WO2002002216A1

WO2002002216A1 - Method and device for feeding fine bubbles

Info

Publication number: WO2002002216A1
Application number: PCT/JP2001/005231
Authority: WO
Inventors: Hisatsune Nashiki; Ichiro Teshiba
Original assignee: Tashizen Techno Works Co., Ltd.
Priority date: 2000-06-30
Filing date: 2001-06-19
Publication date: 2002-01-10
Also published as: AU2001264331A1

Abstract

A fine bubble feeding technique which is capable of efficiently feeding a large amount of fine bubbles to an object liquid. The fine bubble feeding device (10) comprises a fluid feeder (11), a bubble generator (12) and a sucking section (13) which are immersed in object liquid (L), a pressure pipe (15) which connects the fluid feeder (11) and the bubble generator (12), and a suction pipe (17) which connects the fluid feeder (11) and the sucking section (13). The fluid feeder (11) comprises a liquid pump (21) for feeding the object liquid (L) drawn from the suction section (13) to the bubble generator (12) via the pressure pipe (15), and a gas mixer (32) for mixing air into the object liquid (L) being pumped to the bubble generator (12).

Description

Description Fine bubble supply method and fine bubble supply device

The present invention relates to a technique for supplying microbubbles into a liquid that can be used in various fields including cleaning and activating water or other liquids. Background art

Conventionally, it has been known that various effects are produced by dissolving a bubbled gas in a liquid, and it has been applied in various industrial fields such as plant cultivation, seafood cultivation, and wastewater treatment. In this case, as a means of dissolving more of the bubbled gas in the liquid, it has been found effective to increase the gas-liquid contact area by reducing the bubble diameter and increasing the surface area of the entire bubble as a means for dissolving the gas in the liquid more. ing.

Techniques for dissolving gas bubbles into a liquid include a method using a diffuser tube, a method in which air is blown into water by an injector, and a method in which a rotating body with blades is rotated near the water surface to stir the water. There are various methods such as a stirring and mixing method for generating bubbles, a method for generating bubbles in water by depressurizing air-dissolved pressurized water, and a method for generating bubbles by using ultrasonic waves.

In the diffuser method, air bubbles are generated by discharging compressed air, which is sent from a compressor, etc., into the liquid through the micropores.However, since the compressed air expands in volume when released, ^ It is difficult for S to generate fine bubbles on the order of tens of microns. In addition, when actually used, clogging of micropores is apt to occur in a relatively short period of time, so that frequent maintenance is required, and the operation cost is high.

In the case of the stirring and mixing method, it is basically difficult to generate fine bubbles effectively, and the power cost for constantly rotating the rotating body with a large load on the blade is large. In addition, for the decompression method, ejector method, and ultrasonic method for air-dissolved pressurized water, Large scale and high cost make introduction difficult.

Incidentally, Japanese Patent Application Laid-Open No. 2000-4747 discloses a revolving microbubble generator 90 as shown in FIG. The revolving microbubble generator 90 comprises a container body 91 having an inverted conical space 92 and a liquid tangentially formed on a part of the inner wall circumferential surface 91a of the container body 91. It comprises an inlet 93, a gas inlet 94 provided at the upper end of the container body 91, and a swirling fluid outlet 95 provided at the lower part of the container 91.

By injecting liquid into the container body 91 from the tangential direction of the inner wall circumferential surface 91a of the container body 91, the vortex flow in the space 92 generates a rotating flow, and the center of the rotor is negative pressure. By doing so, air in the atmosphere is introduced into the container body 91 from the end 96 a of the beer tube 96 connected to the gas inlet 94 to generate fine bubbles. That is, the liquid is introduced from the liquid introduction port 93, the air is self-primed at a negative pressure from the gas introduction port 94, and fine bubbles are generated from the swirling fluid outlet 95.

The revolving microbubble generator 90 disclosed in Japanese Patent Application Laid-Open No. 2000-4447 is capable of shearing air introduced into a container body 91 from a gas introduction port 94 by a rotational flow of a liquid. Fine bubbles are generated by making small cuts such as twisting with force. Therefore, it is necessary to reduce the diameter of the gas vortex tube 97 formed at the center of the rotating flow to minimize the diameter of the generated bubble. The inner diameter of 4 must be as small as possible. For this reason, the inner diameter of the actual gas inlet 94 is about 1 mm, and the inner diameter of the valve tube 96 connected to the gas inlet 94 is also about the same. Therefore, the amount of gas introduced into the container body 91 from the gas inlet 94 must be small, and it is difficult to supply a large amount of fine bubbles into the liquid.

In addition, the small-diameter vinyl tube 96 connected to the gas inlet 94 is likely to be clogged with dust near its open end 96a exposed to the outside air. Salts in the air sucked into the tube 6 stick to the inner wall of the vinyl tube 96 and cause clogging in a relatively short period of time, which is inconvenient for actual use. You.

If the bullet tube 96 or the gas inlet 94 is clogged with dust or salt, cavitation occurs near the center of the bulge due to the rotating flow generated in the container body 91, and this cavitation edge Contact with the gas inlet 94 on the inner wall of the container body 91 and the opening of the swirling fluid outlet 95, so-called cavitation erosion occurs, causing damage to the surroundings of the opening. This can render the device 90 unusable.

In addition, since the shearing force due to the rotating flow generated in the container body 91 also acts from the side of the gas vortex tube 97 generated in the container body 91, the energy loss is large and the efficiency is low. When the swirling microbubble generator 90 is placed in a deep position of the liquid 98 to supply pressurized gas, when the gas supply amount increases, the gas expansion pressure increases due to the shear force of the rotating flow. It becomes strong and no fine bubbles are generated, and a phenomenon occurs in which the gas is discharged as a large diameter gas mass. In order to prevent this, it is necessary to increase the rotational flow rate generated inside the container body 91 by feeding a large amount of liquid through the container body 91. Therefore, it becomes less practical.

The problem to be solved by the present invention is to provide a fine bubble supply method capable of efficiently supplying a large amount of fine bubbles into a target liquid, and to be able to easily carry out this method, thereby improving workability and durability. Another object of the present invention is to provide a method and an apparatus for supplying fine air bubbles which are excellent in maintainability and can be used in a wide range of fields. Disclosure of the invention

A first method of the microbubble supply method according to the present invention comprises: a cylindrical space in which a fluid can swirl; and a fluid arranged in a tangential direction of a peripheral surface of the cylindrical space to supply the fluid into the cylindrical space. A microbubble generator having an inlet and a fluid outlet arranged on an extension of the central axis of the cylindrical space for allowing the fluid to flow out of the cylindrical space is immersed in the liquid, and the tube is introduced from the fluid inlet into the cylinder. It is characterized in that liquid and gas are fed into the space, a swirling flow is generated in the cylindrical space to generate fine bubbles, and a fluid containing fine bubbles is discharged from the fluid outlet into the liquid. According to this method, the gas and liquid swirling in the cylindrical space move due to the difference in their specific gravities due to the centrifugal force acting on the liquid and moving toward the outer periphery, and the centrifugal force acting on the gas causing the center of the rotational flow. Move in the axial direction. At this time, the gas is sheared and finely divided by the liquid moving in the opposite direction, is accumulated near the center of the swirling flow while being mixed with gas and liquid, and is discharged from the fluid outlet as a fluid containing fine bubbles. That is, the shearing force of the rotating flow of the liquid acts strongly on the gas from the vertical and horizontal directions, and a large amount of fine bubbles can be efficiently supplied into the target liquid.

Here, when the gas-liquid mixed fluid is fed from the fluid inlet into the cylindrical space, the liquid and the gas separately fed from the liquid pump and the gas pump are mixed, and the cylinder is fed from the fluid inlet. The liquid is supplied into the cylindrical space, or a gas is mixed into the liquid via gas mixing means provided in the flow path of the liquid supplied from the liquid pump, and the liquid is supplied from the fluid inlet to the cylindrical space. For example, a feeding method can be adopted. In this case, a decompression device called an aspirator can be used as the gas mixing means. If the aspirator is installed in the middle of a liquid supply pipe connecting the liquid pump and the fluid inlet, the aspirator can be used. The air self-sucked from the atmosphere through the liquid can be mixed with the liquid moving in the liquid supply pipe and supplied to the fluid inlet.

Further, the second method of the microbubble supply method according to the present invention is characterized in that the liquid is disposed in a tangential direction of a cylindrical space in which a fluid can be swirled and a peripheral surface of the cylindrical space for supplying the liquid into the cylindrical space. Liquid inlet, a gas inlet provided to communicate with the cylindrical space to supply gas into the cylindrical space, and an extension of the central axis of the cylindrical space to allow fluid to flow out of the cylindrical space. A microbubble generator equipped with a fluid outlet arranged on a line is immersed in the liquid, and the liquid is fed from the liquid inlet into the cylindrical space and the gas is sent from the gas inlet into the cylindrical space. It is characterized in that it supplies a swirling flow in the cylindrical space to generate fine bubbles, and discharges a fluid mixed with fine bubbles into the liquid from the fluid outlet.

In the second method, similarly to the first method, the gas and the liquid swirling in the cylindrical space are moved in the outer peripheral direction by the centrifugal force acting on the liquid due to the difference in specific gravity, and the gas and the liquid are not swirled. The centrifugal force acts and moves toward the center axis of the rotating flow, and the gas moves in the opposite direction. The liquid is collected near the center of the swirling flow while being gas-liquid mixed, and is released as a fluid containing fine bubbles from the fluid outlet, so that a large amount of fine bubbles are contained in the target liquid. It can be supplied efficiently.

A first device of the microbubble generating device according to the present invention comprises a cylindrical space in which a fluid can be swirled, and a fluid arranged in a tangential direction of a peripheral surface of the cylindrical space to supply the fluid into the cylindrical space. A microbubble generator having an inlet and a fluid outlet arranged on an extension of the central axis of the cylindrical space for allowing fluid to flow out of the cylindrical space; And a liquid supply means and a gas supply means for supplying a liquid and a gas.

In such a configuration, when a liquid and a gas are mixed and supplied from the liquid supply means or the gas supply means to the fine bubble generator via the fluid inlet, the gas is introduced into the cylindrical space. A swirling flow of liquid is generated, and the gas-liquid swirling in the cylindrical space moves in the outer circumferential direction due to the centrifugal force acting on the liquid due to the difference in specific gravity. Move in the direction. At this time, the gas moving in the liquid in the direction of the central axis of the rotational flow is sheared by the opposing centrifugal force and centripetal force to be divided and finely divided. The fluid acts as a shear due to the dynamic pressure energy of the rotating flow, and is further miniaturized and accumulated at the center of the rotating flow, and is discharged as a fluid containing fine bubbles from the fluid outlet. That is, since the shearing force of the rotational flow of the liquid acts on the gas in the vertical and horizontal directions with respect to the moving direction of the gas, a large amount of fine bubbles can be efficiently supplied into the target liquid.

Thus, a large amount of fine bubbles can be supplied to the fine bubble generator immersed in the target liquid simply by mixing and feeding the liquid and gas by the liquid supply means and the gas supply means, It generates and discharges fine bubbles using the centrifugal force, centripetal force and shearing action of the swirling flow, so it is excellent in workability, durability and maintenance, and can be used in a wide range of fields. In addition, by sending a gas-liquid mixture in which a gas and a liquid are mixed in advance to the fine bubble generator, the contact time between the gas and the liquid can be lengthened, and the liquid being sent can be supplied. Being pressurized, the gas dissolves in the liquid. Since the degree of resolution increases, the gas can be dissolved in the liquid even during the feeding process. Here, when the gas-liquid mixed fluid is fed from the fluid inlet into the cylindrical space, as described above, the liquid and the gas separately fed from the liquid pump and the gas pump are mixed. The liquid is fed into the cylindrical space from the fluid inlet, or the gas is mixed into the liquid through a gas mixing means connected to the flow path of the liquid fed by the liquid pump, and the liquid is introduced from the fluid inlet. It is possible to adopt a method of feeding into a cylindrical space. In this case, as the gas mixing means, a decompression device called an aspirator can be suitably used.

A second device of the microbubble supply device according to the present invention includes a cylindrical space in which a fluid can be swirled, and a liquid arranged in a tangential direction of a peripheral surface of the cylindrical space to supply the liquid into the cylindrical space. An inlet, a gas inlet provided in communication with the cylindrical space for supplying gas into the cylindrical space, and an extension of the central axis of the cylindrical space for discharging fluid from the cylindrical space. A microbubble generator having a fluid outlet, liquid supply means for supplying liquid into the cylindrical space via the liquid inlet, and gas into the cylindrical space via the gas inlet. And a body feeding means for feeding air.

With such a configuration, when liquid and gas are supplied from the liquid supply means and the gas supply means into the fine bubble generator via the liquid inlet and the gas inlet, respectively. As in the first microbubble generator described above, a fluid containing microbubbles is discharged from the fluid outlet.

In addition, by separately supplying gas and liquid to the microbubble generator, the microbubble generator is disposed at a position where relatively high hydraulic pressure is applied, for example, at a position deeper than a water depth of 10 m. Even in such a case, since the gas can be sent to the bubble generator as it is, fine bubbles can be stably generated regardless of the level of the liquid pressure. Here, by arranging a plurality of fluid inlets, liquid inlets, and gas inlets at positions symmetrical with respect to the central longitudinal section in the central axis direction of the cylindrical space, a gas-liquid mixed fluid, liquid or gas From a plurality of locations into the cylindrical space and generate a stable swirling flow in the cylindrical space, so that fine bubbles can be generated more efficiently and stably. Can be supplied. In addition, since the stability of the swirling flow can be ensured even when the cylindrical space is increased in the axial direction, it is possible to further improve the efficiency of supplying fine bubbles by increasing the size of the fine bubble generator.

Further, by disposing the fluid outlets of the microbubble generator at both end faces in the direction of the central axis of the cylindrical space, the rotary type disclosed in Japanese Patent Application Laid-Open No. 2000-4747 is disclosed. Compared to a one-sided opening method such as a microbubble generator, the energy flow due to the friction between the swirling flow in the cylindrical space and the inner wall surface at the end of the cylindrical space is reduced, and the microbubbles from multiple fluid outlets Since the mixed fluid can be discharged, the supply efficiency of the fine bubbles is further improved. In addition, since cavitation generated along the central axis of the cylindrical space due to the swirling flow does not contact the inner wall surface of the cylindrical space, no cavitation erosion occurs and the durability of the entire apparatus is reduced. It can be improved and maintenance can be simplified.

By providing a portion having a smaller diameter than the fluid introduction port and the liquid introduction port at the opening end of the fluid introduction port and the liquid introduction port facing the cylindrical space, the fluid and the liquid fed toward the cylindrical space can be reduced. Since the pressure is reduced at the section and the pressure is increased and the pressure is increased, and is jetted into the cylindrical space, a high-speed swirling flow is formed in the cylindrical space, and fine bubbles can be supplied more efficiently. In addition, a relatively large diameter fluid supply pipe or liquid supply pipe can be used as a means for supplying a fluid or liquid to the fluid introduction port or the liquid introduction port. The energy loss can be reduced, and the efficiency of supplying fine bubbles can be further improved. BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is an overall configuration diagram showing a fine bubble supply device of the first embodiment.

FIG. 2 is a front view of a bubble generator included in the fine bubble supply device of FIG.

FIG. 3 is a side view of the bubble generator of FIG.

FIG. 4 is a cross-sectional view taken along the line における in FIG.

FIG. 5 is a sectional view taken along line BB in FIG.

FIG. 6 is a diagram illustrating a state of generation of a swirling flow in the bubble generator. FIG. 7 is a diagram showing a state of generation of fine bubbles in the bubble generator.

FIG. 8 is a diagram showing a state of generation of fine bubbles in the bubble generator.

FIG. 9 is a partially enlarged view of the vicinity of the fluid outlet in FIG.

FIG. 10 is a sectional view showing another embodiment of the bubble generator.

FIG. 11 is an overall configuration diagram showing the fine bubble supply device of the second embodiment.

FIG. 12 is a perspective view showing a bubble generator constituting the microbubble generator of the third embodiment.

FIG. 13 is a sectional view taken along line C-C in FIG.

FIG. 14 is a sectional view taken along line DD in FIG.

FIG. 15 is a diagram showing the structure of a conventional bubble supply device. BEST MODE FOR CARRYING OUT THE INVENTION

FIG. 1 is an overall configuration diagram showing a fine bubble supply device according to a first embodiment of the present invention, FIG. 2 is a front view of a bubble generator constituting the fine bubble supply device shown in FIG. 1, and FIG. 3 is the bubble generator. 4 is a sectional view taken along line AA in FIG. 3, and FIG. 5 is a sectional view taken along line BB in FIG.

As shown in FIG. 1, the microbubble supply device 10 of the present embodiment includes a fluid supply device 11 disposed on the ground, a bubble generator 12 to be injected into the target liquid L, and a suction unit. 13, a pressure feed pipe 15 connecting the fluid supply device 11 and the bubble generator 12, a suction pipe 17 connecting the fluid supply device 11 and the suction part 13, and the like. The fluid supply device 11 includes a liquid pump 21 for pumping the target liquid L sucked through the suction part 13 and the suction pipe 17 to the bubble generator 12 via the pressure feeding pipe 15, And a gas mixing device 23 that mixes the air sucked from the liquid into the target liquid L to be sent to the bubble generator 12 under pressure.

The gas mixing device 23 has a configuration in which an air compressor 24, an air pressure adjusting valve 25, and a pressure gauge 26 are communicated with an air supply pipe 27, and the air supply pipe 27 is connected to the pressure supply pipe 15. The air pressure regulating valve 25 regulates the supply amount of compressed air generated by the air compressor 24. It is an air pressure adjusting means for adjusting the air pressure and functions as a bubble size adjusting means for changing the size of fine bubbles generated in the bubble generator 12.

When the liquid pump 21 and the air compressor 24 are operated, the liquid pump 21 sucks the target liquid L through the suction part 13 and the suction pipe 17 and sends the sucked target liquid L to the pressure feeding pipe 15. At the same time, the air compressor 24 sends air sucked from the atmosphere into the target liquid L moving through the pressure feed pipe 15 through the air supply pipe 27, so that the target liquid L and air are The mixed fluid is sent to the bubble generator 12 via the pressure feed pipe 15. The mixed fluid of the target liquid L and air sent to the bubble generator 12 is converted into a mixed fluid of the fine bubbles and the target liquid L in the bubble generator 12 through a swirling process described later. Since the gas is discharged out of the generator 12 and diffuses into the target liquid L, fine bubbles are continuously supplied into the target liquid L. As shown in FIGS. 2 to 4, the bubble generator 12 constituting the fine bubble supply device 10 is formed of a synthetic resin or the like, has an outer shape of a rectangular parallelepiped, and has a peripheral wall portion 14 and the peripheral wall portion 1. 4 and a lid 16 integrally formed at both ends, and has a cylindrical space S in which liquid and gas can both swirl.

In the peripheral wall portion 14, two fluid inlets 18 for introducing a mixed fluid of liquid and air into the space S are provided in communication with the cylindrical space S. These fluid inlets 18 are formed by joining hollow cylinders 20 projecting outward from the peripheral wall portion 14, and the fluid inlets 18 are formed on the circumferential surface of the cylindrical space S. They are communicated in the same direction as the tangential direction. Further, the two fluid introduction ports 18 are provided at symmetrical positions with respect to the central longitudinal section 19 of the axial length of the cylindrical space S.

Fluid outlets 22 are provided at the center of the lids 16 at both ends of the bubble generator 12, that is, on the extension of the center axis X—X of the cylindrical space S. These fluid outlets 22 are all circular, have the same opening area, and are provided symmetrically with respect to the center longitudinal section 19 of the space S. The fluid outlet 22 serves as a path for discharging the gas-liquid mixed fluid swirling in the bubble generator 12 together with the fine bubbles generated therein into the target liquid L outside. The fine particles released from the bubble generator 12 via the fluid outlet 22 The target liquid L containing fine bubbles is immediately diffused into the target liquid L around the bubble generator 12.

In the bubble generator 12, the gas-liquid mixed fluid is injected from the tangential direction of the peripheral surface of the cylindrical space S, and the high-speed swirl inside the bubble generator generates fine bubbles. It is not necessary to reduce the diameter of the fluid introduction port 18 in correspondence with the above. For example, the diameter may be set to about 1 cm. When the gas-liquid mixture is injected from the fluid inlet 18, the size of the microbubbles generated in the bubble generator 12 varies depending on the amount of air sent from the air compressor 24 to the pressure pipe 15. In addition, an air pressure adjusting valve 25 is provided as a means for continuously or selectively changing the increase and decrease of the air amount.

Here, the bubble generating mechanism in the bubble generator 12 will be described in detail with reference to FIGS. As shown in FIG. 5, the gas-liquid mixed fluid pumped from the fluid inlet 18 into the bubble generator 12 has a central axis connecting the centers of the fluid outlets 22 of the lids 16 at both ends, That is, a gas-liquid swirl flow 29 that rotates at high speed around the central axis X—X of the cylindrical space S or in the vicinity thereof is formed, and the gas-liquid swirl flow 29 is directed toward the middle part of the bubble generator 12. It is divided into an intermediate swirling flow 30 that moves once while swirling, and an end swirling flow 31 that moves while swirling toward both ends of the bubble generator 12.

The intermediate swirling flow 30 moves while swirling toward the central longitudinal section 19 of the bubble generator 12, and the direction of movement is reversed at the central longitudinal section 19 where these collide, and the central axis X— It moves in the vicinity of X toward the fluid outlet 22 direction. After the reversal, the intermediate swirling flow 30 moving around the central axis X—X merges with the end swirling flow 3 1 immediately before the fluid outlet 22 to become a swirling flow 32 and the fluid outlet 2 Released from 2 out.

As shown in FIGS. 6 and 7, the gas-liquid mixed fluid including the intermediate swirling flow 30 and the end swirling flow 31 that swirl at high speed in the bubble generator 12 is subjected to the central axis X— by centrifugal force. The swirling cavity 28 compressed by X toward the inner wall side of the bubble generator 12 and having a negative pressure by the action of centrifugal force is generated along the vicinity of the central axis XX. Then, the gas in the intermediate swirling flow 30 and the end swirling flow 31 is filled with fine bubbles in the swirling cavity 28 in the negative pressure state by boiling under reduced pressure, that is, the gasification phenomenon of the dissolved gas due to the reduced pressure. Appears as 3 3. Fine bubbles 3 3 is accompanied by the flow of the intermediate swirling flow 30 and the end swirling flow 31, and finally, along with the swirling flow 32, from the fluid outlets 22 on both sides of the bubble generator 12. Released into target liquid L.

When the gas-liquid mixed fluid in the bubble generator 12 is discharged from the cylindrical space S to the outside through the fluid outlet 22, a complicated action occurs. In the space S near the fluid outlet 22, an internal pressure reducing portion 34 is generated due to the interaction between the swirling flow 32 and the swirling cavity portion 28, and the fluid outlet 22 outside the space S is generated. External pressure reducing portions 35 are also generated in the vicinity, and fine bubbles are also generated from these portions by the action of boiling under reduced pressure.

As shown in Figs. 8 and 9, a gas-liquid mixture flowing at high speed in the bubble generator 12 has a centripetal force on the gas due to the difference in specific gravity of the gas and liquid, and a centrifugal force on the liquid. As a result, the liquid moves outside the swirl flow 32 and the gas moves toward the center of the swirl flow 32. At this time, the gas contained in the gas-liquid mixed fluid flowing into the bubble generator 12 from the fluid inlet 18 becomes small bubbles while being sheared by the action of the swirling flow, and becomes the central axis X of the swirling flow 32 — Accumulates in the swirling cavity 28 near X and moves toward the fluid outlet 22 while swirling at high speed. It moves toward the distal end 36 of the swirling cavity 28 along with the surrounding fluid. I do. On the tip side 36 of the swirling cavity 28, the liquid surface 37 around the swirling cavity 28, which has the same boundary as the swirling cavity 28 to be released from the bubble generator 12, and the swirling cavity 2 The bubble generator that is about to be drawn into the swirling cavity portion 2 by the negative pressure of 8 1 2 The liquid level 38 at the tip of the liquid L outside the device 2 Due to the action of the suction force due to the pressure, the swirling cavity portion 28 is in close contact with the swirling cavity portion 28 as if it were plugged. Therefore, when the air bubbles pass through the contact portion, they are crushed by the compressive force of the liquid surface 37 and the liquid surface 38.

In addition, the swirling speed of the swirling flow 32 becomes faster at the fluid outlet 22 having a smaller inner diameter than the space S in the bubble generator 12, and near the boundary between the bubble generator 12 and the fluid outlet 22, A shear force is generated due to the difference in turning speed. At this time, the bubbles become finely divided micro bubbles 33 by the above-described compressive force and shear force. The swirling cavity 28 generated in the bubble generator 12 during use of the fine bubble supply device 10 is caused by the inner wall surface of the bubble generator 12 and the flow. Since there is no contact with the inner peripheral surface of the body outlet 22, no cavitation erosion occurs, the durability of the entire apparatus is excellent, and maintenance can be simplified. At this time, if the gas mixture rate of the gas-liquid mixture flowing from the fluid inlet 18 increases, the negative pressure in the swirling cavity 28 decreases, and the adhesion between the liquid level 37 and the liquid level 38 decreases. As a result, the compressive force against the bubbles also decreases, so that the outer diameter of the fine bubbles released from the bubble generator 12 increases, and conversely, if the gas mixing rate is reduced, the ^^ of the fine bubbles decreases. As described above, by increasing / decreasing the gas mixing ratio in the gas-liquid mixed fluid flowing into the bubble generator 12, ^ of the generated fine bubbles can be increased / decreased. Specifically, the above-mentioned air pressure adjusting valve 25 is adjusted to change the amount of compressed air supplied to the pressure feed pipe 15 within a range where the pressure in the bubble generator 12 does not become a positive pressure. Thereby, the size of the generated fine bubbles can be finely adjusted. In the case of the fine bubble supply device 10, since the gas-liquid mixed fluid is supplied to the bubble generator 12 via one pressure supply tube 15, a long air supply tube or the like is required. It is unnecessary, piping and handling are easy, and there is no risk of clogging the air supply pipe.

By using the microbubble supply device 10, microbubbles can be continuously and stably supplied into the target liquid L to increase the amount of dissolved oxygen, purify water, promote the growth of cultured animals and plants, and activate water. By supplying a large amount of gas-liquid mixed fluid from the fluid outlet 22 into the target liquid L, a circulating flow can be generated in the closed water area. The application of the microbubble supply device 10 of the present embodiment is not particularly limited. For example, microbubbles are supplied into a target liquid such as a liquid for growing animals and plants, water to be treated before water purification, and dam lake water. It can be used in various fields.

The space S in the bubble generating section 12 may be any shape as long as the liquid and the gas can be swirled, and is not limited to a cylindrical shape, but may be a polygonal cylinder such as a square cylinder, a pentagonal cylinder, or a hexagonal cylinder. It can be in shape. In the case of a polygonal cylinder, a liquid that supplies fine bubbles by generating high-frequency sound waves or ultrasonic waves due to the vibration generated by collision with the wall surface when a mixed fluid of liquid and gas turns at high speed in space It also has the effect of removing the contents contained in it, so it is also effective in detoxifying harmful substances. FIG. 10 shows another embodiment of the bubble generator. In FIG. 10, members having the same functions as those of the bubble generator 12 of FIG. 3 are denoted by the same reference numerals, and description thereof will be omitted. In the bubble generator 12a shown in FIG. 10, a reduced diameter portion 18a smaller in diameter than the fluid introduction port 18 is provided at the open end of the fluid introduction port 18 facing the cylindrical space S. The gas-liquid mixed fluid sent toward the space S is accelerated and increased in pressure by being constricted by the reduced diameter portion 18a, and is ejected into the space S, and high-speed gas-liquid swirl into the space S Since the stream 29 is formed, fine bubbles can be generated more efficiently. In addition, as a means for feeding the gas-liquid mixed fluid to the fluid inlet 18, a pressure feeding pipe 15 having a relatively large inner diameter can be used, so that energy loss in the feeding process is small, and the efficiency of supplying fine bubbles is reduced. Is greatly improved. FIG. 11 is an overall configuration diagram showing a fine bubble supply device according to a second embodiment of the present invention. In the figure, members having the same functions as those of the microbubble supply device of FIG. 1 are denoted by the same reference numerals, and description thereof will be omitted. In the present embodiment, an aspirator 39, which is one of the decompression devices, is attached in the middle of a pressure feed pipe 15 connecting the liquid pump 21 and the bubble generator 12. When the liquid L sent from the liquid pump 21 through the pressure pipe 15 passes through the aspirator 39, after the air self-absorbed from the atmosphere via the aspirator 39 is mixed into the liquid L , And is supplied to the fluid inlet 18 of the bubble generator 12 as a gas-liquid mixed fluid. Since the intake port of the aspirator 39 is provided with the intake air amount adjusting valve 40, the amount of air mixed into the liquid L can be adjusted. Since the aspirator 39 is used, an air compressor and an air supply pipe are not required, so that the configuration of the apparatus can be simplified and the manufacturing cost can be reduced.

FIG. 12 is a perspective view showing a bubble generator constituting a fine bubble supply device according to a third embodiment of the present invention, FIG. 13 is a cross-sectional view taken along line CC of FIG. 12, and FIG. FIG. 3 is a sectional view taken along line D-D in FIG. In these figures, members having the same functions as those of the bubble generator of the first embodiment are denoted by the same reference numerals, and description thereof will be omitted.

The bubble generator 50 constituting the fine bubble supply device of the present embodiment has a rectangular parallelepiped outer shape similar to the bubble generator 12 of the first embodiment, and has a peripheral wall portion 14 and a peripheral wall portion 14. It consists of a lid 16 integrally formed at both ends, inside which both liquid and gas are present. It has a revolvable cylindrical space S.

The peripheral wall 14 has two liquid inlets 51 for introducing liquid into the space S and two gas inlets 52 for introducing gas into the space S, each of which communicates with the space S. It is provided. The liquid inlet 51 is formed by joining the hollow cylinder 53 to the peripheral wall portion 14, and the gas inlet 52 is formed by joining the hollow cylinder 54 to the peripheral wall 14. The liquid inlet 51 is provided in the same direction as the tangential direction of the circumferential surface of the cylindrical space S, and the gas inlet 52 is provided in a direction orthogonal to the central axis XX of the space S. The two liquid introduction ports 51 and the gas introduction ports 52 are provided at symmetrical positions with respect to the central longitudinal section 19 of the axial length of the cylindrical space S.

When a liquid is sent into the space S from the liquid inlet 51 and a high-speed swirling flow is generated in the space S, the space S is emptied into the space S via the gas inlet 52 by a negative pressure suction force generated in the space S. Since air flows in and a high-speed gas-liquid swirling flow is generated, a large amount of fine bubbles are generated in the space S, and the fluid containing the fine bubbles is discharged from the fluid outlet 22 as in the bubble generator 12 described above. Diffusion into the liquid.

In this way, simply by feeding the liquid from the liquid inlet 51 to the space S, the gas is automatically sucked into the space S via the gas inlet 52 by negative pressure. The need for a pressure feed pipe or the like in the air supply system is eliminated, so that the device configuration can be simplified and the manufacturing cost can be reduced. Also, similar to the bubble generator 12, fine bubbles are generated only by the swirling motion of the gas-liquid mixed fluid in the space S, so the opening area of the fluid outlet 22 and the inner diameter of the gas inlet 52 are reduced. It is not necessary, and clogging due to dust is unlikely to occur.

(Example 1)

The microbubble supply device 10 described as the first embodiment was used in a fish farm (area 10, OOO m ² , water depth 6 m, water depth 5.5 m). 7_ A bubble generator 12 is placed in the water in the tank, and the liquid pump 21 (AC 100 V, 200 W) of the fluid supply device 11 and the bubble generator 12 are salted. The suction part 13 connected with the pressure pipe 15 made of vinyl and connected via the suction pipe 17 with the liquid pump 21 is placed in water.

Activate the liquid pump 21 and send the water sucked from the suction part 13 to the bubble generator 12 At the same time, the compressed air supplied from the compressor 24 (AC 100, 750 W, discharge pressure 8 kgf / cm ² ) is adjusted by the air regulating valve 25, and the air supply pipe 27 is Microbubbles are generated by the bubble generator 12 by being fed into the pumping tube 15 through the airbag. When the amount of dissolved oxygen in the water was measured after the lapse of the specified time, the value increased significantly, and it was confirmed that the amount of dissolved oxygen in the entire water tank increased in a relatively short time. Was.

(Example 2)

The bubble generator 50 described as the third embodiment is immersed in a biotope pond (area 20 m ² , water depth 6 m) in a still water area, and only liquid is supplied from the liquid inlet 51 using a liquid pump. The air was sent into the space S, and the air was sucked into the space S from the gas inlet 52 through the gas supply tube to generate fine bubbles in the bubble generator 50.

In the biotope pond, aquatic plants such as rust, aquatic basin, chromo, hiramo, and Hozakinovosamo were observed at the same time. By increasing the efficiency of supplying dissolved oxygen to animals and plants in the water area, it was possible to raise the inhabitable temperature limit by several degrees. Similarly, it has become possible to breed fish in the watershed and still waters at the same time.

In addition, it was confirmed that even after a long period of time after the supply of fine bubbles by the bubble generator 50 was started, there was no clogging of the device at all, and the device could be used continuously without maintenance. Furthermore, since the dissolved oxygen supply efficiency can be improved only by a liquid pump having relatively low power consumption, maintenance work can be simplified and equipment costs can be reduced. Industrial applicability

INDUSTRIAL APPLICABILITY The present invention can be used in various fields including cleaning and activating water and other liquids.

Claims

The scope of the claims

1. A cylindrical space in which a fluid can swirl, a fluid inlet arranged in a tangential direction of a peripheral surface of the cylindrical space for feeding the fluid into the cylindrical space, and a fluid from the cylindrical space. A microbubble generator having a fluid outlet disposed on an extension of the central axis of the cylindrical space for flowing out is immersed in the liquid, and the liquid and the liquid are introduced into the cylindrical space from the fluid inlet. A method for supplying fine bubbles, wherein a gas is supplied to generate a swirling flow in the cylindrical space to generate fine bubbles, and the fluid containing the fine bubbles is discharged from the fluid outlet into the liquid.

2. A cylindrical space in which a fluid can be swirled, a liquid inlet arranged in a tangential direction of a peripheral surface of the cylindrical space to supply the liquid into the cylindrical space, and a gas into the cylindrical space. A gas inlet provided in communication with the cylindrical space to supply the fluid, and a fluid outlet arranged on an extension of the central axis of the cylindrical space to allow the fluid to flow out of the cylindrical space. The microbubble generator is immersed in a liquid, the liquid is supplied from the liquid inlet into the cylindrical space, and the gas is supplied from the gas inlet into the cylindrical space to form the cylindrical member. A method for supplying fine bubbles, wherein a swirling flow is generated in a space to generate fine bubbles, and a fluid containing fine bubbles is discharged from the fluid outlet into the liquid.

3. A cylindrical space in which the fluid can swirl, a fluid inlet arranged in a tangential direction of a peripheral surface of the cylindrical space for feeding the fluid into the cylindrical space, and a fluid from the cylindrical space. A microbubble generator having a fluid outlet provided on the extension of the central axis of the cylindrical space to cause the liquid to flow out, and a liquid or gas flowing into the cylindrical space via the fluid inlet. A micro-bubble supply device comprising a liquid supply means and a gas supply means for supplying liquid.

4. A cylindrical space in which a fluid can be swirled, a liquid inlet arranged in a tangential direction of a peripheral surface of the cylindrical space for feeding the liquid into the cylindrical space, and a gas flowing into the cylindrical space. A gas inlet provided in communication with the cylindrical space for supplying air, and a fluid outlet provided on the extension of the central axis of the cylindrical space for allowing fluid to flow out of the cylindrical space. A microbubble generator, liquid supply means for supplying liquid into the cylindrical space via the liquid inlet, and gas to the cylindrical space via the gas inlet. And a gas supply means for supplying the air.

5. The microbubble supply device according to claim 3, wherein a plurality of the fluid introduction ports are arranged at positions symmetrical with respect to a central longitudinal section in a central axis direction of the cylindrical space.

6. The microbubble supply device according to claim 4, wherein a plurality of the liquid inlets and the gas inlets are arranged at positions symmetrical with respect to a center longitudinal section in a central axis direction of the cylindrical space.

7. The microbubble generator according to claim 3 or 4, wherein the fluid outlets are arranged on both end faces in the central axis direction of the cylindrical space.

8. The microbubble generator according to claim 3, wherein a reduced diameter portion having a smaller diameter than the fluid introduction port is provided at an opening end of the fluid introduction port facing the cylindrical space.

9. The microbubble generator according to claim 4, wherein a reduced diameter portion having a diameter smaller than that of the liquid inlet is provided at an opening end of the liquid inlet facing the cylindrical space.