Mixing process for the acid stabilization treatment of pesticide formulations

Abstract

The present application relates to the technical field of pesticide preparation processing, and discloses a mixing process for acid stability treatment of pesticide preparation, which comprises the following steps: pressing acid stabilizer and pesticide raw drug base liquid mixture into a mixing flow channel, generating an intermediate phase liquid film with a radial velocity gradient by using a narrow slit, controlling the intermediate phase liquid film to flow through an asymmetric step platform to generate a single-side negative pressure area and adhere to the wall surface, and then using the wall-attached vortex to provide transverse alternating lift to drive the intermediate phase liquid film to generate high-frequency sweeping in the radial plane, and convert the axial kinetic energy into the radial kinetic energy of the cutting liquid film. The present application eliminates the micro mass transfer dead zone by forced convection driven by kinetic energy, realizes continuous updating of the contact interface, effectively suppresses the risk of local acid impact, and significantly enhances the long-term physical stability of the preparation.

Description

Technical Field

[0001] This invention relates to the field of pesticide formulation processing technology, and more specifically, to a mixing process for acid stabilization treatment of pesticide formulations. Background Technology

[0002] Ensuring the chemical and physical stability of dispersion systems such as high-content suspensions or water-in-oil emulsions is currently a core production objective. To maintain the quality of active ingredients during long-term storage, acid regulators are typically added to the system to adjust the pH of the dispersion medium and create a stable chemical environment. Currently, the industry commonly uses mechanically stirred tanks or high-speed shearing equipment to inject acid stabilizers into the main material stream containing active ingredients, achieving material mixing through turbulent diffusion. The dispersed phase in pesticide formulations usually has a high solids content, causing the continuous phase to exhibit obvious non-Newtonian fluid characteristics and high viscosity properties. When acid regulators enter such high-viscosity systems, local high-acid regions constrained by viscous forces are rapidly generated around the injection point. Due to the limitation of the system's mass transfer efficiency by the high-viscosity boundary layer, the microscopic diffusion rate of regulator molecules is lower than the kinetic rate of the neutralization reaction, resulting in transient acid shocks in local areas.

[0003] To address this issue, the industry has attempted to dilute acidic reagents or extend the feeding cycle. These approaches increase the hydraulic load during production and do not eliminate microscopic concentration inconsistencies. Further analysis reveals that existing mixing processes, when handling non-Newtonian fluids, concentrate energy dissipation in the overall flow field construction, exhibiting low efficiency in interface renewal at the submicron scale. This results in sensitive active components undergoing molecular degradation or flocculation due to contact with localized high concentrations of hydrogen ions before overall mixing is achieved. Existing technologies suffer from the following shortcomings: 1. The microscopic mass transfer rate within the mixing field is mismatched with reaction kinetics, leading to an uncontrollable concentration gradient upon material injection, inducing active component degradation; 2. The laminar boundary layer effect in high-viscosity fluids hinders the penetration of acidic factors, making it difficult for existing equipment to achieve stable molecular-level contact between components; 3. Relying on increasing shear strength easily damages the physical structure of the dispersed phase of the formulation, failing to balance mixing uniformity and material protection.

[0004] Therefore, the technical problem to be solved by this invention is how to eliminate the microscopic mass transfer barrier in a high-viscosity system and achieve a smooth transition to an acidic environment through precise intervention in the topology of the mixed field. Summary of the Invention

[0005] This invention provides a mixing process for acid stabilization treatment of pesticide formulations, comprising the following steps: Step S1: The mixture of acid stabilizer and pesticide technical liquid is pressed into the mixing channel. The mixture is squeezed and sheared by the narrow slit in the mixing channel, and an intermediate phase liquid film with radial velocity gradient is generated at the outlet end of the narrow slit. Step S2: Control the intermediate phase liquid film to flow through the asymmetric step step set behind the narrow slit. The sudden expansion of the flow channel caused by the asymmetric step step generates a unilateral negative pressure zone, which induces the intermediate phase liquid film to deflect and adhere to the flow channel wall with the asymmetric step step. Step S3: Asymmetric step steps are used to induce periodically detached wall vortices in the unilateral negative pressure zone. The wall vortices apply a transverse alternating lift force to the intermediate phase liquid film attached to the flow channel wall, driving the intermediate phase liquid film to perform a high-frequency sweeping action in the radial plane of the mixing flow channel, converting the axial translational kinetic energy of the mixture into the radial kinetic energy of cutting the intermediate phase liquid film. Step S4 involves continuously peeling off and renewing the interface between the intermediate phase liquid film and the pesticide base liquid using radial kinetic energy, thereby eliminating the microscopic mass transfer dead zone through forced convection and obtaining a pesticide formulation with a single-peak particle size distribution.

[0006] Preferably, in step S3, the periodic undulating corrugations set on the inner wall of the mixing channel are used to hinder the boundary layer flow of the mixture, and transverse secondary flow vortices with opposite directions are generated on both sides of the central flow field of the mixing channel. The opposing shear force of the transverse secondary flow vortices transforms the two-dimensional stretching morphology of the mesophase liquid film into a three-dimensional layered and wrinkled morphology. By adjusting the pressure drop of the narrow slit, the shear heat generation rate of the mixture in the shear field is made greater than its radial heat dissipation rate, thereby reducing the local kinematic viscosity of the mesophase liquid film at the mixing node.

[0007] Preferably, the flow state of the mixture within the narrowed slit satisfies a Reynolds number Re between 2000 and 3500. The Reynolds number Re is calculated as: Re = (ρ•v•d) / μ, where ρ is the density of the mixture, v is the average flow velocity of the mixture at the narrowed slit, d is the hydraulic diameter of the narrowed slit, and μ is the apparent viscosity of the mixture.

[0008] Preferably, the method includes the following steps: step S401, measuring the initial viscosity value of the mixture before entering the narrowing slit; step S402, adjusting the conveying pressure of the mixture in the mixing channel according to the initial viscosity value, so that the average flow velocity v of the mixture at the narrowing slit meets the range requirement of the Reynolds number Re; wherein, the step height of the asymmetric step is set to 0.5 to 1.2 times the width of the narrowing slit.

[0009] Preferably, by adjusting the flow rate of the mixture at the narrow slit, the instantaneous temperature rise of the intermediate phase liquid film at the mixing node is controlled to be between 5°C and 10°C.

[0010] Preferably, the wall surface of the asymmetric step is provided with a hydrophobic coating made of fluoropolymer; by adjusting the flow rate of the mixture, the shedding frequency of the wall vortex is not less than 10kHz, so as to perform physical crushing action on the intermediate phase liquid film, so that the average particle size of the generated pesticide formulation is in the range of 300nm to 800nm.

[0011] Preferably, before step S1, a pre-shearing action is performed on the mixture by a spiral stator set at the front end of the mixing channel, so that the acid stabilizer is dispersed into micron-sized droplets in the pesticide technical base liquid.

[0012] Preferably, the method further includes the following steps: step S801, monitoring the outlet temperature of the mixture in the expansion section behind the mixing channel; step S802, using the cooling sleeve surrounding the expansion section to perform heat exchange operation on the mixture, so as to restore the temperature of the mixture to the initial feeding temperature of the pesticide technical base liquid.

[0013] Preferably, the periodic undulating ripples are composed of multiple staggered protrusions distributed on the wall, and the radial height of the protrusions is 0.1 to 0.2 times the characteristic radius of the mixing channel.

[0014] Preferably, based on the radial sweeping action of the attached vortex on the intermediate phase liquid film, the renewal frequency of the contact interface between the acid stabilizer and the pesticide technical liquid is increased, so that the absolute value of the zeta potential of the pesticide formulation is not less than 30mV.

[0015] The embodiments of the present invention have at least the following beneficial effects: 1. In the acid stabilization treatment of pesticide formulations, by pre-constructing a premixed phase with a high-viscosity isolation interface, and with the gradient increase of the Reynolds number of the mixing field from laminar to transitional flow, the contact mode between the sensitive active component and the acidic environment is transformed from random collision to controlled orderly exfoliation. In the initial low Reynolds number stage, the high-viscosity interface relies on laminar stability to block the penetration and diffusion of hydrogen ions. As the energy input is programmed to increase, the shear stress generated overcomes the interfacial viscosity, and the isolation layer produces the layer-by-layer shedding of molecular-level components. This ensures that the active component is exposed only in the field where the acid factor has been initially diluted, eliminating the local high acid impact around the mixing injection point, maintaining the instantaneous equilibrium of the chemical potential of the active molecule microenvironment, and thus avoiding irreversible chemical degradation or physical aggregation of the sensitive component.

[0016] 2. Utilizing the asymmetric step-expansion structure within the flow channel to induce self-excited high-frequency slapping of the flow stream, the axial translational kinetic energy of the main material flow is converted into transverse cutting kinetic energy perpendicular to the mainstream direction. Addressing the non-Newtonian fluid characteristics of pesticide suspensions exhibiting a stretch viscosity far exceeding shear viscosity in conventional narrow-diameter flow channels, this alternating transverse shear stress forcibly severs the transient intermediate liquid film thinned by axial stretching, breaking the continuous fibrous filament structure formed by the high-viscosity fluid in laminar flow. This process dissolves the interfacial barrier between the acidic stabilizer and the high-viscosity dispersion system, enabling instantaneous entrainment and penetration of acidic factors into the colloidal microenvironment of the active ingredient, ensuring microscopic uniformity of pH distribution across the entire material system within millisecond-level processes.

[0017] 3. The acceleration gradient generated at the channel diameter change point and the elastic disturbance component set on the inner wall form a kinetic energy feedback closed loop, driving the elastic component to generate high-frequency micro-amplitude vibration, which destroys the physical diffusion hysteresis layer of high solid content formulations at the submicron scale. The flow energy of the mixing field itself is used to realize the continuous renewal of the interface, converting passive molecular diffusion into kinetic energy-driven forced convection, eliminating the microscopic mass transfer dead zone commonly found in ultra-high viscosity systems. This multi-mechanism synergistic mixing method reduces the dependence on external mechanical shear strength while optimizing the zeta potential distribution of the formulation system, making the formulation exhibit extremely high single-peak narrow distribution characteristics, enhancing the conduction rate and long-term physical stability of the agent in the plant. Attached Figure Description

[0018] The above and other objects, features, and advantages of exemplary embodiments of the present invention will become readily apparent from the following detailed description taken in conjunction with the accompanying drawings, in which several embodiments of the invention are illustrated by way of example and not limitation, wherein: Figure 1 This is a four-stage operation flowchart of the acid stabilization mixing process for pesticide formulations of the present invention; Figure 2 This is a diagram showing the three-dimensional morphological evolution of the intermediate phase liquid film driven by geometric constraints according to the present invention. Detailed Implementation

[0019] The principles and spirit of the present invention will now be described with reference to several exemplary embodiments in conjunction with the accompanying drawings. It should be understood that these embodiments are provided merely to enable those skilled in the art to better understand and implement the present invention, and are not intended to limit the scope of the present invention in any way. On the contrary, these embodiments are provided to make the present invention more thorough and complete, and to fully convey the scope of the present invention to those skilled in the art.

[0020] A mixing process for acid stabilization treatment of pesticide formulations includes the following steps: Step S1: The mixture of acid stabilizer and pesticide technical liquid is pressed into the mixing channel. The mixture is squeezed and sheared by the narrow slit in the mixing channel, and an intermediate phase liquid film with radial velocity gradient is generated at the outlet end of the narrow slit. Step S2: Control the intermediate phase liquid film to flow through the asymmetric step step set behind the narrow slit. The sudden expansion of the flow channel caused by the asymmetric step step generates a unilateral negative pressure zone, which induces the intermediate phase liquid film to deflect and adhere to the flow channel wall with the asymmetric step step. Step S3: Asymmetric step steps are used to induce periodically detached wall vortices in the unilateral negative pressure zone. The wall vortices apply a transverse alternating lift force to the intermediate phase liquid film attached to the flow channel wall, driving the intermediate phase liquid film to perform a high-frequency sweeping action in the radial plane of the mixing flow channel, converting the axial translational kinetic energy of the mixture into the radial kinetic energy of cutting the intermediate phase liquid film. Step S4 involves continuously peeling off and renewing the interface between the intermediate phase liquid film and the pesticide base liquid using radial kinetic energy, thereby eliminating the microscopic mass transfer dead zone through forced convection and obtaining a pesticide formulation with a single-peak particle size distribution.

[0021] Preferably, in step S3, the periodic undulating corrugations set on the inner wall of the mixing channel are used to hinder the boundary layer flow of the mixture, and transverse secondary flow vortices with opposite directions are generated on both sides of the central flow field of the mixing channel. The opposing shear force of the transverse secondary flow vortices transforms the two-dimensional stretching morphology of the mesophase liquid film into a three-dimensional layered and wrinkled morphology. By adjusting the pressure drop of the narrow slit, the shear heat generation rate of the mixture in the shear field is made greater than its radial heat dissipation rate, thereby reducing the local kinematic viscosity of the mesophase liquid film at the mixing node.

[0022] Preferably, the flow state of the mixture within the narrowed slit satisfies a Reynolds number Re between 2000 and 3500. The Reynolds number Re is calculated as: Re = (ρ•v•d) / μ, where ρ is the density of the mixture, v is the average flow velocity of the mixture at the narrowed slit, d is the hydraulic diameter of the narrowed slit, and μ is the apparent viscosity of the mixture.

[0023] Preferably, the method includes the following steps: step S401, measuring the initial viscosity value of the mixture before entering the narrowing slit; step S402, adjusting the conveying pressure of the mixture in the mixing channel according to the initial viscosity value, so that the average flow velocity v of the mixture at the narrowing slit meets the range requirement of the Reynolds number Re; wherein, the step height of the asymmetric step is set to 0.5 to 1.2 times the width of the narrowing slit.

[0024] Preferably, by adjusting the flow rate of the mixture at the narrow slit, the instantaneous temperature rise of the intermediate phase liquid film at the mixing node is controlled to be between 5°C and 10°C.

[0025] Preferably, the wall surface of the asymmetric step is provided with a hydrophobic coating made of fluoropolymer; by adjusting the flow rate of the mixture, the shedding frequency of the wall vortex is not less than 10kHz, so as to perform physical crushing action on the intermediate phase liquid film, so that the average particle size of the generated pesticide formulation is in the range of 300nm to 800nm.

[0026] Preferably, before step S1, a pre-shearing action is performed on the mixture by a spiral stator set at the front end of the mixing channel, so that the acid stabilizer is dispersed into micron-sized droplets in the pesticide technical base liquid.

[0027] Preferably, the method further includes the following steps: step S801, monitoring the outlet temperature of the mixture in the expansion section behind the mixing channel; step S802, using the cooling sleeve surrounding the expansion section to perform heat exchange operation on the mixture, so as to restore the temperature of the mixture to the initial feeding temperature of the pesticide technical base liquid.

[0028] Preferably, the periodic undulating ripples are composed of multiple staggered protrusions distributed on the wall, and the radial height of the protrusions is 0.1 to 0.2 times the characteristic radius of the mixing channel.

[0029] Preferably, based on the radial sweeping action of the attached vortex on the intermediate phase liquid film, the renewal frequency of the contact interface between the acid stabilizer and the pesticide technical liquid is increased, so that the absolute value of the zeta potential of the pesticide formulation is not less than 30mV.

[0030] Example 1: When the main material flow of a high-solids-content pesticide suspension at an ambient temperature of 5°C exhibits non-Newtonian fluid pseudoplasticity, the acidic stabilizer, after injection, is restricted by the laminar boundary layer effect. The diffusion of the acidic regulating factor is hindered, and a high-acid encapsulation zone is formed around the injection point. This causes the active component to come into contact with a high concentration of hydrogen ions, resulting in degradation and flocculation. The mixture of the acidic stabilizer and the pesticide technical base liquid is forced into the mixing channel. The narrow slits in the mixing channel compress and shear the mixture, generating an intermediate phase liquid film with a radial velocity gradient at the outlet of the narrow slits. This intermediate phase liquid film is controlled to flow through an asymmetric step set behind the narrow slits. The sudden expansion of the channel caused by the asymmetric step creates a unilateral negative pressure zone, inducing the intermediate phase liquid film to deflect and adhere to the surface. The flow channel wall is provided with the asymmetric step step. At this time, the asymmetric step step induces the periodic detachment of the attached wall vortex in the negative pressure zone on one side. Since there is a core area with extremely low static pressure at the center of the vortex, as the vortex grows periodically and detaches alternately behind the step, the low-pressure core area induces a high-frequency alternating spatial pressure gradient on the surface space of the attached liquid film. Based on the principle of fluid dynamics, this periodic pressure gradient perpendicular to the mainstream direction of the fluid is directly converted into a normal suction force acting on the surface of the liquid film. Thus, the attached wall vortex applies a transverse alternating lift force to the intermediate phase liquid film attached to the flow channel wall, driving the intermediate phase liquid film to sweep at high frequency in the radial plane of the mixing flow channel, converting the axial translational kinetic energy of the mixture into the radial kinetic energy of cutting the intermediate phase liquid film.

[0031] An online viscometer was used to determine the initial apparent viscosity of the mixture before it entered the narrow constriction slit. Based on this initial viscosity, the conveying pressure of the mixture within the mixing channel was adjusted to ensure that the average flow velocity at the narrow constriction slit maintained a Reynolds number Re between 2000 and 3500. The Reynolds number was calculated using the formula Re = (ρ•v•d) / μ, where ρ is the density of the mixture, v is the average flow velocity at the narrow constriction slit, d is the hydraulic diameter of the narrow constriction slit, and μ is the apparent viscosity of the mixture, taking into account the flow rate. In the dynamics of a jet with sudden expansion, the boundary of the wall-attached stability is such that when the step height is less than 0.5 times the width of the narrowing slit, the small expansion ratio makes it impossible to maintain a stable unilateral negative pressure zone, which in turn causes the vortex to collapse prematurely. When it exceeds 1.2 times, the excessive expansion of the recirculation zone will drastically increase the local flow resistance and induce a microscopic mass transfer dead zone. Based on this geometric constraint, the step height of the asymmetric step is set to 0.5 to 1.2 times the width of the narrowing slit, and the shedding frequency of the wall-attached vortex is maintained at no less than 10kHz in conjunction with the adjustment of the delivery pressure. A dynamic pressure sensor is installed at the outlet of the mixing channel to capture fluid pressure pulsations. When the signal characteristic frequency deviates from the target frequency by 10kHz, the output frequency of the variable frequency feed pump is adjusted to change the average flow velocity v of the mixture at the narrow-aperture slit. The average flow velocity v and the vortex shedding frequency f satisfy f=St•v / d, where f is the vortex shedding frequency, St is the Strouhal number, v is the average flow velocity of the mixture at the narrow-aperture slit, and d is the hydraulic diameter of the narrow-aperture slit. This applies to the transition flow at Reynolds numbers Re=2000 to 3500. Within the range, the value of St is determined by the non-Newtonian exponent of the mixture, selected between 0.18 and 0.22. The specific calibration logic is as follows: the measurement and control unit extracts 10 sets of shear stress signals within a 100ms sampling period, calculates the mean of the non-Newtonian exponent through discrete point sampling, and locks the Strouhal number at 0.18 when the non-Newtonian exponent is less than 0.6; sets the Strouhal number lookup step to 0.20 when the non-Newtonian exponent is between 0.6 and 0.9; and fixes the Strouhal number at 0 when the non-Newtonian exponent is greater than 0.9.22. Based on real-time acquisition of apparent viscosity μ and material density ρ using an online viscometer, the Reynolds number Re = (ρ•v•d) / μ is calculated, where Re is the Reynolds number, ρ is the mixture density, and μ is the apparent viscosity of the mixture. Based on the calculation results, the pumping pressure is adjusted in a closed loop to ensure that the sweeping kinetic energy of the mesophase liquid film in the radial plane reaches the critical threshold for cutting the high-viscosity continuous fibrous structure. Simultaneously, periodic undulating corrugations on the inner wall of the mixing channel impede the boundary layer flow of the mixture, generating transverse secondary flow vortices in opposite directions on both sides of the central flow field of the mixing channel. The opposing shear force of these transverse secondary flow vortices transforms the two-dimensional stretched morphology of the mesophase liquid film into a three-dimensional layered and wrinkled morphology. Adjusting the pressure drop of the narrow-diameter slit ensures that the shear heat generation rate of the mixture in the shear field is greater than the radial heat dissipation rate, controlling the instantaneous temperature rise at the mesophase liquid film within the range of 5℃ to 10℃. In-situ frictional heating reduces the local kinematic viscosity and interfacial tension of the mesophase liquid film.

[0032] Radial kinetic energy continuously peels away and renews the interface between the mesophase liquid film and the pesticide base liquid. Forced convection eliminates microscopic mass transfer dead zones, allowing acidic factors to penetrate into the colloidal microenvironment of the pesticide. The resulting pesticide formulation exhibits a unimodal particle size distribution and a zeta potential absolute value not less than 30 mV. This excellent unimodal distribution characteristic stems from the precise matching of the number of capillaries and the critical breakage threshold within the mixing field. According to fluid dynamics calculations, when the frequency of vortex shearing reaches 10 kHz, the local instantaneous shear force acting on the mesophase liquid film is sufficient to overcome the interfacial tension resistance of the high-viscosity base liquid, causing the number of capillaries, representing the ratio of viscous force to surface tension, to exceed the critical breakage value. Under this condition, the liquid film no longer breaks away randomly and coarsely, but rather exhibits a controlled, step-like peeling process. Experimental measurements show that within the frequency range of 10 kHz to 12 kHz, the uniformity of the shear energy level of the mixture after passing through the asymmetric step is improved. With a concentration of over 80%, the droplets achieve a highly consistent energy density upon breakup, resulting in a pesticide formulation with an extremely narrow single-peak particle size distribution and a median diameter stably controlled at around 450 nm. A 35% to 50% mass fraction of the dispersing and stabilizing component is selected as the continuous phase of the pesticide technical material base liquid. An organic acid stabilizer with a concentration of 5% to 12% is used. Adjusting the mixing channel conveying pressure maintains the instantaneous temperature rise of the mixture at the narrow slit at a range of 5°C to 10°C, triggering a thermosensitive thinning effect. Under these conditions, the pesticide formulations prepared exhibit a single-peak particle size distribution of 300 nm to 800 nm, with an absolute Zeta potential of not less than 30 mV. When the Reynolds number Re is less than 2000 or the protrusion height h is less than 0.1R, the radial kinetic energy within the mixing field is insufficient to overcome the resistance of the high-viscosity boundary layer, leading to localized flocculation in the formulation system and a broad bimodal particle size distribution. This verifies the correlation between the flow field topology and specific flow velocity ranges in maintaining the chemical stability of the active components.

[0033] Example 2: The fluid flow characteristics within the pesticide suspension production system lead to slow mass transfer of the acidic regulating factor and trigger local degradation of the active component. The experimental data comes from a continuous confined space high shear rheological testing platform, which includes a variable frequency feed pump with a pressure regulation accuracy of 0.01 MPa and a flow field pressure sensor with a sampling frequency of 50 kHz. Periodic pressure pulsations with an amplitude of 0.2 MPa and a frequency of 5 Hz are superimposed in the main fluid loop and set as the basic environmental disturbance variable. The Reynolds number Re is determined based on the physical constraint relationship between the fluid shear renewal rate and the molecular chain mechanical degradation threshold. When the non-Newtonian index of the mixture is lower than the predetermined threshold, the controller adjusts the output flow rate of the variable frequency feed pump according to the initial apparent viscosity value fed back by the online viscometer so that the Reynolds number Re tends to the lower limit of the value range. The step height of the asymmetric step is calculated based on the proportional relationship between the adhesion effect adsorption torque and the local flow resistance of the fluid. The increase in the step size expands the volume of the single-sided negative pressure zone and correspondingly increases the adhesion vortex shedding energy and the radial pressure drop gradient in the flow channel.

[0034] Multiple experimental control environments were set up to verify the action boundaries of relevant parameters. Control group 1 used a smooth contraction-diffusion flow channel without asymmetric step heights or periodic undulations. Control group 2 had a step height set to 0.3 times the width of the narrowing slit. Control group 3 had a step height set to 1.5 times the width of the narrowing slit. Control group 4 adjusted the delivery pressure of the variable frequency feed pump to maintain the Reynolds number Re at 1500. Control group 5 adjusted the delivery pressure to maintain the Reynolds number Re at 4000. Sample groups 1 to 3 of this invention used flow channels containing asymmetric step heights and periodic undulations, with step heights set to 0.5 times, 0.85 times, and 1.2 times the width of the narrowing slit, respectively. At the same time, the delivery pressure was adjusted to keep the Reynolds number Re constant at 2000, 2750, and 3500, respectively. The mixtures of each group were then injected into the corresponding mixing flow channels. The system was operated under 5Hz periodic pressure pulsation, and relevant physical quantities were measured from the effluent at the outlet of the flow channel. The median diameter of the effluent from control group 1 was 5.45 μm, the absolute value of the zeta potential was 15.2 mV, and the proportion of degradation products caused by free acidic droplets was 8.54%. The median diameter of the effluent from samples 1 to 3 of this invention ranged from 1.12 μm to 1.28 μm, the absolute value of the zeta potential ranged from 32.4 mV to 37.8 mV, and the highest measured proportion of degradation products was 0.28%. The transverse secondary flow vortices generated by the periodic undulating ripples transformed the mesophase liquid film into a three-dimensional layered folded morphology through opposing shear forces. When the pressure pulsation caused a change in the thickness of the flow field boundary layer, the alternating lift released by the wall vortices offset the transverse displacement deviation of the mesophase liquid film and maintained the contact area between the two phases of the liquid film.

[0035] The control groups deviating from the preset parameter range produced corresponding deviation trends in physical change data. In control group 2, the fluid jet detached from the wall due to insufficient sudden expansion ratio, causing the wall vortex to collapse and the median diameter of the effluent to become 3.88 μm. In control group 3, the excessive expansion of the unilateral negative pressure zone caused the frequency of wall vortex shedding to decrease to 4.1 kHz, and the local mass transfer dead zone resulted in the median diameter of the effluent becoming 4.25 μm. In control group 4, the fluid state approached laminar flow, resulting in insufficient lateral alternating lift kinetic energy and the proportion of degradation products increasing to 6.72%. In control group 5, the local instantaneous... When the temperature rises to 15.4℃, the excessive shear heat generation induces physical flocculation of the pesticide active ingredient components, increasing the proportion of corresponding degradation products to 12.45%. The alternating lift induced by the asymmetric step and the transverse secondary flow vortex generated by the periodic undulating ripples act within the preset Reynolds number Re range and step height ratio. The physical morphological transformation at the fluid level reduces the interphase mass transfer resistance in the non-Newtonian fluid state, inhibits the short-term aggregation of acidic regulating factors in the local flow field, reduces the total amount of degradation products generated, and stabilizes the physicochemical parameters of the output formulation.

[0036] Example 3: Temperature fluctuations and batch differences in pesticide technical base liquid in a continuous industrial feeding environment cause dynamic drift in the apparent viscosity of the mixture, altering the fluid shear renewal rate within the mixing channel. Simply applying a fixed conveying pressure cannot maintain a constant shedding frequency of the wall vortices, increasing the risk of local acidic regulating factors agglomerating due to slow mass transfer. The measurement and control unit receives the transient apparent viscosity value μ periodically collected by the online viscometer and calls the preset constant Reynolds number reference value in the memory. Based on fluid physics relationships, the target flow velocity under the current viscosity state is derived. Its physical constraint relationship satisfies the formula Where ρ is the density of the mixture, d is the hydraulic diameter of the narrowed slit, and the servo controller compares the real-time feedback value from the flow meter at the inlet of the mixing channel with the target flow velocity. The system outputs frequency conversion commands to the frequency conversion feed pump, adjusting the conveying pressure of the mixed material into the mixing channel by changing the stator frequency of the pump drive motor. The determination of the constant Reynolds number reference value relies on the rheological characteristic scanning of a specific batch of raw material base liquid. Before formal production, the fluid undergoes a full-range rheological response test from laminar to turbulent flow by adjusting the pumping frequency, while a high-frequency pressure sensor captures the pressure pulsation characteristic signal in the channel in real time. When the power spectral density of the pressure pulsation is detected to have its first obvious characteristic peak around 10kHz, the system records the instantaneous flow rate and pressure value at this time, and calculates the critical Reynolds number at which the batch of material produces stable self-excited oscillation. The critical value is set as a constant reference value for the Reynolds number in the subsequent production process, thereby ensuring that the system can quickly lock the optimal mixing efficiency point for the original drug base liquid with different rheological properties through feedforward servo calculation; at the same time, the periodic undulating ripples set on the inner wall of the mixing channel have a definite spatial geometry. The vertical height from the peak of the periodic undulating ripples to the bottom of the trough is set to 0.15 to 0.25 times the horizontal span between two adjacent peaks. The water-facing side of the peak squeezes the mixture flowing through the area, and the mixture undergoes boundary layer separation on the back side. The resulting local adverse pressure gradient drives the fluid to roll to both sides of the central flow field, forming a stable transverse secondary vortex.

[0037] A series of periodically undulating corrugations composed of equally spaced protrusions are machined on the inner wall of the mixing channel. The radial height h of the protrusions is selected as 0.1 to 0.2 times the characteristic radius R of the mixing channel, and the axial spacing L is 4 to 6 times the radial height h, where h is the radial height of the protrusion, R is the characteristic radius of the mixing channel, and L is the axial spacing between adjacent protrusions. When the mixture flows through the sharp edges of the protrusions, the flow stream generates controlled boundary layer delamination on the backwater surface, generating vortex structures with opposite rotation directions and intertwined on both sides of the flow field at the center of the channel. The opposing shear force of the vortex structures removes the intermediate phase with a thickness of 150 μm to 300 μm. The liquid film is broken down and reconstructed into a three-dimensional layered and folded morphology. The structural changes increase the microscopic contact sites between the acid stabilizer and the pesticide technical liquid, inhibiting local hydrogen ion enrichment and achieving uniform pH distribution across the entire material system. The feedforward adjustment algorithm based on apparent viscosity and the corrugated geometric constraints work together to maintain the compression and shear state of the mixture at the narrow slit and the alternating lift output behind the asymmetric step, enabling the flow field topology in the mixing channel to autonomously adapt to external rheological property fluctuations. The continuously peeling contact interface eliminates mass transfer dead zones, suppresses local acid shock phenomena in the material, and maintains the chemical stability of the formulation components.

[0038] Example 4: When the system faces the situation of switching between different batches of pesticide technical base liquid, the measurement and control unit starts the offline calibration program to establish a constant Reynolds number reference value. The mapping matrix is ​​used in the test component, which applies an increasing gradient shear rate scan to the sample material using a rotational rheometer and acquires dynamic response curves of storage modulus and loss modulus. The main control board extracts the characteristic shear force value corresponding to the intersection of the two response curves as the mechanical boundary parameter for the disintegration of molecular chains in this batch of material. The measurement and control host reverse-calculates the critical flow velocity for structural damage based on this mechanical boundary parameter and the hydraulic diameter of the mixing channel section, and calculates the derating flow velocity boundary according to the set safety ratio. The measurement and control host then converts this into a specific constant Reynolds number reference value. The data is written into the controller's storage area as the initial reference parameter for feedforward servo calculation. The specific calibration steps for the constant Reynolds number reference value are as follows: the feed pump steps at 5% of the rated power, and the drive frequency increases from 10Hz to 50Hz. The measurement and control host synchronously records the peak value of the pressure pulsation wave at the inlet of the mixing channel. During the recording process, the peak finding algorithm inside the measurement and control host performs a first-order difference operation on the input pressure pulsation timing signal in real time to monitor the incremental gradient between the peaks. When the incremental gradient of adjacent peaks continuously exceeds the system's preset fluid noise tolerance, and the difference between the absolute value of the current peak and the average value of the peak in the initial stable section reaches the set threshold, the feature recognition logic is triggered. Specifically, when the peak value of the pressure pulsation wave shows a sudden jump in amplitude of more than 0.15MPa for the first time, the system automatically locks the corresponding Reynolds value at this time and writes it into the non-volatile memory as the constant Reynolds number reference value.

[0039] Before the main material flow enters the mixing channel, the measurement and control node initiates a sensor baseline calibration program to correct physical signal distortion caused by non-Newtonian fluids. The calibration branch guides a reference liquid with known absolute viscosity and standard density through the online viscometer probe area. The acquisition board reads the transient physical readback value output by the probe and compares it with the standard physical property parameters of the reference liquid to extract the numerical deviation. The central processing unit (CPU) fits a dynamic compensation gain coefficient, including zero-point drift and nonlinear response errors, based on this numerical deviation. The calculation logic of this coefficient is as follows: the system establishes a 200-frame cyclic shift buffer and reads the original voltage signal of the online viscometer in real time at a sampling frequency of 1kHz. When the variance fluctuation of the voltage signal in the buffer exceeds 5%, the control algorithm adjusts the dynamic compensation gain coefficient upward or downward in a compensation step of 0.05 until the mean value of the buffer returns to within the standard baseline set by the reference liquid. The CPU then uses this dynamic compensation gain coefficient as a correction multiplier and inputs it in real time for the target flow rate. In the servo computing link, the frequency conversion drive unit receives the apparent viscosity transient value μ after superimposing the compensation gain coefficient, and synchronously refreshes the stator frequency of the feed pump motor. The parameter calibration loop continuously offsets the hardware perception deviation caused by particle deposition or pipe wall slippage.

[0040] Example 5: Before deploying the mixed flow channel in a high-viscosity pesticide suspension production line, the engineering verification node executes an offline optimization parameter-finding procedure to solidify the spatial geometric proportions of the asymmetric step and periodic undulating ripples. The parameter optimization engine sets the objective function to increase the radial kinetic energy within the flow field cross-section. The radial kinetic energy The calculation formula is ,in, The lateral alternating lift force applied to the wall-attached vortex, The radial sweep velocity of the intermediate phase liquid film. As the time constant for a single sweep cycle, the system simultaneously sets the hard physical constraint boundary as the transient temperature rise of the micro nodes in the flow field being less than 10℃ and the frequency of vortex shedding from the wall being higher than 10kHz. The computational fluid dynamics test host receives the rheological constitutive data and thermal conductivity parameters of the pesticide technical liquid. In the three-dimensional digital model, the step height of the asymmetric step step is adjusted by traversing the narrow slit width as the reference measurement within the range of 0.1 to 2.0 times with a step size of 0.05 times.

[0041] Simultaneously, in the flow channel inner wall model, the ratio of the vertical height of the crest to the horizontal span of the periodic undulating ripples is changed proportionally. The flow field solver extracts the particle distribution coordinates and fluid micro-particle temperature vectors at the narrow-diameter slit outlet end under each set of geometric parameter nodes. By comparing the difference between the shear heat generation rate and the radial heat dissipation rate, geometric parameter nodes that trigger temperature rise exceeding the limit are eliminated. The data optimization module locks the lateral alternating lift from the converged available parameter space. The coordinate domain where the amplitude reaches its maximum value outputs a targeted geometric configuration matrix containing a step height of 0.5 to 1.2 times the narrowing slit width and a peak height of 0.15 to 0.25 times the horizontal span. The processing terminal reads this targeted geometric configuration matrix and forms a solid mixing channel. The static flow field spatial boundary generates counter-shear force when the pumped fluid passes through, reducing the micro-mass transfer distance by relying on the limitation of physical structure morphology, and controlling the flocculation and degradation of sensitive components.

[0042] The above description is only a few preferred embodiments of the present invention and an explanation of the technical principles used. Those skilled in the art should understand that the scope of the invention involved in the embodiments of the present invention is not limited to the technical solutions formed by a specific combination of the above-mentioned technical features, but should also cover other technical solutions formed by any combination of the above-mentioned technical features or their equivalent features without departing from the above-mentioned inventive concept. For example, technical solutions formed by replacing the above-mentioned features with (but not limited to) technical features with similar functions disclosed in the embodiments of the present invention.

Claims

1. A mixing process for acid stabilization treatment of pesticide formulations, characterized in that, Includes the following steps: Step S1: The mixture of acid stabilizer and pesticide technical liquid is pressed into the mixing channel. The mixture is squeezed and sheared by the narrow slit in the mixing channel, and an intermediate phase liquid film with radial velocity gradient is generated at the outlet end of the narrow slit. Step S2: Control the intermediate phase liquid film to flow through the asymmetric step step set behind the narrow slit. The sudden expansion of the flow channel caused by the asymmetric step step generates a unilateral negative pressure zone, which induces the intermediate phase liquid film to deflect and adhere to the flow channel wall with the asymmetric step step. Step S3: Asymmetric step steps are used to induce periodically detached wall vortices in the unilateral negative pressure zone. The wall vortices apply a transverse alternating lift force to the intermediate phase liquid film attached to the flow channel wall, driving the intermediate phase liquid film to perform a high-frequency sweeping action in the radial plane of the mixing flow channel, converting the axial translational kinetic energy of the mixture into the radial kinetic energy of cutting the intermediate phase liquid film. Step S4 involves continuously peeling off and renewing the interface between the intermediate phase liquid film and the pesticide base liquid using radial kinetic energy, thereby eliminating the microscopic mass transfer dead zone through forced convection and obtaining a pesticide formulation with a single-peak particle size distribution.

2. The mixing process for acid stabilization treatment of pesticide formulations according to claim 1, characterized in that, In step S3, the periodic undulating corrugations set on the inner wall of the mixing channel are used to hinder the boundary layer flow of the mixture, generating transverse secondary flow vortices in opposite directions on both sides of the central flow field of the mixing channel. The opposing shear force of the transverse secondary flow vortices transforms the two-dimensional stretching morphology of the mesophase liquid film into a three-dimensional layered and wrinkled morphology. By adjusting the pressure drop of the narrow slit, the shear heat generation rate of the mixture in the shear field is made greater than its radial heat dissipation rate, thereby reducing the local kinematic viscosity of the mesophase liquid film at the mixing node.

3. The mixing process for acid stabilization treatment of pesticide formulations according to claim 1, characterized in that, The flow state of the mixture in the narrowed slit satisfies the Reynolds number Re in the range of 2000 to 3500. The Reynolds number Re is calculated as: Re = (ρ•v•d) / μ, where ρ is the density of the mixture, v is the average flow velocity of the mixture at the narrowed slit, d is the hydraulic diameter of the narrowed slit, and μ is the apparent viscosity of the mixture.

4. The mixing process for acid stabilization treatment of pesticide formulations according to claim 3, characterized in that, Includes the following steps: Step S401: Measure the initial viscosity of the mixture before it enters the narrow slit. Step S402: Based on the initial viscosity value, adjust the conveying pressure of the mixture in the mixing channel so that the average flow velocity v of the mixture at the narrowing slit meets the Reynolds number Re range requirement; wherein, the step height of the asymmetric step step is set to 0.5 to 1.2 times the width of the narrowing slit.

5. The mixing process for acid stabilization treatment of pesticide formulations according to claim 2, characterized in that, By adjusting the flow rate of the mixture at the narrow slit, the instantaneous temperature rise of the intermediate phase liquid film at the mixing node is controlled between 5°C and 10°C.

6. The mixing process for acid stabilization treatment of pesticide formulations according to claim 1, characterized in that, The walls of the asymmetric step are coated with a hydrophobic coating made of fluoropolymer. By adjusting the flow rate of the mixture, the shedding frequency of the wall vortex is made not less than 10kHz, so as to perform physical crushing action on the intermediate phase liquid film, and the average particle size of the generated pesticide formulation is in the range of 300nm to 800nm.

7. The mixing process for acid stabilization treatment of pesticide formulations according to claim 1, characterized in that, Before step S1, a pre-shearing action is performed on the mixture by a spiral stator set at the front end of the mixing channel, so that the acid stabilizer is dispersed into micron-sized droplets in the pesticide technical base liquid.

8. The mixing process for acid stabilization treatment of pesticide formulations according to claim 1, characterized in that, It also includes the following steps: Step S801: Monitor the outlet temperature of the mixture in the expansion section behind the mixing channel; Step S802: Use the cooling sleeve surrounding the expansion section to perform heat exchange operation on the mixture to bring the temperature of the mixture back to the initial feeding temperature of the pesticide technical base liquid.

9. A mixing process for acid stabilization treatment of pesticide formulations according to claim 2, characterized in that, The periodic undulating ripples are composed of multiple staggered protrusions distributed on the wall, with the radial height of the protrusions being 0.1 to 0.2 times the characteristic radius of the mixing channel.

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