RU2748485C1 - Ultrafine bubble generation method, ultrafine bubble generation device, and ultrafine bubble-containing liquid - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: invention relates to a method for generating ultrafine bubbles and a device for generating ultrafine bubbles for generating ultrafine bubbles with a diameter of less than 1.0 mcm and liquid containing ultrafine bubbles. The ultrafine bubble generation device contains a generation unit designed to generate ultrafine bubbles by inducing a heating element provided in the liquid to generate heat to create a membrane boiling at the interface between the liquid and the heating element; and a post-processing unit designed to perform a predetermined post-processing of a liquid containing ultrafine bubbles containing ultrafine bubbles generated by the generating unit. The post-processing unit includes a removal unit including a first unit that removes an inorganic ion using a cation exchange resin.

EFFECT: invention is the effective formation of liquid containing ultra-fine bubbles with high purity.

25 cl, 13 dwg

Description

Background of the invention

The technical field to which the invention relates

[0001] The present invention relates to a method for generating ultrafine bubbles and an apparatus for generating ultrafine bubbles for generating ultrafine bubbles with a diameter of less than 1.0 µm and containing ultrafine bubbles of liquid.

Description of the prior art

[0002] Methods have recently been developed to exploit the properties of small bubbles, such as micron-sized microbubbles and nanobubbles nanometer-sized. In particular, the usefulness of ultrafine bubbles (hereinafter also referred to as "UMP") with a diameter of less than 1.0 μm has been confirmed in various fields.

[0003] Japanese Patent No. 6118544 discloses a fine air bubble generating apparatus that generates fine air bubbles by ejecting (ejecting) a pressurized liquid from a depressurizing (depression) nozzle, wherein a gas is compressed and dissolved in the liquid. Japanese Patent No. 4,456,176 discloses a device that generates fine bubbles by repeating the separation and transformation of gas-mixed liquid streams using a mixing unit.

[0004] Both devices described in Japanese Patent Nos. 6118544 and 4456176 generate not only nanometer-sized CMPs, but also relatively large numbers of millimeter-sized millibubbles and micron-sized microbubbles. However, since millibubbles and microbubbles are influenced by buoyancy (buoyancy in the liquid), it is most likely that the bubbles will gradually rise to the surface of the liquid and disappear during long-term storage.

[0005] On the other hand, nanometer-sized CMDs are suitable for long-term storage because they are less likely to experience buoyancy in a liquid and float in a liquid by Brownian motion. However, when UMPs are generated using millibubbles and microbubbles or the energy of the gas-liquid interface of the UMP is small, UMPs are affected by the disappearance of millibubbles and microbubbles and decrease in number over time.

The essence of the invention

[0006] Thus, in order to obtain an UFD-containing liquid in which a decrease in UFD concentration can be suppressed even during long-term storage, it is required to generate a high-purity, high-concentration UFD with high gas-liquid interface energy while forming the UFD-containing liquid.

[0007] The present invention has been made to solve the above problems. Therefore, an object of the present invention is to provide an ultrafine bubble generating apparatus and an ultrafine bubble generating method capable of efficiently forming a UMP-containing liquid with high purity.

[0008] In a first aspect of the present invention, there is provided a method for generating ultrafine bubbles, comprising: a generating step for generating ultrafine bubbles by causing a heating element provided in the liquid to generate heat to create film boiling at an interface between the liquid and the heating element; and a post-processing (post-processing) step for performing a predetermined post-processing of the ultrafine bubble liquid containing the ultrafine bubbles generated in the generation step.

[0009] In a second aspect of the present invention, there is provided an ultrafine bubble generating apparatus, comprising: a generating unit that generates ultrafine bubbles by causing a heating element provided in the liquid to generate heat to create film boiling at an interface between the liquid and the heating element; and a post-processing unit that performs predetermined post-processing of the ultrafine bubble liquid containing the ultrafine bubbles generated by the generating unit.

[0010] In a third aspect of the present invention, there is provided an ultrafine bubble liquid that contains ultrafine bubbles generated by a method for generating ultrafine bubbles, comprising: a generating step for generating ultrafine bubbles by causing a heating element provided in the liquid to generate heat to create film boiling at the interface separation between liquid and heating element; and a post-processing step for performing a predetermined post-processing of the ultrafine bubble liquid containing the ultrafine bubbles generated in the generation step.

[0011] Additional features of the present invention will become apparent from the following description of exemplary embodiments with reference to the accompanying drawings.

Brief Description of Drawings

[0012] Fig. 1 is a diagram illustrating an example of a TPC generating apparatus;

[0013] Fig. 2 is a schematic configuration diagram of a preprocessing unit;

[0014] Figs. 3A and 3B are a schematic diagram of a dissolution unit configuration and a diagram for describing dissolution states in a liquid;

[0015] Fig. 4 is a schematic configuration diagram of a T-TPC generating unit;

[0016] Figs. 5A and 5B are diagrams for describing particulars of a heating element;

[0017] Figs. 6A and 6B are diagrams for describing film boiling states on a heating element;

[0018] FIGS. 7A-7D are diagrams illustrating TFC generation states caused by film boiling bubble expansion;

[0019] FIGS. 8A-8C are diagrams illustrating TFC generation states caused by compression of a film boiling bubble;

[0020] Figs. 9A-9C are diagrams illustrating TFC generation states caused by reheating of a liquid;

[0021] FIGS. 10A and 10B are diagrams illustrating TFC generation states caused by shock waves generated by the disappearance of a film boiling bubble;

[0022] Figs. 11A-11C are diagrams illustrating an example of configurations of a post-processing unit;

[0023] FIG. 12 is a diagram illustrating a fourth post-processing engine; and

[0024] FIG. 13 is a diagram illustrating a fifth post-processing mechanism.

Detailed Description of Embodiments

<TPS Generator Configuration>

[0025] FIG. 1 is a diagram illustrating an example of a TPC generating apparatus applicable to the present invention. The TPC generating apparatus 1 of this embodiment includes a pretreatment unit 100, a dissolving unit 200, a T-TMP generating unit 300, a post-processing unit 400, and a manifold unit 500. Each unit performs a unique treatment of a liquid W such as tap water supplied to the preprocessing unit 100, in the above order, and the thus treated liquid W is collected as a T-UMP containing liquid by the collection unit 500. The functions and configurations of the units are described below. Although the particulars are described below, CMBs generated using film boiling caused by rapid heating are referred to as Thermal Ultrafine Bubbles (T-CMBs).

[0026] FIG. 2 is a schematic diagram of the configuration of the preprocessing unit 100. The pretreatment unit 100 of this embodiment performs degassing treatment of the supplied liquid W. The pretreatment unit 100 generally includes a degassing container 101, an irrigation (sprinkler) head 102, a depressurizing pump 103, a liquid inlet port 104, a liquid circulation path 105, and fluid outlet channel 106. For example, a liquid W such as tap water is supplied to the degassing container 101 from the liquid inlet 104 through the valve 109. In this process, an irrigation head 102 provided in the degassing container 101 sprays the liquid W in the degassing container 101 as a mist. The spray head 102 is designed to provide gasification of the liquid W; however, a centrifuge or the like can be used as a mechanism for providing a quick gasification effect.

[0027] When a certain amount of liquid W is stored in the degassing container 101 and then the depressurizing pump 103 is started with all valves closed, the already gasified gas components are discharged, and gasification and discharge of the gas components dissolved in the liquid W are also ensured. In this process, the internal pressure degassing container 101 can be discharged to about hundreds to thousands of Pa (1.0 torr - 10.0 torr) when monitored by pressure gauge 108. Gases to be removed by pretreatment unit 100 include, for example, nitrogen, oxygen, argon, carbon dioxide and etc.

[0028] The above-described degassing processing can be performed repeatedly on the same liquid W using the liquid circulation passage 105. More specifically, the sprinkler head 102 is operated with the valve 109 of the fluid inlet 104 and the valve 110 of the fluid outlet 106 and the valve 107 of the fluid circulation conduit 105 open. This enables the liquid W stored in the degassing container 101 and degassed once to be re-sprayed in the degassing container 101 from the sprinkler head 102. In addition, when the depressurizing pump 103 is driven, the gasification treatment with the sprinkler head 102 and the degassing treatment by the depressurizing pump 103 are performed repeatedly on the same liquid W. Each time the above-described processing using the liquid circulation channel 105 is repeated, it is possible to gradually reduce the content of gas components in the liquid W. Once the liquid W is obtained, degassed to the required purity, the liquid W is transferred to the block 200 dissolution through the liquid outlet channel 106 with the valve 110 open.

[0029] FIG. 2 illustrates a degassing unit 100 that relieves the pressure of a portion of the gas by gasifying the permeate; however, the method for degassing the solution is not limited thereto. For example, a heating and boiling method can be used to boil the liquid W to gasify the solute, or a film degassing method to increase the liquid-gas interface using hollow fibers. The SEPAREL series (manufactured by DIC Corporation) is available commercially as a hollow fiber degassing unit. The SEPAREL series uses poly (4-methylpentene-1) (PMP) for the hollow fiber starting material and is used to remove air bubbles from ink and the like, supplied mainly for the piezo head. In addition, two or more of an evacuation method, a heating and boiling method, and a film degassing method can be used together.

[0030] FIGS. 3A and 3B are a schematic diagram of the configuration of the dissolution unit 200 and a diagram for describing dissolution states in a liquid. The dissolving unit 200 is a unit for dissolving the desired gas in the liquid W supplied from the pretreatment unit 100. The dissolving unit 200 of this embodiment mainly includes a dissolving container 201, a rotary shaft 203 provided with a swivel plate 202, a liquid inlet 204, a gas inlet 205, a liquid outlet 205, and a pressure (compressor) pump 207.

[0031] The liquid W supplied from the pretreatment unit 100 is supplied to the dissolution container 201 through the liquid introduction port 204 and is stored therein. In this case, gas G is supplied to the dissolution container 201 through the gas inlet 205.

[0032] Once the predetermined amounts of liquid W and gas G are stored in the dissolution container 201, the compressor pump 207 is started, increasing the internal pressure of the dissolution container 201 to about 0.5 MPa. A safety valve 208 is disposed between the compressor pump 207 and the dissolution container 201. By means of the swivel plate 202 in the liquid rotated by the swivel shaft 203, the gas G supplied to the dissolution container 201 is converted into air bubbles, and the contact area between the gas G and the liquid W is increased , promoting dissolution in liquid W. This operation continues until the solubility of gas G reaches almost maximum solubility at saturation. In this case, a unit can be provided to lower the temperature of the liquid to dissolve the gas as much as possible. When the gas has low solubility, it is also possible to increase the internal pressure of the dissolution container 201 to 0.5 MPa or more. In this case, the material and the like of the container must be optimal for safety reasons.

[0033] After a liquid W in which the gas components are dissolved at a desired concentration is obtained, the liquid W is discharged through the liquid outlet 205 and supplied to the T-UMP generating unit 300. In this process, the back pressure valve 209 regulates the pressure of the fluid flow W, preventing the pressure from increasing unnecessarily during delivery.

[0034] FIG. 3B is a diagram schematically illustrating the dissolution states of the gas G placed in the dissolution container 201. The air bubble 2 containing the components of the gas G placed in the liquid W dissolves from the area in contact with the liquid W. The air bubble 2 is thus gradually compressed, and then the liquid 3 with the dissolved gas appears around the air bubble 2. Since the air bubble 2 is influenced lifting force in the liquid, the air bubble 2 can move to a position farther from the center of the liquid 3 with dissolved gas or be separated from the liquid 3 with dissolved gas, becoming a residual air bubble 4. More specifically, in the liquid W supplied to the T-UMP generating unit 300 through the liquid outlet channel 206, there is a mixture of air bubbles 2 surrounded by a liquid 3 with a dissolved gas, and air bubbles 2 and a liquid 3 with a dissolved gas, separated from each other.

[0035] The dissolved gas liquid 3 in the drawings means "a region of the liquid W in which the dissolution concentration of the gas G mixed therein is relatively high." In the gas components actually dissolved in the liquid W, the concentration of the gas components in the liquid 3 with dissolved gas is highest in the region surrounding the air bubble 2. In the case where the liquid 3 with dissolved gas is separated from the air bubble 2, the concentration of the gas components of the liquid 3 s the dissolved gas is highest in the center of the said region, and the concentration gradually decreases from the center. That is, although the dissolved gas region of the liquid 3 is shown in FIG. 3 as surrounded by a dashed line for ease of explanation, such a clear boundary does not actually exist. Additionally, in the present invention, a gas that cannot be completely dissolved can be considered to exist in the form of an air bubble in a liquid.

[0036] FIG. 4 is a schematic configuration diagram of a T-TPC generating unit 300. The T-UMP generating unit 300 generally includes a chamber 301, a liquid inlet 302, and a liquid outlet 303. The flow from the liquid inlet 302 to the liquid outlet 303 through the chamber 301 is generated by a flow pump, not shown. As the flow pump, various pumps can be used, including a diaphragm pump, a gear pump, and a screw pump. In the liquid W introduced from the liquid introduction channel 302, the liquid 3 with dissolved gas from the gas G supplied by the dissolution unit 200 is mixed.

[0037] An element substrate 12 provided with a heating element 10 is disposed on the lower section of the chamber 301. By a predetermined voltage pulse applied to the heating element 10, a film boiling bubble 13 (hereinafter also called film boiling bubble 13) is generated in the region in contact with the heating element 10. Then, due to the expansion and contraction of the film boiling bubble 13, an ultrafine bubble (UMP) 11 containing gas G is generated. As a result, a UMP containing liquid W containing a plurality of UMP 11 is discharged from the liquid outlet channel 303.

[0038] FIGS. 5A and 5B are diagrams for illustrating the detailed configuration of the heating element 10. FIG. 5A illustrates a close-up view of the heating element 10, and FIG. 5B illustrates a cross-sectional view of a wider region of the element substrate 12 including the heating element 10. ...

[0039] As illustrated in FIG. 5A, in the cell substrate 12 of this embodiment, a thermal oxide film 305 as a heat storage layer and an intermediate layer film 306 also serving as a heat storage layer are laminated on the surface of the silicon substrate 304. As the intermediate layer film 306, a SiO ₂ film or a SiN film can be used. A resistive layer 307 is formed on the surface of the intermediate layer film 306, and a wiring (wiring) 308 is partially formed on the surface of the resistive layer 307. The wiring 308 may be an Al alloy wiring of Al, Al-Si, Al-Cu, or the like. like that. On the surfaces of the wiring 308, the resistive layer 307, and the intermediate layer film 306, a protective layer 309 made of an SiO ₂ film or an Si ₃ n ₄ film is formed.

[0040] A cavitation-resistant film 310 for protecting the protective layer 309 from chemical and physical influences due to the heat generated by the resistive layer 307 is formed in and around the area on the surface of the protective layer 309 corresponding to the heat-affected area 311, which ultimately is the heating element 10. The area on the surface of the resistive layer 307, on which the wiring 308 is not formed, is the heat exposure portion 311 in which the resistive layer 307 generates heat. The heating portion of the resistive layer 307, on which the wiring 308 is not formed, functions as a heating element (heater) 10. As described above, layers in the element substrate 12 are sequentially formed on the surface of the silicon substrate 304 by a semiconductor manufacturing method, and the thermal action portion 311 is thus provided on a 304 silicon substrate.

[0041] The configuration illustrated in the drawings is an example, and various other configurations are applicable. For example, a configuration in which the layering order of the resistive layer 307 and the wiring 308 is reversed, and a configuration in which the electrode is connected to the bottom surface of the resistive layer 307 (a so-called plug-in electrode configuration) can be applied. In other words, as described later, any configuration can be used as long as the configuration allows the heat treatment portion 311 to heat the liquid to create film boiling in the liquid.

[0042] FIG. 5B is an example of a cross-sectional view of a region including a circuit connected to a wiring 308 in the element substrate 12. The n-type pocket area 322 and the p-type pocket area 323 are partially provided in the upper layer of the silicon substrate 304, which is a p-type conductor. In the region 322 of the n-type pocket, a p-MOS structure 320 is formed, and in the region 323 of the p-type pocket, an n-MOS structure 321 is formed by introducing and diffusing impurities by ion implantation and the like in conventional MOS technology.

[0043] The p-MOS 320 includes a source region 325 and a drain region 326 created by partially introducing n-type or p-type impurities into the top layer of the n-type pocket region 322, gate wiring 335, and so on. Gate wiring 335 is applied to a portion of the upper surface of the n-type pocket region 322, excluding the source region 325 and the drain region 326, with a gate insulating film 328 with a thickness of several hundred Å between the gate wiring 335 and the upper surface of the n-type pocket region 322.

[0044] The n-MOS structure 321 includes a source region 325 and a drain region 326 created by partially introducing n-type or p-type impurities into the top layer of the p-type pocket region 323, gate wiring 335, and so on. Gate wiring 335 is applied to a portion of the upper surface of the p-type pocket region 323, excluding the source region 325 and the drain region 326, with a gate insulating film 328 with a thickness of several hundred Å between the gate wiring 335 and the upper surface of the p-type pocket region 323. The gate wiring 335 is made of 3000 Å to 5000 Å CVD polycrystalline silicon. The logic (logic circuit) of the C-MOS is tuned with the p-MOS 320 and the n-MOS 321.

[0045] In the p-type pocket region 323, an n-MOS transistor 330 for driving an electrothermal conversion element (heating resistive element) is formed in a portion different from a portion including the n-MOS 321. The n-MOS transistor 330 includes a region Source 332 and drain region 331 partially provided in the upper layer of p-type pocket region 323 with impurity introduction and diffusion steps, gate wiring 333, and so on. The gate wiring 333 is applied to a part of the upper surface of the p-type pocket region 323, excluding the source region 332 and the drain region 331, with a gate insulating film 328 disposed between the gate wiring 333 and the upper surface of the p-type pocket region 323.

[0046] In this example, an NMOS transistor 330 is used as a transistor for driving the electrothermal conversion element. However, the transistor for driving is not limited to the n-MOS transistor 330, and any transistor can be used as long as the transistor has the ability to drive multiple electrothermal conversion elements individually and can realize the above-described precision configuration. Although, in this example, the electrothermal conversion element and the transistor for driving the electrothermal conversion element are formed on the same substrate, they can be formed separately on different substrates.

[0047] An oxide film separation region 324 is formed by oxidizing a region with a thickness of 5000 Å to 10000 Å between elements, such as between p-MOS 320 and n-MOS 321 and between n-MOS 321 and n-MOS transistor 330. Oxide separation region 324 film separates the elements. The portion of the separation region 324 of the oxide film corresponding to the portion 311 of the thermal effect functions as a heat storage layer 334, which is the first layer on the silicon substrate 304.

[0048] By CVD, an interlayer insulating film 336 including a PSG film, a BPSG film or the like with a thickness of about 7000 Å is formed on each surface of elements such as a p-MOS 320, an n-MOS 321, and an n-MOS transistor 330. After the interlayer insulating film 336 is flattened by heat treatment, an Al electrode 337 as the first wiring layer is formed in a contact hole passing through the interlayer insulating film 336 and the gate insulating film 328. On the surfaces of the interlayer insulating film 336 and the Al electrode 337, an interlayer insulating film 338 is formed by plasma CVD, including a SiO ₂ film with a thickness of 10,000 Å to 15,000 Å. On the surface of the interlayer insulating film 338, a resistive layer 307 including a TaSiN film with a thickness of about 500 Å is formed on the surface of the interlayer insulating film 338 by the method of co-sputtering in the regions corresponding to the thermal exposure region 311 and the n-MOS transistor 330. The resistive layer 307 is electrically connected to the Al electrode 337 in the vicinity of the drain region 331 through a through hole formed in the interlayer insulating film 338. On the surface of the resistive layer 307, Al wiring 308 is formed as a second wiring layer for conductive connection to each electrothermal conversion element. The protective layer 309 on the surfaces of the wiring 308, the resistive layer 307, and the interlayer insulating film 338 includes a 3000 Å thick SiN film formed by plasma CVD. The cavitation resistant film 310 applied to the surface of the protective layer 309 includes a thin film with a thickness of about 2000 Å, which is at least one metal selected from the group consisting of Ta, Fe, Ni, Cr, Ge, Ru, Zr, Ir etc. Various materials other than TaSiN described above, such as TaN, CrSiN, TaAl, WSiN and the like, can be used, provided that such material can induce film boiling in a liquid.

[0049] Figs. 6A and 6B are diagrams illustrating film boiling states when a given voltage pulse is applied to the heating element 10. In this case, a case of creating film boiling at atmospheric pressure has been described. In Fig. 6A, the horizontal axis represents time. The vertical axis in the lower graph represents the voltage applied to the heating element 10, and the vertical axis in the upper graph represents the volume and internal pressure of the film boiling bubble 13 generated by film boiling. On the other hand, FIG. 6B illustrates the states of the film boiling bubble 13 in relation to times 1-3 shown in FIG. 6A. Each of the conditions is described below in chronological order. CMPs 11 generated by film boiling, as described below, are mainly generated near the surface of the film boiling bubble 13. The states illustrated in FIG. 6B are states where the TPC 11 generated by the generating unit 300 is re-supplied to the dissolving unit 200 through the circulation path, and the liquid containing the TPC 11 is re-supplied to the liquid channel of the generating unit 300, as illustrated in FIG. one.

[0050] Prior to applying a voltage to the heating element 10, chamber 301 is maintained at substantially atmospheric pressure. After a voltage is applied to the heating element 10, film boiling is generated in the liquid in contact with the heating element 10, and the air bubble thus generated (hereinafter referred to as film boiling bubble 13) expands due to the high pressure from the inside (time 1). It is expected that the bubbling pressure (bubble formation during boiling) in this process is about 8-10 MPa, which is a value close to the saturated vapor pressure of water.

[0051] The time for applying the voltage (pulse duration) is about 0.5 μs - 10.0 μs, and the film boiling bubble 13 expands by inertia from the pressure obtained at time 1 even after the voltage is applied. However, the negative (rarefied) pressure generated during the expansion gradually increases inside the film boiling bubble 13, and the negative pressure acts in such a direction that the film boiling bubble 13 contracts. After some time, the volume of the film boiling bubble 13 becomes maximum at time 2, when the inertial force and the negative pressure are balanced, and then the film boiling bubble 13 is rapidly compressed by the negative pressure.

[0052] When the film boiling bubble 13 disappears, the film boiling bubble 13 does not disappear over the entire surface of the heating element 10, but in one or more very small areas. For this reason, an even greater force on the heating element 10 than when generating bubbles at time 1 is generated in a very small region in which the film boiling bubble 13 disappears (time 3).

[0053] The generation, expansion, contraction and disappearance of the film boiling bubble 13, as described above, are repeated each time a voltage pulse is applied to the heating element 10, and each time new TFCs 11 are generated.

[0054] The states of generation of the TFC 11 in each process of generation, expansion, contraction, and disappearance of the film boiling bubble 13 will now be described in detail with reference to FIGS. 7A to 10B.

[0055] FIGS. 7A-7D are diagrams schematically illustrating TFC 11 generation states caused by the generation and expansion of the film boiling bubble 13. 7A illustrates a state before a voltage pulse is applied to the heating element 10. A liquid W in which liquids 3 are mixed with a dissolved gas flows into the chamber 301.

[0056] FIG. 7B illustrates a state where a voltage is applied to the heating element 10 and a film boiling bubble 13 is uniformly generated almost everywhere in the region of the heating element 10 in contact with the liquid W. When a voltage is applied, the surface temperature of the heating element 10 rapidly rises at a rate 10 ° C / μs. Film boiling occurs at a point in time when the temperature reaches almost 300 ° C, and thus a film boiling bubble 13 is generated.

[0057] Then, the surface temperature of the heating element 10 continues to increase to about 600-800 ° C during the application of the pulse, and the liquid around the film boiling bubble 13 is also rapidly heated. In Fig. 7B, the region of liquid that is around the film boiling bubble 13 and should be heated rapidly is indicated as the not yet bubble-forming high temperature region 14. The liquid 3 with dissolved gas within the not yet bubble-forming high temperature region 14 exceeds the thermal dissolution limit and evaporates. turning into UMP. The air bubbles evaporated in this way have diameters of about 10 nm - 100 nm and a high energy of the gas-liquid interface (interphase interaction). Thus, air bubbles float independently in the liquid W without disappearing in a short time. In this embodiment, the air bubbles generated by the heat from generation to expansion of the film boiling bubble 13 are referred to as the first UMP 11A.

[0058] FIG. 7C illustrates a state where the film boiling bubble 13 expands. Even after a voltage pulse is applied to the heating element 10, the film boiling bubble 13 continues to expand by inertia of the force obtained from its generation, and the high-temperature region 14, which does not yet form bubbles, also shifts and expands by inertia. More specifically, as the film boiling bubble 13 expands, the dissolved gas liquid 3 within the not yet bubble-forming high-temperature region 14 evaporates as a new air bubble and becomes the first UMP 11A.

[0059] Fig. 7D illustrates a state where the film boiling bubble 13 has a maximum volume. When the film boiling bubble 13 expands by inertia, the negative pressure inside the film boiling bubble 13 gradually increases with the expansion, and the negative pressure acts to compress the film boiling bubble 13. At the point in time when the negative pressure and the inertial force are balanced, the volume of the film boiling bubble 13 becomes maximum, and then compression begins.

[0060] In the compression step of the film boiling bubble 13, there are TPCs generated by the processes illustrated in FIGS. 8A-8C (second TPCs 11B) and TPCs generated by the processes illustrated in FIGS. 9A-9C (third TPCs 11C). These two processes are believed to be running at the same time.

[0061] FIGS. 8A-8C are diagrams illustrating TFC 11 generation states caused by compression of the film boiling bubble 13. 8A illustrates a state where the film boiling bubble 13 starts to compress. Although the film boiling bubble 13 begins to contract, the surrounding liquid W still has an inertial force in the direction of expansion. As a consequence, the inertial force acting away from the heating element 10 and the force directed towards the heating element 10 caused by the compression of the film boiling bubble 13 act in the surrounding area extremely close to the film boiling bubble 13, and this area is depressurized. This area is indicated in the figures as the yet non-bubble forming negative pressure area 15.

[0062] The dissolved gas liquid 3 within the not yet bubble-forming negative pressure region 15 exceeds the pressure dissolution limit and evaporates into an air bubble. The air bubbles evaporated in this way have diameters of about 100 nm and therefore float independently in the liquid W without disappearing in a short time. In this embodiment, the air bubbles vaporized by pressure during the compression of the film boiling bubble 13 are referred to as the second UMP 11B.

[0063] Fig. 8B illustrates the process of compressing the film boiling bubble 13. The compression speed of the film boiling bubble 13 is accelerated by negative pressure, and the negative pressure region 15 not yet bubble-forming also moves with the compression of the film boiling bubble 13. More specifically, in the process of compression of the film boiling bubble 13 of the liquid 3 with dissolved gas within a part of the still non-bubble-forming negative pressure regions 15 are deposited one after the other and become the second UMP 11B.

[0064] Fig. 8C illustrates the state just before the disappearance of the film boiling bubble 13. Although the speed of movement of the surrounding liquid W is also increased by the accelerated compression of the film boiling bubble 13, the pressure loss occurs due to the resistance of the flow channel in the chamber 301. As a result, the area occupied by the negative pressure region 15 that does not yet form bubbles is further increased, and a number of second CPS 11B are generated. ...

[0065] Figs. 9A-9C are diagrams illustrating states of generation of TFC by reheating the liquid W during compression of the film boiling bubble 13. Fig. 9A illustrates a state where the surface of the heating element 10 is covered with a shrink film boiling bubble 13.

[0066] Fig. 9B illustrates a state where the compression of the film boiling bubble 13 continues and a part of the surface of the heating element 10 comes into contact with the liquid W. In this state, there is heat stored on the surface of the heating element 10, but this heat is insufficient to cause the film boiling, even if the liquid W comes into contact with this surface. The region of the liquid to be heated by coming into contact with the surface of the heating element 10 is indicated in the figures as the not yet bubble-forming reheated region 16. Although film boiling does not occur, the dissolved gas liquid 3 within the not yet bubble-forming reheated region 16 exceeds thermal dissolution limit and evaporates. In this embodiment, the air bubbles generated by reheating the liquid W during the compression of the film boiling bubble 13 are referred to as the third UMP 11C.

[0067] FIG. 9C illustrates a state where the compression of the film boiling bubble 13 continues further. The smaller the film boiling bubble 13, the larger the area of the heating element 10 in contact with the liquid W, and the third UMP 11C are generated until the film boiling bubble 13 disappears.

[0068] FIGS. 10A and 10B are diagrams illustrating TFC generation states caused by the effect of the disappearance of film boiling bubble 13 generated by film boiling (ie, a type of cavitation). Fig. 10A illustrates the state just before the disappearance of the film boiling bubble 13. In this state, the film boiling bubble 13 is rapidly compressed by the internal negative pressure, and the still non-bubble-forming negative pressure region 15 surrounds the film boiling bubble 13.

[0069] FIG. 10B illustrates the state immediately after the film boiling bubble 13 disappears at time p. When the film boiling bubble 13 disappears, the acoustic waves run concentrically from the point p as the starting point under the influence of such disappearance. Acoustic wave is a generic term for an elastic wave that travels through anything, be it a gas, a liquid, or a solid. In this embodiment, the compression waves of the liquid W, which are the high pressure surface 17A and the low pressure surface 17B of the liquid W, propagate alternately.

[0070] In this case, the liquid 3 with dissolved gas within the still not bubble-forming region 15 of negative pressure resonates due to shock waves created when the film boiling bubble 13 disappears, and the liquid 3 with dissolved gas exceeds the dissolution limit under pressure, and at the moment as long as the low pressure surface 17B passes therethrough, a phase transition is performed. More specifically, some of the air bubbles evaporate in the not yet bubble-forming negative pressure region 15 simultaneously with the disappearance of the film boiling bubble 13. In this embodiment, the air bubbles generated by the shock waves generated when the film boiling bubble 13 disappears are referred to as the fourth CMP 11D.

[0071] The fourth CMD 11D generated by the shock waves generated by the disappearance of the film boiling bubble 13 suddenly appear in a very short time (1 μs or less) in a very narrow region in the form of a thin film. The diameter is rather smaller than the diameter of the first and third CMDs, and the energy of the gas-liquid interface is higher than that of the first and third CMFs. For this reason, the fourth TPCs 11D are considered to have different characteristics from those of the first to third TPCs 11A to 11C, and create different effects.

[0072] Additionally, the fourth TPCs 11D are uniformly generated in many parts of the concentric sphere region in which the shock waves propagate, and the fourth TPCs 11D uniformly exist in the chamber 301 from the moment they are generated. Although many of the first to third TPCs already exist during the generation of the fourth TPCs 11D, the presence of the first to third TPCs does not appreciably affect the generation of the fourth TPCs 11D. It is also believed that the first to third TPCs do not disappear due to the generation of the fourth TPC 11D.

[0073] As described above, it is expected that RPCs 11 are generated in several stages from generation to disappearance of film boiling bubble 13 due to heat generation by heating element 10. First RPCs 11A, second RPCs 11B and third RPCs 11C are generated near the surface of the film boiling bubble, generated by film boiling. In this case, “near” means an area within about 20 µm from the surface of the film boiling bubble. The fourth 11D SAEs are generated in the area through which the shock waves propagate when the air bubble disappears. Although the above example illustrates the steps until the film boiling bubble 13 disappears, the method for generating the TFC is not limited thereto. For example, with the generated film boiling bubble 13 communicating with atmospheric air before the bubble disappears, UMP can also be generated if the film boiling bubble 13 does not reach the disappearing stage.

[0074] The remaining properties of the TPC are described below. The higher the temperature of the liquid, the lower the dissolution capacity of the gas components, and the lower the temperature, the higher the dissolution capacity of the gas components. In other words, the phase transition of the dissolved gas components is stimulated and it becomes easier to generate the CMF as the temperature of the liquid rises. The temperature of the liquid and the solubility of the gas are inversely related, and the gas exceeding the solubility at saturation is converted into air bubbles and appears in the liquid as the temperature of the liquid rises.

[0075] Therefore, when the temperature of the liquid rapidly rises from the normal temperature, the solubility decreases without stopping, and the generation of the UMP starts. Thermal dissolution capacity decreases as the temperature rises and some UMP is generated.

[0076] In contrast, when the temperature of the liquid decreases from normal temperature, the gas dissolving capacity increases, and the generated UMPs are more likely to liquefy. However, this temperature is sufficiently lower than the normal temperature. Additionally, since once generated UFMs have a high internal pressure and a high energy of the gas-liquid interface, even if the temperature of the liquid decreases, it is highly unlikely that a high enough pressure is created to destroy such a gas-liquid interface. In other words, once generated UMP does not disappear easily, provided that the liquid is stored at normal temperature and normal pressure.

[0077] In this embodiment, the first TPCs 11A described with reference to FIGS. 7A-7C and the third TPCs 11C described with reference to FIGS. 9A-9C may be described as TPCs that are generated using such thermal capability. gas dissolution.

[0078] On the other hand, depending on the pressure and the dissolution capacity of the liquid, the higher the pressure of the liquid, the higher the dissolution capacity of the gas, and the lower the pressure, the lower the dissolution capacity. In other words, a phase transition to a gas for a liquid with a dissolved gas dissolved in this liquid is stimulated, and the generation of UFM becomes easier when the pressure of the liquid is reduced. When the pressure of the liquid falls below normal pressure, the dissolution capacity immediately decreases and the generation of UFM begins. The ability to dissolve under pressure decreases as the pressure decreases and some UMP is generated.

[0079] In contrast, when the pressure of the liquid rises above normal pressure, the gas dissolving capacity increases and the generated UMP is more likely to be liquefied. However, this pressure is significantly higher than atmospheric pressure. Additionally, since once generated UFMs have high internal pressure and high energy of the gas-liquid interface, even when the pressure of the liquid increases, it is highly unlikely that a high enough pressure is generated to destroy such a gas-liquid interface. In other words, once generated UMPs do not easily disappear if the liquid is stored at normal temperature and normal pressure.

[0080] In this embodiment, the second TPCs 11B described with reference to FIGS. 8A-8C and the fourth TPCs 11D described with reference to FIGS. 10A-10C may be described as TPCs that are generated using such dissolution ability gas under pressure.

[0081] These first to fourth TPCs generated in various cases are described above separately; however, the above-described generation cases occur concurrently with the film boiling event. Thus, at least two types of the first to fourth TPCs can be generated simultaneously, and these generation cases can interact to generate TPCs. It should be noted that the common thing for all generation cases is that they are caused by a change in the volume of the film boiling bubble generated by the film boiling phenomenon. In this specification, a method for generating TFA using film boiling caused by rapid heating, as described above, is referred to as a thermally ultrafine bubble (T-UMP) generating method. Additionally, the UMP generated by the T-UMP generating method is called the T-UMP, and the liquid containing the T-UMP generated by the T-UMP generating method is called the T-UMP containing fluid.

[0082] Nearly all of the air bubbles generated by the T-UMP generating method are 1.0 μm or less, and it is unlikely that millibubbles and microbubbles will be generated. That is, the T-TPC generating method enables the predominantly and efficient TPC generation. Additionally, the T-UMP generated by the T-UMP generating method have a higher gas-liquid interface energy than the UMP generated by the conventional method, and the T-UMP does not easily disappear when stored at normal temperature and pressure. Moreover, even if new T-CMFs are generated during new film boiling, it is possible to prevent the disappearance of the already generated T-CMFs due to the effect of the new generation. That is, we can say that the amount and concentration of T-UMP contained in the liquid containing T-UMP have hysteresis properties depending on the number of times the film boiling occurs in the liquid containing T-UMP. In other words, it is possible to control the concentration of the T-UMP contained in the liquid containing the T-UMP by controlling the number of heating elements provided in the T-UMP generating unit 300 and the number of applications of the voltage pulse to the heating elements.

[0083] Reference is made to FIG. 1 again. As soon as the UMP containing liquid W with the desired UMP concentration is formed in the T-UMP generating unit 300, the UMP containing liquid W is supplied to the post-processing unit 400.

[0084] FIGS. 11A-11C are diagrams illustrating configuration examples of the post-processing unit 400 of this embodiment. The post-processing unit 400 of this embodiment removes impurities in the UMP-containing liquid W step by step in order from inorganic ions, organic matter, and insoluble solids.

[0085] FIG. 11A illustrates a first post-processing mechanism 410 that removes inorganic ions. The first post-processing mechanism 410 includes an exchange container 411, cation exchange resins 412, a liquid inlet 413, a manifold 414, and a liquid outlet 415. The exchange container 411 contains cation exchange resins 412. The UMP-containing liquid W, formed by the T-UMP generating unit 300, is introduced into the exchange container 411 through the liquid inlet channel 413 and is absorbed by the cation exchange resins 412, so that the cations in the form of impurities are removed. Such impurities include metallic materials and the like peeled off from the element substrate 12 of the T-UMP generating unit 300. For example, metallic materials can be substances such as SiO ₂ , SiN, SiC, Ta, Al ₂ O ₃ and Ta ₂ O ₅ , an amorphous alloy containing Si, Al, W, Pt, Pd, Ta, Fe, Cr, Ni and the like, and platinum group metals such as Ir and Ru.

[0086] The cation exchange resins 412 are synthetic resins in which a functional group (ion exchange group) is incorporated into a high polymer matrix having a three-dimensional network, and the outer shape of the synthetic resins is spherical particles of about 0.4-0.7 mm. A common high polymer matrix is a copolymer of styrene and divinylbenzene, and the functional group may be, for example, from the methacrylic acid series and the acrylic acid series. However, the above material is an example. Provided that the material can effectively remove the required inorganic ions, the above material can be replaced with other materials. The UMP-containing liquid W absorbed in the cation exchange resins 412 for removing inorganic ions is collected by the collection line 414 and transferred to the next stage (stage) through the liquid outlet channel 415. In this process, in the present embodiment, it is not necessary to remove all of the inorganic ions contained in the UMP-containing liquid W supplied from the liquid introduction passage 413, provided that at least a portion of the inorganic ions is removed.

[0087] FIG. 11B illustrates a second post-processing engine 420 that removes organic matter. The second post-processing mechanism 420 includes a collection container 421, a purge filter 422, a vacuum pump 423, a valve 424, a liquid inlet 425, a liquid outlet 426, and an air suction channel 427. The interior of the collection container 421 is divided by the purification filter 422 into two, upper and lower, regions. The liquid inlet 425 is connected to the upper region of both the upper and lower regions, and the air intake channel 427 and the liquid outlet 426 are connected to the lower region. As soon as the vacuum pump 423 is operated with the valve 424 closed, the air in the collection container 421 is discharged through the air suction port 427, bringing the pressure inside the collection container 421 to negative pressure, and then the UMP containing liquid W is introduced from the liquid inlet 425. Then, the UMP-containing liquid W, from which impurities have been removed by the cleaning filter 422, is accumulated in the collection container 421.

[0088] Impurities removed by the purge filter 422 include organic materials that may be mixed in the pipe or any block, such as, for example, organic compounds including silicon, siloxane, and epoxy. The filter film used for the purification filter 422 includes a sub-micron mesh filter (filter with a mesh diameter of 1 μm or less) that can remove bacteria, and an nm mesh filter that can remove viruses. A purification filter with such a small hole diameter can remove air bubbles larger than the hole diameter of the filter. In particular, there may be a case where the filter becomes clogged with small air bubbles trapped in the filter holes (mesh), which can slow down the filtration rate. However, as described above, most of the air bubbles generated by the T-UMP generating method described in the present embodiment have a diameter of 1 μm or less, and it is unlikely that millibubbles and microbubbles will be generated. That is, since the probability of generating millibubbles and microbubbles is very low, it is possible to suppress the deceleration of the filtration rate due to the absorption of air bubbles on the filter. For this reason, it is advantageous to use a purification filter 422 equipped with a filter with a mesh diameter of 1 μm or less in a system performing a T-UMP generating method.

[0089] Filtration examples applicable in this embodiment may be so-called dead-end filtration and tangential (cross-flow) filtration. In dead-end filtration, the flow direction of the supplied liquid and the flow direction of the filtered liquid passing through the filter openings are the same, and more specifically, the flow directions coincide with each other. In contrast, in tangential filtration, the feed liquid flows in a direction along the surface of the filter, and more specifically, the flow direction of the feed liquid and the flow direction of the filtered liquid passing through the filter openings intersect with each other. It is preferable to use tangential filtration to suppress the absorption of air bubbles at the filter openings.

[0090] After a certain amount of UMP containing liquid W has been accumulated in the collection container 421, the vacuum pump 423 is stopped and valve 424 is opened to transfer the T-UMP containing liquid from the collection container 421 to the next stage through the liquid outlet channel 426. Although a vacuum filtration method is used here as a method for removing organic impurities, for example, a gravity filtration method and pressure filtration can also be used as a filtration method using a filter.

[0091] FIG. 11C illustrates a third post-processing mechanism 430 that removes insoluble solids. The third post-processing mechanism 430 includes a deposition container 431, a liquid inlet 432, a valve 433, and a liquid outlet 434.

[0092] First, a predetermined amount of the UMP-containing liquid W is supplied to the deposition container 431 through the liquid introduction port 432 with the valve 433 closed and held there for some time. In this case, the solids in the UMP-containing liquid W settle to the bottom of the deposition container 431 by gravity. Among the bubbles in the UMP-containing fluid, relatively large bubbles, such as microbubbles, rise to the surface of the fluid due to the buoyancy in the fluid and are also removed from the UMP-containing fluid. After sufficient time has elapsed, valve 433 is opened and the UMP-containing liquid W, from which solids and large bubbles have been removed, is transferred to the manifold block 500 through the liquid outlet 434. An example of the application of three post-processing engines is shown sequentially in this embodiment; however, it is not limited thereto, and the order of the three post-processing engines can be changed, or at least one required post-processing engine can be used.

[0093] With the above-described removal treatment to remove impurities included in the post-processing, it is possible to increase the purity of the T-UMP contained in the formed T-UMP containing liquid.

[0094] Reference is made to FIG. 1 again. The T-UMP-containing liquid W, from which impurities are removed by the post-processing unit 400, can be directly transferred to the collection unit 500, or can be returned to the dissolution unit 200 again, realizing a circulation system. In the second case, the post-processing unit 400 functions as a unit performing pre-processing on the liquid supplied to the dissolution unit 200. In the case where the T-UMP-containing liquid is returned to the dissolution unit 200 again after the T-UMP is generated, the dissolution concentration of the gas of the T-UMP containing liquid W, which decreases due to the generation of the T-UMP, may increase. It is preferable that the concentration of the dissolving gas can again be compensated to saturation by the dissolving unit 200. If new T-TFCs are generated by the T-TFC generating unit 300 after compensation, it is possible to further increase the concentration of T-TFCs contained in the T-TFC-containing fluid with the above-described properties. Thus, it is possible to increase the concentration of the UMP contained by a series of circulations through the dissolving unit 200, the T-UMP generating unit 300, and the post-processing unit 400, and it is possible to transfer the UMP-containing liquid W to the collection unit 500 after a predetermined concentration of the contained UMP is obtained. This embodiment shows a form in which the UMP-containing liquid processed by the post-processing unit 400 is returned to the dissolving unit 200 and circulated; however, it is not limited to this, and the liquid containing TPC, after passing through the T-T-UMP generating unit, for example, may be returned to the dissolving unit 200 before being fed to the post-processing unit 400, such that post-processing is performed by the post-processing unit 400 after the concentration of T- UMP increases, for example, through several circulations.

[0095] The effect of returning the generated T-UMP containing fluid W to the dissolving unit 200 is now simply described again, according to the specific verification by the inventors. First, 10,000 units of heating elements 10 were placed on the element substrate 12 in the T-UMP generating unit 300. Commercial pure water was used as the liquid W, and the liquid W flowed in the chamber 301 of the T-UMP generating unit 300 at a flowing fluid rate of 1.0 liter / hour. In this state, a voltage pulse with a voltage of 24 V and a pulse width of 1.0 μs was applied to each of the heating elements at an excitation frequency of 10 kHz.

[0096] The formed T-UMP containing liquid W did not return to the dissolution unit 200 and was collected by the manifold block 500, or the number of circulations was one and approximately 3.6 trillion UMP units per 1.0 ml were confirmed in the T-UMP containing liquid W. collected by the manifold block 500.On the other hand, as a result of performing ten times the operation of returning the T-UMP containing liquid W to the dissolution block 200, or as a result of ten circulations, approximately 36 trillion UMP units per 1.0 ml were confirmed in the T-UMP containing liquid W collected by the manifold block 500. In other words, it was confirmed that the concentration of the contained UMP increases approximately proportionally to the number of circulations. The above-described UMP density was obtained by counting the UMP 11 with a diameter of less than 1.0 μm contained in the UMP-containing liquid W of a given volume using a meter manufactured by Shimadzu Corporation (model number SALD-7500).

[0097] As described above, when the liquid is circulated through the dissolving unit 200, the T-CFC generation unit 300 and the post-processing unit 400 by the circulation path in this order, it is possible to form a liquid with a desired concentration of the CFC.

[0098] The collection unit 500 collects and stores the UMP-containing fluid W transferred from the post-processing unit 400. The T-UMP-containing fluid collected by the manifold block 500 is a high-purity UMP-containing liquid W from which various impurities have been removed.

[0099] In the manifold block 500, the UMP containing fluid W can be classified according to the T-UMP size by performing some filtration processing steps. Since it is expected that the temperature of the T-CMP-containing liquid W is higher than normal temperature, the manifold block 500 may be provided with a cooling block. A cooling unit may be provided for a portion of the post-processing unit 400.

[0100] A schematic description of the TPC generating device 1 is given above; however, it will be understood that the illustrated blocks can be changed and not all of them need to be provided. Depending on the type of liquid W and gas G used and the intended use of the generated T-UMP containing liquid, a part of the above-described blocks may be excluded or another block other than the above-described blocks may be added.

[0101] For example, when the gas to be contained in the UMP is atmospheric air, the degassing unit as the pretreatment unit 100 and the dissolving unit 200 may be omitted. On the other hand, in the event that several types of gases are to be contained in the UMP, another dissolution unit 200 may be added. It is also possible to integrate the functions of some of the blocks illustrated in FIG. 1 into one block. For example, the dissolving unit 200 and the T-TSC generating unit 300 can be integrated with each other by placing the heating element 10 in the dissolving container 201 illustrated in FIGS. 3A and 3B. In this case, the dissolution of the gas and the formation of the T-UMP containing the gas are performed simultaneously in a single unit.

[0102] The impurity removal units, as described in FIGS. 11A-11C, may be provided upstream of the T-TPC generating unit 300 as part of the preprocessing unit, or may be provided both upstream and downstream of it. When the liquid supplied to the TPC generating device is tap water, rainwater, contaminated water, or the like, organic and inorganic impurities may be included in the liquid. If such a liquid W including impurities is supplied to the T-UMP generating unit 300, there is a risk of deterioration of the heating element 10 and stimulation of the salting out phenomenon. With the mechanisms illustrated in FIGS. 11A to 11C provided upstream of the T-UMP generating unit 300, it is possible to remove the above-described impurities in advance and more efficiently form a high purity UMP-containing liquid.

<Modification of the post-processing unit>

[0103] FIG. 12 illustrates a fourth post-processing engine 450 that may be added or replaced by each post-processing unit 400 described above. The fourth post-processing mechanism 450 is an up-processing unit that uses ultrasonic vibrations to further increase the amount of T-UMP contained in the T-UMP containing fluid W.

[0104] The fourth post-processing mechanism 450 includes a storage container 451, a vibration generating unit 455, a liquid introduction port 452, a valve 453, and a liquid discharge port 454. Vibration generating unit 455 includes cable 456, transducer 457, power amplifier 458, and horn 459, and the power supplied through cable 456 is converted by transducer 457 into mechanical vibration amplitude and then increased by power amplifier 458 causing horn 459 to vibrate.

[0105] In the case of operation of the post-processing mechanism 450, first, the T-CMP-containing liquid W is stored (accumulated) in the storage container 451 through the liquid introduction port 452 with the valve 453 closed. The volume of the T-CMP-containing liquid W to be stored is approximately the volume, which at least allows the end of the tip of the horn 459 to be placed in the T-UMP-containing liquid W. Then, with the stored T-UMP-containing liquid W and the storage container open to atmospheric air, the vibration generating unit 455 is actuated to vibrate of the horn 459 placed in the T-CMP-containing liquid W. Therefore, ultrasonic vibrations are generated in the T-CMP-containing liquid W, into which the end of the tip of the horn 459 is placed, and the number of the T-CMP increases.

[0106] In this process, for efficiency, the vibration generating unit 455 is preferably operated multiple times at predetermined intervals for each predetermined time. It is possible to regulate the concentration of the contained T-UMP by changing the frequency and time period and the number of vibrations of the 459 horn.

[0107] The vibration generating unit 455 is stopped, and the valve 453 is opened after repeating a predetermined number of vibrations for a predetermined period of time, and then the T-UMP containing liquid W, adjusted to have the required concentration of contained substances, is transferred to the collection unit 500 through the liquid outlet channel 454 ...

[0108] The following describes the details of a specific verification using the T-TPC generating unit 300 and the post-processing unit 400 including the fourth post-processing engine 450 by the inventors. First, 10,000 units of heating elements 10 were placed on the element substrate 12 in the T-UMP generating unit 300. Commercial pure water was used as the liquid W, and the liquid W flowed in the chamber 301 of the T-UMP generating unit 300 at a flowing fluid rate of 1.0 liter / hour. In this state, a voltage pulse with a voltage of 24 V and a pulse width of 1.0 μs was applied to each of the heating elements at a driving frequency of 10 kHz.

[0109] The formed T-UMP containing liquid W was directly collected by the collection unit 500, and 3.6 trillion UMP units per 1.0 ml were confirmed in the collected T-UMP containing liquid W by checking the concentration of the UMP contained. On the other hand, as a result of feeding the formed T-UMP-containing fluid W into the fourth post-processing mechanism 450 and performing ten times the operation of vibration in the horn 459 at 100 kHz, 80 W for one second, approximately 72 trillion UMP units per 1.0 ml were confirmed. in the collected T-CMD-containing liquid W. In other words, the concentration of the contained CMF can be increased by applying ultrasonic vibrations by the fourth post-processing mechanism 450. The above-described UFD number density was obtained by counting the UFD 11 with a diameter less than 1.0 μm contained in the UFD-containing liquid W of a given volume using a meter manufactured by Shimadzu Corporation (model number SALD-7500).

[0110] An example of a preferable condition for increasing the TFC by applying ultrasonic vibrations to the T-TFC fluid like this embodiment is described below. The ultrasonic horn is placed in water containing T-UMP, communicating with atmospheric air in a container, and within one to five seconds the operation of vibration of the horn is performed at 50-500 kHz, 50-100 W. More preferably, the operation is repeated about two to ten times. In the case of application of ultrasound outside the container for storing the liquid containing T-UMP through the container, the operation of vibration of the horn at 1-10 kHz, 10-50 W is performed for 20-50 seconds with the inside of the container communicating with atmospheric air. Alternatively, the application is repeated approximately two to ten times over five to ten seconds.

[0111] In comparison, UMP was practically not confirmed in the liquid collected in the case where industrial pure water was directly supplied to the fourth post-processing mechanism 450 and ultrasonic vibrations identical to the above were applied. Thus, the fourth post-processing mechanism 450 applying ultrasonic vibrations is not designed to generate new UMP in the fluid containing the UMP, but has the function of increasing the number of UMP in the fluid already containing the UMP.

[0112] FIG. 13 illustrates a fifth post-processing engine 460 that may be added or replaced by the above-described post-processing unit 400. The fifth post-processing mechanism 460 is an up-processing unit that uses high intensity focused ultrasound (HIFU) to further increase the amount of T-UMP contained in the T-UMP containing fluid W.

[0113] The fifth post-processing mechanism 460 includes a storage container 461, a vibration generating unit 465, a liquid introduction port 462, a valve 463, and a liquid discharge port 464. Vibration generating unit 465 includes cable 466, transducer 467, and ultrasonic probe 468. After power is supplied through cable 466, transducer 467 converts the power to mechanical vibration frequencies, and then ultrasonic probe 468 generates ultrasound in the megahertz frequency band. The generated ultrasound is focused at a position at a distance of about a few mm to several tens of mm from the ultrasonic probe 468, and rapid heating and cavitation is induced at the focusing site.

[0114] This rapid heating and cavitation causes the CMF around the focal point to oscillate and split depending on the condition. In addition, in the case where ultrasound generation by the ultrasonic probe 468 continues, the UMPs around the focal point are destroyed, and as a result, more UMPs are generated.

[0115] The vibration generating unit 465 is stopped and the valve 463 is opened after a predetermined time from the ultrasound generation, and then the T-UMP containing liquid W, adjusted to have the desired concentration of contained substances, is transferred to the collection unit 500 through the liquid outlet 464.

[0116] The following describes the details of a specific verification using a T-TPC generating unit 300 and a post-processing unit 400 including a fifth post-processing engine 460 by the inventors. First, 10,000 units of heating elements 10 were placed on the element substrate 12 in the T-UMP generating unit 300. Commercial pure water was used as the liquid W, and the liquid W flowed in the chamber 301 of the T-UMP generating unit 300 at a flowing fluid rate of 1.0 liter / hour. In this state, a voltage pulse with a voltage of 24 V and a pulse width of 1.0 μs was applied to each of the heating elements at a driving frequency of 10 kHz.

[0117] The formed T-UMP containing liquid W was directly collected by the collection unit 500, and 3.6 trillion UMP units per 1.0 ml were confirmed in the collected T-UMP containing liquid W by checking the concentration of the UMP contained. On the other hand, as a result of feeding the formed T-UMP containing liquid W into the fifth post-processing mechanism 460 and generating ultrasound with an ultrasonic probe 468 at 3.0 MHz, 36 watts for 20 seconds, approximately 10.8 trillion UMP units per 1.0 ml confirmed in the collected T-CMF-containing liquid W. In other words, the concentration of the contained CMF can be increased by applying focused ultrasound by the fifth post-processing mechanism 460. The above-described UMP density was obtained by counting the UMP 11 with a diameter of less than 1.0 μm contained in the UMP-containing liquid W of a given volume using a meter manufactured by Shimadzu Corporation (model number SALD-7500).

[0118] In comparison, UMP was practically not confirmed in the liquid collected in the case where industrial pure water was directly supplied to the fifth post-processing mechanism 460, and focused ultrasound identical to the above was applied. Thus, the fifth post-processing mechanism 460, applying focused ultrasound, is not designed to generate new UMP in a fluid containing UMP, but has the function of increasing the amount of UMP in a fluid already containing UMP.

<Liquid and Gas Applicable for Liquid Containing T-UMP>

[0119] A liquid W used to form a T-UMP containing liquid is now described. The liquid W used in this embodiment is, for example, pure water, ion exchange water, distilled water, bioactive water, magnetoactive water, lotion, tap water, sea water, river water, purified and waste water, lake water, ground water , rainwater, etc. A mixed liquid containing the above liquid and the like can also be used. A mixed solution containing water and a soluble organic solvent can also be used. The soluble organic solvent used when mixed with water is not particularly limited; however, the following may represent a specific example of it. A group of 1-4 carbon alcohols including methyl alcohol, ethyl alcohol, n-propyl alcohol, isopropyl alcohol, n-butyl alcohol, sec-butyl alcohol, and t-butyl alcohol. An amide group including n-methyl-2-pyrrolidone, 2-pyrrolidone, 1,3-dimethyl-2-imidazolidinone, N, N-dimethylformamide, and N, N-dimethylacetamide. The ketone group or the ketone group, including acetol and diacetone alcohol. A group of cyclic ethers including tetrahydrofuran and dioxane. A group of glycols including ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, 1,5-pentanediol, 1,2-hexanediol, 1, 6-hexanediol, 3-methyl-1,5-pentanediol, diethylene glycol, triethylene glycol and thiodiglycol. Polyhydric alcohol lower alkyl ether group including ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutylether ether a simple ether of triethylene glycol. A group of polyalkylene glycols including polyethylene glycol and polypropylene glycol. A group of triols including glycerol, 1,2,6-hexanetriol and trimethylpropane. These soluble organic solvents can be used individually, or two or more of them can be used together.

[0120] The gas component that can be introduced into the dissolution unit 200 is, for example, hydrogen, helium, oxygen, nitrogen, methane, fluorine, neon, carbon dioxide, ozone, argon, chlorine, ethane, propane, air, etc. etc. The gas component can be a gas mixture containing some of the above components. Additionally, it is not necessary for the dissolving unit 200 to dissolve the substance in a gaseous state, and the dissolving unit 200 can dissolve a liquid or a solid containing the required components in a liquid W. The dissolution in this case can be spontaneous dissolution, pressure dissolution, or dissolution, caused by hydration, ionization and chemical reaction due to chemical dissociation.

<< Effects of the T-UMP Generation Method >>

[0121] Next, characteristics and effects of the above-described T-TPC generating method are described by comparison with the conventional T-TPC generating method. For example, in a conventional air bubble generating apparatus as represented by the Venturi method, a mechanical pressure relief structure such as a pressure relief nozzle is provided in a portion of the flow channel. The fluid flows at a predetermined pressure, passing through the pressure relief structure, and air bubbles of various sizes are generated in the area downstream of the pressure relief structure.

[0122] In this case, among the generated air bubbles, since relatively large bubbles such as millibubbles and microbubbles are affected by the buoyancy in the liquid, such bubbles rise to the surface of the liquid and disappear. Even UFM, which do not experience the influence of the lifting force in the liquid, can also disappear with millibubbles and microbubbles, since the energy of the gas-liquid interface of the UFM is not very large. Additionally, even if the above-described pressure relief structures are arranged in series, and the same fluid flows through the pressure relief structures repeatedly, it is impossible to maintain the UMP in an amount corresponding to the number of repetitions for a long time. In other words, it was difficult for the UFD-containing liquid generated by the conventional UFD generation method to maintain the concentration of the UFD contained at a predetermined level for a long time.

[0123] In contrast, in the method for generating T-CMP of this embodiment using film boiling, at a location very close to the heating element, a rapid temperature change occurs locally from normal temperature to about 300 ° C and a rapid pressure change from normal pressure to about several megapascals. The heating element has a rectangular shape with one side measuring from several tens to hundreds of microns. This is about 1/10 to 1/1000 the size of a conventional TPC generating unit. Additionally, in the presence of a liquid with dissolved gas within the region of an extremely thin film of the surface of a film boiling bubble, which briefly exceeds the thermal dissolution limit or the dissolution limit under pressure (in an extremely short time less than microseconds), a phase transition occurs and the liquid with dissolved gas is precipitated as UMP ... In this case, relatively large bubbles, such as millibubbles and microbubbles, are hardly generated, and the liquid contains UMP with a diameter of about 100 nm with extremely high purity. Moreover, since the T-UMP generated in this way have a sufficiently high energy of the gas-liquid interface, the T-UMP is not easily destroyed in the environment under normal conditions and can be stored for a long time.

[0124] In particular, the present invention, using the film boiling phenomenon, which enables the local formation of an interface with a gas in a liquid, can form an interface in a part of the liquid near the heating element without affecting the entire region of the liquid, and the region in which the thermal the impact and impact of pressure can be very local. As a result, it is possible to stably generate the required UMP. With the help of additional conditions for the generation of CMP, applied to the formation of a liquid by means of liquid circulation, it is possible to additionally generate new CMP with small effects on the already generated CMP. As a result, it is possible to relatively easily obtain a UMP liquid of the desired size and concentration.

[0125] Moreover, since the T-CMP generating method has the above-described hysteresis properties, it is possible to increase the concentration to a desired concentration while maintaining high purity. In other words, according to the method for generating the T-UMP, it is possible to efficiently form the long-term storage-capable UMP-containing liquid W with high purity and high concentration.

<< Specific application of the liquid containing T-UMP >>

[0126] In general, applications of the ultrafine bubble liquid vary in the type of gas contained. Any type of gas can form UMP, provided that an amount of about PPM to BPM of the gas can dissolve in the liquid. For example, liquids containing ultrafine bubbles can be used in the following applications.

[0127] - The UMP-containing liquid containing air can preferably be used for cleaning in industrial, agricultural, fishing and medical facilities and the like, and for the cultivation of plants and agricultural and fishery products.

[0128] - UMP-containing liquid containing ozone can be preferably used not only for cleaning in industrial, agricultural, fishing and medical facilities and the like, but also in applications intended, for example, for disinfection, sterilization, decontamination and environmental cleaning drains and contaminated soil.

[0129] - UMP-containing liquid containing nitrogen can be preferably used not only for cleaning in industrial, agricultural, fishing and medical facilities and the like, but also in applications intended, for example, for disinfection, sterilization, decontamination and environmental cleaning drains and contaminated soil.

[0130] - The UMP-containing liquid containing oxygen can be preferably used for purification in industrial, agricultural, fishery and medical facilities and the like, and for the cultivation of plants and agricultural and fishery products.

[0131] - UMP-containing liquid containing carbon dioxide can preferably be used not only for cleaning in industrial, agricultural, fishing and medical facilities and the like, but also in applications intended, for example, for disinfection, sterilization, removal of contaminants.

[0132] - UMP-containing liquid containing perfluorocarbons as a medical gas can be preferably used for ultrasound diagnostics and treatment. As described above, the UMP-containing liquid can create effects in various fields in medicine, chemistry, dentistry, food, industrial, agricultural and fishing industries, etc.

[0133] In each of the applications, the purity and concentration of the UMP contained in the UMP containing fluid is important to quickly and reliably create the effect of the UMP containing fluid. In other words, unprecedented effects can be expected in various fields by applying the T-UMP generating method of this embodiment, which enables the generation of the UMP-containing liquid W with high purity and desired concentration. The following is a list of applications in which the T-UMP generating method and the T-UMP containing liquid are expected to be preferably applicable.

(A) Application for liquid cleaning

[0134] - Due to the T-UMP generating unit provided in the water purification unit, it is expected to enhance the water clarification effect and the purification effect of the pH adjusting liquid. The T-UMP generating unit can also be provided for a carbonated water server.

[0135] Due to the T-UMP generating unit provided for a humidifier, a flavoring agent, a coffee machine and the like, it is expected that the humidifying effect, the deodorizing effect and the aromatizing effect in the room will be enhanced.

[0136] If a UMP-containing liquid in which ozone gas is dissolved by the dissolving unit is formed and used for dental treatment, cauterization treatment, and wound treatment using an endoscope, an increase in the medical cleaning effect and antiseptic effect is expected.

[0137] - Due to the T-UMP generating unit provided in the water storage tank of an apartment building, it is expected to increase the effect of water clarification and the effect of dechlorination of drinking water subject to long-term storage.

[0138] - If a liquid containing T-UMP containing ozone or carbon dioxide is used for the brewing process of Japanese sake, net, wine, etc., in which high temperature pasteurization processing cannot be performed, more efficient pasteurization processing is expected than traditional processing. liquid.

[0139] - If a liquid containing UMP is blended into an ingredient during the manufacture of food for a specific use for health reasons and food with beneficial additives, pasteurization processing is possible, and thus it is possible to provide safe and healthy food without loss of taste.

[0140] - The spawning and growth of fish products is expected to be facilitated by the T-UMP generating unit provided for the seawater and fresh water supply path for cultivation in the cultivation area of fish products such as fish and pearls.

[0141] - Due to the T-UMP generating unit provided in the food preserving water purification process, an improvement in the food preservation state is expected.

[0142] - Due to the T-UMP generating unit provided in the decolorizing unit for decolorizing pool water or groundwater, a higher bleaching effect is expected.

[0143] - Due to the T-UMP containing fluid used to repair cracks in concrete blocks, an improvement in the effect of repairing cracks in concrete blocks is expected.

[0144] - Energy efficiency is expected to be improved by the T-UMP contained in the liquid fuel for a liquid fuel vehicle (such as an automobile, a ship, and an aircraft).

(B) Cleaning applications

[0145] Recently, T-UMP containing liquids have attracted attention as cleaning water for removing dirt or the like adhering to clothing. If the T-TPC generating unit described in the above embodiment is provided in the washing machine, and the T-TPC-containing liquid of higher purity and better permeability than the ordinary liquid is supplied to the washing container, further improvement in washing performance is expected.

[0146] - Due to the T-UMP generating unit provided in the shower in the bathtub and the washing machine for the bedpan, not only a cleaning effect is expected for all types of living beings, including the human body, but also the effect of promoting the removal of dirt in the form of water stains and mold in the bathroom and bedpan.

[0147] - Due to the T-UMP generating unit provided in a car wiper, a pressure washer for cleaning wall blocks and the like, a car wash unit, a dishwasher, a food washer unit and the like, further improvement is expected cleaning effects.

[0148] - An improvement in the cleaning effect is expected from the T-UMP containing fluid used for cleaning and maintaining parts manufactured in the factory, including a post-compaction deburring step.

[0149] In the manufacture of semiconductor elements, if a liquid containing T-UMP is used as polishing water for a wafer, an improvement in the polishing effect is expected. Additionally, if the T-UMP containing liquid is used in the resist removal step, the stimulation of peeling of the resist that does not peel off easily is improved.

[0150] - Due to the T-UMP generating unit provided in machines for cleaning and removing contaminants of medical devices such as a medical robot, dental apparatus, container for organ preservation, etc., it is expected to improve the cleaning effect and the decontamination effect these machines. The T-UMP generating unit is also applicable for the treatment of animals.

(C) Pharmaceutical uses

[0151] - If the liquid containing T-UMP is contained in cosmetic preparations and the like, penetration into subcutaneous cells is improved, and the amount of additives that have a negative effect on the skin such as preservatives and surfactants can be significantly reduced. As a result, it is possible to provide safer and more functional cosmetics.

[0152] - If a high concentration nanobubble preparation containing T-UMP is used as contrast agents in medical examinations such as CT and MRI, the reflected light of X-rays and ultrasound waves can be used effectively. This allows a more detailed image to be captured, which is useful for the initial diagnosis of cancer and the like.

[0153] - If water with a high concentration of nanobubbles containing T-UMP is used in a high intensity focused ultrasound (HIFU) ultrasound machine, the power of the ultrasonic waves can be reduced, and thus the treatment (treatment) can be made more non-invasive. In particular, it is possible to reduce damage to normal tissues.

[0154] - It is possible to create a nanobubble preparation by using high concentration nanobubbles containing T-UMP as a source, modifying a phospholipid that forms a liposome in the area of negative electric charge around an air bubble, and applying various medical substances (such as DNA and RNA) through a phospholipid ...

[0155] - If a drug containing water with a high concentration of bubbles created by the generation of T-UMP is transferred into the dental canal for regenerative treatment of pulp and hard tissue of the tooth (dentin), the drug is injected deep into the dentinal tubule due to the percolation effect of nanobubble water , and the disinfection effect is improved. This allows the infected root canal of the dental pulp to be treated safely in a short time.

[0156] As described above, according to the method for generating ultrafine bubbles of the present invention, it is possible to efficiently form a high purity UMP-containing liquid by providing a pre-processing unit and a dissolving unit in front of the T-UMP generating unit.

[0157] Although the present invention has been described with reference to exemplary embodiments, it should be understood that the invention is not limited to the disclosed exemplary embodiments. The scope of the appended claims is to be consistent with the broadest interpretation so as to cover all such modifications and equivalent structures and functions.

Claims (56)

1. A method for generating ultrafine bubbles, comprising: a generating step generating ultrafine bubbles by causing a heating element provided in the liquid to generate heat to create film boiling at the interface between the liquid and the heating element; and a post-processing step in which a predetermined post-processing is performed on the ultrafine bubble liquid containing the ultrafine bubbles generated in the generation step, and wherein the post-processing step includes a first treatment for removing an inorganic ion using a cation exchange resin. 2. A method for generating ultrafine bubbles according to claim 1, wherein the inorganic ion to be removed by the first treatment contains a metal forming a heating element. 3. A method for generating ultrafine bubbles according to claim 1, wherein the inorganic ion removed by the first treatment contains at least one selected from Si, Al, W, Pt, Pd, Ta, Fe, Cr, Ni, Ir and Ru. 4. A method for generating ultrafine bubbles according to claim 1, wherein the post-processing step includes a second treatment for removing organic matter using a purification filter. 5. A method for generating ultrafine bubbles according to claim 4, wherein the organic matter to be removed by the second treatment contains at least one selected from an organic compound containing silicon, siloxane, epoxy resin and bacteria. 6. A method for generating ultrafine bubbles according to claim 1, wherein the post-processing step includes a third treatment to remove the insoluble solid using the insoluble solid precipitation characteristics. 7. A method for generating ultrafine bubbles according to claim 1, wherein the post-processing step includes magnification processing to increase the concentration of ultrafine bubbles contained in the ultrafine bubble liquid. 8. A method for generating ultrafine bubbles according to claim 7, wherein in the enlargement treatment, the concentration of the contained ultrafine bubbles is increased by generating ultrasound in the ultrafine bubble-containing liquid. 9. A method for generating ultrafine bubbles according to claim 7, wherein in the enlargement treatment, the concentration of the contained ultrafine bubbles is increased by applying focused ultrasound to the liquid containing ultrafine bubbles. 10. A method for generating ultrafine bubbles according to claim 1, further comprising: a dissolution step in which any of hydrogen, helium, oxygen, nitrogen, methane, fluorine, neon, carbon dioxide, ozone, argon, chlorine, ethane, propane, air and a gas mixture containing them are dissolved in the liquid to be supplied in the generation step, wherein at the stage of generation, ultrafine bubbles are generated containing a gas inside them, which is dissolved at the stage of dissolution. 11. A method for generating ultrafine bubbles according to claim 1, wherein the generating step is performed again after the post-processing step has been performed. 12. A method for generating ultrafine bubbles according to claim 1, further comprising: a step that collects the ultrafine bubble liquid processed in the post-processing step. 13. A device for generating ultrafine bubbles, comprising: a generating unit configured to generate ultrafine bubbles by causing a heating element provided in the liquid to generate heat to create film boiling at an interface between the liquid and the heating element; and a post-processing unit configured to perform a predetermined post-processing of the ultrafine bubble liquid containing the ultrafine bubbles generated by the generating unit, and wherein the post-processing unit includes a removal unit including a first unit that removes an inorganic ion using a cation exchange resin. 14. The device for generating ultrafine bubbles according to claim 13, wherein the inorganic ion to be removed by the first block contains the metal forming the heating element. 15. The device for generating ultrafine bubbles according to claim 14, wherein the inorganic ion removed by the first block contains at least one selected from Si, Al, W, Pt, Pd, Ta, Fe, Cr, Ni, Ir and Ru. 16. The device for generating ultrafine bubbles according to claim 13, in which the removal unit includes a second unit that removes organic matter using a purification filter. 17. The device for generating ultrafine bubbles according to claim 16, wherein the organic matter to be removed by the second block contains at least one selected from an organic compound containing silicon, siloxane, epoxy resin and bacteria. 18. The device for generating ultrafine bubbles according to claim 16, in which the purification filter has a mesh diameter of 1 µm or less. 19. A device for generating ultrafine bubbles according to claim 13, wherein the removal unit includes a third unit that removes the insoluble solid using the characteristics of the precipitation of the insoluble solid. 20. The device for generating ultrafine bubbles according to claim 13, in which the post-processing unit includes an up-processing unit that increases the concentration of ultrafine bubbles contained in a liquid containing ultrafine bubbles. 21. A device for generating ultrafine bubbles according to claim 20, wherein the boost processing unit increases the concentration of the contained ultrafine bubbles by generating ultrasound in the ultrafine bubble liquid. 22. A device for generating ultrafine bubbles according to claim 20, wherein The boost processing unit increases the concentration of the contained ultrafine bubbles by applying focused ultrasound to the ultrafine bubble liquid. 23. A device for generating ultrafine bubbles according to claim 13, further comprising: a dissolution unit that dissolves any of hydrogen, helium, oxygen, nitrogen, methane, fluorine, neon, carbon dioxide, ozone, argon, chlorine, ethane, propane, air and a gas mixture containing them in a liquid to be supplied to the generating unit, when this the generating unit generates ultra-fine bubbles containing gas inside, which is dissolved by the dissolving unit. 24. A device for generating ultrafine bubbles according to claim 13, further comprising: a circulation path through which the liquid processed by the post-processing unit is supplied to the generating unit. 25. A device for generating ultrafine bubbles according to claim 13, further comprising: a block that collects ultra-fine bubble liquid processed by the post-processing block.

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