Intelligent vacuum control device

Abstract

The invention relates to the technical field of freeze-drying equipment, and discloses an intelligent vacuum control device, which comprises a drying chamber for precooling and drying materials placed in the drying chamber, and a temperature sensor is arranged in the drying chamber; the air inlet valve is connected between the air source and the drying chamber and used for introducing inert gas into the drying chamber; the exhaust valve is connected to the connecting pipe between the cold trap and the drying chamber, the cold trap is further connected with the vacuum pump, and the exhaust valve is used for controlling the speed of exhausting gas outwards by the drying chamber; the vacuum degree detector is used for monitoring the vacuum pressure in the drying chamber in real time; and the control system is used for controlling the opening degrees of the air inlet valve and the exhaust valve so as to adjust the vacuum pressure in the drying chamber in real time. Local overheating or material form damage caused by too high sublimation rate can be prevented, drying efficiency reduction caused by sublimation rate reduction is avoided, and the material drying process tends to be stable; the fixed control mode of a traditional freeze dryer is changed, and the change of the vacuum degree in the drying chamber is quickly responded.

Description

Technical Field

[0001] This invention relates to the field of freeze-drying equipment technology, and more specifically, to an intelligent vacuum control device. Background Technology

[0002] Vacuum freeze-drying technology is widely used in the fields of medicine, food, and biological products because it can effectively preserve the biological activity, nutrients and original structure of materials. Its principle is to solidify water by pre-freezing, and then provide energy to the material by temperature control heating in a high vacuum environment, so that the ice directly sublimates into water vapor and is captured by an ultra-low temperature condenser, thereby achieving low-temperature dehydration.

[0003] While traditional freeze dryers can complete basic pre-cooling, sublimation drying, and desorption drying processes, their control methods are mostly based on programmed control of fixed time-temperature curves or manual adjustment relying on the operator's experience. They cannot achieve intelligent dynamic adjustment of parameters such as vacuum degree in the drying process, which may lead to insufficient drying or energy waste.

[0004] Therefore, it is necessary to propose an intelligent vacuum control device to at least partially solve the problems existing in the prior art. Summary of the Invention

[0005] The summary section introduces a series of simplified concepts, which will be further explained in detail in the detailed description section. The summary section of this invention is not intended to limit the key features and essential technical features of the claimed technical solution, nor is it intended to determine the scope of protection of the claimed technical solution.

[0006] To at least partially solve the above problems, the present invention provides an intelligent vacuum control device, comprising: A drying chamber is used to pre-cool and dry the materials placed inside it, and a temperature sensor is installed inside the drying chamber; The intake valve, connected between the gas source and the drying chamber, is used to introduce inert gas into the drying chamber. An exhaust valve is connected to the connecting pipe between the cold trap and the drying chamber. The cold trap is also connected to a vacuum pump. The exhaust valve is used to control the rate at which the gas is discharged from the drying chamber. A vacuum detector is used to monitor the vacuum pressure inside the drying chamber in real time. The control system is used to control the opening degree of the intake valve and exhaust valve to adjust the vacuum pressure in the drying chamber in real time.

[0007] Preferably, the vacuum detector includes: The Pirani vacuum gauge is used to monitor the vacuum pressure in the drying chamber in real time during the drying stage and feed it back to the control system to control the opening of the inlet and outlet valves. A capacitive vacuum gauge is used to monitor the vacuum pressure in the drying chamber in real time during the drying completion judgment stage and feed it back to the control system. The vacuum pressures monitored by the Pirani vacuum gauge and the capacitive vacuum gauge are compared to determine whether drying has ended.

[0008] Preferably, the drying chamber is provided with multiple shelves for placing materials, and multiple temperature sensors in the drying chamber are used to detect the temperature of the shelves and the materials in the drying chamber.

[0009] Preferably, the control system includes: The data acquisition module is used to continuously collect shelf temperature, material temperature, and vacuum pressure in the drying chamber during the drying stage using temperature sensors and vacuum detectors. The curvature calculation module is used to fit the collected vacuum pressure sequence within a preset time window, calculate the first and second derivatives of its change curve, and obtain the curvature of the vacuum pressure change. The curvature judgment module is used to compare the curvature of the vacuum pressure change in the current time window with the curvature of the vacuum pressure change in the previous time window to determine whether the temperature and vacuum pressure in the drying chamber need to be adjusted. The adjustment module adjusts the heating temperature of the shelf, the opening of the air inlet valve, and the opening of the air outlet valve based on the curvature and trend of the vacuum pressure change within the current time window, so as to keep the curvature of the vacuum pressure change within the set curvature range; wherein, the set curvature range is (-0.1, 0).

[0010] Preferably, the control system further includes: The end judgment module will enter the drying end judgment stage when the vacuum pressure in the drying chamber is lower than the set pressure and the curvature of the vacuum pressure change within the current time window is within the set curvature range. The first vacuum pressure and the second vacuum pressure of the Pirani vacuum gauge and the capacitive vacuum gauge will be automatically acquired. If the difference between the first vacuum pressure and the second vacuum pressure acquired multiple times within the set time is within the set deviation range, the drying stage will end.

[0011] Preferably, it also includes: a wireless data transmission module connected to the control system, used to transmit the collected shelf temperature, material temperature and vacuum pressure in the drying chamber to the remote monitoring terminal in real time, and to receive instructions from the remote control terminal.

[0012] Preferably, the shelf is provided with at least one fluid channel, and the drying chamber is provided with an inlet pipe and an outlet pipe that are connected to the heating system, and the fluid channel is connected to the inlet pipe and the outlet pipe respectively; The inner wall of the drying chamber is provided with at least one air inlet that is connected to the air inlet valve. After the inert gas enters through the air inlet, it first contacts the guide section for heat exchange.

[0013] Preferably, the flow guide is a shelf located on the top layer of the drying chamber and not containing any material, and the air inlet is located at the top of the drying chamber.

[0014] Preferably, the flow guide is a flow guide plate, which is disposed on the side of the inlet pipe or outlet pipe away from the shelf, and the air inlet is disposed on the side wall of the drying chamber; the connecting pipe is connected to the side of the drying chamber away from the flow guide plate.

[0015] Preferably, the deflector includes: The first arc-shaped guide vane has its concave side connected to the outer wall of the liquid inlet or liquid outlet pipe, and its convex side corresponding to the air inlet. Two second arc-shaped guide vanes are respectively set on both sides of the first arc-shaped guide vane, with the concave side of the second arc-shaped guide vane facing away from the shelf; The convex side of the first arc-shaped guide vane and the concave side of the second arc-shaped guide vane form a guide surface.

[0016] Compared with the prior art, the present invention has at least the following beneficial effects: The intelligent vacuum control device of this invention, during the drying stage, controls the opening of the inlet and outlet valves in real time according to the changes in vacuum pressure in the drying chamber through the control system. At the same time, it adaptively adjusts the heating temperature of the material, thereby preventing excessively rapid sublimation rate from causing local overheating or damage to the material's morphology, and avoiding a decrease in drying efficiency due to a reduced sublimation rate, thus making the material drying process more stable. It changes the fixed program control mode of traditional freeze dryers, and can quickly respond to changes in the vacuum degree in the drying chamber according to the vacuum pressure of the material during the drying process, thereby preventing melting or collapse caused by excessively high material temperature.

[0017] The intelligent vacuum control device described in this invention, along with other advantages, objectives, and features of this invention, will be partly apparent from the following description and partly understood by those skilled in the art through study and practice of the invention. Attached Figure Description

[0018] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used in conjunction with embodiments of the invention to explain the invention and do not constitute a limitation thereof. In the drawings: Figure 1 This is a schematic diagram of the intelligent vacuum control device described in this invention; Figure 2This is a schematic diagram showing the connection relationship between the control system and various components in the intelligent vacuum control device described in this invention; Figure 3 This is a schematic diagram of a first implementation of the flow guide in the intelligent vacuum control device of the present invention; Figure 4 This is a schematic diagram of a second implementation of the flow guide in the intelligent vacuum control device of the present invention; Figure 5 This is a top view of the structure of the guide plate installed in the drying chamber of the intelligent vacuum control device described in this invention. Figure 6 This is a top view of the guide plate in the intelligent vacuum control device of the present invention. Detailed Implementation

[0019] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments, so that those skilled in the art can implement it based on the description.

[0020] It should be understood that terms such as “having,” “comprising,” and “including” as used herein do not exclude the presence or addition of one or more other elements or combinations thereof.

[0021] like Figures 1-2 As shown, the present invention provides an intelligent vacuum control device, comprising: Drying chamber 2 is used to pre-cool and dry the materials placed inside it, and a temperature sensor 3 is installed inside the drying chamber 2; Inlet valve 1 is connected between the gas source and the drying chamber 2 and is used to introduce inert gas into the drying chamber 2; An exhaust valve 5 is connected to a connecting pipe 4 between the cold trap 7 and the drying chamber 2. The cold trap 7 is also connected to a vacuum pump 6. The exhaust valve 5 is used to control the speed at which the drying chamber 2 discharges gas. A vacuum detector is used to monitor the vacuum pressure inside drying chamber 2 in real time. The control system is used to control the opening degree of the inlet valve 1 and the exhaust valve 5 to adjust the vacuum pressure in the drying chamber 2 in real time.

[0022] The inlet valve 1 can be a micro-inlet valve or a control valve that can precisely control the amount of inert gas introduced into the drying chamber 2. The inert gas can be nitrogen. The exhaust valve 5 can be an electric butterfly valve, which can connect or close the cold trap 7 and the drying chamber 2, and can adjust the opening to control the exhaust speed when connected. The vacuum pump 6 is used to evacuate the drying chamber 2 and simultaneously pump sublimated water vapor into the cold trap 7. The vacuum detector can monitor the vacuum level in the drying chamber 2 to obtain the changes in vacuum pressure in the drying chamber 2, and realize intelligent control of temperature and vacuum pressure.

[0023] Vacuum drying of materials is mainly divided into three stages. The first stage is pre-cooling, which involves completely freezing the moisture in the material into ice crystals. The second stage is primary drying / sublimation drying, where the pre-frozen ice crystals, under low vacuum conditions, provide enough heat to directly sublimate into water vapor. This allows the ice to sublimate rapidly at low temperatures. The water vapor is extracted by vacuum pump 6 and then captured by cold trap 7 (i.e., condenser). The large amount of water vapor produced by sublimation flows to the even cooler cold trap 7, causing it to liquefy. The third stage is secondary drying / desorption drying, where, under high vacuum conditions, the heating temperature of the material in drying chamber 2 is further increased. The heat provided breaks the binding force between water molecules and the material, allowing the water to be extracted. During the drying stage, the control system controls the opening of the inlet valve 1 and the exhaust valve 5 in real time based on the changes in vacuum pressure in the drying chamber 2. At the same time, it also needs to make adaptive adjustments to the heating temperature of the material to prevent excessively rapid sublimation rate from causing local overheating or damage to the material's morphology, and to avoid a decrease in drying efficiency due to a reduced sublimation rate, thus ensuring that the material drying process can tend to be stable. This changes the fixed program control mode of traditional freeze dryers, and can quickly respond to changes in the vacuum degree in the drying chamber 2 according to the vacuum pressure of the material during the drying process, thereby preventing melting or collapse caused by excessively high material temperature.

[0024] like Figure 2 As shown, in one embodiment, the vacuum detector includes: The Pirani vacuum gauge 8 is used to monitor the vacuum pressure in the drying chamber 2 in real time during the drying stage and feed it back to the control system to control the opening of the inlet valve 1 and the exhaust valve 5. The capacitive vacuum gauge 9 is used to monitor the vacuum pressure in the drying chamber 2 in real time during the drying end judgment stage and feed it back to the control system to compare the vacuum pressures monitored by the Pirani vacuum gauge 8 and the capacitive vacuum gauge 9 to determine whether drying has ended.

[0025] The drying stage and the drying completion judgment stage refer to the first drying / sublimation drying.

[0026] The Pirani vacuum gauge 8 measures vacuum by detecting changes in gas thermal conductivity; the capacitive vacuum gauge 9 measures vacuum by utilizing changes in capacitance, based on the influence of pressure changes on the physical properties of the capacitive sensing element. During the drying stage, when real-time monitoring of the vacuum pressure in the drying chamber 2 is required, the data collected by the Pirani vacuum gauge 8 is used as the basis for the control system. In the drying end judgment stage, the vacuum pressure monitored by both vacuum gauges is used to determine whether drying has ended, which can accurately determine the endpoint of the first drying / sublimation drying, thus automatically entering the second drying / desorption drying stage. Compared to traditional freeze dryers that operate under a fixed program control mode (e.g., a drying / sublimation drying time set to 5 hours per cycle), this invention can determine whether drying is complete, thus avoiding the waste of energy and time caused by over-drying.

[0027] In one embodiment, the drying chamber 2 is provided with a plurality of shelves 10 for placing materials, and a plurality of temperature sensors 3 in the drying chamber 2 are used to detect the temperature of the shelves 10 and the materials in the drying chamber 2.

[0028] Multiple temperature sensors 3 are configured to detect the real-time temperature of the partition 10 and the material and feed it back to the control system. The control system then adjusts the heating temperature of the shelf 10 in real time according to the changes in vacuum pressure to match the vacuum pressure in the drying chamber 2, ensuring that the material drying process can be stable and improving the drying quality of the material.

[0029] In one embodiment, the control system includes: The data acquisition module is used to continuously collect the temperature of the shelf 10, the material temperature, and the vacuum pressure in the drying chamber 2 through the temperature sensor 3 and the vacuum detector during the drying stage. The drying stage refers to the primary drying / sublimation drying stage; The curvature calculation module is used to fit the collected vacuum pressure sequence within a preset time window, calculate the first and second derivatives of its change curve, and obtain the curvature of the vacuum pressure change. The time window can be, for example, 120 seconds. The first and second derivatives of the vacuum pressure change curve are calculated within 120 seconds. The first derivative refers to the rate of change of vacuum pressure, and the second derivative refers to the acceleration of the change of vacuum pressure. The acceleration is the curvature of the vacuum pressure change, which reflects the trend of the rate of water vapor escape per unit time. The curvature calculation module calculates the curvature of the vacuum pressure change curve at a fixed period (e.g., every minute or every 120 seconds, depending on the actual situation). The curvature judgment module is used to compare the curvature of the vacuum pressure change in the current time window with the curvature of the vacuum pressure change in the previous time window to determine whether the temperature and vacuum pressure in the drying chamber 2 need to be adjusted. Specifically, if the curvature in the current time window is consistently lower than or equal to the curvature in the previous time window, it indicates that the water vapor escape is stabilizing and the drying process is stable. In this case, it is sufficient to maintain the current heating temperature of shelf 10 and the current opening of inlet valve 1 and exhaust valve 5 without adjustment. If the curvature in the current time window is greater than the curvature in the previous time window, it indicates that the current heating temperature and vacuum pressure in drying chamber 2 are not optimal, which may cause changes in material quality or a decrease in drying speed. In this case, it is necessary to adjust the heating temperature of shelf 10, the opening of inlet valve 1, or the opening of exhaust valve 5. The adjustment module adjusts the heating temperature of shelf 10, the opening of air inlet valve 1, and the opening of exhaust valve 5 based on the curvature and trend of vacuum pressure change within the current time window, so as to keep the curvature of vacuum pressure change within the set curvature range; wherein, the set curvature range is (-0.1, 0).

[0030] Specifically, the adjustment module adjusts the heating temperature of shelf 10, the opening of air inlet valve 1, and the opening of exhaust valve 5 based on the current curvature and trend and optimization algorithms (such as PID control, fuzzy control logic, or gradient descent method) so that the curvature is maintained at a negative value close to zero, that is, within the set curvature range, so that water vapor can sublimate from the material at the most efficient and stable rate. For example, the adjustment process of the adjustment module can be as follows: if the curvature remains stable within the set curvature range (-0.1, 0), then maintain the current opening of the exhaust valve 5 and the heating temperature of the shelf 10. If the curvature increases positively and exceeds the positive threshold (e.g., curvature greater than 0.5), it indicates that the sublimation rate is too fast, which may lead to local overheating or product shape damage. At this time, the heating temperature of the shelf 10 will be lowered or the opening of the air inlet valve 1 will be increased to make the sublimation process more stable. If the curvature increases negatively and exceeds the negative threshold (e.g., curvature less than -0.5), it indicates that the sublimation rate is decreasing and the drying efficiency is decreasing. At this time, the heating temperature of the shelf 10 will be increased or the opening of the air inlet valve 1 will be reduced (or the opening of the exhaust valve 5 will be increased to enhance the suction speed) in order to provide more energy to increase the sublimation rate. This ensures that the drying stage can always maintain optimal drying efficiency and the most stable sublimation rate, guaranteeing both drying efficiency and drying quality.

[0031] The aforementioned control system can form a closed-loop feedback control, achieving dynamic and adaptive control throughout the entire primary drying / sublimation drying stage, so that the heating temperature and vacuum pressure in drying chamber 2 can both reach the optimal level, ensuring the drying quality of the material while guaranteeing drying efficiency and saving energy.

[0032] In one embodiment, the control system further includes: The end judgment module is activated when the vacuum pressure in the drying chamber 2 is lower than the set pressure (e.g., 10 Pa to 20 Pa) and the curvature of the vacuum pressure change within the current time window is within the set curvature range. Then, the drying end judgment stage is entered. The first vacuum pressure and the second vacuum pressure of the Pirani vacuum gauge 8 and the capacitive vacuum gauge 9 are automatically acquired. If the difference between the first vacuum pressure and the second vacuum pressure acquired multiple times within the set time (e.g., 60 seconds) is within the set deviation range, then the drying stage ends.

[0033] Specifically, after detecting the initial conditions (the vacuum pressure in the drying chamber 2 is lower than the set pressure, and the curvature within the current time window is within the set curvature range), the end judgment module enters the drying end judgment stage. The inlet valve 1 and the exhaust valve 5 are closed, which is the confirmation window period. During this period, the values ​​of the Pirani vacuum gauge 8 and the capacitive vacuum gauge 9, namely the first vacuum pressure and the second vacuum pressure, are acquired synchronously at a set period (e.g., every 20 seconds). At least three sets of data are collected. Then, the moving average of the curvature within the confirmation window period is continuously calculated to ensure that the curvature remains stable (e.g., the standard deviation of the moving average of the curvature is less than 0.05, indicating that the curvature is stable). Then, the first vacuum pressure and the second vacuum pressure in multiple sets of data are compared respectively. The difference between the two can be used for judgment. If the difference between the first vacuum pressure and the second vacuum pressure obtained multiple times within a set time (e.g., 60 seconds) is within the set deviation range, then the drying stage ends. Alternatively, the relative difference between the two can be used to make a judgment, that is... , First vacuum pressure Second vacuum pressure The relative difference parameter is then set with a dynamic threshold. The dynamic threshold is adaptively adjusted based on the vacuum pressure. When the vacuum pressure is lower than the set pressure, the dynamic threshold is set to 5%. If the ambient temperature fluctuation (obtained by a temperature detector set outside the drying chamber 2) exceeds its set fluctuation range (e.g., exceeding ±2℃), the dynamic threshold is set to 3% to reduce the influence of ambient temperature on the vacuum gauge detection. In multiple sets of data, when the following conditions are met When the percentage of groups with the first and second vacuum pressures corresponding to the dynamic threshold is equal to or greater than 80% (for example, if there are 5 data sets and 4 of them meet the requirement), then the drying stage is confirmed to be over.

[0034] In one embodiment, it further includes: a wireless data transmission module connected to the control system, used to transmit the collected shelf 10 temperature, material temperature and vacuum pressure in the drying chamber 2 to a remote monitoring terminal in real time, and to receive instructions from the remote control terminal.

[0035] The wireless data transmission module can transmit all data of the drying process to a remote monitoring terminal or cloud server, which facilitates remote monitoring and fault warning of the freeze dryer. It can also store and analyze the drying process data in the cloud, thus providing a foundation for intelligent factories and product quality traceability.

[0036] like Figure 3 and Figure 4 As shown, in one embodiment, the shelf 10 is provided with at least one fluid channel, and the drying chamber 2 is provided with an inlet pipe 11 and an outlet pipe 12 that are connected to the heating system. The fluid channel is connected to the inlet pipe 11 and the outlet pipe 12 respectively. The inner wall of the drying chamber 2 is provided with at least one air inlet 13 that is connected to the air inlet valve 1. After the inert gas enters through the air inlet 13, it first contacts the guide section for heat exchange.

[0037] After the inert gas is introduced, there is a temperature difference between it and the temperature inside the drying chamber 2. If the inert gas is introduced directly, the local temperature inside the drying chamber 2 will be unstable, thus affecting the uniformity of heating the material. Therefore, a guide section is set in the drying chamber 2. After the inert gas enters through the air inlet 13, it first contacts the guide section, so that the temperature of the inert gas quickly approaches the temperature inside the drying chamber 2, preventing it from being blown directly onto the material and affecting the uniformity of heating.

[0038] For the airflow guide section, the following two implementation methods are provided: like Figure 3 The diagram shows the first implementation of the flow guide, which is a shelf 10 located on the top layer of the drying chamber 2 and without any material placed on it, and the air inlet 13 is located on the top of the drying chamber 2.

[0039] The drying chamber 2 is equipped with multiple shelves 10. The top shelf 10 is located close to the top of the drying chamber 2. The air inlet 13 is located at the inner top of the drying chamber 2 and is connected to the air inlet valve 1. When the air inlet valve 1 is open, the inert gas at the air inlet 13 is first blown toward the shelf 10. Since the shelf 10 is heated by circulating fluid, the inert gas can exchange heat instantly after being blown toward the shelf 10. Then, it flows with the airflow in the drying chamber 2, preventing the inert gas with a large temperature difference from being blown directly toward the material and affecting the drying effect of the material.

[0040] like Figure 4 and Figure 5 The second implementation of the flow guide is shown. The flow guide is a flow guide plate 14, which is located on the side of the liquid inlet pipe 11 or the liquid outlet pipe 12 away from the shelf 10. The air inlet 13 is located on the side wall of the drying chamber 2. The connecting pipe 4 is connected to the side of the drying chamber 2 away from the flow guide plate 14.

[0041] The inlet 13 and the outlet (the connection point between the drying chamber 2 and the connecting pipe 4) are positioned opposite each other. After the inert gas enters through the inlet 13, it first blows through the guide plate 14, and then flows from both sides of the guide plate 14 towards the center of the drying chamber 2. Under the suction of the vacuum pump 6, the inert gas can be drawn more quickly from the outlet 13. Figure 4 The air flows from left to right, quickly mixing with the airflow in drying chamber 2, ensuring pressure consistency throughout drying chamber 2 and improving the accuracy of vacuum detector detection.

[0042] like Figure 6 As shown, the guide vane 14 further includes: The first arc-shaped guide vane 141 has its concave side connected to the outer wall of the liquid inlet pipe 11 or the liquid outlet pipe 12, and its convex side is correspondingly set to the air inlet 13. Two second arc-shaped guide vanes 142 are respectively disposed on both sides of the first arc-shaped guide vane 141, with the concave side of the second arc-shaped guide vane 142 facing away from the shelf 10. The protruding side of the first arc-shaped guide vane 141 and the concave side of the second arc-shaped guide vane 142 form a guide surface.

[0043] A portion of the first arc-shaped guide vane 141 is attached to the inlet pipe 11 or the outlet pipe 12, thus making the overall temperature of the guide vane 14 similar to that of the material. The suction force of the vacuum pump 6 causes the gas to flow to the right, while the inert gas entering from the inlet 13 is first blown onto the first arc-shaped guide vane 141. Under the action of the suction force, it flows along the guide surface to the concave side of the two second arc-shaped guide vanes 142 respectively, so that the inert gas can contact the guide surface and exchange heat. Then it flows from the edge of the second arc-shaped guide vane 142 towards the center of the drying chamber 2. This not only prevents the inert gas from being blown directly onto the material, but also allows it to quickly diffuse in the drying chamber 2 under the action of the suction force, ensuring the consistency of the internal pressure.

[0044] To further enhance the heat exchange capacity of the second arc-shaped guide vane 142, a heat exchange channel can be added based on the above scheme. That is, a heat exchange channel is also provided on the protruding side of the second arc-shaped guide vane 142. A first branch pipe is bypassed on the connecting pipe 4. The first branch pipe is connected to one end of the heat exchange channel, and the other end of the heat exchange channel is connected to the connecting pipe 4 through the second branch pipe. A circulation power unit (small circulation fan) is provided on the first branch pipe. Both the first branch pipe and the second branch pipe are connected to the connecting pipe 4 between the exhaust valve 5 and the cold trap 7.

[0045] Under the action of the circulating power unit, the airflow drawn into the connecting pipe 4 has the same temperature as the drying chamber 2. This airflow can be transported to the heat exchange channel through the circulating power unit and the first branch pipe, and then returned to the connecting pipe 4 from the second branch pipe. The extracted airflow is used to ensure the temperature of the second arc-shaped guide vane 142, so that the inert gas can quickly exchange heat on the guide surface, making its temperature closer to the temperature of the material, preventing a large impact on the heating temperature of the shelf 10, and improving the energy-saving effect.

[0046] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0047] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a connection that allows communication between them; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0048] Although the embodiments of the present invention have been disclosed above, they are not limited to the applications listed in the specification and embodiments. They can be applied to various fields suitable for the present invention. For those skilled in the art, other modifications can be easily made. Therefore, without departing from the general concept defined by the present invention, the present invention is not limited to the specific details and illustrations shown and described herein.

Claims

1. An intelligent vacuum control device, characterized in that, include: A drying chamber (2) is used to pre-cool and dry the materials placed inside it. A temperature sensor (3) is provided inside the drying chamber (2). An intake valve (1) is connected between the gas source and the drying chamber (2) and is used to introduce inert gas into the drying chamber (2); An exhaust valve (5) is connected to a connecting pipe (4) between the cold trap (7) and the drying chamber (2). The cold trap (7) is also connected to a vacuum pump (6). The exhaust valve (5) is used to control the speed at which the drying chamber (2) discharges gas. A vacuum detector is used to monitor the vacuum pressure inside the drying chamber (2) in real time; The control system is used to control the opening of the inlet valve (1) and the exhaust valve (5) to adjust the vacuum pressure in the drying chamber (2) in real time.

2. The intelligent vacuum control device according to claim 1, characterized in that, The vacuum detector includes: The Pirani vacuum gauge (8) is used to monitor the vacuum pressure in the drying chamber (2) in real time during the drying stage and feed it back to the control system to control the opening of the inlet valve (1) and the exhaust valve (5); The capacitive vacuum gauge (9) is used to monitor the vacuum pressure in the drying chamber (2) in real time during the drying end judgment stage and feed it back to the control system to compare the vacuum pressures monitored by the Pirani vacuum gauge (8) and the capacitive vacuum gauge (9) to determine whether the drying is over.

3. The intelligent vacuum control device according to claim 1, characterized in that, The drying chamber (2) is provided with multiple shelves (10) for placing materials, and multiple temperature sensors (3) in the drying chamber (2) are used to detect the temperature of the shelves (10) and the materials in the drying chamber (2).

4. The intelligent vacuum control device according to claim 3, characterized in that, The control system includes: The data acquisition module is used to continuously collect the shelf (10) temperature, material temperature and vacuum pressure in the drying chamber (2) through temperature sensor (3) and vacuum detector during the drying stage; The curvature calculation module is used to fit the collected vacuum pressure sequence within a preset time window, calculate the first and second derivatives of its change curve, and obtain the curvature of the vacuum pressure change. The curvature judgment module is used to compare the curvature of the vacuum pressure change in the current time window with the curvature of the vacuum pressure change in the previous time window to determine whether the temperature and vacuum pressure in the drying chamber (2) need to be adjusted. The adjustment module adjusts the heating temperature of the shelf (10), the opening of the air inlet valve (1) and the opening of the exhaust valve (5) according to the curvature and trend of the vacuum pressure change within the current time window, so as to keep the curvature of the vacuum pressure change within the set curvature range; wherein the set curvature range is (-0.1, 0).

5. The intelligent vacuum control device according to claim 2, characterized in that, The control system further includes: End judgment module: When the vacuum pressure in the drying chamber (2) is lower than the set pressure and the curvature of the vacuum pressure change within the current time window is within the set curvature range, the drying end judgment stage is entered. The first vacuum pressure and the second vacuum pressure of the Pirani vacuum gauge (8) and the capacitive vacuum gauge (9) are automatically acquired. If the difference between the first vacuum pressure and the second vacuum pressure acquired multiple times within the set time is within the set deviation range, the drying stage ends.

6. The intelligent vacuum control device according to claim 4, characterized in that, Also includes: The wireless data transmission module connected to the control system is used to transmit the collected shelf (10) temperature, material temperature and vacuum pressure in the drying chamber (2) to the remote monitoring terminal in real time, and to receive instructions from the remote control terminal.

7. The intelligent vacuum control device according to claim 3, characterized in that, The shelf (10) is provided with at least one fluid channel, and the drying chamber (2) is provided with an inlet pipe (11) and an outlet pipe (12) connected to the heating system. The fluid channel is connected to the inlet pipe (11) and the outlet pipe (12) respectively. The inner wall of the drying chamber (2) is provided with at least one air inlet (13) that is connected to the air inlet valve (1). After the inert gas enters through the air inlet (13), it first contacts the guide section for heat exchange.

8. The intelligent vacuum control device according to claim 7, characterized in that, The flow guide is a shelf (10) located on the top layer of the drying chamber (2) and without any material placed on it, and the air inlet (13) is located on the top of the drying chamber (2).

9. The intelligent vacuum control device according to claim 7, characterized in that, The flow guide is a flow guide plate (14), which is located on the side of the liquid inlet pipe (11) or liquid outlet pipe (12) away from the shelf (10). The air inlet (13) is located on the side wall of the drying chamber (2). The connecting pipe (4) is connected to the side of the drying chamber (2) away from the flow guide plate (14).

10. The intelligent vacuum control device according to claim 9, characterized in that, The guide vane (14) includes: The first arc-shaped guide vane (141) has its concave side connected to the outer wall of the liquid inlet pipe (11) or the liquid outlet pipe (12), and its convex side is correspondingly set to the air inlet (13). Two second arc-shaped guide vanes (142) are respectively set on both sides of the first arc-shaped guide vane (141), and the concave side of the second arc-shaped guide vane (142) is set away from the shelf (10); The convex side of the first arc-shaped guide vane (141) and the concave side of the second arc-shaped guide vane (142) form a guide surface.

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