JP7395152B2 - Fine bubble generating nozzle body - Google Patents

Description

The technology disclosed herein relates to a microbubble generating nozzle body.

Patent Document 1 discloses a fine bubble generating nozzle. This fine bubble generating nozzle includes a nozzle body which is a cylindrical 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 nozzle hole and an outlet hole that is finer than the nozzle hole.

In the fine bubble generating nozzle of Patent Document 1, when gas-dissolved pressurized water in which gas (e.g., 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 nozzle towards the wall. The gas-dissolved pressurized water ejected from the ejection hole collides with the wall and takes a detour within the nozzle cover, and then flows out from the outflow hole to an outflow location (specifically, a bathtub). The pressure of the gas-dissolved pressurized water is gradually reduced to atmospheric pressure by passing through fine ejection holes and even finer outflow holes. In the process of reducing the pressure of the gas-dissolved pressurized water, the gas dissolved in the gas-dissolved pressurized water precipitates, generating fine bubbles. That is, in the fine bubble generation nozzle of Patent Document 1, by reducing the pressure of the gas-dissolved pressurized water during the flow process of the gas-dissolved pressurized water, fine bubbles are included in the gas-dissolved pressurized water flowing out to the outflow location (specifically, the bathtub). be able to.

Japanese Patent Application Publication No. 2007-167557

However, with the microbubble generating nozzle of Patent Document 1, a situation occurs in which the amount of microbubble contained in the gas-dissolved pressurized water flowing out to the outflow location is insufficient.

This specification provides a technique that can contain a large amount of microbubbles in gas-dissolved pressurized water that flows out to an outflow location.

The fine bubble generating nozzle body disclosed in this specification includes a pressure reducing pipe through which gas-dissolved pressurized water in which gas is dissolved in water passes from an upstream end to a downstream end; an inlet opened to introduce the gas-dissolved pressurized water from the outside into the decompression pipe; and an inlet provided downstream of the inlet in the decompression pipe, through which the gas-dissolved pressurized water introduced into the decompression pipe passes. and an outlet opening that is opened at the downstream end that is downstream of the inlet opening. The opening area of the inlet side opening is smaller than the opening area of the inlet, and the opening area of the outlet side opening is larger than the opening area of the inlet side opening. A deceleration portion that decelerates the flow rate of the gas-dissolved pressurized water passing through the pressure reducing pipe is formed on the inner circumferential wall of the first portion between the inlet side openings. The speed reducer is configured to increase the difference in flow velocity between the gas-dissolved pressurized water flowing near the inner circumferential wall of the inlet-side opening and the gas-dissolved pressurized water flowing near the center of the inlet-side opening. The speed reducer is formed along the circumferential direction of the inner circumferential wall of the first portion, and has a multi-step structure in which the inner diameter decreases from the introduction port toward the inlet side opening.

According to the above configuration, when gas-dissolved pressurized water is introduced from the outside into the pressure reducing pipe, the flow rate increases 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 referred to as bubble nuclei), which are the source of fine bubbles, are generated. Thereafter, the gas-dissolved pressurized water discharged from the outlet opening of the pressure reducing pipe is increased in pressure while flowing through a predetermined distribution path until it is discharged to an outflow location. When the pressure of the gas-dissolved pressurized water after bubbles have been precipitated by reduced pressure is increased, the bubbles contained in the gas-dissolved pressurized water are split into fine bubbles.

According to the above configuration, since the deceleration part is formed, the flow direction of the gas-dissolved pressurized water near the deceleration part becomes irregular. At this time, flow separation occurs. As a result, within the pressure reducing pipe, the flow velocity 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 circumferential wall and the flow velocity near the center increases, more bubble nuclei are generated when passing through the inlet side opening. As a result, by using the above fine bubble generating nozzle body, a large amount of fine bubbles based on bubble nuclei can be generated.

The term "gas" used herein includes any gas that can be dissolved in water, such as air, carbon dioxide, and hydrogen. Further, the "deceleration section" includes any configuration capable of causing flow separation by slowing down the flow rate of gas-dissolved pressurized water passing nearby. For example, it may be a stepped structure, a barbed structure, an uneven structure, a thorn (protrusion) structure, a dimple structure, etc., or a combination thereof.

The inner circumferential 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 circumferential wall of other portions. Therefore, this configuration has the advantage that the fine bubble generating nozzle main body having the speed reduction section can be manufactured relatively easily.

FIG. 1 is a perspective view of a microbubble generating nozzle 10 according to a first embodiment. FIG. 2 is a cross-sectional view of the fine bubble generating nozzle 10 taken along line II-II in FIG. 1. FIG. 2 is a perspective view of a nozzle body 20 of the first embodiment. FIG. 3 is an enlarged sectional view of the vicinity of the inlet side opening 24 of the nozzle body 20 of the first embodiment. FIG. 4 is a perspective view of the holder section 40 of the first embodiment. FIG. 7 is an enlarged sectional view of the vicinity of the inlet side opening 24 of the nozzle body 20 of the second embodiment.

(First example)
(Configuration of fine bubble generating nozzle 10)
A fine bubble generating nozzle 10 according to a first embodiment will be described with reference to FIGS. 1 to 5. The fine bubble generating nozzle 10 is a nozzle for supplying water containing fine bubbles to an outflow location such as a bathtub (not shown). As shown in FIG. 1, the microbubble generating nozzle 10 includes a nozzle main body 20 and a holder part 40. In FIGS. 1 and 2, the nozzle body 20 is supported by a holder portion 40. As shown in FIG.

(Configuration 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 the left-right direction, the Y-axis direction as the up-down direction, and the Z-axis direction as the front-back direction. As shown in FIG. 3, the nozzle main body 20 includes a pressure reducing tube 22 and a collar 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, a dividing wall 25 is provided inside the pressure reducing tube 22 to partition the inside of the pressure reducing tube 22 into two pipe sections. Two introduction ports 23 are opened at the rear upstream end 22a of the pressure reducing pipe 22 (the end on the negative side of the Z-axis in the figure). Air-dissolved pressurized water is supplied to the inlet 23 from a water supply means (not shown) for supplying air-dissolved pressurized water in which air is dissolved in water. The introduction port 23 may be connected to the water supply means described above. Here, the air-dissolved pressurized water is a liquid that serves as a raw material for water containing microbubbles that is supplied to the outflow location.

In the pressure reducing pipe 22, in the vicinity of the upstream end 22a and slightly forward of the two inlets 23 (that is, downstream, also referred to as positive direction of the Z axis), there is a 2 Inlet side openings 24 are opened. The opening area of the inlet side opening 24 is smaller than the opening area of the introduction port 23. In other words, the pressure reducing pipe 22 has a reduced diameter at the inlet opening 24 . The partition wall 25 divides a section from the rear upstream end 22a of the pressure reducing pipe 22 (the end on the negative side of the Z axis in the figure) to the middle of the pressure reducing pipe 22 into two pipe parts. There is. Therefore, the front downstream end 22b (the end in the positive direction of the Z-axis in the figure) of the pressure reducing pipe 22 is not divided into two pipe parts by the partition wall 25. Only one outlet opening 26 is opened at the downstream end 22b. In this embodiment, the opening area of the outlet opening 26 (ie, the area on the XY plane) is larger than the total area of the opening areas of the two entrance openings 24 (ie, the area on the XY plane). 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 deceleration section 30 is formed on the inner circumferential wall of the pressure reducing pipe 22 at a portion between the inlet 23 and the inlet opening 24. As shown in FIGS. The speed reducer 30 of this embodiment has a stepped structure in which a step is formed on the inner circumferential wall between the inlet 23 and the inlet opening 24 . As will be explained in detail later, by providing the deceleration section 30, the flow direction of the gas-dissolved pressurized water near the deceleration section 30 becomes irregular, and as a result, the flow velocity near the inner circumferential wall within the pressure reducing pipe 22 becomes irregular. The flow velocity becomes slower than the flow velocity near the direction center. As the difference in flow velocity between the inner circumferential wall and the center increases, more bubbles (also referred to as bubble nuclei), which are the source of fine bubbles, are generated.

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

(Configuration of holder section 40)
Next, the configuration of the holder section 40 will be described with reference to FIGS. 1, 2, and 5. As clearly shown in FIG. 5, the holder part 40 includes an outer cylindrical part 42, an inner cylindrical part 44, and two connecting parts 52. The outer cylindrical portion 42 and the two connecting portions 52 are continuously integrally molded. The inner cylindrical portion 44 is formed and 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 28 of the nozzle body 20 described above is formed in the rear opening.

The two connecting portions 52 are each formed to protrude 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 a bathtub connector (not shown). Note that the bathtub connector is a device for attaching the microbubble generating nozzle 10 to the bathtub. After inserting the nozzle body 20 into the holder part 40, align the mounting hole (not shown) of the bathtub connector with the screw hole B of the connecting part 52, and screw the screw member (not shown) 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 cylindrical member formed and housed 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 outlet ports 50 are formed by the gaps between the inner cylindrical portion 44 and the outer cylindrical portion 42 .

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

(State where nozzle body 20 is supported by holder part 40)
Next, the positional relationship of each component when the nozzle body 20 is supported by the holder part 40 will be explained. As shown in FIGS. 1 and 2, the nozzle body 20 is supported by the holder portion 40, thereby forming the microbubble generating nozzle 10 of this embodiment. In this state, the downstream end portion 22b of the pressure reducing tube 22 and the collar portion 28 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 an inner cylindrical portion 44 (described later) of the holder portion 40. Furthermore, the flange portion 28 is housed within a step 43 formed at the opening of the outer cylindrical portion 42 . At this time, the front surface 28a of the collar portion 28 comes into contact with the step 43. When the nozzle body 20 is supported by the holder section 40 , the upstream end 22 a of the pressure reducing tube 22 projects toward the rear side of the holder section 40 .

As shown in FIG. 2, when the nozzle body 20 is supported by the holder portion 40, the tip portion of the protrusion portion 49 is disposed opposite to the downstream end portion 22b of the pressure reducing pipe 22. More specifically, the tip of the protrusion 49 faces the front end of the partition wall 25. In this state, the downstream end 22b of the pressure reducing pipe 22 and the disc part 46 are arranged to face each other.

By supporting the nozzle body 20 by the holder part 40, the nozzle body 20 and the holder part 40 form a passage space 62, a passage 64, a passage space 66, and a passage 68. The passage space 62, the passage 64, the passage space 66, and the passage 68 are all spaces and passages through which air-dissolved pressurized water flows in this order.

The flow path space 62 is formed between the downstream end 22b of the pressure reducing pipe 22 and the disc 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 above-mentioned outlet side opening 26 at any portion. Specifically, the area on the XY plane 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, and the area between the downstream end 22b and the circle The area of the space between the plate part 46 (more specifically, the center axis is the axis extending perpendicularly from the center of the disk part 46 on the XY plane, and the area between the central axis and the downstream end 22b on the XY plane Of the virtual cylinder whose radius is a line connecting the outside of It is larger than the total area of 26 flow path areas.

The passage 64 is formed on the downstream side of the flow path space 62. Passage 64 is formed between the inner surface of inner cylindrical portion 44 and the outer surface of pressure reducing tube 22 disposed within inner cylindrical portion 44 . Here, the flow area of the passage 64 (that is, the area on the XY plane) is larger than the flow area of any part of the flow path space 62 described above.

A flow path 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 collar 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 tube 22, and the front surface 28a of the collar 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 at any portion. Specifically, the area on the XY plane of the space between the rear end of the inner cylindrical part 44 and the outer surface of the pressure reducing tube 22, and the area of the space between the rear end of the inner cylindrical part 44 and the front surface 28a of the collar part 28 ( More specifically, a hypothetical system whose central axis is an axis extending perpendicularly from the center of the disk portion 46 on the XY plane, and whose radius is a line connecting the central axis and the outside of the inner cylindrical portion 44 on the XY plane. (area of the outer surface portion in 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 areas on the XY plane are larger than the flow area of the passage 64 described above.

Passage 68 is formed downstream of flow path space 66 . The passage 68 is a passage that connects the flow path space 66 and the outlet 50. Passage 68 is formed by a gap between the inner surface of outer cylindrical section 42 and the outer surface of inner cylindrical section 44 . Here, the passage area of the passage 68 (ie, the area on the XY plane) is larger than the passage area of any part of the passage space 66 described above.

(Flow of air-dissolved pressurized water)
With reference to FIGS. 2 and 4, the flow of air-dissolved pressurized water in the micro-bubble generating nozzle 10 and the process by which micro-bubbles are formed will be described. In FIGS. 2 and 4, solid arrows indicate flow paths of air-dissolved pressurized water.

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

The air-dissolved pressurized water introduced from the inlet 23 passes through the inlet side opening 24, which has a smaller opening area than the inlet 23. As a result, the flow rate of the air-dissolved pressurized water increases, and the pressure of the air-dissolved pressurized water is reduced to a pressure lower than atmospheric pressure (that is, the pressure is reduced by 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 the present embodiment, as described above, the deceleration part 30 having a stepped structure is formed on the inner circumferential wall of the portion of the pressure reducing pipe 22 between the inlet 23 and the inlet opening 24 . Therefore, as shown by the wave-shaped arrow in FIG. 4, the air-dissolved pressurized water flowing near the deceleration part 30 hits the deceleration part 30 and flows in an irregular direction. At this time, flow separation occurs. As a result, within the pressure reducing pipe 22, the flow velocity near the inner circumferential wall (see wavy arrows in FIG. 4) is slower than the flow velocity near the radial center (see straight arrows 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 circumferential wall and the vicinity of the center increases, and more bubbles (also referred to as bubble nuclei), which are the source of fine bubbles, are generated.

As described above, in this embodiment, the pressure reducing pipe 22 is formed such that the flow area increases from the inlet side opening 24 to the outlet side opening 26. Therefore, while the air-dissolved pressurized water in the pressure-reducing pipe 22 whose pressure has been reduced 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, the air-dissolved pressurized water flow rate decreases. As a result of the reduced flow rate, the air-dissolved pressurized water is increased in pressure. By increasing the pressure of the air-dissolved pressurized water, some of the air 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 opening 26 is discharged from the outlet 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 rate of the air-dissolved pressurized water discharged into the flow path space 62 through the outlet opening 26 is further reduced. This further increases the pressure of the air-dissolved pressurized water. As a result, some of the bubbles contained in the air-dissolved pressurized water are further split 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 portion of the air-dissolved pressurized water discharged into the flow path space 62 collides with the protrusion 49 and then collides with the disk portion 46 . As a result, the direction in which the air-dissolved pressurized water flows is changed, and the flow rate 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 split 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 passage space 66 . As described above, the flow area of the passage 64 is larger than the flow 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 rate of the air-dissolved pressurized water that passes 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 split 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 rate of the air-dissolved pressurized water is further reduced. Air-dissolved pressurized water is also further pressurized. As a result, some of the bubbles contained in the air-dissolved pressurized water are further split into fine bubbles.

The air-dissolved pressurized water after colliding with the front surface 28a of the collar portion 28 passes through the passage 68 and flows out from the outflow port 50 toward an outflow location (such as a bathtub). As described above, the flow area of the passage 68 is larger than the flow area of any part of the flow path space 66. The flow rate of air-dissolved pressurized water through passageway 68 is further reduced. Then, by flowing out the air-dissolved pressurized water to the outflow location, the flow rate 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 split into fine bubbles.

The structure and operation of the microbubble generating nozzle 10 of this embodiment have been described above. As described above, in this embodiment, the nozzle body 20 has the deceleration part 30, so that when the air-dissolved pressurized water passes through the inlet side opening 24, the difference in flow velocity between the inner circumferential wall and the center increases, causing fine bubbles to form. More bubbles (bubble nuclei), which are the source of , are generated (see FIG. 4). As a result, according to the microbubble generating nozzle 10 of this embodiment, the air-dissolved pressurized water flowing out to the outflow location can contain a large amount of microbubble.

Further, in this embodiment, the speed reducer 30 is formed on the inner circumferential wall of the pressure reducing pipe 22 at a portion between the inlet 23 and the inlet opening 24 . The inner circumferential wall of this portion (that is, the portion between the inlet 23 and the inlet opening 24) is easier to process than the inner circumferential wall of other portions. Therefore, this configuration has the advantage that the nozzle main body 20 having the deceleration part 30 can be manufactured relatively easily.

The nozzle body 20 of this embodiment is an example of a "fine bubble generating nozzle body". A portion of the pressure reducing pipe 22 between the inlet 23 and the inlet 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 differences from the first embodiment. This embodiment is one of the modifications of the first embodiment. In FIG. 6, elements having the same configuration as those in the first embodiment are represented using the same symbols as those used in FIGS. 1 to 5. As shown in FIG. 6, in this embodiment, the shape of the speed reducer 130 formed on the inner circumferential wall of the portion between the inlet port 23 and the inlet side opening 24 of the pressure reducing pipe 22 of the nozzle body 20 is This is different from the first embodiment.

The speed reducer 130 of this embodiment has a so-called "reverse structure" in which an inner wall surface protrudes toward the upstream end 22a of the pressure reducing pipe 22 (the negative side of the Z axis in the figure).

As shown by the wave-shaped arrow in FIG. 6, in this embodiment as well, the air-dissolved pressurized water flowing near the deceleration section 130 hits the deceleration section 130 and flows in an irregular direction. As a result, within the pressure reducing pipe 22, the flow velocity near the inner circumferential wall (see wavy arrows in FIG. 6) is slower than the flow velocity near the radial center (see straight arrows 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 circumferential wall and the vicinity of the center increases, and more bubbles (also referred to as bubble nuclei), which are the source of fine bubbles, are generated. Therefore, when the nozzle body 20 of this embodiment is used, as in the first embodiment, the air-dissolved pressurized water flowing out to the outflow location can contain a large amount of microbubbles.

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

(Modification 1) In each of the above-described embodiments, the deceleration parts 30 and 130 are formed on the inner circumferential wall of the portion of the pressure reducing pipe 22 between the inlet 23 and the inlet side opening 24 (see FIG. (See Figure 6). The present invention is not limited thereto, and the deceleration portion may be formed on the inner circumferential wall of a portion of the pressure reducing pipe 22 that is downstream of the inlet side opening 24 and near the inlet side opening 24 . In still another example, the speed reducer includes the inner circumferential wall of a portion of the pressure reducing pipe 22 between the inlet 23 and the inlet opening 24, and the inlet side downstream of the inlet opening 24. It may be formed both on the inner circumferential wall of the portion near the opening 24.

(Modification 2) The deceleration part is not limited to the stepped structure and the return structure disclosed in the first and second embodiments, and can cause flow separation by slowing down the flow rate of the gas-dissolved pressurized water passing nearby. It may be formed in any possible configuration. For example, it may be a stepped structure, a barbed structure, an uneven structure, a thorn (protrusion) structure, a dimple structure, etc., or a combination thereof.

(Modification 3) In each of the above embodiments, the micro-bubble generating nozzle receives a supply of air-dissolved pressurized water in which air is dissolved in water, precipitates the air in the air-dissolved pressurized water, and converts it into micro-bubbles. Supply bubbly water to the spill point. The fine bubble generating nozzle is not limited to this, and the fine bubble generating nozzle receives a supply of gas-dissolved pressurized water in which a gas other than air (for example, carbon dioxide, hydrogen, etc.) is dissolved in water, and precipitates the gas in the gas-dissolved pressurized water. The water may be changed to microbubbles and water containing the expected microbubbles may be supplied to the outflow location. 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 need to be divided into two pipe parts.

The technical elements described in this specification or the drawings exhibit technical utility alone or in various combinations, and are not limited to the combinations described in the claims as filed. Furthermore, the techniques illustrated in this specification or the drawings can achieve multiple objectives simultaneously, and achieving one of the objectives has technical utility in itself.

10: Fine bubble generation nozzle 20: Nozzle body 22: Decompression tube 22a: Upstream end 22b: Downstream end 23: Inlet 24: Inlet opening 25: Partition wall 26: Outlet opening 28: Flange 28a: Front surface 30: Reduction section 40: Holder section 42: Outer cylindrical section 43: Step 44: Inner cylindrical section 46: Disc section 48: Connecting section 49: Projecting section 50: Outlet 52: Connecting section 62: Channel space 64: Passage 66: Flow path space 68: Passage 130: Reduction part B: Screw hole

Claims (1)

a pressure reducing pipe that passes gas-dissolved pressurized water in which gas is dissolved in water from an upstream end to a downstream end;
an inlet opening at the upstream end and introducing the gas-dissolved pressurized water into the pressure reducing pipe from the outside;
an inlet side opening that is provided downstream of the introduction port of the pressure reduction pipe and allows the gas-dissolved pressurized water introduced into the pressure reduction pipe to pass;
an outlet side opening opened at the downstream end that is downstream of the inlet side opening;
It is equipped with
The opening area of the inlet side opening is smaller than the opening area of the inlet,
The opening area of the outlet side opening is larger than the opening area of the inlet side opening,
A deceleration part that reduces the flow rate of the gas-dissolved pressurized water passing through the pressure reduction pipe is formed on the inner circumferential wall of a first portion of the pressure reduction pipe between the introduction port and the inlet side opening,
The speed reducer is configured to increase a flow velocity difference between gas-dissolved pressurized water flowing near the inner peripheral wall of the inlet-side opening and gas-dissolved pressurized water flowing near the center of the inlet-side opening . ,
The speed reducer is formed along the circumferential direction of the inner circumferential wall of the first portion, and has a multi-step structure in which the inner diameter decreases from the inlet toward the inlet side opening.
Fine bubble generating nozzle body.

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