JP7329397B2 - Fine bubble generating nozzle body - Google Patents

Description

The technology disclosed in this specification relates to a fine bubble generating nozzle body.

Patent Literature 1 discloses a microbubble 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 ejection hole and an outflow hole that is finer than the ejection hole.

In the fine bubble generating nozzle of Patent Document 1, when gas-dissolved pressurized water in which 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 port toward the wall. The gas-dissolved pressurized water ejected from the ejection hole collides with the wall, detours within the nozzle cover, and then flows out from the outflow hole to an outflow location (specifically, a bathtub). The gas-dissolved pressurized water is gradually decompressed to atmospheric pressure by passing through fine jet holes and finer outflow holes. In the process of depressurizing the gas-dissolved pressurized water, the gas dissolved in the gas-dissolved pressurized water is precipitated to generate fine bubbles. That is, in the microbubble generating nozzle of Patent Document 1, the pressure of the gas-dissolved pressurized water is reduced in the flow process of the gas-dissolved pressurized water, so that the gas-dissolved pressurized water flowing out to the outflow location (specifically, the bathtub) contains microbubbles. be able to.

JP 2007-167557 A

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

The present specification provides a technique that allows a large amount of microbubbles to be included in the gas-dissolved pressurized water that flows out to the outflow location.

The fine bubble generating nozzle body disclosed by the present specification includes a decompression pipe for passing gas-dissolved pressurized water in which gas is dissolved in water from an upstream end to a downstream end, and the upstream end an inlet for introducing the gas-dissolved pressurized water into the decompression pipe from a water supply means for supplying the gas-dissolved pressurized water; an inlet-side opening through which the gas-dissolved pressurized water introduced into the inlet-side opening passes; and an outlet-side opening opened at the downstream end located downstream of the inlet-side opening. 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, and the inlet-side opening of the decompression tube is At least one communication hole communicating between the outer peripheral wall and the inner peripheral wall of the decompression tube is opened in a specific portion in the vicinity of the inlet side opening on the downstream side of the pressure reducing tube. The introduction port and the at least one communication hole are arranged in a water supply space into which the gas-dissolved pressurized water is supplied from the water supply means.

According to the above configuration, when the gas-dissolved pressurized water is introduced into the decompression tube from the outside, the flow rate increases by passing through the inlet side opening, resulting in decompression (Venturi effect). When the pressure of the gas-dissolved pressurized water is reduced, the gas dissolved in the gas-dissolved pressurized water is precipitated, and bubbles (also called bubble nuclei) that form fine bubbles are generated. After that, the gas-dissolved pressurized water discharged from the outlet side opening of the decompression pipe is increased in pressure while being circulated through a predetermined flow path until it flows out to the outflow point. When the pressure of the gas-dissolved pressurized water after bubbles are precipitated by depressurization is increased, the bubbles contained in the gas-dissolved pressurized water are split and become fine bubbles.

According to the above configuration, since at least one communication hole is opened in a specific portion of the decompression tube, a negative pressure is generated in the decompression tube by the Venturi effect associated with the gas-dissolved pressurized water passing through the inlet side opening. When this occurs, the negative pressure draws gas-dissolved pressurized water into the decompression tube from the outside through the communication hole. The gas-dissolved pressurized water drawn into the decompression tube through the communication hole collides with the flow of the gas-dissolved pressurized water near the inner peripheral wall of the decompression tube among the gas-dissolved pressurized water flowing in the decompression tube from the inlet side opening toward the outlet side opening. As a result, the flow velocity near the inner peripheral wall becomes slower than the flow velocity near the radial center. As the flow velocity difference between the vicinity of the inner peripheral wall and the vicinity of the center increases, more bubble nuclei are generated. As a result, it is possible to generate a large amount of microbubbles based on the bubble nuclei by using the fine bubble generating nozzle main body.

The term "gas" as used herein includes any gas that can be dissolved in water, such as air, carbon dioxide, and hydrogen.

A total opening area of the at least one communication hole may be smaller than an opening area of the inlet side opening.

According to this configuration, compared to the case where the total opening area of at least one communicating hole is equal to or larger than the opening area of the inlet side opening, the negative pressure generated in the pressure reducing tube causes the outside to pass through the communicating hole. As a result, gas-dissolved pressurized water is easily drawn into the decompression tube. That is, the negative pressure generated in the decompression tube can be effectively used.

The opening area of the decompression tube at the specific portion may be equal to or greater than the opening area of the inlet-side opening and within 110%.

According to this configuration, the opening area of the specific portion of the decompression tube where at least one communication hole is formed is within 110% of the opening area of the inlet side opening. That is, the communication hole is formed within a range in which the increase in the opening area of the decompression tube as viewed from the inlet side opening is within 10%. Since this range is mainly the range immediately after passing through the inlet side opening, a relatively large negative pressure is generated in the gas-dissolved pressurized water passing through this range. Therefore, according to the above configuration, the gas-dissolved pressurized water is easily drawn into the decompression tube from the outside through the communication hole. In other words, the negative pressure generated inside the pressure reducing tube can be made to work more effectively.

FIG. 2 is a perspective view of the microbubble generating nozzle 10. FIG. FIG. 2 is a cross-sectional view of the microbubble generating nozzle 10 taken along line II-II in FIG. 1; 3 is a perspective view of the nozzle body 20; FIG. 4 is an enlarged cross-sectional view of the vicinity of the inlet-side opening 24 of the nozzle body 20. FIG. 4 is a perspective view of the holder part 40. FIG.

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

(Structure of Nozzle Body 20)
The configuration of the nozzle body 20 will be described with reference to FIGS. 1 to 4. FIG. 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-rear direction. As shown in FIG. 3 , the nozzle body 20 includes a decompression tube 22 and a collar portion 28 .

As shown in FIGS. 1 to 4, the decompression pipe 22 is a tubular member capable of decompressing the air-dissolved pressurized water in which air is dissolved in water. As shown in FIG. 2, inside the decompression tube 22, a partition wall 25 is provided to partition the interior of the decompression tube 22 into two tube portions. Two introduction ports 23 are opened at the upstream end portion 22a on the rear side of the decompression tube 22 (the end portion on the negative direction side of the Z axis in the drawing). 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. In this embodiment, the rear side portion of the decompression tube 22 (that is, the rear side portion of the collar portion 28) including the introduction port 23 and the communication hole 30 (described later) is a water supply space to which water is supplied from the water supply means. (not shown). 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 vicinity of the upstream end 22a of the decompression tube 22 and slightly forward (that is, downstream, also referred to as the positive direction of the Z axis) of the two introduction ports 23, two A single inlet side opening 24 is 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 decompression tube 22 has a reduced diameter at the inlet-side opening 24 . The partition wall 25 divides the section from the rear upstream end 22a of the decompression tube 22 (the end on the negative direction side of the Z-axis in the drawing) to the middle of the decompression tube 22 into two pipe sections. there is Therefore, the front downstream end portion 22b of the decompression tube 22 (the end portion on the positive side of the Z axis in the drawing) is not divided into two pipe portions by the dividing wall 25 . Only one outlet side opening 26 is opened in the downstream end 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 of the two inlet side openings 24 (that is, the area on the XY plane). In other words, the decompression tube 22 expands in diameter from the inlet side opening 24 toward the outlet side opening 26 .

In particular, as shown in FIGS. 2 and 4, the portion of the decompression tube 22 that is downstream of each inlet-side opening 24 and immediately after passing through each inlet-side opening 24 (that is, the inlet-side opening 24). Communicating holes 30 for communicating between the outer peripheral wall and the inner peripheral wall of the decompression tube 22 are opened one by one in a nearby portion (hereinafter sometimes referred to as a “specific portion”). The opening area of each communication hole 30 is smaller than the opening area of each inlet-side opening 24 . Further, in this embodiment, the opening area of the decompression tube 22 at the portion where the communication hole 30 is formed (that is, the specific portion) is substantially equal to the opening area of the inlet side opening 24 . That is, in this embodiment, the communication hole 30 is formed within a range where there is almost no increase in opening area when viewed from the inlet side opening 24 .

As shown in FIGS. 2 and 3, the collar portion 28 is a disk-shaped member provided on the outer surface of the decompression 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 portion 40)
Next, the configuration of the holder portion 40 will be described with reference to FIGS. 1, 2, and 5. FIG. As clearly 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 formed. The inner cylindrical portion 44 is formed 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 is formed in the opening on the rear side to accommodate the flange 28 of the nozzle body 20 described above.

The two connecting portions 52 are formed to protrude outward from the outer peripheral surface of the outer cylindrical portion 42 . A screw hole B is provided in the connecting portion 52 . A screw hole B of the connecting portion 52 is a screw hole for attaching the holder portion 40 to a bathtub connector (not shown). 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, the mounting hole (not shown) of the bathtub connector and the screw hole B of the connecting part 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 cylindrical member that is accommodated 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 . A gap between the inner cylindrical portion 44 and the outer cylindrical portion 42 forms four outlets 50 .

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

(State in which the nozzle body 20 is supported by the holder portion 40)
Next, the positional relationship of each component when 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 to form the microbubble generating nozzle 10 of this embodiment. In this state, the downstream end 22 b of the decompression tube 22 and the flange 28 of the nozzle body 20 are inserted into the holder 40 . Specifically, the downstream end portion 22b of the decompression tube 22 is inserted into an inner cylindrical portion 44 (described later) of the holder portion 40 . Also, the collar portion 28 is accommodated within a step 43 formed in the opening of the outer cylindrical portion 42 . At this time, the front surface 28 a of the flange 28 abuts on the step 43 . When the nozzle body 20 is supported by the holder portion 40 , the upstream end portion 22 a of the decompression tube 22 protrudes rearward from the holder portion 40 .

As shown in FIG. 2 , when the nozzle body 20 is supported by the holder portion 40 , the tip portion of the projecting portion 49 is arranged to face the downstream end portion 22 b of the decompression tube 22 . Furthermore, the tip portion of the projecting portion 49 faces the front end portion of the partition wall 25 . In this state, the downstream end 22b of the decompression tube 22 and the disc portion 46 are arranged to face each other.

By supporting the nozzle body 20 on the holder portion 40 , a channel space 62 , a passage 64 , a channel space 66 and a passage 68 are formed by the nozzle body 20 and the holder portion 40 . The channel space 62, the passage 64, the channel space 66, and the passage 68 are spaces and passages for circulating the air-dissolved pressurized water in this order.

A channel space 62 is formed between the downstream end 22b of the decompression tube 22 and the disc portion 46 . The channel area of the channel space 62 is larger than the total area of the above-described outlet-side openings 26 at any portion. Specifically, in front of the downstream end 22b of the pressure reducing tube 22, the area on the XY plane of the space between the extension line of the downstream end 22b and the protrusion 49, and the downstream end 22b and the circle The area of the space between the plate portion 46 (more specifically, the axis extending perpendicularly from the center on the XY plane of the disk portion 46 is the central axis, and the above-mentioned central axis on the XY plane and the downstream end 22b of the virtual cylinder whose radius is the line connecting the outside of the outlet side opening larger than the total area of the 26 channel areas.

A passageway 64 is formed downstream of the channel space 62 . Passage 64 is formed between the inner surface of inner cylindrical portion 44 and the outer surface of vacuum tube 22 disposed within inner cylindrical portion 44 . Here, the channel area of the passage 64 (that is, the area on the XY plane) is larger than the channel area of any portion of the channel space 62 described above.

A channel space 66 is formed downstream of the passage 64 . A flow passage space 66 is formed between the rear end of the inner cylindrical portion 44 and the front surface 28 a of the collar portion 28 . The flow passage 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 decompression tube 22 , and the front surface 28 a of the collar portion 28 . The flow area of the flow space 66 is larger than the flow area of the passage 64 described above at any portion. Specifically, the area on the XY plane of the space between the rear end of the inner cylindrical portion 44 and the outer surface of the decompression tube 22, the area of the space between the rear end of the inner cylindrical portion 44 and the front surface 28a of the collar portion 28 ( More specifically, the center axis is an axis extending perpendicularly from the center of the disk portion 46 on the XY plane, and the radius is a line connecting the center 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 area on the XY plane is larger than the passage area of the passage 64 described above.

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

(Flow of air-dissolved pressurized water)
2 and 4, the flow of the air-dissolved pressurized water in the microbubble generating nozzle 10 and the accompanying process of forming microbubbles will be described. In FIGS. 2 and 4, solid arrows indicate 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 decompression pipe 22 from the outside through the inlet 23 of the nozzle body 20 . The pressure of the air-dissolved pressurized water at this point is greater 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 pressure of the air-dissolved pressurized water is reduced to a pressure lower than the atmospheric pressure (that is, decompression due to the Venturi effect). When the pressure of the air-dissolved pressurized water is reduced, the air dissolved in the air-dissolved pressurized water is precipitated, and air bubbles (also called bubble nuclei) that are the origin of fine air bubbles are generated.

In this embodiment, since the communication hole 30 is opened in the decompression tube 22, when a negative pressure is generated in the decompression tube 22 due to the Venturi effect associated with the passage of the air-dissolved pressurized water through the inlet side opening 24, , the air-dissolved pressurized water is drawn into the decompression tube 22 from the outside through the communication hole 30 by the negative pressure. As shown in FIG. 4, the air-dissolved pressurized water drawn into the decompression tube 22 through the communication hole 30 is part of the air-dissolved pressurized water that flows through the decompression tube 22 from the inlet side opening 24 toward the outlet side opening 26. It collides with the flow of air-dissolved pressurized water near the inner peripheral wall of the decompression pipe 22 . As a result, the flow velocity near the inner peripheral wall becomes slower than the flow velocity near the radial center. As the difference in flow velocity between the vicinity of the inner peripheral wall and the vicinity of the center increases, more bubble nuclei, which are sources of fine bubbles, are generated.

As described above, in this embodiment, the decompression tube 22 is formed so that the passage area increases from the inlet-side opening 24 toward the outlet-side opening 26 . Therefore, while the air-dissolved pressurized water in the decompression pipe 22 decompressed by passing through the entrance-side opening 24 flows through the decompression pipe 22 from the entrance-side opening 24 toward the exit-side opening 26, the air-dissolved pressurized water flow velocity decreases. As a result of the decrease in flow velocity, the pressure of the air-dissolved pressurized water is increased. By increasing the pressure of the air-dissolved pressurized water, some of the air bubbles contained in the air-dissolved pressurized water split into fine air bubbles.

The air-dissolved pressurized water that has flowed through the decompression tube 22 toward the outlet-side opening 26 is discharged from the outlet-side opening 26 into the channel space 62 . As described above, the channel area of the channel space 62 is larger than the channel area of the outlet opening 26 . Therefore, the flow velocity of the air-dissolved pressurized water discharged into the channel space 62 through the outlet-side opening 26 further decreases. 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 divided into fine bubbles.

Also, the air-dissolved pressurized water discharged into the channel space 62 collides with the disk portion 46 . At this time, part of the air-dissolved pressurized water discharged into the channel space 62 collides with the disk portion 46 after colliding with the projecting portion 49 . 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 further decreases. 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.

After colliding with the disk portion 46 , the air-dissolved pressurized water passes through the passage 64 and is discharged into the flow passage space 66 . As described above, the flow area of passage 64 is greater than the flow area of any portion of flow space 62 . The channel area of the channel space 66 is larger than the channel area of the passage 64 . Therefore, the flow velocity of the air-dissolved pressurized water discharged into the channel space 66 through the passage 64 further decreases. 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 28 a 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 further decreases. The air-dissolved pressurized water is also further pressurized. As a result, some of the bubbles contained in the air-dissolved pressurized water are further divided into fine bubbles.

After colliding with the front surface 28a of the flange 28, the air-dissolved pressurized water passes through the passage 68 and flows out from the outflow port 50 toward the outflow location (such as a bathtub). As described above, the flow area of passage 68 is greater than the flow area of any portion of flow space 66 . The flow rate of air-dissolved pressurized water through passageway 68 is further reduced. As the air-dissolved pressurized water flows out to the outflow location, the flow velocity of the air-dissolved pressurized water further decreases, 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 microbubble generating nozzle 10 of this embodiment have been described above. As described above, in this embodiment, since the pressure reducing tube 22 of the nozzle body 20 has the communicating hole 30, the negative pressure generated in the pressure reducing tube 22 by the venturi effect causes the air-dissolved pressurized water to flow from the outside through the communicating hole 30. is drawn into the vacuum tube 22 . As a result, the air-dissolved pressurized water drawn from the communication hole 30 collides with the flow of the air-dissolved pressurized water near the inner peripheral wall flowing from the inlet-side opening 24 toward the outlet-side opening 26 in the decompression tube 22, The flow velocity in the vicinity becomes slower than the flow velocity in the vicinity of the radial center (see FIG. 4). As the difference in flow velocity between the vicinity of the inner peripheral wall and the vicinity of the center increases, more bubble nuclei, which are sources of fine bubbles, are generated. As a result, according to the microbubble generating nozzle 10 of the present embodiment, the air-dissolved pressurized water flowing out to the outflow location can contain a large amount of microbubbles.

Further, in this embodiment, the opening area of the communication hole 30 is smaller than the opening area of the inlet side opening 24 . Therefore, compared to the case where the opening area of the communication hole 30 is equal to or larger than the opening area of the inlet side opening 24, the negative pressure generated in the pressure reduction tube 22 causes the pressure reduction tube 22 to pass through the communication hole 30 from the outside. Air-dissolved pressurized water is likely to be drawn inside. That is, the negative pressure generated within the decompression tube 22 can be effectively used.

Further, in this embodiment, the opening area of the decompression tube 22 at the portion where the communication hole 30 is formed (that is, the specific portion) is substantially equal to the opening area of the inlet side opening 24 . That is, in this embodiment, the communication hole 30 is formed within a range where there is almost no increase in opening area when viewed from the inlet side opening 24 . A relatively large negative pressure is generated in the air-dissolved pressurized water passing through such a specific portion. Therefore, the air-dissolved pressurized water is easily drawn into the decompression tube 22 from the outside through the communication hole 30 . The negative pressure generated within the decompression tube 22 can be used more effectively.

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

(Modification 1) In the embodiment described above, the opening area of the decompression tube 22 at the portion where the communication hole 30 is formed (that is, the specific portion) is substantially equal to the opening area of the inlet side opening 24 . However, the opening area of the decompression tube 22 at the portion where the communication hole 30 is formed (that is, the specific portion) may be greater than or equal to the opening area of the inlet side opening 24 and within 110%. That is, the communication hole 30 may be formed within a range in which the increase in opening area of the decompression tube 22 as viewed from the inlet side opening 24 is within 10%. Since this range is also the range immediately after passing through the inlet side opening 24, a relatively large negative pressure is generated in the air-dissolved pressurized water passing through this range.

(Modification 2) In the above-described embodiment, the outer peripheral wall and the inner wall of the decompression tube 22 are provided downstream of each inlet-side opening 24 and immediately after passing through each inlet-side opening 24 (specific portion). A communication hole 30 communicating with the peripheral wall is opened one by one. Not limited to this, in a modification, a plurality of communication holes 30 may be opened along the radial direction of the decompression tube 22 in a specific portion. In that case, the total opening area of the plurality of communication holes 30 should be smaller than the opening area of the inlet side opening 24 .

(Modification 3) Furthermore, in a modification, the opening area of the communication hole 30 may be equal to or larger than the opening area of the inlet-side opening 24 .

(Modification 4) In each of the above embodiments, the microbubble generating nozzle receives supply of air-dissolved pressurized water in which air is dissolved in water, precipitates the air in the air-dissolved pressurized water, converts it into microbubbles, and converts the air into microbubbles. Water containing air bubbles is supplied to the outflow point. Not limited to this, the fine bubble generating nozzle is supplied with gas-dissolved pressurized water in which 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. Instead of microbubbles, 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.

The technical elements described in this specification or in the drawings exhibit technical utility either singly or in various combinations, and are not limited to the combinations described in the claims as filed. In addition, the techniques exemplified in this specification or drawings can simultaneously achieve a plurality of purposes, and achieving one of them has technical utility in itself.

10: Microbubble generating nozzle 20: Nozzle body 22: Decompression tube 22a: Upstream end 22b: Downstream end 23: Inlet 24: Inlet side opening 25: Partition wall 26: Outlet side opening 28: Collar 28a: Front surface 30: Communication hole 40: Holder portion 42: Outer cylindrical portion 43: Step 44: Inner cylindrical portion 46: Disc portion 48: Connecting portion 49: Protruding portion 50: Outlet 52: Connecting portion 62: Channel space 64: Passage 66: Flow path space 68: Passage B: Screw hole

Claims (3)

a decompression pipe for passing gas-dissolved pressurized water in which gas is dissolved in water from the upstream end to the downstream end;
an inlet opening at the upstream end for introducing the gas-dissolved pressurized water into the decompression pipe from a water supply means for supplying the gas-dissolved pressurized water;
an inlet-side opening provided downstream of the introduction port in the decompression tube and allowing the gas-dissolved pressurized water introduced into the decompression tube to pass through;
an outlet-side opening opened at the downstream end that is downstream of the inlet-side opening;
and
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,
At least one communication hole that communicates between an outer peripheral wall and an inner peripheral wall of the decompression tube is opened in a specific portion of the decompression tube that is downstream of the inlet side opening and in the vicinity of the inlet side opening. has been
The inlet and the at least one communication hole are arranged in a water supply space to which the gas-dissolved pressurized water is supplied from the water supply means,
Fine bubble generation nozzle body. 2. The fine bubble generating nozzle body according to claim 1, wherein a total opening area of said at least one communication hole is smaller than an opening area of said inlet side opening. 3. The fine bubble generating nozzle body according to claim 1 or 2, wherein the opening area of the decompression tube in the specific portion is equal to or larger than the opening area of the inlet side opening and is within 110%.

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