Ship-use urea aqueous solution preparation equipment and method for preparing the same

Abstract

This invention belongs to the technical field of urea aqueous solution production equipment, and more particularly to equipment and methods for preparing urea aqueous solutions for ships. Existing preparation equipment has problems such as the aqueous solution becoming unstable or producing side reactions due to heating by a heater, the temperature of the heated water decreasing due to subsequent flow and reducing the urea dissolution efficiency, and the concentration of the prepared solution not being accurate. This invention proposes the following solutions. This equipment is equipped with a water bath, and a preparation tank is fixed to the inner wall of the bottom of the water bath via support legs. In addition, fresh water for heating the preparation tank is stored in the gap between the water bath and the preparation tank. A lid is fixed to the top of the preparation tank by multiple bolts, and multiple heaters are attached to the inner wall of the water bath. In this invention, by stirring the urea aqueous solution with a stirring rod, the oscillating structure and the intermittent structure can be driven sequentially, and urea particles can be intermittently scattered into the preparation tank in small batches. As a result, the urea particles are not only quickly mixed with the fresh water, but the accuracy of the concentration of the prepared solution can be improved.

Description

Technical Field

[0001] The present invention relates to the technical field of production equipment for urea aqueous solution, and particularly to a preparation equipment for urea aqueous solution for ships and its preparation method.

Background Art

[0002] The exhaust gas emissions of ships are one of the important factors of air pollution. Especially in port cities, a large amount of carbon dioxide, carbon monoxide, nitrogen oxides, sulfur oxides, etc. emitted from ships make air pollution quite serious and harm the health of residents in port cities. The nitrogen oxide emissions of ships need to meet the requirements of IMO Tier III emission limits. Installing an SCR system, which is an exhaust gas purification device for diesel engines, is an effective means to reduce emissions. The system currently needs to use urea as a reducing agent. Compared with automotive urea aqueous solution, the demand for urea aqueous solution for ships is large, and in order to reduce the volume of the urea tank, it is necessary to use a urea aqueous solution with a high concentration. Therefore, generally, a urea aqueous solution with a mass fraction of 40wt% is used as a reducing agent.

[0003] In the prior art, there are still some drawbacks in the process of preparing urea aqueous solution in ships.

[0004] 1. In the prior art, when preparing urea aqueous solution in a ship, it is necessary to heat it using a heater in a preparation tank and mix fresh water and urea granules. However, when heating with a heater, the temperature of the urea aqueous solution around the heater may rise excessively, causing the aqueous solution to become unstable or side reactions to occur. Also, when directly heating water with a heater, the temperature of the water after heating decreases due to subsequent flow, and the dissolution efficiency of urea decreases.

[0005] 2. In the preparation process, when directly putting urea granules into fresh water for preparation, the input amount of urea cannot be precisely controlled, so the concentration of the prepared solution is not accurate.

[0006] In response to the above problems, the present invention proposes a preparation apparatus and method for preparing urea aqueous solution for ships. [Overview of the project] [Problems that the invention aims to solve]

[0007] The object of the present invention is to provide a urea aqueous solution preparation apparatus and method for preparing an aqueous solution for ships in order to solve the drawbacks of the prior art, such as the instability of the aqueous solution or the occurrence of side reactions due to heating by a heater, the decrease in the temperature of the water after heating due to subsequent flow, which reduces the urea dissolution efficiency, and the inaccuracy of the concentration of the prepared solution. [Means for solving the problem]

[0008] To achieve the above objectives, the present invention employs the following technical means.

[0009] The shipboard urea aqueous solution preparation equipment has the following configuration: It includes a water bath, to which a preparation tank is fixed via support legs. The gap between the water bath and the preparation tank is used to contain fresh water for heating the preparation tank. A lid is fixed to the top of the preparation tank by several bolts. Several heaters are fixed to the inner wall of the water bath, and these heaters are used to heat the fresh water in the gap between the water bath and the preparation tank.

[0010] The apparatus is equipped with a stirring rod, which is rotatably connected to the bottom of the lid and used to stir and mix the urea granules and fresh water in the preparation tank. A drive motor is fixed to the top of the lid by bolts, and the output shaft of the drive motor is fixedly connected to the tip of the stirring rod via a coupling.

[0011] The system is equipped with a water inlet pipe, which is connected to an external freshwater storage device. One end of the water inlet pipe is connected to a first pipe and a second pipe via a three-way valve. The first pipe extends into the preparation tank and is used to supply freshwater to the preparation tank. One end of the second pipe extends into the water bath and is used to supply freshwater to the water bath.

[0012] A concentration meter is provided, which is located outside the water bath. One end of the concentration meter extends through the water bath into the preparation tank and is used to detect the concentration of the urea aqueous solution in the preparation tank in real time.

[0013] Two sets of oscillating structures are provided on each side of the bottom of the lid. These oscillating structures are used to quickly mix the urea granules with fresh water when they are sprinkled into the preparation tank.

[0014] An intermittent structure is provided above the lid, which intermittently sprinkles urea granules into the preparation tank, allowing the concentration meter to precisely detect the concentration of the urea solution. A rocking structure is located below the intermittent structure, and one of these rocking structures can supply power to the intermittent structure.

[0015] In one possible design, the oscillating structure comprises a base fixed to the bottom of the lid by bolts. A rotating shaft is rotatably connected within the base, and an oscillating frame is fixed to the outer circumference of the rotating shaft. A dispensing tube is fixedly passed through the oscillating frame, and the oscillating frame causes the dispensing tube to reciprocate, thereby dispensing urea granules to different locations in the preparation tank and rapidly mixing the urea granules with fresh water. One end of the oscillating frame extends outside the base, and multiple arc-shaped grooves are provided on the outer circumference of the rotating shaft. A movable block is fitted onto the outer circumference of the rotating shaft, and multiple guide balls are fixed within the movable block, which cooperate with the arc-shaped grooves. On the side of the base closest to the stirring rod, multiple guide rods are fixed by bolts, and one end of each guide rod slides through the movable block, thereby restricting the position of the movable block. As the moving block reciprocates laterally along the guide rod, the cooperation of the guide ball and arc-shaped groove causes the moving block to oscillate back and forth along its rotation axis and oscillating frame. This allows the guide hose to scatter urea granules into the base through the dispensing pipe, and the stirring rod to agitate the freshwater in the preparation tank. As a result, the scattered urea granules are quickly mixed with the rotating freshwater, improving the efficiency of urea aqueous solution preparation.

[0016] In one possible design, the oscillating structure includes a reciprocating thread on the outer circumference of a stirring rod. The stirring rod is screwed to a nut block by the reciprocating thread. Multiple fixed rods are welded to the bottom of the lid, the lower ends of which slide freely through the nut block and are fixed to the same retaining ring. The retaining ring is fitted around the outer circumference of the stirring rod. Connecting rods are rotatably connected to both sides of the nut block, the lower ends of which are rotatably connected to the top of the corresponding moving block. When the stirring rod rotates, the cooperation of the nut block and the reciprocating thread causes the nut block to reciprocate along the fixed rod, and the nut block, via the connecting rod, causes the moving block to reciprocate laterally along the guide rod, thereby dispersing urea granules into the preparation tank.

[0017] In one possible design, the intermittent structure includes a discharge pipe located above the lid. The top of the discharge pipe communicates with a storage chamber for storing urea granules inside the vessel via a transport pipe. The outer circumference of the discharge pipe is fixed to the top of the lid by several support legs. The bottom of the discharge pipe has several discharge holes, to which a rotating pipe is rotatably connected. The top of the rotating pipe has several supply holes, which cooperate with the discharge holes. A fixed cover is rotatably fitted around the outer circumference of the rotating pipe and communicates with the rotating pipe. Several L-shaped frames are welded to the outer circumference of the fixed cover, and the ends of the L-shaped frames are fixed to the bottom of the discharge pipe. Two supply hoses are provided at the bottom of the fixed cover, the lower ends of which extend into a preparation tank and communicate with a dispensing pipe. As the rotating cylinder rotates and the discharge port and supply port align, the urea granules in the discharge cylinder are dispersed into the preparation tank through the supply hose. This allows the urea granules to be dispersed into the preparation tank intermittently and gradually, improving the accuracy of the concentration of the prepared solution.

[0018] In one possible design, the intermittent structure includes a stationary ring fixed to the outer circumference of a rotating cylinder. A torsion spring is fitted to the outer circumference of the rotating cylinder, and the lower end of the torsion spring is fixed to the top of the stationary ring. A pull cord is wound around the outer circumference of the rotating cylinder, and the lower end of the pull cord extends into the preparation tank and is fixed to the outer circumference of a rotating shaft. When the rotating shaft oscillates, the rotating shaft rotates the rotating cylinder via the pull cord, and the torsion spring becomes charged. When the rotating shaft rotates in the opposite direction, the torsion spring rotates the rotating cylinder back. This allows the rotating cylinder to be driven when the oscillating structure is in operation, enabling intermittent discharge operations.

[0019] In one possible design, a guide wheel is rotatably connected to the side of one of the support legs via a base plate, and the guide wheel is used to guide a pull cord. A sealing ring is fixed to the inner wall of the water bath, and the inner wall of the sealing ring is fixed to the outer circumference of the preparation tank. An insulating layer is provided on the inner wall of the water bath, and both the insulating layer and the sealing ring are made of polyurethane rigid foam plastic. The sealing ring seals the freshwater between the water bath and the preparation tank, preventing heat from escaping from above when the freshwater is heated.

[0020] In one possible design, a drain pipe for discharging the aqueous solution is provided at the bottom of the preparation tank, with one end of the drain pipe extending outside the water bath. Valves are provided on the outer circumference of the drain pipe, the first pipe, and the second pipe. A stirring blade is rotatably connected to the bottom of the preparation tank and fitted around the outer circumference of the drain pipe. A second magnet is bolted to both sides of the top of the stirring blade. Multiple diagonal supports are welded to the lower end of the stirring rod, and the lower ends of the diagonal supports are slidably connected to the inner wall of the bottom of the preparation tank and used to support the stirring rod. A first magnet is fixedly fitted to the lower end of each of the multiple diagonal supports, and a magnetic attraction force is generated between the first and second magnets. When the drive motor rotates the stirring rod to promote the mixing of urea granules and fresh water, the stirring rod rotates the stirring blade via the diagonal supports. The magnetic attraction between the first and second magnets causes the inclined support column to rotate the stirring blade, which in turn stirs the hot water in the water bath. This ensures that the hot water in the water bath is evenly distributed, the hot water evenly heats the preparation tank, and prevents poor preparation of the urea solution due to uneven heating of the preparation tank.

[0021] In one possible design, a rotating shaft is rotatably connected to the stirring rod via a cavity, and a first sprocket is fixed to the outer circumference of the rotating shaft. A support ring is fixed to the outer circumference of the stirring rod, and second sprockets are rotatably connected to both sides of the top of the support ring via base plates. The first sprocket and the two second sprockets are power-driven by a chain. Push plates are slidably connected to both sides of the stirring rod via rails and slide grooves, and both ends of the chain are fixed to the tops of the corresponding push plates. A support block is bolted to the bottom of one of the push plates. When the rotating shaft rotates the first sprocket, the first sprocket raises and lowers the two push plates via the chain, respectively. When the push plate above the support block rises and the driving force of the rotating shaft is lost, the corresponding push plate descends due to the gravity of the support block. As a result, the two pressing plates move up and down alternately, exchanging the aqueous solutions in the upper and lower layers. This ensures that the freshwater and urea granules in the preparation tank are thoroughly and uniformly mixed, allowing the concentration meter to accurately detect the concentration of the urea aqueous solution in the preparation tank at a fixed position.

[0022] In one possible design, a mounting ring is fixed to the bottom of the retaining ring via a connecting column, and a tooth assembly is provided at the bottom of the mounting ring. The tooth assembly consists of multiple teeth. One end of the rotating shaft rotatably extends laterally to the stirring rod, and a bevel gear is fixed to it. The bevel gear cooperates with the teeth. When the stirring rod rotates, the stirring rod rotates the bevel gear via the rotating shaft. The cooperation of the bevel gear and the tooth assembly causes the first sprocket to rotate intermittently. The cooperation of the first sprocket, chain, and push plates causes the two push plates to move up and down alternately, exchanging the upper and lower aqueous solutions.

[0023] The preparation method for the ship-use urea aqueous solution preparation equipment in this application includes the following steps.

[0024] Step S1: Open the valves of the first pipe and the second pipe, and connect the water injection pipe to an external fresh water storage device. Inject fresh water into the water bath tank and the preparation tank through the water injection pipe respectively, and heat the fresh water in the water bath tank with a heater. Thereby, the warm water in the water bath tank heats the preparation tank, facilitating the subsequent preparation of the urea aqueous solution. Also, when the drive motor rotates the stirring rod to promote the mixing of urea granules and fresh water, the stirring rod rotates the stirring blades through the inclined support. Due to the magnetic attraction force generated between the first magnet and the second magnet, the inclined support rotates the stirring blades, and the stirring blades stir the warm water in the water bath tank. Thereby, the warm water in the water bath tank is evenly distributed, the warm water evenly heats the preparation tank, and it is possible to prevent the poor preparation of the urea aqueous solution due to uneven heating of the preparation tank.

[0025] Step S2: When the stirring rod rotates, due to the cooperation of the nut block and the reciprocating screw part, the nut block reciprocates on the fixed rod. The nut block moves the moving block reciprocally in the lateral direction along the guide rod through the connecting rod. Due to the cooperation of the guide ball and the arc-shaped groove, the moving block reciprocally swings the rotating shaft and the swing frame. Thereby, the urea granules are scattered into the base through the spreading pipe by the feeding hose, and the stirring rod stirs the fresh water in the preparation tank, so that the scattered urea granules are quickly mixed with the fresh water, improving the preparation efficiency of the urea aqueous solution.

[0026] Step S3: When one rotating shaft reciprocally swings, the rotating shaft reciprocally rotates the rotating cylinder due to the cooperation of the pulling string and the torsion spring. Due to the cooperation of the supply hole and the discharge hole, the urea granules in the discharge cylinder are intermittently discharged into the preparation tank through the fixed cover and the feeding hose, and the urea granules are added step by step. The concentration meter monitors the urea concentration in the preparation tank in real time, improving the accuracy of the concentration of the preparation solution.

[0027] Step S4. Further, when the stirring rod rotates, the stirring rod rotates the bevel gear via the rotating shaft. Due to the cooperation between the bevel gear and the tooth assembly, the first sprocket rotates intermittently. Due to the cooperation between the first sprocket, the chain, and the pressing plate, the two pressing plates move up and down alternately, exchanging the aqueous solutions in the upper and lower layers. Thereby, the fresh water and urea granules in the preparation tank are sufficiently and uniformly mixed, and the concentration meter can accurately detect the concentration of the urea aqueous solution at a fixed position in the preparation tank.

[0028] In the present invention, a spreading pipe is fixed to the outer periphery of the rotating shaft via a swinging frame, and a plurality of arc-shaped grooves are formed on the outer periphery of the rotating shaft. A moving block is slidably mounted on the outer periphery of the rotating shaft, and a plurality of guide balls are fixed in the moving block. The guide balls cooperate with the arc-shaped grooves. When the moving block reciprocates horizontally along the guide rod, due to the cooperation between the guide balls and the arc-shaped grooves, the moving block reciprocally swings the rotating shaft and the swinging frame. Thereby, the urea granules are scattered into the base through the spreading pipe by the feeding hose, and the stirring rod stirs the fresh water in the preparation tank, so that the scattered urea granules are quickly mixed with the fresh water, improving the preparation efficiency of the urea aqueous solution.

[0029] In the present invention, a torsion spring fixed to the bottom end of the discharge cylinder is mounted on the outer periphery of the rotating cylinder, and the bottom end of the torsion spring is fixed to the top of the fixed ring. A pulling string is wound around the outer periphery of the rotating cylinder, and the bottom end of the pulling string is fixed to the outer periphery of one of the rotating shafts. When the rotating shaft swings, the rotating shaft rotates the rotating cylinder via the pulling string, and the torsion spring is in a tensioned state. When the rotating shaft rotates in the reverse direction, the torsion spring rotates the rotating cylinder in the return direction. Thereby, when the swinging structure operates, it drives the rotating cylinder to complete the intermittent discharging operation.

[0030] In this invention, the stirring rod is screwed to the nut block by a reciprocating screw portion, and the nut block and the movable block are rotatably connected via a connecting rod. A stirring blade is rotatably connected to the bottom of the preparation tank, and second magnets are fixed to both sides of the top of the stirring blade. First magnets are fixedly fitted to the bottom ends of the multiple diagonal support columns, and a magnetic attractive force is generated between the first magnet and the second magnet. When the stirring rod performs stirring, the reciprocating movement of the nut block drives the oscillating structure and rotates the stirring blade, causing the hot water in the water bath to uniformly heat the preparation tank. [Effects of the Invention]

[0031] In this invention, the stirring rod sequentially drives the oscillating structure and the intermittent structure by stirring the urea aqueous solution, allowing urea granules to be intermittently and gradually sprinkled into the preparation tank. This ensures that the urea granules are quickly mixed with fresh water and improves the accuracy of the concentration of the prepared solution. Furthermore, by uniformly heating the preparation tank with the water bath and the hot water in the preparation tank, the loss of urea caused by high-temperature heating using a heater directly is prevented. [Brief explanation of the drawing]

[0032] [Figure 1] This is a schematic three-dimensional diagram of the ship's urea aqueous solution preparation equipment according to Embodiment 1 of the present invention. [Figure 2] This is a schematic three-dimensional cross-sectional diagram of the ship-use urea aqueous solution preparation equipment according to Embodiment 1 of the present invention. [Figure 3] This is a schematic diagram of the three-dimensional exploded structure of the inclined support column, the first magnet, and the stirring blade of the marine urea aqueous solution preparation equipment according to Embodiment 1 of the present invention. [Figure 4] This is a schematic diagram of the collaborative three-dimensional structure of the oscillating structure and intermittent structure of the ship-use urea aqueous solution preparation equipment according to Embodiment 1 of the present invention. [Figure 5] This is a schematic three-dimensional exploded view of the rotating shaft, moving block, and stirring rod of the ship's urea aqueous solution preparation equipment according to Embodiment 1 of the present invention. [Figure 6]This is a schematic diagram of the three-dimensional exploded cross-sectional structure of the rotating cylinder, fixed cover, and guide hose of the marine urea aqueous solution preparation equipment according to Embodiment 1 of the present invention. [Figure 7] This is a schematic three-dimensional exploded view of the fixed ring, rotating cylinder, and fixed cover of the ship's urea aqueous solution preparation equipment according to Embodiment 1 of the present invention. [Figure 8] This is a schematic three-dimensional diagram of the push plate and stirring rod of the ship's urea aqueous solution preparation equipment according to Embodiment 2 of the present invention. [Figure 9] This is a schematic diagram of the three-dimensional exploded structure of the mounting ring, bevel gear, and support ring of the ship's urea aqueous solution preparation equipment according to Embodiment 2 of the present invention. [Figure 10] This is a schematic diagram of the three-dimensional exploded structure of the mounting ring and bevel gear of the ship's urea aqueous solution preparation equipment according to Embodiment 2 of the present invention.

[0033] Symbols in the diagram: 1, water bath; 2, preparation tank; 3, stirring rod; 4, drive motor; 5, diagonal support; 6, lid; 7, water inlet pipe; 8, first piping; 9, second piping; 10, concentration meter; 11, heater; 12, drain pipe; 13, stirring blade; 14, first magnet; 15, second magnet; 16, reciprocating screw section; 17, nut block; 18, fixing rod; 19, retaining ring; 20, base; 21, rotating shaft; 22, oscillating frame; 23, spreading pipe; 24, moving block; 25, connecting rod; 26, guide rod; 27 , arc groove; 28, guide ball; 29, discharge cylinder; 30, support leg; 31, discharge hole; 32, rotating cylinder; 33, supply hole; 34, L-shaped frame; 35, fixed cover; 36, guide hose; 37, fixed ring; 38, torsion spring; 39, pull cord; 40, guide wheel; 41, rotating shaft; 42, first sprocket; 43, support ring; 44, second sprocket; 45, chain; 46, push plate; 47, support block; 48, mounting ring; 49, tooth assembly; 50, bevel gear; 51, sealing ring. [Modes for carrying out the invention]

[0034] Hereinafter, the technical means related to embodiments of the present invention will be clearly and completely described with reference to the drawings relating to embodiments of the present invention. Note that the embodiments described below represent only a portion of the present invention and do not encompass all embodiments.

[0035] Example 1 Referring to Figures 1 to 7, the marine urea aqueous solution preparation equipment of the present invention is applicable to the field of urea aqueous solution production equipment and has the following configuration: It includes a water bath 1, and a preparation tank 2 is fixed to the inner wall of the bottom of the water bath 1 via support legs. Fresh water for heating the preparation tank 2 is contained in the gap between the water bath 1 and the preparation tank 2. A lid 6 is fixed to the top of the preparation tank 2 by a plurality of bolts, and a plurality of heaters 11 are fixed to the inner wall of the water bath 1. The heaters 11 are used to heat the fresh water in the gap between the water bath 1 and the preparation tank 2.

[0036] The apparatus is equipped with a stirring rod 3, which is rotatably connected to the bottom of the lid 6 and is used to stir and mix the urea granules and fresh water in the preparation tank 2. A drive motor 4 is fixed to the top of the lid 6 by bolts, and the output shaft of the drive motor 4 is fixedly connected to the tip of the stirring rod 3 via a coupling.

[0037] The system is equipped with a water inlet pipe 7, which is in communication with an external freshwater storage device. A first pipe 8 and a second pipe 9 are connected to one end of the water inlet pipe 7 via a three-way valve. The first pipe 8 extends into the preparation tank 2 and is used to supply freshwater to the preparation tank 2. One end of the second pipe 9 extends into the water bath 1 and is used to supply freshwater to the water bath 1.

[0038] A concentration meter 10 is provided, which is located outside the water bath 1. One end of the concentration meter 10 penetrates the water bath 1 and extends into the preparation tank 2, and is used to detect the concentration of the urea aqueous solution in the preparation tank 2 in real time.

[0039] Referring to Figures 2 and 3, a drain pipe 12 for discharging the aqueous solution is provided at the bottom of the preparation tank 2, and one end of the drain pipe 12 extends to the outside of the water bath 1. Valves are provided on the outer circumference of the drain pipe 12, the first pipe 8, and the second pipe 9. A stirring blade 13 is rotatably connected to the bottom of the preparation tank 2, and the stirring blade 13 is fitted onto the outer circumference of the drain pipe 12. Second magnets 15 are fixed to both sides of the top of the stirring blade 13 by bolts, and a plurality of diagonal support columns 5 are fixed to the bottom end of the stirring rod 3 by welding. The bottom ends of the diagonal support columns 5 are slidably connected to the inner wall of the bottom of the preparation tank 2 and are for supporting the stirring rod 3. First magnets 14 are fixedly fitted to the bottom ends of the plurality of diagonal support columns 5, and a magnetic attractive force is generated between the first magnet 14 and the second magnet 15. When the drive motor 4 rotates the stirring rod 3 to promote the mixing of urea granules and fresh water, the stirring rod 3 rotates the stirring blade 13 via the inclined support column 5. A magnetic attraction force is generated between the first magnet 14 and the second magnet 15, causing the inclined support column 5 to rotate the stirring blade 13, which in turn stirs the hot water in the water bath 1 and distributes the hot water uniformly. This ensures that the hot water heats the preparation tank 2 uniformly, preventing poor preparation of the urea aqueous solution due to uneven heating in the preparation tank 2.

[0040] Referring to Figures 2, 4, and 5, the apparatus is further provided with two sets of oscillating structures on both sides of the bottom of the lid 6, which are used to quickly mix urea granules with fresh water when sprinkling urea granules into the preparation tank 2. The oscillating structures have the following configuration: A base 20 is provided on the bottom of the lid 6, fixed by bolts, and a rotating shaft 21 is rotatably connected to the base 20. An oscillating frame 22 is fixed to the outer circumference of the rotating shaft 21, and a dispensing pipe 23 is fixedly passed through the oscillating frame 22. The oscillating frame 22 oscillates back and forth, sprinkling urea granules from the dispensing pipe 23 to different positions in the preparation tank 2, thereby promoting the mixing of urea granules with fresh water. One end of the oscillating frame 22 extends to the outside of the base 20, and a plurality of arc-shaped grooves 27 are formed on the outer circumference of the rotating shaft 21. A movable block 24 is slidably mounted on the rotating shaft 21, and a plurality of guide balls 28 are fixed inside the movable block 24, which cooperate with an arc-shaped groove 27. A plurality of guide rods 26 are fixed by bolts to the side of the base 20 that is close to the stirring rod 3, and one end of each guide rod 26 slides through the movable block 24, thereby regulating the position of the movable block 24. When the movable block 24 moves back and forth laterally along the guide rods 26, the cooperation of the guide balls 28 and the arc-shaped groove 27 causes the movable block 24 to reciprocate and oscillate between the rotating shaft 21 and the oscillating frame 22. As a result, the guide hose 36 scatters urea granules into the base 20 through the dispensing pipe 23, and the stirring rod 3 stirs the fresh water in the preparation tank 2, so that the scattered urea granules are quickly mixed with the rotating fresh water, improving the efficiency of preparing the urea aqueous solution.

[0041] Referring to Figure 5, the oscillating structure further comprises the following configuration: A reciprocating screw portion 16 is provided on the outer circumference of the stirring rod 3, and a nut block 17 is attached to the stirring rod 3 and screwed onto the reciprocating screw portion 16. Multiple fixed rods 18 are welded to the bottom of the lid 6, and the lower ends of the fixed rods 18 slide freely through the nut block 17 and are fixed to the same retaining ring 19. The retaining ring 19 is fitted around the outer circumference of the stirring rod 3. Connecting rods 25 are rotatably connected to both sides of the nut block 17, and the lower ends of the connecting rods 25 are rotatably connected to the top of the corresponding movable block 24. When the stirring rod 3 rotates, the nut block 17 and the reciprocating screw portion 16 work together to cause the nut block 17 to reciprocate on the fixed rods 18. The nut block 17 moves the movable block 24 back and forth laterally along the guide rod 26 via the connecting rod 25, thereby dispersing the urea granules into the preparation tank 2.

[0042] Referring to Figures 2, 4, and 6, the device is further provided with an intermittent structure above the lid 6, which is used to ensure the accuracy of concentration detection of the urea aqueous solution by the concentration meter 10 by intermittently scattering urea granules into the preparation tank 2. An oscillating structure is located below the intermittent structure, and one of the oscillating structures supplies power to the intermittent structure. The intermittent structure has the following configuration: It includes a discharge cylinder 29 provided above the lid 6, and the top of the discharge cylinder 29 is connected to a urea granule storage facility inside the ship via a transport pipe. The outer circumference of the discharge cylinder 29 is fixed to the top of the lid 6 via a plurality of support legs 30, and a plurality of discharge holes 31 are formed at the bottom of the discharge cylinder 29. A rotating cylinder 32 is rotatably connected to the bottom of the discharge cylinder 29, and a plurality of supply holes 33 are formed at the top of the rotating cylinder 32. The supply holes 33 cooperate with the discharge holes 31 to control the supply of urea granules. A fixed cover 35 is rotatably mounted on the outer circumference of the rotating cylinder 32, and the fixed cover 35 is in communication with the rotating cylinder 32. Multiple L-shaped frames 34 are welded to the outer circumference of the fixed cover 35, and the tips of the L-shaped frames 34 are fixed to the bottom of the discharge cylinder 29. Two supply hoses 36 are provided at the bottom of the fixed cover 35, and the bottom ends of the supply hoses 36 extend into the preparation tank 2 and are in communication with the dispensing pipe 23. When the rotating cylinder 32 rotates and the discharge hole 31 and the supply hole 33 correspond, the urea granules in the discharge cylinder 29 are dispersed into the preparation tank 2 through the supply hoses 36. As a result, the urea granules are added to the preparation tank 2 intermittently and stepwise, improving the accuracy of the concentration of the prepared solution.

[0043] Referring to Figures 6 and 7, the intermittent structure further comprises the following configuration: A fixed ring 37 is fixed to the outer circumference of the rotating cylinder 32, and a torsion spring 38 fixed to the bottom end of the discharge cylinder 29 is mounted on the outer circumference of the rotating cylinder 32. The bottom end of the torsion spring 38 is fixed to the top of the fixed ring 37. A pull cord 39 is wound around the outer circumference of the rotating cylinder 32, and the bottom end of the pull cord 39 extends into the preparation tank 2 and is fixed to the outer circumference of one of the rotating shafts 21. When the rotating shaft 21 oscillates, the rotating shaft 21 rotates the rotating cylinder 32 via the pull cord 39, and the torsion spring 38 becomes energized. When the rotating shaft 21 rotates in the opposite direction, the torsion spring 38 returns the rotating cylinder 32 to its original position. This drives the rotating cylinder 32 when the oscillating structure is activated, completing the intermittent discharge operation.

[0044] Referring to Figures 2, 4, and 6, a guide wheel 40 is rotatably connected to the side of one of the support legs 30 via a substrate, and the guide wheel 40 guides the pull cord 39. A sealing ring 51 is fixed to the inner wall of the water bath 1, and the inner wall of the sealing ring 51 is fixed to the outer circumference of the preparation tank 2. An insulating layer is provided on the inner wall of the water bath 1, and both the insulating layer and the sealing ring 51 are made of polyurethane rigid foam plastic, and the sealing ring 51 seals the fresh water between the water bath 1 and the preparation tank 2. This prevents heat from escaping from above when the fresh water is heated.

[0045] Example 2 Referring to Figures 8 to 10, the configuration of Embodiment 1 is further enhanced by the following: A rotating shaft 41 is rotatably connected to the stirring rod 3 via a cavity, and a first sprocket 42 is fixed to the outer circumference of the rotating shaft 41. A support ring 43 is fixed to the outer circumference of the stirring rod 3, and second sprockets 44 are rotatably connected to both sides of the top of the support ring 43 via a base plate. The first sprocket 42 and the two second sprockets 44 are power-driven by a chain 45. Push plates 46 are slidably connected to both sides of the stirring rod 3 via rails and slide grooves, and both ends of the chain 45 are fixed to the tops of the corresponding push plates 46. A support block 47 is fixed to the bottom of one of the push plates 46 by a bolt. When the rotating shaft 41 rotates the first sprocket 42, the first sprocket 42 raises and lowers the two push plates 46 via the chain 45, respectively. When the upper push plate 46 of the support block 47 rises and the driving force of the rotating shaft 41 is lost, the corresponding push plate 46 descends due to gravity of the support block 47. As a result, the two push plates 46 move up and down alternately, exchanging the aqueous solutions in the upper and lower layers, so that the fresh water and urea granules in the preparation tank 2 are thoroughly and uniformly mixed, and the concentration meter 10 can accurately detect the concentration of the urea aqueous solution in the preparation tank 2 at a fixed position.

[0046] Referring to Figures 8 to 10, a mounting ring 48 is fixed to the bottom of the retaining ring 19 via a connecting column, and a plurality of tooth assemblies 49 are provided at the bottom of the mounting ring 48. The tooth assemblies 49 consist of a plurality of teeth. One end of the rotating shaft 41 rotatably extends to the side of the stirring rod 3, and a bevel gear 50 is fixed to it. The bevel gear 50 cooperates with the teeth. When the stirring rod 3 rotates, the stirring rod 3 rotates the bevel gear 50 via the rotating shaft 41. The cooperation of the bevel gear 50 and the tooth assemblies 49 causes the first sprocket 42 to rotate intermittently. The cooperation of the first sprocket 42, the chain 45, and the push plates 46 causes the two push plates 46 to move up and down alternately, exchanging the upper and lower layers of aqueous solution.

[0047] The preparation method for the ship-use urea aqueous solution preparation equipment of the present invention includes the following steps.

[0048] In step S1, the valves on the first pipe 8 and the second pipe 9 are opened, and the water inlet pipe 7 is connected to an external freshwater storage device. Freshwater is injected into the water bath 1 and the preparation tank 2, respectively, through the water inlet pipe 7, and the freshwater in the water bath 1 is heated by the heater 11. This causes the hot water in the water bath 1 to heat the preparation tank 2, facilitating the subsequent preparation of the urea aqueous solution. In addition, when the drive motor 4 rotates the stirring rod 3 to promote the mixing of urea granules and freshwater, the stirring rod 3 rotates the stirring blade 13 via the inclined support column 5. A magnetic attraction force is generated between the first magnet 14 and the second magnet 15, and the inclined support column 5 rotates the stirring blade 13, causing the stirring blade 13 to agitate the hot water in the water bath 1 and distribute the hot water uniformly. This causes the hot water to heat the preparation tank 2 uniformly, preventing poor preparation of the urea aqueous solution due to uneven heating in the preparation tank 2.

[0049] In step S2, as the stirring rod 3 rotates, the nut block 17 moves back and forth on the fixed rod 18 through the cooperation of the nut block 17 and the reciprocating screw portion 16. The nut block 17 moves the moving block 24 back and forth laterally along the guide rod 26 via the connecting rod 25. Through the cooperation of the guide ball 28 and the arc-shaped groove 27, the moving block 24 oscillates back and forth between the rotating shaft 21 and the oscillating frame 22. As a result, the guide hose 36 sprays urea granules into the base 20 through the spraying pipe 23, and the stirring rod 3 stirs the fresh water in the preparation tank 2, so that the sprayed urea granules are quickly mixed with the fresh water, improving the efficiency of preparing the urea aqueous solution.

[0050] In step S3, when one of the rotating shafts 21 oscillates back and forth, the rotating shaft 21, in cooperation with the pull cord 39 and the torsion spring 38, causes the rotating cylinder 32 to rotate back and forth. Through the cooperation of the supply hole 33 and the discharge hole 31, the urea granules in the discharge cylinder 29 are intermittently discharged into the preparation tank 2 through the fixed cover 35 and the supply hose 36, and the urea granules are added in stages. The concentration meter 10 monitors the urea concentration in the preparation tank 2 in real time, thereby improving the accuracy of the concentration of the prepared solution.

[0051] In step S4, as the stirring rod 3 rotates, it rotates the bevel gear 50 via the rotating shaft 41. The cooperation of the bevel gear 50 and the tooth assembly 49 causes the first sprocket 42 to rotate intermittently. The cooperation of the first sprocket 42, the chain 45, and the push plates 46 causes the two push plates 46 to move up and down alternately, exchanging the upper and lower layers of aqueous solution. As a result, the fresh water and urea granules in the preparation tank 2 are thoroughly and uniformly mixed, and the concentration meter 10 can accurately detect the concentration of the urea aqueous solution in the preparation tank 2 at a fixed position.

[0052] As is well known to those skilled in the art, the operating principles and wiring methods of the drive motor 4 and heater 11 are common methods or known techniques, and therefore will not be described in detail here. Those skilled in the art can select or design them as needed.

[0053] The above description illustrates preferred specific embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Those skilled in the art will understand that all equivalent substitutions or modifications based on the technical means and concepts of the present invention within the technical scope disclosed by the present invention are included within the scope of protection of the present invention.

Claims

1. A urea aqueous solution preparation facility for ships, A water bath (1) is provided, and a preparation tank (2) is fixed to the inner wall of the bottom of the water bath (1) via legs, and fresh water for heating the preparation tank (2) is contained in the gap between the water bath (1) and the preparation tank (2). A lid (6) is fixed to the top of the preparation tank (2) by a plurality of bolts, and a plurality of heaters (11) are attached to the inner wall of the water bath (1), and the heaters (11) are for heating the fresh water in the gap between the water bath (1) and the preparation tank (2). The apparatus is equipped with a stirring rod (3), which is rotatably connected to the bottom of the lid (6) and is for stirring and mixing the urea granules and fresh water in the preparation tank (2). A drive motor (4) is fixed to the top of the lid (6) by bolts, and the output shaft of the drive motor (4) is connected to the tip of the stirring rod (3) via a coupling. It is equipped with a water inlet pipe (7), the water inlet pipe (7) is in communication with an external freshwater storage device, and a first pipe (8) and a second pipe (9) are connected to one end of the water inlet pipe (7) via a three-way square valve, the first pipe (8) extends into the preparation tank (2) and is for supplying freshwater to the inside of the preparation tank (2), and one end of the second pipe (9) extends into the water bath (1) and is for supplying freshwater to the inside of the water bath (1), The system is equipped with a concentration meter (10), which is located outside the water bath (1), and one end of the concentration meter (10) extends through the water bath (1) into the preparation tank (2) for real-time detection of the concentration of the urea aqueous solution in the preparation tank (2). A pair of oscillating structures are provided on both sides of the bottom of the lid (6) to quickly mix the urea granules with fresh water when sprinkling the urea granules into the preparation tank (2). A urea aqueous solution preparation device for ships is provided, wherein an intermittent structure is provided above the lid (6), and the intermittent structure intermittently sprinkles urea granules into the preparation tank (2) to ensure the accuracy of concentration detection of the urea aqueous solution by the concentration meter (10), and the oscillating structure is positioned below the intermittent structure, with one of the oscillating structures supplying power to the intermittent structure.

2. The rocking structure comprises a base (20) fixed to the bottom of the lid (6) by bolts, and a rotating shaft (21) is rotatably connected within the base (20). A rocking frame (22) is fixed to the outer circumference of the rotating shaft (21), and a dispensing pipe (23) is fixed inside the rocking frame (22). The rocking frame (22) moves back and forth in conjunction with the dispensing pipe (23), dispensing urea granules from the dispensing pipe (23) to different positions in the preparation tank (2), thereby promoting the mixing of the urea granules with fresh water. One end of the oscillating frame (22) extends outward from the base (20), and a plurality of arc-shaped grooves (27) are formed on the outer circumference of the rotating shaft (21). A movable block (24) is slidably mounted on the rotating shaft (21), and a plurality of guide balls (28) are fixed inside the movable block (24), and the guide balls (28) engage with the arc-shaped groove (27), A urea aqueous solution preparation apparatus for ships according to claim 1, wherein a plurality of guide rods (26) are fixed by bolts to the side of the base (20) adjacent to the stirring rod (3), and one end of each guide rod (26) slides through the movable block (24) to restrict the position of the movable block (24).

3. The oscillating structure further includes a reciprocating screw portion (16) provided on the outer circumference of the stirring rod (3), A nut block (17) is attached to the stirring rod (3) and screwed onto the reciprocating screw portion (16). Multiple fixing rods (18) are welded to the bottom of the lid (6). The lower end of the fixing rod (18) slides through the nut block (17) and is fixed to the same retaining ring (19), and the retaining ring (19) is fitted around the outer circumference of the stirring rod (3). The marine urea aqueous solution preparation apparatus according to claim 2, wherein connecting rods (25) are rotatably connected to both sides of the nut block (17), and the lower ends of the connecting rods (25) are rotatably connected to the top of the corresponding movable block (24).

4. The intermittent structure includes a discharge pipe (29) provided above the lid (6), The top of the discharge pipe (29) is connected to the urea granule storage facility inside the ship via a transport pipe, and the outer circumference of the discharge pipe (29) is fixed to the top of the lid (6) via a plurality of support legs (30). A plurality of discharge holes (31) are formed at the bottom of the discharge cylinder (29), and a rotating cylinder (32) is rotatably connected to the bottom of the discharge cylinder (29). Multiple supply holes (33) are formed at the top of the rotating cylinder (32), and the supply holes (33) cooperate with the discharge holes (31) to control the supply of urea granules. A fixed cover (35) is rotatably mounted on the outer circumference of the rotating cylinder (32), and the fixed cover (35) communicates with the rotating cylinder (32). Multiple L-shaped frames (34) are welded to the outer circumference of the fixed cover (35), and the tips of the L-shaped frames (34) are fixed to the bottom of the discharge pipe (29). The ship's urea aqueous solution preparation apparatus according to claim 3, wherein two supply hoses (36) are provided at the bottom of the fixed cover (35), and the bottom ends of the supply hoses (36) extend into the preparation tank (2) and communicate with the dispensing pipe (23).

5. The intermittent structure further comprises a fixing ring (37) fixed to the outer circumference of the rotating cylinder (32), A torsion spring (38) fixed to the bottom end of the discharge cylinder (29) is mounted on the outer circumference of the rotating cylinder (32), and the bottom end of the torsion spring (38) is fixed to the top of the fixing ring (37). A pull cord (39) is wrapped around the outer circumference of the rotating cylinder (32), the bottom end of the pull cord (39) extends into the preparation tank (2) and is fixed to the outer circumference of one of the rotating shafts (21), as described in claim 4.

6. A guide wheel (40) is rotatably connected to one side of the support leg (30) via a base plate, and the guide wheel (40) guides the pull cord (39). A sealing ring (51) is fixed to the inner wall of the water bath (1), and the inner wall of the sealing ring (51) is fixed to the outer circumference of the preparation tank (2). The marine urea aqueous solution preparation apparatus according to claim 5, wherein an insulating layer is provided on the inner wall of the water bath (1), the insulating layer and the sealing ring (51) are both made of polyurethane rigid foamed plastic, and the sealing ring (51) seals the fresh water between the water bath (1) and the preparation tank (2).

7. A drain pipe (12) for discharging the aqueous solution is provided at the bottom of the preparation tank (2), and one end of the drain pipe (12) extends to the outside of the water bath (1). Valves are provided on the outer circumference of the drain pipe (12), the first pipe (8), and the second pipe (9), respectively. A stirring blade (13) is rotatably connected to the bottom of the preparation tank (2), and the stirring blade (13) is fitted around the outer circumference of the drain pipe (12). Second magnets (15) are fixed to both sides of the top of the stirring blade (13) by bolts, and a number of diagonal support columns (5) are fixed to the bottom end of the stirring rod (3) by welding. The bottom end of the diagonal support column (5) is slidably connected to the inner wall of the bottom of the preparation tank (2) and is for supporting the stirring rod (3). A first magnet (14) is fixed to the bottom end of the diagonal support column (5), and a magnetic attractive force is generated between the first magnet (14) and the second magnet (15), as described in claim 6, for preparing urea aqueous solution for ships.

8. A rotating shaft (41) is rotatably connected to the stirring rod (3) via a cavity, and a first sprocket (42) is fixed to the outer circumference of the rotating shaft (41). A support ring (43) is fixed to the outer circumference of the stirring rod (3), and a second sprocket (44) is rotatably connected to both sides of the top of the support ring (43) via a base plate. The first sprocket (42) and the two second sprockets (44) are connected by a chain (45), Push plates (46) are slidably connected to both sides of the stirring rod (3) via rails and slide grooves, and both ends of the chain (45) are fixed to the top of the corresponding push plates (46). A support block (47) is fixed to the bottom of one of the pressing plates (46) by bolts, as described in claim 7, for preparing urea aqueous solution for ships.

9. A mounting ring (48) is fixed to the bottom of the retaining ring (19) via a connecting column, and a plurality of tooth assemblies (49) are provided at the bottom of the mounting ring (48), and the tooth assemblies (49) consist of a plurality of teeth. The marine urea aqueous solution preparation apparatus according to claim 8, wherein one end of the rotating shaft (41) rotatably extends laterally to the stirring rod (3), a bevel gear (50) is fixed to it, and the bevel gear (50) meshes with the teeth.

10. A method for preparing urea aqueous solution for shipboard use, Step S1 involves opening the valves on the first pipe (8) and the second pipe (9), connecting the water inlet pipe (7) to an external freshwater storage device, injecting freshwater into the water bath (1) and the preparation tank (2) respectively through the water inlet pipe (7), heating the freshwater in the water bath (1) with the heater (11), thereby heating the preparation tank (2) with the hot water in the water bath (1) to facilitate the subsequent preparation of the urea aqueous solution, and when the drive motor (4) rotates the stirring rod (3) to promote the mixing of urea granules and freshwater, the stirring rod (3) rotates the stirring blade (13) via the inclined support column (5), generating a magnetic attraction between the first magnet (14) and the second magnet (15), causing the inclined support column (5) to rotate the stirring blade (13), which in turn stirs the hot water in the water bath (1) and distributes the hot water uniformly. As the stirring rod (3) rotates, the nut block (17) and the reciprocating screw portion (16) work together to cause the nut block (17) to reciprocate on the fixed rod (18), and the nut block (17) moves the moving block (24) laterally along the guide rod (26) via the connecting rod (25), and the guide ball (28) and the arc-shaped groove (27) work together to cause the moving block (24) to reciprocate on the rotating shaft (21) and the oscillating frame (22), thereby causing the guide hose (36) to scatter urea granules into the base (20) through the dispensing pipe (23), and the stirring rod (3) to stir the freshwater in the preparation tank (2), so that the scattered urea granules are quickly mixed with the freshwater in step S2. Step S3 involves the following: When the rotating shaft (21) oscillates back and forth, the rotating shaft (21) causes the rotating cylinder (32) to reciprocate through the cooperation of the pull cord (39) and the torsion spring (38), and through the cooperation of the supply hole (33) and the discharge hole (31), the urea granules in the discharge cylinder (29) are intermittently discharged into the preparation tank (2) through the fixed cover (35) and the supply hose (36), thereby adding the urea granules in stages, and the concentration meter (10) monitors the urea concentration in the preparation tank (2) in real time. Furthermore, the method for preparing a marine urea aqueous solution preparation equipment according to claim 9, comprising step S4, in which, when the stirring rod (3) rotates, the stirring rod (3) rotates the bevel gear (50) via the rotating shaft (41), and the cooperation of the bevel gear (50) and the tooth assembly (49) causes the first sprocket (42) to rotate intermittently, and the cooperation of the first sprocket (42), the chain (45), and the push plate (46) causes the two push plates (46) to move up and down alternately, exchanging the upper and lower layers of aqueous solution, thereby thoroughly and uniformly mixing the fresh water and urea granules in the preparation tank (2).

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