Centrifugal-fluidization combined type pelleting coating equipment and coating method

Abstract

The invention relates to the technical field of seed processing, in particular to centrifugation-fluidization combined type pelleting coating equipment and a coating method. Comprising a centrifugal fluidization device, the centrifugal fluidization device comprises a coating tank, the top of the coating tank is connected with a liquid spraying device, the middle of the coating tank is connected with a powder supply device, the powder supply device is located below the liquid spraying device, a centrifugal fluidization composite disc is arranged at an opening in the bottom of the coating tank, and the centrifugal fluidization composite disc is connected with a seed collecting device; the excess material recovery device is connected with the top of the coating tank, and a discharge port of the excess material recovery device is positioned above the powder supply device; and the powder supply device and the centrifugal fluidization device are respectively connected with the high-pressure gas generation device. By adjusting the motion state of crop seeds in the device, the crop seed coating efficiency is improved.

Description

Technical Field

[0001] This invention relates to the field of seed processing technology, and in particular to a centrifugal-fluidized composite pelleting coating device and coating method. Background Technology

[0002] Seed coating technology is a seed treatment technique that coats the surface of seeds with a film-forming agent, creating a uniform and robust protective layer from active ingredients such as insecticides, fungicides, plant growth regulators, and fertilizers. This technology effectively controls seedling pests and diseases, enhances crop resistance, and reduces pesticide application in the field, making it a key measure for achieving "reduced pesticide use and increased efficiency" in agriculture and ensuring food security. Currently, the adoption rate of seed coating in my country continues to rise, with widespread application in staple crops such as corn and wheat, effectively promoting yield increases.

[0003] Current seed coating processes primarily rely on specialized coating equipment, with the core objective of achieving efficient and uniform adhesion of the seed coating agent while ensuring seed viability and safety. However, as the functions of seed coating agents become increasingly complex and the requirements for coating quality rise, existing mainstream coating equipment has gradually revealed numerous limitations in its processes, becoming a bottleneck restricting the further development of coating technology and maximizing its application effects.

[0004] The current seed coating technology has the following defects: (1) poor uniformity and low process efficiency: the uneven layering speed of traditional pelleting coating equipment easily leads to poor pellet roundness and wide particle size distribution; (2) poor seed damage and adaptability: mechanical friction or extrusion during the traditional coating process may cause physical damage to seeds, especially low-viability seeds; (3) poor adaptability to irregular seeds: light, small or smooth seeds have poor flowability in traditional equipment, are easy to clump together, and are difficult to achieve uniform coating or pelleting. Summary of the Invention

[0005] The purpose of this invention is to overcome the above-mentioned defects in the prior art and to propose a centrifugal-fluidized composite pelleting coating device and coating method, which improves the coating effect and coating efficiency of crop seeds by adjusting the movement state of crop seeds in the device.

[0006] The technical solution of this invention is: a centrifugal-fluidized composite pelletizing and coating device, comprising: The centrifugal fluidization device includes a coating tank, the top of which is connected to a spraying device, the middle of which is connected to a powder supply device, the powder supply device being located below the spraying device, and a centrifugal fluidization composite disc being provided at the opening at the bottom of the coating tank, the centrifugal fluidization composite disc being connected to a seed collection device. The residual material recovery device is connected to the top of the coating tank, and its discharge port is located above the powder supply device; The powder feeding device and the centrifugal fluidization device are respectively connected to the high-pressure gas generating device.

[0007] In this invention, the top of the coating tank is provided with a bare seed inlet, and several adaptive air intake ports are provided at intervals on the annular outer wall of the lower part of the coating tank; An outer support tank is provided on the outer ring of the coating tank. The coating tank is set in the cavity of the outer support tank. The body of the outer support tank is provided with a first gas channel. The inlet end of the first gas channel is connected to a high-pressure gas generating device, and the outlet end of the first gas channel is connected to the inlet hole on the centrifugal fluidized composite disc. The annular space between the inner wall of the outer support tank and the outer wall of the coating tank forms a second gas channel. The inlet end of the second gas channel is connected to a high-pressure gas generating device, and the gas in the second gas channel enters the coating tank through the adaptive gas suction port.

[0008] Centrifugal fluidized bed composite disks include: The upper plate is an arc-shaped plate that convexes downwards. Its bottom is connected to the hydraulic telescopic rod, and the hydraulic cylinder of the hydraulic telescopic rod is connected to the output shaft of the motor. The lower plate fits the arc-shaped surface of the upper plate. The lower plate has a seed drop opening that is connected to the seed collection device. The lower plate and the upper plate are coaxially arranged. The arc-shaped surface of the lower plate is larger than that of the upper plate. Several air inlets are spaced apart on the annular periphery of the lower plate that is not covered by the upper plate. The air inlets are connected to the first gas channel. The bottom of the upper tray has a plug rod, and the corresponding lower tray has a socket. When the plug rod is inserted into the socket, the connection between the upper tray and the lower tray is achieved.

[0009] The liquid spraying device includes: The liquid medicine tank is equipped with a pump at its outlet. The infusion tubing delivers the medication from the medicine tank to the cantilever. The cantilever extends into the coating tank at its bottom end and has a fluid channel inside. The upper end of the cantilever is connected to a micro motor located outside the coating tank, and the top end of the cantilever is connected to the infusion pipeline via a rotary joint. Atomizing nozzles are provided at intervals at the bottom of the cantilever.

[0010] The powder supply device includes: The powder silo contains solid powder and has a powder mixing shaft inside. The top of the powder mixing shaft is connected to the output shaft of the powder mixing shaft. Several loosening comb teeth are spaced along the axial direction on the powder mixing shaft. The lower end of the powder silo is connected to a venturi feed pipe through a feed pipe. An auger is installed inside the feed pipe. One end of the Venturi feed tube is connected to a high-pressure gas generating device, where the high-pressure gas generates negative pressure inside the Venturi feed tube to achieve negative pressure feeding; the other end of the Venturi feed tube is connected to a powder ring. The powder ring is located on the inner wall of the middle part of the coating tank. The powder ring has an annular cavity inside, and several nozzles are spaced apart on the annular inner wall of the powder ring.

[0011] The high-pressure gas generating device includes a blower, and two air supply pipes are connected to the outlet of the blower; The first air supply pipe is connected to the Venturi feed pipe of the powder supply device; The second air supply pipe is connected to the centrifugal fluidizing device. The gas flowing into the centrifugal fluidizing device enters the first gas channel and the second gas channel respectively. The second air supply pipe is equipped with a gas valve.

[0012] The seed collection device includes a discharge pipe, which is connected to the seed inlet; When the upper plate descends to be in contact with the upper plate, the seed outlet closes; When the upper plate rises to the point of separating from the lower plate, the seed discharge port opens, and the coated seeds in the coating tank are discharged into the unloading pipe through the seed discharge port.

[0013] The waste material recovery device includes a cyclone separator; The feed inlet of the cyclone separator is connected to the top of the coating tank, drawing the exhaust gas and powder from the coating tank into the cyclone separator; The top of the cyclone separator is equipped with an air outlet, and the bottom of the cyclone separator is connected to a discharge pipe with a discharge valve. The discharge pipe is located directly above the powder silo.

[0014] This application also includes a coating method for the above-mentioned centrifugal-fluidized composite pelletizing coating equipment, comprising the following steps: S1. Enables the liquid and powder to adhere quickly and evenly to the outer surface of crop seeds; The crop seeds entering the coating tank are completely lifted by the airflow from the centrifugal fluidized composite disc, and under the combined action of the gas entering the coating tank through the adaptive air intake, the crop seeds tumble and mix inside the coating tank; at this time, the spraying device and powder supply device are turned on, and the liquid and solid powder are quickly and evenly attached to the surface of the crop seeds. S2. This allows the liquid medicine and powder to grow in layers on the outer surface of crop seeds, resulting in thicker pellets. The centrifugal force on the crop seeds inside the coating tank gradually increases, forming a rotating seed ring; at the same time, the rotating vortex airflow formed by the centrifugal fluidized composite disk causes the crop seeds to tumble and mix violently. At this time, the liquid and powder act on the seed ring, realizing the layered growth of the liquid and powder on the outer surface of the crop seeds. S3. Grind and shape the outer surface of the pelleted coated seeds; The coated seeds are closely attached to the surface of the centrifugal fluidized composite disc. Under the action of centrifugal force generated during the rotation of the centrifugal fluidized composite disc and the friction between the coated seeds and the centrifugal fluidized composite disc, the coated seeds roll at high speed, polishing the surface of the coated seeds to be smooth and round, thus achieving the formation of the coated seeds. S4. Collection of coated seeds.

[0015] In step S1, the high-pressure gas generated by the high-pressure gas generating device is regulated by a gas valve and then enters the centrifugal fluidization device. After entering the first gas channel, the gas is sent to the centrifugal fluidization composite plate and enters the coating tank through the air inlet on the lower plate. After entering the second gas channel, the gas enters the coating tank through the adaptive air inlet. The gas fluidization velocity in the centrifugal fluidization device is 0.1-0.3 m / s. At this time, the rotation speed of the centrifugal fluidized composite disk is 30-100 rpm; In step S2, the gas fluidization velocity in the centrifugal fluidization device is 0.3-0.8 m / s to keep the seeds in the coating tank in a fluidized state; the rotation speed of the centrifugal fluidization composite disc is 100-650 rpm. When the gas is delivered to the lower plate, the upper plate drives the lower plate to rotate. As the gas rotates with the lower plate, it forms a rotating airflow. Then, when the gas enters the coating tank through the evenly distributed air inlet holes on the lower plate, it forms a uniform swirling gas with tangential velocity and is injected into the coating tank, thus forming a rotating vortex airflow inside the coating tank. In step S3, the gas fluidization velocity in the centrifugal fluidization device is 0.3-0.5 m / s. At this time, the gas pressure can maintain a slight positive pressure at the centrifugal fluidization composite disk to prevent the air inlet from being blocked; the rotation speed of the centrifugal fluidization composite disk is 200-450 rpm. In step S4, the hydraulic telescopic rod moves upward, causing the upper plate to move upward until it separates from the lower plate. At this time, the seed drop port of the lower plate opens, and the coated seeds in the coating tank enter the discharge pipe through the seed drop port. The coated seeds are then collected through the discharge pipe.

[0016] The beneficial effects of this invention are: (1) The coating device and coating method proposed in this application realize the process of uninterrupted process in the coating tank. By adjusting the rotation speed of the centrifugal fluidized composite disk and the gas pressure entering the coating tank, the movement state of the seed group can smoothly and continuously transition between full fluidized suspension, semi-fluidized semi-centrifugal and full centrifugal rolling according to the process requirements. The movement state of crop seeds in the cavity is actively controlled, so as to adopt the optimal mechanical environment at different stages of pelleting.

[0017] (2) The high-speed rotating vortex airflow generated by the centrifugal fluidized composite disk works synergistically with the gas entering the coating tank through the adaptive air inlet to apply a tangential velocity to the coated seeds in the fluidized state, so that the coated seeds form a stable three-dimensional spiral circulation in the coating tank, which greatly improves the mixing uniformity and heat and mass transfer efficiency of the coated seeds in the suspended state, and avoids the dead corners or short circuits that may occur in traditional fluidized beds. (3) The device proposed in this application can also recover qualified coating powder with larger particle size and incomplete adhesion, reducing the waste of solid powder and realizing the recycling of resources. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the coating device described in this application; Figure 2 This is a cross-sectional structural diagram of the coated container; Figure 3 This is a schematic diagram of the structure of a centrifugal fluidized bed.

[0019] In the diagram: 1. Liquid tank; 2. Infusion pipeline; 3. Raw seed inlet; 4. Rotary joint; 5. Cyclone separator; 6. Discharge valve; 7. Powder mixing motor; 8. Loosening comb; 9. Powder silo; 10. Gas valve; 11. Screwdriver; 12. Blower; 13. First gas channel; 14. Second gas channel; 15. Lower tray; 16. Hydraulic telescopic rod; 17. Motor; 18. Discharge pipe; 19. Air inlet; 20. Upper tray; 21. Coating tank; 22. Adaptive air suction port; 23. Powder supply ring; 24. Atomizing nozzle; 25. Cantilever; 26. Venturi feed pipe; 27. Insert rod; 28. Insertion hole; 29. ​​External support tank. Detailed Implementation

[0020] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0021] Specific details are set forth in the following description to provide a full understanding of the invention. However, the invention can be practiced in many ways other than those described herein, and those skilled in the art can make similar extensions without departing from the spirit of the invention. Therefore, the invention is not limited to the specific embodiments disclosed below.

[0022] like Figure 1 and Figure 2As shown, the centrifugal-fluidized composite pelletizing and coating equipment described in this application includes a high-pressure gas generating device, a powder feeding device, a liquid spraying device, a centrifugal fluidizing device, a seed collecting device, and a residual material recovery device. High-pressure gas from the high-pressure gas generating device is fed into both the powder feeding device and the centrifugal fluidizing device. The powder feeding device and the liquid spraying device are connected to the centrifugal fluidizing device. The bottom of the centrifugal fluidizing device is connected to the seed collecting device, and the top of the centrifugal fluidizing device is connected to the residual material recovery device.

[0023] The centrifugal fluidization device includes a coating tank 21 arranged vertically. The top of the coating tank 21 is connected to a spraying device and a residual material recovery device. The top of the coating tank 21 is also provided with a bare seed inlet 3, through which crop seeds enter the coating tank 21. The bottom of the coating tank 21 is open, and a centrifugal fluidization composite disc is provided at the opening. Several adaptive air suction ports 22 are spaced apart on the annular outer wall of the lower part of the coating tank 21. The adaptive air suction ports 22 are formed of shape memory alloy sheets.

[0024] An outer support tank 29 is provided on the outside of the coating tank 21. The outer support tank 29 has a cavity shape, and the coating tank 21 is placed inside the cavity of the outer support tank 29. The inner body of the outer support tank 29 has a channel, which is a first gas channel 13. The inlet end of the first gas channel 13 is connected to a high-pressure gas generating device, and the outlet end of the first gas channel 13 is connected to an inlet hole on the centrifugal fluidized composite disc. High-pressure gas flows into the coating tank 21 through the first gas channel 13 to form a high-speed rotating vortex airflow.

[0025] An annular space exists between the inner wall of the outer support tank 29 and the outer wall of the coating tank 21, forming a second gas channel 14. The inlet of the second gas channel 14 is connected to a high-pressure gas generating device, and the gas in the second gas channel 14 enters the coating tank 21 through the adaptive air intake 22, so that the crop seeds in the coating tank are in a fluidized suspension state.

[0026] The centrifugal fluidized bed includes an upper plate 20 and a lower plate 15. The upper plate 20 is located above the lower plate 15, and the lower plate 15 is located at the opening at the bottom of the coating tank 21, thus sealing the bottom opening of the coating tank 21. Figure 3 As shown, the lower plate 15 is connected to the seed collection device, and the lower plate 15 has a seed-dropping port that communicates with the seed collection device. The bottom of the upper plate 20 is connected to the hydraulic telescopic rod 16, and the hydraulic cylinder of the hydraulic telescopic rod 16 is connected to the output shaft of the motor 17. During the extension and retraction process, the hydraulic telescopic rod 16 can drive the upper plate 20 to move up and down, realizing the relative movement between the upper plate 20 and the lower plate 15. During the rotation of the motor 17, it can drive the hydraulic telescopic rod and the upper plate 20 to rotate, realizing the rotation of the upper plate.

[0027] A rod 27 is fixed on the bottom surface of the upper plate 20, and a corresponding insertion hole 28 is provided on the lower plate 15. When the upper plate 20 moves downward until the rod 27 is inserted into the insertion hole 28, the connection between the upper plate 20 and the lower plate 15 can be realized.

[0028] The longitudinal section of the upper plate 20 of this application is a downward convex arc shape, and the corresponding longitudinal section of the lower plate 15 is also a downward convex arc shape. The arc surfaces of the upper plate 20 and the lower plate 15 can fit together completely, and the upper plate 20 and the lower plate 15 are coaxially arranged.

[0029] The arc length of the upper plate 20 is less than the arc length of the lower plate 15, so the upper plate 20 cannot completely cover the lower plate 15. Several air inlets 19 are provided at intervals on the annular periphery of the lower plate 15 that is not covered by the upper plate 20. After the gas enters the first gas channel 13, it enters the coating tank 21 through the air inlets 19.

[0030] When the insert rod 27 of the upper plate is inserted into the insertion hole of the lower plate, the motor 17 drives the upper plate 20 to rotate, which in turn drives the lower plate 15 to rotate at high speed. The airflow, under the rotation of the lower plate 15, forms a swirling airflow. After passing through the air inlet 19 on the lower plate 15, it becomes a uniform swirling gas with tangential velocity and is injected into the coating tank 21. Simultaneously, with the cooperation of the gas entering from the adaptive air intake 22, the crop seeds in the coating tank 21 are kept in a fluidized suspension state.

[0031] The high-pressure gas generating device includes a blower 12, and two air supply pipes are connected to the outlet of the blower 12. The first air supply pipe is connected to the powder supply device, and the second air supply pipe is connected to the centrifugal fluidization device and is connected to the first gas channel 13 and the second gas channel 14 respectively. A gas valve 10 is provided on the second air supply pipe, and the gas pressure in the second air supply pipe is precisely controlled by the gas valve 10.

[0032] The high-pressure airflow generated by the blower 12 is mainly used for two parts after being split: one part of the high-pressure gas is used for the powder feeding device, and the other part of the high-pressure gas flows into the centrifugal fluidization device. By controlling the pressure of the high-pressure gas and the rotation speed of the centrifugal composite disc, the crop seeds in the coating tank can be in a fluidized suspension state completely supported by the airflow, or the crop seeds in the coating tank can be attached to the inner wall of the coating tank and undergo centrifugal motion, or the crop seeds in the coating tank can be in a transitional state between the fluidized suspension state and the centrifugal state.

[0033] The spraying device includes a liquid tank 1, a cantilever 25, and atomizing nozzles 24. The lower end of the cantilever 25 extends into the coating tank, and several atomizing nozzles 24 are fixedly connected to the bottom end of the cantilever 25. The upper end of the cantilever 25 is connected to an external micro motor. During the operation of the motor, the cantilever 25 and the atomizing nozzles 24 are rotated.

[0034] A pump is installed at the outlet of the liquid tank 1. The pump draws out the liquid from the liquid tank 1 and sends it into the cantilever 25 through the infusion pipe 2. The cantilever 25 is hollow. The liquid in the liquid tank 1 enters the cantilever 25 through the infusion pipe 2 and is sprayed onto the outer surface of the crop seeds in the coating tank through the atomizing nozzle 24 at the bottom of the cantilever 25.

[0035] In this embodiment, in order to prevent the rotation of the cantilever 25 from interfering with the infusion pipeline 2, the top of the cantilever 25 is connected to the infusion pipeline 2 by a rotary joint 4.

[0036] The liquid in the liquid tank 1 is sprayed into a liquid mist by the rotating cantilever 25 and atomizing nozzle 24, which ensures that the liquid can evenly coat the outer surface of each crop seed, and at the same time ensures that the liquid mist can cover the entire range of seed movement.

[0037] A powder supply device is located below the spraying device. The powder supply device includes a powder silo 9 and a Venturi feed pipe 26. The powder silo 9 is located above the Venturi feed pipe 26 and contains solid powder, which is fed into the Venturi feed pipe 26. One end of the Venturi feed pipe 26 is connected to the air supply pipe of the blower 12, and the other end is connected to the powder supply ring 23. The blower 12 creates a negative pressure within the Venturi feed pipe 26, which forces the solid powder into the powder supply ring 23.

[0038] The powder silo 9 is vertically oriented and contains a powder stirring shaft. The top of the powder stirring shaft is connected to the output shaft of the powder stirring motor 7. During operation, the powder stirring motor 7 drives the powder stirring shaft to rotate, thereby stirring and loosening the solid powder in the powder silo 9. Simultaneously, several loosening comb teeth 8 are axially spaced on the annular outer surface of the powder stirring motor 7. As the loosening comb teeth 8 rotate with the powder stirring shaft, they stir and break up the solid powder, effectively dispersing the powder in the silo and preventing clumping.

[0039] The powder silo 9 is connected to the venturi feed pipe 26, which is equipped with an auger 11. Under the rotation of the auger 11, the solid powder in the powder silo 9 is evenly fed into the venturi feed pipe 26. The solid powder entering the venturi feed pipe 26 is fed into the powder ring 23 under negative pressure.

[0040] In this embodiment, the powder ring 23 is disposed on the inner wall of the middle part of the coating tank 21. The powder ring 23 has an annular cavity inside, the annular outer wall of the powder ring 23 is fixedly connected to the inner wall of the coating tank 21, and several nozzles are spaced apart on the annular inner wall of the powder ring 23.

[0041] After the solid powder is fed into the annular cavity of the powder ring 23 by the Venturi feed pipe 26, it is evenly sprayed out along the nozzles on the inner wall of the powder ring. When the crop seeds spread out in a ring and roll under the action of centrifugal force, the powder sprayed from the nozzles can naturally and evenly coat the surface of the moist seeds. This powder supply method has a higher powder utilization rate, less dust, and a tighter coating on the seeds.

[0042] The seed collection device includes a discharge pipe 18, which is connected to the seed inlet on the lower tray 15. When the upper tray 15 and the lower tray 20 are in close contact, the upper tray 15 blocks the seed inlet on the lower tray 20, keeping the seed inlet closed and preventing crop seeds in the coating tank from entering the discharge pipe 18. After the seed pelleting process is completed, the upper tray 15 and the lower tray 20 are separated, opening the seed inlet. The coated crop seeds can then enter the discharge pipe 18 through the seed inlet, achieving the unloading and collection of coated seeds.

[0043] The waste material recovery device includes a cyclone separator 5, the inlet of which is connected to the top of the coating tank 21. The top of the cyclone separator 5 has an air outlet, and the bottom of the cyclone separator 5 is connected to a discharge pipe with a discharge valve 6. The discharge pipe is located directly above the powder silo 9.

[0044] The seed pelleting and coating process generates a large amount of waste gas, which contains unused pelleted powder, resulting in significant resource waste. Therefore, after seed pelleting is completed, the cyclone separator 5 is opened. Under the inlet action of the cyclone separator, the waste gas from the coating tank, along with the powder within it, enters the cyclone separator 5, where the gas and solid powder are separated. The separated gas is discharged through the outlet at the top of the cyclone separator, while the unused powder is collected at the bottom. Once a certain level is reached, the discharge valve 6 is opened, and the remaining material falls into the powder silo for secondary use.

[0045] This application also discloses a method for seed coating using the above-mentioned centrifugal-fluidized composite pelleting coating equipment, which specifically includes the following steps.

[0046] The first step, the initial stage, is the initial nucleation stage, which allows the liquid and powder to adhere quickly and evenly to the outer surface of the crop seeds.

[0047] During this stage, the hydraulic telescopic rod 16 retracts, causing the upper plate 20 to move downwards and connect with the lower plate 15. At this time, the motor 17 rotates, driving the centrifugal fluidized composite plate to rotate at a speed of 30-100 rpm. The blower 12 in the high-pressure gas generating device operates, and part of the high-pressure gas it generates enters the Venturi feed pipe of the powder feeding device, while the other part of the high-pressure gas, after its pressure is regulated by the gas valve 10, enters the centrifugal fluidizing device. At this time, the gas fluidization velocity in the centrifugal fluidizing device is 0.1-0.3 m / s. After entering the first gas channel, the gas is sent to the centrifugal fluidized composite plate and enters the coating tank through the air inlet on the lower plate; the gas in the second gas channel enters the coating tank through the adaptive air suction port.

[0048] The crop seeds entering the coating tank are completely lifted by the airflow from the centrifugal fluidized composite disc, and under the combined action of the gas entering the coating tank through the adaptive air inlet 22, the crop seeds tumble and mix within the coating tank 21. At this time, the spraying device and powder supply device are activated, allowing the liquid and solid powder to quickly and evenly adhere to the surface of the tumbling crop seeds.

[0049] The second step, in the intermediate stage, involves layering the liquid and powder onto the outer surface of the crop seeds to thicken the pellets.

[0050] During this stage, by controlling the gas valve 10, the gas fluidization velocity in the centrifugal fluidization device is made to be 0.3-0.8 m / s, so that the seeds in the coating tank are kept in a fluidized state; at the same time, the speed of the motor 17 is gradually increased, thereby gradually increasing the speed of the centrifugal fluidization composite disc, which is 100-650 rpm.

[0051] When the gas is delivered to the lower plate 15, the upper plate 20 drives the lower plate 15 to rotate, and the gas rotates with the lower plate 15, forming a rotating airflow. Then, when it enters the coating tank through the evenly distributed air inlets 19 on the lower plate 15, it forms a uniform swirling gas with tangential velocity and is injected into the coating tank 21, thereby forming a rotating vortex airflow inside the coating tank. The vortex airflow causes the crop seeds to tumble violently inside the coating tank 21.

[0052] Inside the coating tank, the centrifugal force on the crop seeds gradually increases, forming a suspended and rotating seed ring. Under the combined action of the rotating vortex airflow and centrifugal force, the seeds violently tumble and mix, preventing them from sticking together while allowing them to continuously roll, compact, and enlarge under centrifugal force. At this point, the pesticide solution and powder act on the seed ring, achieving layered growth of the pesticide solution and powder on the outer surface of the crop seeds.

[0053] The third step, in the later stage, is to polish the outer surface of the granulated coated seeds to achieve fine polishing of the coated seeds.

[0054] During this stage, gas valve 10 controls the gas fluidization velocity of the centrifugal fluidizing device to be 0.3-0.5 m / s. At this time, the gas pressure is sufficient to maintain a slight positive pressure at the centrifugal fluidizing composite disk to prevent the air inlet 19 from becoming blocked. Simultaneously, motor 17 drives the centrifugal fluidizing composite disk to rotate at a speed of 200-450 rpm.

[0055] At this point, the coated seeds adhere closely to the surface of the centrifugal fluidized bed. Under the combined effects of centrifugal force generated during the rotation of the fluidized bed and friction between the seeds and the bed, the seeds roll at high speed. This stage polishes the surface of the coated seeds until it is smooth and round, achieving the final shaping purpose.

[0056] The fourth step is the collection of coated seeds.

[0057] During this stage, the hydraulic telescopic rod 16 moves upward, causing the upper plate 20 to move upward until it separates from the lower plate 15. At this time, the seed drop port of the lower plate opens, and the coated seeds in the coating tank enter the discharge pipe 18 through the seed drop port. The coated seeds are then collected through the discharge pipe 18.

[0058] The centrifugal-fluidized composite pelletizing coating equipment and method provided by this invention have been described in detail above. Specific examples have been used to illustrate the principles and implementation methods of this invention. The descriptions of the embodiments above are only for the purpose of helping to understand the method and core ideas of this invention. It should be noted that those skilled in the art can make various improvements and modifications to this invention without departing from the principles of this invention, and these improvements and modifications also fall within the protection scope of the claims of this invention. The above description of the disclosed embodiments enables those skilled in the art to implement or use this invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of this invention. Therefore, this invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A centrifugal-fluidized composite pelletizing and coating device, characterized in that, include: The centrifugal fluidization device includes a coating tank, the top of which is connected to a spraying device, the middle of which is connected to a powder supply device, the powder supply device being located below the spraying device, and a centrifugal fluidization composite disc being provided at the opening at the bottom of the coating tank, the centrifugal fluidization composite disc being connected to a seed collection device. The residual material recovery device is connected to the top of the coating tank, and its discharge port is located above the powder supply device; The powder feeding device and the centrifugal fluidization device are respectively connected to the high-pressure gas generating device.

2. The centrifugal-fluidized composite pelletizing and coating equipment according to claim 1, characterized in that, The top of the coating tank is equipped with a bare seed inlet, and several adaptive air intake ports are spaced apart on the annular outer wall of the lower part of the coating tank. An outer support tank is provided on the outer ring of the coating tank. The coating tank is set in the cavity of the outer support tank. The body of the outer support tank is provided with a first gas channel. The inlet end of the first gas channel is connected to a high-pressure gas generating device, and the outlet end of the first gas channel is connected to the inlet hole on the centrifugal fluidized composite disc. The annular space between the inner wall of the outer support tank and the outer wall of the coating tank forms a second gas channel. The inlet end of the second gas channel is connected to a high-pressure gas generating device, and the gas in the second gas channel enters the coating tank through the adaptive gas suction port.

3. The centrifugal-fluidized composite pelletizing and coating equipment according to claim 2, characterized in that, Centrifugal fluidized bed composite disks include: The upper plate is an arc-shaped plate that convexes downwards. Its bottom is connected to the hydraulic telescopic rod, and the hydraulic cylinder of the hydraulic telescopic rod is connected to the output shaft of the motor. The lower plate fits the arc-shaped surface of the upper plate. The lower plate has a seed drop opening that is connected to the seed collection device. The lower plate and the upper plate are coaxially arranged. The arc-shaped surface of the lower plate is larger than that of the upper plate. Several air inlets are spaced apart on the annular periphery of the lower plate that is not covered by the upper plate. The air inlets are connected to the first gas channel. The bottom of the upper tray has a plug rod, and the corresponding lower tray has a socket. When the plug rod is inserted into the socket, the connection between the upper tray and the lower tray is achieved.

4. The centrifugal-fluidized composite pelletizing and coating equipment according to claim 1, characterized in that, The liquid spraying device includes: The liquid medicine tank is equipped with a pump at its outlet. The infusion tubing delivers the medication from the medicine tank to the cantilever. The cantilever extends into the coating tank at its bottom end and has a fluid channel inside. The upper end of the cantilever is connected to a micro motor located outside the coating tank, and the top end of the cantilever is connected to the infusion pipeline via a rotary joint. Atomizing nozzles are provided at intervals at the bottom of the cantilever.

5. The centrifugal-fluidized composite pelletizing and coating equipment according to claim 1, characterized in that, The powder supply device includes: The powder silo contains solid powder and has a powder mixing shaft inside. The top of the powder mixing shaft is connected to the output shaft of the powder mixing shaft. Several loosening comb teeth are spaced along the axial direction on the powder mixing shaft. The lower end of the powder silo is connected to a venturi feed pipe through a feed pipe. An auger is installed inside the feed pipe. One end of the Venturi feed tube is connected to a high-pressure gas generating device, where the high-pressure gas generates negative pressure inside the Venturi feed tube to achieve negative pressure feeding; the other end of the Venturi feed tube is connected to a powder ring. The powder ring is located on the inner wall of the middle part of the coating tank. The powder ring has an annular cavity inside, and several nozzles are spaced apart on the annular inner wall of the powder ring.

6. The centrifugal-fluidized composite pelletizing and coating equipment according to claim 1, characterized in that, The high-pressure gas generating device includes a blower, and two air supply pipes are connected to the outlet of the blower; The first air supply pipe is connected to the Venturi feed pipe of the powder supply device; The second air supply pipe is connected to the centrifugal fluidizing device. The gas flowing into the centrifugal fluidizing device enters the first gas channel and the second gas channel respectively. The second air supply pipe is equipped with a gas valve.

7. The centrifugal-fluidized composite pelletizing and coating equipment according to claim 1, characterized in that, The seed collection device includes a discharge pipe, which is connected to the seed inlet; When the upper plate descends to be in contact with the upper plate, the seed outlet closes; When the upper plate rises to the point of separating from the lower plate, the seed discharge port opens, and the coated seeds in the coating tank are discharged into the unloading pipe through the seed discharge port.

8. The centrifugal-fluidized composite pelletizing and coating equipment according to claim 1, characterized in that, The waste material recovery device includes a cyclone separator; The feed inlet of the cyclone separator is connected to the top of the coating tank, drawing the exhaust gas and powder from the coating tank into the cyclone separator; The top of the cyclone separator is equipped with an air outlet, and the bottom of the cyclone separator is connected to a discharge pipe with a discharge valve. The discharge pipe is located directly above the powder silo.

9. A coating method for a centrifugal-fluidized composite pelletizing coating device according to any one of claims 1-8, characterized in that, Includes the following steps: S1. Enables the liquid and powder to adhere quickly and evenly to the outer surface of crop seeds; The crop seeds entering the coating tank are completely lifted by the airflow from the centrifugal fluidized composite disc, and under the combined action of the gas entering the coating tank through the adaptive air intake, the crop seeds tumble and mix inside the coating tank; at this time, the spraying device and powder supply device are turned on, and the liquid and solid powder are quickly and evenly attached to the surface of the crop seeds. S2. This allows the liquid medicine and powder to grow in layers on the outer surface of crop seeds, resulting in thicker pellets. The centrifugal force on the crop seeds inside the coating tank gradually increases, forming a rotating seed ring; at the same time, the rotating vortex airflow formed by the centrifugal fluidized composite disk causes the crop seeds to tumble and mix violently. At this time, the liquid and powder act on the seed ring, realizing the layered growth of the liquid and powder on the outer surface of the crop seeds. S3. Grind and shape the outer surface of the pelleted coated seeds; The coated seeds are closely attached to the surface of the centrifugal fluidized composite disc. Under the action of centrifugal force generated during the rotation of the centrifugal fluidized composite disc and the friction between the coated seeds and the centrifugal fluidized composite disc, the coated seeds roll at high speed, polishing the surface of the coated seeds to be smooth and round, thus achieving the formation of the coated seeds. S4. Collection of coated seeds.

10. The coating method according to claim 9, characterized in that, In step S1, the high-pressure gas generated by the high-pressure gas generating device is regulated by a gas valve and then enters the centrifugal fluidization device. After entering the first gas channel, the gas is sent to the centrifugal fluidization composite plate and enters the coating tank through the air inlet on the lower plate. After entering the second gas channel, the gas enters the coating tank through the adaptive air inlet. The gas fluidization velocity in the centrifugal fluidization device is 0.1-0.3 m / s. At this time, the rotation speed of the centrifugal fluidized composite disk is 30-100 rpm; In step S2, the gas fluidization velocity in the centrifugal fluidization device is 0.3-0.8 m / s to keep the seeds in the coating tank in a fluidized state; the rotation speed of the centrifugal fluidization composite disc is 100-650 rpm. When the gas is delivered to the lower plate, the upper plate drives the lower plate to rotate. As the gas rotates with the lower plate, it forms a rotating airflow. Then, when the gas enters the coating tank through the evenly distributed air inlet holes on the lower plate, it forms a uniform swirling gas with tangential velocity and is injected into the coating tank, thus forming a rotating vortex airflow inside the coating tank. In step S3, the gas fluidization velocity in the centrifugal fluidization device is 0.3-0.5 m / s. At this time, the gas pressure can maintain a slight positive pressure at the centrifugal fluidization composite disk to prevent the air inlet from being blocked; the rotation speed of the centrifugal fluidization composite disk is 200-450 rpm. In step S4, the hydraulic telescopic rod moves upward, causing the upper plate to move upward until it separates from the lower plate. At this time, the seed drop port of the lower plate opens, and the coated seeds in the coating tank enter the discharge pipe through the seed drop port. The coated seeds are then collected through the discharge pipe.

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