embodiment, the elastic member 803 is a torsion spring, which is passed through a shaft 804, which is mounted on the valve seat 802. One end of the torsion spring abuts against the valve cover plate 801, and the other end of the torsion spring abuts against the valve seat 802. The valve cover plate 801 opens and closes around the shaft 804 under the elastic force of the torsion spring.

[0057] The mixer with the air outlet baffle and the corresponding exhaust aftertreatment system, air outlet baffles are additionally arranged between the air outlet of the sealing plate and the lower section of the mixing pipe, which is more conducive to adjusting the air flow uniformity and ammonia uniformity, and W-shaped arc plates are used, which can effectively reduce and eliminate crystallization, achieve the purposes of controlling overall back pressure, adjusting air flow and ammonia distribution of the air outlet, effectively improving the uniformity index of the gas and ammonia before SCR, and further improving the reduction reaction capacity with nitrogen oxides.

[0058] In this specification, the utility model has been described with reference to its specific embodiments. However, it is obvious that various modifications and changes can still be made without departing from the spirit and scope of the utility model. Therefore, the specification and drawings should be considered as illustrative rather than restrictive.

Claims

1. A mixer with an air baffle, characterized in that The mixer comprises an outer casing, a cover plate, and a mixing pipe. The outer casing and the cover plate enclose a mixing cavity. The mixing cavity is provided with a partition plate which separates the mixing cavity into an upper cavity and a lower cavity. The cover plate is provided with an air inlet corresponding to the upper cavity and an air outlet corresponding to the lower cavity. The mixing pipe extends downward from the upper cavity and passes through the partition plate to the lower cavity. An upper section of the mixing pipe is provided with an inlet, and a lower section of the mixing pipe is provided with an outlet. Exhaust gas enters the upper cavity through the air inlet, enters the mixing pipe through the inlet, mixes with a reducing agent in the mixing pipe, and then enters the lower cavity through the outlet. An air baffle is arranged between the air outlet of the cover plate and the lower section of the mixing pipe. The air baffle covers part of the air outlet. The air baffle is provided with a plurality of first openings. Mixed gas is discharged through the area of the air outlet which is not covered by the air baffle and the first openings of the air baffle.

2. The mixer with an air baffle according to claim 1, characterized in that, The air baffle is a semicircular plate structure which matches the profile of the lower half of the air outlet to cover the bottom of the air outlet.

3. The vented baffle-equipped mixer of claim 1, wherein, The middle region of the air baffle has an arc-shaped protrusion which protrudes towards the air outlet. The arc-shaped protrusion is arranged corresponding to the mixing pipe and extends along a direction parallel to the longitudinal axis of the mixing pipe.

4. The mixer with an air baffle according to claim 2, characterized in that, The first openings are distributed in the upper section and the lower section of the air baffle. The middle section of the air baffle is located between the upper section and the lower section of the air baffle. The middle section of the air baffle is symmetrically provided with a pair of reinforcing ribs and a pair of second openings.

5. The vented baffle-equipped mixer of any one of claims 1 to 4, wherein, The bottom end of the mixing pipe is provided with a W-shaped arc plate. Mixed gas enters the lower cavity through the W-shaped arc plate.

6. The mixer with an air baffle according to claim 5, characterized in that The bottom of the W-shaped arc plate is provided with a plurality of fourth openings. The two ends of the W-shaped arc plate each have an outward extension.

7. The vented baffle-equipped mixer of claim 1, wherein, The top end of the outer casing is provided with a reducing agent nozzle for spraying reducing agent to the top end of the mixing pipe. The mixing pipe comprises a mixing inner pipe, a vortex pipe, and a mixing outer pipe. The vortex pipe is located above the mixing outer pipe. The vortex pipe forms the inlet of the mixing pipe. The lower section of the mixing outer pipe is provided with a plurality of third openings. The bottom end of the mixing inner pipe, the bottom end of the mixing outer pipe, and the third openings on the lower section of the mixing outer pipe form the outlet of the mixing pipe.

8. The vented baffle-equipped mixer of claim 1, wherein, The partition plate is provided with at least one valve assembly. When the exhaust gas is less than a preset pressure, the at least one valve assembly is in a closed state. When the exhaust gas exceeds the preset pressure, the at least one valve assembly is in an open state to form a bypass channel between the upper cavity and the lower cavity. When the at least one valve assembly is in the closed state, all exhaust gas enters the upper chamber through the intake port and enters the mixing pipe through the inlet; when the at least one valve assembly is in the open state, part of the exhaust gas enters the upper chamber through the intake port and enters the mixing pipe through the inlet; another part of the exhaust gas directly enters the lower chamber through the bypass channel formed after the valve assembly is opened.

9. An exhaust gas aftertreatment system characterized by, The mixer with the exhaust baffle according to any one of claims 1 to 8.

10. The exhaust gas aftertreatment system of claim 9, wherein, The system comprises a DOC and intake subassembly, a DPF subassembly, an SCR and an exhaust subassembly, the DOC and intake subassembly and the DPF subassembly are communicated with the intake port of the mixer, the DPF subassembly is located between the DOC and intake subassembly and the intake port of the mixer, and the SCR and the exhaust subassembly are communicated with the exhaust port of the mixer.

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