Ozone water generation device

Abstract

The present invention comprises: an ozone gas supply line (L1a) capable of 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) for controlling the ozone gas supply line (L1a) and the circulation line (L2a). The ozone gas supply line (L1a) has an opening / closing valve (13) capable of switching between allowing or not allowing the ozone gas to circulate in the ozone gas supply line (L1a), and a pressure gauge (14) capable of measuring the gas pressure on the downstream side of the opening / closing 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 so as to be equal to or less than the saturated vapor pressure of the solvent, and controls the switching of the opening / closing valve (13). When the measured value of the pressure gauge (14) is the pressure threshold value or higher, the opening / closing valve (13) is closed.

Description

Ozone water generator

[0001] The present invention relates to a technique that can contribute to an ozone water generating device.

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

[0003] In recent years, attempts to use ozone water have been progressing in cleaning processes carried out in the manufacture of various industrial parts, such as precision electronic parts (e.g., semiconductor elements and display parts such as FPDs), and efforts are being made to increase the concentration of ozone water and ensure a stable industrial supply of the same.

[0004] Patent Document 1 discloses a method for increasing the concentration of ozone water by first cooling (concentrating) ozone gas to obtain ozone water, re-evaporating the ozone gas obtained by the re-evaporation (concentrated ozone gas), collecting the ozone gas obtained by the re-evaporation (concentrated ozone gas) in a cooled collector, and then dissolving the collected material (liquid ozone or solid ozone) in water to obtain ozone water.

[0005] Patent Document 2 discloses a method in which a cleaning solution obtained by simultaneously dissolving ozone gas and carbon dioxide gas in raw water (for example, raw water at 25°C or less (preferably 5°C to 20°C)) is heated to 45°C or more and brought into contact with a resist film (organic film) on a substrate, thereby maintaining a high ozone concentration in the cleaning solution and facilitating removal of the resist film.

[0006] Patent Document 3 discloses that ozone water is generated by mixing ozone gas from an ozone gas generator (in Patent Document 3, a device that uses oxygen gas as a raw material) with raw material water in a gas-liquid mixer, and that by providing an orifice between the ozone gas generator and the gas-liquid mixer, it is possible to prevent the ozone gas generator side from becoming in a negative pressure state (i.e., a state below normal pressure (approximately 101.33 kPa)), thereby increasing the efficiency of dissolving ozone gas.

[0007] Patent Document 4 discloses a system that includes an ozone water circulation line for circulating ozone water and an ozone gas contact mechanism (a permeable membrane made of a fluororesin) that brings the exhaust ozone gas discharged from the ozone water circulation line into contact with raw water, thereby effectively utilizing the exhaust ozone gas to produce highly concentrated ozone water.

[0008] Patent Document 5 discloses that ozone water is generated by mixing ozone gas from an ozone gas generator (in Patent Document 5, a device that uses oxygen gas as a raw material) with raw material water in a gas-liquid mixer, and that ozone water that has been made too low in concentration by the raw material water (ozone water in a tank indicated by reference numeral 34 in Patent Document 5) is passed through the gas-liquid mixer to increase the concentration of the ozone water.

[0009] In Non-Patent Document 1, when ozone can cause a sudden self-decomposition reaction due to an external factor (for example, an electric spark, a trigger due to contamination that induces decomposition, etc.), CF is used as an inhibitor to suppress the self-decomposition reaction. ４ The application of gases is disclosed.

[0010] According to the configurations shown in Patent Documents 1 to 5, it is possible to generate ozone water with a certain level of ozone concentration (for example, about 100 ppm), but in cleaning processes that require a relatively high oxidizing power, it is thought that ozone water with an even higher concentration (for example, 200 ppm or more in the cleaning process of semiconductor elements) will be required.

[0011] JP-A-11-262782 Patent No. 4296393 Patent No. 4746515 Patent No. 5213601 Patent No. 7041466

[0012] Taiyo Nippon Sanso Technical Report No. 28 (2009) "Explosion Range Measurement Device"

[0013] For example, the gas-liquid mixer used in the ozone water generating apparatus shown in Patent Documents 3 and 5 has a configuration including a solvent flow passage through which a solvent (raw water, etc.) flows, and an ozone gas inlet passage that is connected to the solvent flow passage and introduces ozone gas supplied to the gas-liquid mixer into the solvent flow passage.

[0014] In such a gas-liquid mixer, a suction pressure is generated in the ozone gas inlet passage according to the flow rate (flow velocity) of the solvent flowing through the solvent flow passage, etc. Then, the ozone gas introduced from the ozone gas inlet passage into the solvent flow passage is mixed with and dissolved in the solvent according to the suction pressure (hereinafter simply referred to as suction pressure) generated in the ozone gas inlet passage as described above.

[0015] However, if the suction pressure is too low due to the operating conditions of the ozone water generator, the ozone gas will be less likely to dissolve in the solvent, which may make it difficult to generate ozone water of the desired concentration (e.g., high-concentration ozone water).

[0016] If the suction pressure becomes too low as described above, the solvent in the solvent flow passage is likely to flow back toward the ozone gas supply source (such as the ozone gas supply line described below), which is upstream of the ozone gas introduction passage (hereinafter simply referred to as the solvent backflow phenomenon). In this case, moisture (e.g., the solvent itself or water vapor evaporated from the solvent; hereinafter collectively referred to as moisture) flows into and remains on the ozone gas supply source side, making it impossible to supply ozone gas to the gas-liquid mixer as desired, which may make it more difficult to produce ozone water of the desired concentration.

[0017] The present invention has been made in view of the above circumstances, and aims to provide a technique that can contribute to making it easier to generate ozone water of a desired concentration.

[0018] The ozone water generating device of the present invention can contribute to solving the above-mentioned problems, and in one aspect of the generating device, it comprises an ozone gas supply line capable of supplying ozone gas, a circulation line to which the ozone gas is supplied via a gas-liquid mixer and which circulates a solvent capable of dissolving the ozone gas, and a control unit that controls the ozone gas supply line.

[0019] The gas-liquid mixer has a solvent flow passage through which the solvent flows in a circulating state in which the solvent is circulating, and an ozone gas inlet passage that is connected to the solvent flow passage and introduces ozone gas supplied from the ozone gas supply line into the solvent flow passage.

[0020] The ozone gas supply line has a first opening / closing valve that can switch whether or not the ozone gas flows through the ozone gas supply line, and a pressure gauge that can measure the gas pressure downstream of the first opening / closing valve in the ozone gas supply line.

[0021] The control unit is characterized in that it compares the measurement value of the pressure gauge with an arbitrary pressure threshold set to be equal to or lower than the saturated vapor pressure of the solvent, and controls the switching of the first opening / closing valve.

[0022] The control unit may also be characterized in that the vapor pressure of the solvent, which is derived by measuring the temperature of the solvent in the circulation state, is set as the pressure threshold, and when the measurement value of the pressure gauge becomes equal to or greater than the pressure threshold, the control unit closes the first opening / closing valve.

[0023] The ozone gas supply line may also be characterized in that a discharge line capable of discharging moisture that has flowed downstream of the first on-off valve in the ozone gas supply line is provided downstream of the first on-off valve, and the discharge line has a second on-off valve capable of switching whether or not the moisture is allowed to flow through the discharge line.

[0024] The control unit may also be characterized in that the vapor pressure of the solvent, which is derived by measuring the temperature of the solvent in the circulation state, is set as the pressure threshold, and when the measurement value of the pressure gauge becomes equal to or greater than the pressure threshold, the control unit opens the second opening / closing valve.

[0025] Further, a sensor capable of detecting the moisture may be provided downstream of the first opening / closing valve in the ozone gas supply line, and the control unit may open the second opening / closing valve when the sensor detects the moisture.

[0026] The control unit may close the first opening / closing valve when the measured value of the pressure gauge becomes greater than the supply pressure of the ozone gas.

[0027] In another aspect of the generation device, the device is provided with an ozone gas supply line capable of supplying ozone gas, a circulation line to which the ozone gas is supplied via a gas-liquid mixer and which circulates a solvent capable of dissolving the ozone gas, and a control unit which controls the ozone gas supply line.

[0028] The gas-liquid mixer has a solvent flow passage through which the solvent flows in a circulating state in which the solvent is circulating, and an ozone gas inlet passage that is connected to the solvent flow passage and introduces ozone gas supplied from the ozone gas supply line into the solvent flow passage.

[0029] The ozone gas supply line has a first opening / closing valve capable of switching whether or not the ozone gas flows through the ozone gas supply line, a pressure gauge capable of measuring the gas pressure downstream of the first opening / closing valve in the ozone gas supply line, and an exhaust line connected to the ozone gas supply line and capable of exhausting gas components within the ozone gas supply line.

[0030] The exhaust line is connected to the ozone gas supply line upstream of the first open / close valve via a second open / close valve that can switch between allowing and not allowing the gas component to flow through the exhaust line.

[0031] The control unit is characterized in that when the supply of ozone gas in the ozone gas supply line is stopped and the first opening / closing valve is closed, the control unit opens the second opening / closing valve in the exhaust line.

[0032] The ozone gas supply line may further include a purge gas supply line capable of supplying a purge gas into the ozone gas supply line, and the purge gas supply line may have a third on-off valve connected to the ozone gas supply line upstream of the first on-off valve and capable of switching whether or not the purge gas is allowed to flow in the purge gas supply line.

[0033] The control unit may also be characterized in that, when the supply of ozone gas in the ozone gas supply line is stopped and the first opening / closing valve and the second opening / closing valve are closed, the control unit opens the third opening / closing valve.

[0034] The present invention may also be characterized in that an analyzer capable of detecting and analyzing the gas components is connected to the ozone gas supply line upstream of the first on-off valve.

[0035] The control unit may also be characterized in that, when the supply of ozone gas in the ozone gas supply line is stopped and the first opening / closing valve and the second opening / closing valve are closed, the control unit detects and analyzes the gas components using the analyzer.

[0036] As described above, the present invention can contribute to making it easier to generate ozone water of a desired concentration (high-concentration ozone water, etc.).

[0037] 1 is a schematic diagram illustrating the configuration of an ozone water generator A according to an embodiment. (a) is a saturated vapor pressure curve of water, and (b) is a water vapor pressure table. (b) is a schematic diagram illustrating the configuration of an ozone water generator B according to an embodiment. (c) is a schematic diagram illustrating the configuration of a generator B1, which is a modified example of the generator B. (d) is a schematic diagram illustrating the configuration of a generator B2, which is a modified example of the generator B. (e) is a schematic diagram illustrating the configuration of a generator B3, which is a modified example of the generator B. (f) is a schematic diagram illustrating the configuration of a generator B4, which is a modified example of the generator B.

[0038] The ozone water generating device according to the embodiment of the present invention is completely different from the configurations (hereinafter simply referred to as the conventional configuration) that simply use a gas-liquid mixer, as shown in, for example, Patent Documents 3 and 5.

[0039] That is, in this embodiment, an ozone gas supply line capable of supplying ozone gas, a circulation line for circulating a solvent capable of dissolving ozone gas supplied via a gas-liquid mixer, and a control unit for controlling the ozone gas supply line.

[0040] The ozone gas supply line has an on-off valve (a first on-off valve in claim 1) that can switch whether or not ozone gas flows through the ozone gas supply line, and a pressure gauge that can measure the gas pressure downstream of the on-off valve in the ozone gas supply line.

[0041] The control unit is configured to compare the pressure measurement value of the pressure gauge with an arbitrary pressure threshold value set to be equal to or lower than the saturated vapor pressure of the solvent, and to control switching of the on-off valve. When the pressure measurement value of the pressure gauge becomes equal to or higher than the pressure threshold value, the control unit closes the on-off valve.

[0042] According to this embodiment, when the measured value of the pressure gauge is equal to or greater than the pressure threshold value, the controller determines that, for example, the suction pressure has dropped and solvent backflow may occur, and closes the on-off valve, thereby preventing moisture from flowing into the ozone gas supply line (by blocking it with the on-off valve).

[0043] If the inflow of moisture into the ozone gas supply line can be suppressed in this way, when the suction pressure subsequently increases and the solvent backflow phenomenon is resolved (for example, when the pressure gauge measurement value falls below the pressure threshold and it can be determined that the solvent backflow phenomenon has been resolved), it becomes easier to quickly restore a state in which ozone water of the desired concentration can be produced. That is, by opening the on-off valve using the control unit 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 path via the ozone gas inlet path, and the ozone gas can be dissolved in the solvent.

[0044] As described above, the generator of this embodiment may be configured to switch the on-off valve in the ozone gas supply line by comparing the measured value of the pressure gauge in the ozone gas supply line with a pressure threshold. That is, the generator can be designed by appropriately applying common technical knowledge in various fields (e.g., the field of ozone gas or ozone water generation, etc.) and by appropriately referring to prior art documents as needed, as shown in the examples described below. Note that in the examples described below, detailed descriptions will be omitted as appropriate, for example, by referring to similar content by the same reference numerals.

[0045] For example, in a conventional configuration, if the supply pressure of ozone gas supplied to a gas-liquid mixer is simply increased (higher than atmospheric pressure), the ozone gas becomes more soluble in the solvent, and it is possible to obtain highly concentrated ozone water. However, if the supply pressure of ozone gas is simply increased as described above, as shown in Non-Patent Document 1, a rapid self-decomposition reaction of ozone is likely to occur, making it difficult to maintain practical safety and potentially making it impossible to achieve a stable industrial supply.

[0046] Furthermore, in the case of conventional ozone gas generators (ozonizers) applied to conventional configurations, the ozone gas that can be generated is low in concentration (for example, an ozone concentration of 20% by volume or less), and contains a large amount of gases consisting of components other than ozone (for example, oxygen, etc.) (hereinafter referred to as non-ozone components). Even if such low-concentration ozone gas is used, it is difficult to generate high-concentration ozone water, and many non-ozone components end up being dissolved.

[0047] Furthermore, in ozonated water obtained by dissolving low-concentration ozone gas in a solvent under high pressure, non-ozone components are dissolved in a supersaturated state in addition to the ozone component. When such ozonated water is released to the atmosphere, bubbles are generated by the non-ozone components, which tend to scatter into the atmosphere, and the ozone component also tends to scatter, making it impossible to maintain a high concentration of the ozonated water.

[0048] In recent years, it has become possible to generate highly concentrated ozone gas (e.g., ozone concentration of 50% by volume or more) by concentrating ozone gas generated by an ozonizer or the like using, for example, an adsorption concentration method (a method using surface adsorption by silica gel or the like) or a cooling concentration method.

[0049] For example, Meidensha's cooling concentration type ozone gas generator (product name: Pure Ozone Generator) can generate ozone gas with an extremely high concentration (ozone concentration of 90% or more by volume), approaching approximately 100% by volume, and has been certified to the international safety standard SEMI-S2, achieving practical safety.

[0050] The supply pressure of the concentrated ozone gas is not particularly limited, and one example is to set it to a reduced pressure so as to prevent the above-mentioned sudden self-decomposition reaction from occurring, but the supply pressure is not limited to this.

[0051] As an example of setting the reduced pressure state as described above, in the case of ozone gas having an ozone concentration of 90% by volume or more and an oxygen concentration of less than 10% by volume, the total pressure of the ozone gas can be set to a reduced pressure state of 30 kPa (abs) or less (i.e., a state in which the ozone partial pressure is 30 kPa (abs) or less), which allows the ozone gas to be safely maintained.

[0052] In addition, in the case of ozone gas with an ozone concentration of 50% by volume or more and an oxygen concentration of less than 50% by volume, the total pressure of the ozone gas can be reduced to a reduced pressure of 60 kPa (abs) or less (i.e., an ozone partial pressure of 30 kPa (abs) or less), which allows the ozone gas to be safely maintained.

[0053] When the supply pressure of ozone gas is low (for example, in the case of a reduced pressure state as described above), it is conceivable that the solvent backflow phenomenon is likely to occur, and in such a case, it is possible to actively suppress the solvent backflow phenomenon. For example, in the case of the control unit 6 described below, it is possible to appropriately acquire state information described below and actively control (for example, control while detecting, predicting, etc., events that are likely to cause the solvent backflow phenomenon).

[0054] 1 is a schematic diagram illustrating the configuration of an ozone water generator A according to an embodiment. This generator A primarily comprises an ozone gas supply unit 1 capable of supplying ozone gas having an ozone concentration of 50% by volume or more (e.g., under reduced pressure), a circulation unit 2 that introduces and circulates (clockwise in FIG. 1 ) a solvent capable of dissolving the ozone gas from the ozone gas supply unit 1, a solvent supply unit 3 that supplies the solvent and gas to the circulation unit 2, and a control unit 6 that 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., a measurement value of a pressure gauge 14 in an ozone gas supply line L1a described below, a measurement value (circulation flow rate) of a circulation flow meter 22 in a circulation line L2a, a measurement value (solvent temperature) of a resistance temperature detector 24, etc.; hereinafter, these will be collectively referred to as status information as needed), and controls the ozone gas supply unit 1, the circulation unit 2, the solvent supply unit 3, etc.

[0055] Furthermore, in the case of the device A shown in Figure 1, it is equipped with a release section 4 that releases the solvent in the circulation section 2 to the outer periphery of the circulation section 2 (releases the solvent in which ozone gas is dissolved, i.e., ozone water), and an exhaust section 5 that can exhaust the gas phase gas separated from the solvent from the circulation section 2, and each is configured so that state information is appropriately acquired and controlled by a control section 6.

[0056] <Configuration example of ozone gas supply unit 1> The ozone gas supply unit 1 shown in FIG. 1 mainly includes an ozone gas generator 10, an ozone gas supply line L1a that supplies ozone gas generated in the ozone gas generator 10 to the circulation unit 2 (supplying it via a gas-liquid mixer 21 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 (for example, exhaust to adjust the gas pressure of the ozone gas supply line L1a).

[0057] The ozone gas generator 10 of the ozone gas supply unit 1 may be any device capable of generating ozone gas with an ozone concentration of 50% by volume or more and supplying it under reduced pressure, and various configurations are possible. For example, the ozone gas generated by an ozonizer or the like may be concentrated by an adsorption concentration method or a cooling concentration method.

[0058] The adsorption concentration method is a method of concentration using the surface adsorption phenomenon of, for example, silica gel, etc., and if the ozone gas to be concentrated contains impurities such as NOx or heavy metals, there is a possibility that the impurities will also be concentrated during the concentration process. Therefore, if the impurities are present, it is preferable to remove them in advance.

[0059] On the other hand, the cooling concentration method is a method in which liquid ozone obtained by cooling the ozone gas to be concentrated is vaporized. Also, since the vapor pressures of ozone gas and impurities are different (for example, by several orders of magnitude), the ozone gas concentrated by the cooling concentration method (ozone gas after vaporization) will, in principle, contain almost no impurities. Therefore, it can be said that the application of the cooling concentration method is preferable when there is a possibility that impurities are mixed into the ozone gas to be concentrated.

[0060] Next, the ozone gas supply line L1a is provided with a gas flow rate controller 11, which is configured to be able to control the flow rate of ozone gas flowing through the ozone gas supply line L1a. Also, on the upstream side (the ozone gas generator 10 side) of the gas flow rate controller 11, there is provided a pressure gauge 12 that measures the gas pressure of the ozone gas flowing on the upstream side (i.e., the supply pressure of the ozone gas supplied to a gas-liquid mixer 21 described below).

[0061] Furthermore, downstream of the gas flow rate controller 11, there is provided an on-off valve (two on-off valves in FIG. 1) 13 that can freely switch between allowing and not allowing the flow of ozone gas (supply or backflow of ozone gas) in the ozone gas supply line L1a.

[0062] The on-off valve 13 (and various on-off valves described later) may be, for example, a check valve or the like, but is not limited to this and may be any type that can be freely switched as described above. As a specific example, the on-off valve 13 may be a valve that switches depending on the differential pressure between the supply pressure of ozone gas and the measurement value of a pressure gauge 14 described later (differential pressure when supply pressure > measurement value), and is in a closed state when the differential pressure reaches a certain value (for example, 1 kPa or less).

[0063] Furthermore, a pressure gauge 14 for measuring the gas pressure on the downstream side is provided on the downstream side of the on-off valve 13. This pressure gauge 14 can measure the gas pressure corresponding to the suction pressure when ozone gas is sucked by a gas-liquid mixer 21 described below, and can evaluate the suction pressure.

[0064] Next, the gas component discharge line L1b is provided with an on-off valve 15 that is connected in communication between the gas flow rate controller 11 and the on-off valve 13 in the ozone gas supply line L1a and can freely switch between allowing and disabling the flow (exhaust) of gas components such as ozone gas from the ozone gas supply line L1a. Also provided downstream of the on-off valve 15 are an ozone decomposer (ozone killer) 16 that decomposes the gas components (particularly ozone gas) flowing through the gas component discharge line L1b into a safe state, and a vacuum pump 17 that sucks and discharges the ozone gas after the decomposition.

[0065] <Configuration example of circulation unit 2> The circulation unit 2 shown in FIG. 1 mainly includes a circulation line L2a that can introduce and circulate the solvent from the solvent supply unit 3, a circulation tank 20 that is connected to the circulation line L2a and can introduce and store a certain amount of solvent, a reflux line L2b that refluxes the solvent released from the circulation tank 20 to the circulation line L2a, and a gas-liquid mixer 21 that mixes the solvent and ozone gas.

[0066] In the circulation unit 2, the circulation line L2a is configured so 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 and dissolved in the solvent. In the circulation unit 2 shown in Fig. 1, the circulation line L2a and the gas-liquid mixer 21 are depicted as being connected and integrated, but the present invention is not limited to this, and the two may also be configured as separate entities separated from each other.

[0067] The gas-liquid mixer 21 may be, for example, an ejector, an aspirator, a jet pump, or the like, but is not limited thereto and various modes can be applied. That is, the gas-liquid mixer 21 may have a configuration including a solvent flow passage (not shown) through which the solvent flows, and an ozone gas inlet passage (not shown) that is connected to the solvent flow passage and introduces ozone gas supplied to the gas-liquid mixer 21 into the solvent flow passage.

[0068] In the gas-liquid mixer 21 having the solvent flow passage and the ozone gas inlet passage, a suction pressure according to Bernoulli's theorem is generated in the ozone gas inlet passage according to the flow rate (flow velocity) of the solvent flowing through the solvent flow passage. Furthermore, the ozone gas inlet passage generates vapor according to the saturated vapor pressure characteristics of the solvent. For example, when the solvent is raw water, the characteristics are as shown in the saturated vapor pressure curve and water vapor pressure table of FIG. 2.

[0069] 2, a suction pressure range below the saturated vapor pressure of the solvent can be derived as a range (hereinafter referred to as the suction pressure range) in which the ozone gas can be introduced into the solvent flow passage through the ozone gas inlet path and dissolved in the solvent. This allows the control unit 6 to perform various settings taking the suction pressure range into consideration (for example, setting a pressure threshold value described below to a value equal to or lower than the saturated vapor pressure).

[0070] When the control unit 6 measures the temperature of the solvent while it is circulating through the circulation line L2a (hereinafter simply referred to as the "circulation state") (for example, by measuring it with the resistance temperature detector 24 described below), the measured value can be compared with the saturated vapor pressure characteristics of the solvent to derive the vapor pressure at that solvent temperature. Various settings can then be made taking the derived vapor pressure into consideration.

[0071] For example, the derived vapor pressure may be set as a pressure threshold value, which will be described later, or the supply pressure of the ozone gas to the gas-liquid mixer 21 may be set to be higher than the derived vapor pressure.

[0072] Furthermore, it is possible to derive a solvent temperature range (hereinafter referred to as the "suction temperature range") in which the vapor pressure in the ozone gas inlet passage of the gas-liquid mixer 21 is lower than the supply pressure, based on the saturated vapor pressure characteristics of the solvent and the supply pressure of the ozone gas to the gas-liquid mixer 21. Taking into consideration the general solubility characteristics of gases in solvents (the solubility tends to improve as the solvent temperature decreases), it is preferable to set this suction temperature range to a relatively low temperature range in which the solvent does not freeze (for example, a temperature higher than the freezing point of the solvent or a temperature at which the solvent can be maintained in a supercooled state).

[0073] Then, by appropriately controlling the solvent temperature by the control unit 6 so that it is within the inhalable temperature range (control as in the temperature control step described below), it is possible to set the vapor pressure of the ozone gas inlet path of the gas-liquid mixer 21 so that it is smaller than the supply pressure of the ozone gas supplied to the gas-liquid mixer 21. Specifically, it is possible to appropriately set the measurement value of the pressure gauge 14 so that it is smaller than the measurement value of the pressure gauge 12. This makes it easier for the ozone gas in the ozone gas supply line L1a to be introduced into the ozone gas inlet path of the gas-liquid mixer 21, and it becomes possible for the ozone gas to be mixed with and dissolved in the solvent.

[0074] A circulation flow meter 22 that measures the circulation flow rate of the solvent circulating through the circulation line L2a is provided upstream of the gas-liquid mixer 21. Circulation pumps (two circulation pumps in FIG. 1 ) 23 that circulate the solvent are provided downstream of the gas-liquid mixer 21. By providing two circulation pumps 23a, 23b as shown in FIG. 1 , it is possible to operate one of the circulation pumps 23a, 23b normally and have the other function as an auxiliary pump when the primary pressure of one of the pumps drops too much, but the other pump may be omitted as appropriate depending on the status of the circulation unit 2 (circulation conditions, etc.).

[0075] Further, downstream of the circulation pump 23, there are provided a resistance temperature detector 24 (two resistance temperature detectors in FIG. 1) for measuring the solvent temperature, and a temperature regulator (e.g., a cooler) 25 for adjusting the solvent temperature. By appropriately controlling the resistance temperature detector 24 and the temperature regulator 25 with the control unit 6, the solvent temperature can be set to be within the suction temperature range.

[0076] Next, the circulation tank 20 has a cylindrical peripheral wall 20a with a bottom that can accommodate a certain amount of solvent. An inlet 26 communicating with the downstream side of the resistance temperature detector 24b in the circulation line L2a (i.e., the downstream side of the gas-liquid mixer 21), an inlet 26a communicating with a pressure adjustment line L3c (described later), and an exhaust port 26b communicating with a gas exhaust line L5 (described later) are provided on the upper side of the peripheral wall 20a.

[0077] On the lower side of the peripheral wall 20a, there are provided an outlet 27 which is connected to the upstream side of the circulation flow meter 22 in the circulation line L2a (i.e., the upstream side of the gas-liquid mixer 21), and an outlet 28 which is connected to the solvent discharge line L4 described below.

[0078] Next, the reflux line L2b is provided so as to communicate between the upstream side of the solvent discharge line L4 (described below) and the upstream side of the circulation flow meter 22 in the circulation line L2a, and is configured so that the solvent on the upstream side of the solvent discharge line L4 (i.e., the solvent released from the discharge port 28) can be refluxed to the circulation line L2a. The reflux line L2b is also provided with an ozone concentration meter 29 that can measure the ozone concentration of the solvent refluxed through the reflux line L2b. The ozone concentration meter 29 thus provided in the reflux line L2b does not simply measure the ozone concentration of the solvent in the circulation line L2a, but can also measure an ozone concentration similar to that of the solvent actually released from the circulation tank 20 (i.e., the desired ozone water).

[0079] <Configuration Example of Solvent Supply Unit 3> The solvent supply unit 3 shown in FIG. 1 includes a solvent supply line L3a capable of supplying a solvent such as raw water to the circulation line L2a, a concentration adjustment line L3b capable of supplying a concentration adjustment gas (e.g., carbon dioxide gas) that stabilizes the ozone concentration of the solvent in the circulation line L2a, and a pressure adjustment gas (e.g., N ２ and a pressure adjustment line L3c capable of supplying an inert gas such as Ar or He.

[0080] The solvent supply line L3a of the solvent supply unit 3 is connected in communication with both of the circulation pumps 23a, 23b in the circulation line L2a and is equipped with a solvent flow rate controller 31 capable of controlling the flow rate of the solvent flowing through the solvent supply line L3a. Downstream of the solvent flow rate controller 31 are also equipped a water purification unit (e.g., a water purification device) 32 capable of increasing the purity of the solvent flowing through the solvent supply line L3a, and an open / close valve 33 that can switch between allowing and not allowing the solvent to flow through the solvent supply line L3a.

[0081] Next, the concentration adjustment line L3b is provided with a gas flow rate controller 34 that is connected between the circulation pumps 23a, 23b in the circulation line L2a and that can control the flow rate of the concentration adjustment gas flowing through the concentration adjustment line L3b. Further, downstream of the gas flow rate controller 34 is provided with an open / close valve 35 that can switch between allowing and not allowing the concentration adjustment gas to flow through the concentration adjustment line L3b.

[0082] Next, the pressure adjustment line L3c is connected in communication with the inlet 26a of the circulation tank 20 and is equipped with a gas flow controller 36 that can control the flow rate of the pressure adjustment gas flowing through the pressure adjustment line L3c.

[0083] 1 includes a solvent discharge line L4 that discharges the solvent in the circulation tank 20 toward 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 rate controller 41 that can control the discharge flow rate of the solvent discharged through the solvent discharge line L4.

[0084] 1 includes a gas exhaust line L5 that exhausts gas (e.g., a gas phase separated from a solvent) in the circulation tank 20 to the outer periphery of the circulation tank 20. The gas exhaust line L5 is connected to and communicates with the exhaust port 26b in the circulation tank 20, and includes an open / close valve (e.g., a back pressure adjustment valve) 51 that can switch between allowing and not allowing the gas in the circulation tank 20 to circulate (exhaust) while maintaining a constant pressure in the circulation tank 20. In addition, downstream of the open / close valve 51, an ozone concentration measuring instrument 52 that can measure the ozone concentration of the 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 are provided.

[0085] <Configuration example of control unit 6> The control unit 6 shown in FIG. 1 may be configured to appropriately acquire and control the status information of the ozone gas supply unit 1, the circulation unit 2, the solvent supply unit 3, the release unit 4, and the exhaust unit 5 so as to obtain the desired ozone water, and various embodiments can be applied.

[0086] For example, the control unit 6 may be appropriately connected to devices (e.g., measuring instruments, regulators, controllers, on-off valves, circulation pumps, resistance thermometers, etc.) configured in each line (ozone gas supply line L1a, gas component discharge line L1b, circulation line L2a, reflux line L2b, solvent supply line L3a, concentration adjustment line L3b, pressure adjustment line L3c, solvent release line L4, gas exhaust line L5) via signal lines or the like not shown in the figure.

[0087] With this type of configuration, it is possible to operate each line appropriately to obtain status information of the devices, and based on the obtained status information, it is possible to output control commands to the devices and control them.

[0088] <An example of a method for producing ozone water using device A> In the device A described above, it is possible to produce the desired ozone water by appropriately performing, for example, the circulation process, temperature control process, gas-liquid mixing process, release process, and exhaust process described below.

[0089] First, in the circulation step, the solvent is supplied to the circulation line L2a by opening the on-off valve 33 of the solvent supply line L3a, for example, to fill the circulation line L2a with the solvent. The amount of the solvent to be filled in the circulation line L2a can be appropriately set, for example, so that the liquid level of the solvent in the circulation tank 20 is located between the inlet 26 and the outlet 27.

[0090] Then, the circulation line L2a is put into a circulating state at a predetermined circulation flow rate by operating the circulation pump 23 of the circulation line L2a, etc. During this circulating state, the concentration adjustment line L3b and the pressure adjustment line L3c are also operated as necessary to stabilize the ozone concentration of the circulating solvent in the circulation line L2a and adjust the pressure in the circulation tank 20.

[0091] Next, in the temperature control step, the inhalable temperature range is calculated in advance based on the supply pressure of ozone gas in the subsequent ozone gas supply step and the characteristics shown in the saturated vapor pressure curve and vapor pressure table in Figure 2. Then, in the circulation state, the solvent temperature in the circulation line L2a is measured with the resistance temperature detector 24 and adjusted by the temperature regulator 25 so that the solvent temperature falls within the inhalable temperature range. For example, when the target is ozone water with an ozone concentration of 300 ppm or more, the inhalable temperature range is set to be higher than the freezing point of the solvent and not higher than 30°C, preferably not higher than 15°C.

[0092] Next, in the gas-liquid mixing step, in the circulating state, the on-off valve 13 of the ozone gas supply line L1a is opened, for example, to supply ozone gas to the gas-liquid mixer 21. Here, since the temperature of the circulating solvent is within the inhalable temperature range due to the temperature control step in the previous stage, the supply pressure of the ozone gas to the gas-liquid mixer 21 becomes higher than the vapor pressure of the ozone gas inlet path of the gas-liquid mixer 21.

[0093] As a result, the ozone gas supplied to the gas-liquid mixer 21 is introduced into the solvent flow passage through the ozone gas inlet passage in the gas-liquid mixer 21, and is mixed with the solvent in the solvent flow passage to become soluble. Then, by dissolving the ozone gas in the solvent, the solvent has a desired ozone concentration.

[0094] In addition, when the measurement value of the pressure gauge 14 becomes larger than the measurement value of the pressure gauge 12 while the ozone gas is being supplied in the gas-liquid mixing process, the on-off valve 13 is controlled to switch to an open state, thereby making it possible to prevent the solvent from flowing back into the ozone gas supply line L1a.

[0095] Next, in the release step, in the circulating state, the solvent in the circulation tank 20 is released (i.e., the desired ozone water is obtained) by appropriately controlling the release flow rate controller 41 of the solvent release line L4. In addition, by appropriately supplying the solvent from the solvent supply line L3a to the circulation line L2a, the release flow rate of the solvent is controlled so as not to be greater than the circulation flow rate of the solvent in the circulation line L2a.

[0096] This allows the solvent to be released while maintaining a certain amount of solvent stored in the circulation tank 20. That is, in the release step, it becomes possible to continuously extract ozonated water with a desired ozone concentration.

[0097] Next, in the exhaust process, the gas present in the circulation tank 20 (e.g., the gas phase separated from the circulation solvent) is exhausted to the outer periphery of the circulation tank 20 by opening the opening / closing valve 51 of the gas exhaust line L5, for example.

[0098] <Configuration Example of Production Apparatus B According to the Example> The apparatus A is not limited to the configuration shown in Fig. 1 and may be modified as appropriate, for example, as shown in Fig. 3, the solvent supply line L3a and the concentration adjustment line L3b of the solvent supply unit 3 may be provided at positions separated from each other on the circulation line L2a, as in apparatus B. Note that Fig. 3 (and Figs. 4 to 7 described below) appropriately omit elements similar to those shown in Fig. 1.

[0099] 3, an ozone concentration measuring device 29a capable of measuring the ozone concentration of the solvent circulating in the reflux line L2b is provided in the circulation line L2a between the gas-liquid mixer 21 and the circulation flow meter 22. In addition, a gas-liquid mixer 38 (having a configuration similar to that of the gas-liquid mixer 21, for example) that mixes the solvent and the concentration adjustment gas is provided downstream of the pump 23 in the circulation line L2a.

[0100] A solvent supply line L3a is provided so as to communicate with and connect the gas-liquid mixer 21 and the ozone concentration measuring device 29a in the circulation line L2a. In the case of the solvent supply line L3a shown in Figure 3, a temperature regulator (e.g., a heat exchanger) 37 for adjusting the solvent temperature on the upstream side of the solvent flow rate controller 31 is provided in the solvent supply line L3a. This may make it easier to set the solvent temperature of the solvent flowing through the gas-liquid mixer 21 as desired, compared to the case of the apparatus A shown in Figure 1.

[0101] The concentration adjustment line L3b is provided so as to communicate with and be connected to the circulation line L2a downstream of the pump 23 via a gas-liquid mixer 38. This may make it easier to supply the concentration adjustment gas to the solvent in the circulation line L2a compared to the case of the apparatus A in FIG.

[0102] In the above-described device B, as in the device A, the desired ozone water can be produced by appropriately performing the circulation process, temperature control process, gas-liquid mixing process, release process, and exhaust process described above.

[0103] <Example of configuration for easily suppressing or eliminating solvent backflow phenomenon> In the apparatuses A and B, even if the suction pressure decreases depending on the operating conditions of the apparatuses A and B (e.g., solvent temperature, circulation state), etc., and a solvent backflow phenomenon may occur in the ozone gas supply line L1a, the solvent backflow phenomenon can be suppressed or eliminated by previously setting the inhalable pressure range and inhalable temperature range as described above in the control unit 6 and appropriately switching and controlling the opening and closing valve 13.

[0104] An example of a configuration for suppressing or eliminating the solvent backflow phenomenon will be described below based on devices B1 and B2 shown in Figures 4 and 5, which are modifications of device B. Note that in the control unit 6 of devices B1 and B2, the pressure threshold value for comparison with the measurement value of the pressure gauge 14 is set within the inhalable pressure range.

[0105] 4, for example, while ozone gas is being supplied in the gas-liquid mixing process, the control unit 6 reads the measurement value of the pressure gauge 14 at predetermined time intervals and compares the measurement value with a pressure threshold value for judgment. At this time, for example, if the suction pressure of the gas-liquid mixer 21 is decreasing due to the operating status of the device B1, the measurement value of the pressure gauge 14 will increase.

[0106] When the control unit 6 determines that the measured value of the pressure gauge 14 is equal to or greater than the pressure threshold value, the control unit 6 closes the on-off valve 13 and temporarily suspends or stops the gas-liquid mixing process.

[0107] As a result, even if the suction pressure drops and a solvent backflow phenomenon occurs, causing moisture to flow into the ozone gas supply line L1a, the on-off valve 13 can suppress or block the moisture.

[0108] Thereafter, the control unit 6 reads the measurement value of the pressure gauge 14 and compares the measurement value with the pressure threshold value. If it is determined that the measurement value of the pressure gauge 14 is less than the pressure threshold value (i.e., if it is determined that the solvent backflow phenomenon has been resolved), the opening / closing valve 13 is opened, and the gas-liquid mixing process can be resumed.

[0109] 5, a sensor 13c (e.g., a water level sensor, an infrared sensor, an electromagnetic wave sensor, etc.) capable of detecting moisture that has flowed downstream of the on-off valve 13 is provided on the ozone gas supply line L1a downstream of the on-off valve 13 (between the on-off valve 13 and the gas-liquid mixer 21). In addition, a moisture discharge line L1c capable of discharging moisture that has flowed downstream of the on-off valve 13 is connected in communication with the downstream side of the on-off valve 13. This moisture discharge line L1c is equipped with an on-off valve 13d that can switch between allowing and not allowing moisture to flow from the downstream side of the on-off valve 13. This on-off valve 13d is usually kept in a closed state, for example, during the gas-liquid mixing process.

[0110] The control unit 6 of such device B2, for example, monitors the condition downstream of the opening / closing valve 13 (presence or absence of moisture, etc.) using a sensor 13c, and, similar to device B1, reads the measurement value of the pressure gauge 14 at predetermined time intervals and compares the measurement value with a pressure threshold to make a judgment.

[0111] Then, in the control unit 6, when moisture is detected downstream of the opening / closing valve 13 via the sensor 13c, or / and when it is determined that the measurement value of the pressure gauge 14 is equal to or greater than the pressure threshold value, the opening / closing valve 13 is closed and the gas-liquid mixing process is temporarily interrupted or stopped.

[0112] As a result, even if a drop in suction pressure causes a solvent backflow phenomenon, which could lead to moisture flowing into the ozone gas supply line L1a, the moisture can be suppressed or blocked by the on-off valve 13. At this time, the on-off valve 13d may be opened. As a result, even if moisture is flowing downstream of the on-off valve 13, for example, the moisture can be discharged via the moisture discharge line L1c.

[0113] Thereafter, the control unit 6 reads the measurement value of the pressure gauge 14 and compares the measurement value with the pressure threshold value. If it determines that the measurement value of the pressure gauge 14 is less than the pressure threshold value, or / and if no moisture is detected by the sensor 13c, the opening / closing valve 13 is opened (and the opening / closing valve 13d is closed), and the gas-liquid mixing process can be resumed.

[0114] In the ozone gas supply line L1a of the devices B1 and B2 described above, when it is acceptable to allow a certain amount of moisture to flow in due to the solvent backflow phenomenon, for example, as shown in FIGS. 4 and 5, the gas-liquid mixer 21 and the on-off valve 13 in the ozone gas supply line L1a may be arranged apart from each other (separated by a predetermined distance), and an allowable space 13e may be provided between them.

[0115] For example, if the top-bottom direction of devices B1 and B2 is the same as the top-bottom direction shown in Figures 4 and 5 (hereinafter simply referred to as the top-bottom direction), the moisture that flows into the allowable space 13e will be stored sequentially from the bottom side of the allowable space 13e (the gas-liquid mixer 21 side).

[0116] As a result, even if the suction pressure drops and a solvent backflow phenomenon occurs, causing moisture to flow into the ozone gas supply line L1a, it is possible to suppress the inflow of moisture upstream of the opening / closing valve 13 until the allowable space 13e is filled with moisture, without performing switching control of the opening / closing valve 13, etc. (i.e., even if the opening / closing valve 13 is in an open state).

[0117] Furthermore, the capacity of the allowable space 13e can be set as appropriate, and the larger the capacity, the easier it may be to suppress the inflow of moisture to the upstream side of the open / close valve 13.

[0118] <Example of a configuration for removing moisture remaining in the ozone gas supply line L1a> In the case of a conventional configuration, if moisture is present in a portion of the ozone gas supply source that is easily oxidized (for example, a pipe made of a metal material or an organic material, a joint (welded portion), or various equipment), and the portion is exposed to ozone gas, the moisture and the ozone gas interact with each other, facilitating corrosion of the portion. Furthermore, the ozone gas is easily decomposed in the corroded portion, which may make it even more difficult to produce ozone water of the desired concentration.

[0119] On the other hand, in the devices A and B, even if moisture (water vapor, etc.) flows into the ozone gas supply line L1a due to, for example, a solvent backflow phenomenon and remains therein (for example, moisture adhering to the inner 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 (for example, appropriately switching and controlling the opening and closing valves 13, 15, etc.).

[0120] An example of a configuration for discharging moisture in this manner will be described below based on an apparatus B3 shown in Fig. 6, which is a modified example of the apparatus B. When an on-off valve 18a (described later) is closed, the supply of ozone gas from the ozone gas generator 10 is stopped.

[0121] The device B3 shown in FIG. 6 is provided with an open / close valve 18a on the upstream side (the ozone gas generating device 10 side) of the gas flow controller 11 in the ozone gas supply line L1a, which can freely switch between allowing and not allowing the flow of ozone gas (or gas components containing residual moisture and a purge gas described later) on the upstream side.

[0122] A purge gas supply line L1d capable of supplying a purge gas is connected between the on-off valves 13 and 18a in the ozone gas supply line L1a (hereinafter simply referred to as between the on-off valves 13 and 18a) in communication with the two (connected between the gas flow rate controller 11 and the on-off valve 18a in FIG. 6). The purge gas supply line L1d is provided with an on-off valve 18b that can switch between allowing and not allowing the purge gas (or gas components containing moisture and the like remaining in the ozone gas supply line) to flow.

[0123] In the case of the purge gas supply line L1d shown in FIG. 6, an analyzer 18c capable of detecting and analyzing gas components remaining upstream of the on-off valve 18a in the ozone gas supply line is provided upstream of the on-off valve 18b in the purge gas supply line L1d.

[0124] The control unit 6 of the device B3 appropriately executes, for example, the following gas component discharge step, purging step, and analysis step.

[0125] First, in the gas component discharge process, the control unit 6 closes the on-off valves 13, 18a, and 18b and opens the on-off valve 15, and operates the pump 17, thereby sucking and discharging the gas components remaining between the on-off valves 13 and 18a through the gas component discharge line L1b.

[0126] Such a gas component discharge process may be carried out, for example, for about one hour, until the pressure between the opening and closing valves 13 and 18a (measurement value of the pressure gauge 12) does not increase when the gas components are sucked and discharged through the gas component discharge line L1b as described above and then the opening and closing valve 15 is closed.

[0127] In the purge process, the control unit 6 closes the on-off valves 13 and 18a and opens the on-off valves 15 and 18b, and operates the pump 17 appropriately, thereby supplying the purge gas from the purge gas supply line L1d between the on-off valves 13 and 18a, while sucking and discharging the gas components remaining between the on-off valves 13 and 18a through the gas component discharge line L1b (sucking and discharging together with the purge gas).

[0128] Such a purging step may involve using various inert gases (e.g., N ２ It is possible to apply an inert gas such as Ar or He) or dry oxygen (for example, with a dew point of −60° C. or higher), and the method is not particularly limited, and may be carried out as appropriate (for example, for about one hour).

[0129] In the analysis process, for example, after carrying out the gas component discharge process and purge process as described above, the control unit 6 closes the on-off valves 13, 15, and 18a and opens the on-off valve 18b, and operates the analyzer 18c as appropriate, thereby analyzing the gas components remaining between the on-off valves 13 and 18a.

[0130] If it is confirmed by such an analysis step that the gas component contains moisture, the gas component discharge step and purging step may be appropriately repeated.

[0131] The analyzer 18c may be any device capable of analyzing the gas components remaining between the on-off valves 13 and 18a as described above, and examples thereof include a dew point meter, an infrared spectrophotometer (IR), a mass spectrometer (MS), etc.

[0132] When a dew point meter is used, the gas components between the on-off valves 13 and 18a are introduced into the dew point meter (for example, with the on-off valve 18a slightly open) to check whether the dew point increases.

[0133] When an infrared spectrophotometer is used, the gas components between the open / close valves 13 and 18a are introduced into the infrared spectrophotometer (gas cell for infrared spectroscopy), and a wave number of 3000 to 4000 cm, which indicates the presence of water, is detected. －１ One way to check this is to check whether there is an increase in the peak.

[0134] When a mass spectrometer is used, the gas components between the on-off valves 13 and 18a are introduced into the mass spectrometer, and it is possible to confirm whether or not there is an increase in the peak intensity of m / z=18, which indicates the presence of water.

[0135] <Example of a configuration for suppressing temperature rise of the solvent in the circulating state> In the apparatuses A and B, the solvent temperature may be prone to rise, depending on, for example, the operating status and installation environment of the apparatuses A and B. For example, if the ambient temperature on the outer periphery of the circulation line L2a is high (e.g., higher than the desired solvent temperature) or if heat-generating equipment (e.g., the circulation pump 23) is present in the circulation line L2a, the heat from the ambient temperature or the heat from the heat-generating equipment may be transferred into the circulation line L2a, making it impossible to maintain the desired solvent temperature and resulting in a temperature rise. If the solvent temperature cannot be maintained and the temperature rises (e.g., higher than the temperature at the time of dissolution in the gas-liquid mixer 21), the ozone gas dissolved in the solvent may be degassed over time, resulting in a decrease in the ozone concentration.

[0136] In such a case, it is possible to cover at least a portion of the outer periphery of the circulation line L2a with a heat insulating material or to cool it appropriately using a cooling means. For example, in the case of the device B4 shown in Fig. 7, which is a modification of the device B, it is possible to cover at least a portion of the outer periphery of the circulation line L2a, that is, a region R (the region surrounded by a dashed line in Fig. 7), with a heat insulating material or a cooling jacket (not shown). In the case of the region R shown in Fig. 7, the circulation flow meter 22, the circulation pump 23, and the ozone concentration measuring instrument 29a are excluded from this region.

[0137] If such an area R is covered with insulating material, the heat from the ambient temperature of the circulation line L2a and the heat from heat-generating equipment can be prevented from being transferred into the circulation line L2a, making it easier to maintain the desired solvent temperature.

[0138] When region R is covered with a cooling jacket, the heat from the ambient temperature of the circulation line L2a and the heat from heat-generating equipment can be prevented from being transferred into the circulation line L2a, and the circulation line L2a can be cooled, making it easier to maintain the desired solvent temperature.

[0139] The cooling jacket can be applied in various forms and is not particularly limited. For example, when a double-pipe structure is applied, the inner pipe of the double-pipe structure can be used as the circulation line L2a, and the refrigerant can be appropriately circulated through the outer pipe of the double-pipe structure.

[0140] When the cooling jacket cools the solvent circulating in the circulation line L2a, it is preferable to appropriately control the refrigerant temperature of the cooling jacket by the control unit 6 so that it is at least lower than the ambient temperature of the circulation line L2a.

[0141] More preferably, the circulating solvent is cooled to a temperature as low as possible within a range in which the circulating solvent does not freeze. For example, an antifreeze liquid (such as ethylene glycol) is used as a refrigerant, and the temperature of the refrigerant is appropriately controlled to be higher than the temperature at which the circulating solvent freezes and equal to or lower than 0°C.

[0142] By cooling the solvent in this manner, it is possible to maintain the solvent in a supercooled state, and even if the solvent is cooled to the freezing point or below the freezing point, the solvent will not start to freeze and will remain in a non-frozen state.

[0143] In addition to using a heat insulating material or a cooling jacket as described above, it is also possible to fill a container capable of accommodating the circulation line L2a with a refrigerant and immerse the circulation line L2a in the refrigerant to cool it.

[0144] Although the present invention has been described in detail above only with respect to the specific examples, it will be apparent to those skilled in the art that various modifications are possible within the scope of the technical concept of the present invention, and it is natural that such modifications fall within the scope of the claims.

[0145] For example, the devices A, B, and B1 to B4 may be applied separately, or their respective components may be appropriately combined and applied. Furthermore, the technical ideas other than those claimed that can be understood from the above-described embodiments are described below.

[0146] [1-1] An ozone water generating apparatus comprising: an ozone gas supply line capable of supplying ozone gas; and a circulation line to which the ozone gas is supplied via a gas-liquid mixer and which circulates a solvent capable of dissolving the ozone gas, wherein the gas-liquid mixer has: a solvent flow passage through which the solvent flows in a circulation state in which the solvent is circulated; and an ozone gas inlet passage connected to the solvent flow passage and which introduces the ozone gas supplied from the ozone gas supply line into the solvent flow passage, wherein at least a portion of the outer periphery of the circulation line is covered with a heat insulating material.

[0147] [1-2] An ozone water generating apparatus comprising: an ozone gas supply line capable of supplying ozone gas; and a circulation line to which the ozone gas is supplied via a gas-liquid mixer and which circulates a solvent capable of dissolving the ozone gas, wherein the gas-liquid mixer has: a solvent flow passage through which the solvent flows in a circulation state in which the solvent is circulating; and an ozone gas inlet passage connected to the solvent flow passage and which introduces the ozone gas supplied from the ozone gas supply line into the solvent flow passage, wherein at least a portion of the outer periphery of the circulation line is covered with a cooling jacket through which a refrigerant can circulate.

[0148] [1-3] The ozone water generating device according to [1-2], further comprising a control unit capable of controlling the temperature of the refrigerant circulated through the cooling jacket, wherein the control unit controls the temperature of the refrigerant so that it is higher than the temperature at which the solvent becomes frozen in the circulating state and is below zero degrees Celsius.

[0149] [1-4] The ozone water generating device of [1-2], characterized in that the control unit controls the temperature of the solvent in the circulation state so that it is higher than the temperature at which the solvent in the circulation state becomes frozen and lower than the temperature of the outer periphery of the cooling jacket.

[0150] A, B, B1 to B4...Generation device 1...Ozone gas supply section 2...Circulation section 3...Solvent supply section 4...Discharge section 5...Exhaust section 6...Control section L1a...Ozone gas supply line L2a...Circulation line 21...Gas-liquid mixer

Claims

1. An ozone water generating apparatus comprising: an ozone gas supply line capable of supplying ozone gas; a circulation line to which the ozone gas is supplied via a gas-liquid mixer and which circulates a solvent capable of dissolving the ozone gas; and a control unit which controls the ozone gas supply line, wherein the gas-liquid mixer has: a solvent flow passage through which the solvent flows in a circulation state in which the solvent is circulating; and an ozone gas inlet path connected to the solvent flow passage and which introduces ozone gas supplied from the ozone gas supply line into the solvent flow passage, wherein the ozone gas supply line has: a first on-off valve which can switch between allowing and preventing the ozone gas from flowing in the ozone gas supply line; and a pressure gauge which can measure the gas pressure in the ozone gas supply line downstream of the first on-off valve, wherein the control unit compares the measurement value of the pressure gauge with an arbitrary pressure threshold which is set to be equal to or lower than the saturated vapor pressure of the solvent, and controls the switching of the first on-off valve.

2. The ozone water generating apparatus described in claim 1, characterized in that the control unit sets the vapor pressure of the solvent derived by measuring the temperature of the solvent in the circulating state as the pressure threshold, and closes the first opening / closing valve when the measurement value of the pressure gauge becomes equal to or greater than the pressure threshold.

3. The ozone water generating device described in claim 1, characterized in that the ozone gas supply line is provided with a discharge line downstream of the first opening / closing valve in the ozone gas supply line that can discharge moisture that has flowed downstream, and the discharge line has a second opening / closing valve that can switch whether or not the moisture can flow through the discharge line.

4. The ozone water generating apparatus described in claim 3, characterized in that the control unit sets the vapor pressure of the solvent derived by measuring the temperature of the solvent in the circulation state as the pressure threshold, and opens the second opening / closing valve when the measurement value of the pressure gauge becomes equal to or greater than the pressure threshold.

5. The ozone water generating device described in claim 3, characterized in that a sensor capable of detecting the moisture is provided downstream of the first opening / closing valve in the ozone gas supply line, and the control unit opens the second opening / closing valve when the sensor detects the moisture.

6. The ozone water generating device according to claim 1, characterized in that the control unit closes the first opening / closing valve when the measured value of the pressure gauge becomes greater than the supply pressure of the ozone gas.

7. An apparatus comprising: an ozone gas supply line capable of supplying ozone gas; a circulation line to which the ozone gas is supplied via a gas-liquid mixer and which circulates a solvent capable of dissolving the ozone gas; and a control unit for controlling the ozone gas supply line, wherein the gas-liquid mixer has: a solvent flow passage through which the solvent flows in a circulation state in which the solvent is circulating; and an ozone gas inlet passage connected to the solvent flow passage and which introduces the ozone gas supplied from the ozone gas supply line into the solvent flow passage, wherein the ozone gas supply line has: a first open / close valve capable of switching between allowing and not allowing the ozone gas to flow in the ozone gas supply line; a pressure gauge capable of measuring the gas pressure in the ozone gas supply line downstream of the first open / close valve; and an exhaust line connected to the ozone gas supply line and capable of exhausting gas components in the ozone gas supply line, The exhaust line is connected to the upstream side of the first on-off valve in the ozone gas supply line via a second on-off valve that can switch whether or not the gas component is allowed to flow in the exhaust line, and the control unit opens the second on-off valve in the exhaust line when the supply of ozone gas in the ozone gas supply line is stopped and the first on-off valve is closed.

8. The ozone water generating apparatus according to claim 7, characterized in that the ozone gas supply line further comprises a purge gas supply line capable of supplying purge gas into the ozone gas supply line, and the purge gas supply line has a third on-off valve connected to the upstream side of the first on-off valve in the ozone gas supply line and capable of switching whether or not the purge gas is allowed to flow in the purge gas supply line.

9. The ozone water generating device described in claim 8, characterized in that the control unit opens the third opening / closing valve when the supply of ozone gas in the ozone gas supply line is stopped and the first opening / closing valve and the second opening / closing valve are closed.

10. An ozone water generating apparatus as described in claim 7, characterized in that an analyzer capable of detecting and analyzing the gas components is connected to the upstream side of the first opening / closing valve in the ozone gas supply line.

11. The ozone water generating device described in claim 10, characterized in that the control unit detects and analyzes the gas components using the analyzer when the supply of ozone gas in the ozone gas supply line is stopped and the first opening / closing valve and the second opening / closing valve are closed.

Images