CN211008825U

CN211008825U - Urea aqueous solution decomposition mixing device

Info

Publication number: CN211008825U
Application number: CN201922291816.5U
Authority: CN
Inventors: 乔宝英; 牛雨飞; 朱海艳; 薛红娟; 李江飞; 孙治书; 谭林波
Original assignee: Wuxi Yili Environmental Protection Technology Co Ltd
Current assignee: Wuxi Yili Environmental Protection Technology Co Ltd
Priority date: 2019-12-19
Filing date: 2019-12-19
Publication date: 2020-07-14
Anticipated expiration: 2029-12-19

Abstract

The utility model discloses a urea aqueous solution decomposition mixing device, a spoiler and a pore plate are arranged between a front shell and a rear shell, the spoiler and the pore plate divide an inner cavity into an upper spraying cavity, a middle diversion cavity and a lower swirling cavity, a top cover is arranged at the top of the rear shell, and an inclined plane with an included angle with a vertical plane is arranged in the spraying cavity; the guide plate is provided with guide vanes; the spoiler is provided with spoiler blades; the rotational flow plate is provided with rotational flow blades outwards through third blade holes. The utility model discloses an inside cavity only separates through having spoiler and orifice plate and sprays chamber, water conservancy diversion chamber, whirl chamber, and the interior hindrance of airflow channel is few, and the passageway is more smooth and easy, and the turning department of mixed air current process is few in airflow channel, and energy loss is little, and the air current pressure reduces. The top cover of the utility model is provided with an inclined lower plane, and the injection cavity is formed into a cavity body which is asymmetrical along the vertical plane; the nozzle seat is positioned at the low position of the lower plane, and urea sprayed by the nozzle seat can be sprayed towards the direction opposite to the spoiler blade of the spoiler.

Description

Urea aqueous solution decomposition mixing device

Technical Field

The utility model belongs to the technical field of automobile exhaust aftertreatment technique and specifically relates to a urea aqueous solution decomposes mixing arrangement.

Background

With the increasing preservation quantity of automobiles, the pollution of the emission of automobile exhaust to the atmospheric environment is increasingly serious. Nitrogen Oxides (NO) emitted from automobile engine_X) Is one of the main pollution sources causing air pollution, and in order to reduce the pollution of the engine emission to the air, the exhaust emission of the automobile engine needs to be treated. At present, an automobile engine generally adopts a Selective Catalytic Reduction (SCR) technology to carry out aftertreatment on exhaust emission, urea aqueous solution in a urea tank is sprayed into an exhaust pipe through a urea spraying system, and the urea aqueous solution is decomposed into ammonia (NH) at the temperature of the exhaust₃) Ammonia gas (NH) under the action of catalyst₃) Removing Nitrogen Oxides (NO) from exhaust gases_X) Reduction to harmless nitrogen (N)₂) And water (H)₂O), and finally discharged from the exhaust pipe, thereby achieving the purpose of reducing the emission. In order to meet the increasingly stringent emission standard requirements of the sixth phase of China, the NO of the SCR device must be increased_XReducing pollutant emissions, and urea aqueous solution, fully decomposed, decomposed NH₃Mixing with tail gas to increase NO_XThe key to conversion.

Chinese patent application CN109441603A discloses a packaging system between DPF (particulate trap) and SCR in exhaust gas aftertreatment, the transition part of the packaging system is arranged between the DPF input end and the SCR output end, the transition part comprises a transition shell and a transition cavity therein, the transition shell comprises a transition front plate, a transition rear plate and transition side walls clamped between the transition front plate and the transition rear plate, the top and the bottom of the transition front plate are respectively provided with a front plate inlet and a front plate outlet, an ammonia gas generating unit is arranged in the transition cavity, the ammonia gas generating unit comprises a flow guide panel, an arc-shaped crusher and a flow guide bent plate, a vertical rectifying unit is arranged below the ammonia gas generating unit, the vertical rectifying unit comprises an arc-shaped upper orifice plate and an arc-shaped lower orifice plate which are arranged up and down, the vertical rectifying unit is communicated with a horizontal rectifying unit arranged in the output end of the SCR, and the horizontal rectifying unit comprises a rectifying inner pore plate and a rectifying outer pore plate which are coaxially arranged. The packaging system has the following problems: (1) the air flow channel in the packaging system consists of a flow guide panel, an arc-shaped upper orifice plate and an arc-shaped lower orifice plate of a vertical rectifying unit, and a rectifying inner orifice plate and a rectifying outer orifice plate of a horizontal rectifying unit, and the structure of the air flow channel is complex, and a plurality of turning positions are formed in the whole air flow channel. When the mixed airflow flows in the airflow channel, the energy loss generated when the airflow impacts each part is large, namely, a large airflow pressure drop is generated. Moreover, when the mixed airflow passes through the turning points, turbulent flow is easily generated, energy loss is inevitably generated in order to overcome the exchange energy caused by mutual collision among particles during turbulent flow, and after the mixed airflow passes through the turning points at multiple positions in the airflow channel, the energy loss is large, and the pressure drop of the generated airflow is high. (2) The flow guide panel of the packaging system comprises a plurality of panel strips which are parallel to each other, tail gas enters from the flow guide panel and then directly blows to urea liquid drops sprayed in, and the urea liquid drops are easily blown to the inner wall surfaces of the transition shell and the transition rear panel due to the fact that the flow velocity of the entering tail gas is high, urea crystallization is formed on the inner wall surfaces of the transition shell and the transition rear panel, massive solid is generated, and then the exhaust pipe is likely to be blocked, the exhaust effect is influenced, and even the engine is damaged. (3) The horizontal rectifying unit of the packaging system consists of a rectifying inner pore plate and a rectifying outer pore plate; the last circle portion of orifice plate is provided with the less rectification hole in a plurality of apertures in the rectification, and lower circle portion sets up the less rectification hole in several apertures and the great rectification macropore in an aperture, and it is littleer for its hindrance to air mixture of last circle portion in lower circle portion, and air mixture's most gas can pass through from the rectification macropore, and the gas that all the other rectification holes pass through is less, and the air velocity that passes through from the rectification macropore is faster, and mixing time is shorter for the homogeneity that this part air current mixes is high inadequately. (4) This packaging system has set up ammonia generation unit, perpendicular rectification unit, horizontal rectification unit in order to promote urea to ammonia conversion efficiency, improve the distribution degree of consistency and the homogeneity of air current flow speed of ammonia and has handled the urea liquid of spouting and tail gas air current, and every unit all includes a plurality of spare parts, and spare part cost is higher, and every spare part all need assemble to the transition shell on, and assembly cost is higher.

SUMMERY OF THE UTILITY MODEL

The applicant aims at the defects that the existing packaging system between the DPF and the SCR in the aftertreatment has high airflow pressure drop of mixed airflow, the inner wall surfaces of a transition shell and a transition back plate are easy to form crystallization, the airflow mixing uniformity is not high enough, the part cost is high, the assembly cost is high and the like, and provides the urea aqueous solution decomposition and mixing device with a reasonable structure.

The utility model discloses the technical scheme who adopts as follows:

a urea aqueous solution decomposition mixing device is arranged between a DPF and an SCR of tail gas aftertreatment and comprises a front shell, a rear shell, an air inlet cylinder connected to the output end of the DPF and an air outlet cylinder connected to the input end of the SCR, wherein an inner cavity is formed between the front shell and the rear shell; a guide plate is embedded in the air inlet cylinder, a first notch and a second notch are formed in the guide plate, a first air inlet and a second air inlet are formed in the air inlet cylinder, a guide vane is arranged in a first vane hole in the guide plate towards the spraying cavity, and the spraying cavity is communicated with the output end of the DPF through the first air inlet, the second air inlet and the first vane hole; the flow guide cavity is positioned between the spoiler and the pore plate, and a second blade hole on the spoiler is provided with spoiler blades towards the pore plate; the swirl cavity is positioned between the orifice plate, the front shell, the rear shell and the air outlet cylinder, a swirl plate is embedded in the air outlet cylinder, and swirl blades are outwards arranged on the swirl plate through third blade holes.

As a further improvement of the above technical solution:

the inclined plane is a lower plane of the top cover, a nozzle seat is arranged at the lower position of the lower plane, and the urea nozzle stretches into the nozzle seat during operation.

The utility model discloses an inside cavity only separates through having spoiler and orifice plate and sprays chamber, water conservancy diversion chamber, whirl chamber formation air current channel, and the interior hindrance of air current channel is few, and the passageway is more smooth and easy, and when the mixed air current flows in air current channel, the turning department of required process is few, and energy loss is little, and the air current pressure reduces. The utility model has the advantages that the whole structure is simple, required spare part is less, and spare part cost is lower, and the assembly cost of spare part is lower. The top cover of the utility model is provided with an inclined lower plane which causes the spraying cavity to form a cavity body which is asymmetrical along the vertical plane; the nozzle seat is positioned at the lower position of the lower plane, and the spraying port of the urea nozzle in the nozzle seat is adjusted, so that urea spraying rays can be sprayed towards the direction opposite to the spoiler blade of the spoiler. The first air inlet in the air inlet cylinder is communicated with the injection cavity, the second air inlet is communicated with the injection cavity, the included angle between the arched straight chord edges of the first air inlet and the second air inlet and the lower plane of the top cover is an obtuse angle, the tail gas flow coming from the first air inlet and most of the tail gas flow coming from the second air inlet enter the injection cavity, because the jet cavity is an asymmetric cavity, the lower plane of the top cover is obliquely arranged, the tail gas airflow is deflected after impacting the lower plane and the large plane of the rear shell to form rotational flow, so that the flow length of the tail gas airflow is increased in the limited cavity space of the jet cavity, the urea spraying line is opposite to the turbulence blades, so that the tail gas flow of the rotational flow can rotate around the urea spraying line, on one hand, the tail gas flow heats the urea spraying line more uniformly, the volatilization of urea liquid drops is facilitated, the volatilization rate of urea is improved, and the urea crystallization risk is reduced; on the other hand, the path length of the tail gas flow and the urea injection line is increased, so that urea liquid drops and the tail gas flow are fully mixed, and the mixing uniformity is improved.

The opening of the guide vane on the guide plate is over against the spoiler vane on the spoiler.

The guide vanes on the guide plate of the utility model are opened towards the turbulence vanes of the turbulence plate, and can guide and blow the mixed gas flow to the turbulence vanes, on one hand, the urea dropping liquid can be prevented from being blown to the inner wall surface of the rear shell to form urea crystals by directly blowing urea spraying rays by the mixed gas flow, and the risk of urea crystals on the rear shell is reduced; on the other hand, the guide vanes guide the mixed airflow to blow to the turbulence vanes, so that the heat of the tail gas can be fully utilized, urea droplets falling on the turbulence vanes fully absorb heat and volatilize, the volatilization rate of the urea droplets is improved, and NO is further improved_XThe conversion efficiency of (a); in addition, the guide vanes are arranged obliquely downwards, so that the tail gas flow coming from the first air inlet and the second air inlet can form a rotational flow.

The guide plate is also provided with a first through hole, the first through hole is positioned on the outer side of the guide vane, and the first through hole is communicated with the injection cavity and the DPF output end.

The first through hole is formed in the flow guide plate, the first through hole can guide part of the tail gas flow, and the situation that most of the tail gas flow directly enters the jet cavity from the first air inlet and the second air inlet to cause the too fast air flow speed is avoided, so that the rotational flow effect of the mixed air flow is influenced; meanwhile, the problem that the uniformity of mixing is influenced by the reduction of the airflow passing through the first blade holes can be avoided, and the risk of urea crystallization generated on the guide blades is increased by the reduction of the airflow passing through the first blade holes.

The second air inlet is also communicated with the flow guide cavity and the DPF output end.

The utility model discloses second air inlet intercommunication water conservancy diversion chamber in the ventiduct, from the partial tail gas air current that the second air inlet came in directly get into the water conservancy diversion intracavity, preheat preceding shell, back shell, spoiler, the corresponding wall of orifice plate, make and fall onThe urea liquid drops on the corresponding wall surfaces fully absorb heat and volatilize, the evaporation rate of the urea liquid drops is improved, and further NO is improved_XThe conversion efficiency of (2) and the heat of tail gas can also accelerate the further sufficient volatilization of urea liquid drops with smaller particles which are not volatilized before in the mixed gas flow in the diversion cavity.

The first air inlet and the second air inlet are arched, and an included angle between the arched straight chord edge and the inclined plane is an obtuse angle.

The spoiler is an arc-shaped plate and comprises a blade part and a closed part, a plurality of spoiler blade arrays are arranged on the blade part, and the openings of two adjacent rows of spoiler blades are arranged in a staggered manner; a plurality of rows of spoiler blades with consistent orientation are arranged at the outer end of the blade part close to the arc; a plurality of second through holes are formed in the closed portion and close to the arc-shaped outer end.

The utility model discloses a two rows of vortex blades that are close to the outer end on the blade portion of spoiler are towards unanimous, all towards the direction of orifice plate, and the air current in the guide outside flows towards the orifice plate, prevents that the air current from striking the lateral wall face of back shell and making the urea liquid drop form the urea crystallization on the lateral wall face. The utility model discloses a crisscross setting of opening of the vortex blade of adjacent two on the blade portion of spoiler, on the one hand, the urea liquid drop striking that does not volatilize in the air current is on the vortex blade, and the secondary crushing is littleer liquid drop, changes in volatilizing of urea liquid drop, reduces the risk that produces the urea crystallization on the vortex blade, and on the other hand, the air current mixture collides the vortex blade of different orientations and takes place to turn to, and adjacent two air currents that turn to collect the mixture towards the direction that is close to each other, and the homogeneity of mixing is better. The utility model discloses a set up the second through-hole on the cambered surface portion of spoiler, partly air current mixture can follow the second through-hole and pass through, can reduce the air current pressure drop on the one hand, and on the other hand can preheat the edge part of back shell, orifice plate and spoiler from the air current that here passes through, reduces the risk that produces the urea crystallization on the edge part of back shell, orifice plate, spoiler.

The rotational flow plate is a circular plate, and the opening direction of the rotational flow blades of each quarter circle on the circular plate is arranged in a central symmetry manner.

The utility model discloses a whirl blade opening direction of every quarter circle is central symmetry setting on the circular plate of whirl board, and the mixed gas stream turns to once more on the whirl blade of every quarter circle part along the internal face whirl of whirl chamber to the whirl board for the mixed gas stream can have the route of longer mixture under the finite length of play chimney, and the mixed effect of mixed gas stream is better, and the homogeneity of mixing is higher.

The pore plate is distributed with a plurality of third through holes in a staggered manner.

The utility model discloses a crisscross a plurality of third through-holes of being covered with on the arc panel of orifice plate, the mixed gas flow of water conservancy diversion intracavity partly flows the open end along the arc panel of orifice plate, and another part passes through from a plurality of third through-holes, can improve the homogeneity that mixed gas flow mixes on the one hand, and on the other hand has increased and has overflowed passageway and flow area, has reduced the air current pressure drop.

The spoiler and the orifice plate are respectively provided with a plurality of bulges, and the front shell and the rear shell are provided with a plurality of mounting holes corresponding to the bulges; during assembly, the bulges on the spoiler and the orifice plate penetrate through the corresponding mounting holes and are fixed on the outer surface of the front shell or the rear shell through welding.

The spoiler and the orifice plate of the utility model are welded and fixed on the front shell and the rear shell through the corresponding mounting holes, and the spoiler and the orifice plate are arranged on the front shell and the rear shell in a penetrating way, on one hand, the welding stability is high, the connection is more stable, the mode of the front shell and the rear shell is improved, and the vibration and the fatigue damage caused by the component resonance in the using process of the front shell and the rear shell are avoided; on the other hand, the mounting hole has a limiting and error-proofing effect, so that the limitation of the tool is reduced, and the tool cost is reduced. The welding seams between the bulges of the spoiler and the orifice plate and the front shell and the rear shell are positioned on the outer surface of the front shell or the rear shell and are not contacted with urea liquid drops in the inner cavity, so that the welding seams are prevented from being corroded by the urea liquid drops, and the corrosion resistance of the assembly is improved.

The utility model has the advantages as follows:

The utility model discloses second air inlet intercommunication water conservancy diversion chamber in the ventiduct, from the partial tail gas air current that the second air inlet came in directly get into the water conservancy diversion intracavity, preheat preceding shell, back shell, spoiler, the corresponding wall of orifice plate, make the urea liquid drop that falls on corresponding wall fully absorb heat and volatilize, improve the evaporation rate of urea liquid drop, and then improve NO's evaporation rate_XThe conversion efficiency of (2) and the heat of tail gas can also accelerate the further sufficient volatilization of urea liquid drops with smaller particles which are not volatilized before in the mixed gas flow in the diversion cavity.

Drawings

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

Fig. 2 is an exploded view of fig. 1.

Fig. 3 is a front view of fig. 1.

Fig. 4 is a rear view of fig. 1.

Fig. 5 is the schematic diagram of the internal structure of the present invention, and at this time, the rear housing is removed.

Fig. 6 is a perspective view of a baffle.

Fig. 7 is a perspective view of the spoiler.

Fig. 8 is a perspective view of an orifice plate.

FIG. 9 is a perspective view of a swirl plate.

In the figure, the structure comprises a front shell 1, a rear shell 2, an air inlet cylinder 3, an air outlet cylinder 4, an air outlet cylinder 5, a top cover 51, a lower plane 52, an upturned part 6, a nozzle seat 7, a flow guide plate 71, a first notch 72, a second notch 73, a first blade hole 74, a flow guide blade 75, a first through hole 8, a spoiler 81, a blade part 82, a closed part 83, a second through hole 84, a second blade hole 85, a spoiler blade 86, a first bulge 9, a pore plate 91, a third through hole 92, a second bulge 10, a swirl plate 101, a third blade hole 102, a swirl blade 11, a first mounting hole 12, a second mounting hole 13, a third mounting hole 14, an inner cavity 15, an injection cavity 16, a flow guide cavity 17, a swirl cavity 18, a first air inlet 19, a second air inlet 19, a urea injection line 20 and an included angle β.

Detailed Description

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

As shown in fig. 1, the front shell 1 of the present invention is fixed on the rear shell 2, the top of the rear shell 2 is fixed with the top cover 5, and the front shell 1, the rear shell 2 and the top cover 5 enclose an internal cavity 14; a nozzle holder 6 is arranged on the top cover 5, and a urea nozzle extends into the inner cavity 14 (not shown in the figure) through the nozzle holder 6; an air inlet cylinder 3 is arranged between the top cover 5 and the upper part of the front shell 1, a guide plate 7 is embedded in an air inlet channel of the air inlet cylinder 3, guide vanes 74 are arranged on the guide plate 7, an air outlet cylinder 4 is arranged at the lower part of the front shell 1, a rotational flow plate 10 is embedded in an air outlet channel of the air outlet cylinder 4, and rotational flow vanes 102 are arranged on the rotational flow plate 10. The utility model discloses the setting is between DPF and the SCR of tail gas aftertreatment, and inlet cylinder 3 is connected to the DPF output, and outlet cylinder 4 is connected to the SCR input (not shown in the figure). As shown in fig. 2, a spoiler 8 and a hole plate 9 are installed between the front housing 1 and the rear housing 2 and at the middle upper part of the inner cavity 14 from top to bottom through corresponding installation holes, and spoiler blades 85 are provided on the spoiler 8; as shown in fig. 5, the spoiler 8 is located below the deflector 7, the orifice plate 9 is located above the whirl plate 10, the spoiler 8 and the orifice plate 9 divide the inner cavity 14 into an upper spray cavity 15, a middle deflector cavity 16 and a lower whirl cavity 17, and the spray cavity 15, the deflector cavity 16 and the whirl cavity 17 are communicated with each other. The utility model discloses an inside cavity 14 only separates through having spoiler 8 and orifice plate 9 to spray chamber 15, water conservancy diversion chamber 16, whirl chamber 17 and form airflow channel, and the interior hindrance of airflow channel is few, and the passageway is more smooth and easy, and when mixed air current flows in airflow channel, the turning department of required process is few, and energy loss is little, and the air current pressure reduces. The utility model has the advantages that the whole structure is simple, required spare part is less, and spare part cost is lower, and the assembly cost of spare part is lower.

As shown in fig. 2, a first through mounting hole 11 is formed on the front wall surface of the front housing 1 corresponding to the orifice plate 9; the rear wall surface of the rear shell 2 is provided with a second mounting hole 12 and a third mounting hole 13 which are communicated with the spoiler 8 and the orifice plate 9 respectively. The spoiler 8 and the orifice plate 9 are welded and fixed on the front shell 1 and the rear shell 2 through corresponding mounting holes, and the spoiler 8 and the orifice plate 9 penetrate through the front shell 1 and the rear shell 2, so that on one hand, the welding stability is high, the connection is more stable, the mode of the front shell 1 and the rear shell 2 is improved, and the vibration and fatigue damage caused by component resonance in the using process of the front shell 1 and the rear shell 2 are avoided; on the other hand, the mounting hole has a limiting and error-proofing effect, so that the limitation of the tool is reduced, and the tool cost is reduced.

As shown in fig. 2, the top cover 5 includes a lower plane 51 connected to the rear housing 2 and an upturned portion 52 connected to the intake barrel 3, as shown in fig. 4, the lower plane 51 is inclined downward and forms an included angle with a vertical plane, and the inclined lower plane 51 makes the ejection chamber 15 become a cavity body asymmetric along the vertical plane; the nozzle holder 6 is located at the lower position of the lower plane 51, and as shown in fig. 5, in actual operation, the urea nozzle is inserted into the nozzle holder 6, and the urea injection line 20 is injected in a direction facing the spoiler blade 85 of the spoiler 8 by adjusting the injection port of the urea nozzle in the nozzle holder 6.

As shown in figures 2, 3 and 6, two opposite sides of a flow guide plate 7 are provided with a first notch 71 and a second notch 72, the bottom edges of the first notch 71 and the second notch 72 are parallel to each other, as shown in figure 3, an arched first air inlet 18 and a second air inlet 19 are formed in an air inlet cylinder 3, the first air inlet 18 is communicated with an injection cavity 15 and a DPF output end, the second air inlet 19 is respectively communicated with the injection cavity 15, a flow guide cavity 16 and the DPF output end, the area of an air flow channel of the first air inlet 18 and the second air inlet 19 is large, the air flow resistance is small, the air flow pressure drop is small, an included angle β between an arched straight chord edge of the first air inlet 18 and the second air inlet 19 and a lower plane 51 of a top cover 5 is an obtuse angle, most of the air flow of the exhaust entering from the first air inlet 18 and the second air inlet 19 enters the injection cavity 15, the lower plane 51 of the top cover 5 is obliquely arranged because the injection cavity 15 is a cavity which is asymmetrical along a plumb line, the exhaust air flow impacts the lower plane 51 of the lower plane 51 and the rear shell 2 to form a rotational flow, the rotational flow is increased in the exhaust flow space of the urea flow, the urea flow mixing cavity, the urea droplet evaporation rate is increased, the urea droplet evaporation rate of the urea droplet evaporation rate is increased, the urea droplet evaporation rate is increased_XThe conversion efficiency of (2) and the heat of the tail gas can also accelerate the further sufficient volatilization of the urea droplets of smaller particles which are not volatilized before in the mixed gas flow in the diversion cavity 16. A plurality of first blade holes 73 arranged in an array are formed in the guide plate 7, and a guide blade 74 is arranged inwards in the direction towards the injection cavity 15 on each first blade hole 73, as shown in fig. 5, the openings of the guide blades 74 are in the same direction and all face towards the disturbance chamberThe mixed air flow can be guided to blow to the turbulence blades 85 in the direction of the turbulence blades 85 of the flow plate 8, on one hand, urea drops can be prevented from being blown to the inner wall surface of the rear shell 2 to form urea crystals when the mixed air flow directly blows the urea spraying line 20, and the risk of the urea crystals on the rear shell 2 is reduced; on the other hand, the guide vanes 74 guide the mixed gas flow to the spoiler vanes 85, so that the heat of the tail gas can be fully utilized, urea droplets falling on the spoiler vanes 85 can fully absorb heat and volatilize, the volatilization rate of the urea droplets is improved, and further NO is improved_XThe conversion efficiency of (a); in addition, the oblique downward arrangement of the guide vanes 74 also helps the exhaust gas flow from the first air inlet 18 and the second air inlet 19 to form a rotational flow. The first blade hole 73 is further provided with first through holes 75 arranged in an array at two outer sides corresponding to the first notch 71 and the second notch 72; the first blade hole 73 and the first through hole 75 are communicated with the spraying cavity 15 and the DPF output end, and the tail gas flow coming from the first blade hole 73 and the first through hole 75 is driven by the tail gas flow coming from the first air inlet 18 and the second air inlet 19 to form a rotational flow around the urea spraying line 20. The first through holes 75 can guide a part of the tail gas flow, so that the phenomenon that the rotational flow effect of the mixed gas flow is influenced due to the fact that the speed of the gas flow is too high as most of the tail gas flow directly enters the injection cavity 15 from the first air inlet 18 and the second air inlet 19 is avoided; at the same time, the reduction of the air flow through the first vane holes 73, which would affect the uniformity of the mixing, is avoided, and the reduction of the air flow through the first vane holes 73 also increases the risk of urea crystallization on the guide vanes 74.

As shown in fig. 7, the spoiler 8 is an arc-shaped plate, as shown in fig. 2, two outer end portions of the arc-shaped plate are respectively fixed to corresponding side wall surfaces of the rear housing 2, a half arc of the arc-shaped plate, which is opposite to the inclined lower plane 51 of the top cover 5, is a blade portion 81, the other half arc is a closed portion 82, a side edge of the arc-shaped plate, which corresponds to the rear housing 2, is outwardly protruded with a plurality of first protrusions 86, the first protrusions 86 correspond to the third mounting holes 13 of the rear housing 2, during assembly, the first protrusions 86 penetrate the third mounting holes 13 and are fixed to the outer surface of the rear housing 2 by welding, and a welding line is located on the outer surface of the rear housing 2 and does not contact with urea droplets in the internal cavity 14, so that the welding line is prevented from being corroded by the urea droplets, and the. As shown in fig. 7, the blade portion 81 is provided with a plurality of second blade holes 84 arranged in an array, and the second blade holes 84 are provided with spoiler blades 85 downward in a direction toward the orifice plate 9. The plurality of turbulence blades 85 on the blade portion 81 near the arc-shaped outer end face in the same direction and all face the direction of the orifice plate 9, in this embodiment, the two rows of turbulence blades 85 near the arc-shaped outer end face in the direction of the orifice plate 9 to guide the outside airflow to flow toward the orifice plate 9, so as to prevent the airflow from impacting the side wall surface of the rear housing 2 and form urea crystals on the side wall surface; the opening of the vortex blade 85 of adjacent two is crisscross sets up, and on the one hand, the urea liquid droplet striking that does not volatilize in the air current is on vortex blade 85, and the secondary crushing is littleer liquid droplet, changes in volatilizing of urea liquid droplet, produces the risk of urea crystallization on reducing vortex blade 85, and on the other hand, the mixed gas stream bumps and turns to taking place on the vortex blade 85 of different orientations, and adjacent two air streams that turn to converge towards the direction that is close to each other and collide the mixture, and the homogeneity of mixing is better. The closed part 82 is used for blocking and forming rotational flow and guiding the mixed air flow to pass through the blade part 81, a plurality of second through holes 83 are formed in the closed part 82 close to the arc-shaped outer end, a part of the mixed air flow can pass through the second through holes 83, on one hand, air flow pressure drop can be reduced, on the other hand, the edge parts of the rear shell 2, the pore plate 9 and the spoiler 8 can be preheated through the air flow passing through the second through holes 83, and the risk of urea crystallization generated on the edge parts of the rear shell 2, the pore plate 9 and the spoiler 8 is reduced.

As shown in fig. 5, an opening is formed below the sealing portion 82 of the spoiler 8 by suspending one end of the orifice plate 9, as shown in fig. 8, the orifice plate 9 is an arc-shaped plate, a plurality of third through holes 91 are distributed on the arc-shaped panel in a staggered manner, a part of mixed air flow in the diversion cavity 16 flows to the opening below the sealing portion 82 along the arc-shaped panel of the orifice plate 9, and the other part of mixed air flow passes through the third through holes 91, so that the mixing uniformity of the mixed air flow can be improved, the flow passage and the flow area are increased, and the air flow pressure drop is reduced. The both sides that correspond with preceding shell 1, back shell 2 on the orifice plate 9 are protruding respectively and are had a plurality of second arch 92, as shown in fig. 2, second arch 92 respectively with the first mounting hole 11 of preceding shell 1, the second mounting hole 12 of back shell 2 is corresponding, during the assembly, the second arch 92 of orifice plate 9 both sides passes first mounting hole 11, second mounting hole 12 respectively, and pass through welded fastening on the surface of preceding shell 1, back shell 2, welding stability is high, the welding seam is located preceding shell 1, the surface of back shell 2, do not contact with the urea liquid drop in the internal cavity 14, avoided the welding seam to be corroded by the urea liquid drop, and then improved the anti-corrosion ability of subassembly.

As shown in fig. 9, the swirl plate 10 is a circular plate, a plurality of third vane holes 101 arranged in an array are formed in the circular plate, a swirl blade 102 is arranged on each third vane hole 101 in an outward direction, the opening direction of each swirl blade 102 of each quarter circle on the circular plate is arranged in a central symmetry manner, the opening angle of each swirl blade 102 along the surface of the circular plate is 35-45 degrees, the mixed airflow swirls onto the swirl plate 10 along the inner wall surface of the swirl cavity 17, and turns to the swirl blades 102 of each quarter circle again, so that the swirl is further accelerated, the mixed airflow can have a longer mixing path under the limited length of the air outlet barrel 4, the mixed airflow has a better mixing effect and higher mixing uniformity.

When the utility model works practically, the urea nozzle in the nozzle seat 6 sprays urea liquid drops into the spraying cavity 15 to form a urea spraying line 20; the tail gas is output from the output end of the DPF, most of the tail gas flow is guided to enter the spraying cavity 15 through the guide plate 7 in the air inlet cylinder 3 to form rotational flow, a small part of the tail gas flow enters the guide cavity 16, and the urea liquid drops in the spraying cavity 15 absorb the heat of the tail gas flow to complete the first decomposition of the urea liquid drops and form mixed gas flow; the mixed gas flow flows through the spoiler 8, the urea liquid drops which are not decomposed in the mixed gas flow collide with the spoiler blade 85, are crushed into urea liquid drops with smaller particles, further volatilize into the mixed gas flow after absorbing heat, and flow into the flow guide cavity 16 along with the mixed gas flow, so that the secondary decomposition and mixing of the urea liquid drops are completed; part of mixed air flow in the diversion cavity 16 flows to the rotational flow cavity 17 from the third through hole 91 on the pore plate 9, part of mixed air flow directly flows to the rotational flow cavity 17 from an opening at one end of the pore plate 9 and below the closed part 82 of the spoiler 8, the two parts of mixed air flow are converged in the rotational flow cavity 17, urea liquid drops further absorb heat to volatilize into the air flow, and urea is completedThird break up and mixing of droplets; the mixed air flow in the rotational flow cavity 17 rotates in an accelerating way through the rotational flow plate 10 in the air outlet cylinder 4, the mixing path is prolonged, the volatilization and mixing time of urea liquid drops is prolonged, and the urea liquid drops further absorb heat to volatilize into the air flow to complete the fourth decomposition and mixing of the urea liquid drops; the mixed gas stream output from the swirl plate 10 is input to the SCR input. The tail gas air flow is in the utility model discloses an inside cavity 14 interior through quartic decomposition and mixing, the urea dropping liquid has obtained abundant decomposition, the NH that decomposes out₃Fully mixed with tail gas, high mixing uniformity and NO_XThe conversion rate is high.

The above description is illustrative of the present invention and is not intended to limit the present invention, and the present invention may be modified in any manner without departing from the spirit of the present invention. For example, instead of providing the inclined lower surface 51 on the top cover 5, an inclined flat member may be provided directly in the ejection chamber 15 to form an inclined plane, as long as the purpose of forming the ejection chamber 15 into an asymmetrical chamber is achieved. The first blade hole 73, the first through hole 75, the second through hole 83, the second blade hole 84, the third through hole 91, and the third blade hole 101 may be square holes, circular holes, or through holes of other shapes as long as the through holes are formed to allow the mixed gas to pass therethrough; the shapes of the guide vanes 74, the spoiler vanes 85 and the swirl vanes 102 are respectively matched with the shapes of the first vane holes 73, the second vane holes 84 and the third vane holes 101, so that the purposes of guiding, disturbing or accelerating swirl of the mixed air flow are achieved. The guide plate 7 may also be provided with a plurality of elongated holes in an array, and each elongated hole is provided with a plurality of guide vanes 74, so long as the guide vanes 74 can guide the airflow to the spoiler blade 85. A plurality of strip-shaped holes can be formed in the spoiler 8 in an array mode, a plurality of spoiler blades 85 are arranged on each strip-shaped hole, and the purpose that the spoiler blades 85 enable mixed air to turn is achieved. A plurality of strip-shaped holes can be formed in the cyclone plate 10 in an array mode, a plurality of cyclone blades 102 are arranged on each strip-shaped hole, and the purpose that the cyclone blades 102 enable mixed airflow to rotate in an accelerating mode can be achieved.

Claims

1. The utility model provides a urea aqueous solution decomposes mixing arrangement, the setting is between DPF and SCR of tail gas aftertreatment, including preceding shell (1), back shell (2), be connected to air inlet tube (3) of DPF output, be connected to air outlet tube (4) of SCR input, form inside cavity (14) between preceding shell (1) and the back shell (2), be equipped with spoiler (8) and orifice plate (9) from last to down between preceding shell (1) and the back shell (2), spoiler (8) and orifice plate (9) divide into spray chamber (15) on upper portion with inside cavity (14), the whirl chamber (17) of middle water conservancy diversion chamber (16) and lower part, its characterized in that:

a top cover (5) is arranged at the top of the rear shell (2), the injection cavity (15) is positioned among the air inlet cylinder (3), the rear shell (2), the top cover (5) and the spoiler (8), and an inclined plane with an included angle with a vertical plane is arranged in the injection cavity (15); a guide plate (7) is embedded in the air inlet cylinder (3), a first notch (71) and a second notch (72) are formed in the guide plate (7), a first air inlet (18) and a second air inlet (19) are formed in the air inlet cylinder (3), a guide vane (74) is arranged in a first vane hole (73) in the guide plate (7) towards the injection cavity (15), and the injection cavity (15) is communicated with the output end of the DPF through the first air inlet (18), the second air inlet (19) and the first vane hole (73);

the flow guide cavity (16) is positioned between the spoiler (8) and the orifice plate (9), and the second blade hole (84) on the spoiler (8) is provided with spoiler blades (85) facing the orifice plate (9);

the swirl cavity (17) is positioned among the pore plate (9), the front shell (1), the rear shell (2) and the air outlet cylinder (4), a swirl plate (10) is embedded in the air outlet cylinder (4), and swirl blades (102) are outwards arranged on the swirl plate (10) through a third blade hole (101).

2. The decomposition mixing device for an aqueous urea solution according to claim 1, wherein: the inclined plane is a lower plane (51) of the top cover (5), a nozzle seat (6) is arranged at the lower position of the lower plane (51), and a urea nozzle extends into the nozzle seat (6) during operation.

3. The decomposition mixing device for an aqueous urea solution according to claim 1, wherein: the opening of the guide vane (74) on the guide plate (7) is opposite to the spoiler vane (85) on the spoiler (8).

4. The decomposition mixing device for an aqueous urea solution according to claim 1, wherein: the guide plate (7) is further provided with a first through hole (75), the first through hole (75) is located on the outer side of the guide vane (74), and the first through hole (75) is communicated with the injection cavity (15) and the DPF output end.

5. The decomposition mixing device for an aqueous urea solution according to claim 1, wherein: the second air inlet (19) is also communicated with the flow guide cavity (16) and the DPF output end.

6. The decomposition mixing device for an aqueous urea solution according to claim 1, wherein: the first air inlet (18) and the second air inlet (19) are in a bow shape, and an included angle between a straight chord edge of the bow shape and the inclined plane is an obtuse angle.

7. The decomposition mixing device for an aqueous urea solution according to claim 1, wherein: the spoiler (8) is an arc-shaped plate and comprises a blade part (81) and a closed part (82), a plurality of spoiler blades (85) are arranged on the blade part (81) in an array mode, and openings of two adjacent rows of spoiler blades (85) are arranged in a staggered mode; a plurality of rows of spoiler blades (85) with the same orientation are arranged on the blade part (81) close to the outer end of the arc; a plurality of second through holes (83) are formed in the closed part (82) and close to the arc-shaped outer end.

8. The decomposition mixing device for an aqueous urea solution according to claim 1, wherein: the rotational flow plate (10) is a circular plate, and the opening direction of each quarter circle rotational flow blade (102) on the circular plate is arranged in a central symmetry manner.

9. The decomposition mixing device for an aqueous urea solution according to claim 1, wherein: a plurality of third through holes (91) are distributed on the pore plate (9) in a staggered way.

10. The decomposition mixing device for an aqueous urea solution according to claim 1, wherein: a plurality of bulges are respectively arranged on the spoiler (8) and the orifice plate (9), and a plurality of mounting holes are formed in the front shell (1) and the rear shell (2) corresponding to the bulges; during assembly, the bulges on the spoiler (8) and the pore plate (9) penetrate through the corresponding mounting holes and are fixed on the outer surface of the front shell (1) or the rear shell (2) by welding.