In-situ control method for vacuum freeze-drying of traditional Chinese medicine preparation

Abstract

The application provides a traditional Chinese medicine preparation vacuum freeze-drying in-situ control method and relates to the freeze control technical field of traditional Chinese medicine preparations. According to dielectric parameters of different depths of collected materials in-situ, the application calculates characteristic coefficients representing internal density and water unevenness degree; the coefficients are compared with preset reference values, and the width and power of pulse heating are synchronously adjusted according to the deviation. Through calculation of the heterogeneous characteristic coefficients of the materials, the width and power of pulse heating are adjusted in real time, so that the heat in the materials is more uniform, and the loss of effective components caused by heat deviation of the materials is reduced.

Description

Technical Field

[0001] This application belongs to the field of freezing control technology for traditional Chinese medicine preparations, specifically relating to an in-situ control method for vacuum freeze-drying of traditional Chinese medicine preparations. Background Technology

[0002] Traditional Chinese medicine (TCM) reagents typically refer to intermediates or standard substances made from TCM herbs through extraction, separation, and concentration processes. These substances possess a certain content and uniformity of active ingredients and are often in the form of extract powders or freeze-dried powders, used as standardized materials for formulation preparation or quality analysis. Vacuum freeze-drying of TCM preparations is employed because, under low temperature and low pressure, water sublimates directly from ice crystals, maximizing the preservation of heat-sensitive active ingredients.

[0003] Existing pulsed energy supply technologies include two modes: external conduction and internal dielectric heating. For direct internal heating methods like microwave-assisted pulsed heating, the energy absorption uniformity varies due to the multi-component and heterogeneous nature of traditional Chinese medicine materials. Furthermore, differences in internal density and moisture content further amplify this non-uniformity, potentially leading to localized overheating and loss of the effective components of the traditional Chinese medicine materials. Summary of the Invention

[0004] To address the shortcomings of existing technologies, the purpose of this application is to provide an in-situ control method for vacuum freeze-drying of traditional Chinese medicine preparations, which solves the problem that when existing internal pulse heating technology is used for traditional Chinese medicine, uneven heating may occur due to the heterogeneity of the materials, which may easily lead to the loss of effective components.

[0005] Firstly, the objective of this invention can be achieved through the following technical solution: a method for in-situ control of vacuum freeze-drying of traditional Chinese medicine preparations, which is executed cyclically by a freeze-drying main control unit according to a fixed sampling cycle, including the following steps: Real-time acquisition of in-situ dielectric characteristic parameters of traditional Chinese medicine preparation materials, including the real part of the dielectric constant at different depths of the material. With dielectric loss factor ; Based on the real part of the dielectric constant at different depths of the material Standard deviation, calculate the heterogeneity coefficient within the material. ; According to the heterogeneity characteristic coefficient With preset benchmark coefficient The deviation is synchronously and dynamically corrected to adjust the pulse width and power amplitude of pulse heating.

[0006] In conjunction with the first aspect, in some implementations of the first aspect, the method further includes: the heterogeneous characteristic coefficients. The calculation formula is: In the formula, This represents the number of depth sampling points along the material's thickness direction. For the first The real part of the dielectric constant at each depth sampling point This is the average of the real part of the dielectric constant at all depth sampling points; The higher the value, the greater the degree of heterogeneity in the density and moisture content distribution within the material.

[0007] In conjunction with the first aspect, in some implementations of the first aspect, the method further includes: the pulse width correction is based on the effective penetration depth of the pulse heating. Achieve the effective penetration depth Based on real-time acquisition of dielectric loss factor The converted characteristic coefficient is obtained when the heterogeneity is high. When the pulse width is increased, the effective penetration depth is also increased simultaneously. .

[0008] In conjunction with the first aspect, in some implementations of the first aspect, the method further includes: the effective penetration depth. The calculation formula is: In the formula, The pulse angular frequency, The permeability of free space, The equivalent conductivity of the material; the equivalent conductivity of the material Dielectric loss factor With angular frequency The result is obtained through conversion.

[0009] In conjunction with the first aspect, in some implementations of the first aspect, the method further includes: a correction amount for the power amplitude. The calculation formula is: In the formula, As a preset baseline coefficient, This is the proportional correction factor.

[0010] In conjunction with the first aspect, in some implementations of the first aspect, the method further includes: a correction amount for the power amplitude. In, when the characteristic coefficient of a heterogeneous region is... Greater than the preset benchmark coefficient At that time, according to the correction amount Increase pulse power amplitude to compensate for insufficient energy in low-density, high-moisture areas; when the heterogeneous characteristic coefficient Less than the preset benchmark coefficient When this happens, the power amplitude should be reduced accordingly to avoid local overheating.

[0011] In conjunction with the first aspect, in some implementations of the first aspect, the method further includes: the in-situ dielectric characteristic parameters are obtained by a dielectric sensor array arranged below the shelf and collected at multiple points along the material thickness direction, with the real part of the dielectric constant ε′ and the dielectric loss factor ε″ being collected synchronously at each depth sampling point, the collection range covering the full thickness of the material, and the parameters being updated in real time with the drying process.

[0012] In conjunction with the first aspect, in some implementations of the first aspect, the method further includes: when the non-homogeneous characteristic coefficient δ is detected to exceed a preset upper limit threshold, the pulse width and power amplitude are simultaneously reduced to decrease the energy input per unit time.

[0013] Secondly, in order to achieve the above objectives, the present invention discloses a terminal device, including a memory, a processor, and a computer program stored in the memory and capable of running on the processor, wherein when the processor executes the computer program, it implements the method of the first aspect.

[0014] The beneficial effects of this application are: This invention obtains characteristic coefficients from in-situ collected dielectric data, compares them with standard characteristic coefficients, and adjusts the width and power of pulse heating in real time based on the difference. By adjusting the width, the depth of heat penetration into the material can be controlled, and by adjusting the power, energy can be supplemented to areas with high moisture content and low density, thus avoiding local overheating and degradation of the pharmaceutical components. At the same time, this technology can be adapted to different batches of traditional Chinese medicine. Attached Figure Description

[0015] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0016] Figure 1 This is a schematic diagram of the overall process of an embodiment of this application. Detailed Implementation

[0017] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0018] Example 1: Reference Figure 1As shown, this invention proposes an in-situ control method for vacuum freeze-drying of traditional Chinese medicine preparations. Taking an industrial vacuum freeze dryer as an example, the object to be processed is ginseng total saponin concentrate with a solid content of 25% and a density of 1.12 g / cm³. The material tray thickness is 15 mm, and the drying target is a final moisture content ≤3% and an effective component retention rate ≥92%.

[0019] First, configure the preset initial parameters: Fixed sampling period That is, the main control unit completes a complete cycle of data acquisition, calculation, and correction every 10 seconds; Number of depth sampling points in the material thickness direction Evenly distributed across the entire thickness of the material; preset reference coefficient. , serving as a reference value for pulse parameter correction; Power amplitude ratio correction factor ; Initial pulse width Initial pulse power amplitude Initial interval period ; Upper limit threshold of heterogeneous characteristic coefficients , as an abnormal protection trigger condition; Pulse angular frequency Vacuum permeability .

[0020] After the material is loaded onto the tray, it is sent into the freeze-drying chamber. After the chamber door is closed, the pre-freezing program is started: the temperature is reduced to -30℃ at a rate of 1℃ / min, and the temperature is maintained for 120 minutes to ensure that the material is completely frozen and the ice crystal distribution is stable. After the pre-freezing is completed, the main control unit automatically enters the in-situ control process.

[0021] At the start of each sampling cycle, the main control unit drives the dielectric sensor array arranged below the shelf to simultaneously collect data at five depth sampling points along the material thickness direction. Each sampling point simultaneously outputs the real part of the dielectric constant at that depth. With dielectric loss factor .

[0022] Taking the 100th sampling period as an example, the five sets of real parts of the dielectric constant obtained are as follows: , , , , The corresponding dielectric loss factors are as follows: , , , , .

[0023] The collected data is directly transmitted to the computing module of the main control unit, without the need for offline sampling, and the entire process is completed in situ.

[0024] Based on the real parts of the dielectric constant at five depths collected, the main control unit calculates the heterogeneity characteristic coefficients of the current material using the standard deviation formula. First, calculate the average value of the real part of the dielectric constant at all sampling points: Substitute into the formula for the characteristic coefficient of heterogeneity: Substituting the values, we get: The calculation obtained in this period Slightly smaller than the preset benchmark coefficient This indicates that the current material's internal density and moisture content are slightly less heterogeneous than the baseline level. The main control unit uses... and The deviation is a unified input, and the pulse width and power amplitude are corrected synchronously to ensure that the two parameters are matched in a coordinated manner to the heterogeneous state of the material.

[0025] First, based on the average value of the collected dielectric loss factor, the equivalent conductivity of the material is calculated. : Average dielectric loss factor ; Equivalent conductivity calculation formula: ,in Let be the vacuum permittivity, and take . ; Substituting, we get: ; Calculate the effective penetration depth of the pulse under the current material. : Substituting the values, we get: Due to the current Since the degree of heterogeneity is low, there is no need to increase the penetration depth. Therefore, the pulse width is finely adjusted from the initial 200ms to 195ms to maintain the penetration depth and match the heterogeneous stratification of the material, and to avoid excess energy. If the subsequent cycle Increase, such as Then according to For every 0.1 increase, the pulse width increases by 30ms proportionally, thereby increasing the effective penetration depth. The main control unit substitutes the values ​​into the power correction formula to calculate the power amplitude correction amount. : Substitution , , ,have to: This means that the pulse power amplitude in this cycle is reduced by approximately 2W, and the corrected power amplitude is... .

[0026] The corrected logic is: when hour, If positive, it increases the power amplitude to compensate for insufficient energy in low-density, high-moisture areas; when hour, A negative value reduces the power amplitude, preventing localized heat accumulation and overheating, and ensuring the retention rate of heat-sensitive components such as ginsenosides. This is calculated after each cycle. Then, synchronous comparison. With upper limit threshold : like Normally, the corrected pulse parameters are output to the heating execution unit, and the next sampling cycle begins; if The abnormal protection branch is triggered, and the main control unit synchronously reduces the pulse width by 30% and the power amplitude by 25% to reduce the energy input per unit time. Simultaneously, the vacuum level inside the chamber is increased by 5Pa to enhance mass transfer, preventing overheating collapse and degradation of active ingredients in the traditional Chinese medicine preparation due to localized energy overload. After falling below 1.2, it will gradually return to normal correction logic.

[0027] The main control unit synchronously calculates the overall moisture content of the material based on the real part of the average dielectric constant in each cycle. The mapping relationship between moisture content and the real part of the dielectric constant is pre-calibrated and stored in the main control unit. When the overall moisture content of the material is detected... And the non-homogeneous characteristic coefficient Stable for 3 consecutive sampling periods When the temperature is within the specified range, drying is considered complete.

[0028] In the description of this specification, the references to terms such as "an embodiment," "example," "specific example," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0029] The foregoing has shown and described the basic principles, main features, and advantages of this application. Those skilled in the art should understand that this application is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of this application. Various changes and modifications can be made to this application without departing from the spirit and scope thereof, and all such changes and modifications fall within the scope of the claims of this application.

Claims

1. A method for in-situ control of vacuum freeze-drying of traditional Chinese medicine preparations, characterized in that, The freeze-drying main control unit executes the process cyclically according to a fixed sampling period, including the following steps: Real-time acquisition of in-situ dielectric characteristic parameters of traditional Chinese medicine preparation materials, including the real part of the dielectric constant at different depths of the material. With dielectric loss factor ; Based on the real part of the dielectric constant at different depths of the material Standard deviation, used to calculate the heterogeneity coefficient within the material. ; According to the heterogeneity characteristic coefficient With preset benchmark coefficient The deviation is synchronously and dynamically corrected to adjust the pulse width and power amplitude of pulse heating.

2. The method for in-situ control of vacuum freeze-drying of traditional Chinese medicine preparations according to claim 1, characterized in that, The heterogeneous characteristic coefficient The calculation formula is: In the formula, This represents the number of depth sampling points along the material's thickness direction. For the first The real part of the dielectric constant at each depth sampling point This is the average of the real part of the dielectric constant at all depth sampling points; The higher the value, the greater the degree of heterogeneity in the distribution of density and moisture content within the material.

3. The method for in-situ control of vacuum freeze-drying of traditional Chinese medicine preparations according to claim 1, characterized in that, The pulse width correction is based on the effective penetration depth of the pulse heating. Achieve the effective penetration depth Based on real-time acquisition of dielectric loss factor The converted characteristic coefficient is obtained when the heterogeneity is high. When the pulse width is increased, the effective penetration depth is also increased simultaneously. .

4. The method for in-situ control of vacuum freeze-drying of traditional Chinese medicine preparations according to claim 3, characterized in that, The effective penetration depth The calculation formula is: In the formula, The pulse angular frequency, The permeability of free space, The equivalent conductivity of the material; the equivalent conductivity of the material Dielectric loss factor With angular frequency The result is obtained through conversion.

5. The method for in-situ control of vacuum freeze-drying of traditional Chinese medicine preparations according to claim 1, characterized in that, The power amplitude correction amount The calculation formula is: In the formula, As a preset baseline coefficient, This is the proportional correction factor.

6. The method for in-situ control of vacuum freeze-drying of traditional Chinese medicine preparations according to claim 5, characterized in that, The correction amount of the power amplitude In, when the non-homogeneous characteristic coefficient Greater than the preset benchmark coefficient At that time, according to the correction amount Increase pulse power amplitude to compensate for insufficient energy in low-density, high-moisture areas; when the heterogeneous characteristic coefficient Less than the preset benchmark coefficient When this happens, the power amplitude should be reduced accordingly to avoid local overheating.

7. The method for in-situ control of vacuum freeze-drying of traditional Chinese medicine preparations according to claim 1, characterized in that, The in-situ dielectric characteristic parameters are obtained by collecting data at multiple points along the material thickness direction through a dielectric sensor array arranged below the shelf. At each depth sampling point, the real part of the dielectric constant ε′ and the dielectric loss factor ε″ are collected simultaneously. The collection range covers the entire thickness of the material, and the parameters are updated in real time as the drying process progresses.

8. The method for in-situ control of vacuum freeze-drying of traditional Chinese medicine preparations according to claim 1, characterized in that, When the non-homogeneous characteristic coefficient δ is detected to exceed the preset upper limit threshold, the pulse width and power amplitude are simultaneously reduced to decrease the energy input per unit time.

9. A terminal device, comprising a memory, a processor, and a computer program stored in the memory and capable of running on the processor, characterized in that, When the processor executes the computer program, it implements the in-situ control method for vacuum freeze-drying of traditional Chinese medicine preparations as described in any one of claims 1 to 8.

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