Ultra fine bubble production device

Abstract

An ultra fine bubble production device includes: a container portion having a containment space formed therein for containing liquid and gas; a pressurizing portion configured to compress the containment space to generate, in the containment space, pressurized gas dissolved liquid including the liquid and the gas dissolved under pressure in the liquid; a holding portion configured to hold a dissolved state under pressure in which the gas is dissolved under pressure in the liquid; and a depressurizing portion configured to open, in the dissolved state under pressure, a communication path through which an inside and an outside of the containment space communicate with each other, to depressurize the pressurized gas dissolved liquid and generate ultra fine bubbles.

Description

Technical Field

[0001] The present invention relates to an ultra fine bubble production device.Background Art

[0002] In recent years, applied technologies utilizing characteristics of fine bubbles have attracted attention. Bubbles having a diameter of less than 100 µm are called fine bubbles. In particular, ultra fine bubbles that are bubbles having a diameter of less than 1 µm (nano-size) are distinguished from other bubbles, and the usefulness of the ultra fine bubbles has been acknowledged in various fields.

[0003] Various methods of producing ultra fine bubbles have been developed so far. For example, a production method using under-pressure dissolution is widely used, in which gas is dissolved in liquid under pressure, and then the pressure is rapidly reduced to cause supersaturation and thereby cause the gas to precipitate as ultra fine bubbles. An ultra fine bubble production device using under-pressure dissolution, which includes a container portion for containing liquid and gas, and a drive portion for pressurization in the container portion, has been proposed (for example, see Patent Document 1). In the pressurization in the ultra fine bubble production device, a time required for pressure to reach maximum pressure from the start of the pressurization is 2.0 milliseconds or less, and the maximum pressure is 4.00 MPa or more.Citation ListPatent Document

[0004] Patent Document 1: WO 2021 / 090833Summary of InventionTechnical Problem

[0005] An object of the technology of the present disclosure is to provide a technology for improving the performance of an ultra fine bubble production device.Solution to Problem

[0006] To solve the above problems, an ultra fine bubble production device according to the present disclosure has employed the following configuration. That is, the gist of the technology according to the present disclosure is as follows. [1] An ultra fine bubble production device including: a container portion having a containment space formed therein for containing liquid and gas; a pressurizing portion configured to compress the containment space to generate, in the containment space, pressurized gas dissolved liquid including the liquid and the gas dissolved under pressure in the liquid; a holding portion configured to hold a dissolved state under pressure in which the gas is dissolved under pressure in the liquid; and a depressurizing portion configured to open, in the dissolved state under pressure, a communication path through which an inside and an outside of the containment space communicate with each other, to depressurize the pressurized gas dissolved liquid and generate ultra fine bubbles. [2] The ultra fine bubble production device according to [1], in which the pressurizing portion includes a sliding portion configured to be inserted into the container portion to form the containment space together with the container portion, the sliding portion being slidable in the container portion along an insertion direction to the container portion, the sliding portion moves relative to the container portion in the insertion direction thereby causing compression of the containment space, and the holding portion restricts, in the dissolved state under pressure, the sliding portion from moving relative to the container portion in a direction opposite to the insertion direction. [3] The ultra fine bubble production device according to [2], in which the pressurizing portion includes a screw shaft portion extending along the insertion direction, the screw shaft portion having a male screw groove formed in an outer periphery of the screw shaft portion, the holding portion includes a screw hole portion into which the screw shaft portion is inserted, the screw hole portion having a female screw groove to be engaged with the male screw groove of the screw shaft portion, and the screw shaft portion moves toward the container portion in the insertion direction as the screw shaft portion is screwed and advanced into the screw hole portion. [4] The ultra fine bubble production device according to any one of [1] to [3], in which the depressurizing portion includes a valve body configured to transition from a closed state in which the communication path is closed to an open state in which the communication path is opened, and a drive portion configured to apply, to the valve body, energy for the valve body to transition from the closed state to the open state. [5] The ultra fine bubble production device according to [4], in which, when the valve body is in the closed state, the valve body is fitted in the communication path to close the communication path, and the drive portion pushes the valve body from an outer side toward an inner side of the containment space to cause the valve body to transition from the closed state to the open state. [6] The ultra fine bubble production device according to [4] or [5], in which the drive portion includes an igniter configured to burn an ignition agent by being supplied with operating electric power, and applies combustion energy of the ignition agent to the valve body. [7] The ultra fine bubble production device according to [4] or [5], in which the drive portion includes an elastic body configured to apply elastic energy to the valve body by returning from a compressed state to an extended state in which the elastic body is extended compared to the compressed state. Advantageous Effects of Invention

[0007] According to the present disclosure, it is possible to improve the performance of the ultra fine bubble production device.Brief Description of Drawings

[0008] FIG. 1 is an overall perspective view of an ultra fine bubble production device (hereinafter, simply referred to as a "production device") according to a first embodiment. FIG. 2 is a top view of the production device according to the first embodiment. FIG. 3 is a cross-sectional view taken along A-A of FIG. 2. FIG. 4 is a partial cross-sectional view of the production device according to the first embodiment when a valve is in a closed state, and the inside of a containment space is in a gas-liquid separation state. FIG. 5 is a cross-sectional view taken along B-B of FIG. 4. FIG. 6 is a cross-sectional view of the production device according to the first embodiment when the valve is in the closed state, and the inside of the containment space is in a dissolved state under pressure. FIG. 7 is a cross-sectional view of the production device according to the first embodiment when the inside of the containment space is in the dissolved state under pressure, and the valve is in an open state. FIG. 8 is a partial cross-sectional view of the production device according to the first embodiment when the inside of the containment space is in the dissolved state under pressure, and the valve is in an open state. FIG. 9 is a cross-sectional view of a production device according to a second embodiment when a valve is in a closed state, and the inside of a containment space is in a gas-liquid separation state. FIG. 10 is a cross-sectional view of the production device according to the second embodiment when the inside of the containment space is in a dissolved state under pressure, and the valve is in an open state. Description of Embodiments

[0009] Hereinafter, embodiments of the present disclosure will be described. Note that each of the configurations, combinations thereof, and the like in the embodiments is an example, and various additions, omissions, substitutions, and other changes of the configurations may be made as appropriate without departing from the spirit of the present disclosure. The present disclosure is not limited by the embodiments and is limited only by the claims.

[0010] An embodiment of the present disclosure is an ultra fine bubble production device including: a container portion having a containment space formed therein for containing liquid and gas; a pressurizing portion configured to compress the containment space to generate, in the containment space, pressurized gas dissolved liquid including the liquid and the gas dissolved under pressure in the liquid; a holding portion configured to hold a dissolved state under pressure in which the gas is dissolved under pressure in the liquid; and a depressurizing portion configured to open, in the dissolved state under pressure, a communication path through which an inside and an outside of the containment space communicate with each other, to depressurize the pressurized gas dissolved liquid and generate ultra fine bubbles.

[0011] In the present disclosure, "ultra fine bubbles" refer to bubbles having a diameter less than 1 µm. Although most of the bubbles produced by the device according to the present embodiment are ultra fine bubbles, it suffices that the bubbles produced by the device according to the present embodiment include ultra fine bubbles, and may include bubbles that do not satisfy the above-described definition.

[0012] In the present disclosure, the liquid to be contained in the container portion is not particularly limited. Examples of the liquid include liquids that can be used as a solvent (for example, water, alcohols, or oils). Other examples include solutions (for example, culture solution (liquid culture medium), saline, phosphate buffer solution, prepared reagents, or solution cosmetics). Other examples include emulsions (emulsion cosmetics such as milky lotion). The liquid may be a liquid containing any two or more of these. Furthermore, the liquid may include low molecules or high molecules or may include an inorganic substance or an organic material (for example, a biological substance such as a nucleic acid). In a preferred aspect of the present embodiment, the liquid is a liquid that does not include microorganisms or the like. In a preferred aspect of the present embodiment, the water is pure water (for example, distilled water, RO water, RO-EDI water, or ion exchanged water), and in another preferred aspect, the water is ultrapure water. Examples of the ultrapure water include Milli-Q water.

[0013] In the present disclosure, the gas to be contained in the container portion is not particularly limited. Examples of the gas can include air. Other examples can include nitrogen, oxygen, ozone, carbon dioxide, hydrogen, and carbon monoxide, as well as a mixed gas of any two or more of these. In a preferred aspect of the present embodiment, the gas is a gas that does not include microorganisms or the like. The air may be commonly used air, the composition of which is not particularly limited. Examples of the air include a mixed gas containing about 80% of nitrogen and about 20% of oxygen.

[0014] In the present disclosure, for energy application by a drive portion for the valve body to transition to the open state in which the communication path is opened, a form of energy application based on a known pressurization technique can be employed. An example of the energy applied may be chemically-generated energy such as, for example, combustion energy generated by an oxidation reaction of a low explosive or a high explosive. Further, as another method, the energy for the transition may be generated electrically. As an example, energy caused by a piezoelectric element or an electromagnetic actuator driven by applied electric power may be employed. Furthermore, as yet another method, the energy for the transition may be generated physically. As an example, elastic energy of an elastic body or internal energy of a compressed body, such as compressed gas, may be employed. For example, the drive portion may generate energy by releasing the pressure of compressed gas. As yet another method, the energy for the transition may be generated manually (by human power). For example, the drive portion may transmit human power of an operator to apply energy to the valve body. That is, the energy for the transition may be any energy as long as the energy enables transition of the valve body from the closed state to the open state. Further, the energy for the transition may be composite-type energy obtained by appropriately combining the above-described combustion energy, energy generated by electric power, internal energy such as the elastic energy, and energy generated manually (by human power).First Embodiment

[0015] An ultra fine bubble production device according to a first embodiment will be hereinafter described with reference to the drawings.Overall Configuration

[0016] FIG. 1 is an overall perspective view of an ultra fine bubble production device (hereinafter, simply referred to as a "production device") 100 according to the first embodiment. FIG. 2 is a top view of the production device 100 according to the first embodiment. FIG. 3 is a cross-sectional view taken along A-A of FIG. 2. Arrows illustrated in FIGS. 1 to 3 represent the front-rear, up-down, and left-right directions of the production device 100. FIG. 3 illustrates a cross section along the front-rear direction of the production device 100. In the specification, a side where an actuation screw is located, that is indicated by reference numeral 4, is defined as the rear side in the front-rear direction, and a side where a drive portion is located, that is indicated by reference numeral 7, is defined as the front side in the front-rear direction. However, the directions such as front-rear, up-down, and left-right directions in the present specification merely indicate relative positional relationships between members of the production device 100.

[0017] As illustrated in FIG. 1, the production device 100 includes a container 1 (an example of a "container portion" according to the present disclosure), a pressurizing portion 10, a depressurizing portion 20, and a holder 8 (an example of a "holding portion" according to the present disclosure). As illustrated in FIG. 3, a containment space S1, in which liquid L1 and gas G1 are stored, is formed inside the container 1. FIGS. 1 to 3 illustrate a state in which the liquid L1 and the gas G1 in the containment space S1 are separated from each other (hereinafter also referred to as a gas-liquid separation state), and in which a valve indicated by reference numeral 5 in FIG. 3 closes a communication path indicated by reference numeral 14 (hereinafter also referred to as a closed state). The production device 100 compresses the containment space S1 by the pressurizing portion 10 to generate pressurized gas dissolved liquid L2 in which the gas G1 is dissolved under pressure in the liquid L1 (see FIG. 6), and rapidly depressurizes the pressurized gas dissolved liquid L2 in a state where the gas G1 is dissolved under pressure in the liquid L1 (hereinafter, referred to as a dissolved state under pressure), by the depressurizing portion 20 to generate ultra fine bubble liquid L3 containing ultra fine bubbles (see FIG. 7). This will be described in detail later. Components of the production device 100 will be described below.Container

[0018] The container 1 is a cylindrical member having a bottom and extending in the front-rear direction. One end portion (a front end portion) of the container 1 is a closed end and the other end portion (a rear end portion) is an open end. More specifically, the container 1 is formed in a syringe shape having a cylindrical peripheral wall portion 11 extending in the front-rear direction, and a closing portion 12 closing a front end portion of the peripheral wall portion 11, and a rear end portion of the peripheral wall portion 11 is open. However, the shape of the container 1 is not limited to the syringe shape. The shape of the peripheral wall portion 11 according to the present example is a cylindrical shape as an example, but is not limited to the cylindrical shape, and may be, for example, a rectangular cylindrical shape. The peripheral wall portion 11 and the closing portion 12 form a slide hole 13 extending in the front-rear direction in the container 1. The slide hole 13 is formed as a space surrounded by the peripheral wall portion 11 and the closing portion 12, has a bottom portion that is the closing portion 12, and is open at the rear end portion of the container 1. That is, one end portion (the front end portion) of the slide hole 13 is closed by the closing portion 12, and the other end portion (the rear end portion) is open. As described later, inside the container 1, the containment space S1 is formed by a part of the slide hole 13. Furthermore, a communication path 14 is formed in the closing portion 12. The communication path 14 is formed as a through hole extending through the closing portion 12 in the front-rear direction. Thus, through the communication path 14, the inside of the containment space S1 communicates with the outside of the containment space S1. The communication path 14 is formed at the center of the closing portion 12 in a cross section orthogonal to the front-rear direction. The material of the container 1 is not particularly limited, and may be a resin material, for example. As the resin material forming the container 1, examples of materials that can be used include known materials such as nylon 6-12, polyarylate, polycarbonate, polybutylene terephthalate, polyphenylene sulfide, and liquid crystal polymer.Pressurizing Portion

[0019] The pressurizing portion 10 includes a plunger 2 (an example of a "sliding portion" according to the present disclosure), a slider 3, and an actuation screw 4 (an example of a "screw shaft portion" according to the present disclosure), which are integrally connected to each other. The pressurizing portion 10 is disposed on the rear side of the container 1, is held by the holder 8, and is movable along the front-rear direction.Plunger

[0020] The plunger 2 has a substantially circular columnar outer shape, and is inserted into the slide hole 13 through an opening of the slide hole 13 formed at the rear end portion of the container 1. Here, a direction in which the plunger 2 is inserted into the container 1 is referred to as an "insertion direction". In this example, the "insertion direction" is a direction parallel to the front-rear direction and from the open end portion (the rear end portion) of the container 1 toward the closed end portion (the front end portion) thereof (i.e., toward the front side in the front-rear direction). The plunger 2 is inserted into the container 1 by being fitted into the peripheral wall portion 11 of the container 1. As a result, the containment space S1 is formed between the container 1 and the plunger 2. The containment space S1 is formed as a space in the slide hole 13 located forward relative to the plunger 2 in the insertion direction. The plunger 2 is slidable in the container 1 (in the slide hole 13) along the insertion direction. Moving the plunger 2 in the insertion direction by sliding the plunger 2 on the inner wall of the slide hole 13 (the inner peripheral surface of the peripheral wall portion 11), while the valve 5 is in the closed state, causes compression of the containment space S1.

[0021] The plunger 2 includes a plunger main body 21, a plunger rod 22, and a packing 23. The plunger main body 21 is a cylindrical member having a bottom, extending in the front-rear direction, and fitted into the peripheral wall portion 11 of the container 1. A front end portion of the plunger main body 21 is a closed end, and a rear end portion of the plunger main body 21 is an open end. The material of the plunger main body 21 is not particularly limited, but examples thereof include resin materials such as polyphenylene sulfide (PPS) resins, polyacetal (POM) resins, and polyamide (PA) resins. Alternatively, the plunger main body 21 may be made of a metallic material such as aluminum, aluminum alloys (A6061, etc.), or titanium. The plunger rod 22 is a substantially circular columnar shaft body extending in the front-rear direction, and is fixed to the plunger main body 21 in a state of being fitted in the plunger main body 21. The plunger rod 22 can be made of a metal material such as stainless steel or steel, for example. However, the material of the plunger rod 22 is not limited to the above. The plunger main body 21 and the plunger rod 22 are integrally formed by, for example, insert-molding of the plunger main body 21 made of resin onto the plunger rod 22. An annular installation groove extending in the circumferential direction is formed on the outer peripheral surface of the plunger main body 21, and the packing 23 having an annular shape is installed in the installation groove. The packing 23 is a seal member that seals the containment space S1 by pressing the inner walls of the slide hole 13 (the inner peripheral surface of the peripheral wall portion 11) and forms a fitted state between the plunger 2 and the slide hole 13. As the packing 23, for example, an O-ring made of rubber can be used.

[0022] As described above, the plunger 2 is inserted into the container 1 to form the containment space S1 together with the container 1, and is slidable in the insertion direction in the container 1.Slider

[0023] The slider 3 is a cylindrical member having a bottom and extending in the front-rear direction. A front end portion of the slider 3 is an open end and a rear end portion of the slider 3 is a closed end. The slider 3 is disposed on the rear side of the plunger 2 and transmits the axial force of the actuation screw 4 to the plunger 2. A slit 31 extending in the front-rear direction from a middle portion to a front end portion of the slider 3 in the front-rear direction is formed in a top face of the slider 3. A guide groove 32 is formed in a bottom face of the slider 3, and extends in the front-rear direction (i.e., the insertion direction) over the entire length of the slider 3 in the front-rear direction. A recessed portion 33 in which the rear end portion of the plunger main body 21 is fitted is formed at the front end portion of the slider 3. A substantially circular columnar fitting portion 34 protruding toward the rear side is formed at the rear end portion of the slider 3. The material of the slider 3 is not particularly limited, but examples thereof can include the same resin materials as those for the container 1 described above.Actuation Screw

[0024] The actuation screw 4 is a screw member in which a male screw groove is formed on an outer periphery of a shaft portion extending in the front-rear direction (the insertion direction). The actuation screw 4 according to the present embodiment is formed as a screw member without a head, which is also called a stud bolt or a full thread screw. As illustrated in FIG. 3, a male screw groove 41a is formed in an outer peripheral surface 41 of the actuation screw 4. A fitting receptacle portion 43, recessed toward the rear side for receiving the fitting portion of the slider 3 fitted in the fitting receptacle portion 43, is formed at the front end portion of the actuation screw 4. An engagement hole 44 for allowing the actuation screw 4 to engage with a fastening tool is formed at the rear end portion of the actuation screw 4. The engagement hole 44 in the present example is a square hole (a hole having a square cross-sectional shape), and thus can engage with the tip of a square head wrench used as a fastening tool. However, the shape of the engagement hole 44 is not particularly limited, and can be appropriately selected in accordance with the shape of the tip of a fastening tool used for rotating the actuation screw 4. For example, when a hexagonal wrench is used as the fastening tool, the engagement hole 44 may be a hexagonal hole (a hole having a hexagonal cross-sectional shape). The actuation screw 4 is inserted into a screw hole 821 formed in the holder 8. Note that, in the present embodiment, the plunger 2 and the actuation screw 4 are formed as separate members, but in the technology according to the present disclosure, the sliding portion and the screw shaft portion may be formed as an integral member. The material of the actuation screw 4 is not particularly limited, but examples thereof include metal materials such as stainless steel and steel. Alternatively, the actuation screw 4 may be made of a resin material.Depressurizing portion

[0025] The depressurizing portion 20 includes the valve 5 (an example of a "valve body" according to the present disclosure), a coupling member 6, and a drive portion 7. The depressurizing portion 20 is disposed on the front side of the container 1 and is integrally connected to the container 1.Coupling Member

[0026] The coupling member 6 is a tubular member extending in the front-rear direction with both end portions opened, and coupling the container 1 and the drive portion 7 together. The coupling member 6 has a cylindrical large diameter portion including a rear end portion of the coupling member 6, and a cylindrical small diameter portion including a front end portion of the coupling member 6 and having an outer diameter smaller than that of the large diameter portion. The rear end portion of the coupling member 6 is joined to the front end portion (the closing portion 12) of the container 1, and thus the container 1 and the large diameter portion 61 together form a pressure relief space S2. In the large diameter portion 61, a pressure relief hole 63 is formed, through which the inside of the pressure relief space S2 communicates with the outside air. The material of the coupling member 6 is not particularly limited, but examples thereof can include the same resin materials as those for the container 1 described above.Valve

[0027] FIG. 4 is a partial cross-sectional view of the production device 100 according to the first embodiment when the valve 5 is in a closed state, and the inside of the containment space S1 is in a gas-liquid separation state. In FIG. 4, the components other than the container 1, the plunger 2, the valve 5, and the coupling member 6 are not illustrated. When receiving energy from the drive portion 7, the valve 5 can be moved toward the rear side in the front-rear direction, and the valve 5 can transition from the closed state illustrated in FIG. 4 in which the communication path 14 is closed to a state illustrated in FIG. 8 in which the communication path 14 is opened (hereinafter, also referred to as an open state). In the present specification, "open" means a state where a fluid can flow. Transition of the valve 5 from the closed state to the open state when the inside of the containment space S1 is in the dissolved state under pressure causes the pressurized gas dissolved liquid L2 to be depressurized. Here, the direction of the movement of the valve 5 (in this example, toward the rear side in the front-rear direction) when the valve 5 is switched from the closed state to the open state is referred to as an "opening direction". In this example, the "opening direction" is a direction parallel to the front-rear direction and from the closed end portion (the front end portion) of the container 1 toward the open end portion (the rear end portion) thereof (i.e., toward the rear side in the front-rear direction). In this example, the "opening direction" and the "insertion direction" are opposite to each other. The valve 5 includes a valve main body 51 that opens and closes the communication path 14, a valve rod 52 that receives energy from the drive portion 7, and a packing 5a that forms a fitting state between the valve 5 and the communication path 14 when the valve 5 is in the closed state.

[0028] The valve main body 51 is formed in a substantially circular columnar shape extending in the front-rear direction, and includes a stopper portion 511 forming an opening-direction-side end portion (a rear end portion) of the valve main body 51, and an insertion portion 512 extending from the stopper portion 511 toward a direction opposite (front side) to the opening direction. The stopper portion 511 has a diameter larger (wider) than the width of the opening of the communication path 14 near the containment space S1, and thus cannot pass through the communication path 14. Therefore, in the closed state, the stopper portion 511 comes into contact with the closing portion 12 of the container 1 from the opening direction (the rear side), and thus the movement of the valve 5 in a direction opposite to the opening direction (toward the front side) is restricted. Thus, in the closed state, the valve 5 is prevented from passing through the communication path 14 in the direction opposite to the opening direction and opening the communication path 14. The stopper portion 511 has a shape narrowing (reducing in diameter) in the opening direction (toward the rear side) to facilitate advancing in the pressurized gas dissolved liquid L2. This facilitates movement of the valve 5 receiving energy from the drive portion 7 in the opening direction, and thus helps the valve 5 to easily switch from the closed state to the open state. The insertion portion 512 extends from the stopper portion 511 toward the front side, is inserted through the communication path 14, and is connected to the valve rod 52 in the pressure relief space S2. An annular installation groove 513 extending in the circumferential direction is formed in the outer peripheral surface of the insertion portion 512. The material of the valve main body 51 is not particularly limited, but examples thereof include metal materials such as brass. Alternatively, the valve main body 51 may be made of a resin material.

[0029] The valve rod 52 is formed in a circular columnar shape extending in the front-rear direction, and is inserted through the small diameter portion 62 of the coupling member 6. An opening-direction-side end portion (a rear end portion) of the valve rod 52 is located in the pressure relief space S2, and an end portion on the opposite side in the opening direction (a front end portion) of the valve rod 52 is located in the drive portion 7. A fitting hole 521, in which the insertion portion 512 of the valve main body 51 is fitted, is formed in the rear end portion of the valve rod 52. The rear end portion of the valve rod 52 has a diameter larger (wider) than the width of the opening of the communication path 14 near the pressure relief space S2, and thus cannot pass through the communication path 14. Therefore, the valve rod 52 comes into contact with the closing portion 12 of the container 1 from the opposite side in the opening direction (from the front side), and thus the movement of the valve 5 in the opening direction (toward the rear side) is restricted. Thus, in the open state, the valve 5 is prevented from passing through the communication path 14 in the opening direction (see FIG. 8). The material of the valve rod 52 is not particularly limited, but examples thereof can include the same resin materials as those for the container 1 described above.

[0030] FIG. 5 is a cross-sectional view taken along B-B of FIG. 4. In FIG. 5, a cross-section of the valve 5 orthogonal to the opening direction (the front-rear direction in the present example) is illustrated. As illustrated in FIGS. 4 and 5, a slit 522 extending in the opening direction and opening in the rear end surface of the valve rod 52 may be formed in the valve rod 52.

[0031] As illustrated in FIG. 4, the packing 5a, which is an annular seal member, is installed in the installation groove 513 of the valve main body 51. The packing 5a seals the containment space S1 by pressing the inner wall of the communication path 14, and forms a fitting state between the valve 5 and the communication path 14. As the packing 5a, for example, an O-ring made of rubber can be used. In the closed state, the valve 5 is fitted in the communication path 14 to close the communication path 14.

[0032] Note that, to maintain the valve 5 in the closed state, a biasing member that biases the valve 5 in the direction opposite to the opening direction may be provided. For example, as the biasing member, a spring in a compressed state may be interposed between the valve rod 52 and the closing portion 12 of the container 1.Drive Portion

[0033] The drive portion 7 is operated to apply, to the valve 5, energy for transition from the closed state to the open state. Specifically, the drive portion 7 applies combustion energy of the ignition agent to the valve 5 and thereby pushes the valve 5 in a direction from the outside to the inside of the containment space S1 to switch the valve 5 from the closed state to the open state. As illustrated in FIG. 3, the drive portion 7 includes a casing 71, an igniter 72, a fixing member 73, and a piston 74.Casing

[0034] The casing 71 is a tubular member extending in the front-rear direction. The small diameter portion 62 of the coupling member 6 is fitted in and joined to a rear end portion of the casing 71. The igniter 72 is fitted in and fixed to a front end portion of the casing 71 via the fixing member 73. In addition, the front end portion of the valve rod 52 protruding forward from the small diameter portion 62 of the coupling member 6 is inserted into the casing 71. The outer diameter of the rear end portion of the casing 71 is smaller than the outer diameter of the large diameter portion 61 of the coupling member 6. Therefore, the coupling member 6 protrudes radially outward from the rear end portion of the casing 71, and thus, in the depressurizing portion 20, a radial step portion 201 is formed between the coupling member 6 and the drive portion 7. The material of the casing 71 is not particularly limited, but examples thereof include metal materials such as stainless steel and steel. The casing 71 may be made of a resin material that is the same as that for the container 1 described above.Igniter

[0035] The igniter 72 is configured as an electric igniter and is a drive source of the drive portion 7 for generating energy for switching the valve 5 from the closed state to the open state. The igniter 72 includes an igniter main body 721 containing an ignition agent and a conductive pin 722 extending from the igniter main body 721, and is operated by operating electric power supplied from an external power supply (not illustrated) such as a battery to the conductive pin 722 to burn the ignition agent and thereby discharge a combustion product (flame, combustion gas, or the like). This generates combustion energy as the pressure of the combustion products. The igniter 72 is fitted in the front end portion of the casing 71, such that the igniter main body 721 faces the internal space of the casing 71, and the conductive pin 722 faces the external space to the casing 71. The conductive pin 722 is configured to be connectable to a connector (not illustrated) on a power source side. When the conductive pin 722 and the connector on the power source side are connected to each other, the igniter 72 can be supplied with operating electric power.Ignition Agent

[0036] Here, examples of the ignition agent used for the igniter 72 include an explosive containing zirconium and potassium perchlorate (ZPP), an explosive containing titanium hydride and potassium perchlorate (THPP), an explosive containing titanium and potassium perchlorate (TiPP), an explosive containing aluminum and potassium perchlorate (APP), an explosive containing aluminum and bismuth oxide (ABO), an explosive containing aluminum and molybdenum oxide (AMO), an explosive containing aluminum and copper oxide (ACO), an explosive containing aluminum and ferric oxide (AFO), and a combination of two or more of these explosives. Note that an explosive other than these may be used as the ignition agent as long as energy can be generated to switch the valve 5 from the closed state to the open state.Fixing Member

[0037] The fixing member 73 is formed by using resin injection molding. The injection molding can be performed by a known method. Further, a resin material that can be used for the fixing member 73 is the same as that for the container 1. The fixing member 73 fixes the igniter 72 to the casing 71 and the front end portion of the casing 71 is closed by the fixing member 73.Piston

[0038] The piston 74 is formed in a substantially circular columnar shape extending in the front-rear direction, and is disposed between the valve rod 52 and the igniter 72 in the internal space of the casing 71. The piston 74 is movable in the opening direction by sliding on the inner peripheral surface of the casing 71, and transmits combustion energy (pressure) generated by the operation of the igniter 72 to the valve 5. The piston 74 is made of a metal material such as stainless steel or steel. An O-ring or the like may be disposed on a portion of the piston 74 to enhance sealing with a sliding surface (that is, inner peripheral surface of the casing 71) on which the piston 74 slides. Alternatively, the piston 74 may be made of resin and, in such a case, metal may be used in combination for a portion for which heat resistance and pressure resistance is required. However, the material of the piston 74 is not particularly limited.

[0039] As illustrated in FIG. 3, a combustion chamber S3, to which the combustion product of the ignition agent is discharged from the igniter 72, is formed between the igniter 72 and the piston 74 in the internal space of the casing 71. Note that a gas generating agent may be contained in the combustion chamber S3 to increase the energy to be applied to the valve 5. The gas generating agent burns and generates gas when coming into contact with the combustion product of the ignition agent. That is, in addition to the combustion energy of the ignition agent, the combustion energy of the gas generating agent may be applied to the valve 5. One example of the gas generating agent may be exemplified by a single base smokeless explosive (GG) formed of 98 mass% of nitrocellulose, 0.8 mass% of diphenylamine, and 1.2 mass% of potassium sulfate. Various types of gas generating agents used in a gas generator for an air bag and a gas generator for a seat belt pretensioner can be used.Holder

[0040] The holder 8 is configured to hold the dissolved state under pressure. The material of the holder 8 is not particularly limited, but examples thereof include metal materials such as stainless steel and steel. The holder 8 may be made of a resin material that is the same as that for the container 1 described above. As illustrated in FIGS. 1 to 3, the holder 8 includes a base portion 81, a first support portion 82, a guide portion 83, and a second support portion 84.

[0041] The base portion 81 is formed in a plate shape orthogonal to the up-down direction and extending in the front-rear direction. The container 1, the pressurizing portion 10, and the depressurizing portion 20 are mounted on the base portion 81. The first support portion 82, the guide portion 83, and the second support portion 84 are provided upright on the top face of the base portion 81.

[0042] The first support portion 82 is a portion supporting the actuation screw 4 of the pressurizing portion 10, is provided upright, and extends in the left-right direction along the rear end edge of the base portion 81. A screw hole 821 (an example of a "screw hole portion" according to the present disclosure) into which the actuation screw 4 is inserted is formed in the first support portion 82. The screw hole 821 extends in the front-rear direction and extends through the first support portion 82. As illustrated in FIG. 3, a female screw groove 82a is formed on the inner peripheral surface of the screw hole 821, and the female screw groove 82a is engaged with the male screw groove 41a formed on the outer peripheral surface 41 of the actuation screw 4. The engagement between the male screw groove 41a of the actuation screw 4 and the female screw groove 82a of the screw hole 821 allows the actuation screw 4 to be supported by the first support portion 82. The actuation screw 4 is movable in the front-rear direction by rotating the actuation screw 4 relative to the screw hole 821 about the axis. On the other hand, the movement of the actuation screw 4 in the front-rear direction without the rotation operation is restricted by the engagement between the male screw groove 41a and the female screw groove 82a.

[0043] The guide portion 83 is a portion that guides the movement of the slider 3 of the pressurizing portion 10 in the front-rear direction, and is provided upright and located on the front side relative to the first support portion 82. The guide portion 83 includes a pair of guide wall portions 831, 831 provided upright and extending in the front-rear direction along the left and right edges of the base portion 81, and a guide rib 832 provided upright between the pair of guide wall portions 831, 831 in the left-right direction and extending in the front-rear direction. The pair of guide wall portions 831, 831 are adjacent to the left and right sides of the slider 3, and the guide rib 832 is received in the guide groove 32 formed in the bottom face of the slider 3. Accordingly, the movement of the slider 3 in the front-rear direction is guided by the guide portion 83.

[0044] The second support portion 84 is a portion supporting the depressurizing portion 20, is provided upright, and is located on the front side relative to the guide portion 83. A receiving portion 841 that is a recess for receiving the depressurizing portion 20 is formed in the second support portion 84 and opens upward. The inner wall of the receiving portion 841 has a contact portion 842 that contacts the step portion 201 formed in the depressurizing portion 20 from the front side (the front side in the insertion direction). Accordingly, the second support portion 84 supports the depressurizing portion 20 and restricts the movement of the depressurizing portion 20 in the insertion direction. The depressurizing portion 20 and the container 1 are integrally connected as described above, and thus the movement of the container 1 in the insertion direction is also restricted by the second support portion 84.Operation

[0045] Hereinafter, the operation of the production device 100 will be described. FIG. 6 is a cross-sectional view of the production device 100 according to the first embodiment when the valve 5 is in the closed state and the inside of the containment space S1 is in a dissolved state under pressure. FIG. 7 is a cross-sectional view of the production device 100 according to the first embodiment when the inside of the containment space S1 is in the dissolved state under pressure, and the valve 5 is in the open state. FIGS. 6 and 7 correspond to the cross-sectional view of FIG. 3, and illustrate cross-sections of the production device 100 along the front-rear direction. FIG. 8 is a partial cross-sectional view of the production device 100 according to the first embodiment when the inside of the containment space S1 is in the dissolved state under pressure, and the valve 5 is in the open state. FIG. 8 corresponds to FIG. 4, and the components other than the container 1, the plunger 2, the valve 5, and the coupling member 6 are not illustrated.

[0046] First, as illustrated in FIG. 3, in a state where desired liquid L1 and gas G1 are contained in the containment space S1, the container 1, the pressurizing portion 10, and the depressurizing portion 20 are installed in the holder 8. At this time, to prevent the liquid L1 and the gas G1 from flowing out to the pressure relief space S2 via the communication path 14, the communication path 14 is closed by bringing the valve 5 into a closed state and thus the containment space S1 is sealed. In this stage, the containment space S1 is not compressed to such an extent that the gas G1 is dissolved under pressure into the liquid L1, and thus is in a gas-liquid separation state.

[0047] Next, as illustrated in FIG. 6, the inside of the containment space S1 is compressed by the pressurizing portion 10, to dissolve the gas G1 under pressure into the liquid L1 and brought into a dissolved state under pressure (a pressurizing step). Specifically, the actuation screw 4 is rotated to screw and advance the actuation screw 4 in the insertion direction (toward the front side in the front-rear direction), while the valve 5 is kept in the closed state. At this time, the rotation operation of the actuation screw 4 may be performed by the user with his / her bare hand, or may be performed with a fastening tool using the engagement hole 44 formed in the rear end portion of the actuation screw 4. Alternatively, a motor may be connected to the actuation screw 4 to electrically rotate the actuation screw 4.

[0048] As described above, the plunger 2, the slider 3, and the actuation screw 4 are coupled together, and thus the slider 3 and the plunger 2 also move in the insertion direction together with the actuation screw 4. Specifically, as a result of screwing and advancing the actuation screw 4 in the insertion direction along the screw hole 821, the slider 3 coupled to the actuation screw 4 is pushed and moved by the axial force of the actuation screw 4 in the insertion direction, while being guided by the guide portion 83. In a similar manner, the plunger 2 coupled to the slider 3 is pushed in the insertion direction by the axial force of the actuation screw 4 transmitted via the slider 3. Here, as described above, movement of the container 1 in the insertion direction is restricted by the second support portion 84 of the holder 8. Therefore, the plunger 2 inserted into the container 1 slides in the insertion direction in the slide hole 13 of the container 1. The relative movement of the plunger 2 in the insertion direction relative to the container 1 results in a decrease in the volume of the containment space S1. At this time, the valve 5 is in the closed state, and thus the containment space S1 is sealed. Accordingly, the containment space S1 is compressed, and the liquid L1 and the gas G1 are pressurized. The liquid L1 and the gas G1 are gradually pressurized as the actuation screw 4 is screwed and advanced in the insertion direction. In the dissolved state under pressure, the compression of the containment space S1 by the pressurizing portion 10 causes the valve 5 to be pressed toward a direction opposite to the opening direction (toward the front side). However, as described above, the stopper portion 511 restricts the movement of the valve 5 toward the front side, and thus the valve 5 is prevented from passing through the communication path 14 toward the front side and opening the communication path 14. Thus, the valve 5 is kept in the closed state.

[0049] By increasing the pressure applied to the gas G1 to form a supersaturated state of the liquid L1 containing the gas G1 dissolved therein, the pressurized gas dissolved liquid L2 is generated in the containment space S1. In other words, the pressurized gas dissolved liquid L2 is liquid in a state in which the gas G1 is dissolved under pressure in the liquid L1. In this manner, the inside of the containment space S1 is brought into the dissolved state under pressure. Here, in the dissolved state under pressure, the restoring force (repulsive force) of the compressed containment space S1 presses the plunger 2 toward a direction opposite to the insertion direction (toward the rear side). However, the engagement between the male screw groove 41a of the actuation screw 4 and the female screw groove 82a of the holder 8 restricts movement of the actuation screw 4 toward the rear side. Therefore, the plunger 2 is prevented from moving relative to the container 1 in the direction opposite to the insertion direction. In this manner, the holder 8 maintains the containment space S1 in the compressed state and holds the dissolved state under pressure in the containment space S1.

[0050] Next, as illustrated in FIGS. 7 and 8, the ultra fine bubble liquid L3 is generated by causing, in the dissolved state under pressure, the valve 5 of the depressurizing portion 20 to transit from the closed state to the open state, to rapidly depressurize the pressurized gas dissolved liquid L2 (depressurizing step).

[0051] Specifically, the igniter 72 is operated by supplying the operating electric power to the igniter 72 while the dissolved state under pressure is held by the holder 8. The supply of electric power to the igniter 72 may be controlled by a control unit (not illustrated) such as a microcontroller, for example. For example, the user's operation on a predetermined switch (not illustrated) triggers supply of the operating electric power by the control unit from the power supply to the conductive pin 772 of the igniter 72.

[0052] Once the igniter 72 is operated, the ignition agent contained in the igniter main body 721 burns, and a combustion product of the ignition agent is discharged into the combustion chamber S3. As a result, the combustion energy (pressure of the combustion product) of the ignition agent presses the piston 74 in the opening direction of the valve 5 (the rearward direction). The piston 74 moves at a high speed in the opening direction while sliding on the inner peripheral surface of the casing 71. Then, the piston 74 collides with the valve rod 52 of the valve 5 and transmits the combustion energy of the ignition agent to the valve 5 to press the valve 5 in the opening direction. Then, the valve 5 moves in the opening direction at a high speed, which releases the fitting between the valve main body 51 and the communication path 14, and as a result, the valve 5 is instantaneously switched to the open state, and the communication path 14 is opened.

[0053] Here, as a result of the valve 5 being pressed in the opening direction, in the open state, the rear end surface of the valve rod 52 comes into contact with the closing portion 12 of the container 1, and thus the valve 5 is prevented from passing through the communication path 14 in the opening direction. Here, the valve rod 52 has the slit 522 that is open in the rear end surface of the valve rod 52, and thus the slit 522 prevents the valve rod 52 from closing the opening of the communication path 14 near the pressure relief space S2.

[0054] The communication path 14 is opened in the dissolved state under pressure, which unseals the containment space S1 having been sealed (in an airtight state). Then, the pressure in the containment space S1 is released to the pressure relief space S2 through the communication path 14. Specifically, a part of the pressurized gas dissolved liquid L2 in the containment space S1 flows out to the pressure relief space S2 through the communication path 14. Note that, even if the slit 522 is not formed in the valve rod 52, the pressure in the containment space S1 can still be released to the pressure relief space S2. Further, the pressure is released to the outside air through the pressure relief hole 63 formed in the coupling member 6. As a result, the pressurized gas dissolved liquid L2 in the containment space S1 is rapidly depressurized. By rapidly depressurizing the pressurized gas dissolved liquid L2, the gas G1 precipitates as ultra fine bubbles in the liquid L1. As a result, the ultra fine bubble liquid L3 containing the ultra fine bubbles is produced in the containment space S1. In the manner as described above, the ultra fine bubbles are produced by the production device 100.

[0055] After the ultra fine bubbles have been produced, for example, the container 1 and the depressurizing portion 20 are detached from the holder 8 in a state where the plunger 2 is inserted into the container 1, and then the plunger 2 is pulled out from the container 1, and the ultra fine bubble liquid L3 contained in the container 1 may be collected in an appropriate vessel.Actions and Effects

[0056] As described above, the production device 100 according to the first embodiment includes the container 1 having the containment space S1 formed therein for containing liquid L1 and gas G1, the pressurizing portion 10 configured to compress the containment space S1 to generate, in the containment space S1, pressurized gas dissolved liquid L2 including the liquid L1 and the gas G1 dissolved under pressure in the liquid L1, the holder 8 configured to hold a dissolved state under pressure in which the gas G1 is dissolved under pressure in the liquid L1, and the depressurizing portion 20 configured to open, in the dissolved state under pressure, the communication path 14 through which an inside and an outside of the containment space S1 (in this example, the outside is the pressure relief space S2) communicate with each other to depressurize the pressurized gas dissolved liquid L2 and generate ultra fine bubbles.

[0057] That is, the production device 100 according to the present embodiment includes the pressurizing portion 10 for forming the dissolved state under pressure by pressurization, and the depressurizing portion 20 for depressurizing the pressurized gas dissolved liquid L2, and the dissolved state under pressure can be held by the holder 8. In the production device 100, after formation of the dissolved state under pressure by the pressurizing portion 10, and before a reduction in the pressure applied to the pressurized gas dissolved liquid L2 by the depressurizing portion 20, the dissolved state under pressure can be temporarily held by the holder 8. This makes it possible to secure a time for widely dispersing the gas G1 in the liquid L1 in the dissolved state under pressure.

[0058] In general, in the generation of fine bubbles by the under-pressure dissolution method, it is considered that widely dispersing the dissolved gas under pressure in the liquid enlarges the region where fine bubbles can be generated in the subsequent depressurizing step, and thus further improves the final fine bubble concentration.

[0059] In this respect, the production device 100 according to the present embodiment can hold the dissolved state under pressure by the holder 8, and thus allows the pressurized gas dissolved liquid L2 to be depressurized in a state where the gas G1 is widely dispersed in the liquid L1, and can increase the number of ultra fine bubbles generated, as compared with a case where the pressurized gas dissolved liquid L2 is depressurized immediately after the formation of the dissolved state under pressure. As a result, the production device 100 according to the present embodiment can produce a high concentration of ultra fine bubbles in the ultra fine bubble liquid L3.

[0060] The production device 100 according to the present embodiment could generate 10 billion or more ultra fine bubbles per ml. The number and particle diameters of ultra fine bubbles were measured and analyzed by using NanoSight (manufactured by Spectris). However, the above-mentioned number of ultra fine bubbles does not limit the technology according to the present disclosure. In addition, the present embodiment is suitable for generating the ultra fine bubbles in a closed system such as a sterile environment, because in the present embodiment, the ultra fine bubbles are generated in the containment space S1 brought into an airtight state.

[0061] As described above, according to the first embodiment, the performance of the ultra fine bubble production device 100 can be improved.

[0062] Further, the production device 100 according to the present embodiment includes, as separate components, the pressurizing portion 10 that forms the dissolved state under pressure by compressing the containment space S1, and the depressurizing portion 20 that depressurizes the pressurized gas dissolved liquid L2 by opening the communication path 14. Therefore, the driving force required for pressurization and / or the driving force required for depressurization can be reduced as compared with the case where pressurization and depressurization are performed using a component in which the pressurizing means and the depressurizing means are integrated. This facilitates increasing the size of the pressurizing portion 10, for example, and the volume of the containment space S1 can be increased in accordance with the increase in the size of the pressurizing portion 10. Further, a decrease in the driving force required for pressurization and / or depressurization makes it possible to downsize the entire device and reduce the cost, as compared with the case where the containment space S1 has almost the same volume and pressurization and depressurization are performed by an integral component.

[0063] Further, in the present embodiment, the pressurizing portion 10 includes the plunger 2 that is inserted into the container 1 to form the containment space S1 together with the container 1, and that is slidable in the container 1 along the insertion direction relative to the container 1, and relative movement of the plunger 2 to the container 1 in the insertion direction causes the containment space S1. The holder 8 restricts, in the dissolved state under pressure, relative movement of the plunger 2 to the container 1 in a direction opposite to the insertion direction. This allows the holder 8 to hold the dissolved state under pressure.

[0064] In addition, in the present embodiment, the pressurizing portion 10 includes the actuation screw 4 extending along the insertion direction and having the male screw groove 41a formed in the outer periphery of the actuation screw 4, the holder 8 includes the screw hole 821 into which the actuation screw 4 is inserted, and the screw hole 821 has the female screw groove 82a engaged with the male screw groove 41a of the actuation screw 4. Screwing and advancing the actuation screw 4 along the screw hole 821 causes relative movement of the plunger 2 to the container 1 in the insertion direction. Thus, the engagement between the male screw groove 41a and the female screw groove 82a can restrict relative movement of the plunger 2 to the container 1 in the direction opposite to the insertion direction without the rotation operation of the actuation screw 4. Further, the compression of the containment space S1 by the plunger 2 progresses as the actuation screw 4 is screwed and advanced, and thus the liquid L1 and the gas G1 can be gradually pressurized over time by slowly rotating the actuation screw 4 to slowly screw and advance the actuation screw 4. Accordingly, in the dissolved state under pressure, the gas G1 can be widely dispersed in the liquid L1, and a high concentration of ultra fine bubbles can be produced. In the technology according to the present disclosure, the means for restricting the relative movement of the sliding portion to the container portion in the direction opposite to the insertion direction is not limited to the means using the engagement between the screw grooves. The holding portion according to the present disclosure may restrict the movement of the sliding portion by, for example, a latch mechanism.

[0065] In the present embodiment, the depressurizing portion 20 includes the valve 5 configured to transition from the closed state in which the communication path 14 is closed to the open state in which the communication path 14 is opened, and the drive portion 7 that applies, to the valve 5, energy for the valve 5 to transition from the closed state to the open state. That is, the production device 100 according to the present embodiment depressurizes the pressurized gas dissolved liquid L2 by opening the valve 5 in the dissolved state under pressure to open the communication path 14. The depressurization by opening the valve 5 makes it possible to rapidly depressurize the pressurized gas dissolved liquid L2.

[0066] In general, in the generation of fine bubbles by the under-pressure dissolution method, the rate of depressurization in the dissolved state under pressure also affects the concentration of fine bubbles. Assuming that the depressurization rate is low, the bubbles may come into contact with each other and coalesce into bubbles having an increased diameter in the process of precipitation of the bubbles, and as a result, the number of ultra fine bubbles to be generated may decrease.

[0067] In contrast, the production device 100 according to the present embodiment can increase the depressurization rate and thus can suppress the increase in the bubble size and can increase the number of ultra fine bubbles to be generated. As a result, the production device 100 according to the present embodiment can produce a high concentration of ultra fine bubbles in the ultra fine bubble liquid L3.

[0068] In addition, the instantaneous switching of the valve 5 to the open state does not require a large driving force, and thus the pressurized gas dissolved liquid L2 can be rapidly depressurized with a relatively small driving force. Note that the depressurizing portion according to the present disclosure may not be configured to open the communication path by the valve body. For example, instead of opening and closing, by the valve body, the communication path formed in advance in the container portion, a communication path in a state of being opened may be formed in the container portion by actuation of the depressurizing portion.

[0069] Further, in the present embodiment, when the valve 5 is in the closed state, the valve 5 is fitted in the communication path 14 to close the communication path 14, and the drive portion 7 pushes the valve 5 from an outer side toward an inner side of the containment space S1 to cause the valve 5 to transition from the closed state to the open state. That is, the production device 100 according to the present embodiment switches the valve 5 to the open state by pushing the valve 5 to release the fitting with the communication path 14. This makes it possible to instantaneously switch the valve 5 to the open state. In the technology according to the present disclosure, the method of causing the valve body to transition from the closed state to the open state is not limited to the above-described method. For example, a valve body may be disposed to cover the opening of the communication path when in the closed state, and rotating the valve body may cause the valve body to transition to the open state in which the communication path is opened.

[0070] Further, in the present embodiment, the drive portion 7 includes the igniter 72 that is supplied with operating electric power to burn an ignition agent, and applies combustion energy of the ignition agent to the valve 5. The use of the combustion energy makes it possible to instantaneously switch the valve 5 to the open state.

[0071] Further, in the present embodiment, the communication path 14 is formed at a central position of the closing portion 12 of the container 1. Therefore, when the communication path 14 is opened, the pressurized gas dissolved liquid can be widely depressurized. As a result, a high concentration of ultra fine bubbles can be produced.Second Embodiment

[0072] A production device 100A according to a second embodiment will be described below. In the description of the second embodiment, a configuration different from that of the production device 100 described in FIG. 1 and the like will be mainly described, and similar configurations to those of the production device 100 are given the same reference signs as those of the production device 100, and thus detailed description will be omitted.

[0073] FIG. 9 is a cross-sectional view of the production device 100A according to the second embodiment when the valve 5 is in a closed state, and the inside of the containment space S1 is in a gas-liquid separation state. FIG. 10 is a cross-sectional view of the production device 100A according to the second embodiment when the inside of the containment space S1 is in a dissolved state under pressure, and the valve 5 is in an open state. FIGS. 9 and 10 correspond to the cross-sectional view of FIG. 3, and illustrate cross-sections of the production device 100A along the front-rear direction. As illustrated in FIGS. 9 and 10, the production device 100A according to the second embodiment is different from the production device 100 according to the first embodiment in that a drive portion 7A includes a compression spring 76 (an example of the "elastic body" according to the present disclosure) instead of the igniter 72. The container 1, the pressurizing portion 10, the valve 5, the coupling member 6, and the holder 8 of the second embodiment are the same as or similar to those of the first embodiment, and thus the description thereof will be omitted.

[0074] The drive portion 7A according to the second embodiment includes the casing 71, a lid member 75, the compression spring 76, and a piston 77. The drive portion 7A applies, to the valve 5, elastic energy released by the compression spring 76 returning from the compressed state illustrated in FIG. 9 to the extended state illustrated in FIG. 10 in which the compression spring 76 is extended compared to the compressed state.

[0075] The lid member 75 is connected to the front end portion of the casing 71 to close this front end portion. The lid member 75 includes an elastic body support portion 751 having a circular columnar shape and protruding toward the rear side in the internal space of the casing 71.

[0076] The compression spring 76 is a so-called compression coil spring, and serves as a drive source of the drive portion 7A for generating energy for switching the valve 5 from the closed state to the open state. The compression spring 76 is installed on the elastic body support portion 751 of the lid member 75, and the extension and contraction direction of the compression spring 76 coincides with the opening direction of the valve 5. The compression spring 76 can be switched between retention of the compressed state in which the compression spring 76 is compressed in the front-rear direction as illustrated in FIG. 9 and release from the compressed state, by operation on an operation portion (not illustrated) provided in the casing 71, for example. When released from the compressed state, the compression spring 76 extends by its restoring force and enters the extended state illustrated in FIG. 10.

[0077] The piston 77 is a cylindrical member having a bottom and extending in the front-rear direction. A front end portion of the piston 77 is an open end, and a rear end portion of the piston 77 is a closed end. The piston 77 is installed at the rear end portion of the compression spring 76 (the opening-direction-side end portion of the valve 5). The piston 77 can move in the opening direction while sliding on the inner peripheral surface of the casing 71, and transmits, to the valve 5, elastic energy released by the compression spring 76 returning from the compressed state to the extended state. The piston 77 may be made of a metal material such as stainless steel or steel. However, the material of the piston 77 is not particularly limited.

[0078] The operation of the production device 100A will be described below. The pressurizing step of forming the dissolved state under pressure is similar to or the same as that for the production device 100 according to the first embodiment, and thus the description thereof will be omitted. Here, a depressurizing step will be described.

[0079] In the dissolved state under pressure, once the compression spring 76 is released from the compressed state, the compression spring 76 returns to the extended state as illustrated in FIG. 10. The compression spring 76 may not be extended more than the natural length as long as the compression spring 76 is extended more in the extended state than in the compressed state. Elastic energy released by the compression spring 76 returning from the compressed state to the extended state causes the piston 77 to move at a high speed in the opening direction of the valve 5 (toward the rear side) while sliding on the inner peripheral surface of the casing 71. Then, the piston 77 collides with the valve rod 52 of the valve 5 and transmits the elastic energy of the compression spring 76 to the valve 5 to press the valve 5 in the opening direction. Then, the valve 5 moves in the opening direction at a high speed, which releases the fitting between the valve main body 51 and the communication path 14, and as a result, the valve 5 is instantaneously switched to the open state, and the communication path 14 is opened. As a result, the pressurized gas dissolved liquid L2 in the containment space S1 is rapidly depressurized and the ultra fine bubble liquid L3 containing the ultra fine bubbles is produced in the containment space S1. As described above, the ultra fine bubbles are produced by the production device 100A.

[0080] As described above, in the production device 100A according to the second embodiment, the drive portion 7A includes the compression spring 76 that applies elastic energy to the valve 5 by returning from the compressed state to the extended state in which the compression spring 76 is extended compared to the compressed state. The use of the elastic energy makes it possible to instantaneously switch the valve 5 to the open state. As a result, it is possible to rapidly depressurize the pressurized gas dissolved liquid L2.

[0081] Alternatively, a drive portion separate from the production device and attachable and detachable from the production device may be provided. The drive portion may include, for example, a compression spring that is disposed in parallel with the production device and returnable to an extended state in response to a trigger operation, and a hammer that rotates to strike the valve rod 52 upon receiving elastic energy of the compression spring.

[0082] The embodiments of the ultra fine bubble production device according to the present disclosure have been described above, and each of the aspects disclosed in the present specification can be combined with any other features disclosed therein.Reference Signs List

[0083] 1: Container (example of "container portion") 2: Plunger (example of "sliding portion") 4: Actuation screw (example of "screw shaft portion") 5: Valve (example of "valve body") 7, 7A: Drive portion 8: Holder (example of "holding portion") 10: Pressurizing portion 20: Depressurizing portion 100, 100A: Ultra fine bubble production device

Claims

1. An ultra fine bubble production device comprising: a container portion having a containment space formed therein for containing liquid and gas; a pressurizing portion configured to compress the containment space to generate, in the containment space, pressurized gas dissolved liquid including the liquid and the gas dissolved under pressure in the liquid; a holding portion configured to hold a dissolved state under pressure in which the gas is dissolved under pressure in the liquid; and a depressurizing portion configured to open, in the dissolved state under pressure, a communication path through which an inside and an outside of the containment space communicate with each other, to depressurize the pressurized gas dissolved liquid and generate ultra fine bubbles.

2. The ultra fine bubble production device according to claim 1, wherein the pressurizing portion includes a sliding portion configured to be inserted into the container portion to form the containment space together with the container portion, the sliding portion being slidable in the container portion along an insertion direction to the container portion, the sliding portion moves relative to the container portion in the insertion direction thereby causing compression of the containment space, and the holding portion restricts, in the dissolved state under pressure, the sliding portion from moving relative to the container portion in a direction opposite to the insertion direction.

3. The ultra fine bubble production device according to claim 2, wherein the pressurizing portion includes a screw shaft portion extending along the insertion direction, the screw shaft portion having a male screw groove formed in an outer periphery of the screw shaft portion, the holding portion includes a screw hole portion into which the screw shaft portion is inserted, the screw hole portion having a female screw groove to be engaged with the male screw groove of the screw shaft portion, and the screw shaft portion moves toward the container portion in the insertion direction as the screw shaft portion is screwed and advanced into the screw hole portion.

4. The ultra fine bubble production device according to claim 1 or 2, wherein the depressurizing portion includes a valve body configured to transition from a closed state in which the communication path is closed to an open state in which the communication path is opened, and a drive portion configured to apply, to the valve body, energy for the valve body to transition from the closed state to the open state.

5. The ultra fine bubble production device according to claim 4, wherein, when the valve body is in the closed state, the valve body is fitted in the communication path to close the communication path, and the drive portion pushes the valve body from an outer side toward an inner side of the containment space to cause the valve body to transition from the closed state to the open state.

6. The ultra fine bubble production device according to claim 4, wherein the drive portion includes an igniter configured to burn an ignition agent by being supplied with operating electric power, and applies combustion energy of the ignition agent to the valve body.

7. The ultra fine bubble production device according to claim 4, wherein the drive portion includes an elastic body configured to apply elastic energy to the valve body by returning from a compressed state to an extended state in which the elastic body is extended compared to the compressed state.

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