U-type platform post-treatment urea mixing device

Abstract

The present invention discloses a post-processing urea mixing device for a U-shaped platform, wherein an air inlet is provided at the upper part of the front shell, and an air outlet is provided at the lower part; an air inlet baffle is provided on the air inlet, a transverse partition is provided between the air inlet baffle and the rear shell, a central tube is inserted on the transverse partition, and an air outlet assembly is connected to the lower end of the central tube; a plurality of lower air inlets are provided on the central tube and on the wall surface of the tube body located in the external air cavity, and a plurality of first air outlets and a plurality of third air outlets are provided on the air outlet assembly. The airflow in the external air cavity of the present invention can enter the second mixing cavity through the plurality of lower air inlets, and mix again with the new mixed gas in the second mixing cavity in a new round, so that the airflow in the external air cavity can achieve the effect of re-mixing, further improving the mixing effect and mixing uniformity, and reducing the risk of urea crystallization. No crushing plate is provided in the mixing cavity of the present invention, and the airflow has a smaller flow resistance in the mixing cavity, a smaller back pressure value, and a smoother flow.

Description

Technical Field

[0001] The invention relates to the technical field of automobile exhaust post-treatment, in particular to a post-treatment urea mixing device for a U-shaped platform. Background Art

[0002] With the implementation of the National VI emission regulations, the country has become more and more stringent in terms of engine emission limits. At present, diesel engines usually use DOC (oxidation catalyst) + DPF (particulate filter) + SCR (selective catalytic reduction) technology to post-treat exhaust emissions. Among them, the SCR part mainly converts the urea solution injected by the urea injection system into ammonia (NH 3 ), and NO in diesel exhaust x (nitrogen oxides) are mixed and reduced to nitrogen (N 2 ) and water (H 2 O).

[0003] The existing post-treatment urea mixer is usually provided with a crushing plate with a plurality of through holes. When in use, urea crystals are easily formed at the holes of the crushing plate, which reduces the conversion efficiency of the post-treatment. Moreover, due to the presence of the crushing plate, the mixer has a large back pressure value, resulting in large engine losses. Summary of the invention

[0004] In view of the shortcomings of the above-mentioned existing post-processing urea mixers, the applicant provides a post-processing urea mixing device for a U-shaped platform with a reasonable structure, which reduces the risk of urea crystallization and has a small back pressure value.

[0005] The technical solution adopted by the present invention is as follows:

[0006] A post-treatment urea mixing device for a U-shaped platform, wherein an internal cavity is formed between a front shell and a rear shell; an air inlet is provided at the upper portion of the front shell, and an air outlet is provided at the lower portion; an air inlet baffle is provided on the air inlet, a transverse partition is provided between the air inlet baffle and the rear shell, a central tube is inserted through the transverse partition, and an air outlet assembly is connected to the lower end of the central tube; in the internal cavity, the cavity located on the upper side of the transverse partition and the outer side of the central tube is the air inlet cavity, the cavity in the central tube is the second mixing cavity, the internal cavity of the air outlet assembly is the inner air outlet cavity, and the cavity located on the transverse partition is the inner air outlet cavity. The cavity on the lower side and the inner side of the air inlet baffle and the outer side of the central tube and the air outlet assembly is the outgoing air cavity; the air inlet cavity is connected to the air inlet port, the air inlet cavity, the second mixing cavity and the inner air outlet cavity are connected in sequence, and the outgoing air cavity is connected to the air outlet port; a plurality of lower air inlet holes are provided on the wall of the tube body located on the central tube in the outgoing air cavity, and the lower air inlet holes connect the outgoing air cavity and the second mixing cavity; a plurality of first air outlet holes and a plurality of third air outlet holes are provided on the air outlet assembly, the first air outlet holes connect the inner air outlet cavity and the air outlet, and the third air outlet holes connect the inner air outlet cavity and the outgoing air cavity.

[0007] As a further improvement of the above technical solution:

[0008] A guide vane is arranged on the lower air inlet of the central tube, and the guide vane tilts inwardly and obliquely downwardly toward the interior of the central tube.

[0009] The third air outlet of the air outlet component is provided with swirl blades, which are turned outward obliquely toward the outgoing air cavity, and each swirl blade opens in the same direction.

[0010] The air outlet assembly includes a lower guide plate, a front air outlet baffle and a rear air outlet baffle, which are respectively sealed on the front and rear end surfaces of the lower guide plate; a plurality of first air outlet holes are opened on the front air outlet baffle, and a plurality of third air outlet holes are opened on the rear air outlet baffle.

[0011] A plurality of first air outlet holes are radially divergent and distributed around the same circle on the surface of the front air outlet baffle plate, and a second air outlet hole is also provided on the surface of the front air outlet baffle plate; a plurality of third air outlet holes are radially divergent and distributed around the same circle on the surface of the rear air outlet baffle plate, and a fourth air outlet hole is also provided on the surface of the rear air outlet baffle plate.

[0012] The lower guide plate includes a symmetrically arranged lower arc surface and a V-shaped protrusion protruding toward the inner air outlet cavity. A vertical connecting piece is provided on the top of the lower arc surface, and the upper side edge of the connecting piece is welded and fixed on the central tube; the lower arc surface is an outward convex arc surface with a horizontal central axis; the outer contour dimensions of the front air outlet baffle and the rear air outlet baffle match the outer contour dimensions of the lower guide plate.

[0013] A diverter plate is arranged on the inner side of the lower guide plate. The diverter plate is a V-shaped plate with its opening facing downwards. The diverter surfaces on both sides of the diverter plate are outward convex arc surfaces with a horizontal central axis.

[0014] An upper guide plate is vertically inserted into the upper inner part of the central tube to form an interlayer cavity between the central tube and the upper guide plate, which connects the air inlet cavity and the second mixing cavity. The inner side of the upper guide plate is the first mixing cavity, which connects the second mixing cavity. An air inlet channel is provided on the upper guide plate, which connects the first mixing cavity with the air inlet and the air inlet cavity.

[0015] The upper guide plate is a U-shaped plate with its opening facing the air inlet, and its opening constitutes an air inlet channel; the upper guide plate includes a symmetrically arranged upper curved surface and a vertical plane, and the upper curved surface is an outwardly convex curved surface with a vertical central axis.

[0016] The central tube is a rectangular tube; an upper air inlet hole is provided on the front wall of the tube body located in the air inlet cavity, the upper air inlet hole connects the air inlet port and the interlayer cavity, and a lower air inlet hole is provided on the rear wall of the central tube; a support sheet is provided between the air outlet assembly and the inner wall of the rear shell; the top of the rear shell has an inclined plane, the inclined plane has an installation hole, and the installation hole faces the first mixing chamber.

[0017] The beneficial effects of the present invention are as follows:

[0018] The airflow in the outgoing air cavity of the present invention can enter the second mixing cavity through a plurality of lower air inlet holes, and mix with the new mixed gas in the second mixing cavity again, so that the airflow in the outgoing air cavity can achieve the effect of remixing, further improving the mixing effect and mixing uniformity, and reducing the risk of urea crystallization. The mixing cavity of the present invention does not have a breaking plate, and the airflow has a smaller flow resistance in the mixing cavity, a smaller back pressure value, and a smoother flow.

[0019] The guide vanes on the lower air inlet of the present invention can guide the airflow to accelerate in the oblique downward direction into the central tube, which is more conducive to the rapid and full mixing of the incoming airflow with the airflow in the second mixing chamber, thereby improving the mixing effect; the guide vanes can also provide a shielding effect for the urea droplets, thereby preventing the airflow from directly blowing the urea droplets and sweeping the urea droplets onto the rear inner wall surface of the central tube, thereby reducing the risk of urea crystallization in the central tube; the guide vanes 53 inclined obliquely downward also have a guiding effect on the urea droplets falling thereon, and the urea droplets will slide downward along the guide vanes instead of adhering to the guide vanes, thereby avoiding the formation of urea crystals by residual urea droplets and reducing the risk of urea crystallization.

[0020] The swirl blades on the third air outlet of the present invention guide the airflow to flow in the same direction, so that the airflow produces a strong swirl effect, so that the urea droplets and the airflow are mixed more fully, the mixing effect is better, and the mixing uniformity is higher.

[0021] The first and third air outlets of the present invention are radially divergent and distributed on the board surface around the same circumference, so that the airflow in the inner air outlet cavity can be discharged more evenly, which is conducive to the airflow spreading to the surroundings and blowing in different directions after passing through the first air outlet hole 731, thereby improving the uniformity of airflow distribution. The second and fourth air outlets are located in the center of the board surface, and the airflow in the central area of ​​the inner air outlet cavity can flow out through the second and fourth air outlets, thereby improving the uniformity of the airflow and blowing away the urea droplets.

[0022] The lower curved surface of the lower guide plate of the present invention can guide the airflow to flow along the wall surface of the lower guide plate, flush the wall surface of the lower guide plate, effectively reduce the urea droplets remaining on the wall surface of the lower guide plate, and reduce the risk of urea crystallization. The raised portion can turn the airflow in the inner air outlet cavity to form a rotating airflow, improve the mixing effect and mixing uniformity of the airflow and urea droplets, and reduce the risk of urea crystallization.

[0023] The splitter plate of the present invention can split the airflow entering the inner air outlet cavity into two left and right streams. The two airflows are guided by the splitter surfaces on both sides and then merge towards each other. The two airflows violently intersect and collide, so that the exhaust gas and the urea droplets are violently mixed, further improving the mixing effect and mixing uniformity of the airflow and the urea droplets.

[0024] The airflow of the interlayer cavity of the present invention flows downward along the inner wall surface of the central tube and the outer wall surface of the upper guide plate, and while heating the central tube and the wall surface of the upper guide plate, it also continuously flushes the inner wall surface of the central tube, which can effectively reduce the urea droplets remaining on the wall surface of the central tube and the upper guide plate, and reduce the risk of urea crystallization. The airflow of the interlayer cavity flows downward and merges with the airflow flowing down from the first mixing cavity in the second mixing cavity to form an airflow disturbance phenomenon, which can promote the mixing of the airflow and the urea droplets, improve the mixing effect and mixing uniformity, and reduce the risk of urea crystallization.

[0025] The upper curved surface of the upper guide plate of the present invention can guide the airflow to flow along the wall surface of the upper guide plate, flush the wall surface of the upper guide plate, effectively reduce the urea droplets remaining on the wall surface of the upper guide plate, and reduce the risk of urea crystallization.

[0026] The support sheet of the present invention can improve the support strength of the central tube and the air outlet assembly and improve the connection reliability. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is the front view of the present invention.

[0028] Figure 2 It is an exploded view of the present invention.

[0029] Figure 3 It is a three-dimensional cutaway view of the present invention.

[0030] Figure 4 It is a front-to-back longitudinal cross-sectional view of the present invention.

[0031] Figure 5 It is a left-right longitudinal cross-sectional view of the present invention.

[0032] In the figure: 1, front housing; 11, air inlet; 12, air outlet; 2, rear housing; 21, inclined plane; 22, mounting hole;

[0033] 3. Inlet baffle; 4. diaphragm; 5. center tube; 51. upper air inlet hole; 52. lower air inlet hole; 53. guide vane; 6. upper guide plate; 61. upper side arc surface; 62. vertical plane; 63. air inlet channel;

[0034] 7. Air outlet assembly; 71. Lower guide plate; 711. Lower arc surface; 712. Raised portion; 713. Connecting plate; 72. Diverter plate; 721. Diverter surface; 73. Front air outlet baffle; 731. First air outlet hole; 732. Second air outlet hole; 74. Rear air outlet baffle; 741. Third air outlet hole; 742. Swirl blade; 743. Fourth air outlet hole; 8. Support plate;

[0035] 10. Air inlet cavity; 20. Interlayer cavity; 30. First mixing cavity; 40. Second mixing cavity; 50. Inner air outlet cavity; 60. Outer air outlet cavity. DETAILED DESCRIPTION

[0036] The specific implementation of the present invention will be described below in conjunction with the accompanying drawings.

[0037] like Figures 1 to 3 As shown, the cross section of the whole invention along the longitudinal axis is in the shape of a peanut shell, and the front shell 1 is fixed on the rear shell 2, and an internal cavity is formed between the front shell 1 and the rear shell 2; the upper part of the front shell 1 has a cylindrical air inlet 11, and the lower part has a cylindrical air outlet 12, and the air inlet 11 and the air outlet 12 are connected to the internal cavity. The top of the rear shell 2 has an inclined plane 21, and the inclined plane 21 is provided with a mounting hole 22, and the mounting hole 22 is used to insert the nozzle seat, and a urea nozzle (not shown in the figure) is arranged in the nozzle seat, and the urea nozzle can spray urea droplets toward the internal cavity.

[0038] like Figure 1 , Figure 2 , Figure 4 As shown, a semicircular air inlet baffle 3 is vertically arranged at the lower half of the air inlet 11, and a transverse partition 4 is horizontally arranged between the inner side of the air inlet baffle 3 and the inner wall of the rear shell 2, and the transverse partition 4 is fixed to the wall of the air inlet baffle 3 and the rear shell 2 by welding. A central tube 5 is vertically inserted through the transverse partition 4, and there is a gap between the upper end of the central tube 5 and the upper inner wall of the rear shell 2. An upper guide plate 6 is vertically inserted into the upper inner part of the central tube 5, and the upper side of the upper guide plate 6 is welded and fixed to the upper wall of the rear shell 2. The lower end of the central tube 5 is connected to the outlet assembly 7, and the outlet assembly 7 is directly opposite to the air outlet 12; a support sheet 8 is welded and fixed between the rear side of the outlet assembly 7 and the inner wall of the rear shell 2, and the support sheet 8 can improve the support strength of the central tube 5 and the outlet assembly 7, and improve the connection reliability. In the internal cavity between the front shell 1 and the rear shell 2, the cavity located on the upper side of the diaphragm 4 and the outer side of the center tube 5 constitutes an air inlet cavity 10, and the air inlet cavity 10 is connected to the air inlet port 11; the cavity on the inner side of the upper guide plate 6 constitutes a first mixing cavity 30, and the mounting hole 22 of the rear shell 2 faces the first mixing cavity 30; in the center tube 5, the cavity located on the outer side of the upper guide plate 6 constitutes an interlayer cavity 20, and the cavity located below the upper guide plate 6 constitutes a second mixing cavity 40, and the interlayer cavity 20 connects the air inlet cavity 10 and the second mixing cavity 40, and the second mixing cavity 40 is connected to the first mixing cavity 30; the internal cavity of the air outlet component 7 constitutes an inner air outlet cavity 50, and the inner air outlet cavity 50 is connected to the second mixing cavity 40; the cavity on the lower side of the diaphragm 4, the inner side of the air inlet baffle 3, and the outer side of the center tube 5 and the air outlet component 7 constitute an outer air cavity 60, and the outer air cavity 60 is connected to the air outlet port 12.

[0039] like Figure 2As shown, the central tube 5 is a rectangular tube, and an upper air inlet hole 51 is provided on the front wall of the tube body of the central tube 5 located in the air inlet cavity 10. The upper air inlet hole 51 connects the air inlet port 11 and the interlayer cavity 20. The airflow of the air inlet port 11 and the air inlet cavity 10 can enter the interlayer cavity 20 through the upper air inlet hole 51, and the airflow of the air inlet cavity 10 can also enter the interlayer cavity 20 through the upper end of the central tube 5. The airflow of the interlayer cavity 20 flows downward along the inner wall surface of the central tube 5 and the outer wall surface of the upper guide plate 6. While heating the wall surfaces of the central tube 5 and the upper guide plate 6, the inner wall surface of the central tube 5 is continuously flushed, which can effectively reduce the urea droplets remaining on the wall surfaces of the central tube 5 and the upper guide plate 6, and reduce the risk of urea crystallization. The airflow in the interlayer chamber 20 flows downward and merges with the airflow from the first mixing chamber 30 in the second mixing chamber 40 to form an airflow disturbance phenomenon, which can promote the mixing of the airflow and the urea droplets, improve the mixing effect and mixing uniformity, and reduce the risk of urea crystallization. Figure 3 , Figure 4 As shown, a plurality of rectangular lower air inlet holes 52 are provided on the rear wall surface of the tube body of the central tube 5 located in the outgoing air cavity 60 in sequence from top to bottom, and the lower air inlet holes 52 connect the outgoing air cavity 60 with the second mixing cavity 40; a guide blade 53 is provided on each lower air inlet hole 52, and the guide blade 53 tilts inward and obliquely downward toward the inside of the central tube 5; the airflow in the outgoing air cavity 60 can enter the second mixing cavity 40 through the plurality of lower air inlet holes 52, and mix again with the new mixed gas in the second mixing cavity 40 in a new round, so that the airflow in the outgoing air cavity 60 can achieve the effect of remixing, further improve the mixing effect and mixing uniformity, and reduce the risk of urea crystallization; the guide blade 53 is provided on each lower air inlet hole 52, and the guide blade 53 is tilted inward and obliquely downward toward the inside of the central tube 5; the airflow in the outgoing air cavity 60 can enter the second mixing cavity 40 through the plurality of lower air inlet holes 52, and mix again with the new mixed gas in the second mixing cavity 40, so that the airflow in the outgoing air cavity 60 can achieve the effect of remixing, further improve the mixing effect and mixing uniformity, and reduce the risk of urea crystallization; The blades 53 can guide the airflow to accelerate into the central tube 5 in the oblique downward direction, which is more conducive to the rapid and full mixing of the incoming airflow with the airflow in the second mixing chamber 40, thereby improving the mixing effect; the guide blades 53 can also provide a shielding effect for the urea droplets, preventing the airflow from directly blowing the urea droplets and sweeping the urea droplets onto the rear inner wall surface of the central tube 5, thereby reducing the risk of urea crystallization in the central tube 5; the guide blades 53 inclined obliquely downward also have a guiding effect on the urea droplets falling thereon, and the urea droplets will slide downward along the guide blades 53 instead of adhering to the guide blades 53, thereby avoiding the formation of urea crystals by residual urea droplets and reducing the risk of urea crystallization.

[0040] like Figure 2As shown, the upper guide plate 6 is an approximately U-shaped plate with an opening toward the air inlet 11, including an upper curved surface 61 symmetrically arranged on the left and right sides and a vertical plane 62 on the rear side. The front opening of the upper guide plate 6 constitutes an air inlet channel 63, and the air inlet channel 63 connects the first mixing chamber 30 with the air inlet 11 and the air inlet chamber 10. The gas in the air inlet 11 and the air inlet chamber 10 can enter the first mixing chamber 30 through the air inlet channel 63 to mix with urea droplets. The upper curved surfaces 61 on both sides are convex curved surfaces with a vertical central axis, which protrude toward the left and right sides of the air inlet chamber 10 respectively. The upper curved surfaces 61 can guide the airflow to flow along the wall surface of the upper guide plate 6, flush the wall surface of the upper guide plate 6, effectively reduce the urea droplets remaining on the wall surface of the upper guide plate 6, and reduce the risk of urea crystallization.

[0041] like Figure 2 As shown, the air outlet assembly 7 includes a lower guide plate 71, a splitter plate 72, a front air outlet baffle plate 73 and a rear air outlet baffle plate 74. The lower guide plate 71 is transversely arranged directly below the central tube 5, and the front air outlet baffle plate 73 and the rear air outlet baffle plate 74 are respectively sealed on the front and rear end surfaces of the lower guide plate 71, and the upper sides of the lower guide plate 71, the front air outlet baffle plate 73 and the rear air outlet baffle plate 74 are respectively welded and fixed on the lower end pipe opening of the central tube 5; the outer contour dimensions of the front air outlet baffle plate 73 and the rear air outlet baffle plate 74 match the outer contour dimensions of the lower guide plate 71, and the edges of the front air outlet baffle plate 73 and the rear air outlet baffle plate 74 are aligned and welded with the edges of the lower guide plate 71. The splitter plate 72 is transversely arranged on the inner side of the lower guide plate 71, and the front and rear sides of the splitter plate 72 are respectively welded and fixed on the front air outlet baffle plate 73 and the rear air outlet baffle plate 74.

[0042] like Figure 2 , Figure 5 As shown, the top surface and front and rear end surfaces of the lower guide plate 71 are open surfaces, the left and right side surfaces are symmetrically arranged lower side arc surfaces 711, and the bottom is provided with a V-shaped protrusion 712 protruding upward toward the inner outlet cavity 50; the top of the lower side arc surface 711 is provided with a vertical connecting piece 713, and the upper side edge of the connecting piece 713 is aligned with the lower end pipe mouth of the central tube 5 and welded and fixed. The lower side arc surfaces 711 on both sides are convex arc surfaces with horizontal central axes, which protrude to the left and right sides toward the outlet cavity 60 respectively. The lower side arc surfaces 711 can guide the airflow to flow along the wall surface of the lower guide plate 71, flush the wall surface of the lower guide plate 71, effectively reduce the urea droplets remaining on the wall surface of the lower guide plate 71, and reduce the risk of urea crystallization. The protrusion 712 can make the airflow in the inner outlet cavity 50 turn and form a rotating airflow, improve the mixing effect and mixing uniformity of the airflow and urea droplets, and reduce the risk of urea crystallization.

[0043] like Figure 2 , Figure 5As shown, the diverter plate 72 is a V-shaped plate with an opening facing downward, and its left and right sides are symmetrically arranged diverter surfaces 721, and the diverter surfaces 721 are convex arc surfaces with a horizontal central axis, which protrude to the left and right sides toward the outgoing air cavity 60 respectively; the diverter plate 72 can divide the airflow entering the inner outlet air cavity 50 into two left and right streams, and the two airflows are guided by the diverter surfaces 721 on both sides and then merge towards each other, and the two airflows violently intersect and collide, so that the exhaust gas and the urea droplets are violently mixed, and the mixing effect and mixing uniformity of the airflow and the urea droplets are further improved.

[0044] like Figure 1 , Figure 2 As shown, a plurality of rectangular first air outlet holes 731 are provided on the plate surface of the front air outlet baffle 73, and the first air outlet holes 731 connect the inner air outlet cavity 50 and the air outlet 12; the plurality of first air outlet holes 731 are radially divergent and distributed on the plate surface around the same circumference, so that the airflow of the inner air outlet cavity 50 can be discharged more evenly, which is conducive to the airflow to diffuse around and blow in different directions after passing through the first air outlet holes 731, thereby improving the uniformity of airflow distribution. A circular second air outlet hole 732 is also provided on the plate surface of the front air outlet baffle 73, located inside the plurality of first air outlet holes 731, and the opening area of ​​the second air outlet hole 732 is smaller than the opening area of ​​the first air outlet hole 731. The second air outlet hole 732 connects the inner air outlet cavity 50 and the air outlet 12, and the airflow in the central area of ​​the inner air outlet cavity 50 can flow out through the second air outlet hole 732, thereby improving the uniformity of the airflow and blowing away the urea drop point.

[0045] like Figures 2 to 4 As shown, a plurality of rectangular third air outlet holes 741 are provided on the plate surface of the rear air outlet baffle 74, and the third air outlet holes 741 connect the inner air outlet cavity 50 with the outer air outlet cavity 60; the plurality of third air outlet holes 741 are radially divergent and distributed on the plate surface around the same circumference, which is conducive to the diffusion of the air flow to all sides and blowing in different directions, thereby improving the mixing uniformity of the air flow; each third air outlet hole 741 is provided with a swirl blade 742, and the swirl blade 742 is obliquely turned outward toward the outer air cavity 60, and each swirl blade 742 opens in the same direction clockwise or counterclockwise, and the plurality of swirl blades 742 guide the air flow to flow in the same direction, so that the air flow produces a strong swirl effect, so that the urea droplets and the air flow are mixed more fully, the mixing effect is better, and the mixing uniformity is higher. A circular fourth air outlet hole 743 is also provided on the surface of the rear air outlet baffle 74, located inside the plurality of third air outlet holes 741. The opening area of ​​the fourth air outlet hole 743 is smaller than the opening area of ​​the third air outlet hole 741. The fourth air outlet hole 743 connects the inner air outlet cavity 50 with the outer air outlet cavity 60. The airflow in the central area of ​​the inner air outlet cavity 50 can flow out through the fourth air outlet hole 743, thereby improving the uniformity of the airflow and blowing away the urea landing point.

[0046] In actual use, the present invention is arranged between the DPF and the SCR for exhaust gas post-treatment, the air inlet 11 is connected to the DPF output end, and the air outlet 12 is connected to the SCR input end (not shown in the figure). The urea nozzle sprays urea droplets into the first mixing chamber 30; the airflow is output from the DPF, a part of the airflow directly enters the first mixing chamber 30 through the air intake channel 63, mixes with the urea droplets, and then flows downward to the second mixing chamber 40, the other part of the airflow enters the air intake chamber 10, flows through the interlayer chamber 20, enters the second mixing chamber 40 and mixes with the other part of the airflow, and the airflow is mixed in the second mixing chamber 40 and flows downward to the inner air outlet chamber 50; a part of the airflow of the inner air outlet chamber 50 is directly output from the air outlet 12 to the SCR through the first air outlet hole 731 and the second air outlet hole 732, and the other part flows out to the outer air chamber 60 through the third air outlet hole 741 and the fourth air outlet hole 743; a part of the airflow of the outer air chamber 60 is directly output from the air outlet 12 to the SCR, and the other part flows upward, enters the second mixing chamber 40 through the lower air intake hole 52 of the central tube 5, participates in the mixed airflow with the second mixing chamber 40, and is remixed again, and then flows downward after achieving the effect of remixing.

[0047] The above description is an explanation of the present invention, not a limitation of the present invention. The present invention may be modified in any form without violating the spirit of the present invention.

Claims

1. A post-treatment urea mixing device for a U-shaped platform, wherein an internal cavity is formed between a front shell (1) and a rear shell (2); an air inlet (11) is provided at the upper portion of the front shell (1) and an air outlet (12) is provided at the lower portion; the device is characterized in that: An air intake baffle (3) is provided on the air intake port (11), a transverse partition (4) is provided between the air intake baffle (3) and the rear housing (2), a central tube (5) is inserted through the transverse partition (4), and the lower end of the central tube (5) is connected to an air outlet assembly (7); In the internal cavity, the cavity located on the upper side of the diaphragm (4) and the outer side of the central tube (5) is the air inlet cavity (10), the cavity inside the central tube (5) is the second mixing cavity (40), the internal cavity of the air outlet assembly (7) is the inner air outlet cavity (50), and the cavity located on the lower side of the diaphragm (4) and the inner side of the air inlet baffle (3) and the outer side of the central tube (5) and the air outlet assembly (7) is the outer air cavity (60); the air inlet cavity (10) is connected to the air inlet port (11), the air inlet cavity (10), the second mixing cavity (40) and the inner air outlet cavity (50) are connected in sequence, and the outer air cavity (60) is connected to the air outlet port (12); A plurality of lower air inlet holes (52) are provided on the wall surface of the central tube (5) located in the external air cavity (60), and the lower air inlet holes (52) are connected to the external air cavity (60) and the second mixing cavity (40); The air outlet assembly (7) is provided with a plurality of first air outlet holes (731) and a plurality of third air outlet holes (741); the first air outlet holes (731) are connected to the inner air outlet cavity (50) and the air outlet port (12); and the third air outlet holes (741) are connected to the inner air outlet cavity (50) and the outer air outlet cavity (60).

2. The post-processing urea mixing device for a U-shaped platform according to claim 1, characterized in that: A guide vane (53) is provided on the lower air inlet (52) of the central tube (5), and the guide vane (53) tilts inwardly and obliquely downwardly toward the interior of the central tube (5).

3. The post-processing urea mixing device for a U-shaped platform according to claim 1, characterized in that: The third air outlet (741) of the air outlet assembly (7) is provided with a swirl blade (742), the swirl blade (742) is tilted outwardly toward the outgoing air cavity (60), and each swirl blade (742) opens in the same direction.

4. The post-processing urea mixing device for a U-shaped platform according to claim 1, characterized in that: The air outlet assembly (7) comprises a lower air guide plate (71), a front air outlet baffle plate (73) and a rear air outlet baffle plate (74); the front air outlet baffle plate (73) and the rear air outlet baffle plate (74) are respectively sealed on the front and rear end surfaces of the lower air guide plate (71); a plurality of first air outlet holes (731) are provided on the front air outlet baffle plate (73), and a plurality of third air outlet holes (741) are provided on the rear air outlet baffle plate (74).

5. The post-processing urea mixing device for a U-shaped platform according to claim 4, characterized in that: A plurality of first air outlet holes (731) are distributed on the surface of the front air outlet baffle plate (73) in a radially divergent manner and around the same circumference, and a second air outlet hole (732) is also provided on the surface of the front air outlet baffle plate (73); a plurality of third air outlet holes (741) are distributed on the surface of the rear air outlet baffle plate (74) in a radially divergent manner and around the same circumference, and a fourth air outlet hole (743) is also provided on the surface of the rear air outlet baffle plate (74).

6. The post-processing urea mixing device for a U-shaped platform according to claim 4, characterized in that: The lower guide plate (71) comprises a symmetrically arranged lower curved surface (711) and a V-shaped protrusion (712) protruding toward the inner air outlet cavity (50); a vertical connecting piece (713) is provided at the top of the lower curved surface (711); the upper side edge of the connecting piece (713) is welded and fixed to the central tube (5); the lower curved surface (711) is an outer convex curved surface with a horizontal central axis; the outer contour dimensions of the front air outlet baffle (73) and the rear air outlet baffle (74) match the outer contour dimensions of the lower guide plate (71).

7. The post-processing urea mixing device for a U-shaped platform according to claim 4, characterized in that: A flow divider plate (72) is provided on the inner side of the lower guide plate (71); the flow divider plate (72) is a V-shaped plate with an opening facing downward; and the flow divider surfaces (721) on both sides of the flow divider plate (72) are convex arc surfaces with a horizontal central axis.

8. The post-processing urea mixing device for a U-shaped platform according to claim 1, characterized in that: An upper guide plate (6) is vertically inserted into the upper inner portion of the central tube (5), and an interlayer cavity (20) is formed between the central tube (5) and the upper guide plate (6). The interlayer cavity (20) communicates with the air inlet cavity (10) and the second mixing cavity (40). The inner side of the upper guide plate (6) is a first mixing cavity (30), and the first mixing cavity (30) communicates with the second mixing cavity (40). An air inlet passage (63) is provided on the upper guide plate (6), and the air inlet passage (63) communicates with the first mixing cavity (30), the air inlet port (11) and the air inlet cavity (10).

9. The post-processing urea mixing device for a U-shaped platform according to claim 8, characterized in that: The upper guide plate (6) is a U-shaped plate with an opening facing the air inlet (11), and the opening thereof forms an air inlet passage (63); the upper guide plate (6) comprises an upper curved surface (61) and a vertical plane (62) which are symmetrically arranged, and the upper curved surface (61) is an outwardly convex curved surface having a vertical central axis.

10. The post-processing urea mixing device for a U-shaped platform according to claim 1, characterized in that: The central tube (5) is a rectangular parallelepiped tube; an upper air inlet hole (51) is provided on the front wall of the central tube (5) located in the air inlet cavity (10), the upper air inlet hole (51) is connected to the air inlet port (11) and the interlayer cavity (20), and a lower air inlet hole (52) is provided on the rear wall of the central tube (5); a support sheet (8) is provided between the air outlet assembly (7) and the inner wall of the rear shell (2); the top end of the rear shell (2) has an inclined plane (21), the inclined plane (21) has a mounting hole (22), and the mounting hole (22) faces the first mixing cavity (30).

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