Ozone water generating device

Abstract

The present application relates to an ozone water generating apparatus including: an ozone gas supply line (L1a) for supplying ozone gas; a circulation line (L2a) for circulating a solvent capable of dissolving ozone gas supplied via a gas-liquid mixer (21); and a control unit (6) that controls the circulation line (L2a). The ozone gas supply line (L1a) has: an on-off valve (13) for switching to allow and block the flow of ozone gas in the ozone gas supply line (L1a); and a pressure gauge (14) for measuring the gas pressure on the downstream side of the on-off valve (13) in the ozone gas supply line (L1a). The control unit (6) compares the measured value of the pressure gauge (14) with an arbitrary pressure threshold value set to be equal to or less than the saturated vapor pressure of the solvent, and controls the switching of the on-off valve (13). When the measured value of the pressure gauge (14) becomes equal to or higher than the pressure threshold value, the on-off valve (13) is closed.

Description

Technical Field

[0001] This invention relates to a technology that can contribute to ozone water generation devices. Background Technology

[0002] Ozone water, obtained by dissolving ozone in a solvent (e.g., raw water such as pure water), has strong oxidizing power and has therefore been used for sterilization, for example, in water supplies and food. The use of ozone water is considered an environmentally friendly method because ozone easily decomposes into oxygen and leaves no residual chemicals.

[0003] In recent years, attempts to use ozone water in cleaning processes during the manufacture of various industrial components (e.g., precision electronic components such as semiconductor elements or display components of FPDs) have been made, and research is underway on high concentrations of ozone water, its stable industrial supply, and other aspects.

[0004] Patent Document 1 discloses a method for highly concentrating ozone water by means of the following configuration: First, ozone water obtained by cooling (concentrating) ozone gas is revaporized, and the ozone gas obtained by revaporation (concentrated ozone gas) is collected by a cooling collector, and further, the collected substance (liquid ozone or solid ozone) is dissolved in water to obtain ozone water.

[0005] Patent document 2 discloses a method for maintaining a high ozone concentration in a cleaning solution and making the resist film easy to remove by means of a cleaning solution obtained by simultaneously dissolving ozone gas and carbon dioxide gas in raw water (e.g., raw water below 25°C (preferably 5°C to 20°C)) and then contacting the resist film (organic film) on the substrate with the solution heated to above 45°C.

[0006] Patent Document 3 discloses a method for generating ozone water by mixing ozone gas and raw water in an ozone gas generating device (in Patent Document 3, a device that uses oxygen as a raw material) using a gas-liquid mixer. The ozone gas dissolution efficiency can be increased by providing a throttling orifice between the ozone gas generating device and the gas-liquid mixer, and the ozone gas generating device side can be kept from being in a negative pressure state (that is, a state less than atmospheric pressure (about 101.33 kPa)).

[0007] Patent document 4 discloses a configuration that effectively utilizes exhaust ozone gas to highly concentrate ozone water. This configuration has an ozone water circulation pipeline for circulating ozone water and an ozone gas contact mechanism (a permeation membrane formed of fluororesin) that brings exhaust ozone gas discharged from the ozone water circulation pipeline into contact with the raw water.

[0008] Patent Document 5 discloses the generation of ozone water by mixing ozone gas from an ozone gas generating device (in Patent Document 5, a device using oxygen as a raw material) and raw water using a gas-liquid mixer, wherein high-concentration ozone water is prepared by passing ozone water (ozone water in the tank shown by reference numeral 34 in Patent Document 5) whose concentration has been excessively reduced due to the raw water through the gas-liquid mixer.

[0009] Non-Patent Document 1 discloses the use of CF4 gas as an inhibitor to suppress rapid self-decomposition reactions in cases where external factors (e.g., electrical sparks, triggering of decomposition induced by pollutants, etc.) may cause ozone self-decomposition reactions.

[0010] According to the configuration shown in Patent Documents 1 to 5, ozone water with a certain level of ozone concentration (e.g., about 100 ppm) can be generated, but in cleaning processes that require relatively high oxidizing power, it is believed that ozone water with a higher concentration (e.g., more than 200 ppm in the cleaning process of semiconductor devices) is needed.

[0011] Existing technical documents

[0012] Patent documents

[0013] Patent Document 1: Japanese Patent Application Publication No. H11-262782

[0014] Patent Document 2: Japanese Patent No. 4296393

[0015] Patent Document 3: Japanese Patent No. 4746515

[0016] Patent Document 4: Japanese Patent No. 5213601

[0017] Patent Document 5: Japanese Patent No. 7041466

[0018] Non-patent literature

[0019] Non-patent document 1: Taiyo Nippon Sanso Technical Report No. 28 (2009) "Measurement Device for Explosion Limits". Summary of the Invention

[0020] The problem to be solved by the present invention

[0021] For example, as a configuration of a gas-liquid mixer for an ozone water generating device disclosed in Patent Documents 3 and 5, a configuration having a solvent flow channel and an ozone gas introduction channel may be mentioned, through which a solvent (e.g., raw water) flows, and the ozone gas introduction channel is connected to the solvent flow channel and introduces ozone gas supplied to the gas-liquid mixer into the solvent flow channel.

[0022] In the case of such a gas-liquid mixer, a suction pressure is generated in the ozone gas inlet channel based on the flow rate (velocity) of the solvent flowing through the solvent flow channel. Then, based on the suction pressure generated in the ozone gas inlet channel as described above (hereinafter appropriately referred to as suction pressure), the ozone gas introduced from the ozone gas inlet channel into the solvent flow channel is mixed into the solvent and dissolved in the solvent.

[0023] However, if the suction pressure is too low, such as due to the operating conditions of the ozone water generator, it becomes difficult to dissolve ozone gas in the solvent. As a result, it may become difficult to generate ozone water with the desired concentration (high-concentration ozone water, etc.).

[0024] Furthermore, when the suction pressure becomes too low as described above, it is possible for the solvent in the solvent flow channel to flow backward toward the ozone gas supply source side (described later, such as an ozone gas supply line, etc.), which serves as the upstream side of the ozone gas inlet channel (hereinafter appropriately referred to as solvent backflow). In this case, moisture (e.g., the solvent itself, water vapor evaporated from the solvent, etc.; hereinafter appropriately collectively referred to as moisture) flows in and remains on the ozone gas supply source side, and ozone gas cannot be supplied to the gas-liquid mixer as desired. As a result, it becomes even more difficult to generate ozone water with the desired concentration.

[0025] In view of the above, the object of the present invention is to provide a technique that can help make it easier to generate ozone water with a desired concentration.

[0026] Problem-solving methods

[0027] The ozone water generating apparatus according to the present invention can help solve the above-mentioned problems, and in one aspect, the ozone water generating apparatus includes: an ozone gas supply line capable of supplying ozone gas; a circulation line for circulating a solvent capable of dissolving ozone gas, wherein the ozone gas is supplied to the circulation line via a gas-liquid mixer; and a control unit for controlling the ozone gas supply line.

[0028] The gas-liquid mixer has: a solvent flow channel through which solvent flows during solvent circulation; and an ozone gas inlet channel configured to be connected to the solvent flow channel and to introduce ozone gas supplied from an ozone gas supply line into the solvent flow channel.

[0029] The ozone gas supply line includes: a first switching valve capable of switching between allowing and preventing the flow of ozone gas in the ozone gas supply line; and a pressure gauge capable of measuring the gas pressure downstream of the first switching valve in the ozone gas supply line.

[0030] The control unit is configured to compare the pressure gauge reading with an arbitrary pressure threshold set to be equal to or less than the saturated vapor pressure of the solvent, and the control unit is configured to control the switching of the first switching valve.

[0031] Furthermore, the vapor pressure of the solvent, obtained by measuring the temperature of the solvent in the circulation state, is set as a pressure threshold, and the control unit is configured to close the first switching valve when the pressure gauge reading becomes equal to or higher than the pressure threshold.

[0032] Furthermore, a discharge line capable of draining water that has flowed into the downstream side of the first switching valve in the ozone gas supply line can be provided, and the discharge line can have a second switching valve capable of switching between allowing and preventing the flow of water in the discharge line.

[0033] In addition, the control unit can be configured to set the vapor pressure of the solvent, obtained by measuring the temperature of the solvent in the cyclic state, as a pressure threshold, and to open the second switching valve when the pressure gauge reading becomes equal to or higher than the pressure threshold.

[0034] In addition, a moisture-detecting sensor can be placed downstream of the first switching valve in the ozone gas supply line, and the control unit can be configured to open the second switching valve when the sensor detects moisture.

[0035] In addition, the control unit can be configured to close the first switching valve when the pressure gauge reading becomes greater than the ozone gas supply pressure.

[0036] In another aspect of the generating apparatus, the generating apparatus includes: an ozone gas supply line capable of supplying ozone gas; a circulation line for circulating a solvent capable of dissolving ozone gas, wherein the ozone gas is supplied to the circulation line via a gas-liquid mixer; and a control unit configured to control the ozone gas supply line.

[0037] The gas-liquid mixer has: a solvent flow channel through which solvent flows during solvent circulation; and an ozone gas inlet channel configured to be connected to the solvent flow channel and to introduce ozone gas supplied from an ozone gas supply line into the solvent flow channel.

[0038] The ozone gas supply line includes: a first switching valve capable of switching between allowing and preventing the flow of ozone gas in the ozone gas supply line; a pressure gauge capable of measuring the gas pressure downstream of the first switching valve in the ozone gas supply line; and a discharge line connected to the ozone gas supply line and capable of discharging gas components from the ozone gas supply line.

[0039] The discharge line is connected upstream of the first switching valve in the ozone gas supply line via a second switching valve, which is capable of switching between allowing and blocking the flow of gas components in the discharge line.

[0040] The control unit is configured to open the second switch valve in the discharge line when the ozone gas supply in the ozone gas supply line is stopped and the first switch valve is closed.

[0041] In addition, the ozone gas supply line may also include a purge gas supply line capable of supplying purge gas into the ozone gas supply line, and the purge gas supply line is connected to the upstream side of a first switching valve in the ozone gas supply line, and has a third switching valve capable of switching between allowing and blocking the flow of purge gas in the purge gas supply line.

[0042] In addition, the control unit can be configured to open the third switching valve when the supply of ozone gas in the ozone gas supply line is stopped and the first and second switching valves are closed.

[0043] In addition, an analyzer capable of detecting and analyzing gas components can be connected to the upstream side of the first switching valve in the ozone gas supply line.

[0044] In addition, the control unit can be configured to detect and analyze the gas composition by an analyzer when the supply of ozone gas in the ozone gas supply line is stopped and the first and second switching valves are closed.

[0045] As described above, according to the present invention, it is possible to facilitate the generation of ozone water (high concentration ozone water, etc.) with a desired concentration. Attached Figure Description

[0046] Figure 1 This is a schematic configuration diagram illustrating the configuration of the ozone water generating device A according to an embodiment.

[0047] exist Figure 2 In the diagram, (a) is the saturated vapor pressure curve of water, and (b) is the water vapor pressure gauge.

[0048] Figure 3 This is a schematic configuration diagram illustrating the configuration of the ozone water generating device B according to an embodiment.

[0049] Figure 4 This is a schematic configuration diagram used to illustrate the configuration of generating device B1, which is a variant of generating device B.

[0050] Figure 5 This is a schematic configuration diagram used to illustrate the configuration of generating device B2, a variant of generating device B.

[0051] Figure 6 This is a schematic configuration diagram used to illustrate the configuration of generating device B3, which is a variant of generating device B.

[0052] Figure 7 This is a schematic configuration diagram used to illustrate the configuration of generating device B4, which is a variant of generating device B. Detailed Implementation

[0053] The ozone water generating apparatus of the present invention is completely different from the configuration using only a gas-liquid mixer (hereinafter appropriately referred to as the conventional configuration) shown in, for example, Patent Documents 3 and 5.

[0054] That is, in this embodiment, the device includes: an ozone gas supply line capable of supplying ozone gas; a circulation line that allows the solvent capable of dissolving the ozone gas supplied via the gas-liquid mixer to circulate; and a control unit for controlling the ozone gas supply line.

[0055] The ozone gas supply line includes: a switching valve (the first switching valve in claim 1) capable of switching between allowing and preventing the flow of ozone gas in the ozone gas supply line; and a pressure gauge capable of measuring the gas pressure downstream of the switching valve in the ozone gas supply line.

[0056] The control unit is configured to compare the pressure gauge reading with an arbitrary pressure threshold, which is set to be equal to or less than the saturated vapor pressure of the solvent, and the control unit is configured to control the switching of the on / off valve. Then, in the control unit, when the pressure gauge reading becomes equal to or higher than the pressure threshold, the on / off valve switches to the closed state.

[0057] According to this embodiment, a situation where the pressure gauge reading becomes equal to or higher than the aforementioned pressure threshold is considered as follows: for example, the suction pressure decreases and solvent backflow may occur, and the switching valve is closed by the control unit. Thus, it becomes possible to suppress (by blocking the switching valve) the inflow of moisture into the ozone gas supply line.

[0058] If moisture inflow into the ozone gas supply line can be suppressed in this way, then when the subsequent suction pressure increases and the solvent backflow is resolved (e.g., when the pressure gauge reading falls below the pressure threshold and it can be determined that the solvent backflow has been resolved), the state of generating ozone water with the desired concentration can be easily and quickly restored. That is, by using the control unit to open the switching valve and supplying ozone gas from the ozone gas supply line to the gas-liquid mixer, the ozone gas can be introduced into the solvent flow channel via the ozone gas inlet channel, resulting in a state where the ozone gas dissolves in the solvent.

[0059] The generating apparatus of this embodiment can have any configuration, as long as it can control the switching of the on / off valve in the ozone gas supply line based on the comparison between the measured value of the pressure gauge in the ozone gas supply line and the pressure threshold, as described above. That is, general technical knowledge from various fields (e.g., fields of generating ozone gas, ozone water, etc.) can be appropriately applied, and design modifications can be made as needed by referring to prior art documents, etc., and an example of such a configuration is the embodiment described below. Furthermore, in the embodiments described later, detailed descriptions are appropriately omitted, for example, by referring to the same reference numerals for similar content.

[0060] <Reference>

[0061] For example, in a conventional configuration, when the supply pressure of ozone gas to the gas-liquid mixer is set only to high pressure (a pressure higher than atmospheric pressure), the ozone gas readily dissolves in the solvent, and there is a possibility of obtaining high-concentration ozone water. However, when the supply pressure of ozone gas is set only to high pressure as described above, as shown in Non-Patent Document 1, a rapid self-decomposition reaction of ozone may easily occur, making it difficult to maintain practical safety and potentially preventing the achievement of a stable industrial supply.

[0062] Furthermore, in the case of conventional ozone gas generating devices (ozone generators) with standard configurations, the ozone gas that can be generated has a low concentration (e.g., less than 20% ozone concentration by volume) and contains a large amount of gases composed of components other than ozone (e.g., oxygen, etc.) (hereinafter appropriately referred to as non-ozone components). Even with such low-concentration ozone gas, it is difficult to generate high-concentration ozone water, resulting in the dissolution of a large amount of non-ozone components.

[0063] Furthermore, the highly concentrated ozone water prepared by dissolving the aforementioned low-concentration ozone gas in a solvent under high pressure results in both ozone and non-ozone components being dissolved in a supersaturated state. When this ozone water is released into the atmosphere, bubbles generated by the non-ozone components easily dissipate into the atmosphere, while ozone components also easily dissipate, making it impossible to maintain the highly concentrated state of the ozone water.

[0064] In recent years, high concentrations (e.g., ozone concentrations of 50% or more by volume) of ozone gas have been generated by concentrating ozone gas produced by ozone generators, for example, through adsorption concentration methods (such as surface adsorption using silica gel) and cooling concentration methods.

[0065] For example, the cooling and concentrating ozone gas generator (trade name: Pure Ozone Generator) manufactured by Meidensha can also generate ozone gas with an extremely high concentration (over 90% ozone concentration by volume) close to about 100% ozone concentration by volume, and has achieved practical safety by obtaining international safety standard SEMI-S2 certification.

[0066] There is no particular limitation on the supply pressure of ozone gas concentrated in this way, and examples include setting it to a depressurized state so that the aforementioned rapid self-decomposition reaction does not occur, but it is not limited thereto.

[0067] As an example of setting the above-mentioned depressurization state, in the case of ozone gas with an ozone concentration of 90% or more by volume and an oxygen concentration of less than 10% by volume, the total pressure of the ozone gas can be set to a depressurization state of 30 kPa (abs) or less (that is, a state where the ozone partial pressure is 30 kPa (abs) or less), thereby safely maintaining the ozone gas.

[0068] Furthermore, in the case of ozone gas with an ozone concentration of 50% or more by volume and an oxygen concentration of less than 50% by volume, the total pressure of the ozone gas can be set to a reduced pressure state of 60 kPa (abs) or less (that is, a state where the ozone partial pressure is 30 kPa (abs) or less), thereby safely maintaining the ozone gas.

[0069] When the ozone gas supply pressure is low (e.g., under the pressure reduction conditions described above), solvent backflow may easily occur. However, in this case, solvent backflow can be actively suppressed. For example, in the case of the control unit 6, which will be described later, it can be actively controlled by appropriately acquiring the state information described later (e.g., controlling it while detecting, predicting, or otherwise preventing events that may cause solvent backflow).

[0070] <<Example>>

[0071] <Example of the configuration of generation apparatus A according to the embodiment>

[0072] Figure 1 This is a schematic configuration diagram illustrating the arrangement of an ozone water generating apparatus A according to an embodiment. The apparatus A mainly comprises: an ozone gas supply unit 1, capable of supplying ozone gas with an ozone concentration of 50% or more by volume (e.g., capable of supplying ozone gas under reduced pressure); and a circulation unit 2, capable of introducing and circulating a solvent for dissolving the ozone gas from the ozone gas supply unit 1 into the circulation unit. Figure 1 The process involves: a clockwise circulation unit 1, a solvent supply unit 2, a solvent supply unit 3, a control unit 6, and a control unit 6. The control unit 6 appropriately acquires information indicating the status of the ozone gas supply unit 1, the circulation unit 2, the solvent supply unit 3, etc. (e.g., the measured value of the pressure gauge 14 in the ozone gas supply line L1a, which will be described later; the measured value of the circulation flow meter 22 in the circulation line L2a (circulation flow rate); the measured value of the resistance temperature detector 24 (solvent temperature), etc.; hereinafter, as appropriate, they are collectively referred to as status information) and controls the ozone gas supply unit 1, the circulation unit 2, the solvent supply unit 3, etc.

[0073] In addition, Figure 1 In the case of device A shown, the device includes: a discharge unit 4 that discharges the solvent of the circulation unit 2 to the outer periphery of the circulation unit 2 (discharging the solvent in which ozone gas is dissolved, i.e., ozone water); and an exhaust unit 5 that can discharge the gas phase gas separated from the solvent from the circulation unit 2, thereby forming a configuration in which the control unit 6 appropriately acquires and controls the status information.

[0074] <Configuration Example of Ozone Gas Supply Unit 1>

[0075] Figure 1 The ozone gas supply unit 1 shown mainly includes: an ozone gas generating device 10; an ozone gas supply line L1a that supplies ozone gas generated by the ozone gas generating device 10 to a circulation unit 2 (supplying ozone gas via a gas-liquid mixer 21, which will be described later); and a gas component discharge line L1b that is connected to the ozone gas supply line L1a and discharges gas components, such as ozone gas, from the ozone gas supply line L1a (e.g., to regulate the gas pressure of the ozone gas supply line L1a).

[0076] In the ozone gas generating device 10 of the ozone gas supply unit 1, any equipment can be used as long as it can generate ozone gas with an ozone concentration of 50% or more by volume and supply the ozone gas under reduced pressure, and various modes can be adopted. As an example, a configuration in which the ozone gas generated by the ozone generator, etc., is concentrated by adsorption concentration or cooling concentration can be mentioned.

[0077] Furthermore, adsorption concentration methods utilize surface adsorption phenomena, such as on silica gel, for concentration. However, if impurities such as NOx and heavy metals are mixed into the ozone gas to be concentrated, these impurities may also be concentrated during the process. Therefore, in the case of impurities, it is preferable to remove them beforehand.

[0078] On the other hand, cooling concentration is a method of vaporizing liquid ozone obtained by cooling the ozone gas to be concentrated. Furthermore, since ozone gas and impurities have different vapor pressures (e.g., differing by several orders of magnitude), theoretically, ozone gas concentrated by cooling concentration (vaporized ozone gas) will be virtually free of impurities. Therefore, when there is a possibility of impurities being mixed into the ozone gas to be concentrated, cooling concentration can be considered the preferred method.

[0079] Next, the ozone gas supply line L1a includes a gas flow controller 11 to control the flow rate of ozone gas flowing through the ozone gas supply line L1a. Furthermore, upstream of the gas flow controller 11 (on the ozone gas generating device 10 side), it includes a pressure gauge 12 that measures the gas pressure of the ozone gas flowing through the upstream side (that is, the supply pressure of the ozone gas supplied to the gas-liquid mixer 21, which will be described later).

[0080] Furthermore, downstream of the gas flow controller 11, the ozone gas supply line L1a includes a switching valve capable of freely switching between allowing and preventing the flow of ozone gas in the ozone gas supply line L1a (ozone gas supply or backflow). Figure 1 (The two switching valves in the middle) 13.

[0081] For the switching valve 13 (and various switching valves described later), for example, a check valve or the like can be used, but the switching valve is not limited to this and can be of any type, as long as it can be switched as described above. As a specific example, the switching valve 13 can be a valve that switches based on the pressure difference between the ozone gas supply pressure and the measurement value of the pressure gauge 14 described later (the pressure difference when the supply pressure is greater than the measurement value) and closes when the pressure difference reaches a certain value (e.g., 1 kPa or less).

[0082] Furthermore, downstream of the switching valve 13, the ozone gas supply line L1a includes a pressure gauge 14 for measuring the gas pressure downstream. This pressure gauge 14 allows for the measurement of the gas pressure corresponding to the suction pressure when ozone gas is drawn through the gas-liquid mixer 21 (described later), and allows for the assessment of the suction pressure.

[0083] Next, in the ozone gas supply line L1a, the gas component discharge line L1b is connected between the gas flow controller 11 and the switching valve 13, and includes a switching valve 15 that can freely switch between allowing and blocking the flow (exhaust) of gas components (e.g., ozone gas) from the ozone gas supply line L1a. Furthermore, downstream of the switching valve 15, it includes an ozone decomposer (ozone killer) 16 that decomposes the gas components (especially ozone gas) flowing through the gas component discharge line L1b into a safe state, and a vacuum pump 17 that draws in and discharges the decomposed ozone gas.

[0084] <Configuration example of loop unit 2>

[0085] Figure 1 The circulation unit 2 shown mainly includes a circulation pipeline L2a that can introduce solvent from the solvent supply unit 3 and circulate it, a circulation tank 20 connected to the circulation pipeline L2a and capable of introducing and storing a certain amount of solvent, a recirculation pipeline L2b that recirculates the solvent discharged from the circulation tank 20 back to the circulation pipeline L2a, and a gas-liquid mixer 21 that mixes the solvent and ozone gas.

[0086] In this circulation unit 2, the circulation line L2a is configured such that ozone gas supplied from the ozone gas supply unit 1 to the gas-liquid mixer 21 can be introduced into the circulation line L2a via the gas-liquid mixer 21 to dissolve it in the solvent. Figure 1 In the circulation unit 2 shown, the circulation line L2a and the gas-liquid mixer 21 are depicted as connected and integrated, but are not limited thereto, and the two can have independent configurations that are separate from each other.

[0087] Examples of gas-liquid mixers 21 include ejectors, suction devices, and jet pumps, but gas-liquid mixers are not limited to these and can be applied in various configurations. That is, gas-liquid mixer 21 can have any configuration as long as it has a solvent flow channel (not shown) and an ozone gas inlet channel (not shown), through which the solvent flows, and the ozone gas inlet channel is connected to the solvent flow channel and supplies ozone gas to the gas-liquid mixer 21 into the solvent flow channel.

[0088] According to the gas-liquid mixer 21 configured in this way, which has a solvent flow channel and an ozone gas inlet channel, a suction pressure is generated in the ozone gas inlet channel based on Bernoulli's theorem, according to the flow rate (velocity) of the solvent flowing through the solvent flow channel. Furthermore, vapor is generated in the ozone gas inlet channel based on the saturated vapor pressure characteristics of the solvent. For example, when the solvent is raw material water, it has... Figure 2 The characteristics are shown in the saturated vapor pressure curve of water and the water vapor pressure gauge.

[0089] According to such Figure 2 The saturated vapor pressure characteristics of the solvent shown indicate that the range in which the suction pressure becomes less than the saturated vapor pressure of the solvent can be used as the range in which ozone gas can be introduced into the solvent flow channel via the ozone gas introduction channel and can dissolve the ozone gas in the solvent (hereinafter appropriately referred to as the permissible suction pressure range). Therefore, in the control unit 6, it becomes possible to consider various settings of the permissible suction pressure range (e.g., setting the pressure threshold, described later, to be equal to or less than the saturated vapor pressure).

[0090] In the control unit 6, when measuring the solvent temperature (e.g., by means of the resistance temperature detector 24 described later) in a state where the solvent is circulating in the circulation line L2a (hereinafter appropriately referred to as the circulation state), the vapor pressure at that solvent temperature can be obtained by comparing the measured value with the saturated vapor pressure characteristics of the solvent. Then, various settings considering the obtained vapor pressure become possible.

[0091] Examples of settings include setting the obtained vapor pressure to a pressure threshold described later, and setting the ozone gas supply pressure to the gas-liquid mixer 21 to be higher than the obtained vapor pressure.

[0092] Furthermore, based on the saturated vapor pressure characteristics of the solvent as described above and the supply pressure of ozone gas to the gas-liquid mixer 21, a range of solvent temperatures (hereinafter appropriately referred to as the permissible suction temperature range) can be derived, within which the vapor pressure of the ozone gas inlet channel of the gas-liquid mixer 21 becomes less than the supply pressure. Considering the general solubility characteristics of the gas relative to the solvent (the tendency for solubility to increase as the solvent temperature decreases), this permissible suction temperature range is preferably set to a relatively low temperature range at which the solvent does not become solidified (e.g., a temperature higher than the solvent's freezing point or a temperature that can maintain a supercooled state).

[0093] Then, by appropriately controlling the solvent temperature within the permissible suction temperature range by the control unit 6 (as described in the temperature control steps below), the vapor pressure of the ozone gas inlet channel of the gas-liquid mixer 21 can be made less than the supply pressure of the ozone gas supplied to the gas-liquid mixer 21. Specifically, an example setting includes appropriately setting the measurement value of pressure gauge 14 to be less than the measurement value of pressure gauge 12. As a result, the ozone gas in the ozone gas supply line L1a can be easily introduced into the ozone gas inlet channel of the gas-liquid mixer 21, and the ozone gas can be mixed with and dissolved in the solvent.

[0094] Upstream of the gas-liquid mixer 21, the circulation line L2a includes a circulation flow meter 22 for measuring the circulation flow rate of the solvent circulating through the circulation line L2a. Downstream of the gas-liquid mixer 21, it includes a circulation pump for circulating the solvent. Figure 1 (Two circulating pumps in the middle) 23. Through including, as Figure 1 The two circulating pumps 23a and 23b shown can, for example, allow one of them to operate normally and the other to act as an auxiliary pump if the primary pressure of one of the circulating pumps drops too low. However, the other circulating pump can also be omitted appropriately depending on the state of the circulating unit 2 (circulation conditions, etc.).

[0095] Furthermore, downstream of the circulation pump 23, the circulation line L2a includes a resistance temperature detector for measuring the solvent temperature. Figure 1 The control unit 6 includes two resistance temperature detectors 24 and a temperature controller (e.g., a cooler) 25 for adjusting the solvent temperature. By appropriately controlling these resistance temperature detectors 24 and the temperature controller 25, the solvent temperature can be set within the permissible suction temperature range.

[0096] Next, the circulation tank 20 includes a bottom cylindrical outer peripheral wall 20a capable of introducing and storing a certain amount of solvent. On the upper side of the outer peripheral wall 20a, there is an inlet port 26 communicating with the downstream side of the resistance temperature detector 24b in the circulation line L2a (that is, the downstream side of the gas-liquid mixer 21), an inlet port 26a communicating with the pressure regulating line L3c described later, and an exhaust port 26b communicating with the gas exhaust line L5 described later.

[0097] On the lower side of the outer peripheral wall 20a, there is an outlet port 27 that communicates with the upstream side of the circulating flow meter 22 in the circulation pipeline L2a (i.e., the upstream side of the gas-liquid mixer 21) and a discharge port 28 that communicates with the solvent discharge pipeline L4 described later.

[0098] Next, the recirculation line L2b is configured to connect the upstream side of the solvent discharge line L4 (described later) and the upstream side of the circulation flow meter 22 in the circulation line L2a, and has a configuration capable of recirculating the solvent on the upstream side of the solvent discharge line L4 (i.e., the solvent discharged from the discharge port 28) back to the circulation line L2a. Furthermore, the recirculation line L2b includes an ozone concentration meter 29 capable of measuring the ozone concentration of the solvent recirculated by the recirculation line L2b. By installing the ozone concentration meter 29 in the recirculation line L2b in this way, instead of simply measuring the ozone concentration of the solvent in the circulation line L2a, it becomes possible to measure an ozone concentration similar to that of the solvent actually discharged from the circulation tank 20 (i.e., the target ozone water).

[0099] <Configuration example of solvent supply unit 3>

[0100] Figure 1 The solvent supply unit 3 shown includes a solvent supply line L3a capable of supplying solvent (e.g., raw water) to the circulation line L2a, a concentration regulating line L3b capable of supplying a concentration regulating gas (e.g., carbon dioxide gas) to stabilize the ozone concentration of the solvent in the circulation line L2a, and a pressure regulating line L3c capable of supplying a pressure regulating gas (e.g., an inert gas such as N2, Ar, or He) to regulate the pressure in the circulation tank 20.

[0101] In this solvent supply unit 3, the solvent supply line L3a is connected between two circulation pumps 23a and 23b in the circulation line L2a, and includes a solvent flow controller 31 capable of controlling the flow rate of the solvent flowing through the solvent supply line L3a. Furthermore, downstream of the solvent flow controller 31, it includes a water purification unit (e.g., a pure water production device) 32 capable of increasing the purity of the solvent flowing through the solvent supply line L3a, and a switching valve 33 capable of freely switching between allowing and preventing the flow of solvent in the solvent supply line L3a.

[0102] Next, the concentration regulating line L3b is connected between the two circulating pumps 23a and 23b in the circulation line L2a, and includes a gas flow controller 34 capable of controlling the flow rate of the concentration regulating gas flowing through the concentration regulating line L3b. Furthermore, downstream of the gas flow controller 34, it includes a switching valve 35 capable of freely switching between allowing and blocking the flow of the concentration regulating gas in the concentration regulating line L3b.

[0103] Next, the pressure regulating line L3c is connected to the inlet port 26a in the circulation tank 20, and includes a gas flow controller 36 capable of controlling the flow rate of the pressure regulating gas flowing through the pressure regulating line L3c.

[0104] <Configuration example of discharge unit 4>

[0105] Figure 1 The discharge unit 4 shown includes a solvent discharge line L4 that discharges solvent from the circulation tank 20 to the outer periphery of the circulation tank 20. The solvent discharge line L4 is connected in communication with the discharge port 28 in the circulation tank 20 and includes a discharge flow controller 41 capable of controlling the discharge flow rate of the solvent discharged via the solvent discharge line L4.

[0106] <Exhaust Unit 5 Configuration Example>

[0107] Figure 1 The exhaust unit 5 shown includes a gas exhaust line L5 that discharges gas (e.g., gaseous components separated from the solvent by gas-liquid separation) from the circulation tank 20 to the outer periphery of the circulation tank 20. This gas exhaust line L5 is connected to an exhaust port 26b in the circulation tank 20 and includes a switching valve (e.g., a back pressure regulating valve) 51 capable of freely switching between allowing and preventing the flow (exhaust) of gas in the circulation tank 20 while maintaining a constant pressure in the circulation tank 20. Furthermore, downstream of the switching valve 51, it includes an ozone concentration meter 52 capable of measuring the ozone concentration of ozone gas flowing through the gas exhaust line L5, and an ozone decomposer 53 that decomposes the ozone gas flowing through the gas exhaust line L5 into a safe state.

[0108] <Configuration Example of Control Unit 6>

[0109] Figure 1 The control unit 6 shown is sufficient to acquire and control the status information of each of the ozone gas supply unit 1, circulation unit 2, solvent supply unit 3, discharge unit 4 and exhaust unit 5 to obtain the configuration of the target ozone water, and is capable of applying various modes.

[0110] Specifically, examples of configurations include a mode in which the control unit 6 and devices (such as measuring instruments, regulators, controllers, switching valves, circulation pumps, and resistance temperature detectors) configured in each pipeline (ozone gas supply line L1a, gas component discharge line L1b, circulation line L2a, recirculation line L2b, solvent supply line L3a, concentration regulation line L3b, pressure regulation line L3c, solvent discharge line L4, and gas exhaust line L5) are appropriately connected via signal lines, etc., not shown in the figures.

[0111] According to this configuration, each pipeline can be operated appropriately to obtain the status information of the equipment, and based on the obtained status information, control commands can be output to the equipment to control the equipment.

[0112] <Example of ozone generation method for device A>

[0113] In the aforementioned apparatus A, for example, by appropriately executing the following circulation steps, temperature control steps, gas-liquid mixing steps, discharge steps, and exhaust steps, desired ozone water can be produced.

[0114] First, in the circulation step, solvent is supplied to circulation line L2a, for example, by opening the switch valve 33 of solvent supply line L3a, and circulation line L2a is filled with solvent. For example, the circulation volume of filling circulation line L2a is appropriately set such that the solvent level in circulation tank 20 is between inlet port 26 and outlet port 27.

[0115] Then, for example, by operating the circulation pump 23 of circulation line L2a, circulation line L2a enters the circulation state at a predetermined circulation flow rate. In this circulation state, the ozone concentration of the circulating solvent in circulation line L2a is stabilized and the pressure in circulation tank 20 is regulated by operating the concentration regulating line L3b and the pressure regulating line L3c as needed.

[0116] Next, in the temperature control step, the ozone gas supply pressure is based on the ozone gas supply pressure in the next stage ozone gas supply step, and so on. Figure 2 The saturated vapor pressure curve and the characteristics shown by the vapor pressure gauge pre-determine the allowable suction temperature range. Then, in circulation, while measuring the solvent temperature of the circulation line L2a by the resistance temperature detector 24, the temperature regulator 25 adjusts it so that the solvent temperature falls within the allowable suction temperature range. For example, in the case of preparing ozone water with an ozone concentration of 300 ppm or more, the allowable suction temperature range is set to be above the freezing point of the solvent and below 30°C, preferably below 15°C.

[0117] Next, in the gas-liquid mixing step, under circulation conditions, ozone gas is supplied to the gas-liquid mixer 21 by, for example, opening the switch valve 13 of the ozone gas supply line L1a. Here, since the circulating solvent temperature is kept within the allowable suction temperature range by the temperature control step in the previous stage, the supply pressure of the ozone gas supplied to the gas-liquid mixer 21 becomes greater than the vapor pressure of the ozone gas inlet channel of the gas-liquid mixer 21.

[0118] Therefore, the ozone gas supplied to the gas-liquid mixer 21 is introduced into the solvent flow channel via the ozone gas introduction channel in the gas-liquid mixer 21, and mixes with the solvent in the solvent flow channel to form a soluble state. Then, by dissolving the ozone gas in the solvent, the ozone concentration in the solvent is brought to the desired level.

[0119] Furthermore, when ozone gas is supplied via a gas-liquid mixing step, if the measured value of pressure gauge 14 becomes greater than the measured value of pressure gauge 12, the switching valve 13 is switched and controlled to the open state. This suppresses solvent backflow relative to the ozone gas supply line L1a.

[0120] Next, in the discharge step, under circulation conditions, the solvent in the circulation tank 20 is discharged (i.e., the target ozone water is obtained) by appropriately controlling the discharge flow controller 41 of the solvent discharge line L4. Furthermore, by appropriately supplying solvent from the solvent supply line L3a to the circulation line L2a, the discharge flow rate of the solvent is controlled to not exceed the circulation flow rate of the solvent in the circulation line L2a.

[0121] Therefore, solvent can be discharged while maintaining a certain amount of solvent stored in the circulation tank 20. That is, during the discharge step, ozone water with the desired ozone concentration can be continuously extracted.

[0122] Next, in the exhaust step, for example, by opening the switch valve 51 of the exhaust line L5, the gas present in the circulation tank 20 (e.g., the gas phase component separated from the circulating solvent by gas-liquid separation) is discharged to the outer periphery of the circulation tank 20.

[0123] <Example of the configuration of generation apparatus B according to the embodiment>

[0124] Device A is not limited to Figure 1 The configuration shown is as described, and its design can be modified appropriately. For example, as... Figure 3 As shown in device B, a configuration can be adopted in which the solvent supply line L3a and the concentration adjustment line L3b of the solvent supply unit 3 are positioned separately from each other within the circulation line L2a. Furthermore, in Figure 3 (and will be described later) Figures 4 to 7 In the text, the part related to "(" is appropriately omitted") is omitted. Figure 1 The diagram shows a component similar to the one shown.

[0125] exist Figure 3 In the case of apparatus B shown, an ozone concentration meter 29a capable of measuring the ozone concentration of the solvent in the recirculation state in the recirculation line L2b is provided between the gas-liquid mixer 21 and the circulation flow meter 22 in the circulation line L2a. Furthermore, a gas-liquid mixer (for example, having a configuration similar to the gas-liquid mixer 21) 38 for mixing the solvent and the concentration regulating gas is provided downstream of the pump 23 in the circulation line L2a.

[0126] Then, a solvent supply line L3a is configured to connect the gas-liquid mixer 21 and the ozone concentration meter 29a in the circulation line L2a. Figure 3In the case of the solvent supply line L3a shown, a temperature regulator (e.g., a heat exchanger) 37 is provided upstream of the solvent flow controller 31 in the solvent supply line L3a. This temperature regulator regulates the solvent temperature on the upstream side. Thus, with... Figure 1 Compared to device A, it is possible to easily set the solvent temperature of the solvent flowing to the gas-liquid mixer 21 as desired.

[0127] The concentration regulating line L3b is configured to connect downstream of the pump 23 in the circulation line L2a via the gas-liquid mixer 38. Thus, with Figure 1 Compared to device A, it is possible to easily supply the concentration-regulating gas to the solvent in the circulation line L2a.

[0128] In the apparatus B shown above, similar to apparatus A, the desired ozone water can be generated by appropriately performing the above-described circulation steps, temperature control steps, gas-liquid mixing steps, discharge steps, and exhaust steps.

[0129] <Configuration example for easily suppressing or eliminating solvent backflow>

[0130] In devices A and B, even if the suction pressure decreases according to, for example, the operating conditions of devices A and B (e.g., solvent temperature and circulation status) and a state occurs in which solvent backflow may occur relative to the ozone gas supply line L1a, the solvent backflow phenomenon can be suppressed or eliminated by presetting the allowable suction pressure range and allowable suction temperature range as described above in the control unit 6 and appropriately switching and controlling the switching valve 13.

[0131] The following will be based on a modification example of device B. Figure 4 and 5 The devices B1 and B2 shown illustrate an example configuration for suppressing or resolving solvent backflow in this manner. Furthermore, in the control unit 6 of devices B1 and B2, it is assumed that the pressure threshold used for comparison with the measurement value from pressure gauge 14 is set within the permissible suction pressure range.

[0132] exist Figure 4 In the illustrated device B1, for example, when ozone gas is supplied via a gas-liquid mixing step, the control unit 6 reads the measured value of the pressure gauge 14 at predetermined intervals and determines the value by comparing it with a pressure threshold. At this time, for example, if the suction pressure of the gas-liquid mixer 21 decreases according to the operating state of device B1, the measured value of the pressure gauge 14 increases.

[0133] Then, in the control unit 6, if it is determined that the measured value of the pressure gauge 14 is equal to or higher than the pressure threshold, the switching valve 13 is closed, and the gas-liquid mixing step is temporarily interrupted or stopped.

[0134] Therefore, even when the suction pressure decreases and solvent backflow occurs, and moisture may flow into the ozone gas supply line L1a, moisture can be suppressed or blocked by the switching valve 13.

[0135] Subsequently, in the control unit 6, the measured value of the pressure gauge 14 is read and compared with the pressure threshold. If it is determined that the measured value of the pressure gauge 14 is less than the pressure threshold (that is, if it can be determined that the solvent backflow phenomenon has been resolved), the switch valve 13 is opened and the gas-liquid mixing step can be resumed.

[0136] exist Figure 5 In the illustrated device B2, a sensor (e.g., a water level sensor, an infrared sensor, or an electromagnetic wave sensor) 13c is provided downstream of the switching valve 13 in the ozone gas supply line L1a (between the switching valve 13 and the gas-liquid mixer 21) to detect moisture flowing into the downstream side of the switching valve 13. Furthermore, a moisture discharge line L1c, capable of draining moisture flowing into the downstream side of the switching valve 13, is connected to the downstream side of the switching valve 13. This moisture discharge line L1c includes a switching valve 13d that can freely switch between allowing and preventing moisture flow from the downstream side of the switching valve 13. For example, this switching valve 13d is normally closed during the gas-liquid mixing step.

[0137] In the control unit 6 of such device B2, for example, while monitoring the state of the downstream side of the switching valve 13 (whether there is moisture, etc.) via sensor 13c, the determination is made by reading the measured value of pressure gauge 14 at predetermined intervals, similar to device B1, and comparing the measured value with a pressure threshold.

[0138] Then, in the control unit 6, if moisture is detected on the downstream side of the switching valve 13 via the sensor 13c, and / or if the measured value of the pressure gauge 14 is equal to or higher than the pressure threshold, the switching valve 13 is closed, and the gas-liquid mixing step is temporarily interrupted or stopped.

[0139] Therefore, even when the suction pressure decreases and solvent backflow occurs, and moisture may flow into the ozone gas supply line L1a, moisture can be suppressed or blocked by the switching valve 13. At this time, the switching valve 13d can be in the open state. Thus, for example, even if moisture flows into the downstream side of the switching valve 13, moisture can be discharged via the moisture discharge line L1c.

[0140] Subsequently, in the control unit 6, the measured value of the pressure gauge 14 is read and compared with the pressure threshold. If it is determined that the measured value of the pressure gauge 14 is less than the pressure threshold, and / or if moisture is not detected by the sensor 13c, the switching valve 13 is opened (and the switching valve 13d is closed), and the gas-liquid mixing step can be resumed.

[0141] In the ozone gas supply line L1a of the aforementioned devices B1 and B2, where a certain amount of water may flow in due to solvent backflow, for example... Figure 4 and Figure 5 As shown, for example, in the ozone gas supply line L1a, the gas-liquid mixer 21 and the switching valve 13 are arranged separately from each other (separated by a predetermined distance), and an allowable space 13e is provided between them.

[0142] For example, in the vertical direction of devices B1 and B2... Figure 4 and Figure 5 When the vertical directions shown are the same (hereinafter appropriately referred to as the up-down direction), the water flowing into the allowable space 13e is stored sequentially starting from the bottom side (gas-liquid mixer 21 side) of the allowable space 13e.

[0143] Therefore, even when the suction pressure is reduced and solvent backflow occurs, and moisture can flow into the ozone gas supply line L1a, the inflow of moisture to the upstream side of the switch valve 13 can be suppressed without performing switching control of the switch valve 13, etc. (that is, even if the switch valve 13 is in the open state) before the allowable space 13e is filled with moisture.

[0144] Furthermore, the capacity of the allowable space 13e can be appropriately set, and there is a possibility that the larger the capacity, the easier it is to suppress the inflow of moisture to the upstream side of the switch valve 13.

[0145] <Configuration example for removing residual moisture from ozone gas supply line L1a>

[0146] Under normal conditions, if ozone gas is exposed to parts of the ozone gas supply source that are prone to oxidation (e.g., pipes, joints (welded parts), and various devices and instruments made of metallic or organic materials) while moisture is present, the moisture and ozone gas interact, making corrosion in those parts more likely to occur. Furthermore, ozone gas readily decomposes at corroded sites, resulting in the possibility that it will be more difficult to produce ozone water with the desired concentration.

[0147] On the other hand, in devices A and B, even if moisture (water vapor, etc.) flows into and remains in the ozone gas supply line L1a due to phenomena such as solvent backflow (e.g., moisture adheres to the inner circumferential surface of the ozone gas supply line L1a), the moisture can be discharged through the gas component discharge line L1b by appropriately controlling the ozone gas supply line L1a and the gas component discharge line L1b using the control unit 6 (e.g., appropriately switching and controlling the switching valves 13, 15, etc.).

[0148] The following will be based on a variant of device B. Figure 6 The device B3 shown is an example of a configuration for discharging moisture in this manner. Furthermore, when the switch valve 18a, described later, is closed, it is set to stop supplying ozone gas from the ozone gas generating device 10.

[0149] Figure 6 The device B3 shown includes a switching valve 18a on the upstream side (ozone gas generating device 10 side) of the gas flow controller 11 in the ozone gas supply line L1a, which is capable of freely switching between allowing and blocking the flow of ozone gas (or gas components including residual moisture, purge gas, etc., described later) on the upstream side.

[0150] Furthermore, a purge gas supply line L1d, capable of supplying purge gas, is connected between the switching valves 13 and 18a in the ozone gas supply line L1a (hereinafter appropriately referred to as the connection between switching valves 13 and 18a). Figure 6 In the middle, it is connected between the gas flow controller 11 and the switching valve 18a. The purge gas supply line L1d includes a switching valve 18b that can freely switch between allowing and blocking the flow of purge gas (or gas components containing moisture, etc., remaining in the ozone gas supply line).

[0151] exist Figure 6 In the case of the purge gas supply line L1d shown, an analyzer 18c is provided on the upstream side of the switch valve 18b in the purge gas supply line L1d, which is capable of detecting and analyzing the gas composition remaining on the upstream side of the switch valve 18a in the ozone gas supply line.

[0152] In the control unit 6 of such device B3, for example, the following gas component discharge step, purging step and analysis step are appropriately performed.

[0153] First, in the gas component discharge step, by controlling the control unit 6, by closing the switching valves 13, 18a and 18b and opening the switching valve 15, and by operating the pump 17, the gas component remaining between the switching valves 13 and 18a can be drawn and discharged via the gas component discharge line L1b.

[0154] For example, when the gas component is drawn and discharged via the gas component discharge line L1b as described above and then the switch valve 15 is closed, this gas component discharge step is performed until the pressure between the switch valves 13 and 18a (the measurement of the pressure gauge 12) no longer increases (for example, this is performed for about 1 hour).

[0155] During the purging step, by controlling the control unit 6, by closing the switching valves 13 and 18a and opening the switching valves 15 and 18b, and by properly operating the pump 17, while supplying purging gas to the purging gas supply line L1d between the switching valves 13 and 18a, the gas components remaining between the switching valves 13 and 18a can be drawn and discharged (drawn and discharged together with the purging gas) via the gas component discharge line L1b.

[0156] For example, this purging step can be performed appropriately (for example, for about 1 hour), and various inert gases (e.g., inert gases such as N2, Ar or He), dry oxygen (e.g., dry oxygen with a dew point above -60°C) can be used as purging gases, and there are no particular limitations on them.

[0157] In the analysis step, for example, after performing the gas component removal step or purging step as described above, the gas component remaining between the switching valves 13 and 18a can be analyzed by the control unit 6 by closing the switching valves 13, 15 and 18a and opening the switching valve 18b, and by properly operating the analyzer 18c.

[0158] If the presence of moisture in the gas can be confirmed through this analytical procedure, the gas component removal and purging steps described above can be repeated, for example.

[0159] Any analyzer 18c that can analyze the gas composition remaining between the switching valves 13 and 18a as described above is acceptable, and examples of such analyzers include dew point meters, infrared spectrophotometers (IR), mass spectrometers (MS), etc.

[0160] When using a dew point meter, for example, gas components between switching valves 13 and 18a are introduced into the dew point meter (e.g., with switching valve 18a slightly open) to confirm whether there is an increase in dew point.

[0161] In the application of an infrared spectrophotometer, for example, the gas composition between switching valves 13 and 18a is introduced into the infrared spectrophotometer (gas cell for infrared spectroscopy) to confirm the presence of water at 3000 to 4000 cm⁻¹. -1 Does the wavenumber peak increase?

[0162] When using a mass spectrometer, for example, the gas composition between switching valves 13 and 18a can be introduced into the mass spectrometer to confirm whether there is an increase in the peak intensity of m / z=18, which indicates the presence of water.

[0163] <Configuration example for suppressing solvent temperature rise during cycling>

[0164] In devices A and B, for example, there may be situations where the solvent temperature may rise depending on the operating status of devices A and B, the installation environment, etc. For example, if the ambient temperature on the outer periphery of circulation line L2a is high (e.g., higher than the desired solvent temperature), or if there are heat-generating devices (e.g., circulation pump 23) in circulation line L2a, it is conceivable that heat from the ambient temperature and the heat from the heat-generating devices will be transferred to circulation line L2a, and the desired solvent temperature cannot be maintained, resulting in a temperature increase. When the desired solvent temperature cannot be maintained and the temperature increases (e.g., exceeding the time point for dissolution by gas-liquid mixer 21), ozone gas dissolved in the solvent may degas over time, and there is a possibility that the ozone concentration will decrease.

[0165] In this case, it is conceivable that at least a portion of the outer periphery of the circulation line L2a would be covered with insulation material or appropriately cooled by cooling means. For example, in Figure 7 In the case of device B4, a variant of device B shown, the region R (composed of) at least a portion of the outer periphery of the circulation pipeline L2a Figure 7 The area enclosed by the dotted line (in the diagram) can be covered with insulation material or a cooling jacket. Figure 7 In the case of region R shown, it is a region excluding the circulating flow meter 22, the circulating pump 23 and the ozone concentration meter 29a.

[0166] When such an area R is covered with heat-insulating material, heat transfer from the ambient temperature around the circulation line L2a can be suppressed, or heat from the heating device can be suppressed from entering the circulation line L2a, and it becomes easier to maintain the desired solvent temperature.

[0167] When region R is covered with a cooling jacket, heat transfer from the ambient temperature around circulation line L2a or heat from the heating device can be suppressed from entering circulation line L2a. Furthermore, circulation line L2a can be cooled, making it easier to maintain the desired solvent temperature.

[0168] Various configurations can be applied to cooling jackets without particular limitations. For example, in the case of a cooling jacket with a dual-tube structure, a configuration can be used where the inner tube of the dual-tube structure can be used as a circulation line L2a, and the refrigerant can circulate appropriately in the outer tube of the dual-tube structure.

[0169] In the case of solvent circulating in the cooling jacket in the cooling circulation line L2a, it is preferable that the refrigerant temperature of the cooling jacket is appropriately controlled by the control unit 6 and is controlled to become lower than at least the ambient temperature of the circulation line L2a.

[0170] More preferably, for example, the solvent is cooled so that it reaches the lowest possible temperature within a range that prevents the solvent in the circulating state from becoming solidified. For example, an antifreeze (such as ethylene glycol) can be used as the refrigerant, and the temperature of the refrigerant can be appropriately controlled to fall within a temperature range that is higher than the temperature at which the solvent solidifies in the circulating state and equal to or lower than 0°C.

[0171] By cooling the solvent in this way, the supercooled state in the solvent can be maintained, and even if the solvent is cooled to or below the freezing point, the solvent will not begin to solidify and can remain in a non-solidified state.

[0172] In addition to applying insulation materials or cooling jackets as described above, for example, a container capable of accommodating the circulation line L2a can be filled with refrigerant so that the circulation line L2a is immersed in the refrigerant to be cooled.

[0173] As described above, although the present invention has been described in detail with reference only to specific embodiments thereof, it will be clear to those skilled in the art that various modifications and variations can be made within the scope of the technical concept of the present invention, and of course these modifications and variations fall within the scope of the claims.

[0174] For example, devices A, B, and B1 through B4 can be used individually, or their respective components can be appropriately combined with each other. Furthermore, technical concepts beyond those in the claims, as understood from the above embodiments, are described below.

[0175] [1-1]

[0176] An ozone water generating device includes: an ozone gas supply line capable of supplying ozone gas; and a circulation line for circulating a solvent capable of dissolving ozone gas, wherein the ozone gas is supplied to the circulation line via a gas-liquid mixer, wherein the gas-liquid mixer has: a solvent flow channel through which solvent flows during a circulation state; and an ozone gas inlet channel configured to connect to the solvent flow channel and to introduce ozone gas supplied from the ozone gas supply line into the solvent flow channel, wherein at least a portion of the outer periphery of the circulation line is covered with an insulating material.

[0177] [1-2]

[0178] An ozone water generating apparatus includes: an ozone gas supply line capable of supplying ozone gas; and a circulation line for circulating a solvent capable of dissolving ozone gas, wherein the ozone gas is supplied to the circulation line via a gas-liquid mixer, wherein the gas-liquid mixer has: a solvent flow channel through which solvent flows during a circulating state; and an ozone gas inlet channel configured to connect to the solvent flow channel and to introduce ozone gas supplied from the ozone gas supply line into the solvent flow channel, wherein at least a portion of the outer periphery of the circulation line is covered by a cooling jacket in which a refrigerant can circulate.

[0179] [1-3]

[0180] The ozone water generating apparatus according to [1-2] further includes a control unit capable of controlling the temperature of the refrigerant circulating in the cooling jacket, wherein the control unit is configured to control the temperature of the refrigerant so as to be higher than the temperature at which the solvent in the circulating state becomes solidified and equal to or lower than zero degrees Celsius.

[0181] [1-4]

[0182] According to the ozone water generating apparatus described in [1-2], the control unit is configured to control the temperature of the solvent in the circulating state so as to be higher than the temperature at which the solvent in the circulating state becomes solidified and equal to or lower than the temperature of the outer periphery of the cooling jacket.

[0183] Explanation of reference numerals in the attached figures

[0184] A, B, B1 to B4… Generating devices

[0185] 1... Ozone gas supply unit

[0186] 2... Loop Unit

[0187] 3... Solvent supply unit

[0188] 4... Discharge Unit

[0189] 5... Exhaust unit

[0190] 6... Control Unit

[0191] L1a... Ozone gas supply pipeline

[0192] L2a... Circulation pipeline

[0193] 21... Gas-liquid mixer.

Claims

1. An ozone water generating device, comprising: An ozone gas supply line, wherein the ozone gas supply line is capable of supplying ozone gas; A circulation line for circulating a solvent capable of dissolving ozone gas, wherein the ozone gas is supplied to the circulation line via a gas-liquid mixer; as well as Control unit, which controls the ozone gas supply line. The gas-liquid mixer described herein has: A solvent flow channel through which solvent flows during a circulating process; and An ozone gas inlet channel is provided, which is connected to the solvent flow channel and introduces ozone gas supplied from the ozone gas supply line into the solvent flow channel. The ozone gas supply line described herein has: A first switching valve is capable of switching between allowing and preventing the flow of ozone gas in the ozone gas supply line; as well as A pressure gauge capable of measuring the gas pressure downstream of the first switching valve in the ozone gas supply line, and The control unit is configured to compare the measured value of the pressure gauge with an arbitrary pressure threshold, the pressure threshold being set to be equal to or less than the saturated vapor pressure of the solvent, and the control unit is configured to control the switching of the first switching valve.

2. The ozone water generating apparatus according to claim 1, wherein the vapor pressure of the solvent, obtained by measuring the temperature of the solvent in the circulation state, is set as the pressure threshold, and the control unit is configured to close the first switching valve when the measured value of the pressure gauge becomes equal to or higher than the pressure threshold.

3. The ozone water generating device according to claim 1, wherein a discharge pipeline is provided downstream of the first switching valve in the ozone gas supply pipeline, the discharge pipeline being capable of discharging water that has flowed into the downstream side of the first switching valve, and The discharge line has a second switching valve that can switch between allowing and preventing the flow of water in the discharge line.

4. The ozone water generating apparatus according to claim 3, wherein the control unit is configured to set the vapor pressure of the solvent, obtained by measuring the temperature of the solvent in a circulating state, as the pressure threshold, and to open the second switching valve when the measured value of the pressure gauge becomes equal to or higher than the pressure threshold.

5. The ozone water generating device according to claim 3, A moisture-detecting sensor is installed on the downstream side of the first switching valve in the ozone gas supply pipeline. The control unit is configured to open the second switching valve when the sensor detects moisture.

6. The ozone water generating device according to claim 1, wherein the control unit is configured to close the first switching valve when the measured value of the pressure gauge becomes greater than the supply pressure of the ozone gas.

7. An ozone water generating device, comprising: An ozone gas supply line, wherein the ozone gas supply line is capable of supplying ozone gas; A circulation line for circulating a solvent capable of dissolving ozone gas, wherein the ozone gas is supplied to the circulation line via a gas-liquid mixer; as well as A control unit, configured to control the ozone gas supply line, The gas-liquid mixer described herein has: A solvent flow channel through which solvent flows during a circulating process; and An ozone gas inlet channel is provided, which is connected to the solvent flow channel and introduces ozone gas supplied from the ozone gas supply line into the solvent flow channel. The ozone gas supply line described herein has: A first switching valve is capable of switching between allowing and preventing the flow of ozone gas in the ozone gas supply line; A pressure gauge capable of measuring the gas pressure downstream of the first switching valve in the ozone gas supply line; and An exhaust line is provided, which is connected to the ozone gas supply line and is capable of discharging gaseous components from the ozone gas supply line. The discharge line is connected upstream of the first switching valve in the ozone gas supply line via a second switching valve, the second switching valve being capable of switching between allowing and preventing the flow of gas components in the discharge line. The control unit is configured to open the second switch valve in the discharge line when the ozone gas supply to the ozone gas supply line is stopped and the first switch valve is closed.

8. The ozone water generating device according to claim 7, The ozone gas supply line further includes a purge gas supply line capable of supplying purge gas to the ozone gas supply line, and The purge gas supply line is connected upstream of the first switching valve in the ozone gas supply line and has a third switching valve that can switch between allowing and blocking the flow of purge gas in the purge gas supply line.

9. The ozone water generating apparatus according to claim 8, wherein the control unit is configured to open the third switching valve when the supply of ozone gas in the ozone gas supply line is stopped and the first switching valve and the second switching valve are closed.

10. The ozone water generating apparatus according to claim 7, wherein an analyzer capable of detecting and analyzing gas components is connected upstream of the first switching valve in the ozone gas supply line.

11. The ozone water generating apparatus according to claim 10, wherein the control unit is configured to detect and analyze the gas composition by the analyzer when the supply of ozone gas in the ozone gas supply line is stopped and the first switching valve and the second switching valve are closed.

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