JP2013119043A - Microbubble generating device and water treating apparatus using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a microbubble generating device which has compact and simple constitution and can improve water treating capacity by blending water to be treated with active species before disappearance and to provide a water treating apparatus which uses electrical discharge.SOLUTION: The microbubble generating device is provided with: a container body 1 of a nearly conical shape; an air supply hole 2 which is disposed at the bottom surface central part of the container body 1; a liquid introducing port 3 which is disposed at a container flank in a tangential direction; and a gas-liquid discharge hole 4 which is disposed at the top end part of the container. A swirling flow is produced by liquid introduced from the liquid introducing port into the container body 1 and at least two electrodes 6 are disposed on or near its swirling axis 8. Thus compact and simple constitution where microbubbles 7 including the active species generated by discharge are generated and the water to be treated can be quickly blended with the active species immediately after generation to enable effective interaction between the active species and organics or microorganisms in water before disappearance of the active species can be obtained.

Description

  The present invention is a water treatment device that uses discharge in particular, and is used for tap water, well water, river water, drinking water, sewage, industrial water, industrial wastewater, or water used for pools, public baths, hot springs, etc. The present invention relates to a water treatment apparatus for treating water to be treated by decomposing organic substances contained in the water to be treated and sterilizing microorganisms.

  Conventionally, as a device using a discharge and a water treatment apparatus using the device, bubbles are introduced or generated between electrodes disposed in the water to be treated, discharge is performed between the electrodes, and the generated active species is covered. What performs a process by mixing with a treated water is known (for example, refer patent document 1).

  Japanese Patent Application Laid-Open No. H10-228688 describes a device that allows the treatment to be performed efficiently by mixing the water to be treated and the active species generated by the discharge by the high-pressure spray device after the discharge treatment.

JP 2009-034583 A

  However, since such a conventional water treatment apparatus has a discharge treatment device and a mixing apparatus, there is a problem that the entire treatment apparatus becomes large.

  In addition, since the active species has a short lifetime and is less than 1 millisecond for hydroxyl radicals, the active species generated by the discharge treatment device disappear before reaching the mixing device, and the organic species decomposition effect of the active species, sterilization There was a problem that the effect could not be used effectively.

  Accordingly, the present invention solves the above-described conventional problems, and a microbubble generating device that enables a compact and simple configuration that can effectively utilize the organic matter decomposition effect and sterilization effect of active species, and a water using the same. An object is to provide a processing apparatus.

  In order to achieve this object, the present invention provides a substantially conical container body, an air supply hole provided in the center of the bottom surface of the container body, and a liquid introduction hole provided in a tangential direction of the side surface of the container. And a gas-liquid discharge hole provided at the tip of the container, and a swirl flow is generated by the liquid introduced into the container body from the liquid introduction hole, and at least two or more on the swivel axis or in the vicinity thereof An electrode is provided, and a voltage is applied between the electrodes to generate microbubbles containing active species generated by discharge, thereby achieving an intended purpose.

  According to the present invention, the substantially conical container main body, the air supply hole provided in the central portion of the bottom surface of the container main body, the liquid introduction hole provided in the tangential direction of the side surface of the container, and the tip of the container are provided. The gas-liquid discharge hole is provided, a swirling flow is generated by the liquid introduced into the container body from the liquid introducing hole, and at least two or more electrodes are provided on or in the vicinity of the swirling axis. Microbubbles containing the generated active species are generated, allowing the active species to be quickly mixed with the treated water immediately after generation, and allowing compact interaction with organic matter and microorganisms in the water before the active species disappear. A simple configuration is possible.

  Furthermore, the discharge is performed in the gas region decompressed by the centrifugal force due to the swiveling, and thus power saving discharge can be realized.

Schematic diagram of microbubble generating device in Embodiment 1 of the present invention AA sectional view in FIG. Detailed electrode cross section in the first embodiment of the present invention Configuration of the water treatment apparatus according to Embodiment 1 of the present invention

  The microbubble generating device according to claim 1 of the present invention includes a substantially conical container main body, an air supply hole provided in a central portion of the bottom surface of the container main body, and a liquid introduction hole provided in a tangential direction of the side surface of the container. And a gas-liquid discharge hole provided at the tip of the container, and a swirl flow is generated by the liquid introduced into the container body from the liquid introduction hole, and at least two or more on the swivel axis or in the vicinity thereof By providing an electrode, applying a voltage between the electrodes, and generating microbubbles containing active species generated by discharge in the liquid, it is possible to save by discharging in a decompressed gas region. Power discharge can be made possible. In addition, it is possible to mix microbubbles containing active species generated by discharge into treated water immediately after generation, and a compact and simple configuration that can efficiently interact with organic substances and microorganisms in water before extinguishing active species. Make it possible.

  The electrode is configured not to follow the gas flow generated by the swirling flow, thereby disturbing the flow in the gas region and increasing the relative swirling speed difference with the liquid, thereby shearing at the gas-liquid interface. It is possible to increase the action, improve the generation efficiency of microbubbles, and obtain the effect that the water treatment capacity can be improved. Further, by disturbing the gas region, gas mixing at the vicinity of the electrode and the gas-liquid interface is promoted, and the effect of improving the active species generation efficiency and efficiently performing gas-liquid mixing can be obtained.

  The acceleration of the gas flow generated by the swirl flow is configured to change during one swirl, thereby disturbing the flow in the gas region and increasing the relative swirl speed difference with the liquid. Further, it is possible to increase the shearing action at the gas-liquid interface, improve the generation efficiency of microbubbles, and obtain the effect that the water treatment capacity can be improved. Further, by disturbing the gas region, gas mixing at the vicinity of the electrode and the gas-liquid interface is promoted, and the effect of improving the active species generation efficiency and efficiently performing gas-liquid mixing can be obtained.

  The voltage applied to the electrode may be a pulse voltage. As a result, a high voltage can be applied in a short time, and discharge can be generated with low power. In addition, since the application is stopped before the generated discharge is converted into an arc discharge in which heat is almost lost and energy is lost, active species generation and water treatment with reduced energy loss can be achieved.

  Moreover, it is good also as a structure by which the surface of either one of the said electrodes is coated with the dielectric material. As a result, it is possible to prevent a large current from flowing all at once due to arc discharge and damage the electric system, and it is possible to stably form a discharge. Furthermore, since the conductor portion of the electrode is not consumed by discharge, there is an effect that the life of the electrode is prolonged and there is no change in the component of the water to be treated accompanying the elution of the conductor material. Furthermore, since a short circuit between the electrodes can be prevented, there is an effect that the distance between the electrodes can be set as small as possible so that the applied voltage and the power consumption are reduced.

  A microbubble generating device according to any one of claims 1 to 5 provided at a water treatment tank and an inlet of the water treatment tank, and a liquid feed pump for supplying treated water to the device from the water treatment tank outlet. By the water treatment apparatus characterized by being configured, there is an effect that water treatment with high power consumption and high treatment efficiency becomes possible.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(Embodiment 1)
FIG. 1 shows a schematic diagram of a microbubble generating device.

  FIG. 2 shows an AA cross-sectional view in FIG.

  The structure of the microbubble generating device will be described with reference to FIGS.

  The device includes a container body 1, an air supply hole 2 provided on the bottom surface of the container body 1, a liquid introduction hole 3 provided in a tangential direction on the side surface of the container body 1, and a gas / liquid discharge hole provided at the tip of the container body 1. 4 and an electrode 6 inserted into the container body 1 and electrically connected to a high voltage power source 5 provided outside the container body 1. The electrode 6 is composed of a rod-shaped electrode disposed on the pivot shaft 8 and a spiral electrode disposed so as to surround it.

  FIG. 3 shows a detailed cross-sectional view of the electrode in the microbubble generating device.

  An electrode 6 constituted by a rod-shaped electrode existing on the pivot shaft 8 and a spiral electrode arranged so as to surround the electrode is formed by coating an inner conductor 6b with a dielectric 6a.

  Next, the principle of generation of microbubbles 7 containing active species, which is a feature of the present invention, will be described with reference to FIGS.

  When a liquid, for example, water to be treated is introduced from the liquid introduction hole 3, a swirling flow is generated. A region where the swirl flow is generated is referred to as a liquid region 9. Due to the centrifugal force caused by the turning, the pressure on the turning shaft 8 is reduced, and the gas is automatically supplied from the air supply hole 2. The supplied gas creates a gas region 10 around the pivot axis 8. A difference in the swirl speed is created by the difference in density between the liquid and gas. For this reason, a shearing effect that causes the gas to be peeled off due to a velocity shift occurring at the gas-liquid interface between the liquid region 9 and the gas region 10 occurs, and the gas is refined to become microbubbles 7. Since this shearing effect is improved as the turning speed is increased, the shearing effect is effectively increased as the turning distance is shortened and the gas-liquid discharge hole 4 is approached.

  The electrode 6 electrically connected to the high voltage power source 5 is disposed in the gas region 10, and therefore, the electrode 6 is disposed in the gas region 10 being decompressed. And when a high voltage is applied to the electrode 6, it discharges and active species, such as ozone and a hydroxyl radical, are produced | generated. Microbubbles 7 containing active species generated by the shearing action are generated and discharged from the gas-liquid discharge hole 4.

  As shown in FIG. 3, the electrode 6 is coated with the dielectric 6a, so that it is possible to prevent a large current from flowing suddenly due to arc discharge between the electrodes and destroy the power supply circuit and the like. Can be formed. In addition, since the conductor 6b is not consumed by discharge, the life of the electrode can be expected to be increased, and there is no change in the liquid component accompanying the elution of the metal material of the conductor 6b. In addition, since the electrodes can be prevented from being short-circuited, the distance between the electrodes can be set as small as possible so that the applied voltage and the power consumption are reduced.

  Regarding the dielectric 6a, the coating method is preferably a method of forming an inorganic oxide film by a sol-gel method, and the material can be SiO2, Al2O3, MgO, ZrO2, TiO2, ZnO, Y2O3, BaTiO2, etc., but the relative dielectric constant From the viewpoints of the above, BaTiO2, Al2O3, and TiO2 are preferable.

  The conductor 6b needs to be made of a material that can withstand oxidation due to a flowing liquid and deterioration due to oxidation accompanying discharge. For example, metals such as stainless steel, titanium, aluminum, copper, and copper alloys can be used, and stainless steel and titanium are preferable.

  Since the electrode 6 is deprived of heat by the automatically supplied airflow or the liquid swirling around, the heat generation associated with the discharge can be suppressed.

  The distance between the electrodes should be as small as possible for the purpose of reducing the applied voltage and power consumption, and it should be increased for the purpose of increasing the discharge area. Therefore, it is necessary to set an optimum distance between the electrodes. There is. Since the discharge is performed under reduced pressure, an appropriate interelectrode distance is 0.05 to 50 mm according to Paschen's law. When the distance between the electrodes is larger than 50 mm, the applied voltage necessary for the discharge becomes about 100 kV or more, and the high voltage power source 5 becomes large and expensive.

  The voltage waveform applied between the electrodes may be a high voltage rectangular wave, triangular wave, sine wave, or the like, and preferably a high voltage pulse. By using a high voltage pulse, it is possible to apply a high voltage in a short time, and it is possible to generate a discharge with low power. Further, since the application is stopped before the arc discharge in which the generated discharge becomes almost heat and energy is lost, energy loss can be suppressed.

  The magnitude of the voltage applied by the high-voltage power supply 5 varies depending on the shape and size of the electrode, the object to be processed, and the required processing capacity, but it cannot be determined unconditionally. Considering efficiency, it is preferably 1 to 100 kV.

  The electrode 6 is covered with a dielectric 6a while maintaining a constant electrode interval, and has a structure that does not follow the flow of the gas region 10, so that the gas region 10 is disturbed, so that the electrode 6 The turning speed difference is increased, and the generation efficiency of the microbubbles 7 is improved. Desirably, if the acceleration of the gas flow generated by the swirl flow changes during one swirl, the relative swirl speed difference between the gas region 10 and the liquid region 9 is further increased. The generation efficiency is improved.

  The structure that does not follow the flow of the gas region 10 is a structure in which the rod-shaped electrode and the spiral electrode are surrounded by the above-described rod-shaped electrode and the spiral electrode, for example, a structure in which the rod-shaped electrode is surrounded by a spiral electrode reversed in the swiveling direction. A structure electrode, a swirling direction and a reverse spiral double spiral structure, a structure in which a rod-shaped electrode is covered with a cylindrical mesh electrode, a counter mesh plate electrode, a plurality of rod electrodes, and the like are conceivable.

  When the electrode 6 is not present, mainly the swirling flow in the gas region 10 only changes in speed due to the inhibition of the inner surface of the container body 1 and the liquid region 9. However, by these structures, it becomes possible to add the effect of the turbulent flow turbulence by the electrode 6, the change in the direction of the gas flow, and the change in the acceleration acting on the gas, and the effect of increasing the relative speed difference between the liquid region 9 and the gas region 10. obtain. However, the present invention is not limited to these structures as long as similar effects can be obtained.

  Although the air supply hole 2 is provided in the bottom face of the container main body 1, in order to obtain efficient turning and air supply, the center of the bottom face is preferable on the turning shaft 8. However, the structure is not limited to this as long as the structure obtains efficient turning and air supply.

  The electrode 6 is disposed in the gas region 10, but smooth air supply, efficient discharge, disturb the gas region 10 due to the electrode structure and promote gas mixing near the electrode and the gas-liquid interface, In order to improve the efficiency of generating active species and obtain gas-liquid mixing, it is preferable that it is on or near the pivot shaft 8. However, if the same effect can be acquired, it will not be restricted on the turning axis 8.

  Although the container body 1 has a substantially conical shape, it may have a semi-spindle shape or a semi-elliptical sphere shape in which the conical inclined portion has a bulge. Further, it may have a funnel shape in which a conical inclined portion is recessed. Moreover, the shape which united them on the bottom face, for example, a cylinder shape, a spindle shape, an ellipsoidal shape, etc. may be sufficient. In this case, it is necessary to devise such as providing the liquid introduction hole 3 and the air supply hole 2 on the side surface of the combined bottom surface, or providing the air supply hole 2 in the vicinity of the gas-liquid discharge hole 4. Alternatively, a gas / liquid mixture can be introduced.

  According to such a configuration, discharge can be performed under reduced pressure, and a voltage required for discharge can be reduced as compared with the case of discharging in water or atmospheric pressure, so that an effect of suppressing power consumption can be obtained.

  In addition, by integrating the microbubble generator and the electrode 6, it is possible to mix the microbubbles 7 containing the active species generated by the discharge into the water to be treated immediately after the generation, and the organic matter in the water before the active species disappears. There is an effect that a compact and simple configuration capable of efficiently interacting with microorganisms is possible.

  Even in the generation of the microbubbles 7, the suppression of the flow of the gas region 10 due to the presence of the electrode 6 increases the shearing effect at the gas-liquid interface, leading to an improvement in the generation efficiency of the microbubbles 7.

  Further, by disturbing the gas region 10, it is possible to promote the mixing of the gas in the vicinity of the electrode 6 and the gas-liquid interface, and to obtain the effect that the active species generation efficiency is improved and the gas-liquid mixing is performed efficiently.

(Embodiment 2)
FIG. 4 shows a configuration diagram of a water treatment apparatus according to Embodiment 2 of the present invention. The same components as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.

  The water treatment apparatus includes a microbubble generation device, a water treatment tank 11, and a liquid feed pump 13 that sends the water to be treated 12 from the water treatment tank 11 to the microbubble generation device.

  The treated water 12 introduced from the liquid feed pump 13 is mixed with the microbubbles 7 containing active species generated by the discharge at the electrode 6 from the gas supplied from the air supply hole 2 in the microbubble generating device. It is discharged into the treated water 12.

  Active species having a lifetime of 1 millisecond or less are converted into microbubbles 7 immediately after generation by discharge, and when mixed in a microbubble generating device, interact with organic matter and microorganisms in the water 12 to be treated, thereby water treatment. To do.

  Furthermore, if it is an active species such as ozone having a relatively long life, it can interact with organic matter and microorganisms in the water 12 to be treated at the gas-liquid interface of the microbubbles 7 discharged to the water treatment tank 11 and can be treated with water. . Also, the active species in the microbubbles 7 dissolve in the water to be treated 12 during the rise, thereby interacting with organic matter and microorganisms in the water to be treated 12 for water treatment.

  The microbubble 7 here has a diameter of 1 mm or less, preferably 10 μm to 20 μm. Since the surface area per total volume increases due to the microbubbles 7, the probability of interaction at the gas-liquid interface increases and the water treatment effect is improved. In addition, the pressure difference between the inside and outside of the bubble when the diameter is 10 μm is about 0.3 atm higher than the Young-Laplace equation, the dissolution efficiency of the gas in the water to be treated 12 is increased, and the organic matter and microorganisms in the water to be treated 12 The interaction probability is increased and the water treatment effect is improved. Therefore, even active species having a lifetime of 1 millisecond or less effectively act with organic matter and microorganisms in the water 12 to be treated.

  Furthermore, if it is an active species such as ozone having a relatively long life, it becomes microbubbles 7 and the surface area per total volume increases. For example, when the diameter is 10 μm, the rising speed of microbubbles 7 is Stokes' law. Furthermore, since it becomes very late at about 2 mm / min, the interaction time and probability at the gas-liquid interface increase and the water treatment effect is improved. When the diameter is 10 μm, the pressure difference between the inside and outside of the bubble is about 0.3 atm higher than the Young-Laplace equation, so that the efficiency of dissolving the gas in the liquid increases and interacts with organic matter and microorganisms in the treated water 12. Probability increases and water treatment effect improves.

  As the gas to be supplied, air in the atmosphere, high-purity oxygen, ozone, or the like can be used.

  In the present embodiment, the microbubble generating device is provided so as to circumscribe the water treatment tank 11, but may exist in water. In this case, it is preferable that the air supply hole 2 is taken out of the liquid or connected to gas supply means such as a cylinder with an air supply pipe or the like.

  The water treatment device according to the present invention has a simple configuration and is capable of improving the water treatment capacity while suppressing power consumption. Tap water, drinking water, sewage, industrial water, industrial It is useful as a water treatment device for treating water to be treated by decomposing organic substances contained in water (water to be treated) used for sewage, pools, public baths, hot springs, etc. or sterilizing microorganisms.

DESCRIPTION OF SYMBOLS 1 Container body 2 Air supply hole 3 Liquid introduction hole 4 Gas-liquid discharge hole 5 High voltage power supply 6 Electrode 6a Dielectric 6b Conductor 7 Microbubble 8 Swirling axis 9 Liquid area 10 Gas area 11 Water treatment tank 12 Processed water 13 Liquid supply pump

Claims (6)

A substantially conical container body;
An air supply hole provided in a bottom center part of the container body;
A liquid introduction hole provided in a tangential direction of the container side surface;
A gas-liquid discharge hole provided at the tip of the container;
A swirl flow is generated by the liquid introduced into the container body from the liquid introduction hole, and at least two or more electrodes are provided on or near the swivel axis, a voltage is applied between the electrodes, and generated by discharge. A microbubble generating device that generates microbubbles containing active species in a liquid. The microbubble generating device according to claim 1, wherein the electrode is configured not to follow a gas flow generated by a swirling flow. The microbubble generating device according to claim 1, wherein an acceleration of a gas flow generated by the swirl flow is changed during one swirl. The microbubble generating device according to any one of claims 1 to 3, wherein a voltage applied between the electrodes is a pulse voltage. 5. The microbubble generating device according to claim 1, wherein a surface of one of the electrodes is coated with a dielectric. 6. The microbubble generation device according to any one of claims 1 to 5, provided at a water treatment tank and the water treatment tank inlet;
A water treatment apparatus comprising a liquid feed pump for supplying treated water to the device from an outlet of the water treatment tank.

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