CN114060129A - Tail gas aftertreatment urea mixing arrangement - Google Patents

Abstract

The invention discloses a tail gas post-treatment urea mixing device, wherein an air inlet cylinder is connected with an air outlet cylinder through a connecting section, a rear shell is fixed on one side of the air inlet cylinder, the connecting section and the air outlet cylinder, an inner cavity is enclosed by the connecting section and the rear shell, the air inlet cylinder and the air outlet cylinder are communicated with the inner cavity, a transverse partition plate and a guide plate are transversely arranged at the upper part and the lower part of the inner side of the rear shell, and a space is formed between the transverse partition plate and the guide plate; the diaphragm plate is inserted with a mixed outer pipe, and a mixed inner pipe and a crushing plate which are arranged up and down are arranged in the mixed outer pipe. The tail gas flow and the urea liquid drops are mixed and then flow through the multilayer crushing structure, so that the urea liquid drops are crushed to be smaller and more sufficient and are more easily disturbed by the gas flow, the gas flow and the urea liquid drops are fully mixed in the plurality of mixing cavities, the mixing effect is better, the urea mixing uniformity is higher, and the urea crystallization risk is lower.

Description

Tail gas aftertreatment urea mixing arrangement

Technical Field

The invention relates to the technical field of automobile exhaust aftertreatment, in particular to a urea mixing device for exhaust aftertreatment.

Background

At present, in an engine exhaust gas after-treatment system, Selective Catalytic Reduction (SCR) is generally adopted for after-treatment, urea aqueous solution is sprayed into an exhaust gas after-treatment mixer, and Nitrogen Oxides (NO) in the exhaust gas are treated under the action of a catalyst_X) Reduction to harmless nitrogen (N)₂) And water (H)₂O) to achieve the aim of reducing emissions.

The existing urea mixing device has poor urea mixing uniformity, urea crystals are easily formed, the performance of an after-treatment system is influenced, and even more, the emission standard exceeds the standard or the after-treatment system is blocked, so that the power of a vehicle is insufficient.

Disclosure of Invention

The applicant aims at the defects of the existing urea mixing device, and provides a tail gas post-treatment urea mixing device with a reasonable structure, so that the urea mixing uniformity is improved, and the urea crystallization risk is reduced.

The technical scheme adopted by the invention is as follows:

a tail gas aftertreatment urea mixing device is characterized in that an air inlet cylinder is connected with an air outlet cylinder through a connecting section, a rear shell is fixed on one side of the air inlet cylinder, the connecting section and the air outlet cylinder, an inner cavity is enclosed by the connecting section and the rear shell, the air inlet cylinder and the air outlet cylinder are communicated with the inner cavity, a transverse partition plate and a guide plate are transversely arranged on the upper side and the lower side of the inner side of the rear shell, and a space is formed between the transverse partition plate and the guide plate; a mixing outer pipe is inserted on the diaphragm plate, and a mixing inner pipe and a crushing plate which are arranged up and down are arranged in the mixing outer pipe; in the inner cavity, an air inlet cavity is formed by the upper side of the diaphragm plate and the outer side of the mixing outer tube and is communicated with an air inlet cylinder, a first mixing cavity is formed in the mixing inner tube, a second mixing cavity is formed by the cavity in the mixing outer tube, which is positioned on the outer side of the mixing inner tube, a third mixing cavity is formed between the diaphragm plate and the guide plate, and a fourth mixing cavity is formed on the lower side of the guide plate; a cyclone plate and a vertical baffle plate with intervals are vertically arranged in the air outlet cylinder from front to back, and a fifth mixing cavity is formed between the vertical baffle plate and the cyclone plate; the mixing outer tube is provided with an air inlet which is communicated with the air inlet cavity and the second mixing cavity; the mixing inner pipe is provided with a plurality of air inlets which are communicated with the first mixing cavity and the second mixing cavity; the crushing plate is provided with a plurality of first blade holes, the first blade holes are provided with crushing blades, the crushing blades are provided with a plurality of first through holes, and the first blade holes and the first through holes are communicated with the second mixing cavity and the third mixing cavity; a plurality of second blade holes are formed in the guide plate, blades are arranged on the second blade holes, and the second blade holes are communicated with the third mixing cavity and the fourth mixing cavity; a plurality of third through holes are formed in the plate surface of the vertical baffle plate, which is positioned on the lower side of the guide plate, and the third through holes are communicated with the fourth mixing cavity and the fifth mixing cavity; a plurality of cyclone blades are arranged outwards on the cyclone plate towards the air outlet direction, air outlets are formed in the cyclone blades, and the air outlets are communicated with the fifth mixing cavity.

As a further improvement of the above technical solution:

the top cover is arranged at the top of the rear shell, the nozzle seat is arranged on the top cover, and the nozzle seat is right opposite to the interior of the mixed inner pipe.

The crushing plate comprises two side cambered surfaces and a transition surface, and the transition surface is connected with the two side cambered surfaces; the cambered surfaces on the two sides are respectively provided with a plurality of first blade holes, each first blade hole is provided with a crushing blade, the crushing blades are obliquely turned upwards inwards towards the transition surface, and the turning directions of the crushing blades on the cambered surfaces on the two sides are opposite; the transition surface is provided with a plurality of second through holes; the cambered surfaces on the two sides of the crushing plate and the transition surface are both in an upward convex arc shape, and the outer sides of the side cambered surfaces are downward inclined.

The outer sides of the cambered surfaces at the two sides of the crushing plate are provided with flanges which are welded and fixed on the inner wall surface of the mixed outer pipe; a gap is arranged between the side edge of the crushing plate and the inner wall surface of the mixing outer tube.

The rotational flow blades of the rotational flow plate comprise a plurality of outer rotational flow blades and a plurality of inner rotational flow blades, and the outer rotational flow blades and the inner rotational flow blades are semi-spoon-shaped with radian; the outer swirl blades and the inner swirl blades are formed by protruding outwards from the plate surface, and one side edges of the outer swirl blades and the inner swirl blades are cracked from the plate surface to form an outer air outlet and an inner air outlet respectively; the outer swirl blades and the inner swirl blades are uniformly distributed in the circumferential direction respectively, the inner swirl blades are positioned on the inner sides of the outer swirl blades, the outer gas outlet and the inner gas outlet are opened along the same direction anticlockwise or clockwise respectively, and the opening direction and the angle of the inner gas outlet are consistent with those of the outer gas outlet.

The height and size of the inner swirl blades are smaller than those of the outer swirl blades, and the opening area of the inner air outlet is smaller than that of the outer air outlet.

The radian of the outer side part of the outer swirl vane is larger than that of the inner side part, and the height of the outer side part is larger than that of the inner side part.

The blades of the guide plate comprise a left blade and a right blade which are arranged oppositely, the left blade is obliquely turned out downwards to the right and obliquely, and the right blade is obliquely turned out downwards to the left and obliquely.

The air inlet of the mixed inner pipe comprises a plurality of square upper air inlet holes on the pipe wall of the upper half part and a plurality of waist-shaped lower air inlet holes on the pipe wall of the lower half part, and guide vanes are arranged on the upper air inlet holes and are inclined downwards and turned out inwards and obliquely towards the inside of the mixed inner pipe.

The cross section of the mixing outer pipe is in an oblong shape, the upper wall surfaces of two opposite sides of the mixing outer pipe are respectively provided with an air inlet, and the wall surfaces of the other two sides of the mixing outer pipe are respectively provided with a narrow elongated slot; the plate surface of the diaphragm plate is provided with a through hole and a convex part.

The invention has the following beneficial effects:

the tail gas flow and the urea liquid drops are mixed and then flow through the multilayer crushing structure, so that the urea liquid drops are crushed to be smaller and more sufficient and are more easily disturbed by the gas flow, the gas flow and the urea liquid drops are fully mixed in the plurality of mixing cavities, the mixing effect is better, the urea mixing uniformity is higher, and the urea crystallization risk is lower.

The upturning crushing blades and the through holes of the crushing plate can fully crush urea liquid drops into fine liquid drops, so that the urea liquid drops can be fully absorbed by heat, volatilized and pyrolyzed, and the risk of urea crystallization is reduced. The side arc surface and the transition surface of the crushing plate are both of an upward convex arc shape, and the outer side of the side arc surface inclines downwards, so that urea liquid drops dropping on the crushing plate can slide along the arc surface and slide downwards under the action of gravity, urea crystals are prevented from being formed by urea liquid drops through deposition, and the risk of urea crystals is reduced; and the crushing blades arranged oppositely on the cambered surfaces at the two sides can enable the airflow to move towards the two sides along the crushing blades, so that the wall surfaces at the two sides are preheated, urea crystallization is avoided, and the risk of urea crystallization is reduced. Gaps are formed between the left side edge and the right side edge of the crushing plate and the inner wall surface of the mixing outer pipe, urea liquid drops dropping on the crushing plate can slide off from the gaps, urea liquid drops are prevented from depositing on the crushing plate to form urea crystals, and the risk of urea crystallization is reduced.

The swirl blades and the air outlet of the swirl plate guide airflow along the same direction, so that the airflow generates a strong swirl effect, urea liquid drops and the airflow are mixed more fully, the mixing effect is better, and the mixing uniformity is higher. The inner swirl blades and the inner air outlet can guide air flow to the center of the swirl plate, so that the air flow at the center of the swirl plate is enhanced, and the uniformity of the air flow is ensured. The opening direction and the angle of the inner air outlet are consistent with those of the outer air outlet, the uniformity of the air flow direction is ensured, and the mixing uniformity of the air flow is improved. The outer side of the outer rotational flow blade is large in arc shape, the inner side of the outer rotational flow blade is small in arc shape, so that the air flow passing through the outer side of the outer rotational flow blade is not blocked by the blades in the advancing direction of the outer rotational flow blade, the rotational flow effect is ensured, and the mixing uniformity is improved; and because the outer swirl vanes are provided with high and low sides, the convex low sides can compensate materials for the high sides during molding, and molding is facilitated.

The left blade and the right blade which are oppositely arranged on the guide plate can guide the air flow to the middle position of the fourth mixing cavity, so that urea liquid drops and the air flow can be fully mixed, and the uniformity of urea mixing is improved.

The guide vanes of the mixed inner pipe can guide the air flow to be blown into the mixed inner pipe in an inclined downward direction at an accelerated speed, the guide vanes can also provide a shielding effect for urea liquid drops, the air flow is prevented from blowing the urea liquid drops directly to blow the urea liquid drops to the inner wall surface of the mixed inner pipe, the risk of urea crystal formation on the mixed inner pipe is reduced, the guide vanes inclined downward have a guide effect on the urea liquid drops falling on the guide vanes, the urea liquid drops can slide down along the guide vanes and cannot be attached to the guide vanes, the urea liquid drops are prevented from being deposited on the guide vanes to form the urea crystal, and the risk of urea crystal formation is reduced.

Drawings

Fig. 1 is a perspective view of the present invention.

Fig. 2 is an exploded view of the present invention.

Fig. 3 is a front-rear longitudinal sectional view of the present invention.

Fig. 4 is a left-right longitudinal sectional view of the present invention.

Fig. 5 is a perspective view of the mixing inner tube.

Fig. 6 is a cross-sectional view of the breaker plate.

FIG. 7 is a perspective view of a swirl plate.

In the figure: 1. an air inlet cylinder; 2. mixing the outer tube; 21. an air inlet; 22. a long groove; 3. mixing the inner pipe; 31. an upper air inlet hole; 32. a guide vane; 33. a lower air inlet hole; 4. a breaker plate; 41. a side arc surface; 42. a transition surface; 43. flanging; 44. a first blade hole; 45. crushing the leaves; 46. a first through hole; 47. a second through hole; 5. a diaphragm plate; 51. inserting holes; 52. a boss portion; 6. a baffle; 61. a second blade aperture; 62. a left leaf; 63. a right blade; 7. a vertical baffle plate; 71. a third through hole; 8. a swirl plate; 81. an outer swirl vane; 82. an outer air outlet; 83. an inner swirl vane; 84. an inner air outlet; 9. an air outlet cylinder; 10. a connecting section; 11. a rear housing; 12. a top cover; 13. a nozzle holder;

20. an air inlet cavity; 30. a first mixing chamber; 40. a second mixing chamber; 50. a third mixing chamber; 60. a fourth mixing chamber; 70. a fifth mixing chamber.

Detailed Description

The following describes embodiments of the present invention with reference to the drawings.

As shown in fig. 1 to 4, an air inlet cylinder 1 and an air outlet cylinder 9 which are arranged up and down are connected through a connecting section 10, a rear shell 11 is fixed on the rear sides of the air inlet cylinder 1, the connecting section 10 and the air outlet cylinder 9, a top cover 12 is fixed on the top of the rear shell 11, an inner cavity is enclosed by the connecting section 10, the rear shell 11 and the top cover 12, and the air inlet cylinder 1 and the air outlet cylinder 9 are communicated with the inner cavity. The top cover 12 is provided with a nozzle holder 13, through which a urea nozzle (not shown) can spray urea droplets into the inner chamber through the nozzle holder 13.

As shown in fig. 2 to 4, a diaphragm 5 and a baffle 6 are horizontally arranged on the inner side wall surface of the rear housing 11 from top to bottom, and a certain distance is formed between the diaphragm 5 and the baffle 6. The diaphragm plate 5 is inserted with the mixing outer pipe 2, and a certain distance is arranged between the lower end part of the mixing outer pipe 2 and the guide plate 6. The upper part of the inner side of the mixing outer tube 2 is inserted with the mixing inner tube 3, the upper end parts of the mixing outer tube 2 and the mixing inner tube 3 are fixed on the top cover 12, the nozzle seat 13 is over against the inner cavity of the mixing inner tube 3, and the urea nozzle can spray urea liquid drops in the mixing inner tube 3; a crushing plate 4 is fixedly arranged at the lower part of the inner side of the mixing outer pipe 2 and below the mixing inner pipe 3. In an inner cavity defined by the connecting section 10, the rear shell 11 and the top cover 12, cavities positioned on the upper side of the diaphragm plate 5 and on the outer side of the mixing outer tube 2 form an air inlet cavity 20, and the air inlet cavity 20 is communicated with the air inlet cylinder 1; the inner cavity of the mixing inner tube 3 forms a first mixing chamber 30; the cavity in the mixing outer pipe 2 and outside the mixing inner pipe 3 forms a second mixing cavity 40; the cavity between the diaphragm plate 5 and the guide plate 6 is a third mixing cavity 50; the cavity on the lower side of the deflector 6 is a fourth mixing chamber 60. A vertical baffle plate 7 and a swirl plate 8 which are spaced at a certain distance are vertically arranged in the air outlet cylinder 9 from the back to the front in sequence, and a fifth mixing cavity 70 is formed between the vertical baffle plate 7 and the swirl plate 8; the upper end of the vertical baffle 7 is welded and fixed on the inner side surface of the connecting section 10.

As shown in fig. 2 and 4, the mixing outer tube 2 has an upper wall surface provided with air inlets 21 on both left and right sides, and the air inlets 21 communicate the air inlet chamber 20 with the second mixing chamber 40. Narrow elongated grooves 22 are formed in the front and rear side wall surfaces of the mixing outer pipe 2, and the mixing inner pipe 3 can be welded and fixed to the mixing outer pipe 2 through the elongated grooves 22. The cross section of the mixing outer pipe 2 is oblong, and compared with the traditional circular cross section, the oblong cross section has a larger airflow through-flow section, airflow flows more smoothly, and airflow backpressure is smaller.

As shown in fig. 2 to 5, the upper half pipe wall of the inner mixing pipe 3 is provided with a plurality of square upper air inlets 31, the lower half pipe wall of the inner mixing pipe 3 is provided with a plurality of waist-shaped lower air inlets 33, and the upper air inlets 31 and the lower air inlets 33 communicate the first mixing chamber 30 and the second mixing chamber 40. Each upper air inlet 31 is provided with a guide vane 32, the guide vanes 32 are tilted inwards and downwards in an inclined manner towards the inside of the mixing inner tube 3, the guide vanes 32 can guide air flow to be blown into the mixing inner tube 3 in an accelerated manner in an inclined and downwards direction, the guide vanes 32 can also provide a shielding effect for urea liquid drops, the air flow is prevented from blowing the urea liquid drops directly and blowing the urea liquid drops to the inner wall surface of the mixing inner tube 3, the risk of urea crystal formation on the mixing inner tube 3 is reduced, the guide vanes 32 inclined downwards have a flow guiding effect on the urea liquid drops falling on the guide vanes 32, the urea liquid drops can slide downwards along the guide vanes 32 and cannot be attached to the guide vanes 32, the urea liquid drops are prevented from being deposited on the guide vanes 32 to form urea crystals, and the risk of urea crystal is reduced. The air flow after the preliminary mixing on the upper part of the mixing inner tube 3 is further mixed with the air flow entering from the lower air inlet hole 33 downwards, which is more beneficial to improving the mixing effect of the urea liquid drops and the air flow.

As shown in fig. 6, the crushing plate 4 includes arc-shaped side arc surfaces 41 with front and rear sides inclined downward and arc-shaped transition surfaces 42 with middle portions connecting the two side arc surfaces 41; the outer side edges of the two side cambered surfaces 41 are bent downwards to form flanges 43; as shown in fig. 3, the flange 43 is welded and fixed to the inner wall surface of the mixing outer tube 2; the side arc surface 41 and the transition surface 42 are both of an upward convex arc shape, the outer side of the side arc surface 41 inclines downwards, urea liquid drops dropping on the crushing plate 4 slide along the arc surface and slide downwards under the action of gravity, urea liquid drops are prevented from depositing to form urea crystals, and the risk of urea crystallization is reduced. As shown in FIG. 4, a gap of 3-5 mm is formed between the side edge of the crushing plate 4 and the inner wall surface of the mixing outer tube 2, urea droplets dropping on the crushing plate 4 can slide off from the gap, urea crystals are prevented from being formed on the crushing plate 4 by urea droplet deposition, and the risk of urea crystals is reduced. As shown in fig. 6, the arc surfaces 41 on both sides are respectively provided with a plurality of square first blade holes 44, each first blade hole 44 is provided with a crushing blade 45, the crushing blade 45 is tilted and turned upwards and inwards towards the transition surface 42, and the turning directions of the crushing blades 45 on the arc surfaces 41 on both sides are opposite; each crushing blade 45 is provided with a plurality of first through holes 46; the transition surface 42 is provided with a plurality of second through holes 47; the first vane hole 44, the first through hole 46 and the second through hole 47 communicate the second mixing chamber 40 and the third mixing chamber 50. The upturned crushing blades 45 and the through holes can fully crush the urine liquid drops into fine liquid drops, so that the urea liquid drops can be more favorably fully absorbed by heat, volatilized and pyrolyzed, and the risk of urea crystallization is reduced; and the crushing blades 45 arranged oppositely on the cambered surfaces 41 at the two sides can enable the airflow to move towards the two sides along the crushing blades 45, preheat the wall surfaces at the two sides, avoid forming urea crystals and reduce the risk of urea crystallization.

As shown in fig. 2, a through hole 51 for inserting the mixing outer tube 2 is formed in the center of the plate surface of the diaphragm plate 5, two sides of the diaphragm plate 5, which are located on the through hole 51, are respectively protruded upwards to form a protruding portion 52, and the protruding portion 52 can increase the strength of the diaphragm plate 5, thereby preventing the diaphragm plate 5 from deforming under the impact of the air flow.

As shown in fig. 2 and 4, the plate surface of the deflector 6 is provided with a plurality of square second vane holes 61, and the second vane holes 61 communicate the third mixing cavity 50 and the fourth mixing cavity 60; each second blade hole 61 is provided with a blade, the left blade 62 of the left half board surface and the right blade 63 of the right half board surface are oppositely arranged, namely, the left blade 62 is obliquely turned out downwards towards the right, the right blade 63 is obliquely turned out downwards towards the left, and the left blade 62 and the right blade 63 which are oppositely arranged can guide the air flow to the middle position of the fourth mixing cavity 60, so that the urea liquid drops and the air flow can be fully mixed, and the uniformity of urea mixing is improved.

As shown in fig. 2 and 4, a plurality of third through holes 71 are formed in the middle-lower plate surface of the vertical baffle 7 and located on the lower side of the guide plate 6, and the third through holes 71 communicate the fourth mixing chamber 60 and the fifth mixing chamber 70.

As shown in fig. 7, a plurality of semi-spoon-shaped outer cyclone blades 81 and inner cyclone blades 83 with radian are formed on the plate surface of the cyclone plate 8 and protrude outward in the air outlet direction, an outer air outlet 82 is formed on the outer cyclone blade 81, an inner air outlet 84 is formed on the inner cyclone blade 83, and the outer air outlet 82 and the inner air outlet 84 are communicated with the fifth mixing chamber 70; the outer swirl blades 81 and the inner swirl blades 83 are formed by directly protruding outwards from the plate surface, one side edge of each outer swirl blade cracks from the plate surface, and a plurality of outer air outlets 82 and inner air outlets 84 are formed on the plate surface of the swirl plate 8 respectively. A plurality of outer swirl blades 81 evenly arrange around anticlockwise on the circumferencial direction, every gas port 82 that goes out along anticlockwise along same direction opening, every outer swirl blade 81 and gas port 82 that goes out guide the air current along same direction for the air current produces strong whirl effect, makes urea liquid drop and air current mix more abundant, and the mixing effect is better, and the homogeneity of mixing is higher. The radian of the outer side part of the outer cyclone blade 81 close to the outer edge of the cyclone plate 8 is larger than that of the inner side part close to the center of the cyclone plate 8, the protrusion height of the outer side part of the outer cyclone blade 81 is larger than that of the inner side part, the outer side arc of the outer cyclone blade 81 is large, and the inner side arc is small, so that the air flow passing through the outer side part is not blocked by the blades in the advancing direction, the cyclone effect is ensured, and the mixing uniformity is improved; and because the outer swirl vanes 81 have high and low sides, the convex low sides can compensate the high sides in material during molding, and the molding is facilitated. The inner swirl blades 83 are positioned on the inner side of the outer swirl blade 81 and are uniformly arranged in the circumferential direction around the counterclockwise direction, the opening direction and angle of the inner air outlet 84 are consistent with those of the outer air outlet 82, the uniformity of the airflow direction is ensured, and the mixing uniformity of the airflow is improved; the height and the size of the protrusion of the inner swirl vane 83 are smaller than those of the outer swirl vane 81, and the opening area of the inner air outlet 84 is smaller than that of the outer air outlet 82; the inner swirl blades 83 and the inner air outlets 84 can guide the air to flow towards the center of the swirl plate 8, so that the air flow at the center of the swirl plate 8 is enhanced, and the uniformity of the air flow is ensured. In other embodiments, the outer swirl blades 81 and the inner swirl blades 83 may also be uniformly arranged around the clockwise direction, as long as the purpose of guiding the airflow in the same direction to form the swirl flow can be achieved.

In practice, the present invention is arranged between a DPF (particulate trap) for exhaust gas aftertreatment and an SCR, the inlet cylinder 1 being connected to the DPF output and the outlet cylinder 9 being connected to the SCR input (not shown in the figure). The urea nozzle sprays urea liquid drops into the first mixing cavity 30 of the mixing inner pipe 3 through the nozzle seat 13; the gas flow is output from the DPF, enters the air inlet cavity 20 through the air inlet cylinder 1, and then enters the second mixing cavity 40 through the air inlet 21 on the mixing outer pipe 2, and the gas flow in the second mixing cavity 40 is divided into three parts: the first part of airflow enters the upper part of the first mixing cavity 30 through the upper air inlet 31 of the mixing inner pipe 3, is primarily mixed with urea liquid drops to form primary mixed airflow and then flows downwards; the second part of the air flow enters the lower part of the first mixing cavity 30 through the lower air inlet hole 33 of the mixing inner pipe 3, is further mixed with the primary mixed air flow flowing from the upper part to form secondary mixed air flow, then flows downwards, and the third part of the air flow directly flows to the lower part of the second mixing cavity 40 and is further mixed with the secondary mixed air flow flowing from the first mixing cavity 30 to form tertiary mixed air flow; the third mixed airflow is fully crushed downwards by the crushing plate 4 to form turbulent flow, and then enters the third mixing cavity 50 to be further mixed to form fourth mixed airflow; the fourth mixed airflow continues to further crush downwards through the guide plate 6 to form turbulent flow, and then enters the fourth mixing cavity 60 to further mix to form fifth mixed airflow; the fifth mixed airflow enters the fifth mixing chamber 70 through the third through holes 71 of the vertical baffle 7 and is further mixed to form a sixth mixed airflow, and then the sixth mixed airflow is guided by the blades of the cyclone plate 8 to form a strong rotating airflow, so that the mixed airflow is uniformly output to the SCR. After tail gas air current and urea liquid drop mix, the multilayer crushing structure of flowing through makes the urea liquid drop by broken littleer, more abundant, is disturbed by the air current more easily, and the air current carries out the intensive mixing with the urea liquid drop in a plurality of hybrid chambers, and the mixing effect is better, and urea mixing uniformity is higher, and urea crystallization risk is lower.

The foregoing description is illustrative of the present invention and is not to be construed as limiting thereof, as the invention may be modified in any manner without departing from the spirit thereof.

Claims (10)

1. The utility model provides a tail gas aftertreatment urea mixing arrangement, admission section of thick bamboo (1) are connected through linkage segment (10) with play gas cylinder (9), and back shell (11) are fixed in admission section of thick bamboo (1), linkage segment (10), play gas cylinder (9) one side, and linkage segment (10), back shell (11) enclose into there is the inner chamber, admission section of thick bamboo (1), play gas cylinder (9) with the inner chamber intercommunication, its characterized in that:

a transverse partition plate (5) and a guide plate (6) are transversely arranged on the inner side of the rear shell (11) from top to bottom, and a space is formed between the transverse partition plate (5) and the guide plate (6); the diaphragm plate (5) is inserted with a mixing outer pipe (2), and the mixing outer pipe (2) is internally provided with a mixing inner pipe (3) and a crushing plate (4) which are arranged up and down; in the inner cavity, an air inlet cavity (20) is formed on the upper side of the diaphragm plate (5) and the outer side of the mixing outer tube (2), the air inlet cavity (20) is communicated with the air inlet cylinder (1), a first mixing cavity (30) is formed inside the mixing inner tube (3), a second mixing cavity (40) is formed by a cavity on the outer side of the mixing inner tube (3) in the mixing outer tube (2), a third mixing cavity (50) is formed between the diaphragm plate (5) and the guide plate (6), and a fourth mixing cavity (60) is formed on the lower side of the guide plate (6);

a cyclone plate (8) and a vertical baffle plate (7) with intervals are vertically arranged in the air outlet cylinder (9) from front to back, and a fifth mixing cavity (70) is formed between the vertical baffle plate (7) and the cyclone plate (8);

an air inlet (21) is formed in the mixing outer tube (2), and the air inlet (21) is communicated with the air inlet cavity (20) and the second mixing cavity (40);

a plurality of air inlets are formed in the mixing inner tube (3), and the air inlets are communicated with the first mixing cavity (30) and the second mixing cavity (40);

a plurality of first blade holes (44) are formed in the crushing plate (4), crushing blades (45) are arranged on the first blade holes (44), a plurality of first through holes (46) are formed in the crushing blades (45), and the first blade holes (44) and the first through holes (46) are communicated with the second mixing cavity (40) and the third mixing cavity (50);

a plurality of second blade holes (61) are formed in the guide plate (6), blades are arranged on the second blade holes (61), and the second blade holes (61) are communicated with the third mixing cavity (50) and the fourth mixing cavity (60);

a plurality of third through holes (71) are formed in the plate surface of the vertical baffle (7) on the lower side of the guide plate (6), and the fourth mixing cavity (60) and the fifth mixing cavity (70) are communicated through the third through holes (71);

a plurality of cyclone blades are arranged outwards on the cyclone plate (8) towards the air outlet direction, air outlets are formed in the cyclone blades, and the air outlets are communicated with the fifth mixing cavity (70).

2. The exhaust gas aftertreatment urea mixing device of claim 1, wherein: the top of the rear shell (11) is provided with a top cover (12), the top cover (12) is provided with a nozzle seat (13), and the nozzle seat (13) is just opposite to the interior of the mixing inner tube (3).

3. The exhaust gas aftertreatment urea mixing device of claim 1, wherein: the crushing plate (4) comprises two side arc surfaces (41) and a transition surface (42), and the transition surface (42) is connected with the two side arc surfaces (41); a plurality of first blade holes (44) are respectively formed in the cambered surfaces (41) at the two sides, a crushing blade (45) is arranged on each first blade hole (44), the crushing blades (45) are obliquely turned upwards and inwards towards the transition surface (42), and the turning directions of the crushing blades (45) on the cambered surfaces (41) at the two sides are opposite; a plurality of second through holes (47) are formed in the transition surface (42); the cambered surfaces (41) and the transition surfaces (42) on the two sides of the crushing plate (4) are both in an upward convex arc shape, and the outer sides of the side cambered surfaces (41) are downward inclined.

4. The exhaust gas aftertreatment urea mixing device of claim 1, wherein: flanges (43) are arranged on the outer sides of the cambered surfaces (41) on the two sides of the crushing plate (4), and the flanges (43) are welded and fixed on the inner wall surface of the mixing outer pipe (2); a gap is arranged between the side edge of the crushing plate (4) and the inner wall surface of the mixing outer pipe (2).

5. The exhaust gas aftertreatment urea mixing device of claim 1, wherein: the swirl blades of the swirl plate (8) comprise a plurality of outer swirl blades (81) and a plurality of inner swirl blades (83), and the outer swirl blades (81) and the inner swirl blades (83) are semi-spoon-shaped with radian; the outer swirl blades (81) and the inner swirl blades (83) are formed by protruding outwards from the plate surface, and one side edges of the outer swirl blades (81) and the inner swirl blades (83) are cracked from the plate surface to form an outer air outlet (82) and an inner air outlet (84) respectively; the outer swirl blades (81) and the inner swirl blades (83) are uniformly distributed in the circumferential direction respectively, the inner swirl blades (83) are positioned on the inner side of the outer swirl blades (81), the outer gas outlet (82) and the inner gas outlet (84) are opened along the same direction along the anticlockwise direction or the clockwise direction respectively, and the opening direction and the angle of the inner gas outlet (84) are consistent with those of the outer gas outlet (82).

6. The exhaust gas aftertreatment urea mixing device of claim 5, wherein: the height and size of the inner swirl blades (83) are smaller than those of the outer swirl blades (81), and the opening area of the inner air outlet (84) is smaller than that of the outer air outlet (82).

7. The exhaust gas aftertreatment urea mixing device of claim 5, wherein: the radian of the outer side part of the outer swirl vane (81) is larger than that of the inner side part, and the height of the outer side part is larger than that of the inner side part.

8. The exhaust gas aftertreatment urea mixing device of claim 1, wherein: the blades of the guide plate (6) comprise a left blade (62) and a right blade (63) which are arranged oppositely, the left blade (62) is obliquely turned out downwards towards the right and obliquely, and the right blade (63) is obliquely turned out downwards towards the left and obliquely.

9. The exhaust gas aftertreatment urea mixing device of claim 1, wherein: the air inlet holes of the mixed inner pipe (3) comprise a plurality of square upper air inlet holes (31) on the pipe wall of the upper half part and a plurality of waist-shaped lower air inlet holes (33) on the pipe wall of the lower half part, guide vanes (32) are arranged on the upper air inlet holes (31), and the guide vanes (32) are obliquely turned out downwards inwards and obliquely towards the inside of the mixed inner pipe (3).

10. The exhaust gas aftertreatment urea mixing device of claim 1, wherein: the cross section of the mixing outer pipe (2) is oblong, air inlets (21) are respectively formed in the upper wall surfaces of two opposite sides of the mixing outer pipe (2), and narrow elongated slots (22) are respectively formed in the wall surfaces of the other two sides of the mixing outer pipe (2); the plate surface of the diaphragm plate (5) is provided with a through hole (51) and a bulge (52).

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