Membrane extraction apparatus and membrane extraction method

Abstract

The present application belongs to the technical field of battery separator extraction equipment, which comprises an extraction tank, an internal boundary of which defines a containing space; a partition plate arranged in the extraction tank to separate the containing space into an extraction space and a recovery space; a roller group arranged in the extraction space; a liquid inlet arranged at one end of the extraction tank; a baffle mechanism arranged at one end of the partition plate to adjust the overflow width of the extraction liquid; a detection system arranged on the extraction tank to measure the physical properties of the extraction liquid; a temperature control device arranged in the extraction tank to adjust the physical properties of the extraction liquid; and a processor connected with the baffle mechanism and the detection system respectively to receive the overflow width and the physical properties and calculate the Reynolds number of the extraction liquid.

Description

Technical Field

[0001] This invention relates to an extraction apparatus, and more particularly to an apparatus for extracting battery separators. Background Technology

[0002] Countercurrent extraction is a technique for separating mixtures, frequently used to extract organic matter in chemical processes. In continuous countercurrent extraction, the hydrodynamic characteristics of the extractant significantly impact the efficiency of mixture separation and the extraction effect. Specifically, in the field of lithium-ion battery separator technology, traditional countercurrent extraction methods cannot effectively control the fluid properties of the extractant. If the extractant flows through the extraction tank in a laminar flow manner, it cannot remove the white oil at the bottom of the tank, resulting in excessively high oil content at the bottom of the separator and uneven oil content between the bottom and top of the separator. This necessitates using a larger amount of extractant and extracting for a longer time to achieve the desired state for the separator.

[0003] In summary, current conventional techniques for extracting diaphragms rely solely on increasing the feed rate of the extractant to reduce the oil content of the diaphragm. However, increasing the feed rate leads to increased evaporation losses, stronger odors, environmental pollution, and higher recycling costs. In view of these problems, a diaphragm extraction device that can adjust the fluid properties of the extractant to improve the diaphragm extraction effect is urgently needed. Summary of the Invention

[0004] The problem to be solved by the present invention is to provide a diaphragm extraction device that can adjust the fluid properties of the extractant to improve the diaphragm extraction effect.

[0005] To achieve the above objectives, the present invention provides a diaphragm extraction apparatus, characterized in that it comprises: an extraction tank having an internally defined accommodating space; a partition disposed in the extraction tank to divide the accommodating space into an extraction space and a recovery space; a roller assembly disposed in the extraction space to move the diaphragm along a first direction; a liquid inlet disposed at one end of the extraction tank near the extraction space to supply extractant to the extraction space along a second direction, wherein the second direction is opposite to the first direction; a baffle mechanism disposed at one end of the partition to adjust the overflow width of the extractant; a detection system disposed on the extraction tank to measure the physical properties of the extractant in the extraction space; a temperature control device disposed in the extraction tank to adjust the physical properties of the extractant in the extraction space; and a processor connected to the baffle mechanism and the detection system respectively to receive the overflow width and the physical properties, and to calculate the Reynolds number of the extractant.

[0006] More preferably, the baffle mechanism includes: a first baffle plate disposed on the partition, wherein at least one recessed pattern is formed on the first baffle plate, and an overflow space is formed between the first baffle plate and each of the recessed patterns; and a second baffle plate disposed corresponding to the first baffle plate, wherein: at least one blocking pattern is formed on the second baffle plate, wherein each blocking pattern is disposed corresponding to each of the recessed patterns, and the second baffle plate is movable relative to the first baffle plate to move from a first position to a second position, and adjust the area of ​​the overflow space covered by the blocking pattern.

[0007] Preferably, when the second baffle is located in the first position, the area of ​​the overflow space covered by the blocking pattern is at its minimum, so that the overflow width of the extract is at its maximum; and when the second baffle is located in the second position, the area of ​​the overflow space covered by the blocking pattern is at its maximum, so that the overflow width of the extract is at its minimum.

[0008] Preferably, the shape of the recessed pattern includes a semicircle, a triangle, or a quadrilateral; and the shape of the occluding pattern includes a semicircle, a triangle, or a quadrilateral, and the recessed pattern and the occluding pattern may be the same or different.

[0009] More preferably, the detection system includes: a densitometer for detecting the density of the extract in the extraction space; a viscometer for detecting the viscosity of the extract in the extraction space; or a thermometer for detecting the temperature of the extract in the extraction space.

[0010] More preferably, the roller group sequentially includes: a first guide roller, a second guide roller, a third guide roller, a fourth guide roller, and a fifth guide roller along the first direction, wherein: the first guide roller, the third guide roller, and the fifth guide roller are set at a height of H1; and the second guide roller and the fourth guide roller are set at a height of H2, and H1>H2.

[0011] Preferably, the Reynolds number (Re) is calculated according to the following formula:

[0012]

[0013] Where Q is the flow rate of the extract through the baffle mechanism per unit time, v is the kinematic viscosity of the extract in the extraction space, and L is the flow width of the extract when it flows through the baffle mechanism, i.e., the overflow width.

[0014] More preferably, the first direction is an extending direction of movement from the recovery space to the extraction space; and the second direction is an extending direction of movement from the extraction space to the recovery space.

[0015] Preferably, the temperature control device includes: a first electric heating element disposed on the side of the extraction space that contacts the partition; and a second electric heating element disposed on the side of the extraction space that is furthest from the recovery space.

[0016] More preferably, it further includes: a stirring device disposed in the extraction space to stir the extract in the extraction space.

[0017] The present invention further provides a diaphragm extraction method, characterized in that it includes: (S1) obtaining the diaphragm extraction device as described above; (S2) starting the stirring device to stir the extract in the extraction space, and after stirring for a preset time, proceeding to step (S3); (S3) measuring the density of the upper and lower layers of the extract in the extraction space using the detection system, and determining whether the densities of the two are consistent using the processor, wherein: if the densities are consistent, proceeding to step (S4); if the densities are inconsistent, repeating step (S2); (S4) calculating the Reynolds number of the extract in the extraction space using the processor, wherein: if the Reynolds number of the extract is consistent, proceeding to step (S4); if the Reynolds number is inconsistent, proceeding to step (S4); if the Reynolds number is inconsistent, proceeding to step (S5); if the Reynolds number is inconsistent, proceeding to step (S6); if the Reynolds number is inconsistent, proceeding to step (S7); if the Reynolds number is inconsistent, proceeding to step (S8); if the Reynolds number is inconsistent, proceeding to step (S9); if the Reynolds number is inconsistent, proceeding to step (S1); if the Reynolds number is inconsistent, proceeding to step (S2); if the Reynolds number is inconsistent, proceeding to step (S1); if the Reynolds number is inconsistent, proceeding to step (S2); if the Reynolds number is inconsistent, proceeding to step (S3); if the Reynolds number is inconsistent, proceeding to step (S4 ... If the Reynolds number is less than 4500, proceed to step (S5); if the Reynolds number is greater than 8000, proceed to step (S6); if the Reynolds number is between 4500 and 8000, proceed to step (S7); (S5) based on the Reynolds number, control the baffle mechanism to shorten the overflow width, or control the temperature control device to increase the temperature of the extract, and return to step (S4); (S6) based on the Reynolds number, control the baffle mechanism to increase the overflow width, or control the temperature control device to decrease the temperature of the extract, and return to step (S4); and (S7) the extract meets the requirements, and the process ends.

[0018] The advantages of this invention over prior art are as follows: The membrane extraction device of this invention is equipped with a baffle mechanism, which can control the overflow width of the extractant flowing from the extraction space to the recovery space, thereby regulating the Reynolds value of the extractant and improving its fluid properties for membrane extraction. Furthermore, the membrane extraction device of this invention is equipped with a temperature control device, which can control the kinematic viscosity of the extractant by heating or cooling it, thereby regulating the Reynolds value and improving its fluid properties for membrane extraction. Specifically, this invention can control the extractant to extract the membrane with the most suitable fluid properties, quickly and uniformly removing white oil from the membrane while simultaneously cleaning the white oil at the bottom of the extraction tank to prevent it from re-adhering to the membrane surface, ensuring that the extracted membrane directly meets the processing requirements of lithium-ion batteries. In addition, since the membrane extraction device and method provided by this invention do not require increasing the feed volume of the extractant, waste, pollution, and cost losses caused by the extractant can be prevented. Attached Figure Description

[0019] Figures 1A to 1B A series of three-dimensional diagrams are used to illustrate the structural features of the diaphragm extraction device;

[0020] Figure 2A This is a three-dimensional exploded view used to illustrate the structural features of the baffle mechanism;

[0021] Figures 2B to 2C A series of 3D diagrams are used to illustrate how to adjust the overflow width;

[0022] Figures 3A to 3B A series of floor plans illustrating how to adjust the overflow width;

[0023] Figure 4 This is a flowchart illustrating the steps of the membrane extraction method. Detailed Implementation

[0024] To make the above and / or other objects, effects, and features of the present invention more apparent and understandable, preferred embodiments are described in detail below:

[0025] The purpose of this invention is to provide a membrane extraction device 1, wherein, as Figure 1AAs shown, it includes: an extraction tank 2, which internally defines a receiving space 3; a partition 4, disposed in the extraction tank 2, to divide the receiving space 3 into an extraction space 5 and a recovery space 6; a roller group 7, disposed in the extraction space 5, to move along a first direction 8 with the diaphragm; a liquid inlet 9, disposed at one end of the extraction tank 2 near the extraction space 5, to supply extractant to the extraction space 5 along a second direction 10, wherein the second direction 10 is opposite to the first direction 8; and a baffle mechanism 12, which is provided with... At one end of the baffle 4, the overflow width of the extract is adjusted; a detection system 13 is disposed on the extraction tank 2 to measure the physical properties of the extract in the extraction space 5; a temperature control device 14 is disposed in the extraction tank 2 to adjust the physical properties of the extract in the extraction space 5; and a processor 15 is connected to the baffle mechanism 12 and the detection system 13 respectively to receive the overflow width and the physical properties, and calculate the Reynolds number of the extract. In a preferred embodiment, the first direction 8 is the extending direction of movement from the recovery space 6 to the extraction space 5; and the second direction 10 is the extending direction of movement from the extraction space 5 to the recovery space 6. In another preferred embodiment, the first direction 8 and the second direction 10 are parallel to each other, but are not limited thereto. In another preferred embodiment, the processor 15 is disposed on the extraction tank 2, a wearable electronic device, a computer, a mobile phone, a tablet, a remote control, or other mobile device, and can be selectively electrically or signal-connected to the baffle mechanism 12 and the detection system 13. In yet another preferred embodiment, it further includes a stirring device 11, disposed in the extraction space 5, for stirring the extract in the extraction space 5.

[0026] Preferably, to regulate the temperature of the extract, the temperature control device 14 includes a cooling device or a heating device. Specifically, to increase the temperature of the extract, wherein... Figures 1A to 1B As shown, the temperature control device 14 includes: a first electric heating element 29, disposed on the side of the extraction space 5 that contacts the partition 4; and a second electric heating element 30, disposed on the side of the extraction space 5 that is furthest from the recovery space 6. In a preferred embodiment, to reduce the temperature of the extract, the temperature control device 14 includes: a first cooling element, disposed on the side of the extraction space 5 that contacts the partition 4; and a second cooling element, disposed on the side of the extraction space 5 that is furthest from the recovery space 6.

[0027] Specifically, by calculating the Reynolds number (Re), the flow pattern of the extract can be determined. When the Reynolds number (Re) is less than 2000, the flow is laminar, with no mixing between fluid layers, resulting in a smooth and orderly flow. When the Reynolds number (Re) is greater than 4000, the flow is turbulent, with strong mixing between fluid layers, resulting in a complex and disordered flow. When the Reynolds number (Re) is between 2000 and 4000, the flow is in a transitional state, exhibiting flow characteristics between laminar and turbulent flow. Specifically, compared to traditional methods, this invention controls the Reynolds number (Re) of the extract to induce turbulent flow, effectively removing white oil from the diaphragm and simultaneously cleaning the white oil deposited at the bottom of the extraction tank 2, thereby reducing the oil content of the diaphragm. Furthermore, this invention can also reduce the feed rate of the extract and improve the countercurrent extraction effect on separating white oil from the diaphragm by adjusting the overflow width (L) or temperature of the extract.

[0028] Preferably, to measure the physical properties of the extract, the detection system 13 includes: a densitometer 21 for detecting the density of the extract in the extraction space 5; a viscometer 22 for detecting the viscosity of the extract in the extraction space 5; or a thermometer 23 for detecting the temperature of the extract in the extraction space 5. Specifically, to ensure the uniformity of the extract from the separator and avoid the presence of white oil of different concentrations or thicknesses at different locations on the separator, which could affect the performance of the separator in subsequent battery fabrication, the extract is stirred by a stirring device 11 to ensure that the density of the extract in the extraction space 5 is consistent at different heights. In a preferred embodiment, the temperature of the extract affects the viscosity; the higher the temperature, the lower the viscosity. Viscosity, in turn, affects the Reynolds number of the extract. Therefore, the change in the Reynolds number of the extract can be calculated by measuring these two physical properties. In another preferred embodiment, the viscosity measured by the viscometer 22 is the kinematic viscosity (v), but this is not a limitation. In another preferred embodiment, the density of the extract is 1.18 to 1.32, or the flow rate of the extract is 2 to 6 cubic meters per hour, but not limited thereto.

[0029] Preferably, in order to ensure that all parts of the diaphragm are in full contact and react with the extract to effectively remove the white oil on the diaphragm, the roller group 7 sequentially includes the following along the first direction 8: a first guide roller 24, a second guide roller 25, a third guide roller 26, a fourth guide roller 27, and a fifth guide roller 28, wherein: the first guide roller 24, the third guide roller 26, and the fifth guide roller 28 are set at a height of H1; and the second guide roller 25 and the fourth guide roller 27 are set at a height of H2, and H1>H2.

[0030] Even better, in order to precisely control the overflow width of the extract, adjust the Reynolds number of the extract, and make the fluid properties of the extract more efficient and uniform in removing white oil from the diaphragm, such as... Figures 2A to 2C As shown, the baffle mechanism 12 includes: a first baffle 16 disposed on the partition 4, wherein at least one recessed pattern 17 is formed on the first baffle 16, and an overflow space 18 is formed between the first baffle 16 and each of the recessed patterns 17; and a second baffle 19 disposed corresponding to the first baffle 16, wherein at least one blocking pattern 20 is formed on the second baffle 19, wherein each blocking pattern 20 is disposed corresponding to each of the recessed patterns 17, and the second baffle 19 is movable relative to the first baffle 16 to move from a first position to a second position, and adjust the area of ​​the blocking pattern 20 covering the overflow space 18. In a preferred embodiment, when the second baffle 19 is located in the first position, the area of ​​the obstruction pattern 20 covering the overflow space 18 is minimized, making the overflow width of the extract maximized; and when the second baffle 19 is located in the second position, the area of ​​the obstruction pattern 20 covering the overflow space 18 is maximized, and the overflow width of the extract is minimized. However, the first and second positions are not limited to the above, and the initial position of the second baffle 19 relative to the first baffle 16 can be freely set, allowing for more flexible adjustment of the overflow width of the extract. In another preferred embodiment, as... Figure 3A As shown, the overflow space 18 on the first baffle 16 is not blocked by the blocking pattern 20 on the second baffle 19, and the overflow width of the extract is the original length LA; and as shown Figure 3B As shown, the overflow space 18 on the first baffle 16 is blocked by the blocking pattern 20 on the second baffle 19. At this time, the overflow width of the extract is shortened to LB+LC. In this way, the overflow width of the extract can be adjusted, and thus the Reynolds number (Re) of the extract can be adjusted.

[0031] More preferably, in order to cover the recessed pattern 17 with the masking pattern 20 to adjust the overflow width of the extract, the shape of the recessed pattern 17 includes a semicircle, a triangle, or a quadrilateral; and the shape of the masking pattern 20 includes a semicircle, a triangle, or a quadrilateral, and the recessed pattern 17 and the masking pattern 20 may be the same or different. In a preferred embodiment, the quadrilateral includes a rectangle, a square, a trapezoid, or a rhombus, but is not limited thereto. In another preferred embodiment, the recessed patterns 17 formed on the first baffle 16 are equidistant and sequentially arranged along an extending direction to form a serrated structure, wherein: a serrated pattern is formed between every pair of recessed patterns 17, and the shape of the serrated pattern includes a semicircle, a triangle, or a quadrilateral, but is not limited thereto. In another preferred embodiment, the second baffle 19 has the same shape as the first baffle 16, and the blocking pattern 20 is the serrated pattern formed between two pairs of recessed patterns 17, and the space formed between two pairs of blocking patterns 20 is the overflow space 18. In yet another preferred embodiment, the first baffle 16 may be slightly larger or slightly smaller than the second baffle 19, but is not limited thereto.

[0032] Preferably, the Reynolds number (Re) is calculated according to the following formula:

[0033]

[0034] Where Q is the flow rate of the extract through the baffle mechanism 12 per unit time, v is the kinematic viscosity of the extract in the extraction space 5, and L is the flow width of the extract when it flows through the baffle mechanism 12, i.e., the overflow width.

[0035] The following explains the derivation of the formula for calculating the Reynolds number (Re).

[0036] First, as shown in Table 1 below, the Reynolds number (Re) of the extract can be calculated using Formula 1, where ρ is the density of the extract, V is the flow rate of the extract, D is the equivalent diameter, and μ is the dynamic viscosity of the extract. The overflow refers to the portion of the extract that flows through the baffle mechanism 12 after reaching the highest point of the baffle 4.

[0037] Table 1

[0038]

[0039] In addition, in extraction tank 2, the width-to-height ratio of the overflow portion of the extract is large, ranging from 4500:6 to 4500:14, as shown in Table 2 below. According to Formula 2, it can be seen that the equivalent diameter (D) is approximately 4 times the overflow height of the extract. Therefore, it is understandable that when the feed rate of the extract is increased, the overflow height can be increased, and the equivalent diameter (D) can be increased, thereby increasing the Reynolds number (Re) of the extract. However, increasing the feed rate of the extract will lead to problems such as waste, pollution, and increased costs. Therefore, it is necessary to find technical means other than increasing the feed rate to control the Reynolds number of the extract.

[0040] Table 2

[0041]

[0042] Furthermore, as shown in Table 3 below, in order to derive the final formula for calculating the Reynolds number, Formulas 3 to 5 are provided, where: V is the flow rate of the extract, Q is the flow rate of the extract, S is the channel area of ​​the extract, d is the overflow height of the extract, L is the overflow width of the extract, v is the kinematic viscosity of the extract, μ is the dynamic viscosity of the extract, and ρ is the density of the extract. Based on the results of formulas 1 to 5, formula 6 can be derived, which is the formula used in this invention to control the Reynolds number of the extractant. According to formula 6, it can be seen that when the flow rate (Q) of the extractant is fixed, the Reynolds number (Re) of the extractant can be adjusted by adjusting the overflow width (L) or the kinematic viscosity (v) of the extractant. The kinematic viscosity (v) is affected by temperature. When the temperature is higher, the kinematic viscosity (v) of the extractant is lower. Therefore, the Reynolds number can also be controlled by adjusting the temperature of the extractant to optimize the extraction effect under the condition that the extractant is quantitative, so as to efficiently and uniformly extract the diaphragm and remove the white oil on the diaphragm.

[0043] Table 3

[0044]

[0045] The present invention also provides a membrane extraction method, characterized in that, as Figure 4As shown, the process includes: (S1) obtaining the membrane extraction device 1 as described above; (S2) starting the stirring device 11 to stir the extract in the extraction space 5, and after stirring for a preset time, proceeding to step (S3); (S3) using the detection system 13 to measure the density of the upper and lower layers of the extract in the extraction space 5, and using the processor 15 to determine whether the densities are consistent, wherein: if the densities are consistent, proceeding to step (S4); if the densities are inconsistent, repeating step (S2); (S4) using the processor 15 to calculate the Reynolds number of the extract in the extraction space 5, wherein: if the Reynolds number is less than 4 If the Reynolds number is 500, proceed to step (S5); if the Reynolds number is greater than 8000, proceed to step (S6); if the Reynolds number is between 4500 and 8000, proceed to step (S7); (S5) based on the Reynolds number, control the baffle mechanism 12 to shorten the overflow width, or control the temperature control device 14 to increase the temperature of the extract, and return to step (S4); (S6) based on the Reynolds number, control the baffle mechanism 12 to increase the overflow width, or control the temperature control device 14 to decrease the temperature of the extract, and return to step (S4); and (S7) the extract meets the requirements, and the process ends.

[0046] The advantages of this invention over prior art are as follows: The membrane extraction device 1 of this invention is equipped with a baffle mechanism 12, which can control the overflow width of the extractant flowing from the extraction space 5 to the recovery space 6, thereby regulating the Reynolds value of the extractant and improving its fluid properties for membrane extraction. Furthermore, the membrane extraction device 1 of this invention is equipped with a temperature control device 14, which can control the kinematic viscosity of the extractant by heating or cooling it, thereby regulating the Reynolds value and improving its fluid properties for membrane extraction. Specifically, this invention can control the extractant to extract the membrane with the most suitable fluid properties, quickly and uniformly removing white oil from the membrane, and simultaneously cleaning the white oil at the bottom of the extraction tank 2 to prevent it from re-adhering to the membrane surface, so that the extracted membrane can directly meet the processing requirements of lithium-ion batteries. In addition, since the membrane extraction device 1 and membrane extraction method provided by this invention do not require increasing the feed volume of the extractant, waste, pollution, and cost losses caused by the extractant can be prevented.

[0047] However, the above description is only a preferred embodiment of the present invention, and should not be construed as limiting the scope of patent protection of the present invention. Therefore, any simple equivalent changes and modifications made in accordance with the scope of patent protection and the contents of the specification of the present invention shall still fall within the scope of patent protection of the present invention.

Claims

1. A membrane extraction device, characterized by, The method comprises: providing an extraction tank, wherein an accommodation space is defined inside the extraction tank; providing a partition plate in the extraction tank, so as to divide the accommodation space into an extraction space and a recovery space; providing a roller set in the extraction space, so as to move a diaphragm along a first direction; providing a liquid inlet in one end of the extraction tank close to the extraction space, so as to supply an extraction liquid to the extraction space along a second direction, wherein the second direction is opposite to the first direction; providing a baffle mechanism in one end of the partition plate, so as to adjust an overflow width of the extraction liquid; providing a detection system on the extraction tank, so as to measure a physical property of the extraction liquid in the extraction space; providing a temperature control device in the extraction tank, so as to adjust the physical property of the extraction liquid in the extraction space; and providing a processor connected with the baffle mechanism and the detection system, so as to receive the overflow width and the physical property, and calculate a Reynolds number of the extraction liquid. If the Reynolds number is less than 4500, according to the magnitude of the Reynolds number, the processor controls the baffle mechanism to shorten the overflow width, or controls the temperature control device to increase the temperature of the extraction liquid; if the Reynolds number is greater than 8000, according to the magnitude of the Reynolds number, the processor controls the baffle mechanism to increase the overflow width, or controls the temperature control device to decrease the temperature of the extraction liquid. The baffle mechanism comprises:

2. The membrane extraction device according to claim 1, characterized in that a first baffle plate provided on the partition plate, wherein at least one recessed pattern is formed on the first baffle plate, and an overflow space is formed between the first baffle plate and each of the recessed patterns; and a second baffle plate provided corresponding to the first baffle plate, wherein at least one shielding pattern is formed on the second baffle plate, each of the shielding patterns is provided corresponding to each of the recessed patterns, and the second baffle plate can move relative to the first baffle plate from a first position to a second position, so as to adjust the area of the shielding pattern covering the overflow space. When the second baffle plate is located at the first position, the area of the shielding pattern covering the overflow space is the minimum, so that the overflow width of the extraction liquid is the maximum; and 3. The membrane extraction device according to claim 2, characterized in that : when the second baffle plate is located at the second position, the area of the shielding pattern covering the overflow space is the maximum, so that the overflow width of the extraction liquid is the minimum. The shape of the recessed pattern comprises a semicircle, a triangle or a quadrilateral; and the shape of the shielding pattern comprises a semicircle, a triangle or a quadrilateral, and the recessed pattern and the shielding pattern can be the same or different.

4. The membrane extraction device according to claim 2, characterized in that : The detection system comprises: a densimeter for detecting the density of the extraction liquid in the extraction space; 5. The membrane extraction device according to claim 1, characterized in that a viscometer for detecting the viscosity of the extraction liquid in the extraction space; or a thermometer for detecting the temperature of the extraction liquid in the extraction space. ​ ​ ​ 6. The membrane extraction device according to claim 1, characterized in that The roller set comprises, in sequence along the first direction, a first guide roller, a second guide roller, a third guide roller, a fourth guide roller, and a fifth guide roller, wherein the first guide roller, the third guide roller, and the fifth guide roller are disposed at a height of H1, and the second guide roller and the fourth guide roller are disposed at a height of H2, and H1>H2.

7. The membrane extraction device according to claim 1, characterized in that The Reynolds number (Re) is calculated according to the following formula: ； wherein Q is the flow rate of the extractant through the baffle mechanism per unit time, is the kinematic viscosity of the extractant in the extraction space, and L is the flow width of the extractant stream through the baffle mechanism, i.e. the overflow width.

8. The membrane extraction device according to claim 1, characterized in that : The first direction is an extension direction from the recovery space to the extraction space; and The second direction is an extension direction from the extraction space to the recovery space.

9. The membrane extraction device according to claim 1, characterized in that The temperature control device comprises: A first electric heating sheet disposed on a side of the extraction space in contact with the partition; and A second electric heating sheet disposed on a side of the extraction space farthest from the recovery space.

10. The membrane extraction device according to claim 1, characterized in that Further comprising: a stirring device disposed in the extraction space to stir the extraction liquid in the extraction space.

11. A method of membrane extraction, characterized by, Comprising: (S1) obtaining the membrane extraction device according to claim 10; (S2) starting the stirring device to stir the extraction liquid in the extraction space, and after stirring for a predetermined time, entering step (S3); (S3) measuring the densities of the upper layer and the lower layer of the extraction liquid in the extraction space with the detection system, and determining whether the densities of the two layers are consistent with the processor, wherein: if the densities are consistent, entering step (S4); if the densities are inconsistent, re-performing step (S2); (S4) calculating the Reynolds number of the extraction liquid in the extraction space with the processor, wherein: if the Reynolds number is less than 4500, entering step (S5); if the Reynolds number is greater than 8000, entering step (S6); if the Reynolds number is between 4500 and 8000, entering step (S7); (S5) according to the size of the Reynolds number, controlling the baffle mechanism to shorten the overflow width, or controlling the temperature control device to raise the temperature of the extraction liquid, and returning to step (S4); (S6) according to the size of the Reynolds number, controlling the baffle mechanism to raise the overflow width, or controlling the temperature control device to lower the temperature of the extraction liquid, and returning to step (S4); and (S7) the extraction liquid has met the requirements, and the process ends. ​

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