Vacuum freeze dryer

Abstract

The invention discloses a vacuum freeze dryer, particularly relates to the technical field of vacuum freeze drying, and comprises a drying chamber, a refrigerating system, a vacuum system, a heating system, a control system and an energy recovery device. The drying chamber is used for containing materials, the inner wall of the drying chamber is made of efficient heat insulation materials, the refrigerating system comprises a high-precision temperature sensor and an intelligent temperature controller, the refrigerating temperature fluctuation is accurately controlled within + / -1 DEG C, the vacuum degree fluctuation of the vacuum system is kept within + / -5Pa through a vacuum degree sensor and a stabilizing device, and the heating system adopts uniform heating elements. And it is ensured that the heating temperature nonuniformity is smaller than + / -1 DEG C, a control system achieves automatic drying, and an energy recovery device recovers waste cold and waste heat for other links. The problems that an existing vacuum freeze dryer is low in temperature control precision, unstable in vacuum degree, low in automation degree, low in energy utilization rate and the like are solved, the material quality can be effectively kept, the drying efficiency is improved, and energy consumption is reduced.

Description

Technical Field

[0001] The present invention relates to the field of vacuum freeze drying technology, and more specifically, to a vacuum freeze drying machine. Background Art

[0002] A vacuum freeze dryer, also known as a freeze dryer or freeze dryer, is a device used to freeze and vacuum dehydrate a substance to maintain its structure, appearance and nutrients. Its working principle mainly includes freezing, vacuuming, sublimation and condensation. Vacuum freeze dryers are widely used in food, medicine, biotechnology and other fields. Vacuum freeze dryers can effectively maintain the shape, color, nutrients and active ingredients of substances.

[0003] Many vacuum freeze dryers on the market currently have the problem of insufficient precision in temperature control. During the freezing stage, temperature fluctuations may cause uneven size and distribution of ice crystals inside the material, which in turn affects the subsequent sublimation drying process. For example, when the temperature is too low, the material may be over-frozen, resulting in large ice crystals, requiring more energy and time for sublimation, and may damage the cell structure of the material; while when the temperature is too high, the material may not be completely frozen, and partial melting may occur during the sublimation process, affecting the drying effect and product quality.

[0004] During the drying stage, precise temperature control is equally important. If the heating temperature is uneven or unstable, the drying speed of different parts of the material will be inconsistent, resulting in local overheating, deformation or incomplete drying of the product. This may seriously affect the activity and efficacy of some temperature-sensitive biological products and drugs.

[0005] Vacuum degree is one of the key parameters in the vacuum freeze drying process. However, the vacuum degree stability of some existing vacuum freeze dryers is poor during operation. The fluctuation of vacuum degree will affect the sublimation rate of water. When the vacuum degree decreases, the sublimation rate of water slows down, prolonging the drying time and increasing energy consumption; when the vacuum degree is too high, some volatile components in the material may be extracted, affecting the flavor and quality of the product.

[0006] In addition, the sealing of the vacuum system is also an important factor affecting the stability of the vacuum degree. If the equipment has a poor sealing problem, the outside air will continue to penetrate into the drying chamber and destroy the vacuum environment, which will not only affect the drying effect, but may also cause the equipment to frequently start the vacuum pump to maintain the vacuum degree, shortening the service life of the vacuum pump and increasing the maintenance cost of the equipment.

[0007] Many traditional vacuum freeze dryers rely on manual experience to set and adjust parameters during operation, and the degree of automation is low. This not only increases the workload of operators, but also easily leads to inconsistency in the drying process due to the subjectivity and uncertainty of manual operation, affecting the stability of product quality. For example, during the drying process, it is necessary to adjust parameters such as temperature and vacuum degree in a timely manner according to the characteristics of the material and the drying progress. If the operator cannot make judgments and adjustments in a timely and accurate manner, the drying time may be too long or too short, and the product quality may not meet the requirements. Moreover, the data of manual recording and monitoring of the drying process also has problems such as large errors and inconvenience in data analysis and traceability.

[0008] The vacuum freeze-drying process consumes a lot of energy, including refrigeration, heating and vacuum pump operation. Some existing equipment has inefficiencies in energy utilization. For example, the unreasonable design of the refrigeration system and heating system leads to large energy losses during the transmission and conversion process; the poor thermal insulation performance of the equipment leads to serious heat loss and increased energy consumption.

[0009] In addition, during the drying process, due to the lack of effective energy recovery and utilization mechanisms, a large amount of waste heat is directly discharged into the environment, resulting in energy waste. This not only increases the production costs of enterprises, but also does not meet the current requirements of energy conservation and environmental protection.

[0010] Therefore, a vacuum freeze dryer is now proposed. Summary of the invention

[0011] In order to overcome the above defects of the prior art, the present invention provides a vacuum freeze dryer to solve the problems raised in the above background technology.

[0012] To achieve the above object, the present invention provides the following technical solution: a vacuum freeze dryer, comprising:

[0013] Drying chamber, used to place materials to be dried;

[0014] A refrigeration system connected to the drying chamber, used to freeze the material in the drying chamber to a predetermined temperature, the refrigeration system comprising a high-precision temperature sensor and an intelligent temperature controller, the high-precision temperature sensor monitors the freezing temperature in real time, and the intelligent temperature controller accurately controls the refrigeration power according to the feedback signal of the high-precision temperature sensor, so that the fluctuation range of the freezing temperature is within ±1°C;

[0015] A vacuum system connected to the drying chamber, used to reduce the pressure in the drying chamber to a predetermined vacuum degree, the vacuum system comprising a vacuum degree sensor and a vacuum degree stabilizing device, the vacuum degree sensor monitors the vacuum degree in the drying chamber in real time, and the vacuum degree stabilizing device adjusts the working state of the vacuum system according to the feedback signal of the vacuum degree sensor to keep the fluctuation range of the vacuum degree within ±5Pa;

[0016] A heating system is arranged in the drying chamber and is used to heat and dry the frozen material. The heating system uses a uniform heating element to ensure that the material is heated evenly and the non-uniformity of the heating temperature is less than ±1°C;

[0017] A control system is connected to the refrigeration system, the vacuum system and the heating system respectively, and the control system automatically adjusts the working parameters of the refrigeration system, the vacuum system and the heating system according to a preset drying program and parameters such as temperature and vacuum degree collected in real time to realize an automated drying process;

[0018] The energy recovery device is connected to the refrigeration system and the heating system, and is used to recover the waste cold generated by the refrigeration system and the waste heat generated by the heating system, and use the recovered energy in other links that require energy, thereby improving energy utilization.

[0019] Preferably, the inner wall of the drying chamber is made of high-efficiency heat-insulating material.

[0020] Preferably, the uniform heating element is a distributed heating wire or a microwave heating device.

[0021] Preferably, the vacuum stabilization device includes a vacuum pump speed regulator and a vacuum leakage compensation device, wherein the vacuum pump speed regulator adjusts the rotation speed of the vacuum pump according to changes in the vacuum degree, and the vacuum leakage compensation device performs compensation in time when vacuum leakage is detected to maintain vacuum stability.

[0022] Preferably, the control system further comprises a human-machine interaction interface for an operator to input drying parameters, view drying process data and equipment operating status.

[0023] Preferably, the control system further comprises a storage module and an analysis module, wherein the storage module and the analysis module are respectively used to record and analyze data of previous drying processes.

[0024] Preferably, the energy recovery device includes a heat exchanger and an energy storage device, wherein the heat exchanger exchanges waste heat and waste cold and stores them in the energy storage device, and the energy storage device provides energy support for other parts of the device when needed.

[0025] Preferably, the energy storage device is a lead-acid battery, the lead-acid battery is connected to a power generation device, and the power generation device is a temperature difference generator.

[0026] Preferably, the accuracy of the high-precision temperature sensor is ±0.5°C, and the accuracy of the vacuum sensor is ±1Pa.

[0027] Technical effects and advantages of the present invention:

[0028] 1. The refrigeration system uses a high-precision temperature sensor (accuracy of ±0.5℃) for real-time monitoring and an intelligent temperature controller to keep the freezing temperature fluctuation within ±1℃, thus avoiding damage to the material due to temperature fluctuations, ensuring the freezing effect of the material and providing good conditions for subsequent sublimation drying.

[0029] 2. The heating system uses uniform heating elements (such as distributed heating wires or microwave heating devices), and the heating temperature non-uniformity is less than ±1°C, ensuring that the material is heated evenly and preventing local overheating, deformation or incomplete drying. It is especially suitable for temperature-sensitive biological products and drugs to ensure product activity and efficacy.

[0030] 3. The vacuum sensor (accuracy of ±1Pa) in the vacuum system is used for real-time monitoring, and the vacuum stabilization device (vacuum pump speed regulator and vacuum leakage compensation device) is used for adjustment to keep the vacuum fluctuation within ±5Pa, thereby ensuring the stability of the water sublimation rate, reducing the extension of drying time and increase in energy consumption caused by vacuum fluctuations, and avoiding excessive extraction of volatile components that affect product flavor and quality.

[0031] 4. The control system automatically adjusts the working parameters of the refrigeration, vacuum and heating systems according to the preset drying program and the temperature, vacuum degree and other parameters collected in real time, realizes the automated drying process, reduces the workload of operators, reduces the subjectivity and uncertainty of manual operation, ensures the consistency of the drying process, and improves the stability of product quality.

[0032] 5. The energy recovery device recycles waste cold from the refrigeration system and waste heat from the heating system, and stores them in energy storage equipment (lead-acid batteries, etc.) after exchange through a heat exchanger. The lead-acid battery is connected to a thermoelectric generator to provide energy support for other parts of the equipment, thereby improving energy utilization, reducing corporate production costs, and meeting energy-saving and environmental protection requirements.

[0033] 6. The inner wall of the drying chamber is made of high-efficiency thermal insulation material to reduce heat transfer and reduce energy consumption.

[0034] 7. The human-machine interaction interface of the control system is convenient for operators to input parameters, view data and equipment status. The storage module and analysis module record and analyze previous drying data, providing a basis for optimizing drying procedures and parameters, and facilitating traceability and improvement. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 It is a schematic diagram of the overall structure of the present invention.

[0036] Figure 2 It is a rear-view stereoscopic structural schematic diagram of the present invention.

[0037] The accompanying drawings are marked as follows: 1. machine body; 2. drying chamber; 3. control panel; 4. vacuum system; 5. refrigeration system; 6. heating system; 7. energy recovery device. DETAILED DESCRIPTION

[0038] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0039] As attached Figure 1 and Figure 2 A vacuum freeze dryer is shown, comprising:

[0040] Drying chamber 2 is used to place the material to be dried, and its inner wall is made of high-efficiency heat-insulating materials, such as polyurethane foam, which effectively reduces heat transfer and reduces energy consumption;

[0041] A refrigeration system 5 is connected to the drying chamber 2 and is used to freeze the material in the drying chamber 2 to a predetermined temperature. The refrigeration system 5 includes a high-precision temperature sensor and an intelligent temperature controller. The high-precision temperature sensor monitors the freezing temperature in real time. The intelligent temperature controller accurately controls the refrigeration power according to the feedback signal of the high-precision temperature sensor, so that the fluctuation range of the freezing temperature is within ±1°C;

[0042] In specific implementation, when the freezing temperature is set to -30°C, the refrigeration system 5 is started, and the high-precision temperature sensor continuously monitors the temperature. Once the temperature is higher than -29°C, the intelligent temperature controller increases the refrigeration power; if the temperature is lower than -31°C, the refrigeration power is reduced;

[0043] A vacuum system 4 is connected to the drying chamber 2 and is used to reduce the pressure in the drying chamber 2 to a predetermined vacuum degree. The vacuum system 4 includes a vacuum degree sensor and a vacuum degree stabilizing device. The vacuum degree sensor monitors the vacuum degree in the drying chamber 2 in real time. The vacuum degree stabilizing device adjusts the working state of the vacuum system 4 according to the feedback signal of the vacuum degree sensor to keep the fluctuation range of the vacuum degree within ±5Pa. When the vacuum degree drops to 5Pa below the set value, the vacuum pump speed regulator increases the speed of the vacuum pump. If a vacuum leak is detected, the vacuum leak compensation device is immediately started to compensate.

[0044] A heating system 6 is arranged in the drying chamber 2 and is used to heat and dry the frozen material. The heating system 6 uses a uniform heating element, and the uniform heating element uses a distributed heating wire or a microwave heating device as a uniform heating element to ensure that the material is heated evenly and the non-uniformity of the heating temperature is less than ±1°C;

[0045] A control system is connected to the refrigeration system 5, the vacuum system 4 and the heating system 6 respectively. The control system automatically adjusts the working parameters of the refrigeration system 5, the vacuum system 4 and the heating system 6 according to a preset drying program and parameters such as temperature and vacuum degree collected in real time to realize an automated drying process;

[0046] The energy recovery device 7 is connected to the refrigeration system 5 and the heating system 6, and is used to recover the waste cold generated by the refrigeration system 5 and the waste heat generated by the heating system 6, and use the recovered energy in other links that require energy, thereby improving energy utilization;

[0047] In specific implementation, the heat exchanger exchanges the waste cold generated by the refrigeration system 5 and the waste heat generated by the heating system 6 and stores them in the energy storage device (lead-acid battery). The lead-acid battery is connected to the thermoelectric generator. When other parts of the device need energy, the energy storage device provides energy support.

[0048] Specifically, during the energy recovery process, the heat exchanger exchanges waste heat or waste cold heat and generates electricity through a thermoelectric generator, which is stored on the positive and negative plates of the battery respectively. During discharge, the chemical reaction proceeds in reverse, and electrons flow from the negative electrode to the positive electrode through an external circuit, generating current, thereby providing electrical energy and achieving the purpose of saving energy.

[0049] Specifically, an organic body 1 is arranged at the bottom of the drying chamber 2, and a refrigeration system 5 and a heating system 6 connected to the drying chamber 2 are arranged inside the organic body 1, an energy recovery device 7 is arranged between the refrigeration system 5 and the heating system 6, a control screen 3 for displaying a human-computer interaction interface is installed on the outside of the organic body 1, a vacuum system 4 connected to the drying chamber 2 is arranged at the bottom of the organic body 1, and the refrigeration system 5, the vacuum system 4 and the heating system 6 are commonly connected to a control system.

[0050] The control system is connected to the refrigeration system 5, vacuum system 4 and heating system 6 respectively, and transmits control signals and collects parameters such as temperature and vacuum degree through lines. The control screen 3 on the outside of the machine body 1 is a human-machine interactive interface, through which the operator can input drying parameters (such as material type, drying time, target temperature and vacuum degree, etc.), view drying process data (real-time temperature, vacuum degree, remaining drying time, etc.) and equipment operating status (working status of refrigeration system 5, vacuum system 4, heating system 6, etc.). The storage module in the control system records the data of previous drying processes, and the analysis module analyzes these data to provide a basis for optimizing the drying program and parameters.

[0051] During specific implementation, the operator puts the material to be dried into the drying chamber 2, inputs the drying parameters on the control panel 3, and starts the equipment.

[0052] The refrigeration system 5 starts to work and freezes the material in the drying chamber 2 to a predetermined temperature according to a preset program. During the freezing process, a high-precision temperature sensor monitors the temperature in real time, and an intelligent temperature controller continuously adjusts the refrigeration power.

[0053] After reaching the predetermined freezing temperature, the vacuum system 4 is started to reduce the pressure in the drying chamber 2 to a predetermined vacuum degree. The vacuum degree sensor monitors the vacuum degree, and the vacuum degree stabilization device maintains the vacuum degree stable.

[0054] Next, the heating system 6 heats and dries the frozen material. The uniform heating element heats the material evenly, and during the heating process, the control system automatically adjusts the heating power according to the temperature parameters collected in real time to ensure that the heating temperature is uniform and stable.

[0055] During the drying process, the energy recovery device 7 recovers waste cooling and waste heat and stores energy. The control system automatically controls the working parameters of each system according to the preset drying program and real-time parameters to realize the automated drying process. The operator can view the drying process data and equipment operation status at any time through the control screen 3.

[0056] After drying is completed, the equipment automatically stops running and the operator takes out the dried material.

[0057] The specific working process is:

[0058] The operator turns on the equipment through the human-machine interface, that is, performs initial settings on the control screen 3, including inputting relevant information of the material to be dried (such as material type, initial moisture content, expected drying amount, etc.), selecting a suitable drying process program (if the equipment has pre-stored a variety of drying programs for different materials) or manually setting parameters such as the temperature curve, vacuum curve and drying time during the drying process.

[0059] The control system performs self-checking to check whether the sensors (high-precision temperature sensors, vacuum sensors, etc.), actuators (refrigeration compressors, vacuum pumps, heating elements, etc.) and communication lines are working properly. At the same time, the energy state of the energy storage device in the energy recovery device 7 is read to determine whether it can meet the energy demand of this drying process. If the energy storage device is insufficient, the control system can decide whether to start the energy recovery process first or prompt the operator to supplement external energy according to the preset strategy.

[0060] The refrigeration system 5 is started, and the intelligent temperature controller controls the operating frequency of the refrigeration compressor and the opening of the expansion valve according to the preset freezing temperature and the feedback signal of the high-precision temperature sensor, so that the temperature in the drying chamber 2 is rapidly reduced.

[0061] When the temperature reaches the predetermined freezing temperature, the refrigeration system 5 maintains stable operation to ensure that the temperature fluctuation range is within ±1°C. During this process, the moisture in the material gradually freezes into ice crystals, and the structure and active ingredients of the material are protected.

[0062] The control system monitors the temperature changes and the operating status of the refrigeration system 5 in real time, and records relevant data, such as refrigeration power, temperature drop rate, etc., to provide a basis for subsequent data analysis and process optimization.

[0063] After the freezing stage is completed, the vacuum system 4 is started, and the vacuum pump starts to work to reduce the pressure in the drying chamber 2 to a predetermined vacuum degree. The vacuum degree sensor monitors the vacuum degree in the drying chamber 2 in real time and transmits the signal to the control system.

[0064] The vacuum pump speed regulator in the vacuum stabilization device adjusts the speed of the vacuum pump according to the feedback signal of the vacuum sensor to keep the fluctuation range of the vacuum degree within ±5 Pa. At the same time, the vacuum leakage compensation device always monitors whether there is leakage in the system. Once a leakage is detected, the compensation measures are immediately started to ensure the stability of the vacuum environment in the drying chamber 2.

[0065] During the vacuum stage, the control system continues to record data such as the vacuum degree variation curve and the operating parameters of the vacuum pump, so as to evaluate and optimize the performance of the vacuum system 4 .

[0066] The heating system 6 is started, and the uniform heating element begins to heat the frozen material. The control system accurately controls the heating power according to the preset heating temperature curve and the temperature data collected in real time, so that the material is heated evenly and the unevenness of the heating temperature is less than ±1°C.

[0067] During the heating process, the water in the material is directly sublimated from the ice crystal state to water vapor. Since the drying chamber 2 is in a vacuum state, the water vapor can be quickly discharged, thereby achieving the drying of the material.

[0068] As the drying process proceeds, the moisture content of the material gradually decreases. The control system dynamically adjusts parameters such as heating temperature, vacuum degree and drying time based on real-time monitoring of material weight changes (which can be achieved through a weighing sensor installed at the bottom of the built-in tray in the drying chamber 2), temperature and vacuum degree, so as to optimize the drying process, improve drying efficiency and ensure product quality.

[0069] The energy recovery device 7 works simultaneously during the drying stage, and the heat exchanger recovers the waste cold generated by the refrigeration system 5 and the waste heat generated by the heating system 6. For example, the heat absorbed by the refrigerant in the refrigeration system 5 is transferred to the medium that needs to be preheated through the heat exchanger, which can be used for the preheating of the drying chamber 2 or other links that require heat; the heat of the high-temperature exhaust gas discharged by the heating system 6 is used to generate electricity using a thermoelectric generator, which is stored on the positive and negative plates of the battery for storage. During discharge, the chemical reaction is reversed, and electrons flow from the negative electrode to the positive electrode through the external circuit, generating current, thereby providing electrical energy and achieving the purpose of saving energy.

[0070] When the moisture content of the material reaches the preset drying standard or the drying time is over, the drying process stops automatically, the control system shuts down the heating system 6, the refrigeration system 5 and the vacuum system 4, and sends a prompt signal to notify the operator.

[0071] Operators can view detailed data records and analysis reports of the drying process through the human-computer interaction interface, including temperature curve, vacuum curve, drying time, energy consumption and other information. These data can be used to evaluate the drying effect, optimize the drying process, and analyze and improve the performance of the equipment.

[0072] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A vacuum freeze dryer, characterized in that: include: A drying chamber (2) for placing materials to be dried; A refrigeration system (5) connected to the drying chamber (2) and used for freezing the material in the drying chamber (2) to a predetermined temperature. The refrigeration system (5) comprises a high-precision temperature sensor and an intelligent temperature controller. The high-precision temperature sensor monitors the freezing temperature in real time. The intelligent temperature controller accurately controls the refrigeration power according to the feedback signal of the high-precision temperature sensor, so that the fluctuation range of the freezing temperature is within ±1°C. A vacuum system (4) connected to the drying chamber (2) and used to reduce the pressure in the drying chamber (2) to a predetermined vacuum degree, wherein the vacuum system (4) comprises a vacuum degree sensor and a vacuum degree stabilization device, wherein the vacuum degree sensor monitors the vacuum degree in the drying chamber (2) in real time, and the vacuum degree stabilization device adjusts the working state of the vacuum system (4) according to a feedback signal from the vacuum degree sensor to keep the fluctuation range of the vacuum degree within ±5 Pa; A heating system (6) is arranged in the drying chamber (2) and is used to heat and dry the frozen material. The heating system (6) uses a uniform heating element to ensure that the material is heated evenly and the non-uniformity of the heating temperature is less than ±1°C. A control system is connected to the refrigeration system (5), the vacuum system (4) and the heating system (6) respectively, and the control system automatically adjusts the working parameters of the refrigeration system (5), the vacuum system (4) and the heating system (6) according to a preset drying program and parameters such as temperature and vacuum degree collected in real time, so as to realize an automated drying process; The energy recovery device (7) is connected to the refrigeration system (5) and the heating system (6) and is used to recover the waste cold generated by the refrigeration system (5) and the waste heat generated by the heating system (6), and use the recovered energy in other links that require energy, thereby improving energy utilization.

2. A vacuum freeze dryer according to claim 1, characterized in that: The inner wall of the drying chamber (2) is made of high-efficiency heat-insulating material.

3. A vacuum freeze dryer according to claim 2, characterized in that: The uniform heating element is a distributed heating wire or a microwave heating device.

4. A vacuum freeze dryer according to claim 3, characterized in that: The vacuum stabilization device includes a vacuum pump speed regulator and a vacuum leakage compensation device. The vacuum pump speed regulator adjusts the rotation speed of the vacuum pump according to the change of vacuum degree. The vacuum leakage compensation device performs compensation in time when vacuum leakage is detected to maintain vacuum stability.

5. A vacuum freeze dryer according to claim 4, characterized in that: The control system also includes a human-machine interaction interface for operators to input drying parameters, view drying process data and equipment operating status.

6. A vacuum freeze dryer according to claim 5, characterized in that: The control system further comprises a storage module and an analysis module, wherein the storage module and the analysis module are respectively used to record and analyze data of previous drying processes.

7. A vacuum freeze dryer according to claim 6, characterized in that: The energy recovery device (7) comprises a heat exchanger and an energy storage device. The heat exchanger exchanges waste heat and waste cold and stores them in the energy storage device. The energy storage device provides energy support for other parts of the device when needed.

8. A vacuum freeze dryer according to claim 7, characterized in that: The energy storage device is a lead-acid battery, the lead-acid battery is connected to a power generation device, and the power generation device is a temperature difference generator.

9. A vacuum freeze dryer according to claim 8, characterized in that: The accuracy of the high-precision temperature sensor is ±0.5°C, and the accuracy of the vacuum sensor is ±1Pa.

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