Apparatus for producing fine bubble-containing liquid

Abstract

To provide a technique capable of enhancing number density of fine bubbles in a fine bubble-containing liquid.SOLUTION: An apparatus for producing a fine bubble-containing liquid may include a container having an inside surface, a cooler which is configured to cool the inside surface, a supply path for supplying a mixed fluid in which a first fluid of a gas phase and a second fluid of a gas phase are mixed to inside of the container, and a rectifier for rectifying the mixed fluid supplied from the supply path to the inside of the container toward the inside surface. The first fluid may be more condensed than the second fluid. By cooling the mixed fluid by the inside surface, the first fluid may be changed from the gas phase to the liquid phase, and the second fluid of the gas phase may be precipitated as fine bubbles in the first fluid of the liquid phase.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The technology disclosed in this specification relates to an apparatus for producing a liquid containing fine bubbles. [Background technology]

[0002] Patent Document 1 discloses an apparatus for generating a liquid containing fine bubbles. The apparatus includes a container having an inner side and an inner bottom, a cooler configured to cool the inner side and the inner bottom, a first supply path for supplying a first fluid in a gas phase to the inside of the container, and a second supply path for supplying a second fluid in a gas phase to the inside of the container. The first fluid is more likely to condense than the second fluid. In the apparatus, the first fluid in a gas phase and the second fluid in a gas phase are mixed inside the container to form a mixed fluid. In the apparatus, the mixed fluid is cooled by the inner side and the inner bottom, so that the first fluid changes from a gas phase to a liquid phase, and the second fluid in a gas phase precipitates as fine bubbles in the first fluid in a liquid phase.

[0003] In the device of Patent Document 1, the first fluid and the second fluid are mixed in a gas phase, so that the gas molecules of the first fluid and the gas molecules of the second fluid can be uniformly dispersed in the mixed fluid. In addition, by rapidly cooling the mixed fluid in which the gas molecules of the first fluid and the gas molecules of the second fluid are uniformly dispersed, a microbubble-containing liquid in which a large number of microbubbles are precipitated can be produced. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] International Publication No. 2022 / 045116 Summary of the Invention [Problem to be solved by the invention]

[0005] In the above-mentioned device, the faster the rate at which the first fluid changes from the gas phase to the liquid phase, the higher the number density of the microbubbles in the microbubble-containing liquid can be. This specification provides a technique that can further increase the number density of the microbubbles in the microbubble-containing liquid. [Means for solving the problem]

[0006] In a first aspect disclosed in the present specification, an apparatus for generating a microbubble-containing liquid may include a container having an inner surface, a cooler configured to cool the inner surface, a supply path for supplying a mixed fluid obtained by mixing a first fluid in a gas phase and a second fluid in a gas phase into the inside of the container, and a rectifier for rectifying the mixed fluid supplied from the supply path into the inside of the container toward the inner surface. The first fluid may be more easily condensed than the second fluid. The first fluid may be changed from a gas phase to a liquid phase by cooling the mixed fluid by the inner surface, and the second fluid in the gas phase may be precipitated as microbubbles in the first fluid in the liquid phase. Note that the microbubbles referred to in the present specification refer to bubbles having a nano-sized bubble diameter (less than 1 μm).

[0007] According to the above configuration, the mixed fluid flowing into the inside of the container is cooled by the inner surface. As a result, the first fluid changes from a gas phase to a liquid phase, and droplets are attached to the inner surface. In these droplets, the molecules of the second fluid in the gas phase become supersaturated with respect to the molecules of the first fluid in the liquid phase, so that the second fluid in the gas phase precipitates as fine bubbles in the first fluid in the liquid phase. As a result, a liquid containing fine bubbles is generated. The droplets of the liquid containing fine bubbles attached to the inner surface move downward along the inner surface by gravity and accumulate at the bottom of the container. Therefore, a large contact area between the inner surface that cools the mixed fluid and the mixed fluid can always be secured. As a result, the speed at which the first fluid changes from a gas phase to a liquid phase can be increased, and the number density of fine bubbles in the liquid containing fine bubbles can be increased.

[0008] In addition, according to the above configuration, the mixed fluid that has flowed into the container from the supply path is rectified by the rectifier toward the inner surface, making it easier for the mixed fluid to come into contact with the inner surface, thereby accelerating the rate at which the first fluid changes from the gas phase to the liquid phase and increasing the number density of microbubbles in the microbubble-containing liquid.

[0009] In a second aspect, in the device of the first aspect, the cooler may be configured to cool the inner surface over an entire circumference, and the flow straightener may diffuse the mixed fluid toward the entire circumference of the inner surface.

[0010] According to the above configuration, the entire circumference of the inner surface is cooled by the cooler, and the mixed fluid is diffused toward the entire circumference of the inner surface by the flow straightener, so that the contact area between the mixed fluid and the inner surface that cools the mixed fluid can be always ensured to be wide. This makes it possible to increase the speed at which the first fluid changes from the gas phase to the liquid phase, and to increase the number density of the microbubbles in the microbubble-containing liquid.

[0011] In a third aspect, in the device of the second aspect, the cooler may be disposed outside the inner surface and may include a coolant path through which the coolant absorbing heat from the inner surface flows from above to below. The rectifier may rectify the mixed fluid toward a position on the inner surface corresponding to an upstream end of the coolant path.

[0012] When the coolant flows through the coolant path, heat is transferred from the inner surface to the coolant. At this time, the inner surface absorbs heat and the temperature drops, while the coolant is heated and the temperature rises. Therefore, the coolant with the lowest temperature flows at the upstream end of the coolant path, and the coolant with a slightly higher temperature flows at the downstream end of the coolant path. Therefore, the position on the inner surface corresponding to the upstream end of the coolant path has the lowest temperature on the inner surface. According to the above configuration, the mixed fluid flowing into the container is rectified by the rectifier toward the position on the inner surface corresponding to the upstream end of the coolant path, that is, the position with the lowest temperature on the inner surface. This makes it possible to increase the speed at which the first fluid changes from a gas phase to a liquid phase, and to increase the number density of fine bubbles in the fine-bubble-containing liquid. Furthermore, according to the above configuration, after droplets of the micro-bubble-containing liquid adhere to the inner surface at a position corresponding to the upstream end of the coolant path, the droplets are cooled by the coolant flowing through the coolant path while moving downward along the inner surface due to gravity, so that the first fluid can be cooled to a lower temperature.

[0013] In a fourth aspect, in the device of any one of the first to third aspects, the supply path may have an opening that opens toward the inside of the container and expands in diameter from top to bottom. The rectifier may have a diffusion plate disposed opposite the opening and having a protrusion that protrudes toward the opening.

[0014] According to the above configuration, the mixed fluid can be more easily brought into contact with the inner surface, which can increase the rate at which the first fluid changes from the gas phase to the liquid phase and increase the number density of the microbubbles in the microbubble-containing liquid.

[0015] In a fifth aspect, in the device of any of the first to fourth aspects, the supply path may include a nozzle for spraying the first fluid in a gas phase, a suction chamber for sucking in the second fluid in a gas phase by utilizing negative pressure caused by the first fluid in a gas phase sprayed from the nozzle, and a mixing path for mixing the first fluid in a gas phase flowing in from the nozzle and the second fluid in a gas phase flowing in from the suction chamber to form the mixed fluid, and for discharging the mixed fluid into the inside of the container.

[0016] According to the above configuration, the first fluid in gas phase and the second fluid in gas phase can be mixed uniformly with a simple configuration.

[0017] In a sixth aspect, in the device of the fifth aspect, the supply path may further include a return path for returning the second fluid in a gas phase remaining inside the container to the suction chamber.

[0018] According to the above configuration, the second fluid in the gas phase that has not been used for producing the microbubble-containing liquid inside the container can be effectively utilized.

[0019] In a seventh aspect disclosed in the present specification, an apparatus for generating a microbubble-containing liquid may include a container having an inner surface, a cooler configured to cool the inner surface, a first supply path for supplying a first fluid in a gas phase to the inside of the container, a second supply path for supplying a second fluid in a gas phase to the inside of the container, and a rectifier for rectifying the first fluid in a gas phase supplied from the first supply path to the inside of the container toward the inner surface. Inside the container, the first fluid in a gas phase flowing toward the inner surface may be mixed with the second fluid in a gas phase to form a mixed fluid. The first fluid may be more easily condensed than the second fluid. The mixed fluid may be cooled by the inner surface, so that the first fluid changes from a gas phase to a liquid phase, and the second fluid in a gas phase may precipitate as fine bubbles in the first fluid in a liquid phase.

[0020] According to the above configuration, the first fluid in gas phase that has flowed into the container is mixed with the second fluid in gas phase present inside the container to become a mixed fluid, and is then cooled by the inner surface. As a result, the first fluid changes from gas phase to liquid phase, and droplets are attached to the inner surface. In these droplets, the molecules of the second fluid in gas phase become supersaturated with respect to the molecules of the first fluid in liquid phase relative to the equilibrium concentration, so that the second fluid in gas phase precipitates as fine bubbles in the first fluid in liquid phase. As a result, a liquid containing fine bubbles is generated. The droplets of the liquid containing fine bubbles that have attached to the inner surface move downward along the inner surface by gravity and accumulate at the bottom of the container. Therefore, a large contact area between the inner surface that cools the mixed fluid and the mixed fluid can always be ensured. As a result, the speed at which the first fluid changes from gas phase to liquid phase can be increased, and the number density of fine bubbles in the liquid containing fine bubbles can be increased.

[0021] In addition, according to the above configuration, the first fluid in the gas phase that has flowed into the container from the first supply path is rectified toward the inner surface by the rectifier, making it easier for the mixed fluid to come into contact with the inner surface, thereby accelerating the rate at which the first fluid changes from the gas phase to the liquid phase and increasing the number density of microbubbles in the microbubble-containing liquid.

[0022] In an eighth aspect, in the device of the seventh aspect, the cooler may be configured to cool the entire inner surface, and the flow straightener may diffuse the first fluid in a gas phase toward the entire circumference of the inner surface.

[0023] According to the above configuration, the entire circumference of the inner surface is cooled by the cooler, and the first fluid in the gas phase is diffused toward the entire circumference of the inner surface by the flow straightener, so that the contact area between the inner surface that cools the mixed fluid and the mixed fluid can be always ensured to be wide. This makes it possible to increase the speed at which the first fluid changes from the gas phase to the liquid phase, and to increase the number density of the microbubbles in the microbubble-containing liquid.

[0024] In a ninth aspect, in the device of the eighth aspect, the cooler may be disposed outside the inner surface and may include a cooling liquid path through which the cooling liquid absorbing heat from the inner surface flows from above to below. The rectifier may rectify the first fluid in a gas phase toward a position on the inner surface corresponding to an upstream end of the cooling liquid path.

[0025] According to the above configuration, the first fluid in the gas phase that has flowed into the container is rectified by the rectifier toward a position on the inner surface corresponding to the upstream end of the cooling liquid path, i.e., the position on the inner surface where the temperature is the lowest. This makes it possible to increase the speed at which the first fluid changes from the gas phase to the liquid phase, and to increase the number density of microbubbles in the microbubble-containing liquid. Furthermore, according to the above configuration, after droplets of the microbubble-containing liquid adhere to the position on the inner surface corresponding to the upstream end of the cooling liquid path, the droplets are cooled by the cooling liquid flowing through the cooling liquid path while moving downward along the inner surface by gravity, so that the first fluid can be cooled to a lower temperature.

[0026] In a tenth aspect, in the device of any one of the seventh to ninth aspects, the first supply path may have an opening that opens toward the inside of the container and expands in diameter from top to bottom. The rectifier may have a diffusion plate disposed opposite the opening and having a protrusion that protrudes toward the opening.

[0027] According to the above configuration, the mixed fluid can be more easily brought into contact with the inner surface, which can increase the rate at which the first fluid changes from the gas phase to the liquid phase and increase the number density of the microbubbles in the microbubble-containing liquid. [Brief description of the drawings]

[0028] [Figure 1] FIG. 2 is a cross-sectional view of the device 2 of the first embodiment. [Diagram 2] 2 is a perspective view of the rectifier 10 of the device 2 of the first embodiment, seen from above. FIG. [Diagram 3]FIG. 2 is a perspective view of the rectifier 10 of the device 2 of the first embodiment, seen from below. [Figure 4] FIG. 11 is a cross-sectional view of the device 102 of the second embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0029] Example 1 The apparatus 2 of this embodiment shown in Fig. 1 is used to generate a liquid containing fine bubbles in which a second fluid (e.g., air) in a gas phase is precipitated as fine bubbles in a first fluid (e.g., water) in a liquid phase. The first fluid is more easily condensed than the second fluid, and for example, in a normal temperature and pressure environment, the first fluid is in a liquid phase and the second fluid is in a gas phase. The apparatus 2 includes a container 4, a cooler 6, a supply path 8, and a rectifier 10.

[0030] The container 4 is made of a material with high thermal conductivity (e.g., metal) and is formed into a cylindrical shape with a bottom and an axis along the vertical direction. The container 4 has a cylindrical side wall 12 and a disk-shaped bottom wall 14 connected to the lower end of the side wall 12. The side wall 12 has an inner surface 12a and an outer surface 12b. An outlet path 16 for discharging the microbubble-containing liquid is connected to the center of the bottom wall 14.

[0031] The cooler 6 is provided with a coolant path 18 through which a low-temperature coolant (e.g., antifreeze) flows. The coolant path 18 is made of a pipe made of a material with high thermal conductivity (e.g., metal) and is wound in a spiral shape around the outer surface 12b of the container 4. The coolant flows from above to below through the coolant path 18. When the coolant flows through the coolant path 18, heat is transferred from the inner surface 12a of the container 4 to the coolant through the side wall 12 and the coolant path 18. At this time, the inner surface 12a absorbs heat and the temperature drops, and the coolant is heated and the temperature rises. Since the coolant with the lowest temperature flows through the upstream end of the coolant path 18, the temperature at the position on the inner surface 12a corresponding to the upstream end of the coolant path 18 becomes the lowest.

[0032] The supply path 8 includes an introduction member 20, a first supply member 22, and a second supply member 24. The introduction member 20 is attached so as to cover the opening at the top of the side wall 12 of the container 4. The introduction member 20 includes an introduction path 26 and a return path 28. The introduction path 26 includes a suction chamber 26a, a mixing path 26b, and an opening 26c. A cylindrical space is formed in the suction chamber 26a. The upper end of the mixing path 26b is connected to the center of the lower surface of the suction chamber 26a. The mixing path 26b has a shape that first reduces in diameter from the top to the bottom and then expands in diameter. The opening 26c is connected to the lower end of the mixing path 26b. The opening 26c opens toward the inside of the container 4 and has a shape that expands in diameter in a conical shape from the top to the bottom. When the device 2 is viewed in a plan view from above, the center of the opening 26c approximately coincides with the center of the space inside the container 4. The return path 28 is provided with an on-off valve (not shown) that opens and closes as necessary.

[0033] The first supply member 22 includes a first supply path 22a and a nozzle 22b. The first fluid in gas phase is supplied to the first supply path 22a. The nozzle 22b has a shape in which the diameter decreases from the top to the bottom. The nozzle 22b is disposed from the suction chamber 26a to the mixing path 26b. The nozzle 22b sprays the first fluid in gas phase supplied from the first supply path 22a downward.

[0034] The second supply member 24 includes a second supply path 24a and a connecting path 24b. The second supply path 24a is supplied with the second fluid in gas phase. The second supply path 24a supplies the second fluid in gas phase to the suction chamber 26a. The connecting path 24b communicates with the inside of the container 4 via a return path 28. The second fluid in gas phase remaining in the container 4 returns to the suction chamber 26a via the return path 28, the connecting path 24b, and the second supply path 24a.

[0035] When the first fluid in gas phase is sprayed from the nozzle 22b, a negative pressure is generated by the first fluid in gas phase near the outlet of the nozzle 22b, and the second fluid in gas phase flows from the suction chamber 26a toward the mixing path 26b. In the mixing path 26b, the first fluid in gas phase flowing in from the nozzle 22b and the second fluid in gas phase flowing in from the suction chamber 26a mix to form a mixed fluid. The mixed fluid is supplied from the mixing path 26b to the inside of the container 4 through the opening 26c.

[0036] The rectifier 10 is attached to the lower surface of the introduction member 20 inside the container 4. As shown in FIG. 2 and FIG. 3, the rectifier 10 includes a diffusion plate 30, a support plate 32, and a connecting portion 34. The diffusion plate 30 includes a cone-shaped protrusion 30a with a rounded apex. The support plate 32 is formed in a flat plate shape and is fixed to the lower surface of the introduction member 20 (see FIG. 1) via a fastener (not shown). The connecting portion 34 connects the diffusion plate 30 and the support plate 32. A plurality of arc-shaped long holes 34a are formed around the entire circumference of the connecting portion 34. As shown in FIG. 1, the rectifier 10 is attached to the introduction member 20 so that the protrusion 30a of the diffusion plate 30 enters the opening 26c of the introduction member 20. A diffusion path 36 is formed between the surface of the protrusion 30a and the surface of the opening 26c.

[0037] The mixed fluid supplied from the mixing path 26b to the inside of the container 4 collides with the diffusion plate 30 of the rectifier 10, flows through the diffusion path 36, and is sprayed from the multiple long holes 34a toward the inner surface 12a. At this time, the diffusion plate 30 rectifies the mixed fluid toward a position corresponding to the upstream end of the cooling liquid path 18 on the inner surface 12a in the axial direction (up and down direction). The position corresponding to the upstream end of the cooling liquid path 18 is a position that is approximately the same height as the upstream end of the cooling liquid path 18 in the axial direction. In the circumferential direction, the diffusion plate 30 diffuses the mixed fluid toward the entire circumference of the inner surface 12a. In this embodiment, when the device 2 is viewed in a plan view from above, the center of the opening 26c approximately coincides with the center of the space inside the container 4, so that the mixed fluid diffused by the diffusion plate 30 can be sprayed approximately uniformly toward the entire circumference of the inner surface 12a with a simple structure.

[0038] The mixed fluid flowing into the inside of the container 4 is cooled by the inner surface 12a. As a result, the first fluid changes from the gas phase to the liquid phase, and droplets are attached to the inner surface 12a. In these droplets, the molecules of the second fluid in the gas phase become supersaturated with respect to the molecules of the first fluid in the liquid phase, so that the second fluid in the gas phase precipitates as fine bubbles in the first fluid in the liquid phase. As a result, a fine bubble-containing liquid is generated. The droplets of the fine bubble-containing liquid attached to the inner surface 12a move downward along the inner surface 12a by gravity and accumulate at the bottom of the container 4. The fine bubble-containing liquid accumulated at the bottom of the container 4 can be taken out through the take-out path 16 connected to the bottom wall 14.

[0039] In the apparatus 2 of the present embodiment, the first fluid and the second fluid are mixed in a gas phase, so that the gas molecules of the first fluid and the gas molecules of the second fluid can be uniformly dispersed in the mixed fluid. In addition, in the apparatus 2 of the present embodiment, the mixed fluid in which the gas molecules of the first fluid and the gas molecules of the second fluid are uniformly dispersed can be rapidly cooled to produce a microbubble-containing liquid in which a large number of microbubbles are precipitated.

[0040] As described above, the device 2 of this embodiment produces a liquid containing fine bubbles. The device 2 includes a container 4 having an inner surface 12a, a cooler 6 configured to cool the inner surface 12a, a supply path 8 that supplies a mixed fluid, which is a mixture of a first fluid in a gas phase (e.g., water) and a second fluid in a gas phase (e.g., air), to the inside of the container 4, and a rectifier 10 that rectifies the mixed fluid supplied from the supply path 8 to the inside of the container 4 toward the inner surface 12a. The first fluid is more likely to condense than the second fluid. The mixed fluid is cooled by the inner surface 12a, so that the first fluid changes from a gas phase to a liquid phase, and the second fluid in a gas phase precipitates as fine bubbles in the first fluid in a liquid phase.

[0041] According to the above configuration, droplets of the microbubble-containing liquid adhering to the inner surface 12a move downward along the inner surface 12a by gravity and accumulate at the bottom of the container 4. This ensures that the contact area between the inner surface 12a, which cools the mixed fluid, and the mixed fluid is always large. This makes it possible to increase the speed at which the first fluid changes from the gas phase to the liquid phase, and to increase the number density of microbubbles in the microbubble-containing liquid.

[0042] Furthermore, according to the above configuration, the mixed fluid that has flowed into the container 4 from the supply path 8 is rectified by the rectifier 10 toward the inner surface 12a, making it easier for the mixed fluid to come into contact with the inner surface 12a. This can increase the rate at which the first fluid changes from the gas phase to the liquid phase, and can increase the number density of microbubbles in the microbubble-containing liquid.

[0043] In the device 2 of this embodiment, the cooler 6 is configured to cool the entire periphery of the inner surface 12a. The flow straightener 10 diffuses the mixed fluid toward the entire periphery of the inner surface 12a.

[0044] According to the above configuration, the entire circumference of the inner surface 12a is cooled by the cooler 6, and the mixed fluid is diffused toward the entire circumference of the inner surface 12a by the flow straightener 10, so that the contact area between the inner surface 12a that cools the mixed fluid and the mixed fluid can always be secured to be wide. This makes it possible to increase the speed at which the first fluid changes from the gas phase to the liquid phase, and to increase the number density of the microbubbles in the microbubble-containing liquid.

[0045] In the device 2 of this embodiment, the cooler 6 is disposed outside the inner surface 12a and includes a coolant path 18 through which the coolant absorbing heat from the inner surface 12a flows from above to below. The rectifier 10 rectifies the mixed fluid toward a position on the inner surface 12a corresponding to the upstream end of the coolant path 18.

[0046] When the coolant flows through the coolant path 18, heat is transferred from the inner surface 12a to the coolant. At this time, the inner surface 12a absorbs heat and the temperature drops, while the coolant is heated and the temperature rises. Therefore, the coolant with the lowest temperature flows at the upstream end of the coolant path 18, and the coolant with a slightly higher temperature flows at the downstream end of the coolant path 18. Therefore, the position on the inner surface 12a corresponding to the upstream end of the coolant path 18 has the lowest temperature on the inner surface 12a. According to the above configuration, the mixed fluid that has flowed into the inside of the container 4 is rectified by the rectifier 10 toward the position on the inner surface 12a corresponding to the upstream end of the coolant path 18, that is, the position on the inner surface 12a with the lowest temperature. This makes it possible to increase the speed at which the first fluid changes from a gas phase to a liquid phase, and to increase the number density of fine bubbles in the fine-bubble-containing liquid. Furthermore, according to the above-described configuration, after droplets of the micro-bubble-containing liquid adhere to the inner surface 12a at a position corresponding to the upstream end of the cooling liquid path 18, the droplets are cooled by the cooling liquid flowing through the cooling liquid path 18 while moving downward along the inner surface 12a due to gravity, so that the first fluid can be cooled to a lower temperature.

[0047] In the device 2 of this embodiment, the supply path 8 is open toward the inside of the container 4 and has an opening 26c whose diameter increases from top to bottom. The rectifier 10 is disposed opposite the opening 26c and has a diffusion plate 30 having a protrusion 30a protruding toward the opening 26c.

[0048] According to the above-mentioned configuration, the mixed fluid can be more easily brought into contact with the inner surface 12a, which can increase the rate at which the first fluid changes from the gas phase to the liquid phase, thereby increasing the number density of the microbubbles in the microbubble-containing liquid.

[0049] In the device 2 of this embodiment, the supply path 8 may include a nozzle 22b that sprays a first fluid in a gas phase, a suction chamber 26a that uses the negative pressure caused by the first fluid in a gas phase sprayed from the nozzle 22b to suck in a second fluid in a gas phase, and a mixing path 26b that mixes the first fluid in a gas phase flowing in from the nozzle 22b and the second fluid in a gas phase flowing in from the suction chamber 26a to form a mixed fluid and discharges the mixed fluid into the inside of the container 4.

[0050] According to the above configuration, the first fluid in gas phase and the second fluid in gas phase can be mixed uniformly with a simple configuration.

[0051] In the device 2 of this embodiment, the supply path 8 further includes a return path 28 for returning the second fluid in a gas phase remaining inside the container 4 to the suction chamber 26a.

[0052] According to the above-mentioned configuration, the second fluid in the gas phase that has not been used for generating the microbubble-containing liquid inside the container 4 can be effectively utilized.

[0053] Example 2 The apparatus 102 of this embodiment shown in Fig. 4 has a configuration substantially similar to that of the apparatus 2 of the embodiment 1 shown in Fig. 1. In the following, the same components as those of the apparatus 2 of the embodiment 1 are denoted by the same reference numerals, and detailed description thereof will be omitted. The apparatus 102 is used to generate a liquid containing fine bubbles in which a second fluid (e.g., air) in a gas phase is precipitated as fine bubbles in a first fluid (e.g., water) in a liquid phase. The apparatus 102 includes a container 4, a cooler 6, a supply path 104, and a rectifier 10.

[0054] The supply path 104 includes an introduction member 106, a supply member 108, and a discharge member 110. The introduction member 106 is attached so as to cover the opening at the top of the side wall 12 of the container 4. The introduction member 106 is formed with a first supply path 112, a second supply path 114, and a discharge path 116. The first supply path 112 includes a gas introduction chamber 112a, a gas passage path 112b, and an opening 112c. The first fluid in gas phase is supplied to the gas introduction chamber 112a. The upper end of the gas passage path 112b is connected to the center of the lower surface of the gas introduction chamber 112a. The gas passage path 112b extends linearly from above to below. The opening 112c is connected to the lower end of the gas passage path 112b. The opening 112c opens toward the inside of the container 4 and has a shape that expands in a conical shape from above to below. The discharge path 116 is provided with an on-off valve (not shown) that opens and closes as necessary.

[0055] The second fluid in a gas phase is supplied to the supply member 108. The second fluid in a gas phase is supplied from the supply member 108 to the inside of the container 4 via the second supply path 114.

[0056] The second fluid in a gas phase remaining inside the container 4 flows into the discharge member 110 via the discharge path 116. The discharge member 110 discharges the second fluid in a gas phase that has flowed in from the inside of the container 4 to the outside of the container 4.

[0057] The rectifier 10 is attached to the introduction member 106 such that the protrusion 30a of the diffusion plate 30 enters the opening 112c of the introduction member 106. A diffusion path 118 is formed between the surface of the protrusion 30a and the surface of the opening 112c.

[0058] The first fluid in gas phase supplied from the gas passage path 112b to the inside of the container 4 collides with the diffusion plate 30 of the rectifier 10, flows through the diffusion path 118, and is sprayed from the multiple long holes 34a toward the inner surface 12a. At this time, the diffusion plate 30 rectifies the first fluid in gas phase toward a position on the inner surface 12a corresponding to the upstream end of the coolant path 18 in the axial direction (up-down direction). In the circumferential direction, the diffusion plate 30 diffuses the first fluid in gas phase toward the entire circumference of the inner surface 12a.

[0059] The first fluid in gas phase that has flowed into the container 4 mixes with the second fluid in gas phase present inside the container 4 to become a mixed fluid, and is then cooled by the inner surface 12a. As a result, the first fluid changes from gas phase to liquid phase, and droplets adhere to the inner surface 12a. In these droplets, the molecules of the second fluid in gas phase become supersaturated with respect to the molecules of the first fluid in liquid phase more than the equilibrium concentration, so that the second fluid in gas phase precipitates as fine bubbles in the first fluid in liquid phase. As a result, a liquid containing fine bubbles is generated. The droplets of the liquid containing fine bubbles that have adhered to the inner surface 12a move downward along the inner surface 12a by gravity and accumulate at the bottom of the container 4. The liquid containing fine bubbles that has accumulated at the bottom of the container 4 can be taken out via an outlet path 16 connected to the bottom wall 14.

[0060] In the device 102 of this embodiment, the first fluid and the second fluid are mixed in a gas phase, so that the gas molecules of the first fluid and the gas molecules of the second fluid can be uniformly dispersed in the mixed fluid. Also, in the device 102 of this embodiment, by rapidly cooling the mixed fluid in which the gas molecules of the first fluid and the gas molecules of the second fluid are uniformly dispersed, a microbubble-containing liquid in which a large number of microbubbles are precipitated can be produced.

[0061] As described above, the device 102 of this embodiment produces a liquid containing fine bubbles. The device 102 includes a container 4 having an inner surface 12a, a cooler 6 configured to cool the inner surface 12a, a first supply path 112 that supplies a first fluid in a gas phase (e.g., water) to the inside of the container 4, a second supply path 114 that supplies a second fluid in a gas phase (e.g., air) to the inside of the container 4, and a rectifier 10 that rectifies the first fluid in a gas phase supplied from the first supply path 112 to the inside of the container 4 toward the inner surface 12a. Inside the container 4, the first fluid in a gas phase flowing toward the inner surface 12a mixes with the second fluid in a gas phase to form a mixed fluid. The first fluid is more likely to condense than the second fluid. The mixed fluid is cooled by the inner surface 12a, so that the first fluid changes from a gas phase to a liquid phase, and the second fluid in a gas phase precipitates as fine bubbles in the first fluid in a liquid phase.

[0062] According to the above configuration, droplets of the microbubble-containing liquid adhering to the inner surface 12a move downward along the inner surface 12a by gravity and accumulate at the bottom of the container 4. This ensures that the contact area between the inner surface 12a, which cools the mixed fluid, and the mixed fluid is always large. This makes it possible to increase the speed at which the first fluid changes from the gas phase to the liquid phase, and to increase the number density of microbubbles in the microbubble-containing liquid.

[0063] Furthermore, according to the above configuration, the first fluid in the gas phase that has flowed into the container 4 from the first supply path 112 is rectified toward the inner surface 12a by the rectifier 10, so that the mixed fluid can easily come into contact with the inner surface 12a. This can increase the speed at which the first fluid changes from the gas phase to the liquid phase, and can increase the number density of the microbubbles in the microbubble-containing liquid.

[0064] In the device 102 of this embodiment, the cooler 6 is configured to cool the entire periphery of the inner surface 12a. The flow straightener 10 diffuses the first fluid in the gas phase toward the entire periphery of the inner surface 12a.

[0065] According to the above configuration, the entire circumference of the inner surface 12a is cooled by the cooler 6, and the first fluid in the gas phase is diffused toward the entire circumference of the inner surface 12a by the flow straightener 10, so that the contact area between the inner surface 12a that cools the mixed fluid and the mixed fluid can be always ensured to be wide. This makes it possible to increase the speed at which the first fluid changes from the gas phase to the liquid phase, and to increase the number density of the fine bubbles in the microbubble-containing liquid.

[0066] In the device 102 of this embodiment, the cooler 6 is disposed outside the inner surface 12a, and includes a coolant path 18 through which the coolant absorbing heat from the inner surface 12a flows from above to below. The rectifier 10 rectifies the flow of the first fluid in the gas phase toward a position on the inner surface 12a corresponding to the upstream end of the coolant path 18.

[0067] According to the above configuration, the first fluid in the gas phase that has flowed into the container 4 is rectified by the rectifier 10 toward a position on the inner surface 12a corresponding to the upstream end of the coolant path 18, i.e., the position on the inner surface 12a where the temperature is the lowest. This makes it possible to increase the speed at which the first fluid changes from the gas phase to the liquid phase, and to increase the number density of the microbubbles in the microbubble-containing liquid. Furthermore, according to the above configuration, after droplets of the microbubble-containing liquid adhere to the position on the inner surface 12a corresponding to the upstream end of the coolant path 18, the droplets are cooled by the coolant flowing through the coolant path 18 while moving downward along the inner surface 12a by gravity, so that the first fluid can be cooled to a lower temperature.

[0068] In the device 102 of this embodiment, the first supply path 112 is open toward the inside of the container 4 and has an opening 112c that expands in diameter from top to bottom. The rectifier 10 is disposed opposite the opening 112c and includes a diffusion plate 30 having a protrusion 30a that protrudes toward the opening 112c.

[0069] According to the above-mentioned configuration, the mixed fluid can be more easily brought into contact with the inner surface 12a, which can increase the rate at which the first fluid changes from the gas phase to the liquid phase, thereby increasing the number density of the microbubbles in the microbubble-containing liquid.

[0070] (Modification) The first fluid may be a fluid other than water, for example, ethanol. The second fluid may be a fluid other than air, for example, carbon dioxide. The coolant may be a fluid other than antifreeze, for example, water or a refrigerant (for example, R290, etc.).

[0071] The coolant path 18 of the cooler 6 may be in a form other than a piping spirally wound around the outer surface 12b of the container 4. For example, the coolant path 18 may be a cylindrical flow path having an inner cylindrical surface and an outer cylindrical surface, the inner cylindrical surface being in contact with the outer surface 12b of the container 4 and having a thickness in the radial direction. In this case as well, the coolant flows from above to below through the coolant path 18, thereby cooling the inner surface 12a of the container 4.

[0072] The coolant passage 18 of the cooler 6 may be integrally formed with the vessel 4. For example, the coolant passage 18 may be integrated into the side wall 12 of the vessel 4, i.e., between the inner surface 12a and the outer surface 12b.

[0073] The cooler 6 may be configured to cool the inner side surface 12a without using a cooling liquid. For example, the cooler 6 may be configured to cool the inner side surface 12a using a Peltier element or a heat pump.

[0074] In the first embodiment, the supply path 8 may supply the mixed fluid to the inside of the container 4 from the side of the container 4. In the second embodiment, the supply path 104 may supply the first fluid and / or the second fluid to the inside of the container 4 from the side of the container 4.

[0075] The opening 26c of the supply path 8 in the first embodiment and the opening 112c of the supply path 104 in the second embodiment do not have to expand in a conical shape. In addition, the diffusion plate 30 of the rectifier 10 may be a flat plate that does not have the protrusions 30a.

[0076] In the first embodiment, a discharge path (not shown) may be provided for discharging the second fluid in a gas phase remaining inside the container 4 to the outside of the container 4. The discharge path may be provided with an on-off valve (not shown) that opens and closes as necessary. For example, the discharge path may be configured to pass through the introduction member 20 from above to below, and to communicate the inside of the container 4 with the outside of the container 4. Alternatively, the discharge path may be configured to communicate the connection path 24b with the outside of the container 4.

[0077] In the first embodiment, the return path 28 and the connecting path 24b may not be provided, and the second fluid in the gas phase remaining inside the container 4 may not return to the suction chamber 26a.

[0078] In the second embodiment, the discharge path 116 and the discharge member 110 may not be provided, and the second fluid in the gas phase remaining inside the container 4 may not be discharged to the outside of the container 4.

[0079] Although each embodiment has been described in detail above, these are merely examples and do not limit the scope of the claims. The technology described in the claims includes various modifications and variations of the specific examples exemplified above. The technical elements described in this specification or drawings exhibit technical utility alone or in various combinations, and are not limited to the combinations described in the claims at the time of filing. In addition, the technology exemplified in this specification or drawings can achieve multiple objectives simultaneously, and achieving one of these objectives is itself technically useful. [Explanation of symbols]

[0080] 2: Equipment 4: Container 6:Cooler 8: Supply route 10: Rectifier 12: Side wall 12a: Inside surface 12b: Outer surface 14: Bottom wall 16: Extraction route 18: Coolant path 20: Introduction material 22: First supply member 22a: First supply route 22b: Nozzle 24: Second supply member 24a: Second supply route 24b: Connection route 26: Introduction route 26a: Suction chamber 26b: Mixed pathway 26c: opening 28: Reflux route 30: Diffuser 30a:Protrusion 32: Support plate 34:Connection part 34a: Long hole 36: Diffusion Path 102: Equipment 104: Supply route 106: Introduction material 108: Supply material 110: Discharge member 112: First supply route 112a: Gas introduction chamber 112b: Gas passage path 112c: opening 114: Second supply route 116: Excretion route 118: Diffusion Path

Claims

1. An apparatus for producing a liquid containing fine bubbles, comprising: a container having an interior surface; a cooler configured to cool the interior surface; and a supply path for supplying a mixed fluid obtained by mixing a first fluid in a gas phase and a second fluid in a gas phase into the container; a flow rectifier that rectifies the mixed fluid supplied from the supply path into the container toward the inner surface, The first fluid is more easily condensed than the second fluid; The mixed fluid is cooled by the inner surface, causing the first fluid to change from a gas phase to a liquid phase, and the second fluid in the gas phase precipitates as fine bubbles in the first fluid in the liquid phase.

2. The cooler is configured to cool the inner surface all around, The apparatus of claim 1 , wherein the flow straightener spreads the mixed fluid around the entire periphery of the interior surface.

3. the cooler is disposed outside the inner surface and includes a cooling liquid path through which a cooling liquid that absorbs heat from the inner surface flows from above to below, The apparatus of claim 2 , wherein the flow straightener straightens the mixed fluid toward a location on the interior surface corresponding to an upstream end of the coolant path.

4. The supply path is open toward the inside of the container and has an opening whose diameter increases from the top to the bottom, The apparatus of claim 1 , wherein the rectifier comprises a diffuser disposed opposite the opening and having a protrusion that protrudes toward the opening.

5. The supply path is A nozzle for ejecting the first fluid in a gas phase; a suction chamber that sucks in the second fluid in a gas phase by utilizing a negative pressure caused by the first fluid in a gas phase sprayed from the nozzle; The apparatus of claim 1, further comprising a mixing path for mixing the first fluid in gas phase flowing in from the nozzle with the second fluid in gas phase flowing in from the suction chamber to form the mixed fluid, and for discharging the mixed fluid into the inside of the container.

6. The apparatus of claim 5 , wherein the supply path further comprises a return path for returning the second fluid in a gas phase remaining inside the container to the suction chamber.

7. An apparatus for producing a liquid containing fine bubbles, comprising: a container having an interior surface; a cooler configured to cool the interior surface; and a first supply path for supplying a first fluid in a gas phase to an interior of the container; a second supply path for supplying a second fluid in a gas phase to an interior of the container; a rectifier that rectifies the first fluid in a gas phase supplied from the first supply path into the container toward the inner surface, Within the container, the first fluid in a gas phase flowing toward the inner surface mixes with the second fluid in a gas phase to form a mixed fluid, The first fluid is more easily condensed than the second fluid; The mixed fluid is cooled by the inner surface, causing the first fluid to change from a gas phase to a liquid phase, and the second fluid in the gas phase precipitates as fine bubbles in the first fluid in the liquid phase.

8. The cooler is configured to cool the inner surface all around, The apparatus of claim 7 , wherein the flow straightener spreads the first fluid in a gas phase around the entire periphery of the interior surface.

9. the cooler is disposed outside the inner surface and includes a cooling liquid path through which a cooling liquid that absorbs heat from the inner surface flows from above to below, The apparatus of claim 8 , wherein the flow straightener straightens the first fluid in a gas phase toward a location on the interior surface corresponding to an upstream end of the coolant path.

10. The first supply path has an opening that opens toward the inside of the container and expands in diameter from above to below, The apparatus of claim 7 , wherein the rectifier comprises a diffuser plate disposed opposite the opening and having a protrusion that protrudes toward the opening.

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