Microbubble generating device

Abstract

To provide a microbubble generating device which generates a good amount of microbubbles. [Solution] The microbubble generator 1 is a device to be placed in a water supply system, and comprises a microbubble generator 2 and a housing 3. The microbubble generator 2 comprises a first member 5 and a second member 6 surrounding the first member 5. The first member 5 comprises a cylindrical axis 13 extending in the water flow direction, and a plurality of first rectangular columns 14 protruding from the side surface of the circumferential axis 13 in a direction intersecting the water flow direction. The second member 6 comprises a cylindrical portion 16, a plurality of polygonal inner protrusions 17 formed on the inner surface, and a plurality of polygonal outer protrusions 18 formed on the outer surface.

Description

[Technical field]

[0001] The present invention relates to a microbubble generating device. [Background technology]

[0002] In recent years, nanobubble water, which is water containing a large amount of nanobubbles, which are minute bubbles with a diameter of 1 μm or less, has been verified to have various effects such as cleaning ability and beauty effects, and has attracted attention. Nanobubble water generators have been improved to be smaller, simpler, and easier to install, and devices that can be used at home are also provided. Known examples of such generators include a showerhead built-in type in which a microbubble generator is built into the showerhead (see Patent Document 1), and a type in which a microbubble generator is attached between the showerhead and the hose as a hose connector (see Patent Document 2).

[0003] However, the device in Patent Document 1 cannot be retrofitted to the tip of a kitchen or bathroom faucet, and the device in Patent Document 2 has the drawback of being unsuitable for miniaturization. For this reason, small generators that can be attached to kitchen faucets and generate large amounts of nanobubbles have been proposed (see Patent Documents 3 and 4). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2020-11034 A [Patent Document 2] Patent No. 6205099 [Patent Document 3] Patent No. 6984919 [Patent Document 4] Patent No. 7378752 Summary of the Invention [Problem to be solved by the invention]

[0005] Incidentally, particularly in recent years, there has been a demand for devices such as those described in Patent Documents 3 and 4 that are small in size yet generate a greater amount of nanobubbles.

[0006] The present invention provides a microbubble generating device that generates a good amount of microbubbles. [Means for solving the problem]

[0007] In order to solve the above problems, the present invention includes the following inventions.

[0008] The present invention [1] is a device for placement in a water supply system, comprising a microbubble generator and a housing for housing the microbubble generator, the microbubble generator comprising a first member and a second member surrounding the first member, the first member comprising an axis extending in the water flow direction and a plurality of first rectangular pillars protruding from a side of the axis in a direction intersecting the water flow direction, the second member comprising a cylindrical portion, a plurality of polygonal inner protrusions formed on the inner surface of the cylindrical portion, and a plurality of polygonal outer protrusions formed on the outside of the cylindrical portion.

[0009] According to such a microbubble generator, water flowing into the microbubble generator from the upstream of the water supply system collides with the square pillars of the first member inside the second member (first-second member space), so that the bubbles in the water are broken down into fine bubbles, and microbubbles are generated. At this time, the water collides not only with the first square pillars but also with the inner protrusions inside the second member, so that the bubbles are broken down into fine bubbles in more places. In addition, water also enters the space outside the second member and inside the housing (second member-housing space), and collides with the outer protrusions, so that microbubbles are generated in this space as well. In this way, the water flowing in from the water supply system collides with many members such as the first square pillars, the inner protrusions, and the outer protrusions, so that a large amount of microbubbles can be generated. In addition, since the length in the water flow direction is the same as that of conventional generating devices, it can be made compact.

[0010] The present invention [2] includes the microbubble generating device according to [1], in which the outer protrusion contacts the inner surface of the housing.

[0011] According to such a microbubble generating device, water that enters the space between the second member and the housing reliably hits the outer protrusion, so that microbubbles can be reliably generated in that space.

[0012] The present invention [3] includes the microbubble generating device according to [1] or [2], in which the inner protrusion contacts the rectangular column.

[0013] According to such a microbubble generating device, water entering the space between the first and second members reliably collides with at least one of the rectangular column and the inner protrusion, so that microbubbles can be reliably generated in the space.

[0014] The present invention [4] includes the microbubble generating device according to any one of [1] to [3], wherein the dimensions of the inner protrusion and the outer protrusion are each smaller than the dimensions of the rectangular column.

[0015] In such a microbubble generating device, since the inner and outer protrusions are small, a large number of protrusions can be arranged, and a large number of bubbles in the water can collide with the protrusions, thereby generating a large amount of microbubbles.

[0016] The present invention [5] includes the microbubble generating device according to any one of [1] to [4], wherein the inner protrusion and the outer protrusion are triangular prisms or quadrangular prisms, respectively.

[0017] According to such a microbubble generating device, the protrusions are angular, so that the bubbles in the water can be more reliably divided and broken down into smaller pieces, and therefore a large amount of microbubbles can be generated.

[0018] The present invention [6] includes a microbubble generating device described in any one of [1] to [5], wherein the proportion of the surface area occupied by the multiple outer protrusions in the outer surface area of ​​the cylindrical portion is 5% or more and 25% or less.

[0019] According to such a microbubble generating device, the outer protrusions are well balanced in the space between the second member and the housing, so that the bubbles in the water can be more efficiently and reliably divided and broken down, and a large amount of microbubbles can be generated.

[0020] The present invention [7] includes a microbubble generating device according to any one of [1] to [6], wherein the microbubble generator further comprises a vortex generating member arranged upstream of the first member and the second member in the water flow direction.

[0021] According to such a microbubble generator, water flowing into the microbubble generator from the upstream of the water supply system first collides with the vortex generating member, becoming vortex-like, and is then sent to the first and second members located downstream. This generates a vortex-like water flow, which collides smoothly and forcefully with the rectangular column and the inner protrusion within the cylinder, and also smoothly and forcefully with the outer protrusion in the second member-housing space. This causes the bubbles to break down even further, generating a large amount of microbubbles.

[0022] The present invention [8] includes the microbubble generating device described in [7], wherein the vortex generating member is provided with a plurality of second rectangular pillars protruding toward the upstream side in the water flow direction on its surface upstream in the water flow direction.

[0023] In this type of microbubble generator, the bubbles in the water are first broken down into smaller pieces by the second rectangular pillars, and then further refined by the first rectangular pillars and the outer protrusions. In other words, the bubbles are refined by at least two types of rectangular pillars. This makes it possible to generate a large amount of microbubbles more reliably.

[0024] The present invention [9] includes the microbubble generating device described in [7] or [8], wherein the vortex generating member is arranged so as to be in contact with the first member and is arranged at a distance from the second member in the water flow direction.

[0025] With such a microbubble generating device, a portion of the vortex water flow generated by the vortex generating member can be immediately guided to the first member, while the remainder of the vortex water can be reliably guided to the surrounding second member-housing space. Effect of the Invention

[0026] The microbubble generating device of the present invention is capable of generating a large amount of microbubbles. [Brief description of the drawings]

[0027] [Figure 1] FIG. 1 shows an exploded perspective view of a first embodiment of the present invention. [Diagram 2] FIG. 2 shows an exploded perspective view of the first embodiment in FIG. 1, disassembled into a microbubble generator (a vortex generating member, a first member, and a second member) and a housing. [Diagram 3] 3 shows the first embodiment of FIG. 1, with the left drawing being a plan view and the right drawing being a cross-sectional view taken along line AA of the left drawing. [Figure 4] FIG. 4 shows the vortex generating member of FIG. 1, with the upper left diagram being a plan view, the lower left diagram being a front view, and the upper right diagram being a perspective view. [Diagram 5] FIG. 5 shows the vortex generating member with the annular frame portion removed from FIG. 4, with the upper left diagram being a plan view, the lower left diagram being a front view, and the upper right diagram being a perspective view. [Figure 6] FIG. 6 shows the first member in FIG. 1, with the left figure showing a plan view and the right figure showing a front view. [Figure 7] FIG. 7 shows the second member in FIG. 1, with the left figure showing a plan view and the right figure showing a front view. [Figure 8] FIG. 8 shows a perspective view of a modified example of the second member of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0028] First Embodiment A microbubble generating device 1 according to a first embodiment will be described as one example of the present invention with reference to Figs. 1 to 7.

[0029] The microbubble generator 1 (hereinafter abbreviated to "generator") of the first embodiment is a device that is placed in a water supply system, i.e., a flow path through which water flows, to generate microbubbles, and as shown in Figures 1 to 3, it comprises a microbubble generator 2 (hereinafter abbreviated to "generator") and a housing 3.

[0030] The generator 2 is a member for generating a large amount of nanobubbles, which are minute air bubbles, in water flowing from the upstream side of the water supply system. The generator 2 includes a vortex generating member 4 arranged upstream in the water flow direction, a first member 5 arranged downstream of the vortex generating member 4, and a second member 6 arranged downstream of the vortex generating member 4 around the first member 5. The water flow direction is the direction in which water flows from the water supply system toward the generator 1, and coincides with the axial direction of a cylindrical axis 13 described later. In addition, an orthogonal direction (an example of an intersecting direction) perpendicular to the water flow direction coincides with a radial direction or circumferential direction with respect to the axial direction.

[0031] 4 and 5, the vortex generating member 4 integrally comprises a central portion 7, a spiral portion 8, a plurality of second rectangular columns 9, and an annular frame portion 10. The outer shape of the vortex generating member 4 is substantially circular when viewed visually along the water flow direction, more specifically, when viewed from the upstream side to the downstream side (hereinafter, in a plan view).

[0032] The central portion 7 is a portion that supports the helical portion 8. The central portion 7 is disposed in the center of the vortex generating member 4 in a plan view. The central portion 7 has a cylindrical shape, with its upstream end formed in a triangular pyramid shape and its downstream end being recessed.

[0033] The spiral portion 8 is a portion that turns the water flowing from the upstream side into a vortex and guides it to the first member 5 and the second member 6 located downstream (specifically, between the first member 5 and the second member 6, and between the second member 6 and the housing 3). The spiral portion 8 is composed of a plurality of (three) spiral plates. Each spiral plate is a spiral plate-like member and has approximately the same shape as each other. Specifically, the spiral plate has a fan shape in plan view with a central angle of 120 degrees, and when viewed along the radial direction (hereinafter, in a side view), has a shape that is inclined in an oblique direction that intersects both the water flow direction and the radial direction. That is, the spiral plate is inclined downstream as it proceeds in the circumferential direction (specifically, counterclockwise direction) in a plan view. The inclination angle θ1 of the spiral plate (the angle between the spiral plate and the radial direction in a side view) is, for example, 10 degrees or more and 30 degrees or less.

[0034] In a plan view, the multiple helical plates extend radially from the central portion 7 at equal intervals in the circumferential direction. That is, one circumferential edge of one helical plate (e.g., a clockwise edge; one of the edges extending in the radial direction) is separated by an interval 11 in the circumferential direction from the other circumferential edge of another helical plate adjacent to that helical plate (e.g., a counterclockwise edge; one of the edges extending in the radial direction). The interval 11 is defined in a generally rectangular shape in a side view, and serves as an inlet and outlet for water that flows into the vortex generating member 4 and flows out to the first member 5 and the second member 6.

[0035] The second rectangular columns 9 are portions that break down air bubbles contained in the water flowing from the upstream side. The second rectangular columns 9 are formed on the upstream surface of the spiral section 8 so as to protrude toward the upstream side, and are arranged at intervals in the circumferential and radial directions. The second rectangular columns 9 are also formed on the downstream surface of the spiral section 8 so as to protrude toward the downstream side, and are arranged at intervals in the circumferential and radial directions. The total number of the second rectangular columns 9 is, for example, 10 or more and 100 or less on each of the upstream surface and the downstream surface. The second rectangular columns 9 are triangular columns, and the planar shapes of the second rectangular columns 9 are the same as each other, and their heights (lengths in the water flow direction) are also the same as each other. The second rectangular columns 9 arranged on the upstream surface and the second rectangular columns 9 arranged on the downstream surface have the same shape and form a pair. That is, the second rectangular columns 9 are arranged on the downstream surface of the place where the second rectangular columns 9 are arranged on the upstream surface. The dimensions (volume) of the second rectangular pillar 9 are smaller than the dimensions of the first member 5 described below. Specifically, the height (length in the water flow direction) of the second rectangular pillar 9 is smaller than the height (length in the radial direction) of the first rectangular pillar 14, and the triangular area of ​​the second rectangular pillar 9 is smaller than the rectangular area of ​​the first rectangular pillar 14.

[0036] The annular frame 10 is a portion that reinforces the helical portion 8. The inner peripheral edge of the annular frame 10 is continuous with the radial end edges of the helical portion 8, i.e., the multiple helical plates, and its outer peripheral edge approximately coincides with the inner peripheral edge of the housing 3. The annular frame 10 is formed so as to completely enclose the first member 5 and overlap with the second member 6 when viewed from the water flow direction. In other words, the diameter of the annular frame 10 is larger than the diameter of the first member 5 and approximately the same as the diameter of the second member 6. A protrusion 12 is formed on the outer surface of the annular frame 10 to prevent the vortex generating member 4 from rotating in the circumferential direction.

[0037] As shown in FIG. 6, the first member 5 integrally includes a cylindrical shaft 13 and a plurality of first rectangular columns 14.

[0038] The cylindrical shaft 13 is a portion that supports a plurality of first rectangular columns 14. The cylindrical shaft 13 has a cylindrical shape that extends in the axial direction, which is the same direction as the water flow direction. The upper part of the cylindrical shaft 13 contacts the lower end of the central part 7 of the vortex generating member 4. The upper part of the cylindrical shaft 13 is formed with a truncated cone-shaped protrusion 15 so as to fit into the recess of the central part 7 of the vortex generating member 4.

[0039] The first rectangular columns 14 are portions that reduce the size of bubbles contained in the water flowing from the vortex generating member 4 to nanobubbles. The first rectangular columns 14 are formed so as to protrude radially outward from the circumferential side surface of the cylindrical shaft 13. The first rectangular columns 14 are identical in shape to one another and are substantially parallelepipeds. That is, the first rectangular columns 14 are quadrangular columns having a substantially parallelogram shape in side view. In a cross-sectional view perpendicular to the axial direction, they have a rectangular shape that is elongated in the radial direction, and are formed so that the rectangular shape rotates in the circumferential direction of the cylindrical shaft 13 (specifically, counterclockwise) as they move toward the other axial side. The outer peripheral edge of the first rectangular column 14 is curved so as to be convex toward the radially outward side in plan view. That is, the radially outer surface (the surface forming the parallelogram shape) of the first rectangular column 14 is formed in an arc shape.

[0040] A plurality of first rectangular columns 14 (45 pieces) are provided on the circumferential side surface of the cylindrical shaft 13, and are regularly arranged from one axial end to the other axial end of the cylindrical shaft 13. Specifically, a plurality of (five) rectangular columns radially protruding from the cylindrical shaft 13 constitute a set of radial rectangular column groups 22, and a plurality of (nine sets) of radial rectangular column groups 22 are arranged at intervals in the axial direction. The multiple sets of radial rectangular column groups 22 are arranged at equal intervals in the axial direction so as to be parallel to each other, and are also arranged at equal intervals in the axial direction so as to rotate in the circumferential direction, i.e., in a spiral shape.

[0041] As shown in FIG. 5, the first rectangular pillars 14 are arranged on the side of the cylindrical shaft 13 along a spiral line Y with the axial direction of the cylindrical shaft 13 (particularly, a straight line in the axial direction passing through the center of the cylindrical shaft 13) as the spiral axis X. That is, the first rectangular pillars 14 are arranged in a spiral shape with a gentle spiral angle θ2 (for example, 45 degrees or less, 5 degrees or more). Specifically, as shown in FIG. 6, in the positional relationship of two adjacent first rectangular pillars 14 spaced apart from each other in the axial direction, the first rectangular pillar 14 and the other first rectangular pillar 14 are positioned so as to overlap each other in a plan view and to be slightly shifted in the circumferential direction. That is, the other first rectangular pillar 14 arranged on the other axial side is slightly shifted counterclockwise with respect to the first first rectangular pillar 14 located on one axial side. There are multiple sets of rectangular pillars arranged in such a spiral shape. That is, in side view, a plurality (nine) of first rectangular columns 14 adjacent to each other in the axial direction constitute a row of spiral rectangular column group 23, and the spiral rectangular column group 23 is arranged in a plurality (five) rows at equal intervals in the circumferential direction. As a result, a plurality (five) of spiral flow paths are defined between the spiral rectangular column group 23 while the many first rectangular columns 14 are arranged.

[0042] As shown in FIG. 7, the second member 6 is capable of housing the first member 5, and is integrally provided with a cylindrical portion 16, a plurality of inner protrusions 17, and a plurality of outer protrusions .

[0043] The cylindrical portion 16 is a portion that surrounds the first member 5. The cylindrical portion 16 has a cylindrical shape that extends in the water flow direction. The cylindrical portion 16 houses the first member 5, and the axial length of the cylindrical portion 16 is approximately the same as the cylindrical axis 13. Specifically, the cylindrical portion 16 contains the cylindrical axis 13 and the first rectangular column 14. The cylindrical portion 16 is disposed at a distance from the annular frame portion 10 in the water flow direction. This creates a gap 19 between the cylindrical portion 16 and the annular frame portion 10, through which water can pass.

[0044] The multiple inner protrusions 17 are parts that, together with the first rectangular column 14, break down the air bubbles contained in the water flowing from the vortex generating member 4 into nanobubbles. The multiple inner protrusions 17 are formed so as to protrude radially inward from the inner surface of the cylindrical portion 16, and are arranged at intervals from each other in the water flow direction and the radial direction. Each inner protrusion 17 has a triangular shape. Specifically, it is a triangular column extending in the radial direction. The side view shapes of the multiple inner protrusions 17 are the same as each other, and their heights (radial lengths) are also the same as each other. In the water flow direction, the inner protrusions 17 having the apex of a side equilateral triangle on the upstream side of the water flow direction and the inner protrusions 17 having the apex of a side equilateral triangle on the downstream side of the water flow direction are arranged alternately in the water flow direction. Some of the multiple inner protrusions 17 come into contact with the first rectangular column 14. That is, the inner end surface of the inner protrusions 17 comes into contact with the outer end surface of the first rectangular column 14. The total number of the inner protrusions 17 is greater than the total number of the first rectangular prisms 14, and is, for example, 50 or more and 200 or less. The dimensions (volume) of the inner protrusions 17 are smaller than the dimensions (volume) of the first rectangular prisms 14. Specifically, the height (radial length) of the inner protrusions 17 is smaller than the height (radial length) of the first rectangular prisms 14, and the triangular area (side view area) of the inner protrusions 17 is smaller than the rectangular area (side view area) of the first rectangular prisms 14. The volume of one inner protrusion 17 is, for example, 25% or less and 5% or more of the volume of one first rectangular prism 14. The surface area ratio of the inner surface area of ​​the cylindrical portion 16 occupied by the multiple inner protrusions 17 is, for example, 5% or more and 25% or less.

[0045] The outer protrusions 18 are portions that reduce the size of bubbles contained in the water flowing from the vortex generating member 4 to nanobubbles. The outer protrusions 18 are formed so as to protrude radially outward from the outer surface of the cylindrical portion 16, and are arranged at intervals from each other in the water flow direction and the radial direction. Each of the outer protrusions 18 has a triangular shape. Specifically, it is a triangular prism extending in the radial direction. The outer protrusions 18 are triangular prisms, and the side view shapes of the outer protrusions 18 are the same as each other, and their heights (lengths in the water flow direction) are also the same as each other. The outer protrusions 18 have the same shape as the inner protrusions 17, and are formed to form pairs with the inner protrusions 17 with the cylindrical portion 16 sandwiched therebetween. That is, the shape, arrangement, total number, etc. of the outer protrusions 18 are approximately the same as those of the inner protrusions 17. The outer protrusions 18 are formed so as to come into contact with the inner circumferential surface of the housing 3. That is, the outer end faces of the multiple outer protrusions 18 contact the inner circumferential surface of the housing 3. The surface area ratio of the multiple outer protrusions 18 to the outer surface area of ​​the cylindrical portion 16 is, for example, 5% or more and 25% or less.

[0046] The diameter of the generator 2, i.e., the diameter of the vortex generating member 4 or the second member 6, is, for example, 5 mm or more, preferably 10 mm or more, and for example, 50 mm or less, preferably 30 mm or less. The length of the generator 2 in the water flow direction is, for example, 20 mm or more, preferably 30 mm or more, and for example, 80 mm or less, preferably 60 mm or less. The length of the first member 5 and the second member 6 in the water flow direction is, for example, 30 mm or more, preferably 40 mm or more, and for example, 80 mm or less, preferably 60 mm or less. The radial length of each first rectangular column 14 (height of the rectangular column) is longer than the radial length of the inner protrusion 17 and the outer protrusion 18 (height of the triangular column), and is, for example, 2 mm or more, preferably 4 mm or more, and for example, 15 mm or less, preferably 8 mm or less. The length in the water flow direction of each of the second rectangular columns 9 (height of the triangular column) is, for example, 1 mm or more, preferably 2 mm or more, and, for example, 5 mm or less, preferably 4 mm or less. The radial length in the water flow direction of each of the inner protrusions 17 and the outer protrusions 18 (height of the triangular column) is, for example, 0.5 mm or more, preferably 0.8 mm or more, and, for example, 3 mm or less, preferably 2 mm or less. The length in the water flow direction of the housing 3 is, for example, 40 mm or more, preferably 60 mm or more, and, for example, 100 mm or less, preferably 80 mm or less.

[0047] The housing 3 is a member for accommodating the generator 2 and for disposing inside the water supply system. The housing 3 has a substantially cylindrical shape. The outer shape of the inner surface on the upstream side of the housing 3 is approximately the same as the outer shape of the vortex generating part 4. That is, the inside of the housing 3 is configured so that the water generated in the housing 3 directly collides with the entire upper surface of the vortex generating member 4. That is, the shape of the inner surface on the upstream side of the water flow direction of the housing 3 is approximately the same as the outer shape of the annular frame part 10 of the vortex generating member 4. A recess 20 that can be engaged with the protrusion 12 of the vortex generating member 4 is formed at the upper end of the inner surface of the housing 3. A throttle part 21 that reduces in diameter in the radial direction is formed at the lower end of the inner surface of the housing 3. The throttle part 21 supports the second member 17 and the third member 18 from the downstream side in the water flow direction. The housing 3 is formed so that it can be screwed to a member of the water supply system at its upper and lower ends so that it can be disposed or fixed in the water supply system. Specifically, an external thread is formed on the outside of the upper end of the housing 3, and an internal thread is formed on the inside of the lower end.

[0048] Materials for the generator 2 and the housing 3 include, for example, resins such as polyethylene (PE), polypropylene (PP), polyethylene terephthalate (PET), ethylene vinyl acetate copolymer (EVA), polyvinyl chloride (PVC), polyvinylidene chloride (PVDC), polyacetal (POM), silicone rubber, ABS resin, etc., metals such as aluminum, stainless steel, brass, etc., and preferably resins.

[0049] The generator 1 is used by being placed in the middle or at the end of a water supply system. For example, it can be placed at the end of a faucet pipe (tap pipe) placed in a kitchen, washroom, outdoors, etc., between such a faucet pipe and a hose, or in the middle of a water pipe or hose. More specific uses include the end of a kitchen faucet pipe, between a laundry hose and a washing machine, and between a shower head and a shower hose.

[0050] This generator 1 can generate a large amount of nanobubbles. This is presumably due to the following mechanism, but the present invention is not limited to this mechanism. Water flowing from the upstream side of the water supply system directly collides with the entire upper surface of the vortex generating member 4, becomes vortex-shaped by the spiral part 8, and moves downstream. The vortex water is then separated into the inside of the second member 6 (i.e., the space between the first member 5 and the second member 6: the first-second member space) and the outside of the second member 6 (i.e., the space between the housing 3 and the second member 6: the second member-housing space). The water that has entered the first-second member space collides with the multiple first rectangular columns 14 in multiple stages. At this time, since the first rectangular columns 14 are arranged in a spiral shape, the vortex water moves more smoothly and comes into contact with the multiple first rectangular columns 14 with force. It also collides with the inner protrusion 17 on the inner wall of the second member 6. As a result, the bubbles in the water are broken down into nanobubbles (microbubbles with a diameter of 1000 nm or less). The water that enters the second member-housing space also collides with the outer protrusion 18 smoothly and forcefully in a vortex shape, breaking down the bubbles into fine bubbles. After that, the nanobubbles generated in the first-second member space and the nanobubbles generated in the second member-housing space join together near the throttle section 21 and are released from the downstream end of the generator 1. Conventionally, the only part that generated nanobubbles was the first rectangular column 14 of the first member 5 located at the radial center of the water flow, but in the present invention, nanobubbles are generated by providing nanobubble generating members at the radial outer end in the water flow direction, that is, the outer surface of the second member 6 (and thus the inner surface of the housing 3) and the inner surface of the second member 6. In this way, the space in the planar direction perpendicular to the water flow direction is effectively utilized to increase the nanobubble generating parts, which increases the nanobubble generating area and leads to the generation of a large amount of nanobubbles. Furthermore, since there is almost no need to increase the length of this microbubble generator in the water flow direction, the length in the water flow direction (longitudinal length) is the same as that of conventional microbubble generators, and therefore the device can be kept compact.

[0051] Moreover, according to this generator 1, the outer protrusion 18 is disposed so as to come into contact with the inner surface of the housing 3. Therefore, the swirling water that has entered the space between the second member and the housing can be made to reliably collide with the outer protrusion 18. As a result, a large amount of nanobubbles can be generated in that space.

[0052] Moreover, according to this generator 1, the inner protrusion 17 is disposed so as to come into contact with the first rectangular column 14. Water that enters the 1-2 member space can be made to collide with at least either the first rectangular column 14 or the inner protrusion 17. Thus, a large amount of nanobubbles can be generated in that space.

[0053] Furthermore, according to this generator 1, the dimensions of the inner protrusion 17 and the outer protrusion 18 are each smaller than the dimensions of the rectangular column 14. This allows a greater number of protrusions to be densely arranged on the cylindrical portion 16 of the second member 6. This allows air bubbles in the water to collide with a large number of the protrusions 17, 18, generating a large amount of nanobubbles.

[0054] Furthermore, according to this generating device 1, the inner protrusion 17 and the outer protrusion 18 are each triangular in shape. Therefore, each of the protrusions 17, 18 is angular, and can more reliably break up and subdivide air bubbles in the water, making it possible to generate a large amount of nanobubbles.

[0055] Furthermore, according to this generator 1, the proportion of the surface area of ​​the outer surface of the cylindrical portion 16 occupied by the multiple outer protrusions 18 is 5% or more and 25% or less. This results in a good balance of the amount of the outer protrusions 18 occupying the second member-housing space, and allows water to collide with the outer protrusions 18 while maintaining an appropriate force of the water flow. This makes it possible to generate a large amount of nanobubbles.

[0056] Moreover, according to this generator 1, the vortex generating member 4 is provided with a plurality of second rectangular columns 9 on the surface upstream in the water flow direction. Therefore, the air bubbles in the water are first broken down into smaller pieces by the second rectangular columns 9, and then further refined by the first rectangular columns 14, the inner protrusions 17, or the outer protrusions 18. In other words, the bubbles are refined by at least two or more types of rectangular columns. Therefore, nanobubbles can be generated more reliably and in large quantities.

[0057] Moreover, according to this generator 1, the vortex generating member 4 is disposed so as to be in contact with the first member 5, and is disposed at a distance 11 from the second member 6 in the water flow direction. As a result, a portion of the vortex water generated by the vortex generating member 4 can be immediately guided to the first member 5, and the remainder of the vortex water can be reliably guided through the gap 11 to the second member-housing space. This allows the water to collide with any of the first rectangular column 14, the inner protrusion 17, and the outer protrusion 18, generating a large amount of nanobubbles.

[0058] Moreover, according to this generator 1, the housing 3 is formed with a throttle section 21 on the downstream side of the first member 5 and the second member 6 in the water flow direction. Therefore, by increasing the internal pressure of the housing 3, it is possible to increase the collision force between the water and the rectangular columns 14, 9 and the protrusions 17, 18, and it is possible to generate a large amount of nanobubbles. In addition, the water containing nanobubbles can be forcefully discharged from the generator 1.

[0059] <Modification> Although not shown, the generator 1 of the present invention does not necessarily have to include the vortex generating member 4. From the viewpoint of more reliably exerting the functions of the first member 5 and the second member 6 and more reliably generating a large amount of nanobubbles, it is preferable to include the vortex generating member 4.

[0060] As shown in FIG. 8, the second member 6 may be separable into two pieces from the viewpoint of ease of manufacture.

[0061] Although not shown, the inner protrusion 17 and the outer protrusion 18 may have any polygonal shape, such as a quadrangular shape, a pentagonal shape, etc. From the viewpoint of being more angular and reliably generating nanobubbles, a triangular or quadrangular shape is preferable. EXAMPLES

[0062] The present invention will be described in detail below with reference to examples and comparative examples, but the scope of the present invention is not limited thereto.

[0063] <Example 1> The generating device shown in Figures 1 to 7 was produced as Example 1. The diameters of the vortex generating member 4 and the second member 6 were approximately 20 mm, the axial length of the first member 5 was approximately 45 mm, the length of the first rectangular column 14 in the water flow direction was approximately 5 mm, and the radial lengths of the inner protrusion 17 and the outer protrusion 18 were approximately 1 mm. The lengths of the other members were set to the same ratios as those in Figures 1 to 7, based on the above lengths.

[0064] NANOSIGHT (Nanoparticle Analysis System) was used as the measuring device. First, tap water was used as sample water, and the bubbles contained therein were measured. Next, the sample liquid was passed through the generating device of Example 1, and the bubbles contained in the passed nanobubble water were measured. These sample waters were compared with the nanobubble water. As a result, the average particle diameter D50 of the bubbles in the nanobubble water was smaller than the D50 of the sample water, being 67.8 nm. Furthermore, the total amount of bubbles in the nanobubble water was greater than the total amount of bubbles in the sample water, being 4.32 × 10 8 The number of cells / mL had increased.

[0065] <Comparative Example 1> Comparative Example 1 was an instrument obtained by removing the second member 6 from the generating instrument of Example 1, which is described in Example 1 of Japanese Patent No. 7378752. As in Example 1, sample water was compared with nanobubble water obtained by passing the sample water through the instrument of Comparative Example 1. As a result, the average particle diameter D50 of the bubbles in the nanobubble water was smaller than that of the sample water, being 73.6 nm. Furthermore, the total amount of bubbles in the nanobubble water was greater than the total amount of bubbles in the sample water, being 3.58×108 The number of cells / mL had increased.

[0066] The nanobubble water obtained in Example 1 had a smaller average bubble particle size D50 and a larger increase in the total amount of bubbles than the nanobubble water obtained in Comparative Example 1. This shows that the generator of Example 1 can generate more nanobubble water than the generator of Comparative Example 1. [Explanation of symbols]

[0067] 1 Microbubble generating device 2 Microbubble generator 3 Housing 4 vortex generating member 5 first member 6 second member 7 Center 8 Spiral 9 Second prism 10 annular frame portion 11 spacing 12 protrusion 13 Cylinder shaft 14 First prism 15 Convex portion 16 Cylindrical part 17 Inner protrusion 18 Outer protrusion 19 Gap 20 Recess 21 Constriction 22 Radial prisms 23 Spiral prisms

Claims

1. A device for generating a large amount of microbubbles in water flowing in from an upstream side of a water supply system and releasing the microbubbles downstream, comprising: a microbubble generator; and a housing for accommodating the microbubble generator and for disposing the microbubble generator in the middle or at the end of the water supply system; The microbubble generator is A first member; a second member surrounding the first member; Equipped with The first member is An axis extending in the direction of water flow; A plurality of rectangular pillars protruding from the side surface of the shaft in a direction intersecting with the water flow direction; Equipped with The second member is A cylindrical portion extending in a water flow direction and containing the plurality of rectangular columns of the first member; A plurality of polygonal inner protrusions formed on an inner surface of the cylindrical portion; a plurality of polygonal outer protrusions formed on the outer surface of the cylindrical portion; A microbubble generating device comprising:

2. The microbubble generating device according to claim 1 , wherein the outer protrusion contacts an inner surface of the housing.

3. The microbubble generating device according to claim 1 , wherein the inner protrusion contacts the rectangular column.

4. 2. The microbubble generating device according to claim 1, wherein the dimensions of the inner protrusion and the outer protrusion are each smaller than the dimensions of the rectangular column.

5. 2. The microbubble generating device according to claim 1, wherein the inner protrusion and the outer protrusion are each a triangular prism or a quadrangular prism.

6. 2. The microbubble generating device according to claim 1, wherein the proportion of the surface area of ​​the cylindrical portion occupied by the outer protrusions is 5% or more and 25% or less.

7. 2. The microbubble generating device according to claim 1, wherein the microbubble generator further comprises a vortex generating member disposed upstream of the first member and the second member in the water flow direction.

8. 8. The microbubble generating device according to claim 7, wherein the vortex generating member has a plurality of rectangular pillars protruding toward the upstream side in the water flow direction on a surface on the upstream side in the water flow direction.

9. 9. The microbubble generating device according to claim 8, wherein the vortex generating member is arranged so as to be in contact with the first member and is arranged at a distance from the second member in the water flow direction.

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