Processing technology and device of liquid slow-release fertilizer

Abstract

The application belongs to the technical field of fertilizer processing, in particular to a processing technology and device of liquid slow-release fertilizer, which comprises the following steps: S1: urea and formaldehyde solution are put into a reaction tank according to a set molar ratio, mixed uniformly, the pH of the reaction system is adjusted to alkaline (pH=8-9), the temperature is raised to 60-75 DEG C, and the reaction is carried out for 1-2 hours to generate methylene urea; then the temperature is lowered to 40-50 DEG C, the pH is adjusted to acid (pH=4-5), and the reaction is continuously carried out for 0.5-1 hour to form a stable urea-formaldehyde slow-release solution; S2: yeast stock solution, seaweed extract, amino acid, potassium humate, small molecule peptide and deionized water are sequentially added into a high-speed shearing tank, stirred and mixed to form a uniform and stable organic synergistic liquid; the application combines mineral nutrition and organic nutrition through liquid suspension technology, nutrient particles can exist in a long-term suspended state through dispersion technology, have good water solubility, cannot block pipes in drip irrigation, can be quickly absorbed by plants, and are convenient, efficient, fast in dissolution, and labor-saving.

Description

Technical Field

[0001] This invention belongs to the field of fertilizer processing technology, specifically a processing technology and apparatus for liquid slow-release fertilizer. Background Technology

[0002] Slow-release fertilizers, also known as slow-acting or controlled-release fertilizers, contain nutrient compounds that are released slowly or at a controlled rate into the soil for continuous absorption by crops. Compared to traditional fast-acting fertilizers, slow-release fertilizers use special formulations and technologies to gradually release nutrients, allowing plants to absorb the necessary nutrients more stably.

[0003] With the development of agriculture, fertigation is labor-saving and efficient. Currently, the main components of chemical fertilizers used in fertigation are fast-acting nitrogen, phosphorus, and potassium, which need to be used frequently (generally once every 5 to 7 days) to ensure the nutritional needs of crops. In addition, growers need to use them in combination with root-promoting products such as mineral-derived potassium humate and seaweed extract, which is cumbersome.

[0004] Therefore, the present invention provides a processing technology and apparatus for liquid slow-release fertilizer. Summary of the Invention

[0005] In order to overcome the shortcomings of the prior art, at least one technical problem raised in the background art is solved.

[0006] The technical solution adopted by this invention to solve its technical problem is: a processing technology for a liquid slow-release fertilizer, comprising the following steps:

[0007] S1: Add urea and formaldehyde solution to the reaction vessel at the set molar ratio and mix thoroughly. Adjust the pH of the reaction system to alkaline (pH = 8–9), heat to 60–75℃, and react for 1–2 hours to generate methylene urea. Then cool to 40–50℃, adjust the pH to acidic (pH = 4–5), and continue the reaction for 0.5–1 hour to form a stable urea-formaldehyde slow-release solution.

[0008] S2: Add yeast stock solution, seaweed extract, amino acids, mineral potassium humate, small molecule peptides and deionized water in sequence to a high-speed shear tank, stir and mix, transfer the mixture to a high-pressure homogenizer, and circulate it 2-3 times under a pressure of 30-50MPa to form a homogeneous and stable organic synergistic solution.

[0009] S3: Pump the urea-formaldehyde slow-release solution and organic synergist into the suspension reaction tank in proportion, and simultaneously add nitrogen, phosphorus, potassium and trace element water-soluble fertilizer; start the high shear dispersion emulsifier, add the suspension stabilizer, and continuously shear for 20-30 minutes to make the nutrient particle size ≤5μm, forming a long-term stable suspension system.

[0010] S4: The mixture is transferred to a maturation tank and matured for 24 hours under low-speed stirring. During this period, the pH (adjusted to 6.0–7.5) and viscosity are monitored. After maturation, the liquid is filtered through a precision filter to remove impurities and then transported to an automatic filling line for packaging into finished products.

[0011] A processing apparatus for liquid slow-release fertilizer is provided. This apparatus is applied to the above-mentioned processing technology of liquid slow-release fertilizer. In step S1, the reaction tank includes a tank body and a top cover. The top cover is provided with a feeding port at the top. The tank body is provided with a discharge pipe at the bottom. A stirring rod is rotatably provided at the bottom of the tank body. A stirring blade is fixedly provided on the side wall of the stirring rod. The stirring rod is hollow. A motor for driving the stirring tank to rotate is fixed at the bottom of the tank body. A through groove is provided on the side wall of the stirring rod. An installation hole is provided on the top cover. A sampling tube is provided in the middle of the installation hole. The sampling tube passes through the through hole and is inserted into the inner cavity of the stirring rod.

[0012] Preferably, the sampling tube has multiple storage cavities inside, each of which is sealed and slidably fitted with a piston block. Each of the storage cavities has a sampling port on its side wall. A movable rod is sealed and slidably fitted in the middle of the sampling tube, and the multiple piston blocks are fixedly connected to the movable rod.

[0013] Preferably, a housing is fixedly installed at the center of the bottom of the top cover, and a gas storage box is fixedly installed at the bottom of the housing. Both the housing and the gas storage box are circular, and the sampling tube passes through the central hole of the housing and the gas storage box. A movable plate is slidably installed in the inner cavity of the housing. Pull rods are symmetrically fixed on both sides of the top of the movable plate. A spring is sleeved on the pull rod to drive the movable plate to move downward. A cross plate is fixed on the top of the pull rod. A one-way valve is fixed on the side wall of the housing. The gas storage box is connected to the inside of the housing through a one-way valve. An annular extension nozzle is provided on the inner side of the gas storage box.

[0014] Preferably, a second housing is fixed to the bottom of the first housing, and the top of the stirring rod moves through a through hole opened at the center of the bottom of the second housing. The second housing covers the outside of the gas storage box.

[0015] Preferably, a sealed bearing is fixed at the middle of the top of the stirring rod, and the sampling tube slides through the inner ring of the sealed bearing.

[0016] Preferably, the top end of the stirring rod is inclined, and the bottom of the second housing has reflux holes evenly distributed.

[0017] Preferably, a sealing cap is detachably installed in the mounting hole, and the sealing cap is movably sleeved on the sampling tube.

[0018] Preferably, a retaining ring is fixed inside the mounting hole, an elastic block is fixed at the bottom of the sealing cover, and a sealing ring is fixed on the inner wall of the central hole of the sealing cover. Both the elastic block and the sealing ring are made of elastic material, but cavities are provided inside the elastic block and the sealing ring. The elastic block and the sealing ring are connected by a connecting pipe.

[0019] Preferably, the bottom of the sampling tube is designed to be pointed, and a ball bearing is rotatably mounted on the bottom of the sampling tube.

[0020] The beneficial effects of this invention are as follows:

[0021] 1. The processing technology and apparatus for a liquid slow-release fertilizer of the present invention reacts urea with formaldehyde to generate medium- and long-lasting nutrients such as 1-methylene-2-urea and 2-methylene-3-urea. After being applied to the soil, these nutrients are released through decomposition by soil microorganisms, achieving a combination of fast-acting, medium-acting, and long-lasting nutrients. This results in high fertilizer utilization, reduces the frequency of fertilizer application, and minimizes eutrophication caused by nutrient loss. Furthermore, through liquid suspension technology, mineral nutrients are combined with organic nutrients, allowing nutrient particles to remain in a suspended state for a long time through dispersion technology. This results in good water solubility, prevents pipe clogging during drip irrigation, and facilitates rapid absorption by plants. The fertilizer is convenient, efficient, dissolves quickly, and saves labor and effort.

[0022] 2. The processing technology and apparatus for liquid slow-release fertilizer described in this invention, by setting up sampling tubes, enables simultaneous sampling of different parts inside the reaction vessel, which helps to improve the uniformity and comprehensiveness of the samples and ensures the accuracy of the test results.

[0023] 3. The processing technology and apparatus for liquid slow-release fertilizer described in this invention, by setting up a shell, a movable plate, an air storage box, an extended nozzle and other structures, can simultaneously remove the urea-formaldehyde slow-release solution adhering to its surface during the sampling tube removal process, effectively preventing the solution from dripping onto the surface of the equipment and causing contamination; and also reducing the workload of subsequent cleaning of the sampling tube surface. Attached Figure Description

[0024] The invention will now be further described with reference to the accompanying drawings.

[0025] Figure 1 This is a schematic diagram of the method flow of the present invention;

[0026] Figure 2 This is a schematic diagram of the reaction vessel in this invention;

[0027] Figure 3 This is a schematic diagram of the internal structure of the reaction vessel in this invention;

[0028] Figure 4 This is a partial structural cross-sectional view of the present invention;

[0029] Figure 5 This is a cross-sectional view of the sampling tube in this invention;

[0030] Figure 6 yes Figure 3 Enlarged view of point A in the middle;

[0031] Figure 7 yes Figure 3 Enlarged view of section B in the middle.

[0032] In the diagram: 1. Tank body; 2. Top cover; 3. Feed port; 4. Motor; 5. Discharge pipe; 6. Sampling pipe; 7. Stirring rod; 8. Through groove; 9. Stirring blade; 10. Shell 1; 11. One-way valve 1; 12. Movable plate; 13. Pull rod; 14. Spring 1; 15. Slot; 16. Movable rod; 17. Mounting hole; 18. Sealing cover; 19. Shell 2; 20. One-way valve 2; 21. Piston block; 22. Sampling port; 23. Storage chamber; 24. Ball bearing; 25. Gas storage box; 26. Extension nozzle; 27. Return hole; 28. Retaining ring; 29. ​​Elastic block; 30. Connecting pipe; 31. Sealing ring; 32. Sealed bearing. Detailed Implementation

[0033] To make the technical means, creative features, objectives and effects of this invention easier to understand, the invention will be further described below in conjunction with specific embodiments.

[0034] like Figure 1 As shown, the processing technology of a liquid slow-release fertilizer according to the present invention includes the following steps:

[0035] S1: Add urea and formaldehyde solution to the reaction vessel at the set molar ratio and mix thoroughly. Adjust the pH of the reaction system to alkaline (pH = 8–9), heat to 60–75℃, and react for 1–2 hours to generate methylene urea. Then cool to 40–50℃, adjust the pH to acidic (pH = 4–5), and continue the reaction for 0.5–1 hour to form a stable urea-formaldehyde slow-release solution.

[0036] S2: Add yeast stock solution, seaweed extract, amino acids, mineral potassium humate, small molecule peptides and deionized water in sequence to a high-speed shear tank, stir and mix, transfer the mixture to a high-pressure homogenizer, and circulate it 2-3 times under a pressure of 30-50MPa to form a homogeneous and stable organic synergistic solution.

[0037] S3: Pump the urea-formaldehyde slow-release solution and organic synergist into the suspension reaction tank in proportion, and simultaneously add nitrogen, phosphorus, potassium and trace element water-soluble fertilizer; start the high shear dispersion emulsifier, add the suspension stabilizer, and continuously shear for 20-30 minutes to make the nutrient particle size ≤5μm, forming a long-term stable suspension system.

[0038] S4: The mixture is transferred to a maturation tank and matured for 24 hours under low-speed stirring. During this period, the pH (adjusted to 6.0–7.5) and viscosity are monitored. After maturation, the liquid is filtered through a precision filter to remove impurities and then transported to an automatic filling line for packaging into finished products.

[0039] In this invention, urea is reacted with formaldehyde to generate medium- and long-lasting nutrients such as 1-methylene-2-urea and 2-methylene-3-urea. After being applied to the soil, these nutrients are released through decomposition by soil microorganisms, achieving a combination of fast-acting, medium-acting, and long-lasting nutrients. This results in high fertilizer utilization and can appropriately reduce the number of times fertilizers are used, thus reducing problems such as eutrophication of water bodies caused by nutrient loss.

[0040] By combining mineral and organic nutrients through liquid suspension technology, nutrient particles can remain in a suspended state for a long time through dispersion technology. They have good water solubility, will not clog drip irrigation pipes, can be quickly absorbed by plants, are convenient and efficient to use, dissolve quickly, and save labor and effort.

[0041] Seaweed extract and mineral-derived potassium humate contain various functional groups that promote soil aggregate formation, improve soil structure, and adsorb heavy metal ions and salt ions in the soil, alleviating poor crop root growth caused by soil salinization. It also contains natural growth regulators that can regulate crop growth; rich in potassium, calcium, magnesium, and other mineral nutrients, it can activate fixed mineral nutrients in the soil, supplementing crops with various essential and beneficial elements, promoting robust crop growth and improving quality; and its alkaline and acidic groups can adsorb free H+ and OH- in the soil, alleviating poor crop growth caused by soil acidification or salinization.

[0042] Liquid suspension technology can integrate organic raw materials other than nitrogen, phosphorus, potassium, and trace elements, such as yeast extract, seaweed extract, amino acids, mineral-derived potassium humate, and small molecule peptides, to simultaneously supplement plants with nitrogen, phosphorus, and potassium while promoting root development, nourishing the soil, and supplementing various trace elements. It enhances the activity of plant root cells, accelerates cell division and root synthesis and transport, resulting in deeper and wider root systems, increasing the absorption rate and range. It also fixes nitrogen, solubilizes phosphorus, and activates potassium, further improving fertilizer utilization, increasing crop yield, improving crop quality, and reducing environmental pollution. Furthermore, it improves soil aggregate structure, loosens the soil, enhances water and fertilizer retention capacity, regulates pH, reduces heavy metal content in the soil, and reduces the harmful effects of salt ions on seeds and seedlings. This effectively increases crop yield and quality, and enhances crop resistance to cold, drought, and disease.

[0043] like Figures 2 to 7As shown, the present invention discloses a processing device for liquid slow-release fertilizer. This device is applied to the above-mentioned processing technology of liquid slow-release fertilizer. In step S1, the reaction tank includes a tank body 1 and a top cover 2. The top cover 2 is provided with a feeding port 3. The bottom of the tank body 1 is provided with a discharge pipe 5. A stirring rod 7 is rotatably provided at the bottom of the tank body 1. A stirring blade 9 is fixedly provided on the side wall of the stirring rod 7. The stirring rod 7 is hollow. A motor 4 for driving the stirring tank to rotate is fixed at the bottom of the tank body 1. A through groove 8 is provided on the side wall of the stirring rod 7. An installation hole 17 is provided on the top cover 2. A sampling tube 6 is provided in the middle of the installation hole 17. The sampling tube 6 passes through the through hole and is inserted into the inner cavity of the stirring rod 7.

[0044] During operation, urea and formaldehyde solution are added to the reaction tank through feed port 3 at a set molar ratio. Then, motor 4 is started, which drives stirring rod 7 and stirring blade 9 to mix the materials evenly. The reaction is adjusted to prepare urea-formaldehyde slow-release solution, which is then discharged from discharge pipe 5. At the same time, nitrogen gas is introduced into the reaction tank through the top gas pipe to replace the oxygen in the reaction system, block the formaldehyde oxidation path, and reduce the by-product formation rate. After the urea-formaldehyde slow-release solution is prepared, it needs to be sampled and tested, such as to test the free formaldehyde content and the proportion of methylene urea in the solution, to ensure that the urea-formaldehyde slow-release solution meets the usage requirements. A portion of the urea-formaldehyde slow-release solution is taken through sampling tube 6 and tested. Qualified products continue to be processed, while unqualified products are reworked or discarded.

[0045] Furthermore, inserting the sampling tube 6 vertically into the inner cavity of the stirring rod 7 through the mounting hole 17 will not affect the normal rotation of the stirring rod 7, and by opening a through groove 8 on the side wall of the stirring rod 7, the urea-formaldehyde slow-release solution can enter the inner cavity of the stirring rod 7 and be collected by the sampling tube 6.

[0046] In a preferred embodiment of the present invention, the sampling tube 6 is provided with a plurality of storage cavities 23, each of which is sealed and slidably fitted with a piston block 21, and each of the storage cavities 23 is provided with a sampling port 22 on its side wall. A movable rod 16 is sealed and slidably fitted in the middle of the sampling tube 6, and the plurality of piston blocks 21 are fixedly connected to the movable rod 16.

[0047] During operation, pulling the movable rod 16 during sampling causes the piston blocks 21 in multiple storage chambers to move synchronously, creating negative pressure in these chambers simultaneously. This allows the urea-formaldehyde slow-release solution to be drawn through the corresponding sampling port 22. The storage chambers 23 are distributed at different locations in the sampling tube 6 according to a predetermined height, enabling simultaneous sampling of different parts of the reaction vessel. This helps improve the uniformity and comprehensiveness of the samples, ensuring the accuracy of the test results. Furthermore, the sampling tube 6 remains inside the reaction vessel, collecting samples directly during the sampling process. This avoids disturbing the urea-formaldehyde slow-release solution during insertion sampling, which could lead to deviations in the test results.

[0048] In a preferred embodiment of the present invention, a housing 10 is fixedly disposed at the bottom center of the top cover 2, and a gas storage box 25 is fixedly disposed at the bottom of the housing 10. Both the housing 10 and the gas storage box 25 are circular, and the sampling tube 6 passes through the central hole of the housing 10 and the gas storage box. A movable plate 12 is slidably installed in the inner cavity of the housing 10. Pull rods 13 are symmetrically fixed on both sides of the top of the movable plate 12. A spring 14 for driving the movable plate 12 to move downward is sleeved on the pull rod 13. A horizontal plate 15 is fixed on the top of the pull rod 13. A one-way valve 11 is fixed on the side wall of the housing 10. The gas storage box 25 is connected to the inside of the housing 10 through a one-way valve 20. An annular extension nozzle 26 is disposed on the inner side of the gas storage box 25.

[0049] During operation, sampling tube 6 is used to take a sample. After sampling, the movable plate 12 is pulled upward. During the upward movement of the movable plate 12, a negative pressure is generated in the bottom space, which then draws air into the housing 10 through the one-way valve 11. Then, the sampling tube 6 is pulled upward, and the movable plate 12 is released at the same time. Under the rebound action of the spring 14, the movable plate 12 is driven to move downward. The movable plate 12 squeezes the gas below downward, and the gas enters the gas storage box 25 through the one-way valve 20. Finally, it is sprayed out through the extension nozzle 26. The extension nozzle 26 is tilted downward, and the airflow is opposite to the upward movement of the sampling tube 6, so as to blow off the urea-formaldehyde slow-release solution attached to the surface of the sampling tube 6. This effectively avoids the urea-formaldehyde slow-release solution dripping onto the surface of the equipment after the sampling tube 6 is removed, which would cause contamination to the equipment. It also reduces the workload of cleaning the surface of the sampling tube 6. In addition, the extracted gas comes from inside the reaction tank, avoiding the mixing of external gases, thus ensuring that the internal environment of the reaction tank is not disturbed.

[0050] In a preferred embodiment of the present invention, a second housing 19 is fixed to the bottom of the first housing 10, and the top end of the stirring rod 7 moves through a through hole opened in the center of the bottom of the second housing 19. The second housing 19 covers the outside of the gas storage box 25.

[0051] During operation, the top of the stirring rod 7 is inserted into the through hole so that the top of the stirring rod 7 can be further supported by the housing 19, so that the stirring rod 7 can be more stable during rotation.

[0052] In a preferred embodiment of the present invention, a sealing bearing 32 is fixed at the middle of the top end of the stirring rod 7, and the sampling tube 6 slides through the inner ring of the sealing bearing 32.

[0053] During operation, by installing a sealed bearing 32 in the hollow cavity of the stirring rod 7 and inserting the sampling tube 6 into the inner ring of the sealed bearing 32, the friction between the sampling tube 6 and the inner wall of the stirring rod 7 can be reduced, making the stirring rod 7 rotate more smoothly. Furthermore, by setting the sealed bearing 32, a gap exists between the sampling tube 6 and the inner wall of the stirring rod 7, so that the urea-formaldehyde slow-release solution can enter the interior of the stirring rod 7 through the through groove 8, thereby facilitating the aspiration of the urea-formaldehyde slow-release solution sample through the sampling tube 6. In addition, the outer diameter of the sampling tube 6 and the inner diameter of the inner ring of the sealed bearing 32 are matched. During the upward lifting of the sampling tube 6, the inner ring can initially scrape off the urea-formaldehyde slow-release solution adhering to the surface of the sampling tube 6, thereby reducing the difficulty of removing the surface solution by venting.

[0054] In a preferred embodiment of the present invention, the top end of the stirring rod 7 is inclined, and the bottom of the housing 19 is evenly distributed with reflux holes 27.

[0055] During operation, by setting the top of the stirring rod 7 to an inclined position, the solution blown off the surface of the sampling tube 6 can be easily guided so that the solution can flow to the bottom of the shell 19 and return to the inside of the tank 1 through the return hole 27, thus avoiding waste.

[0056] In a preferred embodiment of the present invention, a sealing cap 18 is detachably installed in the mounting hole 17, and the sealing cap 18 is movably sleeved on the sampling tube 6; a retaining ring 28 is fixed inside the mounting hole 17, an elastic block 29 is fixed at the bottom of the sealing cap 18, and a sealing ring 31 is fixed on the inner wall of the center hole of the sealing cap 18. Both the elastic block 29 and the sealing ring 31 are made of elastic material, and both the elastic block 29 and the sealing ring 31 have cavities inside. The elastic block 29 and the sealing ring 31 are connected by a connecting pipe 30.

[0057] During operation, a sealing cap 18 is installed in the mounting hole 17 to guide the sampling tube 6 to be vertically inserted into the middle of the stirring rod 7. Furthermore, when the sealing cap 18 is inserted into the mounting hole 17, the elastic block 29 at the bottom of the sealing cap 18 is compressed by the retaining ring 28, causing deformation. This allows air inside the elastic block 29 to be forced into the sealing ring 31 through the connecting pipe 30, causing the sealing ring 31 to expand and tightly clamp onto the outer wall of the sampling tube 6, thereby improving the airtightness of the connection and preventing gas leakage inside the reaction vessel. By tightly clamping the sealing ring 31 onto the outside of the sampling tube 6, the solution adhering to its surface can be further removed during the removal of the sampling tube 6, improving the cleaning effect. Additionally, the interior of the housing 19 can be rinsed through the mounting hole 17.

[0058] In a preferred embodiment of the present invention, the bottom of the sampling tube 6 is configured as a pointed shape, and a ball bearing 24 is rotatably mounted on the bottom of the sampling tube 6;

[0059] During operation, a ball bearing 24 is provided at the bottom of the sampling tube 6 to reduce friction between it and the bottom of the inner cavity of the stirring rod 7, thereby reducing wear on the bottom of the sampling tube 6. In addition, the bottom of the sampling tube 6 is made into a pointed shape so that the airflow ejected from the extension nozzle 26 can clean the solution at the bottom of the sampling tube 6, preventing the solution at the bottom of the sampling tube 6 from dripping onto the surface of the equipment after the sampling tube 6 is removed.

[0060] The terms "front," "back," "left," "right," "top," and "bottom" all refer to the figures in the accompanying drawings. Figure 1 Based on the perspective of the observer, the side of the device facing the observer is defined as the front, the left side of the observer is defined as the left, and so on.

[0061] In the description of this invention, it should be understood that the terms "center", "longitudinal", "lateral", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting the scope of protection of this invention.

[0062] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of the present invention is defined by the appended claims and their equivalents.

Claims

1. A processing technology for a liquid slow-release fertilizer, characterized in that: Includes the following steps: S1: Add urea and formaldehyde solution to the reaction vessel at the set molar ratio and mix thoroughly. Adjust the pH of the reaction system to alkaline (pH=8–9), raise the temperature to 60–75℃, and react for 1–2 hours to generate methylene urea. Then lower the temperature to 40–50℃, adjust the pH to acidic (pH=4–5), and continue the reaction for 0.5–1 hour to form a stable urea-formaldehyde slow-release solution. S2: Add yeast stock solution, seaweed extract, amino acids, mineral potassium humate, small molecule peptides and deionized water in sequence to a high-speed shear tank, stir and mix, transfer the mixture to a high-pressure homogenizer, and circulate it 2-3 times under a pressure of 30-50 MPa to form a homogeneous and stable organic synergistic solution. S3: Pump the urea-formaldehyde slow-release solution and organic synergist into the suspension reaction tank in proportion, and simultaneously add nitrogen, phosphorus, potassium and trace element water-soluble fertilizer; start the high shear dispersion emulsifier, add the suspension stabilizer, and continuously shear for 20-30 minutes to make the nutrient particle size ≤5 μm, forming a long-term stable suspension system; S4: The mixture is transferred to a maturation tank and matured for 24 hours under low-speed stirring. During this period, the pH (adjusted to 6.0–7.5) and viscosity are monitored. After maturation, the liquid is filtered through a precision filter to remove impurities and then transported to an automatic filling line for packaging into finished products. The reaction vessel in step S1 includes a vessel body and a top cover. The top cover is provided with a feeding port, the bottom of the vessel body is provided with a discharge pipe, a stirring rod is rotatably provided at the bottom of the vessel body, a stirring blade is fixedly provided on the side wall of the stirring rod, the stirring rod is hollow, a motor for driving the stirring vessel to rotate is fixed at the bottom of the vessel body, a through groove is provided on the side wall of the stirring rod, an installation hole is provided on the top cover, a sampling tube is provided in the middle of the installation hole, and the sampling tube passes through the through hole and is inserted into the inner cavity of the stirring rod. The sampling tube has multiple storage cavities inside, each of which is sealed and slidably fitted with a piston block. Each storage cavity has a sampling port on its side wall. A movable rod is sealed and slidably fitted in the middle of the sampling tube, and the multiple piston blocks are fixedly connected to the movable rod. A housing is fixedly installed at the center of the bottom of the top cover. A gas storage box is fixedly installed at the bottom of the housing. Both the housing and the gas storage box are circular. The sampling tube passes through the central hole of the housing and the gas storage box. A movable plate is slidably installed in the inner cavity of the housing. Pull rods are symmetrically fixed on both sides of the top of the movable plate. A spring is sleeved on the pull rod to drive the movable plate to move downward. A horizontal plate is fixed on the top of the pull rod. A one-way valve is fixed on the side wall of the housing. The gas storage box is connected to the inside of the housing through a one-way valve. An annular extension nozzle is provided on the inner side of the gas storage box.

2. A processing apparatus for liquid slow-release fertilizer, wherein the apparatus is applied to the processing technology of the liquid slow-release fertilizer as described in claim 1, characterized in that: The bottom of the first housing is fixed to the second housing, and the top of the stirring rod moves through the through hole opened in the center of the bottom of the second housing. The second housing covers the outside of the gas storage box.

3. The processing apparatus for a liquid slow-release fertilizer according to claim 2, characterized in that: A sealed bearing is fixed at the middle of the top of the stirring rod, and the sampling tube slides through the inner ring of the sealed bearing.

4. The processing apparatus for a liquid slow-release fertilizer according to claim 3, characterized in that: The top of the stirring rod is inclined, and the bottom of the second housing has reflux holes evenly distributed.

5. The processing apparatus for a liquid slow-release fertilizer according to claim 4, characterized in that: A sealing cap is detachably installed in the mounting hole, and the sealing cap is movably sleeved on the sampling tube.

6. The processing apparatus for a liquid slow-release fertilizer according to claim 5, characterized in that: A retaining ring is fixed inside the mounting hole, an elastic block is fixed at the bottom of the sealing cover, and a sealing ring is fixed on the inner wall of the central hole of the sealing cover. Both the elastic block and the sealing ring are made of elastic material, and both the elastic block and the sealing ring have cavities inside. The elastic block and the sealing ring are connected by a connecting pipe.

7. The processing apparatus for a liquid slow-release fertilizer according to claim 6, characterized in that: The bottom of the sampling tube is designed to be pointed, and a ball bearing is rotatably mounted on the bottom of the sampling tube.

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