Production process of water-soluble fertilizer with anti-freezing function

Abstract

The invention provides a production process of a water-soluble fertilizer with an anti-freezing function, and relates to the field of fertilizer preparation, and the production process comprises the following steps: a, mixing main raw materials except water of the water-soluble fertilizer with the anti-freezing function with part of water to form a mixed solution 1; b, respectively adding water to dissolve a surfactant and an anti-freezing synergistic auxiliary agent to form a surfactant solution and an anti-freezing synergistic auxiliary agent solution; c, mixing the surfactant solution and the anti-freezing synergistic additive solution, adding an anti-freezing agent, homogenizing and emulsifying uniformly to form a mixed solution 2, and cooling; and d, mixing the mixed solution 1 and the mixed solution 2, and cooling to obtain the water-soluble fertilizer with the anti-freezing function. In the step d, a liquid inlet pipe of the mixed liquid 1 and a liquid inlet pipe of the mixed liquid 2 converge to a mixing inlet shell, and then are input into a stirring device for stirring and mixing through the mixing inlet shell; the preliminary uniform mixing of the raw materials is realized in the premixing stage, and only short-time fine mixing is required after the raw materials enter the stirring device, so that the stirring time is shortened, and uniform mixing is ensured.

Description

Technical Field

[0001] This invention relates to the field of fertilizer preparation technology, specifically to a production process for a water-soluble fertilizer with antifreeze function. Background Technology

[0002] Water-soluble fertilizers, with their rapid dissolution, ease of fertigation, and improved nutrient utilization, are increasingly widely used in facility agriculture, cash crop cultivation, and agricultural production in cold regions. In northern my country, high-altitude areas, and parts of southern China where winters / late spring frosts are frequent, low temperatures pose significant challenges to the storage, transportation, application, and crop absorption of water-soluble fertilizers, creating an urgent demand for water-soluble fertilizer products with frost-resistant properties.

[0003] The preparation of existing water-soluble fertilizers with antifreeze properties, such as the tea tree-specific cold-resistant and antifreeze water-soluble fertilizer (publication number CN105884508 A), its preparation method, and its application, have the following problems: Mixing relies solely on stirring for a fixed time, without adjusting the inlet flow rate to achieve premixing, which easily leads to uneven mixing. Furthermore, the dispersion efficiency of the material depends entirely on the stirring time, which not only prolongs the production cycle and increases energy consumption, but may also affect the stability of functional components due to excessively high local concentrations. Summary of the Invention

[0004] This invention provides a production process for a water-soluble fertilizer with antifreeze function, in order to solve the technical problems mentioned in the background.

[0005] To solve the above-mentioned technical problems, this invention discloses a production process for a water-soluble fertilizer with antifreeze function, comprising: Step a: Mix the main raw material of the water-soluble fertilizer with antifreeze function (excluding water) with some water to form mixture 1; Step b: Dissolve the surfactant and antifreeze synergist separately in water to form a surfactant solution and an antifreeze synergist solution; Step c: Mix the surfactant solution and the antifreeze synergist solution, then add the antifreeze, homogenize and emulsify to form a uniform mixture 2, and then cool. Step d: Mix mixture 1 and mixture 2, and cool to obtain a water-soluble fertilizer with antifreeze function; The inlet pipes of mixture 1 and mixture 2 first converge into the mixing inlet shell, and then are fed into the stirring device for mixing through the mixing inlet shell; the flow rates of mixture 1 and mixture 2 are adjusted by adjusting the flow rates of the inlet pipes of mixture 1 and mixture 2 to achieve pre-mixing of mixture 1 and mixture 2.

[0006] Preferably, the surfactant is an alkyl glycoside, the antifreeze synergist is sodium alginate, and the antifreeze agent is ethylene glycol.

[0007] The preferred composition of the main raw materials for the antifreeze water-soluble fertilizer is as follows (by weight): 10-40 parts nitrogen fertilizer, 5-25 parts potassium fertilizer, 5-25 parts phosphorus fertilizer, 40-60 parts biochemical humic acid, and 50-100 parts water. The surfactant is 20-40 parts by weight, the antifreeze synergist is 2-5 parts, and the antifreeze is 10-30 parts.

[0008] Preferably, during feeding, the flow rate of the mixture 1 inlet pipe is 0.08 to 0.3 m / s.

[0009] Preferably, the water temperature is 60-75°C when dissolving in step b; and the temperature of both mixture 1 and mixture 2 is 30-40°C when mixing them.

[0010] Preferably, prior to the initial batch production of the current model of water-soluble fertilizer, step d includes: Step d01: Collect the density and viscosity of mixture 1 at the reference temperature; Step d02: Obtain the target mixing ratio range for mixture 1 and mixture 2; Step d03: Based on the target Reynolds number range and the density and viscosity of mixture 1, determine the initial flow range of mixture 1; Step d04: Within the initially set flow range of mixture 1, the flow rate of mixture 1 is gradually adjusted, and the flow rate of mixture 2 is simultaneously adjusted according to the target ratio range of mixture 1 and mixture 2. After each adjustment, the mixing and premixing time of mixture 1 and mixture 2 is controlled, and the density gradient coefficient of the premixed mixture is determined based on the density detection of the premixed mixture. Several target continuous flow ranges that meet the range of the density gradient coefficient of the premixed mixture are selected, and a target continuous flow range - preselected mixing Reynolds number range - premixed mixture density gradient coefficient range is constructed. Step d05: Obtain the viscosity of the commonly used mixture 1 when mixing the mixture 1 with the mixture 1, determine the pre-selected mixing Reynolds number range-pre-selected flow range for each commonly used mixture 1 viscosity; determine the repeating target pre-selected flow range for all commonly used mixture 1 viscosities; Step d06: Divide the stirring device into several liquid level intervals, and determine the target feeding time interval for each liquid level interval under the viscosity conditions at the reference temperature.

[0011] Preferably, for each batch production of the current model of water-soluble fertilizer, step d includes: Step d1: Control the flow rate of the inlet pipe of mixture 1 to the characteristic value in the target pre-selected flow range, and synchronously adjust the flow rate of mixture 2 according to the target ratio range of mixture 1 and mixture 2. Input mixture 1 and mixture 2 into the stirring device, and determine the actual density gradient coefficient based on the actual density detection of the premixed mixture. Step d2: Control the actual stirring speed of the stirring device to the reference stirring speed, continue stirring, and control the feeding based on the median of the target feeding time interval corresponding to each liquid level interval; and perform refractive index detection at least once in each liquid level interval to obtain the real-time refractive index data of the mixture in that liquid level interval; compare the real-time refractive index with the standard refractive index interval corresponding to that liquid level interval. If the real-time refractive index is within the standard interval, it is determined that the mixing uniformity of this stage meets the standard, and the feeding and stirring of the next liquid level interval continues; if the real-time refractive index exceeds the standard interval, the adjustment mechanism is triggered.

[0012] Preferably, the adjustment mechanism is as follows: if the real-time refractive index exceeds the standard range, feeding is paused, and stirring is continued until the refractive index of the current liquid level zone meets the requirements. The total stirring time of the current liquid level zone is determined, and a first ratio is determined between the total stirring time of the current liquid level zone and the median of the target feeding time range of the current liquid level zone. Based on the first ratio, the adjusted feeding time of the next liquid level zone is adjusted. After the adjustment is completed, the feeding and stirring process of the next liquid level zone is resumed, and the refractive index is detected in the next liquid level zone. If the refractive index exceeds the standard again, the above adjustment logic is repeated until the mixing uniformity of the entire liquid level zone meets the standard.

[0013] Preferably, step c includes: Step c1: Obtain the temperature range of the mixture during each homogenization emulsification period of the mixture to be homogenized; Step c2: Mix the surfactant solution and the antifreeze synergist solution to obtain mixture 3. Take a sample and test the actual temperature-viscosity trend curve of mixture 3 in the process homogenization temperature range. Determine the absolute value of the slope of the actual temperature-viscosity trend curve corresponding to each homogenization emulsification period based on the homogenization emulsification period in step c1. Step c3: Mix the sampled mixture 3 with the antifreeze to obtain the viscosity after mixing; determine the viscosity action coefficient based on the viscosity detected in step c1 and the viscosity after mixing. Step c4: Based on the average value of the absolute slope, the viscosity coefficient, and the process relationship of the average value of the absolute slope - viscosity coefficient - homogenization pressure corresponding to all homogenization emulsification periods, determine the homogenization pressure corresponding to each homogenization emulsification period; Step c5: Control homogenization emulsification with the selected value of the homogenization pressure corresponding to the first homogenization emulsification period, and detect the actual temperature rise of the first homogenization emulsification period. If the actual temperature rise is qualified, continue homogenization emulsification based on the corresponding homogenization pressure of the remaining homogenization emulsification period. If the actual temperature rise is not qualified, adjust the corresponding homogenization pressure of the remaining homogenization emulsification period according to the actual temperature rise, and complete the homogenization emulsification of all subsequent homogenization emulsification periods in sequence according to the adjusted parameters until mixture 2 is formed.

[0014] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments.

[0015] Compared with the prior art, the present invention has the following beneficial effects: Alkyl glycosides can lower the freezing point of aqueous solutions, reducing the risk of freezing at low temperatures. Sodium alginate can adsorb onto the surface of ice crystals, preventing them from growing further and avoiding damage to the nutrient structure. Ethylene glycol can further lower the freezing point while improving fluidity at low temperatures. This allows water-soluble fertilizers to remain unfrozen and unseparated at temperatures above -10°C.

[0016] Mixture 1 and Mixture 2 are premixed before entering the mixing device. By precisely controlling the flow rate of the inlet pipe, the two liquids are initially and uniformly mixed before entering the mixing device. This avoids the problem of uneven dissolution caused by local agglomeration of high-concentration raw materials in traditional direct feeding, and ensures the uniformity of the product from the source.

[0017] The premixing stage has already achieved the initial uniform mixing of raw materials. After entering the mixing device, only a short period of fine mixing is needed to meet the product requirements. Compared with the traditional process, the mixing time can be shortened by 30% to 50%, which directly reduces the energy consumption of equipment operation and production costs. Attached Figure Description

[0018] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used in conjunction with embodiments of the invention to explain the invention and do not constitute a limitation thereof. In the drawings: Figure 1 This is a schematic diagram of the process of the present invention. Detailed Implementation

[0019] The preferred embodiments of the present invention will be described below with reference to the accompanying drawings. It should be understood that the preferred embodiments described herein are for illustration and explanation only and are not intended to limit the present invention.

[0020] Furthermore, in this invention, the use of terms such as "first" and "second" is for descriptive purposes only and does not specifically refer to any order or sequence, nor is it intended to limit the invention. They are merely used to distinguish components or operations described using the same technical terms and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the technical solutions and features of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. If a combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this invention.

[0021] The present invention provides the following embodiments: Example 1: This embodiment of the invention provides a production process for a water-soluble fertilizer with antifreeze function, such as... Figure 1 As shown, it includes: Step a: Mix the main raw material of the water-soluble fertilizer with antifreeze function (excluding water) with some water to form mixture 1; Step b: Dissolve the surfactant and antifreeze synergist separately in water to form a surfactant solution and an antifreeze synergist solution; Step c: Mix the surfactant solution and the antifreeze synergist solution, then add the antifreeze, homogenize and emulsify to form a uniform mixture 2, and cool (to 30-40°C). Step d: Mix mixture 1 and mixture 2, and cool to obtain a water-soluble fertilizer with antifreeze function; The inlet pipes of mixture 1 and mixture 2 first converge into the mixing inlet shell, and then are fed into the stirring device for mixing through the mixing inlet shell; the flow rates of mixture 1 and mixture 2 are adjusted by adjusting the flow rates of the inlet pipes of mixture 1 and mixture 2 to achieve pre-mixing of mixture 1 and mixture 2.

[0022] The surfactant is an alkyl glycoside, the antifreeze synergist is sodium alginate, and the antifreeze agent is ethylene glycol.

[0023] During feeding, the flow rate of the mixture 1 inlet pipe is 0.08 to 0.3 m / s; When dissolving in step b, the water temperature is 60–75°C.

[0024] The main raw materials of the water-soluble fertilizer with antifreeze function are composed of the following parts by weight: 10-40 parts nitrogen fertilizer, 5-25 parts potassium fertilizer, 5-25 parts phosphorus fertilizer, 40-60 parts biochemical humic acid, and 50-100 parts water. The surfactant is 20-40 parts by weight, the antifreeze synergist is 2-5 parts, and the antifreeze is 10-30 parts.

[0025] During the premixing process, the volumetric flow rate ratio of mixture 1 and mixture 2 is (2~2.3):1; Specific implementation examples:

[0026] Mixture 1 by weight of 25 parts nitrogen fertilizer, 18 parts phosphate fertilizer, 18 parts potassium fertilizer, and 50 parts biochemical humic acid with 30 parts water. Mixture 2 by weight of alkyl glycoside (dissolved in 30 parts water) and sodium alginate (dissolved in 30 parts water) separately in water at 72℃, then mix them. Add 20 parts ethylene glycol and homogenize to form mixture 2, then cool. When premixing mixture 1 and mixture 2 (both at 30℃), the flow rate in the inlet pipe of mixture 1 is set to 0.08 m / s, and the flow rate in the inlet pipe of mixture 2 is set to 0.037 m / s, with a volumetric flow rate ratio of 2.16:1. The density gradient coefficient of the premixed mixture is measured to be 0.021. After premixing, the mixture is introduced into a stirring device at a stirring speed of 310 rpm for 15.2 minutes, then cooled.

[0027] Based on a 1.5m³ mixing device, with an effective loading height of 1.5m and an inner diameter of 1.13m, the device is divided into 5 equal liquid level zones. Initial liquid level zone: liquid level range 0-0.3m, target feeding time set to 2.9 minutes; Low liquid level zone: liquid level range 0.3~0.6m, target feeding time set to 2.9 minutes; Mid-level liquid level zone: liquid level range 0.6~0.9m, target feeding time set to 3 minutes; High liquid level zone: liquid level range 0.9~1.2m, target feeding time set to 3.2 minutes; Full liquid level zone: liquid level range 1.2~1.5m, target feeding time set to 3.2 minutes; The beneficial effects of the above technical solution are as follows: Alkyl glycosides can lower the freezing point of aqueous solutions, reducing the risk of freezing at low temperatures. Sodium alginate can adsorb onto the surface of ice crystals, preventing them from growing further and avoiding damage to the nutrient structure. Ethylene glycol can further lower the freezing point while improving fluidity at low temperatures. This allows water-soluble fertilizers to remain unfrozen and unseparated at temperatures above -10°C.

[0028] Mixture 1 and Mixture 2 are premixed before entering the mixing device. By precisely controlling the flow rate of the inlet pipe, the two liquids are initially and uniformly mixed before entering the mixing device. This avoids the problem of uneven dissolution caused by local agglomeration of high-concentration raw materials in traditional direct feeding, and ensures the uniformity of the product from the source.

[0029] The premixing stage has already achieved the initial uniform mixing of raw materials. After entering the mixing device, only a short period of fine mixing is needed to meet the product requirements. Compared with the traditional process, the mixing time can be shortened by 30% to 50%, which directly reduces the energy consumption of equipment operation and production costs.

[0030] Example 2, based on Example 1, before the initial batch production of the current model of water-soluble fertilizer, includes the following steps prior to step d: Step d01: Collect the density and viscosity of mixture 1 at a reference temperature (which can be 30°C); Step d02: Obtain the target ratio range of mixture 1 and mixture 2 (both in the temperature range of 30-40℃ during mixing) (the flow rate ratio of mixture 1 to mixture 2 in the premixing stage; the volumetric flow rate ratio of mixture 1 to mixture 2 is (2-2.3):1). Step d03: Based on the target Reynolds number range and the density and viscosity of mixture 1, determine the initial flow range of mixture 1; The target Reynolds number range is 1500–3000 (the specific range can be further selected based on simulation and testing). This range allows the mixture to be in a “transitional flow–low-intensity turbulence” state, which ensures that the two liquids are fully and uniformly mixed without increasing energy consumption, pipe wear, or damage to the nutrient structure due to excessive flow velocity.

[0031] Step d04: Within the initially set flow range of mixture 1, the flow rate of mixture 1 is gradually adjusted, and the flow rate of mixture 2 is simultaneously adjusted according to the target ratio range of mixture 1 and mixture 2 (the volume flow rate ratio of mixture 1 and mixture 2 is (2~2.3):1). After each adjustment, the mixing and premixing time of mixture 1 and mixture 2 is controlled (10S~1min), and the density gradient coefficient of the premixed mixture is determined based on the density detection of the premixed mixture (obtained by mixing mixture 1 and mixture 2 in the shell). Screen several target continuous flow intervals that meet the density gradient coefficient range of the premixed liquid (sort and number the intervals that meet the density gradient coefficient range of the premixed liquid in ascending order of flow rate, and select at least two continuous flow intervals whose number ratio is 1 / 4 to 1 / 3 of the maximum number as target flow intervals), and construct the target continuous flow interval - preselected mixing Reynolds number interval - premixed liquid density gradient coefficient interval. Step d05: Obtain the viscosity of the commonly used mixture 1 when mixing the mixture 1 with the mixture 1, determine the pre-selected mixing Reynolds number range-pre-selected flow range for each commonly used mixture 1 viscosity; determine the repeating target pre-selected flow range for all commonly used mixture 1 viscosities; Step d06: Divide the stirring device into several liquid level intervals, and determine the target feed time interval corresponding to each liquid level interval under the viscosity condition at the reference temperature (this is used as a reference value, which can be determined by testing based on all target pre-selected flow intervals, and finally a feed time interval is obtained).

[0032] The density gradient coefficient of the premixed liquid during the current premixing time = (maximum detection value of the density of the premixed liquid during the current premixing time at all detection locations - maximum detection value of the density of the premixed liquid during the current premixing time at all detection locations) ÷ minimum detection value of the density of the premixed liquid during the current premixing time at all detection locations; at least 2 density detection locations are set inside the mixing chamber; The maximum flow rate and velocity of the adjusted mixture 1 = the maximum value of the target Reynolds number range × the viscosity of the mixture 1 ÷ (the density of the mixture × the diameter of the inlet pipe of the mixture 1). The initial design is as follows: minimum flow rate and velocity of mixture 1 = minimum Reynolds number target range × viscosity of mixture 1 ÷ (density of mixture × diameter of inlet pipe of mixture 1); this is a Reynolds number model determined by combining flow rate, density, viscosity and pipe diameter, which is the existing technology. The maximum value of the initial flow rate range of mixture 1 is set as follows: the maximum value of the initial flow rate and velocity of mixture 1 is set as follows: the cross-sectional area of ​​the inlet pipe of mixture 1. The initial minimum flow rate range of mixture 1 is set as follows: the initial minimum flow rate and velocity of mixture 1 are set as follows: the cross-sectional area of ​​the inlet pipe of mixture 1 is set as follows: Step d04: First, through multiple premixing experiments, the Reynolds number and density gradient coefficient of the mixture are collected at different flow rates. Then, the experimental groups with density gradient coefficients that meet the uniformity requirements (e.g., ≤0.033) are selected from the experimental data. Then, among these qualified flow points, the flow segments with continuous and uninterrupted values ​​are selected as the target continuous flow range. The corresponding Reynolds number range and density gradient coefficient range for each flow range are extracted. Finally, a one-to-one correspondence model / mapping table of "target continuous flow range - premixed Reynolds number range - premixed mixture density gradient coefficient range" is constructed. Thus, in actual production, as long as the flow rate is controlled within the target continuous flow range, the Reynolds number can be ensured to be in a reasonable transitional flow state, thereby ensuring that the density gradient coefficient of the premixed mixture is always qualified.

[0033] Step d05: Adjust the density of mixture 1 to its usual mixing temperature (30-40℃), and determine the viscosity range (usual viscosity) corresponding to the usual mixing temperature. For each viscosity, the calculated flow rate (defined as the preselected flow rate) is determined for each preselected mixing Reynolds number interval based on the preselected mixing Reynolds number interval determined in step d04 and the above formula. Step d05: First, divide the liquid level of the stirring device from empty to full into the following zones: initial liquid level zone (0%–20%), low liquid level zone (20%–40%), medium liquid level zone (40%–70%), high liquid level zone (70%–90%), and full liquid level zone (90%–100%). Then, obtain the standard viscosity of the mixture at a reference temperature (e.g., 30°C) as the calculation benchmark. Next, for each liquid level zone, use the reference rotation speed (range 290–350 r / min) and the reference stirring speed (290–350 r / min) as the calculation benchmark. n) is determined by considering the overall equipment performance, mixing effect, and energy consumption cost: the upper limit of this range does not exceed 90% of the rated speed of the stirring device to avoid overload and wear of the equipment; the lower limit is the minimum speed to ensure effective material flow and prevent sedimentation and stratification; at the same time, through experimental verification at the reference temperature, the turbulence intensity generated in this speed range can fully integrate water-soluble fertilizer mixtures of different viscosities and densities without damaging the nutrient structure due to excessive stirring, and can balance energy consumption and production efficiency while meeting uniformity requirements. Continuous stirring and feeding at the median of the first target continuous flow range determine the premixed mixture addition time corresponding to each liquid level zone being filled with premixed mixture (i.e., the benchmark feeding time corresponding to each liquid level zone, which is set differently for different flow rates). For each liquid level zone, first determine when feeding at 1 times the benchmark feeding time, and when feeding is completed, determine the stirring time corresponding to the uniform mixing of the corresponding liquid level zone (the uniform mixing time of the corresponding liquid level zone - the feeding time of the corresponding liquid level zone). When the ratio of the stirring time to the corresponding benchmark feeding time is less than or equal to the preset ratio, the stirring time is determined as the target feeding time range; when When the ratio of the stirring time to the corresponding baseline feed time is greater than the preset ratio (e.g., 1; which is an empirically optimized threshold for the ratio of stirring time to baseline feed time, and can be dynamically adjusted according to equipment characteristics), the baseline feed time is extended (the flow rate is reduced), and the ratio of the new stirring time to the new baseline feed time is recalculated until the ratio is less than or equal to the preset ratio. At this point, the extended baseline feed time is determined as the target feed time interval for that liquid level interval. Finally, a unique target feed time interval is determined for each liquid level interval, forming a complete segmented feed-stirring control parameter.

[0034] The beneficial effects of the above technical solution are as follows: By precisely controlling the mixture within the target range of 1500 to 3000 Reynolds number, the mixture is kept in a state of "transitional flow to low-intensity turbulence". This ensures that the two liquids are fully and uniformly mixed, while avoiding increased energy consumption, pipe wear and damage to nutrient structure caused by excessive flow rate, thus achieving a balance between mixing efficiency and equipment protection.

[0035] Gradient flow rate adjustment allows for a systematic exploration of the mixing effect under different flow rates; the detection and screening of density gradient coefficients directly quantifies the mixing uniformity, ensuring that the selected flow range can stably produce a uniform premix; the construction of a mapping table of "flow range - Reynolds number - density gradient coefficient" provides a direct reference for actual production, reducing the complexity of on-site debugging.

[0036] By matching pre-selected flow rates to mixtures of different viscosities, the accuracy of flow control has been further refined. The division of liquid level ranges and the determination of target feeding time ranges have enabled segmented and precise control of the stirring process, avoiding the problem of uneven mixing caused by changes in liquid level. By adjusting the feeding time, each liquid level range is made to achieve as much uniform mixing as possible when feeding is completed, dynamically optimizing the mixing efficiency and ensuring that the mixture in each liquid level range meets the uniformity requirements.

[0037] Premixing tests have shown that the above parameters can be directly applied to actual production. Operators only need to control the flow rate within the target range to ensure stable mixing effect, which greatly shortens the production debugging time and reduces the dependence on the professional skills of operators.

[0038] Example 3, for each batch production of the current model of water-soluble fertilizer, step d includes: Step d1: Control the flow rate of the inlet pipe of mixture 1 to the characteristic value in the target pre-selected flow range (which can be the median, i.e., 0.5 times the sum of the maximum and minimum values ​​in the range), and synchronously adjust the flow rate of mixture 2 according to the target ratio range of mixture 1 and mixture 2. Input mixture 1 and mixture 2 into the stirring device, and determine the actual density gradient coefficient based on the actual density detection of the premixed mixture. Step d2: Control the actual stirring speed of the stirring device to the reference stirring speed, and continue stirring. Control the feeding based on the median of the target feeding time interval corresponding to each liquid level interval (depending on whether the time is continuous or intermittent). Perform refractive index detection at least once in each liquid level interval to obtain the real-time refractive index data of the mixture in that liquid level interval. Compare the real-time refractive index with the standard refractive index interval corresponding to that liquid level interval. If the real-time refractive index is within the standard interval, it is determined that the mixing uniformity of this stage meets the standard, and the feeding and stirring of the next liquid level interval continues. If the real-time refractive index exceeds the standard interval, the adjustment mechanism is triggered.

[0039] Each batch can be mixed in subsequent batches based on the final parameters determined in the first mixing of each batch; Standard refractive index range: This is the acceptable concentration range determined through multiple premixing tests for the target water-soluble fertilizer formula before initial mass production. This range is based on the theoretical nutrient concentration of the formula and is set in conjunction with the allowable error range for production (usually ±1% to ±2%). It serves as the benchmark for judging whether the mixing meets the standards.

[0040] The main components of water-soluble fertilizer premixes are soluble nutrients (such as nitrogen, phosphorus, and potassium salts), which alter the refractive properties of the aqueous solution. Under constant temperature conditions, the refractive index of the mixture is directly related only to the concentration of the solute: the higher the concentration, the higher the refractive index; the lower the concentration, the lower the refractive index.

[0041] If the mixture is homogeneous, the nutrient concentration in each region of the premixed solution will be consistent, and the refractive index will remain stable within the standard range. If the mixture is uneven, local areas will exhibit higher or lower nutrient concentrations, resulting in real-time refractive indices exceeding the standard range. Therefore, by detecting the stability of the refractive index, one can quickly determine whether the homogeneity of the mixture meets the standards.

[0042] Adjustment mechanism: If the real-time refractive index exceeds the standard range, feeding is paused, and stirring continues until the refractive index of the current liquid level meets the requirements. The total stirring time for the current liquid level is determined, and a first ratio is established between the total stirring time of the current liquid level and the median of the target feeding time range for the current liquid level. Based on this first ratio, the adjusted feeding time for the next liquid level is adjusted (adjusted feeding time for the next liquid level = median target feeding time for the next liquid level × the first ratio determined in the previous liquid level range) to adapt to the mixing requirements in advance. After adjustment, the feeding and stirring process for the next liquid level is resumed, and refractive index is detected in the next liquid level. If the refractive index exceeds the standard again, the above adjustment logic is repeated until the mixing uniformity across the entire liquid level range meets the standard.

[0043] The beneficial effects of the above technical solution are as follows: The pre-verification process reduces the trial-and-error costs after production starts, while the real-time monitoring and dynamic adjustment mechanism avoids batch rework and waste of raw materials.

[0044] Step d1 uses the characteristic values ​​of the target pre-selected flow range to control the flow rate, combined with dynamic ratio adjustment, to ensure that the antifreeze and basic nutrients are stably mixed in a preset ratio. This avoids local concentration deviations from the source and directly guarantees the consistency of the product's antifreeze performance.

[0045] Step d2 uses refractive index to detect nutrient concentration distribution, which can quickly identify uneven mixing issues within the liquid level range. Compared to the traditional final inspection method, this process control can detect and resolve problems in advance, preventing the entire batch of products from being scrapped due to substandard antifreeze performance.

[0046] Step d1 controls the feed rate based on the target pre-selected flow range characteristic value to ensure that the feed rate of each liquid level zone is consistent with the pre-verified stirring compatibility. Step d2 controls the feed rate based on the median target feed time of the liquid level zone, and at the same time, it is combined with the benchmark stirring speed to achieve "precise matching between feed time and stirring time" - the stirring is completed simultaneously during the feeding process, without the need to extend the stirring time. This not only improves production efficiency, but also avoids non-uniformity due to insufficient stirring, or damage to antifreeze components due to excessive stirring. Real-time refractive index detection directly verifies the effect of "uniformity upon completion of feeding", detects deviations in time and triggers supplementary adjustments to avoid the accumulation of problems. Example 4, based on any one of Examples 1-3, step c includes: Step c1: Obtain the temperature range of the mixture during each homogenization emulsification period of the mixture to be homogenized; Homogenized mixture: Mixture 3 and antifreeze; different temperature and pressure parameters correspond to different homogenization emulsification periods. This is to adapt to the dynamic changes in viscosity of the material during the homogenization process and improve dispersion efficiency and stability.

[0047] Swelling pretreatment period: The material temperature is stabilized at 60-62℃ to allow the sodium alginate particles to fully absorb water and swell, avoiding clumping or local gelation during subsequent dispersion.

[0048] Emulsification and dispersion period: The material temperature is gradually raised to 62-65℃. At this temperature, the good dispersibility of sodium alginate and the high emulsifying activity of alkyl glycosides are utilized to achieve the initial uniform dispersion of each component.

[0049] Homogenization and refinement period: The material temperature continues to rise to 65-70℃, and the viscosity of the system is appropriately reduced to improve shear efficiency, so that antifreeze components such as sodium alginate, alkyl glycosides and ethylene glycol are fully mixed and the particle size is refined, providing a stable dispersion basis for the antifreeze system.

[0050] Stable setting period: The material temperature is maintained at 70℃. The stable high-temperature environment keeps the system viscosity uniform, eliminates the local stress generated during the homogenization process, and provides a stable precursor system for the subsequent cooling process, avoiding stratification or flocculation.

[0051] Step c2: Mix the surfactant solution and the antifreeze synergist solution to obtain mixture 3. Take a sample and test the actual temperature-viscosity trend curve of mixture 3 in the process homogenization temperature range (the horizontal axis is the actual temperature, and the vertical axis is the viscosity of mixture 3 at the corresponding horizontal axis). Determine the absolute value of the slope of the actual temperature-viscosity trend curve corresponding to each homogenization emulsification period according to the homogenization emulsification period in step c1. Step c3: Mix the sampled mixture 3 with the antifreeze to obtain the viscosity after mixing; determine the viscosity action coefficient based on the viscosity detected in step c1 and the viscosity after mixing. Viscosity coefficient = (viscosity after mixing - viscosity of mixture 3 detected in step c1) ÷ viscosity of mixture 3 detected in step c1; Step c4: Based on the average value of the absolute value of the slope corresponding to all homogenization emulsification periods / the total average value (the average value corresponding to each homogenization emulsification period is determined first, and then the average value of the average value of all homogenization emulsification periods is calculated to obtain the total average value), the viscosity action coefficient, and the process relationship of the average value of the absolute value of the slope - viscosity action coefficient - homogenization pressure, determine the homogenization pressure corresponding to each homogenization emulsification period; First, prepare multiple batches of mixture 3 according to the formula, measure the temperature-viscosity curve within the entire process temperature range, calculate the absolute value of the slope in different temperature ranges, and measure the viscosity coefficient of mixture 3 after mixing with antifreeze; then, through multiple sets of small-scale homogenization tests, record the optimal homogenization pressure and temperature corresponding to different slopes and viscosity coefficients, and finally fit and solidify them into a parameter reference table or algorithm model that can be directly called.

[0052] For example, the average absolute value of the slope is 4.25–7.0 mPa·s / ℃, the viscosity coefficient is 0.008–0.015, the homogenization pressure range during the swelling pretreatment period is 78–82 MPa, the homogenization pressure range during the emulsification and dispersion period is 78–80 MPa, the homogenization pressure range during the homogenization and refining period is 95–98 MPa, and the homogenization pressure range during the stabilization and setting period is 68–87 MPa.

[0053] Step c5: Control homogenization emulsification with the selected value of the homogenization pressure corresponding to the first homogenization emulsification period (take the median of the corresponding interval), and detect the actual temperature rise of the first homogenization emulsification period. When the actual temperature rise is qualified (less than or equal to 2℃), continue homogenization emulsification based on the selected value of the homogenization pressure corresponding to the remaining homogenization emulsification period (take the median of the corresponding interval). When the actual temperature rise is unqualified (greater than 2℃), adjust the homogenization pressure corresponding to the remaining homogenization emulsification period (take the median of the corresponding interval) according to the actual temperature rise, and complete the homogenization emulsification of all subsequent homogenization emulsification periods in sequence according to the adjusted parameters until mixture 2 is formed.

[0054] When the actual temperature rise is unqualified (greater than 2℃), determine the temperature rise difference between the actual temperature rise and the maximum qualified temperature rise, and determine the ratio of the temperature rise difference to the maximum qualified temperature rise (temperature rise ratio). The adjusted pressure of emulsification period A (any one of emulsification dispersion period, homogenization and refinement period, and stabilization and shaping period) = the selected value of the corresponding homogenization pressure range of emulsification period A determined in step c4 × (1 - the temperature rise ratio × the pressure adjustment coefficient of emulsification period A). The pressure adjustment coefficients for the emulsification and dispersion period, homogenization and refining period, and stabilization and setting period were obtained through fitting multiple sets of small-scale experiments (selecting several mixtures with different average absolute values ​​of slope and viscosity coefficients, homogenizing them under preset pressures in each emulsification period, and recording the correlation between pressure adjustment ranges and homogenization effects corresponding to different temperature rise differences), with values ​​ranging from 0.3 to 0.5, 0.6 to 0.8, and 0.2 to 0.4, respectively; the above pressure adjustment coefficients can be different depending on the magnitude of the absolute value of the slope of the corresponding viscosity curve; The beneficial effects of the above technical solution are as follows: By dividing the process into multiple stages of homogenization and emulsification, and setting targeted temperature ranges based on the material state at each stage, the characteristics of sodium alginate from swelling to dispersion and the antifreeze components from mixing to setting are precisely matched throughout the entire process.

[0055] The pressure matching logic is constructed based on the absolute value of the slope of the temperature-viscosity trend curve and the viscosity coefficient, which directly links the material properties with the process parameters, so that the pressure setting no longer depends on experience judgment, but is based on the precise control of the material viscosity change law. Based on the actual temperature rise during the first homogenization emulsification period, the pressure in subsequent stages is dynamically adjusted through quantitative calculation logic. This avoids problems such as decreased material thermal stability and system imbalance that may be caused by excessive temperature rise, and also prevents excessive pressure adjustment from affecting dispersion efficiency and particle size refinement. This achieves a dynamic balance between process safety and production efficiency, and reduces downtime or material loss caused by improper parameters.

[0056] The precise matching of temperature and pressure parameters at each stage promotes full contact and interaction between sodium alginate, alkyl glycosides and antifreeze components. This ensures the uniform dispersion and stable coating of antifreeze components in the system, while also preventing the material molecular structure from being damaged due to improper process parameters. This enhances the core performance and storage stability of the final product.

[0057] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this invention and their equivalents, this invention also intends to include these modifications and variations.

Claims

1. A production process for a water-soluble fertilizer with antifreeze function, characterized in that: include: Step a: Mix the main raw material of the water-soluble fertilizer with antifreeze function (excluding water) with some water to form mixture 1; Step b: Dissolve the surfactant and antifreeze synergist separately in water to form a surfactant solution and an antifreeze synergist solution; Step c: Mix the surfactant solution and the antifreeze synergist solution, then add the antifreeze, homogenize and emulsify to form a uniform mixture 2, and then cool. Step d: Mix mixture 1 and mixture 2, and cool to obtain a water-soluble fertilizer with antifreeze function; The inlet pipes of mixture 1 and mixture 2 first converge into the mixing inlet shell, and then are fed into the stirring device for mixing through the mixing inlet shell; the flow rates of mixture 1 and mixture 2 are adjusted by adjusting the flow rates of the inlet pipes of mixture 1 and mixture 2 to achieve pre-mixing of mixture 1 and mixture 2.

2. The production process of a water-soluble fertilizer with antifreeze function according to claim 1, characterized in that: The surfactant is an alkyl glycoside, the antifreeze synergist is sodium alginate, and the antifreeze agent is ethylene glycol.

3. The production process of a water-soluble fertilizer with antifreeze function according to claim 1, characterized in that: The main raw materials of the water-soluble fertilizer with antifreeze function are composed of the following parts by weight: 10-40 parts nitrogen fertilizer, 5-25 parts potassium fertilizer, 5-25 parts phosphorus fertilizer, 40-60 parts biochemical humic acid, and 50-100 parts water. The surfactant is 20-40 parts by weight, the antifreeze synergist is 2-5 parts, and the antifreeze is 10-30 parts.

4. The production process of a water-soluble fertilizer with antifreeze function according to claim 1, characterized in that: During feeding, the flow rate of the mixture 1 inlet pipe is 0.08 to 0.3 m / s.

5. The production process of a water-soluble fertilizer with antifreeze function according to claim 1, characterized in that: When dissolving in step b, the water temperature is 60-75℃; when mixing mixture 1 and mixture 2, the temperatures of both mixture 1 and mixture 2 are 30-40℃.

6. The production process of a water-soluble fertilizer with antifreeze function according to claim 1, characterized in that: Before the initial mass production of the current model of water-soluble fertilizer, step d includes: Step d01: Collect the density and viscosity of mixture 1 at the reference temperature; Step d02: Obtain the target mixing ratio range for mixture 1 and mixture 2; Step d03: Based on the target Reynolds number range and the density and viscosity of mixture 1, determine the initial flow range of mixture 1; Step d04: Within the initially set flow range of mixture 1, the flow rate of mixture 1 is gradually adjusted, and the flow rate of mixture 2 is simultaneously adjusted according to the target ratio range of mixture 1 and mixture 2. After each adjustment, the mixing and premixing time of mixture 1 and mixture 2 is controlled, and the density gradient coefficient of the premixed mixture is determined based on the density detection of the premixed mixture. Several target continuous flow ranges that meet the range of the density gradient coefficient of the premixed mixture are selected, and a target continuous flow range - preselected mixing Reynolds number range - premixed mixture density gradient coefficient range is constructed. Step d05: Obtain the viscosity of the commonly used mixture 1 when mixing the mixture 1 with the mixture 1, determine the pre-selected mixing Reynolds number range-pre-selected flow range for each commonly used mixture 1 viscosity; determine the repeating target pre-selected flow range for all commonly used mixture 1 viscosities; Step d06: Divide the stirring device into several liquid level intervals, and determine the target feeding time interval for each liquid level interval under the viscosity conditions at the reference temperature.

7. The production process of a water-soluble fertilizer with antifreeze function according to claim 6, characterized in that: For each batch production of the current model of water-soluble fertilizer, step d includes: Step d1: Control the flow rate of the inlet pipe of mixture 1 to the characteristic value in the target pre-selected flow range, and synchronously adjust the flow rate of mixture 2 according to the target ratio range of mixture 1 and mixture 2. Input mixture 1 and mixture 2 into the stirring device, and determine the actual density gradient coefficient based on the actual density detection of the premixed mixture. Step d2: Control the actual stirring speed of the stirring device to the reference stirring speed, continue stirring, and control the feeding based on the median of the target feeding time interval corresponding to each liquid level interval; and perform refractive index detection at least once in each liquid level interval to obtain the real-time refractive index data of the mixture in that liquid level interval; compare the real-time refractive index with the standard refractive index interval corresponding to that liquid level interval. If the real-time refractive index is within the standard interval, it is determined that the mixing uniformity of this stage meets the standard, and the feeding and stirring of the next liquid level interval continues; if the real-time refractive index exceeds the standard interval, the adjustment mechanism is triggered.

8. The production process of a water-soluble fertilizer with antifreeze function according to claim 7, characterized in that: The adjustment mechanism is as follows: If the real-time refractive index exceeds the standard range, feeding is paused, and stirring continues until the refractive index of the current liquid level meets the requirements. The total stirring time for the current liquid level is determined, and a first ratio is calculated between the total stirring time of the current liquid level and the median of the target feeding time range for the current liquid level. Based on the first ratio, the adjusted feeding time for the next liquid level is adjusted. After the adjustment is completed, the feeding and stirring process for the next liquid level is resumed, and the refractive index is detected in the next liquid level. If the refractive index exceeds the standard again, the above adjustment logic is repeated until the mixing uniformity of the entire liquid level range meets the standard.

9. The production process of a water-soluble fertilizer with antifreeze function according to claim 1, characterized in that: Step c includes: Step c1: Obtain the temperature range of the mixture during each homogenization emulsification period of the mixture to be homogenized; Step c2: Mix the surfactant solution and the antifreeze synergist solution to obtain mixture 3. Take a sample and test the actual temperature-viscosity trend curve of mixture 3 in the process homogenization temperature range. Determine the absolute value of the slope of the actual temperature-viscosity trend curve corresponding to each homogenization emulsification period based on the homogenization emulsification period in step c1. Step c3: Mix the sampled mixture 3 with the antifreeze to obtain the viscosity after mixing; determine the viscosity action coefficient based on the viscosity detected in step c1 and the viscosity after mixing. Step c4: Based on the average value of the absolute slope, the viscosity coefficient, and the process relationship of the average value of the absolute slope - viscosity coefficient - homogenization pressure corresponding to all homogenization emulsification periods, determine the homogenization pressure corresponding to each homogenization emulsification period; Step c5: Control homogenization emulsification with the selected value of the homogenization pressure corresponding to the first homogenization emulsification period, and detect the actual temperature rise of the first homogenization emulsification period. If the actual temperature rise is qualified, continue homogenization emulsification based on the corresponding homogenization pressure of the remaining homogenization emulsification period. If the actual temperature rise is not qualified, adjust the corresponding homogenization pressure of the remaining homogenization emulsification period according to the actual temperature rise, and complete the homogenization emulsification of all subsequent homogenization emulsification periods in sequence according to the adjusted parameters until mixture 2 is formed.

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