Continuous charcoal-humic acid synergistic coated fertilizer production line and coated fertilizer processing technology

Abstract

The invention relates to the technical field of fertilizer processing technologies, in particular to a continuous charcoal-humic acid synergetic coated fertilizer production line and a coated fertilizer processing technology, the continuous charcoal-humic acid synergetic coated fertilizer production line is used for producing coated fertilizer, and the continuous charcoal-humic acid synergetic coated fertilizer production line comprises an inner layer coating device, a middle layer coating device, an outer layer coating device and a film rolling machine; the inner-layer coating device comprises a fluidized bed and is used for forming a biodegradation layer on the surfaces of fertilizer particles; the middle-layer coating device comprises a fertilizer coating machine and an atomizing spraying device and is used for forming a charcoal-humic acid layer; the outer layer coating device comprises a fertilizer coating machine, an atomizing spraying device and an electrostatic generator and is used for forming a slow release layer; an electrostatic generator is arranged at the spraying position of the atomization spraying device. The method is used for producing the coated fertilizer which is uniform and controllable in thickness of each film layer and can be conveniently applied to soil, the effect that the fertilizer is applied after the soil improvement is preferentially improved is realized, the time of the whole fertilizer application period is accurately controlled, and the matching degree of the fertilizer application period and the crop growth period is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of fertilizer processing technology, and in particular to a continuous biochar-humic acid synergistic coated fertilizer production line and a coated fertilizer processing technology. Background Art

[0002] Fertilizers are substances that provide essential nutrients (such as nitrogen, phosphorus, and potassium) to plants, or indirectly promote plant growth by regulating the physical and chemical properties of the soil. When applied to the soil, fertilizer granules increase soil organic matter, specifically repairing deficiencies in specific elements (such as nitrogen and phosphorus), rapidly replenishing soil nutrients, and improving soil fertility, quickly meeting crop fertilizer needs during peak periods.

[0003] To avoid fertilizer waste and improve soil fertility, coated fertilizers are currently used in poor or poor soils. Coated fertilizers are a new type of fertilizer that uses physical or chemical methods to coat the surface of fertilizer particles with one or more layers of special materials (such as resins, sulfur, polymers, etc.) to regulate the rate of nutrient release. The purpose of coating is to achieve a slow or controlled release of fertilizer nutrients, gradually improving soil fertility, synchronizing nutrient supply with crop demand, and reducing waste and environmental pollution.

[0004] Existing coated fertilizers generally improve the soil in advance by coating it with a soil improvement layer (such as a humic acid layer) and a slow-release layer before fertilizing it, thereby improving the soil's absorption efficiency of the fertilizer. However, in the existing technology, fertilizer coating machines are generally used for fertilizer coating processing. During the actual coating process, the thickness of the coating layer produced by the roller-type coating of the fertilizer coating machine is difficult to accurately control, especially the slow-release layer that requires a long period of decomposition. The decomposition cycle varies greatly at different thicknesses, which affects the soil improvement and fertilization cycle of the coated fertilizer, resulting in errors between the fertilization cycle and the growth cycle required by different crops in the soil, reducing the fertilization effect on the crops.

[0005] Moreover, existing coated fertilizer granules are generally directly sprinkled into the soil manually. During the actual application process, due to the non-uniform diameter of the fertilizer granules themselves and their dispersed granular shape, the coated fertilizer granules will be unevenly distributed after being applied to the soil, and the soil fertility will also be uneven, which can easily affect the growth of crops in the soil.

[0006] Moreover, existing coated fertilizer granules only contain fertilizer granules, but the fertilization effect of a single fertilizer in poor soil or acidic or alkaline soil is not good, and the soil needs to be improved to improve the fertilizer absorption effect. Summary of the Invention

[0007] The purpose of this application is to provide a continuous biochar-humic acid synergistic coated fertilizer production line, which is used to produce a coated fertilizer with controllable and uniformly distributed thickness of each film layer, and convenient and uniform application to the soil, thereby realizing the priority improvement of soil before fertilization, and accurately controlling the entire fertilization cycle time, thereby improving the matching degree between the fertilization cycle and the crop growth cycle.

[0008] In order to solve the above technical problems, the solution adopted by this application is as follows:

[0009] A continuous biochar-humic acid synergistic coated fertilizer production line is used to produce coated fertilizers. The coated fertilizers are sequentially arranged from the inside to the outside as fertilizer particles, a biodegradable layer, a biochar-humic acid layer, and a slow-release layer.

[0010] Preferably, it includes an inner layer wrapping device, an intermediate layer wrapping device, an outer layer wrapping device, and a film rolling machine.

[0011] Preferably, the inner coating device comprises a fluidized bed for forming a biodegradable layer on the surface of the fertilizer particles.

[0012] Preferably, the middle layer coating device includes a fertilizer coating machine and an atomizing spraying device, which is used to form a biochar-humic acid layer outside the biodegradable layer.

[0013] Preferably, the coating position of the fertilizer coating machine is provided with an atomizing spraying device.

[0014] Preferably, the outer coating device includes a fertilizer coating machine, an atomizing spraying device and an electrostatic generator, which is used to form a slow-release layer outside the biochar-humic acid layer.

[0015] Preferably, an electrostatic generator is provided at the spraying position of the atomizing spray device.

[0016] Preferably, the fluidized bed and the fertilizer coating machine are both provided with temperature control components, and the temperature control components include heating elements or cooling elements.

[0017] A continuous biochar-humic acid synergistic coated fertilizer processing process is obtained, and the steps are as follows:

[0018] S1. Screen fertilizer particles with a particle size range of 2-4 mm.

[0019] S2. The fertilizer particles are transported into the fluidized bed so that the fertilizer particles are suspended and tumbled.

[0020] S3. Prepare a 4% chitosan aqueous solution and dissolve it in a 1% acetic acid solution to reduce the viscosity.

[0021] S4. The fluidized bed atomizes the 4% chitosan mixed solution and sprays it on the surface of the fertilizer particles using air flow.

[0022] S5. The air flow temperature is controlled at 60° C. The 4% chitosan solution is heated to evaporate the acetic acid / water, causing the chitosan molecular chains to entangle, adhere and solidify, and form a biodegradable layer with a uniform film structure.

[0023] S6. The fertilizer granules coated with the biodegradable layer are transported to a fertilizer coating machine for continuous rolling and turning. A solution is formed by mixing biochar powder and humic acid colloid in a mass ratio of 3:1. The solution is then sprayed onto the surface of the biodegradable layer through an atomizing spray device to form a biochar-humic acid film layer.

[0024] S7. Applying a drying temperature of 80° C. to the biochar-humic acid film layer accelerates water evaporation, promotes the generation of gaps between humic acid molecules and biochar, and forms a porous structure.

[0025] S8. The fertilizer particles (10) coated with the biochar-humic acid layer are transported to a fertilizer coating machine for continuous rolling and turning, and the polylactic acid particles are sprayed onto the surface of the fertilizer particles (10) by high-pressure atomization.

[0026] S9. Apply 10℃-20℃ cooling to the fertilizer coating machine to keep the polylactic acid in a hardened state, quickly solidify it on the surface of the fertilizer particles, and form a uniform and tight slow-release layer on the surface of the biochar-humic acid layer.

[0027] S10, using an electrostatic generator to ionize the surface of the polylactic acid particles and charge them, accurately controlling the coating thickness of the polylactic acid particles to produce different sustained-release cycles.

[0028] S11. Quantitatively packing the fertilizer granules coated with the slow-release layer into a long strip film package, wherein the film package is a water-soluble film.

[0029] Preferably, the fluidized bed includes a fluidizing chamber, a filter plate is provided in the fluidizing chamber, fertilizer particles are placed above the filter plate, a hot air device and an atomizer are provided below the filter plate, and the atomization port of the atomizer faces the filter plate.

[0030] Preferably, the fertilizer coating machine includes a drum connected to a driving member, and the drum is rotated by the driving member. A cylindrical cavity is provided through the drum, and the coated fertilizer is placed in the cylindrical cavity.

[0031] Preferably, the atomizing spray device includes a fluid pipeline, one end of the fluid pipeline is connected to a pump, the pump is connected to an external liquid injection port, and the other end of the fluid pipeline is connected to a plurality of atomizing heads, which are located inside the barrel cavity.

[0032] Preferably, the electrostatic generator in the outer coating device includes a power supply and electrodes.

[0033] Preferably, the power supply is arranged on the fluid pipeline, the power supply is connected to the electrode, the electrode is passed through the fluid pipeline, and the position of the electrode corresponds to the atomizing head one by one.

[0034] Preferably, the film rolling machine comprises a film coating platform horizontally arranged on the base, and one side of the film coating platform is provided with rollers for storing the upper and lower outer films respectively.

[0035] Preferably, one end of the lower outer film is sequentially arranged through a lower film driving roller shaft and a lower film auxiliary roller shaft, and the lower film auxiliary roller shaft is located above the film coating platform.

[0036] Preferably, one end of the upper outer film is sequentially arranged through an upper film driving roller shaft and an upper film auxiliary roller shaft, and the upper film driving roller shaft and the upper film auxiliary roller shaft are located above the film coating platform.

[0037] Preferably, a heat sealing machine is arranged on the film coating platform.

[0038] Preferably, the upper and lower outer films are arranged in a corresponding upper and lower manner, and a plurality of continuous biochar-humic acid synergistic coated fertilizers are arranged between the upper and lower outer films.

[0039] The technical scheme has at least the following advantages and beneficial effects:

[0040] In the application, a fluidized bed is arranged to form a biodegradable layer on the surface of the fertilizer particles, so that a uniform and thin film structure of the biodegradable layer can be quickly formed on the surface of the fertilizer particles on the fluidized bed, thereby providing a buffering effect while reducing the thickness of the film layer, accelerating the decomposition, and reducing the impact on fertilization; a fertilizer coating machine and an atomizing and spraying device are arranged to form a biochar-humic acid layer and a slow-release layer on the surface of the fertilizer particles in sequence, wherein an electrostatic generator is used to charge the slow-release material sprayed onto the fertilizer particles, so that the slow-release material is continuously and uniformly bonded to the fertilizer, thereby ensuring the uniformity of the thickness of the slow-release layer, and the electrostatic generator can be adjusted to change the number of charges and the electrification time, so that the thickness of the slow-release layer can be accurately controlled, and the instability of the long-period slow-release period can be reduced.

[0041] In the application, a film rolling machine and a heat sealing machine are arranged, and a plurality of coated fertilizer particles are covered in a packaging bag formed by the outer film, thereby forming a long strip-shaped film package, so that the staff can directly place the plurality of fertilizer particles gathered in the long strip-shaped film package in the soil, thereby reducing the workload when the fertilizer particles in a dispersed state are applied, and the distribution of the fertilizer particles in the long strip-shaped film package is more uniform than that in a dispersed state, so that the fertilizer can be uniformly distributed in the soil. BRIEF DESCRIPTION OF DRAWINGS

[0042] Figure 1 The figure is a structural schematic diagram of a fertilizer production line in the application.

[0043] Figure 2 The figure is a front view structural schematic diagram of a fertilizer production line in the application.

[0044] Figure 3 The sectional structure schematic diagram of the fluidized bed in the application.

[0045] Figure 4 The structure schematic diagram of the fertilizer coating machine in the application.

[0046] Figure 5 The sectional structure schematic diagram of the fertilizer coating machine in the application.

[0047] Figure 6 The sectional structure schematic diagram of another fertilizer coating machine in the application.

[0048] Figure 7 The sectional structure schematic diagram of the atomization spraying device in the application.

[0049] Figure 8 The sectional structure schematic diagram of the atomization spraying device in the application. Figure 7 The sectional structure schematic diagram of the atomization spraying device in the application.

[0050] Figure 9 The sectional structure schematic diagram of the atomization spraying device in the application.

[0051] Figure 10 The sectional structure schematic diagram of the atomization spraying device in the application.

[0052] Figure 11 The sectional structure schematic diagram of the atomization spraying device in the application.

[0053] Figure: 1-fluidized bed, 101-fluidized tank, 102-feeding valve, 103-discharging valve, 104-filter plate, 105-hot air device, 106-backflow pipe, 2-fertilizer coating machine, 201-roller, 202-driving part, 203-support frame, 204-cylinder cavity, 205-guide piece, 3-atomization spraying device, 301-fluid pipe, 302-pump, 303-atomization head, 4-film rolling machine, 401-base, 402-film rolling platform, 403-lower film driving roller, 404-lower film auxiliary roller, 405-upper film driving roller, 406-upper film auxiliary roller, 5-conveying belt group, 501-warehouse, 502-conveying belt, 6-feeding device, 7-hot sealing machine, 8-static generator, 801-power supply, 802-electrode, 9-outer film; 10-fertilizer particles, 11-biodegradable layer, 12-biochar-humic acid layer, 13-slow-release layer. DETAILED DESCRIPTION

[0054] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0055] It should be noted that similar reference numerals and letters denote similar items in the following figures. Therefore, once an item is defined in one figure, it does not require further definition or explanation in subsequent figures. Terms such as "center," "upper," "lower," "inner," and "outer" indicate positions or locations based on the positions or locations shown in the figures, or the positions or locations in which the product is typically placed when in use. These terms are used solely for ease of description and simplification of the present application. They do not indicate or imply that the device or component referred to must have a specific position, be constructed, or operate in a specific orientation, and are not to be construed as limiting the present application. It should also be noted that, unless otherwise expressly specified or limited, the terms "disposed," "mounted," and "connected" should be interpreted broadly. For example, they can refer to fixed, removable, or integral connections; mechanical or electrical connections; direct connections or indirect connections through an intermediary; or internal connections between two components. Those skilled in the art will understand the specific meanings of these terms in this application in specific contexts.

[0056] In the existing technology, fertilizer coating technology uses a fertilizer coating machine to drive granular fertilizer to roll continuously through a rotating drum, and then uses a spray device to wrap a slow-release layer on the surface of the rolling granular fertilizer to form a protective layer to control the release rate of fertilizer nutrients in the soil. However, the fertilization effect of a single fertilizer in poor soil or acidic and alkaline soil is not good, and the soil needs to be improved to improve the fertilizer absorption effect.

[0057] In the existing technology, the improvement of saline soil generally uses the high porosity of biochar to absorb salt, and then uses humic acid to reduce the sodium ion concentration in the soil through chelation, combined with organic-inorganic nutrient supplementation to improve the structure of saline-alkali land; the improvement of acidic soil generally uses the alkaline properties of biochar (pH 8-10) to neutralize the soil acidity, and then uses humic acid to enhance the soil buffering capacity, synergistically raising the pH value to a range suitable for crop growth (pH 6-7); the improvement of poor soil generally uses the carbon fixation of biochar and the organic matter supplementation of humic acid to increase the soil organic carbon content, promote the diversity of microbial communities, and thus improve the soil's absorption of fertilizers.

[0058] In the prior art, the preparation of biochar is to heat agricultural waste (such as straw, sawdust) under anaerobic or low oxygen conditions to generate porous structure biochar. The preparation of humic acid is to extract humic acid from organic waste (such as lignite, sludge) by chemical or biological degradation method, and then purify. Mixing the two in proportion can form a biochar-humic acid powder.

[0059] In the prior art, the coated fertilizer is coated with a layer of biochar-humic acid layer (a buffer layer is needed between the two) on the surface of the fertilizer, which can preferentially improve the soil, improve the microbial community, and then make the fertilizer contact with the soil, thereby improving the fertilization effect; and the biochar-humic acid layer is further coated with a slow-release layer, which is used to control the release period of the coated fertilizer, so as to slowly improve the fertilization and match the growth period of crops, so as to fertilize in the period when the crops most need nutrients.

[0060] Embodiment 1

[0061] In order to realize the synchronous improvement of the coated fertilizer to the soil and the fertilization effect, and match the time point of the growth period of crops in the soil, the present application provides a continuous biochar-humic acid synergistic coated fertilizer, which is provided with fertilizer particles, a biodegradation layer, a biochar-humic acid layer, and a slow-release layer from inside to outside.

[0062] The specific composition of each layer of the fertilizer is as follows:

[0063] The fertilizer particles are set as nitrogen, phosphorus and potassium compound fertilizer, and the particle size range is 2-4mm.

[0064] Among them, the fertilizer particles provide nitrogen, phosphorus and other basic nutrient elements for the crops planted in the soil.

[0065] The particle size of the fertilizer particles represents the weight (content) of the fertilizer particles. If the particle size of the fertilizer particles is too small, the nutrient substances carried by the whole fertilizer will be too little to provide sufficient nutrients for the crops in the soil. If the particle size of the fertilizer is too large, the weight of the whole fertilizer will be too heavy, and when the fertilizer particles are suspended and sprayed in the fluidized bed to form the biodegradation layer, the heavy fertilizer particles are difficult to suspend under the action of gravity, and it is difficult to perform the spraying work of the outer layer through the fluidized bed. Therefore, the particle size range of the fertilizer particles needs to be set within a certain range.

[0066] Further, the biodegradation layer is composed of 4% concentration chitosan solution.

[0067] Among them, the biodegradation layer is used to isolate the fertilizer particles and the biochar-humic acid layer, and after the establishment of the microbial community, the biodegradation layer is rapidly degraded (period 7-10 days) by the decomposition of microorganisms.

[0068] Because the biochar-humic acid layer on the outer biodegradable layer increases the activity and number of microorganisms in the soil, the microbial community then rapidly decomposes the biodegradable layer, exposing the fertilizer particles in the inner layer and enriching the soil. To maintain microbial activity, the biodegradation time of the entire biodegradable layer needs to be shortened as much as possible to maintain constant microbial activity over a short period of time (longer periods of time tend to cause inconsistent microbial activity at the beginning and end). Therefore, in this embodiment, the degradation period is generally limited to about one week.

[0069] Among them, if the chitosan concentration in the biodegradable layer is too low, the microorganisms cultured in the external biochar-humus layer will quickly decompose it, exposing the internal fertilizer particles prematurely. At this time, because the microbial community has been cultured on the biochar-humus layer for a short time, the activity of the microbial community has not reached the best, which can easily affect the fertility; and if the chitosan concentration in the biodegradable layer is too high, it will prolong the decomposition cycle of the biodegradable layer by microorganisms.

[0070] Therefore, since different concentrations of chitosan will affect the decomposition efficiency of microorganisms, in order to match the optimal degradation cycle, it is necessary to determine the optimal chitosan concentration ratio of the biodegradable layer.

[0071] In this embodiment, referring to Table 1, in order to determine the optimal chitosan concentration ratio of the biodegradable layer, a plurality of chitosan control groups with different concentrations were set up to determine the optimal chitosan concentration ratio.

[0072] The experimental groups were configured with the following conditions: fixed fertilizer particles, a biochar-humic acid layer, and a slow-release layer, so that the number and activity of multiple groups of microorganisms were consistent. Each experiment was repeated four times at different times, and the detection time was based on the values ​​of four parallel measurements.

[0073] Table 1: Membrane degradation time at different chitosan concentrations

[0074] Chitosan concentration <![CDATA[脱乙酰度A0]]> Membrane degradation cycle (mean ± SD) Activity after microbial degradation 0％ 0％ 0 <![CDATA[3.1×10 8 ]]> 1％ 76％ 2±1 <![CDATA[2.9×10 8 ]]> 2％ 81％ 3±1 <![CDATA[2.8×10 8 ]]> 3％ 83％ 5±1 <![CDATA[2.6×10 8 ]]> 4％ 86％ 7±1 <![CDATA[2.4×10 8 ]]> 5％ 89％ 13±1 1.9 x 10 8 ]] 6％ 91％ 21±1 <![CDATA[1.7×10 8 ]]> 10％ 94％ 30±1 1.1 x 10 8 ]]> 20％ 96％ 35±1 <![CDATA[0.3×10 8 ]]>

[0075] As can be seen from the above table, when the chitosan concentration is around 4%, the degradation period of the entire biodegradable layer will be controlled at around 7 days. At this time, the decline in microbial activity after chitosan degradation is also relatively gentle (the removal of acetyl groups in chitosan has an antibacterial effect, so when the deacetylation degree is low, the impact on microbial activity will also be smaller). Therefore, using a 4% concentration of chitosan solution can achieve the isolation effect and maintain microbial activity.

[0076] Furthermore, the biochar-humic acid layer is formed by mixing biochar and humic acid colloid in a mass ratio of 3:1.

[0077] Among them, biochar adsorbs heavy metals, and humic acid chelates salts, synergistically improving soil microbial activity. Both can also enhance soil buffering capacity, regulate soil pH, and supplement organic matter to maintain the diversity of soil microbial communities, thereby improving fertilizer degradation and rapidly increasing fertilizer.

[0078] Among them, humic acid colloid can chelate Na through its own humic acid carboxyl group during the adjustment process. + , forming a chelate, and then complexing Al through its own humic acid phenolic hydroxyl group 3+ , forming complexes, and also improving the fertility of poor soils (such as salt marshes) and reducing seedling burn through the organic matter it contains. If the humic acid concentration is low, the organic matter content is low, and the activity of microorganisms attached to it will also be reduced, affecting the degradation effect of fertilizer particles. If the humic acid concentration is too high, the concentration of various carboxyl groups and phenolic hydroxyl groups it contains increases. In the binding of heavy metal ions, the stability of compound aggregates will be reduced due to a large number of free radicals, which will more easily lead to the failure of ion chelation. Therefore, the concentration ratio of humic acid colloids needs to be precisely controlled.

[0079] Among them, during the regulation process, biochar can lock macromolecular chelates through the biochar pores, prevent heavy metal ions from flowing back to the soil, and use the voids to provide a living environment for microbial communities, thereby improving the activity of microorganisms. If the biochar content is too low, its overall pore adsorption capacity will also be weakened, and the adsorption of various chelates will be weakened, and the adsorption of water (maintaining humidity) and organic matter (maintaining nutrients) will also be reduced, which will easily increase the environmental pressure of the attached microbial community and reduce the activity of microorganisms. If the biochar content is high, its overall pore adsorption capacity will be too strong, and it will adsorb too many external organic molecules, causing the attached microbial community to compete with the external organic molecules, which will also lead to a decrease in the activity of microorganisms during the proliferation of the microbial community. Therefore, it is also necessary to precisely control the concentration ratio of biochar.

[0080] As can be seen from the above, the ratio between biochar and humic acid colloid affects the soil improvement effect and microbial activity. Therefore, in this example, please refer to Tables 2 and 3. In order to determine the optimal ratio of the biochar-humic acid layer, multiple control groups with different ratios of biochar and humic acid colloid were set up to determine the optimal ratio.

[0081] The configuration conditions of each experimental group are as follows: fixed fertilizer particles, degradation layer and slow-release layer, and the total weight of biochar and humic acid added each time is the same. Each group of experiments is repeated 4 times at different times, and the detection time is based on the values ​​of 4 parallel measurements.

[0082] Table 2: Soil improvement at different biochar concentrations

[0083]

[0084] Table 3: Soil improvement under different humic acid concentrations

[0085]

[0086]

[0087] It can be seen from Tables 2 and 3 above that when the ratio of biochar to humic acid is 3:1, the entire biochar-humic acid layer has the best adsorption effect on heavy metal ions in the soil and the strongest improvement on the activity of microorganisms in the soil. Therefore, the best soil improvement effect can be achieved by mixing biochar and humic acid in a mass ratio of 3:1.

[0088] Furthermore, the sustained-release layer is composed of polylactic acid particles.

[0089] Among them, polylactic acid particles are biodegradable materials, generally made of starch raw materials (such as corn), so they can be completely degraded by microorganisms, reducing the harm to the soil environment. The slow-release layer is covered on the outside of the biochar-humic acid layer, so that workers can add fertilizers to the soil in advance in the easy farming season (dry season) according to the slow-release cycle, which can achieve slow release or controlled release of fertilizer nutrients and biochar-humic acid, so that it can automatically release internal fertilizers during the crop growth period (rainy season), gradually improve the fertility of the soil, synchronize nutrient supply with crop demand, thereby quickly promoting crop growth and increasing crop yields.

[0090] The above-mentioned continuous biochar-humic acid co-coated fertilizer can slowly and gently improve the soil, but this embodiment requires coating multiple layers of materials on the surface of commonly used fertilizer particles to form a complete continuous biochar-humic acid co-coated fertilizer. Therefore, a specific coating device is required to coat the various layers of materials on the outside of the fertilizer particles.

[0091] Therefore please refer to Figures 1-10 The present invention provides a continuous biochar-humic acid synergistic coated fertilizer production device for producing coated fertilizer. The production device includes a fluidized bed 1, a fertilizer coating machine 2, an atomizing spraying device 3, an electrostatic generator 8, a temperature control component, and a film rolling machine 4.

[0092] Among them, in order to uniformly coat the biodegradable layer 11, the biochar-humic acid layer 12 and the slow-release layer 13 on the surface of the fertilizer particles 10 in sequence, so as to simultaneously achieve the improvement and fertilization of the applied soil, the production order of the fertilizer particles 10 on the production line is the inner coating device (coating the biodegradable layer 11) - the middle coating device (coating the biochar-humic acid layer 12) - the outer coating device (coating the slow-release layer 13) - the film rolling machine 4 (encapsulating and molding several coated fertilizer particles 10).

[0093] Furthermore, the fertilizer particles 10 first enter the inner coating device, and a biodegradable layer 11 is coated on the surface of the fertilizer particles 10. The biodegradable layer 11 is used to separate the fertilizer particles 10 and the biochar-humic acid layer 12, providing a buffer between the two to prevent the two from mixing together and affecting the soil improvement effect; and the biodegradable layer 11 is configured as a chitosan layer that can be decomposed by microorganisms. Only when the soil to which the fertilizer is applied is improved and there is a microbial community in the soil, the biodegradable layer 11 will be degraded, and the fertilizer particles 10 inside the exposed area will fertilize the soil, thereby reducing the possibility that the fragile microbial community in the soil will be destroyed by the sudden addition of fertilizer to the soil that has not yet been improved.

[0094] In order to improve the thickness uniformity of the biodegradable layer 11 coated on the surface of the fertilizer granules 10 , the inner coating device for coating the biodegradable layer 11 is configured as a fluidized bed 1 .

[0095] Specifically, the fluidized bed 1 is a device that uses a fluid (gas or liquid) to pass through a layer of solid particles, causing the particles to suspend and exhibit fluid-like behavior; the working principle is that when a fluid (such as air or water) passes upward through a bed of solid particles at a certain speed, the particles will be lifted by the drag force of the fluid, break away from the static state and begin to suspend.

[0096] In this embodiment, the fertilizer particles 10 are transported to the solid particle bed layer of the fluidized bed 1, and then the chitosan solution is sprayed into the fluidized bed 1. The airflow from the bottom to the top of the fluidized bed 1 causes the fertilizer particles 10 to be suspended and tumbled. After the chitosan solution is atomized by the nozzle, it is brought into the airflow and covered on the surface of the fertilizer particles 10, forming a biodegradable layer 11 with a uniform film structure.

[0097] Preferably, the fluidized bed 1 utilizes the circulating flow of the airflow to evenly distribute the atomized solution throughout the coating space, so that the surface of the fertilizer particles 10 suspended and tumbling in the airflow can be evenly coated with a thinner biodegradable layer 11. Moreover, since the atomized solution is coated by the airflow, compared with the drum coating of the commonly used fertilizer coating machine, the biodegradable layer 11 produced is thinner and more likely to decompose quickly after the external biochar-humic acid layer 12 decomposes, thereby accelerating the time for the internal fertilizer particles 10 to act on the soil.

[0098] Furthermore, after the biodegradable layer 11 is formed on the surface of the fertilizer particles 10, it is passed into the intermediate layer coating device to continue to coat the surface of the fertilizer particles 10 with a layer of biochar-humic acid layer 12. The biochar-humic acid layer 12 is located on the outside of the fertilizer and is used to improve the soil in advance before fertilizing the soil, optimize the soil quality, increase the microbial community, and thus increase the soil's absorption efficiency of the fertilizer.

[0099] The intermediate layer coating device for coating the biochar-humic acid layer 12 comprises a fertilizer coating machine 2 and an atomizing spraying device 3.

[0100] Specifically, the fertilizer coating machine 2 belongs to the existing equipment, and the atomizing spraying device 3 is arranged in the fertilizer coating machine 2. The two devices jointly wrap one or more layers of functional film materials on the surface of the fertilizer particles 10. The working principle is that the fertilizer particles 10 continuously roll in the drum 201 of the fertilizer coating machine 2, the atomizing spraying device 3 in the drum 201 sprays the coating material to uniformly cover the surface of the rolling fertilizer, and the coating is formed.

[0101] In this embodiment, the fertilizer particles 10 coated with the biodegradable layer 11 are transported into the drum 201 of the fertilizer coating machine 2, the drum 201 rotates to drive the fertilizer particles 10 to continuously roll and turn over, and the atomizing spraying device 3 is connected to the outside through a pump pressure pipeline to mix the biochar powder and the humic acid colloid mixture, and the atomizing head 303 is inserted into the inside of the rotating drum 201 to spray the biochar-humic acid mixture under high pressure into the inside of the drum 201 to cover the biodegradable layer 11 of the fertilizer particles 10, and form a biochar-humic acid film layer.

[0102] Further, after the biochar-humic acid layer 12 is formed on the surface of the fertilizer particles 10, the fertilizer particles 10 are transported into the outer layer coating device to coat a slow-release layer 13 on the surface of the fertilizer particles 10. The slow-release layer 13 is located outside the biochar-humic acid layer 12, and the slow decomposition of the slow-release layer 13 prolongs the nutrient release period of the biochar-humic acid layer 12, gently improves the soil, and gradually increases the contact degree between the biochar-humic acid layer 12 and the outside soil during the slow decomposition process, and gradually improves the adaptability and degradation effect of the microbial community.

[0103] Among them, because the slow-release layer 13 has a long decomposition period in the soil, different thicknesses of the slow-release layer 13 will produce a large difference in the decomposition period, therefore, the outer layer coating device generates a slow-release layer 13 with uniform thickness distribution outside the biochar-humic acid layer 12, reduces the deviation of the decomposition period, and makes the thickness of the slow-release layer 13 controllable, which is used to produce different slow-release periods and improve the matching of different crops.

[0104] The outer layer coating device comprises a fertilizer coating machine 2, an atomizing spraying device 3, and an electrostatic generator 8.

[0105] Specifically, in this embodiment, the fertilizer particles 10 coated with the biochar-humic acid layer 12 are transported into the drum 201 of the fertilizer coating machine 2, the fertilizer particles 10 continuously roll and turn over, and the atomizing spraying device 3 sprays the slow-release layer 13 powder outside the biochar-humic acid layer 12 of the fertilizer particles 10 under high pressure to form a slow-release layer 13.

[0106] The powder of the sustained-release layer 13 is formed by mixing polylactic acid particles, which are biodegradable materials. When an electrostatic generator 8 is provided at the atomizing head 303, the electrode 802 end of the electrostatic generator 8 is brought into contact with the atomized polylactic acid particles, so that the surface of the polylactic acid particles is ionized and charged, and then directed to be sprayed onto the surface of the fertilizer particles 10. However, when the fertilizer particles 10 are repeatedly rolled in the drum 201, their surface will carry an electric charge due to friction. When the charged polylactic acid particles contact the surface of the fertilizer particles 10, they will be evenly adsorbed to the surface of the fertilizer particles 10 by the Coulomb force (the electric charge polarity carried by the fertilizer particles 10 is opposite to that of the polylactic acid particles), forming a continuous and uniform polylactic acid sustained-release layer 13.

[0107] Preferably, the outer coating device is provided with an electrostatic generator 8 on the coating basis of the fertilizer coating machine 2, and the electrostatic directional adsorption effect forms a polylactic acid slow-release layer 13 outside the biochar-humic acid layer 12 of the fertilizer particles 10. The polylactic acid slow-release layer 13 is formed by the interaction force between the charged polylactic acid particles and the fertilizer particles 10 after rolling friction. During the production process, a charged ion layer is formed on the surface of the fertilizer particles 10 after rolling. After the charged polylactic acid particles adhere to the surface of the fertilizer particles 10, the polylactic acid particles adhere tightly and evenly due to the matching between the charges. After the attachment, the fertilizer particles 10 continue to roll, and a new charged ion layer is generated on its surface, and new charged polylactic acid particles continue to adhere, thereby continuously generating thin layers of polylactic acid particles, and finally forming the slow-release layer 13. The thickness of the slow-release layer 13 formed in this way is relatively uniform and tight.

[0108] The amount of charged ions emitted by the electrostatic generator 8 and the emission time are controllable, so the thickness of the polylactic acid particles coated on the surface of the fertilizer particles 10 can be controlled to produce different slow-release cycles, which is convenient for matching different crop growth cycles.

[0109] Furthermore, after a slow-release layer 13 is formed on the surface of the fertilizer particles 10, they are passed into the film rolling machine 4, and a packaging bag formed by the outer film 9 is used to wrap a number of film-coated fertilizer particles 10 therein to form a long film package, which makes it convenient for the staff to place the several fertilizer particles 10 gathered in the long film package directly into the soil, reducing the workload when applying the fertilizer particles 10 in a dispersed state and making the fertilizer evenly distributed in the soil.

[0110] Among them, the outer film 9 forming the long strip film package is a water-soluble film material (such as a starch-based material). When the outer film 9 is placed in the soil, it can be quickly degraded by the moisture and microorganisms in the soil, so that the several fertilizer particles 10 gathered inside it can contact the soil for soil improvement and fertilization.

[0111] It is worth noting that temperature control components are provided in the fluidized bed 1 coating the biodegradable layer 11 and the fertilizer coating machine 2 coating the biochar-humic acid layer 12 and the slow-release layer 13. The temperature control component includes a heating component and a cooling component, which can heat or cool each device to cooperate with the coating work of various materials on the surface of the fertilizer particles 10.

[0112] Among them, the temperature control component in the fluidized bed 1 coated with the biodegradable layer 11 applies a heating temperature of 60°C to the coated fertilizer. Because the biodegradable layer 11 is composed of chitosan, during the fluidization process, it is necessary to accelerate the rapid solidification of the chitosan film layer on the surface of the fertilizer particles 10 by heating, while avoiding excessively high temperatures that may destroy the molecular structure of chitosan and reduce its biodegradability.

[0113] Among them, the temperature control component in the fertilizer coating machine 2 that coats the biochar-humic acid layer 12 applies a drying temperature of 80°C to the coated fertilizer. When the biochar-humic acid mixture is atomized and sprayed onto the surface of the fertilizer particles 10, high-temperature drying can accelerate water evaporation, promote the formation of gaps between humic acid molecules and biochar, and form a porous structure to enhance its adsorption capacity for heavy metals in the soil and water retention.

[0114] The temperature control component in the fertilizer coating machine 2, which coats the slow-release layer 13, applies a cooling temperature of 10°C-20°C to the fertilizer granules 10 being coated, maintaining the ambient temperature at around 20°C during the coating of the PLA granules. This prevents excessively high temperatures from causing the PLA granules to soften and stick together, which would affect the coating effect. The lower temperature allows the PLA to maintain its hardened state (i.e., glass transition), rapidly solidifying on the surface of the fertilizer granules 10 and forming a dense slow-release layer 13 that resists microbial degradation and prolongs the slow-release period.

[0115] A continuous biochar-humic acid synergistic coated fertilizer production process can be obtained by using the above-mentioned continuous biochar-humic acid synergistic coated fertilizer and its supporting continuous biochar-humic acid synergistic coated fertilizer production device. The steps are as follows:

[0116] S1, screening fertilizer particles 10 within a particle size range of 2-4 mm;

[0117] S2. transporting the fertilizer granules 10 into the fluidized bed 1 so that the fertilizer granules 10 are suspended and tumbled;

[0118] S3, prepare a 4% chitosan aqueous solution and dissolve it in a 1% acetic acid solution to reduce the viscosity;

[0119] S4, the fluidized bed 1 atomizes the chitosan mixed solution with a concentration of 4% and sprays it on the surface of the fertilizer particles using air flow;

[0120] S5, the airflow temperature is controlled at 60℃, and the chitosan solution with a concentration of 4% is heated to evaporate acetic acid / water, so that the chitosan molecular chain is entangled and cohered to form a biodegradable layer 11 with a uniform film structure;

[0121] S6, the fertilizer particles 10 coated with the biodegradable layer are transported to a fertilizer coating machine for continuous rolling and turning, and the biochar powder and humic acid colloid are mixed in a mass ratio of 3:1 to form a solution, which is sprayed on the surface of the biodegradable layer from a atomizing and spraying device to form a biochar-humic acid film layer 12;

[0122] S7, the biochar-humic acid film layer 12 is subjected to a drying temperature of 80℃ to accelerate water evaporation and promote the generation of voids between the humic acid molecules and the biochar to form a porous structure;

[0123] S8, the fertilizer particles 10 coated with the biochar-humic acid layer 12 are transported to a fertilizer coating machine for continuous rolling and turning, and the polylactic acid particles are high-pressure atomized and sprayed onto the surface of the fertilizer particles 10;

[0124] S9, the fertilizer coating machine is subjected to refrigeration at a temperature of 10℃-20℃ to keep the polylactic acid in a hardened state and quickly solidify on the surface of the fertilizer particles 10 to form a uniform and compact slow-release layer 13 on the surface of the biochar-humic acid layer 12;

[0125] S10, the polylactic acid particles 10 are ionized and charged by using an electrostatic generator to accurately control the coating thickness of the polylactic acid particles and produce different slow-release periods;

[0126] S11, the fertilizer particles 10 coated with the slow-release layer 13 are quantitatively packaged into long strip-shaped film packages, and the film packages are water-soluble film packages.

[0127] Example 2

[0128] Further, after the coating work on the fertilizer particles 10 is completed and the fertilizer particles 10 are packaged into long strip-shaped film packages, the coated fertilizer particles 10 can be applied to soil improvement and fertilization. The application method of the coated fertilizer produced by the continuous biochar-humic acid synergistic coated fertilizer production device to soil improvement and fertilization is as follows:

[0129] Sa, loosen the soil to be improved, and dig out long strip-shaped trenches uniformly arranged in the soil.

[0130] Sb, place the fertilizer particles 10 packaged in long strip-shaped film packages in the long strip-shaped trenches, and fill the trenches with soil.

[0131] The long strip-shaped film packages facilitate the workers to quickly place the fertilizer particles 10, and can also be used according to the specified arrangement interval to adapt to the soil environment requiring different improvement effects, so that the effect of the fertilizer can be quickly adjusted according to the arrangement interval when the fertilizer is applied.

[0132] Sc. Watering the soil causes the outer film 9 of the long film package to degrade rapidly due to water solubility, and the fertilizer particles 10 therein are dispersed into the gullies and come into contact with the soil;

[0133] The slow-release layer 13 of the Sd and fertilizer particles 10 is slowly peeled off under the long-term degradation of soil microorganisms, gradually exposing the biochar-humic acid layer 12. The biochar-humic acid layer 12 contacts the soil, increasing the number of microbial communities in the soil.

[0134] Among them, the biochar in the biochar-humic acid layer 12 is generally alkaline, which can neutralize acidic soil, and can adsorb heavy metal ions in the soil through its surface oxygen-containing functional groups, and use its internal pore structure to provide a microbial growth environment; humic acid adsorbs salt ions in the soil, alleviates the osmotic pressure stress of salinized soil, forms stable complexes with heavy metals, and provides organic matter for the soil; the two work together to improve the activity of soil microorganisms, accelerate organic matter mineralization and nutrient circulation.

[0135] After the Se and biochar-humic acid layer 12 are decomposed and peeled off in the soil, the exposed biodegradable layer 11 comes into contact with the soil and is rapidly degraded by microorganisms.

[0136] After the Sf and biodegradable layer 11 are decomposed, the fertilizer granules 10 come into contact with the soil and fertilize the soil.

[0137] Example 2

[0138] In order to realize the coating of the slow-release layer 13 on the surface of the fertilizer granules 10, please refer to Figure 3 In this embodiment, the fluidized bed 1 includes a fluidizing tank 101 , a feed valve port 102 , a discharge valve port 103 , a filter plate 104 , a hot air device 105 , and a return pipe 106 .

[0139] Specifically, the interior of the fluidizing tank 101 is a fluidizing chamber for placing fertilizer particles 10. A feed valve port 102 is provided on the top of the fluidizing tank 101 for feeding the fertilizer particles 10. A filter plate 104 is provided at the lower part of the fluidizing chamber of the fluidizing tank 101. The fertilizer particles 10 entering the fluidizing chamber from the feed valve port 102 will fall above the filter plate 104. A hot air device 105 is fixedly provided at the bottom of the fluidizing chamber below the filter plate 104. The air outlet of the hot air device 105 is directed toward the top of the filter plate 104, blowing hot air to the fertilizer particles 10 on the filter plate 104, so that the fertilizer particles 10 are suspended by the airflow and roll under the action of the airflow. A return pipe 106 is passed through the fluidizing chamber above the filter plate 104. The return pipe 106 connects the fluidizing chamber and the air inlet of the hot air device 105, realizing air circulation in the fluidizing chamber and ensuring that the fertilizer particles 10 remain suspended.

[0140] Among them, an atomizer is also provided at the bottom of the fluidizing tank 101. The atomizing head 303 of the atomizer is inserted under the filter plate 104 of the fluidizing chamber. The pump liquid port of the atomizer is connected to the external chitosan solution for atomizing the chitosan solution. The chitosan solution is coated on the surface of the suspended and tumbling fertilizer particles 10 under the drive of the airflow to achieve the coating of the biodegradable layer 11.

[0141] In addition, a discharge valve is provided below the fluidizing tank 101. The filter plate 104 is tilted in the fluidizing chamber, and the discharge valve is located at the tilted bottom end of the filter plate 104. After the hot air device 105 stops, the coated fertilizer particles 10 are output from the discharge valve to the outside of the fluidizing tank 101 through the tilted filter plate 104.

[0142] It is worth noting that when the fertilizer granules 10 are fed from the feed valve, the discharge valve is closed; when fluidization is performed, both the feed valve and the discharge valve are closed; when the fertilizer granules 10 are discharged from the discharge valve, the feed valve is closed.

[0143] When the fertilizer granules 10 coated with the biodegradable layer 11 are output from the discharge valve, they are automatically transported to the intermediate layer coating device of the next process through the conveyor belt group 5.

[0144] Example 3

[0145] In order to realize the coating of the biochar-humic acid layer 12 on the surface of the fertilizer particles 10, please refer to Figure 4-Figure 6 In this embodiment, the fertilizer coating machine 2 includes a roller 201, a driving member 202, a support frame 203, a cylinder cavity 204, and a guide piece 205.

[0146] Specifically, the driving member 202 is configured as a motor, which is connected to the drum 201 through a gear set (the motor is connected to the gear, and a gear ring is fixedly provided on the outer wall of the drum 201, and the two are meshed and connected) or a belt set (the motor is sleeved on one end of the belt, and the other end of the belt is sleeved on the outer wall of the drum 201). The motor is fixed on the support frame 203, driving the drum 201 to rotate. A barrel cavity 204 is penetrated in the drum 201 along the length direction, and the two ends of the barrel cavity 204 are respectively a feed port and a discharge port. The fertilizer particles 10 are transported to the feed port of the barrel cavity 204 through the conveyor belt group 5, and enter the barrel cavity 204 and roll.

[0147] The atomizing spray device 3 includes a fluid pipeline 301 , a pump 302 , and an atomizing head 303 .

[0148] Specifically, the fluid pipe 301 is fixed on the support frame 203, and one end of the fluid pipe 301 extends into the barrel cavity 204 along the length direction of the drum 201. A number of evenly arranged atomizing heads 303 are fixedly provided in the fluid pipe 301 extending into the barrel cavity 204. The other end of the fluid pipe 301 is connected to the pump 302, and the pump 302 is connected to the external biochar-humic acid mixture, so that the biochar-humic acid mixture is atomized and sprayed into the barrel cavity 204, and sprayed on the surface of the fertilizer particles 10 rolling in the barrel cavity 204, thereby realizing the coating of the biochar-humic acid layer 12.

[0149] Among them, a temperature control component is also fixedly provided on the roller 201 of the fertilizer coating machine 2 for heating the through cavity.

[0150] Among them, the two ends of the length of the roller 201 are arranged on the support frame 203 at an upper and lower angle, and the feed port of the barrel cavity 204 is higher than the discharge port, so that the fertilizer particles 10 rolling in the barrel cavity 204 can gradually roll to the discharge port of the barrel cavity 204. A guide piece 205 is also provided in the barrel cavity 204. The guide piece 205 is set as a spiral piece. While guiding the fertilizer particles 10 in the barrel cavity 204 to the discharge port, the guide piece 205 can also be used to flip the fertilizer particles 10 in the barrel cavity 204 when the roller 201 rolls, thereby increasing its coating effect.

[0151] It is worth noting that when the fertilizer particles 10 coated with the biochar-humic acid layer 12 are output from the discharge port of the barrel cavity 204, they are automatically transported to the outer coating device of the next process through the conveyor belt group 5.

[0152] In order to realize the coating of the slow-release layer 13 on the surface of the fertilizer granules 10, please refer to Figure 4-Figure 8 In this embodiment, the fertilizer coating machine 2 and the atomizing spraying device 3 in the outer coating device have the same structure as the fertilizer coating machine 2 and the atomizing spraying device 3 in the middle coating device.

[0153] The electrostatic generator 8 in the outer coating device includes a power supply 801 and an electrode 802.

[0154] Specifically, the power supply 801 is fixedly mounted on the fluid conduit 301 , and the power supply 801 is fixedly connected to the electrode 802 . The electrode 802 is disposed in the fluid conduit 301 . The position of the electrode 802 corresponds one-to-one to the position of the atomizing head 303 , and contacts the polylactic acid particles transported from the atomizing head 303 .

[0155] When coating the fertilizer particles 10 with the slow-release layer 13, the power supply 801 applies a high-voltage current to the electrode 802, and the electrode 802 generates a corona, so that the surface of the polylactic acid particles in contact with the electrode 802 obtains charged ions, thereby forming the slow-release layer 13 by electrostatic adsorption.

[0156] It is worth noting that when the fertilizer particles 10 coated with the slow-release layer 13 are discharged from the discharge port of the barrel cavity 204, they are automatically transported to the film rolling machine 4 of the next process through the feeding device 6.

[0157] Example 4

[0158] In order to form the outer film 9 into a packaging bag structure, thereby packaging a number of film-coated fertilizer granules 10 into long strips, the outer film 9 is wound on a film rolling machine 4 .

[0159] Please refer to Figure 9 In this embodiment, the film rolling machine 4 includes a base 401, a film laminating platform 402, a lower film driving roller 403, a lower film auxiliary roller 404, an upper film driving roller 405, and an upper film auxiliary roller 406.

[0160] The film rolling machine 4 is used to provide two layers of outer film 9 , and the upper and lower layers of outer film 9 are used to package and shape a plurality of fertilizer particles 10 .

[0161] Specifically, the film coating platform 402 is horizontally fixed above the base 401 , and a roller for storing the upper and lower outer films 9 respectively is provided on one side of the film coating platform 402 , and the roller is rotatably provided on the base 401 .

[0162] One end of the film surface of the lower outer film 9 is located on the lower film driving roller 403, and the lower film driving roller 403 is fixed on the base 401. The lower film driving roller 403 includes a rotating shaft driven by a motor and a driven shaft rotatably arranged on the base 401. The rotating shaft and the driven shaft respectively contact the upper and lower film surfaces of the lower outer film 9, thereby driving the lower film surface to roll out from the roller 201. The film surface after passing through the lower film driving roller 403 is rolled into the lower film auxiliary roller 404. The lower film auxiliary roller 404 is fixed on the base 401 and is located on the platform surface of the coating platform 402, which is used to guide the outer film 9 to the coating platform 402 and provide the coating platform 402 with a lower outer film 9.

[0163] One end of the film surface of the upper outer film 9 is located on the upper film driving roller 405, which is fixed on the base 401 and located above the lower film driving roller 403; the upper film driving roller 405 also includes a rotating shaft and a driven shaft, which respectively contact the upper and lower film surfaces of the upper outer film 9, driving the upper film surface to be output from the roller, and the film surface after passing through the upper film driving roller 405 is rolled into the upper film auxiliary roller 406, which is fixed on the base 401 and located above the platform surface of the coating platform 402, and is used to guide the outer film 9 to the coating platform 402, and provide the coating platform 402 with an upper outer film 9.

[0164] The upper outer film 9 and the lower outer film 9 are arranged one above the other on the surface of the coating platform 402 .

[0165] At this time, the coated fertilizer particles 10 after quantitative weighing are placed between the upper outer film 9 and the lower outer film 9, and then the heat sealing machine 7 set above the film coating platform 402 is used to heat-seal the four sides of the upper outer film 9 and the lower outer film 9 together to form a sealed packaging bag structure, thereby completing the packaging of the quantitative fertilizer particles.

[0166] After the packaging is completed, the packaging bag is cut and separated manually or by a cutter, and separated from the film coating platform 402 of the film rolling machine 4, and the fertilizer granules 10 packaging process can be repeated on the film coating platform 402.

[0167] Among them, the heat sealing machine is a commonly used packaging equipment in the existing field (fertilizer granule bag packaging), and the packaging principle is basic common sense that can be mastered by people in this field, so it is not specifically described in the present invention.

[0168] Example 5

[0169] Please refer to Figure 1 、 Figure 2 and Figure 4 In this embodiment, the conveyor belt group 5 is an existing device, and the conveyor belt 502 is used to transport the fertilizer particles 10 between various coating devices.

[0170] The feeding device 6 is arranged between the outer coating device and the film rolling machine 4, and is used to transport the coated fertilizer particles 10 at the discharge port of the fertilizer coating machine 2 to the coating platform 402 of the film rolling machine 4, and the feeding device 6 includes a conveyor belt group 5, one end of the conveyor belt group 5 is connected to the discharge port of the fertilizer coating machine 2, and the other end is connected to the bottom feed port of the elevator.

[0171] Thus far, various embodiments of the present invention have been described in detail. To avoid obscuring the concept of the present invention, some details well known in the art have been omitted. Based on the above description, those skilled in the art will fully understand how to implement the technical solutions of the present invention. The scope of the present invention is defined by the appended claims.

Claims

1. A continuous biochar-humic acid synergistic coated fertilizer processing process, characterized in that: Here are the steps: S1, screening fertilizer particles (10) within a particle size range of 2-4 mm; S2, transporting the fertilizer particles (10) into the fluidized bed (1), so that the fertilizer particles (10) are suspended and tumbled; S3, prepare a 4% chitosan aqueous solution and dissolve it in a 1% acetic acid solution; S4, fluidized bed (1) atomizes the chitosan mixed solution with a concentration of 4% and sprays it on the surface of the fertilizer particles using air flow; S5, the air flow temperature is controlled at 60°C, the 4% chitosan solution is heated to evaporate the acetic acid / water, the chitosan molecular chains are entangled, adhesion and solidification occur, and a biodegradable layer (11) with a uniform film structure is formed; S6, transporting the fertilizer particles coated with the biodegradable layer (10) to a fertilizer coating machine for continuous rolling and turning, mixing biochar powder and humic acid colloid in a mass ratio of 3:1 to form a solution, and spraying the solution onto the surface of the biodegradable layer from an atomizing spray device to form a biochar-humic acid film layer (12); S7, applying a drying temperature of 80° C. to the biochar-humic acid film layer (12) to accelerate water evaporation, promote the formation of gaps between humic acid molecules and biochar, and form a porous structure; S8, transporting the fertilizer particles (10) coated with the biochar-humic acid layer (12) to a fertilizer coating machine for continuous rolling and turning, and spraying the polylactic acid particles onto the surface of the fertilizer particles (10) by high-pressure atomization; S9, applying 10°C-20°C cooling to the fertilizer coating machine to keep the polylactic acid in a hardened state, quickly solidifying it on the surface of the fertilizer particles (10), and forming a uniform and tight slow-release layer (13) on the surface of the biochar-humic acid layer (12); S10, using an electrostatic generator to ionize and charge the surface of the polylactic acid particles (10), thereby controlling the coating thickness of the polylactic acid particles; S11. The fertilizer particles (10) coated with the slow-release layer (13) are quantitatively packaged into a long strip film package, wherein the film package is a water-soluble film.

2. The continuous biochar-humic acid synergistic coated fertilizer processing process according to claim 1 is characterized in that: A continuous biochar-humic acid synergistic coated fertilizer production line is obtained, which is characterized by: It includes an inner film wrapping device, an intermediate film wrapping device, an outer film wrapping device, and a film rolling machine (4); The inner coating device comprises a fluidized bed (1) for forming a biodegradable layer (11) on the surface of the fertilizer particles (10); The middle layer coating device comprises a fertilizer coating machine (2) and an atomizing spraying device (3), which is used to form a biochar-humic acid layer (12) outside the biodegradable layer (11); The fertilizer coating machine (2) is provided with an atomizing spraying device (3) at the coating position; The outer coating device comprises a fertilizer coating machine (2), an atomizing spraying device (3) and an electrostatic generator (8), and is used to form a slow-release layer (13) outside the biochar-humic acid layer (12); An electrostatic generator (8) is provided at the spraying position of the atomizing spraying device (3); The fluidized bed (1) and the fertilizer coating machine (2) are both provided with temperature control components, which include a heating element (716) or a cooling element.

3. The continuous biochar-humic acid synergistic coated fertilizer processing process according to claim 1 is characterized in that: A continuous biochar-humic acid synergistic coated fertilizer is obtained, wherein the coated fertilizer is sequentially arranged from the inside to the outside as fertilizer particles (10), a biodegradable layer (11), a biochar-humic acid layer (12), and a slow-release layer (13).

4. The continuous biochar-humic acid synergistic coated fertilizer according to claim 3, characterized in that: The fertilizer particles (10) are configured as nitrogen, phosphorus and potassium compound fertilizers.

5. The continuous biochar-humic acid synergistic coated fertilizer production line according to claim 2, characterized in that: The fluidized bed (1) comprises a fluidizing chamber, a filter plate (104) is arranged in the fluidizing chamber, fertilizer particles (10) are placed above the filter plate (104), and a hot air device (105) and an atomizer are arranged below the filter plate (104), with the atomization port of the atomizer facing the filter plate (104).

6. The continuous biochar-humic acid synergistic coated fertilizer production line according to claim 2, characterized in that: The fertilizer coating machine (2) comprises a roller (201), the roller (201) is connected to a driving member (202), the roller (201) is rotated by the driving member (202), a cylinder cavity (204) is provided through the roller (201), and coated fertilizer is placed in the cylinder cavity (204); The atomizing spray device (3) comprises a fluid pipeline (301), one end of the fluid pipeline (301) is connected to a pump (302), the pump (302) is connected to an external liquid injection port, and the other end of the fluid pipeline (301) is connected to a plurality of atomizing heads (303), which are located inside the barrel cavity (204).

7. The continuous biochar-humic acid synergistic coated fertilizer production line according to claim 2, characterized in that: The electrostatic generator (8) in the outer coating device includes a power supply (801) and an electrode (802); The power supply (801) is arranged on the fluid pipeline (301), the power supply (801) is connected to the electrode (802), the electrode (802) is arranged in the fluid pipeline (301), and the position of the electrode (802) corresponds to that of the atomizing head (303).

8. The continuous biochar-humic acid synergistic coated fertilizer production line according to claim 2, characterized in that: The film rolling machine (4) includes a film coating platform (402), which is horizontally arranged on a base (401), and a roller (201) for storing upper and lower outer films (9) is provided on one side of the film coating platform (402); One end of the lower outer film (9) passes through the lower film driving roller (403) and the lower film auxiliary roller (404) in sequence, and the lower film auxiliary roller (404) is located above the laminating platform (402); One end of the upper outer film (9) passes through the upper film driving roller (405) and the upper film auxiliary roller (406) in sequence, and the upper film driving roller (405) and the upper film auxiliary roller (406) are located above the coating platform (402).

9. The continuous biochar-humic acid synergistic coated fertilizer production line according to claim 8, characterized in that: A heat sealing machine (7) is provided on the film laminating platform (402); The upper outer film (9) and the lower outer film (9) are arranged correspondingly up and down, and a plurality of continuous biochar-humic acid synergistic coated fertilizers are arranged between the upper outer film (9) and the lower outer film (9).

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