Supercritical extraction apparatus and method

Abstract

The application is supercritical extraction device, including heat exchange base and reaction kettle, the lower end of the reaction kettle is partially closed in the heat exchange base; the reaction kettle includes kettle body, the extraction cavity with open upper end is arranged in the kettle body, the extraction frame, pressure-bearing exhaust component and closed pressurizing assembly are sequentially arranged in the extraction cavity from bottom to top, the through hole is further arranged in the side wall of the kettle body in the area where the pressure-bearing exhaust component is located; the first temperature sensor is further arranged in the closed pressurizing assembly, the detection end of the first temperature sensor extends into the extraction cavity in the area where the pressure-bearing exhaust component is located; the extraction medium inlet is further arranged at the bottom of the extraction cavity, the extraction medium heat exchange pipe is further arranged in the heat exchange base, the outlet end of the extraction medium heat exchange pipe is in communication with the extraction medium inlet. The application can detect the extraction temperature in the extraction device in real time, and then the accuracy of the extraction temperature can be improved, and the extraction efficiency and effect can be improved.

Description

Technical Field

[0001] This invention relates to the field of environmental treatment equipment technology, specifically a supercritical extraction device. Background Technology

[0002] Supercritical fluid extraction is a novel extraction and separation technology that uses supercritical fluids—fluids in a thermodynamic state with temperatures and pressures above critical temperatures and pressures—as extractants to extract specific components from liquids or solids to achieve separation. Because the fluid in supercritical fluid extraction is a gas at normal pressure and room temperature, it is easy to separate from the extracted components after extraction, making it widely applicable. Common fluids include carbon dioxide, methanol, ammonia, ethylene, propane, propylene, and water.

[0003] During the operation of a supercritical extraction device, the conditions for the supercritical state transition of different fluids vary. For example, the critical temperature of carbon dioxide is 31.1℃ and the critical pressure is 7.39MPa. The extraction temperature and pressure must be met to ensure that carbon dioxide is converted to the supercritical state. Furthermore, for different extractants, in order to achieve their optimal extraction efficiency and effect, in addition to meeting the supercritical conditions of carbon dioxide, it is also necessary to use the control system to adjust the temperature and pressure inside the extraction vessel, so as to meet the fluid state transition while ensuring that the extractant reaches the optimal temperature and pressure state required for extraction.

[0004] However, in practical applications, existing extraction devices have the following problems: 1. The structure of the material frame and the design of the fluid channel inside the extraction vessel are unreasonable, resulting in large air resistance and a single diffusion path after the fluid is sent into the extraction vessel, which makes the contact between the fluid and the extractant insufficient and leads to uneven temperature inside the vessel; 2. The material frame inside the extraction vessel is in a closed environment, and the temperature of the extraction environment cannot be directly measured. It can only be estimated by external devices. Most of the time, the extraction effect can only be improved by adjusting the temperature within a small range and extending the extraction time of each period. However, this not only results in low temperature control accuracy, but also long extraction time, greatly reduced extraction efficiency, and increased cost.

[0005] Therefore, how to design the extraction device structure to make the fluid flow path more dispersed and uniform, the extractant contact more complete, and the temperature inside the extraction vessel monitored are the technical problems that we urgently need to solve. Summary of the Invention

[0006] The purpose of this invention is to provide a supercritical extraction apparatus that can monitor the extraction temperature in real time, thereby improving the accuracy of the extraction temperature, achieving precise extraction temperature control, and enhancing extraction efficiency and effectiveness. Furthermore, based on this supercritical extraction apparatus, this invention also provides a supercritical extraction method.

[0007] The objective of this invention is mainly achieved through the following technical solution: a supercritical extraction device, comprising a heat exchange base and a reaction vessel, wherein the lower end of the reaction vessel is partially enclosed within the heat exchange base; the reaction vessel comprises a vessel body, within which an extraction chamber with an open upper end is provided; within the extraction chamber, an extraction frame, a pressure-bearing exhaust component, and a sealing pressurization assembly are sequentially arranged from bottom to top; a through hole communicating with the extraction chamber is also provided on the side wall of the vessel body in the area where the pressure-bearing exhaust component is located; the sealing pressurization assembly is used to seal the extraction chamber in the area where the extraction frame and the pressure-bearing exhaust component are located and to sequentially press the pressure-bearing exhaust component and seal the extraction frame; a first temperature sensor is also provided within the sealing pressurization assembly, with the detection end of the first temperature sensor extending into the extraction chamber in the area where the pressure-bearing exhaust component is located; an extraction medium inlet is also provided at the bottom of the extraction chamber; an extraction medium heat exchange tube is also provided within the heat exchange base, with the outlet end of the extraction medium heat exchange tube communicating with the extraction medium inlet.

[0008] Based on the above technical solution, the extraction frame is composed of an extraction cylinder and end plates connected to both ends of the extraction cylinder; the extraction cylinder is enclosed by a sintered metal mesh; the end plates are fixedly connected to both ends of the extraction cylinder, and a through hole is formed in the middle of the end plates to communicate with the extraction chamber in the area where the pressure exhaust component is located, and a detachable mesh cover plate is provided in the through hole.

[0009] Based on the above technical solution, the pressure-bearing exhaust component includes an annular body with a diameter smaller than that of the extraction chamber. The sidewall of the annular body is provided with several medium through holes. The lower end of the annular body is connected to a flared opening. The upper end of the extraction frame forms an inclined wall that matches the inner wall of the flared opening. The pressure-bearing exhaust component positions the extraction frame by matching the flared opening with the inclined wall. A first sealing element is also provided between the flared opening and the inclined wall.

[0010] Based on the above technical solution, the closed pressurization assembly includes, from bottom to top, a sealed head, a pressure cap, and a pressure-bearing screw sleeve that are pressed together in sequence. The pressure-bearing screw sleeve is threadedly connected to the inner wall of the extraction chamber and partially extends into the vessel body. It also includes a screw rod that passes through the pressure-bearing screw sleeve and the pressure cap and is connected to the sealed head. The top of the screw rod extends out of the pressure-bearing screw sleeve and is threadedly connected to a lifting nut. A baffle is also fitted between the lifting nut and the pressure-bearing screw sleeve on the screw rod. A sleeve is axially inserted through the middle of the screw rod. The lower end of the sleeve passes through the sealed head and extends into the extraction chamber in the area where the pressure-bearing exhaust component is located. The first temperature sensor is installed inside the sleeve.

[0011] Based on the above technical solution, the lower sidewall of the end cap is further provided with a first sealing groove, and a second sealing element is disposed within the first sealing groove. A sealing plate is also fixedly disposed on the lower end face of the end cap, the sealing plate partially sealing the first sealing groove to compress the second sealing element, and the sealing plate abuts against the pressure-bearing and venting component. The upper sidewall of the end cap is further provided with a second sealing groove, and a third sealing element is disposed within the second sealing groove. The pressure cap partially extends into the second sealing groove to compress the third sealing element.

[0012] Based on the above technical solution, the heat exchange base has a closed heat exchange cavity inside. The heat exchange base is provided with a ventilation hole, a heat exchange medium hole and a mounting hole that communicate with the heat exchange cavity. A second temperature sensor is installed in the mounting hole. The bottom part of the vessel body is located inside the heat exchange cavity, and the extraction medium heat exchange tube is coiled around the outer wall of the vessel body inside the heat exchange cavity.

[0013] Based on the above technical solutions, the heat exchange base is further provided with a sandwich layer inside the side wall, and a heating component is provided inside the sandwich layer; the heat exchange cavity is further provided with a heat insulation layer on the side wall.

[0014] Based on the above technical solution, the extraction medium inlet is located at the middle of the bottom of the extraction chamber, and the port of the extraction medium inlet is also equipped with a mushroom-shaped nozzle.

[0015] Compared with existing technologies, the advantages of this supercritical extraction device are as follows:

[0016] 1. This invention utilizes a pressure-bearing and venting component to bear pressure and collect gas, which can ensure the stable compression of the extraction frame while avoiding excessive compression that could cause deformation or damage. At the same time, the pressure-bearing and venting component is used to collect the extracted medium in a concentrated manner, so that the extraction medium can be collected uniformly and discharged through the through hole, which can better constrain the flow path of the extraction medium and improve the extraction utilization rate of the extraction medium.

[0017] 2. By setting a first temperature sensor to extend into the extraction chamber, the present invention can detect the extraction environment temperature in the extraction chamber in real time. Compared with the existing temperature monitoring methods, this is more direct and accurate, which helps to improve the accuracy of the extraction temperature, achieves precise extraction temperature control, and improves extraction efficiency and effect.

[0018] 3. The extraction frame of this invention uses an extraction cylinder structure made of metal mesh plate to hold the material. The extraction medium has more paths to enter the extraction cylinder during extraction, and the path is more uniform, which makes the material extraction more thorough and complete, thus improving the extraction efficiency and quality.

[0019] 4. The present invention utilizes a mushroom-shaped nozzle design, which allows the input extraction medium to diffuse upwards more widely after entering the extraction cylinder. Combined with the improved structure of the extraction cylinder, this allows for more thorough contact between the material and the fluid, while also resulting in a more uniform temperature within the extraction chamber.

[0020] 5. The heat exchange base of this invention can not only preheat the reaction vessel according to the extraction needs to ensure the reaction temperature requirements, but also control the temperature through heating components. At the same time, the heat exchange tube of the extraction medium is coiled around the outer wall of the vessel in the heat exchange chamber, which can also preheat the extraction medium to shorten the time of its conversion to supercritical and improve the extraction efficiency.

[0021] Furthermore, based on the above-mentioned supercritical extraction device, the present invention also provides a supercritical extraction method, which includes the following steps:

[0022] S1 Place the material in the extraction frame and into the extraction chamber, then install the pressure-bearing exhaust component and the closed pressurization component in sequence;

[0023] The heat exchange medium is introduced into the S2 heat exchange chamber. The liquid extraction medium pressurized to the design pressure is input into the extraction medium heat exchange tube for heat exchange and temperature rise and enters the extraction chamber. Under the action of pressure and temperature in the extraction chamber, the extraction medium is converted into a supercritical state. The supercritical extraction medium extracts the material in the extraction frame and forms a mixed extraction gas. The mixed extraction gas is discharged through the pressure exhaust component and the through hole.

[0024] S3 continuously acquires the gas outlet temperature T2 and the heating temperature T0 of the heat exchange medium in the extraction chamber based on the first temperature sensor and the second temperature sensor, and performs real-time temperature control compensation of the heat exchange medium based on the acquired gas outlet temperature T2 and heating temperature T0 of the heat exchange medium.

[0025] After the designed extraction time is reached (S4), the flow of liquid extraction medium is stopped, and the sealed pressurization component and the pressure venting component are disassembled in sequence, and the extraction frame is removed to complete the supercritical extraction.

[0026] In the above supercritical extraction method, the real-time temperature control and compensation of the heat exchange medium specifically includes:

[0027] The optimal pressure and optimal temperature corresponding to the optimal efficiency conditions of the current supercritical extraction process are obtained, and the gas outlet temperature T2 of the reactor is obtained based on the first temperature sensor, and the heating temperature T0 for heating the outer wall of the reactor is obtained based on the second temperature sensor.

[0028] The optimal pressure, the gas outlet temperature T2, and the optimal temperature are input into a preset temperature compensation model, and the output of the temperature compensation model is received as temperature compensation data.

[0029] The heating temperature T0 is adjusted based on the temperature compensation data to compensate for and adjust the temperature inside the reactor.

[0030] In the supercritical extraction method described above, the extraction gas is preheated on the outer wall of the reactor before entering it, and the extraction gas enters the reactor at the bottom.

[0031] In the above supercritical extraction method, the construction of the temperature compensation model includes:

[0032] S31 Obtain the optimal pressure and optimal temperature corresponding to the optimal efficiency conditions of the current supercritical extraction process, and obtain the gas outlet temperature T2 of the reactor based on the first temperature sensor, and obtain the heating temperature T0 for heating the outer wall of the reactor based on the second temperature sensor.

[0033] S32 inputs the optimal pressure, the gas outlet temperature T2, and the optimal temperature into a preset temperature compensation model, and receives the output of the temperature compensation model as temperature compensation data.

[0034] S33 adjusts the heating temperature T0 according to the temperature compensation data to achieve temperature compensation adjustment inside the reactor.

[0035] In the above supercritical extraction method, a dynamic simulation experiment of ambient pressure open-loop temperature regulation was conducted on the reactor to obtain the external and internal heat transfer parameters of the reactor, including:

[0036] A dynamic simulation test of open-loop temperature regulation at atmospheric pressure was conducted on the reactor, and the gas outlet temperature T2', the heating temperature T0' of the outer wall of the reactor, and the reaction temperature T1' inside the reactor were recorded during the atmospheric pressure test; the pressure inside the reactor was atmospheric pressure during the dynamic simulation test of open-loop temperature regulation at atmospheric pressure.

[0037] The gas outlet of the reactor is sealed, T0' is heated to a constant temperature T and the curve of T0' changing over time is recorded as the first temperature change curve, and the curve of T1' changing over time is recorded as the second temperature change curve.

[0038] Record the moment when the first temperature change curve reaches a constant temperature T as the first moment, and record the moment when the second temperature change curve reaches a constant temperature T as the second moment;

[0039] The external heat transfer parameters of the reactor are calculated based on the difference between the first and second time points, and the difference between the initial temperatures of the isothermal T and the second temperature change curve.

[0040] Open the gas outlet of the reactor, keep T0' at a constant temperature T, and record the curve of T2' changing over time as the third temperature change curve;

[0041] The moment when the third temperature change curve reaches a constant temperature T is recorded as the third moment, and the moment when the gas outlet of the reactor is opened is recorded as the fourth moment;

[0042] The internal heat transfer parameters of the reactor are calculated based on the difference between the fourth and third time points, and the difference between the constant temperature T and the initial temperature of the third temperature change curve.

[0043] In the above supercritical extraction method, a thermal conductivity simulation model of the reactor is constructed based on the external heat transfer parameters and the internal heat transfer parameters. The calculation results generated by pressurizing the thermal conductivity simulation model include:

[0044] A thermal conductivity simulation model of the reactor is constructed based on the internal heat transfer parameters and the external heat transfer parameters, and the internal heat transfer parameters are used as the initial parameters for internal heat transfer in the thermal conductivity simulation model.

[0045] The internal pressure of the reactor in the thermal conductivity simulation model is calculated, and the internal heat transfer parameters are iterated.

[0046] The gas outlet temperature T2'', the outer wall heating temperature T0'', the reaction temperature T1'', and the pressure N inside the reactor are obtained from multiple sets of pressurization calculation results to form multiple sets of data to be fitted as the calculation results.

[0047] In the above supercritical extraction method, constructing the temperature compensation model based on the calculation results includes:

[0048] Based on the data to be fitted, T2'', T1'', T0'' and N are fitted to form a fitting function T0''=f(T2'', T1'', N);

[0049] The fitting function T0''=f(T2'', T1'', N) is used as the temperature compensation model.

[0050] In the above supercritical extraction method, the optimal pressure, the gas outlet temperature T2, and the optimal temperature are input into a preset temperature compensation model, and the output of the temperature compensation model is received as temperature compensation data, including:

[0051] The optimal pressure is used as N in the fitting function, the gas outlet temperature T2 is used as T2'' in the fitting function, and the optimal temperature is used as T1'' in the fitting function.

[0052] The calculation result T0'' of the fitting function is received as temperature compensation data.

[0053] In the above supercritical extraction method, adjusting the heating temperature T0 based on the temperature compensation data to achieve temperature compensation adjustment within the reactor includes:

[0054] The heating temperature T0 is adjusted to the calculated result T0'' of the fitting function to complete the compensation adjustment of the temperature inside the reactor.

[0055] This supercritical extraction method is based on the above-mentioned supercritical extraction device. It can not only ensure sufficient contact between the extraction medium and the material, but also compensate for the temperature inside the reactor by using temperature data collected outside the reactor and a temperature compensation model. This allows the temperature inside the reactor to be controlled relatively stably near the optimal temperature, improving the extraction efficiency and quality, and greatly shortening the extraction time and reducing costs. It is suitable for widespread application and promotion. Attached Figure Description

[0056] The accompanying drawings, which are included to provide a further understanding of embodiments of the invention and form part of this application, do not constitute a limitation thereof. In the drawings:

[0057] Figure 1 This is a schematic diagram of the overall structure of a supercritical extraction device.

[0058] Figure 2 for Figure 1 Cross-sectional view of section BB in the middle;

[0059] Figure 3 for Figure 2 Cross-sectional view of section C;

[0060] Figure 4 This is a schematic diagram of the overall structure of the reactor;

[0061] Figure 5 This is a schematic diagram of the overall structure of the extraction frame;

[0062] Figure 6 This is a schematic diagram of the assembly structure of the extraction frame and the pressure-bearing exhaust component;

[0063] Figure 7 A schematic diagram of the overall structure of the enclosed pressurization assembly;

[0064] The labels in the diagram represent:

[0065] 1. Heat exchange base; 2. Reactor; 3. Reactor body; 4. Extraction chamber; 5. Extraction frame; 6. Pressure-bearing exhaust component; 7. Sealed pressurization assembly; 8. Through hole; 9. First temperature sensor; 10. Extraction medium inlet; 11. Extraction medium heat exchange tube; 12. Extraction cylinder; 13. End plate; 14. Through hole; 15. Mesh cover plate; 16. Annular body; 17. Medium through hole; 18. Trumpet-shaped flare; 19. First sealing element; 20. End cap; 21. Pressure cap; 22. Pressure-bearing screw sleeve; 23. Screw; 24. Lifting nut; 25. Baffle; 26. Sleeve; 27. Second sealing element; 28. Sealing plate; 29. ​​Third sealing element; 30. Heat exchange chamber; 31. Second temperature sensor; 32. Jacket; 33. Insulation layer; 34. Mushroom-shaped nozzle. Detailed Implementation

[0066] To make the objectives, technical solutions, and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the embodiments and accompanying drawings. The illustrative embodiments and descriptions of the present invention are only used to explain the present invention and are not intended to limit the present invention.

[0067] like Figure 1-4 As shown, this embodiment provides a supercritical extraction device, including a heat exchange base 1 and a reaction vessel 2. The lower end of the reaction vessel 2 is partially enclosed within the heat exchange base 1. The reaction vessel 2 includes a vessel body 3, and an extraction chamber 4 with an open upper end is provided inside the vessel body 3. An extraction frame 5, a pressure venting component 6, and a sealing pressurization assembly 7 are arranged sequentially from bottom to top inside the extraction chamber 4. A through hole 8 communicating with the extraction chamber 4 is also provided on the side wall of the vessel body 3 in the area where the pressure venting component 6 is located. The sealing pressurization assembly 7 is used to seal the extraction chamber 4 in the area where the extraction frame 5 and the pressure venting component 6 are located, and to press the pressure venting component 6 and the extraction frame 5 in sequence. A first temperature sensor 9 is also provided inside the sealing pressurization assembly 7, and the detection end of the first temperature sensor 9 extends into the extraction chamber 4 in the area where the pressure venting component 6 is located. An extraction medium inlet 10 is also provided at the bottom of the extraction chamber 4. An extraction medium heat exchange tube 11 is also provided inside the heat exchange base 1, and the outlet end of the extraction medium heat exchange tube 11 is connected to the extraction medium inlet 10.

[0068] In practical applications, the reactor 2 is vertically positioned, with its lower end partially enclosed and connected to the heat exchange base 1, forming an integrated structure. During use, the material is placed in the extraction frame 5 beforehand. Then, the extraction frame 5, the pressure venting component 6, and the sealing pressurization assembly 7 are sequentially installed into the extraction chamber 4. The sealing pressurization assembly 7 applies downward pressure to the extraction frame 5 and the pressure venting component 6 for stability, simultaneously sealing the extraction chamber 4 where the extraction frame 5 and the pressure venting component 6 are located. The reactor body 3 is then heated to the design temperature using the heat exchange base 1. Liquid extraction medium is then introduced into the extraction medium heat exchange tube 11. The liquid extraction medium is preheated within the heat exchange base 1 before being introduced into the reactor. The extraction medium enters the extraction chamber 4 through the inlet 10. Under the influence of temperature and pressure in the extraction chamber 4, the liquid extraction medium is converted into a supercritical state and enters the extraction frame 5 to extract the material. The extracted material is collected from the pressure exhaust component 6 and discharged to the through hole 8. A condenser can be added after the through hole 8 to separate the extracted substances, thus achieving supercritical extraction. During the extraction process, the first temperature sensor 9 continuously monitors the extraction environment temperature in the extraction chamber 4, and can adjust the temperature of the heat exchange base 1 in real time according to the detection results. After the extraction is completed, the sealed pressurization component 7, the pressure exhaust component 6, and the extraction frame 5 are removed in sequence, and the material is reloaded. The above steps are repeated.

[0069] Based on this, this embodiment uses the heat exchange base 1 to heat the reactor 2 and preheat the liquid extraction medium, making it easier to achieve the extraction temperature of the reactor 2. Preheating the liquid extraction medium can increase its overall temperature when entering the extraction chamber 4, shorten the time it takes to convert to a supercritical state, and reduce heat consumption in the extraction chamber 4, avoiding a drop in temperature within the extraction chamber 4. At the same time, the first temperature sensor 9 continuously monitors the extraction environment temperature within the extraction chamber 4, thereby enabling real-time detection of the extraction environment temperature based on the extraction conditions required for material extraction. The temperature of the reactor body 3 can be changed in real-time by controlling the heat exchange temperature of the heat exchange base 1, which in turn changes the temperature within the extraction chamber 4 through heat transfer. This achieves real-time temperature monitoring and adjustment, greatly improving extraction efficiency and quality while reducing extraction costs.

[0070] It should be noted that, in this embodiment, the reactor 2 needs to exchange heat with the heat exchange base 1 to change the temperature inside the extraction chamber 4. Therefore, the reactor body 3 of the reactor 2 can be made of a thermally conductive metal material such as 304 stainless steel to facilitate rapid heat conduction. Similarly, the extraction medium heat exchange tube 11 can also be made of the same or similar heat transfer material to achieve heat exchange of the liquid extraction medium. In practice, in order to reduce heat loss and improve extraction completeness, the extraction chamber 4 at least in the area where the extraction frame 5 and the pressure exhaust component 6 are located at the lower end of the reactor body 3 is enclosed in the heat exchange base 1, or at least the height of the material is lower than that of the heat exchange base 1. At the same time, since the conditions required for the supercritical state of carbon dioxide are easier to achieve, carbon dioxide can be used as the extraction medium in this embodiment. In the following explanations and descriptions, the extraction medium mentioned can be understood as carbon dioxide.

[0071] like Figure 5 As shown, the extraction frame 5 consists of an extraction cylinder 12 and end plates 13 connected to both ends of the extraction cylinder 12; the extraction cylinder 12 is formed by sintered metal mesh; the end plates 13 are fixedly connected to both ends of the extraction cylinder 12, and a through hole 14 is formed in the middle of the end plate 13 to communicate with the extraction chamber 4 in the area where the pressure exhaust component 6 is located, and a detachable mesh cover plate 15 is provided in the through hole 14.

[0072] Sintered metal mesh is manufactured using single or multiple layers of woven metal wire mesh through special lamination pressing and vacuum sintering processes. The mesh openings form natural fluid channels. When in use, the extraction medium can use the mesh openings as a path to enter and exit the extraction frame 5, thus forming a multi-path extraction channel. This results in more thorough and uniform material extraction, improving the extraction effect. At the same time, the end plate 13 with through holes 14 combined with the mesh cover plate 15 not only facilitates the loading, unloading, and sealing of materials but also does not affect the flow of the extraction medium, further improving the utilization rate of the extraction medium and the extraction efficiency.

[0073] In practical implementation, the through hole 14 is provided with an internal thread, and a clamping ring is fitted with the internal thread. The clamping ring is used to press the mesh cover plate 15 and realize the detachable connection of the mesh cover plate 15.

[0074] like Figure 6 As shown, the pressure-bearing exhaust component 6 includes an annular body 16, the diameter of which is smaller than the diameter of the extraction chamber 4. The side wall of the annular body 16 is provided with a plurality of medium through holes 17. The lower end of the annular body 16 is connected to a flared opening 18. The upper end of the extraction frame 5 forms an inclined wall that matches the inner wall of the flared opening 18. The pressure-bearing exhaust component 6 positions the extraction frame 5 by matching the flared opening 18 with the inclined wall. A first sealing component 19 is also provided between the flared opening 18 and the inclined wall.

[0075] After passing through the lower extraction frame 5, the extraction medium can be collected through the flared opening 18 and the annular body 16, and discharged into the external extraction chamber 4 through the medium passage 17 on it, so as to be discharged through the through hole 8. In use, the annular body 16 is horizontally set to evenly bear the downward pressure of the closed pressurizing component 7. Under the action of the downward pressure, the flared opening 18 is paired with the inclined wall to form a wedge-shaped pairing structure, so that the pressure-bearing exhaust component 6 can evenly apply pressure to the extraction frame 5, avoiding local stress on the extraction frame 5 and deformation or damage. At the same time, after pairing, the end face of the flared opening 18 squeezes the first sealing component 19, thereby sealing the extraction chamber 4 in the area where the first sealing component 19 is located, preventing the extraction medium from directly entering the pressure-bearing exhaust component 6 from this gap and ensuring that the extraction medium is fully utilized.

[0076] In specific implementation, the outer diameter of the flared end of the trumpet-shaped flare 18 is equal to or slightly smaller than the inner diameter of the extraction chamber 4, so that when installed, the trumpet-shaped flare 18 can fully compress the first sealing member 19 to deform it and achieve a sealing effect.

[0077] In practice, the first sealing element 19 is an O-ring.

[0078] like Figure 7 As shown, the closed pressurization assembly 7 includes, from bottom to top, a sealed head 20, a pressure cap 21, and a pressure-bearing screw sleeve 22 that are pressed together in sequence. The pressure-bearing screw sleeve 22 is threadedly connected to the inner wall of the extraction chamber 4 and partially extends into the vessel body 3. It also includes a screw 23, which passes through the pressure-bearing screw sleeve 22 and the pressure cap 21 and is connected to the sealed head 20. The top of the screw 23 extends out of the pressure-bearing screw sleeve 22 and is threadedly connected to a lifting nut 24. A baffle 25 is also fitted between the lifting nut 24 and the pressure-bearing screw sleeve 22. A sleeve 26 is axially inserted through the middle of the screw 23. The lower end of the sleeve 26 passes through the sealed head 20 and extends into the extraction chamber 4 in the area where the pressure-bearing exhaust component 6 is located. The first temperature sensor 9 is disposed inside the sleeve 26.

[0079] In use, the end cap 20, pressure cap 21, and pressure-bearing screw sleeve 22 are sequentially installed into the extraction chamber 4. The pressure-bearing screw sleeve 22 is threaded to the inner wall of the extraction chamber 4 to press all the lower components together. During installation, the end cap 20, pressure cap 21, pressure-bearing screw sleeve 22, and screw 23 are installed as a whole. After installation, the lifting nut 24 can rotate the lower baffle 25 so that the baffle 25 presses against the upper end of the pressure-bearing screw sleeve 22, thus stabilizing the overall structure. During disassembly, the lifting nut 24 can be rotated and moved away from the pressure-bearing screw sleeve 22 to leave a disassembly gap. Then, the pressure-bearing screw sleeve 22 is rotated to rise to the disassembly gap height. At this time, the pressure cap 21 separates from the pressure-bearing screw sleeve 22. Then, the pressure-bearing screw sleeve 22 and the lifting nut 24 are rotated upwards simultaneously, and the end cap 20 and pressure cap 21 are lifted synchronously under the drive of the screw 23 until the end cap 20, pressure cap 21, and pressure-bearing screw sleeve 22 are completely removed from the extraction chamber 4.

[0080] In practical implementation, the lifting nut 24 and the pressure sleeve 22 can be provided with disassembly handles around their circumferences to facilitate rotation during installation and removal, thereby reducing the difficulty of installation and removal.

[0081] In a specific implementation, the lower sidewall of the end cap 20 is provided with a first sealing groove, and a second sealing element 27 is provided in the first sealing groove. A sealing plate 28 is also fixedly provided on the lower end face of the end cap 20. The sealing plate 28 partially closes the first sealing groove to compress the second sealing element 27, and the sealing plate 28 abuts against the pressure-bearing exhaust element 6. The upper sidewall of the end cap 20 is also provided with a second sealing groove, and a third sealing element 29 is provided in the second sealing groove. The pressure cap 21 partially extends into the second sealing groove to compress the third sealing element 29.

[0082] To further enhance the sealing effect of the extraction chamber 4, in this embodiment, after the lower end of the end cap 20 is provided with a second sealing element 27, it can be squeezed and deformed in the first sealing groove under the pressure of the sealing plate 28 and the enclosure of the inner wall of the extraction chamber 4 to form a seal. At the same time, a third sealing element 29 is provided at the upper end of the end cap 20. The third sealing element 29 is squeezed and deformed synchronously under the pressure of the pressure cap 21 to seal the upper end of the end cap 20, ensuring that the end cap 20 can completely seal the lower end of the extraction chamber 4, further ensuring the extraction environment pressure and sealing performance. In addition, the sealing plate 28 abuts against the pressure-bearing exhaust element 6, so that when the end cap 20 squeezes the pressure-bearing exhaust element 6, the sealing plate 28 can replace the end cap 20 to bear the force, reducing the degree of damage to the end cap 20 and facilitating its long-term use.

[0083] In practical implementation, the sealing plate 28 can be detachably connected to the lower end of the end cap 20 via screws or other movable connectors, thus facilitating replacement in case of damage. Furthermore, the sealing plate 28 can be made of high-strength metals such as 304 stainless steel, thereby increasing its service life.

[0084] In specific implementation, the second sealing element 27 can be an O-ring, and the third sealing element 29 can be a gasket, and the gasket can be configured with a multi-layer structure.

[0085] Continue reading Figure 3 The heat exchange base 1 has a heat exchange cavity 30 enclosed inside. The heat exchange base 1 is provided with a ventilation hole, a heat exchange medium hole and a mounting hole that communicate with the heat exchange cavity 30. A second temperature sensor 31 is installed in the mounting hole. The bottom part of the vessel body 3 is located inside the heat exchange cavity 30, and the extraction medium heat exchange tube 11 is coiled around the outer wall of the vessel body 3 inside the heat exchange cavity 30.

[0086] The heat exchange base 1 is mainly used to provide a heat source to heat the vessel body 3 and preheat the extraction medium in the extraction medium heat exchange tube 11. During use, a heat source such as hot water at the designed temperature can be introduced into the heat exchange chamber 30 through the heat exchange medium hole. The vessel body 3 and the extraction medium heat exchange tube 11 can be heated by heat transfer. The second temperature sensor 31 can detect the temperature of the heat source in the heat exchange chamber 30 in real time. When necessary, the vent can be opened to release air and balance the pressure in the heat exchange chamber 30.

[0087] In a specific implementation, the heat exchange base 1 is further provided with a jacket 32 ​​inside its side wall, and a heating component is disposed within the jacket; the heat exchange chamber 30 is further provided with a heat insulation layer 33 on its side wall. The heating component can heat the heat source in the heat exchange chamber 30 when the temperature decreases or needs to be increased, so as to adjust the extraction environment temperature according to the extraction needs. The heat insulation layer 33 can play a good role in heat preservation, reducing heat loss in the heat exchange chamber 30. Specifically, the heating component can be a heating coil wound inside the jacket 32.

[0088] Continue reading Figure 3 The extraction medium inlet 10 is located at the bottom center of the extraction chamber 4, and a mushroom-shaped nozzle 34 is also provided at the port of the extraction medium inlet 10. In this embodiment, the mushroom-shaped nozzle 34 is used to achieve the divergent injection of the extraction medium. Under pressure, it diffuses upwards through more paths. Combined with the structural design of the extraction cylinder 12, this allows for more thorough contact between the supercritical extraction medium and the material, and the temperature change within the extraction chamber 4 is more uniform. This further ensures extraction efficiency while also allowing for better temperature control.

[0089] The second embodiment of the present invention also discloses a supercritical extraction method based on the above-mentioned supercritical extraction apparatus, which includes the following steps:

[0090] S1 Place the material in the extraction frame 5 and put it into the extraction chamber 4, and then install the pressure-bearing exhaust component 6 and the closed pressurization component 7 in sequence;

[0091] A heat exchange medium is introduced into the S2 heat exchange chamber 30. The liquid extraction medium, pressurized to the design pressure, is input into the extraction medium heat exchange tube 11 for heat exchange and temperature rise, and then enters the extraction chamber 4. Under the action of pressure and temperature in the extraction chamber 4, the extraction medium is converted into a supercritical state. The supercritical extraction medium extracts the material in the extraction frame 5 and forms a mixed extraction gas. The mixed extraction gas is discharged through the pressure exhaust component 6 and the through hole 8.

[0092] S3 continuously acquires the gas outlet temperature T2 and the heating temperature T0 of the heat exchange medium in the extraction chamber 4 based on the first temperature sensor 9 and the second temperature sensor 31, and performs real-time heat exchange medium temperature control compensation based on the acquired gas outlet temperature and the heating temperature of the heat exchange medium.

[0093] After the designed extraction time is reached (S4), the flow of liquid extraction medium is stopped, and the sealed pressurization component 7 and the pressure exhaust component 6 are disassembled in sequence, and the extraction frame 5 is removed to complete the supercritical extraction.

[0094] It should be noted that supercritical extraction processes generally correspond to optimal extraction temperatures and pressures. The purpose of temperature control compensation in step S3 is to control the temperature and pressure inside reactor 2 at the optimal state in order to improve extraction efficiency.

[0095] In this supercritical extraction method, the temperature detected by the first temperature sensor 9 during use is the reaction temperature inside the reactor 2. However, the measured temperature still deviates from the actual reaction temperature inside the reactor 2, i.e., the extraction chamber 4. Based on this, during the experiment with the supercritical extraction device, the inventors found that the gas outlet temperature T2, i.e., the temperature detected by the first temperature sensor 9, still cannot accurately represent the reaction temperature inside the reactor 2. The main reason is that the temperature field inside the reactor 2 is a dynamic temperature field, which is difficult to control when affected by external heating and cooling and gas discharge. Therefore, in order to further increase the efficiency of the reactor 2, this method further provides a scheme to compensate for the heating temperature T0 by using a preset temperature compensation model.

[0096] Specifically, the real-time temperature control and compensation of the heat exchange medium includes:

[0097] S31 Obtain the optimal pressure and optimal temperature corresponding to the optimal efficiency conditions of the current supercritical extraction process, and obtain the gas outlet temperature T2 of the reactor based on the first temperature sensor, and obtain the heating temperature T0 for heating the outer wall of the reactor based on the second temperature sensor.

[0098] S32 inputs the optimal pressure, the gas outlet temperature T2, and the optimal temperature into a preset temperature compensation model, and receives the output of the temperature compensation model as temperature compensation data.

[0099] S33 adjusts the heating temperature T0 according to the temperature compensation data to achieve temperature compensation adjustment inside the reactor.

[0100] Based on the above compensation scheme, temperature compensation data can be calculated using a pre-set temperature compensation model. Adjusting T0 with this temperature compensation data will control the temperature inside the reactor 2 at the optimal extraction temperature. The temperature compensation model can be a fitted empirical model or a model trained using a neural network. This embodiment of the application, through the above technical means, can compensate and control the temperature inside the reactor 2 based on temperature data collected outside the reactor 2 and the temperature compensation model. This allows the temperature inside the reactor 2 to be controlled relatively stably near the optimal temperature, improving the extraction efficiency within the reactor 2.

[0101] In practice, the gas is preheated on the outer wall of the reactor before entering it, and the extraction gas enters the reactor at the bottom.

[0102] During implementation, the gas pipeline, i.e. the heat exchange tube 11 of the extraction medium, needs to be preheated through the pipe wrapped around the outer wall of the reactor before entering the reactor from the bottom; at the same time, the pipeline and the outer wall of the reactor are immersed in the heating liquid, the temperature of which is the heating temperature T0; due to the difficulty of heat transfer experiments and analysis of supercritical substances, the experiments and analyses in the subsequent embodiments are based on the structure of the reactor of the supercritical extraction device of the above embodiments.

[0103] In practical implementation, the construction of the temperature compensation model includes:

[0104] A dynamic simulation test of open-loop temperature regulation at atmospheric pressure was conducted on the reactor to obtain the external and internal heat transfer parameters of the reactor.

[0105] A thermal conductivity simulation model of the reactor is constructed based on the external heat transfer parameters and the internal heat transfer parameters, and a pressure calculation is performed on the thermal conductivity simulation model to generate calculation results.

[0106] The temperature compensation model is constructed based on the calculation results.

[0107] In the implementation of this application embodiment, the dynamic simulation test of open-loop temperature regulation at atmospheric pressure refers to a dynamic simulation test of temperature regulation of the reactor under atmospheric pressure. Since the test is conducted under atmospheric pressure, T1 can be obtained by installing a temperature sensor inside the reactor, such as the first temperature sensor 9. In this application embodiment, the inventors found in the experiment that T1 is mainly affected by two heat transfer methods in the reaction of the above-mentioned reactor. The first method is the heating of the outer wall of the reactor and the preheating of the gas before it enters the reactor; the second method is the removal of heat by the gas after supercritical extraction. Due to the complexity of the heat transfer law under supercritical conditions, in this application embodiment, the heat transfer process of the first method is summarized by external heat transfer parameters, and the heat transfer process of the second method is summarized by internal heat transfer parameters. That is, the external heat transfer parameters characterize the influence of heating the outer wall of the reactor and the gas preheating; the internal heat transfer parameters characterize the influence of the gas removal after supercritical extraction. For the external heat transfer parameters, they should not change after the reactor is actually pressurized, while for the internal heat transfer parameters, they will change after the reactor is actually pressurized. Based on the above principles, a thermal conductivity simulation model of the reactor can be constructed, and the internal heat transfer parameters can be iteratively updated during the pressurization simulation to achieve simulation of the reactor under different pressure adjustments, and the simulation results are closer to the actual situation.

[0108] In practical implementation, a dynamic simulation test of open-loop temperature regulation at atmospheric pressure is conducted on the reactor to obtain the external and internal heat transfer parameters of the reactor, including:

[0109] A dynamic simulation test of open-loop temperature regulation at atmospheric pressure was conducted on the reactor, and the gas outlet temperature T2', the heating temperature T0' of the outer wall of the reactor, and the reaction temperature T1' inside the reactor were recorded during the atmospheric pressure test; the pressure inside the reactor was atmospheric pressure during the dynamic simulation test of open-loop temperature regulation at atmospheric pressure.

[0110] The gas outlet of the reactor is sealed, T0' is heated to a constant temperature T and the curve of T0' changing over time is recorded as the first temperature change curve, and the curve of T1' changing over time is recorded as the second temperature change curve.

[0111] Record the moment when the first temperature change curve reaches a constant temperature T as the first moment, and record the moment when the second temperature change curve reaches a constant temperature T as the second moment;

[0112] The external heat transfer parameters of the reactor are calculated based on the difference between the first and second time points, and the difference between the initial temperatures of the isothermal T and the second temperature change curve.

[0113] Open the gas outlet of the reactor, keep T0' at a constant temperature T, and record the curve of T2' changing over time as the third temperature change curve;

[0114] The moment when the third temperature change curve reaches a constant temperature T is recorded as the third moment, and the moment when the gas outlet of the reactor is opened is recorded as the fourth moment;

[0115] The internal heat transfer parameters of the reactor are calculated based on the difference between the fourth and third time points, and the difference between the constant temperature T and the initial temperature of the third temperature change curve.

[0116] In practical implementation, this embodiment provides a technical solution for obtaining external and internal heat transfer parameters in actual experiments. For external heat transfer parameters, after sealing the gas outlet of the reactor, the reaction temperature inside the reactor will eventually reach the same temperature as the heating temperature of the outer wall of the reactor during the heating process, i.e., a constant temperature T is reached. The external heat transfer parameters can be calculated using the heat transfer time and the initial temperature difference. Similarly, for internal heat transfer parameters, opening the gas outlet of the reactor will generate a third temperature change curve. The internal heat transfer parameters can be calculated using the temperature difference change and heat transfer time of the third temperature change curve. Since the internal heat transfer parameters are inherently uncertain initial parameters, an approximate initial value can be calculated in this way for subsequent numerical simulations.

[0117] In practical implementation, a thermal conductivity simulation model of the reactor is constructed based on the external heat transfer parameters and the internal heat transfer parameters, and the simulation model is pressurized to generate calculation results, including:

[0118] A thermal conductivity simulation model of the reactor is constructed based on the internal heat transfer parameters and the external heat transfer parameters, and the internal heat transfer parameters are used as the initial parameters for internal heat transfer in the thermal conductivity simulation model.

[0119] The internal pressure of the reactor in the thermal conductivity simulation model is calculated, and the internal heat transfer parameters are iterated.

[0120] The gas outlet temperature T2'', the outer wall heating temperature T0'', the reaction temperature T1'', and the pressure N inside the reactor are obtained from multiple sets of pressurization calculation results to form multiple sets of data to be fitted as the calculation results.

[0121] During implementation, when constructing the thermal conductivity simulation model of the reactor, simulation software with heat transfer analysis capabilities, such as commercial CFD software, can be used. The internal heat transfer parameters are used as initial parameters in the thermal conductivity simulation model. During pressurization calculations, a step size is set for the pressure increase. At each step increase, the internal heat transfer parameters in the model are iteratively calculated until convergence, completing the calculation for that step size change and recording a set of data to be fitted. Multiple sets of data to be fitted can be obtained when multiple step sizes are calculated.

[0122] In practical implementation, constructing the temperature compensation model based on the calculation results includes:

[0123] Based on the data to be fitted, T2'', T1'', T0'' and N are fitted to form a fitting function T0''=f(T2'', T1'', N);

[0124] The fitting function T0''=f(T2'', T1'', N) is used as the temperature compensation model.

[0125] In the implementation of the embodiments of this application, the fitting function T0''=f(T2'', T1'', N) can adopt the polynomial fitting scheme in the prior art, or it can adopt the scheme of performing polynomial fitting on N, T1'' and T2'' and performing polynomial fitting on T0'' and T1'' to form a system of equations.

[0126] In specific implementation, the optimal pressure, the gas outlet temperature T2, and the optimal temperature are input into a preset temperature compensation model, and the output results of the temperature compensation model are received as temperature compensation data, including:

[0127] The optimal pressure is used as N in the fitting function, the gas outlet temperature T2 is used as T2'' in the fitting function, and the optimal temperature is used as T1'' in the fitting function.

[0128] The calculation result T0'' of the fitting function is received as temperature compensation data.

[0129] In specific implementation, adjusting the heating temperature T0 based on the temperature compensation data to achieve temperature compensation adjustment inside the reactor includes:

[0130] The heating temperature T0 is adjusted to the calculated result T0'' of the fitting function to complete the compensation adjustment of the temperature inside the reactor.

[0131] This supercritical extraction method is based on the above-mentioned supercritical extraction device. It can not only ensure sufficient contact between the extraction medium and the material, but also compensate for the temperature inside the reactor by using temperature data collected outside the reactor and a temperature compensation model. This allows the temperature inside the reactor to be controlled relatively stably near the optimal temperature, improving the extraction efficiency and quality, and greatly shortening the extraction time and reducing costs. It is suitable for widespread application and promotion.

[0132] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A supercritical fluid extraction method, characterized in that, Includes the following steps: S1 Place the material in the extraction frame and into the extraction chamber, then install the pressure-bearing exhaust component and the closed pressurization component in sequence; The heat exchange medium is introduced into the S2 heat exchange chamber. The liquid extraction medium pressurized to the design pressure is input into the extraction medium heat exchange tube for heat exchange and temperature rise and enters the extraction chamber. Under the action of pressure and temperature in the extraction chamber, the extraction medium is converted into a supercritical state. The supercritical extraction medium extracts the material in the extraction frame and forms a mixed extraction gas. The mixed extraction gas is discharged through the pressure exhaust component and the through hole. S3 continuously acquires the gas outlet temperature T2 and the heating temperature T0 of the heat exchange medium in the extraction chamber based on the first temperature sensor and the second temperature sensor, and performs real-time temperature control compensation of the heat exchange medium based on the acquired gas outlet temperature T2 and heating temperature T0 of the heat exchange medium. After S4 reaches the designed extraction time, stop the flow of liquid extraction medium, disassemble the sealed pressurization component and the pressure exhaust component in sequence, and take out the extraction frame to complete the supercritical extraction. Specifically, the real-time temperature control and compensation of the heat exchange medium includes: S31 Obtain the optimal pressure and optimal temperature corresponding to the optimal efficiency conditions of the current supercritical extraction process, and obtain the gas outlet temperature T2 of the reactor based on the first temperature sensor, and obtain the heating temperature T0 for heating the outer wall of the reactor based on the second temperature sensor. S32 inputs the optimal pressure, the gas outlet temperature T2, and the optimal temperature into a preset temperature compensation model, and receives the output of the temperature compensation model as temperature compensation data. S33 adjusts the heating temperature T0 according to the temperature compensation data to achieve temperature compensation adjustment inside the reactor; The construction of the temperature compensation model includes: S31 Obtain the optimal pressure and optimal temperature corresponding to the optimal efficiency conditions of the current supercritical extraction process, and obtain the gas outlet temperature T2 of the reactor based on the first temperature sensor, and obtain the heating temperature T0 for heating the outer wall of the reactor based on the second temperature sensor. S32 inputs the optimal pressure, the gas outlet temperature T2, and the optimal temperature into a preset temperature compensation model, and receives the output of the temperature compensation model as temperature compensation data. S33 adjusts the heating temperature T0 according to the temperature compensation data to achieve temperature compensation adjustment inside the reactor; A dynamic simulation test of open-loop temperature regulation at atmospheric pressure was conducted on the reactor to obtain the external and internal heat transfer parameters of the reactor, including: A dynamic simulation test of open-loop temperature regulation at atmospheric pressure was conducted on the reactor, and the gas outlet temperature T2', the heating temperature T0' of the outer wall of the reactor, and the reaction temperature T1' inside the reactor were recorded during the atmospheric pressure test; the pressure inside the reactor was atmospheric pressure during the dynamic simulation test of open-loop temperature regulation at atmospheric pressure. The gas outlet of the reactor is sealed, T0' is heated to a constant temperature T and the curve of T0' changing over time is recorded as the first temperature change curve, and the curve of T1' changing over time is recorded as the second temperature change curve. Record the moment when the first temperature change curve reaches a constant temperature T as the first moment, and record the moment when the second temperature change curve reaches a constant temperature T as the second moment; The external heat transfer parameters of the reactor are calculated based on the difference between the first and second time points, and the difference between the initial temperatures of the isothermal T and the second temperature change curve. Open the gas outlet of the reactor, keep T0' at a constant temperature T, and record the curve of T2' changing over time as the third temperature change curve; The moment when the third temperature change curve reaches a constant temperature T is recorded as the third moment, and the moment when the gas outlet of the reactor is opened is recorded as the fourth moment; The internal heat transfer parameters of the reactor are calculated based on the difference between the fourth time point and the third time point, as well as the difference between the constant temperature T and the initial temperature of the third temperature change curve. A thermal conductivity simulation model of the reactor is constructed based on the external and internal heat transfer parameters, and a pressure calculation is performed on the thermal conductivity simulation model to generate calculation results, including: A thermal conductivity simulation model of the reactor is constructed based on the internal heat transfer parameters and the external heat transfer parameters, and the internal heat transfer parameters are used as the initial parameters for internal heat transfer in the thermal conductivity simulation model. The internal pressure of the reactor in the thermal conductivity simulation model is calculated, and the internal heat transfer parameters are iterated. The gas outlet temperature T2'', the outer wall heating temperature T0'', the reaction temperature T1'', and the pressure N inside the reactor are obtained from multiple sets of pressurization calculation results to form multiple sets of data to be fitted as the calculation results. Constructing the temperature compensation model based on the calculation results includes: Based on the data to be fitted, T2'', T1'', T0'' and N are fitted to form a fitting function T0''=f(T2'', T1'', N); The fitting function T0''=f(T2'', T1'', N) is used as the temperature compensation model.

2. A supercritical extraction apparatus for implementing the supercritical extraction method of claim 1, characterized in that, It includes a heat exchange base and a reaction vessel, wherein the lower end of the reaction vessel is partially enclosed within the heat exchange base; The reactor includes a vessel body, and an extraction chamber with an opening at the top is provided inside the vessel body. An extraction frame, a pressure-bearing exhaust component, and a closed pressurization component are arranged sequentially from bottom to top in the extraction chamber. A through hole communicating with the extraction chamber is also provided on the side wall of the vessel body in the area where the pressure-bearing exhaust component is located. The closed pressurization assembly is used to seal the extraction chamber in the area where the extraction frame and the pressure venting component are located, and to press the pressure venting component and the extraction frame in sequence. The closed pressurization assembly is also equipped with a first temperature sensor, and the detection end of the first temperature sensor extends into the extraction chamber in the area where the pressure venting component is located. The bottom of the extraction chamber is also provided with an extraction medium inlet, and the heat exchange base is also provided with an extraction medium heat exchange tube, the outlet end of which is connected to the extraction medium inlet. in, The extraction frame consists of an extraction cylinder and end plates connected to both ends of the extraction cylinder; The extraction cylinder is enclosed by a sintered metal mesh; The end plate is fixedly connected to both ends of the extraction cylinder, and a through hole is formed in the middle of the end plate to communicate with the extraction chamber in the area where the pressure-bearing exhaust component is located. A detachable mesh cover plate is provided in the through hole. The pressure-bearing exhaust component includes an annular body, the diameter of which is smaller than the diameter of the extraction chamber, and the sidewall of the annular body is provided with several medium through holes. The lower end of the annular body is connected to a flared opening, and the upper end of the extraction frame forms an inclined wall that matches the inner wall of the flared opening. The pressure-bearing exhaust component positions the extraction frame by matching the flared opening with the inclined wall, and a first sealing element is also provided between the flared opening and the inclined wall.

3. The supercritical extraction apparatus according to claim 2, characterized in that, The closed pressurization assembly includes, from bottom to top, a sealed head, a pressure cap, and a pressure-bearing screw sleeve that are pressed together in sequence. The pressure-bearing screw sleeve is threadedly connected to the inner wall of the extraction chamber and extends partially into the vessel body. It also includes a screw rod, which passes through the pressure-bearing screw sleeve and the pressure cap and is connected to the end cap. The top of the screw rod extends out of the pressure-bearing screw sleeve and is threadedly connected to a lifting nut. A baffle is also fitted between the lifting nut and the pressure-bearing screw sleeve on the screw rod. A sleeve is axially inserted through the middle of the screw, and the lower end of the sleeve passes through the end cap and extends into the extraction chamber in the area where the pressure-bearing exhaust component is located. The first temperature sensor is installed inside the sleeve.

4. The supercritical extraction apparatus according to claim 3, characterized in that, The lower end sidewall of the end cap is also provided with a first sealing groove, and a second sealing element is provided in the first sealing groove. A sealing plate is also fixed on the lower end face of the end cap. The sealing plate partially closes the first sealing groove to squeeze the second sealing element, and the sealing plate abuts against the pressure-bearing and venting component. The upper side wall of the end cap is also provided with a second sealing groove, and a third sealing element is provided in the second sealing groove. The pressure cap partially extends into the second sealing groove to compress the third sealing element.

5. The supercritical extraction apparatus according to claim 2, characterized in that, The heat exchange base has a closed heat exchange cavity inside. The heat exchange base is provided with a ventilation hole, a heat exchange medium hole and a mounting hole that communicate with the heat exchange cavity. A second temperature sensor is installed in the mounting hole. The bottom part of the vessel body is located inside the heat exchange chamber, and the extraction medium heat exchange tube is coiled around the outer wall of the vessel body inside the heat exchange chamber.

6. The supercritical extraction apparatus according to claim 5, characterized in that, The heat exchange base is also provided with a sandwich layer inside the side wall, and a heating component is provided inside the sandwich layer; The heat exchange cavity is also provided with a heat insulation layer on its side wall.

7. The supercritical extraction apparatus according to claim 2, characterized in that, The extraction medium inlet is located at the bottom center of the extraction chamber, and the port of the extraction medium inlet is also equipped with a mushroom-shaped nozzle.

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