Passive multistage countercurrent micro-extractor and extraction method thereof

Abstract

The invention discloses a passive multi-stage countercurrent micro-extractor and an extraction method of the passive multi-stage countercurrent micro-extractor. Wherein in the passive multi-stage countercurrent micro-extractor, each stage of micro-extractor is internally provided with a clarification chamber, and the clarification chamber comprises an upper chamber and a lower chamber; the transfer channels are distributed between every two adjacent stages of micro-extractors; the interface adjusting channels are distributed between every two adjacent stages of micro-extractors, between the first-stage micro-extractor and the post-extraction light phase collecting pipe and between the last-stage micro-extractor and the post-extraction heavy phase collecting pipe, and the resistance of the interface adjusting channels is far greater than that of the transfer channel; the heavy phase feeding pipe is connected with the primary micro-extractor; the light phase feeding pipe is connected with the final-stage micro-extractor; the extracted heavy phase collecting pipe is connected with a light phase feeding pipe; and the extracted light phase collecting pipe is connected with the heavy phase feeding pipe. The device has the advantages of no mechanical movable part, small volume, countercurrent operation, high mass transfer efficiency and easiness in amplification, and is particularly suitable for extraction and separation of dangerous mixtures.

Description

Technical Field

[0001] The invention relates to the technical field of liquid-liquid extraction and separation, and in particular to a passive multi-stage countercurrent microextractor and an extraction method thereof. Background Art

[0002] In the separation operation of liquid mixtures involved in industrial production such as chemical, energy, and mining, the liquid-liquid extraction method is often used, that is, an extractant that is insoluble or slightly soluble in the mixed liquid to be separated is added to form an immiscible two-phase system, and the separation operation is achieved by utilizing the difference in solubility of the components in the two phases.

[0003] In order to improve the separation efficiency, the basic design principle of the extraction equipment is to be able to produce a large specific surface area and high mixing efficiency between the two phases, and to be able to operate in a countercurrent manner. The passive microfluidic extractor (hereinafter referred to as the microextractor) without mechanical moving parts is maintenance-free. At the same time, because the characteristic scale is in the micrometer order, the specific surface area between the two phases is increased by an order of magnitude compared with traditional pulse extraction columns, mixing and settling tanks, etc. In addition, the mass transfer distance between the two phases in the microextractor is extremely short, the mass transfer time between the two phases is significantly reduced, and the mass transfer efficiency of the two phases can be further enhanced by chaotic convection, so it has broad application prospects. It is particularly important that the microextractor has a residence volume of only picoliters to milliliters. The extremely small volume makes it inherently safe when dealing with dangerous systems such as explosions, corrosive and toxic leaks, and radioactive criticality.

[0004] However, due to the small characteristic size of the microextractor, viscous force and surface tension dominate compared with inertial force and gravity, resulting in difficulty in separating the two phases in the microextractor. It is difficult to achieve countercurrent extraction in a passive manner, that is, without the aid of mechanical movable parts or external field forces. Summary of the invention

[0005] The present invention aims to solve at least one of the technical problems existing in the prior art. To this end, one object of the present invention is to provide a passive multi-stage countercurrent microextractor, which has the advantages of no mechanical moving parts, small size, countercurrent operation, high mass transfer efficiency, and easy scale-up, and is particularly suitable for extraction and separation applications of dangerous mixtures with radioactivity, corrosiveness, toxicity, explosion, etc.

[0006] The passive multi-stage countercurrent microextractor according to an embodiment of the present invention comprises a microextractor body, a heavy phase feed pipe, a light phase feed pipe, a post-extraction heavy phase collection pipe and a post-extraction light phase collection pipe;

[0007] The microextractor body comprises a multi-stage microextractor, a transfer channel and an interface adjustment channel; each stage of the microextractor has a clarification chamber, and the clarification chamber comprises an upper chamber for accommodating a light phase liquid and a lower chamber for accommodating a heavy phase liquid divided by a two-phase interface; the transfer channel is distributed between the microextractors of each adjacent two stages, and is used to transfer the heavy phase liquid in the lower chamber of the microextractor of the upper stage in the microextractors of the corresponding two adjacent two stages to the upper chamber of the microextractor of the next stage, and is used to transfer the light phase liquid in the upper chamber of the microextractor of the next stage in the microextractors of the corresponding two adjacent two stages to the lower chamber of the microextractor of the upper stage; the interface adjustment channel is distributed between the microextractors of each adjacent two stages, between the first stage microextractor and the post-extraction light phase collection tube, and between the last stage microextractor and the post-extraction heavy phase collection tube, and the resistance of the interface adjustment channel is much greater than the resistance of the transfer channel, and is used to automatically adjust the position of the two-phase interface of each stage of the microextractor and stabilize the two-phase interface;

[0008] One end of the heavy phase feed pipe is connected to the first-stage microextractor, and is used to inject heavy phase liquid into the upper chamber of the first-stage microextractor;

[0009] One end of the light phase feed pipe is connected to the final microextractor for injecting light phase liquid into the lower chamber of the final microextractor;

[0010] One end of the post-extraction heavy phase collecting tube is connected to the light phase feeding tube;

[0011] One end of the post-extraction light phase collecting tube is connected to the heavy phase feeding tube.

[0012] The working principle of the passive multi-stage countercurrent microextractor of the embodiment of the present invention is: extraction is performed in a reciprocating manner of heavy phase feeding cycle and light phase feeding cycle.

[0013] Among them, during the heavy phase feeding cycle, the light phase feeding pipe stops conveying light phase liquid, and the light phase collecting pipe after extraction stops collecting light phase liquid after extraction; at this time, on the one hand, the heavy phase feeding pipe inputs heavy phase liquid into the upper chamber of the first-stage microextractor, and the newly input heavy phase liquid mixes with the light phase liquid in the upper chamber of the first-stage microextractor and then sinks to the lower chamber of the first-stage microextractor after mass transfer. At the same time, due to the incompressibility of the liquid, the original heavy phase liquid in the lower chamber of the upper microextractor in each adjacent two-stage microextractor is forced to enter through the corresponding transfer channel It enters the upper chamber of the next-stage microextractor, mixes and transfers with the light phase liquid in the upper chamber of the corresponding microextractor, and then settles into the lower chamber, while the original heavy phase liquid in the lower chamber of the final microextractor is collected through the post-extraction heavy phase collecting tube, thus completing a heavy phase feeding cycle; on the other hand, due to the large resistance of the first-stage interface adjustment channel, a small amount of heavy phase liquid in the heavy phase feed tube enters the first-stage interface adjustment channel through the post-extraction light phase collecting tube, and automatically adjusts the two-phase interface of each stage of the microextractor through the interface adjustment channels of each stage, so that the two-phase interface is stable.

[0014] During the light phase feeding cycle, the heavy phase feeding pipe stops conveying the heavy phase liquid, and the heavy phase collecting pipe stops collecting the heavy phase liquid after extraction; at this time, on the one hand, the light phase feeding pipe inputs the light phase liquid into the lower chamber of the final microextractor, and the newly input light phase liquid mixes with the heavy phase liquid in the lower chamber of the final microextractor and rises to the upper chamber of the final microextractor after mass transfer. At the same time, the original light phase liquid in the upper chamber of the next microextractor in each adjacent two-stage microextractor is forced to enter the lower chamber of the previous microextractor through the corresponding transfer channel. In the chamber, the heavy phase liquid in the lower chamber of the corresponding microextractor is mixed and mass transferred and then rises to the upper chamber, while the original light phase liquid in the upper chamber of the first-stage microextractor is collected through the post-extraction light phase collecting tube, thus completing a light phase feeding cycle; on the other hand, due to the large resistance of the final-stage interface adjustment channel, a small amount of light phase liquid in the light phase feed tube enters the final-stage interface adjustment channel through the post-extraction heavy phase collecting tube, and the light phase liquid is input into the final-stage interface adjustment channel, and the two-phase interface of each stage of the microextractor is automatically adjusted through the interface adjustment channels of each stage to stabilize the two-phase interface.

[0015] The above-mentioned heavy phase feeding cycle and light phase feeding cycle are cyclically repeated, that is, the heavy phase feeding cycle and the light phase feeding cycle are alternately cycled in sequence, during which the two-phase interface is automatically adjusted between the adjacent two-stage microextractors through the interface adjustment channel until the two-phase interface is stable, and at the same time, the heavy phase liquid is gradually transferred from the first-stage microextractor to the last-stage microextractor, and the light phase liquid is transferred in the opposite direction. The transfer of heavy phase liquid and light phase liquid can be achieved without setting mechanical movable parts in the microextractor body, thereby realizing a passive multi-stage countercurrent microextraction operation that automatically maintains interface balance.

[0016] The passive multi-stage countercurrent microextractor of the embodiment of the present invention has the following advantages: on the one hand, the microextractor body does not contain mechanical moving parts, which can be maintenance-free. Especially when the passive multi-stage countercurrent microextractor of the embodiment of the present invention is used in dangerous systems such as explosion, toxicity, corrosiveness, and radioactivity, it has inherent safety and can avoid personal injury to close maintenance personnel; on the other hand, by setting an interface adjustment channel, the two-phase interface can be automatically adjusted and stabilized, so the operation flexibility is large and the robustness is strong, and the use of cumbersome interface monitoring equipment can be avoided; on the other hand, the passive multi-stage countercurrent microextractor of the embodiment of the present invention can make full use of the advantages of microfluid mixing and enhanced mass transfer, that is, the mass transfer distance is short, the chaotic convection mixing efficiency is high, and the specific surface area is large, so that efficient countercurrent extraction operation can be achieved. On the other hand, since the passive multi-stage countercurrent microextractor of the embodiment of the present invention is small in size, the residence time of the two-phase contact is short and the floor space is small, it has the advantage of saving plant costs. In addition, the passive multi-stage countercurrent microextractor of the embodiment of the present invention is easy to significantly increase the processing flux by enlarging the number or size. In summary, the present invention can be widely used in liquid-liquid extraction in the fields of chemical industry, energy, mining, etc.

[0017] In some embodiments, each stage of the microextractor further comprises an upper mixing unit and a lower mixing unit; the upper mixing unit is located above the two-phase interface and connected to the upper chamber, and the lower mixing unit is located below the two-phase interface and connected to the lower chamber; the upper mixing unit of the first-stage microextractor is connected to one end of the heavy phase feed pipe, and the lower mixing unit of the last-stage microextractor is connected to one end of the light phase feed pipe, and in each two adjacent stages of the microextractors, the lower mixing unit of the microextractor of the upper stage is connected to the upper mixing unit of the microextractor of the lower stage through the transfer channel.

[0018] In some embodiments, each stage of the microextractor is provided with a connection position connected to the corresponding interface regulating channel at a position close to the two-phase interface in the vertical direction.

[0019] In some embodiments, the two-phase interface of each stage of the microextractor is located at the vertical middle position of the clarification chamber.

[0020] In some embodiments, a heavy phase feed valve is provided on the heavy phase feed pipe, and one end of the light phase collection pipe after extraction is located between the heavy phase feed valve and the first-stage microextractor;

[0021] The light phase feed pipe is provided with a light phase feed valve, and one end of the post-extraction heavy phase collecting pipe is located between the light phase feed valve and the final micro-extractor;

[0022] The post-extraction heavy phase collecting pipe is provided with a post-extraction heavy phase drain valve, and the connection point between the final-stage interface regulating channel and the post-extraction heavy phase collecting pipe is located between one end of the post-extraction heavy phase collecting pipe and the post-extraction heavy phase drain valve;

[0023] The post-extraction light phase collecting pipe is provided with a post-extraction light phase drain valve, and the connection point between the first-stage interface regulating channel and the post-extraction light phase collecting pipe is located between one end of the post-extraction light phase collecting pipe and the post-extraction light phase drain valve.

[0024] In some embodiments, it also includes a heavy phase storage tank, a light phase storage tank, a post-extraction heavy phase collection storage tank, a post-extraction light phase collection storage tank and a driving device; the heavy phase storage tank is connected to the other end of the heavy phase feed pipe, the light phase storage tank is connected to the other end of the light phase feed pipe, the post-extraction heavy phase collection storage tank is connected to the other end of the post-extraction heavy phase collection tube, the post-extraction light phase collection storage tank is connected to one end of the post-extraction light phase collection tube, and the driving device is used to drive the heavy phase liquid in the heavy phase storage tank into the first-stage microextractor and to drive the light phase liquid in the light phase storage tank into the last-stage microextractor.

[0025] In some embodiments, the driving device includes a heavy phase feed pump and a light phase feed pump, the heavy phase feed pump is arranged on the heavy phase feed pipe and is located between the heavy phase storage tank and the heavy phase feed valve, and the light phase feed pump is arranged on the light phase feed pipe and is located between the light phase storage tank and the light phase feed valve.

[0026] In some embodiments, the driving device includes a high-pressure gas source, a first pipeline and a second pipeline. The high-pressure gas source is connected to the heavy phase storage tank through the first pipeline, and a heavy phase pressure-reducing valve, a heavy phase pressure-surge switching valve and a heavy phase storage tank pressure relief valve are sequentially arranged on the first pipeline from the high-pressure gas source to the heavy phase storage tank; the high-pressure gas source is connected to the light phase storage tank through the second pipeline, and a light phase pressure-reducing valve, a light phase pressure-surge switching valve and a light phase storage tank pressure relief valve are sequentially arranged on the second pipeline from the high-pressure gas source to the light phase storage tank.

[0027] In some embodiments, the microextractor body includes a plurality of microextractor components that are sealed and connected in sequence from top to bottom, and the plurality of microextractor components together form a multi-stage microextractor, the transport channel, and the interface adjustment channel.

[0028] In some embodiments, the top microextractor component is processed with multiple upper mixing units and multiple upper cavities, and the multiple upper mixing units are correspondingly connected to the multiple upper cavities. The bottom microextractor component is processed with multiple lower mixing units and multiple lower cavities, and the multiple lower mixing units are correspondingly connected to the multiple lower cavities. The remaining microextractor components located between the top microextractor component and the bottom microextractor component are all provided with multiple intermediate cavities. The multiple upper cavities, the multiple intermediate cavities and the multiple lower cavities are correspondingly connected up and down to form multiple clarification chambers. The multiple microextractor components are also processed with channel sections forming the transfer channels, and an interface adjustment channel is processed on one of the multiple microextractor components.

[0029] The present invention also proposes an extraction method of the passive multi-stage countercurrent microextractor of any of the above embodiments.

[0030] According to the extraction method of the passive multi-stage countercurrent microextractor of the embodiment of the present invention, the extraction is performed in a reciprocating manner of heavy phase feeding cycle and light phase feeding cycle;

[0031] Wherein, during the heavy phase feeding cycle, the light phase feeding pipe stops conveying light phase liquid, and the light phase collecting pipe after extraction stops collecting light phase liquid after extraction; at this time, on the one hand, the heavy phase feeding pipe inputs heavy phase liquid into the upper chamber of the first-stage microextractor, and the newly input heavy phase liquid mixes with the light phase liquid in the upper chamber of the first-stage microextractor and then sinks into the lower chamber of the first-stage microextractor after mass transfer, and at the same time, the original heavy phase in the lower chamber of the upper-stage microextractor in each of the two adjacent microextractors is forced to The liquid enters the upper chamber of the microextractor of the next stage through the corresponding transfer channel, mixes with the light phase liquid in the upper chamber of the corresponding microextractor and then settles into the lower chamber, while the original heavy phase liquid in the lower chamber of the microextractor of the last stage is collected through the post-extraction heavy phase collection tube; on the other hand, the heavy phase feed pipe inputs the heavy phase liquid into the interface adjustment channel of the first stage, and the two-phase interface of each stage of the microextractor is automatically adjusted through the interface adjustment channels of each stage to stabilize the two-phase interface;

[0032] During the light phase feeding cycle, the heavy phase feeding pipe stops conveying the heavy phase liquid, and the post-extraction heavy phase collecting pipe stops collecting the post-extraction heavy phase liquid; at this time, on the one hand, the light phase feeding pipe inputs the light phase liquid into the lower chamber of the final microextractor, and the newly input light phase liquid mixes with the heavy phase liquid in the lower chamber of the final microextractor and then rises to the upper chamber of the final microextractor, and at the same time, the original light phase liquid in the upper chamber of the next microextractor in each of the two adjacent microextractors is forced to pass through The light phase liquid passes through the corresponding transfer channel into the lower chamber of the microextractor at the previous stage, mixes with the heavy phase liquid in the lower chamber of the corresponding microextractor and then rises to the upper chamber, while the original light phase liquid in the upper chamber of the first-stage microextractor is collected through the post-extraction light phase collecting tube; on the other hand, the light phase feed pipe inputs light phase liquid into the interface regulating channel of the last stage, and the two-phase interface of each stage of the microextractor is automatically adjusted through the interface regulating channels of each stage to stabilize the two-phase interface.

[0033] Since the extraction method of the embodiment of the present invention adopts the passive multi-stage countercurrent microextractor of the embodiment of the present invention, the extraction method of the embodiment of the present invention has the same technical effect as the passive multi-stage countercurrent microextractor of the embodiment of the present invention, which will not be repeated here.

[0034] Additional aspects and advantages of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] The above and / or additional aspects and advantages of the present invention will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0036] Figure 1 A schematic diagram of a passive multi-stage countercurrent microextractor of the present invention;

[0037] Figure 2 for Figure 1 A partial schematic diagram of

[0038] Figure 3 A schematic diagram of a heavy phase feeding cycle of a passive multi-stage countercurrent microextractor of the present invention;

[0039] Figure 4 A schematic diagram of a light phase feeding cycle of a passive multi-stage countercurrent microextractor of the present invention;

[0040] Figure 5 is a schematic diagram of another passive multi-stage countercurrent microextractor of the present invention;

[0041] Figure 6A schematic diagram of another passive multi-stage countercurrent microextractor of the present invention;

[0042] Figure 7 It is a schematic diagram of the structure explosion of a microextractor body of the passive multi-stage countercurrent microextractor of the present invention;

[0043] Figure 8 The present invention is a schematic diagram of the assembly of a microextractor body of the passive multi-stage countercurrent microextractor.

[0044] Reference numerals:

[0045] Passive multi-stage countercurrent microextractor 1000; microextractor body 10; microextractor 101; upper mixing unit 1011; lower mixing unit 1012; clarification chamber 1013; upper chamber 1013a; lower chamber 1013b; two-phase interface 1013c; transport channel 102; interface adjustment channel 103; microextractor component 104; uppermost cavity 1041; middle cavity 1042; lowermost cavity 1043; heavy phase feed pipe 11; heavy phase feed valve 111; heavy phase feed pump front valve 112; light phase feed pipe 12; light phase feed valve 121; light phase feed pump Front valve 122; heavy phase collecting pipe after extraction 13; heavy phase drain valve 131 after extraction; light phase collecting pipe after extraction 14; light phase drain valve 141 after extraction; heavy phase storage tank 15; light phase storage tank 16; heavy phase collecting storage tank after extraction 17; light phase collecting storage tank after extraction 18; heavy phase feed pump 19; light phase feed pump 20; high-pressure gas source 21; pressure sensor 211; first pipeline 22; heavy phase pressure reducing valve 221; heavy phase pressure switching valve 222; heavy phase storage tank pressure relief valve 223; second pipeline 23; light phase pressure reducing valve 231; light phase pressure switching valve 232; light phase storage tank pressure relief valve 233. DETAILED DESCRIPTION

[0046] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be understood as limiting the present invention.

[0047] Combine the following Figures 1 to 8 The passive multi-stage countercurrent microextractor 1000 and the extraction method thereof according to an embodiment of the present invention are described.

[0048] like Figures 1 to 8 As shown, the passive multi-stage countercurrent microextractor 1000 according to an embodiment of the present invention includes a microextractor body 10, a heavy phase feed pipe 11, a light phase feed pipe 12, a post-extraction heavy phase collection pipe 13 and a post-extraction light phase collection pipe 14.

[0049] Among them, the microextractor body 10 includes a multi-stage microextractor 101, a transfer channel 102 and an interface adjustment channel 103; each stage of the microextractor 101 has a clarification chamber 1013, and the clarification chamber 1013 includes an upper chamber 1013a for accommodating a light phase liquid and a lower chamber 1013b for accommodating a heavy phase liquid divided by a two-phase interface 1013c, that is, a clarification chamber 1013 contains both a light phase liquid and a heavy phase liquid, and the light phase liquid is located above the heavy phase liquid and has a two-phase interface 1013c between it and the heavy phase liquid. The transfer channel 102 is distributed between each two adjacent stages of the microextractors 101, and is used to transfer the heavy phase liquid in the lower chamber 1013b of the upper stage microextractor 101 in the corresponding two adjacent stages of the microextractors 101 to the upper chamber 1013a of the lower stage microextractor 101, and is used to transfer the light phase liquid in the upper chamber 1013a of the lower stage microextractor 101 in the corresponding two adjacent stages of the microextractors 101 to the lower chamber 1013b of the upper stage microextractor 101. The interface adjustment channel 103 is distributed between each two adjacent microextractors 101, between the first microextractor 101 and the light phase collection tube 14 after extraction, and between the final microextractor 101 and the heavy phase collection tube 13 after extraction. The resistance of the interface adjustment channel 103 is much greater than the resistance of the transport channel 102, which is conducive to ensuring the smooth and efficient transport of the heavy phase liquid and the light phase liquid of the two adjacent microextractors 101, thereby improving the extraction efficiency. The interface adjustment channel 103 is used to automatically adjust the position of the two-phase interface 1013c of each microextractor 101 and stabilize the two-phase interface 1013c to improve the extraction efficiency. The microextractor body 10 does not contain mechanical movable parts.

[0050] One end of the heavy phase feed pipe 11 is connected to the first-stage microextractor 101, and is used to inject the heavy phase liquid into the upper chamber 1013a of the first-stage microextractor 101. One end of the light phase feed pipe 12 is connected to the final microextractor 101, and is used to inject the light phase liquid into the lower chamber 1013b of the final microextractor 101. One end of the post-extraction heavy phase collecting pipe 13 is connected to the light phase feed pipe 12. One end of the post-extraction light phase collecting pipe 14 is connected to the heavy phase feed pipe 11.

[0051] like Figure 3 and Figure 4 As shown, the working principle of the passive multi-stage countercurrent microextractor 1000 of the embodiment of the present invention is: extraction is performed in a reciprocating manner of heavy phase feeding cycle and light phase feeding cycle.

[0052] Among them, Figure 3As shown, during the heavy phase feeding cycle, the light phase feeding pipe 12 stops conveying the light phase liquid, and the light phase collecting pipe 14 stops collecting the light phase liquid after extraction; at this time, on the one hand, the heavy phase feeding pipe 11 inputs the heavy phase liquid into the upper chamber 1013a of the first-stage microextractor 101, and the newly input heavy phase liquid mixes with the light phase liquid in the upper chamber 1013a of the first-stage microextractor 101 and then sinks into the lower chamber 1013b of the first-stage microextractor 101. At the same time, due to the incompressibility of the liquid, the original heavy phase liquid in the lower chamber 1013b of the upper microextractor 101 in each adjacent two-stage microextractor 101 is forced to enter the next-stage microextractor through the corresponding transfer channel 102. In the upper chamber 1013a of the extractor 101, the light phase liquid in the upper chamber 1013a of the corresponding microextractor 101 is mixed and mass transferred and then settles into the lower chamber 1013b, and the original heavy phase liquid in the lower chamber 1013b of the final microextractor 101 is collected through the post-extraction heavy phase collecting tube 13, thereby completing a heavy phase feeding cycle; on the other hand, due to the large resistance of the first-stage interface adjustment channel 103, a small amount of heavy phase liquid in the heavy phase feed pipe 11 enters the first-stage interface adjustment channel 103 through the post-extraction light phase collecting tube 14, and automatically adjusts the two-phase interface 1013c of each stage of the microextractor 101 through the interface adjustment channels 103 at each stage, so that the two-phase interface 1013c is stable.

[0053] like Figure 4 As shown, during the light phase feeding cycle, the heavy phase feeding pipe 11 stops conveying the heavy phase liquid, and the post-extraction heavy phase collecting pipe 13 stops collecting the post-extraction heavy phase liquid; at this time, on the one hand, the light phase feeding pipe 12 inputs the light phase liquid into the lower chamber 1013b of the final microextractor 101, and the newly input light phase liquid mixes with the heavy phase liquid in the lower chamber 1013b of the final microextractor 101 and rises to the upper chamber 1013a of the final microextractor 101 after mass transfer. At the same time, the original light phase liquid in the upper chamber 1013a of the next microextractor 101 in each adjacent two-stage microextractor 101 is forced to enter the lower chamber 101 of the previous microextractor 101 through the corresponding transfer channel 102. In 1013b, it rises to the upper chamber 1013a after mixing and mass transfer with the heavy phase liquid in the lower chamber 1013b of the corresponding microextractor 101, and the original light phase liquid in the upper chamber 1013a of the first-stage microextractor 101 is collected through the post-extraction light phase collecting tube 14, thereby completing a light phase feeding cycle; on the other hand, due to the large resistance of the final-stage interface adjustment channel 103, a small amount of light phase liquid in the light phase feeding pipe 12 enters the final-stage interface adjustment channel 103 through the post-extraction heavy phase collecting tube 13 to input the light phase liquid, and the two-phase interface 1013c of each stage of the microextractor 101 is automatically adjusted through the interface adjustment channels 103 at each stage, so that the two-phase interface 1013c is stable.

[0054] The above-mentioned heavy phase feeding cycle and light phase feeding cycle are cyclically repeated, that is, the heavy phase feeding cycle and the light phase feeding cycle are alternately cycled in sequence, during which the two-phase interface 1013c is automatically adjusted between the adjacent two-stage microextractors 101 through the interface adjustment channel 103 until the two-phase interface 1013c is stable, and at the same time, the heavy phase liquid is gradually transferred from the first-stage microextractor 101 to the final-stage microextractor 101, and the light phase liquid is transferred in the opposite direction. There is no need to set mechanical movable parts in the microextractor body 10 to realize the transfer of heavy phase liquid and light phase liquid, thereby realizing a passive multi-stage countercurrent microextraction operation that automatically maintains interface balance.

[0055] The passive multi-stage countercurrent microextractor 1000 of the embodiment of the present invention has the following advantages: on the one hand, the microextractor body 10 does not contain mechanical moving parts, which can be maintenance-free. Especially when the passive multi-stage countercurrent microextractor 1000 of the embodiment of the present invention is used in a dangerous system with explosion, toxicity, corrosion, radioactivity, etc., it has inherent safety and can avoid personal injury to close maintenance personnel; on the other hand, by setting the interface adjustment channel 103, the two-phase interface 1013c can be automatically adjusted and stabilized, so the operation flexibility is large and the robustness is strong, and the use of cumbersome interface monitoring equipment can be avoided; on the other hand, the passive multi-stage countercurrent microextractor 1000 of the embodiment of the present invention can make full use of the advantages of microfluid mixing and enhancing mass transfer, that is, the mass transfer distance is short, the chaotic convection mixing efficiency is high, and the specific surface area is large, so that efficient countercurrent extraction operation can be achieved. On the other hand, since the passive multi-stage countercurrent microextractor 1000 of the embodiment of the present invention is small in size, the residence time of the two-phase contact is short and the floor space is small, it has the advantage of saving plant costs. In addition, the passive multi-stage countercurrent microextractor 1000 of the embodiment of the present invention can be easily enlarged in number or size to significantly increase the processing throughput. In summary, the present invention can be widely used in liquid-liquid extraction in the fields of chemical industry, energy, mining, etc.

[0056] In some embodiments, Figures 1 to 8As shown, each stage of the microextractor 101 also has an upper mixing unit 1011 and a lower mixing unit 1012; the upper mixing unit 1011 is located above the two-phase interface 1013c and is connected to the upper chamber 1013a, and the lower mixing unit 1012 is located below the two-phase interface 1013c and is connected to the lower chamber 1013b; the upper mixing unit 1011 of the first-stage microextractor 101 is connected to one end of the heavy phase feed pipe 11, and the lower mixing unit 1012 of the last-stage microextractor 101 is connected to one end of the light phase feed pipe 12. In each two adjacent stages of the microextractor 101, the lower mixing unit 1012 of the upper-stage microextractor 101 is connected to the upper mixing unit 1011 of the lower-stage microextractor 101 through a transfer channel 102. Thus, in the heavy phase feeding cycle, the upper mixing unit 1011 can make the heavy phase liquid fluid break up and disperse through the light phase liquid, so that the heavy phase liquid and the light phase liquid can be better mixed and transferred, thereby improving the mass transfer rate; in the light phase feeding cycle, the lower mixing unit 1012 can make the light phase liquid fluid break up and disperse through the heavy phase liquid, so that the light phase liquid and the heavy phase liquid can be better mixed and transferred, thereby improving the mass transfer rate.

[0057] Preferably, in each stage of the microextractor 101, the upper mixing unit 1011 is located at the top front end of the clarification chamber 1013, and the lower mixing unit 1012 is located at the bottom rear end of the clarification chamber 1013. Thus, the upper mixing unit 1011 and the lower mixing unit 1012 are reasonably arranged; in the heavy phase feeding cycle, the upper mixing unit 1011 can make the heavy phase liquid fluid break and disperse through the light phase liquid, so that the heavy phase liquid and the light phase liquid are better mixed and transferred, thereby improving the mass transfer rate; in the light phase feeding cycle; in the light phase feeding cycle, the lower mixing unit 1012 can make the light phase liquid fluid break and disperse through the heavy phase liquid, so that the light phase liquid and the heavy phase liquid are better mixed and transferred, thereby improving the mass transfer rate.

[0058] In some embodiments, each stage of the microextractor 101 is provided with a connection position connected to the corresponding interface adjustment channel 103 at a position close to the two-phase interface 1013c in the vertical direction. In other words, the end of the interface adjustment channel 103 is close to the two-phase interface 1013c in the vertical direction. For example, the two-phase interface 1013c can be slightly higher or lower than the end of the interface adjustment channel 103, or can be horizontally flush with the end of the interface adjustment channel 103. In this way, it is beneficial for the interface adjustment channel 103 to maintain the stability of the two-phase interface 1013c.

[0059] Furthermore, the two-phase interface 1013c of each stage of the microextractor 101 is located at the vertical middle position of the clarification chamber 1013. This means that the connection position where each stage of the microextractor 101 is connected to the corresponding interface adjustment channel 103 is close to the vertical middle position of the clarification chamber 1013, which is conducive to ensuring that the vertical dimensions of the upper chamber 1013a and the lower chamber 1013b are basically the same, which is conducive to improving the extraction efficiency.

[0060] Preferably, both front and rear ends of each stage of the microextractor 101 are provided with connection positions connected to the corresponding interface adjustment channel 103 at a position close to the two-phase interface 1013c in the vertical direction.

[0061] In some embodiments, the interface regulating channel 103 increases the flow resistance by designing an inner diameter that is much smaller than the inner diameter of the transport channel 102 and a tortuous structure, so that the resistance of the interface regulating channel 103 is much greater than the resistance of the transport channel 102 .

[0062] In some embodiments, Figure 1 , Figures 3 to 6 As shown, a heavy phase feed valve 111 is provided on the heavy phase feed pipe 11, and one end of the light phase collection pipe 14 after extraction is located between the heavy phase feed valve 111 and the first-stage microextractor 101. Therefore, the heavy phase feed valve 111 can be used to open and close the heavy phase feed pipe 11, so that the heavy phase feed pipe 11 can transport the heavy phase liquid or stop transporting the heavy phase liquid.

[0063] A light phase feed valve 121 is provided on the light phase feed pipe 12, and one end of the extracted heavy phase collecting pipe 1 is located between the light phase feed valve 121 and the final microextractor 101. Thus, the light phase feed valve 121 can be used to open and close the light phase feed pipe 12, so that the light phase feed pipe 12 can transport the light phase liquid or stop transporting the light phase liquid.

[0064] The post-extraction heavy phase collecting pipe 13 is provided with a post-extraction heavy phase drain valve 131, and the connection point between the final interface regulating channel 103 and the post-extraction heavy phase collecting pipe 13 is located between one end of the post-extraction heavy phase collecting pipe 13 and the post-extraction heavy phase drain valve 131. Therefore, the post-extraction heavy phase collecting pipe 13 can be opened and closed by using the post-extraction heavy phase drain valve 131, so that the post-extraction heavy phase collecting pipe 13 collects the post-extraction heavy phase liquid or stops collecting the post-extraction heavy phase liquid.

[0065] The light phase after extraction collecting pipe 14 is provided with a light phase after extraction drain valve 141, and the connection point between the first-stage interface regulating channel 103 and the light phase after extraction collecting pipe 14 is located between one end of the light phase after extraction collecting pipe 14 and the light phase after extraction drain valve 141. Thus, the light phase after extraction drain valve 141 can be used to open and close the light phase after extraction collecting pipe 14, so that the light phase after extraction collecting pipe 14 collects the light phase after extraction liquid or stops collecting the light phase after extraction liquid.

[0066] In some embodiments, it also includes a heavy phase storage tank 15, a light phase storage tank 16, a post-extraction heavy phase collection storage tank 17, a post-extraction light phase collection storage tank 18 and a driving device; the heavy phase storage tank 15 is connected to the other end of the heavy phase feed pipe 11, the light phase storage tank 16 is connected to the other end of the light phase feed pipe 12, the post-extraction heavy phase collection storage tank 17 is connected to the other end of the post-extraction heavy phase collection pipe 13, and the post-extraction light phase collection storage tank 18 is connected to one end of the post-extraction light phase collection pipe 14, and the driving device is used to drive the heavy phase liquid in the heavy phase storage tank 15 into the first-stage microextractor 101 and to drive the light phase liquid in the light phase storage tank 16 into the final microextractor 101. Among them, the heavy phase storage tank 15 is used to store heavy phase liquid, the light phase storage tank 16 is used to store light phase liquid, the post-extraction heavy phase collection storage tank 17 is used to store post-extraction heavy phase liquid, and the post-extraction light phase collection storage tank 18 is used to store post-extraction light phase liquid. During the heavy phase feeding cycle, the driving device drives the heavy phase liquid in the heavy phase storage tank 15 to enter the upper chamber 1013a of the first-stage microextractor 101 through the heavy phase feeding pipe 11. The newly input heavy phase liquid mixes with the light phase liquid in the upper chamber 1013a of the first-stage microextractor 101 and then sinks into the lower chamber 1013b of the first-stage microextractor 101. At the same time, the upper microextractor 101 in each adjacent two-stage microextractor 101 is forced to The original heavy phase liquid in the lower chamber 1013b enters the upper chamber 1013a of the next-stage microextractor 101 through the corresponding transfer channel 102, and after mixing and mass transfer with the light phase liquid in the upper chamber 1013a of the corresponding microextractor 101, it sinks into the lower chamber 1013b, and the original heavy phase liquid in the lower chamber 1013b of the final microextractor 101 is collected through the post-extraction heavy phase collection tube 13, thereby completing a heavy phase feeding cycle. During the light phase feeding cycle, the driving device drives the light phase liquid in the light phase storage tank 16 to enter the lower chamber 1013b of the final microextractor 101 through the light phase feeding pipe 12. The newly input light phase liquid mixes with the heavy phase liquid in the lower chamber 1013b of the final microextractor 101 and then rises to the upper chamber 1013a of the final microextractor 101. At the same time, the next microextractor 101 in each adjacent two-stage microextractor 101 is forced to The original light phase liquid in the upper chamber 1013a enters the lower chamber 1013b of the upper-stage microextractor 101 through the corresponding transfer channel 102, and rises to the upper chamber 1013a after mixing and mass transfer with the heavy phase liquid in the lower chamber 1013b of the corresponding microextractor 101, while the original light phase liquid in the upper chamber 1013a of the first-stage microextractor 101 is collected through the post-extraction light phase collection tube 14, thereby completing a light phase feeding cycle.

[0067] In some embodiments, Figure 1 , Figures 3 to 5As shown, the driving device includes a heavy phase feed pump 19 and a light phase feed pump 20. The heavy phase feed pump 19 is arranged on the heavy phase feed pipe 11 and is located between the heavy phase storage tank 15 and the heavy phase feed valve 111. The light phase feed pump 20 is arranged on the light phase feed pipe 12 and is located between the light phase storage tank 16 and the light phase feed valve 121. The heavy phase feed pump 19 and the light phase feed pump 20 cooperate with each other. When in the heavy phase feeding cycle, the light phase feed pump 20 is turned off and the heavy phase feed pump 19 is turned on, driving the heavy phase liquid in the heavy phase storage tank 15 to enter the upper chamber 1013a of the first-stage microextractor 101 through the heavy phase feed pipe 11; when in the light phase feeding cycle, the heavy phase feed pump 19 is turned off and the light phase feed pump 20 is turned on, driving the light phase liquid in the light phase storage tank 16 to enter the lower chamber 1013b of the final-stage microextractor 101 through the light phase feed pipe 12.

[0068] Optionally, a heavy phase feed pump front valve 112 is also provided on the heavy phase feed pipe 11, and the heavy phase feed pump front valve 112 is located between the heavy phase storage tank 15 and the heavy phase feed pump 19; a light phase feed pump front valve 122 is also provided on the light phase feed pipe 12, and the light phase feed pump front valve 122 is located between the light phase storage tank 16 and the light phase feed pump 20. Among them, in the heavy phase feeding cycle, the front valve 112 of the heavy phase feed pump is closed, and the front valve 122 of the light phase feed pump is opened, and the light phase feed pump 20 sucks the light phase liquid in the light phase storage tank 16 through the front valve 122 of the light phase feed pump, preparing for the subsequent light phase feeding cycle; in the light phase feeding cycle, the front valve 122 of the light phase feed pump is closed, and the front valve 112 of the heavy phase feed pump is opened, and the heavy phase feed pump 19 sucks the heavy phase liquid in the heavy phase storage tank 15 through the front valve 112 of the heavy phase feed pump, preparing for the subsequent heavy phase feeding cycle.

[0069] For example, Figure 3 As shown, in the heavy phase feeding cycle, the heavy phase feed pump front valve 112, the light phase feed valve 121, and the light phase post-extraction drain valve 141 are closed, while the heavy phase feed valve 111, the heavy phase post-extraction drain valve 131, and the light phase feed pump front valve 122 are opened. Figure 4 As shown, in the light phase feed cycle, the heavy phase feed pump front valve 112, the light phase feed valve 121, and the post-extraction light phase drain valve 141 are opened, while the heavy phase feed valve 111, the post-extraction heavy phase drain valve 131, and the light phase feed pump front valve 122 are closed.

[0070] Optional, such as Figure 1 , Figure 3 and Figure 4 As shown, the heavy phase feed pump front valve 112 and the light phase feed pump front valve 122 are both suction valves, the heavy phase feed valve 111 and the light phase feed valve 121 are both discharge valves, and the suction valve and the discharge valve are both active valves, such as solenoid valves and pneumatic ball valves, and the active valves rely on external control signals (such as electrical signals, pneumatic signals or hydraulic signals) to operate. Or, Figure 5As shown, the heavy phase feed pump front valve 112 and the light phase feed pump front valve 122, the heavy phase feed valve 111 and the light phase feed valve 121 are all passive check valves, mainly referring to one-way valves. The check valve relies on the fluid's own pressure or mechanical structure to achieve one-way flow control. No external energy input is required. The check valve is particularly suitable for dangerous occasions such as explosions, high toxicity, high corrosion, and strong radioactivity, and can avoid damage to electrical components.

[0071] In some embodiments, Figure 6 As shown, the driving device includes a high-pressure gas source 21, a first pipeline 22 and a second pipeline 23. The high-pressure gas source 21 is a high-pressure air buffer tank, on which a pressure sensor 211 is provided. The high-pressure gas source 21 is connected to the heavy phase storage tank 15 through the first pipeline 22, and a heavy phase pressure-reducing valve 221, a heavy phase pressure-surge switching valve 222 and a heavy phase storage tank pressure relief valve 223 are sequentially provided on the first pipeline 22 from the high-pressure gas source 21 to the heavy phase storage tank 15; the high-pressure gas source 21 is connected to the light phase storage tank 16 through the second pipeline 23, and a light phase pressure-reducing valve 231, a light phase pressure-surge switching valve 232 and a light phase storage tank pressure relief valve 233 are sequentially provided on the second pipeline 23 from the high-pressure gas source 21 to the light phase storage tank 16. The passive multi-stage countercurrent microextractor 1000 of this embodiment adopts full pneumatic operation, which is more suitable for use in highly radioactive, highly corrosive, and highly toxic environments, and can avoid frequent maintenance and replacement of the fragile heavy phase feed pump 19 and light phase feed pump 20.

[0072] The passive multi-stage countercurrent microextractor 1000 of this embodiment adopts a cycle operation of heavy phase feeding-depressurization of heavy phase storage tank 15-light phase feeding-depressurization of light phase storage tank 16. Specifically, firstly, according to the requirements of heavy phase liquid feed flow rate and light phase liquid feed flow rate, the heavy phase hydraulic pressure and light phase hydraulic pressure are adjusted to an appropriate range through the heavy phase pressure relief valve 221 and the light phase pressure relief valve 231 respectively; then, the cycle operation is performed again.

[0073] Among them, in the heavy phase feeding cycle: the heavy phase pressure switch valve 222, the heavy phase feed valve 111, the heavy phase discharge valve 131 after extraction, and the light phase storage tank pressure relief valve 233 are opened, and the light phase pressure switch valve 232, the light phase feed valve 121, the light phase discharge valve 141 after extraction, and the heavy phase storage tank pressure relief valve 223 are closed, and the high-pressure gas in the high-pressure gas source 21 enters the heavy phase storage tank 15, and the heavy phase liquid is forced to enter the upper chamber 1013a in the first-stage microextractor 101 through the heavy phase feed pipeline 11. The newly input heavy phase liquid and the light phase liquid in the upper chamber 1013a of the first-stage microextractor 101 are mixed and mass transferred, and then sink to the first At the same time, the heavy phase liquid originally in the lower chamber 1013b of the upper-stage microextractor 101 in each of the two adjacent microextractors 101 is forced to enter the upper chamber 1013a of the next-stage microextractor 101 through the corresponding transfer channel 102, and after mixing and mass transfer with the light phase liquid in the upper chamber 1013a of the corresponding microextractor 101, it sinks into the lower chamber 1013b, and the heavy phase liquid originally in the lower chamber 1013b of the final-stage microextractor 101 is collected through the post-extraction heavy phase collecting tube 13, thereby completing a heavy phase feeding cycle.

[0074] During the pressure relief cycle of the heavy phase storage tank 15, the heavy phase pressure surge switch valve 222, the heavy phase feed valve 111, the light phase pressure surge switch valve 232, the light phase feed valve 121, and the light phase drain valve 141 after extraction are closed, and the heavy phase storage tank pressure relief valve 223 and the heavy phase drain valve 131 after extraction are opened, and the pressure in the heavy phase storage tank 15 is relieved to near normal pressure.

[0075] During the light phase feeding cycle: the heavy phase pressure-rush switch valve 222, the heavy phase feed valve 111, the post-extraction heavy phase drain valve 131, and the light phase storage tank pressure relief valve 233 are closed, while the light phase pressure-rush switch valve 232, the light phase feed valve 121, the post-extraction light phase drain valve 141, and the heavy phase storage tank pressure relief valve 223 are opened, and the high-pressure gas in the high-pressure gas source 21 enters the light phase storage tank 16, forcing the light phase liquid to enter the lower chamber 1013b in the final-stage microextractor 101 through the light phase feed pipeline 12, and the newly input light phase liquid and the heavy phase liquid in the lower chamber 1013b of the final-stage microextractor 101 are mixed and mass transferred, and then rise to the final microextractor 101. In the upper chamber 1013a of the extractor 101, at the same time, the original light phase liquid in the upper chamber 1013a of the next-stage microextractor 101 in each adjacent two-stage microextractor 101 is forced to enter the lower chamber 1013b of the previous-stage microextractor 101 through the corresponding transfer channel 102, and rises to the upper chamber 1013a after mixing and mass transfer with the heavy phase liquid in the lower chamber 1013b of the corresponding microextractor 101, while the original light phase liquid in the upper chamber 1013a of the first-stage microextractor 101 is collected through the post-extraction light phase collecting tube 14, thereby completing a light phase feeding cycle.

[0076] During the pressure relief period of the light phase storage tank 16: the light phase pressure surge switch valve 232, the light phase feed valve 121, the heavy phase pressure surge switch valve 222, the heavy phase feed valve 111, and the post-extraction heavy phase drain valve 131 are closed, and the light phase storage tank pressure relief valve 233 and the post-extraction light phase drain valve 141 are opened, and the pressure in the light phase storage tank 16 is relieved to near normal pressure.

[0077] In some embodiments, Figure 7 and Figure 8 As shown, the microextractor body 10 includes a plurality of microextractor components 104 which are sealed and connected in sequence from top to bottom, and the plurality of microextractor components 104 together form a multi-stage microextractor 101, a transfer channel 102 and an interface adjustment channel 103. Therefore, the microextractor body 10 is easy to process and occupies a small space.

[0078] Specifically, the uppermost microextractor component 104 is processed with a multi-stage upper mixing unit 1011 and a multi-stage uppermost cavity 1041, and the multi-stage upper mixing unit 1011 is correspondingly connected to the multi-stage uppermost cavity 1041, and the lowermost microextractor component 104 is processed with a multi-stage lower mixing unit 1012 and a multi-stage lowermost cavity 1043, and the multi-stage lower mixing unit 1012 is correspondingly connected to the multi-stage lowermost cavity 1043, and the uppermost microextractor component 104 and the lowermost microextractor component 104 are connected to each other. The remaining microextractor components 104 between one microextractor component 104 are all provided with multi-stage intermediate cavities 1042, and the multiple uppermost cavities 1041, the multiple intermediate cavities 1042 and the multiple lowermost cavities 1043 are correspondingly connected up and down to form a multi-stage clarification chamber 1013; the multiple microextractor components 104 are also processed with channel sections forming the transfer channel 102, and one of the microextractor components 104 is processed with the interface adjustment channel 103. In this embodiment, the upper mixing unit 1011 and the lower mixing unit 1012 are both feedback oscillation micromixers, and are arranged according to Figure 1 Construct a countercurrent extraction system.

[0079] The present invention also proposes an extraction method using the passive multi-stage countercurrent microextractor 1000 of any of the above embodiments.

[0080] According to the extraction method of the passive multi-stage countercurrent microextractor 1000 of the embodiment of the present invention, extraction is performed in a manner of cyclically repeating a heavy phase feeding cycle and a light phase feeding cycle.

[0081] Among them, during the heavy phase feeding cycle, the light phase feeding pipe 12 stops conveying the light phase liquid, and the light phase collecting pipe 14 stops collecting the light phase liquid after extraction; at this time, on the one hand, the heavy phase feeding pipe 11 inputs the heavy phase liquid into the upper chamber 1013a of the first-stage microextractor 101, and the newly input heavy phase liquid mixes with the light phase liquid in the upper chamber 1013a of the first-stage microextractor 101 and then sinks into the lower chamber 1013b of the first-stage microextractor 101. At the same time, the original heavy phase liquid in the lower chamber 1013b of the upper microextractor 101 in each adjacent two-stage microextractor 101 is forced to pass through the corresponding The transfer channel 102 enters the upper chamber 1013a of the next-stage microextractor 101, mixes and transfers with the light phase liquid in the upper chamber 1013a of the corresponding microextractor 101, and then settles into the lower chamber 1013b, while the original heavy phase liquid in the lower chamber 1013b of the final-stage microextractor 101 is collected through the post-extraction heavy phase collecting tube 13; on the other hand, the heavy phase feeding tube 11 inputs the heavy phase liquid into the first-stage interface regulating channel 103, and the two-phase interface 1013c of each stage of the microextractor 101 is automatically adjusted through the interface regulating channels 103 at each stage to stabilize the two-phase interface 1013c.

[0082] During the light phase feeding cycle, the heavy phase feeding pipe 11 stops conveying the heavy phase liquid, and the heavy phase collecting pipe 13 stops collecting the heavy phase liquid after extraction; at this time, on the one hand, the light phase feeding pipe 12 inputs the light phase liquid into the lower chamber 1013b of the final microextractor 101, and the newly input light phase liquid mixes with the heavy phase liquid in the lower chamber 1013b of the final microextractor 101 and rises to the upper chamber 1013a of the final microextractor 101 after mass transfer. At the same time, the original light phase liquid in the upper chamber 1013a of the next microextractor 101 in each adjacent two-stage microextractor 101 is forced to pass through the corresponding transfer tube 101. The transport channel 102 enters the lower chamber 1013b of the previous microextractor 101, mixes and transfers with the heavy phase liquid in the lower chamber 1013b of the corresponding microextractor 101, and then rises to the upper chamber 1013a, while the original light phase liquid in the upper chamber 1013a of the first-stage microextractor 101 is collected through the post-extraction light phase collecting tube 14; on the other hand, the light phase feeding pipe 12 inputs the light phase liquid to the final interface regulating channel 103, and the two-phase interface 1013c of each stage of the microextractor 101 is automatically adjusted through the interface regulating channels 103 at each stage to stabilize the two-phase interface 1013c.

[0083] The above-mentioned heavy phase feeding cycle and light phase feeding cycle are cyclically repeated, that is, the heavy phase feeding cycle and the light phase feeding cycle are alternately cycled in sequence, during which the two-phase interface 1013c is automatically adjusted between the adjacent two-stage microextractors 101 through the interface adjustment channel 103 until the two-phase interface 1013c is stable, and at the same time, the heavy phase liquid is gradually transferred from the first-stage microextractor 101 to the final-stage microextractor 101, and the light phase liquid is transferred in the opposite direction. There is no need to set mechanical movable parts in the microextractor body 10 to realize the transfer of the heavy phase liquid and the light phase liquid, thereby realizing a passive multi-stage countercurrent microextraction operation that automatically maintains the interface balance.

[0084] Since the extraction method of the embodiment of the present invention adopts the passive multi-stage countercurrent microextractor 1000 of the embodiment of the present invention, the extraction method of the embodiment of the present invention has the same technical effect as the passive multi-stage countercurrent microextractor 1000 of the embodiment of the present invention, which will not be repeated here.

[0085] The following is an experiment of the extraction method of the passive multi-stage countercurrent microextractor 1000 of an embodiment of the present invention. An extraction experiment was carried out using 12 vol% TBP-kerosene as the light phase liquid (extractant) and a 5.0 mol / L HNO3 aqueous solution containing 1114 mg / L zirconium (Zr(NO3)4) as the heavy phase liquid (raw material liquid). Experimental conditions: During the heavy phase feeding cycle, the heavy phase feed flow rate is 11 mL / min and the feeding time is 7.5 seconds; during the light phase feeding cycle, the light phase feed flow rate is 11 mL / min and the feeding time is 7.5 seconds; the temperature is 11-25 degrees Celsius. The experiment shows that the extraction method of the passive multi-stage countercurrent microextractor 1000 of the embodiment of the present invention can make the distribution coefficient of zirconium ions in the two phases reach more than 3 times the distribution coefficient at single-stage equilibrium.

[0086] Although the embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the claims and their equivalents.

Claims

1. A passive multi-stage countercurrent microextractor, characterized in that: It includes a microextractor body, a heavy phase feed pipe, a light phase feed pipe, a post-extraction heavy phase collection pipe and a post-extraction light phase collection pipe; The microextractor body comprises a multi-stage microextractor, a transfer channel and an interface adjustment channel; each stage of the microextractor has a clarification chamber, and the clarification chamber comprises an upper chamber for accommodating a light phase liquid and a lower chamber for accommodating a heavy phase liquid divided by a two-phase interface; the transfer channel is distributed between the microextractors of each adjacent two stages, and is used to transfer the heavy phase liquid in the lower chamber of the microextractor of the upper stage in the microextractors of the corresponding two adjacent two stages to the upper chamber of the microextractor of the next stage, and is used to transfer the light phase liquid in the upper chamber of the microextractor of the next stage in the microextractors of the corresponding two adjacent two stages to the lower chamber of the microextractor of the upper stage; the interface adjustment channel is distributed between the microextractors of each adjacent two stages, between the first stage microextractor and the post-extraction light phase collection tube, and between the last stage microextractor and the post-extraction heavy phase collection tube, and the resistance of the interface adjustment channel is much greater than the resistance of the transfer channel, and is used to automatically adjust the position of the two-phase interface of each stage of the microextractor and stabilize the two-phase interface; One end of the heavy phase feed pipe is connected to the first-stage microextractor, and is used to inject heavy phase liquid into the upper chamber of the first-stage microextractor; One end of the light phase feed pipe is connected to the final microextractor for injecting light phase liquid into the lower chamber of the final microextractor; One end of the post-extraction heavy phase collecting tube is connected to the light phase feeding tube; One end of the post-extraction light phase collecting tube is connected to the heavy phase feeding tube.

2. The passive multi-stage countercurrent microextractor according to claim 1, characterized in that: Each stage of the microextractor also has an upper mixing unit and a lower mixing unit; the upper mixing unit is located above the two-phase interface and connected to the upper chamber, and the lower mixing unit is located below the two-phase interface and connected to the lower chamber; the upper mixing unit of the first-stage microextractor is connected to one end of the heavy phase feed pipe, and the lower mixing unit of the last-stage microextractor is connected to one end of the light phase feed pipe. In each of the two adjacent stages of the microextractor, the lower mixing unit of the microextractor of the upper stage is connected to the upper mixing unit of the microextractor of the lower stage through the transfer channel.

3. The passive multi-stage countercurrent microextractor according to claim 2, characterized in that: Each stage of the microextractor is provided with a connection position connected to the corresponding interface regulating channel at a position close to the two-phase interface in the vertical direction.

4. The passive multi-stage countercurrent microextractor according to claim 3, characterized in that: The two-phase interface of each stage of the microextractor is located at the vertical middle position of the clarification chamber.

5. The passive multi-stage countercurrent microextractor according to any one of claims 1 to 4, characterized in that: The heavy phase feed pipe is provided with a heavy phase feed valve, and one end of the light phase collection pipe after extraction is located between the heavy phase feed valve and the first-stage microextractor; The light phase feed pipe is provided with a light phase feed valve, and one end of the post-extraction heavy phase collecting pipe is located between the light phase feed valve and the final micro-extractor; The post-extraction heavy phase collecting pipe is provided with a post-extraction heavy phase drain valve, and the connection point between the final-stage interface regulating channel and the post-extraction heavy phase collecting pipe is located between one end of the post-extraction heavy phase collecting pipe and the post-extraction heavy phase drain valve; The post-extraction light phase collecting pipe is provided with a post-extraction light phase drain valve, and the connection point between the first-stage interface regulating channel and the post-extraction light phase collecting pipe is located between one end of the post-extraction light phase collecting pipe and the post-extraction light phase drain valve.

6. The passive multi-stage countercurrent microextractor according to claim 5, characterized in that: It also includes a heavy phase storage tank, a light phase storage tank, a post-extraction heavy phase collection storage tank, a post-extraction light phase collection storage tank and a driving device; the heavy phase storage tank is connected to the other end of the heavy phase feed pipe, the light phase storage tank is connected to the other end of the light phase feed pipe, the post-extraction heavy phase collection storage tank is connected to the other end of the post-extraction heavy phase collection pipe, the post-extraction light phase collection storage tank is connected to one end of the post-extraction light phase collection pipe, and the driving device is used to drive the heavy phase liquid in the heavy phase storage tank into the first-stage microextractor and to drive the light phase liquid in the light phase storage tank into the last-stage microextractor.

7. The passive multi-stage countercurrent microextractor according to claim 6, characterized in that: The driving device includes a heavy phase feed pump and a light phase feed pump. The heavy phase feed pump is arranged on the heavy phase feed pipe and located between the heavy phase storage tank and the heavy phase feed valve. The light phase feed pump is arranged on the light phase feed pipe and located between the light phase storage tank and the light phase feed valve.

8. The passive multi-stage countercurrent microextractor according to claim 6, characterized in that: The driving device includes a high-pressure gas source, a first pipeline and a second pipeline. The high-pressure gas source is connected to the heavy phase storage tank through the first pipeline, and a heavy phase pressure-reducing valve, a heavy phase pressure-surge switching valve and a heavy phase storage tank pressure relief valve are sequentially arranged on the first pipeline from the high-pressure gas source to the heavy phase storage tank; the high-pressure gas source is connected to the light phase storage tank through the second pipeline, and a light phase pressure-reducing valve, a light phase pressure-surge switching valve and a light phase storage tank pressure relief valve are sequentially arranged on the second pipeline from the high-pressure gas source to the light phase storage tank.

9. The passive multi-stage countercurrent microextractor according to any one of claims 2 to 4, characterized in that: The microextractor body comprises a plurality of microextractor components which are sealed and connected in sequence from top to bottom, and the plurality of microextractor components together form a multi-stage microextractor, the transport channel and the interface regulating channel.

10. The passive multi-stage countercurrent microextractor according to claim 9, characterized in that: The top microextractor component is processed with multiple upper mixing units and multiple upper cavities, and the multiple upper mixing units are correspondingly connected to the multiple upper cavities. The bottom microextractor component is processed with multiple lower mixing units and multiple lower cavities, and the multiple lower mixing units are correspondingly connected to the multiple lower cavities. The remaining microextractor components located between the top microextractor component and the bottom microextractor component are all provided with multiple intermediate cavities. The multiple upper cavities, the multiple intermediate cavities and the multiple lower cavities are correspondingly connected up and down to form multiple clarification chambers. The multiple microextractor components are also processed with channel sections forming the transfer channels, and one of the multiple microextractor components is processed with an interface adjustment channel.

11. An extraction method of a passive multi-stage countercurrent microextractor according to any one of claims 1 to 10, characterized in that: Extraction is carried out by cyclically repeating heavy phase feeding cycle and light phase feeding cycle; Wherein, during the heavy phase feeding cycle, the light phase feeding pipe stops conveying light phase liquid, and the light phase collecting pipe after extraction stops collecting light phase liquid after extraction; at this time, on the one hand, the heavy phase feeding pipe inputs heavy phase liquid into the upper chamber of the first-stage microextractor, and the newly input heavy phase liquid mixes with the light phase liquid in the upper chamber of the first-stage microextractor and then sinks into the lower chamber of the first-stage microextractor after mass transfer, and at the same time, the original heavy phase in the lower chamber of the upper-stage microextractor in each of the two adjacent microextractors is forced to The liquid enters the upper chamber of the microextractor of the next stage through the corresponding transfer channel, mixes with the light phase liquid in the upper chamber of the corresponding microextractor and then settles into the lower chamber, while the original heavy phase liquid in the lower chamber of the microextractor of the last stage is collected through the post-extraction heavy phase collection tube; on the other hand, the heavy phase feed pipe inputs the heavy phase liquid into the interface adjustment channel of the first stage, and the two-phase interface of each stage of the microextractor is automatically adjusted through the interface adjustment channels of each stage to stabilize the two-phase interface; During the light phase feeding cycle, the heavy phase feeding pipe stops conveying the heavy phase liquid, and the post-extraction heavy phase collecting pipe stops collecting the post-extraction heavy phase liquid; at this time, on the one hand, the light phase feeding pipe inputs the light phase liquid into the lower chamber of the final microextractor, and the newly input light phase liquid mixes with the heavy phase liquid in the lower chamber of the final microextractor and then rises to the upper chamber of the final microextractor, and at the same time, the original light phase liquid in the upper chamber of the next microextractor in each of the two adjacent microextractors is forced to pass through The light phase liquid passes through the corresponding transfer channel into the lower chamber of the microextractor at the previous stage, mixes with the heavy phase liquid in the lower chamber of the corresponding microextractor and then rises to the upper chamber, while the original light phase liquid in the upper chamber of the first-stage microextractor is collected through the post-extraction light phase collecting tube; on the other hand, the light phase feed pipe inputs light phase liquid into the interface regulating channel of the last stage, and the two-phase interface of each stage of the microextractor is automatically adjusted through the interface regulating channels of each stage to stabilize the two-phase interface.

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