JP2012176335A - Microbubble generator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a microbubble generator capable of reliably generating a large number of fine air bubbles with uniform size at a low cost.SOLUTION: The microbubble generator includes: a case body which communicates an inflow opening of liquid to an outflow opening of the liquid with a main path; a squeezing part disposed on the middle of the main path; and a gas mixing means formed on the squeezing part. The gas mixing means includes: a gas introducing hole which penetrates the case body in the thickness direction and is communicated with the main path; an annular slit which is arranged on the squeezing part, is communicated with the gas introduction hole and is opened to the main path; and an annular space which is communicated with the gas introduction hole and is communicated with the annular slit. An oblique introduction means for introducing gas from an annular space, that is, the gas from the annular slit obliquely toward the downstream direction of the flow of liquid in the main path is disposed and, thereby, the gas is obliquely introduced from the outer circumferential side of the main path in the downstream direction of the flow of the liquid.

Description

  The present invention relates to a microbubble generator that generates micrometer-sized fine bubbles in a liquid.

  Micrometer-order microbubbles generated in the liquid have a small bubble volume, so the rising speed is slower than that of normal size bubbles such as a diameter of about 5 mm or more. Continued, the smaller the bubble size, the higher the internal pressure of the bubble due to the effect of surface tension caused by water, and the gas dissolves in water. In addition, it has become known to have utility value in various fields by utilizing water purification, cleaning of mechanical devices, and the function of removing surfactants in waste water. An apparatus for generating microbubbles having such a useful function in a liquid is a condition that generates a large number of microbubbles in the liquid and has a good performance to have certainty of generating microbubbles. It is. For example, there have been conventionally proposed microbubble generators in Patent Documents 1 and 2.

JP 2007-21343 A JP 2008-23435 A

In the microbubble generator of Patent Document 1, a rectifying cylinder 6 is arranged in a double cylinder in a cylindrical casing 4, and a first propeller blade row 7 is installed in the gap between the casing and the rectifying cylinder, and rectification is performed. The second propeller blade cascade 8 is installed in the cylinder, and gas is introduced into the casing through the small holes 18 communicating with the gas introduction port 17, thereby generating microbubbles as a swirling flow in the reverse direction of the inside and outside of the casing. Is to promote. However, the device of Patent Document 1 has a structure in which blades and the like for guiding the fluid in a spiral shape are installed between the casing and the rectifying cylinder, and the manufacturing is not easy and the cost increases. Since the gas introduction part is formed at only one small hole 18, the amount of microbubbles generated is limited, and there is a problem that the functions unique to the microbubbles cannot be fully exhibited.
Patent Document 2 discloses a microbubble in which a longitudinal center of a horizontally long cylindrical casing is a throat portion 6, a cone-shaped portion 5 is formed on one end side, and a divergent nozzle portion 7 is formed on the other end side to communicate with each other through a flow path 23. In the generator, an advancing / retracting rod 8 provided with an air passage 4 for compressed air is installed in the cone-shaped portion 5 to adjust the amount of liquid passing through the throat portion by the advancing / retreating operation of the distal end of the advancing / retreating rod to the throat portion However, it is intended to generate microbubbles. However, also in the apparatus of Patent Document 2, the gas introduction is performed only by the pinhole 42 at the tip of the advance / retreat rod, and the amount of microbubble generation itself is not increased. In addition, the apparatus of Document 2 has a large variation in bubble size as in Document 1, and many bubbles larger than millimeter size are included. As a result, most of the bubbles rise to the interface in contact with the atmosphere, and thus contract in water. There is a problem that the advantageous effect in the application field due to the physical properties of water is not sufficiently obtained due to the small number of bubbles.

  The present invention has been made in view of the above-described conventional problems, and its purpose is to produce a simple structure at a low cost and not only generate a large number of fine bubbles but also uniformly generate micrometer-sized fine bubbles. It is an object of the present invention to provide a microbubble generator that can be reliably generated with a proper distribution and can fully exhibit the function of microbubbles.

  In order to solve the above problems, the present invention provides a case body 2 in which an inflow opening 10a for a liquid L provided on one end side and an outflow opening 10b for a liquid provided on the other end side communicate with each other through a main passage 10, and a main passage 10, and a gas mixing unit 4 formed in the throttle unit. The gas mixing unit penetrates the case body 2 in the thickness direction and communicates with the main passage 10. A hole 6, an annular slit 7 that is disposed in the throttle portion 3 and communicates with the gas introduction hole 6 and opens to the main passage 10; and an annular space 8 that communicates with the gas introduction hole 6 and communicates with the annular slit 7. The generation of microbubbles characterized in that there is provided oblique introduction means 5 for introducing the gas G from the annular space 8 obliquely in the downstream direction DW of the liquid flow in the main passage 10 from the annular slit 7 It is comprised from the container 1.

  At this time, the oblique introduction means 5 may include a wall 20 having an inclined section facing the annular space 8 and provided in an inclined manner in the liquid flow downstream direction DW of the main passage 10 and leading to the annular slit 7.

  The annular slit 7 may be provided in the vicinity of the maximum throttle position P in the throttle unit 3 and on the downstream side of the maximum throttle position.

  Further, the throttle portion 3 is an annular protrusion that is partly in contact with the main passage 10 and the other portion is in contact with the annular space 8 and forms an annular slit 7 around the tip, and the liquid flow in the main passage 10 in the downstream direction DW. It is preferable to include a protruding annular protrusion 22.

  Further, it is more preferable that the annular protrusion 22 has a sharp shape toward the downstream side of the liquid flow in the main passage 10.

  In addition, the microbubble generator of the present invention includes a first case portion 12 having a first taper portion 14 whose diameter is gradually reduced toward the throttle portion 3, and a diameter gradually increasing from the throttle portion 3. The case body 2 is configured by joining the second case portion 52 having the second tapered portion 54 that is large, and the annular protrusion 22 is formed on the throttle portion 3 of the first case portion 12, so that the second case portion 52 is formed. The annular protrusion 22 may be disposed close to the main passage inlet (62) of the throttle portion of the second case portion 52 so as to form an annular slit 7 with a minute gap between the passage mouth edge 62 of the throttle portion.

  At this time, when the annular protrusion 22 is disposed close to the second case portion 52 at the joint portion between the first case portion 12 and the second case portion 52, the gas introduction hole 6 and the annular slit 7 are formed on the outer peripheral side of the annular protrusion. It is preferable to provide an annular space 8 that communicates with.

  Further, the main passage 10 is formed in a circular cross section, and a pair of magnetic bodies as counter electrodes may be disposed at a position near the throttle portion 3 of the case body 2 and at a position facing the diameter direction of the main passage 10.

  According to the microbubble generator of the present invention, the case body in which the liquid inflow opening provided on one end side and the liquid outflow opening provided on the other end side are communicated with each other through the main passage, and provided in the middle of the main passage. The gas mixing means includes a throttle portion and a gas mixing means formed in the throttle portion, and the gas mixing means is arranged in the throttle portion so as to pass through the case body in the thickness direction and communicate with the main passage. An annular slit that communicates with the hole and opens to the main passage; and an annular space that communicates with the gas introduction hole and communicates with the annular slit, the gas from the annular space, and the liquid in the main passage from the annular slit. Since it has a configuration that includes an oblique introduction means that introduces gas in a direction downstream of the flow, it can be manufactured at a low cost with a simple configuration, and not only generates many fine bubbles but also a micrometer-sized micro Bubbles Reliably generate a uniform distribution can be sufficiently exhibit the function of the micro-bubble. In particular, since the gas is introduced obliquely in the downstream direction of the liquid flow of the main passage from the annular slit by the gas oblique introduction means, there is no hindrance when introduced into the passage, and the gas flows smoothly into the main passage. Can be introduced into the liquid passage to reliably generate a large number of equally sized microbubbles.

  In addition, the oblique introduction means is configured to include an inclined wall that faces the annular space and is provided in an inclined manner in the downstream direction of the liquid flow of the main passage and communicates with the annular slit. An inclined wall facing the annular space can be formed, and gas can be introduced into the liquid passage with a smooth flow into the main passage to effectively produce a large number of equally sized microbubbles. .

  Further, the annular slit is provided in the vicinity of the maximum throttle position in the throttle portion and on the downstream side of the maximum throttle position. A special configuration having an introduction means and an annular slit can be realized simultaneously in the throttle part of the venturi tube.

  Further, the throttle portion is an annular protrusion that is partly in contact with the main passage and the other portion is in contact with the annular space and forms an annular slit around the tip, and includes an annular protrusion that protrudes in the downstream direction of the liquid flow in the main passage. Because of the configuration, it is possible to specifically realize the oblique gas introduction means and the formation of the annular space.

  In addition, the annular protrusion is configured to have a sharpened shape toward the downstream direction of the liquid flow in the main passage, thereby realizing oblique gas introduction means and formation of an annular space. It is possible to cause micro vibrations by flowing different phases through the front and back surfaces of the annular space, thereby promoting the generation of microbubbles.

  Also, a first case portion having a first taper portion whose diameter is gradually reduced toward the throttle portion, and a second case portion having a second taper portion whose diameter is gradually increased from the throttle portion. To form a ring-shaped protrusion on the throttle portion of the first case portion, and to form an annular slit with a minute gap between the passage opening edge of the throttle portion of the second case portion. By adopting a configuration in which an annular protrusion is arranged close to the main passage inlet of the throttle part of the second case part, the joint part of the two parts of the first and first case parts is specifically used in the embedded shape. An annular space, a cross-sectionally inclined wall, and an annular slit can be formed.

  In addition, an annular space communicating with the gas introduction hole and the annular slit is provided on the outer peripheral side of the annular protrusion when the annular protrusion is disposed close to the second case part at the joint between the first case part and the second case part. Therefore, a circular gas can be introduced from the outer peripheral side of the main passage toward the obliquely downstream side through the annular slit.

  In addition, the main passage is formed in a circular shape in cross section, and has a configuration in which a pair of magnetic bodies as counter electrodes are arranged at positions near the throttle portion of the case body and in the diameter direction of the main passage. Reduce the surface tension of the liquid, reduce the gas-liquid interfacial tension of the microbubbles to ensure the contraction of the bubbles in the liquid, increase the dissolved oxygen concentration to improve the water quality and make the water purification effect more effective. be able to.

It is a longitudinal cross-sectional view of the microbubble generator which concerns on embodiment of this invention. It is an AA arrow line view of FIG. It is a BB line arrow directional view of FIG. FIG. 2 is an enlarged explanatory view of a part of the microbubble generator of FIG. FIG. 2 is an exploded vertical cross-sectional explanatory view showing the microbubble generator of FIG. (A) is the figure seen from the end surface side of the 1st semi-casket case of FIG. 5, (b) is the figure seen from the end surface side of the 2nd semi-casket case of FIG. It is explanatory drawing which shows the example of installation of the microbubble generator of embodiment. It is action | operation explanatory drawing of the microbubble generator of FIG. It is a longitudinal cross-sectional structure explanatory drawing of the microbubble generator concerning the 2nd Embodiment of this invention. It is a graph which shows the bubbling time of the treated water by the microbubble generator of FIG. 9, and the relationship between surface tension.

  Next, the microbubble generator which concerns on embodiment of this invention is demonstrated with reference to FIGS. The microbubble generator of the present invention is a device for generating a microbubble by pumping a liquid into a passage in the case body and simultaneously introducing a gas into the flow of the liquid. A gas-liquid mixed fluid is generated by introducing gas, and a fluid containing a large number of microbubbles with a diameter of about several tens of microns in a homogeneous distribution is generated. Here, the microbubble refers to a bubble having a size of several tens of microns or less, specifically, a bubble having a size of 50 μm to 1 μm.

  1 to 6 show a microbubble generator 1 according to an embodiment of the present invention. In the drawing, the microbubble generator 1 includes a case body 2, a throttle portion 3, a gas mixing means 4, Gas oblique introduction means 5. The gas mixing means 4 includes a gas introduction hole 6, an annular slit 7, and an annular space 8.

  In the microbubble generator 1 of the embodiment, a main passage 10 penetrating along the axis in the direction of the cylinder axis 100 is formed in a cylindrical case body 2, and a liquid inflow opening is formed on one end side of the main passage 10. 10 a is provided, and a liquid outflow opening 10 b is provided on the other end side of the main passage 10. The inflow opening 10 a and the outflow opening 10 b are communicated with each other through the main passage 10. The case body 20 is formed of a metal or a plastic material and has strength and rigidity that can withstand liquid pumping. The material of the case body 20 may be glass or ceramics. In the embodiment, plastic is used because it is easy to mold and the manufacturing cost is low. For product molding, methods such as cutting from bulk material, casting, and extrusion molding can be used.

  A throttle portion 3 is formed at the middle position in the longitudinal direction of the main passage 10 to restrict the passage into an orifice shape. In the embodiment of FIG. 1, the throttle portion 3 is provided at a position where the entire length L3 is divided into, for example, about 1: 4. The throttling unit 3 reduces the liquid passage to increase the flow rate of the liquid and increase the flow velocity, so that the downstream side pressure after the maximum throttling position is drastically decreased compared to the first taper unit and the low-speed unit on the upstream side. At this time, microbubbles are generated.

  In FIG. 1, the case body 2 includes a first case portion 12 having a first taper portion 14 and a second case portion 52 having a second taper portion 54, and the first and second case portions 12, 52. Are connected in series at an intermediate position of the main passage 10 to form the case body 2. In the present embodiment, as shown in FIG. 5, the first and second case portions 12 and 52 are respectively joined to the separate end portions of the first and second half-cases 16 and 56 to form the case body 2. It is integrated. Thus, the first taper portion 14 of the first case portion 12 is a portion where the inner diameter of the main passage gradually decreases from the inflow opening 10 a toward the throttle portion 3, and the second taper portion of the second case portion 52. 54 is a portion in which the inner diameter of the main passage gradually increases from the throttle portion 3 toward the outflow opening 10b, and these are assembled in series so that the entire main passage is integrally connected and the throttle portion 3 is provided in the middle. As a Venturi tube is formed. The main passage 10 has a circular cross section.

  The first case portion 12 is made of a cylindrical body having a length L1 shorter than that of the second case portion 52, and the second case portion 52 is made of a cylindrical body having a length L2 longer than that of the first case portion 12. .

  The passage in the first case portion 12 is formed by a parallel portion 18 having a parallel wall in cross section and a first taper portion 14 that continues to the parallel portion 18 and gradually decreases the passage diameter toward the throttle portion 3. . One end opening of the parallel part 18 is a liquid inflow opening 10a, and the liquid is introduced as a parallel flow by the parallel part 18 and is pumped toward the throttle part 3 side. The taper angle from the parallel portion 18 of the first taper portion 14 toward the maximum throttle position P is set larger than the taper angle from the maximum throttle position P of the second taper portion 54 to be described later toward the outflow opening 10b, and a steeply inclined wall surface is formed. ing.

  The passage in the second case portion 52 is formed so that the passage diameter on the one end 58 side which is a part of the throttle portion 3 is the smallest, and the passage diameter gradually increases toward the liquid outflow opening 10b on the other end with a gentle gradient. Is formed.

  As shown in FIGS. 1 and 4, the maximum aperture position P of the aperture portion 3 is set at the joint portion of the first and second case portions 12 and 52. Gas mixing means 4 is provided in the throttle portion 3 including the maximum throttle position P.

  As shown in FIGS. 1 and 4, in the vicinity of the narrowed portion 3 of the second case portion 52, a gas introduction hole 6 that penetrates the case body of the second case portion in the thickness direction and communicates with the main passage 10 is provided. Yes. The gas introduction hole 6 is provided on the case body surface side slightly downstream from the maximum throttling position P, and is provided, for example, in a direction penetrating through the thick portion of the case body in communication with the connection port 60 that is threaded. Yes. The gas introduction hole 6 is a guide passage that introduces, for example, air or all other gases into the main passage 10 of the case body 2 from the outside, and is preferably a passage that extends linearly in the thickness direction. The gas introduced into the main passage 10 may be pumped to the gas introduction hole 6 by a blower or the like, or may be naturally sucked to the main passage side.

  An annular space 8 is provided in the vicinity of the throttle portion 3 and communicated with the gas introduction hole 6. In the embodiment, the annular space 8 is annularly provided at a position close to the maximum throttle position P and close to the main passage 10. That is, the annular space 8 is provided in an annular shape so as to be embedded in the thick portion of the constituent wall of the case body 2 so as to surround the main passage 10 at a position outside the main passage 10 in a cross-sectional view. The annular space 8 receives a gas from the gas introduction hole 6 to form a gas reservoir portion that is annularly surrounded outside the main passage 10 and is directed into the main passage 10 via the annular slit 7 as will be described later. Gas is simultaneously introduced from the annular gap so as to go from the outer peripheral side to the cylinder core side. In the embodiment, the annular space 8 has a configuration of the case body 2 in which a recess is provided in one or both of the first and second semi-casing cases in the abutting contact portion between the first semi-casing case 16 and the second semi-casing case 56. It is provided in a ring shape in an embedded state in the thick portion of the wall. The gas mixing means 4 includes a gas introduction hole 6, an annular slit 7, and an annular space 8. When the width (gap) d1 of the annular slit 7 is set to a ratio of the passage inner diameter d2 at the maximum throttle position P and d1 / d2 = 0.0001 to 0.5, the microbubble size (for example, 50 μm or less) is fine. It has been experimentally confirmed that bubbles can be reliably generated. More preferably, the ratio is d1 / d2 = 0.001 to 0.3. If it is less than 0.0001, the gas amount from the gas introduction hole 6 may not be sufficient, and if it exceeds 0.5, it is difficult to obtain microbubbles of uniform size.

  In the embodiment, the cross-sectional shape of the annular space 8 is a rollover L shape, and communicates with the gas introduction hole 6 at the inlet 81. Furthermore, in this embodiment, a part of the annular space 8 is defined by a cross-sectionally inclined wall 20 facing the annular space 8. The cross-sectionally inclined wall 20 faces the annular space 8 and is formed so as to be inclined in the downstream direction DW of the liquid flow in the main passage 10 so as to communicate with the annular slit 7. The cross-sectionally inclined wall 20 constitutes an oblique introduction means 5 that introduces gas obliquely at an inclination while descending from the annular slit 7 in the liquid flow downstream direction DW of the main passage 10. As shown in FIG. 4, the annular space 8 is provided so as to gradually narrow (taper) a space communicating with the annular slit 7 in a sectional view. Specifically, the inclined wall 20 and the passage mouth edge 62 portion of the second half-case 56 are opposed to each other so as to gradually narrow the space toward the annular slit 7. The cross-sectional shape of the annular space 8 is not limited to the rollover L shape, and may be a space shape having an arbitrary cross section.

  An annular slit 7 that communicates with the gas introduction hole 6 through the annular space 8 and opens to the main passage 10 is provided in communication with the annular space 8. In the present embodiment, the annular slit 7 is provided in such a manner that the tip of the inclined wall 20 is opposed to the passage opening edge 62 side of the second case portion 52 with a minute gap in an annular shape. It is formed by opening to the main passage 10. The annular slit 7 introduces the gas from the outside of the annular space 8 in a slanting manner with an inclination in the downstream direction of the liquid flow in the main passage 10. In the present embodiment, the annular slit 7 is provided in the vicinity of the maximum throttle position P in the throttle unit 3, specifically, slightly downstream from the maximum throttle position P, whereby the liquid flow rate is slightly lower than the maximum. The gas is effectively sucked at the portion where the pressure is slightly increased and the pressure is slightly increased, and fine bubbles are generated. Since the gas is introduced into the liquid flowing through the center in a slanting and inclined manner from the outer annular void, an extremely large number of fine bubbles of uniform size can be generated. In the present embodiment, the annular slit 7 is formed of a circular continuous slit, but a dot-like hole or an intermittent hole may be provided in a circular shape.

  In the present embodiment, as shown in FIG. 5, an annular protrusion 22 is formed on the end face side of the first half-case case 16 that becomes the throttle portion 3 of the first case portion 12. The annular protrusion 22 includes a passage wall 23 that forms a part of the main passage with an annular wall that is continuous from the maximum throttle position P at the end of the first tapered portion 14 and gradually increases in diameter, and the first case portion main body. The front and back opposing wall surfaces have an annular wall 20 having an annular cross section that faces the annular space 8 continuously from the end face. In the embodiment, the annular protrusion 22 protrudes toward the downstream side of the liquid flow in the main passage 10 and has a sharp shape. That is, a part of the annular protrusion 22 is in contact with the main passage 10 and the other part is in contact with the annular space 8 to form the annular slit 7 around the tip of the annular protrusion 22. As a result, the fluid to be pumped inward passes and the gas passes outside, so that the tip 22a of the annular protrusion is caused to vibrate finely, and the generation of more fine bubbles can be promoted. In the embodiment, the annular protrusion 22 is formed on the passage opening edge 62 of the restricting portion of the second case portion 52 so as to form an annular slit 7 with a minute gap between the passage opening edge 62 of the restricting portion of the second case portion 52. An annular slit 7 is formed in a close proximity. Therefore, at the joint portion between the first case portion and the second case portion, the case portions 12 and 52 are joined in a state of forming an annular minute gap that opens to the main passage 10 using the butt-contact state. I am letting.

  As shown in FIG. 6, the end surface of the joint portion of the first half case 16 (see FIG. 6A) is annular so as to frame the circumferential notch 64 for positioning at the outer peripheral portion and the main passage 10 at the central portion. The projection 22, the circumferential cutout 64, and the flat portion 65 in the middle of the annular projection 22 are formed. Further, the joint end face (see FIG. 5B) of the second semi-finished case 56 has a circumferential projection 66 and a flat recess 67 that closely contact the circumferential notch 64 and the flat portion 65 of the first half-case 16. And an annular space 8 and a central recess 68 that forms an annular slit 7 between the annular projection 22 and the first semi-cylindrical case.

  Next, the operation of the microbubble generator 1 of the embodiment will be described. As shown in FIG. 7, the microbubble generator 1 of this embodiment arranges the microbubble generator 1 which connected the pressure feed pump 72 via the pressure feed pipe 74 in the water of the process target water source 70, for example, and has gas introduction holes. A known device for connecting a gas supply hose 76 to the connection port 60 of No. 6 and disposing the tip of the hose to the atmosphere open state (or connecting a compressor) and returning the liquid of the water source 70 to the suction side of the pump 72 by a return pipe 77 Alternatively, it can be used in a system. In this case, since the water of the water source 70 is circulated, for example, the physical properties of the water can be greatly changed. Physical changes in water include a decrease in pH (in the case of distilled water), a decrease in surface tension, and an increase in electrical conductivity. By using water whose physical properties have been changed, effects such as improvement of biological functions, improvement of yield of plants and cultured products, purification of water quality and the like can be achieved. As a result, microbubbles of air are generated in the liquid which is seawater or water or fresh water as the liquid, and water purification and aquatic organism growth promotion functions are performed. The liquid is not particularly limited, and tap water, seawater, lake water, chemicals, cleaning liquid, and the like can be used. When a highly corrosive liquid is used, the case body may be configured using a highly corrosion-resistant material. The gas introduced from the gas introduction hole 6 is not particularly limited, and gases such as air, oxygen, nitrogen, carbon dioxide, and ozone can be used. In addition, a control valve or the like for controlling the gas introduction amount may be installed in the gas introduction hole to control the gas flow rate. That is, not only can this device be installed in a liquid in an environmental environment that has a liquid, it can be applied for purposes such as water purification, but it can also be used for various purposes in other applications using the liquid bubbling with this device. It can also be used.

  In FIG. 1, the liquid flows in the F direction from the inflow opening 10a on the left end side of the microbubble generator in the drawing, and exits from the outflow opening 10b on the right end side through the throttle portion 3 in the middle. The liquid that has flowed in from the inflow opening 10a is narrowed in the first taper portion 14 so that the flow rate is rapidly increased, the flow velocity is increased, and the pressure is drastically lowered and introduced into the throttle portion 3. The flow velocity becomes maximum at the maximum throttle position P, and the passage of the throttle portion 3 portion passing through the maximum throttle position is greatly reduced in negative pressure. At this time, a continuous gas in the form of air or other gas is introduced into the main passage 10 at a high speed from the annular slit 7 at a position downstream from the maximum throttling position P where the allowed liquid flows, and becomes a gas-liquid mixed fluid. At this time, the gas introduced into the main passage from the annular slit 7 is drawn into the inside from a circular continuous hole from the outer peripheral side of the passage, so that a sufficient amount of gas is supplied into the passage and the gas is introduced into the passage. As a result of the gas being ejected from a slit having a small uniform width when introduced into the liquid, a large amount of bubbles of uniform size are formed in the liquid. In particular, in the present embodiment, the gas is introduced from the annular slit 7 into the downstream direction DW of the liquid flow in the main passage 10 by the inclined wall 20 in the annular space 8, and the gas is introduced obliquely at an inclination. The size is continuously reduced and introduced into the main passage from the annular slit. As a result, the gas is introduced into the liquid passage while continuously reducing the size of the circle while smoothly flowing into the main passage 10, so that a large number of uniformly sized bubbles are generated and contracted in the liquid to ensure high quality. Can produce a large amount of microbubbles. Furthermore, in the present embodiment, the annular protrusion 22 has a sharp shape toward the downstream of the liquid flow in the main passage 10, and the liquid and gas simultaneously pass through the inner and outer surfaces at a high speed. As a result of minute vibrations, when the gas is introduced into the main passage 10 from the annular slit 7, the bubbles are likely to be finely sheared in the liquid, thereby promoting the generation of more uniform and more fine bubbles. be able to. More specifically, in FIG. 8, in the application of the microbubble generator of the present embodiment, the case where the liquid is water and the gas is air is taken as an example. By introducing the gas G toward the slant at a slant, the air becomes easy to be introduced into the passage by the flow rate of water, and the annular air (gas) is rapidly introduced into the liquid in the main passage through the annular minute gap. The fine bubbles MB are generated smoothly by being introduced. At this time, by introducing the air along the wall surface including the inclined wall 20 inside, the water released from the depressurized state spreads from the passage edge 62 to the wall surface, and the air is sheared all at once. Bubbles MB can be generated. Further, since the air inlet vibrates at this time, the annular protrusion 22 vibrates at a constant flow velocity, and the shock wave IW is easily generated by the force of water when the air is introduced while vibrating. This shock wave IW occurs several times in the main passage 10 and promotes the generation of fine bubbles MB including microbubbles. As a result, the number and size of the generated bubbles basically exist according to a normal distribution, but it has been experimentally confirmed that the size of the bubble is almost uniform and is about 40 μm. Most of the generated bubbles do not rise and disappear in water. The microbubble generator having the above-described configuration has a small number of components, can be manufactured at low cost, and can have high durability. Further, the first and second half-cases can be joined by bonding or screwing.

  Next, a second embodiment of the present invention will be described with reference to FIG. 9. The same members as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof will be omitted. In the microbubble generator 100 of the second embodiment, the main passage 10 is formed with a circular cross section, and a pair of magnetic forces that are in the vicinity of the throttle portion 3 of the case body 2 and are opposed to each other in the diametrically opposite position of the main passage 10. The point which has arrange | positioned the bodies 91 and 92 differs from 1st Embodiment. By arranging a pair of permanent magnets 91 and 92 having N poles and S poles at positions opposed to each other in the diameter direction of the main passage 10, the surface tension of the liquid is greatly reduced, and the gas-liquid interface tension of the microbubbles is reduced to reduce the bubbles. This ensures the contraction of the liquid in the liquid and increases the dissolved oxygen concentration to improve the water quality and make the water purification effect more effective.

  FIG. 10 shows the measurement results of the surface tension (dyn / cm) over time (minutes) when bubbling using the microbubble generator having the configuration of FIG. 9, and the microbubbles using this magnetism are shown. Using the generator, it was confirmed that the surface tension of water decreased by about 20 dyn / cm after 2 hours of bubbling. In addition, the surface tension measurement used Dunui surface tension meter 514-B2 type (made by Ito Seisakusho). Compared to this, the type of microbubble generator that does not use magnetism showed only a decrease of about 10 dyn / cm. The microbubble generator of the present invention generates a swirl flow in the passage by attaching a circumferential groove, a spiral groove, or a swirl vane for controlling the flow direction of liquid in the main passage of the case body 2. Thus, the physical properties may be changed.

The microbubble generator 1 of the present invention can be applied in all fields utilizing the function of improving the yield of plants and cultured products due to physiological activity, water purification, cleaning of mechanical devices, and the function of removing surfactants in waste water. . The applicant conducted a specific verification of their application. (1) For example, freshwater fish and seawater can be treated with treated water using the microbubble generator of FIG. 1 embodiment, a small pump, and a pneumatic compressor, by purifying water and securing abundant oxygen supply into the water. It was confirmed that fish could be grown in the same aquarium. (2) In addition, 250,000 under 1 cm juvenile shrimp of prawns were released to the farm, and the same configuration as in (1) was implemented to ensure a survival rate of 99.7%. In this regard, the conventional survival rate was about 72%. In addition, the aeration at this time was about 0.1% with respect to the normal aeration of 2000 dm ³ , and the effect of microbubbles was confirmed. (3) In addition, as a result of conducting a demonstration experiment on the samurai shellfish, the use of this device is about four times as large as the size of the shell after 6 months for the treated water used and the unused one Was confirmed. (4) Furthermore, supply of treated water by the microbubble generator 1 of the present invention to fruit pears, vegetable eggplants, tomatoes, cucumbers, yeast production during the production process of shochu, reduction of Escherichia coli, Salmonella, Staphylococcus aureus, etc. It was confirmed that an excellent effect can be obtained for each control group by conducting experiments such as confirmation.

  In the microbubble generator of the present invention, liquid flows through the main passage and gas is introduced from the outside through the gas introduction hole to generate microbubbles. When the liquid is flowed and a negative pressure is introduced from the outside, a mist gas containing ultrafine particles of uniform size can be generated.

  The microbubble generator of the present invention is not limited to the configuration of the above-described embodiment, and may be arbitrarily modified without departing from the essence of the invention described in the claims.

DESCRIPTION OF SYMBOLS 1 Microbubble generator 2 Case body 3 Restriction part 4 Gas mixing means 5 Gas oblique introduction means 6 Gas introduction hole 7 Annular slit 8 Annular space 10 Main passage 10a Inflow opening 10b Outflow opening 12 First case part 14 First taper part 16 First semi-cylindrical case 18 Parallel portion 20 Inclined wall in cross section 22 Annular projection 23 Passage wall 52 Second case portion 54 Second taper portion 56 Second semi-finished case 62 Passage edge MB Fine bubble P Maximum throttle position DW Liquid flow downstream direction

  The present invention relates to a microbubble generator that generates micrometer-sized fine bubbles in a liquid.

  Microbubbles of micrometer order size generated in a liquid have a small bubble volume, so that the rising speed is slower than that of a normal size bubble having a diameter of, for example, about 5 mm or more, and stays in the liquid for a long time. Continued, the smaller the bubble size, the higher the internal pressure of the bubble due to the effect of surface tension caused by water, and the gas dissolves in water. In addition, it has become known to have utility value in various fields by utilizing water purification, cleaning of mechanical devices, and the function of removing surfactants in waste water. An apparatus for generating microbubbles having such a useful function in a liquid is a condition that generates a large number of microbubbles in the liquid and has a good performance to have certainty of generating microbubbles. It is. For example, there have been conventionally proposed microbubble generators in Patent Documents 1 and 2.

JP 2007-21343 A JP 2008-23435 A

  In the microbubble generator of Patent Document 1, a rectifying cylinder 6 is arranged in a double cylinder in a cylindrical casing 4, and a first propeller blade row 7 is installed in the gap between the casing and the rectifying cylinder, and rectification is performed. The second propeller blade cascade 8 is installed in the cylinder, and gas is introduced into the casing through the small holes 18 communicating with the gas introduction port 17, thereby generating microbubbles as a swirling flow in the reverse direction of the inside and outside of the casing. Is to promote. However, the device of Patent Document 1 has a structure in which blades and the like for guiding the fluid in a spiral shape are installed between the casing and the rectifying cylinder, and the manufacturing is not easy and the cost increases. Since the gas introduction part is formed at only one small hole 18, the amount of microbubbles generated is limited, and there is a problem that the functions unique to the microbubbles cannot be fully exhibited. Patent Document 2 discloses a microbubble in which a longitudinal center of a horizontally long cylindrical casing is a throat portion 6, a cone-shaped portion 5 is formed on one end side, and a divergent nozzle portion 7 is formed on the other end side to communicate with each other through a flow path 23. In the generator, an advancing / retracting rod 8 provided with an air passage 4 for compressed air is installed in the cone-shaped portion 5 to adjust the amount of liquid passing through the throat portion by the advancing / retreating operation of the distal end of the advancing / retreating rod to the throat portion. However, it is intended to generate microbubbles. However, also in the apparatus of Patent Document 2, the gas introduction is performed only by the pinhole 42 at the tip of the advance / retreat rod, and the amount of microbubble generation itself is not increased. In addition, the apparatus of Document 2 has a large variation in bubble size as in Document 1, and many bubbles larger than millimeter size are included. As a result, most of the bubbles rise to the interface in contact with the atmosphere, and thus contract in water. There is a problem that the advantageous effect in the application field due to the physical properties of water is not sufficiently obtained due to the small number of bubbles.

  The present invention has been made in view of the above-described conventional problems, and its purpose is to produce a simple structure at a low cost and not only generate a large number of fine bubbles but also uniformly generate micrometer-sized fine bubbles. It is an object of the present invention to provide a microbubble generator that can be reliably generated with a proper distribution and can fully exhibit the function of microbubbles.

In order to solve the above problems, the present invention provides a case body 2 in which an inflow opening 10a for a liquid L provided on one end side and an outflow opening 10b for a liquid provided on the other end side communicate with each other through a main passage 10, and a main passage 10, and a gas mixing unit 4 formed in the throttle unit. The gas mixing unit penetrates the case body 2 in the thickness direction and communicates with the main passage 10. A hole 6, an annular slit 7 that is disposed in the throttle portion 3 and communicates with the gas introduction hole 6 and opens to the main passage 10; and an annular space 8 that communicates with the gas introduction hole 6 and communicates with the annular slit 7. , a gas from the annular space 8, the oblique introduction means 5 for introducing a gas G obliquely in the flow downstream DW liquid of the main passage 10 from the annular slit 7 provided obliquely introducing means 5, the annular space 8 facing downstream of the liquid flow in the main passage 10 Provided with inclined downward countercurrent DW viewed contains a section inclined wall 20 leading to the annular slit 7, annular slit 7 is provided on the downstream side than the maximum aperture position at the maximum aperture position P near of the narrowed portion 3 The microbubble generator 1 is configured.

  At that time, the throttle portion 3 is an annular protrusion that is partly in contact with the main passage 10 and the other portion is in contact with the annular space 8 and forms an annular slit 7 around the tip, and the liquid flow in the main passage 10 in the downstream direction DW It is good to include the annular protrusion 22 which protrudes in the.

  Further, it is more preferable that the annular protrusion 22 has a sharp shape toward the downstream side of the liquid flow in the main passage 10.

  In addition, the microbubble generator of the present invention includes a first case portion 12 having a first taper portion 14 whose diameter is gradually reduced toward the throttle portion 3, and a diameter gradually increasing from the throttle portion 3. The case body 2 is configured by joining the second case portion 52 having the second tapered portion 54 that is large, and the annular protrusion 22 is formed on the throttle portion 3 of the first case portion 12, so that the second case portion 52 is formed. The annular protrusion 22 may be disposed close to the main passage inlet (62) of the throttle portion of the second case portion 52 so as to form an annular slit 7 with a minute gap between the passage mouth edge 62 of the throttle portion.

  At this time, when the annular protrusion 22 is disposed close to the second case portion 52 at the joint portion between the first case portion 12 and the second case portion 52, the gas introduction hole 6 and the annular slit 7 are formed on the outer peripheral side of the annular protrusion. It is preferable to provide an annular space 8 that communicates with.

  Further, the main passage 10 is formed in a circular cross section, and a pair of magnetic bodies as counter electrodes may be disposed at a position near the throttle portion 3 of the case body 2 and at a position facing the diameter direction of the main passage 10.

  According to the microbubble generator of the present invention, the case body in which the liquid inflow opening provided on one end side and the liquid outflow opening provided on the other end side are communicated with each other through the main passage, and provided in the middle of the main passage. The gas mixing means includes a throttle portion and a gas mixing means formed in the throttle portion, and the gas mixing means is arranged in the throttle portion so as to pass through the case body in the thickness direction and communicate with the main passage. An annular slit that communicates with the hole and opens to the main passage; and an annular space that communicates with the gas introduction hole and communicates with the annular slit, the gas from the annular space, and the liquid in the main passage from the annular slit. Since it has a configuration that includes an oblique introduction means that introduces gas in a direction downstream of the flow, it can be manufactured at a low cost with a simple configuration, and not only generates many fine bubbles but also a micrometer-sized micro Bubbles Reliably generate a uniform distribution can be sufficiently exhibit the function of the micro-bubble. In particular, since the gas is introduced obliquely in the downstream direction of the liquid flow of the main passage from the annular slit by the gas oblique introduction means, there is no hindrance when introduced into the passage, and the gas flows smoothly into the main passage. Can be introduced into the liquid passage to reliably generate a large number of equally sized microbubbles.

  In addition, the oblique introduction means is configured to include an inclined wall that faces the annular space and is provided in an inclined manner in the downstream direction of the liquid flow of the main passage and communicates with the annular slit. An inclined wall facing the annular space can be formed, and gas can be introduced into the liquid passage with a smooth flow into the main passage to effectively produce a large number of equally sized microbubbles. .

  Further, the annular slit is provided in the vicinity of the maximum throttle position in the throttle portion and on the downstream side of the maximum throttle position. A special configuration having an introduction means and an annular slit can be realized simultaneously in the throttle part of the venturi tube.

  Further, the throttle portion is an annular protrusion that is partly in contact with the main passage and the other portion is in contact with the annular space and forms an annular slit around the tip, and includes an annular protrusion that protrudes in the downstream direction of the liquid flow in the main passage. Because of the configuration, it is possible to specifically realize the oblique gas introduction means and the formation of the annular space.

  In addition, the annular protrusion is configured to have a sharpened shape toward the downstream direction of the liquid flow in the main passage, thereby realizing oblique gas introduction means and formation of an annular space. It is possible to cause micro vibrations by flowing different phases through the front and back surfaces of the annular space, thereby promoting the generation of microbubbles.

  Also, a first case portion having a first taper portion whose diameter is gradually reduced toward the throttle portion, and a second case portion having a second taper portion whose diameter is gradually increased from the throttle portion. To form a ring-shaped protrusion on the throttle portion of the first case portion, and to form an annular slit with a minute gap between the passage opening edge of the throttle portion of the second case portion. By adopting a configuration in which an annular protrusion is arranged close to the main passage inlet of the throttle part of the second case part, the joint part of the two parts of the first and first case parts is specifically used in the embedded shape. An annular space, a cross-sectionally inclined wall, and an annular slit can be formed.

  In addition, an annular space communicating with the gas introduction hole and the annular slit is provided on the outer peripheral side of the annular protrusion when the annular protrusion is disposed close to the second case part at the joint between the first case part and the second case part. Therefore, a circular gas can be introduced from the outer peripheral side of the main passage toward the obliquely downstream side through the annular slit.

  In addition, the main passage is formed in a circular shape in cross section, and has a configuration in which a pair of magnetic bodies as counter electrodes are arranged at positions near the throttle portion of the case body and in the diameter direction of the main passage. Reduce the surface tension of the liquid, reduce the gas-liquid interfacial tension of the microbubbles to ensure the contraction of the bubbles in the liquid, increase the dissolved oxygen concentration to improve the water quality and make the water purification effect more effective. be able to.

It is a longitudinal cross-sectional view of the microbubble generator which concerns on embodiment of this invention. It is an AA arrow line view of FIG. It is a BB line arrow directional view of FIG. FIG. 2 is an enlarged explanatory view of a part of the microbubble generator of FIG. FIG. 2 is an exploded vertical cross-sectional explanatory view showing the microbubble generator of FIG. 1 disassembled into first and second half-cases. (A) is the figure seen from the end surface side of the 1st semi-casket case of FIG. 5, (b) is the figure seen from the end surface side of the 2nd semi-casket case of FIG. It is explanatory drawing which shows the example of installation of the microbubble generator of embodiment. It is action | operation explanatory drawing of the microbubble generator of FIG. It is a longitudinal cross-sectional structure explanatory drawing of the microbubble generator concerning the 2nd Embodiment of this invention. It is a graph which shows the bubbling time of the treated water by the microbubble generator of FIG. 9, and the relationship between surface tension.

  Next, the microbubble generator which concerns on embodiment of this invention is demonstrated with reference to FIGS. The microbubble generator of the present invention is a device for generating a microbubble by pumping a liquid into a passage in the case body and simultaneously introducing a gas into the flow of the liquid. A gas-liquid mixed fluid is generated by introducing gas, and a fluid containing a large number of microbubbles with a diameter of about several tens of microns in a homogeneous distribution is generated. Here, the microbubble refers to a bubble having a size of several tens of microns or less, specifically, a bubble having a size of 50 μm to 1 μm.

  1 to 6 show a microbubble generator 1 according to an embodiment of the present invention. In the drawing, the microbubble generator 1 includes a case body 2, a throttle portion 3, a gas mixing means 4, Gas oblique introduction means 5. The gas mixing means 4 includes a gas introduction hole 6, an annular slit 7, and an annular space 8.

  In the microbubble generator 1 of the embodiment, a main passage 10 penetrating along the axis in the direction of the cylinder axis 100 is formed in a cylindrical case body 2, and a liquid inflow opening is formed on one end side of the main passage 10. 10 a is provided, and a liquid outflow opening 10 b is provided on the other end side of the main passage 10. The inflow opening 10 a and the outflow opening 10 b are communicated with each other through the main passage 10. The case body 20 is formed of a metal or a plastic material and has strength and rigidity that can withstand liquid pumping. The material of the case body 20 may be glass or ceramics. In the embodiment, plastic is used because it is easy to mold and the manufacturing cost is low. For product molding, methods such as cutting from bulk material, casting, and extrusion molding can be used.

  A throttle portion 3 is formed at the middle position in the longitudinal direction of the main passage 10 to restrict the passage into an orifice shape. In the embodiment of FIG. 1, the throttle portion 3 is provided at a position where the entire length L3 is divided into, for example, about 1: 4. The throttling unit 3 reduces the liquid passage to increase the flow rate of the liquid and increase the flow velocity, so that the downstream side pressure after the maximum throttling position is drastically decreased compared to the first taper unit and the low-speed unit on the upstream side. At this time, microbubbles are generated.

  In FIG. 1, the case body 2 includes a first case portion 12 having a first taper portion 14 and a second case portion 52 having a second taper portion 54, and the first and second case portions 12, 52. Are connected in series at an intermediate position of the main passage 10 to form the case body 2. In the present embodiment, as shown in FIG. 5, the first and second case portions 12 and 52 are respectively joined to the separate end portions of the first and second half-cases 16 and 56 to form the case body 2. It is integrated. Thus, the first taper portion 14 of the first case portion 12 is a portion where the inner diameter of the main passage gradually decreases from the inflow opening 10 a toward the throttle portion 3, and the second taper portion of the second case portion 52. 54 is a portion in which the inner diameter of the main passage gradually increases from the throttle portion 3 toward the outflow opening 10b, and these are assembled in series so that the entire main passage is integrally connected and the throttle portion 3 is provided in the middle. As a Venturi tube is formed. The main passage 10 has a circular cross section.

  The first case portion 12 is made of a cylindrical body having a length L1 shorter than that of the second case portion 52, and the second case portion 52 is made of a cylindrical body having a length L2 longer than that of the first case portion 12. .

  The passage in the first case portion 12 is formed by a parallel portion 18 having a parallel wall in cross section and a first taper portion 14 that continues to the parallel portion 18 and gradually decreases the passage diameter toward the throttle portion 3. . One end opening of the parallel part 18 is a liquid inflow opening 10a, and the liquid is introduced as a parallel flow by the parallel part 18 and is pumped toward the throttle part 3 side. The taper angle from the parallel portion 18 of the first taper portion 14 toward the maximum throttle position P is set larger than the taper angle from the maximum throttle position P of the second taper portion 54 to be described later toward the outflow opening 10b, and a steeply inclined wall surface is formed. ing.

  The passage in the second case portion 52 is formed so that the passage diameter on the one end 58 side which is a part of the throttle portion 3 is the smallest, and the passage diameter gradually increases toward the liquid outflow opening 10b on the other end with a gentle gradient. Is formed.

  As shown in FIGS. 1 and 4, the maximum aperture position P of the aperture portion 3 is set at the joint portion of the first and second case portions 12 and 52. Gas mixing means 4 is provided in the throttle portion 3 including the maximum throttle position P.

  As shown in FIGS. 1 and 4, in the vicinity of the narrowed portion 3 of the second case portion 52, a gas introduction hole 6 that penetrates the case body of the second case portion in the thickness direction and communicates with the main passage 10 is provided. Yes. The gas introduction hole 6 is provided on the case body surface side slightly downstream from the maximum throttling position P, and is provided, for example, in a direction penetrating through the thick portion of the case body in communication with the connection port 60 that is threaded. Yes. The gas introduction hole 6 is a guide passage that introduces, for example, air or all other gases into the main passage 10 of the case body 2 from the outside, and is preferably a passage that extends linearly in the thickness direction. The gas introduced into the main passage 10 may be pumped to the gas introduction hole 6 by a blower or the like, or may be naturally sucked to the main passage side.

  An annular space 8 is provided in the vicinity of the throttle portion 3 and communicated with the gas introduction hole 6. In the embodiment, the annular space 8 is annularly provided at a position close to the maximum throttle position P and close to the main passage 10. That is, the annular space 8 is provided in an annular shape so as to be embedded in the thick portion of the constituent wall of the case body 2 so as to surround the main passage 10 at a position outside the main passage 10 in a cross-sectional view. The annular space 8 receives a gas from the gas introduction hole 6 to form a gas reservoir portion that is annularly surrounded outside the main passage 10 and is directed into the main passage 10 via the annular slit 7 as will be described later. Gas is simultaneously introduced from the annular gap so as to go from the outer peripheral side to the cylinder core side. In the embodiment, the annular space 8 has a configuration of the case body 2 in which a recess is provided in one or both of the first and second semi-casing cases in the abutting contact portion between the first semi-casing case 16 and the second semi-casing case 56. It is provided in a ring shape in an embedded state in the thick portion of the wall. The gas mixing means 4 includes a gas introduction hole 6, an annular slit 7, and an annular space 8. When the width (gap) d1 of the annular slit 7 is set to a ratio of the passage inner diameter d2 at the maximum throttle position P and d1 / d2 = 0.0001 to 0.5, the microbubble size (for example, 50 μm or less) is fine. It has been experimentally confirmed that bubbles can be reliably generated. More preferably, the ratio is d1 / d2 = 0.001 to 0.3. If it is less than 0.0001, the gas amount from the gas introduction hole 6 may not be sufficient, and if it exceeds 0.5, it is difficult to obtain microbubbles of uniform size.

  In the embodiment, the cross-sectional shape of the annular space 8 is a rollover L shape, and communicates with the gas introduction hole 6 at the inlet 81. Furthermore, in this embodiment, a part of the annular space 8 is defined by a cross-sectionally inclined wall 20 facing the annular space 8. The cross-sectionally inclined wall 20 faces the annular space 8 and is formed so as to be inclined in the downstream direction DW of the liquid flow in the main passage 10 so as to communicate with the annular slit 7. The cross-sectionally inclined wall 20 constitutes an oblique introduction means 5 that introduces gas obliquely at an inclination while descending from the annular slit 7 in the liquid flow downstream direction DW of the main passage 10. As shown in FIG. 4, the annular space 8 is provided so as to gradually narrow (taper) a space communicating with the annular slit 7 in a sectional view. Specifically, the inclined wall 20 and the passage mouth edge 62 portion of the second half-case 56 are opposed to each other so as to gradually narrow the space toward the annular slit 7. The cross-sectional shape of the annular space 8 is not limited to the rollover L shape, and may be a space shape having an arbitrary cross section.

  An annular slit 7 that communicates with the gas introduction hole 6 through the annular space 8 and opens to the main passage 10 is provided in communication with the annular space 8. In the present embodiment, the annular slit 7 is provided in such a manner that the tip of the inclined wall 20 is opposed to the passage opening edge 62 side of the second case portion 52 with a minute gap in an annular shape. It is formed by opening to the main passage 10. The annular slit 7 introduces the gas from the outside of the annular space 8 in a slanting manner with an inclination in the downstream direction of the liquid flow in the main passage 10. In the present embodiment, the annular slit 7 is provided in the vicinity of the maximum throttle position P in the throttle unit 3, specifically, slightly downstream from the maximum throttle position P, whereby the liquid flow rate is slightly lower than the maximum. The gas is effectively sucked at the portion where the pressure is slightly increased and the pressure is slightly increased, and fine bubbles are generated. Since the gas is introduced into the liquid flowing through the center in a slanting and inclined manner from the outer annular void, an extremely large number of fine bubbles of uniform size can be generated. In the present embodiment, the annular slit 7 is formed of a circular continuous slit, but a dot-like hole or an intermittent hole may be provided in a circular shape.

  In the present embodiment, as shown in FIG. 5, an annular protrusion 22 is formed on the end face side of the first half-case case 16 that becomes the throttle portion 3 of the first case portion 12. The annular protrusion 22 includes a passage wall 23 that forms a part of the main passage with an annular wall that is continuous from the maximum throttle position P at the end of the first tapered portion 14 and gradually increases in diameter, and the first case portion main body. The front and back opposing wall surfaces have an annular wall 20 having an annular cross section that faces the annular space 8 continuously from the end face. In the embodiment, the annular protrusion 22 protrudes toward the downstream side of the liquid flow in the main passage 10 and has a sharp shape. That is, a part of the annular protrusion 22 is in contact with the main passage 10 and the other part is in contact with the annular space 8 to form the annular slit 7 around the tip of the annular protrusion 22. As a result, the fluid to be pumped inward passes and the gas passes outside, so that the tip 22a of the annular protrusion is caused to vibrate finely, and the generation of more fine bubbles can be promoted. In the embodiment, the annular protrusion 22 is formed on the passage opening edge 62 of the restricting portion of the second case portion 52 so as to form an annular slit 7 with a minute gap between the passage opening edge 62 of the restricting portion of the second case portion 52. An annular slit 7 is formed in a close proximity. Therefore, at the joint portion between the first case portion and the second case portion, the case portions 12 and 52 are joined in a state of forming an annular minute gap that opens to the main passage 10 using the butt-contact state. I am letting.

  As shown in FIG. 6, the end surface of the joint portion of the first half case 16 (see FIG. 6A) is annular so as to frame the circumferential notch 64 for positioning at the outer peripheral portion and the main passage 10 at the central portion. The projection 22, the circumferential cutout 64, and the flat portion 65 in the middle of the annular projection 22 are formed. Further, the joint end face (see FIG. 5B) of the second semi-finished case 56 has a circumferential projection 66 and a flat recess 67 that closely contact the circumferential notch 64 and the flat portion 65 of the first half-case 16. And an annular space 8 and a central recess 68 that forms an annular slit 7 between the annular projection 22 and the first semi-cylindrical case.

  Next, the operation of the microbubble generator 1 of the embodiment will be described. As shown in FIG. 7, the microbubble generator 1 of this embodiment arranges the microbubble generator 1 which connected the pressure feed pump 72 via the pressure feed pipe 74 in the water of the process target water source 70, for example, and has gas introduction holes. A known device for connecting a gas supply hose 76 to the connection port 60 of No. 6 and disposing the tip of the hose to the atmosphere open state (or connecting a compressor) and returning the liquid of the water source 70 to the suction side of the pump 72 by a return pipe 77 Alternatively, it can be used in a system. In this case, since the water of the water source 70 is circulated, for example, the physical properties of the water can be greatly changed. Physical changes in water include a decrease in pH (in the case of distilled water), a decrease in surface tension, and an increase in electrical conductivity. By using water whose physical properties have been changed, effects such as improvement of biological functions, improvement of yield of plants and cultured products, purification of water quality and the like can be achieved. As a result, microbubbles of air are generated in the liquid which is seawater or water or fresh water as the liquid, and water purification and aquatic organism growth promotion functions are performed. The liquid is not particularly limited, and tap water, seawater, lake water, chemicals, cleaning liquid, and the like can be used. When a highly corrosive liquid is used, the case body may be configured using a highly corrosion-resistant material. The gas introduced from the gas introduction hole 6 is not particularly limited, and gases such as air, oxygen, nitrogen, carbon dioxide, and ozone can be used. In addition, a control valve or the like for controlling the gas introduction amount may be installed in the gas introduction hole to control the gas flow rate. That is, not only can this device be installed in a liquid in an environmental environment that has a liquid, it can be applied for purposes such as water purification, but it can also be used for various purposes in other applications using the liquid bubbling with this device. It can also be used.

  In FIG. 1, the liquid flows in the F direction from the inflow opening 10a on the left end side of the microbubble generator in the drawing, and exits from the outflow opening 10b on the right end side through the throttle portion 3 in the middle. The liquid that has flowed in from the inflow opening 10a is narrowed in the first taper portion 14 so that the flow rate is rapidly increased, the flow velocity is increased, and the pressure is drastically lowered and introduced into the throttle portion 3. The flow velocity becomes maximum at the maximum throttle position P, and the passage of the throttle portion 3 portion passing through the maximum throttle position is greatly reduced in negative pressure. At this time, a continuous gas in the form of air or other gas is introduced into the main passage 10 at a high speed from the annular slit 7 at a position downstream from the maximum throttling position P where the allowed liquid flows, and becomes a gas-liquid mixed fluid. At this time, the gas introduced into the main passage from the annular slit 7 is drawn into the inside from a circular continuous hole from the outer peripheral side of the passage, so that a sufficient amount of gas is supplied into the passage and the gas is introduced into the passage. As a result of the gas being ejected from a slit having a small uniform width when introduced into the liquid, a large amount of bubbles of uniform size are formed in the liquid. In particular, in the present embodiment, the gas is introduced from the annular slit 7 into the downstream direction DW of the liquid flow in the main passage 10 by the inclined wall 20 in the annular space 8, and the gas is introduced obliquely at an inclination. The size is continuously reduced and introduced into the main passage from the annular slit. As a result, the gas is introduced into the liquid passage while continuously reducing the size of the circle while smoothly flowing into the main passage 10, so that a large number of uniformly sized bubbles are generated and contracted in the liquid to ensure high quality. Can produce a large amount of microbubbles. Furthermore, in the present embodiment, the annular protrusion 22 has a sharp shape toward the downstream of the liquid flow in the main passage 10, and the liquid and gas simultaneously pass through the inner and outer surfaces at a high speed. As a result of minute vibrations, when the gas is introduced into the main passage 10 from the annular slit 7, the bubbles are likely to be finely sheared in the liquid, thereby promoting the generation of more uniform and more fine bubbles. be able to. More specifically, in FIG. 8, in the application of the microbubble generator of the present embodiment, the case where the liquid is water and the gas is air is taken as an example. By introducing the gas G toward the slant at a slant, the air becomes easy to be introduced into the passage by the flow rate of water, and the annular air (gas) is rapidly introduced into the liquid in the main passage through the annular minute gap. The fine bubbles MB are generated smoothly by being introduced. At this time, by introducing the air along the wall surface including the inclined wall 20 inside, the water released from the depressurized state spreads from the passage edge 62 to the wall surface, and the air is sheared all at once. Bubbles MB can be generated. Further, since the air inlet vibrates at this time, the annular protrusion 22 vibrates at a constant flow velocity, and the shock wave IW is easily generated by the force of water when the air is introduced while vibrating. This shock wave IW occurs several times in the main passage 10 and promotes the generation of fine bubbles MB including microbubbles. As a result, the number and size of the generated bubbles basically exist according to a normal distribution, but it has been experimentally confirmed that the size of the bubble is almost uniform and is about 40 μm. Most of the generated bubbles do not rise and disappear in water. The microbubble generator having the above-described configuration has a small number of components, can be manufactured at low cost, and can have high durability. Further, the first and second half-cases can be joined by bonding or screwing.

  Next, a second embodiment of the present invention will be described with reference to FIG. 9. The same members as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof will be omitted. In the microbubble generator 100 of the second embodiment, the main passage 10 is formed with a circular cross section, and a pair of magnetic forces that are in the vicinity of the throttle portion 3 of the case body 2 and are opposed to each other in the diametrically opposite position of the main passage 10. The point which has arrange | positioned the bodies 91 and 92 differs from 1st Embodiment. By arranging a pair of permanent magnets 91 and 92 having N poles and S poles at positions opposed to each other in the diameter direction of the main passage 10, the surface tension of the liquid is greatly reduced, and the gas-liquid interface tension of the microbubbles is reduced to reduce the bubbles. This ensures the contraction of the liquid in the liquid and increases the dissolved oxygen concentration to improve the water quality and make the water purification effect more effective.

  FIG. 10 shows the measurement results of the surface tension (dyn / cm) over time (minutes) when bubbling using the microbubble generator having the configuration of FIG. 9, and the microbubbles using this magnetism are shown. Using the generator, it was confirmed that the surface tension of water decreased by about 20 dyn / cm after 2 hours of bubbling. In addition, the surface tension measurement used Dunui surface tension meter 514-B2 type (made by Ito Seisakusho). Compared to this, the type of microbubble generator that does not use magnetism showed only a decrease of about 10 dyn / cm. The microbubble generator of the present invention generates a swirl flow in the passage by attaching a circumferential groove, a spiral groove, or a swirl vane for controlling the flow direction of liquid in the main passage of the case body 2. Thus, the physical properties may be changed.

  The microbubble generator 1 of the present invention can be applied in all fields utilizing the function of improving the yield of plants and cultured products due to physiological activity, water purification, cleaning of mechanical devices, and the function of removing surfactants in waste water. . The applicant conducted a specific verification of their application. (1) For example, freshwater fish and seawater can be treated with treated water using the microbubble generator of FIG. 1 embodiment, a small pump, and a pneumatic compressor, by purifying water and securing abundant oxygen supply into the water. It was confirmed that fish could be grown in the same aquarium. (2) In addition, 250,000 under 1 cm juvenile shrimp of prawns were released to the farm, and the same configuration as in (1) was implemented to ensure a survival rate of 99.7%. In this regard, the conventional survival rate was about 72%. Further, the aeration at this time was about 0.1% with respect to the normal aeration of 2000 dm3, and the effect of microbubbles was confirmed. (3) In addition, as a result of conducting a demonstration experiment on the samurai shellfish, the use of this device is about four times as large as the size of the shell after 6 months for the treated water used and the unused one Was confirmed. (4) Furthermore, supply of treated water by the microbubble generator 1 of the present invention to fruit pears, vegetable eggplants, tomatoes, cucumbers, yeast production during the production process of shochu, reduction of Escherichia coli, Salmonella, Staphylococcus aureus, etc. It was confirmed that an excellent effect can be obtained for each control group by conducting experiments such as confirmation.

  In the microbubble generator of the present invention, liquid flows through the main passage and gas is introduced from the outside through the gas introduction hole to generate microbubbles. When the liquid is flowed and a negative pressure is introduced from the outside, a mist gas containing ultrafine particles of uniform size can be generated.

  The microbubble generator of the present invention is not limited to the configuration of the above-described embodiment, and may be arbitrarily modified without departing from the essence of the invention described in the claims.

DESCRIPTION OF SYMBOLS 1 Microbubble generator 2 Case body 3 Restriction part 4 Gas mixing means 5 Gas oblique introduction means 6 Gas introduction hole 7 Annular slit 8 Annular space 10 Main passage 10a Inflow opening 10b Outflow opening 12 First case part 14 First taper part 16 First semi-cylindrical case 18 Parallel portion 20 Inclined wall in cross section 22 Annular projection 23 Passage wall 52 Second case portion 54 Second taper portion 56 Second semi-finished case 62 Passage edge MB Fine bubble P Maximum throttle position DW Liquid flow downstream direction

Claims (8)

A case body in which a liquid inflow opening provided on one end side and a liquid outflow opening provided on the other end side communicate with each other through a main passage;
A throttle part provided in the middle of the main passage;
Gas mixing means formed in the throttle part,
The gas mixing means includes a gas introduction hole that penetrates the case body in the thickness direction and communicates with the main passage, an annular slit that is disposed in the throttle portion and communicates with the gas introduction hole and opens to the main passage, and a gas introduction hole. And an annular space that communicates with the annular slit,
A microbubble generator characterized in that it is provided with oblique introduction means for introducing gas from an annular space obliquely toward the downstream of the liquid flow in the main passage from the annular slit.   2. The micro bubble generator according to claim 1, wherein the oblique introduction means includes a wall having an inclined section facing the annular space and provided in an inclined manner in a downstream direction of the liquid flow in the main passage and leading to the annular slit.   3. The microbubble generator according to claim 1, wherein the annular slit is provided in the vicinity of the maximum throttle position in the throttle portion and on the downstream side of the maximum throttle position.   The throttle part is an annular protrusion that partly contacts the main passage and the other part contacts the annular space and forms an annular slit around the tip, and includes an annular protrusion that protrudes in the downstream direction of the liquid flow in the main passage. The microbubble generator according to any one of claims 1 to 3, wherein   5. The microbubble generator according to claim 4, wherein the annular protrusion has a sharp shape toward the downstream side of the liquid flow in the main passage. A first case portion having a first taper portion whose diameter is gradually reduced toward the throttle portion; a second case portion having a second taper portion whose diameter is gradually increased from the throttle portion; To form a case body,
An annular protrusion is formed on the throttle portion of the first case portion, and an annular slit with a minute gap is formed between the passage opening edge of the throttle portion of the second case portion and the main passage inlet of the throttle portion of the second case portion. 6. A microbubble generator according to any one of claims 1 to 5, wherein annular projections are arranged close to each other.   In the joint portion between the first case portion and the second case portion, an annular space communicating with the gas introduction hole and the annular slit is provided on the outer peripheral side of the annular projection when the annular projection is disposed close to the second case portion. The microbubble generator according to claim 1, wherein the microbubble generator is provided. The main passage is formed in a circular cross section, and a pair of magnetic bodies as counter electrodes are arranged at positions near the throttle portion of the case body and in the diameter direction of the main passage. The microbubble generator according to crab.

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