JP6765582B1 - Water treatment equipment and water treatment method - Google Patents

Abstract

The water treatment device (100) is tubular and made of a dielectric material, is opened on one end side, is provided upright in the vertical direction with one end side facing up, and is supported by a grounded support member (11). The central electrode (3), which is provided upright inside the circular tube (4) and the circular tube (4), and a voltage is applied between it and the ground, and the circular tube on one end side. It is provided with a sprinkling portion (5) for supplying conductive water to be treated (6) from a position distant from (4) toward the inner side and the outer peripheral surface of the circular pipe (4).

Description

The present application relates to a water treatment apparatus and a water treatment method.

Ozone or chlorine is commonly used in water treatment. However, industrial wastewater and the like may contain persistent substances that cannot be removed by existing ozone treatment equipment. In particular, removal of dioxins and dioxanes has become a major issue. Accordingly, ozone is generated (O ₃₎ highly active hydroxyl radical than (OH radicals) by discharge, by acting on the water to be treated, a method of removing a hardly decomposable substance with high efficiency has been proposed.

For example, a cylindrical electrode made of a metal material and a linear electrode arranged inside the cylindrical electrode are provided, and water to be treated is supplied as water droplets in a streamer discharge space generated by applying a high voltage between them, and the water droplets are provided. A water treatment apparatus for decomposing an object to be treated is disclosed (see, for example, Patent Document 1). In addition, a cylindrical glass tube whose outer circumference is covered with a metal mesh and a metal bolt arranged coaxially with the center thereof are provided, and a high pulsed voltage is applied between them to form a discharge, and the inside of the glass tube is formed. A water treatment apparatus that treats the water to be treated by spraying the water to be treated from above is disclosed (see, for example, Non-Patent Document 1).

Japanese Unexamined Patent Publication No. 2012-236130

Y. Nakagawa et al., “Decolorization of Rhodamine B in Water by Pulsed High-Voltage Gas Discharge”, Jpn. J. Appl. Phys. Vol. 42, pp.1423-28 (2003)

In the water treatment apparatus according to Patent Document 1, since sparks are not generated by water lumps staying at the upper and lower ends of the cylindrical electrode, water treatment by streamer discharge can be stably performed for a long time. However, in the middle of the cylindrical electrode, the electrodes made of a metal material are directly opposed to each other through the voids, so that a strong discharge, that is, a spark discharge may occur locally depending on the conditions. In particular, when the applied voltage is high or the discharge repetition frequency is high, the electric power applied per unit volume increases and the gas temperature between the electrodes increases, so that spark discharge is likely to occur. Further, if the distance between the electrodes is biased or the water to be treated adheres to the electrodes and the voids are locally narrowed, spark discharge is likely to occur. When a spark discharge occurs, the discharge is localized and the temperature rises locally, so that there is a problem that the production efficiency of O ₃ and H ₂ O _{2, which} are useful for water treatment, decreases, and the water treatment efficiency decreases. It was. Further, when spark discharge occurs frequently, there is a problem that one of the electrodes is consumed or damaged due to a local temperature rise or sputtering.

In the water treatment apparatus according to Non-Patent Document 1, a metal bolt to which a high voltage is applied and a metal mesh grounded are formed of a dielectric barrier type electrode configured so as to face each other via a glass tube, and thus spark. The generation of discharge is suppressed. However, abnormal discharge may occur in a minute gap that is inevitably formed between the metal mesh and the outer peripheral surface of the glass tube. When an abnormal discharge occurs, there is a problem that not only invalid power consumption that does not contribute to water treatment occurs, but also high power is locally applied to the abnormal discharge portion and the glass tube is damaged.

The present application has been made to solve the above-mentioned problems, and an object of the present application is to obtain a water treatment apparatus that suppresses the occurrence of spark discharge and abnormal discharge.

The water treatment apparatus disclosed in the present application is tubular and made of a dielectric material, is opened on one end side, is provided upright in the vertical direction with the one end side facing up, and is supported by a grounded support member. The circular tube, the center electrode provided upright inside the circular tube and applying a voltage to the ground, and the one end side of the circular tube from a position away from the circular tube. It is provided with a sprinkling portion for supplying water to be treated having conductivity toward the inside and the outer peripheral surface of the circular tube, and the water film of the water to be treated formed on the outer peripheral surface of the circular tube is connected to the ground. It is a layer .

According to the water treatment apparatus disclosed in the present application, spark discharge and abnormal discharge can be suppressed.

It is sectional drawing which shows the whole structure of the water treatment apparatus which concerns on Embodiment 1. FIG. It is a flowchart which shows the water treatment in the water treatment apparatus which concerns on Embodiment 1. FIG. It is sectional drawing which shows the whole structure of another water treatment apparatus which concerns on Embodiment 1. FIG. It is sectional drawing of the electric discharge unit provided in the water treatment apparatus which concerns on Embodiment 2. FIG. FIG. 5 is a cross-sectional view taken along the alternate long and short dash line AA of FIG. It is sectional drawing of the electric discharge unit provided with the water treatment apparatus which concerns on Embodiment 3. FIG. It is sectional drawing of the electric discharge unit provided in the water treatment apparatus which concerns on Embodiment 4. FIG. It is sectional drawing of the electric discharge unit provided in the water treatment apparatus which concerns on Embodiment 5. FIG. It is sectional drawing of the electric discharge unit provided with the water treatment apparatus which concerns on Embodiment 6. It is sectional drawing of the electric discharge unit provided in the water treatment apparatus which concerns on Embodiment 7. It is a perspective view of the discharge unit provided in the water treatment apparatus which concerns on Embodiment 8. It is sectional drawing of the electric discharge unit provided in the water treatment apparatus which concerns on Embodiment 9. FIG.

Hereinafter, the water treatment apparatus according to the embodiment of the present application will be described with reference to the drawings, but the same or corresponding members and parts will be described with the same reference numerals in each drawing.

Embodiment 1.
FIG. 1 is a cross-sectional view showing the overall configuration of the water treatment apparatus 100. The water treatment device 100 is a device that performs a treatment of oxidatively decomposing an organic compound contained in water 6 to be treated such as industrial wastewater by using an electric discharge 9. The water treatment device 100 includes a discharge unit 2 having a center electrode 3 and a circular tube 4 inside a treatment tank 1 made of a metal material having excellent corrosion resistance such as stainless steel and titanium and having conductivity, and water 6 to be treated. Is provided with a watering unit 5 for supplying the discharge unit 2. The details of each part will be described below.

At the lower part of the treatment tank 1, an intake pump 13 provided with an intake pipe 16 and a drainage pump 14 provided with a drainage pipe 17 are provided. The water intake pump 13 is operated, and the water to be treated 6 is taken into the water reservoir 18 at the bottom of the treatment tank 1 from the water intake pipe 16. The drainage pump 14 is operated, and the water treated from the drainage pipe 17 is drained to the outside of the treatment tank 1. The water reservoir 18 and the sprinkler 5 are connected by a circulation pipe 15 provided with a circulation pump 12. The circulation pump 12 is operated, and the water to be treated 6 is supplied to the sprinkler portion 5 from the circulation pipe 15. The circulation pipe 15 is provided outside the treatment tank 1, penetrates the wall surface of the treatment tank 1, and is connected to the sprinkler portion 5.

A gas supply unit 19 and an exhaust unit 20 are provided on the upper portion of the processing tank 1. The gas supply unit 19 supplies a gas containing oxygen to the inside of the processing tank 1 at a predetermined flow rate. The exhaust unit 20 exhausts the same amount of gas as the gas supplied by the gas supply unit 19 to the outside of the processing tank 1. By the operation of the gas supply unit 19 and the exhaust unit 20, the inside of the processing tank 1 is replaced with the gas supplied by the gas supply unit 19. The gas to be supplied may contain oxygen gas, for example, oxygen, air, or a gas obtained by mixing nitrogen or a rare gas with oxygen at an arbitrary ratio. When a rare gas such as argon or helium is used, the discharge 9 can be stably formed even at a relatively low voltage, and when air is used, the gas cost can be reduced. In general, the higher the oxygen concentration, the higher the ozone generation efficiency. Therefore, it is preferable to set the oxygen concentration to 80% or more. For example, it is generated by using a PSA (Pressure Swing Adsorption) device that separates oxygen in the air. Ozone can also be used.

The discharge unit 2 is arranged above a support member 11 made of a metal material having excellent corrosion resistance such as stainless steel and titanium and having conductivity. The support member 11 is arranged inside the processing tank 1 in contact with the bottom of the processing tank 1. The circular tube 4 is tubular and made of a dielectric, is open on one end side, and is provided upright in the vertical direction with one end side facing up. The circular tube 4 is supported by the grounded support member 11. A material having a dielectric property is used for the circular tube 4, and a glass or ceramic tube having excellent oxidation resistance is preferable. The center electrode 3 is provided inside the circular tube 4 coaxially with the circular tube 4 and upright on the support member 11 via the insulating member 10 in the vertical direction. A rod-shaped or linear metal member having conductivity is used for the center electrode 3, and a metal rod or wire having excellent corrosion resistance such as stainless steel or titanium is particularly preferable. A voltage is applied to the center electrode 3 to and from the ground. As the insulating member 10, glass, resin, or ceramic can be used. In particular, ceramic is most suitable from the viewpoint of dielectric strength and durability. The support member 11 is provided with an opening 11a, and the water 6 to be treated that has flowed down inside the circular pipe 4 flows down from the opening 11a into the water reservoir 18.

The water treatment device 100 includes a high-voltage power supply 8 outside the treatment tank 1. The high voltage output terminal 8a of the high voltage power supply 8 is connected to the center electrode 3. The ground terminal 8b of the high-voltage power supply 8 is connected to the processing tank 1, and the processing tank 1 and the support member 11 are grounded. When the water 6 to be treated having conductivity is supplied to the discharge unit 2, a high voltage is applied to the center electrode 3, so that the discharge 9 is formed between the inner peripheral surface of the circular tube 4 and the center electrode 3. Will be done. A pulse power supply is preferably used for the high-voltage power supply 8, but an AC power supply may be used as long as a stable discharge can be formed. The polarity of the voltage output when the pulse power supply is used as the high voltage power supply 8, the voltage peak value, the repetition frequency, the pulse width, etc. shall be appropriately determined according to various conditions such as the structure of the center electrode 3 and the gas type. Can be done. Generally, the voltage peak value is preferably 1 kV to 50 kV. This is because a stable discharge is not formed when the voltage is less than 1 kV, and when the voltage exceeds 50 kV, the cost increases remarkably due to the increase in size of the power source and the difficulty of electrical insulation. Further, the repetition frequency is preferably 10 pps (pulse-per-second) or more and 100 kpps or less. This is because if it is less than 10 pps, a very high voltage is required to input sufficient discharge power, and if it is larger than 100 pps, the efficiency of water treatment decreases. Further, the voltage, pulse width, and pulse repetition frequency may be adjusted according to conditions such as the component, concentration, and flow rate of the water to be treated 6.

A gap having a predetermined size is provided between the inner peripheral surface of the circular tube 4 and the outer peripheral surface of the center electrode 3. The size of this gap is determined according to the specifications of the high-voltage power supply 8 or the gas composition inside the treatment tank 1. The size of the predetermined gap is preferably about 1 mm to 100 mm. When the size of the gap is 1 mm or less, the contact area between the water to be treated 6 and the discharge 9 becomes small, and efficient water treatment cannot be performed. Further, when the size of the gap is 100 mm or more, a very high voltage is required to form the discharge 9, the cost of the high-voltage power supply 8 increases, and the difficulty of the insulation design of the entire device increases.

The sprinkler portion 5 supplies the water to be treated 6 having conductivity from a position away from the circular pipe 4 toward the inside and the outer peripheral surface of the circular pipe 4 on one end side of the circular pipe 4. The watering unit 5 includes a nozzle 35 that limits the watering area. For example, the nozzle 35 has a conical shape, and the ejection direction is adjusted so that the water to be treated 6 is appropriately supplied to the inner and outer peripheral surfaces of the circular tube 4. By providing the nozzle 35 so that the sprinkling area is wider than the outer diameter of the circular pipe 4, a part of the water to be treated 6 flows down the inside of the circular pipe 4, and the remaining part is the outer peripheral surface of the circular pipe 4. It flows down while adhering to and forming a water film 7. Since the wall surface of the circular tube 4 by O ₃ or the like generated by discharge 9 is hydrophilic, the outer peripheral surface of the circular tube 4 uniform water film 7 is formed. Immediately after the start of operation of the water treatment device 100, the discharge 9 is not generated, and the outer peripheral surface of the circular tube 4 may not be sufficiently hydrophilized. A water film 7 is formed. The water film 7 formed from the conductive water 6 to be treated substantially functions as a conductive layer on the outer periphery of the circular tube 4. Since the circular tube 4 is supported by the grounded support member 11, the water film 7 becomes a conductive layer having a ground potential. The water treatment device 100 is often operated continuously for a long period of time, and once the outer peripheral surface of the circular tube 4 is hydrophilized, a uniform discharge 9 is maintained thereafter. The sprinkler portion 5 may be provided with a mechanism capable of supplying the water to be treated 6 to the inner and outer peripheral surfaces of the circular pipe 4 to form the water film 7, and is not limited to the configuration provided with the nozzle 35. For example, a shower plate or a mesh-like member may be used for the sprinkler portion 5.

Next, the water treatment method in the water treatment apparatus 100 will be described. FIG. 2 is a flowchart showing water treatment in the water treatment apparatus 100 according to the first embodiment. First, the inside of the processing tank 1 is replaced with the gas supplied from the gas supply unit 19 (step S101). Next, the water intake pump 13 is operated to take the water to be treated 6 into the water reservoir 18 (step S102). Next, the circulation pump 12 is operated to suck the water to be treated 6 from the water reservoir 18 and supply it to the watering unit 5 (step S103). Next, the water to be treated 6 having conductivity from the nozzle 35 provided in the sprinkler portion 5 toward the inside and the outer peripheral surface of the circular pipe 4 from a position away from the circular pipe 4 on one end side of the circular pipe 4. Is supplied, and a water film 7 made of the water to be treated 6 is formed on the outer peripheral surface of the circular pipe 4 (step S104). Next, by operating the high-voltage power supply 8 and applying a voltage between the center electrode 3 and the treatment tank 1, a voltage is applied between the center electrode 3 and the water film 7, and the center electrode 3 and water are applied. An electric field is generated between the film and the film 7 to form a discharge 9 inside the circular tube 4 (step S105). The organic compound contained in the water to be treated 6 is oxidatively decomposed and treated using the electric discharge 9 (step S106). The treated water is drained (step S107). Since the water to be treated 6 supplied to the inside and the outer peripheral surface of the circular pipe 4 flows down to the water reservoir 18, a circulating water flow is formed by the operation of the circulation pump 12. The treated water is discharged into a river, for example, but a treatment facility equipped with activated carbon or the like may be provided after the water treatment device 100. During the treatment, the water intake pump 13 takes water so that the water reservoir 18 maintains a predetermined water level.

The details of the treatment for oxidatively decomposing the organic compound in the water to be treated 6 by using the electric discharge 9 will be described. Inside the treatment tank 1, by discharge 9, OH radicals of oxygen and water vapor as a raw material, O _3, the active species having oxidizing power, such as hydrogen peroxide (H 2 _{O 2)} is generated. Oxygen is supplied from the gas supply unit 19, and water vapor is supplied by evaporating the water to be treated 6. Since the water to be treated 6 is in a vapor-liquid equilibrium state inside the treatment tank 1, the water vapor concentration inside the treatment tank 1 is usually about 1 to 3%. Among active species, OH radical has high oxidizing power and can oxidatively decompose many organic compounds. When the water 6 to be treated flowing down inside the circular tube 4 comes into contact with the discharge 9, the organic compound dissolved in the water 6 to be treated is decomposed by taking in the active species. Further, since O ₃ and H ₂ O ₂ have a relatively long life, a part of O ₃ and H ₂ O ₂ remains in the water to be treated 6 even after the water to be treated 6 has passed through the discharge unit 2. It is transported to the water reservoir 18. Further, since a part of O ₃ and H ₂ O ₂ generated by the discharge 9 diffuses inside the processing tank 1 in the vapor phase state, the surface to be treated flows down the outer peripheral surface of the circular tube 4 or the outside of the circular tube 4. It dissolves in water 6 and is transported to the water reservoir 18. O ₃ and H ₂ O ₂ contained in the water reservoir 18 generate OH radicals by an underwater reaction to oxidatively decompose the organic compound in the water to be treated 6. Thus, O ₃ decomposition of the organic compound contained in the treated water 6, which dissolved the discharge unit 2 and the reaction of the active species when the treatment water 6 passes, the water to be treated 6 in the water reservoir 18 It proceeds by both reaction with OH radicals generated in the water reaction.

In the above, the configuration in which the water to be treated 6 is supplied to the sprinkling section 5 is provided with the circulation pipe 15 and the circulation pump 12, but the configuration for supplying the water to be treated 6 to the sprinkling section 5 is not limited to this. When the concentration of the organic compound contained in the water to be treated 6 is low and a sufficient water treatment effect can be obtained only by passing the water to be treated 6 through the treatment tank 1 once, the intake pump 13 is used as shown in FIG. The water intake pipe 16 provided may be connected to the water sprinkler portion 5.

As described above, in the water treatment apparatus 100 according to the first embodiment, the water film 7 made of the water to be treated 6 having conductivity is formed on at least the outer peripheral surface of the circular tube 4 made of a dielectric material, and the water film 7 and the center thereof. Since a dielectric barrier discharge is formed between the inner peripheral surface of the circular tube 4 and the center electrode 3 by the electric field between the electrodes 3, spark discharge can be suppressed. Further, since the spark discharge is suppressed, the consumption or damage of the center electrode 3 can be suppressed. Furthermore, since the spark discharge is suppressed, local temperature rise is suppressed, useful in water treatment O _3, H ₂ O ₂ or the like generated in is performed efficiently, be performed efficiently water treatment it can. Further, since a uniform water film 7 is formed on at least the outer peripheral surface of the circular tube 4, it is possible to suppress an abnormal discharge that may occur on the outer peripheral surface of the circular tube 4. Further, since abnormal discharge is suppressed, invalid power consumption and damage to the circular tube 4 can be suppressed. Further, when the watering portion 5 is provided with the nozzle 35, the watering area can be easily limited, and the water to be treated 6 can be appropriately supplied to the inner and outer peripheral surfaces of the circular pipe 4. Further, since the water to be treated 6 supplied from the nozzle 35 to the discharge unit 2 flows down while being in contact with the circular pipe 4, the water to be treated 6 functions as substantial cooling water, and the temperature of the circular pipe 4 rises due to the discharge 9. It is possible to suppress the damage of the circular tube 4 caused by the above. Further, since the water film 7 substantially functions as a ground electrode and it is not necessary to provide a metal conductive layer on the outer periphery of the circular tube 4 as in the conventional dielectric barrier discharge configuration, the manufacturing cost of the discharge unit 2 is suppressed. The problem of corrosion of the metal conductive layer does not occur.

Embodiment 2.
The water treatment apparatus 100 according to the second embodiment will be described. FIG. 4 is a cross-sectional view of the discharge unit 2 provided in the water treatment device 100, and FIG. 5 is a cross-sectional view taken along the alternate long and short dash line AA of FIG. The water treatment device 100 according to the second embodiment has a configuration in which a conductive member 21 and a vertical member 27 are arranged on the outer peripheral surface side of the circular pipe 4. Note that FIG. 5 shows only the circular tube 4, the conductive member 21, and the vertical member 27.

The vertical member 27 is provided on the outer peripheral surface side of the circular pipe 4 so as to extend vertically from the support member 11. As shown in FIG. 5, two vertical members 27 are provided facing each other, but the number of the vertical members 27 is not limited to two. The conductive member 21 surrounds the circular tube 4 and is held by the vertical member 27 on the outer peripheral surface side of the circular tube 4 so as to be in contact with the water film 7. As shown in FIG. 4, two conductive members 21 are provided here, but the number of the conductive members 21 is not limited to two. Both the conductive member 21 and the vertical member 27 are made of a conductive material, and are, for example, stainless steel or titanium having excellent corrosion resistance. The conductive member 21 and the vertical member 27 are grounded via the support member 11.

When the conductivity of the water 6 to be treated is low, the water film 7 may not be sufficiently conductive. In this case, although the discharge 9 is formed in the vicinity of the support member 11, the discharge 9 is less likely to be formed as the distance from the support member 11 increases. By providing the plurality of conductive members 21, the water film 7 is grounded at a plurality of points in the vertical direction, so that sufficient conductivity of the water film 7 can be obtained even when the conductivity of the water to be treated 6 is low. A uniform discharge is formed inside the circular tube 4.

The shape, number, and position of the conductive member 21 are arbitrarily determined according to the features of the water to be treated 6. As the conductivity of the water to be treated 6 is lower, it is preferable to increase the number of conductive members 21 and narrow the intervals. For example, the holding structure of the conductive member 21 to the vertical member 27 may be fitted so that the conductive member 21 can be easily increased or decreased. Further, as shown in FIG. 5, the shape of the conductive member 21 is preferably an annular shape having an inner diameter slightly larger than the outer diameter of the circular tube 4. According to this shape, the water film 7 can be grounded without obstructing the flow of the water film 7.

As described above, the water treatment apparatus 100 according to the second embodiment includes the conductive member 21 in contact with the water film 7 on the outer peripheral surface side of the circular tube 4, and the conductive member 21 is grounded. Even when the conductivity of the water 6 to be treated is low, the water film 7 can be sufficiently conductive, and a uniform discharge 9 can be formed inside the circular tube 4. Since a uniform discharge 9 is formed, water treatment can be performed efficiently.

Embodiment 3.
The water treatment apparatus 100 according to the third embodiment will be described. FIG. 6 is a cross-sectional view of the discharge unit 2 provided in the water treatment device 100, and the metal wire 22 is schematically added. The water treatment device 100 according to the third embodiment has a configuration in which a conductive wire is arranged in a circular tube 4 as a conductive member.

As the conductive member, the metal wire 22 which is a conductive wire is spirally wound along the outer peripheral surface of the circular tube 4 at a predetermined pitch. One end side of the metal wire 22 is an open end, and the other end side is connected to the support member 11. The metal wire 22 is grounded via the support member 11. The metal wire 22 is made of a material having excellent corrosion resistance, such as stainless steel or titanium.

Since the metal wire 22 is a grounded conductor, the water film 7 can be grounded over a wide range of the outer peripheral surface of the circular tube 4 even when the conductivity of the water to be treated 6 is low. The diameter of the metal wire 22 and the winding pitch can be appropriately determined according to the material strength, workability, and the conductivity of the water to be treated 6. It is preferable that the lower the conductivity of the water to be treated 6 is, the narrower the pitch around which the metal wire 22 is wound.

As described above, the water treatment apparatus 100 according to the third embodiment includes the metal wire 22 wound on the outer peripheral surface side of the circular tube 4, and the metal wire 22 is grounded, so that the water to be treated 6 is treated. Sufficient conduction of the water film 7 can be obtained even when the conductivity is low, and a uniform discharge 9 can be formed inside the circular tube 4. Since a uniform discharge 9 is formed, water treatment can be performed efficiently. By using the wound metal wire 22 as the conductive member, the water film 7 can be easily grounded at a plurality of places with a simple structure.

Embodiment 4.
The water treatment apparatus 100 according to the fourth embodiment will be described. FIG. 7 is a cross-sectional view of the discharge unit 2 provided in the water treatment device 100, and the metal mesh 23 is schematically added. The water treatment device 100 according to the fourth embodiment has a configuration in which a metal member covering the outer peripheral surface of the circular tube 4 is arranged as a conductive member.

As the conductive member, a metal mesh 23, which is a metal member covering the outer peripheral surface of the circular tube 4, is provided along the outer peripheral surface of the circular tube 4. The metal mesh 23 is made by knitting a metal wire into a cylindrical shape and having elasticity. One end side of the tubular metal mesh 23 is an open end, and the other end side is connected to the support member 11. The metal mesh 23 is grounded via the support member 11. The metal mesh 23 is made of a material having excellent corrosion resistance, such as stainless steel or titanium.

Since the metal mesh 23 is a grounded conductor, the water film 7 can be grounded over a wide range of the outer peripheral surface of the circular tube 4 even when the conductivity of the water to be treated 6 is low. The wire diameter and aperture ratio of the metal mesh 23 can be appropriately determined according to the material strength, processability, and the conductivity of the water to be treated 6. It is preferable that the lower the conductivity of the water to be treated 6 is, the lower the aperture ratio of the metal mesh 23 is.

As the metal mesh 23, it is also preferable to use a tubular body formed by knitting a metal wire or the like. In particular, if the tubular body is made elastic, the conductive member is provided by covering the outer periphery of the circular tube 4, so that the water treatment device 100 can be easily assembled. Further, the metal mesh 23 and the circular tube 4 are in close contact with each other, and the metal mesh 23 can be prevented from falling off. The metal member covering the outer peripheral surface of the circular tube 4 does not necessarily have to be a metal mesh 23, and for example, a thin metal plate or a punched metal formed into a tubular shape may be used.

As described above, the water treatment apparatus 100 according to the fourth embodiment includes the metal mesh 23 that covers the outer peripheral surface of the circular tube 4, and the metal mesh 23 is grounded. Therefore, when the conductivity of the water to be treated 6 is low. The water film 7 can be sufficiently conductive, and a uniform discharge 9 can be formed inside the circular tube 4. Since a uniform discharge 9 is formed, water treatment can be performed efficiently. By using the metal mesh 23 that covers the outer peripheral surface of the circular tube 4 as the conductive member, the water film 7 can be easily grounded at a plurality of places with a simple structure.

Embodiment 5.
The water treatment apparatus 100 according to the fifth embodiment will be described. FIG. 8 is a cross-sectional view of the discharge unit 2 provided in the water treatment device 100. The water treatment device 100 according to the fifth embodiment has a configuration in which a plurality of circular tubes 4 and a center electrode 3 are arranged.

The discharge unit 2 includes a glass tube 41 which is a plurality of circular tubes 4 arranged in a row in the horizontal direction, and a metal bolt 40 which is a center electrode 3 in each of the plurality of glass tubes 41. In FIG. 8, seven metal bolts 40 and seven glass tubes 41 are provided, but the number of these bolts is not limited to seven. The arrangement is not limited to the configuration in which they are arranged in a row in the horizontal direction, and these may be arranged in a matrix.

The support portion that supports the metal bolt 40 and the glass tube 41 is composed of a base plate 24, a first glass tube support member 25, a second glass tube support member 26, and a vertical member 27. The base plate 24, the first glass tube support member 25, the second glass tube support member 26, and the vertical member 27 are all made of a metal member having excellent corrosion resistance such as stainless steel or titanium and having conductivity. The vertical member 27 is provided so as to extend vertically from the base plate 24. The first glass tube support member 25 and the second glass tube support member 26 are provided so as to face the base plate 24 and are held by the vertical member 27. A plurality of the second glass tube support members 26 are provided, and two are provided in FIG. 7, but the number of the second glass tube support members 26 is not limited to this.

The first glass tube support member 25 and the second glass tube support member 26 are provided with through holes at positions where the glass tubes 41 are provided, and slot portions are formed. The through hole of the first glass tube support material 25, which is a circular tube support material, has a diameter similar to the inner diameter of the glass tube 41, and the other end side of the glass tube 41 is the first glass tube support material 25. Hold in contact. The through hole of the second glass tube support member 26 has a diameter slightly larger than the outer diameter of the glass tube 41. The second glass tube support member 26 functions as the conductive member 21 shown in the second embodiment. The glass tube 41 is inserted into the slot portion from above vertically, stands upright vertically, and is held by the first glass tube support member 25.

Each of the plurality of metal bolts 40 is vertically erected on the base plate 24 via the insulating member 10. The metal bolt 40 is arranged coaxially with the glass tube 41 inside the glass tube 41. The metal bolt 40 is easily provided on the insulating member 10 by screwing it into the insulating member 10. The plurality of metal bolts 40 are connected in parallel with the high voltage power supply 8. The ground of the high-voltage power supply 8 is connected to the vertical member 27, and the first glass tube support member 25 and the second glass tube support member 26 are grounded. By operating the high-voltage power supply 8, a discharge is formed between each inner surface of the plurality of glass tubes 41 and each metal bolt 40.

As described above, in the water treatment apparatus 100 according to the fifth embodiment, since the plurality of glass tubes 41 arranged side by side and the metal bolts 40 are provided for each of the plurality of glass tubes 41, an electric discharge is formed in a wider area. , A large amount of water to be treated 6 can be treated at once. Further, since the plurality of glass tubes 41 are held by being inserted into the slot portions formed by the first glass tube support member 25 and the second glass tube support member 26, the water treatment device 100 has a simple configuration. This can be realized and the water treatment device 100 can be easily assembled. Further, since the metal bolt 40 is used for the center electrode 3, the discharge 9 can be formed even at a relatively low voltage due to the electric field concentration associated with the peaks and valleys on the surface of the metal bolt 40.

Embodiment 6.
The water treatment apparatus 100 according to the sixth embodiment will be described. FIG. 9 is a cross-sectional view of the discharge unit 2 provided in the water treatment device 100, and the metal mesh 23 is schematically added. The water treatment device 100 according to the sixth embodiment has a configuration in which a plurality of metal bolts 40, which are the center electrodes 3, are held by the center electrode support member 28.

The center electrode support member 28 faces the base plate 24, and is provided on the base plate 24 between the base plate 24 and the first glass tube support member 25 via an insulating insulator 30. The center electrode support member 28 is made of a metal member having excellent corrosion resistance such as stainless steel or titanium and having conductivity. Each of the metal bolts 40 is provided upright on the center electrode support member 28. The metal bolt 40 is arranged coaxially with the glass tube 41 inside the glass tube 41. An insulating protective tube 29 is attached to each lower portion of the metal bolt 40 so as to cover at least a portion having the same height as the first glass tube support member 25. By providing the insulating protective tube 29, the electric discharge between the metal members between the first glass tube support member 25 and the metal bolt 40 is suppressed. The insulation protection tube 29 is a tubular member having an insulating property, and may be covered on the outer periphery of the metal bolt 40. For example, a glass tube or a ceramic tube is suitable.

As shown in FIG. 9, the discharge unit 2 is provided with one second glass tube support member 26, and a metal mesh 23, which is a metal member, is provided along the outer peripheral surfaces of the glass tubes 41. Even if the number of the second glass tube support member 26 is reduced to one, by providing the metal mesh 23, sufficient conductivity of the water film 7 can be obtained even when the conductivity of the water to be treated 6 is low.

The center electrode support member 28 is connected to the high voltage power supply 8. The ground of the high-voltage power supply 8 is connected to the vertical member 27, and the first glass tube support member 25, the second glass tube support member 26, and the metal mesh 23 are grounded. By operating the high-voltage power supply 8, a discharge is formed between each inner surface of the plurality of glass tubes 41 and each metal bolt 40.

As described above, the water treatment apparatus 100 according to the sixth embodiment includes the central electrode support member 28 having conductivity for holding each metal bolt 40, and connects the high voltage power supply 8 and the individual metal bolts 40. Since the voltage can be applied to the metal bolt 40 without any problem, the configuration of the water treatment device 100 can be simplified. The water treatment apparatus 100 is provided with an insulator 30 that insulates the center electrode support member 28 and the base plate 24, and can collectively insulate the base plate 24 and the individual metal bolts 40 without being individually insulated by the insulating member 10. The configuration can be simplified.

Embodiment 7.
The water treatment apparatus 100 according to the seventh embodiment will be described. FIG. 10 is a cross-sectional view of the discharge unit 2 provided in the water treatment device 100, and the metal mesh 23 is schematically added. The water treatment device 100 according to the seventh embodiment has a configuration in which the center electrode 3 is covered with an insulating protective tube 29.

All of the center electrodes 3 are covered with an insulating protective tube 29 made of a tubular dielectric material. By operating the high-voltage power supply 8, a discharge is formed between each inner surface of the circular tube 4 and the outer peripheral surface of each insulation protection tube 29. Since the discharge 9 and the metal member do not come into contact with each other, the metal component does not mix with the water to be treated 6 due to the elution or sputtering of the metal component.

As described above, in the water treatment apparatus 100 according to the seventh embodiment, since the center electrode 3 is covered with the insulating protective tube 29 made of a tubular dielectric material, the electric discharge does not come into contact with the metal member, and the metal component is contained. Mixing into the water to be treated 6 can be suppressed.

Embodiment 8.
The water treatment apparatus 100 according to the eighth embodiment will be described. FIG. 11 is a perspective view of the discharge unit 2 included in the water treatment device 100. The water treatment device 100 according to the eighth embodiment has a configuration in which a guide plate 32 is arranged between the sprinkler portion 5 and the circular pipe 4.

The guide plate 32 is a plate-shaped member provided between the sprinkler portion 5 and one end side of the circular pipe 4 and provided with a through hole 33 facing the one end side of each circular pipe 4. In FIG. 11, since the five circular tubes 4 are provided, the guide plate 32 is provided with five through holes 33. The through hole 33 limits the area through which the water to be treated 6 supplied from the sprinkler portion 5 toward one end of the circular pipe 4 passes through the guide plate 32. The shape of the through hole 33 is determined so that the water to be treated 6 flows down to the inside of the circular pipe 4 and the outer peripheral surface of the circular pipe 4 in a concentrated manner. Specifically, the through hole 33 is formed so that the diameter of the through hole 33 is slightly larger than the outer diameter of the circular tube 4.

The density of active species produced by the discharge is high near the discharge and low away from the discharge. Therefore, a high water treatment effect can be obtained by allowing the water 6 to be treated to flow down a portion close to the discharge. On the other hand, if the water to be treated 6 flows down a portion away from the circular pipe 4, a high water treatment effect cannot be obtained. By providing the guide plate 32, the water to be treated 6 flows down the inside of the circular pipe 4 and the outer peripheral surface of the circular pipe 4 in a concentrated manner. Therefore, a high water treatment effect can be obtained, and efficient water treatment becomes possible.

As described above, in the water treatment apparatus 100 according to the eighth embodiment, a guide plate provided with a through hole 33 facing the one end side of the circular pipe 4 between the sprinkling portion 5 and one end side of the circular pipe 4. Since 32 is provided, the water to be treated 6 flows down the inside of the circular pipe 4 and the outer peripheral surface of the circular pipe 4 in a concentrated manner, and a high water treatment effect can be obtained.

Embodiment 9.
The water treatment apparatus 100 according to the ninth embodiment will be described. FIG. 12 is a cross-sectional view of the discharge unit 2 provided in the water treatment device 100. The water treatment device 100 according to the ninth embodiment has a configuration in which the circular pipe 4 is supported by the support member 11 at the intermediate portion of the circular pipe 4.

In the first to eighth embodiments, the circular tube 4 is supported by the support member 11 grounded on the other end side, but the support of the circular tube 4 is not limited to the other end side. Absent. As shown in FIG. 12, the configuration may be such that the intermediate portion of the circular tube 4 is supported by the support member 11. A part of the outer circumference of the circular tube 4 is sandwiched between the support members 11 at the intermediate portion, and the circular tube 4 is supported by the support member 11. The place where the circular tube 4 is supported is not limited to one place, and may be supported by a plurality of places. Discharges are likely to form in the vicinity of the supported location.

As described above, in the water treatment apparatus 100 according to the ninth embodiment, since the circular pipe 4 is supported by the support member 11 grounded at the intermediate portion of the circular pipe 4, an electric discharge is formed in the vicinity of the supported portion. It becomes easy to be done.

The present application also describes various exemplary embodiments and examples, although the various features, embodiments, and functions described in one or more embodiments are those of a particular embodiment. It is not limited to application, but can be applied to embodiments alone or in various combinations.
Therefore, innumerable variations not illustrated are envisioned within the scope of the techniques disclosed herein. For example, it is assumed that at least one component is modified, added or omitted, and further, at least one component is extracted and combined with the components of other embodiments.

1 Treatment tank, 2 Discharge unit, 3 Center electrode, 4 Circular pipe, 5 Sprinkler, 6 Water to be treated, 7 Water film, 8 High voltage power supply, 8a High voltage output terminal, 8b ground terminal, 9 Discharge, 10 Insulation member, 11 Support member, 11a opening, 12 Circulation pump, 13 Intake pump, 14 Drainage pump, 15 Circulation pipe, 16 Intake pipe, 17 Drainage pipe, 18 Water reservoir, 19 Gas supply part, 20 Exhaust part, 21 Conductive member, 22 Metal wire, 23 metal mesh, 24 base plate, 25 first glass pipe support material, 26 second glass pipe support material, 27 vertical member, 28 center electrode support material, 29 insulation protection tube, 30 insulation porcelain, 32 guides Plate, 33 through holes, 40 metal bolts, 41 glass pipes, 100 water treatment equipment

Claims (12)

A circular tube that is tubular and made of a dielectric material , is open on one end side, is provided upright in the vertical direction with the one end side facing up, and is supported by a grounded support member.
A center electrode, which is made of a conductive material different from the dielectric material, is provided upright inside the circular tube in the vertical direction, and a voltage is applied to the ground.
On the side of the one end, a sprinkler portion for supplying water to be treated having conductivity toward the inside and the outer peripheral surface of the circular pipe from a position away from the circular pipe is provided.
Between the dielectric material from the outer peripheral surface the conductive formed of the circular tube comprised the Ri water film of water to be treated Do the conductive layer connected to the ground, the center electrode and the circular tube water treatment device according to claim that you form a dielectric barrier discharge. A conductive member is provided on the outer peripheral surface side.
The water treatment apparatus according to claim 1, wherein the conductive member is grounded. The water treatment apparatus according to claim 2, wherein the conductive member is a conductive wire wound along the outer peripheral surface. The water treatment apparatus according to claim 2, wherein the conductive member is a metal member that covers the outer peripheral surface. The water treatment apparatus according to claim 4, wherein the metal member is a metal mesh in which a metal wire is woven into a cylindrical shape and has elasticity. A plurality of the above-mentioned circular tubes arranged side by side,
The water treatment apparatus according to any one of claims 1 to 5, wherein each of the plurality of circular tubes is provided with the center electrode. A circular tube support material that supports the circular tube and
The water treatment apparatus according to claim 6, further comprising a conductive center electrode support material that supports each of the center electrodes. The water treatment apparatus according to any one of claims 1 to 7, wherein the water sprinkling unit includes a nozzle having a limited water sprinkling area. Claims 1 to 8 include a guide plate provided between the watering portion and one end side of the circular pipe and having a through hole facing the one end side of the circular pipe. The water treatment apparatus according to any one of the above. The water treatment apparatus according to any one of claims 1 to 9, wherein the center electrode is covered with an insulating protective tube made of a tubular dielectric material. A circular tube which is tubular and is made of a dielectric material, is provided upright in the vertical direction with one end side facing up, and is supported by a grounded support member, and the above-mentioned. A water treatment method in a water treatment apparatus , which is composed of a conductive material different from a dielectric material and is provided with a center electrode standing upright in the vertical direction inside the circular tube.
On one end side, water to be treated having conductivity is supplied from a position away from the circular tube toward the inside and the outer peripheral surface of the circular tube, and the outer periphery of the circular tube made of the dielectric material is supplied. A step of forming a water film of the conductive water to be treated on the surface,
It is characterized by comprising a step of applying a voltage between the water film which is a conductive layer of a ground potential and the center electrode and forming a dielectric barrier discharge between the circular tube and the center electrode. Water treatment method. A circular tube that is tubular and made of a dielectric, is open on one end side, stands upright in the vertical direction with the one end side facing up, and is supported by a grounded support member.
A center electrode, which is provided upright inside the circular tube in the vertical direction and a voltage is applied to and from the ground,
On the one end side, a sprinkler portion that supplies water to be treated having conductivity toward the inside and the outer peripheral surface of the circular pipe from a position away from the circular pipe.
A guide plate provided between the sprinkling portion and one end side of the circular pipe and having a through hole facing the one end side of the circular pipe is provided.
A water treatment apparatus characterized in that a water film of the water to be treated formed on the outer peripheral surface of the circular tube serves as a conductive layer connected to grounding.

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