JP2010143794A - Ozonizer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an ozonizer where a gap is easily uniformly maintained even if the gap is a discharging space having a double cylindrical structure like a high voltage electrode tube and a grounding electrode tube, where the high voltage electrode tube is easily inserted into the grounding electrode tube and where the efficiency of ozone generation is not lowered. <P>SOLUTION: An outer electrode is a grounding electrode made of a metal, an inner electrode is a high voltage electrode made of a metal and both are arranged to be concentric. An insulating layer 3 of a dielectric material is formed on an inner surface of the grounding electrode tube 1 and the discharging space 5 is made between the grounding electrode tube 1 and the high voltage electrode tube 2. A spacer 4 to keep the distance of the discharging space 5 is fixed on the surface of the high voltage electrode tube 2. A rectangular spacer 4a obtained by laminating two kinds of metal layers, whose thermal expansion coefficients are different, into two layers is set at an upper part in the circumferential direction of the high voltage electrode tube 2. The plate thickness of the spacer 4a is a little smaller than a discharging space distance. Meanwhile, a spacer 4b at a lower part in the circumferential direction of the high voltage electrode tube 2 is set at the same thickness as the distance of the discharging space of a single metal. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an ozone generator that generates ozone from oxygen by silent discharge in a discharge space supplied with oxygen or a gas containing oxygen.

  In each field of water and sewage treatment, pulp bleaching treatment or sterilization treatment, ozone having sterilization, decolorization, and deodorizing power is used. There exists a silent discharge type ozone generator as an ozone generator (for example, refer patent document 1). In a silent discharge type ozone generator, one side or both sides of a pair of electrodes arranged at a certain interval are covered with an insulator (dielectric material), and an AC voltage is applied between the electrodes for discharge. Since the electrode is covered with an insulator, electric charges cannot flow into the electrode, and a large current does not flow. Therefore, there is a feature that no sound is generated during discharge, such as spark discharge or corona discharge.

  8 and 9 are configuration diagrams of a silent discharge type ozone generator, FIG. 8 is a sectional side view, and FIG. 9 is a tube diameter side sectional view. The ozone generator shown in the figure has a double cylindrical structure of a ground electrode tube 1 constituting an outer cylinder and a high voltage electrode tube 2 constituting an inner cylinder. A dielectric insulating layer 3 is formed on the inner surface of the ground electrode tube 1. A plurality of spacers 4 provided between the inner surface of the ground electrode tube 1 and the outer peripheral surface of the high-voltage electrode tube 2 have a thickness of about 1 mm. A minute discharge space 5 is formed. A plurality of spacers 4 are provided at both ends in the tube axis direction, and in FIG. 9, the spacers 4 are equally arranged at the four ends in the electrode tube circumferential direction at both ends in the tube axis direction. The high voltage electrode tube 2 is maintained at a coaxial position with respect to the ground electrode tube 1 by the spacers 4 a and 4 b arranged at four locations in the electrode tube circumferential direction. Both electrode tubes 1 and 2 are connected to a high voltage power supply 6 for applying an AC voltage of 4 to 10 kV.

  A source gas 7 containing oxygen is supplied from one end of the electrode tube of the ozone generator, and an AC voltage of 4 to 10 kV is applied between the electrode tubes 1 and 2 from the high voltage power source 6 to cause silent discharge in the discharge space 5. The ozonized gas 8 is discharged from the other end. As the source gas 7, dried oxygen or air is used.

  When an alternating high voltage is applied between the ground electrode tube 1 and the high voltage electrode tube 2 provided with the insulating layer 3 to cause a silent discharge in the minute discharge space 5, one of oxygen molecules in the source gas is generated. The portion is converted into oxygen atoms according to the accelerated electrons, and the oxygen atoms and oxygen molecules are combined to form ozone.

The distance of the minute discharge space 5 that ozonizes oxygen molecules is formed by the difference between the inner diameter dimension of the ground electrode tube 1 provided with the insulating layer 3 and the outer dimension dimension of the high voltage electrode tube 2. The maintenance of the distance of the space 5 and the support of the high voltage electrode tube 2 are performed by a plurality of spacers 4 installed at both ends of the high voltage electrode tube 2. These spacers 4 are fixed to the high voltage electrode tube 2 by welding or the like.
JP 2006-45037 A JP-A-4-214003

  However, as described above, the ozone generator that maintains the discharge space 5 with the spacer 4 has substantially the same thickness as the spacer 4 and the interval between the discharge spaces 5, so that the high-voltage electrode tube 2 that forms the inner cylinder is provided. The operation of inserting into the grounded electrode tube 1 serving as an outer cylinder was very difficult. If the high voltage electrode tube 2 is forcibly inserted into the ground electrode tube 1, the spacer 4 welded and fixed to the high voltage electrode tube 2 may come into contact with the inner surface of the ground electrode tube 1 and the spacer 4 may come off. .

  On the other hand, if the size of the spacer 4 is reduced in order to insert the high voltage electrode tube 2 into the ground electrode tube 1, the high voltage electrode tube 2, which is an inner cylinder, in the ozone generator horizontally disposed as shown in FIG. 8. Is arranged in an eccentric state on the lower side of the electrode tube with respect to the grounded electrode tube 1 serving as an outer cylinder, and in the discharge space 5, the gap at the upper part of the tube and the gap at the lower part of the tube are non-uniform, thereby reducing the ozone generation characteristics Let

  Further, in order to facilitate the insertion of the high-voltage electrode tube 2 serving as the inner cylinder, when the discharge space 5 is to be maintained at two points only by the spacer 4b at the bottom of the tube without installing the spacer 4a at the top of the tube, The discharge space above the tube cannot be accurately maintained, and this also causes a decrease in ozone generation characteristics.

  On the other hand, if the spacer 4 is extended in the longitudinal direction of the pipe and the cross-sectional area of the spacer 4 in the longitudinal direction of the pipe is too large, the gas flow is hindered. Become.

  Moreover, the proposal which maintains a space | interval of discharge space using a spring member for a spacer is made (for example, refer patent document 2). In the ozone generator described in Patent Document 2, the free end of the spring member is substantially tangential to the dielectric and is in contact with the inner wall of the external electrode. However, since the cross-sectional area of the spring member used as the spacer is larger with respect to the longitudinal direction of the electrode tube, which is the gas flow direction, there is a risk that the gas flow will be hindered and pressure loss will occur, resulting in a decrease in ozone generation efficiency. is there. Further, the spring member is straight, folded, end-bent, or T-shaped or H-shaped, and the spring material itself is not greatly deformed. Before inserting the internal electrode, these spring members are in contact with the internal electrode at only one central portion, and the end portions are not in contact with anything. This is to make the amount of bending of the spring member very small. However, in this case, when the internal electrode is inserted, the inside of the electrode tube and the spring member may come into contact with each other, and the spring member may come off.

  The present invention has been made in view of such points, and even in a discharge space having a double cylinder structure such as a high voltage electrode tube and a ground electrode tube, the gap can be easily maintained uniformly, and An object of the present invention is to provide a silent discharge type ozone generator in which a high voltage electrode tube can be easily inserted into a ground electrode tube and the ozone generation efficiency is not lowered.

  The ozone generator according to the present invention includes an outer electrode tube in which a ground electrode is formed, an inner electrode tube that is inserted into the outer electrode tube and is formed with a high voltage electrode, and the outer electrode tube and the inner electrode tube. Dielectric layers formed on either one of the opposing surfaces, and a plurality of spacers disposed between the outer electrode tube and the inner electrode tube at a plurality of locations in the circumferential direction to form discharge spaces And an AC voltage source that applies an AC voltage between the outer electrode tube and the inner electrode tube, and the plurality of spacers are arranged on one side with the tube axis centers of both electrode tubes interposed therebetween. The first spacer is composed of a first spacer and a second spacer disposed on the other side, and the first spacer has a structure in which a plurality of metals having different thermal expansion coefficients are bonded to each other, thereby securing a free end. Either the outer electrode tube or the inner electrode tube in a state Is crab fixed, the free end is heated by the discharge current in the discharge space, characterized in that the deformation in the tube diameter direction.

  According to this configuration, the first spacer and the second spacer are disposed across the tube axis center of both electrode tubes, and the first spacer receives heat from the discharge in the discharge space and the free end has a tube diameter. Since the first spacer is not deformed during the operation of inserting or removing the inner electrode tube from the outer electrode tube, a gap is formed between the first spacer and the facing surface. For this reason, the size of the first spacer is small during assembly or disassembly work, and the inner electrode tube can be smoothly inserted or removed from the outer electrode tube. In addition, during operation after assembly, the first spacer is heated by the discharge current, and the free end is deformed in the tube radial direction. One spacer presses the surface of one of the electrode tubes facing, and the discharge space is maintained by the first and second spacers. For this reason, the outer electrode tube and the inner electrode tube are automatically coaxially positioned during operation by adjusting the dimension in the tube diameter direction when the first spacer is deformed and the dimension in the tube diameter direction of the second spacer. The distance in the direction perpendicular to the longitudinal direction of the electrode tube in the discharge space can be made uniform, and a decrease in ozone generation efficiency can be prevented.

  In the ozone generator, the thickness of the first spacer before thermal deformation due to discharge in the discharge space is smaller than the distance of the discharge space, and the second spacer has a distance of the discharge space. It can be made of a single metal having the same thickness and fixed to the same electrode tube as the first spacer.

  The second spacer has the same thickness as the distance of the discharge space, and there is substantially no deformation in the tube diameter direction due to the difference in thermal expansion. Therefore, only the first spacer disposed on the other side across the tube axis center with respect to the second spacer is deformed in the tube radial direction by the discharge heat and presses the opposing electrode tube in the tube radial direction, The outer electrode tube and the inner electrode tube are positioned at a coaxial position. Thereby, since the thickness of the second spacer becomes the distance of the discharge space, the distance of the discharge space can be maintained with high accuracy.

  In the ozone generator, the first spacer may be configured such that a spacer central portion or one end portion is fixed to either the outer electrode tube or the inner electrode tube. If it is the structure which a spacer center part is fixed, both ends will become a free end and will be displaced to a pipe diameter direction by heating. If the spacer one end is fixed, the end opposite to the fixed end becomes a free end and is displaced in the tube radial direction by the discharge heat.

  The first spacer has a double structure in which a first metal layer and a second metal layer having different thermal expansion coefficients are bonded together, and the first metal layer is fixed to the electrode tube side, and the first spacer is The metal layer has a large coefficient of thermal expansion, and the second metal layer has a small coefficient of thermal expansion. By using such a bimetal structure, the free end can be displaced in the tube diameter direction.

  In the ozone generator, an electrode tube formed by inserting the inner electrode tube into the outer electrode tube is installed in a horizontal direction in which the longitudinal direction of the electrode tube is a horizontal direction, and the first spacer is a circumference of the electrode tube. The second spacer may be arranged at the lower part in the circumferential direction of the electrode tube.

  In the ozone generator, the outer electrode tube and the inner electrode tube are made of a cylindrical metal material, the dielectric layer is formed on the inner surface of the outer electrode tube, and the outer electrode tube has an outer peripheral surface. It can be set as the structure which welded and fixed the 1st and 2nd spacer.

  In the ozone generator, the outer electrode tube is made of a metal material having a cylindrical shape, and the inner electrode tube is made of a dielectric and is formed on an inner peripheral surface of the insulating tube having one end opened. The first and second spacers can be welded and fixed to the inner peripheral surface of the outer electrode tube.

  In the ozone generator, the outer electrode tube and the inner electrode tube are made of a metal material having a cylindrical shape, the dielectric layer is formed on an outer peripheral surface of the inner electrode tube, and an inner peripheral surface of the outer electrode tube The first and second spacers may be fixed by welding.

  According to the present invention, even in a discharge space having a double cylinder structure such as a high voltage electrode tube and a ground electrode tube, the gap can be easily maintained uniformly, and the high voltage electrode tube is provided in the ground electrode tube. It can be easily inserted, and a decrease in ozone generation efficiency can be prevented.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.
The embodiment of the present invention is a silent discharge type double cylinder type ozone generator. The overall configuration is the same as that of the ozone generator shown in FIGS. 8 and 9, and the structure of the spacer for maintaining the discharge space is different. FIG. 1 is a schematic cross-sectional view of the ozone generator according to the present embodiment as viewed from the direction of arrows AA in FIG.

  The ground electrode tube 1 is a cylindrical tube made of a metal material of low carbon steel or stainless alloy steel. On the inner surface, glass or ceramics, which is an insulating material, is formed on an underlayer that matches the mechanical properties of the steel material. An insulating layer 3 having a low dielectric constant, a low dielectric loss, and a temperature stable electrical property suitable for the generator is formed.

  The high voltage electrode tube 2 is a cylindrical tube made of a metal material of low carbon steel or stainless alloy steel, and lids formed by welding or shivering are provided at both ends thereof. A high voltage power supply terminal (not shown) is provided on the lid of the high voltage electrode tube 2.

  An upper spacer 4a and a lower spacer 4b are arranged between the inner surface of the horizontally placed ground electrode tube 1 and the outer peripheral surface of the high voltage electrode tube 2 to form a minute discharge space 5 of about 1 mm. The upper spacer 4a and the lower spacer 4b have a rectangular outer shape, and are fixed to respective positions in the circumferential direction at both ends and the center of the high-voltage electrode tube 2 in order to maintain the distance of the discharge space 5 by welding. Has been. In FIG. 8, the spacer disposed at the center of the high voltage electrode tube 2 is not shown.

  In the horizontally placed electrode tube (the ground electrode tube 1 and the high voltage electrode tube 2 inserted therein), two upper spacers 4a are arranged on the upper side which is one side across the tube axis center, and the other side. Two lower spacers 4b are arranged on the lower side.

  The upper spacer 4a is configured by bonding two types of metal layers 11 and 12 having different thermal expansion coefficients. The first metal layer 11 fixed to the high voltage electrode tube 2 can be made of SUS304 or SUS316 stainless alloy having a thermal expansion coefficient of 14 to 16 × 10 −6 / ° C. The second metal layer 12 can be composed of a low expansion metal invar having a thermal expansion coefficient of 3 to 6 × 10 −6 / ° C., or a Kovar iron-nickel alloy. These metal layers 11 and 12 are overlapped to form a two-layer plate material joined by cold or hot rolling. The upper spacer 4a is produced by cutting and processing the two-layer plate material into a fixed shape so as to become a spacer. Further, the upper spacer 4a is processed to have a thickness smaller than that of the discharge space 5, and is welded and fixed to the upper portion of the outer peripheral surface of the high voltage electrode tube 2 by a spot welder. As for the welding direction of the upper spacer 4a, the side in contact with the high-voltage electrode tube 2 is the metal layer 11 on the stainless alloy side having a large thermal expansion coefficient. The welding position of the metal layer 11 is a rectangular central portion, and both end portions in the long side direction of the upper spacer 4a form free ends.

  The spacer material used here must be able to withstand discharge and ozone. Therefore, the metal material of the first metal layer 11 may be a heat-resistant alloy having a thermal expansion coefficient of 10 × 10 −6 / ° C. or more in addition to the above-described stainless steel alloy, and includes monel containing nickel and nickel, Inconel, Hastelloy, and chromium alloys may be used. Further, the metal material of the second metal layer 12 is a low expansion metal having a thermal expansion coefficient of 3 to 6 × 10 −6 / ° C., and similarly to the first metal layer 11, heat resistance including nickel, chromium or cobalt. A metal alloy with good is good.

  The lower spacer 4b has the same thickness as the distance of the discharge space 5 because the discharge space 5 formed between the ground electrode tube 1 and the high-voltage electrode tube 2 needs to be evenly spaced. Yes. The lower spacer 4 b is manufactured by processing a plate thickness of a single metal SUS304 or SUS316 stainless alloy to the same thickness as the distance of the discharge space 5. The lower spacer 4b is welded and fixed to the outer peripheral surface of the high voltage electrode tube 2 by a spot welder at a position facing the upper spacer 4a across the tube axis center.

  Thus, the lower spacer 4b installed on the surface of the high-voltage electrode tube 2 and in the lower portion in the circumferential direction has the same thickness as the discharge space 5, while the surface of the high-voltage electrode tube 2 is disposed in the circumferential direction. The upper spacer 4 a installed at the upper part is thinner than the discharge space 5. For this reason, when the high voltage electrode tube 2 is inserted into the ground electrode tube 1, a gap is generated between the ground electrode tube 1 and the upper spacer 4a. As a result, the high voltage electrode tube 2 can be easily inserted. The distance of this gap was 0.05 to 0.3 mm.

  Next, operation | movement of the ozone generator which concerns on this Embodiment comprised as mentioned above is demonstrated. When an AC high voltage is applied from the high voltage power source 6 between the electrodes in which the high voltage electrode tube 2 is inserted into the ground electrode tube 1, a silent discharge is started in the discharge space 5, and a part of the discharge current flows through the upper spacer 4a. This current heats the upper spacer 4a and the temperature rises. Due to this temperature rise, a difference in expansion coefficient is generated between the two metal layers 11 and 12 due to the difference in expansion coefficient between the two metal layers 11 and 12 constituting the upper spacer 4a. The upper spacer 4a is deformed (curved) in the tube diameter direction as shown in FIG. Since the central part of the metal layer 11 is fixed by welding, the free ends of both end parts change in the pipe diameter direction. The deformed distance in the tube diameter direction is 0.05 to 0.3 mm or more, and the free end portion of the upper spacer 4a is in contact with the inner surface of the ground electrode tube 1. The amount of displacement of the upper spacer 4a in the tube diameter direction is the coefficient of thermal expansion of the metal material to be bonded, the plate thickness, the length and width of the spacer, and the end of the spacer that curves with the grounding portion installed in the high-voltage electrode tube The distance is designed and determined by the distance of the discharge space.

  When the high voltage application between the electrodes is stopped and the discharge in the discharge space 5 is stopped, the current flowing through the upper spacer 4a is also eliminated, so that the temperature is lowered and the deformation of the upper spacer 4a is restored. 2 is formed between the upper spacer 4a and the ground electrode tube 1, and the high voltage electrode tube 2 can be easily taken out from the ground electrode tube 1.

  As described above, according to the present embodiment, among the plurality of spacers installed in the circumferential direction of the high-voltage electrode tube 2, the thickness of the upper spacer 4 a before thermal deformation is thinner than the distance of the discharge space 5. When the spacer is fixed to the high voltage electrode tube 2 by welding or the like, the upper spacer 4a is in an extended state. When the high voltage electrode tube 2 is inserted into the ground electrode tube 1, the upper spacer 4a is Since the height is smaller than the distance of the predetermined discharge space 5, the upper spacer 4a on the circumference of the high voltage electrode tube 2 does not come into contact with the inside of the ground electrode tube 1, and the high voltage electrode to the ground electrode tube 1 is The tube 2 can be easily inserted.

  In addition, when ozone is generated and a high voltage is applied between the ground electrode tube 1 and the high voltage electrode tube 2 and discharge occurs in the discharge space 5, the upper spacer 4a is formed of two metals having different thermal expansion coefficients. Since it is a laminated plate, it is bent by the bimetal effect and contacts the inner surface of the ground electrode tube 1. Thereby, the distance of the discharge space 5 which makes an annular shape is maintained uniformly, and the high voltage electrode tube 2 is held. When the discharge is stopped, the temperature of the spacer 4 decreases, the curvature of the upper spacer 4a returns, and the spacer 4 is detached from the ground electrode tube 1 so that the high voltage electrode tube 2 can be taken out smoothly.

  Note that not only the upper spacer 4a but also the lower spacer 4b may have a bimetal configuration similar to that of the upper spacer 4a. It is possible to easily insert the high-voltage electrode tube 2 into the ground electrode tube 1 by making all the spacers or any part of the spacers have the above bimetal configuration without distinguishing between the upper and lower portions. Can do.

  Further, according to the present embodiment, by installing the spacer 4 on the high voltage electrode tube 2, the accuracy of the center circle between the ground electrode tube 1 and the high voltage electrode tube 2 is improved, and the discharge space 5 in the circumference is improved. Silent discharge through the insulating layer 3 is performed stably and uniformly.

  Further, since the spacers 4a and 4b can be suppressed to a small size, the gas flow in the discharge space 5 is not hindered, and the discharge space 5 can be maintained uniformly, so that the ozone generation efficiency can be stably improved.

  The upper spacer 4a shown in FIG. 1 is welded and fixed at the center of the first metal layer 11, but is deformed by the difference in expansion between the first metal layer 11 and the second metal layer 12. If a possible free end is ensured, the welding point is not limited.

  For example, as shown in FIG. 3A, one end of the first metal layer 11 may be fixed by welding. In this case, as shown in FIG.3 (b), a free end turns into the edge part of the other side which is not fixed by welding. Thus, even if one end of the first metal layer 11 is fixed by welding, the high voltage electrode tube 2 can be moved to the same position as the ground electrode tube 1 by the displacement of the upper spacer 4a.

The present invention is also applicable to the double cylinder type ozone generator shown in FIGS.
FIG. 4 is a diagram illustrating a configuration example of an ozone generator in which an internal electrode tube in which a high voltage electrode is formed is configured by a glass tube. The ground electrode tube 21 is manufactured by processing a SUS metal tube. Further, the conductive high voltage electrode 23 is formed on the inner surface of the glass tube whose one end is open (for example, aluminum is vapor-deposited) to produce the insulating tube 24. The insulating tube 24 is inserted into the ground electrode tube 21, and the discharge space 5 is formed by the spacer 4. The upper spacer 4a and the lower spacer 4b are fixed to the inner surface of the ground electrode tube 21 by welding. The high voltage power supply 6 applies an alternating voltage to the high voltage electrode 23 via the power supply electrode 25.

  FIG. 5 is a diagram showing a configuration example of an ozone generator in which an internal electrode tube in which a high voltage electrode is formed is made of ceramic or glass. The ground electrode tube 21 is manufactured by processing a SUS metal tube. An insulating layer 26 made of ceramic or glass is formed on the surface of the high voltage electrode tube 22, the high voltage electrode tube 22 is inserted into the ground electrode tube 21, and the discharge space 5 is formed by the spacer 4. Similar to the ozone generator shown in FIG. 1, the upper spacer 4 a and the lower spacer 4 b are welded and fixed to the inner surface of the ground electrode tube 21.

  In the ozone generator configured as shown in FIGS. 4 and 5, at least the upper spacer 4a has a bimetal structure having a thickness smaller than the distance of the discharge space 5, and is heated by the discharge current and curved in the tube diameter direction. Let

  The inventor has examined the relationship between the displacement of the discharge space and the ozone generation concentration in the above-described double cylinder type ozone generator. The contents of verification will be described below.

  FIG. 6 is a diagram showing the relationship between the discharge space ratio and the ozone generation concentration, and FIG. 7 is a diagram showing the distance ratio a: b of the discharge space. As shown in FIG. 7, the distance of the discharge space 5 is determined by the inner diameter of the ground electrode tube 1, the outer diameter of the high-voltage electrode tube 2, and the spacer 4. The distance of the upper discharge space 5a across the tube axis center is a, and the distance of the lower discharge space 5b is b.

  The upper discharge space 5a and the lower discharge space are within the optimum distance of 0.2 mm to 1 mm of ozone generation conditions in the discharge space 5 (in the actual ozone generator, oxygen is 0.3 mm and air is 0.5 mm). The distance ratio a: b to 5b was 1: 1, and the ozone generation concentration was 100% (the injection power of the ozone generator and the amount of oxygen or air gas were constant). As a result of changing the distance between the discharge spaces 5a and 5b, as shown in FIG. 6, the ozone generation concentration is such that the ratio of a: b increases from 1: 1 to a or b, that is, the center position of the high-voltage electrode tube 2 changes. It can be seen that when the distance a or b of the discharge space 5 is deviated from the center position of the ground electrode tube 1 and becomes narrower or narrower, the ozone generation concentration decreases. Since the generated concentration varies depending on the cooling method, gas air, oxygen, flow rate, and injection power conditions, it is indicated in%.

The following is considered as a cause of the decrease in the ozone generation concentration.
When the discharge space is wide due to the drift of the gas flow rate, more gas flows and more gas flows, so the discharge residence time of the gas in the discharge space is short, which reduces oxygen dissociation and ozone generation. Along with this, a decrease in ozone generation concentration is also shown. In a narrow discharge space, the gas flow is poor and the production efficiency is reduced.

  On the other hand, when the discharge space is widened, a difference occurs in the voltage sharing from the high-frequency power source applied to the ground electrode tube and the high-voltage electrode tube in the other narrow discharge space, and the discharge space 5 having a high generation efficiency is used. If it is wider than the distance, the discharge density becomes small, and the ozone generation efficiency decreases.

  On the other hand, if it is narrow, the concentration of discharge occurs, preventing efficient generation of ozone in the discharge space. When the discharge space is further narrowed, a portion that does not discharge occurs due to Paschen's law, and uniform ozone generation in the discharge space becomes impossible.

  Therefore, when the high voltage electrode tube is located at the center of the ground electrode tube and the discharge space is uniform, the ozone concentration is the highest and the generation efficiency is good. As shown in FIG. 6, when the position of the electrode tube is shifted, that is, when the distance of the discharge space is biased, a shift occurs from the optimum distance of the discharge space where the ozone generation concentration is high, and further, the effective discharge area is reduced. The generation concentration and generation efficiency are reduced.

  Therefore, in order to maintain a high ozone generation concentration and generation efficiency, the distance between the discharge space 5 of the ground electrode tube 1 and the high voltage electrode tube 2 needs to be uniform over the entire circumference in the circumferential direction. .

The cross-sectional schematic diagram which looked at the ozone generator which concerns on one Embodiment from the AA arrow direction of FIG. The figure which shows the state which the upper spacer deform | transformed in the ozone generator shown in FIG. (A) Partial sectional view of the electrode tube before heating in the modified example in which one side of the spacer is fixed by welding, (b) Partial sectional view of the electrode tube after heating in the modified example Configuration diagram of glass tube type ozone generator Configuration diagram of ceramic tube type ozone generator Diagram showing the relationship between discharge space ratio and ozone generation concentration Figure showing distance ratio a: b of discharge space Cross section side view of silent discharge type ozone generator Pipe diameter side cross section of silent discharge type ozone generator

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Ground electrode tube 2 High voltage electrode tube 3 Insulating layer 4a Upper spacer 4b Lower spacer 5 Discharge space 6 High voltage power source 7 Source gas 8 Ozonized gas 11 Metal layer (1st layer)
12 Metal layer (second layer)
13 Welded part

Claims (8)

One of an outer electrode tube on which a ground electrode is formed, an inner electrode tube that is inserted into the outer electrode tube to form a high-voltage electrode, and an opposing surface of the outer electrode tube and the inner electrode tube A plurality of spacers formed between the outer electrode tube and the inner electrode tube at a plurality of locations in the circumferential direction to form discharge spaces; the outer electrode tube; An AC voltage source for applying an AC voltage to the inner electrode tube,
The plurality of spacers comprises a first spacer disposed on one side across the tube axis center of both electrode tubes, and a second spacer disposed on the other side,
The first spacer has a structure in which a plurality of metals having different thermal expansion coefficients are bonded to each other, and is fixed to either the outer electrode tube or the inner electrode tube with a free end secured, and the discharge space The free end is deformed in the tube radial direction by being heated by the discharge current at
An ozone generator characterized by that. The thickness of the first spacer before thermal deformation due to discharge in the discharge space is smaller than the distance of the discharge space,
2. The ozone generator according to claim 1, wherein the second spacer is made of a single metal having the same thickness as the distance of the discharge space, and is fixed to the same electrode tube as the first spacer. .   The ozone generator according to claim 1 or 2, wherein the first spacer has a spacer central portion or one end fixed to either the outer electrode tube or the inner electrode tube.   The first spacer has a double structure in which a first metal layer and a second metal layer having different thermal expansion coefficients are bonded to each other, the first metal layer being fixed to the electrode tube side, The ozone generator according to any one of claims 1 to 3, wherein the thermal expansion coefficient of the first metal layer is large and the thermal expansion coefficient of the second metal layer is small. An electrode tube formed by inserting the inner electrode tube into the outer electrode tube is installed in a horizontal direction in which the electrode tube longitudinal direction is a horizontal direction,
The first spacer is disposed at an upper portion in the circumferential direction of the electrode tube, and the second spacer is disposed at a lower portion in the circumferential direction of the electrode tube.
The ozone generator according to claim 2.   The outer electrode tube and the inner electrode tube are made of a cylindrical metal material, the dielectric layer is formed on the inner surface of the outer electrode tube, and the first and second outer electrodes are formed on the outer peripheral surface of the inner electrode tube. The ozone generator according to any one of claims 1 to 5, wherein the spacer is fixed by welding. The outer electrode tube is made of a cylindrical metal material,
The inner electrode tube is composed of an insulating tube made of a dielectric and one end open, and a high voltage electrode formed on the inner peripheral surface of the insulating tube,
The ozone generator according to any one of claims 1 to 5, wherein the first and second spacers are fixed by welding to an inner peripheral surface of the outer electrode tube.   The outer electrode tube and the inner electrode tube are made of a cylindrical metal material, the dielectric layer is formed on an outer peripheral surface of the inner electrode tube, and the first and first electrodes are formed on an inner peripheral surface of the outer electrode tube. The ozone generator according to any one of claims 1 to 5, wherein two spacers are fixed by welding.

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