JP6893755B2 - Ozone gas generation system - Google Patents

Description

The present invention relates to an ozone gas generation system that outputs high-concentration ozone gas by a combination configuration of an ozone power source and an ozone generator utilizing a discharge phenomenon. In particular, the present invention relates to an ozone gas generation system capable of outputting high-concentration ozone gas or high-generation ozone gas by a combination of an ozone generator using electric discharge and an ozone power source.

Generally, a discharge-type ozone gas generator is composed of a combination of an ozone power source that supplies power for generating ozone gas and an ozone generator having a built-in discharge cell (ozone generation cell) for generating ozone gas.

The discharge cell has a discharge space through a dielectric, and by applying a high voltage ozone generation AC voltage from the ozone power source to the ozone generator, a dielectric barrier discharge (dielectric barrier discharge) is performed in the discharge space of the discharge cell. Silent discharge) can be induced. A discharge generator that uses an oxygen gas to which a catalyst gas for generating ozone gas is added as a raw material gas in the discharge space that generates a dielectric barrier discharge, or a high-purity oxygen gas that does not add a catalyst gas as a raw material gas. Two types of discharge generators are configured, which are supplied and coated with a photocatalyst material for generating ozone gas on the dielectric barrier discharge surface. By applying discharge energy to the raw material gas supplied to each of these two types of discharge generators, high-concentration ozone gas is generated via a catalyst.

An ozone gas generator has a configuration in which ozone gas generated in a discharge cell is collected and ozone gas having a predetermined ozone concentration can be taken out from an ozone generator. Examples of the ozone generator used in the ozone gas generator include the ozone generator disclosed in Patent Document 1.

The ozone generators disclosed in various prior art documents are, of course, intended for ozone generators to which a catalyst gas for generating ozone gas is added or a photocatalytic material is applied to the discharge surface. In the subsequent invention elements, the above-mentioned measures are naturally taken without specifying that the ozone generator is a raw material gas obtained by adding a catalyst gas to the raw material gas or a photocatalytic material applied to the discharge surface. The explanation will be made on the assumption of an ozone generator.

Further, the total ozone generation amount Y (g / h) generated per unit time by the ozone generator is input to the total gas flow rate Q (L / min) of the raw material gas supplied to the discharge space of the discharge cell and the ozone generator. The amount corresponds to the total discharge power DW (W) to be generated, and the following equation (1) is satisfied.

Y = Q ・ C ... (1)
In addition, "C" in the formula (1) is the ozone generation concentration (g / m ³ ) generated in the discharge cell.

That is, the total ozone production amount Y (g / h) generated by the ozone generator is the product of the generated ozone generation concentration C (g / m ³ ) and the total gas flow rate Q (L / min) of the supplied raw material gas. It becomes the corresponding value.

Incidentally, the ozone generation concentration C (g / m ³ ) generated in the discharge cell corresponds to the discharge power DW (watt = joule / sec.) Injected into the unit gas volume V (cm ^{3) per unit time.} The unit gas volume V (cm ³ ) simply satisfies the following equation (2) in the entire ozone gas generator.
V (cm ³ / sec) = 1000 ・ Q / 60… (2)

That is, the ozone generation concentration C (g / m ³ ) generated in the discharge cell is the specific power value DW corresponding to the discharge energy amount (joule / cm ³ ) injected into the unit gas volume V (cm ^{3) of the ozone generation cell.} It is determined by / Q (W ・ min / L).

Therefore, the ozone production concentration C (g / m ³ ) increases in proportion to the specific power value DW / Q (W · min / L). The ozone production concentration C (g / m ³ ) is expressed by the following equation (3).
C (g / m ³ ) = A ・ DW / Q ... (3)

In equation (3), "A (g / J)" is a unique proportional constant indicating the ozone generation capacity per unit discharge energy of the discharge cell. The eigenvalue "A (g / J)" indicates the ability value to generate ozone through various catalytic chemical reactions due to electron collision and electric discharge. More specifically, this "A (g / J)" can be said to be an eigenvalue depending on the discharge form, gas type, discharge surface material, and gap length d.

By the way, the amount of ozone staying in the discharge space in the discharge cell that generates the ozone generation concentration C derived by the equation (3) with respect to the total amount of ozone generated per unit time Y (g / h). Ys (g) is represented by the following equation (4).
Ys (g) = C ・ d ・ S / 1000000 ... (4)

In equation (4), "d" is the discharge gap length (cm), and "S" is the total discharge area (cm ² ) of the ozone generator. The amount of ozone Ys staying in the discharge space of the discharge cell is not only the ability value A and the specific power value DW / Q value capable of generating ozone, but also the discharge gap length d, which is a discharge cell structural factor, and the total discharge area S. It is a fixed value determined by, and is also a parameter value that cannot be changed once the discharge cell structure is determined.

FIG. 15 is a graph showing the characteristics of the extracted ozone concentration Ct with respect to the specific power value DW / Q in the conventional ozone generator.

The amount of extracted ozone Yt in the ozone generator is a value substantially corresponding to the product of the extracted ozone concentration Ct and the supplied gas flow rate Q. That is, the raw material gas having the maximum gas flow rate Q in the possible range is supplied, and the extracted ozone amount Yt (extracted ozone amount Yt) in the ozone generator is obtained from the extracted ozone concentration Ct value and the specific power value DW / Q value shown in FIG. The maximum value of = Ct · Q) is obtained, and the maximum value of the discharged discharge power DW (= specific power value (DW / Q) · Q) to be injected is also found.

In the ozone gas generator, ozone having an ozone generation concentration C and an ozone amount Ys calculated by the formulas (3) and (4) is generated. On the other hand, as shown in FIG. 15, in the ozone gas generator utilizing the discharge phenomenon, the characteristic of the extracted ozone concentration Ct with respect to the specific power value DW / Q of the ozone generator is the characteristic 8000a. In the characteristic 8000a, the tangent line (two-point chain line) showing the characteristic of the extracted ozone concentration Ct with respect to the low specific power value DW / Q indicates the ozone generation concentration C corresponding to the ozone amount Ys staying in each discharge cell.

On the other hand, the extracted ozone concentration Ct at a high specific power value DW / Q is a value obtained by removing the concentration Cd that decomposes the ozone generated in each discharge cell from the ozone generation concentration C (two-point chain line) generated from each discharge cell. It becomes. That is, the extracted ozone concentration Ct indicates the actual ozone concentration that can be extracted from the ozone gas generator.

Here, an ozone generator that uses high-purity oxygen gas as a raw material gas will be examined. In such an ozone generator, the main factor of the ozone generation capacity indicated by the generated ozone concentration characteristic (two-point chain line), which is determined for the specific power value DW / Q (W · min / L), is the patent. It is considered that it is a dielectric barrier discharge (silent discharge) generated in the discharge space of the discharge cell shown in Documents 2 to 6. As shown in each patent document, the amount of oxygen atom dissociation due to electron collision in the discharge space is very small, and the ozone generation capacity caused by this electron collision is only a small part of the high-concentration ozone generation. Absent.

That is, when the total discharge power DW is supplied to the ozone generator and a dielectric barrier discharge is generated in the discharge space of the discharge cell, "catalytic action of a trace amount of nitrogen gas contained in the supplied raw material gas" or "discharge" or "discharge". Due to the "photocatalyst function" arranged on the entire surface of the electrode surface constituting the cell, the amount of dissociation of oxygen atoms increases, so that high-concentration ozone gas can be generated.

As described above, the oxygen atom dissociation ability due to a small amount of nitrogen gas and the oxygen atom dissociation ability of the photocatalyst arranged on the electrode surface are the main factors for generating ozone gas.

As for the ozone production concentration C (g / m ³ ) generated in the discharge cell, the higher the oxygen atom dissociation capacity described above, the higher the A (g / J) value represented by the equation (3), and in the discharge space. A large amount of ozone gas is produced.

Further, in the discharge cell, by injecting the discharge energy (J), ozone gas having an ozone concentration according to the equation (3) with A (g / J) as a parameter is generated, but the generated ozone gas is simultaneously generated. There are self-decomposition in the discharge cell and decomposition due to collision with the discharge gas. The total amount of ozone decomposition, which is the sum of the autolysis of ozone gas in the discharge cell and the decomposition due to collision with the discharge gas, is larger than the amount of normal ozone gas autolysis in the extracted atmosphere.

This means that oxygen atom dissociation due to electron collision occupies a large proportion of the ozone generation capacity in the discharge space. That is, the amount of decomposition of ozone gas that dissociates ozone generated by collision with electrons, ions, and discharge gas in the discharge plasma and returns it to oxygen, and the amount of ozone decomposition that ozone in a high-concentration ozone state in the discharge cell self-decomposes. , It is shown that the amount of ozone decomposition in the discharge plasma cannot be ignored because it is larger than the amount of ozone decomposition in the normal atmosphere.

Therefore, it is considered that the concentration Cd that decomposes the ozone gas generated in each discharge cell also depends on the total discharge power DW and the total gas flow rate Q to be input.

In the conventional ozone gas generator shown in FIG. 15, considering the practical environment of the device, a gas flow rate range of about 2.4 L / min or more is required as the total gas flow rate Q of the raw material gas, and cooling for cooling the ozone generator is required. It is assumed that it is desirable to set the temperature to 5 ° C. or higher as a constraint condition. The ozone gas generator is operated assuming that the upper limit of the cooling temperature constraint condition for cooling the ozone generator is about 30 ° C. with respect to room temperature (20 ° C.).

In the above constraint conditions, be enhanced extraction ozone concentration Ct in the high specific power value DW / Q (500W · min / L vicinity), the conventional ozone generating apparatus, a high-concentration ozone gas of greater than 400 g / m ³ I couldn't take it out.

Japanese Patent No. 3607890 Japanese Patent No. 3642572 Japanese Patent No. 4953814 Japanese Patent No. 5069800 Japanese Patent No. 4825314 Japanese Patent No. 4932037

The conventional ozone gas generator is composed of an existing ozone power source and an existing discharge cell-shaped ozone generator.

In the conventional ozone gas generator, if the total discharge power DW is increased and the high specific power value DW / Q (near 500 W / min / L) is set under the condition of a large gas flow rate region where the total gas flow rate Q of the raw material gas is relatively large. Since the amount of ozone gas decomposed in the ozone gas generator is larger than the ozone generation concentration C generated in each discharge cell, the extracted ozone concentration Ct cannot be increased to a predetermined concentration or higher.

Therefore, in the conventional ozone gas generator, there is a limit to the ozone concentration Ct taken out, and the ozone concentration that can be taken out from the ozone gas generator can be set in a large gas flow rate range. There was a problem that it was not possible to extract a higher concentration of ozone gas.

In particular, in the conventional ozone gas generator having the characteristics shown in FIG. 15, the ozone gas having a high concentration (concentration in the region 99a) exceeding ^{400 g / m 3} in the ozone concentration characteristics with respect to the specific power value DW / Q in the large gas flow rate range. Could not be taken out.

Further, regarding the discharge cell, there is a problem that even if the discharge input power is increased and the amount of ozone generated is increased, the amount of decomposition of ozone gas is rather large and the ozone concentration that can be taken out cannot be increased. Further, if the discharge input power is increased and the discharge power density is increased in order to increase the amount of extracted ozone Yt, there is also a problem that the load applied voltage becomes high. Further, when the AC output has a higher frequency, there is a problem that the discharge power density in power supply control is restricted, for example, the ozone power supply cannot stably supply the ozone generation AC voltage.

An object of the present invention is to provide an ozone gas generation system capable of solving the above-mentioned problems, suppressing the system configuration to the minimum necessary, and outputting high-concentration ozone to the outside.

The ozone gas generation system according to the present invention includes an ozone generator having a plurality of discharge cells stacked in multiple stages, and an ozone power source that applies an AC voltage for ozone generation to the ozone generator. A raw material gas containing oxygen is supplied, and the ozone generator generates a dielectric barrier discharge in the discharge spaces of the plurality of discharge cells, generates ozone gas from the raw material gas supplied to the discharge spaces, and generates the ozone gas. Output to the outside, the plurality of discharge cells each include flat plate-shaped first and second electrodes, a dielectric is formed on the second electrode, and the discharge is performed between the first and second electrodes. Spaces are provided, and the plurality of discharge cells are each provided on the discharge surface of the first electrode, and Nφ ozone gas outlets for taking out the ozone gas generated in the discharge space, and the first It has an ozone gas extraction path provided inside the electrode, connected to each of the Nφ ozone gas outlets, and aggregates the ozone gas taken out from the Nφ ozone gas outlets and outputs the ozone gas to the outside, and generates the ozone. The vessel is characterized by satisfying the following conditions (a) and (b). Condition (a) and condition (b) are as follows. Condition (a) In each of the plurality of discharge cells, the division area dso obtained by dividing the discharge area st of the discharge surface by the number of divisions Nφ is ^{set in the range of 30 cm 2} or more and ^{less than 160 cm 2.} Condition (b) The discharge. The discharge gap length in space is set to less than 80 μm.

Ozone gas generating system of the present invention according to claim 1, by satisfying the above conditions (a) and the condition (b), the discharge area of the discharge surface of each Nφ number of virtual discharge cells 30 cm ² or more, 160cm ² It is possible to realize a state set in the range of less than.

Therefore, the ozone gas generation system of the present invention according to claim 1 satisfies the above-mentioned conditions (a) and (b), and enables the raw material gas flow rate and the discharge power to be supplied to the discharge surface of each discharge cell. By setting the maximum in the range and maximizing the amount of ozone taken out, it is possible to create conditions that allow high-concentration ozone gas to be taken out.

Further, since the ozone gas generation system of the present invention according to claim 1 only needs to satisfy the condition (a), the discharge area st of each of the plurality of discharge cells can be set to Nφ times the divided area dso.

As a result, according to the first aspect of the present invention, the number of layers in the plurality of discharge cells stacked in multiple stages can be reduced, and the number of parts required for the plurality of discharge cells provided in the ozone generator 300 can be reduced. it can.

Objectives, features, aspects, and advantages of the present invention will become more apparent with the following detailed description and accompanying drawings.

It is explanatory drawing which shows the structure of the ozone gas generation system which is Embodiment 1 of this invention. It is explanatory drawing which shows the structure of the discharge surface in the discharge cell of the ozone generator shown in FIG. It is a graph which shows the characteristic of the total ozone decomposition amount Yd with respect to the gas residence time To of each ozone generator of A type to C type discharge cell shapes. It is a graph which shows the characteristic of the extraction ozone concentration Ct with respect to the specific power value DW / Q of the ozone generator of each A type to C type discharge cell shape. It is a graph which shows the characteristic of the extraction ozone concentration Ct with respect to the total gas flow rate Q of the raw material gas of each ozone generator of A type to C type discharge cell shapes. It is a graph which shows the characteristic of the load peak voltage Vp applied to each ozone generator of A type to C type discharge cell shape with respect to the operating frequency f of the power source for ozone. It is explanatory drawing which shows typically the plane structure of the ground cooling electrode which is 1st aspect of Embodiment 2. It is explanatory drawing which shows typically the plane structure of the dielectric electrode which is 1st aspect of Embodiment 2. It is explanatory drawing which shows typically the plane structure of the ground cooling electrode which is the 2nd aspect of Embodiment 2. It is explanatory drawing which shows typically the plane structure of the dielectric electrode which is the 2nd aspect of Embodiment 2. It is explanatory drawing which shows typically the plane structure of the ground cooling electrode which is the 3rd aspect of Embodiment 2. It is explanatory drawing which shows typically the plane structure of the dielectric electrode which is the 3rd aspect of Embodiment 2. It is explanatory drawing which shows typically the plane structure of the ground cooling electrode which is the 4th aspect of Embodiment 2. It is explanatory drawing which shows typically the plane structure of the dielectric electrode which is the 4th aspect of Embodiment 2. It is a graph which shows the characteristic of the extracted ozone concentration Ct with respect to the specific power value DW / Q in the conventional ozone generator.

<Embodiment 1>
(Principle and outline)
FIG. 1 is an explanatory diagram showing a configuration of an ozone gas generation system according to a first embodiment of the present invention. As shown in the figure, the ozone gas generation system 1000 of the first embodiment has an ozone generator 200 having a discharge cell (combination of S1 and S2) arranged on a flat plate electrode (1,3a, 3b) via a dielectric. The ozone generator 200 is provided with an ozone power source 100 that applies an AC voltage for ozone generation.

Then, a dielectric barrier discharge is generated in the discharge space of the discharge cells (S1 and S2) in the ozone generator 200, ozone gas is generated from the raw material gas containing oxygen gas supplied to this discharge space, and the ozone gas is taken out to the outside. ing.

The ozone gas generation system 1000 is configured to have one discharge space (a space formed by a pair of discharge surfaces) and one ozone gas outlet per unit of discharge cells. Hereinafter, the pair of discharge surfaces constituting the discharge space may be referred to as "one unit discharge surface" or "one discharge surface". Further, the discharge power dw (W), the discharge area so (cm ² ), the raw material gas flow rate qo (L / min), etc. supplied to one unit of the discharge cell are used as parameter symbols related to the generation of ozone gas per unit of the discharge cell. Shown in lowercase.

On the other hand, the total discharge power DW (W), the total discharge area S (cm ² ), the total gas flow rate Q (L / min) of the raw material gas, etc. supplied to the entire plurality of discharge cells in the ozone generator 200 generate ozone. It is shown in capital notation as a parameter symbol of the vessel 200. In principle, symbols whose parameter values do not change due to differences in one unit of discharge cell or ozone generator will be described in capital letters.

In order to obtain the condition for maximizing the extraction ozone concentration Ct of the ozone generator 200, in one unit of the discharge cell, the discharge area so related to the discharge shape of the discharge space and the discharge that can be charged into the one unit of the discharge space (discharge surface). The optimization of the power density J and the raw material gas flow rate qo flowing through one unit of the discharge space will be examined.

Incidentally, the range of the discharge gap length d of the discharge space of the discharge cell in the ozone gas generation system 1000 is applied to an ozone generator of several tens of μm or more and less than several hundred μm. In particular, the discharge gap length d is more effective in the range of 20 μm to 100 μm.

In an ozone generator in which the discharge area so (cm ² ) is set within a predetermined area range and the discharge gap length d is set to be applied, one unit of discharge is particularly provided as a condition for extracting higher concentration ozone gas. The average gas flow velocity vo / d flowing in the cell should be within a range of less than approximately (1.6 / d) cm / s.

Further, the flow rate qo of the raw material gas supplied to one unit of the discharge cell (one discharge surface) is set to less than about 0.25 L / min. Therefore, even if the specific power value dw / qo of the ozone gas generation system 1000 is set high, ozone decomposition and generation due to collision of ozone gas with respect to the ozone gas production amount y (= C · qo) in one unit of the discharge cell. The total amount of ozone decomposition yd, which is combined with the self-decomposition of ozone itself, can be suppressed to a low level, and high-concentration ozone gas can be taken out from one unit of the discharge cell.

Also, as discharge power density supplied to the discharge cells of one unit is 2.5W ^/ cm ² ~6W ^/ cm 2 range, by the discharge power dw (W), the ozone gas in a unit discharge cell The total ozone decomposition amount yd, which is the sum of the ozone decomposition due to the collision of ozone gas and the self-decomposition of the generated ozone itself, can be suppressed with respect to the production amount y (= C · qo). As a result, the ozone gas taken out from the discharge cell and the ozone amount yy can be stored to the maximum.

Further, the ozone gas generation system 1000 constitutes an ozone generator 200 by stacking n stages of discharge cells S1 and S2, each of which has one discharge surface (one discharge space). Therefore, the number of discharge surfaces (discharge spaces) is 2n, and the ozone gas generation system 1000 is 2n times as much as the ozone power source 100 that supplies 2n times the total discharge power DW (= 2 ・ n ・ dw) [W]. The discharge area S (= 2 · n · so) [cm ² ] and the raw material gas flow rate Q (= 2 · n · qo) [L / min] 2n times are achieved. Therefore, the ozone gas generation system 1000 can obtain a high-concentration extracted ozone concentration Ct from the ozone generator 200, and can maximize the amount of ozone gas extracted ozone Yt with respect to the supplied gas flow rate Q.

Further, the output frequency of the high-frequency / high-voltage AC voltage for ozone generation output from the ozone power supply 100 is increased in the range of 20 kHz to 50 kHz as compared with the conventional output frequency of 20 kHz or less. Therefore, the ozone power supply 100 can supply the total discharge power DW to the ozone generator 200 by setting the peak voltage value of the ozone generation AC voltage applied to the ozone generator 200 to 7 kVp or less.

Further, the discharge surface of the discharge cell (basic cells S1 and S2) is formed in a circular shape in a plan view, and the diameter (outer diameter) of the discharge surface is reduced so that the raw material gas passes through the discharge space of the discharge cell. The gas stay time To [ms], which is the time, is shortened.

Furthermore, by suppressing the average gas flow velocity vo / d flowing through the discharge cell to less than approximately 0.035 / d [cm / s], the amount of gas supplied with respect to the amount of ozone generated in the discharge cell can also be suppressed, and the amount of gas supplied in the discharge cell can be suppressed. In, a high ozone generation concentration C is secured, and the decomposition amount Yd, which is the sum of ozone decomposition due to collision of ozone gas and self-decomposition of the generated ozone itself, is suppressed to a low level. As a result, the extraction ozone concentration Ct that can be extracted from the ozone generator 200 can be increased.

Further, the internal excitation inductance value Lt of the parallel resonance transformer 25 functioning as a high-frequency / high-voltage transformer constituting the ozone power supply 100 and the capacitance value of the ozone generator 200 itself composed of a plurality of discharge cells stacked in multiple stages. Together with C0, the ozone power supply 100 is configured to output and control a high frequency that matches the operating frequency range in which parallel resonance is possible.

As a result, the ozone power supply 100 becomes an ozone power supply in which a parallel resonance circuit is formed in the output portion of the parallel resonance transformer 25, which is a step-up transformer, and supplies a more stable ozone generation AC voltage to the ozone generator 200. can do.

(overall structure)
The configuration and features of the ozone gas generation system according to the first embodiment of the present invention will be described with reference to FIGS. 1 to 6.

FIG. 1 is an explanatory diagram showing a configuration of an ozone gas generation system 1000 according to a first embodiment of the present invention. As shown in FIG. 1, the ozone gas generation system 1000 of the first embodiment is an ozone power supply 100 that applies an ozone generation AC voltage for the total discharge power DW to the ozone generator 200 and the ozone generator 200 that generate ozone gas. Is included as the main component.

The ozone gas generation system 1000 of the first embodiment is often installed together with other devices such as a semiconductor manufacturing device and a cleaning device. In particular, high-purity ozone gas is required, and it is required to increase the processing speed and the processing capacity. Therefore, it is desirable that the ozone gas generation system 1000 can take out ozone gas having a concentration higher than the ozone concentration obtained by the existing device, and the taken out ozone amount Yt is larger than the gas flow rate Q to be supplied.

FIG. 2 is an explanatory diagram showing the structure of the discharge surface in the discharge cell of the ozone generator 200 shown in FIG. In FIGS. 1 and 2, the ozone gas generation system 1000 includes an ozone generator 200 that generates ozone gas, and an ozone power supply 100 that supplies the ozone generator 200 with an AC voltage for ozone generation for total discharge power DW. ing.

The ozone power supply 100 includes an AC-DC converter circuit unit 21, an inverter circuit unit 22, a current limiting reactor 23, a power supply control circuit 24, and a parallel resonance transformer 25 as main configurations.

The inverter circuit unit 22, which is an inverter unit, receives electric power (voltage) input from a commercial power source via the AC-DC converter circuit unit 21 and converts this voltage into a required high-frequency AC to obtain a high-frequency AC voltage. , Output to the parallel resonance transformer 25 via the current limiting reactor 23. The output frequency f of the high-frequency AC voltage by the inverter circuit unit 22 is set within the range of 20 kHz to 50 kHz. That is, the operating frequency f of the ozone power supply 100 is in the range of 20 kHz to 50 kHz.

In the specification of the present application, the range indicated by "AA to BB" indicates, in principle, AA or more and less than BB.

The parallel resonance transformer 25, which is a step-up transformer, boosts the high-frequency AC voltage to a high voltage to obtain an AC voltage for ozone generation, and uses this AC voltage for ozone generation as the high voltage terminal HV of the ozone generator 200 and a low voltage. It is supplied between the voltage terminals LV.

The total discharge power DW supplied to the ozone generator 200 by the ozone generating AC voltage is defined. Further, the parallel resonance transformer 25 is provided with measures for improving the power factor of the load, as will be described in detail later.

The high voltage terminal HV is electrically connected to the high voltage electrodes 3a and 3b of each discharge cell in the ozone generator 200. The low voltage terminal LV is electrically connected to the ground cooling electrode 1 in the ozone generator 200.

By controlling the current / voltage of the AC-DC converter circuit unit 21 and the inverter circuit unit 22 including the high-frequency inverter by the power supply control circuit 24, the voltage value of the AC voltage for ozone generation supplied to the ozone generator 200 is controlled. Can be done.

The ozone generator 200 is configured by stacking a plurality of basic cells S1 and S2, each of which has a basic discharge surface. The basic configuration is a pair of basic cells S1 and S2. Hereinafter, this basic configuration will be referred to as a "basic discharge cell set". The basic discharge cell set is composed of a ground cooling electrode 1, dielectric electrodes 2a and 2b, high pressure electrodes 3a and 3b, and insulating plates 4a and 4b.

The basic cell S1 includes a laminated structure of a ground cooling electrode 1, a dielectric electrode 2a, a high voltage electrode 3a, and an insulating plate 4a, which are directed from the bottom to the top.

The basic cell S2 includes a laminated structure of a ground cooling electrode 1, a dielectric electrode 2b, a high voltage electrode 3b, and an insulating plate 4b, which are directed from above to below. The ground cooling electrode 1 is shared between the basic cells S1 and S2.

Then, the low-pressure cooling plate 5 is provided above the basic cell S1 and below the basic cell S2. A set of basic discharge cells composed of a pair of basic cells S1 and S2 having such a configuration is stacked in multiple stages. Each unit of basic cell has a pair of discharge surfaces for forming a discharge space. That is, when the basic discharge cell set consisting of the basic cells S1 and S2 is stacked in 6 stages, 12 basic cells of 1 unit are stacked.

The details of the structures of the basic cells S1 and S2 will be described later. A predetermined number of basic discharge cell sets are stacked on the base 10 in the vertical direction of FIG. 1 to form the main part of the ozone generator 200.

The plurality of stacked discharge cells (plural sets of basic discharge cell sets) are a laminated pressing plate 7 provided on top of the uppermost basic cell (basic cell S1), a laminated pressing plate 7, and each basic cell S1. , The laminated cell pressing rod 8 penetrating S2 is fastened to the base 10 with a predetermined tightening force via the laminated cell pressing spring 6.

The entire plurality of discharge cells are covered with the generator cover 11. The generator cover 11 has a substantially box shape with one side removed, and a flange provided on the peripheral edge of the opening is fastened to the base 10 with a cover tightening bolt (not shown). An O-ring (not shown) is sandwiched between the opening peripheral edge of the generator cover 11 and the base 10, and the internal space formed by the generator cover 11 and the base 10 has a closed structure. There is.

The base 10 is provided with a raw material gas inlet 31 for supplying a raw material gas such as high-purity oxygen gas in the internal space. _{The raw material gas G IN} supplied from the raw material gas inlet 31 fills the internal space inside the generator cover 11 and enters the gaps between the discharge spaces of the plurality of discharge cells.

The base 10 has an ozone gas outlet 32 that emits ozone gas generated in the discharge space from the ozone generator 200 to the outside via the manifold block 9, and a cooling water inlet / outlet for entering / exiting cooling water that cools the discharge cell (not shown). ) Is provided.

That is, the ozone _{gas outlet 32 for outputting the ozone gas G OUT} to the outside is an opening at the end of the ozone gas passage provided in the base 10, and the cooling water inlet / outlet is connected to the cooling water passage provided in the base 10. (Not shown). The cooling water passage and the ozone gas passage provided in the base 10 are formed by independent passages.

In the ozone gas generation system 1000 having such a configuration, it is a ratio to the discharge power DW to be input to the discharge surface (total discharge area S) of a plurality of discharge cells in the ozone generator 200 in order to further increase the amount of ozone taken out Yt. The discharge power density J (= DW / S) is specified. Further, in order to set the condition in which the extraction ozone concentration Ct can be increased, the discharge of one unit of the basic cell is defined so as to specify the average gas flow velocity vo / d supplied to the one unit of the discharge cell (basic cell S1 or S2). Reduce the surface diameter. By making it small in this way, the amount of ozone decomposition yd in one discharge cell (basic cell) is suppressed to a low level, and high-concentration ozone gas can be taken out. Further, by dispersing the supply gas in a multi-stage laminated cell structure in which the basic discharge cell set (combination of the basic cells S1 and S2) is laminated with the number of stacks n (≧ 2), the raw material gas is 2n times the raw material gas flow rate qo. The total gas flow rate Q (= 2 ・ n ・ qo) can be supplied.

Further, when the discharge power density J (= DW / S) that can be applied to each discharge cell in the ozone generator 200 is increased, the load applied voltage Vd becomes high when the desired total discharge power DW is supplied. The output frequency of the ozone power supply 100 is increased to 20 to 50 kHz for the purpose of suppressing the load applied voltage Vd to a low level, supplying the desired total discharge power DW, and ensuring the maximum amount of extracted ozone Yt. .. The load applied voltage Vd indicates the effective value of the ozone generating AC voltage output from the ozone power supply 100.

Further, in the ozone power supply 100, the internal excitation inductance value Lt of the parallel resonance transformer 25 and the capacitance value C0 of the ozone generator 200 itself configured to include a plurality of discharge cells stacked in multiple stages are used in parallel. A high-frequency AC voltage having an output frequency that can resonate is output from the inverter circuit unit 22.

Specifically, the ozone power supply 100 sets the operating frequency f in the vicinity of the parallel resonance frequency fc that satisfies the following equation (5).

fc = 1 / (2π ・ (Lt ・ C0) ^0.5 )… (5)
As a result, the ozone power supply 100 becomes an ozone power supply in which a parallel resonance circuit is formed on the output side of the parallel resonance transformer 25, and a more stable ozone generation AC voltage can be supplied to the ozone generator 200.

As shown in FIGS. 1 and 2, a manifold block 9 extending in the stacking direction of a plurality of discharge cells (S1 and S2) is provided so as to partially overlap the peripheral end of the ground cooling electrode 1 in a plan view. There is.

The ground cooling electrode 1 has a circular upper surface and a lower surface as discharge surfaces in a plan view. That is, the upper surface of the ground cooling electrode 1 serves as the discharge surface of the basic cell S1, and the lower surface of the ground cooling electrode 1 serves as the discharge surface of the basic cell S2. As described above, in the basic cell S1, a discharge space is formed between the pair of discharge surfaces by using the upper surface of the ground cooling electrode 1 and the lower surface of the dielectric electrode 2a as a pair of discharge surfaces. Similarly, in the basic cell S2, the lower surface of the ground cooling electrode 1 and the upper surface of the dielectric electrode 2b are used as a pair of discharge surfaces, and a discharge space is formed between the pair of discharge surfaces. An opening 15 for taking out the ozone gas generated in these two discharge spaces is provided. Further, in order to cool both sides of the basic discharge cells S1 and S2, a cooling water path (not shown) is provided inside the ground cooling electrode 1.

The opening 15 is connected to the ozone gas output path 92 of the manifold block 9 via an output path 17 provided inside the ground cooling electrode 1. On the other hand, the cooling water output path 91 and the cooling water input path 93 provided in the manifold block 9 are connected to the cooling water path provided inside the ground cooling electrode 1.

As described above, the cooling water path provided on the base 10, the cooling water output path 91 and the cooling water input path 93 provided on the manifold block 9, and the cooling water path provided on the ground cooling electrode 1 are included. A cooling mechanism for cooling a plurality of discharge cells of the ozone generator 200 is configured.

Further, a plurality of discharge spacers 13 for forming a discharge gap length d (mm) are provided on the upper surface and the lower surface of the ground cooling electrode 1, and the dielectric electrodes 2a and 2b and the dielectric electrodes 2a and 2b are provided through the plurality of discharge spacers 13. The high voltage electrodes 3a and 3b are overlapped. As a result, a discharge space having a discharge gap length d can be formed between the ground cooling electrode 1 and the high pressure electrode 3a (dielectric electrode 2a) and between the ground cooling electrode 1 and the high pressure electrode 3b (dielectric electrode 2b). it can.

Further, as one ozone generation method, the upper surface and the lower surface of the ground cooling electrode 1 are configured with an ozone generator in which a photocatalyst material (not shown) for generating ozone is applied.

_{The raw material gas G IN} is supplied from the outer peripheral portion of the ground cooling electrode 1. At this time, the raw material gas flow rate qo (Q / n) dispersed in the basic discharge cell set having the number of layers n is supplied to each discharge cell (basic cell S1 or basic cell S2). Then, by applying an AC voltage for ozone generation between the ground cooling electrode 1 and the high-voltage electrodes 3a and 3b, a dielectric barrier discharge is formed on the entire discharge surface of each discharge cell. Therefore, in the discharge space, the light energy of the dielectric barrier discharge and the activation of the photocatalyst promote the oxygen atom dissociation of the oxygen gas contained in the raw material gas supplied to the discharge space.

As a result, the ozone generator 200 promotes a three-body collision chemical reaction between oxygen atoms and oxygen gas generated during the pause period of intermittent discharge, which is a feature of dielectric barrier discharge, and in the discharge space of each discharge cell, Highly efficient ozone generation capacity can be demonstrated. That is, the ozone generator 200 can generate ozone gas having a concentration proportional to the total discharge area S of the plurality of discharge cells and the specific power value DW / Q.

_{Since the raw material gas G IN} is supplied from the outer periphery of the ground cooling electrode 1, the ozone gas generated in the discharge space of each discharge cell enters the opening 15 at the center of the ground cooling electrode 1 along the gas flow. , It is taken out as _{an output ozone gas G OUT} via an output path 17 which is an ozone passage provided in the ground cooling electrode 1.

The ozone gas generated by each discharge cell is collected in the ozone generator 200, and the ozone gas having a predetermined concentration is finally taken out from the ozone gas outlet 32 via the ozone gas output path 92 of the manifold block 9.

The amount of ozone Yt finally taken out from the ozone generator 200 is the amount of ozone gas generated in each discharge space of one unit of discharge cell y, the amount of ozone decomposition due to collision during discharge in each discharge space, and the amount of ozone decomposed in the discharge cell. It is the sum of the amount of extracted ozone yt obtained by subtracting the amount of ozone decomposition yd, which is the sum of the amount of self-ozone decomposition of ozone.

The ozone production amount y (g / h) generated per unit time in each discharge cell of FIG. 2 is the raw material gas flow rate qo (L / min) supplied to the discharge space and the discharge power dw (W) to be input to each discharge cell. ), The photocatalyst function in which ozone is applied to the discharge surface acts, and it is expressed by the following equation (6).

y = qo ・ C ... (6)
^{In equation (6), "C" is the ozone concentration (g / m 3} ) calculated by the amount of ozone generated per unit time in one unit of discharge cell and the flow rate of raw material gas qo in the discharge space. Become.

^{That is, one discharge space volume dv (cm 3} ), which is the volume of the discharge space formed in one unit of the discharge cell, is expressed by the following equation (7).
dv (cm ³ ) = d ・ so… (7)

Therefore, the amount of ozone ys (g) remaining in the discharge space after being generated in one discharge space is the generated ozone generation concentration C (g / m ³ ) and the discharge space volume dv calculated by the equation (7). The ozone production amount y corresponds to the product of (cm ^3).

In the equation (7), "d" is the discharge gap length (cm), "so" is the discharge area (cm ² ) of the discharge surface in one unit of the discharge cell, and these parameters "d", "so" is a fixed value that defines the discharge cell structure.

The ozone generation concentration C (g / m ³ ) generated in the discharge cell corresponds to the discharge power dw injected into the unit gas volume dv (cm ^{3) per unit time.} The unit gas volume dv is shown again in the following equation (8) (same as equation (2)) for one unit of discharge cell.

dv (cm ³ / sec) = 1000 ・ Q / (n ・ 60)… (8)
That is, the ozone generation concentration C (g / m ³ ) generated in one unit discharge cell is the specific power value dw / qo (W ·) corresponding to the amount of discharge energy (joule / cm ^{3) injected into the unit gas volume dv.} Determined by min / L), the amount of ozone ys (g) staying in the discharge space as shown in the following equation (9) is higher in proportion to the specific power value dw / qo (W · min / L). Become.
ys (g) = C · d · s / 1000000 ... (9)

Here, the specific power value dw / qo in one unit of the discharge cell is shown, but since it is shown in the same ratio as the total specific power value DW / Q when stacked in multiple stages (2n times), the ratio will be changed in the future. Expressed as power value DW / Q.

However, in the ozone gas generator using an actual discharge, the extracted ozone concentration Ct does not increase in proportion to the specific power value DW / Q as shown in FIG. 15, and the extracted ozone with respect to the specific power value DW / Q The characteristic of the concentration Ct is the characteristic 8000a.

In the characteristic 8000a, the tangent line (two-point chain line) of the extraction ozone concentration Ct characteristic with a low specific power value DW / Q is defined as the characteristic of ^{the ozone generation concentration C (g / m 3) generated in the discharge cell (ozone generation cell).} To.

On the other hand, as shown in the characteristic 8000a of FIG. 15, the extracted ozone concentration Ct in the region of high specific power value DW / Q is the ozone generated in each discharge cell from the ozone generation concentration C generated from each discharge cell. It can be judged that the value is obtained by removing the concentration Cd that decomposes.

As shown in FIG. 15, in a large flow rate region where the raw material gas flow rate Q is approximately 3.0 L / min or more, the characteristic 8000a of the extracted ozone concentration Ct with respect to the specific power value DW / Q of the ozone generator is saturated at a predetermined concentration value. doing. Therefore, even if the total discharge power DW is increased and the specific power value DW / Q is increased, the extracted ozone concentration Ct cannot be increased.

Even if the specific power value DW / Q is increased, the ozone concentration Ct extracted from the predetermined concentration value does not increase, but rather the cause of the decreasing tendency is generated by the electrons, ions, discharge gas generated in the discharge cell and the discharge space. Ozone gas is decomposed by collision with ozone, and the self-decomposition of ozone staying in the discharge cell is large.

That is, when ozone gas generated in the discharge space passes through the electron space during discharge, it collides with electrons, ions, discharge gas, etc. and decomposes, and ozone decomposes by itself. Due to the large amount, the extracted ozone concentration Ct is lowered.

The total amount of ozone decomposition Yd (= 2.n.yd) that decomposes ozone in the discharge cell is the amount of electrons generated in the discharge space ne, the molecular weight of the discharge gas ng, the average gas flow velocity vo / d, and the gas residence time To. It is expressed by the following equation (10) depending on the gas temperature Tg. In addition, "yd" means the amount of ozone decomposition of one unit discharge cell.

Yd = B (ne, ng, vo / d, To, Tg, C) ... (10)
As shown in the equation (10), the total amount of ozone decomposition Yd can be obtained by the function of B (...).

Therefore, if the total amount of ozone decomposition Yd that decomposes ozone gas in a plurality of discharge cells can be reduced corresponding to the specific power value DW / Q, the extracted ozone concentration Ct can be increased.

The total ozone decomposition amount Yd for ozone decomposition in a plurality of discharge cells is the decomposition amount of ozone gas in a plurality of discharge spaces. As shown in FIG. 15, the total gas flow rate Q is approximately 3.0 L / min or more. It can be seen that in the large flow rate region of the above, the ratio (specific power value DW / Q) of the total discharge power DW input to generate the ozone gas and the gas flow rate Q is uniquely determined.

From this, it was found that the total ozone decomposition amount Yd, which depends on the specific power value DW / Q, has a unique characteristic determined by the conditions of the structure of the ozone generator itself. That is, if the structure of the ozone generator and the output conditions of the ozone power source are reviewed, the total ozone decomposition amount Yd depending on the specific power value DW / Q can be reduced, and the extracted ozone amount Yt can be increased. The present invention focuses on this point.

In the cross section of one discharge surface of the ground cooling electrode 1 shown in FIG. 2, attention is paid to the amount of ozone decomposition of ozone gas generated in the discharge cell.

When the raw material gas is supplied at the raw material gas flow rate Q (raw material gas flow rate), it is dispersed in the raw material gas flow rate qo (= Q / (2.n)) flowing through each of the 2n 1-unit discharge cells (basic cells S1 or S2). Consider the case where the discharge power dw (= DW / (2.n)) is input per unit of the discharge cell.

In this case, the ozone production amount y [= Y / (2 · n)] (g / h) of the ozone gas generated in one discharge space is the amount generated by the raw material gas flowing through the discharge space. The ozone production amount y in one unit of the discharge cell is the gas flowing in the discharge cell based on the gas residence time To, which is the time to pass through the discharge space, and the unit peripheral length l (cm) on one discharge surface. It is closely related to the two elements consisting of the average gas flow velocity vo / d (cm / s) (= qo · 0.001 / (60 · sav)) in the cross section sav (= l · d). These two elements are eigenvalues determined by the shape of the discharge cell. The unit peripheral length l (cm) indicates the peripheral length (cm) along the outer circumference of the representative discharge surface, which is one discharge surface among the pair of discharge surfaces forming one discharge space. That is, the peripheral length (cm) of the discharge diameter of the average area sav (= so / 2) of one discharge surface is the unit peripheral length l (cm).

The gas residence time To is closely related to both the amount of ozone decomposition due to the collision of electrons, ions, and discharge gas with the ozone gas generated on the discharge surface in the discharge space and the amount of self-ozone decomposition of ozone itself staying in the discharge space. is connected with. Further, the average gas flow velocity vo / d (cm / s) based on the unit circumference length l (cm) is closely related to the ozone generation capacity generated in one unit of the discharge cell, and ozone generation. If the average gas flow velocity vo / d of the gas is larger than the capacity, the total gas flow rate Q is large, and the ozone concentration that can be taken out is low.

Therefore, the gas residence time To and the gas temperature Tg are factors that increase the amount of decomposition due to the collision of ozone gas passing through the discharge space and the amount of self-decomposition of ozone itself, and promote the factors that increase the amount of ozone decomposition in the discharge cell. ing. Further, when the average gas flow velocity vo / d (cm / s) is larger than the ability to generate ozone in the discharge space, the extracted ozone concentration Ct becomes lower.

That is, the amount of ozone generated by the ozone gas generated by the energy of the dielectric barrier discharge of the discharge power density J (= wd / so) that can be input in one discharge space y [= Y / (2 ・ n)] (g / h). ), Regarding the ozone amount ys (g) staying in the discharge space, when taking out ozone at a high concentration of this ozone amount ys, the ozone decomposition amount yd due to the gas stay time To of the gas in the discharge space The impact cannot be ignored.

Specifically, the larger the gas stay time To, the longer the ozone decomposition time. Therefore, the ozone decomposition amount yd, which is the total of the decomposition amount due to the collision with the discharge gas and the self-decomposition amount of the staying ozone itself, is growing.

Further, when the average gas flow velocity vo / d (cm / s) is larger than the ability to generate ozone in the discharge space, the extracted ozone concentration Ct becomes lower.

Further, when the discharge power density J is increased, the gas temperature Tg tends to increase, but if the entire discharge surface is cooled and the discharge heat energy is sufficiently removed, the discharge power density J that can be input is increased. The ozone decomposition amount yd does not increase as much as the shape of the discharged cell, and can be suppressed by the cooling capacity to some extent.

Ozone decomposition by the gas temperature Tg is related to the cooling capacity of the discharge electrode surface, and the temperature rise of the gas temperature Tg can be suppressed by making the cooling capacity sufficient. Since suppressing the temperature rise of the gas temperature Tg is an essential problem in the design of the ozone generator, the increase in the amount of ozone decomposition due to the gas temperature Tg is not considered here.

Next, when a normal large flow rate of raw material gas of 3.0 L / min or more is flowed, the average gas flow velocity flowing through the discharge space based on the gas residence time To in the discharge space and the unit circumference length l (cm). Consider a discharge cell shape suitable for vo / d and discharge power density J. The gas stay time To is as shown in the following equation (11).

To (ms) = (d ・ so) / qo… (11)
In equation (11), "d" is the discharge gap length (mm), "so" is the discharge area (cm ² ) on the discharge surface of one unit of discharge cell, and "qo" is per discharge space. Raw material gas flow rate (L / min).

On the other hand, "S" indicates the total discharge area (cm ² ) in the ozone generator 200, and "Q" indicates the total gas flow rate (L / min) of the raw material gas supplied into the ozone generator 200. “N” indicates the number (pieces) of the laminated basic discharge cell sets (combination of basic cells S1 and S2) of the ozone generator 200 shown in FIG. 1, and the number of discharge surfaces is 2.n.

Further, the average gas flow velocity vo / d (cm / s) flowing on the discharge surface based on the unit peripheral length l (cm) depends on the shape of the discharge cell. For example, in the case of a disk-shaped discharge cell, the gas cross section sav flowing through the discharge cell based on the unit peripheral length l (cm) is per unit gap length flowing into the discharge diameter equivalent to 1/2 of the discharge area so. When defined by the average gas flow velocity vo, it is expressed by the following equation (12).

vo (cm / s) = qo / (2π ・ (so / 2π) ^0.5 )
= F (so) · {1 / To} ... (12)
The average gas flow velocity vo per unit gap length is a value that depends on the reciprocal of the function f (so) and the gas residence time To in the discharge space.

The discharge power density J (W / cm ² ) that can be applied to one discharge space is expressed by the following equation (13).

J (W / cm ² ) = DW / S = dw / so ... (13)
In equation (13), "DW" is the total discharge power.

In the discharge space, the factor that simply increases the ozone decomposition amount yd in proportion is the gas residence time To. In order to shorten the gas residence time To, the discharge area so on the discharge surface of one unit of the discharge cell can be reduced and the same discharge power dw [= DW / (2 ・ n)] can be applied. The amount of ozone decomposition yd can be reduced by the amount that the gas residence time To shown in (11) is shortened.

However, when the discharge area so of one unit of the discharge cell is reduced, the average gas flow velocity vo / d (cm / s) flowing on the discharge surface based on the unit peripheral length (cm) becomes as shown by the equation (12). growing. Therefore, the ozone extraction concentration Ct can be increased even under the condition that the flow rate qo of the raw material gas supplied into the discharge surface is low.

If the discharge area so in one unit of the discharge cell is reduced, the inventor of the present application needs to set the condition for shortening the gas residence time To in the discharge space under the condition that the flow rate qo of the raw material gas supplied to the discharge space is low. I found that. That is, the inventor of the present application can shorten the time required for decomposition including ozone decomposition due to collision of generated ozone and self-decomposition of the staying ozone itself, and as a result, the amount of ozone decomposition yd in the discharge space. Recognized that it can be reduced.

Therefore, it is desirable to set the average gas flow velocity vo / d to the optimum conditions and shorten the gas residence time To so that high-concentration ozone can be extracted. That is, in order to reduce the ozone decomposition amount yd when taking out ozone generated in the discharge space, it is necessary to reduce the discharge area so in one unit of the discharge cell.

Then, as a method of shortening the gas residence time To, the diameter of the discharge surface in the discharge cell is reduced so that the discharge power density J is within a desirable range, and the discharge surface is charged into the discharge space formed by the reduced diameter discharge surface. A method of setting the discharge power dw can be considered. According to this method, the amount of ozone decomposition yd in one discharge space can be reduced, and as a result, a predetermined amount of ozone gas can be extracted from one discharge space at a higher concentration.

That is, the inventor of the present application defines an ozone cell structure (discharge area so on the discharge surface) capable of extracting high-concentration ozone gas from one discharge space and a setting of discharge power density J as means for extracting high-concentration ozone gas. 1 It is important to appropriately set the condition range of various factors including the discharge power dw to be input to the discharge space and the raw material gas flow rate qo for keeping the average gas flow velocity vo / d within the specified range.

Further, as a method of maintaining the above-mentioned conditions regarding one discharge space and increasing the gas flow rate at which high-concentration ozone gas can be taken out, a basic discharge cell set having basic cells S1 and S2 is laminated in multiple stages (n times). Is desired. By stacking the basic discharge cell sets in n stages, it is possible to construct an ozone gas generation system in which the discharge power DW (= 2 ・ n ・ dw) and the total gas flow rate Q (= 2 ・ n ・ qo) are increased, resulting in this. It is possible to extract high-concentration ozone gas in a relatively large gas flow rate range.

In addition, in the ozone gas system having the above configuration, by setting the total discharge power DW (= 2 · n · dw) and the total gas flow rate Q to the maximum possible range, the amount of ozone taken out Yt (= Ct · Q) Can be maximized.

As described above, in order to make it possible to take out high-concentration ozone, as a means of reducing the ozone decomposition amount yd, in order to shorten the gas residence time To in the discharge space, the discharge area so of one discharge surface is made small within the specified value range. It is desirable to use an ozone gas generation system.

Further, in order to increase the amount of ozone taken out Yt, it is desirable to make an ozone gas generation system in which the total discharge power DW and the discharge power density J are optimized within the specified value range.

Next, as an ozone gas generation system capable of extracting high-concentration ozone, there is a means for cooling the ozone generator to a lower flow rate or a lower flow rate, but the required fields requiring low flow rate ozone gas are limited. Further, as a means for cooling the ozone generator to a lower temperature, the equipment attached to the ozone gas generation system becomes large, and the ozone gas generation system itself becomes more expensive and larger than the conventional device.

Based on the above, the constraint condition of the ozone gas generation system that can extract high-concentration ozone is to set the gas flow rate range of the total gas flow rate Q to a large flow rate of approximately 3.0 L / min or more, and to cool the ozone generator 200. Consider the condition where the temperature is 5 ° C or higher. Under these conditions, for example, it is necessary to realize an ozone gas generation system 1000 capable of extracting high-concentration ozone ^{of 400 g / m 3 or more as one embodiment and extracting ozone having an increased amount of extracted ozone Yt.} Become. In this case, not only the total discharge area S of the ozone generator 200 is secured, but also a stable ozone power source 100 capable of setting the discharge power density J and the total discharge power DW to be supplied to the discharge space to the maximum possible is obtained. That is also important.

In order to obtain a predetermined amount of ozone gas at a high concentration, the ozone power source 100 needs to input the total discharge power DW to the ozone generator 200 to increase the discharge power density J of the ozone generator 200. In this case, if the output frequency of the ozone generation AC voltage of the ozone power supply 100 is less than the conventional output frequency of 20 kHz, the load voltage applied to the ozone generator 200 becomes high, and the ozone power supply 100 and the ozone generator Problems such as the need to strengthen the withstand voltage of the 200 itself occur.

Therefore, as an ozone power supply 100 for applying a load application voltage Vd having a peak voltage of 7 kVp (5.0 kVrms) or less, a high frequency ozone generation AC voltage having an output frequency f of 20 kHz to 50 kHz (20 kHz or more and less than 50 kHz) is used. It is desirable to use a power source for ozone to output. Further, if the ozone power source has an output frequency f of more than 30 kHz, the noise generated from the power source itself increases rapidly, and the malfunction of the measuring device and the external device attached to the ozone gas generation system increases. Furthermore, in order to maintain the resonance frequency close to the load with the ozone generator, frequency control according to the load fluctuation of the output frequency f becomes indispensable, and it becomes very difficult to output stable power as a power source for ozone. Become. Therefore, it is more desirable to limit the output frequency f of the ozone power supply 100 to less than 20 kHz to 30 kHz.

The following two types of power sources can be considered as an ozone power source that applies a high-frequency load application voltage Vd of 20 kHz to 50 kHz.

First power supply: A power supply in which a series resonance circuit is provided between the inverter section of the ozone power supply and the ozone generator.
Second power supply: A power supply in which a high-frequency / high-voltage transformer is provided between the inverter section of the ozone power supply and the ozone generator.

In the first power supply, the transformer on the output side of the ozone power supply is eliminated, a series resonance circuit having a high resonance Q value (for example, Q value of 10 or more) is provided between the inverter and the ozone generator, and a load is applied. It is necessary to boost the voltage to Vd. In the first power supply, the ozone power supply itself can be made compact due to the advantage that there is no high-frequency / high-voltage transformer.

However, since the first power supply resonates between the inverter section, the series resonance circuit, and the circuit straddling the three main components of the ozone generator, the feedback current of the resonated load current returns to the inverter section, so that the inverter The power loss of the part becomes very large.

Further, since the first power supply resonates up to the load applied voltage Vd, the load applied voltage Vd changes due to subtle load condition fluctuations, and even if the operating frequency of the inverter section is controlled, a stable load applied voltage Vd can be obtained. Difficult to put into an ozone generator. In addition, since the operating frequency is always variable, there is a problem that power supply noise becomes large.

Due to the above problems, practically, the discharge power DW output by the high-frequency ozone power supply is suitable only for an ozone gas generation system of less than 1.5 kW. In addition, mounting a plurality of small ozone power sources, which are the first power sources, causes the ozone generator configuration to become complicated and the control to become complicated, and further, the control loss and the number of parts in the ozone power source increase. Problem arises.

Therefore, under the condition that the gas flow rate range of the total gas flow rate Q (raw material gas flow rate) of the raw material gas is approximately 3.0 L / min or more and the cooling temperature for cooling the ozone generator is 5 ° C. or higher, 400 g / m. It is not suitable for the ozone gas generation system of the first embodiment, which aims to extract ^{three or more high-concentration ozone gases.} This is because the ozone gas generation system of the first embodiment requires a total discharge power DW that satisfies the specific power value DW / Q of 600 W · min / L or more.

In the second power supply, by providing a high-frequency / high-voltage transformer (translation for parallel resonance 25) between the inverter section (inverter circuit section 22) and the ozone generator, the number of turns on the primary side of the high-voltage / high-voltage transformer The voltage can be boosted at a constant value determined by the turns ratio between and the number of turns on the secondary side. Further, by providing a parallel resonance circuit with the load on the secondary side and thereafter of the transformer, the output frequency supplied to the load and the load applied voltage Vd are set to substantially constant values, and the total discharge power DW is set to the ozone generator 200. Can be supplied.

As a result, the load current resonating with the inverter section does not return as a feedback current, the power loss of the inverter section can be made relatively small, the load applied voltage Vd is constant regardless of the degree of resonance with the load, and the total load is stable. The discharge power DW can be supplied.

Therefore, in the second power source, the discharge power DW output by the high-frequency ozone power source can be set to 1.8 kW or more, and the second power source has the merit that a stable output can be input to the ozone generator. There is.

The ozone power source 100 according to the first embodiment satisfies the above-mentioned second power source requirement. Then, the ozone power source 100 and the ozone generator 200 are combined to form the ozone gas generation system 1000.

Therefore, in the ozone gas generation system 1000 of the first embodiment, the gas flow rate range of the total gas flow rate Q of the raw material gas is set to about 3.0 L / min or more, and the cooling temperature for cooling the ozone generator 200 is set to 5 ° C. or more. Under the conditions, ^{high-concentration ozone of 400 g / m 3} or more can be extracted. Further, the ozone gas generation system 1000 is an ozone gas generation system in which the flow rate at which high-concentration ozone gas can be taken out can be increased and the cooling capacity of the ozone generator is at the same level as the conventional one.

Further, the operating frequency of the inverter circuit unit 22 is set so as to be the resonance frequency between the internal inductance of the parallel resonance transformer 25 itself and the capacitance of the load (ozone generator 200). Therefore, there is an advantage that the resonance circuit after the secondary side of the parallel resonance transformer 25 can be shared by the parallel resonance transformer 25 without newly providing a resonance reactor on the output side of the parallel resonance transformer 25.

As described above, it is important to set the discharge space in one unit of the discharge cell in the generator to the optimum range as a means of the ozone generator for extracting high-concentration ozone gas with a total gas flow rate Q in which the raw material gas is relatively large. Explained. Hereinafter, the details of the ozone gas generation system 1000 of the first embodiment will be described with reference to FIG.

The total discharge power DW input from the ozone power source 100 is set to a constant 5.0 kW, and the number of stages n of the basic discharge cell set having the basic cells S1 and S2 of the ozone generator 200 is 6 (12 discharge spaces in total). The discharge gap length d was set to a constant length satisfying the condition of several tens to several hundreds μm, and the following three types of ozone generators were prepared.

A type discharge cell-shaped generator ... Total discharge area S is 2500 cm ² ,
B type discharge cell-shaped generator ... Total discharge area S is 1250 cm ² ,
C type discharge cell-shaped generator ... Total discharge area S is 625 cm ² ,
Then, the ozone concentration that can be taken out by each of the A-type discharge cell-shaped generator to the C-type discharge cell-shaped generator was determined.

In the A-type discharge cell-shaped generator, one discharge area so is set to about 209 cm ² , the discharge diameter (discharge surface diameter) is set to about φ170 (mm), and the discharge power density J that can be input is set to ^{2 W / cm 2.}

In the B-type discharge cell-shaped generator, one discharge area so is set to about 104 cm ² , the discharge diameter is set to about φ115 (mm), and the discharge power density J that can be applied is set to ^{4 W / cm 2.}

In the C-type discharge cell-shaped generator, one discharge area so is about 52 cm ² , the discharge diameter is about φ81 (mm), and the discharge power density J that can be input is set to ^{8 W / cm 2.}

The cooling water temperature for cooling the ozone generator was set to a constant 5 ° C.

As shown in FIG. 2, by making the discharge diameter of one discharge surface relatively small, the gas residence time To in one discharge space can be charged to one unit of discharge cells (basic cells S1 or S2). The A-type discharge cell-shaped generator is 1 times, the B-type discharge cell-shaped generator is 1/2, and the C-type discharge cell-shaped generator is 1/4 of the increase rate.

By setting the number of layers n of the basic discharge cell set to 6 (the number of discharge surfaces 12 (the number of discharge spaces 12)), the average gas flow velocity vo / d in one unit of the discharge cell is an A type discharge cell-shaped generator. Is 1/12, the B-type discharge cell-shaped generator is 1/6, and the C-type discharge cell-shaped generator is 1/3. Therefore, the flow velocity in one discharge space has a large average gas flow velocity vo / d only at a ratio of 1/12 corresponding to the number of layers n (number of discharge surfaces 12) for each type with respect to the rate of increase in the discharge power density J. It doesn't become.

As a result, it can be seen that the total ozone decomposition amount Yd when the ozone gas generated in the ozone generator 200 passes through the discharge space is smaller in the discharge cell having a smaller discharge diameter. The details of the shape of one unit of the discharge cell and the effect of extracting high-concentration ozone gas on the stacking of the discharge cells will be described later.

FIG. 3 shows that when the ozone generator 200 of the first embodiment is an A discharge cell-shaped type generator, a B-type discharge cell-shaped generator, and a C-type discharge cell-shaped generator, the raw material gas is on each discharge surface. It is a graph which shows the characteristic of the total ozone decomposition amount Yd with respect to the gas stay time To of the discharge space in the case of flowing.

In FIG. 3, the total ozone decomposition amount Yd characteristic 5000a of the A type discharge cell shape generator, the total ozone decomposition amount Yd characteristic 5000b of the B type discharge cell shape generator, and the total ozone decomposition amount Yd characteristic of the C type discharge cell shape generator. Ozonolysis amount Yd characteristic is 5000c.

Further, the characteristic 5000s1 and the characteristic 5000s2 shown by the broken line indicate the upper and lower limits in consideration of the boundary value of the setting in the discharge power density J.

The characteristic 5000s1 is a boundary characteristic corresponding to a setting of ^{2.5 W / cm 2 in} the discharge power density J between the A-type discharge cell-shaped generator and the B-type discharge cell-shaped generator.

The characteristic 5000s2 is a boundary characteristic corresponding to a setting of ^{6.0 W / cm 2 in} the discharge power density J between the B-type discharge cell-shaped generator and the C-type discharge cell-shaped generator.

The characteristics 5000a, 5000b, and 5000c shown in FIG. 3 are compared. As shown in FIG. 3, if the discharge diameter is reduced, the total ozone decomposition amount Yd increases at a constant rate corresponding to the gas residence time To in the range where the gas residence time To is 50 ms or less. On the other hand, it was experimentally confirmed that the total ozone decomposition amount Yd was smaller as the discharge diameter was smaller in the range where the gas residence time To was 50 ms or more.

That is, if the condition is set so that the discharge diameter of the discharge surface is small, the ozone decomposition amount yd in the discharge space is reduced, and the ozone amount Yt taken out from the ozone generator 200 is increased by that amount. In this respect, the C-type discharge cell-shaped generator is the most excellent.

The region 99a shown by the alternate long and short dash line corresponds to the total amount of ozone decomposition Yd in the range where high-concentration ozone gas can be taken out, which will be described later. As shown in FIG. 3, the total ozone decomposition amount Yd in the region 99a is suppressed to about 400 g / h to 900 g / h in the range of the gas residence time To in the discharge space of 20 ms to 80 ms, and the characteristic 5000a. Since it is sufficiently lower than the total amount of ozone decomposition Yd, it can be expected that a high concentration of ozone gas will be extracted.

FIG. 4 is a graph showing the characteristics of the extracted ozone concentration Ct with respect to the specific power value DW / Q of each of the A-type discharge cell-shaped generator, the B-type discharge cell-shaped generator, and the C-type discharge cell-shaped generator. ..

In FIG. 4, the ozone extraction concentration Ct characteristic 4000a of the A-type discharge cell-shaped generator, the ozone extraction concentration Ct characteristic 4000b of the B-type discharge cell-shaped generator, and the ozone extraction concentration of the C-type discharge cell-shaped generator The characteristic 4000c of Ct is shown.

Further, the characteristics 4000s1 and 4000s2 shown by the broken lines indicate the upper and lower limits in consideration of the boundary value of the discharge cell shape in which the discharge power density J can be set to the maximum possible range, as in FIG.

The characteristic 4000s1 shows the characteristic result of the lower limit boundary of the discharge cell shape of the discharge power density J at which the extraction ozone concentration Ct is 400 g / m ³ , and the discharge power density J can be set up to ^{about 2.5 W / cm 2.} It has a cell shape.

The characteristic 4000s2 shows the characteristic result of the upper limit boundary of the discharge cell shape of the discharge power density J at which the extraction ozone concentration Ct is 400 g / m ³ , and the discharge power density J can be set up to ^{about 6.0 W / cm 2.} It has a cell shape.

The characteristic of the extracted ozone concentration Ct indicates the ozone generation concentration in the discharge space according to the specific power value DW / Q. However, when the discharge power density J that can be input to the ozone generator is different in the discharge cell shape, the extracted ozone concentration The characteristics of Ct are also different.

However, in the A type to C type ozone generators having each characteristic (4000a, 4000b, 4000c), the characteristic (tangential characteristic of the alternate long and short dash line) with respect to the specific power value DW / Q in FIG. 4 corresponding to the ozone generation concentration. Looking at the gradient, the smaller the discharge diameter of the discharge surface and the larger the discharge cell shape that allows the discharge power density J to be increased, the smaller the result. That is, it is shown that the ozone generation capacity generated in the discharge space is smaller in the discharge cell shape in which the discharge power density J can be increased.

The characteristics 4000a, 4000b, and 4000c shown in FIG. 4 show the ozone generation concentration characteristics minus the decomposition amount of ozone gas. ^{The amount of ozone gas decomposed is the amount of ozone decomposition generated by the collision of ozone gas with electrons ne, ions n +} and discharge gas ng during discharge when the ozone gas passes through the discharge space, and the amount of ozone that stays during the discharge. It is the sum of the amount of self-decomposition.

As for the ozone generation concentration characteristic, which is the tangential characteristic of the characteristic with respect to the specific power value DW / Q, the A type discharge cell-shaped generator has the largest, the discharge cell diameter is smaller, and the discharge power density J that can be input is larger, the ozone is ozone. The produced concentration characteristic tends to be low.

That is, the ozone generation capacity is inversely proportional to the discharge power density J. The ozone generation capacity due to the catalytic action of nitrogen gas in the discharge space and the photocatalytic action on the discharge surface tends to be lower as the discharge cell shape has a higher discharge power density J.

However, as shown in FIG. 3, in an ozone generator in which discharge cells having different discharge diameters are stacked in multiple stages, if the discharge diameter is reduced, the gas residence time To in the discharge space can be shortened, and the generated ozone can be shortened. The amount of decomposition of This is because the decomposition of ozone gas occurs during the decomposition in which the ozone gas collides with electrons and discharge gas in the discharge space and the period of stay in the discharge. Therefore, the total amount of decomposition between the self-decomposition of the generated ozone itself and the decomposition due to collision can be simply reduced by shortening the gas residence time To.

Due to the above factors, the characteristics of the ozone concentration Ct taken out from the A-type discharge cell-shaped generator, the B-type discharge cell-shaped generator, and the C-type discharge cell-shaped generator are different. In the region 99a shown in FIG. 4, ^{high-concentration ozone of 400 g / m 3} or more can be extracted.

In other words, in the A-type discharge cell-shaped generator, the amount of ozone generated is high, but the gas residence time To is relatively long, so the amount of ozone decomposition, which is the sum of the decomposition due to collision and the self-decomposition of ozone itself, becomes large. As a result, it is shown that only ozone gas having a concentration of less than ^{400 g / m 3 can be extracted at the maximum.}

In the B-type discharge cell-shaped generator, the amount of ozone generated is lower than that in the A-type discharge cell-shaped generator, but the gas residence time To is shorter, so the sum of the decomposition due to collision and the self-decomposition of ozone itself The amount of ozone decomposed becomes smaller. Therefore, as a result, the B-type generator can extract high-concentration ozone of ^{400 g / m 3} or more in the range of the specific power value DW / Q of 600 W · min / L or more.

The present invention is to find out the discharge cell shape and operating conditions of an ozone generator capable of extracting high-concentration ozone such as a B-type discharge cell-shaped generator, and it is desirable to satisfy the following requirements. The inventor found.

When the total gas flow rate Q of the raw material gas supplied to the ozone generator 200 is set to about 3.0 L / min or more, the total discharge power DW input from the ozone power source 100 needs to be at least 1.8 kW or more. ..

Further, in the C type discharge cell-shaped generator, since the discharge power density J is increased in order to input the predetermined discharge power DW, the ozone generation amount determined by the ozone generation capacity (two-point chain line) in the discharge space is extremely large. To be low. Therefore, by shortening the gas residence time To, the extracted ozone concentration Ct becomes low even if the decomposition amount of the ozone amount, which is the sum of the decomposition due to collision and the autolysis of ozone itself, is reduced.

As a result, it was found that the C-type discharge cell-shaped generator can extract a concentration of less than ^{320 g / m 3} at the maximum under the conditions of the total gas flow rate Q of the raw material gas and the input discharge power DW.

From this, in ^{order to realize an ozone generator capable of extracting ozone having a high concentration of 400 g / m 3} or more, there is an optimum discharge cell shape, and in the ozone generator of the first embodiment, the upper limit of the discharge cell shape is provided. As the range, it is desirable that the discharge power density J is limited to less than about 6 W / cm ² as shown in the boundary characteristic 4000s2, and the lower limit of the discharge power density J is the discharge as shown in the boundary characteristic 4000s1. The result is that it is desirable that the power density J is set to about 2.5 W / cm ^{2 or more.}

FIG. 5 is a graph showing the characteristics of the extracted ozone concentration Ct with respect to the total gas flow rate Q of the raw material gas of each of the A-type discharge cell-shaped generator, the B-type discharge cell-shaped generator, and the C-type discharge cell-shaped generator. is there.

In FIG. 5, characteristic 3000a indicates the characteristics of an A-type discharge cell-shaped generator, characteristic 3000b indicates characteristics of a B-type discharge cell-shaped generator, and characteristic 3000c indicates characteristics of a C-type discharge cell-shaped generator. Shown.

The region 99a, which is a characteristic frame, ^{indicates a gas flow rate range in which high-concentration ozone having a extraction ozone concentration of 400 g / m 3} or more can be obtained, and the total gas flow rate Q of the raw material gas supplied in the B-type discharge cell-shaped generator. It was found that a high concentration ^{of 400 g / m 3} or more can be obtained at less than about 25 L / min.

Further, the characteristic frame 99b indicates a gas flow rate range in which a relatively high concentration of ozone gas can be obtained as compared with the ozone concentration characteristic 3000a obtained by an A type discharge cell-shaped generator equivalent to a conventional ozone generator, and a B type discharge. It was found that in the cell-shaped generator, the total gas flow rate Q of the raw material gas to be supplied was less than 50 L / min, and high-concentration ozone gas could be obtained.

Further, in FIG. 5, when the total gas flow rate Q of the raw material gas to be supplied is less than about 3.0 L / min, a high concentration ozone gas of ^{400 g / m 3 or more can be obtained even in the A type discharge cell-shaped generator.} be able to. However, in this case, the total amount of ozone that can be extracted is less than 100 g / h, and there are few markets that require a small amount of ozone. Further, since the purpose of this ozone generator is to be able to take out a large flow rate of ozone gas and obtain a high concentration ozone gas, those that can obtain a high concentration ozone gas at a low gas flow rate are out of range.

Further, it is conceivable to obtain a high concentration ozone gas of ^{400 g / m 3} or more by setting the cooling temperature of the generator to less than 5 ° C. as a special ozone generator in the A type discharge cell shape generator. However, if the cooling temperature is less than 5 ° C, ancillary equipment with increased cooling capacity is required and there is no practical merit. Therefore, in the first embodiment, the cooling temperature is applied as the ozone gas generation system 1000. The temperature was set to 5 ° C. or higher.

The ozone generator 200 applies an AC voltage for ozone generation between the ground cooling electrode 1 of each discharge cell and the high-voltage electrodes 3a and 3b, and causes a discharge phenomenon in the discharge space in which the raw material gas containing oxygen gas is injected. It is generated to generate ozone gas.

An AC voltage for ozone generation is applied from the parallel resonance transformer 25 of the ozone power supply 100 shown in FIG. 1 to the high voltage terminal HV which is the feeding portion of the high voltage electrodes 3a and 3b via the high voltage bushing. The total discharge power DW is defined by the AC voltage for ozone generation.

Then, a dielectric barrier discharge is generated in the discharge space of each discharge cell (basic cell S1 or basic cell S2) via the dielectric electrodes 2a and 2b. At this time, the power density of the discharge power density J (= DW / S) (W / cm ² ) that can be charged to each discharge cell based on the total discharge power DW is charged to the discharge cell. As shown in FIG. 2, the ozone gas generated in the discharge space of each discharge cell is the ozone gas output of the manifold block 9 from the opening 15 provided in the center of the discharge space through the output path 17 in the ground cooling electrode 1. It is collected in path 92 and taken out of the ozone generator 200.

A cooling space (not shown) for cooling is provided inside the ground cooling electrode 1 and the low pressure cooling plate 5, and the cooling water path provided on the base 10, the cooling water output path 91 of the manifold block 9, and the cooling water output path 91 of the manifold block 9 are provided. Each discharge cell is cooled by flowing cooling water into the ground cooling electrode 1 and the low-pressure cooling plate 5 via the cooling water input path 93. As described above, a cooling mechanism for cooling the discharge cell to a predetermined cooling temperature is configured including the ground cooling electrode 1, the low-pressure cooling plate 5, the base 10, and the manifold block 9.

Hereinafter, the shape of one discharge surface in one unit of discharge cells will be described, and further, the effect of stacking a plurality of discharge cells will be described.

In the ozone gas generation system 1000, a condition in which a basic discharge cell set having basic cells S1 and S2 is laminated in multiple stages (6 stages) (discharge surface: 12 surfaces) and a high concentration of ozone gas can be taken out has been described.

Here, in order to clarify the scope of application of the present invention, the conditions under which high-concentration ozone gas can be taken out in one discharge space in one unit of discharge cell will be described. Hereinafter, a discharge cell capable of extracting ozone gas having a ^{higher concentration (equivalent to 400 g / m 3} or more) in a large flow rate range of approximately 3.0 L / min or more in the gas flow rate range of the total gas flow rate Q (raw material gas flow rate) of the raw material gas. The effect of stacking the above will be described.

From the extracted ozone concentration Ct characteristics with respect to the total gas flow rate Q shown in FIG. 5 in the laminated ozone generator. The raw material gas flow rate qo supplied to one unit of the discharge cell (one discharge surface) satisfies the range of about 0.5 L / min to about 2.5 L / min in order to efficiently take out a predetermined amount of ozone gas at a high concentration. As described above, it is desirable to set the discharge cell shape in which the discharge area so of one discharge surface is reduced.

That is, in order to extract high-concentration ozone gas up to a high gas flow rate range, a means is taken to increase the number of layers n of the basic discharge cell set in order to stack one unit of discharge cells in multiple stages, and one discharge area so is approximately 30 cm. It is important to set it to ² to approximately 160 cm ^2. Further, in order to obtain a high-output extraction ozone amount Yt at the total gas flow rate Q of the raw material gas, one unit of discharge cells in which the discharge diameter of the discharge surface is reduced and the discharge area so is defined is stacked in multiple stages ( laminating increase the number n) taking steps, and substantially 2.5 W / cm ² ~ substantially ozone gas generator system 1000 is set in a range of 6.0 W / cm ² is desirable to put it discharge power density J.

Then, the discharge power dw (= so · J) is obtained from the one discharge area so and the discharge power density J, and the raw material gas flow rate qo supplied to one discharge space having a discharge gap length d of several tens to several hundreds μm is abbreviated. Consider the case where the B type discharge cell shape is adopted in the range of 0.5 L / min to about 2.5 L / min. In this case, ^{high-concentration ozone having an ozone concentration of more than 400 g / m 3} can be taken out, and the ozone flow rate that can be taken out can be increased in proportion to the number n of multiple layers. Further, in the B type discharge cell shape, in order to obtain the maximum amount of extracted ozone Yt in the possible range in the total gas flow rate Q, the discharge is performed so as to satisfy the above-mentioned conditions and to be the maximum in the possible range. The discharge power dw (= so · J) is determined from the power density J, and the raw material gas flow rate qo supplied to one discharge space having a discharge gap length d of several tens to several hundreds μm is set to the maximum possible range. Is desirable.

1 discharge area so as specific method prescribed in 30cm ² ~160cm ² is the diameter of the discharge surface of the circular discharge cells in plan view as an example in the range of Fai70mm～fai140mm, the discharge area so In order to make an ozone generator with an increased total gas flow rate Q of the raw material gas, one unit of discharge cells is stacked in multiple stages, and the total discharge area S (= 2.n) of the generator is specified.・ It is necessary to secure so).

Further, in the generator of a discharge cell shape defining the discharge area so one discharge surface to 30cm ² ~160cm ^2, to a lower value of the discharge power density J (= DW / S) to the total discharge power DW to be introduced as a parameter In order to specify, the total discharge area S of the ozone generator must be increased, and it becomes necessary to increase the number of stacked sheets n (= S / (2.so)) of the reference discharge cell set. In order to avoid increasing the manufacturing cost of the ozone generator when the number of layers n is increased, the discharge power density J that can be applied to one discharge surface is set to a high value within the most effective condition range in the ozone gas generation system 1000. It is desirable to do.

In order to configure the ozone gas generation system 1000 in which the total gas flow rate Q of the raw material gas capable of extracting high-concentration ozone gas is increased to a larger gas flow rate, the discharge area so, the discharge power density J, the input discharge power dw and one discharge With respect to the raw material gas flow rate qo supplied to the space, it is indispensable to realize a one-unit discharge cell that satisfies the above-mentioned conditions and increase the above-mentioned number of laminated sheets n.

Further, in order to configure the ozone gas generation system 1000 that maximizes the high output extracted ozone amount Yt in the region where the total gas flow rate Q of the raw material gas is large, the discharge area so, the discharge power density J, and the input discharge power dw And, the raw material gas flow rate qo supplied to one discharge space is set to the maximum value within the possible range, one discharge surface satisfying the above-mentioned conditions is realized, and the basic discharge cell sets are laminated in multiple stages with the number of layers n. Is required.

That is, in the ozone generator 200, 2n of 1 discharge surfaces satisfying the above-mentioned conditions are provided, and an ozone power source that outputs an ozone generation AC voltage satisfying the total discharge power DW (= 2 · n · dw) to be input. 100 is needed.

As a result, the ozone gas generation system 1000 can supply the total gas flow rate Q (= α, 2, n, qo) of the raw material gas to be supplied to the 2n discharge spaces. The α value is a constant indicating the impairment rate when 2 n discharge surfaces are laminated and ozone gas is merged.

Next, various conditions regarding the operation of the ozone generator for extracting high-concentration ozone gas will be described.

FIG. 6 is applied to an A-type discharge cell-shaped generator, a B-type discharge cell-shaped generator, and a C-type discharge cell-shaped generator when the total discharge power DW with respect to the operating frequency f of the ozone power supply 100 is applied. It is a graph which shows the characteristic of the load peak voltage Vp which is performed.

Hereinafter, the grounds for setting the operating frequency of the ozone power supply 100 to 20 kHz to 50 kHz will be described with reference to FIG.

In FIG. 6, the characteristic 7000a shows the characteristic of the load peak voltage Vp when the discharge power density J (= DW / S) of the A type discharge cell-shaped generator is 2 W / cm ^2.

The characteristic 7000b indicates the characteristic of the load peak voltage Vp when the discharge power density J of the B-type discharge cell-shaped generator is 4 W / cm ^2.

The characteristic 7000c indicates the load peak voltage Vp characteristic when the discharge power density J of the C type generator is 8 W / cm ^2.

It was experimentally found that the B-type discharge cell-shaped generator can extract the highest concentration of ozone gas in the region 99a in the characteristic 7000b of the load peak voltage Vp when the discharge power density J is 4 W / cm ^2. ..

The characteristic 7000s1 and the characteristic 7000s2 shown by the broken line are characteristic diagrams showing the upper and lower limits in consideration of the boundary value of the discharge cell shape of the discharge power density J in the range of the present invention.

The characteristic 7000s1 shows the boundary characteristic of the discharge cell shape having a discharge power density J of at least 2.5 W / cm ^2. The characteristic 7000s2 is a boundary characteristic of the discharge cell shape of ^{6 W / cm 2} at which the setting of the discharge power density J is the maximum limit.

Therefore, from the relationship between the region 99a and the characteristics 7000s1 and 7000s2, a ^{high concentration ozone gas of 400 g / m 3} or more can be obtained at a predetermined gas flow rate Q, and a desired extracted ozone amount Yt is obtained at the supplied gas flow rate Q. In order to obtain the discharge power density J (= DW / S), the lower limit of the discharge power density J is about 2.5 W / cm ² or more, and the upper limit of the discharge power density J is about 6. It was desirable to set the condition range to 0 W / cm ^2.

Hereinafter, a power supply system in which the operating frequency f of the ozone power supply 100 is 20 kHz to 50 kHz will be described. Then, in the ozone power supply 100, the inverter circuit unit 22 which is a high frequency inverter unit is adopted, and the parallel resonance type is realized between the parallel resonance transformer 25 which is a high frequency / high voltage transformer and the ozone generator 200. Explain what you did.

As shown in FIG. 6, when the operating frequency f becomes low, a relatively large total discharge power DW is input, and when the discharge power density J (= DW / S) is increased, the load peak voltage Vp increases. ..

When the load peak voltage Vp becomes high, it is necessary to increase the ozone generator 200 in order to sufficiently secure the withstand voltage of the ozone generator 200. If the load peak voltage Vp is less than 10 kVp for the ozone power supply 100, the inverter circuit unit 22 can be relatively compact and stable.

Further, when the load peak voltage Vp becomes 7 kVp or more, it is necessary to increase the parallel resonance transformer 25 or increase the spatial distance between the high-voltage part and the low-voltage part of the ozone generator in order to secure the withstand voltage. It is generated and the ozone generator itself becomes large.

Further, there arises a problem that the turns ratio of the parallel resonance transformer 25 becomes large. Therefore, it is desirable that the ozone gas generation system 1000 supplies the desired total discharge power DW so that the load peak Vp at the load applied voltage Vd is less than 7 kVp (5.0 kVrms).

As shown in FIG. 6, when the load peak voltage Vp is limited to the ozone power supply 100 having a load peak voltage Vp of less than 7 kVp (5.0 kVrms) ^{, high-concentration ozone gas of 400 g / m 3} or more can be taken out, and the total gas flow rate Q is The operating frequency f is preferably 20 kHz or higher for the ozone gas generation system 1000 that maximizes the amount of extracted ozone Yt.

On the other hand, when the operating frequency f becomes high, the ozone generation capacity generated by the ozone generator 200 tends to decrease. Therefore, as a high-concentration ozone gas generator capable of extracting high-concentration ozone of ^{400 g / m 3 or more, the operating frequency} It is desirable that f is less than 50 kHz.

In addition, the gas flow rate range of the total gas flow rate Q (raw material gas flow rate) is approximately 3.0 L / min or ^{more, and high-concentration ozone gas of 400 g / m 3} or more can be taken out, and the total gas flow rate Q is taken out. In order to make the ozone gas generation system 1000 for maximizing the amount of ozone Yt, an ozone power source 100 that supplies a total discharge power DW of 1.8 kW or more is required. Therefore, as the parallel resonance transformer 25 capable of outputting 1.8 kW or more, it is particularly desirable that the operating frequency f is 20 kHz or more and less than 30 kHz in consideration of the noise countermeasure aspect of the ozone power supply and the stable supply aspect of the output power. ..

As described above, as shown in FIG. 6, the gas flow rate range of the total gas flow rate Q (raw material gas flow rate) of the raw material gas is approximately 3.0 L / min or more, and high-concentration ozone of ^{400 g / m 3 or more can be extracted.} It can be seen that the ozone gas generation system 1000 needs to satisfy the following conditions.

-Set one discharge area so in one unit of discharge cell to about 30 cm ² to about 160 cm ² .
The discharge power dw (= so · J) in the discharge space of the discharge cell of 1 unit from 1 discharge area so and the discharge power density J is defined.

Further, it is desirable to satisfy the following conditions as conditions for configuring the ozone gas generation system 1000 in which the total gas flow rate Q of the raw material gas is set to the maximum possible range and a high output ozone amount Yt can be obtained. ..

And discharging power density J to (= DW / S) as defined in 2.5W ^/ cm ² ~6W ^/ cm 2 range settings.
The raw material gas flow rate qo supplied to one discharge space having a discharge gap length d of several tens to several hundreds of μm is defined in a range of approximately 0.5 L / min to approximately 2.5 L / min.

By setting the raw material gas flow rate qo and one discharge area so so as to satisfy the above-mentioned conditions, the average gas flow velocity vo / d in one discharge space is set to the optimum speed, and the gas residence time To in the discharge space is set. Can be shortened, and high-concentration ozone gas can be taken out.

Furthermore, it is desirable to configure the ozone generator as follows.
-The ozone concentration that can be taken out from one discharge surface is set to a high concentration, and an ozone generator in which discharge cells having basic cells S1 and S2 are stacked in multiple stages is used.

Further, it is desirable that the ozone power source 100 satisfies the following conditions.
-The output frequency of the AC voltage for ozone generation can be set in the range of 20 kHz to less than 50 kHz, and the output control of the desired total discharge power DW can be performed.

By satisfying the above conditions and configuring the ozone gas generation system 1000, it is possible to obtain an effect that a large flow rate and a high concentration of ozone gas can be taken out. Further, the ozone gas generation system 1000 can be configured compactly and inexpensively.

(Various conditions of ozone gas generation system 1000)
The ozone gas generation system 1000 has a large flow rate of approximately 3.0 L / min or more in the gas flow rate range of the total gas flow rate Q (raw material gas flow rate) of the raw material gas, and the ozone concentration that can be taken out is high (400 g / m ³ ). As described above, the discharge cells are stacked in multiple stages.

It is desirable that the ozone gas generation system 1000 is provided with an ozone power source 100 ozone power source having a specific power value DW / Q range of 600 or more in order to take out high-concentration ozone gas of ^{400 g / m 3 or more.}

In particular, the range of the total discharge power DW due to the ozone generation AC voltage supplied by the ozone power source 100 is preferably about 1.8 kW to 15 kW.

In the ozone power supply 100, if the discharge gap length d in the discharge space becomes long, the gas residence time To becomes very long, the amount of ozone decomposition with respect to the amount of ozone generated in the discharge space becomes very large, and the high concentration ozone gas Cannot be taken out.

Further, if the discharge gap length d becomes too short, the gas flow velocity passing through the discharge space increases, and the ozone gas generated by the approaching of the discharge surfaces collides with the wall of the discharge surface, or the gas collides in the discharge space. Since the collision with the generated electrons, ions, and discharge gas increases, the amount of ozone decomposition becomes very large. As described above, if the discharge gap length d becomes too short, it becomes impossible to take out high-concentration ozone gas. Therefore, it is desirable that the discharge gap length d be in the short gap length range under the condition of several tens to several hundreds of μm. In particular, in order to take out a higher concentration ozone gas, it is more effective to set the discharge gap length d in the range of 20 μm to 100 μm.

As for the range of the total gas flow rate Q of the raw material gas, the range in which ^{a high concentration ozone gas of 400 g / m 3} or more can be obtained is about 3 SLM to 25 SLM, and a high concentration ozone gas can be obtained as compared with the conventional apparatus. As the range to be used, a range of about 3 SLM to 50 SLM is desirable.

(Effect of Embodiment 1)
The ozone power source 100 of the first embodiment includes an ozone generator 200 having a pair of flat plate electrodes 1 and high-voltage electrodes 3a (3b), each of which serves as a discharge surface, having basic cells S1 (S2) arranged via a dielectric. The ozone generator 200 is provided with an ozone power source 100 that applies an AC voltage for ozone generation.

A raw material gas containing oxygen was supplied to the ozone generator 200, and the ozone generator 200 generated a dielectric barrier discharge in the discharge space formed by the discharge surface of the basic cells S1 (S2) and supplied the discharge space. Ozone gas is generated from the raw material gas, and the ozone gas is output to the outside.

The ozone generator 200 includes a plurality of basic discharge cell sets (combination of basic cells S1 and S2) stacked in multiple stages. The ozone generator 200, which outputs ozone with a high concentration, satisfies the following conditions (1) and (2).

(1) a plurality of discharge cells, the discharge area so that 30cm ² ~160cm ² (30cm ² or more, 160cm less than ²⁾ formed by a respective discharge surface (discharge surface of a unit discharge cell) is set to a range of To.

(2) The raw material gas flow rate qo of the raw material gas supplied to the discharge space formed by the discharge surfaces of each of the plurality of discharge cells is 0.5 L / min to 2.5 L / min (0.5 L / min or more). It is set in the range of less than 5 L / min).

Further, in order to set the gas flow rate Q to be supplied to the ozone generator 200 and the discharge power DW to the maximum possible range and obtain a higher extraction ozone amount Yt, the ozone generator 200 is subjected to the above condition (1). ), In addition to the condition (2), the following condition (3) must be satisfied.

(3) the discharge power density J to be introduced into the plurality of discharge cells each discharge ^space, set in the range of ^{2.5W / cm 2 ~6W / cm 2} (2.5W / cm 2 or more and less than 6W / cm ²⁾ Will be done.

The ozone gas generation system 1000 of the first embodiment exerts the following effects on the discharge surface of each of the plurality of discharge cells by satisfying the above-mentioned conditions (1) to (3). When satisfying the three conditions, the discharge gap length d of the ozone generator needs to be set to a short gap length of several tens to several hundreds of μmn. This point will be described in detail below.

A dielectric barrier discharge with a short gap having a discharge gap length of several tens to several hundreds of μm can realize high electric field discharge. That is, the short-gap dielectric barrier discharge becomes a discharge having high energy discharge light energy, and works more effectively to photoexcite the gas containing the catalyst gas or the photocatalyst applied to the discharge surface, and as a result. The effect of promoting the dissociation of oxygen gas is further enhanced. Therefore, when realizing an ozone gas generation system and an ozone gas generation method that satisfy the conditions (1) to (3), it is desirable to set the discharge gap length of the ozone generator to several tens to several hundreds of μm.

By satisfying the above-mentioned conditions (1) and (2), the ozone gas generation system 1000 shortens the gas residence time To in the discharge space (formed by a pair of discharge surfaces) of each discharge cell to reduce the total gas residence time To. The amount of ozone decomposition Yd can be suppressed.

As a result, the ozone gas generation system 1000 satisfies the above-mentioned conditions (1) and (2), and maximizes the raw material gas flow rate qo and the discharge power dw supplied to the discharge surface of each discharge cell within a possible range. By setting to and maximizing the amount of ozone taken out yy, it is possible to create a condition for taking out high-concentration ozone gas.

By further satisfying the condition (3), the ozone gas generation system 1000 can secure a predetermined amount or more of ozone that can be taken out from each discharge cell and can take out efficiently, and further increase the amount of ozone taken out Yt. Can be done.

As a result, the ozone gas generation system 1000 has the effect of suppressing the system configuration to the minimum necessary, efficiently increasing the amount of high-concentration ozone or the amount of extracted ozone Yt, and outputting it to the outside.

As described above, the ozone gas generation system 1000 satisfies the conditions (1) to (3) by further satisfying the above-mentioned condition (3) in addition to the condition (1) and the condition (2). The raw material gas flow rate qo supplied to the discharge space of each discharge cell and the discharge power dw can be set to the maximum possible to maximize the amount of ozone taken out yy.

As a result, the ozone gas generation system 1000 of the first embodiment has an effect that the system configuration can be suppressed to the minimum necessary and a high concentration ozone gas or a high generation amount of ozone gas can be output to the outside.

Further, the ozone generator 200 in the ozone gas generation system 1000 of the first embodiment further satisfies the following condition (4).

(4) The cooling temperature of the ozone generator 200 by the cooling mechanism is 5 ° C. or higher.

The ozone generator 200 of the ozone gas generation system 1000 of the first embodiment further satisfies the above-mentioned condition (4), thereby eliminating the need to extremely lower the cooling temperature of the ozone generator 200 by the above-mentioned cooling mechanism. , The cooling mechanism can be simplified. The upper limit of the above constraint condition is assumed to be about 30 ° C. with respect to room temperature (20 ° C.). Further, when the cooling effect is more important, it is desirable to set the cooling temperature to 0 ° C. or higher, which is the temperature at which water freezes.

Further, the ozone generator 200 in the ozone gas generation system 1000 of the first embodiment further satisfies the following conditions (5) and (6).

(5) The total gas flow rate Q supplied to all of the plurality of discharge cells in the ozone generator 200 is 3.0 L / min or more.

(6) The specific power value DW / Q, which is the ratio of the total discharge power DW applied to the entire plurality of discharge cells in the ozone generator 200 to the total gas flow rate Q, is 600 (W · min / L) or more. ..

The purpose of condition (5) is to extract high-concentration ozone gas, and as an incidental effect of achieving the purpose of condition (5), condition (6) is an effect of maximizing the amount of ozone gas to be output. Play.

The ozone power source 100 and the ozone generator 200 of the ozone gas generation system 1000 further achieve the following effects by satisfying the above-mentioned conditions (5) and (6).

The ozone gas generation system 1000 has a sufficiently large total gas flow rate Q with respect to the raw material gas supplied to a plurality of discharge cells capable of extracting high-concentration ozone ^{of, for example, 400 g / m 3} or more by satisfying the above-mentioned condition (5). Finally, a high-concentration ozone gas can be obtained, and the amount of extracted ozone Yt can be increased.

By satisfying the above-mentioned condition (6), the ozone gas generation system 1000 can satisfy the conditions (1) to (6) in addition to the effect of the condition (5), for example, the following effects. Play. The total gas flow rate Q supplied to the ozone generator 200 and the total discharge power DW can be maximized as much as possible to maximize the amount of extracted ozone Yt.

As a result, the ozone gas generation system 1000 of the first embodiment has an effect that the system configuration can be suppressed to the minimum necessary and a relatively large capacity and high concentration ozone gas can be output to the outside.

Further, the discharge surfaces of the basic cells S1 and S2 constituting the discharge cell in the ozone generator 200 each have a circular shape in a plan view, and the ozone generator 200 further satisfies the following condition (7).

(7) The outer diameter of the discharge surface of each of the plurality of discharge cells is set in the range of 70 mm to 140 mm (70 mm or more and less than 140 mm).

Further, a modified example of the ozone gas generation system 1000 in which the number of discharge cells is increased by arranging n basic discharge cell sets (combination of basic cells S1 and S2) having the above-mentioned discharge surfaces on the same plane in the ozone generator is configured. For example, the same effect as that of the basic configuration shown in FIG. 1 is obtained.

By satisfying the above-mentioned condition (7), the ozone gas generation system 1000 relatively easily realizes the discharge area so satisfying the condition (1), and the average gas flow velocity vo flowing into the average cross-section sav in which the gas flows. It is relatively easy to set / d to an appropriate value.

In addition, the ozone power supply 100 of the ozone gas generation system 1000 outputs the ozone generation AC voltage to the ozone generator 200 with the output frequency f (operating frequency f) in the range of 20 kHz to 50 kHz (20 kHz or more and less than 50 kHz). doing. The output frequency f (operating frequency f) of the more practical ozone power supply 100 is preferably in the range of 20 kHz to 30 kHz (20 kHz or more and less than 30 kHz).

Therefore, the ozone gas generation system 1000 realizes the discharge power DW desired by the ozone generator 200 by setting the peak voltage value of the ozone generation AC voltage applied to the plurality of discharge cells in the ozone generator 200 to 7 kVp or less. be able to.

Further, the parallel resonance transformer 25 of the ozone power supply 100 has an internal excitation inductance value Lt, and the plurality of discharge cells in the ozone generator 200 have an overall capacitance value C0.

The ozone power supply 100 sets the output frequency f in the vicinity of the parallel resonance frequency fc that satisfies the above equation (5).

The ozone gas generation system 1000 sets the output frequency f in the vicinity of the parallel resonance frequency fc to perform parallel resonance when the total discharge power DW is applied to the ozone generator 200, thereby causing the inverter unit (inverter circuit unit 22). The output power factor of the inverter can be increased.

That is, the output power factor in the inverter circuit unit 22 can be increased by performing parallel resonance between the parallel resonance transformer 25 and the ozone generator 200 when the total discharge power DW is applied.

As a result, the ozone power source 100 can supply an ozone generating AC voltage satisfying the desired total discharge power DW to the ozone generator on the load side.

As the desired total discharge power DW, a total discharge power DW of 1.8 kW or more can be considered. Then, it is possible to set the discharge power density can be put into each discharge cell in the ozonizer 200 J a (= DW / S) within a range of ^{2.5W / cm 2 ~6W / cm 2} .

As a result, the ozone gas generation system 1000 maximizes the total gas flow rate Q and the total discharge power DW to be supplied in order to extract high-concentration ozone gas by realizing a highly efficient ozone power source 100. Even if it is set, it has the effect of realizing an ozone gas generation system with a compact configuration as a whole.

<Development to method invention>
In the first embodiment, it has been described as the ozone gas generation system 1000 which is the invention of the apparatus. However, as a modification of the present invention, it is also possible to develop an ozone gas generation method using the above-mentioned ozone power source 100 and ozone generator 200.

That is, an ozone generating AC voltage is applied to the ozone generator 200 having a discharge cell arranged on a pair of flat plate electrodes 1, 3 (3a, 3b) via a dielectric (2a, 2b) and the ozone generator 200. Using the ozone power source 100, it is possible to develop an ozone gas generation method that generates high-concentration ozone gas.

The ozone gas generation method, which is a modification of the first embodiment, executes the following steps (1) and (2) in accordance with the above-mentioned conditions (1) and (2) of the ozone gas generation system 1000.

(1) A step of setting the discharge area so on the discharge surface of each of the plurality of discharge cells to ^{a range of about 30 cm 2} or more and ^{less than 160 cm 2.}
(2) The raw material gas flow rate qo of the raw material gas supplied to the discharge space formed by the pair of discharge surfaces of each of the plurality of discharge cells is set in the range of 0.5 L / min or more and less than 2.5 L / min. Steps to do.

Further, in order to maximize the gas flow rate Q supplied to the ozone generator 200 and the total discharge power DW as much as possible and to obtain the maximum amount of extracted ozone Yt, the ozone gas generation method is described in the above step ( In addition to 1) and step (2), it is desirable to perform the following step (3).

(3) a discharge power density J to be introduced to the plurality of discharge cells each discharge space is set within the range of 2.5W ^/ cm ² ~6W ^/ cm 2 steps.

In the above ozone gas generation method, by executing step (1) and step (2), the gas residence time To in the discharge space of each discharge cell can be shortened and the amount of ozone gas decomposition can be suppressed.

Therefore, in the above ozone gas generation method, by executing steps (1) and (2), the raw material gas flow rate qo and the discharge power dw supplied to the discharge space of each discharge cell can be set to the maximum possible range. , It has the effect of extracting high concentration of ozone gas.

In the ozone gas generation method, if the gas flow rate q and the discharge power dw to be supplied to the discharge surface of each discharge cell are set to the maximum possible by further executing step (3), the amount of ozone taken out yt can be increased. It has an effect that can be maximized.

As a result, the ozone gas generation method, which is a modification of the present invention, has the effect of being able to output a high concentration of ozone or a high amount of ozone gas to the outside.

Further, the ozone gas generation method can perform steps for satisfying the conditions (4) to (7) corresponding to the above-mentioned conditions (4) to (7) of the ozone gas generation system 1000. , The same effect as that of the ozone gas generation system 1000 is obtained.

<Embodiment 2>
(Problem of Embodiment 1)
In the above-described first embodiment, as shown in the demonstration test and the principle and outline of the discharge cell shape for extracting high-concentration ozone, the ozone generator 200 is a set of n basic discharge cells stacked in multiple stages. (S1, S2) are included. The ozone generator 200, which extracts high-concentration ozone gas up to a high gas flow rate range, satisfies the condition (1). Condition (1) is reprinted below.

(1) a plurality of discharge cells, the discharge area so that 30cm ² ~160cm ² (30cm ² or more, 160cm less than ²⁾ formed by a respective discharge surface (discharge surface in a unit discharge cell) is set to a range of To.

As described above, in the ozone gas generation system 1000 of the first embodiment, the restriction of the condition (1) is imposed on the discharge area so of one unit of the discharge cell. Here, in the ozone gas generation system 1000, a configuration is configured such that high-concentration ozone gas is taken out in a high gas flow rate region, and a high output extracted ozone amount Yt can be obtained in a region where the total gas flow rate Q of the raw material gas is large. Suppose.

Assuming the above configuration, the smaller the discharge area so of one unit of the discharge cell, the more the basic discharge cell sets are laminated in order to secure the discharge area S (= 2n · so) required for the ozone generator 200. It was necessary to increase the number of sheets n.

When the ozone generator 200 is configured by setting a large number of layers n, the number of parts increases as the number of basic discharge cell sets required increases, and the number of assembly work steps in the ozone generator 200 increases. And test inspection work will increase. Therefore, the manufacturing cost of the ozone generator 200 is high. Further, there will be problems such as the need to manage the discharge gap accuracy of each discharge cell of the ozone generator 200 itself and the control of the stacking tightening accuracy. For this reason, the difficulty of manufacturing the ozone generator 200 increases, and as a result, the ozone gas generation system 1000 becomes large, which causes problems such as cost increase.

(Improvement of ozone generator 200)
The ozone gas generation system 2000 of the second embodiment is an improvement of the ozone generator 200 to the ozone generator 300 in view of the above-mentioned problems of the ozone generator 200 of the first embodiment. The ozone gas generation system 2000 and the ozone generator 300 are not shown in the drawings.

The ozone generator 300 employs a structure in which the number of internal parts can be reduced, high-concentration ozone gas can be taken out, and the flow rate of the taken out ozone gas can be increased.

Therefore, the discharge area st of one unit of the discharge cell corresponding to the basic cell S1 or the basic cell S2 included in the basic discharge cell set is 3 to 6 times, specifically, 3 to 6 times the area so defined in the condition (1). The discharge area st is ^{set within several hundred cm 2} , and Nφ (Nφ ≧ 2) pieces of ozone gas outlets for taking out ozone gas from the discharge surface of one unit of the discharge cell are dispersedly arranged on the discharge cell surface.

By providing Nφ ozone gas outlets, there are Nφ virtual discharge cells having Nφ division areas dso (= st / Nφ) obtained by dividing the total discharge area st of one unit discharge cell by the number of divisions Nφ. It can be substantially identified with the case.

As a result, the ozone generator 300 used in the ozone gas generation system 2000 of the second embodiment can reduce the number of laminated sheets n of the basic discharge cell set as compared with the ozone generator 200 of the first embodiment, and the conditions ( Almost the same as the effect of the first embodiment satisfying 1), the effect of extracting high-concentration ozone gas can be exhibited.

Further, in the ozone generator 300, in one set of basic discharge cells, one ozone gas take-out passage for collecting ozone gas taken out from Nφ ozone gas outlets and outputting it to the outside is provided. It is provided in the electrodes constituting this discharge cell and is connected to Nφ ozone gas outlets.

Therefore, the ozone gas generated in the entire discharge cell can be collectively taken out in one set of basic discharge cell sets without using parts such as piping joints for providing a passage for passing ozone gas. Further, the ozone generator 300 adopts a configuration in which the discharge area st of one unit of the discharge cell having the above-mentioned characteristics is ^{set to a size of about several hundred cm 2} and the basic discharge cell sets are stacked in multiple stages.

As a result, the ozone generator 300 has a configuration in which ozone gas generated in each of a plurality of discharge cells (n sets of basic discharge cell sets) stacked in multiple stages can be collectively taken out to the outside, and ozone generation according to the first embodiment is performed. Compared with the vessel 200, it is possible to realize a simple configuration in which the number of stacked sheets n of the basic discharge cell set is reduced. Therefore, the ozone generator 300 is an ozone generator in which the assembly man-hours and the test man-hours are significantly reduced as compared with the ozone generator 200.

The ozone generator 300 satisfies the following condition (a) with respect to a virtual discharge space defined by Nφ divided areas dso obtained by dividing the discharge area st of one unit of the discharge cell surface by the number of divisions Nφ. There is.

(a) For a plurality of discharge cells, the division area dso obtained by dividing the discharge area st of each discharge surface (the discharge surface of one unit of the discharge cell) by the number of divisions Nφ is set in the range of ^{30 cm 2} or more and ^{less than 160 cm 2.} To.

As a result, in the ozone generator 300, the discharge space in one unit of the discharge cell is divided into Nφ virtual discharge spaces, so that the generated ozone gas passes through the discharge space and out of the Nφ ozone gas outlets. , The gas stay time To until reaching the latest ozone gas outlet can be shortened.

Therefore, in the ozone generator 300, the total amount of ozone decomposition due to the decomposition of ozone gas in the discharge space of one unit of discharge cell colliding with electrons and discharge gas and the self-decomposition of the ozone gas staying in the discharge space itself. Yd can be suppressed, high-concentration ozone gas can be taken out at a relatively high gas flow rate, and a compact and inexpensive ozone gas generator can be obtained.

The ozone generator 300 can output high-concentration ozone gas having an extracted ozone concentration Ct of 400 g / m ³ or more, and takes out high ozone gas amount Yt (= Ct · Q) of 72 g / h or more. It is necessary to set the total raw material gas flow rate Q of the raw material gas containing oxygen supplied to the ozone generator 300 to 3 SLM or more.

Therefore, it is necessary to stack the basic discharge cell sets in multiple stages in the ozone generator 300. At this time, since the area of one unit of the discharge cell of the ozone generator 300 is sufficiently larger than that of the ozone generator 200, the number of stacked sheets n of the basic discharge cell set can be suppressed to be small.

Further, in the ozone generator 200 of the first embodiment, it was shown that the high-concentration ozone gas can be taken out by setting the discharge gap length d in the discharge space in the range of 20 μm to 100 μm.

The ozone generator 300 of the second embodiment satisfies the following condition (b).
(b) The discharge gap length d in the discharge space is set to less than 80 μm.

When the discharge gap length d in the discharge space is set to a short gap length of less than 80 μm, the condition (b) is satisfied in the gas pressure loss ΔP from the raw material gas supply port to the external ozone gas outlet 32 via the ozone generator 300. The proportion of gas pressure loss ΔPa in the discharge space defined by the discharge gap length d increases.

Therefore, the ozone generator 300 satisfies the condition (b) and limits the discharge gap length to less than 80 μm in a unit discharge cell having Nφ ozone outlets dispersed and arranged with a number of divisions Nφ. Ozone gas can flow at a substantially uniform gas flow rate Q / n (L / min), and high-concentration ozone gas can be output.

By accurately setting the discharge gap length d in the discharge space on one discharge cell surface, the degree of variation in gas loss ΔPp in the process from Nφ ozone gas outlets with different arrangements to one ozone gas outlet path can be determined. It can be ignored due to the gas pressure loss ΔPa in the discharge space defined by the discharge gap length d.

As a result, when the flow simulation of the gas flow rate in one unit of the discharge cell is executed, one unit has a size of three to six times the divided area dso defined in the condition (a) for the discharge area of one unit of the discharge cell. Since the discharge area st of the entire discharge cell can be set, the discharge area st of one unit of the discharge cell can be set to be relatively large within ^{several hundred cm 2.}

Then, on one discharge cell surface, ozone gas outlets distributed and arranged with a number of divisions Nφ are provided, and the raw material gas flows from the outer circumference of one unit of the discharge cell and is taken out from Nφ ozone gas outlets. Variations in the flow rate can be suppressed, and ozone gas can be extracted with a more uniform gas flow.

Further, the ozone generator 300 of the second embodiment further satisfies the following condition (d).
(d) The discharge power density J in the discharge space of each of the plurality of discharge cells is set in the range of ^{2.5 W / cm 2} or more and less than 6 W / cm ^2.

In order to satisfy the above condition (d), the ozone generator 300 sets the discharge power DW to the maximum possible range in the total gas flow rate Q of the raw material gas to be supplied, and applies it to the ozone generator 300, which is a load. The load voltage can be suppressed within an allowable value, and the ozone power source 100 using a compact ozone inverter unit (inverter circuit unit 22) can be realized.

Further, since the ozone generator 300 satisfies the above condition (d), the amount of extracted ozone Yt can be increased in an environment of a total gas flow rate Q and a total discharge power DW, which are gas flow rates exceeding about 5 SLM.

As a result, the ozone generator 300 becomes an ozone generator having both a high concentration of ozone gas and a high output ozone amount Yt, and can be realized compactly and inexpensively.

The specific discharge cell shape used in the ozone generator 300 in the ozone gas generation system 2000 of the second embodiment will be described below.

In order to take out ozone gas having a high concentration and a large flow rate, one discharge area so is defined in the range of 30 to ^{100 m 2 in one unit of the discharge cell as in the ozone generator 200 of the first embodiment.} An ozone generator in which the discharge area so is made as small as possible and the number of stacked sheets n of the basic discharge cell set is large is indispensable.

In this case, when the basic discharge cell sets are stacked in multiple stages, the number of discharge cell parts in the ozone generator 200 increases, and as the number of layers n increases, the number of layers stacked in the ozone generator 200 increases. It becomes difficult to manage the tightening stress of the basic discharge cell set of n.

Therefore, in the ozone generator 200, the number of layers n is preferably about 10, and in the stress lamination design of the ozone generator, the number of layers n needs to be 20 or less. Therefore, in the structural design of the ozone generator 200, it is desirable to reduce the number of layers n.

From the above viewpoint, the ozone generator 300 of the second embodiment can take out high-concentration ozone gas even if the discharge area st in one unit of the discharge cell is set relatively wide, and the extracted ozone amount Yt of a predetermined amount or more can be obtained. The obtained discharge cell shape is adopted.

7 to 14 schematically show the planar structure of the ground cooling electrode 51 (51A to 51D) and the dielectric electrode 52 (52A to 52D) in one unit of the discharge cell adopted in the ozone generator 300 of the second embodiment. It is explanatory drawing shown in.

FIG. 7 is an explanatory view schematically showing the planar structure of the ground cooling electrode 51A, which is the first aspect of the second embodiment. FIG. 8 is an explanatory view schematically showing a planar structure of the dielectric electrode 52A according to the first aspect of the second embodiment.

FIG. 9 is an explanatory view schematically showing the planar structure of the ground cooling electrode 51B, which is the second aspect of the second embodiment. FIG. 10 is an explanatory view schematically showing a planar structure of the dielectric electrode 52B according to the second aspect of the second embodiment.

FIG. 11 is an explanatory view schematically showing the planar structure of the ground cooling electrode 51C, which is the third aspect of the second embodiment. FIG. 12 is an explanatory view schematically showing a planar structure of the dielectric electrode 52C according to the third aspect of the second embodiment.

FIG. 13 is an explanatory view schematically showing the planar structure of the ground cooling electrode 51D, which is the fourth aspect of the second embodiment. FIG. 14 is an explanatory view schematically showing the planar structure of the dielectric electrode 52D according to the fourth aspect of the second embodiment.

Hereinafter, when the ground cooling electrodes 51A to 51D are collectively referred to, they are simply referred to as "ground cooling electrodes 51", and when the dielectric electrodes 52A to 52D are collectively referred to, they are simply referred to as "dielectric electrodes 52".

In the first to fourth aspects, a combination structure of a ground cooling electrode 51 and a dielectric electrode 52 is adopted as a pair of flat plate electrodes. That is, the flat plate-shaped first electrode serves as the ground cooling electrode 51, and the second electrode serves as the dielectric electrode 52. A discharge space is provided between the ground cooling electrode 51 and the dielectric electrode 52. The combination of the ground cooling electrode 51 and the dielectric electrode 52 constitutes a unit of discharge cell.

Actually, in the ozone generator 300 of the second embodiment, two dielectric electrodes 52 are arranged so as to face both surfaces of the ground cooling electrode 51. That is, the ground cooling electrode 51 corresponds to the ground cooling electrode 1 of the first embodiment shown in FIG. 1, and the dielectric electrode 52 corresponds to each of the dielectric electrodes 2a and 2b of the first embodiment.

Therefore, a first basic cell is provided by the ground cooling electrode 51 and the dielectric electrode 52 provided above the ground cooling electrode 51, and the first basic cell is the basic cell S1 of the first embodiment shown in FIG. Corresponds to.

Further, a second basic cell is provided by the ground cooling electrode 51 and the dielectric electrode 52 provided below the ground cooling electrode 51, and the second basic cell is the basic cell S2 of the first embodiment shown in FIG. Corresponds to.

In the second embodiment, the one unit discharge cell, which is the basic unit of the plurality of discharge cells, means one of the first and second basic cells, and the combination of the first and second basic cells is used. It is a basic discharge cell set. Therefore, when the number of stacked basic discharge cell sets is n, the plurality of discharge cells are 2n 1-unit discharge cells and n sets of basic discharge cell sets.

By stacking the basic discharge cell sets in the ozone generator 300 of the second embodiment with the number of stacked n, from a plurality of discharge cells (2 n 1-unit discharge cells, n sets of basic discharge cell sets). A group of discharge cells is configured.

Therefore, the ozone gas generation system 2000 of the second embodiment has a structure in which the ozone generator 200 of the ozone gas generation system 1000 of FIG. 1 is replaced with the ozone generator 300.

Further, in the ozone generator 300, the basic cell S1 is replaced with the first basic cell, the basic cell S2 is replaced with the second basic cell, and the manifold block 9 is a manifold block 59 (59A to 59D) described later. The main difference from the ozone generator 200 is that it is replaced with.

The ozone generator 300 of the second embodiment has the same configuration as the ozone generator 200 of the first embodiment, except for the main differences described above.

In the first aspect shown in FIGS. 7 and 8, the total discharge area st of one unit of the discharge cell is set to about 5 times the area so that satisfies the condition (1) described in the first embodiment. ..

In the second aspect shown in FIGS. 9 and 10, the total discharge area st of one unit of the discharge cell is set to about three times the area so that satisfies the condition (1) described in the first embodiment. ..

In the third aspect shown in FIGS. 11 and 12, the total discharge area st of one unit of the discharge cell is set to about four times the area so that satisfies the condition (1) described in the first embodiment. ..

In the fourth aspect shown in FIGS. 13 and 14, the total discharge area st of one unit of the discharge cell is set to about 6 times the area so that satisfies the condition (1) described in the first embodiment. ..

As shown in FIGS. 7, 9, 11 and 13, manifold blocks 59 (59A to 59D) are provided adjacent to the ground cooling electrode 51 and the ground cooling electrode 51.

Hereinafter, when the manifold blocks 59A to 59D are collectively referred to, they are simply referred to as "manifold blocks 59".

As shown in FIGS. 7, 9, 11 and 13, the ground cooling electrode 51 has a rectangular shape including a trapezium in a plan view, and Nφ (Nφ ≧ 2) ozone gas outlets are formed on the upper surface and the lower surface thereof. 75 (75a to 75f) are dispersedly provided.

Both the upper surface and the lower surface of the ground cooling electrode 51 are discharge surfaces that form a discharge space, and the Nφ ozone gas outlets 75 provided on the upper surface and the Nφ ozone gas outlets 75 provided on the lower surface match in a plan view. ing. Hereinafter, when the ozone gas outlets 75a to 75f are collectively referred to, they are simply referred to as "ozone gas outlet 75".

Inside the ground cooling electrode 51, an ozone gas extraction path that connects to each of the Nφ ozone gas outlets 75 provided on the upper surface and the lower surface, aggregates the ozone gas extracted from the Nφ ozone gas outlets 75, and outputs the ozone gas to the outside. 77 (77A to 77D) and a cooling water flow path 70 (70A to 70D) are provided.

Hereinafter, when the ozone gas take-out paths 77A to 77D are collectively referred to, they are simply referred to as "ozone gas take-out paths 77", and when the cooling water channels 70A to 70D are collectively referred to, they are referred to as a unit "cooling water flow path 70".

The ozone gas take-out path 77 is connected to the ozone gas output path 92 provided in the manifold block 59, and the ozone gas G _OUT generated by each of the plurality of discharge cells can be output to the manifold block 59.

Cooling water passage 70 is connected to a cooling water input path 93 of the manifold block 59 and the cooling water output path 91, the cooling water input path 93 and enter the cooling water W _IN, after flowing the cooling water to the cooling water flow path 70 _{, The cooling water W OUT} is output from the cooling water output path 91. The ground cooling electrode 51 can be cooled by flowing cooling water through the cooling water flow path 70.

In the ground cooling electrode 51, a photocatalyst film (not shown) is applied to the discharge surface facing the dielectric electrode 52, and a predetermined number of discharge spacers 73 (discharge spacers 73A to 73) for forming a discharge gap length d on the discharge surface. 73D) is provided. Hereinafter, when the discharge spacers 73A to 73D are collectively referred to, they are simply referred to as "discharge spacer 73".

Further, the ground cooling electrode 51 is formed by laminating two thin plates and then closely pressurizing the two plates, and forming a half-etched groove on at least one of the two laminated plates to form a groove of the ground cooling electrode 51. The cooling water flow path 70 and the ozone gas extraction path 77 described above can be provided inside.

In the first to fourth aspects of the second embodiment, one unit of the discharge cell having a discharge area st of about 3 to 6 times as much as the discharge area so of the one unit of the discharge cell of the first embodiment is used. It is adopted. Specifically, the discharge area st of the first aspect is set to about 5 times the discharge area so, and the discharge area st of the second aspect is set to about 3 times the discharge area so. The discharge area st is set to about 4 times the discharge area so, and the discharge area st in the fourth aspect is set to about 6 times the discharge area so.

In the second embodiment, the discharge power density J when the discharge power DW to be input to the plurality of discharge cells is set to the maximum within the possible range is 4.0 W / m ^2, and the number of stacked basic discharge cell sets n is set. "10" is adopted, and the ozone generator 300 is realized with the minimum standard configuration.

When the discharge area st of the second aspect shown in FIGS. 9 and 10 is set to "1" with respect to the reference, the first aspect is about 1.7 times the reference, and the third aspect is about 1. Three times, the fourth aspect is about twice the standard.

(First aspect)
Hereinafter, the structure of one unit of the discharge cell in the first aspect will be described with reference to FIGS. 7 and 8. As shown in FIGS. 7 and 8, the one unit discharge cell in the first aspect constitutes a pair of flat plate electrodes, that is, a ground cooling electrode 51A (flat plate-shaped first electrode) and a dielectric electrode 52A (flat plate). It has a combined structure with the second electrode). The dielectric electrode 52A is, for example, a ceramic plate, and is an electrode having a dielectric.

The space where the ground cooling electrode 51A and the dielectric electrode 52A face each other becomes the discharge space, and the area where the ground cooling electrode 51A and the dielectric electrode 52A overlap in a plan view is the discharge area st. In the first aspect, "5" is adopted as the number of divisions Nφ.

The ground cooling electrode 51A has a trapezoidal shape with rounded corners in a plan view, and five ozone gas outlets 75a to 75e are provided on each of the upper surface and the lower surface thereof.

Like the ground cooling electrode 51A, the dielectric electrode 52A has a trapezoidal shape with rounded corners in a plan view, and the dielectric electrode 52A has a trapezoidal conductivity slightly smaller than the dielectric electrode 52A in a plan view. A sex membrane 62A is provided.

By arranging the dielectric electrode 52A on the ground cooling electrode 51A so that the ground cooling electrode 51A and the dielectric electrode 52A match in a plan view with the conductive film 62A located above, the first The first basic cell of the embodiment is configured.

Further, by arranging the dielectric electrode 52A under the ground cooling electrode 51A so that the ground cooling electrode 51A and the dielectric electrode 52A match in a plan view with the conductive film 62A located below, the dielectric electrode 52A is arranged. The second basic cell of the first aspect is configured.

The first and second basic cells are each one unit of discharge cell in the first aspect. Further, the combination of the first and second basic cells is a basic discharge cell set. Therefore, the upper surface of the ground cooling electrode 51A is the discharge surface of the first basic cell, and the lower surface of the ground cooling electrode 51A is the discharge surface of the second basic cell.

_{As shown in FIG. 7, oxygen gas G IN,} which is a raw material gas, is supplied to the basic discharge cell set from the outer peripheral portion of the ground cooling electrode 51A (dielectric electrode 52A).

The discharge area st of one unit of the discharge cell of ^{the first aspect is set to about 350 cm 2} which is equivalent to five times the discharge area so of the first embodiment, and the basic discharge cell sets of the first aspect are laminated in multiple stages. The ozone generator 300 has a plurality of discharge cells (discharge cell groups).

An AC voltage for generating ozone is applied between the conductive film 62A and the ground cooling electrode 51A from the ozone power source 100 to each of the first and second basic cells of the first aspect, and the first and second basic cells are subjected to. In each of the basic cells of the above, a dielectric barrier discharge is generated in the discharge space between the dielectric electrode 52A and the ground cooling electrode 51A. As a result, ozone gas is generated in the discharge spaces of the first and second basic cells, and the generated ozone gas is divided and flows into each of the five ozone gas outlets 75a to 75e.

Inside the ground cooling electrode 51A, an ozone gas take-out path 77A connected to each of the five ozone gas outlets 75a to 75e, and the ozone gas taken out from the five ozone gas outlets 75a to 75e is aggregated and output to the outside, and cooling. A water flow path 70A is provided.

The ozone gas take-out path 77A is connected to the ozone gas output path 92 provided in the manifold block 59.

Therefore, the ozone gas generated in the discharge spaces of the first and second basic cells described above flows into the ozone gas outlets 75a to 75e provided on the upper surface and the lower surface of the ground cooling electrode 51A, respectively. After that, the ozone gas take-out path 77A merges into one and _{is integrated into the ozone gas output G out} , and the ozone gas G _OUT is output to the ozone gas output path 92 of the manifold block 59A. As a result, ozone gas can be taken out from the ozone gas outlet 32 (see FIG. 1) via the ozone gas output path 92 of the manifold block 59A.

Therefore, the above-mentioned ozone gas extraction process is performed for each basic discharge cell set, and the ozone gas generated in each of the basic discharge cell sets stacked in multiple stages with the number of stacked n is collected in the ozone gas output path 92 of the manifold block 59A.

Cooling water passage 70A is connected to a cooling water input path 93 of the manifold block 59 and the cooling water output path 91, and enter the cooling water W _IN from the cooling water input path 93 and flushed with cooling water in the cooling water passage 70A After that, the cooling water W _OUT is output from the cooling water output path 91. The ground cooling electrode 51A can be cooled by flowing cooling water through the cooling water flow path 70A.

A photocatalyst film (not shown) is applied to the discharge surface of the ground cooling electrode 51A facing the dielectric electrode 52A, and four discharge spacers 73A for forming a discharge gap length d are provided on the discharge surface in a dispersed manner. Be done. The discharge gap length d is defined by the formation height of the four discharge spacers 73A.

The four discharge spacers 73A are integrally provided (connected) with the ground cooling electrode 51A on the upper surface and the lower surface of the ground cooling electrode 51A, respectively, and the four discharge spacers 73A provided on the upper surface discharge the first basic cell. The gap length d is defined, and the four discharge spacers 73A provided on the lower surface define the discharge gap length d of the second basic cell.

The one-unit discharge cell in the first aspect satisfies the following conditions (a) and (b).
(a) The divided area dso obtained by dividing the discharge area st by the number of divisions N is set in the range of ^{30 cm 2} or more and ^{less than 160 cm 2.}
(b) The discharge gap length in the discharge space is set to less than 80 μm.

Further, the discharge cell of the first aspect satisfies the following condition (c).
(c) Five virtual circular discharge regions 79a to 79e centered on the five ozone gas outlets 75a to 75e in a plan view are contained in the discharge space (planar shape of the ground cooling electrode 51A) without overlapping each other. The five ozone gas outlets 75a to 75e are arranged so as to be formed, and the radius r (discharge diameter D1 / 2) of each of the five virtual circular discharge regions 79a to 79e is {r = (0.8. dso / π) ^0.5 } is satisfied.

The five virtual circular discharge regions 79a to 79e do not overlap with the four discharge spacers 73A, the ozone gas extraction path 77A, and the cooling water flow path 70A in a plan view.

The virtual circular discharge regions 79a to 79e are set to 80% of the divided area dso in consideration of the four discharge spacers 73A, the ozone gas extraction path 77A, the cooling water flow path 70A, and the like, respectively.

(Second aspect)
Hereinafter, the structure of the 1-unit discharge cell in the second aspect will be described with reference to FIGS. 9 and 10. As shown in FIGS. 9 and 10, the 1-unit discharge cell in the second aspect constitutes a pair of flat plate electrodes, that is, a ground cooling electrode 51B (flat plate-shaped first electrode) and a dielectric electrode 52B (flat plate). It has a combined structure with the second electrode). The dielectric electrode 52B is, for example, a ceramic plate, and is an electrode having a dielectric.

The space where the ground cooling electrode 51B and the dielectric electrode 52B face each other becomes the discharge space, and the area where the ground cooling electrode 51B and the dielectric electrode 52B overlap in a plan view is the discharge area st. In the second aspect, "3" is adopted as the number of divisions Nφ.

The ground cooling electrode 51B has a trapezoidal shape with rounded corners in a plan view, and three ozone gas outlets 75a to 75c are provided on each of the upper surface and the lower surface thereof.

Like the ground cooling electrode 51B, the dielectric electrode 52B has a trapezoidal shape with rounded corners in a plan view, and the dielectric electrode 52B has a trapezoidal conductivity slightly smaller than the dielectric electrode 52B in a plan view. The sex membrane 62B is provided.

By arranging the dielectric electrode 52B on the ground cooling electrode 51B so that the ground cooling electrode 51B and the dielectric electrode 52B match in a plan view with the conductive film 62B located above, the second The first basic cell of the embodiment is configured.

Further, by arranging the dielectric electrode 52B under the ground cooling electrode 51B so that the ground cooling electrode 51B and the dielectric electrode 52B match in a plan view with the conductive film 62B located below, the dielectric electrode 52B is arranged. The second basic cell of the second aspect is configured.

The first and second basic cells are each one unit of discharge cell in the second aspect. Further, the combination of the first and second basic cells is a basic discharge cell set. Therefore, the upper surface of the ground cooling electrode 51B is the discharge surface of the first basic cell, and the lower surface of the ground cooling electrode 51B is the discharge surface of the second basic cell.

_{As shown in FIG. 9, oxygen gas G IN,} which is a raw material gas, is supplied to the basic discharge cell set from the outer peripheral portion of the ground cooling electrode 51B (dielectric electrode 52B).

The discharge area st of the discharge cell of the second aspect ^{is set to about 230 cm 2} which is equivalent to three times the discharge area so of the first embodiment, and the basic discharge cell set of the second aspect is laminated with the number of stacked n. The ozone generator 300 has a plurality of discharge cells (discharge cell group).

An AC voltage for generating ozone is applied between the conductive film 62B and the ground cooling electrode 51B from the ozone power source 100 to each of the first and second basic cells of the second aspect, and the first and second basic cells are subjected to. In each of the basic cells of the above, a dielectric barrier discharge is generated in the discharge space between the dielectric electrode 52B and the ground cooling electrode 51B. As a result, ozone gas is generated in the discharge spaces of the first and second basic cells, and the generated ozone gas is divided and flows into each of the three ozone gas outlets 75a to 75c.

Inside the ground cooling electrode 51B, an ozone gas take-out path 77B connected to each of the three ozone gas outlets 75a to 75c, and the ozone gas taken out from the three ozone gas outlets 75a to 75c is aggregated and output to the outside, and cooling. A water flow path 70B is provided.

The ozone gas take-out path 77B is connected to the ozone gas output path 92 provided in the manifold block 59.

Therefore, the ozone gas generated in the discharge spaces of the first and second basic cells described above flows into the ozone gas outlets 75a to 75c provided on the upper surface and the lower surface of the ground cooling electrode 51B, respectively. After that, the ozone gas take-out path 77B merges into one and _{is integrated into the ozone gas output G out} , and the ozone gas G _OUT is output to the ozone gas output path 92 of the manifold block 59B. As a result, ozone gas can be taken out through the ozone gas output path 92 of the manifold block 59B.

Therefore, the above-mentioned ozone gas extraction process is performed for each basic discharge cell set, and the ozone gas generated in each of the basic discharge cell sets stacked in multiple stages with the number of stacked n is collected in the ozone gas output path 92 of the manifold block 59B.

Cooling water passage 70B is connected to a cooling water input path 93 of the manifold block 59 and the cooling water output path 91, the cooling water input path 93 and enter the cooling water W _IN, after flowing the cooling water to the cooling water passage 70B _{, The cooling water W OUT} is output from the cooling water output path 91. The ground cooling electrode 51B can be cooled by flowing cooling water through the cooling water flow path 70B.

A photocatalyst film (not shown) is applied to the discharge surface of the ground cooling electrode 51B facing the dielectric electrode 52B, and four discharge spacers 73B for forming a discharge gap length d are provided on the discharge surface in a dispersed manner. .. The discharge gap length d is defined by the formation height of the four discharge spacers 73B.

The four discharge spacers 73B are integrally provided (connected) with the ground cooling electrode 51B on the upper surface and the lower surface of the ground cooling electrode 51B, respectively, and the four discharge spacers 73B provided on the upper surface discharge the first basic cell. The gap length d is defined, and the four discharge spacers 73B provided on the lower surface define the discharge gap length d of the second basic cell.

The one-unit discharge cell in the second aspect satisfies the above-mentioned conditions (a) and (b) as in the first aspect.

Further, the discharge cell of the second aspect satisfies the following condition (c).
(c) Three virtual circular discharge regions 79a to 79c centered on the three ozone gas outlets 75a to 75c in a plan view are contained in the discharge space (planar shape of the ground cooling electrode 51B) without overlapping each other. The three ozone gas outlets 75a to 75c are arranged so as to be formed, and the radius r (discharge diameter D1 / 2) of each of the three virtual circular discharge regions 79a to 79c is {r = (0.8. dso / π) ^0.5 } is satisfied.

The three virtual circular discharge regions 79a to 79c do not overlap with the four discharge spacers 73B, the ozone gas extraction path 77B, and the cooling water flow path 70B in a plan view.

The virtual circular discharge regions 79a to 79c are set to 80% of the divided area dso in consideration of the four discharge spacers 73B, the ozone gas extraction path 77B, the cooling water flow path 70B, and the like.

(Third aspect)
Hereinafter, the structure of the 1-unit discharge cell in the third aspect will be described with reference to FIGS. 11 and 12. As shown in FIGS. 11 and 12, the 1-unit discharge cell in the third aspect constitutes a pair of flat plate electrodes, that is, a ground cooling electrode 51C (flat plate-shaped first electrode) and a dielectric electrode 52C (flat plate). It has a combined structure with the second electrode). The dielectric electrode 52C is, for example, a ceramic plate, and is an electrode having a dielectric.

The space where the ground cooling electrode 51C and the dielectric electrode 52C face each other becomes the discharge space, and the area where the ground cooling electrode 51C and the dielectric electrode 52C overlap in a plan view is the discharge area st. In the third aspect, "4" is adopted as the number of divisions Nφ.

The ground cooling electrode 51C has a square shape with rounded corners in a plan view, and four ozone gas outlets 75a to 75d are provided on the upper surface and the lower surface thereof, respectively.

Like the ground cooling electrode 51C, the dielectric electrode 52C has a square shape with rounded corners in a plan view, and the dielectric electrode 52C has a square-shaped conductivity slightly smaller than the dielectric electrode 52C in a plan view. A sex membrane 62C is provided.

By arranging the dielectric electrode 52C on the ground cooling electrode 51C so that the ground cooling electrode 51C and the dielectric electrode 52C match in a plan view with the conductive film 62C located above, the third The first basic cell of the embodiment is configured.

Further, by arranging the dielectric electrode 52C under the ground cooling electrode 51C so that the ground cooling electrode 51C and the dielectric electrode 52C match in a plan view with the conductive film 62C located below, the dielectric electrode 52C is arranged. The second basic cell of the third aspect is configured.

The first and second basic cells are each one unit of discharge cell in the third aspect. Further, the combination of the first and second basic cells is a basic discharge cell set. Therefore, the upper surface of the ground cooling electrode 51C is the discharge surface of the first basic cell, and the lower surface of the ground cooling electrode 51C is the discharge surface of the second basic cell.

_{As shown in FIG. 11, oxygen gas G IN,} which is a raw material gas, is supplied to the basic discharge cell set from the outer peripheral portion of the ground cooling electrode 51C (dielectric electrode 52C).

The discharge area st of the discharge cell of the third aspect ^{is set to about 320 cm 2} which is four times the discharge area so of the first embodiment, and the basic discharge cell sets of the third aspect are laminated in multiple stages with the number of layers n. The ozone generator 300 has a plurality of discharge cells (discharge cell groups).

An AC voltage for generating ozone is applied between the conductive film 62C and the ground cooling electrode 51C from the ozone power source 100 to each of the first and second basic cells of the third aspect, and the first and second basic cells are subjected to. In each of the basic cells of the above, a dielectric barrier discharge is generated in the discharge space between the dielectric electrode 52C and the ground cooling electrode 51C. As a result, ozone gas is generated in the discharge spaces of the first and second basic cells, and the generated ozone gas is divided and flows into each of the four ozone gas outlets 75a to 75d.

Inside the ground cooling electrode 51C, an ozone gas take-out path 77C connected to each of the four ozone gas outlets 75a to 75d, and the ozone gas taken out from the four ozone gas outlets 75a to 75d is aggregated and output to the outside, and cooling. A water flow path 70C is provided.

The ozone gas take-out path 77C is connected to the ozone gas output path 92 provided in the manifold block 59.

Therefore, the ozone gas generated in the discharge spaces of the first and second basic cells described above flows into the ozone gas outlets 75a to 75d provided on the upper surface and the lower surface of the ground cooling electrode 51C, respectively. After that, the ozone gas take-out path 77C merges into one and _{is integrated into the ozone gas output G out} , and the ozone gas G _OUT is output to the ozone gas output path 92 of the manifold block 59C. As a result, ozone gas can be taken out through the ozone gas output path 92 of the manifold block 59C.

Therefore, the above-mentioned ozone gas extraction process is performed for each basic discharge cell set, and the ozone gas generated in each of the basic discharge cell sets stacked in multiple stages with the number of stacked n is collected in the ozone gas output path 92 of the manifold block 59C.

Cooling water passage 70C is connected to a cooling water input path 93 of the manifold block 59 and the cooling water output path 91, the cooling water input path 93 and enter the cooling water W _IN, after flowing the cooling water to the cooling water passage 70C _{, The cooling water W OUT} is output from the cooling water output path 91. The ground cooling electrode 51C can be cooled by flowing cooling water through the cooling water flow path 70C.

A photocatalyst film (not shown) is applied to the discharge surface of the ground cooling electrode 51C facing the dielectric electrode 52C, and seven discharge spacers 73C for forming a discharge gap length d are provided on the discharge surface in a dispersed manner. .. The discharge gap length d is defined by the formation height of the seven discharge spacers 73C.

The seven discharge spacers 73C are integrally provided (connected) with the ground cooling electrode 51C on the upper surface and the lower surface of the ground cooling electrode 51C, respectively, and the seven discharge spacers 73C provided on the upper surface discharge the first basic cell. The gap length d is defined, and the seven discharge spacers 73C provided on the lower surface define the discharge gap length d of the second basic cell.

The one-unit discharge cell in the third aspect satisfies the above-mentioned conditions (a) and (b) as in the first and second aspects.

Further, the discharge cell of the third aspect satisfies the following condition (c).
(c) In a plan view, the four virtual circular discharge regions 79a to 79d centered on the four ozone gas outlets 75a to 75d are within the discharge space (planar shape of the ground cooling electrode 51C) without overlapping each other. The four ozone gas outlets 75a to 75d are arranged so as to be formed, and the radius r (discharge diameter D1 / 2) of each of the four virtual circular discharge regions 79a to 79d is {r = (0.8. dso / π) ^0.5 } is satisfied.

The four virtual circular discharge regions 79a to 79d do not overlap with the seven discharge spacers 73C, the ozone gas extraction path 77C, and the cooling water flow path 70C in a plan view.

The virtual circular discharge regions 79a to 79d are set to 80% of the divided area dso in consideration of the seven discharge spacers 73C, the ozone gas extraction path 77C, the cooling water flow path 70C, and the like, respectively.

(Fourth aspect)
Hereinafter, the structure of one unit of the discharge cell in the fourth aspect will be described with reference to FIGS. 13 and 14. As shown in FIGS. 13 and 14, one unit of the discharge cell in the fourth aspect includes a ground cooling electrode 51D (a flat plate-shaped first electrode) and a dielectric electrode 52D (a flat plate-shaped first electrode) constituting a pair of flat plate electrodes. It has a combination structure of a flat plate-shaped second electrode). The dielectric electrode 52D is, for example, a ceramic plate, and is an electrode having a dielectric.

The space where the ground cooling electrode 51D and the dielectric electrode 52D face each other becomes the discharge space, and the area where the ground cooling electrode 51D and the dielectric electrode 52D overlap in a plan view is the discharge area st. In the fourth aspect, "6" is adopted as the number of divisions Nφ.

The ground cooling electrode 51D has a trapezoidal shape with rounded corners in a plan view, and is provided with six ozone gas outlets 75a to 75f.

Like the ground cooling electrode 51D, the dielectric electrode 52D has a trapezoidal shape with rounded corners in a plan view, and the dielectric electrode 52D has a trapezoidal conductivity slightly smaller than the dielectric electrode 52D in a plan view. A sex membrane 62D is provided.

By arranging the dielectric electrode 52D on the ground cooling electrode 51D so that the ground cooling electrode 51D and the dielectric electrode 52D match in a plan view with the conductive film 62D located above, the fourth The first basic cell of the embodiment is configured.

Further, by arranging the dielectric electrode 52D under the ground cooling electrode 51D so that the ground cooling electrode 51D and the dielectric electrode 52D match in a plan view with the conductive film 62D located below, the dielectric electrode 52D is arranged. The second basic cell of the fourth aspect is configured.

The first and second basic cells are each one unit of discharge cell in the fourth aspect. Further, the combination of the first and second basic cells is a basic discharge cell set. Therefore, the upper surface of the ground cooling electrode 51D is the discharge surface of the first basic cell, and the lower surface of the ground cooling electrode 51D is the discharge surface of the second basic cell.

_{As shown in FIG. 13, oxygen gas G IN,} which is a raw material gas, is supplied to the basic discharge cell set from the outer peripheral portion of the ground cooling electrode 51D (dielectric electrode 52D).

The discharge area st of the discharge cell of the fourth aspect ^{is set to about 480 cm 2} , which is equivalent to six times the discharge area so of the first embodiment, and a plurality of basic discharge cell sets of the fourth aspect are stacked in multiple stages. The ozone generator 300 will have a discharge cell.

An AC voltage for generating ozone is applied between the conductive film 62D and the ground cooling electrode 51D from the ozone power source 100 to each of the first and second basic cells of the fourth aspect, and the first and second basic cells are subjected to. In each of the basic cells of the above, a dielectric barrier discharge is generated in the discharge space between the dielectric electrode 52D and the ground cooling electrode 51D. As a result, ozone gas is generated in the discharge spaces of the first and second basic cells, and the generated ozone gas is divided and flows into each of the six ozone gas outlets 75a to 75f.

Inside the ground cooling electrode 51D, an ozone gas take-out path 77D that is connected to each of the six ozone gas outlets 75a to 75f, aggregates the ozone gas taken out from the six ozone gas outlets 75a to 75f, and outputs the ozone gas to the outside, and cooling. A water flow path 70D is provided.

The ozone gas take-out path 77D is connected to the ozone gas output path 92 provided in the manifold block 59.

Therefore, the ozone gas generated in the discharge spaces of the first and second basic cells described above flows into the ozone gas outlets 75a to 75f provided on the upper surface and the lower surface of the ground cooling electrode 51D, respectively. After that, the ozone gas take-out path 77D merges into one and _{is integrated into the ozone gas output G out} , and the ozone gas G _OUT is output to the ozone gas output path 92 of the manifold block 59D. As a result, ozone gas can be taken out through the ozone gas output path 92 of the manifold block 59D.

Therefore, the above-mentioned ozone gas extraction process is performed for each basic discharge cell set, and the ozone gas generated in each of the basic discharge cell sets stacked in multiple stages with the number of stacked n is collected in the ozone gas output path 92 of the manifold block 59D.

Cooling water passage 70D is connected to a cooling water input path 93 of the manifold block 59 and the cooling water output path 91, and enter the cooling water W _IN from the cooling water input path 93, after flowing the cooling water to the cooling water passage 70D _{, The cooling water W OUT} is output from the cooling water output path 91. The ground cooling electrode 51D can be cooled by flowing cooling water through the cooling water flow path 70D.

A photocatalyst film (not shown) is applied to the discharge surface of the ground cooling electrode 51D facing the dielectric electrode 52D, and six discharge spacers 73D for forming a discharge gap length d are provided on the discharge surface in a dispersed manner. .. The discharge gap length d is defined by the formation height of the six discharge spacers 73D.

The six discharge spacers 73D are integrally provided (connected) with the ground cooling electrode 51D on the upper surface and the lower surface of the ground cooling electrode 51D, respectively, and the six discharge spacers 73D provided on the upper surface are used to discharge the first basic cell. The gap length d is defined, and the six discharge spacers 73D provided on the lower surface define the discharge gap length d of the second basic cell.

The one-unit discharge cell in the fourth aspect satisfies the above-mentioned conditions (a) and (b) as in the first to third aspects.

Further, the discharge cell of the fourth aspect satisfies the following condition (c).
(c) In a plan view, the six virtual circular discharge regions 79a to 79f centered on the six ozone gas outlets 75a to 75f are within the discharge space (planar shape of the ground cooling electrode 51D) without overlapping each other. The six ozone gas outlets 75a to 75f are arranged so as to be formed, and the radius r (discharge diameter D1 / 2) of each of the six virtual circular discharge regions 79a to 79f is {r = (0.8. dso / π) ^0.5 } is satisfied.

The six virtual circular discharge regions 79a to 79f do not overlap with the six discharge spacers 73D, the ozone gas extraction path 77D, and the cooling water flow path 70D in a plan view.

Each of the virtual circular discharge regions 79a to 79f is set to an area of 80% of the divided area dso in consideration of the formation regions of the six discharge spacers 73D, the ozone gas extraction path 77D, the cooling water flow path 70D, and the like.

The supply of the ozone generation AC voltage from the ozone power source 100 to one unit of the discharge cell according to the first to fourth aspects described above will be described.

When the conductive films 62A to 62D in the first to fourth aspects are generically referred to, they are simply referred to as "conductive film 62". When the cooling water flow paths 70A to 70D are generically referred to, they are simply referred to as "cooling water flow path 70". When the manifold blocks 59A to 59D are generically referred to, they are simply referred to as "manifold blocks 59".

The high-voltage terminal HV of the ozone power source 100 is electrically connected to the conductive film 62 in the ozone generator 300. The low voltage terminal LV is electrically connected to the ground cooling electrode 51 in the ozone generator 300.

Therefore, the ozone generator 300, like the ozone generator 200 of the first embodiment, has a ground cooling electrode 51 and a conductive film 62 of a discharge cell (first or second basic cell) of one unit from the ozone power source 100. An AC voltage for ozone generation is applied between the and.

That is, the ozone power supply 100 sets the output frequency f to a range of 20 kHz or more and less than 50 kHz, and boosts the high frequency AC voltage to a high voltage together with the inverter circuit unit 22 (inverter unit) that outputs a high frequency AC voltage. It includes a parallel resonance transformer 25 (step-up transformer) that obtains an AC voltage for generating ozone.

When the AC voltage for ozone generation is applied from the parallel resonance transformer 25 of the ozone power supply 100 shown in FIG. 1 to the high voltage terminal HV which is the feeding part of the conductive film 62 via the high voltage bushing, the discharge power is generated. It is thrown in. This discharge power is defined by the discharge power DW set to the maximum possible range by the applied AC voltage for ozone generation.

Then, a dielectric barrier discharge is generated in the discharge space of each discharge cell (first basic cell or second basic cell) via the dielectric electrode 52. At this time, power is input to the discharge cell at the discharge power density J (= DW / S) (W / m ² ) of the discharge power that can be input to each discharge cell based on the discharge power DW. Ozone gas is generated in the discharge space of each discharge cell.

As described above, the cooling water flow path 70 is provided inside the ground cooling electrode 51, and the inside of the low-pressure cooling plate 5 is provided with a cooling space (not shown) for cooling, which is provided on the base 10. Each basic discharge by flowing cooling water into the cooling water flow path 70 and the low-pressure cooling plate 5 of the ground cooling electrode 51 via the cooling water path, the cooling water output path 91 of the manifold block 59, and the cooling water input path 93. The cell set is being cooled.

As described above, a cooling mechanism for cooling the basic discharge cell set to a predetermined cooling temperature is configured including the cooling water flow path 70 of the ground cooling electrode 51, the low pressure cooling plate 5, the base 10, and the manifold block 59.

The ozone gas generation system 2000 of the second embodiment satisfies the following condition (e) as in the first embodiment.
(e) The cooling temperature of the ozone generator 300 by the cooling mechanism is 5 ° C. or higher.

Further, the ozone generator 300 in the ozone gas generation system 2000 of the second embodiment further satisfies the following conditions (f) and (g) as in the first embodiment.

(f) The total gas flow rate Q supplied to the entire plurality of discharge cells (n sets of basic discharge cell sets) stacked in the ozone generator 300 is 3.0 L / min or more.
(g) The specific power value DW / Q, which is the ratio of the total discharge power DW and the total gas flow rate Q applied to the entire plurality of discharge cells, is 600 (W · min / L) or more.

The total discharge power DW is defined by the ozone generating AC voltage supplied from the ozone power source 100.

The purpose of condition (f) is to extract high-concentration ozone gas, and as an incidental effect of achieving the purpose of condition (f), condition (g) is an effect of maximizing the amount of ozone gas to be output. Play.

(Effect of Embodiment 2)
As described above, the ozone generator 300 of the second embodiment has the following features.

One unit of the discharge cell, which is one of the first and second basic cells, includes the ground cooling electrode 51, which is the first and second electrodes constituting the pair of flat plate electrodes, and the sickness dielectric electrode 52, and the second. A dielectric is formed on the dielectric electrode 52, which is an electrode of the above, and a discharge space is provided between the ground cooling electrode 51 and the dielectric electrode 52 poles.

One unit of discharge cells is provided on the upper surface and the lower surface of the ground cooling electrode 51, and Nφ (≧ 2) ozone gas outlets 75 for taking out the ozone gas generated in the discharge space, and the inside of the ground cooling electrode 51. It is provided in the above and has an ozone gas take-out route 77 that is connected to each of the Nφ ozone gas outlets 75 and aggregates the ozone gas taken out from the Nφ ozone gas outlets 75 and outputs the ozone gas to the outside.

Then, the ozone generator 300 satisfies the following conditions (a) and (b).
(a) For one unit of discharge cell, which is a constituent unit of a plurality of discharge cells, the division area dso obtained by dividing the discharge area st of the discharge surface by the number of divisions Nφ is set in the range of ^{30 cm 2} or more and ^{less than 160 cm 2.} ..
(b) The discharge gap length d in the discharge space is set to less than 80 μm.

Ozone generation system 2000 of the second embodiment, by satisfying the conditions described above (a) and the condition (b), Nφ number of discharge area of the discharge surface of the virtual discharge cell 30 cm ² or more, a range of less than 160cm ² The state set to can be realized.

This point will be described in detail below. By satisfying the above condition (a), the ozone generator 300 can set a virtual state in which Nφ virtual circular discharge regions 79 are distributed and arranged around Nφ ozone gas outlets 75. Therefore, each of the Nφ virtual discharge cells each having the virtual circular discharge region 79 can exhibit the same effect as the one unit discharge cell in the first embodiment that satisfies the condition (1).

Further, one unit of the discharge cell provided in the ozone generator 300 satisfies the above condition (b) in which the discharge gap length d is less than 80 μm.

When the discharge gap length d in the discharge space is set to a short gap length of less than 80 μm, the discharge gap length d is defined in the gas pressure loss ΔP from the raw material gas supply port to the ozone gas outlet 32 via the ozone generator 300. The proportion of gas pressure loss ΔPa in the discharge space increases.

Therefore, in the ozone generator 300, by satisfying the condition (b) and limiting the discharge gap length to less than 80 μm, each of the Nφ ozone is dispersedly arranged so that the virtual circular discharge region 79 can be formed. In one set of basic discharge cell sets having outlets 75, ozone gas can flow at an almost uniform gas flow rate Q / n (L / min) around each of Nφ ozone gas outlets 75, and high-concentration ozone gas. Can be output.

That is, in the ozone generator 300, by satisfying the above condition (b), the degree of variation in the gas loss ΔPp in the process from Nφ ozone gas outlets 75 having different arrangements to one ozone gas extraction path 77 is discharged. The gas pressure loss ΔPa in the discharge space defined by the gap length d makes it negligible.

Further, in one set of basic discharge cell sets, ozone gas outlets 75 dispersedly arranged with the number of divisions Nφ are provided, and by flowing the raw material gas from the outer circumference of one set of basic discharge cell sets, Nφ ozone gas outlets 75 are provided. The variation in the flow rate of the ozone gas to be taken out can be suppressed, and the ozone gas can be taken out with a more uniform gas flow.

As described above, by satisfying the above-mentioned conditions (a) and (b), the ozone generator 300 of the second embodiment has a high concentration of ozone gas as in the case of the ozone generator 200 of the first embodiment. Can exert the effect of taking out.

Therefore, the ozone gas generation system 2000 of the second embodiment satisfies the above-mentioned conditions (a) and (b), and has a raw material gas flow rate qo and a discharge power dw to be supplied to the discharge surface of one unit of the discharge cell. Is set to the maximum within the possible range, and the extraction ozone amount yt is maximized to create conditions for extracting high-concentration ozone gas.

Further, the discharge area st of the 1-unit discharge cell in the first to fourth aspects of the second embodiment is three times the discharge area so of the one-unit discharge cell of the first embodiment that satisfies the condition (1). It is up to 6 times larger.

Therefore, when the discharge cell group is provided in the ozone generator 300 by stacking the basic discharge cell sets in multiple stages, the ozone generator 300 of the second embodiment is basic as compared with the ozone generator 200 of the first embodiment. Since the number of stacked discharge cell sets n can be reduced, the number of parts such as the ground cooling electrode 51 and the dielectric electrode 52 can be minimized. As described above, in the first embodiment, the basic discharge cell set means a combination of the basic cells S1 and S2.

That is, since the ozone gas generation system 2000 of the second embodiment only needs to satisfy the condition (a) instead of the condition (1) required in the first embodiment, the discharge area st of one unit of the discharge cell is set. The divided area dso can be multiplied by Nφ.

As a result, the ozone gas generation system 2000 of the second embodiment is composed of a plurality of discharge cells (n sets of basic discharge cell sets) provided in the ozone generator 300 by reducing the number n of stacked basic discharge cell sets. The number of parts required for the discharge cell group can be reduced.

Further, since the ozone gas take-out path 77 is provided inside the ground cooling electrode 51, the member for the ozone gas take-out path provided outside can be suppressed to the ozone gas output path 92 provided in the manifold block 59.

Therefore, the ozone generator 300 can significantly reduce the required number of members for the ozone gas take-out route provided externally, and can reduce the manufacturing cost.

As described above, in the ozone gas generation system 2000 of the second embodiment, in addition to the above conditions (a) and (b), the discharge surface of one unit of the discharge cell is further satisfied by satisfying the above condition (c). It is possible to enhance the identity with the case where the discharge area is ^{set in the range of 30 cm 2} or more and ^{less than 160 cm 2 (in the case of the first embodiment).}

If Nφ ozone gas outlets 75 are arranged so as to satisfy the above condition (c), Nφ virtual discharge spaces (virtual circular discharge regions 79) in which the discharge cell diameter is reduced can be created in one unit of discharge cells. Since it can be formed, ozone gas can be taken out in the same state as the actual discharge space in which the discharge cell diameter is actually reduced.

Therefore, the gas residence time To, which is the time for the ozone gas generated by the basic discharge cell set in the ozone generator 300 to pass through any of Nφ virtual circular discharge regions 79, is shortened. Therefore, in the ozone generator 300, due to the decomposition of ozone gas colliding with electrons and discharge gas in Nφ virtual circular discharge regions 79 and the autolysis of ozone itself staying in the virtual circular discharge region 79. Since the total amount of decomposition can be suppressed, high-concentration ozone gas can be taken out.

As described above, the ozone gas generation system 2000 of the second embodiment can further enhance the conditions under which high-concentration ozone gas can be taken out by satisfying the above-mentioned conditions (a) to (c).

Since the ozone gas generation system 2000 of the second embodiment further satisfies the above-mentioned condition (d) regarding the discharge power density J, it is possible to secure a predetermined amount or more of ozone that can be taken out from one unit of the discharge cell, and It can be taken out efficiently, and the amount of ozone taken out Yt can be further increased.

As a result, the ozone gas generation system 2000 has the effect of suppressing the system configuration to the minimum necessary, efficiently increasing the amount of high-concentration ozone or the amount of extracted ozone Yt, and outputting it to the outside.

As described above, the ozone gas generation system 2000 satisfies the conditions (a) to (d) by further satisfying the above-mentioned condition (d) in addition to the conditions (a) to (c). The raw material gas flow rate qo supplied to the discharge space of each discharge cell and the discharge power dw can be set to the maximum possible to maximize the amount of ozone taken out yy.

As a result, the ozone gas generation system 2000 of the second embodiment has an effect that the system configuration can be suppressed to the minimum necessary and a high concentration ozone gas or a high generation amount of ozone gas can be output to the outside.

The ozone generator 300 of the ozone gas generation system 2000 of the second embodiment needs to extremely lower the cooling temperature of the ozone generator 300 by the above-mentioned cooling mechanism by further satisfying the above-mentioned condition (e) regarding the cooling mechanism. It is possible to eliminate the property and simplify the cooling mechanism. The upper limit of the above constraint condition is assumed to be about 30 ° C. with respect to room temperature (20 ° C.). Further, when the cooling effect is more important, it is desirable to set the cooling temperature to 0 ° C. or higher, which is the temperature at which water freezes.

The ozone power source 100 and the ozone generator 300 of the ozone gas generation system 2000 further satisfy the above-mentioned condition (f) (condition regarding total gas flow rate Q) and condition (g) (condition regarding specific power value DW / Q). The following effects are achieved.

The ozone gas generation system 2000 has a sufficiently large total gas flow rate Q with respect to the raw material gas supplied to a plurality of discharge cells capable of extracting high-concentration ozone ^{of, for example, 400 g / m 3} or more by satisfying the above-mentioned condition (f). Finally, a high-concentration ozone gas can be obtained, and the amount of extracted ozone Yt can be increased.

By satisfying the above-mentioned condition (g), the ozone gas generation system 2000 supplies the ozone gas generator 300 in an environment satisfying the conditions (a) to (g) in addition to the effect of the condition (f). The total gas flow rate Q and the total discharge power DW can be maximized within the possible range to maximize the amount of extracted ozone Yt.

As a result, the ozone gas generation system 2000 of the second embodiment has an effect that the system configuration can be suppressed to the minimum necessary and a relatively large capacity and high concentration ozone gas can be output to the outside.

In the ozone gas generation system 2000 of the second embodiment, the discharge surface shapes of the ground cooling electrode 51 and the dielectric electrode 52, which are the first and second electrodes constituting one unit of the discharge cell, are not circular. It is composed of a rectangular shape including a trapezium.

Therefore, the ozone gas generation system 2000 facilitates the change of the installation shape of the ozone generator 300, and makes the ozone gas generation system 2000 in combination with the ozone generator 300 and peripheral devices such as the ozone power supply 100 more compact. Can be done.

Further, since the planar shape of the dielectric electrode 52 is made rectangular, there is an advantage that the dielectric electrode 52 can be easily processed with a dielectric, and the conductive film 62 can be attached to the dielectric electrode 52 relatively easily. This makes it easier to mass-produce the dielectric electrode 52, and the effect of reducing the production cost of the discharge cell can be exhibited.

In addition, by integrally connecting the ground cooling electrode 51 and a predetermined number of discharge spacers 73 (73A to 73D), the number of parts in one unit of the discharge cell can be reduced.

The predetermined number of discharge spacers 73 may be integrally connected to the dielectric electrode 52 instead of the ground cooling electrode 51, and the ground cooling electrode 51, the dielectric electrode 52, and the conductive film 62 are integrally connected. You may.

In addition, the ozone power source 100 of the ozone gas generation system 2000 sets the output frequency f (operating frequency f) in the range of 20 kHz to 50 kHz (20 kHz or more and less than 50 kHz) as in the first embodiment, and sets the ozone generation AC voltage. Is output to the ozone generator 300. The output frequency f (operating frequency f) of the more practical ozone power supply 100 is preferably in the range of 20 kHz to 30 kHz (20 kHz or more and less than 30 kHz).

Therefore, the ozone gas generation system 2000 of the second embodiment, like the ozone gas generation system 1000 of the first embodiment, generates ozone applied to a plurality of discharge cells (n sets of basic discharge cell sets) in the ozone generator 300. The peak voltage value of the AC voltage for use can be set to 7 kVp or less to realize the discharge power DW desired by the ozone generator 300.

Further, the parallel resonance transformer 25 of the ozone power supply 100 has an internal excitation inductance value Lt, and the plurality of discharge cells in the ozone generator 300 have an overall capacitance value C0.

Then, the ozone power supply 100 sets the output frequency f in the vicinity of the parallel resonance frequency fc that satisfies the above-mentioned equation (5), as in the first embodiment.

The ozone gas generation system 2000 sets the output frequency f in the vicinity of the parallel resonance frequency fc to perform parallel resonance when the total discharge power DW is applied to the ozone generator 300, thereby causing the inverter unit (inverter circuit unit 22). The output power factor of the inverter can be increased.

That is, the output power factor in the inverter circuit unit 22 can be increased by performing parallel resonance between the parallel resonance transformer 25 and the ozone generator 300 when the total discharge power DW is applied.

As a result, the ozone power source 100 can supply the ozone generation AC voltage satisfying the desired total discharge power DW to the ozone generator 300 on the load side.

<Others>
In the first embodiment, the ozone generator 200 having a circular shape in view of the shape of the discharge surface in the discharge cell is shown, but the discharge cell shape may be a square or rectangular flat plate cell. .. In this case as well, the multi-stage discharge cells may be stacked by setting the discharge power density J so that the condition (2) can be satisfied.

Further, as the discharge cell, the coaxial cylindrical electrode tube may be a short tube, the discharge power density J may be set within the range satisfying the condition (3), and a large number of one electrode tube may be arranged side by side.

In the first and second embodiments, the configuration having the internal excitation inductance value Lt of the parallel resonance transformer 25, which is a high-frequency / high-voltage transformer of the ozone power supply 100, is shown. In addition to this configuration, it is also possible to add a resonance reactor that resonates in parallel to the output section of the transformer 25 for parallel resonance to configure a power supply for ozone.

Further, as the ozone generator 200 and the ozone generator 300, oxygen gas is supplied as a raw material gas, and a photocatalyst is applied to the discharge surface of the discharge cell. The present invention is not limited to this, and instead of the ozone generators 200 and 300, an ozone generator that supplies oxygen gas containing nitrogen as a raw material gas may be used.

Although the present invention has been described in detail, the above description is exemplary in all aspects and the invention is not limited thereto. It is understood that innumerable variations not illustrated can be assumed without departing from the scope of the present invention.

1,51,51A to 51D Ground cooling electrode 2a, 2b, 52, 52A to 52D Dielectric electrode 3a, 3b High pressure electrode 4a, 4b Insulation plate 5 Low pressure cooling plate 6 Laminated cell presser spring 7 Laminated cell presser plate 8 Laminated cell presser Rods 9, 59, 59A to 59D Manifold block 10 base 11 Ozone generator cover 21 AC-DC converter circuit part 22 Inverter circuit part 23 Current limiting reactor 24 Power supply control circuit 25 Parallel resonance transformer 62.62A to 62D Conductive film 70,70A to 70D Cooling water flow path 73,73A to 73D Discharge spacer 75,75a to 75f Ozone gas outlet 77,77A to 77D Ozone gas output path 79,79a to 70f Virtual circular discharge area 100 Ozone power supply 200,300 Ozone generation Instrument 1000,2000 Ozone gas generation system

Claims (7)

An ozone generator (300) having a plurality of discharge cells stacked in multiple stages,
The ozone generator is provided with an ozone power source (100) that applies an AC voltage for ozone generation.
A raw material gas containing oxygen is supplied to the ozone generator, and the ozone generator is supplied with oxygen-containing raw material gas.
The ozone generator generates a dielectric barrier discharge in the discharge spaces of the plurality of discharge cells, generates ozone gas from the raw material gas supplied to the discharge spaces, and outputs the ozone gas to the outside.
Each of the plurality of discharge cells includes flat first and second electrodes (51A to 51D, 52A to 52D), and a dielectric is formed on the second electrode, and the first and second electrodes are formed. The discharge space is provided between them,
The plurality of discharge cells are provided on the discharge surface of the first electrode, respectively, and have Nφ (≧ 2) ozone gas outlets (75a to 75f) for taking out the ozone gas generated in the discharge space.
Ozone gas extraction paths (77A to 77D) provided inside the first electrode, connected to each of the Nφ ozone gas outlets, aggregate the ozone gas taken out from the Nφ ozone gas outlets, and output the ozone gas to the outside. ) And
The ozone generator is characterized by satisfying the following conditions (a) and (b).
(a) In each of the plurality of discharge cells, the division area dso obtained by dividing the discharge area st of the discharge surface by the division number Nφ is set in the range of ^{30 cm 2} or more and ^{less than 160 cm 2.}
(b) The discharge gap length in the discharge space is set to less than 80 μm.
Ozone gas generation system. The ozone gas generation system according to claim 1.
The ozone generator is characterized by further satisfying the following condition (c).
(c) The Nφ so that the Nφ virtual circular discharge regions (79a to 79f) centered on the Nφ ozone gas outlets are formed in the discharge space without overlapping each other in a plan view. The ozone gas outlets are arranged, and the radius r of the Nφ virtual circular discharge regions ^{satisfies {r = (0.8 · dso / π) 0.5} }.
Ozone gas generation system. The ozone gas generation system according to claim 2.
The ozone generator is characterized by further satisfying the following condition (d).
(d) The discharge power density J in the discharge space of each of the plurality of discharge cells is set in the range of ^{2.5 W / cm 2} or more and less than 6 W / cm ^2.
Ozone gas generation system. The ozone gas generation system according to claim 3.
The ozone generator further includes a cooling mechanism for cooling the plurality of discharge cells to a predetermined cooling temperature.
The ozone generator is characterized by further satisfying the following condition (e).
(e) The predetermined cooling temperature is set to 5 ° C. or higher.
Ozone gas generation system. The ozone gas generation system according to claim 4.
The ozone power source and the ozone generator further satisfy the following conditions (f) and (g).
(f) The total gas flow rate Q supplied to the entire plurality of discharge cells is 3.0 L / min or more.
(g) The specific power value DW / Q, which is the ratio of the total discharge power DW applied to the entire plurality of discharge cells to the total gas flow rate Q, is 600 (W · min / L) or more, and the total discharge The electric power DW is defined by the ozone generating AC voltage.
Ozone gas generation system. The ozone gas generation system according to any one of claims 1 to 5.
In each of the plurality of discharge cells
The first and second electrodes have a rectangular shape including a trapezium in a plan view, and have a rectangular shape.
A predetermined number of discharge spacers (73A to 73D) that define the discharge gap length are provided between the first and second electrodes.
At least one of the first and second electrodes and the predetermined number of discharge spacers are integrally connected.
Ozone gas generation system. The ozone gas generation system according to any one of claims 1 to 6.
The power source for ozone is
An inverter unit (22) that outputs a high-frequency AC voltage by setting the output frequency f to a range of 20 kHz or more and less than 50 kHz.
A step-up transformer (25) that boosts the high-frequency AC voltage to a high voltage to obtain the ozone-generating AC voltage.
Ozone gas generation system.

Images