Microbubble generating tool

Abstract

To provide a microbubble generating tool which generates a large amount of micro bubbles.SOLUTION: A microbubble generating tool 1 is disposed at a water supply system and includes a microbubble generating body 2 and a housing 3. The microbubble generating body 2 includes: a first member 5; and a second member 6 which encloses the first member 5. The first member 5 includes: a columnar shaft 13 extending in a water flow direction; and a plurality of first prismatic columns 14 located on a side surface of the columnar shaft 13 and protruding in an intersection direction intersecting with the water flow direction. The second member 6 includes: a cylindrical part 16; a plurality of polygonal inner projections 17 formed on an inner surface; and a plurality of polygonal outer projections 18 formed on an outer surface.SELECTED DRAWING: Figure 1

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 tiny bubbles with a diameter of 1 μm or less, has been attracting attention due to its verified cleansing properties, beauty benefits, and other various effects. Nanobubble water generators have been improved to be smaller, simpler, and easier to install, and devices that can be used at home are now available. Known examples of such generators include a showerhead-integrated 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 a 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 the like and are capable of generating large amounts of nanobubbles have been proposed (see Patent Documents 3 and 4). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2020-11034 [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] Recently, 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 to be placed in a water supply system, comprising a microbubble generator and a housing for accommodating the microbubble generator, wherein the microbubble generator comprises a first member and a second member surrounding the first member, wherein the first member comprises an axis extending in the direction of water flow and a plurality of first rectangular pillars protruding from the side of the axis in a direction intersecting the water flow direction, and wherein the second member comprises 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 this microbubble generator, water flowing into the microbubble generator from the upstream of the water supply system collides with the rectangular pillars of the first member inside the second member (first-second member space), thereby breaking down the bubbles in the water and generating microbubbles. During this process, the water collides not only with the first rectangular pillars but also with the inner protrusions inside the second member, breaking down the bubbles in more locations. Furthermore, water also enters the space outside the second member and inside the housing (second member-housing space), where it collides with the outer protrusions, generating microbubbles in this space as well. In this way, water flowing in from the water supply system collides with many components, such as the first rectangular pillars, the inner protrusions, and the outer protrusions, generating a large amount of microbubbles. Furthermore, because the length in the water flow direction is the same as that of conventional generators, it can be made compact.

[0010] The present invention [2] includes the microbubble generator according to [1], wherein 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 is sure to collide with the outer protrusion, so that microbubbles can be surely generated in that space.

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

[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 pillar and the inner protrusion, thereby reliably generating microbubbles in the space.

[0014] The present invention [4] includes the microbubble generator 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 prism.

[0015] In this microbubble generator, the inner and outer protrusions are small, so many protrusions can be arranged, and many bubbles in the water can collide with the protrusions, thereby generating a large amount of microbubbles.

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

[0017] Such a microbubble generating device has angular projections that can more reliably break up and subdivide the bubbles in the water, thereby generating a large amount of microbubbles.

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

[0019] With this microbubble generator, 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 broken down and subdivided, thereby generating a large amount of microbubbles.

[0020] The present invention [7] includes a microbubble generator 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] With this microbubble generator, water flowing into the microbubble generator from the upstream of the water supply system first collides with the vortex generating member, forming a vortex, before being sent to the first and second members located downstream. This generates a vortex-like water flow that smoothly and forcefully collides with the rectangular column and the inner protrusion within the cylinder, and similarly smoothly and forcefully collides with the outer protrusion in the space between the second member and the housing. This further breaks down the bubbles, generating a large amount of microbubbles.

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

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

[0024] The present invention [9] includes the microbubble generator according to [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 generator, 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. [Effects of the Invention]

[0026] The microbubble generating device of the present invention can generate a large amount of microbubbles. [Brief explanation of the drawings]

[0027] [Figure 1] FIG. 1 shows an exploded perspective view of a first embodiment of the present invention. [Figure 2] FIG. 2 is an exploded perspective view of the first embodiment of FIG. 1, disassembled into a microbubble generator (vortex generating member, first member, and second member) and a housing. [Figure 3] 3 shows the first embodiment of FIG. 1, with the left drawing showing a plan view and the right drawing showing a cross section 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. [Figure 5] FIG. 5 shows the vortex generating member with the annular frame 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 of FIG. 1, with the left drawing showing a plan view and the right drawing showing a front view. [Figure 7] FIG. 7 shows the second member of FIG. 1, with the left drawing showing a plan view and the right drawing showing a front view. [Figure 8] FIG. 8 shows a perspective view of a modified second member of the present invention. DETAILED DESCRIPTION OF THE INVENTION

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

[0029] The microbubble generator 1 (hereinafter abbreviated as "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 as "generator") and a housing 3.

[0030] The generator 2 is a component for generating a large amount of nanobubbles, which are tiny 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 the cylindrical axis 13 described below. The orthogonal direction (an example of an intersecting direction) perpendicular to the water flow direction coincides with the radial or circumferential direction relative to the axial direction.

[0031] As shown in Figures 4 and 5, the vortex generating member 4 integrally comprises a central portion 7, a spiral portion 8, a plurality of second rectangular pillars 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 spiral 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 formed in a concave shape.

[0033] The spiral portion 8 is a portion that turns water flowing from the upstream side into a vortex and guides it toward 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 multiple (three) spiral plates. Each spiral plate is a spiral plate-like member and has approximately the same shape. Specifically, in a plan view, the spiral plate has a fan shape with a central angle of 120 degrees. When viewed radially (hereinafter, in a side view), the spiral plate has a shape that is inclined in an oblique direction that intersects both the water flow direction and the radial direction. That is, in a plan view, the spiral plate is inclined downstream as it progresses in the circumferential direction (specifically, counterclockwise). 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 plan view, the multiple spiral plates extend radially from the center 7 and at equal intervals in the circumferential direction. That is, one circumferential edge of one spiral plate (e.g., a clockwise edge; one of the edges extending in the radial direction) is separated by a circumferential interval 11 from the other circumferential edge of another spiral plate adjacent to that spiral 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 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 multiple second prismatic columns 9 are components that break down air bubbles contained within water flowing from the upstream side. The multiple second prismatic columns 9 are formed on the upstream surface of the spiral portion 8 so as to protrude toward the upstream side, and are arranged at intervals in the circumferential and radial directions. The multiple second prismatic columns 9 are also formed on the downstream surface of the spiral portion 8 so as to protrude toward the downstream side, and are arranged at intervals in the circumferential and radial directions. The total number of second prismatic columns 9 on each of the upstream and downstream surfaces is, for example, 10 to 100. The multiple second prismatic columns 9 are triangular columns, and the multiple second prismatic columns 9 have the same shape in plan view and the same height (length in the water flow direction). The multiple second prismatic columns 9 arranged on the upstream surface and the multiple second prismatic columns 9 arranged on the downstream surface have the same shape and form pairs. That is, a second prismatic column 9 is arranged on the downstream surface of a location where a second prismatic column 9 is arranged on the upstream surface. The dimensions (volume) of the second prism 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 prism 9 is smaller than the height (length in the radial direction) of the first prism 14, and the triangular area of ​​the second prism 9 is smaller than the rectangular area of ​​the first prism 14.

[0036] The annular frame 10 is a portion that reinforces the spiral portion 8. The inner peripheral edge of the annular frame 10 is continuous with the spiral portion 8, i.e., the radial end edges of the multiple spiral 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 pillars 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 center 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 that it fits into the recess in the center part 7 of the vortex generating member 4.

[0039] The first rectangular pillars 14 are components that reduce the size of bubbles contained in the water flowing from the vortex generating member 4 to nanobubbles. The first rectangular pillars 14 are formed so as to protrude radially outward from the circumferential side surface of the cylindrical shaft 13. The first rectangular pillars 14 are identical in shape and are substantially parallelepipeds. That is, the first rectangular pillars 14 are quadrangular pillars 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 the rectangular shape is formed so as to rotate 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 pillar 14 is curved so as to be convex radially outward in plan view. That is, the radially outer surface of the first rectangular pillar 14 (the surface forming the parallelogram shape) is formed in an arc shape.

[0040] A plurality (45 pieces) of first rectangular pillars 14 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 (five pieces) of rectangular pillars protruding radially from the cylindrical shaft 13 constitute a set of radial rectangular pillar groups 22, and a plurality (nine sets) of radial rectangular pillar groups 22 are arranged at intervals in the axial direction. The multiple sets of radial rectangular pillar groups 22 are arranged parallel to each other at equal intervals in the axial direction, and are also arranged so as to rotate in the circumferential direction, i.e., spirally, at equal intervals in the axial direction.

[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 whose spiral axis X is 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). That is, the first rectangular pillars 14 are arranged in a spiral shape with a gentle spiral angle θ2 (e.g., 45 degrees or less, 5 degrees or more). Specifically, as shown in FIG. 6, in the positional relationship between two adjacent first rectangular pillars 14 spaced apart from each other in the axial direction, one first rectangular pillar 14 and the other first rectangular pillar 14 are positioned so as to overlap each other in a plan view and be slightly offset in the circumferential direction. That is, the other first rectangular pillar 14 arranged on the other axial side is slightly offset counterclockwise from the one first rectangular pillar 14 located on one axial side. There are multiple sets of such spirally arranged rectangular pillars. That is, in side view, a plurality (nine) of first rectangular pillars 14 adjacent to each other in the axial direction constitute a row of spiral rectangular pillar groups 23, and the spiral rectangular pillar groups 23 are arranged in a plurality (five) of rows at equal intervals in the circumferential direction. As a result, a plurality (five) of spiral flow paths are defined between the spiral rectangular pillar groups 23 while arranging a large number of first rectangular pillars 14.

[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 that allows water to pass through.

[0044] The multiple inner protrusions 17, together with the first rectangular pillars 14, refine the air bubbles contained in the water flowing from the vortex generating member 4 into nanobubbles. The multiple inner protrusions 17 are formed 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 pillar extending in the radial direction. The multiple inner protrusions 17 have the same shape in side view and the same height (radial length). In the water flow direction, inner protrusions 17 with the vertex of an equilateral triangle on the upstream side of the water flow direction and inner protrusions 17 with the vertex of an 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 contact the first rectangular pillars 14. That is, the inner end faces of the inner protrusions 17 contact the outer end faces of the first rectangular pillars 14. The total number of inner protrusions 17 is greater than the total number of first prismatic columns 14, e.g., 50 to 200. The dimensions (volume) of the inner protrusions 17 are smaller than the dimensions (volume) of the first prismatic columns 14. Specifically, the height (radial length) of the inner protrusions 17 is smaller than the height (radial length) of the first prismatic columns 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 prismatic columns 14. The volume of one inner protrusion 17 is, for example, 5% or more and 25% or less of the volume of one first prismatic column 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 multiple outer protrusions 18 are components that reduce the size of air bubbles contained in the water flowing from the vortex generating member 4 to nanobubbles. The multiple outer protrusions 18 are formed to protrude radially outward from the outer surface of the cylindrical portion 16 and are arranged at intervals from one another in the water flow direction and the radial direction. Each of the multiple outer protrusions 18 has a triangular shape. Specifically, it is a triangular prism extending in the radial direction. As triangular prisms, the multiple outer protrusions 18 have the same shape in side view and the same height (length in the water flow direction). The multiple outer protrusions 18 have the same shape as the multiple inner protrusions 17 and are formed to form pairs with the multiple inner protrusions 17, with the cylindrical portion 16 sandwiched between them. In other words, the shape, arrangement, total number, etc. of the outer protrusions 18 are substantially the same as those of the inner protrusions 17. The multiple outer protrusions 18 are formed to contact 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, respectively, 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 second rectangular pillar 9 (height of the triangular pillar) 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 inner protrusion 17 and outer protrusion 18 (height of the triangular pillar) 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 component for accommodating the generator 2 and for placement inside the water supply system. The housing 3 has a substantially cylindrical shape. The outer shape of the upstream inner surface of the housing 3 substantially matches the outer shape of the vortex generating unit 4. That is, the inside of the housing 3 is configured so that water generated in the housing 3 directly impinges on the entire upper surface of the vortex generating unit 4. That is, the shape of the upstream inner surface of the housing 3 in the water flow direction substantially matches the outer shape of the annular frame 10 of the vortex generating unit 4. The upper end of the inner surface of the housing 3 is formed with a recess 20 that can be mated with the protrusion 12 of the vortex generating unit 4. The lower end of the inner surface of the housing 3 is formed with a tapered portion 21 that reduces in diameter in the radial direction. The tapered portion 21 supports the second member 17 and the third member 18 from the downstream side in the water flow direction. The upper and lower ends of the housing 3 are formed to be threadably mated with components of the water supply system so that the housing 3 can be placed 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, and ABS resin, and metals such as aluminum, stainless steel, and brass, with resin being preferred.

[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) located in a kitchen, bathroom, 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, or 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 portion 8, and moves downstream. The vortex water then splits into two parts: 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 enters the first-second member space collides with multiple first rectangular columns 14 in multiple stages. Because the first rectangular columns 14 are arranged in a spiral, the vortex water moves more smoothly and comes into contact with the multiple first rectangular columns 14 with force. The vortex water also collides with the inner protrusions 17 on the inner wall of the second member 6. These mechanisms break down the bubbles in the water into nanobubbles (microbubbles with a diameter of 1000 nm or less). Water entering the second member-housing space also slams into the outer protrusions 18 in a smooth, powerful vortex, breaking down the bubbles. The nanobubbles generated in the first-second member space and the second member-housing space then merge near the throttle section 21 and are released from the downstream end of the generator 1. Conventionally, nanobubbles were generated only in the first rectangular pillar 14 of the first member 5, which is located at the radial center of the water flow. However, in the present invention, nanobubbles are generated by providing nanobubble-generating components at the radially outer ends of the water flow, i.e., 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 nanobubble generation area is increased by effectively utilizing the space in the planar direction perpendicular to the water flow direction, thereby increasing the nanobubble generation area and generating a large amount of nanobubbles. Furthermore, this microbubble generator does not require much increase in length in the water flow direction, and since its length in the water flow direction (longitudinal length) is the same as that of conventional microbubble generators, it can maintain its compact size.

[0051] Furthermore, 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 reliably made to collide with the outer protrusion 18. As a result, a large amount of nanobubbles can be generated in that space.

[0052] Furthermore, according to this generator 1, the inner protrusion 17 is arranged so as to come into contact with the first rectangular pillar 14. Water that enters the 1-2 member space can be made to collide with at least either the first rectangular pillar 14 or the inner protrusion 17. Therefore, 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 greater number of the protrusions 17, 18, generating a large amount of nanobubbles.

[0054] Furthermore, according to this generator 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 bubbles in the water, thereby generating a large amount of nanobubbles.

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

[0056] Furthermore, according to this generator 1, the vortex generating member 4 is provided with a plurality of second rectangular pillars 9 on the surface on the upstream side in the water flow direction. Therefore, bubbles in the water are first broken down by the second rectangular pillars 9, and then further refined by the first rectangular pillars 14, the inner protrusions 17, or the outer protrusions 18. In other words, bubbles are refined by at least two or more types of rectangular pillars. This makes it possible to generate nanobubbles more reliably and in larger quantities.

[0057] Furthermore, 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. This allows a portion of the vortex-like water generated by the vortex generating member 4 to be immediately guided to the first member 5, while the remainder of the vortex-like water can be reliably guided through the gap 11 into the space between the second member and the housing. This allows the water to collide with either the first rectangular column 14, the inner protrusion 17, or the outer protrusion 18, generating a large amount of nanobubbles.

[0058] Furthermore, 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, thereby generating a large amount of nanobubbles. In addition, 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 enabling the first member 5 and the second member 6 to perform their functions 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 parts 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 square or pentagonal shape. From the viewpoint of being more angular and reliably generating nanobubbles, a triangular or square shape is preferred. [Example]

[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 generator 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 in the water flow direction of the first rectangular column 14 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 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 generator 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, at 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, at 4.32 × 10 8 The number of cells / mL had increased.

[0065] <Comparative Example 1> Comparative Example 1 was an apparatus obtained by removing the second member 6 from the generating apparatus 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 apparatus of Comparative Example 1. As a result, the average particle diameter D50 of the bubbles in the nanobubble water was 73.6 nm, which was smaller than the D50 of the sample water. Furthermore, the total amount of bubbles in the nanobubble water was greater than the total amount of bubbles in the sample water, at 3.58 × 108 The number of cells / mL had increased.

[0066] The nanobubble water obtained in Example 1 had a smaller average bubble particle diameter D50 and a larger increase in the total amount of bubbles than the nanobubble water obtained in Comparative Example 1. Therefore, it was found 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 cylindrical axis 14 first rectangular pillar 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. 1. A device for placement in a water supply system, comprising: A microbubble generator and a housing for accommodating the microbubble generator are provided. 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 of the shaft in a direction intersecting with the water flow direction; Equipped with The second member is A cylindrical portion; a plurality of polygonal inner protrusions formed on the 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. 2. The microbubble generator according to claim 1, wherein the outer protrusions are in contact with the inner surface of the housing.

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

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 pillar.

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 generator according to claim 1, wherein the proportion of the surface area of ​​the outer protrusions to the outer surface area of ​​the cylindrical portion is 5% or more and 25% or less.

7. 2. The microbubble generator 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 direction of water flow.

8. 8. The microbubble generator 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 the surface on the upstream side in the water flow direction.

9. 9. The microbubble generator 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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