JP2007075674A - Microbubble generator and sanitary washing device equipped with it - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a small-sized microbubble mixing device which can be used even for small-sized apparatuses. <P>SOLUTION: A microbubble generator comprises a bubble mixing part 6 which is equipped with at least a pair of electrodes, and mixes bubbles generated by electrolysis of water with flowing water under pressure, and a gas-liquid spouting part 7 which spouts the water mixed with the bubbles. By dissolving the bubbles generated by the electrolysis of water, diameters of bubbles to be dissolved can be controlled by velocity of liquid on the surfaces of the electrodes, and bubble growth rate, that is, current density, which dispenses with a booster pump and a tank, enabling miniaturization of the device, which enables incorporation into small apparatuses. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a fine bubble generating apparatus that generates fine bubbles by pressurizing and mixing bubbles generated by electrolysis of water into flowing water.

  Conventionally, as a method for generating fine bubbles, a method using an ejector, a method for making bubbles fine by a swirling flow, and a method using pressure dissolution are known (for example, Patent Document 1 and Patent Document 2). FIG. 6 shows a flow of the fine bubble generator by the pressure dissolution method.

  In FIG. 6, the pressure-dissolving type fine bubble generator includes a water channel 100, a pressure-dissolving unit 101 provided in the channel 100, and a pressure reducing valve 107 connected to the outlet of the pressure-dissolving unit 101. Has been. The pressure dissolution unit 101 is connected to the flow path 100, and a suction unit 102 that mixes air with running water via an intake valve 103, a pump 104 that transports water, a tank 105 that dissolves air into running water, and releases excess air. The air vent valve 106 is configured.

In the above configuration, the water that has flowed into the pressure dissolving part 101 from the flow path 100 sucks air through the suction port of the suction valve 103 by the suction part 102 and mixes the gas and liquid. The intake valve 103 sucks air in an amount more than that dissolved in the flowing water, and the flowing water mixed with gas and liquid is pressurized by the pump 104 and sent to the tank 105. Air is dissolved in running water in the tank 105, and undissolved air is released to the atmosphere from an air vent valve 106 provided in the tank 105. The flowing water in which the air has been dissolved is rapidly depressurized by the pressure reducing valve 107, and the gas that has been pressurized and dissolved in the water is precipitated as fine bubbles at once.
Japanese Patent Laid-Open No. 2002-191949 JP 2004-283810 A

  However, the conventional pressure dissolution method and swirl flow method require a pump for pressurizing water, a tank for mixing gas and liquid, and the like, and there is a problem that the apparatus is increased in size.

  In relatively large equipment such as a bath apparatus or a water heater, when using fine bubble water, fine bubbles can be generated using the above-mentioned pressure dissolution method or swirl flow method. In order to use it for a small device such as a washing machine and a dishwasher, there is a problem that it cannot be incorporated in a small device because the fine bubble generating device is enlarged. Further, when the ejector is used, the fine bubble generating device can be reduced in size, but the ejector method has a problem that the bubble diameter to be mixed becomes large.

  In view of the above-described conventional problems, the problem to be solved by the present invention is to provide a small-sized microbubble mixing device that can also be used for small-sized devices.

  In order to solve the above problems, a fine bubble generating apparatus of the present invention has at least one pair of electrodes, a bubble mixing part that pressurizes and mixes bubbles generated by electrolysis of water into flowing water, and mixing of bubbles The gas-liquid ejection part which ejects the pressurized water which was made is provided.

By using the above means, a pressure pump and a tank are not required to generate fine bubbles, and the apparatus can be miniaturized.

  Since the microbubble generator of the present invention does not require a pressure pump or a tank, the apparatus can be miniaturized and can be incorporated into a small device by miniaturization.

  The first invention has at least one pair of electrodes, and includes a bubble mixing portion that pressurizes and mixes bubbles generated by electrolysis of water into flowing water, and a gas-liquid ejection portion that ejects pressurized water mixed with bubbles. It is possible to generate fine bubbles with bubbles obtained by electrolysis of water, and to obtain fine bubbles by opening and decompressing the bubbles dissolved under pressure in the bubble mixing part at the gas-liquid ejection part The apparatus can be reduced in size.

  That is, the diameter of bubbles generated on the electrode surface by electrolysis of water is extremely small immediately after the start of electrolysis, and as the electrolysis progresses, the bubbles grow and coalesce and then leave the electrode surface. Since the diameter of the detached bubbles is determined by the liquid flow velocity on the electrode surface and the bubble growth rate, that is, the current density, a pressure pump and a tank are not required to generate fine bubbles, thereby miniaturizing the device. can do.

  In the second invention, in particular, the size of the bubble mixing portion in the first invention is reduced, so that the degree of freedom of installation is improved, and the bubble mixing portion and the gas-liquid ejection portion can be provided adjacent to each other. Further, by this, it is possible to continuously pressurize and depressurize the bubbles, prevent coalescence of dissolved bubbles in the flow path, and mix fine bubbles.

  In particular, the third aspect of the present invention has a water inlet and a water outlet in the bubble mixing portion of the first invention or the second invention, and the cross-sectional area of the water outlet is smaller than the water inlet. The internal pressure of the bubble mixing part can be increased with a simple configuration.

  In particular, the fourth aspect of the invention includes the bubble mixing portion of any one of the first to third aspects of the invention on the core electrode, the flow path provided on the outer periphery of the core electrode, the case surrounding the flow path, and the case inner wall. By comprising the provided electrode and the flow rate variable means for changing the flow rate of the flow path, water can be electrolyzed between the core electrode and the electrode provided on the inner wall of the case, and the electrode is formed in a cylindrical shape, for example By doing so, it can be incorporated into the nozzle or hose.

  In the fifth aspect of the invention, in particular, the flow rate variable means of the fourth aspect of the invention is configured to change the flow rate of the flow path in a direction to increase the flow rate, thereby increasing the flow rate of the flow path and pressurizing the flow path. By increasing the flow velocity on the electrode surface, the separation of bubbles from the electrode surface can be accelerated, and the bubbles can be reduced in diameter.

  In the sixth aspect of the invention, in particular, the flow rate variable means of the fifth aspect of the invention is configured so that the flow rate increases toward the downstream side of the flow path, so that the gas mixing amount due to electrolysis increases to the downstream side. Therefore, by increasing the pressure, it is possible to prevent the bubbles from being miniaturized and the bubbles from being combined in the flow path.

  In the seventh aspect of the invention, in particular, the flow rate variable means of any one of the fourth to sixth aspects of the invention is configured to narrow at least a part of the flow path, so that the flow rate can be accelerated with a simple configuration. The bubble can be reduced in diameter.

In an eighth aspect of the present invention, in particular, in the bubble mixing portion of any one of the first to third aspects, a configuration including a bubble generating means comprising a solid polymer film and electrodes formed on both surfaces of the solid polymer film By reducing the distance between the electrodes, the load of the power source can be suppressed and the amount of bubbles generated by electrolysis can be increased, and fine bubbles can be generated with a simple and small configuration.

  According to a ninth aspect of the invention, in particular, in any one of the first to eighth aspects of the invention, at least the anode is a lead dioxide electrode, and ozone generated along with oxygen on the surface of the lead dioxide electrode is mixed by electrolysis. In addition to being able to obtain a sterilizing and bleaching action by ozone, ozone is generated by electrolysis, so an ozone generator such as a discharge device is not required, and the ozone dissolution efficiency can be increased by dissolving quickly after generation. .

  In the tenth aspect of the invention, the sanitary washing apparatus includes the fine bubble generating apparatus according to any one of the first to ninth aspects, so that the cleaning efficiency can be improved and the apparatus can be downsized.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the present invention is not limited to the present embodiment. Further, in the description of the present embodiment, the same reference numerals are given to the same configurations and effects and the redundant description is not performed.

(Embodiment 1)
FIG. 1 is a cross-sectional view showing a fine bubble generator in a first embodiment of the present invention. In FIG. 1, the fine bubble mixing device includes a core electrode 1, a flow path 2 provided on the outer periphery of the core electrode 1, a case 3 surrounding the flow path 2, an electrode 4 provided on the inner wall of the case 3, and a flow path 2. A bubble mixing part 6 having a coiled spring 5 as a flow rate varying means for changing the flow rate inside, and a gas-liquid ejection part 7 are provided. The coiled spring 5 is configured to rotate at a pitch such that the cross-sectional area of the flow path that forms the pitch of the coiled spring 5 is narrower than the cross-sectional area of the flow path that is formed between the case 3 and the core electrode 1. It is said.

  The bubble mixing part 6 includes a water inlet 8, a water outlet 9 that leads to the gas-liquid jet part 7, electrode terminals 10 and 11, an O-ring 12 for sealing the flow path 2, and a DC power source 13. ing. Further, the water outlet 9 is formed so that the cross-sectional area of the water outlet 9 is smaller than that of the water inlet 8 in order to increase the internal pressure in the case 3 and pressurize bubbles to dissolve in water. The gas-liquid ejection part 7 is provided adjacent to the water outlet 9 of the bubble mixing part 6 due to the downsizing of the bubble mixing part 6.

  The operation and action of the fine bubble mixing device configured as described above will be described below. As shown by the arrow in the side sectional view of FIG. 1 shown in FIG. 2, water enters from the water inlet 8 at the side surface position eccentric from the center of the case 3, and is formed on the outer periphery of the core electrode 1. The coil spring 5 is spirally disposed in the flow path along the outer periphery of the core electrode 1 and flows around the outer periphery of the core electrode 1 in a spiral manner. The bubbles generated by the electrolysis by the core electrode 1 and the electrode 4 are pressurized and dissolved in water, discharged from the discharge port 9 at the side surface eccentric from the center of the case 3, and opened and depressurized at the gas-liquid jet part. Fine bubbles can be obtained.

  That is, the coil-shaped springs 5 arranged in a spiral form have a cross-sectional area of the flow path that forms between the pitches of the coil-shaped springs 5 than the cross-sectional area of the flow path 2 that is formed between the case 3 and the core electrode 1. It is set as the structure made to turn by the pitch which becomes narrow. Therefore, the flow velocity of the swirl flow that spirally flows along the coil spring 5 is faster than that without the coil spring 5, and the flow velocity is accelerated.

In particular, the cylindrical channel space formed between the case 3 and the core electrode 1 has a channel cross section with a large aspect ratio, and if there is no coiled spring 5, the side surface position is eccentric from the center of the case 3. Water flowing in from the water inlet 8 provided in the water flows spirally along the outer periphery of the core electrode 1 in the upstream, but the swirling flow is lost toward the downstream, and the cylindrical axial flow component is gradually reduced. It becomes the main body, and the flow rate of water is substantially reduced downstream.

  However, in this embodiment, the coil spring 5 is provided in a cylindrical flow path space formed between the case 3 and the core electrode 1, and the flow is a swirling flow and a fast flow rate state continues. The area of the boundary layer between the electrode 4 and water becomes very thin. And by accelerating the flow velocity on the surface of the electrode 4, the separation of bubbles from the surface of the electrode 4 can be promoted, the growth of bubbles on the surface of the electrode 4 can be prevented, and fine bubbles can be mixed into water. .

  On the other hand, the electrolysis of water occurs when a DC voltage is applied between the core electrode 1 and the electrode 4 by the DC power source 13, and oxygen gas and chlorine gas are generated on the anode side, and hydrogen gas is generated on the cathode side. The gas generated by electrolysis initially forms small nuclei in a state of adhering to the surface of the electrode 4, and gradually grows with the progress of electrolysis and separates from the electrode surface while coalescing with adjacent bubbles.

  The bubble growth rate depends on the current density of the electrolysis, and the bubble diameter detached from the electrode 4 surface is related to the surface smoothness of the electrode 4, the flow velocity of the electrode 4 surface, and the internal pressure state in the case 3. Since the water discharge port 9 is formed so that its cross-sectional area is smaller than that of the water intake port 8, the internal pressure in the case 3 can be increased, and bubbles generated by electrolysis having a simple configuration can be added. Can be melted under pressure.

  Furthermore, by increasing the flow velocity on the surface of the electrode 4, it is possible to accelerate the separation of the bubbles and to refine the bubbles. In particular, as the core electrode 1 and the electrode 4, a noble metal electrode formed by sintering or plating a noble metal such as platinum on the surface of titanium can be used, but it is desirable to use a plated electrode having high surface smoothness.

  Then, the case where the fine bubble mixing apparatus in this Embodiment is integrated in a warm water washing | cleaning apparatus is demonstrated. FIG. 3 shows a cross-sectional view of a sanitary washing apparatus incorporating the fine bubble generating apparatus of the present embodiment.

  In FIG. 3, a horizontally long sanitary washing device main body 16 is installed on the outer periphery of the toilet 14 on the annular heating toilet seat 15 and the rear end of the toilet 14. And the heat exchanger 17 is provided in the sanitary washing apparatus main body 16, and the hot water after heat exchange wash | cleans the local part of the human body 20 after the stool for ejection from the ejection part 19 of the washing nozzle 18. FIG.

  The sanitary washing device main body 16 includes a shut-off valve 21 and a flow rate control device 22 as main components therein, and other components such as a control board are not shown.

  The fine bubble generator of the present embodiment includes a core electrode 1, a channel provided on the outer periphery of the core electrode 1, a case 3 surrounding the channel, and an electrode 4 provided on the inner wall of the case 3 In the part 6, the case 3 and the electrode 4 installed on the inner peripheral surface of the case 3 are formed in a cylindrical shape and incorporated in a long cylindrical cleaning nozzle 18. The water inlet 8 and the outlet 9 of the case 3 lead to the internal flow path of the cleaning nozzle 18, and the gas-liquid jetting part 7 is composed of a jetting part 19 that is a small hole for discharging the cleaning water of the cleaning nozzle 18. It is.

Therefore, the case 3 and the electrode 4 installed on the inner peripheral surface of the case 3 are simply formed in a cylindrical shape, and incorporated into the cleaning nozzle 18 by taking advantage of the small size which is a feature of the fine bubble generating device in the present embodiment. By further downsizing, the jet part 19 of the cleaning nozzle 18 can be made into the gas-liquid jet part 7, and the pressurization and depressurization of the bubbles can be performed continuously and dissolved in the washing water. Since the coalesced bubbles in the flow path 2 can be prevented, the bubbles can be further refined.

  Thus, according to the present embodiment, by dissolving bubbles generated by electrolysis of water, the diameter of the bubbles to be dissolved is controlled by the flow rate of the liquid on the electrode surface, the bubble growth rate, that is, the current density. can do. For this reason, fine bubbles can be generated with bubbles obtained by electrolysis of water, and fine bubbles can be obtained by opening and decompressing the bubbles that are dissolved under pressure in the bubble mixing part at the gas-liquid ejection part. The apparatus can be reduced in size.

  In addition, by reducing the size of the bubble mixing part, the degree of freedom of installation is improved, and the bubble mixing part and the gas-liquid ejection part can be provided adjacent to each other, and the pressure of the bubbles and the decompression of the bubbles are continuously performed. Thus, coalescence of dissolved bubbles in the flow path can be prevented, and the bubbles can be further miniaturized.

  In addition, the bubble mixing part is a core electrode, a flow path provided on the outer periphery of the core electrode, a case surrounding the flow path, and an electrode provided on the inner wall of the case, and the electrode is formed in a cylindrical shape. Can be incorporated.

(Embodiment 2)
FIG. 4 is a cross-sectional view showing the bubble mixing part of the fine bubble generating apparatus according to the second embodiment of the present invention. The present embodiment is different from the first embodiment in that a plurality of coiled springs 23 and 24 having different pitches are provided in the flow path 2 instead of the coiled spring 5 in the first embodiment. The same reference numerals are assigned to the parts to be played, detailed description is omitted, and different points will be mainly described.

  The microbubble mixing device includes a core electrode 1, a flow path 2 provided on the outer periphery of the core electrode 1, a case 3 surrounding the flow path 2, an electrode 4 provided on the inner wall of the case 3, and an inlet side in the flow path 2. A gas bubble mixing part 6 provided with a coiled spring material 23 and a coiled spring 24 as a flow rate varying means that is arranged in series from the outlet side to the outlet side and changes the flow rate in the flow path 2, and a gas-liquid jet part 7. Has been. The cross-sectional area of the flow path that constitutes the pitch between the helical springs 23 and 24 arranged in a spiral shape is configured by the coil-shaped spring material 24 from the cross-sectional area of the flow path that is configured by the coil-shaped spring material 23. Further, the cross-sectional area of the flow path is reduced.

  As in the first embodiment, water enters from the water inlet 8 at the side surface position eccentric from the center of the case 3, flows into the outer periphery of the core electrode 1, and is arranged spirally along the outer periphery of the core electrode 1. By the coiled spring 23 and the coiled spring 24, the outer circumference of the core electrode 1 flows spirally and flows again from the discharge port 9 provided on the side surface.

  The cross-sectional area of the flow path that constitutes the pitch between the helical springs 23 and 24 arranged in a spiral shape is configured by the coil-shaped spring material 24 from the cross-sectional area of the flow path that is configured by the coil-shaped spring material 23. Since the cross-sectional area of the flow path becomes narrower, the flow velocity becomes faster toward the downstream side, and the pressure can be increased as it goes to the downstream side where the amount of gas contamination due to electrolysis increases. It is possible to prevent the bubbles from being miniaturized and the bubbles from being coalesced in the flow path.

(Embodiment 3)
FIG. 5 is a cross-sectional view showing the configuration of the bubble mixing part of the fine bubble generating apparatus according to the third embodiment of the present invention.

In FIG. 5, the bubble mixing part 25 is located in the center of the flow path 27 in the cylindrical case 26 constituting the bubble generating means, extends along the longitudinal direction, and clamps a porous noble metal electrode 28 as an electrode on both sides. 29, a rod-shaped electrolyte membrane 30 as a solid polymer membrane crimped at 29 is provided, and a water inlet 31 provided on the side surface is shifted from the center at one end of the case 26, and is shifted from the center at the other end of the case 26. The water outlet 32 provided on the side surface and the electrode terminal 33 are provided. The gas-liquid ejection part 34 is provided adjacent to the water outlet 32 of the bubble mixing part 25 due to the downsizing of the bubble mixing part 25.

  The operation and action will be described below. By applying a DC voltage from the electrode terminal 33 to the porous noble metal electrode 28, water is electrolyzed and fine bubbles are generated. The amount of bubbles generated by this electrolysis depends on the amount of current that flows, and the amount of current increases as the electrolysis time increases and the distance between the electrodes decreases.

  Generally, even if it is attempted to reduce the distance between the electrodes in order to obtain a large amount of current by ordinary electrolysis, calcium ions, magnesium ions, etc. in tap water are deposited on the electrode surface with the passage of time of electrolysis and block the electrodes. Therefore, the distance between the electrodes needs to be separated by about several mm. In order to obtain sufficient bubbles, the electrode area must be increased and the applied voltage must be increased.

  However, in the present embodiment, the distance between the porous noble metal electrodes 28 is the thickness of the electrolyte membrane 30, so the distance between the electrodes is reduced, the electrolytic current can be increased, and the amount of bubbles generated can be increased.

  In addition, since the electrolyte does not pass calcium ions or magnesium ions, scale deposition between the electrodes is prevented, and a high amount of current can be obtained stably at all times, and the electrode area can be increased by making the electrodes porous. In addition, the apparatus can be miniaturized.

  As the porous noble metal electrode 28, a noble metal electrode formed by sintering or plating a noble metal such as platinum on the surface of titanium can be used. When a lead dioxide electrode is used as the porous noble metal electrode 28, the electrode On the surface, oxygen generated by electrolysis of water is oxidized to ozone, and ozone gas-dissolved water can be obtained.

  Even when a general noble metal electrode is used as the anode, the gas generated by the anode surface reaction contains a slight amount of ozone. However, the use of a lead dioxide electrode as the anode can increase the efficiency of ozone generation.

  Ozone has poor dissolution efficiency in water, and when ozone gas is generated by gas-phase discharge or the like and then dissolved in water, the generated ozone gas cannot be completely dissolved in water and released, so that high-concentration ozone-dissolved water can be obtained. Although it was difficult, the ozone generated by electrolysis by dissolving and generating ozone directly by electrolysis increases the efficiency of dissolution in water because the bubble diameter is small and the concentration is high. Can be generated efficiently.

  By using ozone-dissolved water, sterilization bleaching action by ozone can be obtained, and ozone is generated by electrolysis, so there is no need for an ozone generator such as a discharge device. The dissolution efficiency of ozone can be increased.

  As described above, the fine bubble generating apparatus according to the present invention dissolves bubbles generated by electrolysis of water, so that the diameter of the bubbles to be dissolved depends on the flow rate of liquid on the electrode surface, the bubble growth rate, that is, the current density. Can be controlled. Therefore, since a pressurization pump and a tank become unnecessary, an apparatus can be reduced in size and it can also be integrated in a small apparatus by reducing an apparatus.

Sectional drawing of the fine bubble generator in Embodiment 1 of this invention Side sectional view of the microbubble generator Sectional drawing of the sanitary washing apparatus using the fine bubble generator of Embodiment 1 Sectional drawing of the fine bubble generator in Embodiment 2 of this invention Sectional drawing of the bubble mixing part in Embodiment 3 of this invention Configuration of conventional microbubble generator

Explanation of symbols

1 Core electrode
2 Flow path 3 Case 4 Electrode 5, 23, 24 Coil spring (flow rate variable means)
6, 25 Bubble mixing part 7 Gas-liquid ejection part 8 Water inlet 9 Water outlet 16 Sanitary washing device body 18 Cleaning nozzle 19 Ejection part (gas-liquid ejection part)
28 Porous noble metal electrode (electrode)
30 Electrolyte membrane (solid polymer membrane)

Claims (10)

A fine bubble generating apparatus having at least one pair of electrodes and including a bubble mixing portion that pressurizes and mixes bubbles generated by electrolysis of water into flowing water, and a gas-liquid jetting portion that jets water containing bubbles. 2. The fine bubble mixing device according to claim 1, wherein the bubble mixing portion and the gas-liquid jetting portion are provided adjacent to each other. The fine bubble generating device according to claim 1 or 2, wherein the bubble mixing part has a water inlet and a water outlet, and the cross-sectional area of the water outlet is smaller than the water inlet. The bubble mixing part includes a core electrode, a flow path provided on the outer periphery of the core electrode, a case surrounding the flow path, an electrode provided on the inner wall of the case, and a flow rate variable means for converting a flow rate in the flow path. The fine bubble mixing device according to any one of claims 1 to 3, further comprising: 5. The fine bubble generating device according to claim 4, wherein the flow rate variable means is configured to change the flow rate of the flow path in a direction to increase the flow rate. 6. The fine bubble generating device according to claim 5, wherein the flow velocity varying means is configured such that the flow velocity increases toward the downstream side of the flow path. The microbubble generator according to any one of claims 4 to 6, wherein the flow rate variable means is configured to narrow at least a part of the flow path. The fine bubble generating device according to any one of claims 1 to 3, wherein the bubble mixing portion includes a bubble generating means including a solid polymer film and electrodes formed on both surfaces of the solid polymer film. 9. The microbubble generator according to claim 1, wherein at least the anode is a lead dioxide electrode, and ozone generated together with oxygen on the surface of the lead dioxide electrode is mixed by electrolysis. A sanitary washing device comprising the fine bubble generating device according to any one of claims 1 to 9.

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