JP2021122524A - Fine bubble generation nozzle body - Google Patents

Abstract

To provide a technology in which fine air bubbles can be contained in a large quantity into gas dissolution pressurized water being made to flow out into a flow-out place.SOLUTION: A fine bubble generation nozzle body includes: a decompression tube for making gas dissolution pressurized water pass from an upstream end toward a downstream end; an inlet port opened at the upstream end of the decompression tube; an inlet side opening provided at the downstream side from the inlet port; and an outlet side opening opened at the downstream end of the decompression tube. An opening area of the inlet side opening is smaller than the opening area of the inlet port, and the opening area of the outlet side opening is larger than the opening area of the inlet side opening. A speed reduction part for reducing a flow rate of the gas dissolution pressurized water passing through the inside of the decompression tube is formed at least in a portion of an inner circumferential wall of a first portion between the inlet port and the inlet side opening and an inner circumferential wall of a second portion at the downstream side from the inlet side opening and in the vicinity of the inlet side opening of the decompression tube.SELECTED DRAWING: Figure 2

Description

The technique disclosed herein relates to a fine bubble generating nozzle body.

Patent Document 1 discloses a fine bubble generating nozzle. The fine bubble generating nozzle includes a nozzle body which is a tubular member having fine ejection holes, and a nozzle cover attached to the tip of the nozzle body. The nozzle cover has a wall facing the ejection hole and an outflow hole finer than the ejection hole.

In the fine bubble generating nozzle of Patent Document 1, when gas-dissolved pressurized water in which a gas (for example, air, carbon dioxide, hydrogen, etc.) is dissolved in water is supplied to the nozzle body, the gas-dissolved pressurized water passes through the nozzle body. It is ejected from the ejection hole toward the wall. The gas-dissolved pressurized water ejected from the ejection hole collides with the wall and circumvents in the nozzle cover, and then flows out from the outflow hole to the outflow point (specifically, the bathtub). The gas-dissolved pressurized water is gradually depressurized to atmospheric pressure by passing through a fine ejection hole and a finer outflow hole. In the process of depressurizing the gas-dissolved pressurized water, the gas dissolved in the gas-dissolved pressurized water is precipitated and fine bubbles are generated. That is, in the fine bubble generation nozzle of Patent Document 1, the gas dissolution pressurized water is depressurized in the flow process of the gas dissolution pressurized water, so that the gas dissolution pressurized water flowing out to the outflow point (specifically, the bathtub) contains the fine bubbles. be able to.

JP-A-2007-167557

However, in the fine bubble generation nozzle of Patent Document 1, a situation occurs in which the amount of fine bubbles contained in the gas-dissolved pressurized water flowing out to the outflow portion is insufficient.

The present specification provides a technique capable of containing a large amount of fine bubbles in the gas-dissolved pressurized water flowing out to the outflow point.

The microbubble generating nozzle main body disclosed by the present specification includes a pressure reducing pipe for passing gas-dissolved pressurized water in which a gas is dissolved in water from an upstream end to a downstream end, and the upstream end. And an introduction port for introducing the gas-dissolving pressurized water into the decompression pipe from the outside, and the gas-dissolving pressurized water provided in the decompression pipe on the downstream side of the introduction port and introduced into the decompression pipe. It is provided with an inlet-side opening to be allowed to be used, and an outlet-side opening opened at the downstream-side end portion on the downstream side of the inlet-side opening. The opening area of the inlet side opening is smaller than the opening area of the introduction port, the opening area of the outlet side opening is larger than the opening area of the inlet side opening, and the pressure reducing pipe is the same as the introduction port. At least one of the inner peripheral wall of the first portion between the inlet-side openings and the inner peripheral wall of the second portion on the downstream side of the inlet-side opening and near the inlet-side opening. A deceleration portion for reducing the flow velocity of the gas-dissolved pressurized water passing through the decompression pipe is formed in the portion.

According to the above configuration, when the gas-dissolved pressurized water is introduced into the pressure reducing pipe from the outside, the flow velocity is increased by passing through the inlet side opening, and as a result, the pressure is reduced (Venturi effect). When the gas-dissolved pressurized water is depressurized, the gas dissolved in the gas-dissolved pressurized water is precipitated, and bubbles (also called bubble nuclei) that are the sources of fine bubbles are generated. After that, the gas-dissolved pressurized water discharged from the outlet-side opening of the pressure reducing pipe is increased in pressure while being circulated through a predetermined distribution route until it is discharged to the outflow point. When the pressure of the gas-dissolving pressurized water after the bubbles are precipitated by the reduced pressure is increased, the bubbles contained in the gas-dissolving pressurized water are split into fine bubbles.

Then, according to the above configuration, since the deceleration portion is formed, the flow direction of the gas-dissolved pressurized water in the vicinity of the deceleration portion becomes irregular. At this time, the flow is separated. As a result, the flow velocity in the pressure reducing pipe near the inner peripheral wall of the pressure reducing pipe becomes slower than the flow velocity near the radial center of the pressure reducing pipe. As the difference between the flow velocity near the inner peripheral wall and the flow velocity near the center becomes large, more bubble nuclei are generated when passing through the inlet side opening. As a result, by using the above-mentioned fine bubble generation nozzle main body, a large amount of fine bubbles based on the bubble nuclei can be generated.

The term "gas" as used herein includes any gas that is soluble in water, such as air, carbon dioxide, and hydrogen. Further, the "deceleration unit" includes an arbitrary configuration capable of causing flow separation by slowing the flow velocity of the gas-dissolved pressurized water passing in the vicinity. For example, any one of a step structure, a return structure, an uneven structure, a thorn (projection) structure, a dimple structure, and the like, or a combination thereof may be used.

The deceleration portion may be formed on the inner peripheral wall of at least the first portion.

The inner peripheral wall of the first portion (that is, the portion of the pressure reducing pipe between the inlet and the inlet side opening) is easier to process than the inner peripheral wall of the other portion. Therefore, according to this configuration, there is an advantage that the fine bubble generating nozzle main body having the deceleration portion can be manufactured relatively easily.

The perspective view of the fine bubble generation nozzle 10 of 1st Example. FIG. 2 is a cross-sectional view of the fine bubble generating nozzle 10 along the line II-II of FIG. The perspective view of the nozzle body 20 of 1st Example. An enlarged cross-sectional view of the vicinity of the inlet side opening 24 of the nozzle body 20 of the first embodiment. The perspective view of the holder part 40 of 1st Example. An enlarged cross-sectional view of the vicinity of the inlet side opening 24 of the nozzle body 20 of the second embodiment.

(First Example)
(Structure of Fine Bubble Generation Nozzle 10)
The fine bubble generation nozzle 10 of the first embodiment will be described with reference to FIGS. 1 to 5. The fine bubble generation nozzle 10 is a nozzle for supplying water containing fine bubbles to an outflow point such as a bathtub (not shown). As shown in FIG. 1, the fine bubble generating nozzle 10 includes a nozzle body 20 and a holder portion 40. In FIGS. 1 and 2, the nozzle body 20 is supported by the holder portion 40.

(Structure of nozzle body 20)
The configuration of the nozzle body 20 will be described with reference to FIGS. 1 to 4. In the following description, the X-axis direction in FIG. 2 may be referred to as a left-right direction, the Y-axis direction may be referred to as a vertical direction, and the Z-axis direction may be referred to as a front-back direction. As shown in FIG. 3, the nozzle body 20 includes a pressure reducing tube 22 and a flange portion 28.

As shown in FIGS. 1 to 4, the pressure reducing pipe 22 is a tubular member capable of reducing the pressure of air-dissolved pressurized water in which air is dissolved in water. As shown in FIG. 2, inside the pressure reducing pipe 22, a partition wall 25 for partitioning the inside of the pressure reducing pipe 22 into two pipe portions is provided. Two introduction ports 23 are opened at the upstream end 22a (the end on the negative direction side of the Z axis in the drawing) on the rear side of the pressure reducing pipe 22. Air-dissolved pressurized water is supplied to the introduction port 23 from a water supply means (not shown) for supplying air-dissolved pressurized water in which air is dissolved in water. The water supply means may be connected to the introduction port 23. Here, the air-dissolved pressurized water is a liquid that is a raw material of water containing fine bubbles supplied to the outflow point.

Of the pressure reducing pipe 22, 2 is located near the upstream end 22a and slightly forward of the two inlets 23 (that is, toward the downstream side, also referred to as the Z-axis in the positive direction). The entrance side openings 24 are opened. The opening area of the entrance side opening 24 is smaller than the opening area of the introduction port 23. In other words, the pressure reducing pipe 22 is reduced in diameter at the inlet side opening 24. The partition wall 25 divides the section from the upstream end 22a on the rear side of the pressure reducing pipe 22 (the end on the negative direction of the Z axis in the drawing) to the middle of the pressure reducing pipe 22 into two pipes. There is. Therefore, the downstream end 22b on the front side of the pressure reducing pipe 22 (the end on the positive direction side of the Z axis in the drawing) is not divided into two pipes by the partition wall 25. Only one outlet side opening 26 is opened in the downstream side end portion 22b. In this embodiment, the opening area of the outlet side opening 26 (that is, the area on the XY plane) is larger than the total area of the opening areas (that is, the area on the XY plane) of the two inlet side openings 24. In other words, the pressure reducing pipe 22 is expanded in diameter from the inlet side opening 24 toward the outlet side opening 26.

As shown in FIGS. 2 and 4, a speed reducing portion 30 is formed on the inner peripheral wall of the portion of the pressure reducing pipe 22 between the introduction port 23 and the inlet side opening 24. The speed reducing portion 30 of this embodiment has a stepped structure in which a step is formed on the inner peripheral wall between the introduction port 23 and the inlet side opening 24. As will be described in detail later, since the deceleration unit 30 is provided, the flow direction of the gas-dissolved pressurized water in the vicinity of the deceleration unit 30 becomes irregular, and as a result, the flow velocity in the pressure reducing pipe 22 near the inner peripheral wall has a diameter. It is slower than the flow velocity near the center of direction. As the difference in flow velocity between the vicinity of the inner peripheral wall and the vicinity of the center increases, more bubbles (also called bubble nuclei) that are the source of fine bubbles are generated.

As shown in FIGS. 1 to 3, the flange portion 28 is a disk-shaped member provided on the outer surface of the pressure reducing pipe 22 near the intermediate portion in the front-rear direction. As shown in FIG. 2, the outer diameter of the flange portion 28 is larger than the outer diameter of the pressure reducing pipe 22.

(Structure of holder portion 40)
Subsequently, the configuration of the holder portion 40 will be described with reference to FIGS. 1, 2, and 5. As is notably shown in FIG. 5, the holder portion 40 includes an outer cylindrical portion 42, an inner cylindrical portion 44, and two connecting portions 52. The outer cylindrical portion 42 and the two connecting portions 52 are continuously and integrally molded. The inner cylindrical portion 44 is formed so as to be housed inside the outer cylindrical portion 42.

The outer cylindrical portion 42 is a cylindrical member. As shown in FIGS. 2 and 5, a step 43 for accommodating the flange portion 28 of the nozzle body 20 described above is formed in the opening on the rear side.

Each of the two connecting portions 52 is formed so as to project outward from the outer peripheral surface of the outer cylindrical portion 42. The connecting portion 52 is provided with a screw hole B. The screw hole B of the connecting portion 52 is a screw hole for attaching the holder portion 40 to the bathtub connector (not shown). The bathtub connector is a device for attaching the fine bubble generating nozzle 10 to the bathtub. After inserting the nozzle body 20 into the holder portion 40, the mounting hole of the bathtub connector (not shown) and the screw hole B of the connecting portion 52 are aligned, and the screw member (not shown) is screwed into the screw hole B. By doing so, the fine bubble generating nozzle 10 and the bathtub connector are connected.

The inner cylindrical portion 44 is a tubular member formed inside the outer cylindrical portion 42. The inner cylindrical portion 44 is connected to the inner surface of the outer cylindrical portion 42 via four connecting portions 48. Four outlets 50 are formed by the gap between the inner cylindrical portion 44 and the outer cylindrical portion 42.

A disk portion 46 is formed at the front end portion of the inner cylindrical portion 44. The disk portion 46 closes the front end portion of the inner cylindrical portion 44. A protrusion 49 is formed along the Y axis at the center of the disk portion 46 in the XY plane. The protrusion 49 is a substantially wall-shaped protrusion member that protrudes rearward from the rear surface of the disk portion 46. As is notably shown in FIG. 5, the protruding portion 49 divides the rear surface of the disc portion 46 into left and right. As shown in FIG. 2, the vicinity of the tip of the protrusion 49 is relative to the direction from the rear to the front (that is, the flow direction of the air-dissolved pressurized water (see the arrow in FIG. 2)). It is slightly inclined. In other words, the vicinity of the tip of the protrusion 49 is formed so as to be rounded and pointed toward the rear.

(A state in which the nozzle body 20 is supported by the holder portion 40)
Subsequently, the positional relationship of each component in a state where the nozzle body 20 is supported by the holder portion 40 will be described. As shown in FIGS. 1 and 2, the nozzle body 20 is supported by the holder portion 40, so that the fine bubble generating nozzle 10 of this embodiment is formed. In this state, the downstream end portion 22b and the flange portion 28 of the pressure reducing pipe 22 of the nozzle body 20 are inserted into the holder portion 40. Specifically, the downstream end 22b of the pressure reducing pipe 22 is inserted into the inner cylindrical portion 44 (described later) of the holder portion 40. Further, the flange portion 28 is housed in a step 43 formed in the opening of the outer cylindrical portion 42. At this time, the front surface 28a of the flange portion 28 comes into contact with the step 43. In a state where the nozzle body 20 is supported by the holder portion 40, the upstream end portion 22a of the pressure reducing pipe 22 projects to the rear side of the holder portion 40.

As shown in FIG. 2, in a state where the nozzle body 20 is supported by the holder portion 40, the tip portion of the protruding portion 49 is arranged so as to face the downstream end portion 22b of the pressure reducing pipe 22. Furthermore, the tip portion of the protrusion 49 faces the front end portion of the partition wall 25. Then, in this state, the downstream end portion 22b of the pressure reducing pipe 22 and the disk portion 46 are arranged so as to face each other.

When the nozzle body 20 is supported by the holder portion 40, the nozzle body 20 and the holder portion 40 form a flow path space 62, a passage 64, a flow path space 66, and a passage 68. The flow path space 62, the passage 64, the flow path space 66, and the passage 68 are all spaces and passages for flowing the air-dissolved pressurized water in this order.

The flow path space 62 is formed between the downstream end portion 22b of the pressure reducing pipe 22 and the disk portion 46. The flow path area of the flow path space 62 is larger than the total area of the flow path areas of the outlet side opening 26 described above in any portion. More specifically, the area of the space between the extension line of the downstream end 22b and the protrusion 49 in front of the downstream end 22b of the pressure reducing pipe 22 on the XY plane, and the downstream end 22b and the circle. The area of the space between the plate portion 46 (more specifically, the axis extending vertically from the center of the disk portion 46 on the XY plane is the central axis, and the central axis and the downstream end portion 22b on the XY plane are the central axes. Of the virtual cylinders whose radius is the line connecting the outside of the cylinder, all of the outer surface portions in the range between the downstream end portion 22b and the disk portion 46) are the above-mentioned outlet side openings. It is larger than the total area of the flow path areas of 26.

The passage 64 is formed on the downstream side of the flow path space 62. The passage 64 is formed between the inner surface of the inner cylindrical portion 44 and the outer surface of the pressure reducing pipe 22 arranged in the inner cylindrical portion 44. Here, the flow path area of the passage 64 (that is, the area on the XY plane) is larger than the flow path area of any part of the above-mentioned flow path space 62.

The passage space 66 is formed on the downstream side of the passage 64. The flow path space 66 is formed between the rear end of the inner cylindrical portion 44 and the front surface 28a of the flange portion 28. The flow path space 66 is a space defined by the rear end of the inner cylindrical portion 44, the inner surface of the outer cylindrical portion 42, the outer surface of the pressure reducing pipe 22, and the front surface 28a of the flange portion 28. The flow path area of the flow path space 66 is larger than the flow path area of the above-mentioned passage 64 in any portion. More specifically, the area of the space between the rear end of the inner cylindrical portion 44 and the outer surface of the pressure reducing tube 22 on the XY plane, the area of the space between the rear end of the inner cylindrical portion 44 and the front surface 28a of the flange portion 28 ( More specifically, a virtual axis whose central axis is an axis extending vertically from the center of the disk portion 46 on the XY plane and whose radius is a line connecting the central axis on the XY plane and the outside of the inner cylindrical portion 44. Area of the outer surface portion of the range between the rear end of the inner cylindrical portion 44 and the front surface 28a) and the space between the rear end of the inner cylindrical portion 44 and the inner surface of the outer cylindrical portion 42. Both of the areas on the XY plane are larger than the flow path area of the passage 64 described above.

The passage 68 is formed on the downstream side of the flow path space 66. The passage 68 is a passage connecting the flow path space 66 and the outflow port 50. The passage 68 is formed by a gap between the inner surface of the outer cylindrical portion 42 and the outer surface of the inner cylindrical portion 44. Here, the flow path area of the passage 68 (that is, the area on the XY plane) is larger than the flow path area of any part of the above-mentioned flow path space 66.

(Flow of air-dissolved pressurized water)
With reference to FIGS. 2 and 4, the flow of air-dissolved pressurized water in the fine bubble generation nozzle 10 and the process of forming fine bubbles accordingly will be described. In FIGS. 2 and 4, the solid arrow indicates the flow path of the air-dissolved pressurized water.

As shown in FIGS. 2 and 4, first, air-dissolved pressurized water is introduced into the pressure reducing pipe 22 from the outside through the introduction port 23 of the nozzle body 20. The pressure of the air-dissolved pressurized water at this point is higher than the atmospheric pressure.

The air-dissolved pressurized water introduced from the introduction port 23 passes through the inlet side opening 24 having an opening area smaller than that of the introduction port 23. As a result, the flow velocity of the air-dissolved pressurized water increases, and the air-dissolved pressurized water is depressurized to a pressure lower than the atmospheric pressure (that is, decompression due to the Venturi effect). When the air-dissolved pressurized water is depressurized, the air dissolved in the air-dissolved pressurized water is precipitated and bubbles are generated.

However, in this embodiment, as described above, the reduction portion 30 having a stepped structure is formed on the inner peripheral wall of the portion of the pressure reducing pipe 22 between the introduction port 23 and the inlet side opening 24. Therefore, as shown by the corrugated arrow in FIG. 4, the air-dissolved pressurized water flowing in the vicinity of the deceleration unit 30 hits the deceleration unit 30 and flows in an irregular direction. At this time, the flow is separated. As a result, the flow velocity in the pressure reducing pipe 22 near the inner peripheral wall (see the wavy arrow in FIG. 4) is slower than the flow velocity near the center in the radial direction (see the straight arrow in FIG. 4). As a result, when the air-dissolved pressurized water passes through the inlet side opening 24, the difference in flow velocity between the vicinity of the inner peripheral wall and the vicinity of the center becomes large, and more bubbles (also referred to as bubble nuclei) that are the sources of fine bubbles are generated.

As described above, in the present embodiment, the pressure reducing pipe 22 is formed so that the flow path area increases from the inlet side opening 24 toward the outlet side opening 26. Therefore, the air-dissolved pressurized water in the pressure reducing pipe 22 that has been decompressed by passing through the inlet side opening 24 flows through the pressure reducing pipe 22 from the inlet side opening 24 toward the outlet side opening 26. Flow velocity decreases. As a result of the decrease in flow velocity, the pressure of the air-dissolved pressurized water is increased. When the pressure of the air-dissolved pressurized water is increased, some of the bubbles contained in the air-dissolved pressurized water are split into fine bubbles.

The air-dissolved pressurized water that has flowed through the pressure reducing pipe 22 toward the outlet-side opening 26 is discharged from the outlet-side opening 26 into the flow path space 62. As described above, the flow path area of the flow path space 62 is larger than the flow path area of the outlet side opening 26. Therefore, the flow velocity of the air-dissolved pressurized water discharged into the flow path space 62 through the outlet side opening 26 is further reduced. As a result, the pressure of the air-dissolved pressurized water is further increased. As a result, some of the bubbles contained in the air-dissolved pressurized water are further divided into fine bubbles.

Further, the air-dissolved pressurized water discharged into the flow path space 62 collides with the disk portion 46. At this time, a part of the air-dissolved pressurized water discharged into the flow path space 62 collides with the protruding portion 49 and then collides with the disc portion 46. As a result, the direction in which the air-dissolved pressurized water flows is changed, and the flow velocity of the air-dissolved pressurized water is further reduced. The pressure of the air-dissolved pressurized water is further increased, and as a result, some of the bubbles contained in the air-dissolved pressurized water are further divided into fine bubbles.

The air-dissolved pressurized water after colliding with the disk portion 46 passes through the passage 64 and is discharged into the flow path space 66. As described above, the flow path area of the passage 64 is larger than the flow path area of any part of the flow path space 62. The flow path area of the flow path space 66 is larger than the flow path area of the passage 64. Therefore, the flow velocity of the air-dissolved pressurized water that has passed through the passage 64 and is discharged into the flow path space 66 is further reduced. The pressure of the air-dissolved pressurized water is further increased, and as a result, some of the bubbles contained in the air-dissolved pressurized water are further divided into fine bubbles.

Then, the air-dissolved pressurized water discharged into the flow path space 66 collides with the front surface 28a of the collar portion 28. As a result, the direction in which the air-dissolved pressurized water flows is changed, and the flow velocity of the air-dissolved pressurized water is further reduced. The pressure of air-dissolved pressurized water is further increased. As a result, some of the bubbles contained in the air-dissolved pressurized water are further divided into fine bubbles.

The air-dissolved pressurized water after colliding with the front surface 28a of the flange portion 28 passes through the passage 68 and flows out from the outflow port 50 toward the outflow point (bathtub or the like). As described above, the flow path area of the passage 68 is larger than the flow path area of any part of the flow path space 66. The flow velocity of the air-dissolved pressurized water passing through the passage 68 is further reduced. Then, when the air-dissolved pressurized water flows out to the outflow location, the flow velocity of the air-dissolved pressurized water is further reduced, and the pressure of the air-dissolved pressurized water is further increased. As a result, some of the bubbles contained in the air-dissolved pressurized water are further divided into fine bubbles.

The configuration and operation of the fine bubble generating nozzle 10 of this embodiment have been described above. As described above, in the present embodiment, since the nozzle body 20 has the deceleration portion 30, the difference in flow velocity between the vicinity of the inner peripheral wall and the vicinity of the center when the air-dissolved pressurized water passes through the inlet side opening 24 becomes large, and fine bubbles More bubbles (cell nuclei) are generated (see FIG. 4). As a result, according to the fine bubble generation nozzle 10 of this embodiment, the air-dissolved pressurized water flowing out to the outflow portion can contain a large amount of fine bubbles.

Further, in the present embodiment, the speed reduction portion 30 is formed on the inner peripheral wall of the portion of the pressure reducing pipe 22 between the introduction port 23 and the inlet side opening 24. The inner peripheral wall of this portion (that is, the portion between the introduction port 23 and the entrance side opening 24) is easier to process than the inner peripheral wall of the other portion. Therefore, according to this configuration, there is an advantage that the nozzle body 20 having the deceleration unit 30 can be manufactured relatively easily.

The nozzle body 20 of this embodiment is an example of a “fine bubble generating nozzle body”. Of the pressure reducing pipe 22, the portion between the introduction port 23 and the inlet side opening 24 is an example of the “first portion”.

(Second Example)
With reference to FIG. 6, the fine bubble generating nozzle of the second embodiment will be described focusing on the points different from those of the first embodiment. This embodiment is one of the modifications of the first embodiment. In FIG. 6, elements having the same configuration as that of the first embodiment are represented by using the same reference numerals as those used in FIGS. 1 to 5. As shown in FIG. 6, in this embodiment, the shape of the deceleration portion 130 formed on the inner peripheral wall of the portion between the introduction port 23 and the inlet side opening 24 of the pressure reducing pipe 22 of the nozzle body 20 is the first. It is different from one embodiment.

The deceleration unit 130 of this embodiment has a so-called "return structure" in which the inner wall surface protrudes toward the upstream end 22a side (negative direction side of the Z axis in the drawing) of the pressure reducing pipe 22.

As shown by the wavy arrow in FIG. 6, in this embodiment as well, the air-dissolved pressurized water flowing in the vicinity of the deceleration unit 130 hits the deceleration unit 130 and flows in an irregular direction. As a result, the flow velocity in the pressure reducing pipe 22 near the inner peripheral wall (see the wavy arrow in FIG. 6) is slower than the flow velocity near the center in the radial direction (see the straight arrow in FIG. 6). As a result, when the air-dissolved pressurized water passes through the inlet side opening 24, the difference in flow velocity between the vicinity of the inner peripheral wall and the vicinity of the center becomes large, and more bubbles (also referred to as bubble nuclei) that are the sources of fine bubbles are generated. Therefore, even when the nozzle body 20 of the present embodiment is used, the air-dissolved pressurized water flowing out to the outflow portion can contain a large amount of fine bubbles as in the first embodiment.

Although the examples have been described in detail above, these are merely examples and do not limit the scope of claims. The techniques described in the claims include various modifications and modifications of the specific examples illustrated above.

(Modification 1) In each of the above embodiments, the speed reduction portions 30 and 130 are formed on the inner peripheral wall of the portion of the pressure reducing pipe 22 between the introduction port 23 and the inlet side opening 24 (FIG. 4, FIG. (See FIG. 6). Not limited to this, the speed reducing portion may be formed on the inner peripheral wall of the pressure reducing pipe 22 on the downstream side of the inlet side opening 24 and in the vicinity of the inlet side opening 24. Further, in still another example, the deceleration portion includes the inner peripheral wall of the portion of the pressure reducing pipe 22 between the introduction port 23 and the inlet side opening 24, and the inlet side which is downstream of the inlet side opening 24. It may be formed on both the inner peripheral wall of the portion near the opening 24.

(Modification 2) The deceleration unit is not limited to the step structure and the return structure disclosed in the first and second embodiments, and may cause flow separation by slowing the flow velocity of the gas-dissolved pressurized water passing in the vicinity. It may be formed in any configuration that can be used. For example, any one of a step structure, a return structure, an uneven structure, a thorn (projection) structure, a dimple structure, and the like, or a combination thereof may be used.

(Modification 3) In each of the above embodiments, the fine bubble generating nozzle receives the supply of air-dissolved pressurized water in which air is dissolved in water, precipitates the air in the air-dissolved pressurized water and changes it into fine bubbles, and the air is fine. Supply water containing air bubbles to the outflow point. Not limited to this, the fine bubble generation nozzle receives the supply of gas-dissolved pressurized water in which a gas other than air (for example, carbon dioxide gas, hydrogen, etc.) is dissolved in water, and precipitates the gas in the gas-dissolved pressurized water. It may be changed to fine bubbles and water containing the expected fine bubbles may be supplied to the outflow point. That is, the "gas" is not limited to air, and may be any gas such as carbon dioxide or hydrogen.

(Modification 4) The partition wall 25 of the pressure reducing pipe 22 may be omitted. That is, the pressure reducing pipe 22 does not have to be divided into two pipe portions.

The technical elements described herein or in the drawings exhibit their technical usefulness alone or in various combinations, and are not limited to the combinations described in the claims at the time of filing. In addition, the techniques illustrated in the present specification or drawings can achieve a plurality of purposes at the same time, and achieving one of the purposes itself has technical usefulness.

10: Fine bubble generation nozzle 20: Nozzle body 22: Pressure reducing pipe 22a: Upstream side end 22b: Downstream side end 23: Introducing port 24: Inlet side opening 25: Partition wall 26: Outlet side opening 28: Flange 28a: Front surface 30: Deceleration part 40: Holder part 42: Outer cylindrical part 43: Step 44: Inner cylindrical part 46: Disk part 48: Connection part 49: Protruding part 50: Outlet 52: Connecting part 62: Flow path space 64: Passage 66: Flow path space 68: Passage 130: Deceleration part B: Screw hole

Claims (2)

A decompression pipe that allows gas-dissolved pressurized water in which gas is dissolved in water to pass from the upstream end to the downstream end.
An introduction port that is opened at the upstream end and introduces the gas-dissolved pressurized water into the pressure reducing pipe from the outside.
An inlet-side opening provided on the downstream side of the decompression pipe and passing the gas-dissolved pressurized water introduced into the decompression pipe.
An outlet-side opening opened at the downstream end, which is downstream of the inlet-side opening,
Is equipped with
The opening area of the inlet side opening is smaller than the opening area of the introduction port.
The opening area of the outlet side opening is larger than the opening area of the entrance side opening.
Of the pressure reducing pipe, the inner peripheral wall of the first portion between the introduction port and the inlet side opening, and the second portion on the downstream side of the inlet side opening and near the inlet side opening. A deceleration portion for decelerating the flow velocity of the gas-dissolved pressurized water passing through the decompression pipe is formed on at least a part of the inner peripheral wall of the above.
Fine bubble generation nozzle body. The fine bubble generating nozzle body according to claim 1, wherein the deceleration portion is formed on the inner peripheral wall of at least the first portion.

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