A reaction kettle for urea anti-caking agent production

Abstract

This invention discloses a reaction vessel for the production of urea anti-caking agent, relating to the field of chemical production equipment. It includes a reaction frame, a high-temperature dissolving vessel, a low-temperature forming vessel, a stirring component, an electric heating component, a material conveying component, and a water-cooled circulation component. The high-temperature dissolving vessel achieves constant temperature heating of 88°C through a heating jacket and electric heating tubes, ensuring complete dissolution of polyvinyl alcohol. The low-temperature forming vessel employs a spiral cooling channel, a guide ball, and a special channel hole structure to achieve slow and uniform cooling to 40°C, preventing crystallization and adhesion to the walls. The two vessels are safely transferred at high temperatures via a top-sealed conveying pump. The stirring device forms a multi-layer vortex to enhance mixing. This invention features segmented temperature control in two vessels, uniform heat exchange, and stable operation, effectively improving product quality and production efficiency, and is suitable for continuous industrial production.

Description

Technical Field

[0001] This invention relates to the field of chemical production equipment technology, specifically to a reaction vessel for the production of urea anti-caking agent. Background Technology

[0002] Urea, a fertilizer product used in large quantities in agricultural production, is prone to clumping during storage and transportation due to its hygroscopic nature and the salt bridging effect between particles. Clumped urea has poor flowability and is inconvenient to apply, seriously affecting fertilization efficiency. Current technology usually uses urea anti-caking agents to spray the surface of urea particles. By forming a protective film on the particle surface to block water vapor and inhibit particle adhesion, the problem of urea clumping is solved. At present, the preparation of urea anti-caking agents mostly uses a base liquid, polyvinyl alcohol, AEO-9 and viscosity modifier, and adds defoamers to eliminate the air bubbles generated during preparation.

[0003] Existing reaction equipment for the production of urea anti-caking agents is mostly a single-reactor batch reactor. During the preparation reaction, a base liquid, polyvinyl alcohol (PVA), AEO-9, viscosity modifier, and defoamer are added to the reactor. Since PVA is difficult to dissolve at room temperature / low temperature, directly adding and mixing it in a low-temperature reactor will result in insoluble particles and agglomeration. Therefore, the reactor needs to be heated during the preparation process to promote the dissolution of PVA. Furthermore, to ensure the emulsion colloidal structure formed by PVA and AEO-9 is fixed and prevents phase separation, additional measures are taken. To address the issue of stratification, the dissolved polyvinyl alcohol (PVA) needs to be cooled. Existing single-stage batch reactors, which are heated and then immediately cooled, have insufficient holding time, resulting in incomplete PVA dissolution. Furthermore, the rapid cooling of the reactor wall from high to low temperature causes a sharp drop in PVA solubility, leading to instantaneous crystallization and solidification on the inner wall, forming a hard shell. The thicker the shell, the more uneven the temperature inside the reactor, resulting in hot interiors and crystallized surfaces. This leads to inconsistent product batches, difficulty in cleaning the crystallized shell, waste of raw materials, and blockage of the discharge. Therefore, we propose a reactor for the production of urea anti-caking agents. Summary of the Invention

[0004] The purpose of this invention is to provide a reaction vessel for the production of urea anti-caking agents, so as to solve the problems mentioned in the background art.

[0005] To achieve the above objectives, the present invention provides the following technical solution: a reaction vessel for the production of urea anti-caking agent, comprising a reaction frame on which two reaction vessel bodies are mounted, one of which is a high-temperature dissolving vessel and the other is a low-temperature forming vessel. Both reaction vessel bodies are topped with lids, which are sealed to the reaction vessel bodies via flanges. The lids are equipped with stirring components for stirring within the reaction vessel bodies. The high-temperature dissolving vessel is equipped with a heating jacket containing electric heating elements, each comprising a plurality of electric heating tubes connected in series along the circumference of the heating jacket. The lid is equipped with a temperature probe; when the set temperature is detected in the high-temperature dissolving vessel, the electric heating elements output heat constantly to maintain a constant temperature within the vessel. A material conveying assembly connects the high-temperature dissolving vessel and the low-temperature forming vessel, pumping the high-temperature dissolved solution into the low-temperature forming vessel for cooling and shaping. The cryogenic molding vessel is equipped with a cooling jacket, and a spiral cooling channel is arranged inside the cooling jacket. The spiral cooling channel forms a water inlet chamber and a water return chamber through a partition wall plate. The bottom of the water inlet chamber and the bottom of the water return chamber are connected to a water cooling circulation component. When the temperature probe of the vessel lid detects that the cryogenic molding vessel has reached the set temperature, the water circulation component stops replenishing cooling water. The cooling water circulates and cools itself in the water inlet chamber, the water return chamber, and the spiral cooling channel.

[0006] Preferably, the bottom of the reactor body is provided with a discharge port, and a sealing plug is installed at the discharge port. A jacket is axially distributed inside the high-temperature dissolving reactor to form a heating jacket. The outer wall of the high-temperature dissolving reactor is provided with a heat insulation layer, and the inner wall of the jacket that contacts the material inside the reactor body is an enamel anti-corrosion layer.

[0007] Preferably, the electric heating element further includes an explosion-proof electrical control box installed outside the high-temperature dissolving vessel. The explosion-proof electrical control box is electrically connected to the electric heating tube. When the temperature probe on the vessel lid detects that the temperature inside the high-temperature dissolving vessel has reached a certain temperature, the explosion-proof electrical control box controls the electric heating tube to output heat at a constant rate to maintain a constant temperature inside the vessel.

[0008] Preferably, the kettle lid is provided with a feeding port, and the kettle lid is also provided with a plurality of exhaust gas outlets and a material extraction port in sequence, with the exhaust gas outlets symmetrically distributed on both sides of the material extraction port.

[0009] Preferably, the material conveying assembly includes a material transport pump, with rigid conveying pipes connected to both ends of the material transport pump. One rigid conveying pipe is connected to the extraction port on the lid of the high-temperature melting kettle, and the other rigid conveying pipe is connected to the extraction port on the lid of the low-temperature forming kettle.

[0010] Preferably, the stirring component includes a mounting bracket installed on the top of the vessel lid, on which a stirring motor is mounted. A transmission bearing is installed at the output end of the stirring motor, and the transmission bearing is rotatably connected to the vessel lid in a sealed manner. A rotating rod is connected to the bottom of the transmission bearing, and multiple layers of stirring groups are distributed on the outer side of the rotating rod. Each layer of stirring group consists of two symmetrical stirring rod groups. The stirring rods are installed at an incline on the rotating rod, and multiple combing holes are distributed on the stirring rods. When the rotating rod drives the multiple stirring rods to rotate, stirring vortices of different layers are formed in the reaction vessel.

[0011] Preferably, the low-temperature forming vessel has a second jacket distributed axially to form a cooling jacket. The bottom of the second jacket is a conical funnel shape, and the bottom opening of the conical funnel shape is sealed to the top of the discharge port. The side of the second jacket that is in contact with the liquid inside the vessel is highly polished.

[0012] Preferably, the spiral cooling channel is fixed on the side of the jacket away from the highly polished side, the bottom of the spiral cooling channel is connected to the water inlet chamber, and the top of the spiral cooling channel is provided with a drainage pipe at the water return chamber. The spiral cooling channel and the wall panel are provided with channel holes.

[0013] Preferably, the lower half of the channel hole is a semi-circular arc structure and the upper half is a triangular structure. Both sides of one of the partition walls are provided with guide balls. One guide ball is located at the lowest end of the spiral cooling channel of the water inlet chamber, and the other guide ball is located at the highest end of the water return chamber. The middle of the guide ball is a through hole, and the two ends of the through hole are funnel-shaped guide openings.

[0014] Preferably, the water-cooling circulation component includes an inlet installation pipe communicating with the bottom of the inlet chamber, a U-shaped circulation pipe installed at the bottom of the inlet installation pipe, a return installation pipe installed at the bottom of the return chamber, and one end of the U-shaped circulation pipe connected to the return installation pipe. A supplementary water pipe is connected to the side wall of the inlet installation pipe, and a solenoid valve is installed on the supplementary water pipe. The supplementary water pipe draws cooling water into the inlet chamber through a water pump. When the temperature probe on the lid detects that the temperature inside the low-temperature forming kettle reaches ℃, the solenoid valve closes, stopping the supply of cooling water to the cooling jacket.

[0015] Compared with the prior art, the beneficial effects of the present invention are: This invention separates the high-temperature dissolution and low-temperature molding processes through a dual-reactor segmented independent operation structure, which can achieve precise constant temperature of 88°C and slow cooling of 40°C respectively. This completely solves the problems of unstable temperature control and mutual interference between processes in traditional single-reactor equipment, making polyvinyl alcohol dissolve more fully and the colloidal system molding more stable, thus greatly improving the product consistency and finished product qualification rate of urea anti-caking agent.

[0016] This invention achieves uniform heat and cold transfer through a fully enclosed heating jacket, spiral cooling channel, guide ball disturbance heat exchange, and special channel hole design. It effectively avoids local overheating and degradation or local overcooling and crystallization on the wall, reduces raw material loss and pipeline blockage, makes the entire production process continuous and smooth, and significantly improves the stability of equipment operation and heat exchange efficiency.

[0017] This invention adopts a top-sealed conveying system, constant temperature automatic control, vortex-enhanced stirring, and centralized waste gas collection design. The production process is leak-free, volatilization-free, and splash-free, making it safer and more environmentally friendly. At the same time, it can achieve continuous production, shorten the production cycle, and reduce energy consumption. The overall device has a reasonable structure and is easy to operate, making it more suitable for the industrialized and standardized production needs of urea anti-caking agents. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the overall structure of the present invention; Figure 2 This is a schematic diagram of the structure of the present invention from a bottom view; Figure 3 This is a partial cross-sectional view of the high-temperature melting vessel and electric heating element of the present invention; Figure 4 This is a schematic diagram of the structure of the high-temperature melting kettle of the present invention with the electric heating element removed; Figure 5 This is a schematic diagram of the stirring component structure of the present invention; Figure 6 This is a partial cross-sectional view of the low-temperature forming reactor of the present invention; Figure 7 This is a schematic diagram of a partial cross-section of the jacket 2 structure; Figure 8 This is a schematic diagram of a partial cross-section of a single flow guide ball; Figure 9 for Figure 7 A magnified structural diagram of region A in the middle.

[0019] In the diagram: 1-Reaction frame; 2-High-temperature melting vessel; 3-Low-temperature forming vessel; 4-Vessel lid; 5-Stirring component; 6-Electric heating element; 7-Material conveying assembly; 8-Water cooling circulation component; 11-Discharge port; 12-Sealing plug; 21-Heating jacket; 22-Jacket one; 23-Insulation layer; 31-Cooling jacket; 32-Spiral cooling channel; 33-Partition wall plate; 34-Water inlet chamber; 35-Water return chamber; 36-Jacket two; 37-Channel hole; 38-Guide ball; 39-Drainage pipe; 41 - Temperature probe; 42 - Feed inlet; 43 - Exhaust gas outlet; 44 - Extraction port; 51 - Mounting bracket; 52 - Agitator motor; 53 - Transmission bearing; 54 - Rotating rod; 55 - Rotating agitator; 56 - Combing hole; 61 - Electric heating element; 62 - Explosion-proof electrical control box; 71 - Material transport pump; 72 - Rigid conveying pipe; 81 - Water inlet installation pipe; 82 - U-shaped circulation pipe; 83 - Water return installation pipe; 84 - Make-up water pipe; 85 - Solenoid valve; 381 - Through hole; 382 - Guide port. Detailed Implementation

[0020] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0021] Please see Figure 1-9 The present invention provides a technical solution: a reaction vessel for the production of urea anti-caking agent. The reaction vessel of the present invention mainly includes a reaction frame 1, which is welded from steel profiles and is used to stably support the high-temperature dissolving vessel 2 and the low-temperature forming vessel 3, so that the two vessels maintain a fixed relative position, ensuring smooth connection of material conveying pipelines and stable and reliable equipment operation.

[0022] The high-temperature melting vessel 2 is a closed pressure vessel body. The vessel body is equipped with a heating jacket 21. The heating jacket 21 is formed by welding the jacket 22 to the outer wall of the vessel body to form a closed annular cavity. The cavity can contain air or heat transfer medium to ensure that heat can be transferred evenly and stably to the material inside the vessel. Multiple electric heating tubes 61 are evenly arranged circumferentially inside the heating jacket 21. All electric heating tubes 61 are connected in series to ensure that the heating power of each electric heating tube 61 is consistent, so that the temperature distribution of the heating jacket 21 is uniform and avoids local overheating or local underheating.

[0023] The electric heating tube 61 adopts a mature industrial product, model SRY2-380V / 4kW finned electric heating tube. When the explosion-proof electrical control box 62 is connected to the external power supply, the current flows through the high resistance alloy wire inside the electric heating tube 61. The resistance wire generates a large amount of Joule heat under the action of the current. The heat is dissipated outward through the metal tube wall of the electric heating tube 61 and the heat dissipation area is increased by the fins, which quickly transfer the heat to the medium in the heating jacket 21. After the medium is heated, the temperature rises, and the heat is then evenly transferred to the inner wall of the high-temperature melting vessel 2 through heat conduction, and finally transferred to the material in the vessel, realizing the heating, warming and heat preservation of the material.

[0024] The electric heating element 61 is electrically connected to the explosion-proof electrical control box 62 installed outside the high-temperature melting kettle 2. The explosion-proof electrical control box 62 is a BXK58 explosion-proof temperature control box, which integrates a PID automatic temperature control module, an AC contactor, an over-temperature protection module, and a power switch module. A temperature probe 41 is fixedly installed on the kettle cover 4. The temperature probe 41 is a K-type thermocouple of model WRN-130. The temperature measuring end of the temperature probe 41 extends into the material inside the high-temperature melting kettle 2 to collect the actual temperature of the material in real time and convert the temperature signal into an electrical signal for continuous transmission to the explosion-proof electrical control box 62.

[0025] When the temperature probe 41 detects that the material temperature has risen to 88℃, the PID temperature control module inside the explosion-proof electrical control box 62 automatically adjusts the output current according to the preset temperature, controls the electric heating tube 61 to maintain constant power and constant heat output, so that the material temperature is stably maintained at 88℃, with a temperature fluctuation range of no more than ±1℃, thereby achieving precise constant temperature heating and ensuring that polyvinyl alcohol can be fully dissolved, does not degrade, does not change color, and does not reduce viscosity.

[0026] The outer wall of the high-temperature dissolving vessel 2 is entirely covered with an insulation layer 23. The insulation layer 23 is made of rock wool or aluminum silicate fiber and has a thickness of not less than 50mm. It can effectively prevent the heat in the heating jacket 21 from being lost to the outside air, improve heating efficiency, reduce energy consumption, and at the same time avoid the outer wall of the vessel from being too hot and causing burns to the operators. The inner wall of the jacket 22 that comes into contact with the material is made of enamel anti-corrosion layer. It has a high surface smoothness, is solvent resistant, high temperature resistant, and non-stick. It can effectively prevent polyvinyl alcohol from adhering to the vessel wall and forming scale or paste during the high-temperature dissolution process.

[0027] The low-temperature forming kettle 3 is used to keep the material that has been melted at high temperature warm, slowly cool it, and shape it at a low temperature of 40°C. The kettle body is equipped with a cooling jacket 31. The cooling jacket 31 is formed by the jacket 36 and the outer wall of the kettle body to form a closed cavity. The cavity is equipped with a spiral cooling channel 32. The spiral cooling channel 32 is arranged in a continuous spiral shape along the axial direction of the kettle body. The spiral structure can greatly increase the contact area between the cooling water and the kettle wall, prolong the residence time of the cooling water in the jacket, and achieve a slow, uniform, gentle, and impact-free cooling effect, avoiding the large amount of polyvinyl alcohol crystallization, precipitation, and wall adhesion caused by excessive cooling speed.

[0028] The spiral cooling channel 32 is divided into an inlet chamber 34 and a return chamber 35 by a partition wall plate 33. The inlet chamber 34 is located at the lower part of the cooling jacket 31, and the return chamber 35 is located at the upper part of the cooling jacket 31. Cooling water enters from the bottom inlet chamber 34, flows upward along the spiral cooling channel 32, and then re-enters the return chamber 35 along the guide pipe 39, forming a cooling circulation channel that enters from the bottom and exits from the top, and completely surrounds the vessel body, so that the material in the vessel is cooled evenly from top to bottom.

[0029] The water-cooled circulation component 8 includes an inlet pipe 81, a U-shaped circulation pipe 82, a return pipe 83, a makeup water pipe 84, a solenoid valve 85, and a cooling water pump. The cooling water pump adopts existing mature industrial equipment, model ISG50-160 horizontal pipeline centrifugal pump. The impeller inside the pump body rotates at high speed under the drive of the motor, generating centrifugal force to draw cooling water from the external cooling water tank into the pump body and pressurize the cooling water to obtain sufficient pressure. The cooling water is then pushed along the makeup water pipe 84 to the inlet pipe 81 and finally sent into the inlet chamber 34, providing continuous power for the entire cooling cycle.

[0030] The solenoid valve 85 is a normally closed explosion-proof solenoid valve with model number 2W-250-25. When the solenoid valve 85 is energized, a magnetic field is generated inside the coil. The magnetic field attracts the internal valve core to move upward, and the valve passage is opened, allowing cooling water to smoothly enter the inlet chamber 34 through the replenishment water pipe 84. When the solenoid valve 85 is de-energized, the magnetic field disappears, and the valve core moves downward under the pushing force of the return spring, automatically closing the valve passage, cutting off the replenishment path of cooling water, and preventing new cooling water from entering the cooling jacket 31.

[0031] Cooling water is pumped into the inlet chamber 34 under the pressure of the cooling water pump and flows along the inlet chamber 34 toward the spiral cooling channel 32. A guide ball 38 is installed on the partition wall plate 33. The guide ball 38 is arranged at the connection position between the inlet chamber 34 and the spiral cooling channel 32. One guide ball 38 is located at the bottom end of the spiral cooling channel 32, and the other guide ball 38 is located at the top end of the spiral cooling channel 32. A through hole 381 is opened in the middle of the guide ball 38. The two ends of the through hole 381 are flared guide ports 382. The large end of the guide port 382 faces the inlet chamber 34, and the small end faces the inside of the spiral cooling channel 32.

[0032] Cooling water first flows in from the large end of the guide port 382, ​​and flows out from the small end after passing through the through hole 381. As the water flows from the large end to the small end, the flow cross section gradually contracts and the water flow velocity gradually increases, forming a jet effect. At the same time, the high-speed water flow generates radial pressure and circumferential thrust on the inner wall of the guide ball 38, causing the guide ball 38 to roll, disturb, and oscillate slightly at the inlet position of the spiral cooling channel 32, breaking the original stable laminar flow state of the cooling water and making the cooling water form strong turbulence. This greatly improves the heat exchange efficiency between the cooling water and the vessel wall, allowing the material in the low-temperature forming vessel 3 to be cooled more quickly, evenly, and stably, avoiding local overcooling or local lag in cooling.

[0033] The partition wall plate 33 has a channel hole 37. The lower half of the channel hole 37 is a semi-circular arc structure, and the upper half is a triangular structure. The function of the semi-circular arc structure is to provide a smooth, continuous, dead-angle-free, and sharp-edge-free flow bottom for the cooling water, reduce water flow resistance, avoid eddies, air blockages, and stagnant water areas, and ensure that the cooling water can flow smoothly and stably. The function of the triangular structure is to gradually reduce the flow area of ​​the water flow, so as to steadily increase the flow rate of the cooling water, and promote the cooling water to move upward quickly, continuously, and without interruption along the spiral cooling channel 32. This ensures that the spiral cooling channel 32 is filled with cooling water throughout, avoiding problems such as flow deviation, flow interruption, and local heat exchange failure, thereby preventing polyvinyl alcohol crystallization, wall adhesion, and blockage due to local low temperature.

[0034] Temperature probes 41 are also installed on the lid 4 of the cryogenic molding kettle 3. Temperature probes 41 detect the material temperature in real time and feed it back to the control system. When the temperature probes 41 detect that the material temperature has dropped to 40°C, the control system immediately outputs a signal to de-energize and close the solenoid valve 85, stopping the replenishment of new cooling water into the cooling jacket 31. At this time, the cooling water that has entered the cooling jacket 31 forms a closed self-circulation between the water inlet chamber 34, the water return chamber 35, the spiral cooling channel 32, and the U-shaped circulation pipe 82, continuously maintaining the material temperature in the cryogenic molding kettle 3 at a stable 40°C, achieving slow cooling and gentle shaping, and ensuring that the product's colloidal structure is stable, does not separate, does not precipitate, and does not crystallize.

[0035] Complete usage process: The ingredients are prepared according to the following proportions for each ton of urea anti-caking agent: Material 1 Solvent A 190 kg, a colorless and transparent liquid; Material 2 Viscosity regulator 5 kg; Material 3 AEO-95 kg; Material 4 Polyvinyl alcohol 65 kg, a white granular solid; Material 5 Defoamer 1 kg, added in two portions, each time 0.5 kg.

[0036] When feeding and stirring, open the feed inlet 42 of the high-temperature melting kettle 2 and feed materials 1, 2, 3 and 4 into the kettle in sequence. Close the feed inlet 42 to keep it sealed. Start the stirring component 5. The stirring motor 52 drives the rotating rod 54 and the stirring rod 55 to rotate. The stirring rod 55 is arranged at an angle and, together with the combing holes 56 on the stirring rod 55, forms a multi-layer axial and radial stirring vortex in the kettle, so that the solid polyvinyl alcohol particles are evenly dispersed in the liquid, avoiding settling, clumping and agglomeration.

[0037] The explosion-proof electrical control box 62 is activated to slowly heat up and melt the material. The electric heating tube 61 is powered on and heats up. The heat is evenly transferred to the material through the heating jacket 21. The system controls the heating rate to rise slowly, and with continuous stirring, the polyvinyl alcohol gradually swells, softens, melts and dissolves. The small amount of organic waste gas generated during the heating process is collected and treated centrally through the waste gas emission port 43, resulting in zero emissions of fugitive waste gas.

[0038] The constant temperature reaction temperature probe 41 monitors the material temperature in real time. When the temperature rises to 88℃, the explosion-proof electrical control box 62 enters the PID automatic constant temperature mode, controlling the electric heating tube 61 to output heat at a constant temperature, so that the material is kept at 88℃ for 2 hours. Under this condition, the polyvinyl alcohol is completely dissolved, and the system is in a transparent and homogeneous colloidal state. Material 1, material 2, material 3, and material 4 are fully compounded and stable. After the constant temperature is completed, the first batch of 0.5 kg of defoamer is added through the feed inlet 42 and stirred evenly to eliminate foam.

[0039] The high-temperature material is conveyed in a closed system by starting the material transport pump 71. The semi-finished material in the high-temperature melting kettle 2 is sucked into the rigid conveying pipe 72 through the extraction port 44 on the kettle cover 4. Under the pressure of the pump body, it is conveyed to the extraction port 44 on the kettle cover 4 of the low-temperature forming kettle 3 and enters the interior of the low-temperature forming kettle 3. The entire conveying process is a top-level closed conveying process with no leakage, no volatilization, no splashing, and no crystallization blockage, making it safe and environmentally friendly.

[0040] After the low-temperature insulated reaction material enters the low-temperature molding kettle 3, the stirring component 5 continues to operate, and the material continues to be stirred and reacted for 1 hour to further stabilize and homogenize the colloidal system, preparing it for subsequent cooling and shaping.

[0041] The spiral water channel circulation cooling starts the cooling water pump, and the cooling water is pressurized and pumped into the inlet chamber 34. It enters through the large end of the guide ball 382 and flows out through the small end, which pushes the guide ball 38 to roll and disturb, forming turbulence to enhance heat transfer. The cooling water flows upward along the spiral cooling channel 32. The lower semi-circular arc of the channel hole 37 ensures smooth water flow, and the upper triangular structure increases the water flow speed, so as to achieve slow, uniform and gentle cooling of the material. The entire cooling process lasts for about 2 hours to avoid rapid cooling that causes crystals to stick to the wall.

[0042] When the temperature probe 41 detects that the material temperature has dropped to 40℃ during the constant temperature setting and secondary addition of defoamer, the solenoid valve 85 automatically shuts off and stops replenishing cooling water. The cooling water circulates in a closed loop within the cooling jacket 31 to maintain a stable material temperature. At this time, the second batch of 0.5 kg of defoamer is added through the feed inlet 42 and stirred evenly to complete the final product formulation.

[0043] The discharge filter opens the sealing plug 12 of the discharge port 11, and the finished material is discharged smoothly under the action of stirring and gravity. After the filter removes trace impurities, the finished urea anti-caking agent that can be directly used for urea granule spraying is obtained. The product is clear and transparent, with stable viscosity, does not separate, does not settle, and does not clog the nozzle.

[0044] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0045] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A reaction vessel for the production of urea anti-caking agent, comprising a reaction rack (1), characterized in that: Two reactor bodies are installed on the reactor frame (1). One reactor body is a high-temperature melting reactor (2), and the other reactor body is a low-temperature forming reactor (3). The top of the two reactor bodies is equipped with a reactor cover (4), and the reactor cover (4) is sealed to the reactor body through a flange. The reactor cover (4) is equipped with a stirring component (5) for stirring inside the reactor body. The high-temperature melting vessel (2) is equipped with a heating jacket (21), and electric heating elements (6) are distributed inside the heating jacket (21). The electric heating elements (6) include a number of electric heating tubes (61) connected in series along the circumference of the heating jacket (21). The vessel lid (4) is equipped with a temperature probe (41). When the set temperature is detected in the high-temperature melting vessel (2), the electric heating elements (6) output heat at a constant rate to maintain a constant temperature inside the vessel. A material conveying assembly (7) connects the high-temperature melting vessel (2) and the low-temperature molding vessel (3). The material conveying assembly (7) is used to pump the high-temperature melting solution into the low-temperature molding vessel (3) for cooling and shaping. The low-temperature forming kettle (3) is provided with a cooling jacket (31), and a spiral cooling channel (32) is arranged in the cooling jacket (31). The spiral cooling channel (32) forms a water inlet chamber (34) and a water return chamber (35) through a partition wall plate (33). The bottom of the water inlet chamber (34) and the bottom of the water return chamber (35) are connected to a water cooling circulation component (8). When the temperature probe (41) of the kettle cover (4) detects that the low-temperature forming kettle (3) has reached the set temperature, the water circulation component stops replenishing the cooling water. The cooling water is self-circulated and cooled in the water inlet chamber (34), the water return chamber (35) and the spiral cooling channel (32).

2. The reaction vessel for producing urea anti-caking agent according to claim 1, characterized in that: The bottom of the reactor body is provided with a discharge port (11), and a sealing plug (12) is installed at the discharge port (11). The high temperature dissolving reactor (2) has a jacket (22) axially distributed inside to form a heating jacket (21). The outer wall of the high temperature dissolving reactor (2) is provided with a heat insulation layer (23). The inner wall of the jacket (22) in contact with the material in the reactor body is an enamel anti-corrosion layer.

3. The reaction vessel for producing urea anti-caking agent according to claim 2, characterized in that: The electric heating element (6) also includes an explosion-proof electrical control box (62) installed outside the high-temperature melting kettle (2). The explosion-proof electrical control box (62) is electrically connected to the electric heating tube (61). When the temperature probe (41) on the kettle cover (4) detects that the temperature inside the high-temperature melting kettle (2) reaches 88°C, the explosion-proof electrical control box (62) controls the electric heating tube (61) to output heat at a constant rate to maintain a constant temperature inside the kettle.

4. A reaction vessel for producing urea anti-caking agent according to claim 2, characterized in that: The lid (4) is provided with a feeding port (42), and the lid (4) is also provided with a number of exhaust ports (43) and a material extraction port (44) in sequence. The exhaust ports (43) are symmetrically distributed on both sides of the material extraction port (44).

5. A reaction vessel for producing urea anti-caking agent according to claim 4, characterized in that: The material conveying assembly (7) includes a material transport pump (71), with rigid conveying pipes (72) connected to both ends of the material transport pump (71). One of the rigid conveying pipes (72) is connected to the extraction port (44) on the lid (4) of the high-temperature melting kettle (2), and the other rigid conveying pipe (72) is connected to the extraction port (44) on the lid (4) of the low-temperature forming kettle (3).

6. A reaction vessel for producing urea anti-caking agent according to claim 4, characterized in that: The stirring component (5) includes a mounting bracket (51) installed on the top of the vessel cover (4). A stirring motor (52) is installed on the mounting bracket (51). A transmission bearing (53) is installed at the output end of the stirring motor (52). The transmission bearing (53) is rotatably connected to the vessel cover (4). A rotating rod (54) is connected to the bottom of the transmission bearing (53). Multiple layers of stirring groups are distributed on the outside of the rotating rod (54). Each layer of stirring group consists of two symmetrical rotating stirring rods (55). The rotating stirring rods (55) are installed at an angle on the rotating rod (54). Multiple combing holes (56) are distributed on the rotating stirring rods (55). When the rotating rod (54) drives the multiple rotating stirring rods (55) to rotate, different layers of stirring vortices are formed in the reactor body.

7. A reaction vessel for producing urea anti-caking agent according to claim 2, characterized in that: The low-temperature forming kettle (3) has a jacket two (36) axially distributed inside to form a cooling jacket (31). The bottom of the jacket two (36) is a conical funnel shape, and the bottom opening of the conical funnel shape is sealed to the top of the discharge port (11). The side of the jacket two (36) that is in contact with the liquid inside the kettle is highly polished.

8. A reaction vessel for producing urea anti-caking agent according to claim 7, characterized in that: The spiral cooling channel (32) is fixed on the side of the jacket (36) away from the highly polished side. The bottom of the spiral cooling channel (32) is connected to the water inlet chamber (34), and the top of the spiral cooling channel (32) is provided with a drain pipe (39) at the water return chamber (35). The spiral cooling channel (32) and the wall panel are provided with channel holes (37).

9. A reaction vessel for producing urea anti-caking agent according to claim 8, characterized in that: The lower half of the channel hole (37) is a semi-circular arc structure, and the upper half is a triangular structure. Both sides of one of the partition walls (33) are provided with guide balls (38). One guide ball (38) is located at the lowest end of the spiral cooling channel (32) of the water inlet chamber (34), and the other guide ball (38) is located at the highest end of the water return chamber (35). The middle of the guide ball (38) is a through hole (381), and the two ends of the through hole (381) are trumpet-shaped guide openings (382).

10. A reaction vessel for producing a urea anti-caking agent according to claim 7, characterized in that: The water cooling circulation component (8) includes an inlet installation pipe (81) connected to the bottom of the inlet chamber (34), a U-shaped circulation pipe (82) installed at the bottom of the inlet installation pipe (81), a return water installation pipe (83) installed at the bottom of the return water chamber (35), and one end of the U-shaped circulation pipe (82) connected to the return water installation pipe (83). A supplementary water pipe (84) is connected to the side wall of the inlet installation pipe (81), and a solenoid valve (85) is installed on the supplementary water pipe (84). The supplementary water pipe (84) draws cooling water into the inlet chamber (34) through a water pump. When the temperature probe (41) of the kettle cover (4) detects that the temperature inside the low-temperature forming kettle (3) reaches 40°C, the solenoid valve (85) closes and stops supplementing cooling water into the cooling jacket (31).

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