JP5210974B2 - Microbubble generator - Google Patents

Description

  The present invention relates to a fine bubble generating device, and more particularly to a fine bubble generating device that is used by being attached to a liquid supply pipe and discharges a liquid containing fine bubbles.

  For example, it is possible to obtain an excellent cleaning effect by the action of air bubbles by including air bubbles in a cleaning liquid for cleaning objects to be cleaned, such as tableware, semiconductors, glass substrates, and the like, and other objects to be cleaned. It is known. It is also known that when bubbles are included in the cleaning liquid, the cleaning effect can be improved as the bubbles become smaller and the bubbles are present at higher density. For this reason, for example, a bubble generating device has been developed that can generate fine bubbles having a bubble diameter of about 5 to 20 μm at a high density (see, for example, Patent Document 1).

JP 59-16527 A

  In the bubble generating device of Patent Document 1, a first bubble generator that forms a large number of bubbles by injecting a gas into the liquid, and a first device that depressurizes and stirs the liquid in which the gas is dissolved to form fine bubbles. The two bubble generators are communicated with each other via a water tank and are provided separately. In addition, two water tanks are required, and a pressurizing pump or the like is required, resulting in a large apparatus.

  It is an object of the present invention to provide a fine bubble generating apparatus that is used by being attached to a liquid supply pipe and that can regularly generate a large amount of fine bubbles with a simple configuration.

  The present invention is a fine bubble generating device that is used by being attached to a liquid supply pipe and discharges a liquid containing fine bubbles, the throttle part having a reduced diameter flow path from the liquid supply pipe, and the throttle A gas is supplied to the space between the throttle portion and the diffuser portion in communication with outside air, and a diffuser portion having a portion that is arranged downstream from the portion and has an inner wall whose inner diameter expands toward the downstream side. The baffle plate connecting plate is provided in the center of the cross section of the diffuser portion so as to extend in the discharge direction inside the diffuser portion. The installation plate is provided with a plurality of baffle plates that stand from the flat plate base and are arranged opposite to the discharge direction. The baffle plates are respectively provided at the tip portion and the diffuser portion. With the gap between the inner wall and the inner wall, A plurality of flow openings are formed in the flat plate base so as to be alternately provided on one side and the other side of the base, and adjacent to the upstream side of each baffle. The object is achieved by providing a microbubble generator. In the specification of the present application, “attached to the liquid supply pipe” means “attached to the front end portion or midway of the liquid supply pipe”.

  According to the fine bubble generating apparatus of the present invention, it is used by being attached to a liquid supply pipe, and a large amount of fine bubbles can be generated constantly with a simple configuration.

It is a schematic diagram explaining the use condition of the fine bubble generating device concerning one desirable embodiment of the present invention. (A) is a schematic diagram explaining the structure of the fine bubble generator which concerns on preferable one Embodiment of this invention, (b) is a schematic perspective view explaining the structure of a baffle plate connection board. (A) is sectional drawing of the fine bubble generator which looked at Fig.2 (a) from the side, (b) is sectional drawing of the fine bubble generator which looked at Fig.2 (a) from the top. It is explanatory drawing of the analysis conditions for the simulation by a computer. It is a chart which shows the analysis result of the average pressure in a section. It is explanatory drawing of the observation method of a fine bubble, and the calculation method of a bubble diameter. It is explanatory drawing of the measuring method of a bubble raise speed.

  As shown in FIG. 1, a microbubble generator 10 according to a preferred embodiment of the present invention is used by being attached to a liquid supply hose as a liquid supply pipe 12 connected to a faucet part 11 of a water supply, for example, A liquid (water in this embodiment) containing fine bubbles, preferably having a bubble diameter of about 30 to 60 μm, can be easily supplied to the washing tank 13 for dishwashing.

  The fine bubble generating device 10 of the present embodiment is a bubble generating device that is used by being attached to the tip of the liquid supply pipe 12 and discharges water containing fine bubbles. 3 (a) and 3 (b), the throttle part 15 having a reduced diameter of the flow path 14 from the liquid supply pipe 12, and the downstream side of the throttle part 15 are arranged at intervals, and the inner wall surface 16a A diffuser portion 16 having a portion whose inner diameter smoothly expands toward the downstream side, communicates with the outside air through the gas injection hole 17, and gas (in the present embodiment, the gap portion 26 between the throttle portion 15 and the diffuser portion 16). The baffle plate connecting plate 19 extends in the discharge direction X from a position away from the inlet portion 16b inside the diffuser portion 16 and is configured to have a diffuser portion. 16 is provided at the center of the cross section. The baffle plate connecting plate 19 may extend from the inlet portion 16b in the discharge direction X, but it extends from the position away from the inlet portion 16b in the discharge direction X from the viewpoint of reliably preventing the backflow of the liquid. It is preferable to do. Further, the baffle plate continuous plate 19 is provided with a plurality of baffle plates 21 standing from the flat plate base 20 and arranged opposite to the discharge direction X. Each of the plates 21 has one surface side and the other of the flat plate base 20 with the spaces S1, S2, and S3 (see FIG. 3A) held between the tip portion 21a and the inner wall surface 16a of the diffuser portion 16, respectively. A plurality of flow openings 22 are formed in the flat plate base 20 adjacent to the upstream sides of the baffle plates 21. In the present specification, the above-mentioned “section central portion” means a center portion of a cross section orthogonal to the discharge direction X. In the present embodiment, “one surface side” means the side where the gas injection hole 17 exists.

  In the present embodiment, the mesh member 23 is attached so as to cover the outlet portion 16 c of the diffuser portion 16.

  In the present embodiment, the fine bubble generating device 10 is made of, for example, a metal or synthetic resin material, and as shown in FIGS. 3A and 3B, the overall length L1 is approximately 74 mm, for example. It has a sleeve shape. In the microbubble generator 10, the throttle portion 15, the diffuser portion 16, the gas chamber portion 18, etc. are arranged concentrically by processing and forming the inside of the substantially cylindrical sleeve shape so as to have a predetermined shape. In addition, it is provided continuously through the axial direction.

  The most upstream side portion inside the microbubble generator 10 is a connection flow path portion 24 having a circular cross section with an inner diameter D1 of about 9.5 mm and a length L2 of about 20 mm, for example. The connection flow path portion 24 is connected to the tip end portion of the liquid supply pipe 12 (see FIG. 1), so that the connection flow path section 24 and the liquid supply pipe 12 are connected to the throttle portion 15. The flow path 14 of the water which goes to is formed.

  The throttle part 15 provided on the downstream side of the connection flow path part 24 is a part that reduces the diameter of the flow path 14 from the liquid supply pipe 12 and reduces the water passing therethrough. In the present embodiment, the throttle portion 15 is formed in a substantially truncated cone shape having a length L3 of, for example, about 20 mm, in which the inner diameter of the inner wall surface is smoothly reduced from the upstream side toward the downstream side. The throttle portion 15 is formed so that the inner diameter D2 of the upstream inlet portion is about 7.5 mm, for example, and the inner diameter D3 of the downstream outlet portion is about 3 mm, for example. As a result, the throttle portion 15 is inclined from the upstream side toward the downstream side while the inner wall surface thereof is inclined from the upstream side toward the downstream side, for example, at an angle θ1 of about 10 °, except for the upstream end portion. The cross-sectional area is gradually reduced.

  The diffuser unit 16 provided on the downstream side of the throttle unit 15 is a part that releases the water that has passed through the throttle unit 15 in the discharge direction X while entraining the air supplied to the gas chamber unit 18. In the present embodiment, the diffuser portion 16 has an inner diameter of the inner wall surface 16a that is smoothly enlarged from the upstream side toward the downstream side, and has a length L4 of, for example, about 40 mm, and is directed in the direction opposite to the throttle portion 15. It is formed in a truncated cone shape. The diffuser portion 16 is formed so that the inner diameter D4 of the upstream inlet portion 16b is about 3 mm, for example, and the inner diameter D5 of the downstream outlet portion is about 6 mm, for example. As a result, the diffuser portion 16 has its inner wall surface 16a inclined from the upstream side to the downstream side while being inclined at an angle θ2 of, for example, about 2.5 ° from the downstream side to the upstream side except for the downstream end portion. The cross-sectional area is gradually enlarged toward.

  In the present embodiment, the diffuser portion 16 is provided with a baffle plate continuous plate 19 extending in the discharge direction X so as to partition the hollow interior of the diffuser portion 16 at the central portion of the cross section. The baffle plate continuous plate 19 is opened in the diffuser unit 16 while entraining air from the reduced pressure state by the throttle unit 15, and generates a large number of fine bubbles in the water passing through the diffuser unit 16 in the discharge direction X. It is a member. In the present embodiment, as shown in FIG. 2B, the baffle plate connecting plate 19 includes a flat plate base portion 20, a plurality of baffle plates 21 erected from the flat plate base portion 20, and the upstream side of each baffle plate 21. And a flow opening 22 formed in the flat plate base 20 adjacent to each other.

  In the present embodiment, the flat plate base 20 constituting the baffle plate continuous plate 19 is formed of a flat plate member having a thickness of about 0.5 mm, for example, and is formed in a vertically long strip shape having a length L5 of about 16 mm, for example. (See FIG. 3B). The flat plate base portion 20 is formed so that both side edges 20a gradually expand in the discharge direction X so that the width thereof is the same size as the gradually expanding inner diameter of the diffuser portion 16 at the mounting position. Yes. By joining and fixing the both side edge portions 20a to the inner wall surface 16a of the diffuser portion 16, the flat plate base portion 20 traverses the central portion of the diffuser portion 16 having a circular cross section in the diametrical direction, and moves the interior of the diffuser portion 16 up and down. It is attached so as to partition. Further, in the present embodiment, the flat plate base portion 20 is provided in the central portion of the cross section of the diffuser portion 16 so as to extend in the discharge direction X from a position separated from the inlet portion 16b of the diffuser portion 16 by, for example, L6 = 16 mm.

  In the present embodiment, the baffle plates 21 that constitute the baffle plate continuous plate 19 are provided at three locations so as to stand from the flat plate base 20 and to be opposed to the discharge direction. The baffle plates 21 are provided so as to stand alternately on one surface side and the other surface side of the flat plate base 20. The baffle plates 21 each have a rectangular shape with a width b of, for example, about 3 mm and a height h of, for example, about 2.5 mm (see FIGS. 3A and 3B), and the upstream side thereof. For example, it is erected in an inclined state at an angle θ3 of about 60 ° with respect to the opening surface of the circulation opening 22 adjacent to the opening. Thus, in the present embodiment, the three baffle plates 21 are spaced between the center of their tip portions and the inner wall surface 16a of the diffuser portion 16 with a spacing S1 of, for example, about 0.8 mm in the baffle plate 21 on the most upstream side. In the central baffle plate 21, for example, an interval S <b> 2 of about 1 mm is held, and in the baffle plate 21 on the most downstream side, for example, an interval S <b> 3 of about 1.2 mm is held.

  Here, in this embodiment, it is preferable that the baffle plate 21 is inclined and inclined at an angle of 30 to 90 ° with respect to the opening surface of the flow opening 22 adjacent to the upstream side. Since the baffle plate 21 is inclined and inclined at an angle of 30 to 90 °, the flow is branched by the collision of water containing large bubbles, and the tip portion of the baffle plate 21 and the diffuser portion 16 Due to the shear stress between the inner wall surfaces 16a, the miniaturization of the bubbles can be promoted.

  In the present embodiment, a U-shaped cut 25 (see FIG. 2B) is inserted into the flat plate base 20 and bent, whereby the baffle plate 21 and the flow opening 22 adjacent to the upstream side thereof are simultaneously formed. It is supposed to be formed.

  In this embodiment, the flow opening 22 formed adjacent to the upstream side of the baffle plate 21 is preferably formed along the U-shaped cut 25 so that the width b is about 3 mm, for example. The length L7 is formed to have a rectangular shape with a size of about 2.5 mm, for example (see FIGS. 3A and 3B). The flow openings 22 are arranged in a row in the discharge direction X together with the baffle plate 21 and are provided at three locations on the flat plate base 20. Further, in the present embodiment, the flow opening 22 is continuously arranged in the discharge direction X with an interval of, for example, about 2 mm between the opening edges of the adjacent flow openings 22.

  Here, it is preferable that the baffle plate 21 and the flow opening 22 are provided in the flat plate base 20 in two to five locations in a row in the discharge direction X. The baffle plate 21 and the flow opening 22 are provided in the flat plate base 20 at two to five locations, so that the device can be made compact by meandering the flow path, and a sufficient distance can be provided to promote the refinement of large bubbles. It becomes possible to earn.

  In the present embodiment, the gas chamber portion 18 that supplies air to the interval portion 26 between the diffuser portion 16 and the throttle portion 15 surrounds the interval portion 26 having a width B of about 1 mm, for example. By forming a flat cylindrical drum-shaped inner peripheral wall surface 18a on the outer side of this, it is provided as an air reservoir. That is, the gas chamber portion 18 communicates with the outside air through a gas injection hole 17 having a diameter of, for example, about 0.4 mm that opens to the outer peripheral surface of the fine bubble generating device 10, and the air is sent from the outside air. The air is always retained. As a result, it is possible to efficiently mix the stagnant air into the water passing through the gap portion 26 from the throttle portion 15 toward the diffuser portion 16 while supplying the air to the gap portion 26. As will be described later, a large amount of fine bubbles having a bubble diameter of about 30 to 60 μm are regularly generated in the water mixed with air by the action of the diffuser portion 16 on the downstream side.

  In this embodiment, the mesh member 23 attached to cover the outlet portion 16c of the diffuser portion 16 includes, for example, a mesh having an opening of about 500 / inch and a wire diameter of about 0.025 mm. The mesh member 23 is detachably attached to the distal end portion of the microbubble generator 10 so as to cover the outlet portion 16c of the diffuser portion 16 through, for example, a peripheral edge locking portion 23a.

  And according to the fine bubble generator 10 of the present embodiment having the above-described configuration, it is used by being attached to the distal end portion of the liquid supply pipe 12 to generate a large amount of fine bubbles constantly with a simple configuration. Can do. In other words, according to the present embodiment, the fine bubble generating device 10 is arranged with a narrowed portion 15 having a reduced diameter in the flow path of the water supplied from the liquid supply pipe 12 and a downstream side of the narrowed portion 15. The diffuser unit 16 has a gas chamber 18 that supplies air to the space 26 between the throttle unit 15 and the diffuser unit 16, and a plurality of baffle plates 21 are provided at the center of the cross section of the diffuser unit 16. In addition, the baffle plate continuous plate 19 in which the flow openings 22 are continuously arranged in the discharge direction X is spaced S1, S2, S3 between the baffle plate 21 and the inner wall surface 16a of the diffuser portion 16 (see FIG. 3A). It is provided in the state which hold | maintained.

  Therefore, in this embodiment, it is possible to supply the air discharged from the throttle unit 15 toward the diffuser unit 16 with the air staying in the gas chamber unit 18 through the interval portion 26 and efficiently mixing the water. Become. Further, the water mixed with air flows into the diffuser portion 16 in which the inner wall surface 16a has an inner diameter smoothly expanding toward the downstream side, the pressure is reduced, and the baffle plate 21 arranged continuously in the discharge direction X. And the flow of the dissolved air by flowing in the discharge direction X through the spaces S1, S2, S3 and the flow opening 22 between the inner wall surface 16a while decreasing the pressure stepwise in multiple stages. It will promote foaming. Further, the water mixed with air collides with the baffle plate 21 in sequence, so that the air mixed into the water is crushed into small pieces. Furthermore, when water mixed with air is branched at the flat plate base portion 20 of the baffle plate continuous plate 19 or passes through the flow opening 22, bubbles are broken by shear stress, and finer bubbles are generated. It will be.

[Simulation by computer]
Further, the applicant of the present application uses “COSMOSFloWorks 2008 / PE SP0.0.Build:279” (manufactured by SolidWorks), which is a well-known fluid simulation software, under the analysis conditions shown in FIG. About the fine bubble generator 10 of the said embodiment shown to (b), the mechanism of generation | occurrence | production of a fine bubble was confirmed by analyzing the average pressure in a cross section with a computer. The analysis results are shown in FIG.

  According to the analysis result shown in FIG. 5, the average pressure in the cross section in the diffuser portion decreases stepwise due to the collision at the baffle plate portion of the baffle plate continuous plate. It was predicted and confirmed that fine bubbles were generated efficiently due to the pressure drop in multiple stages.

  Due to these actions, the fine bubble generating device 10 of the present embodiment has a simple configuration that can be attached to the tip of the liquid supply pipe 12, but the water fed from the liquid supply pipe 12. A large amount of fine bubbles is constantly generated, and preferably water containing fine bubbles with a bubble diameter of about 30 to 60 μm is easily directed from the outlet portion 16c of the diffuser portion 16 toward the washing tank 13 for dishwashing, for example. Can be discharged.

  Moreover, according to the fine bubble generator 10 of this embodiment, since the mesh member 23 is attached so as to cover the outlet portion 16c of the diffuser portion 16, the mesh eyes of the mesh member 23 are sheared into a fluid containing bubbles. By the action of applying stress, it becomes possible to generate fine bubbles in a more stable state.

  The present invention is not limited to the above-described embodiment, and various modifications can be made. For example, it is not always necessary to attach a mesh member to cover the outlet part of the diffuser part, and the shape and dimensions of the throttle part, the diffuser part, the gas chamber part, the baffle plate connecting plate, etc. are within a range that does not impair each function. It can be changed as appropriate. In addition, the baffle plate and the distribution opening do not necessarily have a rectangular shape, and can also have various other shapes such as a substantially horseshoe shape and a substantially circular shape. Further, the baffle plate and the flow opening can be formed by making a U-shaped or C-shaped cut into the flat plate base. Further, the baffle plate and the flow opening need not be formed at the same time by cutting and bending the flat plate base portion, and can be formed individually.

  As the liquid used in the apparatus of the present invention, various liquids such as alcohol, acetone, methyl ethyl ketone, liquid detergent, liquid bleach and the like can be used in addition to water. In addition to air, various gases such as oxygen, nitrogen, hydrogen, and chlorine can be used as the gas.

  The “one surface side” of the flat plate base 20 of the baffle plate continuous plate 19 is not limited to the side where the gas injection hole 17 exists. That is, the baffle plate continuous plate 19 can be installed on the inner wall surface 16a of the diffuser portion 16 at an arbitrary rotation angle with the longitudinal direction of the diffuser portion (the direction coincident with the discharge direction X) as the rotation axis.

  Furthermore, the apparatus of the present invention can be used by being incorporated in a shower head or the like.

  Hereinafter, the fine bubble generating device of the present invention will be described in more detail with reference to Examples 1 and 2, but the present invention is not limited thereto.

Examples 1 and 2
A fine bubble generator having the same configuration as the fine bubble generator 10 of the above embodiment shown in FIGS. 3A and 3B except that the mesh member is not attached is referred to as the fine bubble generator of Example 1. did. A microbubble generator having the same configuration as the microbubble generator 10 of the above-described embodiment shown in FIGS. 3A and 3B to which a mesh member is attached was used as the microbubble generator of Example 2. These fine bubble generating devices are respectively attached to the water absorption hoses connected to the liquid supply device, and the water in which the fine bubbles are generated is discharged and stored in a beaker. As shown in FIG. While observing, the bubble diameter of the fine bubbles was calculated as the Stokes diameter D by the equation (1) according to the Stokes law. In addition, as shown in FIG. 7, the bubble rising speed V in the formula (1) is measured by measuring the elapsed time when the reflected light intensity sensors are installed in a beaker at intervals of 5 cm and the bubbles rise and disappear. Then, the elapsed time until the bubbles rose and disappeared at a certain distance was calculated by measuring with a stopwatch.

  According to the observation result of the water stored in the beaker, in the case of using any of the fine bubble generators of Example 1 and Example 2, small fine bubbles are generated at high density and stay in the water. It was observed that Moreover, the bubble diameter by Stokes diameter D of the generated fine bubbles was 48 to 55 μm in Example 1, and 37 to 45 μm in Example 2.

  As a comparative example, when the bubble generating device in which the baffle plate continuous plate was removed from the fine bubble generating device of Example 1 and Example 2, water in which bubbles were generated was discharged into a beaker, and the diffuser part It was observed that the bubbles contained in the water discharged from the outlet part of the water had a large bubble diameter, and many bubbles changed their direction in the direction of rising after discharge, resulting in a turbulent flow of bubbles.

10 Fine Bubble Generator 11 Tap Port 12 Water Supply Pipe (Liquid Supply Hose)
13 Washing tank 14 Flow path from liquid supply pipe 15 Restriction part 16 Diffuser part 16a Inner wall surface 16b of diffuser part Inlet part 16c of diffuser part Outlet part 17 of diffuser part Gas injection hole 18 Gas chamber part 19 Baffle plate connection plate 20 Flat base portion 21 Baffle plate 22 Distribution opening 23 Mesh member 24 Connection flow path portion 25 Notch 26 Space portion X between the throttle portion and the diffuser portion Discharge direction

Claims (6)

A fine bubble generator that is used by being attached to a liquid supply pipe and discharges a liquid containing fine bubbles,
A throttle part having a reduced diameter flow path from the liquid supply pipe, a diffuser part having a portion that is arranged at an interval on the downstream side of the throttle part and the inner diameter of the inner wall surface increases toward the downstream side; It is configured to have a gas chamber portion that communicates with the outside air and supplies gas to a gap portion between the throttle portion and the diffuser portion,
Inside the diffuser portion, a baffle plate continuous plate is provided in the central portion of the cross section of the diffuser portion extending in the discharge direction,
The baffle plate continuous plate is provided with a plurality of baffle plates standing from the flat plate base and arranged opposite to the discharge direction in a row in the discharge direction.
The plurality of baffle plates are provided so as to alternately stand on one surface side and the other surface side of the flat plate base portion with a gap maintained between the tip portion and the inner wall surface of the diffuser portion. And
In addition, a fine bubble generating apparatus in which a plurality of flow openings are formed in the flat plate base so as to be adjacent to each upstream side of the baffle plates. The fine bubble generating device according to claim 1, wherein a bubble diameter of the fine bubbles is 30 to 60 µm. The fine bubble generating device according to claim 1 or 2, wherein a mesh member is attached to cover an outlet portion of the diffuser portion. The fine bubble generator according to any one of claims 1 to 3, wherein the baffle plate and the flow opening are provided in 2 to 5 locations on the flat plate base portion so as to be continuous in the discharge direction. The fine bubble generating device according to any one of claims 1 to 4, wherein the baffle plate is inclined and inclined at an angle of 30 to 90 ° with respect to an opening surface of the circulation opening adjacent to the upstream side. The said baffle plate and the said distribution | circulation opening are formed in the said flat plate base part by making a U-shaped, U-shaped, or C-shaped cut and bending. Fine bubble generator.