WO2023089904A1 - Method for manufacturing ozone solution and method for utilizing ozone solution - Google Patents

Abstract

Provided are a method for manufacturing an ozone solution with which it is possible to manufacture, using a small and simple configuration, an ozone solution that can be employed at a prescribed point in time, and a method for utilizing an ozone solution. In order to achieve the above, a liquid in which ultrafine bubbles are generated is stored for a prescribed time, the ultrafine bubbles are removed by a defoaming means at a desired timing, ozone gas is dissolved in the liquid, and sterilization is performed using an ozone solution thereby produced.

Description

Manufacturing method and utilization method of ozone solution

The present invention relates to a method for producing and utilizing an ozone solution.

Ozone-dissolved water has useful effects such as sterilization, cleaning, and deodorizing effects, and is widely used in industrial fields such as the medical and food fields. Patent Literature 1 discloses a method for producing ozone-dissolved water in which high-concentration ozone gas is dissolved.

JP 2019-206463 A

It is said that ozone dissolved in water is extremely unstable and halves in ten minutes. Therefore, there is a restriction that the ozone-dissolved water must be generated near the place of use and used before the ozone decomposes and becomes lower than the desired ozone concentration. Moreover, the method for producing ozone-dissolved water in Patent Document 1 uses an ultraviolet light source or the like, and is a large-scale method.

Therefore, the present invention provides a method for producing an ozone solution and a method for utilizing the ozone solution that can produce an ozone solution having a desired concentration with a simple configuration.

Therefore, the method of utilizing the dissolved ozone solution of the present invention includes a first dissolving step of dissolving ozone gas in a liquid, and an ultra-fine bubble generating step of generating ultra-fine bubbles in the dissolved ozone solution in which the ozone gas is dissolved in the first dissolving step. a storage step of storing the liquid containing the ultra-fine bubbles generated in the ultra-fine bubble generation step; a defoaming step of defoaming the ultra-fine bubbles contained in the liquid stored in the storage step; characterized by comprising a second dissolving step of dissolving the ultra-fine bubbles defoamed in the defoaming step in a liquid, and an applying step of applying the ozone solution in which the ozone gas is dissolved in the second dissolving step. .

According to the present invention, it is possible to provide a method for producing an ozone solution and a method for utilizing the ozone solution that can produce an ozone solution with a desired concentration at a desired time in a small size and with a simple configuration.

Further features of the present disclosure will become apparent from the following description of embodiments with reference to the accompanying drawings.

It is a figure which shows an example of a UFB generation apparatus. 4 is a schematic configuration diagram of a pretreatment unit; FIG. FIG. 3 is a diagram for explaining a schematic configuration diagram of a dissolving unit and a dissolving state of a liquid; 2 is a schematic configuration diagram of a T-UFB generation unit; FIG. FIG. 3 is a diagram showing the detailed structure of a heating element; FIG. 4 is a diagram showing how film boiling occurs when a predetermined voltage pulse is applied to a heating element; FIG. 4 is a diagram schematically showing how film boiling bubbles are generated and UFB is generated; FIG. 4 is a diagram showing how UFB is generated as a film boiling bubble shrinks. FIG. 4 is a diagram showing how UFB is generated when a film boiling bubble contracts. FIG. 10 is a diagram showing how UFB is generated by impact when film boiling bubbles disappear. 4 is a diagram showing a configuration example of a post-processing unit; FIG. FIG. 4 is a schematic diagram showing a defoaming unit for defoaming USB; It is the flowchart which showed the procedure of the ozone solution utilization method. FIG. 10 is a diagram showing the results of comparative evaluation of the sterilization effects of ozone-dissolved liquids.

(First embodiment)
In this embodiment, ozone ultra-fine bubbles (hereinafter simply referred to as UFB) having a diameter of less than 1.0 μm are used to generate an ozone solution with a desired concentration. A first embodiment of the present invention will be described below with reference to the drawings.

<<Configuration of UFB generator>>
FIG. 1 is a diagram showing an example of an ultra-fine bubble generator (also referred to as a UFB generator) applicable to the present invention. The UFB generator 1 of this embodiment includes a pretreatment unit 100, a dissolution unit 200, a T-UFB generation unit 300, a posttreatment unit 400, and a recovery unit 500. The liquid W such as tap water supplied to the pretreatment unit 100 is treated in the order described above and is recovered by the recovery unit 500 as a TUFB-containing liquid. The function and configuration of each unit will be described below. Although the details will be described later, in this specification, UFB generated by utilizing film boiling accompanying rapid heat generation is referred to as T-UFB (Thermal-Ultra Fine Bubble).

FIG. 2 is a schematic configuration diagram of the pretreatment unit 100. As shown in FIG. The pretreatment unit 100 of the present embodiment deaerates the supplied liquid W. As shown in FIG. The pretreatment unit 100 mainly has a deaeration container 101, a shower head 102, a decompression pump 103, a liquid introduction path 104, a liquid circulation path 105, and a liquid extraction path . A liquid W such as tap water is supplied from the liquid introduction passage 104 to the degassing container 101 via the valve 109 . At this time, the shower head 102 provided in the deaeration container 101 atomizes the liquid W into the deaeration container 101 . The shower head 102 is for promoting vaporization of the liquid W, but a centrifugal separator or the like can be substituted as a mechanism for producing the effect of promoting vaporization.

After a certain amount of the liquid W is stored in the degassing container 101, when the decompression pump 103 is operated with all the valves closed, the already vaporized gas component is discharged and dissolved in the liquid W. Vaporization and evacuation of gaseous components present are also promoted. At this time, the internal pressure of the degassing container 101 may be reduced to about several hundred to several thousand Pa (1.0 Torr to 10.0 Torr) while checking the pressure gauge 108 . Gases deaerated by the pretreatment unit 100 include, for example, nitrogen, oxygen, argon, and carbon dioxide.

The degassing process described above can be repeatedly performed on the same liquid W by using the liquid circulation path 105 . Specifically, the shower head 102 is operated with the valve 109 of the liquid introduction path 104 and the valve 110 of the liquid outlet path 106 closed and the valve 107 of the liquid circulation path 105 opened. As a result, the liquid W stored in the degassing container 101 and subjected to the degassing process once is sprayed again into the degassing container 101 via the shower head 102 . Furthermore, by activating the decompression pump 103, the vaporization process by the shower head 102 and the degassing process by the decompression pump 103 are performed on the same liquid W at the same time. Then, the gas component contained in the liquid W can be reduced step by step each time the above-described repeated processing using the liquid circulation path 105 is performed. When the liquid W degassed to the desired purity is obtained, the valve 110 is opened to send the liquid W to the dissolving unit 200 through the liquid lead-out path 106 .

Although FIG. 2 shows the pretreatment unit 100 that vaporizes the dissolved matter by reducing the pressure of the gas portion, the method of degassing the dissolved liquid is not limited to this. For example, a heat boiling method in which the liquid W is boiled to vaporize the dissolved matter may be employed, or a membrane degassing method in which hollow fibers are used to increase the interface between the liquid and the gas may be employed. SEPAREL series (manufactured by Dainippon Ink Co., Ltd.) is commercially available as a degassing module using hollow fibers. This uses poly-4-methylpentene-1 (PMP) as the raw material of the hollow fiber membrane, and is mainly used for the purpose of degassing air bubbles from the ink supplied to the piezo head. Furthermore, two or more of the vacuum degassing method, the heat boiling method, and the membrane degassing method may be used in combination.

FIGS. 3(a) and 3(b) are schematic diagrams of the dissolving unit 200 and diagrams for explaining the dissolving state of the liquid. The dissolving unit 200 is a unit that dissolves ozone gas (hereinafter referred to as gas G) in the liquid W supplied from the pretreatment unit 100 . The dissolving unit 200 of this embodiment mainly has a dissolving container 201 , a rotating shaft 203 to which a rotating plate 202 is attached, a liquid introduction path 204 , a gas introduction path 205 , a liquid outlet path 206 and a pressure pump 207 .

Methods such as ultraviolet irradiation, discharge, and electrolysis are commonly used to generate ozone gas. In the present invention, the method for generating ozone gas is not specified, and any available ozone gas generating device may be connected to the gas introduction path 205 .

The liquid W supplied from the pretreatment unit 100 is supplied to the dissolution container 201 through the liquid introduction path 204 and stored therein. On the other hand, the gas G is supplied to the dissolving container 201 through the gas introduction path 205 . When predetermined amounts of the liquid W and the gas G are stored in the dissolving container 201, the pressure pump 207 is operated to increase the internal pressure of the dissolving container 201 to approximately 0.5 MPa. A safety valve 208 is arranged between the pressure pump 207 and the dissolving container 201 . Further, by rotating the rotating plate 202 in the liquid via the rotating shaft 203, the gas G supplied to the dissolution container 201 is bubbled, the contact area with the liquid W is increased, and the dissolution in the liquid W is facilitated. Facilitate. Such operations are continued until the solubility of the gas G reaches approximately the maximum saturation solubility. At this time, means for lowering the temperature of the liquid may be arranged in order to dissolve as much gas as possible. It is also possible to increase the internal pressure of the dissolving container 201 to 0.5 MPa or higher. In that case, it is necessary to optimize the material of the container from a safety point of view.

When the liquid W in which the components of the gas G are dissolved at the desired concentration is obtained, the liquid W is discharged through the liquid lead-out path 206 and supplied to the T-UFB generation unit 300 . At this time, the back pressure valve 209 adjusts the flow pressure of the liquid W so that the pressure during supply does not become higher than necessary.

FIG. 3(b) is a diagram schematically showing how the mixed gas G is dissolved in the dissolution container 201. FIG. Bubbles 2 containing the component of gas G mixed in liquid W dissolve from the portion in contact with liquid W. As shown in FIG. Therefore, the bubble 2 gradually shrinks, and the gas-dissolved liquid 3 exists around the bubble 2 . Since buoyancy acts on the bubble 2 , the bubble 2 moves to a position off the center of the gas-dissolved liquid 3 or separates from the gas-dissolved liquid 3 to become a residual bubble 4 . That is, the liquid W supplied to the T-UFB generation unit 300 through the liquid lead-out path 206 includes the gas-dissolved liquid 3 surrounding the bubbles 2, and the gas-dissolved liquid 3 and the bubbles 2 separated from each other. There are mixed states.

In the figure, the gas-dissolved liquid 3 means "a region in which the mixed gas G has a relatively high dissolved concentration in the liquid W". In the gas component actually dissolved in the liquid W, the concentration is highest around the bubble 2 or even in the state separated from the bubble 2, and the concentration of the gas component is continuous as the distance from that position increases. relatively low. That is, in FIG. 3B, the area of the gas-dissolved liquid 3 is surrounded by a dashed line for explanation, but such a clear boundary does not actually exist. In addition, in the present invention, even if a gas that is not completely dissolved exists in the liquid in the form of bubbles, it is allowed.

4 is a schematic configuration diagram of the T-UFB generation unit 300. FIG. The T-UFB generation unit 300 mainly includes a chamber 301, a liquid introduction path 302, and a liquid outlet path 303. Flow from the liquid introduction path 302 to the liquid outlet path 303 through the chamber 301 is controlled by a flow pump (not shown). formed by Various types of pumps such as diaphragm pumps, gear pumps, and screw pumps can be used as fluid pumps. The liquid W introduced from the liquid introduction path 302 is mixed with the gas-dissolved liquid 3 of the gas G mixed by the dissolving unit 200 .

An element substrate 12 provided with heat generating elements 10 is arranged on the bottom surface of the chamber 301 . By applying a predetermined voltage pulse to the heating element 10 , a bubble 13 caused by film boiling (hereinafter also referred to as a film boiling bubble 13 ) is generated in a region in contact with the heating element 10 . As the film boiling bubbles 13 expand and contract, ultra-fine bubbles (UFB 11) containing the gas G are generated. As a result, a UFB-containing liquid W containing a large number of UFBs 11 is drawn out from the liquid lead-out path 303 .

FIGS. 5(a) and 5(b) are diagrams showing the detailed structure of the heating element 10. FIG. FIG. 5(a) shows the vicinity of the heating elements 10, and FIG. 5(b) shows a cross-sectional view of the element substrate 12 in a wider area including the heating elements 10. As shown in FIG.

As shown in FIG. 5A, in the element substrate 12 of this embodiment, a thermal oxide film 305 as a heat storage layer and an interlayer film 306 also serving as a heat storage layer are laminated on the surface of a silicon substrate 304. . A SiO ₂ film or a SiN film can be used as the interlayer film 306 . A resistance layer 307 is formed on the surface of the interlayer film 306 , and wiring 308 is partially formed on the surface of the resistance layer 307 . As the wiring 308, an Al alloy wiring such as Al, Al--Si, or Al--Cu can be used. A protective layer 309 made of an SiO ₂ film or a Si ₃ N ₄ film is formed on the surfaces of these wirings 308 , resistance layer 307 and interlayer film 306 .

On the surface of the protective layer 309, the portion corresponding to the heat acting portion 311 that eventually becomes the heating element 10 and its surroundings are covered with the protective layer 309 against chemical and physical impacts accompanying the heat generation of the resistance layer 307. An anti-cavitation film 310 is formed to protect the . A region on the surface of the resistance layer 307 where the wiring 308 is not formed is a heat acting portion 311 where the resistance layer 307 generates heat. A heat-generating portion of the resistance layer 307 where the wiring 308 is not formed functions as a heat-generating element (heater) 10 . Thus, the layers of the element substrate 12 are sequentially formed on the surface of the silicon substrate 304 by semiconductor manufacturing techniques, whereby the silicon substrate 304 is provided with the heat acting portion 311 .

The configuration shown in the figure is an example, and various other configurations are applicable. For example, a configuration in which the resistive layer 307 and the wiring 308 are stacked in reverse order, and a configuration in which an electrode is connected to the lower surface of the resistive layer 307 (so-called plug electrode configuration) are applicable. In other words, as will be described later, any configuration may be used as long as the liquid can be heated by the heat acting portion 311 to cause film boiling in the liquid.

FIG. 5(b) is an example of a cross-sectional view of a region including a circuit connected to the wiring 308 in the element substrate 12. As shown in FIG. An N-type well region 322 and a P-type well region 323 are partially provided on the surface layer of the silicon substrate 304, which is a P-type conductor. A P-MOS 320 is formed in the N-type well region 322 and an N-MOS 321 is formed in the P-type well region 323 by introducing and diffusing impurities such as ion implantation by a general MOS process.

The P-MOS 320 is composed of a source region 325 and a drain region 326 obtained by partially introducing an N-type or P-type impurity into the surface layer of the N-type well region 322, a gate wiring 335, and the like. A gate wiring 335 is deposited on the surface of the portion of the N-type well region 322 excluding the source region 325 and the drain region 326 via a gate insulating film 328 with a thickness of several hundred angstroms.

The N-MOS 321 is composed of a source region 325 and a drain region 326 formed by partially introducing an N-type or P-type impurity into the surface layer of a P-type well region 323, a gate wiring 335, and the like. A gate wiring 335 is deposited on the surface of the portion of the P-type well region 323 excluding the source region 325 and the drain region 326 via a gate insulating film 328 with a thickness of several hundred angstroms. The gate wiring 335 is made of polysilicon deposited by CVD to a thickness of 3000 Å to 5000 Å. These P-MOS 320 and N-MOS 321 constitute a C-MOS logic.

In the P-type well region 323, an N-MOS transistor 330 for driving an electrothermal conversion element (heating resistance element) is formed in a portion different from the N-MOS 321. The N-MOS transistor 330 is composed of a source region 332 and a drain region 331 partially formed in the surface layer of the P-type well region 323 by steps such as impurity introduction and diffusion, a gate wiring 333, and the like. A gate wiring 333 is deposited on the surface of a portion of the P-type well region 323 excluding the source region 332 and the drain region 331 via a gate insulating film 328 .

In this example, an N-MOS transistor 330 is used as a driving transistor for the electrothermal conversion element. However, the drive transistor may be any transistor that has the ability to individually drive a plurality of electrothermal conversion elements and that can obtain the fine structure described above. Not limited. Also, in this example, the electrothermal conversion element and its driving transistor are formed on the same substrate, but they may be formed on separate substrates.

Between the P-MOS 320 and the N-MOS 321, and between the N-MOS 321 and the N-MOS transistor 330, an oxide film isolation region 324 is formed by field oxidation to a thickness of 5000 Å to 10000 Å. ing. Each device is isolated by this oxide film isolation region 324 . A portion of the oxide film isolation region 324 corresponding to the heat acting portion 311 functions as the first heat storage layer 334 on the silicon substrate 304 .

An interlayer insulating film 336 made of a PSG film or BPSG film having a thickness of about 7000 Å is formed on the surface of each element of the P-MOS 320, N-MOS 321 and N-MOS transistor 330 by CVD. After the interlayer insulating film 336 is flattened by heat treatment, an Al electrode 337 serving as a first wiring layer is formed via a contact hole penetrating the interlayer insulating film 336 and the gate insulating film 328 . An interlayer insulating film 338 made of an SiO2 film with a thickness of 10000 Å to 15000 Å is formed on the surfaces of the interlayer insulating film 336 and the Al electrode 337 by plasma CVD. A resistive layer 307 made of a TaSiN film having a thickness of about 500 .ANG. The resistance layer 307 is electrically connected to the Al electrode 337 near the drain region 331 through a through hole formed in the interlayer insulating film 338 . Al wiring 308 is formed on the surface of the resistance layer 307 as a second wiring layer serving as wiring to each electrothermal conversion element. The wiring 308, the resistance layer 307, and the protective layer 309 on the surface of the interlayer insulating film 338 are made of a 3000 Å thick SiN film formed by plasma CVD. The anti-cavitation film 310 deposited on the surface of the protective layer 309 is made of at least one metal selected from Ta, Fe, Ni, Cr, Ge, Ru, Zr, Ir, etc., and is a thin film with a thickness of about 2000 Å. consists of Various materials other than TaSiN, such as TaN _0.8 , CrSiN, TaAl, and WSiN, can be used for the resistive layer 307 as long as they can cause film boiling in a liquid.

FIGS. 6(a) and 6(b) are diagrams showing how film boiling occurs when a predetermined voltage pulse is applied to the heating element 10. FIG. Here, the case of film boiling under atmospheric pressure is shown. In FIG. 6A, the horizontal axis indicates time. The vertical axis of the lower graph indicates the voltage applied to the heating element 10, and the vertical axis of the upper graph indicates the volume and internal pressure of the film boiling bubbles 13 generated by film boiling. On the other hand, FIG. 6(b) shows how the film boiling bubbles 13 correspond to timings 1 to 3 shown in FIG. 6(a). Each state will be described below in chronological order. As will be described later, the UFB 11 generated by film boiling is mainly generated in the vicinity of the surface of the film boiling bubbles 13 . In the state shown in FIG. 6B, as shown in FIG. 1, the UFB 11 generated in the T-UFB generation unit 300 is supplied again to the dissolution unit 200 through the circulation path, and the liquid is supplied to the T-UFB generation unit. 300 shows a state in which the liquid is re-supplied to the liquid path.

Before the voltage is applied to the heating element 10, the inside of the chamber 301 is kept at substantially atmospheric pressure. When a voltage is applied to the heating element 10, film boiling occurs in the liquid in contact with the heating element 10, and the generated bubbles (hereinafter referred to as film boiling bubbles 13) expand due to the high pressure acting from the inside (timing 1). . The foaming pressure at this time is considered to be about 8 to 10 MPa, which is close to the saturated vapor pressure of water.

Although the voltage application time (pulse width) is about 0.5 to 10.0 usec, the film boiling bubble 13 expands due to the inertia of the pressure obtained at timing 1 even after the voltage is no longer applied. However, inside the film boiling bubble 13 , the negative pressure generated along with the expansion gradually increases and acts in the direction of shrinking the film boiling bubble 13 . The volume of the film boiling bubble 13 reaches its maximum at timing 2 when the inertial force and the negative pressure are balanced, and then rapidly shrinks due to the negative pressure.

When the film boiling bubble 13 disappears, the film boiling bubble 13 disappears not in the entire surface of the heating element 10 but in one or more very small areas. Therefore, in the heating element 10, a force larger than that at the time of foaming shown at timing 1 is generated in a very small area where the film boiling bubbles 13 disappear (timing 3).

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

Next, with reference to FIGS. 7 to 10, how the UFB 11 is generated in each process of generation, expansion, contraction and disappearance of the film boiling bubbles 13 will be described in more detail.

7(a) to (d) are diagrams schematically showing how the UFB 11 is generated as the film boiling bubbles 13 are generated and expanded. FIG. 7A shows the state before a voltage pulse is applied to the heating element 10. FIG. Inside the chamber 301, the liquid W mixed with the gas-dissolved liquid 3 is flowing.

FIG. 7(b) shows how a voltage is applied to the heating element 10 and the film boiling bubbles 13 are generated uniformly over almost the entire area of the heating element 10 in contact with the liquid W. FIG. When a voltage is applied, the surface temperature of the heating element 10 rises rapidly at a rate of 10° C./μsec or more, and when it reaches approximately 300° C., film boiling occurs and film boiling bubbles 13 are generated.

After that, the surface temperature of the heating element 10 rises to about 600 to 800° C. during pulse application, and the liquid around the film boiling bubble 13 is also rapidly heated. In the drawing, a region of the liquid located around the film boiling bubbles 13 and rapidly heated is shown as an unfoamed high-temperature region 14 . The gas-dissolved liquid 3 contained in the unfoamed high-temperature region 14 exceeds the thermal solubility limit and precipitates to become UFB. The deposited bubbles have a diameter of about 10 nm to 100 nm and have a high gas-liquid interfacial energy. Therefore, it floats in the liquid W while maintaining its independence without disappearing in a short time. In this embodiment, the bubbles generated by the thermal action when the film boiling bubbles 13 are generated and expanded are referred to as first UFB 11A.

FIG. 7(c) shows the process in which the film boiling bubbles 13 expand. Even after the application of the voltage pulse to the heating element 10 ends, the film boiling bubbles 13 continue to expand due to the inertia of the force obtained when they are generated, and the non-bubbled high-temperature regions 14 also move and diffuse due to inertia. That is, in the process in which the film boiling bubbles 13 expand, the gas-dissolved liquid 3 contained in the unfoamed high-temperature region 14 is newly precipitated as bubbles to form the first UFB 11A.

FIG. 7(d) shows a state in which the film boiling bubble 13 has reached its maximum volume. The film boiling bubble 13 expands due to inertia, but the negative pressure inside the film boiling bubble 13 gradually increases with the expansion, and acts as a negative pressure to contract the film boiling bubble 13 . Then, when this negative pressure balances with the inertial force, the volume of the film boiling bubbles 13 reaches its maximum, and thereafter begins to contract.

In the contraction stage of the film boiling bubble 13, the UFB (second UFB 11B) generated by the process shown in FIGS. 8(a) to (c) and the UFB generated by the process shown in FIGS. (third UFB). These two processes are thought to coexist.

FIGS. 8(a) to 8(c) are diagrams showing how the UFB 11 is generated as the film boiling bubbles 13 contract. FIG. 8(a) shows a state in which the film boiling bubbles 13 have started contracting. Even if the film boiling bubble 13 starts contracting, the surrounding liquid W still has an inertial force in the expanding direction. Therefore, the inertial force acting in the direction away from the heating element 10 and the force directed toward the heating element 10 due to the contraction of the film boiling bubble 13 act on the extreme periphery of the film boiling bubble 13, resulting in a decompressed region. Become. In the drawing, such a region is indicated as an unfoamed negative pressure region 15. FIG.

The gas-dissolving liquid 3 contained in the non-foaming negative pressure region 15 exceeds the pressure solubility limit and precipitates as bubbles. The precipitated bubbles have a diameter of about 100 nm, and do not disappear in a short period of time and float in the liquid W while maintaining their independence. In the present embodiment, the bubbles deposited by the pressure action when the film boiling bubbles 13 contract in this manner are referred to as second UFB 11B.

FIG. 8(b) shows the process of contraction of the film boiling bubble 13. The speed at which the film boiling bubbles 13 shrink is accelerated by the negative pressure, and the unfoamed negative pressure region 15 also moves with the contraction of the film boiling bubbles 13 . That is, in the process of contraction of the film boiling bubbles 13, the gas-dissolved liquid 3 at the location through which the unfoamed negative pressure region 15 passes is deposited one after another to form the second UFB 11B.

FIG. 8(c) shows the state immediately before the film boiling bubble 13 disappears. The accelerated contraction of the film boiling bubbles 13 also increases the moving speed of the surrounding liquid W, but pressure loss occurs due to the flow path resistance in the chamber 301 . As a result, the area occupied by the unfoamed negative pressure area 15 becomes even larger, and a large number of second UFBs 11B are generated.

9(a) to (c) are diagrams showing how UFB is generated by reheating the liquid W when the film boiling bubbles 13 are contracted. FIG. 9A shows a state in which the surface of the heating element 10 is covered with shrinking film boiling bubbles 13 .

FIG. 9(b) shows a state in which the contraction of the film boiling bubbles 13 progresses and part of the surface of the heating element 10 is in contact with the liquid W. FIG. At this time, heat remains on the surface of the heating element 10 to such an extent that film boiling does not occur even when the liquid W is brought into contact with the surface. In the figure, the area of the liquid that is heated by contact with the surface of the heating element 10 is shown as an unfoamed reheating area 16 . Although film boiling does not occur, the gas-dissolved liquid 3 contained in the unfoamed reheating region 16 is precipitated beyond the thermal solubility limit. In the present embodiment, bubbles generated by reheating the liquid W when the film boiling bubbles 13 contract in this manner are referred to as third UFB 11C.

FIG. 9(c) shows a state in which the shrinkage of the film boiling bubbles 13 has progressed further. As the film boiling bubbles 13 become smaller, the area of the heat generating element 10 in contact with the liquid W becomes larger, so the third UFB 11C is generated until the film boiling bubbles 13 disappear.

FIGS. 10(a) and 10(b) are diagrams showing how UFB is generated by impact (so-called cavitation) when the film boiling bubbles 13 generated by film boiling are destroyed. FIG. 10(a) shows a state immediately before the film boiling bubble 13 disappears. The film boiling bubbles 13 are rapidly contracted by the internal negative pressure, and are surrounded by the non-foamed negative pressure region 15 .

FIG. 10(b) shows the state immediately after the film boiling bubble 13 disappears at the point P. When the film boiling bubble 13 disappears, the acoustic wave spreads concentrically with the point P as a starting point due to the impact. Acoustic waves are a general term for elastic waves that propagate regardless of gas, liquid, or solid. be done.

In this case, the gas-dissolved liquid 3 contained in the unfoamed negative pressure region 15 is resonated by the shock wave when the film boiling bubbles 13 disappear, and undergoes a phase transition exceeding the pressure solubility limit at the timing when the low pressure surface 17B passes. . That is, at the same time when the film boiling bubbles 13 disappear, a large number of bubbles are precipitated in the non-bubbled negative pressure region 15 . In this embodiment, a bubble generated by a shock wave when the film boiling bubble 13 disappears is called a fourth UFB 11D.

The fourth UFB 11B generated by the shock wave when the film boiling bubble 13 disappears suddenly appears in a very narrow film-like region in a very short time (1 μS or less). The diameter is significantly smaller than the first to third UFBs, and the gas-liquid interfacial energy is higher than the first to third UFBs. Therefore, it is considered that the fourth UFB 11D has different properties and produces different effects from those of the first to third UFBs 11A to 11C.

In addition, since the fourth UFB 11D is uniformly generated throughout the concentric spherical region where the shock wave propagates, it is uniformly present in the chamber 301 from the time of generation. At the timing when the fourth UFB 11D is generated, many first to third UFBs already exist, but the existence of these first to third UFBs does not greatly affect the generation of the fourth UFB 11D. do not have. Also, it is considered that the generation of the fourth UFB 11D will not cause the first to third UFBs to disappear.

As described above, it is assumed that the UFB 11 is generated in a plurality of stages from the generation of the film boiling bubbles 13 by the heat generated by the heating element 10 to the disappearance of the bubbles. The first UFB 11A, the second UFB 11B and the third UFB 11C are generated near the surface of film boiling bubbles generated by film boiling. Here, the neighborhood is a region within about 20 μm from the surface of the film boiling bubble. The fourth UFB 11D is generated in a region where a shock wave generated when bubbles disappear (disappear) propagates. In the above example, an example was shown until the film boiling bubbles 13 disappeared, but the present invention is not limited to this in order to generate UFB. For example, by communicating with the atmosphere before the generated film boiling bubbles 13 disappear, UFB can be generated even when the film boiling bubbles 13 are not exhausted.

Next, I will explain the remaining characteristics of UFB. The higher the temperature of the liquid, the lower the dissolution properties of the gaseous components, and the lower the temperature, the higher the dissolution properties of the gaseous components. That is, the higher the temperature of the liquid, the more likely the phase transition of dissolved gaseous components is promoted, and the more easily the UFB is generated. The temperature of the liquid and the solubility of the gas are in an inversely proportional relationship. As the temperature of the liquid rises, the gas exceeding the saturation solubility becomes bubbles and precipitates in the liquid.

For this reason, when the temperature of the liquid rises sharply from room temperature, the dissolution characteristics suddenly drop, and UFB begins to be generated. Then, as the temperature rises, the thermal dissolution characteristics decrease, resulting in a situation in which a large amount of UFB is generated.

On the contrary, when the temperature of the liquid drops from normal temperature, the dissolution characteristics of the gas rise and the generated UFB becomes easier to liquefy. However, such temperatures are well below ambient temperature. Furthermore, even if the temperature of the liquid drops, the UFB once generated has a high internal pressure and a high gas-liquid interfacial energy, so the possibility of a high pressure acting to break the gas-liquid interface is extremely low. That is, the UFB once produced does not disappear easily as long as the liquid is stored at normal temperature and normal pressure.

In this embodiment, the first UFB 11A described in FIGS. 7A to 7C and the third UFB 11C described in FIGS. It can be said that the UFB is generated using

On the other hand, in the relationship between liquid pressure and dissolution characteristics, the higher the liquid pressure, the higher the gas dissolution characteristics, and the lower the pressure, the lower the dissolution characteristics. That is, the lower the pressure of the liquid, the more likely the phase transition of the gas-dissolved liquid dissolved in the liquid to the gas is promoted, and the UFB is likely to be generated. When the pressure of the liquid is lowered from normal pressure, the dissolution characteristics drop sharply and UFB begins to be generated. As the pressure decreases, the pressure dissolution characteristics decrease, resulting in a situation in which a large amount of UFB is generated.

On the contrary, when the pressure of the liquid rises from normal pressure, the dissolution characteristics of the gas rise and the generated UFB becomes easier to liquefy. However, such a pressure is sufficiently higher than the atmospheric pressure, and even if the pressure of the liquid rises, the UFB once generated has a high internal pressure and a high gas-liquid interfacial energy, and thus destroys the gas-liquid interface. It is extremely unlikely that such high pressure would act. That is, the UFB once produced does not disappear easily as long as the liquid is stored at normal temperature and normal pressure.

In this embodiment, the second UFB 11B described in FIGS. 8A to 8C and the fourth UFB 11D described in FIGS. It can be said that the UFB is generated using

Above, the first to fourth UFBs with different generated factors have been individually explained, but the above-mentioned generating factors occur simultaneously and frequently with the event of film boiling. Therefore, at least two types of UFBs among the first to fourth UFBs may be generated simultaneously, and these generation factors may cooperate with each other to generate UFBs. However, it is common that all generation factors are caused by changes in the volume of film boiling bubbles generated by the film boiling phenomenon. In this specification, the method of producing UFB by utilizing film boiling accompanying rapid heat generation is referred to as T-UFB (Thermal-Ultra Fine Bubble) production method. Further, the UFB produced by the T-UFB producing method is called T-UFB, and the liquid containing T-UFB produced by the T-UFB producing method is called T-UFB-containing liquid.

Most of the bubbles generated by the T-UFB generation method are 1.0 μm or less, and millibubbles and microbubbles are difficult to generate. That is, according to the T-UFB generation method, UFB is predominantly and efficiently generated. In addition, the T-UFB produced by the T-UFB production method has a higher gas-liquid interfacial energy than the UFB produced by the conventional method, and does not disappear easily as long as it is stored at normal temperature and normal pressure. Furthermore, even if new T-UFB is generated by new film boiling, the previously generated T-UFB is prevented from disappearing due to the impact. In other words, it can be said that the number and concentration of T-UFB contained in the T-UFB-containing liquid have hysteresis characteristics with respect to the number of occurrences of film boiling in the T-UFB-containing liquid. In other words, the concentration of T-UFB contained in the T-UFB-containing liquid can be adjusted by controlling the number of heating elements arranged in the T-UFB generation unit 300 and the number of voltage pulse applications to the heating elements. .

Refer to Figure 1 again. After the T-UFB-containing liquid W having the desired UFB concentration is generated in the T-UFB generation unit 300 , the UFB-containing liquid W is supplied to the post-processing unit 400 .

11(a) to (c) are diagrams showing a configuration example of the post-processing unit 400 of this embodiment. The post-treatment unit 400 of the present embodiment removes impurities contained in the UFB-containing liquid W in stages in the order of inorganic ions, organic substances, and insoluble solids.

FIG. 11(a) shows a first post-treatment mechanism 410 for removing inorganic ions. The first post-treatment mechanism 410 includes an exchange container 411 , a cation exchange resin 412 , a liquid introduction path 413 , a water collection pipe 414 and a liquid outlet path 415 . The exchange container 411 contains a cation exchange resin 412 . The UFB-containing liquid W produced by the T-UFB production unit 300 is injected into the exchange container 411 via the liquid introduction path 413 and absorbed by the cation exchange resin 412, where cations as impurities are removed. be. Such impurities include metal materials separated from the element substrate 12 of the T-UFB generation unit 300, such as SiO ₂ , SiN, SiC, Ta, Al ₂ O ₃ , Ta ₂ O ₅ and Ir. be done.

The cation exchange resin 412 is a synthetic resin in which a functional group (ion exchange group) is introduced into a polymer matrix having a three-dimensional network structure. presenting. A styrene-divinylbenzene copolymer is generally used as the polymer base, and methacrylic acid-based and acrylic acid-based functional groups can be used as the functional group. However, the above materials are only examples. Various changes can be made to the above materials as long as the desired inorganic ions can be effectively removed. The UFB-containing liquid W absorbed by the cation exchange resin 412 and from which the inorganic ions have been removed is collected by the water collecting pipe 414 and sent to the next step through the liquid lead-out path 415 .

FIG. 11(b) shows a second post-treatment mechanism 420 for removing organic matter. The second post-treatment mechanism 420 includes a container 421 , a filtration filter 422 , a vacuum pump 423 , a valve 424 , a liquid introduction path 425 , a liquid extraction path 426 and an air suction path 427 . The inside of the storage container 421 is divided into upper and lower regions by a filtration filter 422 . The liquid introduction path 425 connects to the upper area of the upper and lower areas, and the air suction path 427 and the liquid lead-out path 426 connect to the lower area. When the vacuum pump 423 is driven with the valve 424 closed, the air in the container 421 is discharged through the air suction path 427, the pressure inside the container 421 becomes negative, and the UFB-containing liquid is drawn from the liquid introduction path 425. W is introduced. Then, the UFB-containing liquid W from which impurities have been removed by the filtration filter 422 is stored in the container 421 .

Impurities removed by the filtration filter 422 include organic materials that can be mixed in the tubes and each unit, such as organic compounds containing silicon, siloxane, and epoxy. Filter membranes that can be used for the filtration filter 422 include a sub-μm mesh filter that can remove even bacteria and an nm mesh filter that can remove viruses.

After a certain amount of the UFB-containing liquid W is stored in the container 421, the vacuum pump 423 is stopped and the valve 424 is opened. liquid. Here, the vacuum filtration method is used as a method for removing organic impurities, but gravity filtration or pressure filtration can also be used as a filtration method using a filter.

FIG. 11(c) shows a third post-treatment mechanism 430 for removing undissolved solids. The third post-treatment mechanism 430 comprises a sedimentation container 431 , a liquid introduction channel 432 , a valve 433 and a liquid outlet channel 434 .

First, with the valve 433 closed, a predetermined amount of the UFB-containing liquid W is stored in the precipitation container 431 from the liquid introduction path 432 and left for a while. During this time, the solids contained in the UFB-containing liquid W settle to the bottom of the sedimentation container 431 due to gravity. Among the bubbles contained in the UFB-containing liquid, relatively large-sized bubbles such as microbubbles also rise to the surface of the liquid due to buoyancy and are removed from the UFB-containing liquid. When the valve 433 is opened after a sufficient amount of time has passed, the UFB-containing liquid W from which solids and large-sized bubbles have been removed is sent to the recovery unit 500 through the liquid lead-out path 434 . In the present embodiment, an example in which three post-processing mechanisms are applied in order has been shown, but the present invention is not limited to this, and any post-processing mechanism may be employed as appropriate.

Refer to Figure 1 again. The T-UFB-containing liquid W from which impurities have been removed in the post-treatment unit 400 may be sent to the recovery unit 500 as it is, or may be returned to the dissolution unit 200 again. In the latter case, the dissolved gas concentration of the T-UFB-containing liquid W, which has decreased due to the production of T-UFB, can be replenished to the saturation state in the dissolving unit 200 again. Further, if new T-UFB is generated by the T-UFB generation unit 300, the concentration of UFB in the T-UFB-containing liquid can be further increased based on the characteristics described above. That is, the UFB content concentration can be increased by the number of circulations through the dissolving unit 200, the T-UFB generation unit 300, and the post-treatment unit 400, and after the desired UFB content concentration is obtained, the UFB-containing liquid W can be sent to the recovery unit 500 .

The recovery unit 500 recovers and stores the UFB-containing liquid W sent from the post-treatment unit 400 . The T-UFB-containing liquid recovered by the recovery unit 500 becomes a high-purity UFB-containing liquid from which various impurities have been removed.

In the recovery unit 500, several stages of filtering may be performed to classify the UFB-containing liquid W by T-UFB size. Further, since the TUFB-containing liquid W obtained by the T-UFB method is expected to have a temperature higher than normal temperature, the recovery unit 500 may be provided with a cooling means. Note that such a cooling means may be provided in a part of the post-processing unit 400 .

A unit for removing impurities as shown in FIGS. 11(a) to (c) may be provided upstream of the T-UFB generation unit 300, or may be provided both upstream and downstream. If the liquid supplied to the UFB generator is tap water, rain water, or contaminated water, the liquid may contain organic or inorganic impurities. If the liquid W containing such impurities is supplied to the T-UFB generation unit 300, there is a risk that the heating elements 10 will be degraded or salting out will occur. By providing a mechanism as shown in FIGS. 11(a) to 11(c) upstream of the T-UFB generation unit 300, the above impurities can be removed in advance.

The above is the outline of the UFB generation device 1, but of course the multiple units shown in the figure can be changed, and it is not necessary to prepare all of them. Depending on the intended use of the T-UFB-containing liquid to be produced, some of the units described above may be omitted, or other units may be added in addition to the units described above.

The bubble diameter of the T-UFB containing liquid containing ozone gas generated by this UFB generator 1 is 200 nm or less, the particle size distribution range is small, and the state of containing ozone gas can be maintained even after being left for half a year or more. . Therefore, the storage stability is better than that of UFB-containing liquids produced by other methods, which will be described later.

Unlike millibubbles and microbubbles, ultra-fine bubbles (UFB) with a diameter of less than 1.0 μm are not easily affected by buoyancy, so as long as the liquid is stored at normal temperature and pressure, it will not disappear easily. Therefore, the ozone UFB-containing liquid thus generated can be stored in a container or the like for a long period of time. Moreover, since it is housed in a predetermined container, it can be easily transported and can be transported by a general method.

FIG. 12 is a schematic diagram showing a defoaming unit 600 for defoaming USB in an ozone UFB-containing liquid in this embodiment. Here, as the defoaming unit 600, a transmitting unit of a commercially available ultrasonic cleaner is used. Note that the defoaming unit 600 is not limited to this. In other words, there is a shear type defoaming method in which bubbles are destroyed by the shearing force acting on the gap between the rotating disc and the orifice plate in the ozone UFB-containing liquid, and a swirling flow of the ozone UFB-containing liquid to concentrate only the bubbles in the center to eliminate and dissolve the bubbles. Defoaming by centrifugal separation may be used.

The antifoaming unit 600 is filled with water 601 such as tap water, and is set in a container 610 containing an ozone UFB-containing liquid 611 diluted as necessary. Next, ultrasonic waves are oscillated at 1.6 MHz and 100 W for 15 minutes. The ozone UFB-containing liquid 611 contains, in addition to the UFB, bubbles larger than the UFB, and aggregates of the UFB and large-sized bubbles. UFB and aggregates containing UFB are defoamed by ultrasonic waves, and ozone contained in UFB and aggregates is dissolved in water to obtain an ozone solution. This ozone-dissolved liquid is the same as the ozone-dissolved liquid generated in the pretreatment unit 100 (see FIG. 1), and it is known that the ozone concentration is halved in about one hour. In other words, it is preferable to perform the defoaming treatment in the defoaming unit 600 immediately before using the ozone solution. As a guideline, it is preferable to use the ozone solution within 30 minutes after it is produced.

In this embodiment, ultrasonic waves were applied at 1.6 MHz and 100 W for 15 minutes. The conditions may be adjusted such that the frequency is about 1 to 5 MHz, the intensity is about 50 to 250 W, and the time is about 5 to 30 minutes, and the conditions may be appropriately optimized according to the performance of the ultrasonic device. As a result, the UFB is defoamed and an ozone-dissolved liquid in which ozone gas is dissolved can be produced.

When the UFB-containing liquid is irradiated with a green laser beam, the laser beam is scattered by the bubbles and a green emission line can be visually observed. When the bubbles disappear, the scattering of the laser beam disappears and the emission line cannot be observed. By such a method, it is possible to confirm the state in which the bubbles (USB) in the UFB-containing liquid are defoamed and dissolved.

Here, an example of a method for measuring the ozone concentration of an ozone-dissolved liquid prepared by defoaming and dissolving UFB in an ozone UFB-containing liquid will be described. When ozone is reacted with an absorption solution (neutral phosphate-buffered potassium iodide solution), potassium iodide is oxidized to
Formula: 2KI + _O3 + _H2O → _I2 + _O2 + 2KOH
The reaction liberates iodine and develops a yellow-brown color in a potassium iodide solution. The absorbance of this coloring solution at a wavelength of 352 nm is measured to determine the concentration of ozone. The method will be described below.

As an ozone absorbing solution (neutral phosphate buffered potassium iodide solution), dissolve 27.2 g of potassium dihydrogen phosphate, 28.4 g of anhydrous disodium hydrogen phosphate, and 20 g of potassium iodide in about 800 mL of water. Then adjust to pH 6.8-7.2 with 10% sodium hydroxide solution and make up to 1000 mL with water. The prepared ozone-absorbing liquid and ozone-dissolving liquid are mixed and stirred at a ratio of 1:1 (for example, 10 ml each), and the absorbance at a wavelength of 352 nm is measured using a spectrophotometer. The ozone absorbing solution and distilled water are mixed and stirred at a ratio of 1:1, and the absorbance is measured in the same manner as the blank absorbance.

Next, we will explain how to calculate the ozone concentration from the absorbance. To prepare the standard solution, take 10 mL of 0.1N iodine standard solution and make up to 100 mL with water. Take 4.17/F (factor) = X mL of this solution (F: described in the reagent, approximately 1), and make up to 100 mL with the above ozone absorbing solution. 1 mL of the prepared reference solution corresponds to 10 μg of ozone. Next, take 1.0, 3.0, 5.0, 7.0, 9.0 and 10.0 mL of the standard solution, add the above ozone absorbing solution to make 10 mL each, and add 10 mL each of distilled water. to mix. Then, absorbance at a wavelength of 352 nm is measured to create a calibration curve. By using the obtained calibration curve, the ozone concentration of the ozone solution can be calculated.

As a result of measuring the ozone concentration in this way, even after long-term storage without decomposing ozone in the state of the ozone UFB-containing liquid, the ozone-dissolved liquid immediately after being created by defoaming the UFB of the ozone UFB-containing liquid with ultrasonic waves was confirmed to be in a state of high ozone concentration.

Regarding the ozone-UFB-containing liquid generated by a method other than T-UFB, the concentration of the ozone-dissolved liquid immediately after defoaming by ultrasonic waves was confirmed, but compared to the ozone-UFB-containing liquid generated by the T-UFB method, The resulting ozone concentrations were low.

FIG. 13 is a flow chart showing the procedure of the ozone solution utilization method in this embodiment. Hereinafter, the method for utilizing the ozone solution in this embodiment will be described using this flow chart. In addition, "S" means a step in each process.
In the ozone dissolved liquid utilization method in this embodiment, first, the dissolved ozone liquid is generated by the dissolving unit 200 in S001, and then the ozone UFB-containing liquid containing ozone gas is generated by the T-UFB generation unit 300 in S002. Here, it is also possible to increase the UFB concentration by circulating the T-UFB generation unit 300 multiple times. Then, in S003, the generated ozone UFB-containing liquid is stored in a container or the like (not shown). The container containing the ozone UFB-containing liquid is then transported to a location where the ozone UFB-containing liquid is utilized. Since it is in a liquid state in a container, it can be transported by common methods.

The UFB containing ozone gas has a size of 200 nm or less in diameter. Unlike millibubbles and microbubbles, UFBs are not easily affected by buoyancy, so they rise to the liquid surface and float in the liquid without disappearing. Therefore, the ozone UFB-containing liquid can contain ozone at an ozone solubility (generally 0.6 g/L in water at room temperature) or more, and can maintain a stable concentration. That is, even after such storage and transportation, the UFB in the ozone UFB-containing liquid does not disappear, and the ozone UFB-containing liquid can have long-term storage stability, storage efficiency, and transportation efficiency.

After that, in S004, the ozone UFB-containing liquid is diluted as necessary. By diluting the ozone UFB-containing liquid to a desired concentration, an ozone-dissolved liquid having a concentration suitable for the purpose of use can be prepared.

Next, in S005, the ozone UFB in the ozone-containing liquid is defoamed and dissolved by a defoaming unit 600 (see FIG. 12) such as an ultrasonic device, and in S006 an ozone-dissolved liquid having a desired concentration is generated. Thereafter, in S007, the generated ozone solution is utilized for desired purposes such as sterilization, deodorization, and cleaning. Here, considering the reduction of ozone in the ozone-dissolved liquid after ozone dissolution, the time from defoaming of UFB in S005 to application as the ozone-dissolved liquid in S007 is preferably within 30 minutes as a standard.

In this way, the liquid in which the ultra-fine bubbles containing ozone are generated is generated in advance, the ultra-fine bubbles are defoamed by the defoaming means at a desired timing, and the ozone gas is dissolved in the liquid. Desired processing such as sterilization is performed with an ozone solution. As a result, an ozone solution having a desired concentration that can be applied at a desired time can be produced in a small size and with a simple configuration.

Below, several examples will be given to explain the utilization of the ozone solution in S007.

(Example 1)
In this embodiment, a case will be described in which the ozone solution produced by the above production method is utilized for sterilization in S007 of FIG.

FIG. 14 compares the sterilization effect of an ozone-dissolved liquid (hereinafter also referred to as a sterilization liquid) generated by irradiating an ozone UFB-containing liquid generated by the T-UFB method with ultrasonic waves to eliminate UFB. It is the figure which showed the result of having evaluated. Bacteria and fungi were prepared as samples for sterilization evaluation. The bacterial samples used were "Gram-negative bacilli" Escherichia coli, Salmonella and Vibrio parahaemolyticus. As mold samples, Aspergillus, Blue mold, Rhizopus and Ketama mold were used. As a comparison sample, when 400 ppm of hypochlorous acid water was used, when the ozone UFB-containing liquid was ultrasonically defoamed and dissolved after 30 days, the ozone-dissolved liquid which did not generate UFB was left for one day. When used, the case of distilled water in which ozone is not dissolved is shown.

Here, I will briefly explain the classification of bacteria. Bacteria are generally classified into two groups according to the structure of the outer wall of the cell. One is "Gram-positive bacteria" which has a relatively thick and hard outer wall, and the other is "Gram-negative bacteria" which has a relatively thin and fragile outer membrane. On the other hand, conventionally, bacteria are also classified according to their external shape, such as long-shaped "bacilli" and round-shaped "cocci." Bacteria can thus be classified from these combinations as "Gram-positive bacilli," "Gram-positive cocci," "Gram-negative bacilli," and "Gram-negative cocci," and the like. Escherichia coli, Salmonella, and Vibrio parahaemolyticus used as samples in this embodiment are included in "Gram-negative bacilli" and are typical Gram-negative bacilli. On the other hand, Bacillus natto is known as a representative of "Gram-positive bacilli".

On the other hand, "Kabi" is a common name for fungi that spans multiple classification items, and is a term that refers to a part of fungi, or a common name for a colony of microorganisms that looks similar to it and can be observed with the naked eye. is. Therefore, there are molds with various lifestyles. Aspergillus, blue mold, cruciferous mold, and vertebrate mold used as samples in this embodiment are so-called weed-like molds that quickly emerge in an artificial environment.

The test method for confirming the effect of the disinfectant solution in this example will be described below. First, each bacterial or fungal cell suspension was brought into contact with each sterilization solution for 72 hours. A 10e(+6)-fold dilution was prepared from the liquid after contact, and 100 μL of the dilution was smeared onto a plate medium. Furthermore, the smeared plate medium was cultured and the number of bacteria was measured. The results shown in FIG. 13 were obtained from the above tests.

As can be seen from FIG. 13, when the sterilization solution of this example was used, 98% or more of all bacteria samples and 90% or more of all mold samples were sterilized. Bacteria or fungi could be inactivated. Hypochlorous acid water of 400 ppm as a comparative sample had a 100% sterilization effect. Similarly, the sterilization effect of 90% or more reduction rate was also confirmed for the sterilization solution obtained by defoaming and dissolving the UFB with ultrasonic waves after storing the ozone UFB water for 30 days.

In addition, when using an ozone-dissolved solution that does not generate UFB and is used for comparison, and in the case of distilled water that does not dissolve ozone, ozone has no sterilizing effect and the reduction rate is 0%. Met. It is believed that the ozone-dissolved solution left for one day lost the dissolved ozone over time and could not obtain the sterilization effect.

(Example 2)
It is known that the ozone solution has a higher cleaning effect than tap water or the like. Therefore, in this embodiment, the ozone-dissolved liquid obtained by defoaming the UFB with ultrasonic waves or the like immediately before use is caused to flow over the surface of the object in a state of high ozone concentration in S006 of FIG. As a result, contaminants stuck to the object can be peeled off from the surface of the object and washed. Its cleaning effect is higher than that of tap water or a detergent in which a surfactant is dissolved.

(Example 3)
Ozone is known to have a strong oxidizing action and to detoxify harmful organic substances. Examples of harmful organic substances include persistent chlorides such as trichlorethylene, tetrachlorethylene, dichloromethane and carbon tetrachloride. Substances that have a detoxifying effect are not limited to this. In this embodiment, the ozone-dissolved liquid obtained by defoaming the UFB with ultrasonic waves or the like immediately before use is used as a solution containing harmful substances in a state of high ozone concentration in S006 of FIG. Mix, stir. As a result, chemical reactions with hard-to-decompose harmful organic substances can be caused to reduce the molecular weight and change them into harmless organic substances.

In each of the above examples, it was explained that the ozone solution obtained by defoaming and dissolving the UFB in the ozone UFB-containing liquid has the effects of sterilization, cleaning, and detoxification of harmful chemical substances. Although individual explanations are omitted, it can be suitably used in places where there is immediate effect by using it as an ozone dissolution liquid rather than using it as an ozone UFB-containing liquid, such as deodorizing effect and surface modification of plastics and metals. can.

(Other embodiments)
In the above, the case of generating the ozone UFB-containing liquid by the T-UFB method has been described, but the generation method is not limited to the T-UFB method as long as UFB containing ozone can be generated. For example, in the air bubble generator represented by the venturi system, a mechanical pressure reduction structure such as a pressure reduction nozzle is provided in a part of the flow path, and the liquid is caused to flow at a predetermined pressure so as to pass through this pressure reduction structure. It is also possible to generate an ozone-encapsulated UFB. Alternatively, a piezoelectric element or the like may be used to generate the ozone UFB-containing liquid.

Regardless of which generation method is adopted, the ultra-fine bubble-containing liquid containing ozone is generated in advance, and the UFB is defoamed to turn ozone into a liquid at the desired timing when the ozone-containing liquid is actually used. should be dissolved in As a result, it is possible to produce an ozone solution having a desired concentration that can be applied at a desired time, with a small size and a simple configuration.

10 heating element 100 pretreatment unit 200 dissolution unit 300 T-UFB generation unit 400 posttreatment unit 500 recovery unit 600 defoaming unit W liquid

The present disclosure is not limited to the above embodiments, and various modifications and variations are possible without departing from the spirit and scope of the present disclosure. Accordingly, the following claims are appended to publicize the scope of the present disclosure.

This application claims priority based on Japanese Patent Application No. 2021-186986 filed on November 17, 2021, and the entire contents thereof are incorporated herein.

Claims (11)

1. a first dissolving step of dissolving ozone gas in a liquid;
   an ultra-fine bubble generating step of generating ultra-fine bubbles in the ozone solution obtained by dissolving the ozone gas in the first dissolving step;
   a storage step of storing the liquid containing the ultra-fine bubbles generated in the ultra-fine bubble generation step;
   A defoaming step of defoaming ultra-fine bubbles contained in the liquid stored in the storage step;
   a second dissolving step of dissolving the ultra-fine bubbles defoamed in the defoaming step in a liquid;
   an applying step of applying an ozone solution in which ozone gas is dissolved in the second dissolving step;
   A method of utilizing an ozone solution, characterized by having
2. The method of utilizing the ozone solution according to claim 1, wherein in the defoaming step, ultra-fine bubbles are defoamed by ultrasonic waves.
3. The method of utilizing the ozone-dissolved liquid according to claim 1 or 2, wherein the ultra-fine bubble generation step generates ultra-fine bubbles by causing film boiling in the liquid.
4. The method of utilizing the dissolved ozone solution according to any one of claims 1 to 3, wherein in the applying step, the dissolved ozone solution is brought into contact with bacteria or fungi to inactivate them.
5. The method of utilizing the dissolved ozone solution according to any one of claims 1 to 3, wherein in the applying step, the object is washed by flowing the dissolved ozone solution while contacting the object.
6. The method of utilizing the dissolved ozone solution according to any one of claims 1 to 3, wherein in the application step, the dissolved ozone solution is brought into contact with the harmful substance to detoxify the harmful substance.
7. The method for utilizing the ozone-dissolved liquid according to any one of claims 1 to 6, further comprising a step of diluting the liquid containing ultra-fine bubbles before the defoaming step.
8. The method for utilizing the ozone-dissolved liquid according to any one of claims 1 to 7, wherein in the storage step, the liquid containing ultra-fine bubbles is stored in a predetermined container and transported.
9. The method of utilizing the dissolved ozone solution according to any one of claims 1 to 8, wherein the applying step is performed within 30 minutes after the second dissolving step.
10. a first dissolving step of dissolving ozone gas in a liquid;
    an ultra-fine bubble generating step of generating ultra-fine bubbles in the ozone solution obtained by dissolving the ozone gas in the first dissolving step;
    a defoaming step of defoaming the ultra-fine bubbles generated in the ultra-fine bubble generating step by defoaming means;
    a second dissolving step of dissolving the ozone gas contained in the ultra-fine bubbles defoamed in the defoaming step into a liquid;
    A method for producing an ozone solution, comprising:
11. The method for producing an ozone solution according to claim 10, wherein in the defoaming step, ultra-fine bubbles are defoamed by ultrasonic waves.

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