A multi-process control method for processing of a traditional Chinese medicine preparation

Abstract

The application discloses a multi-process control method for processing of traditional Chinese medicine preparation, and relates to the technical field of traditional Chinese medicine preparation processing.The method comprises the following steps: obtaining an oil droplet particle size oil-in-water emulsion system and atomizing granulation through crushing and high-speed homogenization; adopting a drying mode combining multi-stage program temperature control and staged pressure reduction; strictly controlling the material temperature through linkage control logic of first pressure reduction and then temperature increase; utilizing double-layer conveying belts to cool the material temperature through segmented gradient clean airflow; and finally, adopting multi-index comprehensive judgment of total mixing through two-dimensional continuous mixing equipment low shear total mixing, so as to solve the problems of the prior art, greatly guarantee the retention rate of sesame oil aroma, and reduce the free oil exudation rate to less than or equal to 1%. The linkage logic of first pressure reduction and then temperature increase is established to avoid thermal damage. The gradient cooling clean airflow and the environmental humidity closed-loop control are adopted to guarantee the particle integrity and improve the production quality.

Description

Technical Field

[0001] This invention relates to the field of traditional Chinese medicine preparation processing technology, and specifically to a multi-process control method for traditional Chinese medicine preparation processing. Background Technology

[0002] The raw materials for traditional Chinese medicine preparations are mostly natural animal and plant medicinal materials, which generally have characteristics such as complex composition, high heat sensitivity, high oil and sugar content, and large differences in toughness. In the continuous processes of pulverization, emulsification granulation, drying, cooling, and mixing, problems such as uneven pulverization and poor quality consistency are very likely to occur. Establishing a multi-process collaborative control method covering the entire process can ensure uniform and stable product quality and achieve a high degree of consistency.

[0003] Existing technologies, such as application number CN202311861199.9, disclose improvements to the structure of a mixing machine by incorporating a stirring mechanism to enhance mixing efficiency. Application number CN201811131424.6 discloses a method for producing Polygonatum sibiricum tablets, in which granulated and dried granules are fed into a two-dimensional mixer for mixing. Application number CN201811493156.8 discloses a granulation process for Carthamus tinctorius tablets, in which granulated granules, volatile oil, and magnesium stearate are added to a two-dimensional mixer and mixed thoroughly.

[0004] The aforementioned technologies still have limitations in terms of integrated processes: 1. Existing powdered oil preparation technologies are mainly based on spray drying, with the core process being emulsification → spray drying. The spray drying process requires instantaneous evaporation of moisture in a high-temperature hot airflow. For heat-sensitive materials such as sesame oil containing volatile aroma components and unsaturated fatty acids, high-temperature treatment will accelerate the volatilization of aroma components and the oxidative rancidity of unsaturated fatty acids, leading to a significant decline in the sensory quality and nutritional value of the product. There is a contradiction between the inherent high-temperature drying characteristics of oil powdering technology with spray drying as its core and the protection of heat-sensitive components.

[0005] 2. While existing technologies for granulating traditional Chinese medicine include methods that atomize binders and spray them into the granulation pan, there remains a significant gap in the systematic process control of emulsification-atomization-granulation for oily materials. Current technologies spray the binder into the granules via atomization, but the oil phase is often directly atomized without a pretreatment step of oil-water emulsification. This leads to uneven distribution of the oil phase within the granules, resulting in clumping and free oil seepage. Furthermore, there is a lack of engineering technology linking emulsion stability control to atomization and granulation, and a lack of systematic process solutions for oily materials from emulsification to granulation.

[0006] 3. Existing vacuum or reduced-pressure drying technologies are mostly single-stage isotropic and isotropic modes. Once the parameters are determined, they remain essentially constant throughout the drying process. However, the drying process of wet granules is essentially a dynamic process of changing moisture content and surface state. A single-parameter drying mode cannot guarantee the uniformity of drying at each stage, from high-moisture-content wet granules to low-moisture-content dry granules. The conventional operating procedure is to first heat up and then vacuum, or both simultaneously. However, if the order of heating and vacuuming is not adequately considered for heat-sensitive components, it may lead to accelerated loss of aroma components. Furthermore, if the heating rate is not simultaneously constrained while reducing pressure, it may also exacerbate the volatilization of heat-sensitive components. There is a limitation in the systematic linkage between temperature and pressure control.

[0007] 4. Current technologies mostly employ natural cooling or simple air cooling for the cooling of high-temperature granules after drying, lacking precise control over the cooling rate and the temperature and humidity of the cooling environment. For sesame oil-containing granules, rapid cooling can easily lead to thermal stress cracks on the granule surface, causing the internal sesame oil to seep out; while improper control of the ambient humidity during the cooling process can easily cause condensation and moisture return on the granule surface due to temperature differences, affecting the stability of subsequent mixing and tableting processes.

[0008] 5. Existing two-dimensional mixers are mainly used for intermittent batch mixing in the final mixing process. The feeding and discharging of the equipment cannot be carried out concurrently within the same cycle, making it difficult to achieve truly continuous production line rhythm between the mixing process and other processes. Mixing parameters mostly use empirically fixed values, lacking analysis of the impact of shear strength on the integrity of oil-containing particles during the mixing process. There is a lack of a systematic shear protection mechanism for the mixing process of oil-containing particles, and the criteria for judging mixing uniformity are relatively lenient, making it difficult to meet the requirements for high content uniformity. Summary of the Invention

[0009] To address the aforementioned technical shortcomings, the present invention aims to provide a multi-process control method for the processing of traditional Chinese medicine preparations.

[0010] To solve the above technical problems, the present invention adopts the following technical solution: The present invention provides a multi-process control method for the processing of traditional Chinese medicine preparations, including the following steps: Step 1, pulverization control: According to the formula, group the raw materials of each group and put them into the premixing equipment, and sequentially perform the mixing and pre-pulverization, sieving, remixing or ultra-fine pulverization process until the particle size of the pulverized material meets the standard.

[0011] Step 2, Emulsification Granulation Control: Determine the ratio of sesame oil to water, mix the sesame oil and water according to the ratio, and process them into a homogeneous emulsion system using a high-speed homogenization emulsification method. Then, atomize the emulsion system and spray it into the granulation pot, and simultaneously control the granulation parameters until the wet granules are uniform.

[0012] Step 3, Drying Control: The wet particles are dried using a thermally conductive molten medium vacuum program temperature and pressure reduction method, with real-time monitoring of drying parameters until drying is complete.

[0013] Step 4, Cooling Control: The dried material is fed into a double-layer food-grade conveyor belt and circulated and blown by clean air until cooling is complete.

[0014] Step 5, Overall Mixing Control: The cooled materials and auxiliary materials are fed into a two-dimensional continuous mixing device according to a preset ratio. The mixing parameters are controlled to achieve continuous mixing until the mixture is uniform.

[0015] The beneficial effects of this invention are as follows: 1. This invention provides a multi-process control method for the processing of traditional Chinese medicine preparations. First, an oil-in-water emulsion system with oil droplet particle size is obtained through pulverization and high-speed homogenization, followed by atomization granulation. Then, a drying method combining multi-stage programmed temperature control and graded decompression is adopted. The material temperature is strictly controlled through a linkage control logic of first reducing pressure and then increasing temperature. Then, the material temperature is cooled by segmented stepped clean airflow using a double-layer conveyor belt. Finally, the material is mixed with low shear using a two-dimensional continuous mixing device, and the overall mixing condition is judged by multiple indicators. This solves the shortcomings of the prior art, greatly ensures the retention rate of sesame oil aroma, and reduces the free oil leakage rate to ≤1%. The linkage logic of first reducing pressure and then increasing temperature is established to avoid thermal damage. The closed-loop control of stepped cooling clean airflow and environmental humidity ensures particle integrity and improves production quality. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 This is a schematic diagram of the implementation steps of the method of the present invention. Detailed Implementation

[0018] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0019] Please see Figure 1As shown, a multi-process control method for processing traditional Chinese medicine preparations includes the following steps: Step 1, pulverization control: group the raw materials according to the formula, put each group of raw materials into the premixing equipment, and sequentially perform mixing and pre-pulverization, sieving, remixing or ultra-fine pulverization processes until the particle size of the pulverized material meets the standard.

[0020] In a specific embodiment, the specific process of step 1 is as follows: S1-1, each raw material is homogenized and grouped according to its oil content and sugar content, into a high-toughness group and a normal group.

[0021] It should be noted that the high-toughness group has an oil content ≥5% and a sugar content ≥8.0%, while the ordinary group has an oil content <5% or a sugar content <8.0%. The oil content of the raw materials was determined by Soxhlet extraction, and the sugar content was determined by phenol-sulfuric acid spectrophotometry.

[0022] Grouping allows for differentiated setting of pre-grinding gradient speeds during pulverization, preventing substandard pulverization of tough materials and over-grinding of ordinary materials; reducing issues such as clumping, sticking to equipment, and screen clogging of high-oil and high-sugar materials; and matching exclusive process parameters to each group to improve pulverization uniformity and batch consistency, providing a foundation for stable emulsification, drying, and granulation in the later stages.

[0023] S1-2, Pre-grinding: Start the premixing equipment, refer to the pre-grinding control parameter table, control the pre-grinding speed, and synchronously mix and pre-grind the raw materials after each group; at the same time, monitor the flowability, refer to the flow aid control table, and add flow aid according to the flowability; monitor the grinding status in real time until the fineness of the grinding material meets the standard.

[0024] Preferably, the process of setting the pre-grinding control parameter table is as follows: First, preset the basic parameters of each raw material, and group the raw materials according to the oil content and sugar content, setting them as a high-toughness test group and a normal test group. Put the raw materials in the high-toughness test group and the normal test group into the premixing device and start it. Set different pre-grinding speeds according to the gradient, and control the premixing device to rotate according to each pre-grinding speed in sequence. Then, use sensors to collect the premixing effect parameters in real time, analyze the mixing effect value of each group using different pre-grinding speeds, and select the pre-grinding speed with the largest mixing effect value as the reference pre-grinding speed for each group. In this way, obtain the reference pre-grinding speed corresponding to the basic parameters of each raw material in the high-toughness test group and the normal test group, as the pre-grinding control parameter table.

[0025] It should be noted that the basic parameters refer to the basic operating conditions parameters that are collected before the raw materials are put into production, including at least the amount of material fed and the moisture content of the material.

[0026] In this embodiment, all preset data were set by professionals according to actual needs.

[0027] In the above, the premixing effect parameters are quantitative parameters for evaluating the overall effect of pre-grinding, including particle size distribution range, number of agglomerates, and residual fiber segments.

[0028] The mixing effect value is obtained by normalizing each premixing effect parameter, taking the mean, and then taking the reciprocal of the mean.

[0029] In the above, flowability monitoring involves: collecting material flowability parameters online via sensors, including at least the material bulk density, angle of repose, and discharge velocity; and dynamically matching and adjusting the flow aid control parameters based on the real-time collected flowability parameters and a preset flow aid control table. The flow aid control parameters include at least the flow aid dosage and dosage velocity.

[0030] It should be noted that the process of constructing and setting the gliding agent control table is consistent with the process of setting the pre-pulverizing control parameter table, and will not be repeated here.

[0031] The fineness of the pulverized material meets the standard: the fineness of the pulverized material is considered to meet the standard if it falls within the preset acceptable fineness range. The fineness of the material is collected in real time by an online particle size detection sensor.

[0032] S1-3. Sieving: The pre-crushed material is automatically conveyed to the sieving device. Referring to the sieving control parameter table, the sieving speed and amplitude are controlled, and a screen of preset specifications is used for sieving. The qualified material is automatically sent to the re-mixing process; the unqualified material is automatically returned to the pre-crushing equipment for re-mixing and pre-crushing until it is qualified.

[0033] It should be noted that the process of constructing and setting the sieving control parameter table is consistent with the process of setting the pre-grinding control parameter table, and will not be repeated here.

[0034] Among them, qualified materials are those that can pass through the screen normally; unqualified materials are those that cannot pass through the screen.

[0035] S1-4. Remixing: All qualified materials after screening are sent to the remixing equipment. The mixing time and speed are controlled according to the mixing control parameter table. The mixing uniformity is monitored in real time by a near-infrared spectrometer. After the mixing uniformity meets the standard, the material automatically enters the ultrafine grinding process.

[0036] It should be noted that the process of constructing and setting the mixing control parameter table is consistent with the process of setting the pre-grinding control parameter table, and will not be repeated here.

[0037] The process for determining whether the mixing uniformity meets the standard is the same as the process for determining whether the fineness of the pulverized material meets the standard, and will not be repeated here.

[0038] S1-5. Ultrafine Grinding: Start the supersonic airflow pulverizer and introduce high-pressure, high-purity nitrogen gas with a purity ≥99.99% and a working pressure of 0.8-1.5MPa; refer to the ultrafine grinding control parameter table to control the airflow speed and use the adiabatic expansion characteristics of the gas to control the material temperature, and grind the material particle size to below 10μm to complete the grinding process.

[0039] It should be noted that the process of constructing and setting the ultrafine grinding control parameter table is consistent with the process of setting the pre-grinding control parameter table, and will not be repeated here.

[0040] The process utilizes the heat absorption properties of high-pressure gas through adiabatic expansion to regulate the temperature of the material inside the grinding chamber in real time, preventing excessive temperature rise, oil oxidation, and damage to effective components. Through the collision, shearing, and grinding action of supersonic airflow, the mixed material is subjected to ultrafine processing, and the grinding continues until the overall particle size of the material is stably controlled below 10μm. After passing the ultrafine grinding, the material is automatically conveyed into the subsequent emulsification and granulation process.

[0041] Material particle size crushed to below 10μm means that the average particle size of the material detected is less than 10μm within multiple consecutive sampling time windows.

[0042] The process utilizes the adiabatic expansion and heat absorption properties of high-pressure gas to regulate the temperature of materials inside the crushing chamber in real time: High-pressure, high-purity nitrogen gas is ejected at high speed through a dedicated supersonic nozzle of the crushing equipment. The high-pressure gas quickly enters the low-pressure environment of the crushing chamber and undergoes adiabatic expansion. During the rapid expansion, the gas does work on the outside and its internal energy decreases. Relying on the Joule-Thomson effect, it continuously absorbs heat from inside the crushing chamber, achieving active cooling of the crushing chamber. Temperature sensors are distributed and deployed on the inner wall of the crushing chamber and in the material fluidization area to continuously collect the ambient temperature inside the chamber and the surface temperature of the material in real time. When the detected temperature exceeds the upper limit of the preset safe temperature range inside the chamber and there is a risk of material overheating, the flow rate of high-pressure nitrogen gas is increased by a preset unit amount, and the nozzle airflow velocity is increased by a preset unit amount to enhance the adiabatic expansion and heat absorption efficiency of the gas, accelerate the heat removal rate, and quickly reduce the temperature of the chamber. When the detected temperature is lower than the lower limit of the preset safe temperature range inside the chamber, the working pressure and injection flow rate of nitrogen gas are reduced by a preset unit amount to weaken the expansion and heat absorption intensity, maintain the dynamic stability of the temperature inside the chamber, and avoid excessive low temperature causing material moisture absorption and agglomeration.

[0043] Step 2, Emulsification Granulation Control: Determine the ratio of sesame oil to water, mix the sesame oil and water according to the ratio, and process them into a homogeneous emulsion system using a high-speed homogenization emulsification method. Then, atomize the emulsion system and spray it into the granulation pot, and simultaneously control the granulation parameters until the wet granules are uniform.

[0044] In a specific embodiment, the specific process of step 2 is as follows: S2-1, extract the formula in the current production line, and then determine the ratio of sesame oil to water in the formula in the current production line; mix sesame oil and water in a certain proportion to form a stable water-in-oil emulsion, and use a high-shear homogenization method to obtain a uniform emulsion system.

[0045] The formula includes the types and quantities of each raw and auxiliary material.

[0046] Preferably, the specific process of determining the ratio of sesame oil to water in the current production line formula in S2-1 is as follows: construct a 1:1 simulated production line, set different formulas, and preset different ratios of sesame oil to water. Then, for each formula and each candidate ratio cross combination, conduct simulation tests according to the steps in S2-1 to S2-3.

[0047] After emulsification, equal amounts of emulsion were placed in sealed containers and left to stand at a constant temperature of 25°C. The state after standing for different durations was recorded, and stability indicators were collected. The emulsion system was continuously monitored using a laser particle size analyzer, with the detection range set to 0.1–10 μm, and the particle size distribution of oil droplets in the emulsion was collected.

[0048] Simultaneously collect atomization effect indicators after atomization, analyze the influence of different sesame oil to water ratios on key quality attributes under each formula, and based on the degree of influence, select an optimal sesame oil to water ratio range for each formula. Solidify the mapping relationship between the optimal sesame oil to water ratio range and the formula into a ratio decision rule library.

[0049] The stability indicators mentioned above include the stable retention rate and the duration of uniform system maintenance.

[0050] Particle size distribution indicators include particle size distribution concentration factor and the proportion of fine particles, with fine particles being oil droplets with a diameter of less than 1 μm.

[0051] Atomization performance indicators include the uniformity of atomized particles and the effective coverage area of ​​atomization.

[0052] The specific data collection processes for stability indicators, particle size distribution indicators, and atomization effect indicators are all existing technologies and will not be elaborated here.

[0053] The analysis process for the degree of influence is as follows: Stability index, particle size distribution index, and atomization effect index are used as key quality attributes. The deviation coefficients of each key quality attribute under different sesame oil to water ratios for each formulation are calculated. Each deviation coefficient is normalized by dividing the deviation coefficient of a single key quality attribute by the sum of the deviation coefficients of all key quality attributes. The result is used as the evaluation weight for the corresponding key quality attribute. The detection values ​​of the stability index, particle size distribution index, and atomization effect index are then normalized separately. The normalized index values ​​are multiplied by their respective weights, and the weighted sum is used to obtain the comprehensive quality coefficient corresponding to different sesame oil to water ratios for each formulation. Multiple sesame oil to water ratios with comprehensive quality coefficients greater than a preset quality threshold are selected and integrated to form a continuous and reasonable range, which is used as the optimal sesame oil to water ratio range for the current formulation. The deviation coefficient is calculated using existing technology: Deviation coefficient = Standard deviation ÷ Arithmetic mean.

[0054] The formula and ratio decision rule library in the current production line are compared to obtain the optimal range of sesame oil to water ratio in the current production line formula, which is used as the ratio of sesame oil to water in the current production line formula.

[0055] S2-2. The homogeneous emulsion system is dispersed into fine droplets through an atomizing nozzle under uninterrupted flow conditions and continuously sprayed into a granulation pot containing the material after the crushing process; the atomizing pressure and spray rate are dynamically matched with reference to the atomizing control parameter reference table.

[0056] It should be noted that the process of constructing and setting the atomization control parameter reference table is consistent with the process of setting the pre-pulverization control parameter table, and will not be repeated here. The atomization control parameters include at least atomization pressure and spray rate.

[0057] S2-3. While the material is being atomized and sprayed, the mechanical action of the granulation pot is controlled to keep the material in a state of continuous agitation, so that it can be evenly coated and bonded by the atomized droplets; the granulation intensity is controlled by referring to the granulation control reference table.

[0058] Mechanical actions include stirring, cutting, or fluidizing air. Granulation intensity includes stirring speed, cutting speed, air volume, or air temperature. The process for constructing and setting up the granulation control reference table is consistent with the process for setting up the pre-grinding control parameter table, and will not be repeated here.

[0059] S2-4. Real-time acquisition of wet particle size data through particle size sensor. When the wet particle size is detected to be within the preset particle size range and the particle size deviation coefficient is less than the preset deviation coefficient threshold, the wet particles are determined to be uniform and the emulsification granulation control step is completed.

[0060] The wet particle size data includes wet particle size and particle size deviation coefficient, etc.

[0061] Among them, steps S2-1 to S2-3 are carried out in time: after the emulsion system is prepared, it is immediately transferred to atomization spraying. Atomization spraying and synchronous granulation are carried out simultaneously in the same granulation pot, and the process parameters of each step are not set independently.

[0062] Step 3, Drying Control: The wet particles are dried using a thermally conductive molten medium vacuum program temperature and pressure reduction method, with real-time monitoring of drying parameters until drying is complete.

[0063] In a specific embodiment, the specific process of step 3 is as follows: S3-1, using a heat-conducting molten medium as the heat transfer medium, heat is transferred to the wet particles through the jacket or internal heat exchange element of the drying equipment.

[0064] It should be noted that the temperature fluctuation range of the wet particles does not exceed ±2℃ of the preset temperature value to ensure that the heat-sensitive aroma components in the sesame oil do not undergo significant degradation or volatilization.

[0065] The heat transfer medium is any one or more combinations of heat transfer oil, high-temperature circulating water, ethylene glycol aqueous solution, or steam.

[0066] S3-2. Based on the change law of moisture content of wet granules and the heat-sensitive characteristics of sesame oil, the drying process is divided into several temperature control stages. The temperature setpoint, heating rate and holding time of each stage are related to each other and together form a continuous temperature control curve, and then corresponding control is carried out.

[0067] It should be noted that, following typical drying kinetics, the temperature control stage is divided into a preheating and equalization stage, a constant-rate drying stage, a falling-rate drying stage, and a final drying equilibrium stage. The specific division is existing technology and will not be elaborated here.

[0068] For example, in the preheating and temperature equalization stage: 30→40℃, linear temperature increase, rate ≤1℃ / min; by utilizing the boiling point of water to drop to a rough vacuum state of about 85~90℃, the surface evaporation rate is reduced and thermal shock is avoided; the initial temperature is close to room temperature to prevent condensation, and the final temperature is close to the wet bulb temperature to guide a gentle transition.

[0069] Constant-rate drying stage: 40~45℃ (constant temperature), 50~60kPa; in this stage, all the heat is used to evaporate water, and the surface temperature of the material is maintained at the wet-bulb temperature; the pressure is combined to lower the boiling point to about 60~70℃, and the temperature difference drives the evaporation rate, so that the material does not heat up additionally, thus protecting the heat-sensitive aroma.

[0070] Decreasing drying stage: 45→50℃ (stepwise temperature increase, 2~3℃ per step), 20~40kPa; in the early stage of decreasing speed, capillary force is dominant, and appropriate temperature increase can only slightly improve the driving force; in the later stage of decreasing speed, diffusion control is required, and moderate temperature increase is needed to improve the diffusion coefficient of water molecules, but the temperature is strictly controlled at ≤50℃ throughout the process to avoid the heat-sensitive damage threshold of sesame oil.

[0071] Final drying equilibrium stage; 50℃ (constant temperature), 5~10kPa; utilizing the boiling point of water to drop to an ultimate vacuum of about 33℃, the boiling point is reduced to the maximum extent by utilizing the vacuum, and the bound water is deeply removed below 50℃, while residual gas and volatile substances in the particle pores are discharged to protect the emulsion layer structure.

[0072] During the constant-rate drying stage, the material temperature is maintained at 40-45℃, and the surface temperature is close to the wet-bulb temperature of air (approximately 30-35℃). The volatilization rate of sesame oil aroma components at room temperature is very low, and the loss is negligible. During the falling-rate drying stage, the material temperature gradually rises to 50℃. At this temperature, the loss rate of characteristic sesame oil aroma components may still be below the detection limit, but the loss begins to accelerate above 65-75℃. In the final drying equilibrium stage, the temperature is maintained at 50℃. At this temperature, the release of total volatile organic compounds from sesame oil is typically very low, and the aroma retention rate can reach a relatively high level.

[0073] The above examples are merely illustrative examples provided to facilitate understanding of the present invention and do not constitute a limitation on the scope of protection of the present invention.

[0074] For example, the temperature setpoints, heating rates, and holding times for each stage are determined using the following method: First, single-factor experiments are used to determine the feasible range of each parameter; then, response surface methodology is used to establish a quadratic regression model of aroma retention rate, drying rate, and color difference with temperature and pressure; with aroma retention rate ≥ preset retention rate threshold and color difference ≤ preset color difference as constraints, and maximizing the drying rate as the optimization objective, the quadratic regression model is solved to obtain the temperature setpoint (i.e., the optimal temperature) and pressure combination; based on the average drying rate under this optimal combination and the amount of moisture to be removed in this stage, the holding time = moisture content ÷ average drying rate; the heating rate is set to 0.8~1.2℃ / min based on the heat balance and material uniformity requirements of the preheating stage. The specific calculation process of parameter fitting and model optimization is prior art and will not be elaborated here.

[0075] The temperature is set at each stage to segmented target temperatures. The temperature rises linearly and uniformly from the end temperature of the previous stage to the target temperature of the current stage according to the preset heating rate. After the target temperature is reached, the temperature is maintained at a constant holding temperature for a preset holding time. The single-stage heating segment and the constant-temperature holding segment are connected in sequence, with each stage transitioning continuously without temperature abrupt changes. The segments are connected in series to form a complete, continuous and segmented controllable temperature control curve.

[0076] It should be noted that the initial material before drying and the finished material after each drying stage were used to enrich the characteristic aroma components of sesame oil using headspace solid-phase microextraction. The aroma components were qualitatively and quantitatively detected by gas chromatography, and the initial content of characteristic aroma components in the initial material and the remaining content of characteristic aroma components in the dried material were determined respectively. The aroma retention rate = the remaining content of characteristic aroma components after drying ÷ the initial content of characteristic aroma components × 100%.

[0077] S3-3. Simultaneously implement pressure reduction control during the drying process to lower the boiling point of water and maintain the evaporation rate.

[0078] Preferably, the specific process of S3-3 is as follows: First, extract the upper and lower limits of temperature and pressure for each stage, treat the temperature of each stage as an independent factor, treat the pressure of each stage as an independent factor, and select n parameters based on the upper and lower limits of temperature and pressure to form an orthogonal array such as L27(n^8).

[0079] According to the orthogonal array arrangement, drying experiments were conducted for each set of parameters. The same batch of wet granules was used in each experiment. After the drying experiment was completed, the drying effect data was measured. The drying effect data included multiple effect parameters in each stage. The effect parameters included total drying time, retention rate of characteristic aroma components of sesame oil, color difference, free sesame oil exudation rate, uniformity of granule moisture content, and granule breakage rate.

[0080] For each effect parameter, a quadratic regression model is established with temperature and pressure as independent variables, and contour plots are drawn. The contour plots of multiple effect parameters in the same stage are superimposed on the same temperature-pressure plane plot, and the intersection of the superimposed areas is the temperature-pressure feasible region that satisfies all drying effects in that stage. The center of the feasible region is used as the standard setpoint for that stage. When there are conflicts between different effect parameters, a single feasible region may not exist. In this case, Pareto front analysis is used to determine the standard setpoint.

[0081] It should be noted that conflicts exist: for example, high retention rates require low temperature and low pressure, but short drying times require high temperature and low pressure. A single feasible domain may not exist: no single set of parameters can simultaneously maximize all indicators. The Pareto frontier analysis method is existing technology and will not be elaborated upon here.

[0082] The initial drying effect data and the final drying effect data in each stage are used as the input state vector and output state vector, respectively. Temperature and pressure are used as the operating variables. The transfer function in each stage is established by multivariate nonlinear fitting. The transfer functions of the four stages are cascaded to obtain the cascaded model.

[0083] The initial drying effect data of wet particles is extracted, and the optimal sequence of operating variables is predicted by the cascade model as the standard setpoint for each stage. At the end of each stage, the drying effect data is measured by online sensors and compared with the predicted value of the cascade model. If the deviation exceeds the preset allowable threshold, the correction algorithm is activated: extended Kalman filtering or rolling time domain estimation is used to back-infer the unmeasured disturbances in the model, and the sequence of operating variables for the remaining stages is re-optimized before control is implemented.

[0084] S3-4. Real-time temperature is collected by inserting a temperature sensor. When the real-time temperature deviates from ±2℃ of the temperature control curve, the flow rate or temperature of the heat transfer medium is automatically adjusted to keep the material temperature within the preset process window. Real-time monitoring is conducted by a vacuum sensor. When the pressure fluctuation exceeds ±2kPa, the pumping speed of the vacuum pump or the opening of the gas supply valve is automatically adjusted.

[0085] S3-5. Drying is considered complete if all of the following conditions are met: (1) The moisture content of the particles is within the preset acceptable moisture content range; (2) The color uniformity parameter is within the preset color uniformity parameter range; (3) The retention rate of the characteristic aroma components of sesame oil is greater than the preset retention rate threshold; (4) The free sesame oil seepage rate is less than the preset seepage rate threshold.

[0086] Color uniformity parameters, including color difference and lightness, were collected using a colorimeter. The mass difference of the granule sample before and after drying was determined by sampling and weighing combined with a constant-temperature drying method. The moisture content of the granules was then calculated by dividing the difference by the previous mass. A fixed quantity of the granules was taken and subjected to room-temperature centrifugation or rapid extraction with organic solvents to fully extract the sesame oil from the surface of the granules and the free sesame oil that had seeped out. The extracted / leached oil was collected and weighed, and the moisture content was calculated based on the ratio of the free sesame oil mass to the total mass of the granules.

[0087] Step 4, Cooling Control: The dried material is fed into a double-layer food-grade conveyor belt and circulated and blown by clean air until cooling is complete.

[0088] In a specific embodiment, the specific process of step 4 is as follows: S4-1, the dried material is transferred to the double-layer food-grade conveyor belt cooling device through a sealed conveying device. The double-layer food-grade conveyor belt is arranged in an up-down staggered manner, with the upper layer for feeding and the lower layer for discharging. The dried material receives the discharge from the drying equipment at the beginning of the upper conveyor belt and flows sequentially through the upper conveyor belt → material drop transition device → lower conveyor belt → discharge port during the conveying process.

[0089] S4-2. Clean airflow blowing devices are installed in sections from the feed end to the discharge end of the conveyor belt. The airflow direction is set to blow vertically towards the material layer, blow horizontally, or a combination of both. The cooling area is divided into several temperature sections along the conveying direction. The air supply temperature, air volume, and air speed of each section are independently controlled based on the real-time feedback of the material temperature.

[0090] In the above, the supply air temperature control is as follows: based on the real-time temperature deviation of the material in the corresponding section, the heat exchange load of the heat exchange unit in this section is independently adjusted, thereby changing the supply air temperature of the clean airflow; the air volume control is as follows: by individually adjusting the operating frequency of the fan in each section or the opening of the pipeline regulating valve, the total supply air volume of this section is independently controlled; the air velocity control is as follows: under a fixed air outlet structure, combined with the linkage adjustment of the section air pressure and the air outlet guide opening, the blowing air velocity of this section can be independently adjusted; the above specific adjustment methods are all conventional technical means in this field and will not be described in detail here.

[0091] S4-3. Cooling is considered complete if all of the following conditions are met: (1) The material temperature is within the preset cooling temperature range; (2) The moisture content is within the preset acceptable moisture content range; (3) The color uniformity parameter is within the preset color uniformity parameter range and the appearance is undamaged; (4) The particle repose angle is ≤ the preset repose angle threshold.

[0092] The particle repose angle was collected using the fixed funnel stacking method. The particles were naturally stacked to form a stable pile, and the stacking height and bottom radius were measured and calculated. The specific detection operation is existing technology and will not be described in detail here.

[0093] Step 5, Overall Mixing Control: The cooled materials and auxiliary materials are fed into a two-dimensional continuous mixing device according to a preset ratio. The mixing parameters are controlled to achieve continuous mixing until the mixture is uniform.

[0094] In a specific embodiment, the specific process of step 5 is as follows: S5-1, before mixing, a detachable low-shear auxiliary mixing element is set inside the cylinder to perform mirror polishing on the inner wall of the cylinder of the two-dimensional continuous mixing device, and the surface roughness of the inner wall of the cylinder is controlled to meet the standard.

[0095] For example, the specific content of achieving the standard for the surface roughness of the inner wall of the cylinder is as follows: The same batch of cooled, uniformly sized sesame oil-containing particles are divided into several experimental groups, with each group having the same amount of material. Each group of material is then fed into a two-dimensional continuous mixing device with different inner wall surface roughnesses for mixing, while keeping other parameters consistent.

[0096] During the mixing process, data on content uniformity, particle size distribution consistency, flowability, and appearance were monitored. Then, a roughness-quality index relationship curve was plotted with the content uniformity, particle size distribution consistency, flowability, and appearance data as the ordinate and the roughness of the inner wall of the cylinder as the abscissa. The comprehensive score S for each group was calculated, and the maximum roughness value that satisfies S ≤ comprehensive score threshold was selected as the upper limit of roughness. Controlling the surface roughness of the inner wall of the cylinder to be less than the upper limit of roughness is considered to meet the standard.

[0097] It should be noted that the calculation process for the comprehensive score is as follows: the content uniformity data, particle size distribution consistency data, flowability data, and appearance data are all subjected to dimensionless normalization, and the mean values ​​are calculated to obtain the comprehensive score.

[0098] The data on content uniformity include the relative standard deviation of the effective ingredient content and the pass rate of content uniformity; the data on particle size distribution consistency include the proportion of qualified particle size and the particle size deviation coefficient; the data on flowability include the particle angle of repose and compressibility; and the data on appearance include surface smoothness and color difference. The detection and data acquisition methods for the above parameters are all existing conventional techniques in this field and will not be elaborated upon here.

[0099] Dimensionless normalization: The reverse and forward parameters are calculated using reverse range normalization and forward range normalization respectively, and then uniformly converted into dimensionless normalized values ​​in the interval of 0 to 1, eliminating the differences in the dimensions and magnitudes of different parameters.

[0100] S5-2. A continuous feeding device and a continuous discharging device are added to the feeding port and the discharging port of the two-dimensional continuous mixing equipment, respectively. The front end of the two-dimensional continuous mixing equipment is sealed and connected to the discharge port of the cooling conveyor belt. After the material is cooled, it is directly fed into the feeding port of the mixer through the closed conveying pipeline and the quantitative feeding device. The auxiliary materials are added continuously or by a micro feeder according to the flowability.

[0101] S5-3. Extract material characteristics and mixing uniformity targets, set up a mixing decision rule base, determine rotation frequency, oscillation frequency and the cooperative relationship between rotation and oscillation, and then carry out cooperative control.

[0102] It should be noted that the setup process for the hybrid decision rule base is the same as that for the proportional decision rule base, and will not be repeated here.

[0103] S5-4. Monitor the material temperature during the mixing process in real time and automatically adjust the rotation frequency and oscillation frequency according to the material temperature.

[0104] Specifically, when the material temperature is higher than the preset upper limit temperature, the rotation frequency and oscillation frequency of the mixing cylinder are reduced to reduce material friction and shear heat generation and avoid overheating of the material; when the material temperature is lower than the preset lower limit temperature, the rotation frequency and oscillation frequency are appropriately increased to accelerate material tumbling and heat exchange and ensure uniform mixing.

[0105] S5-5. Test the uniformity of content, consistency of particle size distribution, flowability and appearance. When all indicators are qualified, the mixture is judged to be uniform and the total mixing is stopped.

[0106] Appearance indicators include surface finish and color difference.

[0107] Among them, if the content uniformity index, particle size distribution consistency index, flowability index, and appearance index are within the preset qualified ranges for the content uniformity index, particle size distribution consistency index, flowability index, and appearance index, respectively, the corresponding index is judged to be qualified.

[0108] The examples described in this invention are not limited to the specific embodiments listed above. The examples are merely illustrative to facilitate understanding of the invention and do not constitute a limitation on the scope of protection of this invention. Any modifications, equivalent substitutions, etc., made within the spirit and principles of this invention should be included within the scope of protection.

[0109] The above description is merely an example and illustration of the concept of the present invention. Those skilled in the art can make various modifications or additions to the specific embodiments described or use similar methods to replace them, as long as they do not deviate from the concept of the invention or exceed the scope defined in this specification, they should all fall within the protection scope of the present invention.

Claims

1. A multi-process control method for processing traditional Chinese medicine preparations, characterized in that, The steps include the following: Step 1, Grinding control: According to the formula, group the raw materials into the premixing equipment and perform mixing, pre-grinding, sieving, remixing or ultra-fine grinding processes in sequence until the particle size of the ground material meets the standard. Step 2, Emulsification Granulation Control: Determine the ratio of sesame oil to water, mix the sesame oil and water in the ratio, and process them into a homogeneous emulsion system using a high-speed homogenization emulsification method. Then, atomize the emulsion system and spray it into the granulation pot, and simultaneously control the granulation parameters until the wet granules are uniform. Step 3, Drying Control: The wet particles are dried using a thermally conductive molten medium vacuum program temperature and pressure reduction method, with real-time monitoring of drying parameters until drying is complete; Step 4, Cooling Control: The dried material is fed into a double-layer food-grade conveyor belt and circulated and blown by clean air until cooling is complete; Step 5, Overall Mixing Control: The cooled materials and auxiliary materials are fed into a two-dimensional continuous mixing device according to a preset ratio. The mixing parameters are controlled to achieve continuous mixing until the mixture is uniform.

2. The multi-process control method for processing traditional Chinese medicine preparations according to claim 1, characterized in that, The specific process of step 1 is as follows: S1-1. Each raw material is homogenized and grouped according to its oil content and sugar content, into a high-toughness group and a regular group; S1-2, Pre-grinding: Start the premixing equipment, refer to the pre-grinding control parameter table, control the pre-grinding speed, and synchronously mix and pre-grind the raw materials after each group; at the same time, monitor the flowability, refer to the flow aid control table, and add flow aid according to the flowability; monitor the grinding status in real time until the fineness of the grinding material meets the standard; S1-3, Sieving: The pre-crushed material is automatically conveyed to the sieving device. Referring to the sieving control parameter table, the sieving speed and amplitude are controlled, and a screen of preset specifications is used for sieving. The qualified material is automatically sent to the re-mixing process; the unqualified material is automatically returned to the pre-crushing equipment for re-mixing and pre-crushing until it is qualified. S1-4. Remixing: All qualified materials after screening are sent to the remixing equipment. The mixing time and speed are controlled according to the mixing control parameter table. The mixing uniformity is monitored in real time by a near-infrared spectrometer. After the mixing uniformity meets the standard, the material automatically enters the ultrafine grinding process. S1-5. Ultrafine Grinding: Start the supersonic airflow pulverizer and introduce high-pressure, high-purity nitrogen gas with a purity ≥99.99% and a working pressure of 0.8-1.5MPa; refer to the ultrafine grinding control parameter table to control the airflow speed and use the adiabatic expansion characteristics of the gas to control the material temperature, and grind the material particle size to below 10μm to complete the grinding process.

3. The multi-process control method for processing traditional Chinese medicine preparations according to claim 2, characterized in that, The process for setting the pre-grinding control parameter table is as follows: First, the basic parameters of each raw material are preset. The raw materials are grouped according to their oil and sugar content, into a high-toughness test group and a normal test group. The raw materials in the high-toughness test group and the normal test group are put into the premixing equipment and started. Different pre-grinding speeds are set according to the gradient. The premixing equipment is controlled to rotate at each pre-grinding speed in sequence. Then, the premixing effect parameters are collected in real time using sensors. The mixing effect value of each group using different pre-grinding speeds is analyzed. The pre-grinding speed with the largest mixing effect value is selected as the reference pre-grinding speed for each group. In this way, the reference pre-grinding speed corresponding to the basic parameters of each raw material in the high-toughness test group and the normal test group is obtained as the pre-grinding control parameter table.

4. The multi-process control method for processing traditional Chinese medicine preparations according to claim 1, characterized in that, The specific process of step 2 is as follows: S2-1. Extract the formula from the current production line, and then determine the ratio of sesame oil to water in the formula of the current production line; mix sesame oil and water in proportion to form a stable oil-in-water emulsion, and use high-shear homogenization to obtain a homogeneous emulsion system. S2-2. The homogeneous emulsion system is dispersed into fine droplets through an atomizing nozzle under the condition of uninterrupted flow and continuously sprayed into a granulation pot containing the material after the crushing process. The atomization pressure and spray rate are dynamically matched with reference to the atomization control parameter reference table; S2-3. While the material is being atomized and sprayed, the mechanical action of the granulation pot is controlled to keep the material in a state of continuous agitation, so that it can be evenly coated and bonded by the atomized droplets; the granulation intensity is controlled by referring to the granulation control reference table. S2-4. Real-time acquisition of wet particle size data through particle size sensor. When the wet particle size is detected to be within the preset particle size range and the particle size deviation coefficient is less than the preset deviation coefficient threshold, the wet particles are determined to be uniform and the emulsification granulation control step is completed.

5. The multi-process control method for processing traditional Chinese medicine preparations according to claim 4, characterized in that, The specific process for determining the ratio of sesame oil to water in the current production line formula in S2-1 is as follows: Construct a 1:1 simulated production line, set different formulas, and preset different ratios of sesame oil and water. Then, for each formula and each candidate ratio cross combination, conduct simulation tests according to the steps in S2-1 to S2-3. After emulsification, equal amounts of emulsion were placed in sealed containers and left to stand at a constant temperature of 25°C. The state after standing for different durations was recorded, and stability indicators were collected. The emulsion system was continuously monitored using a laser particle size analyzer, with the detection range set to 0.1–10 μm, and the particle size distribution of oil droplets in the emulsion was collected. Simultaneously collect atomization effect indicators after atomization, analyze the influence of different sesame oil to water ratios on key quality attributes under each formula, and based on the degree of influence, select an optimal sesame oil to water ratio range for each formula. Solidify the mapping relationship between the optimal sesame oil to water ratio range and the formula into a ratio decision rule library. The formula and ratio decision rule library in the current production line are compared to obtain the optimal range of sesame oil to water ratio in the current production line formula, which is used as the ratio of sesame oil to water in the current production line formula.

6. The multi-process control method for processing traditional Chinese medicine preparations according to claim 1, characterized in that, The specific process of step 3 is as follows: S3-1. A heat-conducting molten medium is used as the heat transfer medium to transfer heat to the wet particles through the jacket or internal heat exchange element of the drying equipment. S3-2. Based on the change law of moisture content of wet granules and the heat-sensitive characteristics of sesame oil, the drying process is divided into several temperature control stages. The temperature setpoint, heating rate and holding time of each stage are related to each other and together form a continuous temperature control curve, and then corresponding control is carried out. S3-3. Simultaneously implement pressure reduction control during the drying process to lower the boiling point of water and maintain the evaporation rate; S3-4. Real-time temperature is collected by inserting a temperature sensor. When the real-time temperature deviates from ±2℃ of the temperature control curve, the flow rate or temperature of the heat transfer medium is automatically adjusted to keep the material temperature within the preset process window. Real-time monitoring is conducted by a vacuum sensor. When the pressure fluctuation exceeds ±2kPa, the pumping speed of the vacuum pump or the opening of the gas supply valve is automatically adjusted. S3-5. Drying is considered complete if all of the following conditions are met: (1) The moisture content of the particles is within the preset acceptable moisture content range; (2) The color uniformity parameter is within the preset color uniformity parameter range; (3) The retention rate of the characteristic aroma components of sesame oil is greater than the preset retention rate threshold; (4) The free sesame oil seepage rate is less than the preset seepage rate threshold.

7. The multi-process control method for processing traditional Chinese medicine preparations according to claim 6, characterized in that, The specific process of S3-3 is as follows: The temperature control stage includes the preheating and equalization stage, the constant-rate drying stage, the falling-rate drying stage, and the final drying equilibrium stage. First, the upper and lower limits of temperature and pressure for each stage are extracted. The temperature of each stage is taken as an independent factor, and the pressure of each stage is taken as an independent factor. Based on the upper and lower limits of temperature and pressure, n parameters are selected to form an orthogonal array such as L27(n^8). According to the orthogonal array, drying experiments were conducted for each set of parameters. The same batch of wet granules was used in each experiment. After the drying experiment was completed, the drying effect data was measured. The drying effect data included multiple effect parameters in each stage. The effect parameters included total drying time, retention rate of characteristic aroma components of sesame oil, color difference, free sesame oil exudation rate, uniformity of granule moisture content, and granule breakage rate. For each effect parameter, a quadratic regression model is established with temperature and pressure as independent variables, and contour plots are drawn. The contour plots of multiple effect parameters in the same stage are superimposed on the same temperature-pressure plane plot, and the intersection of the superimposed areas is the temperature-pressure feasible region that satisfies all drying effects in that stage. The center of the feasible region is used as the standard setpoint for that stage. When there are conflicts between different effect parameters, a single feasible region may not exist. In this case, Pareto front analysis is used to determine the standard setpoint. The initial drying effect data and the final drying effect data in each stage are used as the input state vector and output state vector, respectively. Temperature and pressure are used as the operating variables. The transfer function in each stage is established by multivariate nonlinear fitting. The transfer functions of the four stages are cascaded to obtain the cascaded model. The initial drying effect data of wet particles is extracted, and the optimal sequence of operating variables is predicted by the cascade model as the standard setpoint for each stage. At the end of each stage, the drying effect data is measured by online sensors and compared with the predicted value of the cascade model. If the deviation exceeds the preset allowable threshold, the correction algorithm is activated: extended Kalman filtering or rolling time domain estimation is used to back-infer the unmeasured disturbances in the model, and the sequence of operating variables for the remaining stages is re-optimized before control is implemented.

8. The multi-process control method for processing traditional Chinese medicine preparations according to claim 1, characterized in that, The specific process of step 4 is as follows: S4-1. The dried material is transferred to the double-layer food-grade conveyor belt cooling device through a sealed conveying device. The double-layer food-grade conveyor belt is arranged in an up-down staggered manner, with the upper layer for feeding and the lower layer for discharging. The dried material receives the discharge from the drying equipment at the beginning of the upper conveyor belt and flows sequentially through the upper conveyor belt → material drop transition device → lower conveyor belt → discharge port during the conveying process. S4-2. Clean airflow blowing devices are installed in sections from the feed end to the discharge end of the conveyor belt. The airflow direction is set to blow vertically towards the material layer, blow horizontally, or a combination of both. The cooling area is divided into several temperature zones along the conveying direction. The air supply temperature, air volume, and air speed of each zone are independently controlled based on the real-time feedback of the material temperature. S4-3. Cooling is considered complete if all of the following conditions are met: (1) The material temperature is within the preset cooling temperature range; (2) The moisture content is within the preset acceptable moisture content range; (3) The color uniformity parameter is within the preset color uniformity parameter range and the appearance is undamaged; (4) The particle repose angle is ≤ the preset repose angle threshold.

9. The multi-process control method for processing traditional Chinese medicine preparations according to claim 1, characterized in that, The specific process of step 5 is as follows: S5-1. Before mixing, a detachable low-shear auxiliary mixing element is installed inside the cylinder to perform mirror polishing on the inner wall of the cylinder of the two-dimensional continuous mixing equipment, and control the surface roughness of the inner wall of the cylinder to meet the standard. S5-2. A continuous feeding device and a continuous discharging device are added to the feeding port and the discharging port of the two-dimensional continuous mixing equipment, respectively. The front end of the two-dimensional continuous mixing equipment is sealed and connected to the discharge port of the cooling conveyor belt. After the material is cooled, it is directly fed into the feeding port of the mixer through a closed conveying pipeline and a quantitative feeding device. The auxiliary materials are added continuously or by a micro-feeder according to their flowability. S5-3. Extract material characteristics and mixing uniformity targets, set up a mixing decision rule base, determine rotation frequency, oscillation frequency and the cooperative relationship between rotation and oscillation, and then perform cooperative control. S5-4. Monitor the material temperature during the mixing process in real time and automatically adjust the rotation frequency and oscillation frequency according to the material temperature; S5-5. Test the uniformity of content, consistency of particle size distribution, flowability and appearance. When all indicators are qualified, the mixture is judged to be uniform and the total mixing is stopped.

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