JP2008086868A - Microbubble generator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a microbubble generator, which has a simple constitution and enables a generation of microbubbles in which the bubble particle diameter and the distribution are stable. <P>SOLUTION: The microbubble generator adopts an ejector type microbubble generator combining an ejector portion 1 in which a liquid inflow port 2, a nozzle part 6, a leading-in chamber 13 with a gas suction port 16 opened, and a discharge opening 3 are arranged in sequence, and a negative pressure produced by a spout of the liquid in which the flow rate is increased by the passing of the nozzle part 6, from the nozzle part 6 sucks down the gas from the gas suction port 16 through the leading-in chamber 13 to obtain a gas-liquid mixing fluid, and a bubble crushing part 27 provided on a passage portion of the downstream side from the leading-in chamber 13, and crushing bubbles V1 contained in the gas-liquid mixing fluid. The generator generates microbubbles by a fundamental principle that the bubbles V1 of the gas-liquid mixing fluid obtained in the ejector 1 are finely pulverized by the bubble crushing part 27. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a microbubble generator that generates microbubbles suitable for, for example, dissolving oxygen in water.

  In farms and ginger, it is required to efficiently increase the dissolved oxygen concentration of water in aquariums.

  Therefore, in aquaculture farms and ginger, microbubbles (particle size: several tens of μm) made of air or oxygen are generated in water, effectively expanding the surface area caused by microbubbles and extending the floating time to effectively create bubbles. It is practiced to dissolve in water.

  Conventionally, as a microbubble generator for generating such microbubbles, an apparatus employing a reduced pressure deposition method, an ultrasonic method, a two-layer swirl flow method, or the like has been proposed.

The apparatus of the reduced pressure precipitation method dissolves high pressure air (gas) in water (liquid) and dissolves it, and then decompresses the high pressure water at once to generate bubbles.

-An ultrasonic system apparatus pressure-dissolves air (gas) in water (liquid) and then applies ultrasonic vibration to water to precipitate dissolved air (gas).

-As shown in Patent Document 1, a two-layer swirl flow type device forms a swirl flow by flowing water (liquid) into a cylindrical container from a tangential direction, and is generated at the axial center of the container. External air (gas) is sucked in from the axial end of the container by the negative pressure, and bubbles are generated by the shearing effect of the swirling flow.
JP 2003-126665 A

  However, the microbubble generator using the vacuum deposition method or the ultrasonic method requires a compressor that pressurizes the air in addition to the pump that supplies water (liquid), so the scale of the device tends to increase. Cannot be realized. In addition, since a device for press-fitting air is necessary, the cost burden is large.

  The microbubble generator of the two-layer swirling flow method generates microbubbles using the liquid that is pumped, and thus has the advantage of a simple configuration, but forms a cylindrical bubble at the axial center of the container, Depending on the negative pressure generated by the swirling flow, it is difficult to establish microbubble generation, in which liquid and air are mixed and stirred by the negative pressure generated in the shaft center, and the gas-liquid mixed fluid is ejected from the container. Therefore, there is a problem that the particle size and distribution of microbubbles are difficult to determine.

  Accordingly, an object of the present invention is to provide a microbubble generator capable of generating microbubbles having a simple structure and a stable bubble particle size and distribution.

  In order to achieve the above object, a liquid inflow port into which a liquid flows in, a nozzle portion having a smaller diameter than the liquid inflow port, a suction chamber with an open gas suction port, and a discharge port are arranged in this order. An ejector section that draws gas from the gas suction port through the suction chamber and leads to the discharge port as a gas-liquid mixed fluid by the negative pressure generated when the liquid whose flow velocity is increased by passing through the nozzle section is ejected from the nozzle section; In addition, an ejector-type microbubble generator that is provided in a flow path portion on the downstream side from the drawing chamber and has a bubble crushing portion that crushes bubbles contained in the gas-liquid mixed fluid is employed.

  That is, according to the same configuration, the liquid drawn in from the liquid inflow port draws the gas from the gas suction port through the drawing chamber due to the negative pressure generated when the liquid is ejected as a high-speed flow from the nozzle portion. Thereby, it becomes a gas-liquid mixed fluid. Bubbles contained in the gas-liquid mixed fluid are crushed and refined in the bubble crushing portion, and become fine bubbles and microbubbles. The fluid containing the microbubbles is ejected from the discharge port.

  The invention according to claim 2 is configured such that the bubble crushing portion is disposed close to the drawing chamber in order to suppress the bubble formation toward the bubble crushing portion.

  The invention according to claim 3 is formed so that the drawn-in gas is mixed while diffusing from the surroundings with respect to the liquid flow in the drawing-in chamber in order to suppress the bubble formation.

  The invention according to claim 4 uses, as the bubble crushing portion, a plurality of needle-like protrusions arranged so that the sharpened portion faces the nozzle portion so that the fineness of the bubble is sufficiently achieved with a simple structure. Adopted a configuration to crush bubbles.

  According to the first aspect of the present invention, since the bubbles in the gas-liquid mixed fluid obtained at the ejector portion are finely crushed at the bubble crushing portion to form microbubbles (fine bubbles), a device such as a compressor for press-fitting gas Is unnecessary.

  Therefore, microbubbles can be generated with a simple configuration. In addition, the structure for crushing bubbles in the bubble crushing part is more stable and easier to generate microbubbles than the two-layer swirl flow method that generates microbubbles depending on the negative pressure due to swirl flow. And distribution.

  According to the second aspect of the present invention, since bubbles are prevented from being combined between the drawing chamber and the bubble crushing portion, the bubbles contained in the gas-liquid mixed fluid can be effectively refined in the bubble crushing portion. Can be made.

  According to the invention of claim 3, since the drawn gas is diffused into the liquid flow, the bubble bubbles are suppressed, so that the bubbles contained in the gas-liquid mixed fluid are effectively contained in the bubble crushing portion. Can be refined.

  According to the fourth aspect of the present invention, the bubbles contained in the gas-liquid mixed fluid collide with the pointed portions of the needle-like protrusions and are pulverized, so that generation of sufficiently fine bubbles can be expected. Moreover, a simple and inexpensive structure is sufficient.

  Hereinafter, the present invention will be described based on an embodiment shown in FIGS.

  1 shows the entire microbubble generator, FIG. 2 shows the right side of the device, FIG. 3 shows a state in which a part (right side portion) of the device is disassembled, and FIG. Shows the situation.

  The microvalve generator will be described. Reference numeral 1 in FIG. 1 denotes an ejector body that constitutes an ejector section. The ejector body 1 has, for example, a short cylindrical shape having an inflow port 2 at the left end and a discharge port 3 (also shown in FIG. 3) at the right end. The inner surface of the outlet 2 is formed with a threaded portion 2a serving as a joint portion, and is connected to a discharge pipe (not shown) connected to a pump (not shown) for supplying a liquid, for example, water. is there. That is, it has a structure in which water (liquid) flows from the inlet 2.

  In the flow path 4 continuing from the inflow port 2 to the discharge port 3, in order from the inflow port 2 side, a tapered portion 5 that gradually decreases from the diameter of the inflow port 2, a nozzle portion 6 that is formed with a reduced diameter, and a nozzle portion 6 A concave portion 7 having an opening larger than the diameter of the concave portion 7 (also shown in FIG. 3) and a concave portion 8 having an opening larger than the opening of the concave portion 7 are formed (in series). The opening of the recess 8 is continuous with the discharge port 3.

  A diffuser member 10 is incorporated in the recess 7. The diffuser member 10 includes, for example, an annular flange portion 11 that overlaps the end surface of the recess 8 as shown in FIG. 3, and a cylindrical inflow portion 12 that protrudes from the flange portion 11 into the recess 7. The outer shape of the inflow portion 12 is slightly smaller than the inner diameter and depth dimension of the recess 7 as shown in FIG. The inner diameter is larger than the diameter of the nozzle portion 6. Due to the combination of the inflow portion 12 and the recessed portion 7, the gas drawing space 13 (the present application) is used at a point immediately after the jet port 6 a of the nozzle portion 6 by using the annular separation portion between the inflow portion 12 and the recessed portion 7. Equivalent to the pull-in chamber).

  An air suction port 16 (corresponding to the gas suction port of the present application) formed by a minute port is formed on the wall surface of the gas drawing space 13, for example, the wall surface portion of the recess 7 facing the outer surface of the inflow portion 12. Yes. The air suction port 16 communicates with a suction pipe connection port 17 formed on the outer surface of the ejector body 1. The air suction port 16 communicates with an air introduction pipe detachably connected to the suction pipe connection port 16, for example, an air introduction tube 19 with a flow rate valve 18 (for example, comprising a needle valve). Reference numeral 19 a denotes a joint for connecting the end of the air introduction tube 19. Note that the end of the air introduction tube 18 is open to the atmosphere. Thereby, the air suction port 16 and the air introduction tube 19 are supplied to the water flow through the gas drawing space 13 by using the negative pressure generated when the water whose flow velocity is increased is ejected from the ejection port 6 a of the nozzle portion 6. The atmosphere (air) is drawn from. That is, a gas-liquid mixed fluid is obtained. Of course, by changing the opening degree of the flow valve 18, the air flow rate to be drawn is varied.

  The gas intake space 13 is formed in an annular shape around the flow path 4 and is opened around the flow path 4 while remaining in the same circular shape (shown in FIG. 4). The water flow is ejected from the nozzle portion 6 from around. In other words, it is mixed with the water flow while diffusing.

  The flange portion 11 of the diffuser member 10 is positioned and fixed by a fixing member 20 attached to the discharge port 3. For example, the fixing member 20 has a flange portion 23 as shown in FIG. 3 and a cylindrical portion 24 protruding from the flange portion 23. The flange portion 23 is fixed to the end surface of the discharge port 3 with a fastener, for example, a screw member 22. The cylinder part 24 is inserted into the recess 8. The flange portion 11 is sandwiched between the end surfaces of the concave portion 8 at the tip of the cylindrical portion 24. A diffuser 25 is formed for effective air drawing over the flow path portion from the duct formed by the diffuser member 10 and the fixing member 20 to the discharge port 3 surrounded by the cylindrical portion 24 immediately after the jet port 6a. is doing.

  A bubble crushing portion 27 for crushing bubbles contained in the gas-liquid mixed fluid is assembled to a flow path portion on the downstream side of the gas drawing space 13, for example, the discharge port 3. As the bubble crushing portion 27, for example, a needle-like protrusion having a pointed portion at the tip, specifically, for example, a plurality of small-diameter screw members 28 having a pointed head 28a at the tip are used. The plurality of screw members 28 are assembled to the discharge port 3 by utilizing the fixing member 20 constituting the diffuser 25. That is, as shown in FIG. 2, a narrow beam member, for example, a cross-shaped beam member 29 is integrally formed on the flange portion 23 of the fixing member 20 so as to straddle the opening of the flange portion 23. The gas-liquid mixed fluid is ejected from the four outlet portions 30 formed between the beam member 29 and the flange portion 23 from the jet outlet 6a of the nozzle portion 6. The plurality of screw members 28 are assembled to each part of the beam member 29. That is, the screw member 28 includes, for example, as shown in FIGS. 1 to 3, a beam portion 29 a intersecting the center of the beam portion 29 (a portion disposed at the center of the discharge port 3), the beam portion 29 a and the flange portion 23. Screwed from the outside at five points such as the middle of the beam portion 29b disposed between them (the portion closer to the center outer side of the discharge port 3). Specifically, the screw member 28 is screwed in such a manner that the entire shaft portion protrudes into the cylindrical portion 24 while leaving the head portion. All of the five screw members 28 are arranged in parallel along the flow path 4 with a layout in which the pointed head 28 a faces the nozzle portion 6. With the screw members 28 scattered in the flow path 4, the bubbles V1 contained in the gas-liquid mixed fluid collide with the tip of the pointed head 28a. By this collision, the bubbles V1 in the gas-liquid mixed fluid are crushed (miniaturized). In any of the screw members 28, the tip (pointed head 28 a) is arranged as close as possible to the outlet opening of the gas drawing space 13, and here, as much as possible in the inflow portion 12 that forms the inlet of the diffuser 25. They are placed close together.

  Next, the operation of the thus configured microbubble generator will be described.

  For example, a case where oxygen is dissolved in ginger water will be described as an example. A discharge tube end (not shown) extending from the ginger water supply pump is connected to the inflow port 2, and the suction pipe connection port 17 is connected. Then, the ejector body 1 to which the air introduction tube 19 with the flow valve 18 is connected is put in water. Of course, the end of the air introduction tube 19 and the flow valve 19 are arranged on the water so that air in the atmosphere can be taken in.

  Thereafter, a water supply pump (not shown) is operated. Thereby, the water discharged from the pump is pumped from the inlet 2 to the inside 4 of the ejector body 1. When the water flowing in from the inflow port 2 sequentially passes through the tapered portion 5 and the nozzle portion 6 having a small diameter, the flow velocity is gradually increased. And the water used as the high-speed flow is jetted from the jet nozzle 6a of the nozzle part 6 to the flow-path part with a larger diameter than the jet nozzle 6a. The negative pressure generated at this time acts on the gas drawing space 13. This negative pressure draws air in the atmosphere. That is, air in the atmosphere is sucked from the air suction port 17 through the air introduction tube 19. At this time, since the gas drawing space 13 has a flat ring shape, the air from the air suction port 16 collides with the inner wall surface of the space 13 as shown in FIG. , Around the water stream ejected from the ejection port 6a. Subsequently, air bubbles are mixed into the water flow while diffusing from the entire front end of the inflow portion 12 forming the outlet opening of the gas drawing space 13. This diffusion suppresses foaming. As a result, a gas-liquid mixed fluid containing bubbles with a suppressed particle size is generated.

  This gas-liquid mixed fluid goes to the bubble crushing portion 27 through the inflow portion 12. At this time, since the distance between the two is kept as short as possible, the bubble formation is also suppressed here.

  When the bubble V1 contained in the gas-liquid mixed fluid passes through the bubble crushing portion 27, a behavior occurs in which the bubble V1 collides with the tip of the pointed portion 28a of the screw member 28. Then, the bubble V1 is crushed by the tip 28a and becomes a fine bubble V2. Fine bubbles, that is, microbubbles are generated by the refinement of the bubbles V1 by the crushing. The microbubbles are ejected from the open portion 30 forming the discharge port 3 into the water while being diffused in a conical shape.

  As described above, the microvalve generating device is structured to generate the microbubbles by crushing the bubbles V1 contained in the gas-liquid mixed fluid drawn by the ejector body 1, so that the necessary equipment is only a pump used for supplying water. Well, there is no need for equipment such as a compressor to press-fit gas.

  Therefore, microbubbles can be generated with a simple structure mainly including the ejector body 1 and the bubble crushing portion 27. Moreover, since the microbubbles are generated by physically crushing the bubbles V1 contained in the gas-liquid mixed fluid at the bubble crushing unit 27, the microbubbles of the two-layer swirl flow method depending on the negative pressure due to the swirl flow. Compared to the generation, the microvalve has a stable bubble particle size and distribution.

  In particular, when the bubble crushing portion 27 is brought close to the bubble drawing space 13 or the air is drawn in while being diffused in the water flow, the bubbles that become larger are suppressed, so that the bubbles are refined in the bubble crushing portion 27. The effect of can be fully extracted.

  In addition, when a needle-like protrusion such as a screw member having a sharp tip is used as the bubble crushing portion 27, the phenomenon that the tip collides with the bubble and the bubble is crushed can be effectively exhibited. Generation of microbubbles can be expected. In addition, a simple structure is required. In particular, using the ejector body that forms the diffuser 25 by assembling two parts of the diffuser member 25 and the fixing member 20 in the recesses 7 and 8 formed in the inside of the ejector body 1, and using the fixing member 20, the bubble crushing portion When 27 is assembled to the flow path 4, a micro-bubble generator can be realized by a combination of cast parts that can be easily formed with a reduced number of parts.

  In addition, when adjusting the size of the microbubbles, if the opening degree of the flow valve 18 is changed to the throttle side, the amount of air drawn is reduced and the particle size of the microbubbles is reduced. Also, if the opening degree of the flow valve 18 is changed to the open side, the amount of air that is drawn in increases and the particle size of the microbubbles increases, so that the particle size of the microbubbles (the degree of occurrence) immediately according to the situation at the site. Can be adjusted. Note that the initial bubble particle size in the microbubble generator can be adjusted by changing the protruding amount of the screw member 20 as shown by the two-dot chain line in FIG.

  However, the present invention is not limited to the above-described embodiment, and it goes without saying that various modifications may be made without departing from the spirit of the present invention. For example, in one embodiment, for example, a structure using a needle-like member is used as the bubble crushing portion. However, the present invention is not limited to this, and other members may be used as long as the bubbles can be crushed. Moreover, in one embodiment, although the case where it used with fresh water was mentioned as an example, you may apply not only to this but to the case where it uses with other liquids, such as seawater. Of course, the gas is not air but other gas (oxygen or the like) may be used.

The front sectional view of the microbubble generating device concerning one embodiment of the present invention. The right view of the microbubble generator. The exploded view for demonstrating the assembly structure of a diffuser and a bubble crushing part. Sectional drawing which follows the A line in FIG.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Ejector body (ejector part), 2 ... Inflow port, 3 ... Discharge port, 4 ... Flow path, 6 ... Nozzle part, 6a ... Outlet, 10 ... Diffuser member, 13 ... Space for gas drawing-in (intake chamber) ), 16 ... Air intake port (gas intake port), 18 ... Flow valve, 19 ... Air introduction tube, 20 ... Fixing member, 25 ... Diffuser, 27 ... Bubble crushing part, 28 ... Screw member (needle member) .

Claims (4)

A liquid inlet into which a liquid flows, a nozzle portion having a smaller diameter than the liquid inlet, a suction chamber having an open gas suction port, and a discharge port are arranged in this order, and the liquid whose flow rate is increased by passing through the nozzle portion is the nozzle. An ejector portion that draws gas from the gas suction port through the drawing chamber and guides it to the discharge port as a gas-liquid mixed fluid by negative pressure generated by jetting from the portion;
A microbubble generator characterized by comprising: a bubble crushing section that is provided in a flow path portion downstream from the drawing chamber and crushes bubbles contained in the gas-liquid mixed fluid.   The microbubble generator according to claim 1, wherein the bubble crushing unit is disposed close to the drawing chamber.   3. The microbubble generator according to claim 1, wherein the drawing chamber is formed so that the drawn gas is mixed while diffusing from the surroundings with respect to the liquid flow. 4.   2. The bubble crushing portion is formed of a plurality of needle-like protrusions arranged in a flow path portion with a sharp portion facing the nozzle portion, and the bubbles are crushed at the sharp portion. The microbubble generator as described in any one of Claim 3 thru | or 3.

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