Fine bubble-containing liquid concentration device, fine bubble-containing liquid manufacturing device, and method for concentrating fine bubble-containing liquid

Abstract

To provide a fine bubble-containing liquid manufacturing device that can efficiently concentrate and recover fine bubble, and to provide a fine bubble concentrated liquid manufacturing device and a method for generating fine bubble concentrated liquid.SOLUTION: A fine bubble-containing liquid concentration device includes a filter 5200 having a micropore of which pore diameter is larger than a diameter of a predetermined fine bubble.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a fine bubble-containing liquid concentrating device, a fine bubble-containing liquid manufacturing device, and a fine bubble-containing liquid concentrating method. [Background technology]

[0002] In recent years, technologies that utilize the properties of minute bubbles (fine bubbles) have been developed. Fine bubbles are distinguished by the names microbubbles, which have a diameter of 1.0 μm to 100 μm, and ultra-fine bubbles (UFB), which have a diameter of less than 1.0 μm.

[0003] Patent Document 1 discloses a method for generating UFBs with a diameter of less than 1.0 μm by driving a heating resistor element to generate film boiling in a liquid. Patent Document 1 also discloses an apparatus for efficiently generating a highly concentrated UFB-containing liquid by circulating the generated UFB-containing liquid through a filter disposed in a circulation path. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent Publication No. 2021-126603 Summary of the Invention [Problem to be solved by the invention]

[0005] However, the filter used in Patent Document 1 uses a physical filter with a mesh size smaller than the diameter of the generated UFB to prevent the UFB from passing through. In this case, the pressure loss when the liquid passes through the filter is large, making it impossible to increase the flow rate and efficiently generate a high-concentration fine bubble-containing liquid.

[0006] Therefore, the present invention provides an apparatus for concentrating fine bubble-containing liquid, an apparatus for producing fine bubble-containing liquid, and a method for concentrating fine bubble-containing liquid, which are capable of efficiently concentrating and recovering fine bubbles. [Means for solving the problem]

[0007] Therefore, the apparatus for concentrating fine bubble-containing liquid of the present invention comprises a storage section for storing fine bubble-containing liquid containing fine bubbles, a filter means capable of separating the liquid supplied from the storage section into a fine bubble-containing liquid containing predetermined fine bubbles that cannot pass through micropores and a liquid that does not contain the predetermined fine bubbles, and a supply means for supplying the fine bubble-containing liquid stored in the storage section to the filter means, wherein the pore diameter of the micropores is larger than the diameter of the predetermined fine bubbles stored in the storage section. [Effects of the Invention]

[0008] According to the present invention, it is possible to provide a fine bubble-containing liquid concentrating device, a fine bubble-containing liquid manufacturing device, and a fine bubble-containing liquid concentrating method that can efficiently concentrate and recover fine bubbles. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a schematic diagram showing an ultra-fine bubble concentrate manufacturing apparatus. [Figure 2] FIG. 2 is a block diagram showing a control configuration in the UFB concentrate manufacturing apparatus. [Figure 3] FIG. 2 is a schematic diagram showing an example of the internal structure of a cross-flow filter unit. [Figure 4] 10 is a flowchart showing a concentration process of a UFB-containing liquid. [Figure 5] FIG. 1 is a schematic diagram showing the relationship between UFB particle size and pressure in a fluid. [Figure 6] 1 is a schematic diagram showing a UFB concentrate manufacturing apparatus. [Figure 7]FIG. 1 is a diagram illustrating an example of an apparatus for producing a UFB-containing liquid. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In this embodiment, as an example of a fine bubble concentrating device, a UFB-containing liquid concentrating device for efficiently concentrating ultrafine bubbles, particularly those with a diameter of less than 1.0 μm, will be described.

[0011] 1 is a schematic diagram showing an apparatus for concentrating ultra-fine bubble-containing liquid (hereinafter referred to as a UFB-containing liquid concentrator) 5000 according to this embodiment. The UFB-containing liquid concentrator 5000 circulates a UFB-containing liquid W2 to increase the UFB concentration in the UFB-containing liquid W2. Here, the liquid W1 is a liquid that does not contain UFBs of a desired size, and the UFB-containing liquid W2 is a liquid that contains UFBs of a desired size.

[0012] The UFB-containing liquid concentrating apparatus 5000 mainly comprises an ultra-fine bubble-containing liquid supply unit (hereinafter referred to as the UFB-containing liquid supply unit) 5100, a cross-flow filter unit 5200, and a filtrate recovery unit 5300. The UFB-containing liquid concentrating apparatus 5000 further comprises an ultra-fine bubble concentrated liquid recovery unit (hereinafter referred to as the UFB concentrated liquid recovery unit) 5400. The cross-flow filter unit 5200 comprises a liquid inlet unit 310, a micropore flow path unit 320, and a concentration flow path unit 330. The liquid inlet unit 310 is a unit where liquid flows from the UFB-containing liquid supply unit 5100 into the cross-flow filter unit 5200, and the micropore flow path unit 320 is a unit where liquid from which UFB has been filtered flows out from the cross-flow filter unit 5200 to the filtrate recovery unit 5300. The concentration flow path unit 330 is a unit where liquid that does not pass through the micropores flows out from the cross-flow filter unit 5200.

[0013] UFB-containing liquid supply unit (storage unit) 5100 mainly includes flow paths 5110 and 5111, a UFB concentration sensor 5120, and a mass measurement unit 5130. UFB-containing liquid supply unit 5100 is capable of storing UFB-containing liquid W2, and UFB-containing liquid W2 stored in UFB-containing liquid supply unit 5100 is supplied by pump 5140 through flow path 5110 and via liquid inlet unit 310 to cross-flow filter unit 5200. UFB-containing liquid W2 flowing out of concentration flow path unit 330 of cross-flow filter unit 5200 through flow path 5111 is returned to UFB-containing liquid supply unit 5100 and stored therein by setting three-way valve 5210.

[0014] The UFB concentration sensor (concentration detection means) 5120 measures the UFB concentration of the UFB-containing solution W2 in the UFB-containing solution supply unit 5100. The mass measurement unit 5130 measures the remaining amount of UFB-containing solution W2 in the UFB-containing solution supply unit 5100. The composition / ingredients / UFB concentration / particle size / UFB gas species of the UFB-containing solution W2 are not particularly limited. It may be UFB-containing water with a pure water solvent, or a UFB-containing solution to which additives have been intentionally added.

[0015] The mass measuring unit 5130 may be a liquid level sensor that detects the liquid level in the supply unit rather than a mass measuring unit, since the purpose of the mass measuring unit 5130 is to obtain the remaining amount of UFB-containing liquid W2 in the UFB-containing liquid supply unit 5100. Furthermore, the UFB-containing liquid W2 stored in the UFB-containing liquid supply unit 5100 may be produced by any UFB production method.

[0016] In this embodiment, a UFB-containing liquid generated in advance by the T-UFB method using film boiling was used. However, when the UFB-containing liquid concentrating device 5000 is used alone, a UFB-containing liquid generated by a method in which the liquid is decompressed using the Venturi effect or the like to separate dissolved gases and generate UFBs may be used.

[0017] FIG. 2 is a block diagram showing the control configuration of the UFB-containing liquid concentrating device 5000. The CPU 500 controls the entire device using RAM 502 as a work area according to a program stored in ROM 501 via a main bus 510. The UI control unit 503 accepts user-operated settings such as device ON / OFF control, pump flow rate setting, target UFB concentration setting, and final mass setting, and stores the set values ​​in RAM 502. The drive control unit 504 controls the pump 5140 and three-way valve 5210 to operate according to the set values, based on various values ​​set by the UI control unit 503 and sensor control unit 505 and read by the CPU 500 from RAM 502. Under the instruction of the CPU 500, the sensor control unit 505 stores the readings of the UFB concentration sensor 5120 and mass measurement unit 5130 in RAM 502. The readings may be acquired periodically at any set elapsed time, or at any timing based on a signal from the UI control unit 503.

[0018] FIG. 3 is a schematic diagram showing an example of the internal structure of a crossflow filter unit 5200. The crossflow filter unit 5200 can filter UFB350 from a UFB-containing solution W2. In the crossflow filter unit 5200, the supply liquid (UFB-containing solution W2) passes through a filter membrane (micropore flow path unit) 320 in the supply direction (rightward in the figure) with a positive pressure relative to the permeation side. A liquid W1 containing no UFB350 or containing UFBs finer than the desired size of UFB350 (first fine bubbles) passes through the micropores of the filter membrane 320. UFBs finer than the desired size of UFB350 can pass through the micropores of the filter membrane 320. In other words, the filter membrane 320 can separate UFB350 of the desired size from UFBs finer than the desired size of UFB350. A plurality of hollow fibers 1501 with micropores are arranged in the crossflow filter section 5200. When the UFB-containing solution W2 passes through the hollow fibers 1501, a portion of it passes through the hollow fibers 1501 as a filtrate (liquid W1 that does not contain UFBs 350 with a particle size equal to or larger than the desired size) due to the pressure of the pump 5140. The filtrate (liquid W1) that has passed through the hollow fibers 1501 is sent to the filtrate recovery section 5300 through a flow path 5220 (see FIG. 1). The UFB-containing solution W2 that has not passed through the hollow fibers 1501 passes through a flow path 5221 and is then sent to the UFB-containing solution supply section 5100 through a flow path 5111 or to the UFB concentrate recovery section 5400 through a flow path 5301, depending on whether the three-way valve 5210 is open or closed. In its initial state, the three-way valve 5210 is in an open / closed state in which the UFB-containing solution W2 is sent to the UFB-containing solution supply unit 5100. In this manner, the three-way valve 5210 can selectively switch between sending the UFB-containing solution W2 to the UFB-containing solution supply unit 5100 or to the UFB concentrate recovery unit 5400.

[0019] 1 again. If the UFB concentration read by the UFB concentration sensor 5120 is less than the desired concentration, the CPU 500 controls the open / close state of the three-way valve 5210 so that the UFB-containing solution W2 that has passed through the cross-flow filter unit 5200 is sent to the UFB-containing solution supply unit 5100. On the other hand, if the UFB concentration is equal to or greater than the desired concentration (above a predetermined value), the CPU 500 controls the open / close state of the three-way valve 5210 so that the UFB-containing solution W2 that has passed through the cross-flow filter unit 5200 is sent to the UFB concentrate recovery unit 5400. Alternatively, if the remaining mass of the UFB-containing solution W2 measured by the mass measurement unit 5130 is equal to or less than the desired value, the CPU 500 controls the three-way valve 5210 so that the UFB-containing solution W2 is sent to the UFB concentrate recovery unit 5400.

[0020] FIG. 4 is a flowchart showing the process of concentrating a UFB-containing liquid in the UFB-containing liquid concentrating apparatus 5000. The series of processes shown in FIG. 4 are performed by the CPU 500 of the UFB-containing liquid concentrating apparatus 5000 by loading program code stored in the ROM 501 into the RAM 502 and executing it. Alternatively, some or all of the functions of the steps in FIG. 4 may be realized by hardware such as an ASIC or electronic circuit. This process begins with the UFB-containing liquid produced by a predetermined UFB production device stored in the UFB-containing liquid supply unit 5100. Note that the symbol "S" in the description of each process indicates a step in the flowchart. Below, the process of concentrating a UFB-containing liquid in the UFB-containing liquid concentrating apparatus 5000 will be described with reference to FIG. 3 and in accordance with the flowchart of FIG. 4.

[0021] When the concentration process begins, the CPU 500 sets the pump flow rate, target UFB concentration, and final mass instructed by the UI control unit 503 in S401. Then, in S402, the CPU 500 starts the operation of the device. Specifically, the three-way valve 5210 is opened or closed so that the liquid can be sent from the crossflow filter unit 5200 to the UFB-containing liquid supply unit 5100, and the pump 5140 is started according to the pump flow rate set in S401. After starting the pump 5140, the CPU 500 determines in S403 whether a predetermined time has elapsed. If the predetermined time has not elapsed, the process is repeated until the predetermined time has elapsed. If the predetermined time has elapsed, the process proceeds to S404. In S404, the CPU 500 writes the measured values ​​of the mass measurement unit 5130 and the UFB concentration sensor 5120 to the RAM 502. Then, in S405, the CPU 500 determines whether the mass of the UFB-containing liquid supply unit 5100 is equal to or greater than the final mass setting. If the mass is equal to or greater than the end mass setting, the process returns to S403 and repeats. If the mass is not equal to or greater than the end mass setting, the process proceeds to S406.

[0022] In S406, the CPU 500 determines whether the UFB concentration in the UFB-containing solution supply unit 5100 is less than the set value (less than a predetermined value). If the UFB concentration is less than the set value, the process returns to S403 and repeats. If the UFB concentration is not less than the set value, that is, if the UFB concentration has reached the desired concentration, the process proceeds to S407. In S407, the CPU 500 opens and closes the three-way valve 5210 to enable delivery of the solution from the cross-flow filter unit 5200 to the UFB concentrate recovery unit 5400. This allows UFB-containing solution W2 with a UFB concentration equal to or greater than the set value to be delivered to the UFB concentrate recovery unit 5400. Thereafter, in S408, the CPU 500 waits for a certain period of time until delivery to the UFB concentrate recovery unit 5400 is completed.

[0023] Then, in S409, the CPU 500 determines whether the UFB-containing liquid supply unit 5100 has become empty (mass ≈ 0) based on the measurement value of the mass measurement unit 5130. Note that the mass does not need to be zero precisely. It is sufficient if the UFB-containing liquid supply unit 5100 does not contain a quantity of UFB-containing liquid W2 that can be delivered by the pump 5140. If the UFB-containing liquid supply unit 5100 contains a quantity of UFB-containing liquid W2 that can be delivered, the process returns to S408 and repeats. If the UFB-containing liquid supply unit 5100 does not contain a quantity of UFB-containing liquid W2 that can be delivered, the process proceeds to S410.

[0024] In S410, the CPU 500 stops the operation of the pump 5140, and then in S411, opens and closes the three-way valve 5210 so that liquid can be sent from the crossflow filter section 5200 to the UFB concentrate recovery section 5400, thereby completing the process.

[0025] In this embodiment, the inventors recovered the UFB-containing solution W2 in the UFB concentrated solution recovery unit 5400, and then measured the number and average particle size of UFB particles contained in the recovered UFB-containing solution W2 using a measuring device (model number SALD (registered trademark)-7500nano) manufactured by Shimadzu Corporation. The above-mentioned measuring device (model number SALD (registered trademark)-7500nano) manufactured by Shimadzu Corporation may also be used as the UFB concentration sensor 5120. In this case, a configuration is required in which the UFB-containing solution W2 is transferred from the UFB-containing solution supply unit 5100 to a measurement container. Furthermore, the filtrate recovered in the filtrate recovery unit 5300 was also measured as appropriate using the above-mentioned measuring device to check for the presence or absence of leaked UFB particles.

[0026] Figure 5 is a schematic diagram showing the relationship between UFB particle size (diameter) and pressure in a fluid. When a UFB with diameter d1 exists under a certain fluid pressure P1, and is placed under a fluid pressure P2 that is smaller than the fluid pressure P1, how does the diameter of the UFB change? Let us consider the case of adiabatic change in thermodynamics.

[0027] During adiabatic change, the relationship between volume and pressure can be expressed by the following equation using Poisson's formula:

[0028] TIFF2025132589000002.tif8150

[0029] (P1: pressure before change, V1: volume before pressure change, P2: pressure after change, V2: volume after pressure change, γ: specific heat ratio of the gas) From this relation, the following equation is established:

[0030] (Formula 2) V1 γ =(P2 / P1)×V2 γ

[0031] Here, V1 and V2 can be expressed by the following equations.

[0032] (Formula 3) V1=(4 / 3)π(d1 / 2) 3

[0033] (Equation 4) V2=(4 / 3)π(d2 / 2) 3

[0034] (d1: UFB diameter before pressure change, d2: UFB diameter after pressure change)

[0035] Substituting these into equation (2), we get

[0036] (Equation 5) ((4 / 3)π(d1 / 2) 3 ) γ =(P2 / P1)×((4 / 3)π(d2 / 2) 3 ) γ

[0037] Then, by rearranging equation (5), we get

[0038] (Formula 6) (d2 / d1) 3γ =P1 / P2

[0039] This becomes:

[0040] Therefore, the UFB diameter d2 after the pressure change can be expressed by the following equation:

[0041] TIFF2025132589000003.tif8150

[0042] In other words, when P2 is smaller than P1 (pressure is low), d2 is larger than d1, and it can be seen that the bubble expands after the pressure change.

[0043] According to the above formula, for example, when an oxygen UFB with a diameter of 100 nm under 1 atmosphere is decompressed to 0.5 atmospheres under adiabatic conditions, the diameter d2 of the oxygen UFB is, Since the specific heat ratio γ of a diatomic molecular gas such as oxygen is generally about 7 / 5, by substituting each value into (Equation 7),

[0044] TIFF2025132589000004.tif16150

[0045] In other words, the diameter of the oxygen UFB increases from 100 nm to 118 nm.

[0046] Next, let us consider the change in UFB diameter when the UFB-containing liquid W2 passes through the micropores in the hollow fiber membrane in the crossflow filter section 5200. When the UFB-containing liquid W2 passes through the micropores, it passes through a relatively narrow flow path, which causes a pressure loss and reduces the pressure of the fluid. Therefore, it is thought that the UFB diameter in the flow path immediately after passing through the micropores will increase.

[0047] However, micropores generally have a complex structure, making it difficult to directly measure or simulate the pressure when passing through the micropores. Therefore, a practical method for measuring the pressure before and after passing through the micropores is to install pressure meters on flow path 5110, which is upstream of crossflow filter section 5200, and on flow path 5220 after passing through the micropores in crossflow filter section 5200, and check the pressure. Another similar method is to install flow meters on flow path 5110 and flow path 5220, and calculate the pressure using Bernoulli's equation from the respective flow rate values ​​and the average diameter of the micropores.

[0048] Generally, the pore size of a crossflow filter is defined as the ability to block substances with diameters larger than the pore size, i.e., the smallest diameter of a substance passing through the micropores is equal to or smaller than the pore size of the crossflow filter. Therefore, in this embodiment, the filter pore size is defined as the smallest diameter (minimum pore size) in the micropore path when passing through the micropores. Typical methods for measuring filter pore size include the gas permeation method (analyzing pore size from N2 or Ar gas adsorption isotherms in low-temperature liquid nitrogen or liquid argon, etc.). Another method is the bubble point method (applying air pressure to paper completely immersed in a test liquid, and calculating the pore size from the pressure at which bubbles appear).

[0049] Hereinafter, first and second examples in which the pore diameter of the crossflow filter section 5200 in the above embodiment is varied will be described together with comparative examples (first to fifth comparative examples).

[0050] In the first and second examples and the first to fifth comparative examples, a UFB-containing solution containing oxygen gas (number concentration: 420 million particles / mL, mode diameter: 90 nm, number-equivalent average particle diameter: 110 nm) was produced in advance by generating UFBs by dissolving oxygen gas in ultrapure water. This was then used as the UFB-containing solution to be concentrated in the UFB-containing solution concentrating device described with reference to FIG. 1 . Specifically, 100 mL of the UFB-containing solution was stored in the UFB-containing solution supply unit 5100, and concentration was repeated using the cross-flow filter unit 5200 with the pump 5140 operating at a flow rate of 10 mL / min until the measurement value in the mass measurement unit 5130 reached 25 g or less in S505. After concentration, the pump 5140 was operated until the measurement value in the mass measurement unit 5130 reached approximately 0 mg in S509 (until all of the UFB-containing solution W2 in the UFB-containing solution supply unit 5100 was sent to the UFB concentrated solution recovery unit 5400). Thereafter, the number concentration, mode diameter (the particle diameter most commonly observed in the distribution), and number-equivalent average particle diameter of the UFB-containing liquid in the UFB concentrated liquid recovery unit 5400 were obtained.

[0051] (First Example) The type of cross-flow filter used was one with a hollow fiber membrane made of polyvinylidene fluoride (PVDF) and a pore size of 100 nm.

[0052] (Second Example) The cross-flow filter used was one with a hollow fiber membrane made of PVDF and a pore size of 200 nm.

[0053] (First Comparative Example) The cross-flow filter used was one with a hollow fiber membrane made of PVDF and a pore size of 10 nm.

[0054] (Second Comparative Example) The cross-flow filter used had a hollow fiber membrane made of polyacrylonitrile (PAN) and a pore size of 5 nm.

[0055] (Third Comparative Example) The cross-flow filter used had a hollow fiber membrane made of PAN with a pore size of 1.5 nm.

[0056] (Fourth Comparative Example) The type of cross-flow filter used was one with a hollow fiber membrane made of polysulfone (PSU) and a pore size of 1.5 nm.

[0057] (Fifth Comparative Example) The cross-flow filter used was one with a hollow fiber membrane made of PVDF and a pore size of 500 nm.

[0058] TIFF2025132589000005.tif177147 Table 1 compares the detection results for each example and each comparative example. The detection results shown here include concentration efficiency, concentration ratio, UFB number concentration, mode diameter, and number-equivalent average particle diameter. For "concentration efficiency," the time from the start of operation of the UFB-containing liquid concentrating device 5000 to the end of operation, i.e., the time elapsed from the start to the end of the flowchart in FIG. 4, was measured. A value of "○" indicates an elapsed time of 20 minutes or less, and an "×" indicates an elapsed time of more than 20 minutes. In this embodiment, a liquid containing UFBs with a diameter of 80 nm or greater is concentrated. Therefore, if leakage of UFBs with a diameter of 80 nm or greater is detected in the filtrate recovery unit 5300, the concentration efficiency, concentration ratio, number concentration, mode diameter, and number-equivalent average particle diameter are not obtained, and are indicated in the table as (-).

[0059] As shown in Table 1, it was confirmed that in the first and second examples, a UFB-containing liquid could be recovered at a high concentration ratio. Furthermore, in the first to fourth comparative examples, the concentration efficiency and concentration ratio were inferior to those of the first and second embodiments. This is presumably because the pore size of the cross-flow filter was small, resulting in a low flow rate through the micropores to the filtrate recovery unit 5300, which took a long time for the concentration process and resulted in a long operating time, resulting in large UFB losses within the cross-flow filter and various flow paths. In the fifth comparative example, UFB with particle diameters of 80 nm or more were confirmed in the filtrate recovered in the filtrate recovery unit 5300. This is thought to be due to the large pore size of the cross-flow filter, which caused UFB with diameters of 80 nm or more to leak out.

[0060] Here, we will look at the ratio between the pore size of the crossflow filter and the diameter (lower limit value) of the UFB.

[0061] Crossflow filter pore size: UFB diameter = 500:80 500:80=6.25:1≒6:1 From this, it can be said that if the pore size of the crossflow filter is larger than six times the desired UFB diameter, UFB of the desired diameter will leak out, even taking into account the expansion of the UFB. Therefore, it is desirable that the crossflow filter pore size be six times or less than the desired UFB diameter. In other words, taking into account the results of Table 1, the crossflow filter pore size is desirably less than 500 nm, and even more desirably 100 nm or more but less than 500 nm. Note that in the above, a liquid containing UFB with a diameter of 80 nm or more was used as the target for concentration, but it goes without saying that the appropriate crossflow filter pore size will change depending on the size of the bubbles to be concentrated.

[0062] As described above, according to this embodiment, the minimum pore size of the cross-flow filter is larger than the desired UFB diameter, so pressure loss is kept low and a high flow rate can be achieved compared to the configuration of Patent Document 1. Therefore, fine bubbles can be concentrated and collected more efficiently than in the past.

[0063] (Second embodiment) The second embodiment of the present invention will be described below with reference to the drawings. Note that the basic configuration of this embodiment is the same as that of the first embodiment, so only the characteristic configuration will be described below.

[0064] 6 is a schematic diagram showing the configuration of a UFB-containing liquid concentrating apparatus 5000 according to the second embodiment. In the first embodiment, the liquid was sent to the crossflow filter unit 5200 by a pump 5140 on a flow path 5110 provided upstream of the crossflow filter (see FIG. 1). In this embodiment, a pump 5141 is provided on a flow path 5220 downstream of the crossflow filter unit 5200, and a pump 5142 is provided on the flow path 5221. Suction by the pumps 5141 and 5142 controls the circulation of the UFB-containing liquid W2 in the UFB-containing liquid supply unit 5100, the supply of the UFB-containing liquid W2 to the UFB concentrate recovery unit 5400, and the supply of the liquid W1 to the filtrate recovery unit 5300.

[0065] Furthermore, pressure gauges 5230 and 5231 may be provided on flow path 5110 and on flow path 5220 before pump 5141, and the values ​​of these pressure gauges may be read by CPU 500 to control the flow rates of pumps 5141 and 5142. By referring to the values ​​of pressure gauges 5230 and 5231, the pressures in flow path 5220 and flow path 5221 can be determined, and the degree of expansion of the UFB can be controlled.

[0066] Furthermore, the flow rate ratio of pump 5141 to pump 5142 is set to 1:2 to 1:6, and the flow rate of pump 5142 is set to be greater than the flow rate of pump 5141. In this way, by setting the flow rate of pump 5142 greater than the flow rate of pump 5141, UFB of the desired diameter can pass through hollow fibers 1501, and unnecessary pressure loss can be reduced, allowing liquid W1 to pass through hollow fibers 1501. This allows UFB to be efficiently concentrated and recovered in UFB concentrate recovery unit 5400.

[0067] In this embodiment, the flow rates of pump 5141 and pump 5142 are 30 mL / min and 120 mL / min, respectively. The flow rate conditions of pump 5141 and pump 5142 are preferably changed according to the height of the liquid surface in UFB concentrate recovery unit 5400, within a range of a flow rate ratio of 1:2 to 1:6. In other words, the higher the liquid surface height in UFB concentrate recovery unit 5400, the more preferably the flow rate conditions are used.

[0068] In this way, pumps 5141 and 5142 may be installed downstream of the cross-flow filter section 5200, and the circulation of the UFB-containing liquid W2 in the UFB-containing liquid supply section 5100 and the supply of liquid to the filtrate recovery section 5300 may be controlled by suction.

[0069] (Third embodiment) The third embodiment of the present invention will be described below with reference to the drawings. Note that the basic configuration of this embodiment is the same as that of the first embodiment, so only the characteristic configuration will be described below.

[0070] In this embodiment, a configuration will be described in which the UFB-containing liquid concentrating device 5000 described in the first and second embodiments is incorporated as a UFB concentration unit into a UFB-containing liquid manufacturing (fine bubble-containing liquid manufacturing) device.

[0071] FIG. 7 is a diagram illustrating an example of a UFB-containing liquid manufacturing apparatus according to a third embodiment. The UFB-containing liquid manufacturing apparatus 1 of this embodiment includes a pretreatment unit 100, a dissolving unit 200, a T-UFB production unit 300, a UFB concentration unit 5000, and a recovery unit 1000. For example, tap water is supplied to the pretreatment unit 100, where degassing and other processes are performed. The dissolving unit 200 dissolves a gas, such as oxygen, to be contained in the UFB in the liquid supplied from the pretreatment unit 100. The UFB production unit 300 generates UFB in the liquid using a predetermined method. The UFB-containing liquid generated in the UFB production unit 300 is supplied to the UFB concentration unit 5000, where it is concentrated using the method described in the above embodiment. The concentrated UFB-containing liquid is then recovered in the recovery unit 1000. In this specification, UFB generated using film boiling due to sudden heat generation is referred to as T-UFB (Thermal-Ultra Fine Bubbles). However, the T-UFB generating unit 300 may generate UFB by utilizing film boiling caused by sudden heat generation, or may generate UFB by using a Venturi system, piezo, or the like.

[0072] (Other embodiments) Although the above explanation has been given using UFB as an example, the present disclosure can be applied to fine bubbles in general. However, in the case of UFB, buoyancy is less likely to act and the bubbles rarely rise to the liquid surface and disappear, making it possible to more effectively utilize the concentrated liquid manufacturing device of the present invention.

[0073] In this way, the fine bubble-containing liquid is circulated and filtered using a cross-flow filter with a pore size larger than the desired fine bubble diameter, thereby providing a fine bubble concentrate manufacturing apparatus and a fine bubble concentrate production method that can efficiently concentrate and recover fine bubbles of the desired diameter.

[0074] The disclosure of this embodiment includes the following configurations and methods.

[0075] (Configuration 1) a storage section for storing a fine bubble-containing liquid containing fine bubbles; a filter means capable of separating the liquid supplied from the reservoir into a fine bubble-containing liquid containing predetermined fine bubbles that cannot pass through the micropores and a liquid not containing the predetermined fine bubbles; a supply means for supplying the fine bubble-containing liquid stored in the storage section to the filter means; A fine bubble-containing liquid concentrating device comprising: The fine bubble-containing liquid concentrating device is characterized in that the pore diameter of the micropores is larger than the diameter of the specified fine bubbles stored in the storage section.

[0076] (Configuration 2) The fine bubble-containing liquid concentrating device according to configuration 1, wherein the filter means is a cross-flow filter having a hollow fiber membrane, and the micropores are provided in the hollow fiber membrane.

[0077] (Configuration 3) a first liquid delivery means for delivering the fine bubble-containing liquid that has not passed through the micropores to a collection section; a second liquid delivery means for delivering the fine bubble-containing liquid that has not passed through the micropores to the storage section; a switching means for selectively switching whether the fine bubble-containing liquid that has not passed through the micropores is sent to the storage section or to the recovery section; 3. The fine bubble-containing liquid concentrating device according to claim 1 or 2, comprising:

[0078] (Configuration 4) The apparatus further comprises a concentration detection means for detecting the concentration of fine bubbles contained in the fine bubble-containing liquid stored in the storage section, The fine bubble-containing liquid concentrating device according to Configuration 3, wherein the switching means sends the fine bubble-containing liquid that did not pass through the micropores to the storage section when the content concentration is less than a predetermined value, and sends the fine bubble-containing liquid that did not pass through the micropores to the recovery section when the content concentration is equal to or greater than the predetermined value.

[0079] (Configuration 5) The filter means has a liquid inlet section through which the fine bubble-containing liquid flows from the reservoir section into the filter means, a micropore flow path section through which the liquid that has passed through the micropores flows out from the filter means, and a concentration flow path section through which the liquid that has not passed through the micropores flows out from the filter means, 5. The apparatus for concentrating fine bubble-containing liquid according to any one of configurations 1 to 4, wherein the pressure in the micropore flow path section is lower than the pressure in the liquid inlet section.

[0080] (Configuration 6) 6. The apparatus for concentrating fine bubble-containing liquid according to any one of configurations 1 to 5, wherein the pore diameter of the micropores is six times or less the diameter of the predetermined fine bubbles stored in the storage section.

[0081] (Configuration 7) 7. The apparatus for concentrating fine bubble-containing liquid according to any one of configurations 1 to 6, wherein the supply means has a pump disposed between the storage section and the filter means.

[0082] (Configuration 8) The fine bubble-containing liquid concentrating device according to configuration 5, wherein the supply means comprises a first pump for sending the liquid that has passed through the micropores from the micropore flow path section, and a second pump for sending the liquid that has not passed through the micropores from the concentration flow path section.

[0083] (Configuration 9) 9. The apparatus for concentrating a fine bubble-containing liquid according to any one of configurations 1 to 8, wherein the fine bubbles are ultrafine bubbles having a diameter of less than 1.0 μm.

[0084] (Configuration 10) 10. The apparatus for concentrating fine bubble-containing liquid according to claim 9, wherein the pore diameter of the micropores is 100 nm or more and less than 500 nm.

[0085] (Configuration 11) A generating means for generating fine bubbles in a liquid; a storage section for storing a fine bubble-containing liquid containing the fine bubbles generated by the generating means; a filter means capable of separating the liquid supplied from the reservoir into a fine bubble-containing liquid containing predetermined fine bubbles that cannot pass through the micropores and a liquid not containing the predetermined fine bubbles; a supply means for supplying the fine bubble-containing liquid stored in the storage section to the filter means; A fine bubble-containing liquid manufacturing apparatus comprising: The fine bubble-containing liquid manufacturing apparatus is characterized in that the pore diameter of the micropores is larger than the diameter of the predetermined fine bubbles stored in the storage section.

[0086] (Method 1) a storing step of storing a fine bubble-containing liquid containing fine bubbles in a storage section; a filtering step in which the liquid supplied from the reservoir is separated by a filtering means into a fine bubble-containing liquid containing predetermined fine bubbles that cannot pass through the micropores and a liquid not containing the predetermined fine bubbles; a supplying step of supplying the fine bubble-containing liquid stored in the storing step to the filter means; A method for concentrating a fine bubble-containing liquid, comprising: The method for concentrating a fine bubble-containing liquid, wherein the pore diameter of the micropores is larger than the diameter of the predetermined fine bubbles stored in the storing step. [Explanation of symbols]

[0087] 500 CPU 5000 UFB concentrate production equipment 5100 UFB-containing liquid supply section 5120 UFB concentration sensor 5200 Crossflow filter section 5300 Filtrate recovery section

Claims

1. a storage section for storing a fine bubble-containing liquid containing fine bubbles; a filter means capable of separating the liquid supplied from the reservoir into a fine bubble-containing liquid containing predetermined fine bubbles that cannot pass through the micropores and a liquid not containing the predetermined fine bubbles; a supply means for supplying the fine bubble-containing liquid stored in the storage section to the filter means; A fine bubble-containing liquid concentrating device comprising: The fine bubble-containing liquid concentrating device is characterized in that the pore diameter of the micropores is larger than the diameter of the specified fine bubbles stored in the storage section.

2. 2. The apparatus for concentrating fine bubble-containing liquid according to claim 1, wherein the filter means is a cross-flow filter having a hollow fiber membrane, and the micropores are provided in the hollow fiber membrane.

3. a first liquid delivery means for delivering the fine bubble-containing liquid that has not passed through the micropores to a recovery section; a second liquid delivery means for delivering the fine bubble-containing liquid that has not passed through the micropores to the storage section; a switching means for selectively switching whether the fine bubble-containing liquid that has not passed through the micropores is sent to the storage section or to the recovery section; The fine bubble-containing liquid concentrating device according to claim 1 or 2, comprising:

4. The apparatus further comprises a concentration detection means for detecting the concentration of fine bubbles contained in the fine bubble-containing liquid stored in the storage section, The fine bubble-containing liquid concentrating device according to claim 3, wherein the switching means sends the fine bubble-containing liquid that did not pass through the micropores to the storage section when the content concentration is less than a predetermined value, and sends the fine bubble-containing liquid that did not pass through the micropores to the recovery section when the content concentration is equal to or greater than the predetermined value.

5. The filter means has a liquid inlet section through which the fine bubble-containing liquid flows from the reservoir section into the filter means, a micropore flow path section through which the liquid that has passed through the micropores flows out from the filter means, and a concentration flow path section through which the liquid that has not passed through the micropores flows out from the filter means, The fine bubble-containing liquid concentrating device according to claim 1, wherein the pressure in the micropore flow path section is lower than the pressure in the liquid inlet section.

6. 2. The apparatus for concentrating fine bubble-containing liquid according to claim 1, wherein the pore diameter of the micropores is six times or less the diameter of the predetermined fine bubbles stored in the storage section.

7. 2. The apparatus for concentrating fine bubble-containing liquid according to claim 1, wherein the supply means has a pump disposed between the storage section and the filter means.

8. 6. The fine bubble-containing liquid concentrating device according to claim 5, wherein the supply means comprises a first pump for sending the liquid that has passed through the micropores from the micropore flow path section, and a second pump for sending the liquid that has not passed through the micropores from the concentration flow path section.

9. 2. The apparatus for concentrating fine bubble-containing liquid according to claim 1, wherein the fine bubbles are ultrafine bubbles having a diameter of less than 1.0 μm.

10. 10. The apparatus for concentrating fine bubble-containing liquid according to claim 9, wherein the pore diameter of the micropores is 100 nm or more and less than 500 nm.

11. A generating means for generating fine bubbles in a liquid; a storage section for storing a fine bubble-containing liquid containing the fine bubbles generated by the generating means; a filter means capable of separating the liquid supplied from the reservoir into a fine bubble-containing liquid containing predetermined fine bubbles that cannot pass through the micropores and a liquid not containing the predetermined fine bubbles; a supply means for supplying the fine bubble-containing liquid stored in the storage section to the filter means; A fine bubble-containing liquid manufacturing apparatus comprising: The fine bubble-containing liquid manufacturing apparatus is characterized in that the pore diameter of the micropores is larger than the diameter of the predetermined fine bubbles stored in the storage section.

12. a storing step of storing a fine bubble-containing liquid containing fine bubbles in a storage section; a filtering step in which the liquid supplied from the reservoir is separated by a filtering means into a fine bubble-containing liquid containing predetermined fine bubbles that cannot pass through the micropores and a liquid not containing the predetermined fine bubbles; a supplying step of supplying the fine bubble-containing liquid stored in the storing step to the filter means; A method for concentrating a fine bubble-containing liquid, comprising: A method for concentrating a fine bubble-containing liquid, wherein the pore diameter of the micropores is larger than the diameter of the predetermined fine bubbles stored in the storing step.

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