OZONE GENERATOR

An ozone generator includes a container, a first metal electrode, a dielectric electrode, a heat pipe, a heat sink, and a power supply unit. The first metal electrode is a cylindrical electrode the axial direction of which is a first direction, and disposed in the container. A cooling medium is supplied to an outer peripheral surface thereof. The dielectric electrode is a cylindrical electrode that is disposed to be opposed to an inner peripheral surface of the first metal electrode, and is coaxial with the first metal electrode. The heat pipe is disposed to be opposed to an inner peripheral surface of the dielectric electrode, and has electrical conductivity. The heat sink is disposed on the outside as an outer space of a space between the first metal electrode and the heat pipe, and connected to the heat pipe.

FIELD

Embodiments of the present invention relate to an ozone generator.

BACKGROUND

In a discharge type ozone generator, it is important to enhance efficiency in cooling a discharge space for improving efficiency in generating ozone, and prevent pyrolysis of generated ozone.

CITATION LIST

Patent Literature

SUMMARY OF THE INVENTION

Problem to be Solved by the Invention

In the discharge type ozone generator described above, the discharge space is cooled from a grounding electrode side, but there is a demand for cooling the discharge space also from a high-voltage electrode side to prevent pyrolysis of the generated ozone, and further improving efficiency in generating ozone.

Means for Solving Problem

An ozone generator according to an embodiment includes a container, a first metal electrode, a dielectric electrode, a heat pipe, a heat sink, and a power supply unit. A material gas is caused to flow into the container. The first metal electrode is a cylindrical electrode the axial direction of which is a first direction, and disposed in the container. A cooling medium is supplied to an outer peripheral surface thereof. The dielectric electrode is a cylindrical electrode that is disposed to be opposed to an inner peripheral surface of the first metal electrode, and is coaxial with the first metal electrode. The heat pipe is disposed to be opposed to an inner peripheral surface of the dielectric electrode, and has electrical conductivity. The heat sink is disposed on the outside as an outer space of a space between the first metal electrode and the heat pipe, and connected to the heat pipe. The power supply unit applies voltage to the heat pipe to cause electric discharge in the material gas in at least one of a first gap and a second gap to generate ozone by the electric discharge, the first gap being a gap into which the material gas is caused to flow between the first metal electrode and the dielectric electrode, the second gap being a gap into which the material gas is caused to flow between the dielectric electrode and the heat pipe.

DETAILED DESCRIPTION

The following describes an ozone generator according to embodiments with reference to the attached drawings.

First Embodiment

FIG. 1is a diagram illustrating an example of a schematic configuration of an ozone generator according to a first embodiment.FIG. 2is a diagram for explaining an example of processing of generating ozone performed by the ozone generator according to the first embodiment. The ozone generator according to the present embodiment is an ozone generator of dielectric barrier discharge type. As illustrated inFIG. 1, the ozone generator includes an ozone generator main body11and a storage container12(an example of a container) that houses the ozone generator main body11in an airtight state and receives a material gas that flows therein. In the present embodiment, the storage container12is a cylindrical container the axial direction of which is a first direction d1. The storage container12includes a plurality of metal electrodes13, dielectric electrodes14, heat pipes15, and heat sinks16disposed therein.

The metal electrode13(an example of a first metal electrode) is a cylindrical electrode the axial direction of which is the first direction d1as illustrated inFIG. 1andFIG. 2. Cooling water (an example of a cooling medium) is supplied to an outer peripheral surface of the metal electrode13. In the present embodiment, the metal electrode13is water-cooled by cooling water supplied to the outer peripheral surface thereof, but the embodiment is not limited thereto. The metal electrode13may be air-cooled by a cooling gas (an example of the cooling medium) supplied to the outer peripheral surface thereof. In the present embodiment, the metal electrode13is used as a grounding electrode.

As illustrated inFIG. 1andFIG. 2, the dielectric electrode14is a cylindrical electrode that is disposed to be opposed to an inner peripheral surface of the metal electrode13and coaxial with the metal electrode13. Between the dielectric electrode14and the metal electrode13, there is disposed a gap I1(hereinafter, referred to as a first discharge gap I1, an example of a first gap) into which a material gas such as oxygen or dry air is caused to flow.

As illustrated inFIG. 1andFIG. 2, the heat pipe15is a heat pipe that is disposed to be opposed to an inner peripheral surface of the dielectric electrode14and has electrical conductivity. In the present embodiment, as illustrated inFIG. 2, the heat pipe15is in intimate contact with the inner peripheral surface of the dielectric electrode14. That is, the heat pipe15is in contact with the inner peripheral surface of the dielectric electrode14. In the present embodiment, the heat pipe15is made of metal or an alloy containing at least one of iron, aluminum, nickel, copper, molybdenum, titanium, chromium, tungsten, silver, gold, and platinum. Alternatively, the heat pipe is coated by the metal or alloy described above. Due to this, ozone resistance of the heat pipe15can be enhanced. In the present embodiment, the heat pipe15is used as a high-voltage electrode.

The heat sink16is disposed on the outside of the dielectric electrode14. Specifically, the heat sink16is disposed on the outside, that is, an outer space of a space between the metal electrode13and the heat pipe15. In other words, the heat sink16is disposed on the outside of the first discharge gap I1and a second discharge gap I2(described later). The heat sink16is connected to the heat pipe15. Due to this, the gas in the first discharge gap I1can be cooled by both of the heat pipe15and the cooling water supplied to the outer peripheral surface of the metal electrode13, so that pyrolysis of ozone due to heat generated in the first discharge gap I1can be prevented, and efficiency in generating ozone can be enhanced. In the present embodiment, the heat sink16is a fin disposed on an outer peripheral surface of the heat pipe15in a pinholder shape, a bellows shape, a plate shape, and the like. When the heat sink16is cooled by air cooling, oil cooling, and the like, the heat generated by the gas in the first discharge gap I1is radiated by the heat sink16via the heat pipe15.

The ozone generator main body11has a function of interrupting a current flow into the heat pipe15, and interrupting a current flow into the dielectric electrode14at the time when the dielectric electrode14is in an anomaly state and the like (for example, a fuse17). The fuse17is disposed between the heat pipe15and a power supply C. The power supply C (an example of a power supply unit) applies voltage to the heat pipe15to discharge electricity in the material gas in the first discharge gap I1(hereinafter, referred to as dielectric barrier discharge), and generates ozone by the dielectric barrier discharge.

In the present embodiment, the storage container12includes a space22on a gas inlet side and a space23on a gas outlet side. The space22on the gas inlet side and the space23on the gas outlet side are connected to each other (communicate with each other) via the first discharge gap I1. The storage container12also includes a gas inflow port24for causing the material gas to flow into the storage container12. The storage container22includes an ozone gas ejection port25for ejecting the gas (hereinafter, referred to as an ozone gas) that has flowed into the space23on the gas outlet side to the outside. The storage container12also includes a cooling water inflow port26for causing cooling water to flow into a closed space21of the metal electrode13, and a cooling water ejection port27for ejecting, to the outside, high-temperature cooling water that has heat-exchanged with the metal electrode13. The closed space21is a space disposed on the outer peripheral surface side of the metal electrode13, and filled with the cooling water.

Next, the following describes a procedure of processing of generating ozone performed by the ozone generator according to the present embodiment. First, the material gas that has flowed into the space22on the gas inlet side flows into the first discharge gap Subsequently, voltage (for example, AC voltage) is applied to the heat pipe15from the power supply C, and dielectric barrier discharge is caused in the material gas that has flowed into the first discharge gap I1. Due to this, an oxygen molecule contained in the material gas that has flowed into the first discharge gap I1is dissociated into an oxygen atom, another oxygen atom is connected thereto to ozonize the material gas, and the ozone gas is generated. Thereafter, the generated ozone gas flows out to the space23on the gas outlet side, and is ejected to the outside through the ozone gas ejection port25.

To remove the heat that is generated in the discharge gap I1due to the dielectric barrier discharge, cooling water is caused to flow into the closed space21from the outside via the cooling water inflow port26. Due to this, heat is exchanged between the metal electrode13and the cooling water, and the inside of the discharge gap is cooled. Thereafter, the cooling water the temperature of which is raised due to heat exchange is ejected to the outside via the cooling water ejection port27.

Additionally, in a case in which an anomaly appears in the heat pipe15due to a dielectric breakdown and the like, the fuse17disposed between the heat pipe15and the power supply C is blown out by a short-circuit current flowing in the heat pipe15in which the anomaly appears, and the heat pipe15is disconnected from the other heat pipe15. Accordingly, an electric charge charged in the first discharge gap I1between the normal heat pipe15and the metal electrode13can be prevented from flowing into the heat pipe15in which an anomaly appears, so that, even when an anomaly appears in some of the heat pipes15, ozone can be continuously generated by causing dielectric barrier discharge between the normal heat pipe15and the metal electrode13. In the present embodiment, the ozone generator main body11includes the fuse17, but does not necessarily include the fuse17in a case of having a function similar to that of the fuse17or a case in which there is no need.

As described above, the ozone generator having the configuration described above uses the heat pipe15as a high-voltage electrode, applies voltage to the heat pipe15, and causes dielectric barrier discharge in the material gas in the first discharge gap I1between the metal electrode13and the dielectric electrode14to generate ozone by the dielectric barrier discharge. At this point, the heat pipe15enhances movement efficiency of the heat generated in the gas in the first discharge gap I1, and the gas in the first discharge gap I1is cooled (air-cooled) also with the heat pipe15.

Accordingly, the material gas in the first discharge gap I1is cooled by both of the heat pipe15and the cooling water supplied to the outer peripheral surface of the metal electrode13, and a temperature rise of the gas in the first discharge gap I1can be suppressed, so that efficiency in generating ozone in the first discharge gap I1can be enhanced. The cooling water is not used for cooling the gas in the first discharge gap I1by the heat pipe15. Thus, it is not required to newly dispose members such as a gasket, a tube, and piping for causing the cooling water to flow into the inner part of the high-voltage electrode of the ozone generator in the related art, so that the structure of the ozone generator can be prevented from being complicated. Additionally, the number of points at which the cooling water for cooling the gas in the first discharge gap I1is caused to flow is reduced, so that a risk of leakage of the cooling water in the ozone generator can be reduced, and the weight of the ozone generator can be reduced.

In a case of disposing the heat sink16in the storage container12and cooling the heat sink16with the material gas, the heat sink16is preferably disposed at a position at which the temperature of the material gas is lower within the storage container12. Thus, in the present embodiment, the heat sink16is disposed in the vicinity of a position at which the material gas is caused to flow into the storage container12. For example, the heat sink16is disposed in the space22on the gas inlet side, and in the vicinity of the gas inflow port24. Due to this, the heat sink16can be cooled with the material gas having a lower temperature, so that efficiency in cooling the gas in the first discharge gap I1by the heat pipe15can be further enhanced, and efficiency in generating ozone in the first discharge gap I1can be enhanced. The heat sink16is disposed in the vicinity of the gas inflow port24in the present embodiment, but it is sufficient that the heat sink16is disposed on an upstream side of the first discharge gap I1in an inflow direction Dl of the material gas.

To further enhance efficiency in cooling the gas in the first discharge gap I1with the heat pipe15and the heat sink16, the ozone generator may be configured such that a stirring unit such as a fan is disposed in the space22on the gas inlet side (for example, in the vicinity of the gas inflow port24) to stir the material gas in the storage container12to enable heat to be easily radiated from the heat sink16. Due to this, the heat sink16can be cooled with the material gas having a lower temperature, so that efficiency in cooling the gas in the first discharge gap I1by the heat pipe15can be further enhanced, and efficiency in generating ozone in the first discharge gap I1can be enhanced.

In this way, with the ozone generator according to the first embodiment, the material gas in the first discharge gap I1is cooled by both of the heat pipe15and the cooling water supplied to the metal electrode13, and a temperature rise of the gas in the first discharge gap I1can be suppressed, so that efficiency in generating ozone in the first discharge gap I1can be enhanced.

Second Embodiment

The present embodiment is an example of causing dielectric barrier discharge in the material gas in the second discharge gap into which the material gas is caused to flow between the dielectric electrode and the heat pipe. In the following description, description about the same points as the first embodiment will not be repeated.

FIG. 3Ais a diagram for explaining an example of processing of generating ozone performed by the ozone generator according to a second embodiment. As illustrated inFIG. 3A, in the present embodiment, the dielectric electrode14is in intimate contact with the inner peripheral surface of the metal electrode13. In other words, the dielectric electrode14is in contact with the inner peripheral surface of the metal electrode13. In the present embodiment, the heat pipe15is disposed to be opposed to the inner peripheral surface of the dielectric electrode14and to be separated from the inner peripheral surface. That is, a gap I2(hereinafter, referred to as a second discharge gap I2, an example of a second gap) into which the material gas is caused to flow is disposed between the heat pipe15and the dielectric electrode14.

Similarly to the first embodiment, the ozone generator uses the heat pipe15as a high-voltage electrode, applies voltage to the heat pipe15to cause dielectric barrier discharge in the material gas in the second discharge gap I2between the dielectric electrode14and the heat pipe15, and generates ozone by the dielectric barrier discharge. In this case, the heat pipe15enhances movement efficiency of heat generated by the gas in the second discharge gap I2, and the gas in the second discharge gap I2is cooled (air-cooled) also with the heat pipe15.

FIG. 3Bis a diagram illustrating an example of a temperature change of the gas in the first discharge gap and the second discharge gap of the ozone generator according to the second embodiment. InFIG. 3B, a vertical axis represents a position between the heat pipe15and the metal electrode13, and a horizontal axis represents a temperature of the gas between the heat pipe15and the metal electrode13. As illustrated inFIG. 3B, in a case of not using the heat pipe15as the high-voltage electrode, the temperature of the gas in the first discharge gap I1rises as being closer to the high-voltage electrode. In contrast, in a case of using the heat pipe15as the high-voltage electrode, the gas in the first discharge gap I1can be cooled also with the heat pipe15, so that the temperature of the gas in the first discharge gap I1is reduced. Thus, according to the present embodiment, a temperature rise of the gas in the first discharge gap I1can be suppressed, so that efficiency in generating ozone in the first discharge gap I1can be enhanced.

Accordingly, with the ozone generator according to the second embodiment, a working effect similar to that of the first embodiment can be obtained.

In the present embodiment, to enhance efficiency in cooling the gas in the second discharge gap I2, a spiral-shaped groove is disposed on the outer peripheral surface of the heat pipe15in the first direction d1to generate a swirl flow of the material gas in the second discharge gap I2. Due to this, the gas in the second discharge gap I2is caused to flow from the space22on the gas inlet side toward the space23on the gas outlet side while being stirred, so that the gas in the second discharge gap I2can be cooled more uniformly.

Third Embodiment

The present embodiment is an example of causing dielectric barrier discharge in the material gas in both of the first discharge gap into which the material gas is caused to flow between the metal electrode and the dielectric electrode and the second discharge gap into which the material gas is caused to flow between the dielectric electrode and the heat pipe. In the following description, description about the same points as the embodiments described above will not be repeated.

FIG. 4is a diagram for explaining an example of processing of generating ozone performed by the ozone generator according to a third embodiment. As illustrated inFIG. 4, in the present embodiment, the dielectric electrode14is disposed to be opposed to the inner peripheral surface of the metal electrode13and to be separated from the inner peripheral surface. That is, the first discharge gap I1into which the material gas is caused to flow is disposed between the dielectric electrode14and the metal electrode13. Additionally, in the present embodiment, the heat pipe15is disposed to be opposed to the inner peripheral surface of the dielectric electrode14and to be separated from the inner peripheral surface. That is, the second discharge gap I2into which the material gas is caused to flow is disposed between the heat pipe15and the dielectric electrode14.

Similarly to the first and the second embodiments, the ozone generator uses the heat pipe15as the high-voltage electrode, applies voltage to the heat pipe15to cause dielectric barrier discharge in the material gas in the first discharge gap I1between the metal electrode13and the dielectric electrode14and in the second discharge gap I2between the dielectric electrode14and the heat pipe15, and generates ozone by the dielectric barrier discharge. In this case, the heat pipe15enhances movement efficiency of heat generated by the gas in the second discharge gap I2, and the gas in the second discharge gap I2is cooled (air-cooled) also with the heat pipe15.

FIG. 5is a diagram illustrating an example of a temperature change of the gas in the first discharge gap and the second discharge gap of the ozone generator according to the third embodiment. InFIG. 5, a vertical axis represents a position between the heat pipe15and the metal electrode13, and a horizontal axis represents the temperature of the gas between the heat pipe15and the metal electrode13. As illustrated inFIG. 5, in a case of not using the heat pipe15as the high-voltage electrode, the temperature of the gas in the second discharge gap I2rises as being closer to the high-voltage electrode. In contrast, in a case of using the heat pipe15as the high-voltage electrode, the gas in the discharge gap can be cooled also with the heat pipe15, so that the temperature of the gas in the second discharge gap I2is reduced. Thus, according to the present embodiment, a temperature rise of the gas in the second discharge gap I2can be suppressed, so that efficiency in generating ozone in the second discharge gap I2can be enhanced.

Accordingly, with the ozone generator according to the third embodiment, a working effect similar to that of the first embodiment can be obtained.

Also in the present embodiment, to enhance efficiency in cooling the gas in the second discharge gap12, a spiral-shaped groove is disposed on the outer peripheral surface of the heat pipe15in the first direction d1to generate a swirl flow of the gas in the second discharge gap I2. Due to this, the gas in the second discharge gap I2is caused to flow from the space22on the gas inlet side toward the space23on the gas outlet side while being stirred, so that the gas in the second discharge gap I2can be cooled more uniformly.

Fourth Embodiment

The present embodiment is an example of causing dielectric barrier discharge in the material gas in both of the first discharge gap and the second discharge gap, and including a flow channel for the material gas that passes through the first discharge gap after passing through the second discharge gap. In the following description, description about the same points as the third embodiment will not be repeated.

FIG. 6is a diagram for explaining an example of processing of generating ozone performed by the ozone generator according to a fourth embodiment. As illustrated inFIG. 6, in the present embodiment, a dielectric14is disposed between a first space23aon the gas outlet side continuous to the first discharge gap I1and a second space23bon the gas outlet side continuous to the second discharge gap I2in the space23on the gas outlet side. Due to this, the first space23aon the gas outlet side and the second space23bon the gas outlet side are isolated (separated) from each other. In the present embodiment, the second space23bon the gas outlet side includes the gas inflow port24, and the first space23aon the gas outlet side includes the ozone gas ejection port25. With the configuration described above, as illustrated inFIG. 6, the ozone generator according to the present embodiment forms a flow channel (serial flow channel) for the material gas that passes through the first discharge gap I1after passing through the second discharge gap I2.

In the ozone generator, a chiller is often used for circulating the cooling water to be supplied to the closed space21. In such a case, the temperature of the cooling water in the closed space21becomes lower than the temperature of the material gas. Thus, the temperature of the gas in the second discharge gap I2becomes higher than the temperature of the material gas in the first discharge gap I1. Due to this, in a case in which the ozone generator includes a flow channel (parallel flow channel) for the material gas that passes through only one of the first discharge gap I1and the second discharge gap I2, efficiency in generating the ozone gas in the second discharge gap I2is decreased. Thus, in the present embodiment, a serial flow channel is formed for the material gas that passes through the first discharge gap I1after passing through the second discharge gap I2.

Accordingly, with the ozone generator according to the fourth embodiment, even when ozone cannot be sufficiently generated in the second discharge gap I2in which the temperature of the material gas easily rises, ozone is generated again in the first discharge gap I1having a high effect of cooling the material gas, so that efficiency in generating the ozone gas can be enhanced.

Fifth Embodiment

The present embodiment is an example in which a plurality of heat pipes are arranged in parallel in the first direction to be opposed to the inner peripheral surface of one dielectric electrode. In the following description, description about the same points as the third embodiment will not be repeated.

FIG. 7is a diagram for explaining an example of processing of generating ozone performed by the ozone generator according to the fifth embodiment. As illustrated inFIG. 7, in the present embodiment, two heat pipes15aand15bare arranged in parallel in the first direction d1to be opposed to the inner peripheral surfaces of the dielectric electrodes14that are disposed in the storage container12. A heat sink16aconnected to the heat pipe15apositioned on the upstream side in the inflow direction Dl of the material gas is positioned in the space22on the gas inlet side. On the other hand, a heat sink16bconnected to the heat pipe15bpositioned on the downstream side in the inflow direction Dl of the material gas is positioned in the space23on the gas outlet side. The example of arranging the heat pipes15in parallel in the first direction d1to be opposed to the inner peripheral surface of one dielectric electrode14can also be applied to the ozone generator according to the first to the third embodiments.

Accordingly, with the ozone generator according to the fifth embodiment, a discharge area in a longitudinal direction of the heat pipe15disposed in the dielectric electrode14can be prolonged, so that a diameter of the storage container12can be reduced.

First Modification

The present modification is an example in which the heat sink is disposed on the upstream side of the metal electrode in the inflow direction of the material gas, and a diameter of the gas inflow port is smaller than a diameter of the ozone gas ejection port. In the following description, description about the same configuration as that in the embodiments described above will not be repeated.

FIG. 8is a diagram for explaining an example of a configuration of the space on the gas inlet side of the ozone generator according to a first modification. In the present modification, the heat sink16is disposed in the space22on the gas inlet side. In other words, the heat sink16is disposed on the upstream side of the first discharge gap I1in the inflow direction Dl of the material gas.

As illustrated inFIG. 8, in the present modification, a plurality of the gas inflow ports24are disposed in the space22on the gas inlet side so that the material gas is introduced from the inner peripheral surface of the space22on the gas inlet side toward the center of the space22on the gas inlet side. The diameter of the gas inflow port24is smaller than the diameter of the ozone gas ejection port25. Due to this, a flow speed of the material gas can be increased at the time of being caused to flow into the storage container12, so that cooling efficiency of the heat sink16disposed in the space22on the gas inlet side can be enhanced.

Second Modification

The present modification is an example in which a cylindrical metal electrode (hereinafter, referred to as a normal metal electrode) coaxial with the dielectric electrode is disposed, in place of the heat pipe, to be opposed to the inner peripheral surfaces of some of the dielectric electrodes in the storage container, and the flow speed of the material gas flowing into the first discharge gap and the second discharge gap is higher than the flow speed of the material gas flowing into a third discharge gap into which the material gas is caused to flow between the normal metal electrode and the dielectric electrode or the metal electrode. In the following description, description about the same configuration as that of the embodiments described above will not be repeated.

FIG. 9is a diagram for explaining an example of a configuration of the space on the gas inlet side of the ozone generator according to a second modification. In the present modification, as illustrated inFIG. 9, a normal metal electrode900(an example of a second metal electrode) is disposed, in place of the heat pipe15, to be opposed to the inner peripheral surfaces of some of the dielectric electrodes14disposed in the storage container12. In the present modification, in the space22on the gas inlet side, an area22ain which the heat sink16is disposed (hereinafter, referred to as a heat pipe electrode area) is isolated (separated) from an area22bin which the normal metal electrode900is disposed (hereinafter, referred to as a metal electrode area). In the present modification, as illustrated inFIG. 9, the ozone generator includes a wall901for partitioning the heat pipe electrode area22aand the metal electrode area22bbetween the heat pipe electrode area22aand the metal electrode area22b. In the ozone generator, the diameter of the gas inflow port24for causing the material gas to flow into the heat pipe electrode area22ais smaller than the diameter of the gas inflow port24for causing the material gas to flow into the metal electrode area22b.

With the configuration described above, the flow speed of the material gas flowing into the first discharge gap I1and the second discharge gap I2becomes higher than the flow speed of the material gas flowing into the third discharge gap into which the material gas is caused to flow between the normal metal electrode900and the dielectric electrode14or the metal electrode13. Due to this, the flow speed of the material gas flowing into the first discharge gap I1and the second discharge gap I2can be increased, so that cooling efficiency of the heat sink16can be enhanced.

Third Modification

The present modification is an example in which the gas inflow port for the material gas that flows into the storage container is disposed so that the material gas swirls in a circumferential direction along the inner peripheral surface of the storage container. In the following description, description about the same points as the embodiments described above will not be repeated.

FIG. 10is a diagram for explaining an example of a configuration of the space on the gas inlet side of the ozone generator according to a third modification. In the present modification, as illustrated inFIG. 10, the material gas is swirled along the inner peripheral surface of the storage container12by disposing the gas inflow port24to cause the material gas to flow in a tangential direction of the inner peripheral surface of the space22on the gas inlet side. Due to this, the material gas that is caused to flow into the storage container12is stirred, and the temperature of the entire material gas in the storage container12can be lowered, so that cooling efficiency of the heat sink16disposed in the space22on the gas inlet side can be enhanced.

Fourth Modification

The present modification is an example of including a material gas pipe that is disposed to surround the heat sink, and has an ejection hole for ejecting the material gas toward the heat sink. In the following description, description about the same points as the first to the fourth embodiments will not be repeated.

FIG. 11is a diagram for explaining an example of a configuration of the space on the gas inlet side of the ozone generator according to a fourth modification. In the present modification, as illustrated inFIG. 11, the ozone generator includes a doughnut-shaped material gas pipe1101that circularly surrounds the heat sink16positioned in the space22on the gas inlet side. The material gas pipe1101is connected to the gas inflow port24, and the material gas is caused to flow into the pipe. The material gas pipe1101has an ejection hole1102for ejecting the material gas flowing therein toward a region that is circularly surrounded by the material gas pipe1101(that is, the heat sink16). Due to this, the material gas can be caused to hit the side surface of the heat sink16, so that cooling efficiency of the heat sink16can be enhanced.

Fifth Modification

The present modification is an example in which a pipe for cooling is disposed between the heat sink and the material gas pipe to surround the heat sink, and a cooling medium is supplied into the pipe for cooling. In the following description, description about the same points as the fourth modification will not be repeated.

FIG. 12andFIG. 13are diagrams for explaining an example of a configuration of the space on the gas inlet side of the ozone generator according to a fifth modification. In the present modification, as illustrated inFIG. 12andFIG. 13, the ozone generator includes a doughnut-shaped pipe for cooling1201that is disposed between the heat sink16and the material gas pipe1101to circularly surround the heat sink16. The cooling medium is supplied into the pipe for cooling1201. In the present embodiment, as illustrated inFIG. 12, the pipe for cooling1201is connected to the closed space21, and the cooling medium supplied to the closed space21is supplied into the pipe for cooling1201. Due to this, after causing the material gas ejected from the ejection hole1102for the material gas pipe1101to hit the pipe for cooling1121to be cooled, the material gas can be caused to hit the side surface of the heat sink16, so that cooling efficiency of the heat sink16can be further enhanced.

Sixth Modification

The present modification is an example of including a wall for partitioning between a discharge space in which the metal electrode, the dielectric electrode, and the heat pipe are disposed, and a non-discharge space in which the heat sink is disposed. In the following description, description about the same points as the embodiments described above will not be repeated.

FIG. 14is a diagram for explaining an example of a configuration of the space on the gas inlet side of the ozone generator according to a sixth modification. In the present modification, as illustrated inFIG. 14, the ozone generator includes, in the space22on the gas inlet side, a wall1403that partitions between a discharge space1401(an example of a first area) and a non-discharge space1402(an example of a second area). In discharge space1401, the metal electrode13, the dielectric electrode14, and the heat pipe15are disposed. In the non-discharge space1402, the heat sink16is disposed. Due to this, the heat sink16is disposed on the outside of the discharge space1401. The wall1403is orthogonal to the first direction d1.

The gas inflow port24is disposed in the discharge space1401, and the material gas is caused to flow thereinto through the gas inflow port24. A cooling medium (for example, an insulating oil or air) for cooling the heat sink16is introduced into the non-discharge space1402through a cooling medium inflow port1404that is disposed on one end of an inner peripheral surface of the non-discharge space1401, and the cooling medium is ejected through a cooling medium ejection port1405that is disposed on the other end of the inner peripheral surface of the non-discharge space1402.

Due to this, it is possible to reduce a temperature rise in the heat sink16due to influence of a temperature rise of the material gas in at least one of the first discharge gap I1and the second discharge gap I2, so that cooling efficiency of the heat sink16can be enhanced.

Seventh Modification

The present modification is an example in which an outer diameter of the heat sink is equal to or smaller than an outer diameter of the heat pipe, and the heat sink has a polygonal cross section. In the following description, description about the same points as the embodiments described above will not be repeated.

FIG. 15is a diagram illustrating an example of the heat sink included in the ozone generator according to a seventh modification. As illustrated inFIG. 15, in the present modification, an outer diameter1501of the heat sink16is caused to be identical to an outer diameter1502of the heat pipe15. Additionally, as illustrated inFIG. 15, the cross section of the heat sink16is caused to have a polygonal shape such as a star shape to increase the surface area of the heat sink16. Due to this, it is possible to shorten a distance between the heat sinks16that are disposed to be adjacent to each other in the storage container12, so that the number of heat sinks16housed in the storage container12can be increased.

Eighth Modification

The present modification is an example in which the wall disposed in the space on the gas inlet side has a connection hole that connects the discharge space with the non-discharge space at one end thereof, and has the gas inflow port at an end opposite to the end at which the connection hole is disposed in the non-discharge space. In the following description, description about the same points as the sixth modification will not be repeated.

FIG. 16is a diagram for explaining an example of a configuration of the space on the gas inlet side of the ozone generator according to an eighth modification. In the present modification, as illustrated inFIG. 16, the wall1403has a connection hole1601that connects the discharge space1401with the non-discharge space1402at one end thereof. In the space22on the gas inlet side, the gas inflow port24is disposed at an end opposite to the end at which the connection hole1601is disposed in the non-discharge space1402.

Due to this, the heat sink16can be cooled without supplying a cooling medium other than the material gas to the non-discharge space1402, and it is possible to suppress a temperature rise of the heat sink16due to influence of a temperature rise of the material gas in the first discharge gap I1or the second discharge gap I2, so that cooling efficiency of the heat sink16can be enhanced with a simpler configuration.

Ninth Modification

The present modification is an example in which the metal electrode includes a metal electrode not including the dielectric electrode and the heat pipe disposed on the inner peripheral surface side thereof (hereinafter, referred to as a non-discharge electrode), and the material gas is introduced into the non-discharge space through a pipe of the non-discharge electrode. In the following description, description about the same points as the eighth modification will not be repeated.

FIG. 17is a diagram for explaining an example of a configuration of the space on the gas inlet side of the ozone generator according to a ninth modification. In the present modification, as illustrated inFIG. 17, the metal electrode13includes a non-discharge electrode1701(an example of a third metal electrode) as the metal electrode13connected to the non-discharge space1402, the dielectric electrode14and the heat pipe15being not disposed to be opposed to the inner peripheral surface thereof. In the present modification, the non-discharge electrode1701is connected to the gas inflow port24disposed in the space23on the gas outlet side, and the material gas is caused to flow into the pipe thereof. The material gas passed through the pipe of the non-discharge electrode1701is caused to flow into the non-discharge space1402. With the configuration described above, the ozone generator causes the material gas to flow into the non-discharge space1402through the pipe of the non-discharge electrode1701. Due to this, the material gas cooled in the non-discharge electrode1701can be caused to flow into the non-discharge space1402, so that cooling efficiency of the heat sink16can be enhanced under the condition that the temperature of the cooling water supplied to the outer peripheral surface of the non-discharge electrode1701is lower than the temperature of the material gas.

Tenth Modification

The present modification is an example in which the heat pipes are connected to one heat sink. In the following description, description about the same points as the embodiments described above will not be repeated.

FIG. 18is a diagram illustrating an example of a configuration of the heat sink of the ozone generator according to a tenth modification. In the present modification, as illustrated inFIG. 18, the heat pipes15are connected to one heat sink16. Thus, in the present modification, the number of the heat sinks16disposed in the storage container12is smaller than the number of the heat pipes15disposed in the storage container12. For example, the ozone generator according to the present modification includes one heat sink16disposed therein corresponding to three heat pipes15. In this case, the outer diameter of the heat sink16may be increased to easily radiate the heat of the heat pipe15by the heat sink16.

Typically, the outer diameter of the heat sink16is often caused to be larger than the outer diameter of the heat pipe15. Thus, if the heat sink16is disposed for each heat pipe15disposed in the storage container12, the size of the storage container12is increased to prevent the adjacent heat sinks16from being in contact with each other. In contrast, according to the present modification, the heat pipes15can share the one heat sink16, so that the size of the ozone generator can be prevented from being increased due to the heat sink16.

Eleventh Modification

The present modification is an example in which the heat sinks connected to adjacent heat pipes are alternately connected to the upstream side and the downstream side of the heat pipes in the inflow direction of the material gas. In the following description, description about the same points as the embodiment described above will not be repeated.

FIG. 19is a diagram illustrating an example of a configuration of the heat sink of the ozone generator according to an eleventh modification. In the present modification, as illustrated inFIG. 19, the heat sink16(hereinafter, referred to as a first heat sink16) connected to a first heat pipe15among the heat pipes15disposed in the storage container12is disposed on the upstream side of the first heat pipe15in the inflow direction Dl of the material gas. The heat sink16(hereinafter, referred to as a second heat sink16) connected to a second heat pipe15adjacent to the first heat pipe15among the heat pipes15disposed in the storage container12is disposed on the downstream side of the second heat pipe15in the inflow direction Dl of the material gas. In the ozone generator, as provision for a case in which the fuse17blows due to an anomaly of the electrode caused by long-term deterioration and the like, an insulation distance between the adjacent heat pipes15needs to be maintained. In a case of increasing the size of the heat sink16(cooling fin) to enhance a cooling capacity of the heat pipe15, adjacent cooling fins need to be prevented from colliding with each other. Thus, in the present modification, the heat sinks16connected to the adjacent heat pipes15are alternately connected to the upstream side and the downstream side of the heat pipe15in the inflow direction Dl of the material gas. Due to this, the distance between the adjacent heat pipes15can be shortened while maintaining the insulation distance between the adjacent heat pipes15in the storage container12, so that the size of the storage container12can be reduced.

Twelfth Modification

The present modification is an example of using the heat pipe as a grounding electrode. In the following description, description about the same points as the embodiments described above will not be repeated.

FIG. 20is a diagram for explaining an example of processing of generating ozone performed by the ozone generator according to a twelfth modification. As illustrated inFIG. 20, the ozone generator according to the present modification includes a high-voltage electrode2000that is disposed between the inner peripheral surface of the metal electrode13and the heat pipe15as a cylindrical electrode coaxial with the metal electrode13. By applying a dielectric to the inner peripheral surface of the high-voltage electrode2000, a dielectric electrode14ais brought into intimate contact with the inner peripheral surface. A gap I3(hereinafter, referred to as a third discharge gap I3) into which the material gas is caused to flow is disposed between the dielectric electrode14aand the high-voltage electrode2000.

In the present modification, by applying a dielectric to the inner peripheral surface of the metal electrode13, a dielectric electrode14bis brought into intimate contact with the inner peripheral surface of the metal electrode13. In the present modification, the heat pipe15is used as a grounding electrode that is grounded. A gap I4(hereinafter, referred to as a discharge gap I4) into which the material gas is caused to flow is disposed between the dielectric electrode14band the heat pipe15.

In the ozone generator according to the present modification, voltage is applied to the high-voltage electrode200to cause dielectric barrier discharge in the material gas within the third discharge gap I3and the fourth discharge gap I4, and ozone is generated by the dielectric barrier discharge. With the ozone generator according to the present modification, the heat pipe15has the same potential as that of the storage container12, so that the heat sink16can be disposed on the outside of the storage container12. By water-cooling the heat sink16disposed on the outside of the storage container12, efficiency in cooling the gas in the third discharge gap I3and the fourth discharge gap I4by the heat pipe15can be further enhanced, and efficiency in generating ozone in the third discharge gap I3and the fourth discharge gap I4can be further enhanced.

As described above, according to the first to the fifth embodiments and the first to the twelfth modifications, the material gas in the first discharge gap I1and the second discharge gap I2is cooled by both of the heat pipe15and the cooling water supplied to the outer peripheral surface of the metal electrode13, and a temperature rise of the gas in the first discharge gap I1and the second discharge gap I2can be suppressed, so that efficiency in generating ozone in the first discharge gap I1and the second discharge gap I2can be enhanced.

In the ozone generator according to the embodiments and the modifications described above, the heat sink16is preferably at an upper position than the first discharge gap I1and the second discharge gap I2are. Due to this, the heat generated in the heat pipe15is enabled to easily move to the heat sink16, and heat radiation efficiency of the heat pipe15can be enhanced.

In the embodiments and the modifications described above, the heat pipe15is used as the high-voltage electrode, and the metal electrode13is used as the grounding electrode. Alternatively, the metal electrode13may be used as the high-voltage electrode, and the heat pipe15may be used as the grounding electrode. For example, in a case of using the metal electrode13as the high-voltage electrode and using the heat pipe15as the grounding electrode in the configuration of the ozone generator illustrated inFIG. 2, the dielectric electrode14is in intimate contact with the outer peripheral surface of the metal electrode13. Due to this, the dielectric electrode14is brought into intimate contact with both two surfaces of the metal electrode13opposed to the two heat pipes15adjacent to the metal electrode13.

In the ozone generator according to the first to the fourth embodiments and the first to the eleventh modifications, the storage container12is installed in a state in which the heat pipe15extends in parallel with a horizontal direction. Alternatively, the storage container12may be installed in a state in which the extending direction of the heat pipe15is inclined with respect to the horizontal direction, or in a state in which the extending direction of the heat pipe15orthogonally intersects with the horizontal direction.

Some embodiments and modifications of the present invention have been described above. However, these embodiments and modifications are merely examples, and do not intend to limit the scope of the invention. These novel embodiments and modifications can be implemented in various other forms, and can be variously omitted, replaced, and modified without departing from the gist of the present invention. These embodiments and the modifications thereof are encompassed by the scope and the gist of the present invention, and also encompassed by the invention described in CLAIMS and an equivalent thereof.