Urea solution storage device and storage method

Abstract

The invention relates to the technical field of storage, in particular to a urea solution storage device and a urea solution storage method.The urea solution storage device comprises a tank body, the tank body is composed of a cylindrical barrel and a conical bottom, a liquid discharging pipe is arranged at the lowest point of the conical bottom, and the urea solution storage device further comprises a stirring mechanism and a liquid discharging mechanism, an upper discharging mechanism is coaxially arranged in the hollow pipe; and an aeration mechanism. A high-concentration area and a low-concentration area in the tank body can be mixed to form radial diffusion, so that urea molecules are uniformly dispersed, local concentration supersaturation is avoided, and the device can be regularly started and used in the storage tank; in the synchronous stirring process, the liquid is sucked from the bottom of the hollow pipe and diffused to the periphery from the top of the hollow pipe, so that an axial circulating flow field is formed, and no stirring dead zone exists in the tank body; the aeration mechanism is arranged, released bubbles can generate disturbance in the rising process, the surface tension of the solution is destroyed, the shearing force generated when the bubbles are broken can disperse tiny crystal particles, and the crystal particles are prevented from being agglomerated.

Description

Technical Field

[0001] The present invention relates to the field of storage technology, and in particular to a urea solution storage device and a storage method. Background Art

[0002] Urea, also known as carbamide or urea, is an organic compound composed of carbon, nitrogen, oxygen, and hydrogen. It appears as white crystals and is one of the simplest organic compounds. Urea is the primary nitrogenous end product of protein metabolism in mammals and some fish.

[0003] Urea is primarily used in thermal power plants as a reducing agent in Selective Catalytic Reduction (SCR) denitrification technology. SCR is a widely used flue gas denitrification technology that reduces nitrogen oxides (NOx) into nitrogen and water under the action of a catalyst, thereby reducing nitrogen oxide emissions in the atmosphere.

[0004] However, existing storage devices (tanks) have a "non-flow zone" (dead zone) at the bottom of the cone, caused by slow fluid flow. This zone is typically defined as a flow rate of less than 0.05 m / s. When urea solution is retained in this dead zone, it is prone to crystallization and accumulation of impurities, forming a solid accumulation layer that affects the subsequent use of the storage device. Summary of the Invention

[0005] The object of the present invention is to solve the above-mentioned deficiencies and provide a urea solution storage device and a storage method.

[0006] In order to solve the above technical problems, the present invention adopts the following technical solution: a urea solution storage device, comprising a tank body, the tank body comprising a cylindrical barrel and a conical bottom, the conical bottom being docked at the bottom of the cylindrical barrel, a drain pipe being provided at the lowest point of the conical bottom, and further comprising:

[0007] The stirring mechanism includes a hollow tube vertically arranged in the tank along the center line of the tank, a stirring blade arranged on the outer wall of the hollow tube and used to mix the high-concentration area and the low-concentration area in the tank, and an upper discharge mechanism coaxially arranged inside the hollow tube for sucking the solution distributed at the cone bottom downward and discharging upward;

[0008] The aeration mechanism is arranged at the connection between the columnar barrel and the conical bottom, and is used for releasing bubbles and generating buoyancy to drive the bottom solution convection during the rising process of the bubbles.

[0009] Furthermore, the upper row mechanism includes a guide vane coaxially arranged in the hollow tube, a lower suction port arranged outside the lower end of the guide vane and fixed at the bottom of the hollow tube, and an upper row port connected to the interior of the hollow tube is arranged outside the upper end of the guide vane and slotted at the high point of the cylindrical barrel.

[0010] Furthermore, a power shaft for driving the guide blade to rotate inside the hollow tube is provided through the end surface of the guide blade, a motor is provided at the top end of the power shaft which passes through the top surface of the tank body, and a transmission component 1 for driving the hollow tube to move synchronously is provided on the power shaft;

[0011] The transmission assembly includes a first support plate arranged in the hollow tube and rotatably sleeved on the outside of the power shaft, a first ring gear arranged on the upper side of the first support plate and fixed to the inner wall of the hollow tube, the inner side of the first ring gear is engaged with a first gear rotatably connected to the upper end of the first support plate, and a second gear sleeved and fixed on the outside of the power shaft is provided on the side of the first gear away from the first ring gear.

[0012] Furthermore, the aeration mechanism includes an air source conduit extending from the outside of the tank body into the tank body, and an air distribution pipe fixedly arranged at the inner end of the air source conduit, and a plurality of aeration holes are evenly arranged on the upper side of the air distribution pipe.

[0013] Furthermore, an inner tube is coaxially rotatably provided inside the air distribution pipe, and a power assembly for driving the inner tube to rotate inside the air distribution pipe is provided at the outer end of the inner tube;

[0014] The power assembly includes a third gear coaxially arranged at the outer end of the inner tube, and a rack vertically arranged and meshing with the outer side of the third gear.

[0015] Furthermore, a block is provided on the outside of the lower suction port to close or open the upper port of the discharge pipe, and a scraper is provided on the outer side of the block to fit against the bottom of the cone and scrape off the crystalline material accumulated on the bottom of the cone, and an electric push rod is provided on the outer side of the block to drive the block to move vertically up and down along the axis of the tank body.

[0016] Furthermore, a transmission assembly 2 is provided on the upper portion of the blocking block and rotates synchronously with the hollow tube;

[0017] The second transmission component includes a second support plate rotatably mounted on the outside of the hollow tube and a second gear ring fixedly mounted on the top surface of the block, the inner side of the second gear ring is engaged with a fourth gear rotating on the end surface of the second support plate, and a fifth gear fixedly mounted on the outside of the hollow tube is provided on the side of the fourth gear away from the meshing point between the second gear ring and the fourth gear.

[0018] Furthermore, a support ring is rotatably provided on the outer end of the second gear ring, and a connecting rod fixedly connected to the rack is provided on the outer side of the support ring.

[0019] Furthermore, a heating or cooling jacket for controlling the temperature of the solution is provided on the inner side of the tank.

[0020] A urea solution storage method, during storage, can first periodically use the blocking block to move downward to close the upper end opening of the drainage pipe and open the aeration hole, then use the stirring mechanism to stir in the tank body to form a radial flow field, and under the action of the upper discharge mechanism, push the solution at the cone bottom to be sucked from the bottom of the hollow tube, and diffuse to the surroundings at the top of the hollow tube to form an axial circulation flow field, and under the action of the aeration mechanism, the released bubbles generate disturbances during the rising process, destroying the surface tension of the solution, and the shear force when the bubbles burst can disperse tiny crystalline particles, and the superimposed bubble flow and stirring flow form a composite flow field of "mechanical stirring + gas-liquid agitation".

[0021] Compared with the prior art, the present invention has the following beneficial effects: the present invention can mix the high-concentration area and the low-concentration area in the tank body through the stirring mechanism, form radial diffusion, make the urea molecules evenly dispersed, avoid local concentration oversaturation, and can be started and used regularly in the storage tank; and through the upper discharge mechanism, during the stirring process, it is simultaneously sucked in from the bottom of the hollow tube and diffused to the surrounding areas at the top of the hollow tube, forming an axial circulation flow field, so that there is no stirring dead zone in the tank body; and through the aeration mechanism, the released bubbles will generate disturbances during the rising process, destroying the surface tension of the solution, and the shear force when the bubbles burst can disperse tiny crystalline particles, further preventing the crystalline particles from agglomerating. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The accompanying drawings, which constitute part of this application, are intended to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are intended to explain the present invention and do not constitute an undue limitation of the present invention. In the accompanying drawings:

[0023] Figure 1 A three-dimensional structural diagram of an embodiment of the present invention from one perspective;

[0024] Figure 2 A perspective structural diagram of a cross section of an embodiment of the present invention;

[0025] Figure 3 is a schematic planar structural diagram of a cross section of an embodiment of the present invention from a front perspective;

[0026] Figure 4 A three-dimensional structural diagram of the internal structure of an embodiment of the present invention from one perspective;

[0027] Figure 5 A three-dimensional structural diagram of the internal structure of an embodiment of the present invention from another perspective;

[0028] Figure 6 A three-dimensional structural diagram showing a cross-sectional view of a partial internal structure of an embodiment of the present invention;

[0029] Figure 7 This is a schematic diagram of the structural connection included in the transmission assembly in one embodiment of the present invention;

[0030] Figure 8 Schematic diagram of the structural connection included in the transmission component 2 in one embodiment of the present invention.

[0031] In the figure: 100, cylindrical cylinder; 101, cone bottom; 1, stirring mechanism; 11, hollow tube; 12, stirring blade; 2, upper discharge mechanism; 21, guide blade; 211, power shaft; 22, lower suction port; 23, upper discharge port; 3, aeration mechanism; 31, air source conduit; 32, air distribution pipe; 33, aeration hole; 34, inner tube; 4, transmission component 1; 41, first support plate; 42, first ring gear; 43, first gear; 44, second gear; 5, power component; 51, third gear; 52, rack; 6, block; 7, scraper; 8, transmission component 2; 81, second support plate; 82, second ring gear; 83, fourth gear; 84, fifth gear; 9, support ring; 91, connecting rod. DETAILED DESCRIPTION

[0032] The technical solutions in the embodiments of the present invention will be described clearly and completely below. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. In the absence of conflict, the embodiments in this application and the features in the embodiments can be combined with each other. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0033] like Figure 1-8 As shown, the present invention provides a urea solution storage device, including a tank body, which is composed of a cylindrical barrel 100 and a conical bottom 101. The conical bottom 101 is connected to the bottom of the cylindrical barrel 100, and a drain pipe is provided at the lowest point of the conical bottom 101. The device also includes:

[0034] The stirring mechanism 1 includes a hollow tube 11 vertically disposed within the tank along the centerline of the tank, a stirring blade 12 disposed on the outer wall of the hollow tube 11 and used to mix the high-concentration area and the low-concentration area within the tank, and an upper discharge mechanism 2 coaxially disposed within the hollow tube 11 for sucking the solution distributed on the conical bottom 101 downward and discharging it upward;

[0035] The aeration mechanism 3 is provided at the connection between the cylindrical barrel 100 and the conical bottom 101 and is used for releasing bubbles and generating buoyancy to drive the bottom solution convection during the rising process of the bubbles.

[0036] In a specific implementation, the tank body is formed by integrally forming a cylindrical barrel 100 and a conical bottom 101, and a drain pipe is installed at the lowest point of the conical bottom 101 on the lower side of the tank body to discharge the residual urea solution in the tank body;

[0037] The hollow tube 11 installed vertically and along the axis of the tank body and the stirring blades 12 welded equidistantly outside the hollow tube 11 can evenly mix the high-concentration area and the low-concentration area in the tank body, forming radial diffusion, so that the urea molecules are evenly dispersed, avoiding local oversaturation of concentration, and can be started and used regularly in the storage tank; and the upper discharge mechanism 2 installed in the hollow tube 11 can suck in from the bottom of the hollow tube 11 during the stirring process, diffuse to the surrounding areas at the top of the hollow tube 11, and form an axial circulation flow field, so that there is no stirring dead zone in the tank body, especially the solution located at the cone bottom 101 will be circulated and discharged under the action of the upper discharge mechanism 2;

[0038] The aeration mechanism 3 installed in the tank body releases bubbles that will cause disturbances during the rising process, destroying the surface tension of the solution, and the shear force when the bubbles burst can disperse the tiny crystalline particles. Combined with the bubble flow and stirring flow superimposed on the stirring mechanism 1, a composite flow field of "mechanical stirring + gas-liquid stirring" can be formed to disperse the urea microcrystals and prevent the crystal particles from agglomerating.

[0039] In one embodiment, the upper discharge mechanism 2 includes a guide vane 21 coaxially arranged in the hollow tube 11, a lower suction port 22 provided on the outside of the lower end of the guide vane 21 and fixed at the bottom of the hollow tube 11, and an upper discharge port 23 communicating with the interior of the hollow tube 11 is provided on the outside of the upper end of the guide vane 21 and slotted at the high point of the cylindrical barrel 100. With this design, through the guide vane 21 coaxially installed in the hollow tube 11, the lower suction port 22 communicating at the bottom of the hollow tube 11, and the upper discharge port 23 communicating at the top of the hollow tube 11, when the guide vane 21 is rotated by an external force, the rotating flow field generated causes the solution at the lower suction port 22 to be sucked in, and then diffused to the surroundings at the upper discharge port 23, forming an axial circulation flow field, thereby ensuring that there is no dead zone in the tank.

[0040] In one embodiment, a power shaft 211 is provided through the end surface of the guide blade 21 to drive the guide blade 21 to rotate inside the hollow tube 11. The top end of the power shaft 211 passes through the top surface of the tank and is provided with a motor. The power shaft 211 is provided with a transmission component 4 to drive the hollow tube 11 to move synchronously.

[0041] The transmission assembly 4 includes a first support plate 41 arranged in the hollow tube 11 and rotatably sleeved on the outside of the power shaft 211, a first ring gear 42 arranged on the upper side of the first support plate 41 and fixed on the inner wall of the hollow tube 11, the inner side of the first ring gear 42 is engaged with a first gear 43 rotatably connected to the upper end of the first support plate 41, and a second gear 44 sleeved and fixed on the outside of the power shaft 211 is provided on the side of the first gear 43 away from the first ring gear 42. With this design, the motor is started by starting the power shaft 211 passing through the center of the end face of the guide blade 21 and the motor installed on the coupling at the top of the power shaft 211. On the one hand, it drives the guide blade 21 mounted on the power shaft 211 to rotate inside the hollow tube 11, forming an axial circulating flow field. On the other hand, it drives the second gear 44 mounted on a section of the power shaft 211 to rotate. Through the first gear 43 meshing with the outside of the second gear 44 and the first gear ring 42 meshing with the outside of the first gear 43, the force is transmitted to drive the hollow tube 11 welded to the outer wall of the first gear ring 42, thereby realizing that the stirring blade 12 installed outside the hollow tube 11 mixes and stirs the solution in the storage tank, forming a radial flow field.

[0042] In one embodiment, the aeration mechanism 3 includes an air source conduit 31 extending from the exterior of the tank body into the interior of the tank body, an air distribution pipe 32 fixedly mounted at the inner end of the air source conduit 31, and a plurality of aeration holes 33 evenly distributed on the upper side of the air distribution pipe 32. With this design, through the air source conduit 31 inserted through a slot in the tank body, the air distribution pipe 32 mounted at the inner end of the air source conduit 31, and the plurality of aeration holes 33 evenly distributed on the air distribution pipe 32, when the air source power transmission device connected to the exterior of the air source conduit 31 is activated, bubbles are released upward from the aeration holes 33 through the air source conduit 31 and air distribution pipe 32. During the bubbles' rise, the resulting disturbance can disrupt the surface tension of the solution, while the shear force generated when the bubbles burst can disperse tiny crystalline particles, effectively preventing crystallization.

[0043] It should be noted that the gas source introduced into the air source conduit 31 can be compressed air, nitrogen, ammonia, CO2, and water vapor. Among them, compressed air is suitable for preventing urea solution from crystallizing (cooperating with stirring to prevent urea precipitation) and homogenizing treatment; nitrogen is used to prevent urea solution from contacting and oxidizing with O2 (such as automotive urea solution with a urea concentration greater than 32.5%), or to inhibit microbial reproduction (the metabolic rate of microorganisms is reduced by 80% in an N2 environment); ammonia is used in conjunction with the aeration mechanism 3 for pH adjustment; CO2 is used to adjust the pH of the urea solution to a weak acidity (pH 5.5-6.5) and inhibit urea hydrolysis (the hydrolysis rate is reduced by 30%), which is suitable for scenarios where the formation of ammonium carbamate needs to be controlled; water vapor is used to heat the solution (such as preventing urea crystallization in winter) to achieve temperature increase.

[0044] In one embodiment, an inner tube 34 is coaxially arranged inside the gas distribution pipe 32, and a power assembly 5 is provided at the outer end of the inner tube 34 to drive the inner tube 34 to rotate inside the gas distribution pipe 32;

[0045] The power assembly 5 includes a third gear 51 coaxially arranged at the outer end of the inner tube 34, and a rack 52 vertically arranged and meshingly engaged with the outer side of the third gear 51. With this design, through the inner tube 34 installed inside the gas distribution pipe 32 and the third gear 51 sleeved on the outer end of the inner tube 34, when an external force is applied to vertically move the rack 52, the meshing connection between the rack 52 and the third gear 51 causes the third gear 51 and the inner tube 34 passing through the end face of the third gear 51 to rotate within the gas distribution pipe 32, thereby closing or opening the aeration holes 33 uniformly arranged on the gas distribution pipe 32. This prevents the solution in the storage tank from backflowing into the gas distribution pipe 32 in the absence of air supply, effectively reducing the occurrence of blockage.

[0046] It should be noted that a number of evenly distributed aeration holes 33 are also machined on one side of the inner tube 34. When the inner tube 34 rotates, the aeration holes 33 thereon will correspond to the aeration holes 33 on the air distribution pipe 32 to generate bubbles. When the aeration holes 33 of the above two structures are misaligned, the aeration holes 33 on the air distribution pipe 32 will be closed to prevent the solution from flowing back into the air distribution pipe 32.

[0047] In one embodiment, a block 6 is provided on the outside of the lower suction port 22 to close or open the upper end of the discharge pipe. A scraper 7 is provided on the outside of the block 6 to fit over the conical bottom 101 and scrape off any crystallized material that has accumulated on the conical bottom 101. An electric push rod is also provided on the outside of the block 6 to drive the block 6 to move vertically up and down along the axis of the tank. With this design, during storage, when the electric push rod is activated and drives the block 6 to move vertically downward, the upper end of the discharge pipe is sealed, preventing solution from entering the discharge pipe and being clogged by crystals.

[0048] In addition, by installing a block 6 on the outside of the lower suction port 22 and a scraper 7 on the outside side of the block 6, since the bottom surface of the scraper 7 is adapted to the slope of the cone bottom 101, when the block 6 is rotated by external force, the scraper 7 will effectively destroy the crystallization layer on the surface of the cone bottom 101, further preventing crystallization.

[0049] It should be noted that a through groove is provided on the lower side of the peripheral surface of the block 6 and is connected to the upper end opening of the drainage pipe. When the block 6 moves upward, the through groove can guide the solution into the drainage pipe for external drainage.

[0050] In one embodiment, a transmission assembly 8 is provided on the upper portion of the blocking block 6 and rotates synchronously with the hollow tube 11;

[0051] The transmission assembly 2 8 includes a second support plate 81 rotatably mounted on the outside of the hollow tube 11 and a second gear ring 82 fixedly mounted on the top surface of the block 6. The inner side of the second gear ring 82 is meshed with a fourth gear 83 that rotates on the end surface of the second support plate 81. A fifth gear 84 that is fixedly mounted on the outside of the hollow tube 11 is provided on the side of the fourth gear 83 away from the meshing point between the second gear ring 82 and the fourth gear 83. With this design, through the fourth gear 83 mounted on the second support plate 81 rotatably mounted on the outside of the hollow tube 11, and the second gear ring 82 and the fifth gear 84 that mesh on both sides of the fourth gear 83, when the hollow tube 11 rotates, the force transmitted through the fifth gear 84, the fourth gear 83, and the second gear ring 82 drives the block 6 welded at the lower end of the second gear ring 82 to rotate, thereby causing the scraper 7 welded on the outside of the block 6 to destroy the crystal layer on the upper surface of the cone bottom 101.

[0052] In one embodiment, a support ring 9 is rotatably mounted on the outer end of the second gear ring 82, and a connecting rod 91 is mounted on the outer side of the support ring 9, which is fixedly connected to the rack 52. This design allows the support ring 9 to rotate in phase within the guide groove slotted and mounted on the outer end of the second gear ring 82, and the connecting rod 91 welded to the outer end of the support ring 9, and the upper end of the connecting rod 91 is welded and fixed to the rack 52. This allows the force of the vertical movement of the rack 52 to move synchronously with the blocking block 6 mounted on the second gear ring 82, thereby sealing the upper end opening of the drain pipe while simultaneously opening the aeration holes 33 on the aeration mechanism 3, thereby facilitating regular crystallization processing operations within the closed tank area.

[0053] In one embodiment, the tank body is equipped with a heating or cooling jacket inside to control the solution temperature. This design utilizes a heating jacket that circulates hot water to prevent the temperature from falling below -11°C, which could cause urea solution crystallization. The cooling jacket, on the other hand, prevents solution volatilization or decomposition during high summer temperatures through a water-cooling circulation system, ensuring the tank's storage temperature remains between 5°C and 25°C.

[0054] A urea solution storage method, during storage, the block 6 can be periodically moved downward to close the upper end opening of the drain pipe and open the aeration hole 33, and then the stirring mechanism 1 is used to stir in the tank body to form a radial flow field, and under the action of the upper discharge mechanism 2, the solution at the cone bottom 101 is pushed to be sucked from the bottom of the hollow tube 11 to the top of the hollow tube 11 and diffused to the surrounding areas, forming an axial circulation flow field. In addition, under the action of the aeration mechanism 3, the released bubbles generate disturbances during the rising process, destroying the surface tension of the solution, and the shear force when the bubbles burst can disperse tiny crystalline particles. The superimposed bubble flow and stirring flow form a composite flow field of "mechanical stirring + gas-liquid agitation".

[0055] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

[0056] It should be noted that if the embodiments of the present invention involve directional indications (such as up, down, left, right, front, back, etc.), the directional indications are only used to explain the relative position relationship, movement status, etc. between the components under a certain specific posture. If the specific posture changes, the directional indications will also change accordingly.

[0057] In addition, if there are descriptions involving "first", "second", etc. in the embodiments of the present invention, the descriptions of "first", "second", etc. are only for descriptive purposes and cannot be understood as indicating or suggesting their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of such features. In addition, the meaning of "and / or" appearing throughout the text includes three parallel schemes. Taking "A and / or B" as an example, it includes scheme A, or scheme B, or schemes in which A and B are satisfied at the same time. In addition, "several" refers to more than two. In addition, the technical solutions between the various embodiments can be combined with each other, but it must be based on the ability of ordinary technicians in this field to implement. When the combination of technical solutions is mutually contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

Claims

1. A urea solution storage device, comprising a tank body, wherein the tank body is composed of a cylindrical barrel (100) and a conical bottom (101), wherein the conical bottom (101) is docked at the bottom of the cylindrical barrel (100), and a drain pipe is provided at the lowest point of the conical bottom (101), characterized in that: Also includes: A stirring mechanism (1) comprises a hollow tube (11) vertically arranged in the tank along the center line of the tank, a stirring blade (12) arranged on the outer wall of the hollow tube (11) and used to mix the high-concentration area and the low-concentration area in the tank, and an upper discharge mechanism (2) coaxially arranged inside the hollow tube (11) for sucking the solution distributed on the cone bottom (101) downward and discharging it upward; An aeration mechanism (3) is provided at the connection between the columnar barrel (100) and the conical bottom (101), and is used for releasing bubbles and generating buoyancy to drive convection of the bottom solution during the rising process of the bubbles.

2. The urea solution storage device according to claim 1, characterized in that: The upper discharge mechanism (2) comprises a guide vane (21) coaxially arranged in the hollow tube (11), a lower suction port (22) arranged outside the lower end of the guide vane (21) and fixed at the bottom of the hollow tube (11), and an upper discharge port (23) communicating with the interior of the hollow tube (11) is provided outside the upper end of the guide vane (21) and slotted at a high point of the cylindrical barrel (100).

3. The urea solution storage device according to claim 2, characterized in that: The end surface of the guide blade (21) is provided with a power shaft (211) for driving the guide blade (21) to rotate inside the hollow tube (11); the top end of the power shaft (211) passes through the top surface of the tank body and is provided with a motor; the power shaft (211) is provided with a transmission component (4) for driving the hollow tube (11) to move synchronously; The transmission assembly (4) includes a first support plate (41) arranged in the hollow tube (11) and rotatably sleeved on the outside of the power shaft (211), a first gear ring (42) arranged on the upper side of the first support plate (41) and fixed on the inner wall of the hollow tube (11), a first gear (43) rotatably connected to the upper end of the first support plate (41) is engaged on the inner side of the first gear ring (42), and a second gear (44) sleeved and fixed on the outside of the power shaft (211) is provided on the side of the first gear (43) away from the first gear ring (42).

4. The urea solution storage device according to claim 1, characterized in that: The aeration mechanism (3) comprises an air source conduit (31) extending from the outside of the tank body into the tank body, and an air distribution pipe (32) fixedly arranged at the inner end of the air source conduit (31), wherein a plurality of aeration holes (33) are evenly arranged on the upper side of the air distribution pipe (32).

5. The urea solution storage device according to claim 4, characterized in that: An inner tube (34) is coaxially rotatably provided inside the air distribution pipe (32), and a power assembly (5) for driving the inner tube (34) to rotate inside the air distribution pipe (32) is provided at the outer end of the inner tube (34); The power assembly (5) comprises a third gear (51) coaxially arranged at the outer end of the inner tube (34), and a rack (52) vertically arranged and meshing with the outer side of the third gear (51).

6. The urea solution storage device according to claim 5, characterized in that: The outside of the lower suction port (22) is provided with a block (6) for closing or opening the upper end of the discharge pipe, the outside of the block (6) is provided with a scraper (7) that fits on the cone bottom (101) and scrapes off the crystalline material accumulated on the cone bottom (101), and the outside of the block (6) is provided with an electric push rod that drives the block (6) to move vertically up and down along the axis of the tank body.

7. The urea solution storage device according to claim 6, characterized in that: The upper portion of the blocking block (6) is provided with a second transmission assembly (8) which rotates synchronously with the hollow tube (11); The transmission assembly 2 (8) comprises a second support plate (81) rotatably sleeved on the outside of the hollow tube (11) and a second gear ring (82) fixedly arranged on the top surface of the block (6); the inner side of the second gear ring (82) is meshed with a fourth gear (83) that rotates on the end surface of the second support plate (81); and a fifth gear (84) that is sleeved and fixed on the outside of the hollow tube (11) is provided on the side of the fourth gear (83) away from the meshing point between the second gear ring (82) and the fourth gear (83).

8. The urea solution storage device according to claim 7, characterized in that: The outer end of the second gear ring (82) is grooved and rotatably provided with a support ring (9), and the outer side of the support ring (9) is provided with a connecting rod (91) fixedly connected to the rack (52).

9. The urea solution storage device according to claim 1, characterized in that: The inner side of the tank is provided with a heating or cooling jacket for controlling the temperature of the solution.

10. A urea solution storage method, using the urea solution storage device according to any one of claims 1 to 9, characterized in that: During storage, the block (6) can be periodically moved downward to close the upper end opening of the drainage pipe and open the aeration hole (33), and then the stirring mechanism (1) can be used to stir in the tank body to form a radial flow field, and under the action of the upper discharge mechanism (2), the solution at the cone bottom (101) is pushed to be sucked from the bottom of the hollow tube (11) and diffused to the top of the hollow tube (11) to form an axial circulation flow field. Under the action of the aeration mechanism (3), the released bubbles generate disturbances during the rising process, destroying the surface tension of the solution, and the shear force when the bubbles burst can disperse tiny crystalline particles. The superimposed bubble flow and stirring flow form a composite flow field of "mechanical stirring + gas-liquid agitation".

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