JPH09165206A - Ozone generating method and ozone generating apparatus - Google Patents

Abstract

(57) Abstract: An ozone generator capable of maintaining a high conversion efficiency of oxygen atoms to ozone and obtaining ozone of high concentration. SOLUTION: An oxygen atom generating part for dissociating the supplied oxygen gas under a predetermined low pressure to generate oxygen atoms, and an oxygen atom-containing gas fed from the oxygen atom generating part are reacted with the reaction gas under high pressure. And a plurality of ozone generators that generate ozone by reacting in a non-discharge at a predetermined oxygen atom concentration, and reduce the pressure in the oxygen atom generators to a predetermined low pressure and reduce the oxygen atom-containing gas. Is provided with a reduced-pressure feeding means for feeding each to a plurality of ozone generators,
A plurality of ozone generators are arranged in series, and the reaction gas containing ozone generated in the former ozone generator is sequentially fed to the latter ozone generator, and the ozone generated in each ozone generator is Accumulate.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ozone generating method and an ozone generating apparatus using air as a raw material gas, and more particularly to a method or apparatus for maintaining a high ozone conversion efficiency and efficiently generating a high concentration of ozone. .

[0002]

2. Description of the Related Art FIG. 11 shows, for example, Japanese Patent Publication No. 59-4876.
1 shows a conventional coaxial cylindrical silent discharge type ozone generator shown in Japanese Patent Laid-Open No. In the figure, 41 is a can body in which a ground metal pipe 42 having a cooling water inlet 49 and a cooling water outlet 50 is formed inside, and a raw material air inlet 51 such as air or oxygen and an ozone gas outlet 52 are formed at predetermined positions, 44
Is a high-voltage electrode tube made of a dielectric material such as glass, which is inserted concentrically into the ground metal tube 42 and forms a predetermined discharge gap 43 by a plurality of spacers 53. Are formed. Reference numeral 46 is a power supply for applying a high AC voltage to the conductive film 45 from the power supply line 47 through the bushing 48. In such a conventional ozone generator, it goes without saying that the ground metal tube 42 and the high-voltage electrode tube 44 are formed in the can body 41 in multiple sets depending on the ozone generation capacity.

Next, the operation will be described. The conventional ozone generator is configured as described above, and when an AC high voltage is applied to the high-voltage electrode tube 44, a gentle glow discharge called silent discharge occurs in the discharge gap 43, and the inflowing raw material air is ozonized. The gas containing ozone is taken out from the ozone gas outlet 52. In the discharge gap 43, the heat generated by the discharge causes heat generation, and unless it is cooled effectively, the gas temperature in the discharge gap 43 rises and ozone generation is reduced.
Therefore, the ground metal pipe 42 is cooled by the cooling water.

In the conventional silent discharge type ozone generator which simultaneously generates oxygen atoms (O) and ozone (O3) in the discharge space, it is necessary to maintain the discharge space at the high pressure and low temperature necessary for ozone generation. To be done. Therefore, in order to keep the discharge space at a low temperature, the conventional silent discharge ozone generator has a structure in which the gap in the discharge space is shortened to cool one or both of the ground electrode and the high-voltage electrode with water. Regarding the reduction of the gap in the discharge space, there was a problem that the machining accuracy of the discharge tube and the metal electrode tube was important in order to uniformly form the short gap with the cylindrical electrode, and the initial cost of the device increased. . In addition, the device is complicated because the electrode structure is limited to cool the electrode. Furthermore, even if the electrode is cooled, it is necessary to keep the temperature of the discharge space at 350 K or less at most, considering the ozone generation efficiency.
It was difficult to apply high power density (discharge space / discharge area), and it was impossible to realize a compact device.

Since the silent discharge ozone generator generates ozone in the discharge field, the generated ozone collides with the electrons existing in the discharge space and is decomposed again as can be seen from the reaction formula shown below. O ₃ + e → 0 + 0 ₂ + e The rate of the above reaction is a function of electron energy, and if the dissociation rate of oxygen molecules due to electron collision in the discharge field, that is, several to several tens of times faster than the production rate of oxygen atoms, Has been done. Therefore, in a silent discharge ozone generator that simultaneously generates oxygen atoms and ozone by electric discharge, the ozone that has been generated will return to oxygen atoms and molecules, and the energy efficiency of ozone generation will decrease. Furthermore, when air is used as a source gas in a silent discharge ozone generator, a nitrogen atom (N) and its excited species are generated by collision of a nitrogen molecule (N ₂ ) with an electron, and these are oxygen atoms. react with nitrogen oxides (NO _X) is generated, NO _X reacts with ozone as a result, ozone is decomposed lowering the ozone production efficiency like the above.

[0006]

The problems in the conventional silent discharge type ozone generator for simultaneously generating oxygen atoms and ozone by electric discharge as described above are listed as follows: The device structure becomes complicated. -It is difficult to make the device compact because high-density power cannot be input. -The generated ozone is decomposed by electron collision in the discharge field, and the generation efficiency is low.・ NOX is generated in the air raw material and ozone is decomposed, further lowering the production efficiency. It is mentioned.

The present invention has been made in order to solve the problems of the conventional silent discharge type ozone generator as described above. By separating the production of oxygen atoms and ozone, the oxygen atoms are kept at an appropriate concentration. By increasing the efficiency of ozone generation by mixing with the reaction gas, and by further adding the generated oxygen atoms to the reaction gas multiple times, it is possible to efficiently reduce the ozone conversion efficiency and to obtain a high concentration of ozone. An object of the present invention is to provide an ozone generating method or an ozone generating apparatus that can generate the ozone.

[0008]

According to a first aspect of the present invention, there is provided an ozone generating method in which a supplied oxygen gas is dissociated under a predetermined low pressure of atmospheric pressure or less to generate a first gas containing oxygen atoms. And a second gas containing oxygen atoms supplied under pressure and a first gas containing oxygen atoms generated in this oxygen atom generating step are mixed under a higher pressure than the oxygen atom generating step. In the ozone generating method having an ozone generating step of reacting with non-discharge to generate ozone, in the ozone generating step, the first gas is divided into a plurality of steps to obtain a second gas at a predetermined oxygen atom concentration. To produce ozone, and accumulate ozone produced in each step.

The ozone generating method according to claim 2 of the present invention is
In the ozone generation process according to claim 1, the first gas is 20
The ozone is generated by adding it to the second gas at a predetermined oxygen atom concentration in the following steps and accumulating the ozone generated in each step.

An ozone generator according to claim 3 of the present invention is
It includes an oxygen atom generating part that dissociates the supplied oxygen gas under a predetermined low pressure of atmospheric pressure or less to generate a first gas containing oxygen atoms, and an oxygen atom supplied from the oxygen atom generating part. A second gas containing oxygen supplied under pressure with a first gas
Gas under a pressure higher than that of the oxygen atom generating part, and a plurality of ozone generating parts that generate ozone by reacting in a non-discharge at a predetermined oxygen atom concentration, and the pressure in the oxygen atom generating part is below atmospheric pressure. And a reduced pressure feeding means for reducing the pressure to the predetermined low pressure and maintaining the reduced pressure state of the first gas to feed the first gas to the plurality of ozone generators, respectively. The plurality of ozone generators are arranged in series. Then, the second gas containing ozone generated in the ozone generating section in the former stage is sequentially fed to the ozone generating section in the latter stage, and the ozone generated in each ozone generating section is configured to be accumulated. Is.

An ozone generator according to claim 4 of the present invention is
In the third aspect of the present invention, the plurality of ozone generating parts are provided so that the individual oxygen atom generating parts are close to each other.

An ozone generator according to claim 5 of the present invention is
In the invention of claim 3, the plurality of ozone generators are integrated including the oxygen atom generator and the reduced pressure supply means by using the reduced pressure chambers of the corresponding reduced pressure supply means as the oxygen atom generators. It has a configured structure.

An ozone generator according to claim 6 of the present invention is
In the invention according to any one of claims 3 to 5, the plurality of ozone generators arranged in series has 20 stages or less.

An ozone generator according to claim 7 of the present invention is
An oxygen atom generating part for dissociating the supplied oxygen gas under a predetermined low pressure of atmospheric pressure or less to generate a first gas containing oxygen atoms, and a first oxygen atom generating part containing oxygen atoms fed from the oxygen atom generating part. An ozone generation unit that mixes the first gas and a second gas containing oxygen supplied under pressure under a pressure higher than that of the oxygen atom generation unit, and causes ozone to react by reacting in a non-discharge at a predetermined oxygen atom concentration. And ozone, the pressure inside the oxygen atom generating part is reduced to a predetermined low pressure equal to or lower than the atmospheric pressure, and the first gas is maintained at a reduced pressure and is supplied to the ozone generating part. In the apparatus, the ozone generator has a plurality of rows of holes provided at a predetermined distance in the direction in which the second gas flows, and the reduced pressure supply means maintains the reduced pressure state of the first gas, Feeding the ozone into the ozone generator from multiple rows of holes Are those that you configured.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows a Japanese Patent Application No. 7-251018 filed earlier by the inventor of the present application in order to solve the above-mentioned problems of the conventional ozone generator (September 28, 1995). This is an example of an ozone generator proposed in (application). In this example, oxygen atoms and ozone are not generated simultaneously in the discharge field as in the conventional apparatus shown in FIG. 11, but the oxygen atom generation chamber and the ozone generation chamber are separated.
It is configured so that the optimum conditions for the production of oxygen atoms and ozone can be controlled independently. In addition, the ejector method is used as a reduced pressure supply means for reducing the pressure of the gas containing oxygen atoms generated in the oxygen atom generation chamber and feeding the oxygen atom gas to the ozone generation chamber in the reduced pressure state. ing.

In the figure, 1 is an inlet of a reaction gas containing oxygen, 2 is a nozzle, 3 is a throat, 4 is a diffuser, 5 is an outlet of an ozone-containing gas, and these are basic constituent members constituting an ejector. . A gap 10 is provided between the nozzle 2 and the throat 3. Reference numeral 6 denotes an oxygen atom generator having a discharge chamber 7 therein, which is an apparatus for generating oxygen atoms from a raw material gas containing oxygen supplied from a raw material gas inlet 8. Reference numeral 9 is a decompression chamber for guiding the oxygen atom-containing gas generated by the oxygen atom generator 6 to the diffuser portion while maintaining a low pressure, and the pressure there is atmospheric pressure or less, specifically several Torr to several hundreds. Maintained at Torr level.

Next, the operation will be described. Oxygen-containing reaction gas (for example, air) flows through the nozzle 2 while being pressurized by a compressor or a floor, and flows into the throat 3. At this time, a gap provided between the nozzle 2 and the throat 3 Since the gas existing in the decompression chamber 9 is entrained from the decompression chamber 9, the decompression chamber 9 and the discharge chamber 7 inside the oxygen atom generator 6 are below atmospheric pressure, specifically, several Torr to several hundreds.
The pressure is reduced to about Torr. Under such a low pressure, in the discharge chamber 7 to which the oxygen-containing gas is supplied from the raw material gas inlet 8, the reaction of O ₂ + e → O + O + e (1) occurs and the oxygen atom O is generated. In the above formula, e represents an electron.

The oxygen atom O generated by the equation (1) is converted to ozone by the reaction of O + O ₂ + M → O ₃ + M (2) or O + O + M → O ₂ + M ・ ・ ・ It disappears because it returns to oxygen molecule by the reaction of (3). However,
M represents the third object. Since the equations (2) and (3) are so-called three-body collision reactions, the reactions proceed in proportion to the square of the pressure, and therefore the reactions of the equations (2) and (3) are extremely slow in a low pressure discharge field. Become. Here, if the O ₂ concentration is sufficiently higher than the O concentration, the ozone generation reaction represented by the equation (2) occupies the majority, and the reaction of the equation (3) can be ignored.

Therefore, as in the apparatus illustrated in FIG. 1, when the oxygen atom generating chamber separated from the ozone generating chamber is discharged under a low pressure, the oxygen atoms generated by the reaction of the formula (1) are converted into (2), ( Since it hardly disappears according to the formula (3), oxygen atoms can be obtained with high electric efficiency (number of oxygen atoms generated / discharge power). The oxygen atoms thus generated are sucked into the gap 10 between the nozzle 2 and the throat 3 from the decompression chamber 9 while being kept at a low pressure, and the oxygen-containing reaction gas (flowing in the nozzle 2 ( (For example, air) is mixed in an ozone generating chamber composed of the throat 3 and the diffuser 4, and is efficiently converted to ozone under high pressure by the reaction shown by the formula (2) with oxygen in the reaction gas.

In order to estimate the effect of the ozone generator having the structure shown in FIG. 1 described above, FIG. 2 shows a simulation by changing the concentration of oxygen atoms in the mixed gas, and shows the ozone generation efficiency. It shows the obtained results. Regarding the ozone generation efficiency of the conventional device, experimental values under the standard operating conditions of the recent cylindrical silent discharge ozone generator using air and pure oxygen as the source gases are shown. From this result, compared with the conventional device that simultaneously generates oxygen atoms and ozone in the discharge field, the oxygen atom generation chamber and the ozone generation chamber are separated, and the generation of oxygen atoms and ozone are independently controlled under optimum conditions. By adopting a controllable structure,
In particular, it has been found that a high ozone generation efficiency can be achieved in a low ozone concentration range of about 2 to ³ g / Nm ³ . However, FIG. 2 shows that in the configuration of the ozone generator shown in FIG. 1, the ozone generation efficiency decreases as the ozone concentration generated is increased.

FIG. 3 shows a process in which oxygen atoms generated by discharge are mixed with air at 350 K and atmospheric pressure and converted into ozone in the apparatus shown in FIG. 1 and finally converted into ozone. The ratio of oxygen atoms (number of generated ozone molecules / initial number of oxygen atoms, that is, ozone conversion efficiency) is shown on the vertical axis, and the concentration of oxygen atoms when injected into the ozone generation chamber and mixed with the reaction gas is shown on the horizontal axis. It is a thing. From FIG. 3, the proportion of oxygen atoms finally converted to ozone is 0.01%, 0.1%, 1%, 1
When it is 0% and 20%, it is about 99% and 9 respectively.
It was found to be 5%, 64%, 20% and 13%. From this result, it can be seen that the conversion efficiency from oxygen atoms to ozone sharply decreases as the oxygen atom concentration increases. this is,
This is because the increase in the oxygen atom concentration increases the rate of the recombination reaction of oxygen atoms represented by the above formula (3), and the oxygen atoms generated by the discharge return to oxygen molecules. That is, it is understood that in order to efficiently convert the generated oxygen atoms into ozone, it is necessary to suppress the concentration of oxygen atoms to be added to the reaction gas to be mixed.

As described above, in the ozone generator as shown in FIG. 1, in which the problem of the conventional device shown in FIG. 11 is improved by separating the oxygen atom producing chamber and the ozone producing chamber, the discharge field is improved. Since there is no ozone or NO _x in
It does not occur the decomposition of ozone by electron impact and NO _X, only if it is can generate ozone at a high efficiency, which has a lower concentration of oxygen atoms when it is mixed with a reaction gas such as air in the ozone production chamber Has been. When the oxygen atom concentration when mixed with the reaction gas also becomes high, the recombination reaction of the oxygen atoms shown in the above formula (3) becomes dominant and the ozone conversion efficiency sharply decreases. In a high region, there is a problem that energy efficiency for ozone generation is lowered. The present invention has been made to further solve such a problem, and separates the oxygen atom and ozone generation chambers and divides the oxygen atoms generated in the oxygen atom generation chamber into a plurality of times at a predetermined low concentration. By adding it to the reaction gas in the ozone generation chamber, high concentration ozone can be generated with high efficiency.

Embodiment 1 The main reaction and the competitive reaction when the oxygen atoms generated by the discharge are converted into ozone are as shown in the above equations (2) and (3). Here, the reaction rate constants of the respective reactions are kn 4 and kn 5
Then, the efficiency η when the oxygen atoms generated by the discharge are converted into ozone is expressed by the following equation.

[0024]

[Equation 1]

From the equation (4), the ozone conversion efficiency is a function of the concentration ratio of oxygen atoms and oxygen molecules, and the ozone conversion efficiency η decreases as the oxygen atom concentration increases. From this, in order to obtain a relatively high concentration of ozone, when a high concentration of oxygen atoms was added at once to the reaction gas containing oxygen molecules,
It can be seen that it is impossible to generate ozone with high efficiency because the ozone conversion efficiency decreases. Since the conversion efficiency from oxygen atoms to ozone decreases as the oxygen atom concentration increases as shown in equation (4), a method of generating ozone with a relatively high concentration as efficiently as possible is one with high ozone conversion efficiency. A method of dividing the concentration of oxygen atoms into a plurality of times and sequentially adding them to the reaction gas can be considered.

In the ozone generation chamber provided separately from the discharge chamber for generating oxygen atoms by discharge, the above (2),
In addition to the ozone generation and decomposition reactions represented by the formula (3), the reaction represented by O + O ₃ → O ₂ + O ₂ (7) occurs. Since the reaction of the formula (3) can be ignored when adding a low concentration of oxygen atoms, the oxygen atoms generated by the discharge are efficiently converted to ozone,
Further, since the reaction rate of the equation (7) is extremely slow, ozone generated in the ozone generating chamber is hardly decomposed.

Therefore, oxygen atoms are added to the reaction gas at a low concentration in the ozone generation chamber to efficiently convert it into ozone to generate an ozone-containing gas, which is further reduced in the generated reaction gas containing ozone. When the operation of adding oxygen atoms at a concentration is repeated, the generated ozone is hardly decomposed in a short time, so the conversion of oxygen atoms to ozone remains highly efficient, and the concentration of ozone finally generated Will be accumulated and increased according to the number of times that oxygen atoms are added to the ozone-containing gas at a low concentration. That is, even when a high concentration of ozone is obtained, it is possible to suppress a decrease in ozone conversion efficiency.

FIG. 4 shows the relationship between the number of divided injections of oxygen atoms and the ozone conversion efficiency using the total addition concentration of oxygen atoms added to the reaction gas as a parameter. The total added concentration of oxygen atoms is 0.1%, 1.0
%, 10%, and 20%, and the addition concentration per each time corresponds to the value obtained by dividing the total addition concentration by the number of additions. For example, in the graph of A, when the total addition concentration of oxygen atoms to the reaction gas is 1.0%, when the oxygen atoms having a concentration of 1.0% are added at once, and when the total addition concentration is 0.5 % × 2), 10 times (0.1% × 1)
0), the ozone conversion efficiency η when added 20 times (0.05% × 20) and a plurality of times is shown with the number of additions as the horizontal axis.

From this figure, it is possible to improve the ozone conversion efficiency η by decreasing the addition concentration per time and increasing the number of additions when the total addition concentration of oxygen atoms to the reaction gas is kept constant. I understand. However, when the number of additions exceeds 10, the improvement in ozone change efficiency shows a saturation phenomenon, and when the number of additions exceeds 20, it seems that improvement in ozone change efficiency can hardly be expected.
FIG. 5 shows the ozone concentration generated on the abscissa (logarithmic scale) based on the result shown in FIG. 4, and is re-reproduced into the relationship between the generated ozone concentration and the ozone conversion efficiency. In FIG. 5, A
The group has a total oxygen atom concentration of 0.1%, the group B has a total oxygen atom concentration of 1.0%, the group C has a total oxygen atom concentration of 10%, and the group D has a total oxygen atom concentration of 10%. Total concentration of oxygen atoms is 20
The data for% is shown. Further, in FIG. 6, both the vertical axis and the horizontal axis are rewritten with a linear scale.

From FIG. 5 or FIG. 6, for example, when ozone is generated with the total concentration of oxygen atoms added to the reaction gas being 1.0% (that is, data of group B), The ozone concentration produced by reacting with the number of additions is about 11
g / Nm ³ , and the ozone conversion efficiency at this time is about 65%, but the addition concentration of oxygen atoms is set to 0.05%.
The ozone concentration generated by adding it in 0 times is about 14
g / Nm ³ and ozone conversion efficiency at this time is 80%
It turns out that it is improved to some extent. From the above, in the ozone generation chamber, oxygen atoms are added at a low concentration of a few percent or less to the reaction gas to efficiently convert it into ozone to generate ozone-containing gas, and the reaction containing this generated ozone By repeating the operation of adding a lower concentration of oxygen atoms to the gas multiple times, it is possible to suppress the decrease in conversion efficiency from oxygen atoms to ozone, and finally add oxygen atoms to the reaction gas all at once. It was proved that it is possible to generate higher concentration of ozone than in the case.

The present invention is based on the results of the above findings. In an ozone generator in which an oxygen atom and an ozone generation chamber are separated, an oxygen atom-containing gas generated by discharge under low pressure is converted into an oxygen molecule. The reaction gas (for example, air) is sequentially supplied to the ozone generation chambers divided into a plurality of stages, and the oxygen atom-containing gas is supplied to each ozone generation chamber at a low pressure, instead of being added to the reaction gas containing Is maintained and the oxygen atoms are mixed so as to have a predetermined low concentration when mixed with the reaction gas in the ozone generating chamber.

The first embodiment of the present invention will be specifically described below. FIG. 7 is a diagram showing a schematic configuration of the ozone generator according to the first embodiment of the present invention. FIG.
1 that are the same as or equivalent to those in FIG. In FIG. 7, 100 is a first-stage ozone generating unit, 200 is a second-stage ozone generating unit arranged at the rear of the first-stage ozone generating unit 100, and 300 is an N-th.
This is the ozone generating section in the second stage. Also in the first embodiment, the reduced pressure feeding means has a device configuration using an ejector system similar to that of the ozone generator shown in FIG. The ozone generating section in each stage is provided with a nozzle 2, a throat 3, a diffuser 4, a decompression chamber 9, and a gap 10 as in the device of FIG. Reference numeral 6 denotes an oxygen atom generator having a discharge chamber 7 therein, which is an apparatus for generating oxygen atoms from a raw material gas containing oxygen supplied from a raw material gas inlet 8. Reference numeral 400 is an oxygen atom supply pipe for supplying oxygen atoms generated in the oxygen atom generator 6 to the ozone generating section of each stage. Further, 11 is a pressurizing means such as a compressor or a blower.

Next, the operation will be described. The reaction gas pressurized by the pressurizing means 11 flows into the nozzle 2 provided in the first-stage ozone generator 100 from the inlet 1 thereof, and the pressurized reaction gas is blown out to the throat 3. It At this time, the gas existing in the decompression chamber 9 is drawn in through the gap 10 provided between the nozzle 2 and the throat 3, so that the decompression chamber 9 and the discharge chamber 7 inside the oxygen atom generator 6 are entrained.
Is reduced to below atmospheric pressure, specifically, to several Torr to several hundred Torr. Under such a low pressure, in the discharge chamber 7 to which the oxygen-containing gas is supplied from the raw material gas inlet 8, the reaction of O ₂ + e → O + O + e shown in the formula (1) occurs, and the oxygen atom O is generated. In the above formula, e represents an electron.

The oxygen atom O generated by the equation (1) is
It is converted to ozone by the reaction of O + O ₂ + M → O ₃ + M shown in the formula (2), or the reaction of O + O + M → O ₂ + M shown in the formula (3) Then, it returns to the oxygen molecule and disappears. However, M
Represents the third object.

Since the equations (2) and (3) are so-called three-body collision reactions, the reactions proceed in proportion to the square of the pressure. Therefore, in the low pressure discharge field, the reactions of the equations (2) and (3) are performed. Will be extremely slow. Here, if the O ₂ concentration is sufficiently higher than the O concentration, the ozone generation reaction represented by the equation (2) occupies most, and the reaction of the equation (3) can be ignored. Therefore, when the discharge is performed under a low pressure as in the present invention, oxygen atoms generated by the reaction of the formula (1) are hardly extinguished by the formulas (2) and (3), so that high electrical efficiency (number of generated oxygen atoms / discharge) Power)
Oxygen atoms can be obtained with. The oxygen atoms thus generated are sucked into the gap 10 between the nozzle 2 and the throat 3 from the decompression chamber 9 via the oxygen atom supply pipe 400 while being kept at a low pressure, and the inside of the nozzle 2 is sucked. The reaction gas containing the flowing oxygen is mixed with the reaction gas at a predetermined low concentration in the ozone generation chamber composed of the throat 3 and the diffuser 4, and the oxygen molecules in the reaction gas react with the reaction represented by the formula (2). It is efficiently converted to ozone under high pressure. In order to add oxygen atoms to the reaction gas at a predetermined concentration, a bubble for controlling the amount of oxygen atoms generated in the oxygen atom generator 6 or controlling the flow rate of the oxygen atom-containing gas in the oxygen atom supply pipe. Etc. may be provided as appropriate.

In this way, the first-stage ozone generator 1
The ozone-containing gas (reaction gas containing ozone generated) obtained in No. 00 is further introduced into the nozzle 2 of the second-stage ozone generating section 200 from the outlet 5 of the ozone-containing gas while being pressurized. It In the second-stage ozone generator 200, the oxygen atom-containing gas generated in the oxygen atom generator 6 is the same as in the first-stage ozone generator 100.
The gap 10 between the nozzle 2 and the throat 3 is maintained from the decompression chamber 9 while maintaining a low pressure via the oxygen atom supply pipe 400.
And is mixed with a predetermined concentration with the ozone-containing reaction gas obtained in the first-stage ozone generation chamber flowing through the nozzle 2 in the ozone generation chamber composed of the throat 3 and the diffuser 4. , Oxygen molecules in the reaction gas and the reaction represented by the formula (2) are efficiently converted to ozone under high pressure.

As described above, in the ozone generation chamber, the reaction represented by the formula (7) occurs in addition to the ozone generation and decomposition reactions represented by the formulas (2) and (3). Is extremely slow, and the ozone generated in the ozone generation chamber is hardly decomposed. Therefore, in the second-stage ozone generation unit 200, the first-stage ozone generation unit 1
Generated in 00 and the ozone generator 20 in the second stage
Ozone generated at 0 will be accumulated. As in the present embodiment, a plurality of stages (N stages) of ozone generators are arranged in series, the reaction gas is fed to the ozone generator of the first stage by the pressurizing means, and the reaction is performed in the ozone generator chamber. Oxygen atoms are added to the gas at a prescribed low concentration to efficiently convert it to ozone to generate an ozone-containing gas, and the ozone-generating gas in the next stage further has a prescribed low concentration for the generated ozone-containing gas. By repeating the operation of adding oxygen atoms to generate ozone, the generated ozone accumulates more and more, so the conversion of oxygen atoms to ozone is highly efficient, and the concentration of ozone is high. Can be obtained.

That is, in the present embodiment, since oxygen gas is dissociated under a low pressure as in the conventional ozone generator, the life of oxygen atoms is extended, and as a result, oxygen atoms can be efficiently generated. The oxygen atom generation chamber needs only to satisfy the conditions to keep the discharge stable and efficiently generate oxygen atoms.Therefore, the temperature inside the generation chamber is high and there is no need to cool the electrodes. It is possible to provide an inexpensive device with a high degree of structure and a simple structure. Moreover, since a high power density can be input, the device can be made compact. Furthermore, since the oxygen atom-containing gas generated in the oxygen atom generation chamber is configured to react with the reaction gas containing oxygen molecules at a predetermined low concentration in a plurality of times, it suppresses a decrease in ozone conversion efficiency, and As compared with the conventional ozone generator, it is possible to generate higher concentration ozone.

Embodiment 2 FIG. 8 is a diagram showing a schematic configuration of an ozone generator according to Embodiment 2 of the present invention.
Also in the present embodiment, as in the first embodiment, the ejector system is used as the reduced pressure feeding means. still,
The same reference numerals as those in FIG. 1 indicate that they are the same as or equivalent to those in FIG. In the figure, 1 is an inlet of a reaction gas containing oxygen, 2 is a nozzle, 3 is a throat, 4 is a diffuser, and 5 is an outlet of an ozone-containing gas. These are the basic constituent members that make up the ejector. In the present embodiment, the first-stage ozone generators 10 arranged in columns are provided.
It is characterized in that the oxygen atom generator 6 is separately provided for each of the 0th, second-stage ozone generation unit 200 and the Nth-stage ozone generation unit 300. The ozone generator of each stage
As in the apparatus of FIG. 1, the nozzle 2, the throat 3, the diffuser 4, the decompression chamber 9, and the gap 10 are provided. Decompression chamber 9
In order to guide the oxygen atom-containing gas generated in the oxygen atom generator 6 to the mixing point with the reaction gas while maintaining a low pressure, the pressure there is below atmospheric pressure, specifically, several Torr to several hundreds. Maintained at Torr level.

Next, the operation will be described. The reaction gas pressurized by the pressurizing means 11 flows into the nozzle 2 provided in the first-stage ozone generator 100 from the inlet 1 thereof, and the pressurized reaction gas is discharged from the nozzle 2 to the throat 3. To be blown out. At this time, since the gas existing in the decompression chamber 9 is drawn in through the gap 10 provided between the nozzle 2 and the throat 3, the discharge chamber of the oxygen atom generator 6 provided for the ozone generating section 100 of the first stage. The pressure of 7 is also lower than atmospheric pressure, specifically several Torr to several hundred Torr equivalent to that of the decompression chamber 9.
The pressure is reduced to a certain degree. Under such a low pressure, in the discharge chamber 7 of each oxygen atom generator 6 to which the oxygen-containing gas is supplied from the raw material gas inlet 8, the same reaction as that described in the first embodiment occurs, resulting in high electric power. Efficiency (number of oxygen atoms generated /
Oxygen atoms can be obtained with discharge power). The oxygen atoms generated in this way pass through the decompression chamber 9 while being kept at a low pressure and the gap 1 between the nozzle 2 and the throat 3 is reduced.
Oxygen molecules in the reaction gas in the ozone generation chamber composed of the oxygen-containing reaction gas flowing into the nozzle 2 and flowing into the nozzle 2, the throat 3 and the diffuser 4 and the reaction represented by the above equation (2). Is efficiently converted to ozone under high pressure.

In this way, the first stage ozone generation
The ozone-containing gas (reaction gas containing ozone generated) obtained in No. 00 is further introduced into the nozzle 2 of the second-stage ozone generating section 200 from the outlet 5 of the ozone-containing gas while being pressurized. It In the second-stage ozone generator 200, the oxygen atom generators 6 individually provided in the second-stage ozone generator 200 are the same as in the first-stage ozone generator.
Similarly, the oxygen atom-containing gas generated in 1 is sucked from the decompression chamber 9 into the gap 10 between the nozzle 2 and the throat 3 while being kept at a low pressure, and then flows through the nozzle 2.
Ozone-containing gas obtained in the ozone generation chamber of the second stage, and oxygen molecules in the reaction gas in the ozone generation chamber composed of the throat 3 and the diffuser 4 efficiently react under high pressure by the reaction shown in equation (2). Converted to ozone. Thus, in the second stage ozone generation part 200, the ozone generated in the first stage ozone generation part 100 and the ozone generated in the second stage ozone generation part 200 are accumulated. .

Also in the second embodiment, the oxygen atom generating section and the ozone generating section are provided separately, and a plurality of stages (N stages) of ozone generating sections are arranged in series. In the same manner as in the first embodiment, in each ozone generation chamber, oxygen atoms are added to the reaction gas at a predetermined low concentration to efficiently convert into ozone to generate ozone-containing gas. In addition, it is possible to repeat the operation of adding ozone atoms at a predetermined low concentration to generate ozone in the ozone generating section in the next stage, and the generated ozone accumulates more and more, so conversion from oxygen atoms to ozone Can obtain high-concentration ozone while maintaining high efficiency. Further, in the second embodiment, the oxygen atom-containing gas supplied from the oxygen atom generator 6 provided in each stage is different from that in the first embodiment in that a relatively long flow path such as an oxygen atom supply pipe is used. Since the oxygen gas having a short life is immediately mixed with the reaction gas through a short supply pipe, the probability that oxygen atoms having a short life will be broken by recombination before mixing with the reaction gas is small, and the oxygen atoms generated by the oxygen atom generator 6 are small. Has the advantage that it is more efficiently mixed with the reaction gas.

Embodiment 3 In the first or second embodiment, the oxygen atom generator 6 and the decompression chamber 9 are separated from each other. However, in the present embodiment, an integrated ozone generation unit in which the oxygen atom generator and the decompression chamber are integrated is provided. The configuration is such that a plurality of stages are arranged in series. FIG. 9 is a diagram showing a schematic configuration of a main part of the ozone generator according to the third embodiment,
FIG. 9A is a vertical cross-sectional configuration diagram thereof, and FIG. 9B is FIG.
FIG. 3A is a sectional view taken along line AA ′ of FIG. In the figure, 1 is an inlet of a reaction gas containing oxygen, 2 is a nozzle, 3 is a throat, 4 is a diffuser, 5 is an outlet of an ozone-containing gas, and these are basic constituent members constituting an ejector. In the integrated ozone generator of each stage in the present embodiment, a low-pressure silent discharge type oxygen atom generator and an ejector which is a reduced pressure supply means are integrally formed. 8 is a raw material gas inlet containing oxygen, 20 is a dielectric tube such as glass, 2
1 is a power supply electrode, 22 is a high-voltage AC power supply, and 23 is a discharge field, and these constitute an oxygen atom generator. In the present embodiment, such integrated ozone generators are arranged in N stages in series according to the number of times (N) the oxygen atom-containing gas is added.

The integrated ozone generating section of each stage is integrated with the ozone generating section including the oxygen atom generator 6 and the decompression chamber 9 in the first or second embodiment, and its basic operation. Is the same as in the first or second embodiment described above. Oxygen atoms generated in the discharge field 23 are sucked from the decompression section into the space between the nozzle 2 and the throat 3 while being kept at a low pressure, mixed with the reaction gas containing oxygen flowing in the nozzle, and the first stage In the ozone generation chamber, the oxygen molecules in the reaction gas are efficiently converted to ozone under a high pressure by the reaction shown in the equation (2). The ozonized gas obtained in the first-stage integrated ozone generating section is introduced from the ozonized gas outlet 5 into the inlet of the ejector of the second-stage integrated ozone generating section, that is, the nozzle 2, It is supplied to the ozone generating chamber of the integrated ozone generating section of the stage.

Then, the oxygen atom-containing gas generated in the second-stage integrated ozone generation section and the ozonized gas supplied from the first-stage integrated ozone generation section are used in the second-stage ozone generation. By being mixed in the chamber, it is further converted into ozone, and ozonized gas having an ozone concentration higher than that in the first stage is generated. When the structure has two or more stages, ozone is generated through the same process as the second stage after the third stage, and is accumulated in the ozone generated in all stages. Similar to the ozone generator described in the first or second embodiment, the low-concentration oxygen atom-containing gas is divided into a plurality of times and can be sequentially added to the reaction gas. Since the atom generator and decompression chamber are integrated, the generated oxygen atoms are mixed with the reaction gas in a very short time, and the oxygen atoms generated by the discharge return to oxygen molecules by recombination. It is possible to realize an apparatus having a high ozone generation efficiency even in a region where the generated ozone concentration is high and the loss due to is very small.

Fourth Embodiment FIG. 10 is a diagram showing a schematic configuration of an ozone generator according to Embodiment 4 of the present invention. In the figure, the same or corresponding members as those described in FIGS. 7 to 9 are designated by the same reference numerals, and detailed description thereof will be omitted. In the present embodiment, as a method of adding the oxygen atom-containing gas generated by the discharge into the reaction gas in a plurality of times, a hole is provided around the diffuser part that constitutes the ozone generation chamber, and the oxygen atom-containing gas is supplied from this hole. Is to be injected.

In FIG. 10, reference numeral 500 is an ozone generating chamber composed of the throat 3 and the diffuser 4, and a plurality of holes 501 are provided in the wall around the diffuser 4. Reference numeral 502 denotes a decompression chamber provided with an oxygen atom supply passage 503 for guiding the oxygen atom-containing gas generated by the oxygen atom generator 6 to the outer wall portion of the diffuser 4 while maintaining a low pressure, and the throat of the ozone generation chamber 500. 3 and the outside of the diffuser 4 are formed. The pressure in the decompression chamber 502 is maintained below atmospheric pressure, specifically, about several Torr to several hundred Torr.

Next, the operation will be described. The method of generating oxygen atoms in the oxygen atom generator 6 is exactly the same as that of the ozone generator shown in the first embodiment. The reaction gas mixed with the oxygen atom-containing gas is pressurized by a pressurizing means (not shown), and then injected into the diffuser 4 through the throat 3. At this time, since the oxygen atom-containing gas existing in the decompression chamber 502 is drawn from the hole 501 provided in the diffuser 4, the decompression chamber 502 and the discharge chamber 7 inside the oxygen atom generator 6 are below atmospheric pressure, specifically, several To
The pressure is reduced to about rr to several hundred Torr. The numerous holes 501 provided in the diffuser 4 allow a sufficient time (for example, about 1 ms) for the oxygen atoms injected from the holes in the first row to be converted into ozone in the direction of the flow of the reaction gas. After that, the holes are provided at a distance such that oxygen atoms are injected from the holes in the second row. Needless to say, when performing the injection in two or more steps, the holes in the third and subsequent rows are also provided at the same distance.

As described above, by injecting the oxygen atom of a predetermined low concentration into the ozone generating chamber 500 in a plurality of times in sequence, ozone is efficiently produced in the diffuser 4 by the reaction represented by the above equation (2). Can be converted to. In the ozone generator configured as described above, since the oxygen atom generator and the ozone generator are separated, the oxygen atom chamber has a low pressure (several) as in the ozone generator described in the first embodiment. Torr-several hundred Torr), high temperature, high pressure (about 760 Torr or more) in ozone generation chamber, low temperature (400 Torr)
Since it is possible to independently set the optimum conditions for each generation (for example, about K or less), it is possible to generate oxygen atoms and ozone with high efficiency.

Further, since the low-concentration oxygen atom-containing gas is divided into a plurality of times and sequentially added to the reaction gas, the loss due to the recombination of the oxygen atoms generated by the discharge into the oxygen molecules is small. Therefore, it is possible to realize a device having a higher ozone generation efficiency in a region where the generated ozone concentration is higher than that of the conventional ozone generating device. Moreover, since the number of rows of holes provided in the diffuser only needs to be set to a plurality of stages in order to add oxygen atoms to the reaction gas in a plurality of times, the ozone generation chamber has no relation to the number of additions. Only one is required, and it is possible to realize a compact multi-stage addition type ozone generator having a very simple structure.

In the above-described first to fourth embodiments, the method of dissociating oxygen to generate oxygen atoms is described only by electric discharge. As described in detail in Japanese Patent Application No. 7-251018, as a concrete method of discharge, non-equilibrium discharge such as glow discharge, silent discharge, Masquelo wave discharge, or thermal plasma such as arc discharge or high frequency discharge is used. It goes without saying that the same effect can be obtained by using any of the above methods.

[0052]

According to the first aspect of the present invention, an oxygen atom generating step of generating a first gas containing oxygen atoms by dissociating the supplied oxygen gas under a predetermined low pressure of atmospheric pressure or less, , A first gas containing oxygen atoms generated in the oxygen atom generating step and a second gas containing oxygen supplied under pressure are mixed under a pressure higher than that in the oxygen atom generating step, and the reaction is performed without discharge. In the ozone generating method having an ozone generating step of generating ozone, the ozone generating step divides the first gas into a plurality of steps to generate a second gas at a predetermined oxygen atom concentration with high ozone conversion efficiency. Since ozone was added to efficiently generate ozone and the ozone generated in each process was accumulated, it is possible to obtain high-concentration ozone while maintaining high efficiency in conversion of oxygen atoms to ozone. How to generate ozone There is an effect that can do today.

According to the second aspect of the present invention, in the ozone generating step, the first gas is divided into 20 times or less and added to the second gas at a predetermined oxygen atom concentration to generate ozone, Since ozone generated in each process is accumulated, a high concentration of ozone can be obtained while maintaining high efficiency in conversion of oxygen atoms to ozone without unnecessarily complicating the ozone generation process. There is an effect that it is possible to provide a method of generating ozone.

According to a third aspect of the present invention, an oxygen atom generating part for dissociating the supplied oxygen gas under a predetermined low pressure of atmospheric pressure or less to generate a first gas containing oxygen atoms,
1st containing the oxygen atom sent from this oxygen atom generating part
Gas and a second gas containing oxygen which is supplied under pressure are mixed under a pressure higher than that of the oxygen atom generating portion, and a plurality of ozone generation is performed by causing non-discharge reaction at a predetermined oxygen atom concentration to generate ozone. And a pressure reducing means for reducing the pressure in the oxygen atom generating section to the predetermined low pressure below atmospheric pressure and maintaining the reduced pressure state of the first gas to supply the ozone generating sections respectively. A plurality of ozone generators are arranged in series, and the second gas containing ozone generated in the ozone generator in the front stage is sequentially fed to the ozone generator in the rear stage. Since the ozone generated in step 1 is configured to be accumulated, there is an effect that it is possible to provide an ozone generator capable of obtaining high-concentration ozone while maintaining high efficiency in conversion of oxygen atoms into ozone.

According to the fourth aspect of the present invention, the plurality of ozone generating portions are provided with the individual oxygen atom generating portions close to each other, and the generated oxygen atoms are mixed with the reaction gas in a short time. The probability that oxygen atoms having a short life will be broken by recombination before being mixed with the reaction gas is reduced, and the generated oxygen atoms are mixed with the reaction gas more efficiently.

According to the fifth aspect of the present invention, the plurality of ozone generators use the pressure reducing chambers of the respective pressure reducing and feeding means corresponding to the respective ozone generating portions as the oxygen atom generating portions, so that the oxygen atom generating portions and the pressure reducing and feeding means are formed. Since the integrated configuration including and, the generated oxygen atoms are mixed with the reaction gas in a very short time, and the loss due to the oxygen atoms generated by the discharge returning to the oxygen molecules by recombination is extremely high. In addition, it is possible to provide an Ozo generator having a small size, a high ozone generation efficiency even in a region where the generated ozone concentration is high, and a miniaturized structure having a simple structure.

According to the sixth aspect of the present invention, since the plurality of ozone generating sections arranged in series are set to 20 stages or less, the conversion of oxygen atoms into ozone is performed without making the apparatus structure unnecessarily complicated. Has the effect of providing an ozone generator capable of obtaining high-concentration ozone while maintaining high efficiency.

According to a seventh aspect of the present invention, an oxygen atom generating part for dissociating the supplied oxygen gas under a predetermined low pressure of atmospheric pressure or less to generate a first gas containing oxygen atoms,
A first gas containing oxygen atoms supplied from the oxygen atom generating section and a second gas containing oxygen atoms pressurized and supplied are mixed under a pressure higher than that of the oxygen atom generating section to obtain a predetermined oxygen atom concentration. In the ozone generating section for reacting with non-discharge to generate ozone, the pressure in the oxygen atom generating section is reduced to a predetermined low pressure equal to or lower than atmospheric pressure, and the first gas is maintained in a reduced pressure state to generate ozone. In the ozone generator, the ozone generator has a plurality of rows of holes provided at a predetermined distance in the flowing direction of the second gas. Since the means is configured to supply the first gas to the inside of the ozone generating section through the holes in the plurality of rows while maintaining the depressurized state, it has a very simple structure and converts oxygen atoms to ozone. A high concentration of ozone can be obtained while maintaining high efficiency in conversion. It there is an effect that it provides an ozone generator capable.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing a schematic configuration of an ozone generator related to the present invention.

FIG. 2 is a diagram comparing the ozone generation efficiency of the ozone generator of FIG. 1 and the conventional silent discharge ozone generator with the simulation results.

FIG. 3 is a diagram showing the relationship between the concentration of oxygen atoms added to a reaction gas and ozone conversion efficiency.

FIG. 4 is a diagram showing the relationship between the number of divided injections of oxygen atoms and ozone conversion efficiency with the total concentration of oxygen atoms added to the reaction gas as a parameter.

5 is a diagram showing the ozone concentration for generating the data of FIG. 4 on the horizontal axis (logarithmic scale).

FIG. 6 is a diagram in which both axes are rewritten with linear scales.

FIG. 7 is a cross-sectional view showing a schematic configuration of the first embodiment of the present invention.

FIG. 8 is a sectional view showing a schematic configuration of a second embodiment of the present invention.

FIG. 9 is a sectional view showing a schematic configuration of a third embodiment of the present invention.

FIG. 10 is a sectional view showing a schematic configuration of a fourth embodiment of the present invention.

FIG. 11 is a cross-sectional view showing a schematic configuration of a conventional ozone generator.

[Explanation of symbols]

1 Reactant gas inlet 2 Nozzle 3
Throat 4 Diffuser 5 Ozone-containing gas outlet 6
Oxygen atom generator 7 Discharge chamber 8 Raw material gas inlet 9
Decompression chamber 10 Gap 11 Pressurizing means 2
0 Dielectric tube 21 Feed electrode 22 AC power supply 2
3 Discharge field 100 1st stage ozone generation part 200 2nd stage ozone generation part 300 Nth stage ozone generation part 400 Oxygen atom supply pipe 500 Ozone generation chamber 501 Hole 502 Decompression chamber 503 Oxygen atom supply path

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Noriichi Tabata 2-3-2 Marunouchi, Chiyoda-ku, Tokyo Sanryo Electric Co., Ltd.

Claims (7)

[Claims] 1. An oxygen atom generating step of dissociating the supplied oxygen gas under a predetermined low pressure of atmospheric pressure or less to generate a first gas containing oxygen atoms, and the oxygen atom generating step. First containing oxygen atom
And a second gas containing oxygen which is pressurized and supplied are mixed under a pressure higher than that in the oxygen atom generating step, and are reacted without discharging to generate ozone. In the method, in the ozone generation step, the first gas is divided into a plurality of steps and added to the second gas at a predetermined oxygen atom concentration to generate ozone, and the ozone generated in each step. A method for generating ozone, which comprises: 2. The ozone generating step divides the first gas into 20 steps or less and adds the first gas to the second gas at a predetermined oxygen atom concentration to generate ozone, and the ozone generated in each step. The ozone generating method according to claim 1, wherein the ozone is accumulated. 3. An oxygen atom generating part for dissociating the supplied oxygen gas under a predetermined low pressure of atmospheric pressure or less to generate a first gas containing oxygen atoms, and the oxygen atom generating part supplies the oxygen gas. The first gas containing oxygen atoms and the second gas containing oxygen supplied under pressure are mixed under a pressure higher than that of the oxygen atom generating part, and the reaction is performed without discharge at a predetermined oxygen atom concentration. And a plurality of ozone generators that generate ozone, and the pressure in the oxygen atom generator is reduced to the predetermined low pressure that is equal to or lower than atmospheric pressure, and the first gas is maintained in a reduced pressure state to maintain the plurality of the plurality of ozone generators. A plurality of ozone generators are provided in series, and the second gas containing ozone generated in the ozone generator in the former stage is provided in the latter stage. It is sequentially sent to the generator, and each An ozone generator characterized in that ozone generated in the ozone generator is accumulated. 4. The ozone generator according to claim 3, wherein the plurality of ozone generators are respectively provided with oxygen atom generators that are close to each other. 5. The plurality of ozone generators are integrated together with the oxygen atom generator and the reduced pressure feeder by using the reduced pressure chambers of the respective reduced pressure feeders as the oxygen atom generators. The ozone generator according to claim 3, wherein: 6. The plurality of ozone generators arranged in series has 20 stages or less.
The ozone generator according to any one of 1. 7. An oxygen atom generating part for dissociating the supplied oxygen gas under a predetermined low pressure of atmospheric pressure or less to generate a first gas containing oxygen atoms, and the oxygen atom generating part supplies the oxygen gas. The first gas containing oxygen atoms and the second gas containing oxygen supplied under pressure are mixed under a pressure higher than that of the oxygen atom generating part, and the reaction is performed without discharge at a predetermined oxygen atom concentration. And an ozone generating section for generating ozone to reduce the pressure in the oxygen atom generating section to the predetermined low pressure below atmospheric pressure, and to maintain the depressurized state of the first gas in the ozone generating section. In the ozone generator provided with a reduced-pressure feed means for feeding, the ozone generator has a plurality of rows of holes provided at a predetermined distance in a direction in which the second gas flows, The reduced pressure feeding means reduces the pressure of the first gas. Maintains state ozone generator, characterized in that so as to feed the inside of the ozone generator from the hole of the plurality of rows.