Fine bubble generation device

Abstract

To provide a compact device for generating fine bubbles excellent in such generating efficiency.SOLUTION: A fine bubble generation device S comprises: a gyration chamber A having a cylindrical wall face a1 and toric edge face a2; a gyration flow generating part B generating a gyration flow of flowing water in the gyration chamber A; a cylindrical restriction part C formed on the edge face a2 and having a bore smaller than that of the gyration chamber A; and an expansion chamber D provided near to a downstream side of the restriction part C and having a space expanded compared with an area of an outlet side opening of the restriction part C. In the device S, an inflow part c1 of the restriction part C is provided at a near side along the flowing water direction W toward the edge face a2 in a cross-sectional view by a flat surface including a shaft center X when defining a direction heading for the expansion chamber D from the gyration chamber A along the shaft center X of the restriction part C as the flowing water direction W.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to a fine bubble generator that can form a swirling flow in the middle of a flowing water path and effectively generate fine bubbles.

Background Art

[0002] Conventionally, as a technology related to such a fine bubble generator, for example, there is one shown in the following Patent Document 1 (refer to paragraphs

[0007] ,

[0010] ,

[0025] ,

[0026] of the specification, FIG. 6, etc.).

[0003] The technology according to Patent Document 1 is a fine bubble ejection nozzle attached to a liquid storage tank, which ejects a liquid in which air is pressurized and dissolved into the liquid storage tank. This fine bubble ejection nozzle has a nozzle body that supplies liquid inside and ejects the liquid from a jet outlet provided at the tip, and a nozzle cover attached to the tip of the nozzle body. In the nozzle cover, a cylindrical wall member provided at a position facing the jet hole changes the flow direction of the liquid, and the liquid is ejected from an orifice provided at a position separated from the jet hole.

[0004] Three jet holes facing the circumferential direction are provided on the tip side wall of the nozzle body, and the liquid containing dissolved air pumped inside is given a flow component along the circumferential direction of the wall member when passing through each jet hole. The liquid is then ejected downward from an orifice formed on the bottom surface of the nozzle cover. By this ejection, the pressure of the liquid decreases to atmospheric pressure, and the dissolved air separates from the liquid to generate white and turbid fine bubbles. In this device, the pressure of the liquid ejected from the nozzle body to the nozzle cover is once decompressed inside the nozzle cover, and the pressure of the liquid ejected from the orifice further decreases. Therefore, the degree of negative pressure around the high-speed flow from the orifice is alleviated, and the generation of large bubbles is alleviated. It is also said that the generation of a large metallic sound during ejection is suppressed.

Prior Art Documents

Patent Documents

[0005] Patent Document 1 Japanese Patent Application Laid-Open No. 2007-167557 Summary of the Invention Problems to be Solved by the Invention

[0006] In the device of the above Patent Document 1, the liquid ejected from the ejection port of the nozzle body into the nozzle cover flows spirally inside the nozzle cover and reaches the lower orifice, and is ejected while maintaining the spiral state.

[0007] However, while the liquid is flowing toward the orifice along the wall surface of the nozzle cover, the spiral state is gradually relaxed, and the flow direction of the liquid changes to the direction along the axis of the nozzle cover. For this reason, the circumferential velocity of the liquid when passing through the orifice decreases, and the swirling speed of the liquid when passing through the orifice decreases. When the swirling speed of the liquid decreases, the liquid pressure at the center of the swirling flow does not sufficiently decrease, and the separation effect of the dissolved air is not sufficiently exerted.

[0008] As described above, in the conventional fine bubble generator, there is still room for improvement from the viewpoint of the bubble generation effect, and there is a need for a fine bubble generator that can generate more bubbles and generate fine bubbles. Means for Solving the Problems

[0009] (Characteristic Configuration) The characteristic configuration of the fine bubble generator according to the present invention is a swirling chamber having a cylindrical wall surface and an annular end surface, a swirling flow generation unit that generates a swirling flow of running water in the swirling chamber, a cylindrical throttle portion formed on the end surface and having an inner diameter smaller than the inner diameter of the swirling chamber, an expansion chamber that is adjacent to the downstream side of the throttle portion and has a space expanded with respect to the area of the outlet-side opening of the throttle portion, When the direction from the swirling chamber toward the expansion chamber along the axis of the throttle portion is defined as the flowing water direction, in a cross-sectional view taken along a plane including the axis, the inflow portion of the throttle portion is provided on the front side along the flowing water direction with respect to the end face.

[0010] (Effect) In this configuration, the flowing water that has become a swirling flow in the swirling flow generating portion is made to flow through the throttle portion, where the swirling radius is further reduced to generate cavitation in the flowing water to obtain fine bubbles. To increase the amount of fine bubbles generated in the throttle portion, it is preferable to increase the flow velocity of the flowing water in the throttle portion as much as possible and lower the water pressure at the center of the swirling flow. Therefore, in this configuration, in a cross-sectional view taken along a plane including the axis of the throttle portion, the inflow portion of the throttle portion is provided on the front side along the flowing water direction with respect to the end face of the swirling chamber. As a result, the flowing water that has become a swirling flow in the swirling flow generating portion obtains a velocity component in the direction opposite to the flowing water direction when flowing into the throttle portion. The swirling direction of the flowing water flowing into the throttle portion becomes one with a shallow swirling pitch along the flowing water direction. Thus, the flowing water becomes a state where it is difficult to flow down along the throttle portion.

[0011] However, when the inflow amount of the flowing water to the swirling flow generating portion is constant, the outflow amount from the throttle portion also becomes constant. That is, instead of the swirling pitch in the throttle portion becoming shallow, the swirling flow velocity in the circumferential direction increases. For this reason, the water pressure near the swirling center further decreases, cavitation is likely to occur, and the amount of fine bubbles generated increases.

[0012] In addition, since the pressure reducing effect at the center of the throttle portion is enhanced by the decrease in the swirling pitch, the throttle portion can be configured to be short, and the apparatus can be miniaturized.

[0013] In the fine bubble generating apparatus according to the present invention, it is advantageous that an annular region adjacent to the end face in a state of surrounding the throttle portion is formed in a conical shape having a generatrix recessed toward the axis.

[0014] (Effect) With the present configuration, by making the end face of the throttle portion into a curved conical surface, it becomes difficult to decelerate the swirling flow velocity of the flowing water from the swirling chamber to the throttle portion, and it becomes easier for the flow direction to be redirected in the direction opposite to the flowing water direction of the device. As a result, the effect of reducing the swirling pitch and the effect of increasing the flow velocity in the circumferential direction in the throttle portion are further promoted, and it becomes easier to generate fine bubbles.

[0015] In the fine bubble generator according to the present invention, in a cross-sectional view taken along a plane including the axis, it is preferable that the first radius of the curve formed at the boundary between the wall surface and the end face is made smaller than the second radius of the curve formed by the generatrix.

[0016] (Effect) With this configuration, the wall surface of the swirling chamber has a large radius even at a position close to the end face. As a result, when flowing water flows from the swirling chamber to the throttle portion, the relatively gentle swirling flow formed in the region near the wall surface is maintained even in the region near the end face, and then flows into the throttle portion and the swirling flow velocity increases. That is, the speed difference between the two becomes large, and the pressure difference between the two is maintained large, and the effect of generating fine bubbles in the throttle portion is further enhanced.

[0017] In the fine bubble generator according to the present invention, in a cross-sectional view taken along a plane including the axis, the inner diameter of the throttle portion can be made the same at any position along the flowing water direction, or smaller toward the back side in the flowing water direction.

[0018] (Effect) The flowing water that has flowed into the throttle portion has an increased swirling flow velocity and a reduced swirling pitch in the flowing water direction. However, due to friction with the inner wall and the like, the swirling flow weakens as it flows down and changes to a linear flow along the flowing water direction. Therefore, in this configuration, the inner diameter of the throttle portion is configured to be constant along the flowing water direction, or to become smaller toward the downstream side. Thereby, the flow resistance is maintained at a predetermined value also on the downstream side of the throttle portion, and the generation of fine bubbles is maintained by alleviating the change from the swirling flow to the linear flow.

[0019] In the microbubble generator according to the present invention, it is preferable to form a chamfered portion that expands in diameter toward the downstream side in the inner surface of the throttle portion.

[0020] (Effect) By forming a chamfered portion in the downstream region of the throttle portion, the flow path area rapidly expands, and the pressure of the flowing water that has increased by flowing through the narrow region of the throttle portion instantaneously decreases at the chamfered portion. For this reason, the refinement of bubbles is promoted.

[0021] In the microbubble generator according to the present invention, the swirling flow generation portion includes a disk-shaped main body portion arranged coaxially with the axis, and a plurality of blade portions provided around the main body portion, and is arranged in the swirling chamber. It is advantageous that a main body recess is formed in the main body portion, which has an area larger than that of the throttle portion while overlapping the inlet-side opening of the throttle portion when viewed in the direction along the axis and is arranged opposite to the throttle portion.

[0022] (Effect) By providing a swirling flow generation portion having blade portions around it in the swirling chamber as in this configuration, a swirling flow can be reliably formed along the wall surface of the swirling chamber.

[0023] Also, by forming a main body recess larger than the throttle portion on the surface of the central main body portion facing the throttle portion, even when the blade portion and the main body portion are installed close to the throttle portion, the distance between the throttle portion and the main body portion is maintained, and the inflow of flowing water from the swirling chamber to the throttle portion is smoothly maintained.

[0024] Therefore, it is possible to form a swirling flow with a high flow velocity at the throttle portion while reducing the size of the swirling chamber along the flowing water direction.

[0025] The microbubble generator according to the present invention can form a faucet device by being provided in a water discharge part that discharges running water.

[0026] The microbubble generator according to the present invention includes a water purification cartridge through which running water flows, a switching mechanism that switches the running water between normal running water and purified water, and a water discharge part that discharges the running water or the purified water, and can be combined to form a faucet device. In particular, the microbubble generator is attached to the water discharge part and includes a swirling flow generation part that generates a swirling flow of the running water, a swirling chamber through which the swirling flow passes, and a cylindrical throttle part that is connected to an end face of the swirling chamber toward the downstream of the running water and has an inner diameter smaller than the inner diameter of the swirling chamber. It is preferable that an inflow part of the throttle part is configured to protrude into the swirling chamber with respect to the end face.

[0027] When configuring the faucet device, the microbubble generator can be provided on the downstream side with respect to the water purification cartridge.

Brief Description of the Drawings

[0028]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Mode for Carrying Out the Invention

[0029] (Overview) The microbubble generator S according to the present invention (hereinafter simply referred to as "the present device S") is provided, for example, in the water discharge part 1 of the faucet device J, and obtains running water containing fine bubbles when washing food ingredients or tableware. An embodiment of the present device S will be described with reference to FIGS. 1 to 4.

[0030] As shown in FIG. 1, the present device S is provided in the water discharge part 1 of the faucet device J. A water purification cartridge 2 is installed on the upstream side of the present device S, and normal running water and purified water are switched by a switching mechanism K. These running waters flow into the swivel chamber A.

[0031] The configuration of the present device S is shown in Fig. 2. The present device S has, in order from the upstream side of the flowing water, a cover F, a swivel plate b, a base part 3, and a bottom E. The swivel plate b is inserted and arranged inside the base part 3, and these are covered by the cover F. Fixing holes fa for fixing are provided at opposite positions on the side surface of the cover F, and the fixing member f1 is inserted with the cover F aligned with the base part 3 to fix the two.

[0032] On the opposite side of the base part 3, a bottom E having a number of water discharge holes e1 is fixed using a bayonet structure. Note that ring-shaped seal packings (not shown) are provided between the cover F and the base part 3, and between the base part 3 and the bottom E.

[0033] (Swirling flow generation part) As shown in Figs. 2 and 3, the swirling chamber A includes a cylindrical wall surface a1 and an annular end surface a2. In the center of the swirling chamber A, a swivel plate b is provided as a swirling flow generation part B. The swivel plate b has a central main body part b1 and blade parts b2 integrally formed on the outer peripheral part. The swivel plate b is provided with a fixing convex part b3 on the outer peripheral part of the blade parts b2, and this convex part b3 is fitted and held in a concave part a3 formed in the wall surface a1 of the swirling chamber A.

[0034] The outermost peripheral part of the blade parts b2 is offset to the most upstream side, and the central side is offset to the downstream side. That is, the plurality of blade parts b2 are formed in a funnel shape as a whole, and the main body part b1 has a shape recessed on the downstream side. With this configuration, before the fluid collides with the main body part b1 and reaches the outer wall surface a1, it becomes a swirling flow by the blade parts b2. That is, since the flow in the radially outward direction becomes a swirling flow without decelerating, the swirling flow velocity formed in the swirling chamber A can be maintained high.

[0035] The flowing water that has passed through the plurality of blade parts b2 formed around it is redirected to the downstream side by the wall surface a1 and heads toward the end surface a2. Since the surface shape of the wall surface a1 is a smooth cylindrical surface, the flowing water reaches the end surface a2 while minimizing the decrease in speed.

[0036] (Throttle part) As shown in FIGS. 2 and 3, the end face a2 of the swirling chamber A is integrally formed with the wall face a1. The wall face a1 and the end face a2 form part of a substantially cylindrical base portion 3. The base portion 3 is pre-formed as a single member by resin molding or the like and is fixed to the faucet device J using a bayonet structure or the like. A cylindrical throttle portion C is integrally formed at the center of the end face a2. The throttle portion C is configured such that its inner diameter is narrower than the inner diameter of the wall face a1 of the swirling chamber A, and it is a portion that allows the spiral flow to flow into the downstream expansion chamber D while further increasing the velocity of the spiral flow.

[0037] The cross-section of the throttle portion C is shown in FIGS. 3 and 4. Here, when the direction from the swirling chamber A toward the expansion chamber D along the axis X of the throttle portion C is defined as the flowing water direction W, in a cross-sectional view taken by a plane including the axis X, the inflow portion c1 of the throttle portion C is provided on the front side along the flowing water direction W with respect to the end face a2. That is, while the end face a2 of the swirling chamber A is an annular plane, the outer surface of the throttle portion C is displaced toward the side of the swirling plate b as it approaches the axis X of the throttle portion C. More specifically, the outer surface of the throttle portion C has a bell-shaped contour or an S shape, approaches the swirling plate b closer at positions nearer the axis X, and the change in the distance from the swirling plate b becomes smaller at positions even nearer the axis X.

[0038] While forming such an outer surface, in a cross-sectional view taken by a plane including the axis X of the throttle portion C, the inflow portion c1 of the throttle portion C is provided on the front side along the flowing water direction W with respect to the end face a2 of the swirling chamber A. To increase the generation amount of fine bubbles in the throttle portion C, it is necessary to increase the flow velocity of the flowing water as much as possible and lower the water pressure at the center of the spiral flow. With this configuration, the flowing water that has become a spiral flow in the swirling chamber A obtains a velocity component in the direction opposite to the flowing water direction W when flowing into the throttle portion C. As a result, what had a swirling pitch of p1 in the swirling chamber A becomes a shallow swirling pitch p2 along the flowing water direction W after flowing into the throttle portion C, and the flowing water becomes a state where it is difficult to flow down through the throttle portion C.

[0039] However, when the inflow rate of the flowing water into the swirling chamber A is constant, the outflow rate from the throttle portion C also becomes constant. That is, if the swirling pitch p2 of the swirling flow in the throttle portion C becomes shallower, the circumferential flow velocity increases. For this reason, the water pressure near the swirling center decreases more, cavitation is likely to occur, and the generation amount of fine bubbles increases.

[0040] In addition, by reducing the swirling pitch and enhancing the pressure reducing effect, the throttle portion C can be shortened, and the apparatus S can be miniaturized.

[0041] The outer surface shape of the throttle portion C is, for example, a bell contour shape. In different expressions, it is preferably a conical shape in which an annular region adjacent to the throttle portion C in a surrounding state on the end face a2 has a generatrix concave toward the axis X. By changing the outer surface into a curved surface shape from the end face a2 toward the inflow portion c1 of the throttle portion C, it becomes difficult to decelerate the swirling speed of the flowing water from the swirling chamber A to the throttle portion C. Furthermore, the flowing water is more likely to be redirected in the opposite direction toward the swirling plate b. As a result, the effect of reducing the swirling pitch p2 and the effect of increasing the swirling speed in the throttle portion C are further promoted, and fine bubbles are likely to be generated.

[0042] In addition to the conical shape of the boundary between the end face a2 and the throttle portion C, it is preferable to define the surface shape at the boundary position between the wall surface a1 of the swirling chamber A and the end face a2. Specifically, as shown in FIG. 4, in a cross-sectional view by a plane including the axis X, the first radius r1 of the curve formed at the boundary portion between the wall surface a1 and the end face a2 is preferably configured to be smaller than the second radius r2 of the curve formed by the generatrix related to the conical shape of the outer surface of the end face a2 and the throttle portion C. That is, the change in the surface shape at the boundary between the end face a2 and the wall surface a1 is made to change abruptly compared to the change in the surface shape at the boundary between the end face a2 and the throttle portion C.

[0043] With this configuration, even if the wall surface a1 of the swirling chamber A is located close to the end surface a2, it will have the same radius. When the flowing water flows from the swirling chamber A to the throttle portion C, the swirling flow at a predetermined speed formed in the region close to the wall surface a1 is maintained even in the region near the end surface a2. Thereafter, the flowing water flows into the throttle portion C and the swirling flow velocity increases, but the pressure difference is maintained at a large value by increasing the speed difference between the two, and the cavitation generation effect in the throttle portion C is further enhanced.

[0044] Regarding the shape of the inner surface c2 of the throttle portion C, for example, in a cross-sectional view by a plane including the axis X, the inner diameter of the throttle portion C is made the same at any position along the flowing water direction W, or is formed to be smaller toward the back side in the flowing water direction W. Figures 3 and 4 show the latter shape.

[0045] The flowing water that has flowed into the throttle portion C has an increased swirling flow velocity and a reduced swirling pitch p2 along the flowing water direction W. However, due to friction with the inner surface c2 and the like, the swirling flow velocity weakens as it flows down and changes to a linear flow along the flowing water direction W. The degree of this change to the linear flow changes according to the length along the axis X of the throttle portion C. For example, the greater the length along the axis X, the greater the influence of the linear flow.

[0046] Therefore, when used in the water discharge portion 1 of the faucet device J as in this embodiment, the length of the throttle portion C is formed short in order to achieve compactness. In that case, the inner diameter of the throttle portion C is made constant along the flowing water direction W. However, when a die release gradient is required as in the case of obtaining the throttle portion C by injection molding, it is preferably configured to be smaller toward the downstream side. Thereby, in the downstream region of the throttle portion C, the flow resistance increases due to the reduction of the opening diameter, the flow velocity along the axis X decreases, and the circumferential velocity increases to compensate for it. Therefore, the change from the swirling flow to the linear flow is alleviated and the decompressed state at the center of the swirling flow is maintained, and the formation of cavitation continues.

[0047] Regarding the outlet shape of the throttle portion C, as shown in FIGS. 3 and 4, it is advisable to form a chamfered portion c3 that expands in diameter toward the downstream side in the downstream region of the inner surface c2 of the throttle portion C. In this embodiment, the generatrix is in the shape of a straight cone. The angle of the generatrix is, for example, inclined at 45 degrees with respect to the axis X, but the setting of this angle is arbitrary.

[0048] By providing such a chamfered portion c3, the flow passage area rapidly expands, and the pressure of the flowing water that has increased by flowing through the narrow region of the throttle portion C instantaneously decreases at the chamfered portion c3. Therefore, the refinement of air bubbles is promoted.

[0049] As shown in FIGS. 3 and 4, a turning plate b is located near the entrance of the throttle portion C. In the main body portion b1 of the turning plate b, in a view along the axis X of the throttle portion C, it overlaps with the inflow portion c1 of the throttle portion C and has an area larger than that of the throttle portion C, and a main body recess b4 is formed opposite to the throttle portion C. That is, when the flowing water flows backward along the outer surface of the throttle portion C toward the turning plate b in order to flow into the throttle portion C, the distance between the throttle portion C and the main body portion b1 is widened to prevent a decrease in the flow velocity. Further, according to this configuration, it is possible to form a swirling flow with a high flow velocity in the throttle portion C while reducing the dimension of the swirling chamber A along the flowing water direction W.

[0050] (Expansion chamber) As shown in FIGS. 3 and 4, an expansion chamber D is adjacently provided on the downstream side of the throttle portion C. The expansion chamber D is cylindrical and has an inner diameter slightly larger than the inner diameter of the swirling chamber A. Here, the flowing water containing fine bubbles is temporarily stored and discharged as water discharge from a large number of water discharge holes e1 formed at the bottom E. By ensuring a large inner diameter of the expansion chamber D, the flow rate range of the fluid swirling at high speed in the throttle portion C rapidly expands, and the degree of pressure release of the fluid increases. As a result, the generation rate of fine bubbles in the region where the fluid moves from the throttle portion C to the expansion chamber D can be increased.

[0051] (Example) In the apparatus S according to the above embodiment, the specific dimensions, materials used, etc. of each part can be configured as follows.

[0052] For example, the swivel plate b and the base portion 3 can be made of ABS resin (Acrylonitrile-Styrene-Acrylate resin). If it is ABS resin, it has the necessary strength and is also excellent in forming engaging claws and the like. In addition, there are few molding defects such as sink marks during resin molding, and the cost is reasonable. However, it is not limited to this, and in addition, PC (polycarbonate), PP (polypropylene), POM (polyacetal), etc. may be used.

[0053] When the inner surface c2 of the throttle portion C is formed to be narrower toward the downstream side, an inclination of 1 to 5 degrees can be provided with respect to the axis X. If the inclination angle is excessive, the flow resistance becomes excessive and an effective swirling flow cannot be formed.

[0054] (Another Embodiment of the Swivel Plate) As shown in FIG. 5, the outer peripheral portion of the blade portion b2 of the swivel plate b may be provided with an annular portion b5. With this configuration, when the swivel plate b is fixed to the base portion 3, the swivel plate b can be supported by the entire annular portion b5. In addition, the rigidity of each blade portion b2 is increased by the annular portion b5, and the relative position between the blade portions b2 is less likely to change. Therefore, the degree of freedom in setting the shape of the blade portion b2 increases, and it is possible to obtain a blade portion b2 in which the mounting state is stabilized even in the device S with a high flow rate.

[0055] (Combinations of Component Configurations) In the above embodiments, the configurations of each part have been described separately, but the configurations of each part can be combined in various ways. Below, variations of the combinations of each part are shown.

[0056] As a basic configuration, this device S includes a swivel chamber A having a cylindrical wall surface a1 and an annular end surface a2, a swirling flow generation unit B that generates a swirling flow of flowing water in the swivel chamber A, a cylindrical throttle portion C formed on the end surface a2 of the swivel chamber A and having an inner diameter smaller than the inner diameter of the swivel chamber A, and an expansion chamber D that is adjacent to the downstream side of the throttle portion C and has a space expanded with respect to the area of the outlet-side opening of the throttle portion C. When the direction from the swivel chamber A toward the expansion chamber D along the axis X of the throttle portion C is defined as the flowing water direction W, in a cross-sectional view taken by a plane including the axis X, the inflow portion c1 of the throttle portion C is provided on the front side along the flowing water direction W with respect to the end surface a2.

[0057] With respect to such a device S, an annular region adjacent to the throttle portion C in a surrounding state on the end surface a2 may be formed in a conical shape having a generatrix recessed toward the axis X.

[0058] In addition to the device S of the above

[0053] or

[0054] , in a cross-sectional view taken by a plane including the axis X, the first radius r1 of the curve formed at the boundary between the wall surface a1 and the end surface a2 may be configured to be smaller than the second radius r2 of the curve formed by the generatrix.

[0059] In addition to any one of the devices S from the above

[0053] to

[0055] , in a cross-sectional view taken by a plane including the axis X, the inner diameter of the throttle portion C may be the same at any position along the flowing water direction W, or may be formed to be smaller toward the back side in the flowing water direction W.

[0060] In addition to any one of the devices S from the above

[0053] to

[0056] , a chamfered portion c3 in a state of having an increasing diameter toward the downstream side may be formed in the downstream region of the inner surface c2 of the throttle portion C.

[0061] In addition to any one of the devices S from

[0053] to

[0057] described above, the swirling flow generation unit B includes a disk-shaped main body b1 arranged coaxially with the axis X, and a plurality of blade parts b2 provided around the main body b1, and is arranged in the swirling chamber A. In the main body b1, in a view along the direction of the axis X, a main body recess b4 may be formed that overlaps the inlet-side opening of the throttle part C and has an area larger than that of the throttle part C and is arranged opposite to the throttle part C.

Industrial Applicability

[0062] The fine bubble generator S according to the present invention can be widely applied as a device that forms a swirling flow in the middle of a flowing water path and effectively generates fine bubbles.

Explanation of Signs

[0063] A Swirling chamber a1 Wall surface a2 End face B Swirling flow generation unit b2 Blade part C Throttle part c1 Inflow part c3 Chamfered part D Expansion chamber r1 First radius r2 Second radius S Fine bubble generator W Flowing water direction X Axis

Claims

1. A swirling chamber having a cylindrical wall surface and an annular end face, a swirling flow generation unit that generates a swirling flow of flowing water in the swirling chamber, a cylindrical throttle portion formed on the end face and having an inner diameter smaller than the inner diameter of the swirling chamber, an expansion chamber that is adjacent to the downstream side of the throttle portion and has a space expanded with respect to the area of the outlet side opening of the throttle portion, and when the direction from the swirling chamber toward the expansion chamber along the axis of the throttle portion is defined as the flowing water direction, a fine bubble generator in which, in a cross-sectional view taken along a plane including the axis, an inflow portion of the throttle portion is provided on the front side along the flowing water direction with respect to the end face.

2. The fine bubble generator according to claim 1, wherein an annular region adjacent to the throttle portion in a surrounding state on the end face is formed in a conical shape having a generatrix recessed toward the axis.

3. The fine bubble generator according to claim 2, wherein, in a cross-sectional view taken along a plane including the axis, a first radius of a curve formed at a boundary portion between the wall surface and the end face is configured to be smaller than a second radius of a curve formed by the generatrix.

4. The fine bubble generator according to claim 2, wherein, in a cross-sectional view taken along a plane including the axis, the inner diameter of the throttle portion is the same at any position along the flowing water direction or is formed to be smaller toward the back side in the flowing water direction.

5. The fine bubble generator according to claim 4, wherein a chamfered portion having a diameter that expands toward the downstream side is formed in a downstream region of the inner surface of the throttle portion.

6. The swirling flow generation unit includes a disk-shaped main body portion arranged coaxially with the axis and a plurality of blade portions provided around the main body portion, and is arranged in the swirling chamber, and a main body recess is formed in the main body portion, which has an area larger than that of the throttle portion while overlapping the inlet side opening of the throttle portion in a direction view along the axis and is arranged opposite to the throttle portion, according to any one of claims 1 to 5.

7. It includes a water discharge portion for discharging flowing water, A faucet device in which the fine bubble generator according to any one of claims 1 to 5 is attached to the water discharge portion.

8. A water purification cartridge for flowing flowing water, a switching mechanism for switching the flowing water between normal flowing water and purified water, a water discharge portion for discharging the flowing water or the purified water, and a fine bubble generator for obtaining the flowing water or the purified water containing fine bubbles, and the fine bubble generator a swirling flow generation unit that generates a swirling flow of the flowing water, A swirling chamber through which the swirling flow passes, a cylindrical throttle portion that is connected to an end face of the swirling chamber toward the downstream of the flowing water and has an inner diameter smaller than the inner diameter of the swirling chamber, and a faucet device in which an inflow portion of the throttle portion is provided so as to protrude into the swirling chamber with respect to the end face.

9. The faucet device according to claim 8, wherein the fine bubble generator is provided on the downstream side with respect to the water purification cartridge.

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