An automatic counter-current cascade extraction device and control method

Abstract

The application relates to an automatic countercurrent cascade extraction device and a control method, which comprises at least n extraction tubes for realizing cascade extraction, which are arranged in S1 to Sn stages, and a liquid suction and stirring unit is arranged in each stage; the extraction tubes can be controlled to move to the next stage as a whole or be reset reversely; when moving to the next stage as a whole, the liquid suction and stirring unit injects the water-phase liquid sucked into the extraction tube of the upper stage after moving; at this time, the S(n+1) stage is a water-phase feeding stage, new water-phase liquid is added into the extraction tube of the S(n+1) stage, the S1 stage is a water-phase discharging stage, and a water-phase discharging receiving tube is arranged in the water-phase discharging stage; after being reset reversely, the next extraction operation is carried out. The application realizes automatic stirring mixing, phase separation and liquid separation of the cascade extraction operation, reduces the workload of manual operation, and eliminates misoperation.

Description

Technical Field

[0001] This invention belongs to the field of liquid-liquid extraction technology, specifically relating to an automatic countercurrent cascade extraction device and control method. Background Technology

[0002] Countercurrent liquid-liquid extraction (CLI) is an important process technology in chemical separation, typically using organic extractants to extract target components from the aqueous phase. It has wide applications in uranium and thorium mining, nuclear fuel reprocessing, and rare earth element extraction. Developing an extraction process requires process testing, especially in the early stages of research, to determine parameters such as reagent concentration, acidity, flow ratio, and number of stages. Cascade extraction experiments are frequently used in these studies. Cascade extraction uses test tubes or separatory funnels as extractors, performing extraction step-by-step, row-by-row operations. Compared to using extraction columns, mixing and clarifying tanks, or centrifugal extractors, this method offers advantages such as smaller scale, lower feed consumption (tens to hundreds of milliliters), lower cost, and greater flexibility. The disadvantages of cascade extraction include a large workload, typically requiring hundreds or even thousands of test tube extraction / separation operations, and a higher probability of error, which can often render the entire experiment unusable.

[0003] Figure 1a and Figure 1b The diagram illustrates the cascade experiment procedure for a 12-stage extraction process. This cascade experiment requires six extraction tubes and a tube rack, numbered according to the extraction stage (S1-S12). Each extraction tube contains both an organic and an aqueous phase, and is numbered (t1 to tn). The extraction tubes are placed on the tube rack at their respective stage positions. After shaking, mixing, and centrifugation to separate the phases, the tubes are returned to their original positions. The aqueous phase is then removed from left to right and added to the next extraction tube, while the tube is simultaneously moved to the next stage position. Figure 1a A batch of six extraction tubes is called a single extraction operation. After extraction and phase separation, the aqueous phase feed solution is transferred out as the aqueous effluent. Figure 1b After extraction and phase separation, the aqueous phase feed solution in the 12th stage extraction tube is transferred to the next stage, while the remaining organic phase feed solution is transferred out of the process system along with the extraction tube, serving as the organic phase effluent. Figure 1a and Figure 1b It can be seen that a complete process of adding and discharging aqueous phase and adding and discharging organic phase can be completed through two rows of extraction operations.

[0004] Completing a 12-stage extraction experiment requires 6 liquid-liquid separation operations and 6 extraction tube sorting operations. Liquid-liquid separation is generally performed using a dropper and is done visually. Cascade experiments typically require more than 50 stages to reach material equilibrium, necessitating hundreds of liquid-liquid separation and extraction tube sorting operations. This workload is substantial and can easily lead to fatigue and operational errors. Summary of the Invention

[0005] The purpose of this invention is to address the shortcomings of manual operation in cascade extraction experiments by providing an automatic countercurrent cascade extraction device and control method, which can automate the cascade extraction operation, reduce the workload of manual operation, and eliminate misoperation.

[0006] To achieve the above objectives, the technical solution of the present invention is as follows:

[0007] An automatic countercurrent cascade extraction device includes at least n extraction tubes for cascade extraction, wherein the n extraction tubes are arranged in stages S1 to Sn. Each extraction tube contains an aqueous phase feed solution and an organic phase feed solution. Each stage is equipped with a feed solution suction and stirring unit to stir the feed solution in the extraction tube at the corresponding stage and suction the aqueous phase feed solution after settling and phase separation. The extraction tubes can be controlled to move to the next stage one stage or to reverse and reset. When the whole device moves to the next stage one stage, the feed solution suction and stirring unit injects the suctioned aqueous phase feed solution into the moved next stage extraction tube. At this time, stage S(n+1) is the aqueous phase feed stage, and new aqueous phase feed solution is added to the extraction tube in stage S(n+1). Stage S1 is the aqueous phase discharge stage, and an aqueous phase discharge receiving tube is set at the aqueous phase discharge stage. When the device is reversed and reset, the next extraction operation is performed.

[0008] Furthermore, in a specific embodiment, in the automatic countercurrent cascade extraction device described above, when the organic phase is discharged, the S(n+1) stage station is the organic phase discharge station, and the extraction tube with only the organic phase liquid remaining in the S(n+1) stage station is taken out; at this time, the S1 stage station is the organic phase feed station, and an extraction tube containing new organic phase liquid is set at the organic phase feed station.

[0009] Furthermore, in a specific embodiment, the automatic countercurrent cascade extraction device described above has an S0 level station on one side of the S1 level station. An aqueous phase effluent receiving pipe or an extraction pipe containing a new organic phase feed liquid is placed in the S0 level station. When the entire extraction pipe moves to the next level station, the aqueous phase effluent receiving pipe or the extraction pipe containing a new organic phase feed liquid placed in the S0 level station moves to the S1 level station.

[0010] Furthermore, in a specific embodiment, the automatic countercurrent cascade extraction device described above includes a liquid suction and stirring unit comprising a suction tube connected to an injection pump. The suction tube can be inserted to the bottom of the extraction tube, and the injection pump enables pulse stirring and suction and release of the aqueous phase liquid.

[0011] Furthermore, the extraction tubes in the S1 to Sn stages simultaneously draw aqueous phase liquid according to a set volume through the corresponding liquid suction and stirring unit at each stage. Then, the suction tube is pulled out of the extraction tube, and the entire extraction tube is moved to the next stage one station. Subsequently, the suction tube injects the aqueous phase liquid into the moved next stage extraction tube.

[0012] Furthermore, in a specific embodiment, the automatic countercurrent cascade extraction device described above has an aqueous phase feed pipeline installed at the S(n+1) stage station to add new aqueous phase liquid to the extraction tube in the S(n+1) stage station.

[0013] Furthermore, in a specific embodiment, the automatic countercurrent cascade extraction device described above includes an extraction operation turntable, a pump tube lifting platform, and an aqueous phase outlet receiving tube turntable. The extraction operation turntable is uniformly provided with a plurality of extraction tube placement holes along its circumference, wherein n consecutive extraction tube placement holes constitute the S1 to Sn stage positions. The pump tube lifting platform is provided with a suction tube corresponding to the S1 to Sn stage positions, and the suction tube is connected to an injection pump. An aqueous phase feed pipeline is provided at the extraction tube placement hole position corresponding to the S(n+1) stage position. The aqueous phase outlet receiving tube turntable is positioned higher than the extraction operation turntable, and the aqueous phase outlet receiving tube turntable is uniformly provided with a plurality of receiving tube placement holes along its circumference. The aqueous phase outlet receiving tube is placed in the receiving tube placement hole, and there is an empty hole between two adjacent aqueous phase outlet receiving tubes. During the rotation of the aqueous phase outlet receiving tube turntable, the hole position of the receiving tube placement hole can be aligned with the extraction tube placement hole at the S1 stage of the extraction operation turntable.

[0014] Furthermore, in a specific embodiment, in the automatic countercurrent cascade extraction device described above, aqueous phase feed liquid and organic phase feed liquid are added to the extraction tubes placed at the S1 to Sn stages on the extraction operation turntable, and organic phase feed liquid is added to the other extraction tubes outside the S1 to Sn stages.

[0015] Furthermore, in a specific embodiment, in the automatic countercurrent cascade extraction device described above, the bottom of the aqueous phase effluent receiving tube on the aqueous phase effluent receiving tube turntable is slightly higher than the top of the extraction tube on the extraction operation turntable.

[0016] Furthermore, in a specific embodiment, the automatic countercurrent cascade extraction device described above automatically controls the rotation of the extraction operation turntable and the aqueous phase outlet receiving pipe turntable, as well as the lifting and lowering of the pump pipe lifting platform, the stirring of the feed liquid, and the suction and release of the aqueous phase feed liquid through a program set by the control system.

[0017] In a specific embodiment, the present invention further provides a control method for the above-mentioned automatic countercurrent cascade extraction device, comprising the following steps:

[0018] 1) Add aqueous and organic phase feed solutions to the extraction tubes placed at the S1 to Sn level stations of the extraction operation turntable, and add organic phase feed solutions to other extraction tubes outside the S1 to Sn level stations; align one empty hole of the aqueous phase outlet receiving tube turntable with the S1 station of the extraction operation turntable.

[0019] 2) The pump tube lifting platform descends, and the suction tube is inserted into the bottom of the extraction tube at the S1 to Sn level. Pulse stirring is achieved by the injection pump, and the mixture is allowed to stand and separate after stirring.

[0020] 3) The suction pipe draws a fixed volume of aqueous liquid, and the pump pipe lifting platform rises.

[0021] 4) The extraction operation turntable rotates one station, and the turntable rotates to the next position of the aqueous phase effluent receiving pipe.

[0022] 5) Release the aqueous phase liquid from each suction tube;

[0023] 6) Add aqueous phase liquid into the extraction tube corresponding to the S(n+1) level station, the extraction operation turntable rotates and resets, and the aqueous phase liquid receiving tube turntable rotates to the next empty hole position in sequence.

[0024] 7) The pump tube lifting platform descends, the suction pipe is inserted into the bottom of the extraction tube of the S1 to Sn level station, and pulse stirring is achieved by the injection pump. After stirring, the phase is separated by standing. The suction pipe draws the aqueous phase liquid at a fixed volume, and the pump tube lifting platform rises.

[0025] 8) The extraction operation turntable rotates one station, while the aqueous phase liquid receiving tube turntable does not rotate, releasing the aqueous phase liquid in each suction tube, and the extraction tube corresponding to the S(n+1) level station is taken out.

[0026] 9) Repeat steps 2) to 8) until the last extraction tube enters the S1 level station.

[0027] Furthermore, in a specific embodiment, the control method of the automatic countercurrent cascade extraction device as described above, wherein after step 9), if it is necessary to continue the cascade extraction operation, an extraction tube containing organic phase liquid is placed in the extraction tube placement hole other than the S1 to Sn level stations of the extraction operation turntable, the aqueous phase liquid outlet receiving tube that has been injected with aqueous phase liquid is taken out and a new aqueous phase liquid outlet receiving tube is placed in the original position, and steps 2) to 9) are repeated to continue the cascade extraction operation.

[0028] The beneficial effects of this invention are as follows: The automatic countercurrent cascade extraction device and control method provided by this invention realize the automatic completion of stirring, mixing, phase separation, and liquid separation in the cascade extraction operation, reducing the workload of manual operation and eliminating misoperation. Through the rational design of the device structure, the inlet and outlet operations of the aqueous phase and the organic phase are matched, realizing the automatic setting and operation of the system. The device has a simple structure and high operating efficiency. Attached Figure Description

[0029] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0030] Figure 1a , Figure 1b This is a schematic diagram of a traditional manual cascade extraction process;

[0031] Figures 2a-2d This is a schematic diagram of the operation scheme of the automatic countercurrent cascade extraction device of the present invention;

[0032] Figure 3 This is a perspective view of the rotary automatic countercurrent cascade extraction device in a specific embodiment of the present invention;

[0033] Figure 4 This is a top view of the rotary automatic countercurrent cascade extraction device in a specific embodiment of the present invention.

[0034] In the diagram, 1-Pump pipe lifting platform; 2-S1 station; 3-S2 station; 4-S3 station; 5-S4 station; 6-S5 station; 7-S6 station; 8-S7 station; 9-S8 station; 10-Extraction operation turntable; 11-Extraction tube; 12-Aqueous phase outlet receiving tube turntable; 13-Aqueous phase outlet receiving tube; 14-Empty hole position; 15-Base and support; 16-S0 station. Detailed Implementation

[0035] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0036] Unless otherwise defined, the technical or scientific terms used in this invention shall have the ordinary meaning as understood by one of ordinary skill in the art to which this invention pertains.

[0037] The terms “comprising”, “including”, etc., as used herein indicate the presence of the steps, features, operations, or components, but do not preclude the addition of one or more other steps, features, operations, or components.

[0038] Cascade extraction is a stepwise two-phase countercurrent extraction process that includes mixing, clarification, and aqueous phase transfer operations. Traditional extraction operations include... Figure 1a and Figure 1b As shown, after the liquids in a series of extraction tubes are mixed and clarified, the operation proceeds from left to right, transferring the aqueous phase to the next stage using a pipette before the next extraction operation. Figure 1a A batch of six extraction tubes is called a single extraction operation. After extraction and phase separation, the aqueous phase feed solution is transferred out as the aqueous effluent. Figure 1b After extraction and phase separation, the 12th stage extraction tube transfers the aqueous phase feed to the next stage, while the remaining organic phase feed is transferred out of the process system along with the extraction tube as the organic phase effluent.

[0039] This invention proposes an automatic countercurrent cascade extraction device, comprising at least n extraction tubes for cascade extraction, wherein the n extraction tubes are arranged in stages S1 to Sn, and each extraction tube contains an aqueous phase feed solution and an organic phase feed solution; each stage is equipped with a feed solution suction and stirring unit to stir the feed solution in the extraction tube at the corresponding stage, and after settling and phase separation, the aqueous phase feed solution is suctioned; the extraction tubes can be controlled to move to the next stage one stage or to reverse and reset. When the whole assembly moves to the next stage one stage, the feed solution suction and stirring unit injects the suctioned aqueous phase feed solution into the moved next stage extraction tube. At this time, stage S(n+1) is the aqueous phase feed stage, and new aqueous phase feed solution is added to the extraction tube in stage S(n+1). Stage S1 is the aqueous phase discharge stage, and an aqueous phase discharge receiving tube is set at the aqueous phase discharge stage; when the assembly is reversed and reset, the next extraction operation is performed. When the organic phase is discharged, the S(n+1) level station is the organic phase discharge station, and the extraction tube with only organic phase liquid remaining in the S(n+1) level station is taken out; at this time, the S1 level station is the organic phase feed station, and an extraction tube containing new organic phase liquid is set at the organic phase feed station.

[0040] In some specific embodiments, for n-stage cascade extraction, n+2 stages are set up, labeled S0 to S(n+1). In stages S1 to Sn, each extraction tube contains both aqueous and organic phase feed solutions. Each stage is equipped with a feed solution suction and stirring unit, capable of pulse stirring and liquid suction of the two-phase mixture. Stage S0 contains an aqueous phase outlet receiving tube or an extraction tube containing the organic phase feed solution, while stage S(n+1) contains an aqueous phase feed line, labeled F1.

[0041] In some specific embodiments, the feed liquid suction and stirring unit includes a suction pipe connected to an injection pump. One injection pump is installed at each stage from S1 to Sn, labeled P1-Pn. The suction pipes of the pumps can be raised and lowered. The suction pipes of pumps P1 to Pn descend to the bottom of the extraction tube. The organic and aqueous phase feed liquids from stages S1 to Sn are pulse-stirred by the pumps at each stage, and then allowed to settle and separate (see...). Figure 2a (S1 to S6 workstations are shown). The lifting and lowering of the P1-Pn pump pipes, pulse stirring, suction of the aqueous phase liquid, and feeding through the F1 pipeline are all automatically controlled by the operating system.

[0042] In some specific embodiments, the aqueous phase liquid in the extraction tubes of stages S1 to Sn is simultaneously extracted by the injection pump of each stage according to a set volume, and the pump tubes of stages P1 to Pn rise above the extraction tube opening ( Figure 2b (As shown); then all extraction tubes are moved one station to the right, and the aqueous phase feed liquid in the suction tube is released into the corresponding extraction tube of this stage after the movement (as shown). Figure 2c As shown in the diagram, at this stage, the extraction tube has been moved from the previous stage. Then, all extraction tubes move one position to the left, and the pump tubes from P1 to Pn descend to continue the pulse stirring-static phase separation-liquid separation operation.

[0043] In some specific embodiments, the aqueous phase effluent receiving pipe is placed at station S0. When the aqueous phase effluent receiving pipe moves to station S1 ( Figure 2c (Called a1), the aqueous phase liquid in the P1 pump pipe is released into the aqueous phase outlet receiving pipe. After moving back to the S0 station to the left, it can be removed by manual or automated operation.

[0044] In some specific embodiments, the extraction tube containing the organic phase feed liquid is placed at station S0. When the extraction tube containing the organic phase feed liquid is transferred from station S0 to station S1, it receives the aqueous phase feed liquid released from pump pipe P1, and two-phase liquid-liquid extraction can be performed. After the nth stage extraction tube undergoes extraction-static phase separation-aqueous phase suction, only the organic phase feed liquid remains, and it enters station S(n+1) (…). Figure 2c When it reaches station S7 in the process, it can be removed manually or automatically and discharged as an organic phase liquid.

[0045] In some specific embodiments, the present invention achieves matching of the inlet and outlet operations of the aqueous phase and the organic phase in the following manner: The aqueous phase outlet receiving pipe and the organic phase feed extraction pipe are alternately placed at station S0. When the aqueous phase outlet receiving pipe is placed at station S0, the system automatically sets the system to add the aqueous phase feed solution from pipeline F1 to the extraction pipe at station S(n+1) (i.e., station S7). Figure 2d As shown). When the organic phase feed tube is placed in the S0 station, the system automatically sets the station to S(n+1) level (i.e., S7 station) to remove the organic phase outlet tube (i.e., the extraction tube with only organic phase feed remaining).

[0046] Example

[0047] This embodiment describes an automatic countercurrent cascade extraction device with a rotary structure. Taking a 14-stage countercurrent cascade extraction process with 7 extraction stations as an example, the structure and control method of the device are explained in detail.

[0048] like Figure 3 , Figure 4 As shown, the rotary automatic countercurrent cascade extraction device includes an extraction operation turntable 10, a pump tube lifting platform 1, and an aqueous phase outlet receiving pipe turntable 12. The extraction operation turntable 10 is uniformly provided with a number of extraction tube placement holes along the circumference, and extraction tubes 11 are placed in the holes. The n consecutive extraction tube placement holes are the S1 to Sn level stations. Figure 3 The numbers 2-8 indicate extraction stations S1 to S7, a total of 7 stations. Station S0 (16) is located on the other side of station S1. The pump lifting platform 1 is equipped with suction tubes corresponding to the positions of stations S1 to Sn, and these suction tubes are connected to the injection pump. The S(n+1) level station (… Figure 3 An aqueous feed pipe is provided at the extraction tube placement hole corresponding to station S8 (9). The aqueous phase effluent receiving tube turntable 12 is positioned higher than the extraction operation turntable 10. Several receiving tube placement holes are evenly arranged around the circumference of the aqueous phase effluent receiving tube turntable 12. The aqueous phase effluent receiving tube 13 is placed in the receiving tube placement hole, and there is an empty hole 14 between two adjacent aqueous phase effluent receiving tubes 13. During the rotation of the aqueous phase effluent receiving tube turntable 12, the hole position of the receiving tube placement hole can be aligned with the extraction tube placement hole at station S1 (2) of the extraction operation turntable.

[0049] The extraction operation turntable 10, the pump tube lifting platform 1, and the aqueous phase outlet receiving pipe turntable 12 are mounted on the base and support 15.

[0050] In this embodiment, eight stainless steel suction tubes are installed on the pump tube lifting platform 1. These suction tubes are connected to an external injection pump, enabling pulse stirring and liquid suction and release. When the lifting platform is lowered to its lowest position, the ends of the stainless steel suction tubes are close to the bottom of the extraction tube, allowing for the suction of the aqueous phase liquid from the extraction tube. When the lifting platform is raised to its highest position, the ends of the stainless steel suction tubes are slightly higher than the top of the aqueous phase outlet receiving tube, without interfering with the rotation of the turntable of the aqueous phase outlet receiving tube.

[0051] In this embodiment, 18 extraction tube placement holes are distributed at equal angles (20° intervals) along the edge of the extraction operation turntable 10, of which 8 holes are operation positions ( Figure 3 (As shown in Figure 2-9). The extraction tube is a commercially available 15mL plastic centrifuge tube. The extraction tube in the operating position is aligned with the suction tube of the pump lifting platform 1.

[0052] In this embodiment, the aqueous phase effluent receiving tube turntable 12 has 20 equally spaced holes for placing the aqueous phase effluent receiving tubes. Adjacent aqueous phase effluent receiving tubes are placed with one empty hole between them. The aqueous phase effluent receiving tubes are relatively flat round bottles, placed behind the turntable, with the bottom of the bottle slightly higher than the top of the extraction tube on the extraction operation turntable, so as not to interfere with the extraction operation turntable. Hole number 1 on the aqueous phase effluent receiving tube turntable is empty and is initially aligned with the S1 station.

[0053] The rotation of the two turntables, the lifting and lowering of the pump pipe lifting platform, and the operation of the injection pump are all automatically controlled by the operating system according to the set program. Parameters such as pulse stirring time, settling time, and volume of aqueous phase liquid can be set from the operating system.

[0054] The operation process of cascade extraction using the rotary automatic countercurrent cascade extraction device of this embodiment is as follows.

[0055] (1) Operational preparation

[0056] A certain volume of organic phase feed solution is pre-added to the extraction tubes, and 18 extraction tubes are placed on the extraction operation turntable. Extraction tubes 7 through 1 are placed in reverse order from station S1 to S7, and a certain volume of aqueous phase feed solution is added next. Extraction tubes 8 through 18 are also placed in reverse order. The aqueous phase effluent receiving tube is placed on the aqueous phase effluent receiving tube turntable, spaced one hole apart. Before starting the extraction operation, hole 1 on the aqueous phase effluent receiving tube turntable is aligned with station S1 on the extraction operation turntable, and the suction tube at station S1 passes through this hole to operate the extraction tube.

[0057] Set parameters such as pulse stirring time, settling time, and aqueous phase liquid suction volume in the operating system.

[0058] (2) Extraction-liquid separation operation

[0059] The pump tube lifting platform descends, and the suction tube is inserted into the bottom of the extraction tube at the S1 to Sn level. The pulse stirring is started by the injection pump, and the mixture is stirred for a set time and then allowed to stand for phase separation.

[0060] Aqueous liquid is drawn in a fixed volume through the suction pipe, and the pump pipe lifting platform rises.

[0061] The extraction operation turntable rotates counterclockwise by one station, and the aqueous phase outlet receiving pipe turntable rotates clockwise by one station, so that the No. 2 hole (which has an aqueous phase outlet receiving pipe) is aligned with the S1 station.

[0062] Release the aqueous phase liquid from each of the suction tubes. Specifically, the aqueous phase liquid from station S1 is released into the aqueous phase liquid receiving tube at hole No. 2, and the aqueous phase liquid from suction tubes at stations S2 to S7 is released into extraction tubes No. 7 to No. 2, respectively.

[0063] Extraction tube 1 is in position S8. After a certain volume of aqueous liquid is added through the aqueous feed pipe, the extraction operation turntable rotates clockwise by one position (returning to the initial position). The aqueous liquid outlet receiving pipe turntable also rotates by one position, so that hole 3 (which is an empty hole) is aligned with position S1.

[0064] The pump tube lifting platform descends, the suction pipe is inserted into the bottom of the extraction tube of the S1 to S7 level station, and pulse stirring is achieved by the injection pump. After stirring, the mixture is allowed to stand and separate into phases. The suction pipe draws the aqueous phase liquid at a fixed volume, and the pump tube lifting platform rises.

[0065] The extraction turntable rotates counterclockwise one station again, while the turntable for the aqueous phase outlet receiving tube does not rotate. At this point, extraction tube No. 8 reaches station S1. The aqueous phase liquid in the suction tubes from S1 to S7 is released into extraction tubes No. 8 to S2. Extraction tube No. 1 leaves station S7 and enters station S8. At this point, no more aqueous phase liquid is added to station S8, and extraction tube No. 1 exits as the organic phase, leaving the extraction process.

[0066] Repeat steps to The cascade extraction operation continues until extraction tube #18 enters station S1. At this point, there are 10 organic phase effluent tubes and 10 aqueous phase effluent receiving tubes, totaling 20 runs. If further cascade extraction is needed, remove the extraction tube that has left station S7 and replace it with a new extraction tube (containing organic phase feed); remove the aqueous phase effluent receiving tube and replace it with a new one in its original position, continuing the cascade extraction operation. After 40 runs of extraction, the extraction tubes and aqueous phase effluent receiving tubes can be replaced again to continue the cascade extraction operation until material distribution equilibrium is reached.

[0067] Other embodiments of the invention will readily occur to those skilled in the art upon consideration of the specification and practice of the invention disclosed herein. This application is intended to cover any variations, uses, or adaptations of the invention that follow the general principles of the invention and include common knowledge or customary techniques in the art not disclosed herein. Thus, the invention also intends to include such variations and adaptations if they fall within the scope of the claims and their equivalents.

[0068] The above embodiments are merely illustrative examples of the present invention. The present invention may also be implemented in other specific ways or forms without departing from its spirit or essential characteristics. Therefore, the described embodiments should be considered illustrative rather than limiting in any respect. The scope of protection of the present invention should be defined by the claims, and any variations equivalent to the intent and scope of the claims should also be included within the scope of the present invention.

Claims

1. An automatic countercurrent cascade extraction apparatus, comprising at least n extraction tubes for realizing cascade extraction, said n extraction tubes being arranged in stages S1 to Sn, each extraction tube containing an aqueous phase feed solution and an organic phase feed solution, characterized in that, Each workstation is equipped with a corresponding liquid suction and stirring unit to stir the liquid in the extraction tube at the corresponding workstation, and after settling and phase separation, the aqueous phase liquid is suctioned out. The extraction tube can be controlled to move to the next workstation or reverse reset. When the whole unit moves to the next workstation, the liquid suction and stirring unit injects the suctioned aqueous phase liquid into the next workstation after the move. At this time, the S(n+1) workstation is the aqueous phase feed workstation, and new aqueous phase liquid is added to the extraction tube in the S(n+1) workstation. The S1 workstation is the aqueous phase discharge workstation, and an aqueous phase discharge receiving tube is set at the aqueous phase discharge workstation. After reversing reset, the next extraction operation is performed.

2. The automatic countercurrent cascade extraction apparatus as described in claim 1, characterized in that, When the organic phase is discharged, the S(n+1) level station is the organic phase discharge station, and the extraction tube with only organic phase liquid remaining in the S(n+1) level station is taken out; at this time, the S1 level station is the organic phase feed station, and an extraction tube containing new organic phase liquid is set at the organic phase feed station.

3. The automatic countercurrent cascade extraction apparatus as described in claim 1, characterized in that, An S0 station is set up on one side of the S1 station. An aqueous phase effluent receiving pipe or an extraction pipe containing a new organic phase feed liquid is placed in the S0 station. When the extraction pipe moves to the next station, the aqueous phase effluent receiving pipe or the extraction pipe containing a new organic phase feed liquid placed in the S0 station moves to the S1 station.

4. The automatic countercurrent cascade extraction apparatus as described in claim 1, characterized in that, The liquid suction and stirring unit includes a suction tube connected to an injection pump. The suction tube can be inserted to the bottom of the extraction tube, and the injection pump is used to realize pulse stirring and suction and release of the aqueous liquid.

5. The automatic countercurrent cascade extraction apparatus as described in claim 4, characterized in that, The extraction tubes in the S1 to Sn stages simultaneously draw aqueous phase liquid through the corresponding liquid suction and stirring units at each stage according to the set volume. Then, the suction tube is pulled out from the extraction tube, and the entire extraction tube is moved to the next stage one station. Subsequently, the aqueous phase liquid in the suction tube is injected into the moved next stage extraction tube.

6. The automatic countercurrent cascade extraction apparatus as described in claim 1, characterized in that, An aqueous feed pipeline is installed at the S(n+1) level station to add new aqueous feed liquid to the extraction tube in the S(n+1) level station.

7. The automatic countercurrent cascade extraction apparatus as described in claim 1, characterized in that, The system includes an extraction operation turntable, a pump tube lifting platform, and an aqueous phase outlet receiving tube turntable. The extraction operation turntable has a plurality of extraction tube placement holes evenly arranged around its circumference, wherein n consecutive extraction tube placement holes constitute the S1 to Sn level stations. The pump tube lifting platform is provided with a suction tube corresponding to the S1 to Sn level stations, and the suction tube is connected to an injection pump. An aqueous phase feed pipeline is provided at the extraction tube placement hole corresponding to the S(n+1) level station. The aqueous phase outlet receiving tube turntable is positioned higher than the extraction operation turntable and has a plurality of receiving tube placement holes evenly arranged around its circumference. The aqueous phase outlet receiving tube is placed in the receiving tube placement hole, with an empty hole space between two adjacent aqueous phase outlet receiving tubes. During the rotation of the aqueous phase outlet receiving tube turntable, the hole position of the receiving tube placement hole can be aligned with the extraction tube placement hole at the S1 level of the extraction operation turntable.

8. The automatic countercurrent cascade extraction apparatus as described in claim 7, characterized in that, Aqueous and organic phase feed solutions are added to the extraction tubes placed at the S1 to Sn level stations on the extraction operation turntable, while organic phase feed solutions are added to other extraction tubes outside the S1 to Sn level stations.

9. The automatic countercurrent cascade extraction apparatus as described in claim 7, characterized in that, The bottom of the aqueous phase effluent receiving tube on the turntable is slightly higher than the top of the extraction tube on the extraction operation turntable.

10. The automatic countercurrent cascade extraction apparatus as described in claim 7, characterized in that, The system automatically controls the rotation of the extraction turntable and the aqueous phase outlet receiving pipe turntable, as well as the lifting and lowering of the pump pipe lifting platform, the stirring of the feed liquid, and the suction and release of the aqueous phase feed liquid, all through a program set by the control system.

11. A control method for the automatic countercurrent cascade extraction apparatus according to any one of claims 7-10, characterized in that, Includes the following steps: 1) Add aqueous and organic phase feed solutions to the extraction tubes placed at the S1 to Sn level stations of the extraction operation turntable, and add organic phase feed solutions to other extraction tubes outside the S1 to Sn level stations; align one empty hole of the aqueous phase outlet receiving tube turntable with the S1 station of the extraction operation turntable. 2) The pump tube lifting platform descends, and the suction tube is inserted into the bottom of the extraction tube at the S1 to Sn level. Pulse stirring is achieved by the injection pump, and the mixture is allowed to stand and separate after stirring. 3) The suction pipe draws a fixed volume of aqueous liquid, and the pump pipe lifting platform rises. 4) The extraction operation turntable rotates one station, and the turntable rotates to the next position of the aqueous phase effluent receiving pipe. 5) Release the aqueous phase liquid from each suction tube; 6) Add aqueous phase liquid into the extraction tube corresponding to the S(n+1) level station, the extraction operation turntable rotates and resets, and the aqueous phase liquid receiving tube turntable rotates sequentially to the next empty hole position. 7) The pump tube lifting platform descends, the suction pipe is inserted into the bottom of the extraction tube of the S1 to Sn level station, and pulse stirring is achieved by the injection pump. After stirring, the phase is separated by standing. The suction pipe draws the aqueous phase liquid at a fixed volume, and the pump tube lifting platform rises. 8) The extraction operation turntable rotates one station, while the aqueous phase liquid receiving tube turntable does not rotate, releasing the aqueous phase liquid in each suction tube, and the extraction tube corresponding to the S(n+1) level station is taken out. 9) Repeat steps 2) to 8) until the last extraction tube enters the S1 level station.

12. The control method for the automatic countercurrent cascade extraction apparatus as described in claim 11, characterized in that, After step 9), if it is necessary to continue the cascade extraction operation, place the extraction tube containing the organic phase liquid into the extraction tube placement hole other than the S1 to Sn stage stations of the extraction operation turntable, remove the aqueous phase liquid outlet receiving tube that has been injected with the aqueous phase liquid, and put a new aqueous phase liquid outlet receiving tube in the original position, and repeat steps 2) to 9) to continue the cascade extraction operation.

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