WO2022172426A1 - Ozone generator and ozone generation method - Google Patents

Abstract

The present application relates to an ozone generator and an ozone generation method. Provided is an ozone generator that generates ozone using an oxygen-containing gas introduced in a gas flow direction. The ozone generator (10) comprises a discharge space site (52) at which electrons are caused to collide with the gas by discharge, an extraction site at which ozone that is converted and generated from the oxygen contained in the gas that has undergone electron collision at the discharge space site is extracted, and a decomposition reaction suppression mechanism that suppresses a decomposition reaction in which the generated ozone is decomposed by electron collision.

Description

Ozone generator and ozone generation method

This application relates to an ozone generator and an ozone generation method.

An ozone generator that generates ozone using a discharge generated in a discharge space between a high-voltage electrode and a ground electrode is known (for example, Patent Document 1). This ozone generator causes electron collisions with oxygen gas (O ₂ ) in a discharge space to generate ozone (O ₃ ).

In the ozone generator described above, oxygen radicals (O) are generated by dissociation from oxygen gas (O ₂ ) that has undergone electron collision (O ₂ +e→O+O+e, where e indicates an electron). The generated oxygen radicals combine with oxygen gas present in the surroundings to generate ozone (O ₃ ) (O+O ₂ +M→O ₃ +M, where M indicates the third body).

JP-A-62-132706

However, if the generated ozone is further bombarded with electrons in the same discharge space, the ozone decomposition reaction (O ₃ +e→O+O ₂ +e) can also proceed. If the ozone decomposition reaction progresses with respect to the generated ozone, the efficiency of generating ozone generated by the ozone generator may decrease.

The present application has been made in view of the above circumstances, and aims to provide an ozone generator and method capable of suppressing a decrease in ozone generation efficiency.

An ozone generator according to one aspect of the present application is an ozone generator that generates ozone using a gas containing oxygen that is introduced in the gas flow direction, and includes a discharge space portion that causes electron collision with the gas by discharge. a derivation part for deriving generated ozone converted from oxygen contained in the gas by electron collision in the discharge space part; and a decomposition reaction suppression mechanism for suppressing the decomposition reaction of the generated ozone by electron collision. Prepare.

An ozone generating method according to one aspect of the present application is a method of generating ozone using a gas containing oxygen introduced in the direction of gas flow, and causes electron collisions with the gas in a discharge space portion by discharge. a discharge step, a derivation step of deriving from the derivation portion ozone generated by electron collision in the discharge space portion, which is converted from oxygen contained in the gas, and suppressing the decomposition reaction in which the generated ozone is decomposed by the electron collision. and a decomposition reaction suppression step of suppressing using a mechanism.

In one aspect of the present application, it is possible to provide an ozone generator and method capable of suppressing a decrease in ozone generation efficiency.

1 is a schematic diagram showing the configuration of an ozone generator according to Embodiment 1. FIG. 4 is a graph showing the relationship between changes in gas pressure P and conversion time τ from oxygen radicals to ozone. FIG. FIG. 4 is a schematic diagram showing the configuration of an ozone generator according to Embodiment 2; FIG. 11 is an explanatory diagram showing the relationship between the waveform of power supply output and discharge power in Embodiment 2;

Hereinafter, embodiments of the ozone generator and method disclosed by the present application will be described in detail with reference to the accompanying drawings. In addition, the embodiment shown below is an example, and this application is not limited by these embodiments.

Embodiment 1.
FIG. 1 is a schematic diagram showing the configuration of an ozone generator according to Embodiment 1. FIG. The ozone generator 10 comprises a high frequency power source 1, a high voltage electrode 2, a ground electrode 3, a high voltage side dielectric 4 and a ground side dielectric 5, as shown in FIG. Further, the ozone generator 10 introduces a gas containing oxygen gas, which is a raw material for generating ozone, from left to right on the page of FIG. Lead out in lead-out direction 55 .

A high frequency power supply 1 is connected to a high voltage electrode 2 and a ground electrode 3 and applies a high frequency voltage between the high voltage electrode 2 and the ground electrode 3 . The high voltage electrode 2 and the ground electrode 3 are made of metal, for example. The high voltage side dielectric 4 and the ground side dielectric 5 are made of, for example, an alumina ceramic plate.

As shown in FIG. 1, the high-voltage electrode 2 has a width of Ld along the gas introduction direction 54 of the gas containing oxygen gas, and extends toward the back of the paper surface of FIG. 1 perpendicular to the gas introduction direction 54. It is an electrode member extending with a length Lw. As shown in FIG. 1, the high-voltage electrode 2 is connected to a high-voltage side dielectric 4, which will be described later, at the bottom of FIG.

As shown in FIG. 1, the ground electrode 3 has a width Ld along the gas introduction direction 54 of the oxygen gas-containing gas, and extends toward the back of the paper surface of FIG. 1 perpendicular to the gas introduction direction 54. It is an electrode member extending with a length Lw. One end of the ground electrode 3 is grounded, and the ground electrode 3 is arranged so as to face the high-voltage electrode 2 while being spaced apart in the vertical direction with respect to the plane of FIG. Furthermore, as shown in FIG. 1, the ground electrode 3 is connected to the ground side dielectric 5 described later in the upper part of FIG. are placed facing each other.

The high voltage side dielectric 4 and the ground side dielectric 5 are arranged so as to be vertically separated from each other by a separation distance d with respect to the plane of FIG. A space between the high-voltage side dielectric 4 and the ground side dielectric 5 functions as a discharge space portion, which will be described later. That is, a discharge electrode in which the high voltage electrode 2 is provided on a portion of one surface of the high voltage side dielectric 4 and a discharge electrode in which the ground electrode 3 is provided on a portion of one surface of the ground side dielectric 5 are provided. An ozone generation unit 11 is configured by arranging the high-voltage side dielectric 4 and the ground side dielectric 5 so that the other surfaces face each other.

The high-voltage side dielectric 4 and the ground side dielectric 5 are separated from each other by a value larger than d in the vertical direction with respect to the plane of FIG. 1, a discharge space portion 52 with a separation distance d in the vertical direction of the paper surface of FIG. An enlarged portion 53, in which the separation distance in the vertical direction with respect to the plane of the paper is enlarged from d to a value larger than d in the gas lead-out direction 55, and expands the flow of the gas flowing out from the discharge space portion 52 to be led out. Prepare. The reduced portion 51 has, for example, a reduced angle of 45 degrees. The enlarged portion 53 has, for example, an enlarged angle of 10 degrees. The reduced portion 51 functions as an example of an introduction portion for introducing gas, and the expanded portion 53 functions as an example of an extraction portion for extracting ozone.

In other words, the ozone generator 10 of the present embodiment is an ozone generator in which a pair of discharge electrodes each having a metal electrode provided on a part of one surface of a dielectric are arranged with the other surface of the dielectric facing each other. It has a generating unit 11 and a high frequency power supply 1 for applying voltage to metal electrodes. The ozone generating unit 11 has a gas flow path through which gas containing oxygen flows between the pair of discharge electrodes, and the distance between the other surfaces of the dielectric is the largest at the portion where the metal electrode is provided. It is narrow and widens upstream and downstream of the gas flow path.

The discharge space portion 52 is a space in which discharge plasma is generated when the high-frequency power supply 1 applies a high voltage to the high-voltage electrode 2 and the ground electrode 3 . The discharge space portion 52 is a space having length, width and height Ld, Lw and d, which will be described later. The high-voltage electrode 2 is arranged so that the width Ld portion of the high-voltage electrode 2 faces the width Ld portion forming the discharge space portion 52 of the high-voltage side dielectric 4 . The ground electrode 3 is arranged so that the width Ld portion of the ground electrode 3 faces the width Ld portion forming the discharge space portion 52 of the ground-side dielectric 5 . Therefore, in the ozone generator 10 according to the present embodiment, the discharge space of the contracted portion 51, the discharge space portion 52, and the expanded portion 53, which are the spaces formed by the high voltage side dielectric 4 and the ground side dielectric 5, is reduced. The portion 52 is configured to generate electron collisions by electric discharge.

In the ozone generator 10 according to the present embodiment, the length Ld of the high-voltage side dielectric 4 and the ground side dielectric 5 is greater than the length Lw of the extension direction perpendicular to the gas introduction direction 54 in the gas introduction direction 54 . is designed to be small. Preferably, the length Ld in the gas introduction direction 54 is 1/10 or less of the length Lw in the extending direction perpendicular to the gas introduction direction 54 . Further, in the ozone generator 10 according to this embodiment, the distance d between the high voltage side dielectric 4 and the ground side dielectric 5 is set to 0.2 mm or less. By adopting such a configuration, the ozone generator 10 according to the present embodiment can shorten the time during which the generated ozone stays in the discharge space portion 52, as will be described later, with a relatively simple configuration. It becomes a device capable of suppressing a decrease in ozone generation efficiency. Therefore, such a configuration including the high voltage side dielectric 4 and the ground side dielectric 5 functions as an example of a decomposition reaction suppression mechanism that suppresses the decomposition reaction in which generated ozone is decomposed by electron collision.

The ozone generator 10 according to the present embodiment is configured to have lengths Ld, Lw and d through the high-voltage side dielectric 4 when the high-frequency power supply 1 applies a high voltage to the high-voltage electrode 2 and the ground electrode 3. A discharge plasma is generated in the discharge space portion 52 . At this time, the gas containing oxygen gas introduced into the discharge space portion 52 in the direction of the gas introduction direction 54 indicated by the arrow in FIG. 53, is discharged downstream from the enlarged portion 53 in the direction of the gas discharge direction 55 indicated by the arrow.

When the oxygen gas introduced into the discharge space portion 52 and the discharge plasma generated in the discharge space portion 52 react with each other, the oxygen gas is dissociated by electron collision and oxygen radicals (O) are generated (O ₂ +e→O+O+e: e indicates an electron). When the generated oxygen radicals (O) react with oxygen gas, the ozone generator 10 generates ozone in the discharge space portion 52 (O+O ₂ +M→O ₃ +M, where M indicates the third body). However, when electron collisions occur with the produced ozone, the produced ozone can be decomposed into oxygen radicals and oxygen gas (O ₃ +e→O+O ₂ +e). If the produced ozone is decomposed, the production efficiency of ozone discharged from the ozone generator may be lowered.

Here, the rate of conversion from oxygen radicals to ozone is examined. The process of reduction by conversion of oxygen radicals into ozone is represented by the following equation (1). [O] and [O ₂ ] indicate particle densities (particles/cm ³ ) of oxygen radicals (O) and oxygen gas (O ₂ ). k indicates a reaction rate constant (cm ⁶ /s). However, assuming that the supply gas is oxygen gas, M, which is the third body, was oxygen gas (O ₂ ). It is reported that when the gas temperature (K) is T, k is 6.45×10 ⁻³⁵ exp (663/T).
d[O]/dt=-k×[O]×[O ₂ ] ² (1)

The conversion time τ for the conversion from oxygen radicals (O) to ozone (O ₃ ) is determined by the formula (2) in relation to the above formula (1).
τ=1/(k×[O ₂ ] ² ) (2)

FIG. 2 is a graph showing the relationship between the change in gas pressure P and the conversion time τ from oxygen radicals to ozone. Considering the above equation (2), the conversion time τ (sec) from oxygen radicals (O) to ozone (O ₃ ) when the gas pressure P (kPa) changes is shown. The graph also shows cases where the gas temperature is 300K, 500K, and 1000K. (2) and FIG. 2, the conversion time τ to ozone is inversely proportional to the square of the gas pressure. When the gas temperature is 300 K, it is 0.29 msec at 10 kPa and 2.9 μsec at 100 kPa. Also, as is clear from FIG. 2, it can be interpreted that the conversion time τ to ozone increases when the gas temperature increases. Considering this interpretation, it is possible to lengthen the conversion time τ (sec) from oxygen radicals (O) to ozone (O ₃ ) by realizing a discharge space portion 52 with a high temperature and a low gas pressure. becomes.

When the time τg (sec) in which the gas stays in the discharge space portion 52 is shorter than the conversion time τ in which the oxygen radicals (O) are converted into ozone (O ₃ ), the oxygen radicals react with the oxygen radicals in the discharge space portion 52. The oxygen gas thus generated is converted into ozone at an enlarged portion 53 outside the discharge space portion 52 and downstream from the enlarged portion 53 . The ozone generator 10 according to the present embodiment does not have a mechanism for intentionally generating discharge plasma in the expanded portion 53 converted into ozone, and discharge plasma is intended downstream of the expanded portion 53 as well. It does not have a mechanism to generate Further, regarding the high-voltage side dielectric 4 and the ground side dielectric 5 for forming the discharge space portion 52 that causes electron collision, the length Ld of the gas introduction direction 54 is the length of the extension direction perpendicular to the gas introduction direction 54 It is configured to be smaller than the height Lw. With such a configuration, compared with a configuration in which the length Ld of the gas introduction direction 54 is longer than the length Lw of the extending direction perpendicular to the gas introduction direction 54, the same discharge area is secured while the gas is in the discharge space. The amount of time it will stay at site 52 is reduced. Therefore, it is possible to suppress the influence of the generated ozone being decomposed by electron collision. When the amount of gas to be supplied is expressed by Q (m ³ /s) and the volume of the discharge space portion 52 is expressed by V (m ³ ), the time τg (sec) during which the gas stays in the discharge space portion 52 is V/Q. . Further, when the discharge length Ld in the gas flow direction, the discharge space length Lw of the discharge space portion 52 in the direction perpendicular to the gas flow, and the separation distance d that is the discharge gap length are used, and the gas flow velocity in the discharge space is vg, the gas is The time τg (sec) for staying in the discharge space portion 52 is represented by the following equation (3).
τg=Ld×Lw×d/Q=Ld/vg (3)

The ozone generator 10 according to the present embodiment is configured so that the time (τg) for the gas to stay in the discharge space portion 52<the conversion time (τ) for conversion from oxygen radicals (O) to ozone (O ₃ ). I have By configuring τg<τ, the ozone generator 10 generates O radicals in the discharge space portion 52 and starts to react with the O radicals in the discharge space portion 52, but the oxygen gas that has started the reaction is is converted to ozone (O ₃ ) outside the discharge space portion 52 . Therefore, the ozone generator 10 according to the present embodiment suppresses decomposition of the generated ozone due to electron collision in the discharge space portion 52, so that the ozone generator 10 has a relatively simple configuration and high ozone generation efficiency. obtain.

In the ozone generator 10 of the present embodiment, the length Ld in the gas flow direction of the electrode surface of the discharge space portion 52 formed by the high voltage side dielectric 4 and the ground side dielectric 5 is set to the direction perpendicular to the gas flow direction. is shorter than the length Lw, preferably 1/10 or less (Ld/Lw<0.1). In addition, in the ozone generator 10 of the present embodiment, by flowing the gas along the direction of the shorter Ld side from the longer Lw side of the discharge surface configured by Ld×Lw, (3 ) becomes smaller, Ld/vg in the expression (3) becomes smaller, and it becomes possible to set the residence time of the discharge space portion 52 to be small. Further, in the ozone generator 10 of the present embodiment, the separation distance d, which is the length of the discharge gap, is set to 0.2 mm or less to increase the gas flow velocity, thereby further providing the reduced portion 51 and the expanded portion 53. By increasing the gas flow velocity by , vg in equation (3) increases and Ld/vg in equation (3) decreases, making it possible to set the residence time of discharge space portion 52 short. Therefore, the ozone generator 10 according to the present embodiment suppresses decomposition of the generated ozone due to electron collision in the discharge space portion 52, so that the ozone generator 10 has a relatively simple configuration and high ozone generation efficiency. obtain. That is, the above-described configuration including the reduced portion 51, the discharge space portion 52, and the expanded portion 53 functions as an example of the decomposition reaction suppression mechanism of the present application that suppresses the decomposition reaction in which generated ozone is decomposed by electron collision.

In the ozone generator 10 of the present embodiment, an open space having dimensions of Ld×Lw×d is secured as the discharge space portion 52 into which oxygen gas is introduced. No flow-restricting material is intentionally placed in this open space to restrict the flow of oxygen gas introduced. Therefore, this ozone generator can move the oxygen gas introduced from the longer Lw side of the discharge surface as quickly as possible by the shorter Ld on the discharge surface. It is possible to provide an ozone generator and method with high generation efficiency. In other words, the ozone generator converts oxygen radicals into ozone by moving the oxygen gas introduced from the side of the discharge surface with longer Lw as quickly as possible by the shorter Ld on the discharge surface. Since ozone is generated outside the discharge space portion 52 after being discharged from the discharge space portion 52 before, the collision of electrons in the discharge space portion 52 with the generated ozone can be suppressed. It is possible to provide an ozone generator and method with a simple configuration and high ozone generation efficiency.

The operation of the ozone generator 10 according to this embodiment will be described. This ozone generator introduces a gas containing oxygen gas, which is a raw material for generating ozone, from left to right on the page of FIG. 1, that is, in a gas introduction direction 54 indicated by an arrow in FIG. The ozone generator accelerates the introduced gas by means of a constricted portion 51 whose separation narrows in the direction of flow. The ozone generator uses the gas velocity increase due to acceleration to reduce the gas pressure in the discharge space region 52 . When the gas pressure in the discharge space portion 52 is lowered, as shown in FIG. 2, the conversion time τ (sec) from oxygen radicals (O) to ozone (O ₃ ) is lengthened. The ozone generator decelerates the gas passing through the discharge space section 52 by means of the enlarged section 53 where the separation increases in the direction of flow. The ozone generator utilizes the velocity reduction of the gas due to deceleration to discharge the static pressure-restored gas downstream. With such a configuration, the ozone generator 10 according to the present embodiment increases the gas flow velocity in the discharge space portion 52 while lengthening the conversion time τ to ozone in the discharge space portion 52, and discharges the gas. It is possible to shorten the time τg for staying in the spatial part 52 . That is, the step of performing discharge using the discharge space portion 52 functions as an example of the discharge step of causing electron collision with the gas by discharge, and the step of leading gas from the expanded portion 53 leads ozone from the lead-out portion. The decomposition reaction of the present application, which functions as an example of the process and is executed using the reduced portion 51, the discharge space portion 52, and the enlarged portion 53, suppresses the decomposition reaction in which generated ozone is decomposed by electron collision. It functions as an example of a suppression process.

Embodiment 2.
FIG. 3 is a schematic diagram showing the configuration of an ozone generator according to Embodiment 2. FIG. In the ozone generator of this embodiment, a plurality of ozone generation units are connected in parallel to one high-frequency power source.

As shown in FIG. 3, the high-frequency power supply 1 of the ozone generator 10 of this embodiment is composed of a single-phase inverter circuit 12 and a frequency control circuit 13 . The frequency control circuit 13 includes a drive circuit for the single-phase inverter circuit 12 and controls the power frequency output from the single-phase inverter circuit 12 . A plurality of ozone generation units 11 are connected in parallel to the output terminal of the single-phase inverter circuit 12 . A reactor 14 is connected between the high-voltage electrode 2 of each ozone generating unit 11 and the output terminal of the single-phase inverter circuit 12 . All the potentials of the ground electrodes 3 of the respective ozone generating units 11 are set to the ground potential. In this embodiment, hereinafter, an ozone generator in which five ozone generating units are connected in parallel will be described.

In each ozone generating unit 11, AC discharge (barrier discharge) is generated between the high voltage electrode 2 and the ground electrode 3 via the high voltage side dielectric 4 and the ground side dielectric 5. Note that the ground-side dielectric 5 is not necessarily required, and the ground electrode 3 alone may be used. In each ozone generation unit 11, pulse-like energy is injected into the discharge space by resonance between the capacitance component (C) between the high-voltage electrode 2 and the ground electrode 3 and the inductance component (L) of the reactor 14. Note that the capacitive component between the high voltage electrode 2 and the ground electrode 3 is mainly determined by the capacitive component of the high voltage side dielectric 4 and the capacitive component of the ground side dielectric 5 .

That is, when the power frequency f of the high-frequency power source 1 satisfies the following equation (4), pulse-like energy is injected into the discharge space.
f=1/2π√(L×C) (4)

In the ozone generator 10 of the present embodiment, if the inductances of the reactors 14 connected to the five ozone generating units 11 are respectively L1, L2, L3, L4, and L5, then L1>L2>L3>L4>L5. is set to be The capacitive component (C) between the high-voltage electrode 2 and the ground electrode 3 in the five ozone generating units 11 is set substantially the same.

In the ozone generator 10 configured in this manner, the resonance frequencies of the ozone generating unit 11 connected to the reactors 14 having inductances L1, L2, L3, L4, and L5 are f1, f2, f3, f4, and f5, respectively. Then, f1<f2<f3<f4<f5.

FIG. 4 is an explanatory diagram showing the relationship between the power output waveform of the high-frequency power supply 1 and the discharge power injected into each of the five ozone generating units 11 in this embodiment. A waveform 15 shown in the upper part of FIG. 4 is a waveform of the power output of the high frequency power supply. The diagram shown in the lower part of FIG. 4 is the waveform of the discharge power injected into each of the five ozone generating units. Here, assuming that the number of ozone generation units 11 connected in parallel is n, the duration of one cycle of the power supply output shown by the waveform 15 is defined by the pulse discharge time τd in each ozone generation unit 11. It is set to the multiplied time n×τd. This time τd is shorter than the time τg during which the gas stays in the discharge space, and is set to the same extent as the conversion time τ for converting oxygen radicals (O) into ozone (O ₃ ) shown in equation (2). ing. Also, the time n×τd of one cycle of the power supply output is set to be approximately the same as τg. The time of one cycle of the power output and the amount of change in the power frequency during one cycle are set so as to satisfy τd≈τ and n×τd≈τg.

The power output of the high frequency power supply is controlled by the frequency control circuit 13 so that the frequency changes during one cycle, as shown by the waveform 15 in FIG. As the power supply frequency changes, among the five ozone generation units 11, the power output from the power supply is concentrated and injected into the ozone generation unit 11 whose resonance frequency matches the power supply frequency. The power supply output is controlled to increase in frequency during one cycle, as shown by waveform 15 in FIG. Then, the power supply frequency and the resonance frequency will match in order from the ozone generating unit having the lowest resonance frequency. Here, among the five ozone generating units 11, the ozone generating units having the lowest resonance frequencies are referred to as unit 1, unit 2, unit 3, unit 4 and unit 5, respectively. As shown in FIG. 4, during one period of the waveform 15 of the power supply output, power is first injected into the unit 1 having the lower resonance frequency, and discharge occurs in this unit 1 only during the time τd. As the power supply frequency increases, discharge occurs in the order of unit 2, unit 3, unit 4, and unit 5. FIG. When one cycle of power supply output ends, discharge occurs again in the order of unit 1, unit 2, unit 3, unit 4, and unit 5 in the next cycle. In this way, the sequential discharge of the five ozone generating units 11 is periodically generated.

In one ozone generation unit 11, when the power supply frequency and the resonance frequency match, discharge occurs for time τd, during which oxygen radicals are generated due to dissociation of oxygen molecules. After that, while the discharge is stopped, ozone is generated from the oxygen radicals, and at the same time the gas is exhausted out of the discharge space part by the gas flow. As shown in FIG. 4, in one ozone generation unit 11, the next discharge occurs after 5×τd time has elapsed.

In the ozone generator configured in this manner, a plurality of ozone generation units are connected in parallel to one high-frequency power supply, and power is supplied to each ozone generation unit in a pulsed manner. Therefore, since the power supply itself does not have a rest period, the power supply capacity can be used up all the time, and the ozone generator can be configured with an inexpensive power supply system.

In addition, in the ozone generator of the present embodiment, five reactors having different inductances are connected to the five ozone generating units 11, respectively. As another configuration, a reactor with the smallest inductance L5 may be connected in series to the output terminal of the single-phase inverter circuit 12, and reactors having inductances with different differences from L5 may be connected to the respective ozone generating units 11. . By configuring in this way, the inductance of each reactor can be reduced, so that the ozone generator can be downsized.

In the ozone generator of this embodiment, five ozone generation units are connected in parallel. The number of ozone generation units connected in parallel may be two or more. When the number of ozone generation units connected in parallel is n, the time for one cycle of power output from the high-frequency power source is set to n×τd.

In the ozone generator of this embodiment, the power output is controlled so that the frequency increases during one cycle. The power supply output may be controlled to decrease in frequency during one cycle. If the power supply output is controlled to decrease in frequency during one cycle, the order of the ozone generating units that match the power supply frequency and the resonance frequency is simply reversed.

While this application describes various exemplary embodiments and examples, various features, aspects, and functions described in one or more embodiments may not apply to particular embodiments. can be applied to the embodiments singly or in various combinations.
Therefore, numerous variations not illustrated are envisioned within the scope of the technology disclosed herein. For example, modification, addition or omission of at least one component, extraction of at least one component, and combination with components of other embodiments shall be included.

1 high-frequency power supply, 2 high-voltage electrode, 3 ground electrode, 4 high-voltage side dielectric, 5 ground side dielectric, 10 ozone generator, 11 ozone generation unit, 12 single-phase inverter circuit, 13 frequency control circuit, 14 reactor, 15 waveform , 51 Reduced portion, 52 Discharge space portion, 53 Enlarged portion, 54 Gas introduction direction, 55 Gas discharge direction.

Claims (10)

In an ozone generator that generates ozone using a gas containing oxygen introduced in the gas flow direction,
a discharge space portion that causes electron collision by discharge with respect to the gas;
a lead-out portion where the discharge space portion conducts the electron collision to lead out the ozone generated by converting the oxygen contained in the gas;
An ozone generator comprising: a decomposition reaction suppression mechanism that suppresses a decomposition reaction in which the generated ozone is decomposed by the electron collision. The decomposition reaction suppressing mechanism is configured to make the residence time of the gas in the discharge space portion shorter than the conversion time of the oxygen to the ozone by the electron collision in the discharge space portion. The ozone generator according to claim 1, characterized in that: The decomposition reaction suppression mechanism is
a high-voltage-side dielectric and a ground-side dielectric which constitute the discharge space portion and which are arranged apart from each other;
a high-voltage electrode connected to the high-voltage side dielectric and a ground electrode connected to the ground-side dielectric for applying voltage between the discharge space parts;
A width Ld of the high-voltage electrode and the ground electrode in the gas flow direction is configured to be shorter than a length Lw of the high-voltage electrode and the ground electrode in a direction perpendicular to the gas flow direction. Item 3. The ozone generator according to Item 1 or 2. 4. The ozone generator according to claim 3, wherein the discharge space portion is configured as a gap between the high voltage side dielectric and the ground side dielectric. Between the high voltage side dielectric and the ground side dielectric,
the discharge space portion where the distance between the high-voltage side dielectric and the ground side dielectric is the separation distance d and continues with the length Lw in the direction perpendicular to the gas flow direction;
a contraction portion located upstream of the discharge space portion in the gas flow direction, the distance being reduced to the separation distance d along the gas flow direction;
5. The ozone according to claim 4, further comprising an enlarged portion positioned downstream of said discharge space portion in said gas flow direction, said distance being enlarged from said separation distance d along said gas flow direction. Generator. a reduction angle of the reduced portion is 45 degrees;
The ozone generator according to claim 5, wherein the expansion angle of the expansion portion is 10 degrees. 3. The ozone generation according to claim 2, wherein the decomposition reaction suppression mechanism is configured such that the discharge in the discharge space portion is pulsed discharge having a discharge stop time longer than the conversion time. Device. An ozone generator comprising a plurality of ozone generating units each having a pair of discharge electrodes and a power supply whose power supply frequency changes periodically,
A plurality of the ozone generating units are connected in parallel to the power supply, and reactors having different inductances are connected between the plurality of ozone generating units and the power supply. Device. The discharge electrode has a dielectric and a metal electrode provided on a part of one surface of the dielectric, and a pair of the discharge electrodes are arranged with the other surfaces of the dielectric facing each other. a gas flow path through which a gas containing oxygen flows between the pair of discharge electrodes; 9. The ozone generator according to claim 8, wherein the flow path widens upstream and downstream. In the ozone generating method for generating ozone using a gas containing oxygen introduced in the gas flow direction,
a discharge step of causing electron collision by discharge in the discharge space portion with respect to the gas;
a derivation step of deriving from the derivation portion the ozone generated by converting the oxygen contained in the gas by the electron collision in the discharge space portion;
A method for generating ozone, comprising: a decomposition reaction suppression step of suppressing a decomposition reaction in which the generated ozone is decomposed by the electron collision using a decomposition reaction suppression mechanism.

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