Tank System

Abstract

To provide a tank system that enables stable adjustment of the concentration of bubbles contained in liquid supplied to the outside. [Solution] The tank system 10A comprises a tank 20 for storing liquid, a first pipe 21 for supplying a first liquid from the outside into the inside of the tank, a bubble generator 30 capable of generating bubbles up to a predetermined concentration while generating and discharging bubbles with a bubble diameter of less than 1 μm into the liquid inside the tank that has been sucked in, a second pipe 22 for sending the second liquid inside the tank, once the bubbles have reached the predetermined concentration, to the outside of the tank, and a concentration adjustment structure 50 for adjusting the concentration of bubbles by mixing the second liquid sent from the second pipe with a third liquid outside the tank.

Description

[Technical Field]

[0001] The present invention relates to a tank system. [Background technology]

[0002] There is a demand for the use of a bubble generator that generates a gas-liquid mixture containing bubbles with a diameter of 1 μm or less in a liquid in various industrial fields. Patent Document 1 proposes that a bubble generator be installed in a tank provided in the circulation system of an air conditioning system, and that the gas-liquid mixture stored in the tank be used to remove contaminants in the circulation system. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2008-190754 Summary of the Invention [Problem to be solved by the invention]

[0004] The technology proposed in Patent Document 1 leaves room for improvement in terms of stably adjusting the concentration of bubbles contained in the liquid supplied to the outside.

[0005] One object of the present invention is to provide a tank system that makes it possible to stably adjust the concentration of bubbles contained in liquid supplied to the outside. [Means for solving the problem]

[0006] The present invention is based on the following (1) 5 The gist of the invention is as described in

[0007] (1) a tank for storing a liquid; a first pipe for supplying a first liquid from the outside to the inside of the tank; a bubble generator that generates bubbles having a diameter of less than 1 μm in the liquid in the tank and discharges the bubbles to a predetermined concentration; a second pipe for sending the second liquid inside the tank, in which the concentration of bubbles has reached the predetermined concentration, to the outside of the tank; a concentration adjusting structure that adjusts the concentration of the bubbles by mixing the second liquid delivered from the second pipe with a third liquid outside the tank; a first flow rate measuring device for measuring a first flow rate of the first liquid; a second flow meter for measuring a second flow rate of the second liquid; a control device that controls the circulation of the liquid inside the tank by the bubble generator, The control device has a control unit that controls the start and / or stop of the circulation by the bubble generator based on the first flow rate and the second flow rate. Tank system. (2 )the above( 1 In the tank system according to The control device an input unit for inputting designation information for designating the concentration of the bubbles contained in the discharged liquid that is discharged to the outside of the tank via the concentration adjusting structure; a mixing ratio of the second liquid and the third liquid that are joined in the concentration adjusting structure is determined based on the designation information input to the input unit; Tank system. ( 3 )the above( 1 In the tank system according to the control device has a time measurement unit that measures a first time period during which the circulation continues, The control unit further determines a second time period as a time period for further continuing the circulation based on the first flow rate, the second flow rate, and the first time period, and controls the circulation to be stopped upon the lapse of the second time period. Tank system. ( 4 )the above( 1 In the tank system according to the control device further includes a display unit configured to make predetermined information recognizable; the information is displayed on the display unit according to the concentration of the bubbles in the liquid inside the tank. Tank system. ( 5 )the above( 1 In the tank system according to a third pipe for supplying the third liquid; One end of the third pipe is connected to the second pipe, and the other end of the third pipe is connected to the first pipe. Tank system. [Effects of the Invention]

[0008] According to the present invention, it is possible to provide a tank system that makes it possible to stably adjust the concentration of bubbles contained in liquid that is supplied to the outside. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a schematic diagram illustrating the configuration of an embodiment of a tank system according to the present invention. [Figure 2] FIG. 2 is a cross-sectional view for explaining the configuration of one embodiment of the bubble generating device. [Figure 3] 3A and 3B are schematic block diagrams for explaining the configuration of an embodiment of the control unit. [Figure 4] FIG. 4 is a schematic diagram illustrating the configuration of an embodiment of a tank system according to the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0010] An embodiment of the present invention will be described.

[0011] The present invention is not limited to the embodiments described below.

[0012] [1-1 Tank system configuration] The tank system 10 (referred to as tank system 10A in FIG. 1) includes a tank 20 that stores a liquid, a bubble generator 60, a first pipe 21, and a second pipe 22.

[0013] (tank) The tank 20 is not particularly limited as long as it has a space capable of storing a liquid therein. In the example of FIG. 1, the tank 20 has a structure with an open top, but this is merely an example, and the tank 20 may have a structure with a closed top. Examples of the tank 20 include a water tank installed in various buildings such as a building or an apartment building, a facility such as a swimming pool, a bathtub installed in a bathroom or a public bath, a tank for storing a coolant for a cooling device, a storage tank connected to various devices and storing a liquid to be delivered to the devices, and a storage unit installed in a cleaning device. A gas-liquid mixture (internal liquid) is temporarily stored in the tank 20 and is discharged from the second pipe 22.

[0014] (first tube) The first pipe 21 provided in the tank system 10A is configured to allow a liquid (external liquid) to flow (be supplied) from an external liquid supply source (not shown) into the inside of the tank 20. The liquid flowing from the first pipe 21 toward the outlet 21A is referred to as the first liquid. The outlet 21A of the first pipe 21 is disposed so as to be located within the space of the tank 20, but the position of the outlet 21A of the first pipe 21 is not particularly limited. The first pipe 21 can be formed using piping or the like.

[0015] The first pipe 21 may be provided with a pump (not shown) configured to send the first liquid to the outlet 21A (to send the first liquid in the direction of arrow F1 toward the inside of the tank 20). However, may be omitted. In this case, it is possible to cause the first liquid to flow in the first pipe 21 toward the outlet by providing a configuration for causing the first liquid to flow into the first pipe 21 in the external liquid supply source (such as a configuration in which a pump is disposed in the supply source).

[0016] 1 and the like, first pipe 21 is preferably provided with a valve (valve 23) for adjusting the flow rate of the first liquid. However, valve 23 may be omitted. Even in this case, as described above for the pump, it is possible to adjust the flow rate of the first liquid flowing through first pipe 21 by providing a configuration in an external liquid supply source for causing liquid to flow into first pipe 21 and forming a configuration that can adjust the amount of liquid flowing into first pipe 21.

[0017] (Second tube) The second pipe 22 provided in the tank system 10A is not particularly limited as long as it has a structure that allows the liquid inside the tank 20 to flow out. The liquid inside the tank 20 is referred to as the internal liquid. Furthermore, the liquid sent out from the second pipe 22 to the outside (the liquid flowing in the second pipe 22 to the outside) is referred to as the second liquid. After the bubble generator 60 is activated, the internal liquid and the second liquid become a gas-liquid mixture, which will be described later. The second pipe 22 is a pipe that sends out a liquid having a bubble concentration equal to or higher than a predetermined value as the internal liquid (an internal liquid that has become a gas-liquid mixture containing bubbles equal to or higher than a predetermined concentration) to the outside of the tank. The second pipe 22 is preferably arranged so that one end (a liquid inlet) is immersed in the internal liquid stored in the tank 20. The second pipe 22 can be formed using piping, as with the first pipe 21.

[0018] It is preferable that the second pipe 22 is provided with a pump (pump 24) for adjusting the flow rate of the second liquid (the amount sent from the internal liquid to the second pipe 22). However, the pump 24 may be omitted. Even in this case, the second liquid can be sent out in the direction of the arrow F2 inside the second pipe 22 by providing a configuration in which the pressure outside the second pipe 22 is lower than the pressure inside the second pipe 22 (such as a configuration in which the pressure inside the tank 20 is increased).

[0019] Furthermore, it is preferable that the second pipe 22 is provided with a valve (discharge amount adjustment valve (not shown)) for adjusting the flow rate of the second liquid. However, the discharge amount adjustment valve may be omitted. Even in this case, as described above for the pump 24, a configuration for causing the liquid to flow into the second pipe 22 (such as a configuration for increasing the pressure inside the tank 20) ​​is provided, and the amount of the second liquid flowing through the second pipe 22 can be adjusted in accordance with the adjustment of the pressure inside the tank 20.

[0020] (Concentration adjustment structure) The tank system 10A preferably has a concentration adjustment structure 50. In the example shown in Fig. 1, the concentration adjustment structure 50 is exemplified as a concentration adjustment structure 50A having a second pipe 22 and a third pipe 25 and a connection portion between the second pipe 22 and the third pipe 25. Next, the concentration adjustment structure 50 will be described further using the concentration adjustment structure 50A as an example.

[0021] As described above, the concentration adjusting structure 50A has the second pipe 22 and the third pipe 25, and also has a junction where the second pipe 22 and the third pipe 25 join together.

[0022] (third tube) The concentration adjusting structure 50A is provided with a third pipe 25. The third pipe 25 can be formed using piping or the like, similar to the first pipe 21. The third pipe 25 is, for example, a pipe structure connected to the second pipe 22 outside the tank 20. A liquid outside the tank 20 flows through the third pipe 25. In this specification, the liquid outside the tank 20 flowing through the third pipe 25 is referred to as the third liquid. In the example of FIG. 1, the third pipe 25 is a pipe that supplies the third liquid. The third liquid is a liquid different from the second liquid. The third liquid flows through the third pipe 25 toward the junction between the second pipe 22 and the third pipe 25. The third liquid then joins with the second liquid at the junction between the second pipe 22 and the third pipe 25. When the third liquid and the second liquid join, the third liquid and the second liquid are mixed. The mixture of the third liquid and the second liquid flows out of the tank system 10A as a discharged liquid.

[0023] 1 shows a portion (one end) of the third pipe 25 that is connected to the second pipe 22. The third pipe 25 may be connected at one end (downstream side) to the second pipe 22 and at the other end (upstream side) to the first pipe 21 (not shown). In this case, at least a portion of the liquid flowing through the first pipe 21 becomes the liquid that flows into the third pipe 25. That is, at least a portion of the liquid flowing through the first pipe 21 also serves as the third liquid.

[0024] Moreover, one end (downstream side) of the third pipe 25 may be connected to the second pipe 22, and the other end (upstream side) may be connected to a supply source of the first liquid (not shown).

[0025] In addition to the above, the third pipe 25 may have one end (downstream side) connected to the second pipe 22 and the other end (upstream side) connected to a supply source of a liquid different from either the first liquid or the second liquid (not shown).

[0026] The concentration adjusting structure 50A has a structure for adjusting the flow rate ratio between the second liquid and the third liquid. In the example of FIG. 1, a pump 24 and a valve 26 are provided as the structure for adjusting the flow rate ratio. The pump 24 adjusts the amount (flow rate) of the second liquid flowing through the second pipe 22. The valve 26 adjusts the amount (liquid volume) of the third liquid flowing through the third pipe 25. By adjusting the amounts of the second liquid and the third liquid, it is possible to adjust the flow rate ratio between the second liquid and the third liquid. Note that the example of FIG. 1 is just an example, and a control valve may be provided at the connection between the second pipe and the third pipe. The control valve is a valve that adjusts the flow rate ratio between the second liquid and the third liquid.

[0027] When a concentration adjusting structure 50B, which will be described later, is employed as the concentration adjusting structure 50, the third pipe 25 described above may be omitted.

[0028] (liquid) The internal liquid, first liquid, second liquid, and third liquid are not particularly limited, and examples thereof include solvents and solvents in which compounds are dissolved, dispersed, or mixed (solutions, dispersions, mixed liquids, etc.). Examples of solvents include water and organic solvents. Examples of water include tap water, well water, seawater, pure water, ultrapure water, and water that has passed through a supercritical state (supercritical water). Examples of organic solvents include alcohol and oil. Examples of compounds dissolved in solvents include inorganic compounds such as covalently bonded substances of carbon dioxide, nitrogen, and oxygen, inorganic electrolytes such as sodium chloride, and various organic compounds such as aliphatic hydrocarbons, aromatic hydrocarbons, alcohols, peptides, and fatty acids. When the internal liquid, first liquid, second liquid, and third liquid are not distinguished, the internal liquid, first liquid, second liquid, and third liquid used in the tank system may be collectively referred to as the liquids to be used. Furthermore, the liquid into which bubbles are to be added may be referred to as the raw material liquid. In the example of Fig. 1, the first liquid and the third liquid are preferably raw material liquids. The internal liquid and the second liquid are gas-liquid mixtures in which gas is contained in the raw material liquids. All of the first liquid, the third liquid, the internal liquid, and the second liquid are used liquids.

[0029] The raw material liquid may be determined depending on the application of the gas-liquid mixture containing fine bubbles or ultrafine bubbles as bubbles.

[0030] The uses of gas-liquid mixtures may be determined based on their effects. The effects of incorporating fine or ultrafine bubbles into a liquid include solubility, separation, cleansing, fluidity, and improved medical and diagnostic quality. The solubility effects of bubbles include improved ozonated water, improved mixing of oil and additives, promotion of oil-water emulsification, oxygen enrichment of liquid fertilizer by incorporating oxygen-containing bubbles, and improved water quality for fish farming. The separation effects of bubbles include the purification of contaminated soil and water purification. The cleansing effects include improved cleansing of precision instruments, household appliances, food ingredients, and the human body, as well as improved cleansing in production line cleaning processes. The efficiency benefits of bubbles include fuel production by promoting the emulsification of oil (such as waste oil) and water with bubbles. The medical and diagnostic quality benefits of bubbles include improved effectiveness of ultrasound therapy by combining ultrasound with bubbles.

[0031] Therefore, examples of the raw material liquid include liquids used to generate gas-liquid mixtures for achieving various effects using bubbles. More specific examples of the raw material liquid include the various types of water mentioned above, such as tap water, well water, seawater, pure water, ultrapure water, and water that has passed through a supercritical state (supercritical water). Examples of water that can be used as the raw material liquid include water that exists in water sources such as spring water, reservoirs, and lakes before being subjected to water purification treatment, and water that has been subjected to water purification treatment. Examples of the raw material liquid include liquids used in food products such as juices and sugar water, cleaning solutions used in hospitals, etc., liquids used in medical applications such as saline, and various liquid fuels such as gasoline, diesel, kerosene, and jet fuel.

[0032] (Bubble generator) The bubble generator 60 is configured to be able to generate bubbles up to a predetermined concentration while generating and discharging bubbles with a diameter of less than 1 μm in the liquid (internal liquid) inside the tank 20 that has been sucked in.

[0033] The bubble generator 60 includes a bubble generator 30, an intake pipe 31 that introduces the internal liquid in the tank 20 into the bubble generator 30, and a discharge pipe 32 that discharges the internal liquid that has passed through the bubble generator 30 into the interior space of the tank 20. The bubble generator 60 is disposed floating on or near the surface of the internal liquid in the tank 20, but this is merely an example. A pump 33 is preferably disposed in the intake pipe 31 and / or the discharge pipe 32. The pump 33 is configured to adjust the amount of internal liquid that passes through the bubble generator 30. A valve (not shown) may be provided in addition to the pump 33. The provision of a valve enables more reliable adjustment of the amount of liquid that passes through the bubble generator 30 depending on whether the valve is open or closed (the degree to which the valve is open). The intake pipe 31 and the discharge pipe 32 may be configured as piping, similar to the first pipe 21 described above.

[0034] (Bubble generating part) The bubble generation unit 30 generates bubbles in the internal liquid sent from the suction pipe 31 to the bubble generation unit 30. In the example of FIG. 1 , the internal liquid (internal liquid sucked into the suction pipe 31) flowed from inside the tank 20 into the suction pipe 31 passes through the bubble generation unit 30, and then passes through the discharge pipe 32 and is returned to the tank 20 again. After passing through the bubble generation unit 30, the internal liquid becomes a gas-liquid mixture in which gas bubbles (gas bubbles generated in the bubble generation unit 30) are dispersed among the liquid components. If the internal liquid is already a gas-liquid mixture at the stage when it is sent to the suction pipe 31, more gas bubbles will be added to the internal liquid. Therefore, by having the internal liquid pass through the bubble generator 60, the concentration of gas bubbles contained in the internal liquid can be increased.

[0035] (bubbles) At least some of the bubbles generated by the bubble generating unit 30 have a bubble diameter of less than 1 μm (the average bubble diameter of at least some of the bubbles is less than 1 μm). However, it is preferable that at least some of the bubbles generated by the bubble generating unit 30, and that all of the bubbles generated by the bubble generating unit 30 have a bubble diameter of less than 1 μm (the average bubble diameter of all the bubbles generated is less than 1 μm). Bubbles with a bubble diameter of 100 μm or less are sometimes referred to as fine bubbles. Bubbles with a diameter of 1 μm or more and 100 μm or less are sometimes referred to as microbubbles. Bubbles with a diameter of less than 1 μm are sometimes referred to as ultrafine bubbles or nanobubbles. The term "fine bubbles" is used as a term that encompasses both microbubbles and ultrafine bubbles. It is preferable that at least some of the bubbles generated by the bubble generating unit 30 are ultrafine bubbles. For example, at least some of the bubbles generated by the bubble generating unit 30 in the liquid used are ultrafine bubbles. When the liquid to be used is a gas-liquid mixture containing gas bubbles, the liquid to be used has ultrafine bubbles dispersed in it. However, this does not exclude the gas-liquid mixture to be used containing bubbles other than ultrafine bubbles, and the gas-liquid mixture may also contain microbubbles.

[0036] (Components in bubbles) There are no particular limitations on the gas components in the bubbles generated by the bubble generating unit 30. The gas components in the bubbles generated by the bubble generating unit 30 may be gas taken into the bubble generating unit 30 from the outside, or may be gasifiable components dissolved in the liquid sent to the bubble generating unit 30. For example, in the case where the liquid is water, examples of gasifiable components dissolved in the liquid include dissolved carbon dioxide dissolved in the water, oxygen (dissolved oxygen), and nitrogen (dissolved nitrogen) dissolved in the water.

[0037] (bubble diameter) The bubble diameter refers to the diameter of the bubbles. The average bubble diameter refers to the average value of the bubble diameters. The average bubble diameter can be determined from the bubble size distribution. The average bubble diameter of some bubbles can be determined from the bubble size distribution. The bubble diameter can be determined when measuring the bubble size distribution. The bubble size and average bubble diameter can be determined using a technique for measuring the bubble size distribution (particle size distribution) of bubbles contained in a gas-liquid mixture. An example of a technique for measuring the bubble size distribution (particle size distribution) is a method using a laser diffraction / scattering particle size distribution measuring device. Methods for determining the bubble size distribution include particle size analysis (particle tracking analysis) in accordance with JIS Z 8829:2021.

[0038] (Bubble concentration) The bubble concentration (number / cm ) of the gas-liquid mixture generated in the bubble generating section 30 3 However, from the viewpoint of effectively exhibiting the function of the gas-liquid mixture containing bubbles having a predetermined bubble diameter, the bubble concentration of bubbles less than 1 μm in the gas-liquid mixture is 20 million bubbles / cm 3 Preferably, it is 50 million particles / cm or more. 3 More preferably, it is 60 million particles / cm 3 It is more preferable that the liquid contains 20 million bubbles per cm with a diameter of less than 1 μm. 3 If the gas-liquid mixture contains more than 50 million bubbles per cm with a diameter of less than 1 μm, it can exhibit anti-fouling effects. 3 If the concentration is above 60 million bubbles per cm with a diameter of less than 1 μm, the liquid can effectively remove biofilms (aggregates formed on solid surfaces by microorganisms). 3In this way, these effects can be further enhanced. The description regarding the bubble concentration of the gas-liquid mixture generated by the bubble generating unit 30 also applies to the bubble concentration of the internal liquid in the tank 20. It should be noted that the bubble concentration of the internal liquid in the tank 20 can also be increased to the bubble concentration of the gas-liquid mixture described above by passing the internal liquid through the bubble generating device 60. Therefore, the effects obtained when the gas-liquid mixture satisfies the above-mentioned range of bubble concentration can also be achieved for the internal liquid in the tank 20.

[0039] The upper limit of the bubble concentration of the gas-liquid mixture generated by the bubble generating unit 30 is not particularly limited, but from the viewpoint of easiness in generating bubbles stably, the upper limit of the bubble concentration of the gas-liquid mixture is set to 5 billion bubbles / cm. 3 The bubble concentration can be determined using the method exemplified above as a method for determining the bubble diameter or average bubble diameter of the bubbles.

[0040] (Potential of the bubble) The bubbles contained in the gas-liquid mixture preferably have a negative potential. The negatively charged state of the bubbles can be achieved by using a cavitation-type bubble generator 60 (e.g., the bubble generator 100), which will be described later, and can be achieved depending on the magnitude of static electricity caused by cavitation in the liquid fluid in the liquid flow path of the bubble generator 100 and friction of the fluid in the flow path (friction between the bubbles and the components forming the flow path). The magnitude of the negative potential can be determined depending on various conditions, such as the diameter of the bubbles.

[0041] (Production of gas-liquid mixture) As described above, the gas-liquid mixture can be produced by passing the liquid component (internal liquid in the example of FIG. 1) serving as the raw material of the gas-liquid mixture through the gas bubble generator 60, for example.

[0042] The bubble generator 60 is configured to generate fine bubbles such as ultrafine bubbles as bubbles in a liquid, and to form a gas-liquid mixture with the bubbles dispersed in the liquid. Examples of such bubble generators 60 include devices (bubble generators) that employ various bubble generation mechanisms as needed, such as cavitation, micropore, ultrasonic, swirling flow, static mixer, Venturi, steam condensation, pressurized dissolution, gas-liquid mixed shear, and electrolysis.

[0043] However, from the viewpoint of efficiently generating fine bubbles such as ultrafine bubbles having a negative potential as bubbles contained in the gas-liquid mixture, it is preferable to prepare the gas-liquid mixture using a cavitation-type device as the bubble generator 60. As the cavitation-type device, a device such as that shown in the following "Example of a bubble generator" can be used. Next, an example of a bubble generator that can be used as the bubble generator 60 will be described with reference to FIG. 2. FIG. 2 is a cross-sectional view schematically showing an embodiment of a bubble generator 100 that can be used as the bubble generator 60 of FIG. 1.

[0044] (An example of a bubble generator) As shown in FIG. 2, the bubble generation device 100 includes a receiving section 110 that receives a liquid component (referred to as raw material liquid) as a raw material, a bubble generation mechanism 120 that generates a gas-liquid mixture in which gas bubbles are dispersed in the raw material liquid supplied from the receiving section 110, and a discharge section 130 that discharges the gas-liquid mixture. When the bubble generation device 100 is applied as the bubble generation device 60 shown in the example of FIG. 1, the receiving section 110 corresponds to the suction pipe 31, and the discharge section 130 corresponds to the discharge pipe 32. The raw material liquid supplied from the receiving section 110 is a liquid that flows from the suction pipe 31 into the bubble generation device 100. The gas-liquid mixture that flows out from the discharge section 130 is a liquid that further flows toward the discharge pipe 32. The bubble generation mechanism 120 of the bubble generation device 100 corresponds to the bubble generation section 30 that constitutes the bubble generation device 60.

[0045] (Bubble generation mechanism) The bubble generation mechanism 120 has a flow path forming body 121 and multiple collision bodies 124. The flow path forming body 121 forms a liquid flow path 122 on its inner circumferential surface 121A side and has a throttle structure 123. The throttle structure 123 has a first portion 123A having a portion where the cross-sectional diameter of the inner circumferential surface 121A (the cross-sectional diameter determined by a cross section cut along a plane normal to the longitudinal direction of the liquid flow path 122) decreases from an upstream end 125 (inlet) to a downstream end 126 (outlet). The throttle structure 123 also has a second portion 123B having a portion where the cross-sectional diameter of the inner circumferential surface 121A increases from the upstream end 125 to the downstream end 126. The first portion 123A is located upstream of the second portion 123B. The multiple collision bodies 124 protrude inward from the inner circumferential surface 121A of the flow path forming body 121 and are adjacent to each other with a predetermined region sandwiched between them. The multiple collision bodies 124 are arranged at positions between (or at the boundary between) the first portion 123A and the second portion 123B in the longitudinal direction of the liquid flow path 122. However, this does not prohibit the multiple collision bodies 124 from being formed in either the first portion 123A or the second portion 123B. The multiple collision bodies 124 form gaps between their tips to narrow the flow path. Furthermore, the bubble generation mechanism 120 is configured so that the flow path formation body 121 can pass the raw material liquid from the upstream end 125 to the downstream end 126. As described above, it is preferable that a pump (not shown) for supplying raw material liquid is installed upstream and / or downstream of the bubble generation device 100. This pump supplies raw material liquid to the bubble generation device 100 so that the water pressure, flow velocity, and water volume of the raw material liquid are each equal to or greater than predetermined values. In the bubble generation device 100, the concentration of fine bubbles (such as microbubbles and ultrafine bubbles) generated varies depending on the pressure, flow velocity, and flow rate of the liquid flowing through the liquid flow path 122. In the bubble generator 100, by increasing at least one of the pressure, flow velocity, and flow rate of the liquid, it is possible to generate fine bubbles at a high concentration in the liquid.

[0046] (Production of gas-liquid mixture) Using the bubble generator 100, a bubble mixture is obtained as follows. The raw material liquid is injected as a liquid fluid into the receiver 110 of the bubble generator 100. The receiver 110 corresponds to the suction pipe 31 constituting the bubble generator 60, as described above. The receiver 110 is connected to the upstream end 125 (inlet) of the bubble generation mechanism 120, and the raw material liquid flows into the bubble generation mechanism 120 from the upstream end 125. In the bubble generation mechanism 120, the raw material liquid moves through the first portion 123A of the throttle structure 123 in a direction generally from the upstream end 125 toward the downstream end 126 (indicated by the arrow LF), thereby increasing its flow rate. The raw material liquid then passes through a gap formed at the position of the impactor 124 and continues toward the downstream end 126. At this time, a cavitation effect occurs in the raw material liquid, causing dissolved components (e.g., dissolved oxygen) in the raw material liquid to turn into bubbles. The size of the bubbles is adjusted depending on conditions such as the size of the gap and the structure of the collision body 124. In this way, a gas-liquid mixture is generated as a liquid in which bubbles having a desired bubble diameter are dispersed in the raw material liquid. The generated gas-liquid mixture can flow out from the downstream end 126 via the discharge part 130. The discharge part 130 corresponds to the discharge pipe 32 that constitutes the bubble generator 60.

[0047] The bubbles dispersed in the gas-liquid mixture obtained by the gas bubble generator 100 are formed by cavitation occurring in the raw material liquid as described above, and are gasified components that accompany the cavitation of components dissolved in the raw material liquid. Such bubbles contain vaporized oxygen (dissolved oxygen) and vaporized nitrogen (dissolved nitrogen) that were dissolved in the water that constitutes the raw material liquid. The gas components in the bubbles may be determined depending on the effect desired from the gas-liquid mixture. For example, if the gas-liquid mixture is desired to have a biofilm removal effect, it is preferable that the oxygen component in the bubbles be small. In order to further enhance the desired effect, it is preferable that the gas bubble generator 100 be equipped with a gas supply structure.

[0048] (Control device) The tank system 10A is preferably provided with a control device 40. The control device 40 controls the circulation of the internal liquid by the bubble generator 60. Circulation of the internal liquid by the bubble generator 60 means that the internal liquid in the tank 20 passes through each component of the bubble generator 60 (the internal liquid flows from the tank 20 through the suction pipe 31, the bubble generator 30, and the discharge pipe 32 in that order) and is returned to the tank 20. As shown in FIGS. 3A and 3B, the control device 40 has a control unit 45. It is preferable that the control device 40 has a memory unit 47. As shown in FIG. 3B, the control device 40 may further have a display unit and an input unit, as described below. FIGS. 3A and 3B are block diagrams schematically showing an example of the configuration of the control device.

[0049] In addition to circulating the internal liquid using the bubble generator 60, the control device 40 is preferably configured to be able to further control the flow state of the liquid used in the tank system 10A (controlling the amount of the first liquid flowing into the tank 20 and the amount of the second liquid flowing out of the tank 20).

[0050] (Flow Meter) 1, a tank system 10A is provided with a first flow rate measuring device 41 and a second flow rate measuring device 42. A time measuring unit 43 is further provided in the tank system 10A.

[0051] (First flow meter) In the example shown in FIG. 1, the tank system 10A is provided with a first flow rate meter 41. The first flow rate meter 41 detects the flow rate (inflow rate) of the liquid flowing through the first pipe 21. The first flow rate meter 41 is not particularly limited, and a sensor having a drive method such as an electromagnetic type or an impeller type may be used. The drive method of the first flow rate meter 41 is the same as that of the second flow rate meter 42 described later. In the example shown in FIG. 1, the first flow rate meter 41 is connected to the control unit 45 described later via wiring or the like so as to be able to transmit signals (e.g., electrical signals). However, this is just one example, and these may be connected wirelessly so as to be able to transmit signals. Note that the connection between the control unit 45 and the connection target via wiring may be wired or wireless. This also applies to the connection between the second flow rate meter 42 and the control unit 45, and the connection of the control unit 45 to valves, pumps (valve 23 and pump 24), and the time measurement unit 43 (time measurement device). Examples of the flow meter of the first flow measuring instrument and the flow meter of the second flow measuring instrument described below include an ultrasonic flow meter, an electromagnetic flow meter, a Karman vortex flow meter, and a differential pressure flow meter.

[0052] (Second flow meter) The tank system 10A is provided with a second flow rate measuring device 42. In the example shown in Fig. 1, the second flow rate measuring device 42 detects the flow rate (inflow rate) of the liquid flowing through the second pipe 22. The driving method of the second flow rate measuring device 42 may be the same as that described in the description of the first flow rate measuring device 41.

[0053] (Time measurement section) In the tank system 10A, it is preferable that a time measurement unit 43 is provided as the measurement unit 46. As shown in the example of FIG. 1, the time measurement unit 43 can be a timer provided in the control device 40. The time measurement unit 43 is configured to measure the time (duration) during which the internal liquid continues to be pumped to the bubble generation unit 30. In the example of FIG. 1, the duration can be specified as the operation duration of the pump 33 that pumps the internal liquid toward the bubble generation unit 30. Therefore, in the example of FIG. 1, the time measurement unit 43 is configured to measure the operation duration of the pump 33. In the example of FIG. 1, this operation duration corresponds to the time during which the internal liquid continues to circulate. Note that, although the time measurement unit 43 is provided in the control device 40 in the example of FIG. 1, it may be provided separately from the control device 40.

[0054] (Control unit) The control unit 45 is composed of a CPU (Central Processing Unit), ROM (Read Only Memory), RAM (Random Access Memory), etc. When performing AI (Artificial Intelligence) calculations, the control unit 45 may have a calculation chip such as a GPU (Graphics Processing Unit). The control unit 45 performs calculations based on various signals and programs received from the measurement unit 46. The control unit 45 transmits signals to control the drive of each unit based on the results of the calculations. The control unit 45 controls the start of circulation of the internal liquid and / or the stop of circulation of the internal liquid by the bubble generator 60 based on the first flow rate and the second flow rate. The start of circulation of the internal liquid may be referred to as "start of circulation." The stop of circulation of the internal liquid may be referred to as "stop of circulation." In this specification, the start of circulation of the internal liquid and / or the stop of circulation of the internal liquid will be referred to as "liquid circulation control."

[0055] Specifically, the control of liquid circulation by the control unit 45 can be achieved by controlling the operation of each unit, such as the pump 33, provided in the bubble generation device 60. In the example of FIG. 1, the control unit 45 starts the operation of the pump 33. In this case, the start of circulation of the internal liquid is achieved. The control unit 45 also stops the operation of the pump 33. In this case, the stop of circulation of the internal liquid is achieved. Note that, if the bubble generation device 60 is provided with a valve that controls the progress of the liquid, it is preferable that the control unit 45 can also control the operation of the valve.

[0056] (Storage part) The control device 40 is preferably provided with a storage unit 47. The storage unit 47 is configured by, for example, a hard disk drive, a silicon disk drive, etc. The storage unit 47 stores various programs, data tables, etc., used by the control unit 45 to execute calculations for controlling the operation of each unit.

[0057] An example of liquid circulation control by the control unit 45 will be described.

[0058] (liquid circulation control) The control unit 45 receives information on the first flow rate measured by the first flow rate meter 41 and information on the second flow rate measured by the second flow rate meter 42. The control unit 45 determines the amount of internal liquid in the tank 20 based on the first flow rate and the second flow rate. The control unit 45 determines the concentration of bubbles contained in the internal liquid stored in the tank 20 based on the initial value of the concentration of bubbles contained in the internal liquid in the tank 20 and the amount of internal liquid replaced in the tank 20. The amount of internal liquid in the tank 20 can be determined as follows. A program and a data table for calculating the amount of internal liquid in the tank 20 based on the first flow rate and the second flow rate are stored in advance in the memory unit 47. The control unit 45 reads data from the program and the data table from the memory unit 47 as needed. The control unit 45 determines the amount of internal liquid in the tank 20 based on the program and the data table. The concentration of bubbles can also be determined in the same manner as the amount of internal liquid in the tank 20.

[0059] The control unit 45 then determines whether the concentration of bubbles contained in the internal liquid in the tank 20 is decreasing or whether the concentration of bubbles contained in the internal liquid is increasing. The control unit 45 transmits a signal to start or stop circulation of the internal liquid in the tank 20 according to the determined bubble concentration. When the bubble generator 60 receives these signals, the flow of the internal liquid into the bubble generation unit 30 starts or stops. The flow of the internal liquid into the bubble generation unit 30 can be started or stopped by, for example, starting or stopping the operation of the pump 33.

[0060] As for the control of transmitting a signal to start circulation of the internal liquid or a signal to stop circulation of the internal liquid, the following control can be given as an example.

[0061] (First example of control) When the concentration of bubbles contained in the internal liquid decreases based on the "concentration of bubbles contained in the internal liquid" determined at a predetermined time, the control unit 45 transmits a signal to start circulating the internal liquid. When the concentration of bubbles contained in the internal liquid increases or remains constant, the control unit 45 transmits a signal to stop circulating the internal liquid. This enables the control unit 45 to control the concentration of bubbles contained in the internal liquid in the tank to be approximately constant based on the "concentration of bubbles contained in the second liquid" determined at a predetermined time.

[0062] (Second example of control) When the concentration of bubbles contained in the internal liquid decreases below a predetermined concentration, the control unit 45 transmits a signal to start circulating the internal liquid. When the concentration of bubbles contained in the internal liquid exceeds the predetermined concentration or remains at the predetermined concentration, the control unit transmits a signal to stop circulating the internal liquid. This enables the control unit 45 to control the concentration of bubbles contained in the internal liquid in the tank 20 to approximately a predetermined concentration based on a predetermined bubble concentration.

[0063] (Third example of control) When the control device 40 includes the time measurement unit 43, the control unit 45 may be configured to control the time for which the circulation of the internal liquid continues. The control of the time for which the circulation of the internal liquid continues can be realized, for example, as follows.

[0064] The time measurement unit 43 measures a first time period during which the internal liquid continues to circulate. The control unit 45 receives information about the measured first time period. The control unit 45 further determines a second time period as a time period for which circulation is to continue based on the first flow rate, the second flow rate, and the first time period. At this time, the second time period can be determined as "the time period until the concentration of bubbles contained in the internal liquid reaches a predetermined concentration" (concentration arrival time). The second time period can be determined as follows. A program and a data table for calculating the concentration arrival time are pre-stored in the memory unit 47. The control unit 45 reads the program, data, etc. from the memory unit 47 as needed. The control unit 45 determines the second time period (concentration arrival time) based on the read program and data. The program for calculating the concentration arrival time period may be a program for calculating the relationship between the "concentration of bubbles contained in the internal liquid in the tank 20" and the "time period for which circulation is to continue" based on the first flow rate, the second flow rate, and the first time period.

[0065] The time measurement unit 43 transmits information about the second time to the control unit 45. The control unit 45 receives the information about the second time. Furthermore, the control unit 45 transmits a signal to stop the circulation of the internal liquid when the second time has elapsed. The bubble generator 60 receives the signal to stop the circulation of the internal liquid. The operation of the pump 33 of the bubble generator 60 then stops. In this way, the control unit 45 can stop the circulation of the internal liquid when the set bubble concentration is reached. This makes it possible to more precisely control the concentration of bubbles contained in the internal liquid in the tank 20 to approximately the predetermined concentration.

[0066] [1-2 Actions and Effects] In conventional technologies, a gas-liquid mixture is used regardless of whether the state of the bubbles contained therein is unstable. Therefore, the conventional technologies have room for improvement in terms of suppressing fluctuations in the concentration of bubbles contained in a gas-liquid mixture intended for use for a desired purpose. In order to supply a gas-liquid mixture with an adjusted bubble concentration to the outside, it is conceivable to adjust the concentration of bubbles contained in the gas-liquid mixture while measuring the bubble concentration in real time. However, in this case, the bubble concentration is adjusted while the concentration of bubbles contained in the gas-liquid mixture is unstable. Therefore, there is a risk of fluctuations in the concentration of bubbles contained in the gas-liquid mixture.

[0067] According to the tank system of the present invention, a gas-liquid mixture is formed as the internal liquid in the tank, and thus bubbles tend to stabilize while the gas-liquid mixture temporarily remains in the tank. According to the present invention, the internal liquid can be supplied to the outside in a gas-liquid mixture state in which the bubbles are stabilized. Furthermore, according to the present invention, the second liquid flowing from the internal liquid into the second pipe can be mixed with a third liquid, which is a liquid from outside the tank. This makes it possible to adjust the concentration of bubbles contained in the gas-liquid mixture that constitutes the internal liquid. According to the present invention, the bubbles contained in the second liquid can be stabilized, and therefore the concentration of bubbles contained in the gas-liquid mixture supplied to the outside can be stably adjusted.

[0068] [1-3 Variations] (Variation 1) In the tank system 10 of the present invention, as shown in Fig. 3B, the control device 40 of the tank system 10A described above may further be provided with an input unit 70. This embodiment will be referred to as Modified Example 1 of the tank system.

[0069] The input unit 70 is configured to allow input of designation information that designates the concentration of bubbles contained in the liquid (external supply liquid) discharged to the outside from the second tube 22. The input unit 70 may be a digital information input unit or an analog information input unit. The external supply liquid is the second liquid or a mixture of the second liquid and a third liquid.

[0070] In the first variation of the tank system, the mixing ratio of the second liquid and the third liquid that are to be merged in the concentration adjustment structure 50 is determined based on designation information input to the input unit 70. "Determining the mixing ratio of the second liquid and the third liquid" can be achieved, for example, by the control unit 45 performing the following control. The control unit 45 receives the designation information input to the input unit 70. Furthermore, the control unit 45 calculates the mixing ratio of the second liquid and the third liquid that corresponds to the designation information based on the received designation information and the concentration value of bubbles contained in the internal liquid stored in the tank 20. The control unit 45 then controls the flow rate ratio of the second liquid and the third liquid based on the calculated mixing ratio information. Specifically, for example, in the example of FIG. 1 , the control unit 45 transmits signals to control the pump 24 and the valve 26 of the concentration adjustment structure 50. The concentration adjustment structure 50 receives signals to control the pump 24 and the valve 26 from the control unit 45. Then, depending on the content of the signal, the operations of pump 24 and valve 26 are adjusted. Note that, when the third liquid contains bubbles, control unit 45 may correct the mixing ratio depending on the concentration of bubbles contained in the third liquid.

[0071] According to the first modification of the tank system 10A, it is possible to obtain an external supply liquid according to the designation information based on the designation information input to the input unit 70. In the example of FIG. 3B, the input unit 70 is provided in the control device 40, but it may be provided separately from the control device 40. The same applies to the display unit 80 shown in FIG. 3B and described later.

[0072] (Variation 2) 3B, in the tank system 10 of the present invention, the control device 40 of the tank system 10A described above may further be provided with a display unit 80. This embodiment will be referred to as Modified Example 2 of the tank system.

[0073] The display unit 80 is configured to make predetermined information recognizable. The display unit 80 may have a dial-type channel rotation structure, a liquid crystal display panel structure, or a touch panel structure. Examples of predetermined information include warning information. If the display unit 80 has a touch panel structure, it may also have the functions of the input unit 70. Furthermore, the display unit 80 may have a sound output mechanism using a speaker or the like as an output function.

[0074] According to the second modification of the tank system 10A, information (such as warning information) corresponding to the bubble concentration of the internal liquid stored inside the tank 20 is displayed on the display unit 80 in accordance with the bubble concentration of the internal liquid stored inside the tank 20. The display on the display unit 80 can be realized, for example, by the control unit 45 performing the following control. For example, the control unit 45 calculates the bubble concentration of the internal liquid stored inside the tank 20. While the liquid is being discharged from the second pipe 22, the control unit 45 estimates the bubble concentration of the internal liquid stored inside the tank 20 from the flow rate of the liquid supplied from the first pipe 21, the amount of liquid in the tank 20, the flow rate of the liquid discharged from the second pipe 22, information related to the operation of the bubble generator 60, and the like. The control unit 45 determines whether the calculated bubble concentration of the internal liquid is below a predetermined value. The control unit 45 determines that the calculated bubble concentration of the internal liquid is not below the predetermined value. In this case, the control unit 45 does not transmit a signal to the display unit to display the warning information. The control unit 45 determines that the calculated bubble concentration of the internal liquid is lower than a predetermined bubble concentration. In this case, the control unit 45 transmits a signal to the display unit to display warning information. The display unit 80 receives the signal to display the warning information and displays the warning information on the screen of the display unit 80. The display unit 80 may emit a warning sound as the warning information using a sound function. The warning information may be issued in multiple stages, and examples of the warning that is the subject of the warning information include a warning to call attention before the bubble concentration falls below a specified value, a warning that is issued when the bubble concentration falls below the specified value, etc.

[0075] The amount of internal liquid stored inside the tank 20 may be measured by a sensor or the like inside the tank 20, and an alarm may be issued when the amount falls below a predetermined amount. Also, the control unit 45 may estimate the amount of internal liquid stored inside the tank 20 from the flow rate of the liquid supplied from the first pipe 21 and the flow rate of the liquid discharged from the second pipe 22, etc.

[0076] With this configuration, it becomes easy to maintain the amount of the internal liquid stored inside the tank 20 at a certain value or above. When the amount of the internal liquid is at a certain value or above, even when the internal liquid is pumped out from the second pipe, variations in the bubbles contained in the internal liquid are unlikely to occur, and the second liquid can be supplied to the outside with a stable concentration of bubbles.

[0077] (Variation 3) In the tank system 10 of the present invention, the tank system 10A described above may be provided with a temperature measuring device (not shown). An example of the temperature measuring device is a sensor configured to be able to measure the temperature of the internal liquid in the tank 20. This embodiment is referred to as Modified Example 3 of the tank system.

[0078] In the tank system variation 3, it is preferable that a temperature adjustment device (not shown) that adjusts the temperature of the tank 20 is further provided. Examples of the temperature adjustment device include a refrigeration device and a heating device. Furthermore, in the tank system variation 3, it is preferable that a stirring device (not shown) that stirs the liquid inside the tank 20 is further provided.

[0079] For example, in the third variation of the tank system, if a heating device capable of raising the temperature of the internal liquid in the tank is provided as the temperature adjustment device, the heating device may be configured to apply heat to the tank based on temperature information determined by the temperature measuring device until the temperature of the internal liquid in tank 20 reaches a predetermined temperature. With this configuration, when the internal liquid (second liquid) in the tank is used as a cleaning liquid, the second liquid can be heated to a temperature suitable for cleaning. This improves the cleaning ability of the second liquid.

[0080] Note that while liquid is being discharged from the second pipe 22, the control unit 45 may estimate a change in the temperature of the internal liquid stored inside the tank 20 from information such as the flow rate of the liquid supplied from the first pipe 21, the amount of liquid in the tank 20, the flow rate of the liquid discharged from the second pipe 22, and the temperature of the internal liquid stored inside the tank 20. If the temperature of the internal liquid in the tank is likely to fall below a predetermined value, the control unit 45 may adaptively heat the liquid using a heating device or the like in accordance with the flow rate of the liquid supplied from the first pipe 21, the amount of liquid in the tank 20, and the flow rate of the liquid discharged from the second pipe 22, thereby stably preventing the temperature from falling below the predetermined value.

[0081] Furthermore, when the tank system variation 3 is provided with the display unit 80 shown in the variation 2, the display unit 80 may display or sound temperature-related warning information. The display unit 80 issues a warning to call attention to the temperature before it falls below a specified value that is suitable for cleaning, and issues a warning when the temperature falls below the specified value.

[0082] (Variation 4) In the tank system 10 of the present invention, the above-described tank system 10A may further be provided with a concentration measuring device (not shown). An example of the concentration measuring device is a bubble concentration sensor (not shown) for measuring the concentration of bubbles. The bubble concentration sensor is configured to be able to measure the concentration of bubbles contained in the internal liquid within the tank. This embodiment is referred to as Modified Example 4 of the tank system.

[0083] In the fourth modification of the tank system, it is preferable that an agitator (not shown) for agitating the liquid inside the tank 20 is further provided.

[0084] In the fourth modification of the tank system, the control unit 45 may be configured to send the internal liquid outward from the second pipe in accordance with the bubble concentration measured by the concentration meter.

[0085] For example, in the fourth modification of the tank system, the bubble concentration is measured at predetermined time intervals using a concentration meter. The control unit 45 receives information on the measured bubble concentration. The control unit 45 also determines whether the profile of the measured bubble concentration is generally constant (determines whether the difference between multiple consecutive measurements of the bubble concentration does not exceed a predetermined value). If the control unit 45 determines that the bubble concentration profile is generally constant, the control unit 45 transmits a signal permitting the operation of the pump 24 so that the internal liquid can be sent out from the second pipe. If the control unit 45 determines that the bubble concentration profile is not generally constant, the control unit 45 does not transmit a signal permitting the operation of the pump 24. With this configuration, the internal liquid, i.e., the gas-liquid mixture, can be sent out only when the concentration of bubbles contained in the internal liquid in the tank 20 has been more reliably stabilized.

[0086] (Variation 5) The tank system 10 of the present invention may employ a concentration adjustment structure 50B as the concentration adjustment structure 50, as shown in FIG. 4 (referred to as tank system 10B in FIG. 4). As shown in FIG. 4, the tank system 10B has a structure in which the third pipe 25 is omitted from the tank system 10A described above. This embodiment is referred to as tank system variant 4. FIG. 4 is a diagram schematically showing another example of a tank system (variation 5). In the tank system 10B, the concentration adjustment structure 50B is formed by a combination of a bubble generator 60 and a valve 23. Note that in the example of FIG. 4, a time measurement unit 43 is provided separately from the control device 40, but this is just an example.

[0087] The concentration adjustment structure 50B controls, for example, the concentration of bubbles contained in the internal liquid in the tank 20, the amount of the internal liquid in the tank 20, and the flow rate of the first liquid. That is, the concentration (target concentration) of bubbles contained in the liquid to be discharged (discharge liquid) from the tank is compared with the concentration of bubbles contained in the internal liquid in the tank 20. If the concentration of bubbles contained in the internal liquid in the tank 20 is lower than the target concentration, the bubble generator 60 is operated to increase the concentration to the target concentration. At this time, it is preferable that the valve 23 is closed. If the concentration of bubbles contained in the internal liquid in the tank 20 is higher than the target concentration, the bubble generator 60 is stopped, the valve 23 is opened, and the first liquid is supplied into the tank 20 until the concentration of bubbles contained in the internal liquid reaches the target concentration. In the tank system 10B, it is preferable that the control unit 45 compares the concentration of bubbles contained in the internal liquid in the tank 20 with the target concentration. In this case, the control unit 45 controls the operation of the bubble generator 60 and the valve 23.

[0088] This allows tank system 10B to also control the concentration of bubbles contained in the liquid discharged to the outside from second pipe 22. However, from the perspective of more effectively utilizing the ability to stabilize the concentration of bubbles contained in the internal liquid stored in tank 20, it is preferable to adjust the concentration of bubbles by having the second liquid and third liquid merge in concentration adjusting structure 50A as shown in tank system 10A described above rather than tank system 10B.

[0089] According to the description of this specification, the following inventions can be grasped. (A1) A tank for storing a liquid; a first pipe for supplying a first liquid from the outside to the inside of the tank; a bubble generator that generates bubbles having a diameter of less than 1 μm in the liquid in the tank and discharges the bubbles to a predetermined concentration; a second pipe for sending the second liquid inside the tank, in which the concentration of bubbles has reached the predetermined concentration, to the outside of the tank; a concentration adjusting structure that adjusts the concentration of the bubbles by mixing the second liquid delivered from the second pipe with a third liquid outside the tank; A tank system comprising: (A2) In the tank system described in (A1) above, a first flow rate measuring device for measuring a first flow rate of the first liquid; a second flow meter for measuring a second flow rate of the second liquid; a control device that controls the circulation of the liquid inside the tank by the bubble generator, The control device has a control unit that controls the start and / or stop of the circulation by the bubble generator based on the first flow rate and the second flow rate. Tank system. (A3) In the tank system described in (A2) above, The control device an input unit for inputting designation information for designating the concentration of the bubbles contained in the discharged liquid that is discharged to the outside of the tank via the concentration adjusting structure; a mixing ratio of the second liquid and the third liquid that are joined in the concentration adjusting structure is determined based on the designation information input to the input unit; Tank system. (A4) In the tank system described in (A2) or (A3), the control device has a time measurement unit that measures a first time period during which the circulation continues, The control unit further determines a second time period as a time period for further continuing the circulation based on the first flow rate, the second flow rate, and the first time period, and controls the circulation to be stopped upon the lapse of the second time period. Tank system. (A5) In the tank system according to any one of (A2) to (A4), the control device further includes a display unit configured to make predetermined information recognizable; the information is displayed on the display unit according to the concentration of the bubbles in the liquid inside the tank. Tank system. (A6) In the tank system according to any one of (A1) to (A5), a third pipe for supplying the third liquid; One end of the third pipe is connected to the second pipe, and the other end of the third pipe is connected to the first pipe. Tank system. [Explanation of symbols]

[0090] 10A: Tank System 20: Tank 21: First tube 22: Second tube 23: Valve 24: Pump 25: Third tube 26: Valve 30: Bubble generating section 31:Suction pipe 32: Discharge pipe 33: Pump 40: Control device 41: First flow measuring instrument 42: Second flow meter 43: Time measurement section 45: Control section 47: Storage section 50: Concentration adjustment structure 60: Bubble generator 70: Input section 80:Display section 100: Bubble generator

Claims

1. a tank for storing a liquid; a first pipe for supplying a first liquid from the outside to the inside of the tank; a bubble generator that generates bubbles having a diameter of less than 1 μm in the liquid in the tank and discharges the bubbles to a predetermined concentration; a second pipe for sending the second liquid inside the tank, in which the concentration of bubbles has reached the predetermined concentration, to the outside of the tank; a concentration adjusting structure that adjusts the concentration of the bubbles by mixing the second liquid delivered from the second pipe with a third liquid outside the tank; a first flow rate measuring device for measuring a first flow rate of the first liquid; a second flow meter for measuring a second flow rate of the second liquid; a control device that controls the circulation of the liquid inside the tank by the bubble generator, The control device has a control unit that controls the start and / or stop of the circulation by the bubble generation device based on the first flow rate and the second flow rate. Tank system.

2. 2. The tank system according to claim 1, The control device an input unit for inputting designation information for designating the concentration of the bubbles contained in the discharged liquid that is discharged to the outside of the tank via the concentration adjusting structure; a mixing ratio of the second liquid and the third liquid that are joined in the concentration adjusting structure is determined based on the designation information input to the input unit; Tank system.

3. 2. The tank system according to claim 1, the control device has a time measurement unit that measures a first time period during which the circulation continues, The control unit further determines a second time period as a time period for further continuing the circulation based on the first flow rate, the second flow rate, and the first time period, and controls the circulation to be stopped upon the lapse of the second time period. Tank system.

4. 2. The tank system according to claim 1, the control device further includes a display unit configured to make predetermined information recognizable; the information is displayed on the display unit according to the concentration of the bubbles in the liquid inside the tank. Tank system.

5. 2. The tank system according to claim 1, a third pipe for supplying the third liquid; One end of the third pipe is connected to the second pipe, and the other end of the third pipe is connected to the first pipe. Tank system.

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