JP7207910B2 - Particle extraction device, particle extraction method - Google Patents

Description

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

Conventionally, microbubbles, which are bubbles with a diameter of about 1 μm to 100 μm, have been known, but in recent years attention has focused on even finer bubbles with a diameter of 1 μm or less. Such bubbles are called ultrafine-bubbles (UFB) or nanobubbles, and their use is expanding in various fields such as cleaning, agriculture, fisheries, and medicine.

However, depending on the technical field, defoaming of UFB may be required when separating and extracting fine particles from a liquid containing UFB and fine particles. However, UFB does not disappear even if the liquid is pressurized, depressurized, or boiled, so it is very difficult to eliminate the foam. Therefore, in recent years, various techniques for defoaming microbubbles have been proposed (see, for example, 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. Further, Patent Literature 1 discloses a technique for improving yield by preventing impurities (particles) such as nanobubbles (UFB) from being contained in a liquid material for nanoimprinting. Specifically, a particle-free liquid material can be obtained by filtering the crude liquid material and leaving the UFB-laden particles on the primary side of the filter.

JP 2016-164977 A ([0149] to [0151] etc.)

Materials from the 8th Fine Bubble International Symposium (sponsored by the Fine Bubble Industry Association), 2016

In addition, the present inventors have tried the slow freeze-thaw separation described in Non-Patent Document 1 on a trial basis. As a result, it was confirmed that when the fine particles were separated and extracted from the liquid containing fine bubbles and fine particles, the fine particles aggregated. Furthermore, the conventional technique described in Non-Patent Document 1 requires a special testing machine for controlling the freezing speed and a power supply, and has the problem that continuous processing is difficult.

In addition, when separating and extracting fine particles from a liquid containing fine bubbles (UFB) and fine particles using the conventional technology described in Patent Document 1, when the diameter of the fine particles is greatly different from the diameter of the UFB, the fine particles are filtered. can be separated. However, if the diameter of the microparticles is close to the diameter of the UFB (that is, about 100 nm), separation of the microparticles would be difficult.

The present invention has been made in view of the above problems, and its object is to provide a particle extraction device and a particle extraction method that can reliably eliminate fine bubbles and reliably separate and extract solid particles. to do.

As a means (means 1) for solving the above problems, there is provided 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, comprising: and a large number of pores communicating with the downstream side and having a pore size of 2 to 50 times the diameters of the microbubbles and the solid fine particles, and directed from the upstream side to the downstream side through the pores There is a fine particle extractor characterized by comprising a porous body that allows the solid fine particles to pass through together with the liquid while defoaming the fine air bubbles by allowing the liquid to pass through the porous body.

Therefore, in the invention described in the above means 1, when the liquid passes through the pores of the porous body from the upstream side toward the downstream side, the microbubbles contained in the liquid collide with the inner wall surfaces of the pores. It is presumed that the foam disappears when it pops or adheres to the inner wall surface of the pores. Therefore, fine air bubbles can be defoamed with certainty. Further, when the liquid passes through the fine pores from the upstream side toward the downstream side, the fine bubbles disappear, while the solid fine particles pass together with the liquid. Since the solid fine particles are "solid", unlike microbubbles which are "gas" fine particles, even if they collide with each other, they are unlikely to be crushed. 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 are millibubbles with a diameter larger than 100 μm, microbubbles with a diameter of 100 μm or less but larger than 1 μm, and ultra-fine bubbles with a diameter of 1 μm or less. (UFB). In addition, the "microbubbles" in this invention shall mean a microbubble and an ultra-fine bubble among said bubbles. In addition to microbubbles, the liquid also contains solid microparticles having a diameter similar to that of the microbubbles. Here, "the same diameter as the microbubbles" means, for example, a diameter within ±50 nm of the diameter of the microbubbles.

The fine particle extracting device has a porous body having a large number of pores communicating between the upstream side and the downstream side and having a pore size larger than the diameters of the microbubbles and the solid fine particles. In addition, it is preferable that the porous body is made of, for example, a ceramic material. Examples of ceramic materials forming the porous body include alumina, aluminum nitride, silicon nitride, boron nitride, zirconia, titania, mullite, magnesia, ceria, doped ceria and mixtures thereof. As the material for forming the porous body, in addition to the ceramics described above, for example, glass or metal (stainless steel, etc.) may be used, and the material can be selected regardless of the presence or absence of conductivity. In addition to these inorganic materials, organic materials such as synthetic resins can also be used.

Moreover, it is preferable that the fine particle extracting device includes forced passage means for forcibly passing the liquid from the upstream side toward the downstream side through the pores. In this way, the liquid is forced to pass through the pores of the porous body, and therefore passes through the pores without clogging. Accordingly, fine bubbles contained in the liquid can be efficiently defoamed, and solid fine particles contained in the liquid can be efficiently separated. Furthermore, it is preferable that the forced passage means is pressure-feeding means for pressure-feeding the liquid to the porous body side. In this way, 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, fine bubbles contained in the liquid can be defoamed more efficiently, and solid fine particles contained in the liquid can be separated more efficiently.

The pore diameter of the pores is 2 to 50 times , preferably 10 to 20 times, the diameters of the microbubbles and solid fine particles. By making the pore diameter of the pores twice or more the diameter of the microbubbles and the solid fine particles, the resistance when the liquid passes through the pores becomes small. can be done. In addition, by setting the pore diameter of the pores to be 50 times or less the diameter of the microbubbles and the solid fine particles, when the liquid passes through the pores, the microbubbles contained in the liquid collide with the inner walls of the pores and burst. Therefore, fine air bubbles can be defoamed with certainty.

In addition, it is preferable that the microparticle extraction device includes a processing tank for storing liquid, and the porous body is arranged 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 fine bubbles contained in the liquid can be efficiently eliminated, and solid fine particles contained in the liquid can be efficiently removed. can be separated well.

Another means (means 2) for solving the above 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. to a porous body having a large number of pores that communicate with the upstream side and the downstream side and have a pore diameter that is 2 to 50 times the diameter of the fine bubbles and the solid fine particles, through the pores. There is a fine particle extraction method characterized by performing a defoaming step in which the fine bubbles are eliminated by passing the liquid from the upstream side toward the downstream side, and the solid fine particles are passed along with the liquid. .

Therefore, according to the invention described in means 2, in the defoaming step, when the liquid is passed through the pores of the porous body from the upstream side toward the downstream side, the microbubbles contained in the liquid are removed from the pores. It is presumed that the foam collides with the inner wall surface and bursts, or adheres to the inner wall surface of the pore and disappears. Therefore, fine air bubbles can be defoamed with certainty. Further, in the defoaming step, when the liquid passes through the fine pores from the upstream side toward the downstream side, the microbubbles are defoamed while the solid fine particles pass together with the liquid. Since the solid fine particles are "solid", unlike microbubbles which are "gas" fine particles, even if they collide with each other, they are unlikely to be crushed. As a result, solid fine particles can be reliably separated and extracted by the porous body.

In addition, in the defoaming step, it is preferable to force the liquid to pass through the pores from the upstream side toward the downstream side. In this way, the liquid is forced to pass through the pores of the porous body, and therefore passes through the pores without clogging. Accordingly, fine bubbles contained in the liquid can be efficiently defoamed, and solid fine particles contained in the liquid can be efficiently separated. Furthermore, in the defoaming step, it is preferable to forcibly pass the liquid by pumping the liquid to the porous body side. In this way, 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, fine bubbles contained in the liquid can be defoamed more efficiently, and solid fine particles contained in the liquid can be separated more efficiently.

It is preferable that the diameter of the microbubbles 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, ultra-fine bubbles having a diameter of less than 1 μm can be defoamed as fine bubbles.

1 is a schematic cross-sectional view showing a particle extraction device according to this embodiment; FIG. FIG. 2 is an enlarged cross-sectional view showing a porous body; Explanatory drawing which shows the state before a defoaming process. Explanatory drawing which shows a defoaming process. 4 is a graph showing the number of particles contained in pure water on the primary side and the secondary side when the number of particles contained in supply water is taken as 100%. Graph showing the relationship between particle diameter and particle concentration.

An embodiment embodying the present invention will be described in detail below with reference to the drawings.

As shown in FIG. 1, the particle extraction apparatus 10 of the present embodiment is an apparatus for separating and extracting solid particles W2 from pure water W3 (liquid) containing fine bubbles W1 and solid particles W2. The fine bubbles W1 are for cleaning the semiconductor contained in the pure water W3, and are bubbles (UFB) with 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 microbubbles W1. In addition, the particle extraction device 10 includes a processing tank 11 that stores pure water W3. The processing bath 11 is formed in a substantially cylindrical shape using a stainless steel plate, and includes a ceiling plate 12, a bottom plate 13 and side plates .

As shown in FIGS. 1 and 2, the particle extraction device 10 has a porous body 21. As shown in FIG. The porous body 21 has a first end (upper end in FIG. 1) and a second end (lower end in FIG. 1) that is open only at the second end, 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 hollow cylindrical member. More specifically, the porous body 21 is placed in the processing bath 11 and attached to the bottom plate 13 of the processing bath 11 via a fixing jig 15 press-fitted into the end on the second end side. The bottom plate 13 is provided with a through hole 16 passing through the central portion of the bottom plate 13 , and a fixing jig 15 is fitted in the through hole 16 . Therefore, the internal space of the porous body 21 communicates with the outside of the processing bath 11 .

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

As shown in FIG. 2, the porous body 21 has inside a large number of pores 24 communicating the upstream side 22 and the downstream side 23, and thus has suitable liquid permeability. The porous body 21 allows the pure water W3 to pass through the pores 24 from the upstream side 22 toward the downstream side 23, thereby defoaming the fine bubbles W1 and allowing the solid fine particles W2 to pass therethrough together with the pure water W3. It has become. The porous body 21 is a member containing fine particles 25 made of alumina. The 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 this embodiment. That is, the pore diameter A1 is 15 times the diameters of the microbubbles W1 and solid fine particles W2.

Further, as shown in FIG. 4, the processing tank 11 can be equipped with a gas supply source 31 (nitrogen cylinder), which is a pumping means for pumping the pure water W3 to the porous body 21 side. Specifically, the ceiling plate 12 of the processing bath 11 is provided with a supply port 17 penetrating through the central portion of the ceiling plate 12 . A gas supply channel 32 is connected to the processing bath 11 to supply gas W4 (nitrogen in this embodiment) from the gas supply source 31 through the supply port 17 into the processing bath 11 . When the gas W4 is supplied from the gas supply source 31 into the processing bath 11, the pure water W3 in the processing bath 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 functions as forced passage means for forcibly passing the pure water W3 from the upstream side 22 toward the downstream side 23 through the pores 24 .

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

First, pure water W3 containing fine bubbles W1 and solid fine particles W2 is put into the container 41. As shown in FIG. Next, the pure water W3 in the container 41 is poured into the processing bath 11 through the supply port 17 (see FIG. 3). Then, a defoaming step for defoaming the microbubbles W1 is performed. Specifically, the gas W4 is supplied from the gas supply source 31 into the processing tank 11 through the gas supply channel 32 (see FIG. 4). Along with this, the pure water W3 in the processing bath 11 is pressed by the gas W4 supplied into the processing bath 11 and is pressure-fed toward the porous body 21 also in the processing bath 11 . The pure water W3 contacts the upstream side surface 22 (outer side surface) of the porous body 21 while being pressurized to a predetermined pressure (0.3 MPaG in this embodiment). At this time, the pure water W3 passes through the pores 24 of the porous body 21 from the upstream side 22 toward the downstream side 23 (inner side). As a result, the fine bubbles W1 contained in the pure water W3 collide with the inner wall surfaces of the pores 24 and disappear. 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. The pure water W3 containing the solid fine particles W2 is discharged into the internal space of the porous body 21 from the openings of the pores 24 on the side of the downstream side 23 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 particle extraction device 10 will be described.

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

Then, the end of the porous body 21 on the second end side is press-fitted into the fixing jig 15 . Next, the porous body 21 to which the fixing jig 15 is attached is inserted into the processing tank 11 and the fixing jig 15 is fitted into the 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 bath 11, and the fine particle extraction apparatus 10 is completed.

Next, the method for evaluating the particulate extractor and the results thereof will be described.

First, a sample for measurement was prepared as follows. A microparticle extraction device having pores of a porous body with a pore diameter of 1500 nm, that is, a microparticle extraction device that is the same as the microparticle extraction device 10 of the present embodiment was prepared and used as an example. On the other hand, a microparticle extractor having a pore diameter of 110 nm in the porous body was prepared and used as a comparative example.

Next, a liquid (pure water) permeation test was performed on each measurement sample (Example and Comparative Example). Specifically, first, pure water containing UFB (100 nm diameter) and polystyrene particles (100 nm diameter) at a ratio of 0:1, that is, pure water containing only polystyrene particles and not containing UFB was prepared. Next, after supplying the prepared pure water into the treatment tank, the pure water is brought into contact with the outer surface of the porous body while being pressurized to 0.3 MPaG, and the pure water is applied from the outer surface to the inner surface of the porous body. was passed through. The passing treatment was continued until the weight of pure water on the primary side (upstream side of the porous body) was halved. After that, the pure water remaining on the primary side, the pure water on the secondary side (downstream side of the porous body), and the pure water (supply water) before passing treatment were collected. Furthermore, the number of particles contained in the sampled pure water was measured using Nanosite (trade name, NS-300) manufactured by Malvern Panalytical. The above 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, the number of particles on the secondary side is 0%, so the polystyrene particles do not pass through the secondary side (downstream side) of the porous body. was confirmed. On the other hand, in the example in which the pores of the porous body had a pore diameter of 1500 nm, the number of particles was about 20%, so 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 do not pass through the pores unless the pore diameter of the pores is considerably larger than the diameter of the particles (polystyrene particles).

Also, 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 and no polystyrene particles was prepared. Also, pure water containing UFB and polystyrene particles at a ratio of 1:0.5 was prepared and 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, each measurement sample (Samples 1 to 4) was subjected to a permeation test with respect to the fine particle extraction apparatus of the above-described example in which the pore size of the pores of the porous body was 1500 nm. Specifically, first, the pure water of samples 1 to 4 is brought into contact with the outer surface of the porous body in a state of being pressurized to 0.3 MPaG, and the pure water is passed through from the outer surface to the inner surface of the porous body. processed. After the weight of the pure water on the primary side (upstream side of the porous body) is halved, the pure water remaining on the primary side, the pure water on the secondary side (downstream side of the porous body), and the pure water before passing treatment Water (supply water) was sampled, and the number of particles contained in the sampled pure water was measured using Nanosite (NS-300). The above results are shown in FIG.

As a result, since the number of particles on the secondary side was 0% in sample 1 containing no polystyrene particles, it was confirmed that the 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 a permeation test was conducted by changing the ratio of UFB and polystyrene particles (see Samples 2 to 4), it was confirmed that the number of particles on the secondary side increased as the ratio of polystyrene particles increased. rice field. From the above, it was proved that particles (polystyrene particles) pass together with the liquid when pure water passes through the porous body. It was confirmed that the particles could be separated and extracted from water.

Also, test water containing UFB and polystyrene particles at a ratio of 1:1 was prepared. Then, a defoaming test for defoaming the UFB contained in the test water was performed by passing the test water through the same porous body as the porous body 21 of the present embodiment. In addition, a defoaming test was conducted to defoam UFB contained in the test water by subjecting the test water to slow freezing (slow integrated melting separation) described in Patent Document 1. Furthermore, using Nanosite (NS-300), the particle concentration (pc/ml: here, the concentration of polystyrene particles) in the test water after the defoaming test is measured, and the diameter of the particles (polystyrene particles) is measured. bottom. The above results are shown in FIG.

As a result, the presence of particles up to a diameter of 220 nm was confirmed in the defoaming test by slow freezing, so it is presumed that the polystyrene particles aggregated. On the other hand, in the antifoaming test by permeation, the existence of particles was confirmed only up to a diameter of 150 nm, so aggregation of polystyrene particles was not confirmed. From the above, it was proved that the agglomeration of the particles can be prevented by defoaming the UFB by permeating the liquid through the porous body.

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

(1) In the particle extraction device 10 of the present embodiment, when the pure water W3 passes through the pores 24 of the porous body 21 from the upstream side 22 toward the downstream side 23, fine bubbles contained in the pure water W3 It is presumed that W1 collides with the inner wall surface of the pore 24 and bursts, or adheres to the inner wall surface of the pore 24, thereby defoaming. In addition, it is presumed that the microbubbles W1 also disappear when they adhere to the surface of the porous body 21 (the upstream side surface 22 and the downstream side surface 23). As described above, by allowing the pure water W3 to pass through the porous body 21, the microbubbles W1 can be reliably eliminated. Further, when the pure water W3 passes through the pores 24 from the upstream side 22 toward the downstream side 23, the microbubbles W1 disappear, while the solid fine particles W2 pass together with the pure water W3. Since the solid fine particles W2 are "solid", unlike the fine bubbles W1 which are "gas" fine particles, they are unlikely to be crushed even if they collide. As a result, the porous body 21 can reliably separate and extract the solid fine particles W2.

(2) In this 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 side under pressure, 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 in a state of being pressurized by the pure water W3, it is possible to solve the problem that the air in the porous body 21 enters the processing tank 11 through the pores 24. can.

(3) In the prior art described in Non-Patent Document 1, air bubbles are eliminated by performing slow freeze-thaw separation, but a special tester for controlling the freezing speed and a power supply are required. , there is a problem that continuous processing is difficult. On the other hand, in the present embodiment, the microbubbles W1 can be eliminated simply by passing the pure water W3 through the pores 24 of the porous body 21. FIG. Therefore, there is no need to install the special testing machine described above. Moreover, the particle extraction device 10 of this 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 eliminated.

(4) In the prior art described in Patent Document 1, since the liquid is filtered through a filter having a relatively small pore size (several tens of nanometers), resistance increases when the liquid passes through the filter, and the liquid contains There is a problem that it takes a long time to separate the particles contained in the particles. On the other hand, in the present embodiment, 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 the diameter (100 nm) of the microbubbles W1 and the solid fine particles W2. It is designed to let As a result, the pure water W3 has less resistance when it passes through the pores 24, so that the defoaming of the fine bubbles W1 and the separation of the solid fine particles W2 can be performed quickly.

In addition, you may change the said embodiment as follows.

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

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

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

- In the above embodiment, the pure water W3 is used as the liquid in the processing bath 11, but the liquid is not limited to this, and water of not so high purity, such as tap water, may of course be used.

- The solid fine particles W2 in 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-described embodiment was formed in a substantially cylindrical shape using a stainless steel plate. However, the processing bath 11 may be formed using a glass container or a pipe made of polyvinyl chloride (vinyl chloride pipe).

The fine particle extracting apparatus 10 of the above-described embodiment is used for defoaming the microbubbles W1 for cleaning semiconductors, but may be used for defoaming microbubbles for cleaning foods, medical instruments, and the like. . Further, the fine particle extracting device 10 may be a device that eliminates microbubbles, and may not be a device that eliminates microbubbles for cleaning. For example, the particulate extractor 10 may be used for defoaming microbubbles used to promote the growth of crops.

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

(1) The fine particle extracting apparatus according to the above means 1, wherein the liquid is pure water.

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

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

REFERENCE SIGNS LIST 10 Fine particle extraction device 11 Treatment tank 21 Porous body 22 Upstream side 23 Downstream side 24 Pore 31 Gas supply source A1 as forced passage means and pressure feed means Pore diameter W1 Fine bubbles W2 Solid fine particles W3: pure water as a liquid

Claims (11)

A device for separating and extracting solid fine particles from a liquid containing fine bubbles and solid fine particles having a diameter similar to that of the fine bubbles,
Having a large number of pores communicating the upstream side and the downstream side and having a pore diameter of 2 to 50 times the diameters of the microbubbles and the solid fine particles, and passing through the pores from the upstream side to the downstream side A fine particle extracting device, comprising: a porous body that eliminates the fine bubbles by allowing the liquid to pass through toward the porous body and allows the solid fine particles to pass through together with the liquid. 2. The particle extraction device according to claim 1, wherein the fine bubbles and the solid particles have a diameter of less than 1 [mu]m. 3. The fine particle extracting device according to claim 1, wherein the diameter of the fine pores is 10 to 20 times the diameters of the microbubbles and the solid fine particles. 4. The particulate extractor according to any one of claims 1 to 3, further comprising forced passage means for forcibly passing said liquid from said upstream side toward said downstream side through said pores. . 5. The fine particle extracting apparatus according to claim 4, wherein the forced passage means is pressure-feeding means for pressure-feeding the liquid to the porous body side. 6. The fine particle extraction apparatus according to claim 1, further comprising a processing tank for storing the liquid, wherein the porous body is arranged in the processing tank. A method 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,
For a porous body having a large number of pores that communicate with the upstream side and the downstream side and have a pore size that is 2 to 50 times the diameter of the fine bubbles and the solid fine particles, the upstream side is connected through the pores. A method for extracting fine particles, characterized in that a defoaming step is performed in which the fine bubbles are eliminated by passing the liquid from the outlet toward the downstream side, and the solid fine particles are passed along with the liquid. 8. The method according to claim 7, wherein the diameter of the microbubbles 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. particulate extraction method. 9. The fine particle extraction method according to claim 7 or 8, wherein the diameter of the pores is 10 to 20 times the diameters of the microbubbles and the solid fine particles. 10. The fine particle extraction according to any one of claims 7 to 9, wherein in the defoaming step, the liquid is forced to pass through the pores from the upstream side toward the downstream side. Method. 11. The fine particle extraction method according to claim 10, wherein in the defoaming step, the liquid is forcibly passed through the porous body by pumping the liquid toward the porous body.

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