JP2024055861A - Fine bubble generation device and watering device - Google Patents

Abstract

To provide a new fine bubble generation device which can generate fine bubbles simply and effectively, and to provide a watering device.SOLUTION: A fine bubble generation device has at least a load generation part and a turbulent flow generation part F. The load generation part comprises: a diameter reduction passage B; and a small diameter passage C which is continuous with the diameter reduction passage B. The turbulent flow generation part F has a turbulent flow generation structure 7 where a liquid current flowing in a passage comprising a diameter expanding passage D which is continuous with the small diameter passage C and a large diameter passage E which is continuous with the diameter expanding passage D collides. The above object is achieved by the fine bubble generation device. The turbulent flow generation structure 7 comprises: a recessed part 7a which is provided in a circular shape in a downstream direction Y along an inner peripheral surface 6 of the large diameter passage E and with which liquid 18 collides to be bounced back, a protruding part 7b which is provided in a circular shape at a center side of the large diameter passage E and partitions the recessed part 7a; and an outlet passage 7c which is provided at a center side of the protruding part 7b and causes turbulent flow liquid 19 bounced back to flow in the downstream direction Y.SELECTED DRAWING: Figure 3

Description

The present invention relates to a microbubble generating device that generates microbubbles in liquid and a water sprinkler equipped with the same.

Liquids containing tiny (also called "micro") bubbles are expected to be used in a variety of industrial fields, and in recent years, various methods for generating microscopic bubbles have been proposed. Among the bubbles generated, those with a size of 1 to 100 μm are called microbubbles.

For example, Patent Document 1 proposes a microbubble water generator as a means for generating microbubbles, which can be easily attached to household appliances such as shower heads and washing machines by directly connecting to a tap water supply pipe. This microbubble water generator is connected to the water supply end of a shower hose at the first cylindrical part of the main body case, and to the water intake end of the shower head at the second cylindrical part. A water intake plate with multiple water intake holes is fitted into the first cylindrical part, and a nozzle arranged downstream of the water intake plate is composed of a first water passage whose diameter gradually decreases along the direction of flow of tap water passing through the water intake plate, and a second water passage whose diameter gradually increases along the direction of flow of tap water, communicating with the outlet side of the first water passage. The water intake hole has a central axis from the inlet side to the outlet side that is inclined with respect to the central axis of the water intake plate.

Patent Document 2 proposes a bubble generating device that can generate a large amount of high-density bubbles with smaller diameters, for example, less than 1 μm, in a short time without requiring a high pump discharge pressure. This bubble generating device includes a metal capillary through which water passes, and a pump that pumps water containing gas components into the metal capillary. Inside the metal capillary, a throttle section is provided in which the water passage is narrower than the front and rear of the water flow direction. The throttle section has a rectangular cross section perpendicular to the flow direction. The gas components contained in the water are dissolved in the water by pumping the water into the throttle section, bubbles are precipitated by a decrease in pressure at the throttle section, turbulence is generated in the water at the throttle section, and the bubbles in the water are crushed by the shear force of the turbulence, and the bubbles are crushed by shock waves caused by transonic flow in the water that exits the throttle section.

Patent Document 3 proposes a liquid treatment device that can perform gas dissolution treatment using a liquid treatment nozzle with a structure that uses a screw member to perform cavitation treatment much more efficiently than before, and can generate sufficient cavitation even when using a liquid to be treated that is deficient in dissolved gas. This liquid treatment device is provided with a gas-liquid mixer having a spiral flow path upstream of the liquid treatment nozzle. As a result, the mixed phase flow is caused to flow through the spiral flow path of the gas-liquid mixer, and the centrifugal force of the forced spiral flow causes the gas phase and liquid phase to be stirred and mixed, so that the gas phase is supplied to the screw member of the liquid treatment nozzle in a state where it is crushed into fine bubbles. This increases the contact efficiency between the gas-containing liquid and the screw root, and the gas dissolution efficiency can be improved.

JP 2019-25451 A WO2018/021182 JP 2020-189274 A

Liquids containing fine bubbles are expected to be used in a variety of fields, including cleaning, beauty, agriculture, and medicine. The object of the present invention is to provide a new fine bubble generator that can generate fine bubbles simply and effectively, and a watering device equipped with the same.

The microbubble generating device according to the present invention has at least a negative pressure generating section and a turbulent flow generating section, the negative pressure generating section being composed of a narrowing diameter flow path and a small diameter flow path connected to the narrowing diameter flow path, and the turbulent flow generating section having a turbulent flow generating structure with which liquid flows flowing through a flow path composed of an expanding diameter flow path connected to the small diameter flow path and a large diameter flow path connected to the expanding diameter flow path collide.

According to this invention, the load generating section is composed of a narrowing diameter flow path and a small diameter flow path connected to the narrowing diameter flow path, so that the flow rate increases and negative pressure is generated in the liquid, and bubbles can be precipitated from the dissolved air in the liquid by the cavitation effect. In addition, the turbulence generating section has a turbulence generating structure with which the liquid flow flowing through the flow path composed of an expanding diameter flow path connected to the small diameter flow path and a large diameter flow path connected to the expanding diameter flow path collides, so that the turbulence generating structure can make the liquid turbulent and pressurize it to break down the bubbles. As a result, fine bubbles can be generated simply and effectively.

In the micro-bubble generating device according to the present invention, the turbulence generating structure is composed of a circular recess along the inner circumferential surface of the large-diameter flow path in the downstream direction against which the liquid collides and bounces off, a circular protrusion on the central side of the large-diameter flow path that defines the recess, and an outlet flow path on the central side of the protrusion that directs the rebounded turbulent liquid in the downstream direction.

According to this invention, the turbulence generating structure is composed of the recess, the protrusion, and the outlet flow path, so that the liquid flowing along the inner circumferential surface of the large diameter flow path hits the recess and bounces off, generating turbulence. The generated turbulent liquid flows downstream in the flow path provided on the center side of the protrusion.

In the microbubble generating device according to the present invention, the flow path provided continuously to the center side of the large diameter flow path is a second load generating section, and the second load generating section is composed of a second small diameter flow path having the same or approximately the same diameter as the small diameter flow path.

According to this invention, the flow path provided continuously to the center side of the large diameter flow path is the second load generating section, and this second load generating section is composed of a second small diameter flow path having the same or approximately the same diameter as the small diameter flow path, so that negative pressure can be generated again in the liquid to cause bubbles to precipitate from the dissolved air in the liquid.

In the microbubble generating device according to the present invention, the liquid flowing through the load generating section is pressurized liquid. According to this invention, by flowing pressurized liquid through the load generating section, the cavitation effect in the load generating section can be further enhanced.

In the microbubble generator according to the present invention, the circular convex portion has one or more notches in the height direction. According to this invention, even if there is a solid object that restricts the flow of liquid in the large diameter flow path, the notches in the convex portion can prevent the flow path from being blocked by the solid object.

In the microbubble generating device according to the present invention, the large-diameter flow path may be provided with free solid objects that regulate the flow of liquid, or free solid objects whose components gradually decrease, as necessary. According to this invention, by arbitrarily placing free solid objects that regulate the flow of liquid in the large-diameter flow path, the flow of liquid can be regulated to be more in line with the inner circumferential surface of the large-diameter flow path. As a result, the liquid can be effectively struck against the recesses to generate a stable turbulent flow. In addition, by arbitrarily placing free solid objects whose components gradually decrease in the large-diameter flow path, the components can be contained in the microbubble-containing fluid. As a result, the microbubble-containing fluid can be utilized by using the components.

In the microbubble generating device according to the present invention, a second enlarged diameter flow path is connected to the second small diameter flow path.

In the micro-bubble generating device according to the present invention, an air intake is provided at the boundary between the small diameter flow path and the expanded diameter flow path, or at the end of the small diameter flow path on the expanded diameter flow path side. According to this invention, since the air intake is provided at the end of the small diameter flow path on the expanded diameter flow path side or in its vicinity (boundary), any gas can be introduced into the flow path from the air intake depending on the application. As a result, functional water into which gas has been introduced can be obtained, and effects according to the type of gas can be achieved.

The sprinkler device according to the present invention is characterized in that it is provided with the micro-bubble generating device according to the present invention in the grip section. According to this invention, since the micro-bubble generating device is provided in the grip section of the sprinkler device, micro-bubbles can be generated in the grip section, which has an appearance that is no different from that of a normal grip section. As a result, it is possible to provide a sprinkler device that is simple and capable of generating micro-bubbles effectively.

According to the present invention, the flow rate increases in the load generating section, generating negative pressure in the liquid, and the cavitation effect causes bubbles to precipitate from the dissolved air in the liquid. In addition, the liquid can be made turbulent and pressurized to break down the bubbles, so fine bubbles can be generated simply and effectively. As a result, liquids containing fine bubbles can be expected to be used in a variety of fields, including cleaning, beauty, agriculture, and medicine.

FIG. 1 is a perspective view showing an example of a fine bubble generating device according to the present invention. 2A and 2B are a front view and a side view, respectively, of the fine bubble generating device shown in FIG. 1 . FIG. 2 is a cross-sectional view of the micro-bubble generating device shown in FIG. 2 is a diagram showing the flow of liquid in the micro-bubble generating device shown in FIG. 1 . FIG. 4 is a configuration diagram of the second member as viewed from the flange portion side. FIG. 2 is a cross-sectional view showing another example of a fine bubble generating device according to the present invention. FIG. 1 is a cross-sectional view showing an example of a micro-bubble generating device in which a solid object is disposed in a turbulent flow generating channel. FIG. 1 is a cross-sectional view showing an example of a fine bubble generating device equipped with an air intake port. 1A is an external view of a grip portion of the sprinkler device according to an embodiment of the present invention, and FIG. 1B is a partial cross-sectional view of a micro-bubble generating device provided within the grip portion.

The microbubble generating device and water sprinkler device according to the present invention will be described with reference to the drawings. Note that the following embodiment is an example of the technical idea of the present invention, and the technical scope of the present invention is not limited to the following description and drawings, but includes inventions with similar technical ideas.

[Basic configuration]
1 to 5, the fine-bubble generator 1 according to the present invention has at least a load generating section and a turbulent flow generating section F, the load generating section being composed of a narrowing diameter flow path B and a small-diameter flow path C continuing to the narrowing diameter flow path B, and the turbulent flow generating section F has a turbulent flow generating structure 7 where liquid flows collide through a flow path composed of an enlarged diameter flow path D continuing to the small-diameter flow path C and a large-diameter flow path E continuing to the enlarged diameter flow path D. A water sprinkler 70 according to the present invention is equipped with the fine-bubble generator 1 described above in a grip section 71.

In this micro-bubble generator 1, the load generating section is composed of a narrowing flow path B and a small-diameter flow path C connected to the narrowing flow path B, so that the flow rate increases and negative pressure is generated in the liquid, and bubbles can be precipitated from the dissolved air in the liquid by the cavitation effect. In addition, the turbulence generating section F has a turbulence generating structure 7 where the liquid flowing through the flow path composed of an expanding flow path D connected to the small-diameter flow path C and a large-diameter flow path E connected to the expanding flow path D collides, so that the liquid can be made turbulent and pressurized to break down the bubbles. As a result, micro-bubbles can be generated simply and effectively. This micro-bubble generator 1 is connected to a pipe, and by flowing liquid through it, micro-bubbles are generated, and the liquid containing the micro-bubbles can be supplied downstream.

In the present invention, "bubbles" refers to spherical objects contained in a liquid, and is synonymous with "fine bubbles" as used in the present invention. These bubbles are microbubbles with a diameter of 1 to 100 μm, and the fine bubble generator 1 can be preferably used as a generator of microbubbles with a diameter of 1 to 100 μm.

Each component is explained in detail.

<Microbubble generator>
The fine-bubble generator 1 is not particularly limited as long as it has at least a load generating section and a turbulent flow generating section F, but examples of the structure include those shown in Fig. 1 to Fig. 5. In the illustrated fine-bubble generator 1, the turbulent flow generating section F is located in a large-diameter flow passage E at the center of the flow passage, and therefore, for ease of manufacture, it is preferable that the two members (the first member 10 and the second member 20) are connected in a separable manner at the large-diameter flow passage E. The connection is preferably performed by fixing the flange portion 13 provided on the outer periphery of the downstream opening 17 of the first member 10 and the flange portion 23 provided on the outer periphery of the upstream opening 27 of the second member 20 through the respective connecting holes 16, 26. In the illustrated example, the first member 10 and the second member 20 are divided into two in the flow direction Y and connected by a large diameter flow passage E in the center of the flow direction Y, but this is not limited to this. The first member 10 and the second member 20 may be split vertically so as to have a cross section parallel to the flow direction Y, and the two vertically split members may be connected together (not illustrated).

Below, we will explain the specific structural form of the micro-bubble generating device 1, in which two members (first member 10 and second member 20) are connected in a separable manner by a large-diameter flow path E, based on Figures 1 to 5, and each of the flow paths A to H realized by that structural form.

(First member)
As shown in Figures 1 to 3, the first member 10 has an opening 11 on the upstream side through which liquid flows in, and an opening 17 on the downstream side through which liquid flows out to the second member 20. A flow path is formed in the main body 12. As shown in Figure 3, the flow paths are arranged in succession from the upstream side in the following order: an inflow flow path A, a reduced diameter flow path B, a small diameter flow path (first small diameter flow path) C, and an expanded diameter flow path (first expanded diameter flow path) D. Note that, in the present invention, the device has at least a load generating section and a turbulent flow generating section F, and the negative pressure generating section can be preferably configured by the reduced diameter flow path B and the small diameter flow path C.

The upstream side of the first member 10 is provided with a connecting portion (e.g., a threaded portion) 15 for connecting to a piping member (not shown). The downstream side of the first member 10 is provided with a flange portion 13 for connecting to the second member 20. This flange portion 13 is provided on the outer periphery of the downstream opening 17, and can be fixed to the flange portion 23 provided on the outer periphery of the upstream opening 27 of the second member 20 by the respective connecting holes 16, 26. The shape of the connecting portion 15 is designed according to the type of piping member. When the piping member is in a screw-type form, it is preferable that the connecting portion 15 also has a screw-type form corresponding to the piping member, as shown in FIG. 1, etc. On the other hand, when the piping member is a hose or a polyvinyl chloride pipe, it is preferable that the connecting portion 15 also has a connecting structure corresponding to the piping member. The main body 12 of the first member 10 has a notch 14, which is not an essential component, but is provided so that the first member 10 can be fixed and screwed with a tool such as a wrench when, for example, screwing and fastening the first member 10 to the piping member (not shown).

(Second member)
As shown in Figs. 1 to 3, the second member 20 has an opening 27 on the upstream side into which the liquid flowing out from the first member 10 flows, and an opening 21 on the downstream side into which the liquid flows out. A flow path is formed in the main body 22. As shown in Fig. 3, the flow path is arranged in the following order from the upstream side: a turbulent flow-forming flow path (large diameter flow path) E, a turbulent flow generating section F, a small diameter flow path (second small diameter flow path) G, and an expanded diameter flow path (second expanded diameter flow path) H. Note that, in the present invention, at least a load generating section and a turbulent flow generating section F are provided, but the turbulent liquid 19 can be generated by a turbulent flow generating structure 7 in which liquid flows flowing through a flow path composed of an expanded diameter flow path (first expanded diameter flow path) D and a large diameter flow path E collide. In addition, the load generating section connected to the turbulent flow generating section F is preferably composed of a second small diameter flow path G and a second expanded diameter flow path H, but its installation is optional and is provided as necessary.

The second member 20 has a flange portion 23 on the upstream side for connecting to the first member 10. This flange portion 23 is provided on the outer periphery of the upstream opening 27, and can be fixed to the flange portion 13 provided on the outer periphery of the downstream opening 17 of the first member 10 by the respective connecting holes 16, 26. Figure 5 is a configuration diagram of the second member 20 viewed from the flange portion 23 side, and shows an example in which four connecting holes 26 are provided at equal intervals. Reference numeral 31 denotes a seal member installation portion where a seal member is installed, and when connecting the two flange portions 13, 23, the seal member is placed in the seal member installation portion 31.

The downstream side of the second member 20 is provided with a connecting portion (e.g., a threaded portion) 25 for connecting to a piping member (not shown). The shape of this connecting portion 25 is designed according to the type of piping member. When the piping member is in a screw-type form, as shown in FIG. 1, etc., it is preferable that the connecting portion 25 also has a screw-type form corresponding to the piping member. On the other hand, when the piping member is a hose or a polyvinyl chloride pipe, it is preferable that the connecting portion 25 also has a connection structure corresponding to the piping member. The main body 22 of the second member 20 is provided with a notch 24. Although this notch 24 is not an essential component, it is provided for fixing and screwing the second member 20 with a tool such as a spanner when, for example, screwing and fastening with the above-mentioned piping member (not shown).

(Flow path and liquid flow)
3 is configured in the following order from the upstream side toward the downstream direction Y: an inlet flow path A, a reduced diameter flow path B, a small diameter flow path (first small diameter flow path) C, an expanded diameter flow path (first expanded diameter flow path) D, a large diameter flow path E, a small diameter flow path (second small diameter flow path) G, and an expanded diameter flow path (second expanded diameter flow path) H. The turbulent flow generating section F has a turbulent flow generating structure 7 where liquid flows collide with each other through a flow path configured of the expanded diameter flow path D continuing from the small diameter flow path C and the large diameter flow path E continuing from the expanded diameter flow path D.

The inflow flow path A is the first flow path when liquid flows into this micro-bubble generator 1. The inner diameter of the inner circumferential surface 2 is the same throughout the entire length of flow path A. The inner diameter size is not particularly limited, but can be, for example, about 5 to 15 mm. The example shown is about 11 mm. Note that the inner diameters of the following flow paths are merely examples, and are not limited to the respective descriptions.

The narrowed flow path B is a flow path located continuously between the inlet flow path A and the first small diameter flow path C. The inner diameter of the inner circumferential surface 3 of the narrowed flow path B is continuously reduced toward the first small diameter flow path C in the downstream direction. The inner diameter size is not particularly limited, but it can be reduced to about one-third (e.g., about 4 mm) of the inner diameter on the inlet flow path A side (e.g., about 11 mm).

The first small diameter flow passage C is a flow passage located continuously between the narrow diameter flow passage B and the first wide diameter flow passage D. The inner diameter of the inner peripheral surface 4 is the same as the diameter of the downstream side of the narrow diameter flow passage B over the entire length of the flow passage C. The inner diameter size is not particularly limited, but can be, for example, about 4 mm as described above.

The first expanded diameter flow passage D is a flow passage located continuously between the first small diameter flow passage C and the large diameter flow passage E. The inner diameter of the inner peripheral surface 5 of the first expanded diameter flow passage D increases continuously toward the large diameter flow passage E in the downstream direction. The inner diameter size is not particularly limited, but it can be expanded to about three times (e.g., about 11 mm) the inner diameter of the first small diameter flow passage C (e.g., about 4 mm), and can be the same inner diameter as the inlet flow passage A, for example.

The large diameter flow passage E is a flow passage located continuously between the first expanded diameter flow passage D and the second small diameter flow passage G. The inner diameter of the inner peripheral surface 6 is the same as the diameter of the downstream side of the first expanded diameter flow passage D over the entire length of the flow passage E. The inner diameter size is not particularly limited, but can be, for example, about 11 mm as described above.

The second small diameter flow passage G is a flow passage located continuously between the large diameter flow passage E and the second wide diameter flow passage H. The role of this second small diameter flow passage G is the same as that of the first small diameter flow passage C described above. The inner diameter of the inner peripheral surface 8 is the same as the inner diameter of the outlet flow passage 7c provided downstream of the large diameter flow passage E over the entire length of the flow passage G. The inner diameter size is not particularly limited, but can be, for example, about 4 mm, the same as that of the first small diameter flow passage C.

The second expanded diameter flow passage H is a flow passage located next to the second small diameter flow passage G. The inner diameter of the inner peripheral surface 9 of the second expanded diameter flow passage H increases continuously in the downstream direction. The inner diameter size is not particularly limited, but the inner diameter can be expanded to about 3 to 4 times (e.g., about 11 to 17 mm) the inner diameter of the second small diameter flow passage G (e.g., about 4 mm).

The liquid flows f1 to f9 of the liquid 18 in each of these flow paths are shown in FIG. 4. As shown in FIG. 4, the liquid flow f1 in the inlet flow path A becomes the liquid flow f2 toward the center in the reduced diameter flow path B, and becomes the liquid flow f3 that moves straight downstream in the first small diameter flow path C. Then, in the first expanded diameter flow path D, it becomes the liquid flow f5 that moves straight and the liquid flow f4 that moves along the expanded inner circumferential surface 5. The liquid flow f4 that moves along the expanded inner circumferential surface 5 moves along the inner circumferential surface 6 of the large diameter flow path E, and the liquid flow f6 that hits the recess 7a that constitutes the turbulence generating structure 7 and becomes the turbulent flow 19 becomes the liquid flow f7 that flows out of the outlet flow path 7c. Then, the liquid flow f8 that flows through the second small diameter flow path G becomes the liquid flow f9 in the second expanded diameter flow path H and flows out of the opening 21.

<Air bubble precipitation>
The load generating section is composed of a reduced diameter flow path B and a small diameter flow path C that is continuous with the reduced diameter flow path B. Because the load generating section is composed of a reduced diameter flow path B and a small diameter flow path C that is continuous with the reduced diameter flow path B, the flow rate increases to generate negative pressure in the liquid, and the cavitation effect causes bubbles to precipitate from the dissolved air in the liquid.

It is preferable that the liquid flowing into the load generating section is a pressurized liquid. Because bubbles are unlikely to be generated at a pressure of 0.15 MPa or less and are likely to be generated at a pressure of 0.15 MPa or more, it is preferable that the pressure is 0.15 MPa or more. There is no particular upper limit, but since the number of bubbles increases as the pressure increases, it is preferable that the pressure is high. The upper limit can be set to 5.0 MPa because of the simple structure that can withstand pressure and durability and can withstand the allowable pressure of a power sprayer that can be easily connected and used. By flowing liquid with a pressure in the range of 0.15 to 5 MPa into the load generating section, the flow rate increases, the cavitation effect can be further enhanced, and bubbles can easily precipitate from the dissolved air.

<Occurrence of turbulence>
The turbulent flow generating section F has a turbulent flow generating structure 7 where liquid flows collide with each other through a flow path composed of an expanded diameter flow path D connected to a small diameter flow path C and a large diameter flow path E connected to the expanded diameter flow path D. Since the turbulent flow generating section F is composed of an expanded diameter flow path D connected to a small diameter flow path C and a large diameter flow path E connected to the expanded diameter flow path D, as shown in FIG. 4, the liquid flow f5 proceeds straight in the first expanded diameter flow path D and a liquid flow f4 proceeds along the expanded inner circumferential surface 5. The liquid flow f4 proceeds along the expanded inner circumferential surface 5 proceeds along the inner circumferential surface 6 of the large diameter flow path E and hits the recess 7a constituting the turbulent flow generating structure 7 to become a turbulent liquid 19. Furthermore, the turbulent liquid 19 is pressurized when passing through the small diameter outlet flow path 7c, so that the bubbles generated in the load generating section described above can be broken down. As a result, fine bubbles can be generated simply and effectively.

As shown in Figures 4 and 5, the turbulence generating structure 7 constituting the turbulence generating section F is composed of a recess 7a that is provided in a circular shape in the downstream direction Y along the inner circumferential surface 6 of the large-diameter flow path E and against which the liquid 18 collides and bounces off, a convex portion 7b that is provided in a circular shape on the center side of the large-diameter flow path E and divides the recess 7a, and an outlet flow path 7c that is provided on the center side of the convex portion 7b and flows the rebounded turbulent liquid 19 in the downstream direction Y. In this micro-bubble generating device 1, the turbulence generating structure 7 is composed of the recess 7a, the convex portion 7b, and the outlet flow path 7c, so that as described above, the liquid flowing along the inner circumferential surface 6 of the large-diameter flow path E collides with the recess 7a and bounces off, generating a turbulent liquid flow f6. The generated turbulent liquid 19 flows in the downstream direction Y through the outlet flow path 7c provided on the center side of the convex portion 7b.

As shown in FIG. 5, it is preferable that the circular convex portion 7b has one or more notches in the height direction. In the example of FIG. 5, two notches are provided. In this micro-bubble generator 1, even if there is a solid object (e.g., a loose solid object 41 described later) that restricts the flow of liquid in the large diameter flow path E, the notch 7d of the convex portion 7b can prevent the flow path from being blocked by the solid object. FIG. 6 shows another example of the micro-bubble generator 1 according to the present invention in which such a notch 7d is not provided. The notch 7d is not a required component and can be provided as needed, and the depth of the notch can also be selected as desired.

<Separation of Second Bubbles>
The flow path provided in continuation with the outlet flow path 7c on the center side of the large diameter flow path E is the second load generating section. The second load generating section is composed of a second small diameter flow path G having the same or approximately the same diameter as the small diameter flow path C. In this micro-bubble generating device 1, the flow path provided in continuation with the center side of the large diameter flow path E is the second load generating section that is connected to the turbulent flow generating section F, and the second load generating section is composed of the second small diameter flow path G having the same or approximately the same diameter as the first small diameter flow path C. Therefore, negative pressure can be generated again in the liquid to separate bubbles from the dissolved air in the liquid. The negative pressure generating section described above is referred to as the first negative pressure generating section, and may be described separately from the second negative pressure generating section.

It is preferable that the liquid flowing through this second negative pressure generating section is subjected to a pressure similar to that described above for the first negative pressure generating section. A detailed description of this will be omitted here.

<Free solids>
If necessary, free solid objects 41 that regulate the flow of the liquid may be placed in the large-diameter flow path E, or free solid objects 41 whose components gradually decrease may be placed in the large-diameter flow path E. In this micro-bubble generator 1, by arbitrarily placing free solid objects 41 that regulate the flow of the liquid in the large-diameter flow path E, the flow of the liquid can be regulated so as to be more aligned with the inner circumferential surface 6 of the large-diameter flow path E. As a result, the liquid can be effectively struck against the recesses 7a to generate a stable liquid flow f6 (turbulent flow).

In addition, by arbitrarily placing free solids 41, the components of which gradually decrease, in the large-diameter flow path E, the components can be contained in the microbubble-containing fluid. As a result, the microbubble-containing fluid can be utilized depending on the components. Such components can be selected according to the application of the microbubble generator 1; for example, when used in the cleaning-related field, free solids containing detergent components can be used; when used in the beauty-related field, free solids containing beauty components can be used; when used in the agricultural-related field, free solids containing nutritional components, pesticide components, pest control components, etc. can be used; and when used in the medical-related field, free solids containing medicinal components can be used.

The size and shape of the free solid matter 41 are not particularly limited, but it is preferable that the size and shape are such that they can enter the large-diameter flow path E and moderately regulate the flow without excessively impeding the liquid flow. The shape is also not particularly limited, and can be selected from spheres, cubes, irregular shapes, etc., as long as it does not impair the effects of the present invention.

The free solids 41 are not fixed in the large-diameter flow path E and exist in a free state, so they move around randomly. Therefore, depending on the pressure of the fluid, it is possible to make the vibration frequency of the liquid and the vibration frequency of the free solids 41 equal, causing resonance. When resonance occurs, more air bubbles can be precipitated than usual.

<Vaporization of air bubbles>
As described above, the micro-bubble generator 1 according to the present invention is characterized in that it can precipitate bubbles from the dissolved air in the liquid by the cavitation effect, but on the other hand, after the micro-bubble-containing fluid is discharged from the nozzle, the precipitated bubbles vaporize. In this way, the dissolved oxygen that is already present in the liquid precipitates and then vaporizes, thereby degassing the liquid. Degassed water has the advantage of improving permeability and providing antioxidant effects, so that liquids can be degassed and used according to the application and purpose.

<Air intake>
Fig. 8 is a cross-sectional view showing an example of a fine-bubble generator 1 equipped with an intake port 61. In the fine-bubble generator 1, the intake port 61 may be provided at the boundary between the small-diameter flow path C and the expanded-diameter flow path D, or may be provided at the end of the small-diameter flow path C on the expanded-diameter side as shown in Fig. 8. Since the intake port 61 is provided at the end of the small-diameter flow path C on the expanded-diameter flow path D side or in the vicinity thereof (boundary), any gas can be introduced into the flow path from the intake port 61 depending on the application. As a result, functional water into which gas has been introduced can be obtained, and an effect according to the type of gas can be achieved.

The diameter and length of the intake port 61 are not particularly limited. An intake pipe (not shown) is connected to the intake port 61 by fitting, welding, screwing, etc., and a gas supply pipe or gas supply tube is connected to the intake pipe to supply gas. The type of gas is selected according to the purpose and use, and examples of the gas include air, hydrogen, oxygen, nitrogen, carbon dioxide, etc., but other gases may also be used. In terms of uses, for example, various applications such as enhancing cleaning effects by adding any gas to the fine bubble-containing fluid can be expected. For example, it is expected that adding hydrogen will exert an antioxidant effect, adding oxygen will promote crop growth in the agricultural field, and adding nitrogen will maintain the freshness of fresh food.

In addition, in Figures 1 to 7, the first member 10 and the second member 20 are connected by flange portions 13, 23, but in the micro-bubble generator 1 shown in Figure 8, no flange portions are provided, and the members are connected by a first connecting portion (female thread portion) 51 and a second connecting portion (male thread portion) 52. This type of connection has the advantage that the size (particularly the outer diameter) of the micro-bubble generator 1 can be reduced, and can be similarly applied to the micro-bubble generators 1 in Figures 1 to 7. Note that the reference numeral 53 denotes an optional seal portion (e.g., a packing).

<Water sprinkler system>
Fig. 9 shows an example of a sprinkler device 70 according to the present invention. The sprinkler device 70 according to the present invention is provided with the fine-bubble generating device 1 according to the present invention in a grip portion 71. Fig. 9(A) is an external view of the grip portion 71 of the sprinkler device 70, and Fig. 9(B) is a partial cross-sectional view of the fine-bubble generating device 1 provided in the grip portion 71. By providing the fine-bubble generating device 1 in the grip portion 71 of the sprinkler device 70, fine bubbles can be generated in a grip portion having an appearance that is the same as that of a normal shape. As a result, a sprinkler device 70 that can generate fine bubbles simply and effectively can be provided.

9, reference numeral 72 denotes a water intake section that takes in water, and a hose (not shown) is inserted into the water intake section 72. Reference numeral 73 denotes a pipe section that sends water that has passed through the grip section 71 to a tip nozzle (not shown), and a watering nozzle (not shown) is connected to the tip of the pipe section 73. Reference numeral 74 denotes a water volume adjustment lever, and by moving the water volume adjustment lever 74 back and forth with a finger, the internal flow path is expanded or narrowed, thereby adjusting the amount of water. Note that the structural form of the grip section 71, the water intake section 72, the pipe 73, and the water volume adjustment lever 74 is not limited to the example of FIG. 9, and various structural forms can be used. Furthermore, the size and length of the micro-bubble generator 1 provided in the grip section 71 are not particularly limited, and can be designed arbitrarily depending on the size and length of the grip section 71.

According to the micro-bubble generator 1 described above, the flow rate increases in the load generating section, generating negative pressure in the liquid, and the cavitation effect causes bubbles to precipitate from the dissolved air in the liquid. In addition, the liquid can be made turbulent and pressurized to break down the bubbles, so that micro-bubbles can be generated simply and effectively. As a result, liquids containing micro-bubbles can be expected to be applied in various fields such as cleaning, beauty, agriculture, and medicine. For example, this micro-bubble generator 1 is expected to be preferably applied in cleaning-related fields, beauty-related fields, agriculture-related fields, and medicine-related fields. It is also expected to be used in industrial fields such as food-related fields, pharmaceutical-related fields, cosmetics-related fields, electronic devices such as solar cells, secondary batteries, and semiconductor devices, and functional materials.

LIST OF SYMBOLS 1 Micro-bubble generator 2 Inner circumferential surface of A flow path 3 Inner circumferential surface of B flow path 4 Inner circumferential surface of C flow path 5 Inner circumferential surface of D flow path 6 Inner circumferential surface of E flow path 7 Turbulence generating structure 7a Concave 7b Convex 7c Outlet flow path 7d Cut 8 Inner circumferential surface of G flow path 9 Inner circumferential surface of H flow path 10 First member 11 Opening 12 Main body 13 Flange 14 Cut 15 Connection 16 Connection hole 17 Opening 18 Liquid 19 Turbulent liquid 20 Second member 21 Opening 22 Main body 23 Flange 24 Cut 25 Connection 26 Connection hole 27 Opening 31 Seal member installation portion 41 Free solid 51 First connection (female thread)
52 Second connecting portion (male thread portion)
53 Sealing material 61 Air intake 70 Sprinkler device 71 Grip portion 72 Water intake portion 73 Pipe portion 74 Water volume adjustment lever A Inflow passage B Reducing diameter passage C Small diameter passage (first small diameter passage)
D. Enlarged diameter flow passage (first enlarged diameter flow passage)
E Large diameter flow passage (turbulent flow passage)
F: turbulent flow generating section G: small diameter flow passage (second small diameter flow passage)
H: Enlarged diameter flow passage (second enlarged diameter flow passage)
f1 to f9 Liquid flow in flow paths A to F Y Downstream (flow direction)

Claims (9)

A microbubble generator comprising at least a load generating section and a turbulent flow generating section, the load generating section being composed of a narrowing diameter flow path and a small diameter flow path connected to the narrowing diameter flow path, and the turbulent flow generating section being composed of an expanding diameter flow path connected to the small diameter flow path and a large diameter flow path connected to the expanding diameter flow path, and having a turbulent flow generating structure with which liquid flows flowing through the flow path collide. The microbubble generator according to claim 1, wherein the turbulence generating structure is composed of a concave portion that is circularly arranged in the downstream direction along the inner circumferential surface of the large-diameter flow path and against which the liquid collides and bounces off, a convex portion that is circularly arranged on the center side of the large-diameter flow path and defines the concave portion, and an outlet flow path that is arranged on the center side of the convex portion and flows the bounced turbulent liquid in the downstream direction. The microbubble generator according to claim 1 or 2, wherein the flow path provided continuously to the center side of the large diameter flow path is a second load generating section, and the second load generating section is composed of a second small diameter flow path having the same or approximately the same diameter as the small diameter flow path. The microbubble generator according to claim 1 or 2, wherein the liquid flowing through the load generating section is a pressurized liquid. The microbubble generator according to claim 2, wherein the circular convex portion has one or more notches in the height direction. The fine bubble generator according to claim 1 or 2, wherein the large diameter flow path is provided with free solid objects that regulate the flow of liquid, or free solid objects whose components gradually decrease. The microbubble generator according to claim 3, wherein a second enlarged diameter flow path is connected to the second small diameter flow path. The microbubble generator according to claim 1 or 2, wherein an air intake is provided at the boundary between the small diameter flow path and the expanded diameter flow path, or at the end of the small diameter flow path on the expanded diameter flow path side. A water sprinkler comprising a microbubble generating device according to any one of claims 1 to 8 in a grip portion.