Fine bubble generator.

Abstract

To provide a fine bubble generator that can be easily attached to an existing water pipe, shower head, etc., and can stably generate fine bubbles. [Solution] A fine bubble generator capable of generating fine bubbles from gas dissolved in a liquid, comprising: an outer tube portion having a flow path formed therein through which the liquid flows in a longitudinal direction from the base end to the tip end; and an inner tube portion formed in a cylindrical shape and disposed in the flow path, wherein the flow path is formed in a cylindrical shape and has an inner tube arrangement area in which the inner tube portion is disposed; and a pressurizing area located toward the tip end of the inner tube arrangement area and which applies pressure to the liquid, wherein the inner tube portion has a plurality of water passage holes in its side wall portion through which the liquid passes in a direction inclined by a first angle relative to the radial direction when viewed from the longitudinal direction, and the first angle is between 1 and 85 degrees.

Description

[Technical Field]

[0001] The present invention relates to a fine bubble generator. [Background technology]

[0002] In recent years, fine bubbles contained in liquids such as water have been attracting attention. Fine bubbles are generally defined as bubbles with a diameter of less than 100 μm. Because fine bubbles have a small gas-liquid interfacial area (bubble surface area), their internal pressure is high and they rise slowly through the liquid. For example, using warm water containing fine bubbles in a bathtub can provide a massage effect and a warming effect while bathing. Furthermore, because fine bubbles have surfactant properties, using water containing fine bubbles for laundry, for example, can improve cleaning power. Furthermore, fine bubbles have a water purification effect, attaching dirt suspended in the liquid to the bubbles and causing it to rise to the surface. Furthermore, fine bubbles have a physiologically stimulating effect, supplying living organisms with bubbles containing oxygen and other nutrients.

[0003] There are several principles for generating fine bubbles, including the pressurized dissolution method, in which gas is dissolved in liquid under high pressure and then reduced pressure to cause the gas in the liquid to precipitate as fine bubbles; the turbulent flow method, in which a two-phase liquid is mixed and sheared to cause an unstable state at the gas-liquid interface, thereby generating fine bubbles; and the collapse method, in which fine bubbles are generated by the generation and collapse of cavitation bubbles in liquid, or by applying sudden pressure fluctuations using ultrasound or shock waves to previously added millimeter-order bubbles, causing them to expand and then collapse under pressure.

[0004] For example, Patent Document 1 describes a fine bubble generator that has a gas dissolving tank and generates fine bubbles by dissolving gas under pressure in the gas dissolving tank. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Publication No. 2024-059206 Summary of the Invention [Problem to be solved by the invention]

[0006] However, the fine bubble generator described in Patent Document 1 has a complicated configuration, including the provision of a gas dissolution tank, making it difficult to attach to, for example, existing water pipes or shower heads.

[0007] The present invention aims to provide a fine bubble generator that can be easily attached to existing water pipes, shower heads, etc., and that can stably generate fine bubbles. [Means for solving the problem]

[0008] In order to solve the above problems, the present invention proposes the following means. A fine bubble generator according to one aspect of the present invention is a fine bubble generator capable of generating fine bubbles from gas dissolved in liquid, and comprises: an outer tube portion having a flow path formed therein through which the liquid flows in a longitudinal direction from a base end to a tip end; and an inner tube portion formed in a cylindrical shape and disposed in the flow path, the flow path being formed in a cylindrical shape and having an inner tube portion disposed in an inner tube arrangement region in which the inner tube portion is disposed; and a pressurizing region positioned on the tip side of the inner tube arrangement region and applying pressure to the liquid, the inner tube portion having a side wall portion having a plurality of water passage holes through which the liquid passes in a direction inclined by a first angle with respect to the radial direction as viewed from the longitudinal direction, the first angle being between 1 degree and 85 degrees. In the pressurized region, the flow path is formed in a circular shape when viewed from the longitudinal direction, and in the pressurized region, the inner diameter of the flow path becomes smaller as it progresses toward the tip, and then the inner diameter becomes larger again as it progresses toward the tip. [Effects of the Invention]

[0009] According to the present invention, it is possible to provide a fine bubble generator that can be easily attached to existing water pipes, shower heads, etc., and that can stably generate fine bubbles. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 1 is a perspective view showing a fine bubble generator according to an embodiment of the present invention. [Figure 2] FIG. [Figure 3] FIG. [Figure 4] 4 is a cross-sectional view taken along line F4-F4 of the inner cylindrical portion shown in FIG. 3. FIG. [Figure 5] 5 is a detailed view of the area indicated by the dashed line A5 of the inner cylindrical portion shown in FIG. 4. FIG. [Figure 6] FIG. 10 is a side view showing an inner cylindrical portion according to a modified example. [Figure 7] 1 is a diagram showing the measurement results of particle diameters of fan bubbles generated in Example 1, Example 2, Comparative Example 1, and Comparative Example 2. FIG. [Figure 8] 1 is a diagram showing the measurement results of the number of particles of fan bubbles generated by Example 1, Example 2, Comparative Example 1, and Comparative Example 2. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0011] Hereinafter, a fine bubble generator according to an embodiment will be described with reference to the drawings. In the following description, components having the same or similar functions will be assigned the same reference numerals. Duplicate descriptions of those components may be omitted.

[0012] [Fine Bubble Generator 100] The fine bubble generator 100 according to this embodiment will be described with reference to Fig. 1 to Fig. 6. First, the fine bubble generator 100 will be described as a whole. However, the fine bubble generator 100 does not need to have all of the components described below, and some components may be omitted as appropriate.

[0013] FIG. 1 is a perspective view showing a fine bubble generator 100 according to this embodiment. The fine bubble generator 100 is a device capable of generating fine bubbles from gas dissolved in a liquid. Fine bubbles are generally bubbles with a diameter of less than 100 μm. The fine bubble generator 100 is a device that can be attached to a water pipe. As shown in FIG. 1, the fine bubble generator 100 comprises an outer cylindrical portion 1 and an inner cylindrical portion 2.

[0014] In this embodiment, the longitudinal direction of the outer tubular part 1 is the longitudinal direction L of the fine bubble generator 100, and one side of the longitudinal direction L is the tip side L1 and the other side is the base side L2.

[0015] FIG. 2 is a side view showing the outer cylindrical portion 1. As shown in FIG. As shown in Figures 1 and 2, the outer cylinder 1 is a member formed in a cylindrical shape. A flow path 3 is formed inside the outer cylinder 1, through which a liquid flows in the longitudinal direction L from the base end side L2 toward the tip end side L1. The flow path 3 is formed from the base end 1t to the tip end 1s of the outer cylinder 1, and is a hole that penetrates the outer cylinder 1 in the longitudinal direction L. The flow path 3 has an inner cylinder arrangement region 31 and a pressurized region 32 located on the tip end side L1 of the inner cylinder arrangement region 31.

[0016] In this embodiment, the radial direction of the outer cylindrical part 1 is defined as the radial direction R of the fine bubble generator 100, and the circumferential direction of the outer cylindrical part 1 is defined as the circumferential direction C of the fine bubble generator 100.

[0017] The inner cylinder arrangement region 31 is a region where the inner cylinder portion 2 is arranged. The inner cylinder arrangement region 31 is formed in a cylindrical shape. The inner diameter of the inner cylinder arrangement region 31 is formed to be larger than the outer diameter of the inner cylinder main body portion 21 of the inner cylinder portion 2, which will be described later. The inner diameter of the inner cylinder arrangement region 31 is smaller than the outer diameter of the flange portion 22 of the inner cylinder portion 2, which will be described later.

[0018] A flange locking portion 33 that locks a flange portion 22 of the inner tube portion 2, which will be described later, is formed on the base end side L2 of the inner tube arrangement region 31. The flange locking portion 33 is formed in a circular shape when viewed from the longitudinal direction L. The inner diameter of the flange locking portion 33 is formed slightly larger than the outer diameter of the flange portion 22.

[0019] The pressurized region 32 is a region that applies pressure to the liquid flowing in the longitudinal direction L. The pressurized region 32 is located on the tip side L1 of the inner cylinder arrangement region 31. The pressurized region 32 is connected to the inner cylinder arrangement region 31 in the longitudinal direction L. The pressurized region 32 is formed in a circular shape when viewed from the longitudinal direction L. The inner diameter of the pressurized region 32 decreases toward the tip side L1 and then increases again toward the tip side L1. The pressurized region 32 has a first tapered portion 32a, a reduced diameter portion 32b located on the tip side L1 of the first tapered portion 32a, and a second tapered portion 32c located on the tip side L1 of the reduced diameter portion 32b.

[0020] The first tapered portion 32a gradually applies pressure to the liquid flowing in the longitudinal direction L. The first tapered portion 32a constitutes the base end of the pressurized region 32. The first tapered portion 32a is formed in a circular shape when viewed in the longitudinal direction L. The inner diameter of the first tapered portion 32a decreases toward the tip side L1. The inner diameter of the tip of the first tapered portion 32a is smaller than the inner diameter of the base end of the first tapered portion 32a. The first tapered portion 32a is formed in a truncated cone shape.

[0021] The reduced diameter portion 32b applies pressure to the liquid flowing in the longitudinal direction L. The reduced diameter portion 32b is located on the tip side L1 of the first tapered portion 32a. The reduced diameter portion 32b is in communication with the first tapered portion 32a. The reduced diameter portion 32b is formed in a circular shape when viewed in the longitudinal direction L. The inner diameter of the reduced diameter portion 32b is smaller than the inner diameter of the inner cylinder arrangement region 31. The reduced diameter portion 32b is formed in a cylindrical shape.

[0022] The second tapered portion 32c reduces the pressure of the liquid flowing in the longitudinal direction L. The second tapered portion 32c is located on the distal end side L1 of the reduced diameter portion 32b. The second tapered portion 32c is formed in a circular shape when viewed in the longitudinal direction L. The inner diameter of the second tapered portion 32c increases as it progresses toward the distal end side L1. The inner diameter of the distal end of the second tapered portion 32c is larger than the inner diameter of the proximal end of the second tapered portion 32c. The second tapered portion 32c is formed in a truncated cone shape.

[0023] A female screw 1a is formed on the inner surface of the base end of the outer cylindrical part 1. The female screw 1a has a shape that screws onto a male screw of a water pipe to which the fine bubble generator 100 is attached. A male screw 1b is formed on the outer surface of the tip end of the outer cylindrical part 1. The male screw 1b has a shape that screws onto a female screw to which the fine bubble generator 100 is attached.

[0024] The outer cylinder 1 is formed from a material containing synthetic resin, such as polyvinyl chloride.

[0025] FIG. 3 is a side view showing the inner cylindrical portion 2. As shown in FIG. As shown in Figures 1 and 3, the inner cylinder 2 is formed in a cylindrical shape and is a member that is placed in the inner cylinder placement area 31 of the flow path 3. The inner cylinder 2 is a member that is detachable from the outer cylinder 1. The inner cylinder 2 has an inner cylinder main body 21 and a flange 22 that is provided at the base end of the inner cylinder main body 21. The inner cylinder main body 21 and the flange 22 are formed integrally.

[0026] The inner cylinder main body 21 is a cylindrical box-shaped member. A cylindrical space is formed inside the inner cylinder main body 21. The inner diameter of the inner cylinder main body 21 is smaller than the inner diameter of the water pipe to which the fine bubble generator 100 is attached. The inner cylinder main body 21 is open on the base end side L2. The inner cylinder main body 21 is closed on the tip end side L1. The inner cylinder main body 21 has a cylindrical side wall 21a and a circular bottom wall 21b. The side wall 21a and the bottom wall 21b are integrally formed.

[0027] FIG. 4 is a cross-sectional view of the inner cylindrical portion 2 shown in FIG. 3 taken along line F4-F4. As shown in Figures 3 and 4, the side wall portion 21a has a plurality of water passage holes 4 formed therein, through which liquid can pass. The plurality of water passage holes 4 penetrate from the outer surface 21s of the side wall portion 21a to the inside of the inner cylinder main body portion 21. The plurality of water passage holes 4 are formed in a rectangular shape when viewed from the radial direction R. The cross-sectional area of ​​the plurality of water passage holes 4 is larger than the inner diameter of the inner cylinder main body portion 21.

[0028] As shown in FIG. 4, the multiple water passage holes 4 have a shape that allows liquid to pass through in a direction inclined at a first angle D1 with respect to the radial direction R when viewed from the longitudinal direction L. The liquid passes along the inner surface 21t of the side wall portion 21a that forms the water passage holes 4. In other words, the first angle D1 is the angle at which the inner surface 21t is inclined with respect to the radial direction R. The first angle D1 is preferably 1 to 85 degrees. The first angle D1 is more preferably 20 to 75 degrees. The first angle D1 is even more preferably 40 to 65 degrees. In this embodiment, the first angle D1 is approximately 55 degrees.

[0029] As shown in Fig. 4, the multiple water passage holes 4 are inclined in the same direction. In this embodiment, the inner surface 21t is inclined at a first angle D1 counterclockwise with respect to the radial direction R when viewed from the base end side L2, and liquid that passes through the multiple water passage holes 4 rotates counterclockwise when viewed from the base end side L2. The inclination direction of the multiple water passage holes 4 is not limited, as long as all of the water passage holes 4 are inclined in approximately the same direction. The multiple water passage holes 4 may also be configured to rotate clockwise when viewed from the base end side L2.

[0030] FIG. 5 is a detailed view of the area indicated by the dashed line A5 of the inner cylindrical portion 2 shown in FIG. As shown in FIG. 5, the inner surface 21t forming the multiple water holes 4 is inclined at a second angle D2 with respect to the outer surface 21s when viewed from the longitudinal direction L. The second angle D2 is preferably 5 to 89 degrees. The second angle D2 is more preferably 15 to 70 degrees. The second angle D2 is further preferably 25 to 50 degrees. In this embodiment, the second angle D2 is approximately 35 degrees.

[0031] The cross section of the side wall portion 21a is formed in a triangular shape as shown in FIG. 5. When viewed from the longitudinal direction L, an imaginary line V1 connecting the ends of the side wall portion 21a where the outer surface 21s is formed is inclined at a third angle D3 with respect to the inner surface 21t. The third angle D3 is preferably 5 to 89 degrees. The third angle D3 is more preferably 10 to 65 degrees. The third angle D3 is further preferably 15 to 40 degrees. In this embodiment, the third angle D3 is approximately 22.5 degrees.

[0032] The multiple water passage holes 4 are formed at equal intervals in the circumferential direction C. The multiple water passage holes 4 are formed to be approximately equal in size. The multiple water passage holes 4 are formed to be approximately equal in shape. The multiple water passage holes 4 are formed to be approximately rotationally symmetric when viewed from the longitudinal direction L. Eight water passage holes 4 are formed.

[0033] The flange portion 22 protrudes outward in the circumferential direction C from the base end of the inner tube main body portion 21. The flange portion 22 is formed in a circular shape when viewed in the longitudinal direction L. The outer diameter of the flange portion 22 is larger than the outer diameter of the inner tube main body portion 21.

[0034] The inner cylindrical portion 2 is formed to contain a synthetic resin, for example, polyvinyl chloride.

[0035] [Fine Bubble Generator 100 Function] Next, the operation of the fine bubble generator 100 will be described.

[0036] When the fine bubble generator 100 is used, the inner cylinder 2 is placed in the inner cylinder placement area 31 of the outer cylinder 1, as shown in FIG. 1 . The inner cylinder 2 is placed in an orientation in which the longitudinal direction of the outer cylinder 1 and the longitudinal direction of the inner cylinder 2 are substantially aligned with the longitudinal direction L. The inner cylinder 2 is placed so that its opening faces the base end side L2. The inner cylinder 2 is inserted up to a position where the flange 22 abuts against the flange locking portion 33. A packing or the like may be interposed between the flange 22 and the flange locking portion 33, for example.

[0037] The fine bubble generator 100 is attached to a water pipe with the inner cylinder part 2 arranged in the inner cylinder arrangement area 31. Specifically, the fine bubble generator 100 is attached to the main valve of a building's water pipe. The fine bubble generator 100 is attached so that tap water (liquid) flows from the base end side L2 to the tip end side L1. The base end side L2 of the fine bubble generator 100 is connected to the inlet side, and the tip end side L1 is connected to the outlet side. The female screw 1a at the base end of the fine bubble generator 100 is screwed onto the water pipe. The male screw 1b at the tip end of the fine bubble generator 100 is screwed onto the water pipe.

[0038] In the fine bubble generator 100 attached to a water pipe, water flows in the flow path 3 from the base end side L2 to the tip end side L1.

[0039] Water that flows into the flow path 3 flows inside from the opening on the base end side L2 of the inner cylindrical portion 2. Because the inner diameter of the inner cylindrical portion 2 is smaller than the inner diameter of the water pipe, the water that flows into the inner cylindrical portion 2 is pressurized. Because the tip end side L1 of the inner cylindrical portion 2 is closed by the bottom wall portion 21b, the water that flows into the inner cylindrical portion 2 passes through the water passage hole 4.

[0040] Because the water passage hole 4 is smaller than the inner diameter of the inner cylindrical portion 2, the water passing through the water passage hole 4 is further pressurized. As a result, the water passes through the water passage hole 4 with force. Because the water passage hole 4 is inclined at a first angle D1 with respect to the radial direction R, the water that passes through the water passage hole with force flows toward the tip side L1 while forming a vortex that rotates in the circumferential direction C. Because the base side L2 is closed by the flange portion 22, the water that passes through the water passage hole 4 does not flow toward the base side L2, but flows toward the tip side L1.

[0041] The water flowing toward the tip side L1 while forming a vortex rotating in the circumferential direction C flows from the inner cylinder arrangement region 31 into the pressurized region 32. The water that has flowed into the pressurized region 32 passes through the first tapered portion 32a from the base side L2 toward the tip side L1.

[0042] The water passing through the first tapered portion 32a is pressurized as it proceeds toward the tip end L1 because the inner diameter of the first tapered portion 32a becomes smaller as it proceeds toward the tip end L1. The pressurized water, swirling in a circumferential direction C, passes through the reduced diameter portion 32b.

[0043] The water that has passed through the reduced diameter section 32b flows into the second tapered section 32c. Because the inner diameter of the second tapered section 32c is larger than that of the reduced diameter section 32b, the water flowing into the second tapered section 32c is released from the pressure applied by the reduced diameter section 32b. Therefore, the water flows forcefully toward the second tapered section 32c. Specifically, the pressurized water flows forcefully toward the second tapered section 32c while forming a vortex that rotates in the circumferential direction C. At this time, the gas dissolved in the water is sheared, generating fine bubbles.

[0044] The water containing fine bubbles passes through the second tapered section 32c and flows toward the water pipe. Since the fine bubble generator 100 according to this embodiment is attached to the main valve of the water pipe of a building, the water containing fine bubbles flows into the water pipe inside the building. Therefore, the water used in the building contains fine bubbles.

[0045] According to the fine bubble generator 100 of this embodiment, the inner cylindrical portion 2 has, in the side wall portion 21a, a plurality of water passage holes 4 through which liquid passes in a direction inclined by a first angle D1 with respect to the radial direction R when viewed from the longitudinal direction L, and the first angle D1 is 1 to 85 degrees, so that fine bubbles can be generated stably without a complex configuration. Therefore, the generator can be easily attached to existing water pipes, shower heads, etc., while still being able to generate fine bubbles stably.

[0046] According to the fine bubble generator 100 of this embodiment, the inner surface 21t is inclined at a second angle D2 with respect to the outer surface 21s when viewed from the longitudinal direction L, and the second angle D2 is 5 to 89 degrees, so fine bubbles can be generated stably without a complex configuration. Therefore, the generator can be easily attached to existing water pipes, shower heads, etc., and still generate fine bubbles stably.

[0047] According to the fine bubble generator 100 of this embodiment, the multiple water passage holes 4 are formed in a rectangular shape when viewed from the radial direction R, which stabilizes the flow of liquid passing through the multiple water passage holes 4 and enables stable generation of fine bubbles. Therefore, fine bubbles can be generated stably without a complex configuration, and fine bubbles can be generated stably while the generator can be easily attached to existing water pipes, shower heads, etc.

[0048] According to the fine bubble generator 100 of this embodiment, eight water passage holes 4 are provided, which stabilizes the flow of liquid passing through the water passage holes 4 and enables stable generation of fine bubbles. Therefore, fine bubbles can be generated stably without a complex configuration, and fine bubbles can be generated stably while being easily attached to existing water pipes, shower heads, etc.

[0049] According to the fine bubble generator 100 of this embodiment, the inner diameter of the flow path 3 becomes smaller in the pressurized region 32 as it proceeds toward the tip side L1, and then becomes larger again as it proceeds toward the tip side L1. Therefore, the liquid that passes through the water passage 4 and rotates in the circumferential direction C can be pressurized and then depressurized, and fine bubbles can be generated in the liquid passing through the flow path 3.

[0050] According to the fine bubble generator 100 of this embodiment, the inner cylindrical portion 2 is formed to contain synthetic resin, so that the fine bubbles can be easily generated. The fine bubble generator 100 has a configuration that allows for stable fine bubble generation, so there is no need to use a highly rigid material such as metal. Processing using synthetic resin is easier than processing using metal. Therefore, the fine bubble generator 100 can generate fine bubbles easily and stably.

[0051] In the fine bubble generator 100 according to this embodiment, the liquid passing through the water passage hole 4 of the inner cylindrical portion 2 passes from the inside to the outside of the inner cylindrical portion 2. Therefore, the liquid passing through the water passage hole 4 advances toward the tip side L1 while rotating in the circumferential direction C between the inner surface of the outer cylindrical portion 1 and the outer surface 21s of the inner cylindrical portion 2. At this time, the space between the inner surface of the outer cylindrical portion 1 and the outer surface 21s of the inner cylindrical portion 2 is formed in an annular shape, allowing the liquid to stably rotate in the circumferential direction C, and fine bubbles are stably generated in the pressurized region 32. The space between the inner surface of the outer cylindrical portion 1 and the outer surface 21s of the inner cylindrical portion 2 is formed by placing the inner cylindrical portion 2 in the inner cylindrical placement region 31, resulting in a simple configuration. In other words, fine bubbles can be stably generated without a complex configuration. Therefore, the fine bubble generator 100 can be easily attached to existing water pipes, shower heads, etc., while still being able to stably generate fine bubbles.

[0052] In the fine bubble generator 100 according to this embodiment, when the inner cylinder part 2 is arranged in the inner cylinder arrangement area 31, the shape of the internal space of the first tapered part 32a is a truncated cone. Therefore, the liquid can proceed to the tip side L1 while stably rotating in the circumferential direction C, and fine bubbles are stably generated in the second tapered part 32c. In other words, fine bubbles can be stably generated without a complex configuration. Therefore, the fine bubble generator 100 can be easily attached to existing water pipes, shower heads, etc., and can stably generate fine bubbles.

[0053] (Variation) Next, an inner cylindrical portion 2B according to a modified example will be described with reference to FIG.

[0054] FIG. 6 is a side view showing an inner cylindrical portion 2B according to a modified example. The inner cylindrical portion 2B is a modified example of the inner cylindrical portion 2. The inner cylindrical portion 2B differs from the inner cylindrical portion 2 in that it has a plurality of protrusions 23.

[0055] As shown in FIG. 6 , the inner cylinder portion 2B has an inner cylinder main body portion 21, a flange portion 22, and a plurality of protrusions 23. The plurality of protrusions 23 are members that protrude in the radial direction R from the outer surface 21s of the side wall portion 21a. The plurality of protrusions 23 are formed at equal intervals in the longitudinal direction L and the circumferential direction C. The plurality of protrusions 23 are formed to be approximately equal in size. The plurality of protrusions 23 are formed to be approximately equal in shape. The plurality of protrusions 23 are formed to be approximately rotationally symmetrical when viewed from the longitudinal direction L. The plurality of protrusions 23 are formed in three rows in the longitudinal direction L. The plurality of protrusions 23 are formed in eight rows in the circumferential direction C. That is, 24 protrusions 23 are formed.

[0056] The plurality of protrusions 23 are formed of a material containing synthetic resin, such as polyvinyl chloride. The inner cylinder main body 21 and the plurality of protrusions 23 are integrally formed.

[0057] Like the inner cylindrical portion 2, the inner cylindrical portion 2B is disposed in the inner cylindrical portion arrangement region 31 of the outer cylindrical portion 1 when in use. Liquid passing through the water passage hole 4 of the inner cylindrical portion 2B collides with the multiple protrusions 23 in the space between the inner surface of the outer cylindrical portion 1 and the outer surface 21s of the inner cylindrical portion 2B. Specifically, the liquid rotates in the circumferential direction C and advances toward the tip side L1 while colliding with the multiple protrusions 23. At this time, the gas contained in the liquid is sheared. Since the total number of bubbles contained in the liquid before passing through the pressurized region 32 increases, the total number of fine bubbles contained in the liquid after passing through the pressurized region 32 increases. Therefore, by using the inner cylindrical portion 2B, the total number of fine bubbles generated increases.

[0058] The configuration of the multiple protrusions 23 formed on the inner cylindrical portion 2B is not limited. The multiple protrusions 23 may be formed, for example, in two rows in the longitudinal direction L. The material of the protrusions 23 is also not limited. The protrusions 23 may be formed, for example, from a material containing metal.

[0059] In the fine bubble generator 100, the multiple water passage holes 4 are formed in a rectangular shape when viewed from the radial direction R, but the shape of the multiple water passage holes 4 is not limited. The multiple water passage holes 4 may have any shape that allows the liquid that passes through them to flow stably. The multiple water passage holes 4 may also be, for example, circular.

[0060] The fine bubble generator 100 is provided with eight water passage holes 4, but the number of water passage holes 4 is not limited. The multiple water passage holes 4 may be configured to allow a stable flow of liquid that passes through them. For example, six water passage holes 4 may be provided.

[0061] In the fine bubble generator 100, the flow path 3 is formed in a circular shape in the pressurizing region 32 when viewed from the longitudinal direction L, and the inner diameter of the flow path 3 decreases toward the tip end L1 in the pressurizing region 32, and then increases again toward the tip end L1, but the shape of the flow path 3 is not limited. The flow path 3 may have any shape that allows stable generation of fine bubbles.

[0062] The inner cylindrical portion 2 is formed from a material containing synthetic resin, but the material of the inner cylindrical portion 2 is not limited. The inner cylindrical portion 2 may be formed from a material that can stably generate fine bubbles. The inner cylindrical portion 2 may be formed from a material containing metal, for example. Specifically, the inner cylindrical portion 2 may be formed from a material containing stainless steel.

[0063] Although the embodiments of the present invention have been described in detail above with reference to the drawings, the specific configuration is not limited to this embodiment, and design modifications and the like are also included within the scope of the present invention. Furthermore, the components shown in the above-described embodiments and modifications can be configured by appropriately combining them. [Example]

[0064] The present invention will be explained in more detail below with reference to examples, but the present invention is not limited to the following examples.

[0065] (experiment) The fine bubbles generated when water was passed through a fine bubble generator were measured. The particle size and number of fine bubbles contained in the water that passed through the fine bubble generator were measured. The measurement was carried out 10 times and the average value was calculated.

[0066] The flow rate of water flowing through the fine bubble generator was approximately 24.2 L / min. The dynamic water pressure of the water flowing through the fine bubble generator was approximately 0.14 MPa. The static water pressure of the water flowing through the fine bubble generator was approximately 0.93 MPa. The water temperature of the water flowing through the fine bubble generator was approximately 22°C. Ultrapure water was used as the water flowing through the fine bubble generator. The water used for the measurements contained approximately 552,000 fine bubbles / mL. Therefore, the number of fine bubbles generated by the fine bubble generator was determined by subtracting 552,000 from the number of fine bubble particles contained in the water that passed through the fine bubble generator.

[0067] Example 1, Example 2, Comparative Example 1, and Comparative Example 2 have been described. Example 1 is a fine bubble generator 100 using an inner cylindrical part 2. Example 2 is a fine bubble generator 100 using an inner cylindrical part 2B. Comparative Example 1 is a fine bubble generator in which an inner cylindrical part with a circular water passage hole is arranged in the inner cylindrical arrangement area 31 of the outer cylindrical part 1. Comparative Example 2 is an existing fine bubble generator.

[0068] Fig. 7 is a diagram showing the measurement results of the particle diameters of the fan bubbles generated by Example 1, Example 2, Comparative Example 1, and Comparative Example 2. Fig. 8 is a diagram showing the measurement results of the particle counts of the fan bubbles generated by Example 1, Example 2, Comparative Example 1, and Comparative Example 2.

[0069] According to the results shown in Figure 7, the particle diameter of the bubbles contained in Examples 1 and 2 was less than 100 μm, confirming that fine bubbles were generated. Furthermore, according to the results shown in Figure 7, the particle diameter of the bubbles contained in Examples 1 and 2 was less than 1 μm, confirming that ultrafine bubbles were generated. Ultrafine bubbles are fine bubbles with a particle diameter of less than 1 μm, and are bubbles that do not rise to the surface of the liquid for several weeks to several months.

[0070] According to the results shown in Fig. 8, the number of fine bubbles generated by Example 1 is greater than the number of fine bubbles generated by Comparative Example 1 and Comparative Example 2. In other words, by using the fine bubble generator 100, fine bubbles can be generated stably.

[0071] Moreover, according to the results shown in Fig. 8, the number of fine bubbles generated by Example 2 is greater than the number of fine bubbles generated by Comparative Example 1 and Comparative Example 2. In particular, looking at the sixth measurement, the number of particles measured is 3.75 times or more the average number of particles measured in Comparative Example 1. In other words, by using the fine bubble generator 100 using the inner cylindrical portion 2B, a large amount of fine bubbles can be generated. [Explanation of symbols]

[0072] 100 Fine Bubble Generator 1. Outer cylinder 2 Inner cylinder 2B Inner cylinder part 21 Inner cylinder main body 21a Side wall part 21b Bottom wall 21s outer surface 21t inner surface 22 Flange 23 Protrusion 3 Flow path 31 Inner cylinder arrangement area 32 Pressure Area 32a First tapered section 32b Reduced diameter part 32c Second tapered section 33 Flange locking part 4 Water vent D1 First angle D2 second angle D3 Third Angle V1 Virtual Line L Longitudinal direction L1 Tip side L2 proximal side R Radial direction C circumferential direction

Claims

1. A fine bubble generator capable of generating fine bubbles from gas dissolved in liquid, an outer cylindrical portion having a flow path formed therein through which the liquid flows in a longitudinal direction from a base end to a tip end; an inner cylinder portion formed in a cylindrical shape and disposed in the flow path; Equipped with The flow path is an inner cylinder arrangement region formed in a cylindrical shape and in which the inner cylinder portion is arranged; a pressurizing region that is located distal to the inner cylinder arrangement region and applies pressure to the liquid; and the inner cylindrical portion has, in a side wall portion, a plurality of water passage holes through which the liquid passes in a direction inclined by a first angle with respect to a radial direction as viewed from the longitudinal direction, the first angle is between 1 degree and 85 degrees; The flow path is formed in a circular shape when viewed from the longitudinal direction in the pressurized region, In the pressurized region, the flow path has an inner diameter that decreases as the flow path advances toward the tip end, and then the inner diameter increases again as the flow path advances toward the tip end. Fine bubble generator.

2. The side wall portion has an outer surface and an inner surface that forms the water passage hole, the inner surface is inclined at a second angle relative to the outer surface when viewed in the longitudinal direction; the second angle is between 5 degrees and 89 degrees; The fine bubble generator according to claim 1.

3. The plurality of water passage holes are formed in a rectangular shape when viewed from the radial direction. The fine bubble generator according to claim 1 or 2.

4. The number of the water passage holes is eight. The fine bubble generator according to claim 1 or 2.

5. The inner cylindrical portion is formed containing a synthetic resin. The fine bubble generator according to claim 1 or 2.

6. The inner cylindrical portion has a plurality of protrusions protruding in the radial direction from an outer surface of the side wall portion. The fine bubble generator according to claim 1 or 2.

7. Attached to the water pipe, The fine bubble generator according to claim 1 or 2.

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