JP2020037067A - Fine particle extraction device and method - Google Patents

Abstract

To provide a fine particle extraction device capable of surely separating and extracting solid fine particles while defoaming fine bubbles without fail.SOLUTION: A fine particle extraction device 10 of the present invention comprises a function separating and extracting solid fine particles W2 from a liquid W3 including fine bubbles W1 and the solid fine particles W2 having a diameter nearly equal to that of the fine bubble W1 using a porous body 21 comprised in the device 10. The porous body 21 has many pores which communicate an upstream side face 22 and a downstream side face 23 and have a bore diameter larger than the diameters of the fine bubble W1 and the solid fine particle W2. Besides, the porous body 21 defoams the fine bubble W1 by making the liquid W3 pass from the upstream side face 22 toward the downstream side face 23 through the pores, and makes the solid fine particle W2 pass together with the liquid W3.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a fine particle extracting apparatus for separating and extracting solid fine particles from a liquid containing fine bubbles and solid fine particles, and a method for extracting fine particles.

  Conventionally, microbubbles, which are bubbles having a diameter of about 1 μm to 100 μm, have been known. In recent years, attention has been paid to finer bubbles having a diameter of 1 μm or less. Such bubbles are called Ultrafine-Bubble (UFB) or nanobubbles, and their use is expanding in various fields such as cleaning, agriculture, fisheries, and medical care.

  However, depending on the technical field, defoaming of UFB may be required, for example, when separating and extracting fine particles from a liquid containing UFB and fine particles. However, UFB is very difficult to defoam because it does not disappear even if the liquid is pressurized or depressurized or boiled. Therefore, in recent years, various techniques for defoaming fine bubbles have been proposed (for example, see Non-Patent Document 1 and Patent Document 1). Non-Patent Document 1 introduces that “slow freeze-thaw separation” is effective as a method for separating (defoaming) UFB. Patent Literature 1 discloses a technique for improving yield by preventing impurities (particles) such as nanobubbles (UFB) from being included in a liquid material for nanoimprint. Specifically, by filtering the crude liquid material and leaving particles containing UFB on the primary side of the filter, a liquid material containing no particles can be obtained.

JP-A-2006-164977 ([0149] to [0151] etc.)

8th Fine Bubble International Symposium (organized by Fine Bubble Industry Association), 2016

  In addition, the present inventors experimentally performed the slow freeze-thaw separation described in Non-Patent Document 1. As a result, it was confirmed that when the fine particles were separated and extracted from the liquid containing the fine bubbles and the fine particles, the fine particles would aggregate. Furthermore, the conventional technique described in Non-Patent Document 1 requires a special tester for controlling the speed of freezing and a power supply, and has a problem that continuous processing is difficult.

  In addition, when fine particles are separated and extracted from a liquid containing fine bubbles (UFB) and fine particles by using the conventional technology described in Patent Document 1, when the diameter of the fine particles is significantly different from the diameter of UFB, fine particles are filtered. Can be separated. However, when the diameter of the fine particles is close to the diameter of the UFB (that is, when the diameter is about 100 nm), it is presumed that separation of the fine particles is difficult.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a fine particle extracting apparatus and a fine particle extracting method capable of reliably separating and extracting solid fine particles while reliably eliminating fine bubbles. Is to do.

  Means for solving the above problem (means 1) is an apparatus for separating and extracting the solid fine particles from a liquid containing fine bubbles and solid fine particles having a diameter similar to that of the fine bubbles. And a large number of pores communicating with the downstream side and having a pore size larger than the diameter of the fine bubbles and the solid fine particles, and allowing the liquid to pass from the upstream side to the downstream side through the pores. Accordingly, there is provided a fine particle extraction device comprising a porous body for eliminating the fine bubbles and passing the solid fine particles together with the liquid.

  Therefore, in the invention described in the above means 1, when the liquid passes from the upstream side to the downstream side through the pores of the porous body, the fine bubbles contained in the liquid collide with the inner wall surface of the pores. It is presumed that the foam disappears by popping out or attaching to the inner wall surface of the pore. For this reason, it is possible to reliably eliminate fine bubbles. Further, when the liquid passes from the upstream side to the downstream side through the pores, the fine bubbles disappear and the solid fine particles pass together with the liquid. Since the solid fine particles are “solid”, they are unlikely to be crushed even if they collide, unlike fine gas bubbles which are “gas” fine particles. As a result, solid fine particles can be reliably separated and extracted by the porous body.

  By the way, the bubbles that can exist in the liquid include a millibubble that is a bubble having a diameter larger than 100 μm, a microbubble that is a bubble having a diameter of 100 μm or less but larger than 1 μm, and an ultrafine bubble that is a bubble having a diameter of 1 μm or less. (UFB). In the present invention, “fine bubbles” refer to microbubbles and ultrafine bubbles among the above-mentioned bubbles. In addition, the liquid contains, in addition to the fine bubbles, solid fine particles having the same diameter as the fine bubbles. Here, the “diameter comparable to that of the fine bubbles” refers to, for example, a diameter of the fine bubbles within a diameter of ± 50 nm.

  The fine particle extraction device includes a porous body communicating with the upstream side surface and the downstream side surface and having a large number of pores having a pore diameter larger than the diameter of the fine bubbles and the solid fine particles. The porous body is preferably made of, for example, a ceramic material. Examples of the ceramic material constituting the porous body include alumina, aluminum nitride, silicon nitride, boron nitride, zirconia, titania, mullite, magnesia, ceria, doped ceria, and mixtures thereof. Further, as a material for forming the porous body, in addition to the above-described ceramics, for example, glass or metal (such as stainless steel) may be used, and a material can be selected irrespective of conductivity. In addition, not only such inorganic materials but also organic materials such as synthetic resins can be used.

  Further, it is preferable that the fine particle extraction device includes a forced passage means for forcibly passing the liquid from the upstream side to the downstream side via the fine holes. With this configuration, the liquid is forcibly passed through the pores of the porous body, so that the liquid passes without clogging the pores. Therefore, fine bubbles contained in the liquid can be efficiently defoamed, and solid fine particles contained in the liquid can be efficiently separated. Further, it is preferable that the forced passage means is a pressure feeding means for pressure-feeding the liquid toward the porous body. With this configuration, the liquid is supplied to the porous body side in a pressurized state, so that the liquid passes through the pores of the porous body without clogging. Therefore, the fine bubbles contained in the liquid can be more efficiently defoamed, and the solid fine particles contained in the liquid can be separated more efficiently.

  The size of the pores is not particularly limited. For example, the pore size of the pores is 2 to 50 times, preferably 10 to 20 times the diameter of the fine bubbles and solid fine particles. preferable. By making the pore diameter twice or more the diameter of fine bubbles and solid fine particles, the resistance of the liquid when passing through the pores is reduced, so that defoaming of fine bubbles and separation of solid fine particles can be performed quickly. Can be. Also, by setting the pore diameter of the pores to 50 times or less the diameter of the fine bubbles and solid fine particles, when the liquid passes through the pores, the fine bubbles contained in the liquid collide with the inner wall surface of the pores and pop. This facilitates the defoaming of fine bubbles.

  In addition, it is preferable that the fine particle extraction device includes a processing tank for storing liquid, and a porous body is disposed in the processing tank. In this way, the liquid stored in the processing tank can be brought into contact with the porous body arranged in the processing tank, so that the fine bubbles contained in the liquid can be efficiently defoamed and the solid fine particles contained in the liquid can be efficiently removed. Can be separated well.

  Another means (means 2) for solving the above-mentioned problem is a method of separating and extracting the solid fine particles from a liquid containing fine bubbles and solid fine particles having a diameter similar to that of the fine bubbles. The porous body having a large number of pores communicating with the upstream side face and the downstream side face and having a pore diameter larger than the diameters of the microbubbles and the solid fine particles, from the upstream side face to the downstream side face via the pores. A fine particle extraction method characterized by performing a defoaming step of defoaming the microbubbles by passing the liquid toward the liquid, while passing the solid fine particles together with the liquid.

  Therefore, according to the invention described in the means 2, in the defoaming step, when passing the liquid from the upstream side to the downstream side through the pores of the porous body, the fine bubbles contained in the liquid cause It is presumed that the foam collides with the inner wall surface and pops out, or adheres to the inner wall surface of the pores to defoam. For this reason, it is possible to reliably eliminate fine bubbles. Further, in the defoaming step, when the liquid passes from the upstream side to the downstream side through the pores, the fine bubbles are defoamed, and the solid fine particles pass together with the liquid. Since the solid fine particles are “solid”, they are unlikely to be crushed even if they collide, unlike fine gas bubbles which are “gas” fine particles. As a result, solid fine particles can be reliably separated and extracted by the porous body.

  In the defoaming step, it is preferable to force the liquid to pass from the upstream side to the downstream side via the fine holes. With this configuration, the liquid is forcibly passed through the pores of the porous body, so that the liquid passes without clogging the pores. Therefore, fine bubbles contained in the liquid can be efficiently defoamed, and solid fine particles contained in the liquid can be efficiently separated. Further, in the defoaming step, it is preferable to force the liquid to pass by forcing the liquid to the porous body side. With this configuration, the liquid is supplied to the porous body side in a pressurized state, so that the liquid passes through the pores of the porous body without clogging. Therefore, the fine bubbles contained in the liquid can be more efficiently defoamed, and the solid fine particles contained in the liquid can be separated more efficiently.

  In addition, it is preferable that the diameter of the fine bubbles to be defoamed in the defoaming step and the diameter of the solid fine particles passing through the porous body in the defoaming step are each less than 1 μm. In this way, in the defoaming step, ultrafine bubbles having a diameter of less than 1 μm can be defoamed as fine bubbles.

FIG. 1 is a schematic cross-sectional view illustrating a particle extraction device according to the present embodiment. The expanded sectional view showing a porous body. Explanatory drawing which shows the state before a defoaming process. Explanatory drawing which shows a defoaming process. The graph which shows the number of particles contained in pure water of the primary side and the secondary side when the number of particles contained in supply water is 100%. 5 is a graph showing the relationship between particle diameter and particle concentration.

  Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.

  As shown in FIG. 1, the fine particle extraction device 10 of the present embodiment is a device for separating and extracting solid fine particles W2 from pure water W3 (liquid) containing fine bubbles W1 and solid fine particles W2. The microbubbles W1 are for cleaning the semiconductor housed in the pure water W3, and are bubbles (UFB) having a diameter of 1 μm or less (specifically, 100 nm). On the other hand, the solid fine particles W2 are polystyrene particles having the same diameter (specifically, 100 nm) as the fine bubbles W1. Further, the fine particle extraction device 10 includes a treatment tank 11 for storing the pure water W3. The processing tank 11 is formed in a substantially cylindrical shape using a stainless steel plate, and includes a ceiling plate 12, a bottom plate 13 and a side plate 14.

  As shown in FIGS. 1 and 2, the fine particle extraction device 10 includes a porous body 21. The porous body 21 is open only at the second end of the first end (the upper end in FIG. 1) and the second end (the lower end in FIG. 1), and has a length of 20 mm, an outer diameter of 12 mm, an inner diameter of 9 mm, and a thickness of 1.5 mm. Is a member having a hollow cylindrical shape. More specifically, the porous body 21 is disposed in the processing tank 11 and is attached to the bottom plate 13 of the processing tank 11 via a fixing jig 15 press-fitted to the second end. The bottom plate 13 is provided with a through hole 16 penetrating through the center of the bottom plate 13, and a fixing jig 15 is fitted into the through hole 16. Therefore, the internal space of the porous body 21 communicates with the outside of the processing tank 11.

Further, the porous body 21 has an upstream side surface 22 (outside surface) with which the pure water W3 contacts, and a downstream side surface 23 (inside surface) located on the opposite side of the upstream side surface 22. The porous body 21 is formed using a porous ceramic material (in this embodiment, alumina (Al ₂ O ₃ )) having a property of allowing pure water W3 to pass between the upstream side surface 22 and the downstream side surface 23. Have been.

  As shown in FIG. 2, the porous body 21 has a suitable liquid permeability because it has a large number of pores 24 communicating the upstream side surface 22 and the downstream side surface 23 therein. The porous body 21 passes the pure water W3 from the upstream side surface 22 to the downstream side surface 23 through the pores 24, so that the fine bubbles W1 are eliminated and the solid fine particles W2 are allowed to pass together with the pure water W3. It has become. The porous body 21 is a member including fine particles 25 formed of alumina. Further, the pore diameter A1 of the pores 24 is larger than the diameter (100 nm) of the fine bubbles W1 and the diameter (100 nm) of the solid fine particles W2, and is 1500 nm in the present embodiment. That is, the pore diameter A1 is 15 times the diameter of the fine bubbles W1 and the solid fine particles W2.

  As shown in FIG. 4, a gas supply source 31 (nitrogen cylinder), which is a pumping means for pumping pure water W3 toward the porous body 21, can be attached to the processing tank 11. Specifically, the ceiling plate 12 of the processing tank 11 is provided with a supply port 17 that penetrates a central portion of the ceiling plate 12. The processing tank 11 is connected to a gas supply channel 32 that supplies a gas W4 (in the present embodiment, nitrogen) from the gas supply source 31 to the processing tank 11 via the supply port 17. When the gas W4 is supplied from the gas supply source 31 into the processing tank 11, the pure water W3 in the processing tank 11 is pushed toward the porous body 21 and passes through the pores 24 of the porous body 21. become. That is, the gas supply source 31 has a function as a forced passage unit that forcibly passes the pure water W3 from the upstream side surface 22 to the downstream side surface 23 through the fine holes 24.

  Next, a method of separating and extracting the solid fine particles W2 from the pure water W3 (fine particle extracting method) will be described.

  First, pure water W3 containing fine bubbles W1 and solid fine particles W2 is put in the container 41. Next, the pure water W3 in the container 41 is poured into the processing tank 11 through the supply port 17 (see FIG. 3). Then, a defoaming step of defoaming the fine bubbles W1 is performed. Specifically, the gas W4 is supplied from the gas supply source 31 into the processing tank 11 via the gas supply flow path 32 (see FIG. 4). Along with this, the pure water W3 in the processing tank 11 is pressed by the gas W4 supplied into the processing tank 11, and is pressure-fed to the porous body 21 in the processing tank 11 as well. The pure water W3 contacts the upstream side surface 22 (outer surface) of the porous body 21 in a state where the pure water W3 is pressurized to a predetermined pressure (0.3 MPaG in the present embodiment). At this time, the pure water W3 passes from the upstream side surface 22 to the downstream side surface 23 (inner side surface) through the pores 24 of the porous body 21. As a result, the fine bubbles W1 contained in the pure water W3 are defoamed by colliding with the inner wall surface of the pores 24, for example. On the other hand, the solid fine particles W2 contained in the pure water W3 pass through the pores 24 together with the pure water W3. Then, the pure water W3 containing the solid fine particles W2 is discharged into the internal space of the porous body 21 from the opening on the downstream side surface 23 side of the pore 24, and is stored in the container 42 arranged below the porous body 21. At this point, the solid fine particles W2 are separated and extracted.

  Next, a method for manufacturing the fine particle extraction device 10 will be described.

  First, the porous body 21 is produced by extrusion molding. Specifically, after adding an organic binder, water, and the like to alumina powder having an average particle size of 5.5 μm, the mixture is kneaded and kneaded by a mixer to obtain a clay-like extruded soil for extrusion molding. Next, an extruder is used to form the extruded scale, thereby obtaining a precursor of the porous body 21. Then, by drying the formed precursor, a formed body having the same shape as the shape of the porous body 21 (that is, cylindrical shape) is obtained. Thereafter, the molded body is degreased and fired at 1500 ° C. in an air atmosphere to obtain the porous body 21.

  Then, the end on the second end side of the porous body 21 is pressed into the fixing jig 15. Next, the porous body 21 with the fixing jig 15 attached thereto is inserted into the processing tank 11, and the fixing jig 15 is fitted into a through hole 16 provided in the bottom plate 13 of the processing tank 11. At this point, the porous body 21 is attached in the processing tank 11, and the fine particle extraction device 10 is completed.

  Next, an evaluation method of the fine particle extraction device and the result thereof will be described.

  First, a measurement sample was prepared as follows. A fine particle extraction device in which the pore diameter of the porous body is 1500 nm, that is, the same fine particle extraction device as the fine particle extraction device 10 of the present embodiment was prepared, and this was used as an example. On the other hand, a fine particle extraction device in which the pore diameter of the porous body was 110 nm was prepared, and this was used as a comparative example.

  Next, a liquid (pure water) permeation test was performed on each measurement sample (Example, Comparative Example). Specifically, first, pure water containing UFB (diameter 100 nm) and polystyrene particles (diameter 100 nm) at a ratio of 0: 1, that is, pure water containing only polystyrene particles and not containing UFB was prepared. Next, after the prepared pure water is supplied into the treatment tank, the pure water is brought into contact with the outer surface of the porous body in a state where the pure water is pressurized to 0.3 MPaG, and the pure water is supplied from the outer surface to the inner surface of the porous body. Was passed through. The passing process was continued until the weight of pure water on the primary side (upstream side of the porous body) became half. Thereafter, pure water remaining on the primary side, pure water on the secondary side (downstream side of the porous body), and pure water (supply water) before the passage treatment were collected. Furthermore, the number of particles contained in the collected pure water was measured using a nanosite (NS-300) manufactured by Malvern Panalytical. The results are shown in FIG.

  As a result, in the comparative example in which the pore diameter of the pores of the porous body is 110 nm, since the number of particles on the secondary side is 0%, no polystyrene particles pass through the secondary side (downstream side) of the porous body. Was confirmed. On the other hand, in Examples in which the pore diameter of the porous body was 1500 nm, since the number of particles was about 20%, it was confirmed that the polystyrene particles passed through the secondary side of the porous body. From the above, it was proved that the particles would not pass through the pores unless the pore diameter of the pores was significantly larger than the diameter of the particles (polystyrene particles).

  In addition, a sample for measurement was prepared as follows. Pure water containing UFB and polystyrene particles at a ratio of 1: 0, that is, pure water containing only UFB but not containing polystyrene particles was prepared. Further, pure water containing UFB and polystyrene particles at a ratio of 1: 0.5 was prepared, and this was used as Sample 2. Further, Sample 3 was pure water containing UFB and polystyrene particles at a ratio of 1: 1, and Sample 4 was pure water containing UFB and polystyrene particles at a ratio of 1: 5.

  Next, the transmission test of each measurement sample (samples 1 to 4) was performed on the fine particle extraction device of the above example in which the pore diameter of the porous body was 1500 nm. Specifically, first, pure water of samples 1 to 4 is brought into contact with the outer surface of the porous body in a state where the pure water is pressurized to 0.3 MPaG, and pure water passes from the outer surface to the inner surface of the porous body. Processing was performed. Then, after the weight of the pure water on the primary side (upstream side of the porous body) is reduced by half, the pure water remaining on the primary side, the pure water on the secondary side (downstream side of the porous body), the pure water before the passage treatment, Water (supply water) was sampled, and the number of particles contained in the sampled pure water was measured using nanosites (NS-300). The results are shown in FIG.

  As a result, in Sample 1 containing no polystyrene particles, since the number of particles on the secondary side was 0%, it was confirmed that UFB did not pass through the secondary side of the porous body. That is, it is presumed that the UFB is defoamed when the pure water passes through the porous body. In addition, when the transmission test was performed by changing the ratio between UFB and polystyrene particles (see Samples 2 to 4), it was confirmed that as the ratio of polystyrene particles increased, the number of particles on the secondary side also increased. Was. From the above, it was proved that the particles (polystyrene particles) passed along with the liquid when the pure water passed through the porous body. Therefore, if the fine particle extraction device of the above embodiment was used, the pure water containing the UFB and the particles could be obtained. It was confirmed that particles could be separated and extracted from water.

  Test water containing UFB and polystyrene particles at a ratio of 1: 1 was prepared. Then, a defoaming test was performed in which the UFB contained in the test water was defoamed by allowing the test water to pass through the same porous body as the porous body 21 of the present embodiment. In addition, a defoaming test for defoaming UFB contained in the test water was performed by subjecting the test water to slow freezing (slow integrated melting and separation) described in Patent Document 1. Further, the particle concentration (pc / ml: here, the concentration of polystyrene particles) of the test water after the defoaming test is measured using nanosite (NS-300), and the diameter of the particles (polystyrene particles) is measured. did. FIG. 6 shows the above results.

  As a result, in the defoaming test by slow freezing, the presence of particles was confirmed to a range where the diameter was 220 nm, and it is presumed that polystyrene particles were aggregated. On the other hand, in the defoaming test by permeation, since the presence of particles was confirmed only up to the range where the diameter was 150 nm, aggregation of the polystyrene particles was not confirmed. From the above, it was proved that agglomeration of particles could be prevented by defoaming UFB by allowing liquid to pass through the porous body.

  Therefore, according to the present embodiment, the following effects can be obtained.

  (1) In the fine particle extraction device 10 of the present embodiment, when the pure water W3 passes from the upstream side surface 22 to the downstream side surface 23 through the pores 24 of the porous body 21, fine bubbles contained in the pure water W3 It is presumed that W1 collides with the inner wall surface of the pore 24 and pops out, or adheres to the inner wall surface of the pore 24 and defoams. Further, it is presumed that the fine bubbles W1 disappear when attached to the surface (the upstream side surface 22 or the downstream side surface 23) of the porous body 21. As described above, by passing pure water W3 through the porous body 21, the fine bubbles W1 can be reliably eliminated. Further, when the pure water W3 passes from the upstream side surface 22 to the downstream side surface 23 through the pores 24, the fine bubbles W1 are defoamed, while the solid fine particles W2 pass along with the pure water W3. Since the solid fine particles W2 are "solid", unlike the fine bubbles W1 which are fine particles of "gas", they do not easily collapse even if they collide. As a result, the solid fine particles W2 can be reliably separated and extracted by the porous body 21.

  (2) In the present embodiment, as the gas W4 is supplied into the processing tank 11 in a pressurized state, the pure water W3 in the processing tank 11 is pushed toward the porous body 21 by the gas W4. ing. As a result, since the pure water W3 is supplied to the porous body 21 in a pressurized state, the pure water W3 passes through the pores 24 of the porous body 21 without clogging. Therefore, the fine bubbles W1 contained in the pure water W3 can be efficiently defoamed, and the solid fine particles W2 contained in the pure water W3 can be efficiently separated. Further, since the inside of the processing tank 11 is pressurized by the pure water W3, it is possible to solve the problem that the air in the porous body 21 passes through the pores 24 and enters the processing tank 11. it can.

  (3) In the conventional technology described in Non-Patent Document 1, bubbles are defoamed by performing slow freeze-thaw separation, but a special testing machine for controlling the speed of freezing and a power supply are required. However, there is a problem that continuous processing is difficult. On the other hand, in the present embodiment, the fine bubbles W1 can be defoamed only by allowing the pure water W3 to pass through the pores 24 of the porous body 21. For this reason, there is no need to install the special testing machine described above. Moreover, the fine particle extraction device 10 of the present embodiment has a function of pumping the pure water W3 to the porous body 21 side. Therefore, since the pure water W3 continuously passes through the porous body 21, the fine bubbles W1 can be continuously defoamed.

  (4) In the prior art described in Patent Document 1, since the liquid is filtered with a filter having a relatively small pore size (several tens of nm), the resistance when the liquid passes through the filter increases, and the liquid is included in the liquid. There is a problem that it takes a long time to separate the particles. On the other hand, in the present embodiment, the pure water W3 (liquid) is passed through the porous body 21 in which the pore diameter A1 (1500 nm) of the pores 24 is 15 times as large as the diameter (100 nm) of the fine bubbles W1 and the solid fine particles W2. It is made to let. As a result, the resistance when the pure water W3 passes through the pores 24 decreases, so that the defoaming of the fine bubbles W1 and the separation of the solid fine particles W2 can be performed quickly.

  The above embodiment may be modified as follows.

  -Although the porous body 21 of the above-described embodiment has a cylindrical shape, the porous body 21 may have another cylindrical shape such as a rectangular cylindrical shape, an elliptical cylindrical shape, and a triangular cylindrical shape. Further, the porous body is not limited to a cylindrical shape, and may have another shape such as a disk shape or a flat shape.

  In the above-described embodiment, the gas supply source 31 that supplies the gas W4 into the processing tank 11 is used as the forced passage unit and the pressure feeding unit. May be used. For example, a piston or the like provided in the processing tank 11 so as to be able to reciprocate along the axial direction of the processing tank 11 (the vertical direction in FIG. 1) may be used as the forced passage means and the pressure feeding means. In this case, by moving the piston downward, the pure water W3 is pushed by the piston and is pressure-fed to the porous body 21 side, and passes from the upstream side surface 22 to the downstream side surface 23 through the fine holes 24. Become.

  -In the above-mentioned embodiment, nitrogen was used as gas W4 supplied into processing tank 11, but other gases, such as air, oxygen, and argon, may be used, for example.

  In the above embodiment, the pure water W3 is used as the liquid in the processing tank 11, but the present invention is not limited to this, and it is a matter of course that water with a not so high purity, such as tap water, may be used.

  -The solid fine particles W2 of the above embodiment were polystyrene particles. However, the solid fine particles W2 may be fine particles made of other materials such as silica, aluminum oxide, acrylic resin, borosilicate glass, quartz, gold, iron oxide, platinum, and palladium.

  -The processing tank 11 of the above embodiment was formed in a substantially cylindrical shape using a stainless steel plate. However, the processing tank 11 may be formed using a glass container or a pipe (PVC pipe) made of polyvinyl chloride.

  -Although the particle extraction device 10 of the above-mentioned embodiment was used for defoaming the microbubbles W1 for cleaning semiconductors, it may be used for defoaming of microbubbles for cleaning foods, medical instruments, and the like. . Further, the fine particle extraction device 10 only needs to defoam fine bubbles, and does not need to defoam fine bubbles for cleaning. For example, the fine particle extraction device 10 may defoam fine bubbles used for promoting the growth of agricultural products.

  Next, in addition to the technical ideas described in the claims, technical ideas grasped by the above-described embodiments will be listed below.

  (1) In the means (1), the liquid is pure water.

  (2) The fine particle extraction apparatus according to the above (1), wherein the pore diameter of the fine pores is 1000 nm or more and 2000 nm or less.

  (3) The fine particle extraction device according to the above (1), wherein the porous body is made of a ceramic material.

DESCRIPTION OF SYMBOLS 10 ... Fine particle extraction apparatus 11 ... Processing tank 21 ... Porous body 22 ... Upstream side surface 23 ... Downstream side surface 24 ... Micropore 31 ... Gas supply source A1 as a forced passage means and a pressure feeding means ... Micropore diameter W1 ... Microbubbles W2 ... Solid fine particles W3: pure water as liquid

Claims (11)

A device for separating and extracting the solid fine particles from a liquid containing fine bubbles and solid fine particles having a diameter similar to the fine bubbles,
The upstream side and the downstream side communicate with each other, and the pore diameter has a large number of pores larger than the diameter of the fine bubbles and the solid fine particles, and the liquid flows from the upstream side to the downstream side through the pores. A fine particle extraction device comprising: a porous body that passes the solid fine particles together with the liquid while allowing the fine bubbles to disappear by passing the fine bubbles.   2. The fine particle extraction device according to claim 1, wherein the diameter of the fine bubbles and the solid fine particles is less than 1 [mu] m.   3. The fine particle extraction device according to claim 1, wherein a diameter of the fine pores is 2 to 50 times, preferably 10 to 20 times the diameter of the fine bubbles and the solid fine particles. 4. .   4. The fine particle extraction device according to claim 1, further comprising a forced passage unit that forcibly passes the liquid from the upstream side surface to the downstream side surface through the pores. 5. .   The fine particle extraction device according to claim 4, wherein the forcible passage means is a pumping means for pumping the liquid toward the porous body.   The apparatus according to any one of claims 1 to 5, further comprising a processing tank for storing the liquid, wherein the porous body is disposed in the processing tank. A method for separating and extracting the solid fine particles from a liquid containing fine particles and solid fine particles having a diameter similar to that of the fine bubbles,
For a porous body that communicates the upstream side surface and the downstream side surface and has a large number of pores whose diameters are larger than the diameters of the microbubbles and the solid fine particles, from the upstream side surface to the downstream side surface through the pores A fine bubble extraction step, wherein a fine bubble is defoamed by allowing the liquid to pass therethrough, while a defoaming step of passing the solid fine particles together with the liquid is performed.   The diameter of the fine bubbles to be defoamed in the defoaming step and the diameter of the solid fine particles passing through the porous body in the defoaming step are each less than 1 μm. Method for extracting fine particles.   The method for extracting fine particles according to claim 7 or 8, wherein the pore diameter of the fine pores is at least 2 times and at most 50 times, preferably at least 10 times and at most 20 times the diameter of the fine bubbles and the solid fine particles. .   The fine particle extraction according to any one of claims 7 to 9, wherein in the defoaming step, the liquid is forcibly passed from the upstream side surface to the downstream side surface through the pores. Method.   The method for extracting fine particles according to claim 10, wherein in the defoaming step, the liquid is forcibly passed by pumping the liquid to the porous body side.

Images