JP2008149209A - Fine air bubble producer and fine air bubble supply system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fine air bubble producer having a novel structure capable of stably forming fine air bubbles, and a fine air bubble supply system capable of stably supplying a sufficiently large amount of fine air bubbles. <P>SOLUTION: The fine air bubble producer has a pressure reducing plate, which has a large number of pores permitting a supplied air dissolved liquid to flow, provided to the other opening part of a cylindrical casing of which one opening is set to a fine air bubble discharge port and the air dissolved liquid is allowed to flow through the pores of the pressure reducing plate at a speed exceeding the speed of the sonic wave in an air bubble fluid formed by the flow of the air dissolved liquid through the pressure reducing plate. A regulating plate for shock wave propagation direction, which demarcates a semi-hermetically closed region preventing the energy of the shock wave formed by the flow of air dissolved liquid through the pressure reducing plate from diffusing in the outflow direction of the air dissolved liquid, is provided in parallel to the pressure reducing plate at the place speed apart from the pressure reducing plate in the casing. The fine air bobble supply system is equipped with the fine air bubble producer. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a fine bubble generator that generates fine bubbles (referred to as “microbubbles”) having a diameter of about several μm by supplying a pressurized gas solution, for example, and the generation of the fine bubbles. The present invention relates to a fine bubble supply system having a container.

  At present, the diameter in water (under normal pressure) is in the range of several μm to 50 μm, so-called “microbubbles”, or so-called “nanobubbles” that are 0.1 μm or less. The microbubbles referred to have superior characteristics such as the following (1) to (4) as compared with the normal bubbles having a diameter of 1 mm or more. For example, microbubble baths, semiconductor cleaning treatments, and medical use As an application, it has already been put to practical use in angiography, reduction of ship frictional resistance, production of natural gas hydrate, etc., and it is considered useful in water purification treatment, for example, oyster and shellfish culture.

(1) The bubble interface surface area is remarkably large.
For example, if the bubbles have the same gas phase volume ratio (void ratio), the bubble interfacial surface area of microbubbles with a diameter of 10 μm will be 100 times larger than bubbles with a diameter of 1 mm (normal bubbles), and the bubble interfacial surface area should be large. As a result, the substance transfer and the substance adsorption due to the difference in the surface activity of the bubble surface are remarkably increased, so that it has a strong detergency.
(2) The bubble bubble pressure is large.
The pressure inside the bubble of a microbubble having a diameter of 10 μm is 100 times as large as that of a bubble having a diameter of 1 mm (usually a bubble), for example, about 3 atm. Microbubbles increase the gas dissolution efficiency due to the high pressure inside the bubble and reduce the diameter due to the self-pressurizing effect. As a result, the bubbles become adiabatic and compressed, and the inside of the bubbles is in an extreme state of ultra-high pressure and ultra-high temperature. As a result, the bubbles generate OH free radicals with strong oxidizing power and decompose harmful chemical substances. It has the chemical activity ability.
(3) Gas dissolution efficiency is high.
As described in the above (1) and (2), microbubbles with a large bubble bubble pressure have the property of efficiently dissolving gas depending on the reason that the interfacial surface area is extremely large and the reason based on Henry's law. Have For example, when microbubbles are formed with oxygen or ozone gas, water purification treatment can be performed with high efficiency. Therefore, the microbubbles are useful when used in the fishery industry such as oyster and shellfish farming.
(4) The bubble rising speed is slow.
Generally, as the bubble diameter decreases, the ascending speed decreases. Specifically, for example, the rising speed of bubbles with a diameter of 1 mm (normal bubbles) is 100 mm / sec, whereas microbubbles with a diameter of 10 μm are 30 μm / sec. Since the residence time of bubbles in water is long, many advantages such as a cleaning effect, a purification effect of harmful substances, and oxygen enrichment can be obtained.

  Various methods have been proposed and implemented as methods for generating such microbubbles. For example, water and air introduced by a pressure pump are sent to a gas-liquid mixing tank with good stirring, and after the gas is dissolved in water, a pressure reducing action is applied to the gas-liquid mixed water by a discharge nozzle to remove initial bubbles A method of generating microbubbles (pressure dissolution method) is known (see Non-Patent Document 1 and Patent Document 1). ).

The fine bubble discharge nozzle shown in Non-Patent Document 1 includes a net cartridge composed of a decompression plate in which a plurality of pores are formed and a plurality of metal meshes (mesh bodies) provided immediately thereafter. According to such a configuration, it is described that the gas-liquid mixed liquid discharged from the pores collides and decelerates by colliding with the wire mesh at high speed, thereby forming a bubble nucleus and depositing fine bubbles. .
In addition, the nozzle for generating fine bubbles disclosed in Patent Document 1 includes a plurality of orifices and a plurality of mesh bodies, and is pressurized when the gas-liquid mixture passes through the orifices. The pressure is reduced when discharged from the orifice, thereby generating fine bubbles, and by providing a plurality of gas-liquid mixing and stirring mechanisms that further refine the fine bubbles by passing through the mesh body, It is described that fine bubbles having a small bubble diameter can be generated.

"Matsushita Electric Works Technical Report", No41, Jul, 1990 Japanese Patent No. 3620797

In general, in the method of generating fine bubbles by the pressure dissolution method as described above, when the gas-liquid mixed water passes through the pores or orifices, the pressure is reduced to generate initial bubbles, and then the initial bubbles rapidly Immediately after expansion, it receives crushing action and shearing action by a wire mesh or mesh body, and crushes and breaks up to produce a large amount of fine bubbles.
By the way, it is mathematical (theoretical) about how much pressure reduction action is given to gas-liquid mixed water to generate initial bubbles and how much pressure action and shear action are given to generate fine bubbles. ) No elucidation has been made, and neither the non-patent document 1 nor the patent document 1 has been described in detail regarding the mechanism of generating fine bubbles.
Therefore, in the fine bubble discharge nozzle disclosed in Non-Patent Document 1 and the nozzle disclosed in Patent Document 1, specific configurations such as the size of the pores or orifices, the size of the opening diameter of the mesh body or the wire mesh, and the like. It is inferred that this was determined experimentally through trial and error. For example, the optimum conditions for stably obtaining fine bubbles in the nozzle configuration are individually determined depending on conditions such as flow rate and pressure by the pump. Must be determined experimentally.
In addition, the metal mesh and the mesh body constituting the nozzle as described above are actually small in size of several hundreds μm, so that clogging is likely to occur and there is a problem in practicality.

  As described above, the method of generating fine bubbles by the pressure dissolution method does not manifest by a simple mechanism of dissolving the gas in the liquid by the pressurizing action and generating bubbles by the pressure reducing action. As described in Non-Patent Document 1, even if a pressurized gas-liquid mixture is depressurized by passing it through a nozzle at a high speed, a small amount of bubbles with a large diameter can be obtained. Disappears and a large amount of fine bubbles cannot be obtained.

Based on the above circumstances, the present inventors have conducted extensive research. As a result, in the method of generating fine bubbles by the pressure dissolution method, the flow velocity passing through the pores is optimized and the pressure reducing action is achieved. The present inventors have found that a large amount of fine bubbles can be reliably obtained by forming a semi-sealed region for receiving energy for crushing and splitting the initial bubbles generated upon receiving, and have completed the present invention.
An object of the present invention is to provide a microbubble generator having a novel structure capable of stably generating microbubbles having a bubble diameter of 50 μm or less.
Another object of the present invention is to provide a fine bubble supply system capable of stably supplying a sufficiently large amount of fine bubbles.

The fine bubble generator of the present invention is a fine bubble generator in which fine bubbles are generated by supplying a pressurized gas solution.
A cylindrical casing in which one opening is a fine bubble discharge port, and a decompression plate provided with a plurality of pores formed in the other opening of the casing through which a gas solution to be supplied flows. The gas solution is passed through the pores of the decompression plate at a speed exceeding the speed of the sound wave in the bubble fluid generated by the gas solution being passed through the decompression plate. In addition, the shock wave propagation direction regulating plate that divides the semi-sealed region that prohibits the energy of the shock wave generated thereby from diffusing in the outflow direction of the gas solution is separated from the decompression plate inside the casing at a position separated from the decompression plate. It is provided in parallel.

  In the fine bubble generator of the present invention, the size and number of pore diameters are set so that the pores in the decompression plate satisfy the relationship of the following formulas (1) and (2). Thus, the gas solution can be passed through the pores of the decompression plate at a speed exceeding the speed of sound in the bubble fluid generated when the gas solution flows through the decompression plate.

In the above formulas (1) and (2), Va is the speed of sound waves in the bubble fluid [m / sec], P ₀ is the pressure of the gas solution [Pa], and Q is the flow rate of the gas solution [m. ³ / sec], d is the pore diameter [mm], and n is the number of pores [pieces].

  In the fine bubble generator of the present invention, it is preferable that the size of the gap between the decompression plate and the shock wave propagation direction regulating plate is smaller than 1.5 mm.

Furthermore, in the fine bubble generator of the present invention, the casing is cylindrical,
The shock wave propagation direction restricting plate is a disc-shaped member having an outer diameter smaller than the inner diameter of the casing and forming an annular gap between the outer peripheral surface of the shock wave propagation direction restricting plate and the inner peripheral surface of the casing. There,
An opening formed in the central portion while turning and stirring the fine bubble liquid generated in the semi-sealed region, which flows through the annular gap toward the discharge port, and flows inward in the radial direction of the casing. It is preferable that the stirring plate that flows out through the pressure plate is provided in parallel to the decompression plate and the shock wave propagation direction restriction plate at a position separated from the shock wave propagation direction restriction plate.

  The fine bubble supply system of the present invention includes a vortex pump that mixes a gas with a liquid and discharges it as a gas-liquid mixture, and pressurizes the gas-liquid mixture supplied from the vortex pump to dissolve the gas in the liquid. A pressure dissolution means for generating a gas solution and the fine bubble generator for generating fine bubbles by supplying the gas solution from the pressure dissolution means are provided.

  According to the fine bubble generator of the present invention, the pressurized gas solution is discharged at a flow rate equal to or higher than the speed of the sound wave in the bubble fluid generated when the gas solution flows through the pressure reduction plate. And a shock wave propagation direction restricting plate is provided in parallel with the pressure reducing plate at a position spaced from the decompression plate to form a semi-sealed region for restricting the propagation direction of the shock wave energy. A sufficient decompression action on the dissolved solution can be obtained, and the action of the energy of the shock wave generated in the semi-enclosed region can be obtained with certainty. As a result of being able to be crushed and broken down by the energy of shock waves, it is possible to reliably generate a sufficiently large amount of fine bubbles. .

  Further, since the stirring plate is provided, the stirring action is obtained by turning the flow direction of the fine bubble liquid generated in the semi-sealed region, so that the fine bubbles can be further miniaturized. it can.

  According to the fine bubble supply system of the present invention including the fine bubble generator as described above, fine bubbles having a bubble diameter of 50 μm, so-called microbubbles, can be stably supplied in a sufficiently large amount.

The present invention will be described below with reference to the drawings.
FIG. 1 is an explanatory view showing an outline of the configuration of an example of the fine bubble supply system of the present invention, and FIG. 2 shows an outline of an example of the configuration of the fine bubble generator of the present invention with a part of the casing broken. FIG. 3 is an exploded perspective view, and FIG. 3 is an axial sectional view of the microbubble generator shown in FIG.
The fine bubble supply system 10, for example, pumps a liquid such as water W in a bathtub 11 by a vortex pump 15, mixes a gas such as air A with this, and a pressurized dissolution tank (gas-liquid mixing tank) which is a pressure dissolution means. The gas dissolved water WA produced by dissolving air in water in the pressurized dissolution tank 18 is supplied to the fine bubble generator 20, thereby generating fine bubbles and circulating them into the bathtub 11. It is configured as a system. In FIG. 1, 12 is a suction filter for removing the dust in the water W in the bathtub 11, and 16 is adjusting the air A to be introduced into an appropriate amount according to the flow rate of the water W and achieving the expected value. This is a flow rate adjusting valve for obtaining the discharge pressure.

The pressure dissolution tank 18 pressurizes the gas-liquid mixed water supplied from the vortex pump 15 to dissolve the air in the water, and excludes air that is not dissolved in the water but is in the form of bubbles (usually bubbles). It has a function.
The pressure in the pressurized dissolution tank 18, that is, the pressure applied to the supplied gas-liquid mixed water is, for example, 2 to 4 atmospheres (about 2 × 10 ⁵ to 4 × 10 ⁵ Pa), and the air is dissolved in water. The time required for this is, for example, 5 to 6 seconds.

The fine bubble generator 20 generates an initial bubble by adding a pressure reducing action to the pressurized gas dissolved water WA supplied from the pressurized dissolution tank 18, and crushes and splits the initial bubble. In this way, fine bubbles are generated.
The configuration of the fine bubble generator 20 will be described in detail. As shown in FIGS. 2 and 3, for example, a cylindrical casing 21 made of plastics having a fine bubble discharge port 22 at one end, and the casing 21. A disc-shaped decompression plate 25 having an outer diameter equivalent to the inner diameter of the casing 21 provided in the opening 23 on the other end side is provided. The holes 26 are formed at concentric positions so as to be spaced apart at equal angular intervals. Reference numeral 27 denotes a gas-dissolved water supply pipe connected to the pressurized dissolution tank 18.

The fine bubble generator 20 generates a shock wave in a bubble fluid and collapses the initial bubble by the action of the energy of the shock wave to generate a fine bubble.
For example, when a jet plane flies at a speed exceeding the sound speed of air, it is known that a strong shock wave (pressure wave) is generated from the tip of the jet plane. In the fine bubble generator 20, a shock wave is generated in a bubble fluid. In order to cause the gas dissolved water WA to pass through the pores of the decompression plate 25 at a speed exceeding the speed of the sound wave in the bubble fluid generated when the gas dissolved water WA flows through the pores 26 of the decompression plate 25. 26 is distributed.

  In the fine bubble generator 20, the gas dissolved water WA is passed through the pores 26 of the decompression plate 25 at a speed exceeding the speed of sound waves in the bubble fluid generated by the fine bubbles 26. The energy of the shock wave generated by flowing through the hole 26 is prohibited from diffusing in the axial direction of the casing 21, and a semi-sealed region for propagating the energy in the radial direction is defined, and the gas dissolved water WA The shock wave propagation direction regulating plate having a function as a baffle plate that prohibits direct outflow in the direction of the fine bubble discharge port 22 is located in the casing 21 at a position spaced apart in the axial direction of the decompression plate 25 and the casing 21. It is provided in parallel with the decompression plate 25.

The shock wave propagation direction restricting plate 30 is a disc having a diameter smaller than the inner diameter of the casing 21, and an annular gap 31 is provided between the outer peripheral surface of the shock wave propagation direction restricting plate 30 and the inner peripheral surface of the casing 21. Is formed.
Since the shock wave propagation direction regulating plate 30 regulates the propagation direction of the energy of the shock wave, only the circular region facing the formation region of the plurality of pores 26 in the decompression plate 25, that is, the region where the gas dissolved water WA is discharged. However, the diameter of the circular region is at least 150% larger than that of the circular region.
Moreover, it is preferable that the magnitude | size g of the clearance gap (separation distance) between the shock wave propagation direction control plate 30 and the decompression plate 25 is 0.2-1.5 mm, for example. Thereby, the effect | action by the energy of the shock wave which generate | occur | produces in the semi-sealed area | region S can be acquired reliably.

Further, in the fine bubble generator 20, the fine bubble generator 20 flows through the annular bubble 31 formed between the outer peripheral surface of the shock wave propagation direction regulating plate 30 and the inner peripheral surface of the casing 21 in the direction of the fine bubble discharge port 22. A stirring plate 35 for turning the flow of the fine bubble water MB generated in the semi-enclosed space S and stirring the fine bubble water MB by this is provided.
The stirring plate 35 has a disk shape having the same diameter as the inner diameter of the casing 21, and an opening 36 through which the fine bubble water MB flows out in the direction of the fine bubble discharge port 22 is formed at the center. Therefore, the fine bubble water MB flowing out from the semi-sealed region S is prohibited from flowing axially outward along the inner wall of the casing 21 and flows toward the radially inner side of the casing 21. Turned around.
The size h of the separation distance between the stirring plate 35 and the shock wave propagation direction regulating plate 30 is preferably 3 to 10 mm, for example. Thereby, sufficient stirring action with respect to the fine bubble water MB produced | generated in the semi-sealed area | region S can be acquired.

  As described above, in the fine bubble generator 20, the gas dissolved water WA flowing out from the pores 26 of the decompression plate 25 is turned by the shock wave propagation direction regulating plate 30 so as to flow outward in the radial direction. It flows out from the semi-sealed region S through the annular gap 31 formed between the outer peripheral surface of the propagation direction restricting plate 30 and the inner peripheral surface of the casing 21, and thereafter the diameter is decreased by the stirring plate 35. A meandering flow path that is turned so as to flow inward in the direction and is discharged from the fine bubble discharge port 22 through the opening 36 is formed. By providing such a flow path, sufficient stirring action for the fine bubble water MB generated in the semi-sealed region S can be obtained, and further bubble refinement can be achieved.

As described above, in the fine bubble generator according to the present invention, the gas dissolved water WA in a pressurized state supplied from the pressurized dissolution tank 18 is passed through the decompression plate 25. Is caused to flow through the pores 26 of the decompression plate 25 at a speed exceeding the speed of the sound wave in the bubble fluid generated by the above, and a shock wave is generated in the bubble fluid.
In the fine bubble generator 20, the pore diameter and the number of the pores 26 formed in the decompression plate 25 are set so as to satisfy the above formulas (1) and (2). The WA can flow through the pores 26 of the decompression plate 25 at a speed exceeding the speed of sound in the gas dissolved water WA.

The above formula (1) is defined as follows: Q (m ³ / min) is the flow rate of the dissolved gas WA flowing through the pores 26, V (m / sec) is the flow velocity, and A (m ² ) is the total area. Since the flow rate Q is indicated by the product of the flow velocity V and the total area A, it can be obtained by setting the flow velocity V to be equal to or higher than the velocity Va of the sound wave in the bubble fluid.

The above formula (2) is derived as follows. That is, generally, the velocity (sound velocity) Va of the sound wave in the bubble fluid is very small, the pressure is P [Pa], the void ratio (bubble volume / total volume) is α, and the density of the liquid is ρ [kg / m ³ ]. Then, it is shown by the following formula (A).
Further, from Bernoulli's theorem, when the flow velocity V becomes equal to the sonic velocity Va in the bubble fluid, the sonic velocity Va is expressed by the following equation (b), and the pressure of the pressurized dissolution tank 18 (pressurized pressure against the gas solution) ) Is P ₀ , this value is the pressure when V = 0, and therefore K in the following formula (B) is represented by the following formula (C). Here, when the liquid is water as in this embodiment, the density ρ is 10 ³ [kg / m ³ ], and the void ratio α in the semi-closed region S is 0.1. The above formula (2) is obtained from (b) and formula (c).

For example, when the pressure in the pressurized dissolution tank 18 (the pressurized pressure of the gas dissolved water WA to be supplied) P _{0 is set} to 3 atmospheres (3 × 10 ⁵ Pa), the gas dissolved water WA is reduced to the decompression plate 25. The velocity of sound Va in the bubble fluid generated by flowing through the gas is 22.6 m / sec from the above equation (2). From this calculation result, the pore diameter d of the pores 26 and The number n of the pores 26 is set.
And, by being configured so as to obtain a velocity equal to or higher than the sound velocity Va in the bubble fluid, basically, a shock wave can be reliably generated in the semi-sealed region S, and the pore 26 can be passed. Thus, a sufficient pressure reducing action on the gas-dissolved water WA can be obtained, and initial bubbles can be generated reliably.

Hereinafter, the operation of the fine bubble supply system 10 will be described.
First, when the vortex pump 15 is actuated, the water W in the bathtub 11 is pumped up through the suction filter 12 and the air (outside air) A adjusted to an appropriate amount by the flow rate adjusting valve 16 is sucked into the water W And air A are mixed and discharged into the pressurized dissolution tank 18 as gas-liquid mixed water.
Then, in the pressurized dissolution tank 18, air A is dissolved in the water W by pressurizing the supplied gas-liquid mixed water, and air that is in the form of bubbles without being dissolved is excluded. As a result, the gas-dissolved water WA in which air is dissolved in water to the limit and saturated is generated.
Thereafter, the gas dissolved water WA in a pressurized state is supplied to the fine bubble generator 20, and the velocity Va of sound waves in the bubble fluid generated when the gas dissolved water WA flows through the decompression plate 25. By passing through the pores 26 of the decompression plate 25 at a speed exceeding 1, initial bubbles are generated in the semi-sealed region S due to the decompression action, and the generated initial bubbles are generated in the semi-sealed region S. It is crushed, broken up by energy, and refined, thereby producing fine bubbles. Here, the shock wave is prohibited from diffusing with respect to the axial direction of the casing 11 by providing the shock wave propagation direction regulating plate 30, for example, with respect to the outflow direction (axial direction) of the gas dissolved water WA. Are propagated along the vertical direction (the surface direction of the shock wave propagation direction regulating plate 30) and act on the initial bubble mixed water flowing outward in the radial direction.
And the fine bubble water MB produced | generated in the semi-sealed area | region S flows out toward an axial direction outward via the cyclic | annular space | gap 31, and directs toward the fine bubble discharge port 22 as it is by the stirring plate 35 after that. By being prohibited from flowing, the liquid is turned inward in the radial direction, whereby the fine bubbles are further refined while being agitated and further from the fine bubble discharge port 22 through the opening 36 of the stirring plate 35. The fine bubble water MB is supplied by being refluxed.

Thus, according to the fine bubble generator 20 having the above-described configuration, the pressurized gas-dissolved water WA is converted into the sound wave in the bubble fluid generated when the gas-dissolved water WA flows through the decompression plate 25. The pore 26 of the decompression plate 25 is allowed to flow at a flow velocity equal to or higher than the velocity Va, and a shock wave propagation direction restricting plate 30 is disposed in parallel to the pressure plate 25 at a position away from the decompression plate 25 to change the propagation direction of the energy of the shock wave. By forming the semi-sealed region S to be regulated, it is possible to obtain a sufficient pressure reducing action on the gas dissolved water WA and to surely obtain the action of the energy of the shock wave generated in the semi-sealed region S. The initial bubble can be generated reliably by the action, and the generated initial bubble can be crushed by the energy of the shock wave, broken down and refined Kill result, it is possible to sufficiently ensure produce large quantities of fine bubbles.
In addition, since the stirring plate 35 is further provided, the flow direction of the fine bubble water MB generated in the semi-sealed region S is changed, so that the stirring action is obtained, so that the fine bubbles are further refined. Can be achieved.
Therefore, according to the fine bubble supply system 10 including such a fine bubble generator 20, fine bubbles having a bubble diameter of 50 μm, so-called microbubbles, can be stably supplied in a sufficiently large amount.

Hereinafter, experimental examples performed for confirming the effects of the present invention will be described.
With reference to the structure shown in FIG. 2 and FIG. 3, the fine bubble generator (20) based on this invention was produced. The specific configuration of each component is as follows.
[Case (21)]
Material: Plastics, Inner Diameter: φ46mm, Length: 50mm
[Decompression plate (25)]
Material: stainless steel, diameter: φ46 mm, thickness: 2 mm, pore diameter (d): φ1.1 mm, number (n) 8 pieces, forming position: equiangular spacing on a concentric circle with a radius of 6 mm centering on the shape center Separated positions [Shock wave propagation direction regulating plate (30)]
Material: Plastics, Diameter: φ40mm, Thickness: 5mm, Separation distance (g) from decompression plate: 1.0mm
[Stirring plate (35)]
Material: Plastics, Diameter: φ46 mm, Thickness: 5 mm, Opening diameter of opening: φ26 mm, Separation distance from shock wave propagation direction regulating plate (h): 1 mm

A fine bubble supply system (10) is constructed according to the configuration shown in FIG. 1 using the fine bubble generator, water having a temperature of 20 ° C. as liquid and air as gas, and water 10 liter / min (flow rate (Q)). : 0.17 × 10 ⁻³ m ³ / sec), the air is mixed at a rate of 300 cc / min, and the pressure (pressurized pressure) P ₀ in the pressurized dissolution tank is set to 3 atm (3 × 10 ⁵ Pa) was set and operated.
The bubbles obtained by this fine bubble generator are confirmed to be so-called “microbubbles” having an average bubble diameter of about 32 μm, and fine bubble water is supplied at 10 liters / min. It was confirmed that the flow rate can be obtained stably. Here, the bubble diameter was measured by observing bubbles rising up the thin tube with a CCD camera equipped with a 4.5 × zoom lens.

As mentioned above, although embodiment of this invention was described, this invention is not limited to said embodiment, A various change can be added.
For example, the liquid constituting the gas solution supplied to the fine bubble generator and the type (combination) of the gas dissolved therein are not limited to water and air. Examples of the liquid include seawater and silicone. Examples of the gas include oil, and examples of the gas include oxygen, ozone, and carbon dioxide gas.
Further, the material, thickness, and other specific configurations of each plate constituting the fine bubble generator are not particularly limited, and may be a configuration without a stirring plate.

The microbubbles (microbubbles) obtained by the microbubble generator of the present invention are, for example, a milky shape that looks like pure white milk, and further has the characteristics as described above. When applied to the above, a beauty effect, a thermal effect, a cleaning effect, etc. can be obtained, and it is expected to be extremely useful.
Also, since the microbubbles themselves have a cleaning effect, a purification effect of harmful substances, etc., for example, semiconductor cleaning treatment, applied to medical applications such as angiography, reduction of ship frictional resistance, natural gas hydrate production, etc. In this case, by using oxygen, ozone, or the like as a gas to be dissolved in the liquid, it is possible to obtain a higher cleaning effect and a harmful substance purification effect, which is extremely useful.
Furthermore, it is expected to be useful when used in water purification (water quality improvement) treatment and fisheries industries such as oyster and shellfish culture.

It is explanatory drawing which shows the outline of a structure in an example of the fine bubble supply system of this invention. It is a disassembled perspective view which shows the outline in one structural example of the microbubble generator of this invention in the state which fractured | ruptured a part of casing. It is an axial sectional view of the fine bubble generator shown in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Fine bubble supply system 11 Bathtub 12 Suction filter 15 Eddy current pump 16 Flow rate adjustment valve 18 Pressurization dissolution tank 20 Fine bubble generator 21 Casing 22 Fine bubble discharge port 23 Opening part 25 Depressurization plate 26 Pore 27 Gas dissolution water supply pipe 30 Shock wave propagation direction regulating plate 31 Annular gap 35 Stirring plate 36 Opening S Semi-enclosed region W Water A Air WA Gas dissolved water MB Fine bubble water

Claims (5)

In a fine bubble generator in which fine bubbles are generated by supplying a pressurized gas solution,
A cylindrical casing in which one opening is a fine bubble discharge port, and a decompression plate provided with a plurality of pores formed in the other opening of the casing through which a gas solution to be supplied flows. The gas solution is passed through the pores of the decompression plate at a speed exceeding the speed of the sound wave in the bubble fluid generated by the gas solution being passed through the decompression plate. In addition, the shock wave propagation direction regulating plate that divides the semi-sealed region that prohibits the energy of the shock wave generated thereby from diffusing in the outflow direction of the gas solution is separated from the decompression plate inside the casing at a position separated from the decompression plate. A microbubble generator characterized by being provided in parallel. 2. The fine bubble generator according to claim 1, wherein the pores in the decompression plate have a pore size and number set so as to satisfy the relationship of the following formulas (1) and (2): .

  The fine bubble generator according to claim 1 or 2, wherein the size of the gap between the decompression plate and the shock wave propagation direction regulating plate is smaller than 1.5 mm. The casing is cylindrical,
The shock wave propagation direction restricting plate is a disc-shaped member having an outer diameter smaller than the inner diameter of the casing and forming an annular gap between the outer peripheral surface of the shock wave propagation direction restricting plate and the inner peripheral surface of the casing. There,
An opening formed in the central portion while turning and stirring the fine bubble liquid generated in the semi-sealed region, which flows through the annular gap toward the discharge port, and flows inward in the radial direction of the casing. The agitating plate that flows out through the shock wave is provided in parallel with the decompression plate and the shock wave propagation direction restriction plate at a position separated from the shock wave propagation direction restriction plate. The described fine bubble generator.   A vortex pump that mixes a gas with a liquid and discharges it as a gas-liquid mixture, and a pressurized solution that generates a gas solution by dissolving the gas into the liquid by pressurizing the gas-liquid mixture supplied from the vortex pump A fine bubble supply system comprising: a means and a fine bubble generator according to any one of claims 1 to 4 which generates fine bubbles by supplying a gas solution from the pressure dissolution means.

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