Purification device and control method for purification device

Abstract

In a container (50), a sample undergoes heavy solution-based gravity separation. An overflow pipe (80) is provided on top of the container and lets a supernatant overflow from the top of the container (50), the supernatant containing a substance having been separated due to the gravity separation in the container (50). A controller controls the flow of the heavy solution into and out from the container (50). The controller lets a portion of the supernatant resulting from the gravity separation overflow from the container (50) via the overflow pipe (80), and then lets the remaining supernatant in the overflow pipe (80) flow back in the container (50) and overflow again via the overflow pipe (80).

Description

Technical Field

[0001] The present invention relates to a purification apparatus and a control method thereof.

Background Art

[0002] In order to recover a target substance which is a component to be recovered, a mixed sample containing the target substance is purified. Non-Patent Document 1 discloses a purifier that recovers microplastics contained in a mixed sample by performing specific gravity separation on the mixed sample collected from the sea using a heavy liquid.

Prior Art Documents

Non-Patent Documents

[0003]

Non-Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In such a purifier, the target substance separated from the sample may adhere to the inner wall of the purifier and remain. There has been a concern that such remaining of the target substance may reduce the recovery rate.

Means for Solving the Problems

[0005] The purification device according to the first aspect of the present disclosure is a purification device that purifies a sample containing a target substance by specific gravity separation, and includes a container, an overflow pipe, and a control device. In the container, the sample is separated by specific gravity using a heavy liquid. The overflow pipe is provided at the upper part of the container and is a pipe for overflowing the supernatant liquid containing the target substance separated by specific gravity separation in the container from the upper part of the container. The control device controls the inflow and outflow of the heavy liquid to the container. The control device causes a part of the supernatant liquid generated by specific gravity separation to overflow from the container through the overflow pipe, then causes the supernatant liquid remaining in the overflow pipe to flow back into the container, and then causes it to overflow again through the overflow pipe.

[0006] The control method according to the second aspect of the present disclosure is a control method executed by a control device in a purification device. The purification device includes a container, an overflow pipe, and a control device. In the container, the sample is separated by specific gravity using a heavy liquid. The overflow pipe is provided at the upper part of the container and is a pipe for overflowing the supernatant liquid containing the target substance separated by specific gravity separation in the container from the upper part of the container. The control device controls the inflow and outflow of the heavy liquid to the container. The control method includes a step of causing a part of the supernatant liquid generated by specific gravity separation to overflow from the container through the overflow pipe, a step of causing the supernatant liquid remaining in the overflow pipe to flow back into the container, and a step of causing the flowed-back supernatant liquid to overflow again through the overflow pipe.

Advantages of the Invention

[0007] According to the purification device of the present disclosure, when a part of the supernatant generated by specific gravity separation overflows from the overflow pipe, the target substance remaining in the overflow pipe is removed by reversing the supernatant remaining in the overflow pipe into the container, thereby peeling the remaining target substance from the inner wall of the overflow pipe and returning it to the supernatant in the container. Then, by overflowing the supernatant containing the target substance from the overflow pipe again, the target substance remaining on the inner wall can be recovered. Therefore, the possibility of the target substance remaining on the inner wall of the purifier can be reduced, and its recovery rate can be improved.

Brief Description of the Drawings

[0008]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Embodiments for Carrying Out the Invention

[0009] This embodiment will be described in detail with reference to the drawings. For the same or corresponding parts in the drawings, the same reference numerals are given, and the description will not be repeated in principle.

[0010] [1. Configuration of the Purification Device] While referring to FIG. 1, the main configuration of the purification apparatus 1 according to the embodiment will be described. FIG. 1 is a diagram schematically showing the purification apparatus 1 according to the embodiment. As shown in FIG. 1, the purification apparatus 1 includes a purifier 100 for purifying a mixed sample, and a control device 500 for controlling the purifier 100. The purification apparatus 1 according to the embodiment purifies the mixed sample by controlling the purifier 100 by the control device 500, and recovers the component (target substance) to be recovered contained in the mixed sample. "Purification" includes taking out the target substance from the mixture.

[0011] The "mixed sample" purified by the purification apparatus 1 may be in any form as long as it contains the target substance. For example, examples of the "mixed sample" include seawater and sand collected from the sea or the coast, and processed products such as foods and cosmetics. In the embodiment, seawater and sand collected from the sea or the coast are exemplified as the "mixed sample". Hereinafter, the "mixed sample" is also simply referred to as the "sample".

[0012] The "target substance" to be recovered by the purification apparatus 1 may be any component that is recovered by the purification apparatus 1. For example, examples of the "target substance" include microplastics which are fine plastic particles having a size of 5 mm or less. In the embodiment, microplastics contained in seawater and sand collected from the sea or the coast are exemplified as the "target substance".

[0013] The purifier 100 includes a container 50 for accommodating a sample, pipes 11 to 22, pumps 31 to 33, electromagnetic valves 41 to 43, ports 61 to 64, a stirrer 71, a stir bar 72, an overflow pipe 80, a decomposition liquid reservoir 110, a heavy liquid reservoir 120, a rinse liquid reservoir 130, waste liquid reservoirs 140, 150, a detection filter 210, and a supernatant liquid reservoir 215.

[0014] The pipe 11 connects the decomposition liquid reservoir 110 and the solenoid valve 41. The pipe 12 connects the solenoid valve 41 and the pump 31. The pipe 13 connects the pump 31 and the port 61 provided on the outer peripheral portion of the container 50. Thus, the decomposition liquid reservoir 110 and the port 61 of the container 50 are connected by the pipes 11, 12, and 13 via the solenoid valve 41 and the pump 31.

[0015] The pipe 14 connects the heavy liquid reservoir 120 and the solenoid valve 42. The pipe 15 connects the solenoid valve 42 and the pump 32. The pipe 16 connects the pump 32 and the port 62 provided on the outer peripheral portion of the container 50. Thus, the heavy liquid reservoir 120 and the port 62 of the container 50 are connected by the pipes 14, 15, and 16 via the solenoid valve 42 and the pump 32.

[0016] The pipe 17 connects the rinse liquid reservoir 130 and the solenoid valve 41. That is, while the solenoid valve 41 is connected to the decomposition liquid reservoir 110 by the pipe 11, it is also connected to the rinse liquid reservoir 130 by the pipe 14. Thus, the rinse liquid reservoir 130 and the port 61 of the container 50 are connected by the pipes 17, 12, and 13 via the solenoid valve 41 and the pump 31.

[0017] The pipe 18 connects the rinse liquid reservoir 130 and the solenoid valve 42. That is, while the solenoid valve 42 is connected to the heavy liquid reservoir 120 by the pipe 14, it is also connected to the rinse liquid reservoir 130 by the pipe 18. Thus, the rinse liquid reservoir 130 and the port 62 of the container 50 are connected by the pipes 18, 15, and 16 via the solenoid valve 42 and the pump 32.

[0018] The pipe 19 connects the waste liquid reservoir 140 and the solenoid valve 43. The pipe 20 connects the solenoid valve 43 and the pump 33. The pipe 21 connects the pump 33 and the port 63 provided on the outer peripheral portion of the container 50. Thus, the waste liquid reservoir 140 and the port 63 of the container 50 are connected by the pipes 19, 20, and 21 via the solenoid valve 43 and the pump 33.

[0019] The pipe 22 connects the pump 33 and the port 64 provided on the outer peripheral portion of the container 50. That is, the pump 33 is connected to the port 63 of the container 50 by the pipe 21 and is also connected to the port 64 of the container 50 by the pipe 22. Thus, the waste liquid reservoir 140 and the port 64 of the container 50 are connected by the pipes 19, 20, and 22 via the solenoid valve 43 and the pump 33.

[0020] The pipe 23 connects the waste liquid reservoir 150 and the solenoid valve 43. That is, the solenoid valve 43 is connected to the waste liquid reservoir 140 by the pipe 19 and is also connected to the waste liquid reservoir 150 by the pipe 23. Thus, the waste liquid reservoir 150 and the port 63 of the container 50 are connected by the pipes 23, 20, and 21 via the solenoid valve 43 and the pump 33. Also, the waste liquid reservoir 150 and the port 64 of the container 50 are connected by the pipes 23, 20, and 22 via the solenoid valve 43 and the pump 33.

[0021] The decomposition liquid reservoir 110 stores a decomposition liquid for treating impurities. "Impurities" are foreign substances other than the target substance in the mixed sample. In the embodiment, organic impurities having the properties of organic substances are exemplified as "impurities". The "decomposition liquid" may be any liquid as long as it can decompose the impurities. In the embodiment, the "decomposition liquid" decomposes organic impurities. For example, as the "decomposition liquid", oxidizing agents such as hydrogen peroxide solution (H2O2), a mixture of hydrogen peroxide solution (H2O2) and iron(II) oxide (FeO), etc. can be mentioned. When the "mixed sample" is seawater and sand, examples of the "organic impurities" include wood chips and plankton mixed in the seawater or sand.

[0022] The heavy liquid reservoir 120 stores a heavy liquid for separating a sample by a specific gravity difference. The "heavy liquid" may be any liquid as long as it can separate the sample by a specific gravity difference. In an embodiment, the "heavy liquid" causes inorganic impurities having the properties of inorganic substances to settle by a specific gravity difference. For example, examples of the "heavy liquid" include sodium chloride (NaCl), sodium iodide (NaI), zinc chloride (ZnCl2), etc. When the "mixed sample" is seawater and sand, examples of the "inorganic impurities" include sand, glass, and stones. The specific gravity of the "heavy liquid" is set to be greater than the specific gravity of the "target substance" to be recovered by the purification device 1 and less than the specific gravity of the "inorganic impurities". For example, when the "target substance" to be recovered by the purification device 1 is microplastics and the "inorganic impurities" are sand, glass, and stones, the specific gravity of the "heavy liquid" may be set to be greater than the specific gravity of microplastics and less than the specific gravity of sand, glass, and stones. Specifically, the specific gravity of the "heavy liquid" may be set to about 1.5 to about 1.7.

[0023] The rinse liquid reservoir 130 stores a rinse liquid for cleaning the inside of the container 50. The "rinse liquid" may be any liquid as long as it can clean the inside of the container 50. For example, an example of the "rinse liquid" is water. Note that the "rinse liquid" not only serves to clean the inside of the container 50 but also has the role of diluting the decomposition liquid introduced into the container 50.

[0024] The waste liquid reservoirs 140 and 150 store waste liquids such as the heavy liquid, rinse liquid, and seawater contained in the mixed sample discharged from the container 50.

[0025] The pump 31 introduces the decomposition liquid sucked from the decomposition liquid reservoir 110 or the rinse liquid sucked from the rinse liquid reservoir 130 into the container 50 via the port 61 based on the control of the control device 500.

[0026] Based on the control of the control device 500, the pump 32 introduces the heavy liquid sucked from the heavy liquid reservoir 120 or the rinse liquid sucked from the rinse liquid reservoir 130 into the container 50 via the port 62. The pump 32 is also hereinafter referred to as the "introduction pump 32".

[0027] Based on the control of the control device 500, the pump 33 discharges the waste liquid sucked from the container 50 via the port 63 or the port 64 to the waste liquid reservoir 140 or the waste liquid reservoir 150. The pump 33 is also hereinafter referred to as the "discharge pump 33".

[0028] Based on the control of the control device 500, the solenoid valve 41 switches the path connected to the port 61 between the path between the decomposition liquid reservoir 110 and the port 61 of the container 50 (the path via the pipes 11, 12, 13) and the path between the rinse liquid reservoir 130 and the port 61 of the container 50 (the path via the pipes 17, 12, 13).

[0029] Based on the control of the control device 500, the solenoid valve 42 switches the path connected to the port 62 between the path between the heavy liquid reservoir 120 and the port 62 of the container 50 (the path via the pipes 14, 15, 16) and the path between the rinse liquid reservoir 130 and the port 62 of the container 50 (the path via the pipes 18, 15, 16).

[0030] Based on the control of the control device 500, the solenoid valve 43 switches the path connected to the ports 63, 64 between the path between the waste liquid reservoir 140 and the ports 63, 64 of the container 50 (the path via the pipes 19, 20, 21 or the path via the pipes 19, 20, 22) and the path between the waste liquid reservoir 150 and the ports 63, 64 of the container 50 (the path via the pipes 23, 20, 21 or the path via the pipes 23, 20, 22).

[0031] Port 61 introduces the decomposition liquid in the decomposition liquid reservoir 110 or the rinsing liquid in the rinsing liquid reservoir 130, which is sucked in by the pump 31, into the container 50. Port 62 introduces the heavy liquid in the heavy liquid reservoir 120 or the rinsing liquid in the rinsing liquid reservoir 130, which is sucked in by the pump 32, into the container 50. Ports 63 and 64 discharge the waste liquid in the container 50, which is sucked in by the pump 33, to the waste liquid reservoir 140 or the waste liquid reservoir 150. Port 62 is also referred to as "introduction port 62" hereinafter. Ports 63 and 64 are also referred to as "discharge ports 63 and 64" hereinafter.

[0032] Inside ports 61 to 64, a filter (not shown) is provided so that the target substance contained in the sample is not discharged from the container 50. The filter is a mesh having a mesh size capable of trapping microplastics as the target substance. For example, the filter (mesh) is a wire mesh made of SUS (Steel Use Stainless) or a membrane filter made of PTFE (polytetrafluoroethylene) (Teflon (registered trademark)). When microplastics are the target component, the mesh size of the filter (mesh) needs to be such that particles of 0.1 to 5.0 mm do not pass through, and about 0.1 mm is preferred.

[0033] The stirrer 71 is, for example, a thermostatic stirrer and is disposed below the container 50. The stirrer 71 stirs the sample in the container 50 by rotating the stir bar 72 provided in the container 50 based on the control of the control device 500. Further, the stirrer 71 keeps the temperature of the sample in the container 50 constant by applying heat to the container 50 from below the container 50 based on the control of the control device 500.

[0034] The overflow pipe 80 is connected to the discharge port 55 provided at the top of the container 50, and overflows and discharges the supernatant of the sample containing the target substance from the container 50 to the outside. Hereinafter, in this specification, unless otherwise specified, "overflow" means discharging the supernatant in the container 50 to the outside through the overflow pipe 80.

[0035] The detection filter 210 recovers the target substance contained in the supernatant by filtering the supernatant of the sample that has overflowed from the overflow pipe 80. The supernatant that has passed through the detection filter 210 is recovered by the supernatant reservoir 215. The detection filter 210 is a mesh having a mesh size capable of trapping microplastics, which are the target components. For example, the detection filter 210 (mesh) is a wire mesh made of SUS or a membrane filter made of PTFE (registered trademark). When microplastics are the target components, the mesh size of the detection filter 210 (mesh) needs to be such that particles of 0.1 to 5.0 mm do not pass through, and about 0.1 mm is preferable.

[0036] The control device 500 may be implemented by a general-purpose computer or a dedicated computer for controlling the purifier 100. The control device 500 controls the pumps 31 to 33, the electromagnetic valves 41 to 43, and the stirrer 71 in the purifier 100.

[0037] [2. Hardware Configuration] With reference to FIG. 2, the hardware configuration of the purifying apparatus 1 according to the embodiment will be described. FIG. 2 is a diagram for explaining the hardware configuration of the purifying apparatus 1 according to the embodiment. As shown in FIG. 2, the control device 500 includes, as main hardware elements, an arithmetic device 501, a memory 502, a communication device 503, a display device 504, an input device 505, a data reading device 506, and a storage 510.

[0038] The arithmetic unit 501 is a computer that reads programs (for example, the control program 511 and the OS (Operating System) 513) stored in the storage 510, expands the read programs in the memory 502, and executes them. For example, by executing the control program 511, the arithmetic unit 501 executes a purification process (to be described later with reference to FIG. 3) for controlling the purifier 100. The arithmetic unit 501 is composed of, for example, a CPU (Central Processing Unit), an FPGA (Field Programmable Gate Array), a GPU (Graphics Processing Unit), or an MPU (Multi Processing Unit). Note that the arithmetic unit 501 may be composed of a processing circuitry.

[0039] The memory 502 provides a storage area for temporarily storing program codes, work memories, etc. when the arithmetic unit 501 executes an arbitrary program. The memory 502 is composed of a volatile memory such as a DRAM (Dynamic Random Access Memory) or an SRAM (Static Random Access Memory), or a non-volatile memory such as a ROM (Read Only Memory) or a flash memory.

[0040] The communication device 503 transmits and receives data to and from other devices via a network (not shown). The communication device 503 supports an arbitrary communication method such as Ethernet (registered trademark), wireless LAN (Local Area Network), Bluetooth (registered trademark), etc.

[0041] The display device 504 is composed of, for example, an LCD (Liquid Crystal Display), and displays a program design screen, an alert screen at the time of abnormality, etc.

[0042] The input device 505 is composed of, for example, a keyboard or a mouse, and is used by the user to input design information, etc. during the design of the program. The input device 505 may include a start switch for starting the execution of the purification process by the arithmetic unit 501.

[0043] The data reading device 506 reads the data stored in the recording medium 507. The recording medium 507 may have other configurations as long as it can record various data, such as a CD (Compact Disc), a DVD (Digital Versatile Disc), or a USB (Universal Serial Bus) memory.

[0044] The storage 510 provides a storage area for storing various data required for the purification process, etc. The storage 510 is composed of, for example, a non-volatile memory device such as an HDD (Hard Disk Drive) or an SSD (Solid State Drive). The storage 510 stores the control program 511, the control data 512, and the OS 513.

[0045] The control program 511 is a program in which the content of the purification process is described and is executed by the arithmetic unit 501. The control program 511 may be designed by the user using the input device 505, may be read from the recording medium 507 by the data reading device 506, or may be acquired from another device such as a server via the network by the communication device 503.

[0046] The control data 512 is data used when the arithmetic unit 501 executes the control program 511. For example, the control data 512 includes data such as setting values for controlling the pumps 31 to 33, the solenoid valves 41 to 43, and the stirrer 71. The control data 512 may be input by the user using the input device 505, may be read from the recording medium 507 by the data reading device 506, or may be acquired from another device such as a server via the network by the communication device 503.

[0047] OS513 provides basic functions for the arithmetic unit 501 to execute various processes.

[0048] [3. Sample purification process] Next, referring to FIG. 3, the sample purification process will be described. FIG. 3 is a flowchart of the purification process executed by the purification device 1. Each step shown in FIG. 3 is realized by the arithmetic unit 501 of the control device 500 executing the OS513 and the control program 511. In the figure, "S" is used as an abbreviation for "STEP".

[0049] As a preparation, the user introduces a sample into the container 50 of the purification device 1. For example, the user inputs the sample into the container 50 from an inlet (not shown). Then, the user starts the control of the purifier 100 by the control device 500 by performing a start operation using the input device 505 of the control device 500.

[0050] When the control of the purifier 100 by the control device 500 starts, as shown in FIG. 3, the control device 500 discharges the waste liquid in the container 50 to the waste liquid reservoir 150 through the pipes 20 - 23 and the ports 63, 64 by controlling the pump 33 and the solenoid valve 43 (S1). Note that microplastics and the like, which are the target components contained in the sample, are not discharged outside by the filter provided inside the ports 63, 64 and remain in the container 50.

[0051] Next, the control device 500 stops the pump 33 on the discharge side and introduces the decomposition liquid in the decomposition liquid reservoir 110 into the container 50 through the pipes 11 - 13 and the port 61 by controlling the pump 31 and the solenoid valve 41 (S2).

[0052] Next, the control device 500 rotates the stirrer 72 provided in the container 50 while applying a certain amount of heat to the container 50 by controlling the stirrer 71 to stir the sample (S3). The temperature of the container 50, the rotation speed, and the rotation time of the stirrer 72 are preset by the user. By stirring the sample in this way, the oxidation treatment with the oxidant is performed, and the organic contaminants contained in the sample are decomposed. Note that heating is not necessarily required during the stirring of the sample, but by maintaining the temperature of the sample at a constant temperature by heating, the decomposition by the oxidation treatment is facilitated.

[0053] Next, the control device 500 discharges the waste liquid in the container 50 contained in the sample after the organic contaminants are decomposed to the waste liquid reservoir 150 through the pipes 20 to 23 and the ports 63 and 64 by controlling the pump 33 and the solenoid valve 43 (S4). Note that microplastics or the like, which are the target substances contained in the sample, are not discharged to the outside by the filter provided inside the ports 63 and 64 and remain in the container 50.

[0054] Next, the control device 500 stops the pump 33 on the discharge side and introduces the rinse liquid in the rinse liquid reservoir 130 into the container 50 through the pipes 17, 12, 13 and the port 61 by controlling the pump 31 and the solenoid valve 41 to wash the inside of the container 50 (S5). At this time, the control device 500 introduces a preset amount of rinse liquid into the container 50 by controlling the suction amount of the pump 31.

[0055] Next, the control device 500 discharges the waste liquid in the container 50 after the rinse liquid is introduced to the waste liquid reservoir 150 through the pipes 20 to 23 and the ports 63 and 64 by controlling the pump 33 and the solenoid valve 43 (S6). Thereby, the inside of the container 50 is washed with the rinse liquid. Note that microplastics or the like, which are the target substances contained in the sample, are not discharged to the outside by the filter provided inside the ports 63 and 64 and remain in the container 50. Note that thereafter, the control device 500 may dry the sample by leaving the sample as it is for a predetermined period (for example, one day).

[0056] Next, the control device 500 performs a specific gravity separation process using a heavy liquid to collect the sample (S7). Details of S7 will be described later with reference to FIG. 6.

[0057] Next, the control device 500 stops the pump 33 on the discharge side and controls the pump 32 and the solenoid valve 42 to introduce the rinsing liquid in the rinsing liquid reservoir 130 into the container 50 through the pipes 18, 15, 16 and the port 62 to wash the inside of the container 50 (S8). At this time, the control device 500 introduces a preset amount of rinsing liquid into the container 50 by controlling the suction amount of the pump 32.

[0058] Next, the control device 500 controls the pump 33 and the solenoid valve 43 to discharge the waste liquid in the container 50 after the rinsing liquid is introduced into the waste liquid reservoir 140 through the pipes 19 to 22 and the ports 63, 64 (S9). Thereby, the inside of the container 50 is washed with the rinsing liquid.

[0059] [4. Recovery of the target substance according to the comparative example] FIG. 4 is a flowchart of the recovery process of the target substance in the comparative example. Each step shown in FIG. 4 is performed in place of S7 in the purification process shown in FIG. 3. In other words, in one implementation example of the comparative example, S101 to S104 in FIG. 4 are performed after S1 to S6 in FIG. 3, and S8 to S12 in FIG. 3 are performed after S101 to 104 in FIG. 4 are implemented.

[0060] Referring to FIG. 4, the control device 500 controls the pump 32 and the solenoid valve 42 to introduce the heavy liquid in the heavy liquid reservoir 120 into the container 50 through the pipes 14 to 16 and the port 62 (S101). At this time, the control device 500 introduces a preset amount of heavy liquid into the container 50 by controlling the suction amount of the pump 32.

[0061] Thereafter, the control device 500 leaves the sample as it is for a predetermined period (for example, 1 to 3 hours) (S102). When the heavy liquid is introduced into the sample in the container 50 and left in this way, the inorganic impurities contained in the sample settle near the bottom of the container 50 due to the specific gravity difference.

[0062] Next, the control device 500 controls the pump 32 and the solenoid valve 42 again to introduce the heavy liquid in the heavy liquid reservoir 120 into the container 50 again through the pipes 14 to 16 and the port 62 (S103). At this time, the control device 500 controls the suction amount of the pump 32 to introduce a preset amount of heavy liquid into the container 50 by the user. When the heavy liquid is introduced into the sample in the container 50 again in this way, the liquid level of the sample separated by specific gravity gradually rises in the container 50, and eventually the supernatant of the sample containing the target substance reaches the discharge port 55 of the container 50. Then, the supernatant of the sample overflows to the outside through the discharge port 55 and the overflow pipe 80.

[0063] The supernatant of the sample overflowed through the overflow pipe 80 is filtered by the detection filter 210, and only the waste liquid is recovered by the supernatant reservoir 215. Microplastics, which are target substances lighter in specific gravity than the heavy liquid, remain on the detection filter 210.

[0064] After the microplastics are recovered by purifying the sample, the control device 500 controls the pump 33 and the solenoid valve 43 to discharge the waste liquid in the container 50 after the microplastics are recovered to the waste liquid reservoir 140 through the pipes 19 to 22 and the ports 63, 64 (S104).

[0065] According to the sample recovery process of the comparative example shown in FIG. 4, when the supernatant liquid overflows from the overflow pipe 80 in S23, there is a concern that the target substance may adhere to the inner wall of the overflow pipe 80 and remain. Therefore, in the purification apparatus 1 according to the present embodiment, by reversing the flow of the supernatant liquid in the overflow pipe 80, the gas-liquid interface in the overflow pipe is moved, and the target substance remaining on the inner wall is returned to the supernatant liquid again.

[0066] [5. Recovery of Sample by Reverse Flow of Supernatant Liquid] FIG. 5 is a diagram for explaining the recovery of the target substance by the reverse flow of the supernatant liquid in the embodiment.

[0067] Referring to FIG. 5, when a part of the supernatant liquid generated by specific gravity separation overflows from the container 50 through the overflow pipe 80, the gas-liquid interface of the overflow pipe 80 is at the position indicated by the dotted line 82. In this state, when the heavy liquid in the container 50 is discharged from the discharge ports 63 and 64 as shown by the arrow A1, the supernatant liquid remaining in the overflow pipe 80 flows back into the container as shown by the arrow A2. Then, the gas-liquid interface in the overflow pipe 80 also moves to the position indicated by the dotted line 81. Due to the impact force caused by the movement of this gas-liquid interface, the surface tension of the supernatant liquid, the force due to the water flow, etc., the target substance adhering to the inner wall of the overflow pipe 80 is peeled off. The peeled target substance is returned into the container together with the supernatant liquid and mixed into the heavy liquid in the container 50. After that, when the container 50 is left for a predetermined period, the target substance gathers again in the supernatant liquid in the container 50. In this state, when the heavy liquid is introduced into the container 50 from the introduction port 62 as shown by the arrow A3, the supernatant liquid overflows through the overflow pipe 80.

[0068] Thus, in the purification apparatus 1 according to the present embodiment, by reversing the flow of the supernatant liquid remaining in the overflow pipe and moving the gas-liquid interface in the overflow pipe 80, the target substance remaining on the inner wall of the overflow pipe 80 can be recovered.

[0069] Further, by repeatedly moving the gas-liquid interface in the directions indicated by arrow A2 and arrow A4, opportunities to remove the target substance adhering to the overflow pipe 80 may be provided multiple times. As a result, for example, even a target substance that was not removed during the first movement of the gas-liquid interface may be removed during a subsequent movement of the gas-liquid interface and recovered in the supernatant liquid.

[0070] In this case, when moving the gas-liquid interface in the direction indicated by arrow A4, it is not always necessary to discharge the supernatant liquid to the outside every time. It is sufficient to discharge the supernatant liquid to the outside only in the last cycle and recover the target substance. Thus, when the gas-liquid interface moves multiple times within the overflow pipe 80, the movement of the supernatant liquid in the direction indicated by arrow A4 that does not reach the above-described discharge to the outside is also considered to be included in "overflowing". Naturally, when the gas-liquid interface moves multiple times within the overflow pipe 80, the supernatant liquid may be discharged to the outside every time.

[0071] Similarly, when repeatedly moving the gas-liquid interface, it is not always necessary to return the gas-liquid interface to within the container 50 every time when moving the gas-liquid interface in the direction indicated by arrow A2. Thus, when the gas-liquid interface moves multiple times within the overflow pipe 80, the movement of the supernatant liquid in the direction indicated by arrow A2 that does not reach the above-described container 50 is also considered to be included in "flowing back". Naturally, when the gas-liquid interface moves multiple times within the overflow pipe 80, the gas-liquid interface may be returned to within the container 50 every time.

[0072] In summary, after overflowing the supernatant liquid generated by specific gravity separation, the backflow and overflow of the supernatant liquid from the overflow pipe may be repeated multiple times.

[0073] [6. Processing related to recovery of target substance by backflow of supernatant liquid] FIG. 6 is a flowchart showing control processing for recovering a target substance by backflow of the supernatant liquid in the present embodiment. Each step shown in FIG. 6 is realized by the arithmetic unit 501 of the control device 500 executing the OS 513 and the control program 511.

[0074] Each step shown in FIG. 6 corresponds to the subroutine of S7 in FIG. 3. In other words, in one implementation example, the arithmetic unit 501 executes S71 to S77 in FIG. 5 after S1 to S6 in FIG. 3, and then executes S8 to S9 in FIG. 3.

[0075] In S71, the arithmetic unit 501 controls the introduction pump 32 and the solenoid valve 42 to introduce a first introduction amount of the heavy liquid from the introduction port 62 into the container 50. The first introduction amount is an amount of the heavy liquid appropriate for separating the sample by specific gravity in the container 50.

[0076] In S72, the arithmetic unit 501 leaves the sample as it is for a predetermined period. When the heavy liquid is introduced into the sample in the container 50 and left as it is in this way, the inorganic impurities contained in the sample settle near the bottom of the container 50 due to the specific gravity difference.

[0077] In S73, the arithmetic unit 501 controls the introduction pump 32 and the solenoid valve 42 to introduce a second introduction amount of the heavy liquid from the introduction port 62 into the container 50, so that a part of the supernatant overflows through the overflow pipe 80. The second introduction amount is, for example, a value obtained by adding the amount of the portion mainly assumed to contain the target substance in the supernatant to the amount obtained by subtracting the first introduction amount from the volume in the container 50. When the second introduction amount of the heavy liquid is introduced, the portion mainly containing the target substance in the supernatant is discharged to the outside.

[0078] In S74, the arithmetic unit 501 controls the discharge pump 33 and the solenoid valve 43 to discharge a first discharge amount of the heavy liquid in the container 50 through the discharge ports 63 and 64, so that the supernatant in the overflow pipe 80 flows back into the container. The first discharge amount corresponds to, for example, the volume in the container 50 and the overflow pipe 80 included in the range from the dotted line 81 to the dotted line 82 in FIG. 4. As a result, the gas-liquid interface in the overflow pipe 80 moves, and the target substance adhering to the inner wall of the overflow pipe 80 is returned into the container 50 together with the supernatant.

[0079] In S75, the arithmetic unit 501 leaves the sample as it is for a predetermined period. When the heavy liquid is introduced into the sample in the container 50 and left in this way, the target substance returned to the container 50 gathers in the supernatant again. In S75, the period for leaving the sample may be the same as, for example, the period for leaving the sample in S73, but it may also be different.

[0080] In S76, the arithmetic unit 501 controls the introduction pump 32 and the solenoid valve 42 to introduce a third introduction amount of the heavy liquid into the container 50 from the introduction port 62, so that the supernatant in the container 50 overflows through the overflow pipe 80. The third introduction amount is, for example, a value obtained by adding the amount of the portion mainly containing the target substance in the supernatant to the first discharge amount. When the third introduction amount of the heavy liquid is introduced, the portion mainly containing the target substance in the supernatant is discharged to the outside. It is considered that at least a part of the target substance that adhered to the inside of the overflow pipe 80 during the overflow in S73 and returned to the supernatant during the backflow in S74 is included in the supernatant discharged to the outside in S76. In other words, in S76, at least a part of the target substance adhering to the inner wall of the overflow pipe 80 can be recovered.

[0081] In S77, the arithmetic unit 501 controls the discharge pump 33 and the solenoid valve 43 to discharge the heavy liquid in the container 50 through the discharge ports 63 and 64.

[0082] In S73 and S76, the arithmetic unit 501 introduces a heavy liquid into the container 50 through the introduction port 62, and the supernatant liquid overflows through the overflow pipe 80. In this way, the configuration for introducing the heavy liquid for specific gravity separation into the container 50 can also be utilized for the overflow in the overflow pipe. Also, in S74, the arithmetic unit 501 discharges the heavy liquid in the container 50 from the discharge ports 63 and 64, causing the supernatant liquid in the overflow pipe 80 to flow backward. In this way, the configuration for discharging the waste liquid after specific gravity separation from the container 50 can also be utilized for causing the supernatant to flow backward in the overflow pipe 80. That is, with a simple configuration, the overflow and backward flow in the overflow pipe 80 can be executed.

[0083] In S71, S73, and S76, the arithmetic unit 501 controls the rotation speed and rotation time of the introduction pump 32 to introduce the heavy liquid in the first to third introduction amounts. In this way, the introduction pump for providing the driving force for introducing the heavy liquid into the container 50 can also be utilized for controlling the introduction amount of the heavy liquid. That is, the introduction amount of the heavy liquid can be controlled with a simple configuration.

[0084] However, the control of the introduction amount is not limited to this. A sensor (not shown) for detecting the introduction amount may be provided in the purifier 100, and the arithmetic unit 501 may introduce the first to third introduction amounts based on the detection value of the sensor. The sensor may be, for example, a liquid amount sensor (such as a weight sensor and / or a liquid level sensor) for detecting the liquid amount in the container 50, a sensor for detecting the amount of the heavy liquid introduced into the container 50 (such as a flow rate sensor provided in the pipe 16), and / or a sensor for detecting the amount of the supernatant liquid discharged from the overflow pipe 80 (such as a liquid amount sensor of the supernatant liquid reservoir 215).

[0085] Similarly, in S74, the arithmetic unit 501 discharges the heavy liquid in the first discharge amount by controlling, for example, the rotation speed and rotation time of the discharge pump 33. The control of the discharge amount may be performed by various sensors.

[0086] In this way, by controlling the amount of heavy liquid introduced into and discharged from the container 50, it is possible to control such that only the portion mainly containing the target substance in the supernatant liquid is discharged to the outside, or the gas-liquid interface in the purifier is returned to an appropriate position for leaving the container 50 unattended.

[0087] Further, the driving force for introducing and discharging the heavy liquid is not limited to that by a pump, and it may utilize its own weight or use suction due to a change in atmospheric pressure.

[0088] As described above, in the purification apparatus according to the present embodiment, a part of the supernatant liquid generated by specific gravity separation overflows from the container through the overflow pipe 80, and then the supernatant liquid remaining in the overflow pipe 80 is made to flow back into the container 50 and then overflows again through the overflow pipe 80. Thereby, even if the target substance remains on the inner wall of the overflow pipe 80 during the first overflow, it can be returned into the container 50 together with the supernatant liquid by the backflow and recovered by overflowing again. Therefore, the possibility of the target substance remaining on the inner wall of the purifier 100 can be reduced, and its recovery rate can be improved.

[0089] [Aspect] Those skilled in the art will understand that the above-described plurality of exemplary embodiments are specific examples of the following aspects.

[0090] (Item 1) A purification apparatus according to one aspect is a purification apparatus that purifies a sample containing a target substance by specific gravity separation, and includes a container, an overflow pipe, and a control device. In the container, the sample is separated by specific gravity using a heavy liquid. The overflow pipe is provided at the upper part of the container and is a pipe for overflowing the supernatant liquid containing the target substance separated by specific gravity in the container from the upper part of the container. The control device controls the inflow and outflow of the heavy liquid with respect to the container. The control device causes a part of the supernatant liquid generated by specific gravity separation to overflow from the container through the overflow pipe, then causes the supernatant liquid remaining in the overflow pipe to flow back into the container, and then causes it to overflow again through the overflow pipe.

[0091] According to the purification device described in claim 1, when a part of the supernatant liquid generated by specific gravity separation overflows from the overflow pipe, the target substance remaining in the overflow pipe can be peeled off from the inner wall of the overflow pipe and returned to the supernatant liquid in the container by reversing the supernatant liquid remaining in the overflow pipe into the container. Then, by overflowing the supernatant liquid containing the target substance from the overflow pipe again, the target substance remaining on the inner wall can be recovered. Therefore, the possibility of the target substance remaining on the inner wall of the purifier can be reduced, and its recovery rate can be improved.

[0092] (Claim 2) In the purification device described in claim 1, the control device moves the gas-liquid interface in the overflow pipe by reversing the supernatant liquid remaining in the overflow pipe into the container.

[0093] According to the purification device described in claim 2, due to the impact force caused by the movement of the gas-liquid interface in the overflow pipe, the target substance adhering to the inner wall of the overflow pipe is more likely to be peeled off. Therefore, the possibility of the target substance remaining on the inner wall of the purifier can be reduced, and its recovery rate can be improved.

[0094] (Claim 3) The purification device described in claim 1 or 2 further includes an introduction port for introducing the heavy liquid into the container and a discharge port for discharging the heavy liquid from the container. The control device causes the supernatant liquid to overflow through the overflow pipe by introducing the heavy liquid into the container from the introduction port, and reverses the supernatant liquid in the overflow pipe by discharging the heavy liquid in the container from the discharge port.

[0095] According to the purification device described in claim 3, the configuration for introducing the heavy liquid for specific gravity separation into the container 50 can also be used for the overflow in the overflow pipe. In addition, the configuration for discharging the waste liquid after specific gravity separation from the container can also be used for reversing the supernatant in the overflow pipe. That is, with a simple configuration, the overflow and reverse flow in the overflow pipe can be controlled.

[0096] (Item 4) In the purification apparatus according to Item 3, the control device introduces a first introduction amount of heavy liquid into the container from the introduction port, and after a supernatant liquid is generated in the container, the control device introduces a second introduction amount of heavy liquid into the container from the introduction port, so that a part of the supernatant liquid overflows through the overflow pipe, and discharges a first discharge amount of heavy liquid from the container through the discharge port, so as to reverse the supernatant liquid in the overflow pipe and return it into the container, and introduces a third introduction amount of heavy liquid into the container from the introduction port, so that the supernatant liquid that has flowed back into the container overflows through the overflow pipe.

[0097] According to the purification apparatus described in Item 4, it is possible to control such that only the part mainly containing the target substance in the supernatant liquid is discharged to the outside, or the gas-liquid interface in the purifier is returned to an appropriate position for leaving the container.

[0098] (Item 5) The purification apparatus according to Item 4 further includes an introduction pump for introducing heavy liquid into the container from the introduction port and a discharge pump for discharging the heavy liquid from the container from the discharge port. The control device controls the rotation speed and rotation time of the introduction pump to introduce each of the first to third introduction amounts of heavy liquid into the container, and controls the rotation speed and rotation time of the discharge pump to discharge the first discharge amount of heavy liquid from the container.

[0099] According to the purification apparatus described in Item 5, the introduction pump for providing the driving force for introducing the heavy liquid into the container can also be used for controlling the introduction amount of the heavy liquid. The discharge pump for providing the driving force for discharging the heavy liquid from the container can also be used for controlling the discharge amount of the heavy liquid. That is, it is possible to control the introduction amount and discharge amount of the heavy liquid with a simple configuration.

[0100] (Item 6) In the purification apparatus according to any one of Items 1 to 5, the control device repeats the backflow and overflow of the supernatant liquid from the overflow pipe a plurality of times after the supernatant liquid generated by specific gravity separation first overflows.

[0101] According to the purification device described in Item 6, opportunities to remove the target substance adhering to the overflow pipe can be provided many times. As a result, for example, even a target substance that was not removed during the first movement of the gas-liquid interface may be removed during a subsequent movement of the gas-liquid interface and potentially recovered into the supernatant liquid.

[0102] (Item 7) A control method according to another aspect is a control method executed by a control device in a purification device. The purification device includes a container, an overflow pipe, and a control device. In the container, a sample is separated by specific gravity using a heavy liquid. The overflow pipe is provided at the upper part of the container and is a pipe for overflowing the supernatant liquid containing the target substance separated by specific gravity in the container from the upper part of the container. The control device controls the inflow and outflow of the heavy liquid to the container. The control method includes a step of overflowing a part of the supernatant liquid generated by specific gravity separation from the container through the overflow pipe, a step of causing the supernatant liquid remaining in the overflow pipe to flow back into the container, and a step of overflowing the flowed-back supernatant liquid again through the overflow pipe.

[0103] According to the control method described in Item 7, when a part of the supernatant liquid generated by specific gravity separation overflows from the overflow pipe, the target substance remaining in the overflow pipe can be removed from the inner wall of the overflow pipe and returned to the supernatant liquid in the container by causing the supernatant liquid remaining in the overflow pipe to flow back into the container. Then, by overflowing the supernatant liquid containing the target substance again from the overflow pipe, the target substance remaining on the inner wall can be recovered. Therefore, the possibility of the target substance remaining on the inner wall of the purifier can be reduced, and its recovery rate can be improved.

[0104] It should be considered that all aspects of the embodiments disclosed this time are illustrative and not restrictive in any way. The scope of the present invention is indicated not by the above description but by the claims, and it is intended that all modifications within the meaning and scope equivalent to the claims are included.

Explanation of Reference Numerals

[0105] 1 Refining device, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23 Pipes, 31, 32, 33 Pumps, 41, 42, 43 Solenoid valves, 50 Vessel, 55 Discharge port, 61, 62, 63, 64 Ports, 71 Stirrer, 72 Stirring bar, 80 Overflow pipe, 100 Refiner, 110 Decomposition liquid reservoir, 120 Heavy liquid reservoir, 130 Rinse liquid reservoir, 140, 150 Waste liquid reservoirs, 210 Detection filter, 215 Supernatant liquid reservoir, 500 Control device, 501 Arithmetic unit, 502 Memory, 503 Communication device, 504 Display device, 505 Input device, 506 Data reading device, 507 Recording medium, 510 Storage, 511 Control program, 512 Control data.

Claims

1. A purification apparatus for purifying a sample containing a target substance by specific gravity separation, comprising: a container for subjecting the sample to specific gravity separation using a heavy liquid; an overflow pipe provided at the upper part of the container for overflowing a supernatant liquid containing the target substance separated by specific gravity separation in the container from the upper part of the container; a control device for controlling the inflow and outflow of the heavy liquid to and from the container, wherein the control device causes a part of the supernatant liquid generated by specific gravity separation to overflow from the container through the overflow pipe, then causes the supernatant liquid remaining in the overflow pipe to flow back into the container, and then causes it to overflow again through the overflow pipe.

2. The purification apparatus according to claim 1, wherein the control device moves the gas-liquid interface in the overflow pipe by causing the supernatant liquid remaining in the overflow pipe to flow back into the container.

3. The purification apparatus according to claim 1, further comprising an introduction port for introducing the heavy liquid into the container and a discharge port for discharging the heavy liquid from the container, wherein the control device causes the supernatant liquid to overflow through the overflow pipe by introducing the heavy liquid into the container from the introduction port, and causes the supernatant liquid in the overflow pipe to flow back by discharging the heavy liquid in the container from the discharge port.

4. The purification apparatus according to claim 3, wherein the control device introduces a first introduction amount of the heavy liquid into the container from the introduction port, after a supernatant liquid is generated in the container, introduces a second introduction amount of the heavy liquid into the container from the introduction port to cause a part of the supernatant liquid to overflow through the overflow pipe, discharges a first discharge amount of the heavy liquid in the container through the discharge port to cause the supernatant liquid in the overflow pipe to flow back into the container, and introduces a third introduction amount of the heavy liquid into the container from the introduction port to cause the supernatant liquid that has flowed back into the container to overflow through the overflow pipe.

5. The purification apparatus according to claim 3, further comprising an introduction pump for introducing the heavy liquid into the container from the introduction port and a discharge pump for discharging the heavy liquid in the container from the discharge port, wherein the control device controls the rotation speed and rotation time of the introduction pump to introduce each of the first to third introduction amounts of the heavy liquid into the container. ​ ​ ​ ​ ​ ​ ​ ​ ​ The purification apparatus according to claim 4, wherein the heavy liquid with the first discharge amount is discharged from the container by controlling the rotational speed and rotational time of the discharge pump.

6. The purification apparatus according to claim 1, wherein the control device repeats the backflow and overflow of the supernatant liquid from the overflow pipe a plurality of times after the supernatant liquid generated by the specific gravity separation is first caused to overflow.

7. A container for separating a sample containing a target substance by specific gravity separation using a heavy liquid, An overflow pipe provided at the upper part of the container for discharging the supernatant liquid containing the target substance separated by specific gravity separation in the container by overflowing from the upper part of the container, In a purification apparatus comprising a control device for controlling the inflow and outflow of the heavy liquid to and from the container, a control method executed by the control device, Overflowing a part of the supernatant liquid generated by specific gravity separation from the container through the overflow pipe, Backflowing the supernatant liquid remaining in the overflow pipe into the container, And overflowing the backflowed supernatant liquid again through the overflow pipe.

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