JPS62132706A - Ozonizer - Google Patents

Abstract

PURPOSE:To improve the ozone formation efficiency, by providing a construction in which a porous insulating material is installed in a direction perpendicular to the original gas flow in a box where the original gas flows and ozone forming reaction by silent discharge is carried out in the porous insulating material. CONSTITUTION:A porous insulating material 12 is provided in a direction perpendicular to the flow of an original flow gas 7 in a box 11 where the original gas 7 flows. Plural high-voltage electrodes 13 and earthing electrodes 14 are alternately placed in the direction perpendicular to the original gas flow 7 in or on the surface of the insulating material 12. A high voltage is applied from a high-voltage electric power source 15 across the high-voltage electrodes 13 and earthing electrodes 14 to carry out discharge in minute voids in the porous insulating material 12 between both electrodes and the original gas 7 is introduced into the box 11 to cause ozone forming reaction in the porous insulating material 12 and give the aimed ozone gas 8. Thereby the ozone forming reaction can be accelerated and ozone decomposing reaction can be suppressed to improve the ozone formation efficiency.

Description

[Detailed description of the invention] Industrial applications This invention relates to an ozone generator.

PRIOR ART Conventional ozonizers include a flat type in which electrodes are arranged in a parallel plate shape and a cylindrical type in which electrodes are arranged in a cylindrical shape, as illustrated in FIGS. 1 and 2. In principle, both A dielectric layer 3 made of glass, mica, ceramics, etc. is formed in close contact with the high-voltage side electrode 1 of the opposing electrodes 1 and 2, and a silent discharge 6 is generated in the gap 5 to ozone the raw material gas 7. be.

Problems to be Solved by this Invention The ozone generation efficiency η, that is, the ratio of ozone generation to power consumption, of these conventional ozonizers is significantly lower than the theoretical value expected from the thermochemical equation, and the amount of power consumed is Only about a few square meters are used for ozone production.

This is because the electrons generated by the discharge cause the ozone production reaction02+e→O+O+e (Fl)0-1-02-
Not only 1-M→Oa+M (F'2) but also the ozone decomposition reaction Os+e-+02+o+e (D2) is caused, and the gas temperature rises due to the discharge, and the following ozone decomposition reaction 03+0→202 (DI) is also active. The main reason is that.

In this way, the first drawback of conventional ozonizers is the power efficiency η
In other words, the running cost is high.

In addition, in order to generate stable silent discharge, the discharge gap 5
It is necessary to keep the interval between the two electrodes to a few nanometers or less, and if the ozone generation efficiency is to be improved even slightly, it is said that a discharge gap length of about 1 nanometer is desirable.

However, it is extremely difficult to form a uniform gap of only 1 m in a large device such as an industrial ozonizer, and the manufacturing cost is high.

Therefore, this invention solves the problems of the conventional ozonizer as described above, reduces the manufacturing cost structurally, promotes the ozone production reaction (FM, F2), suppresses the ozone decomposition reaction, and ozone The purpose of the present invention is to provide an ozone generator that can dramatically improve generation efficiency.

Effects of the Invention The ozone generator according to the present invention provides a porous insulator in a direction perpendicular to the original gas flow within the box through which the original gas flows, and a porous insulator in the direction perpendicular to the gas flow within or on the surface of the insulator. The device is characterized in that a plurality of high-voltage electrodes and a ground electrode are arranged alternately, and a high voltage is applied between these two electrodes from a high-voltage power source.

Example DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be explained below with reference to illustrated embodiments.

FIG. 3(a) shows the first part of the ozone generator according to the present invention.
An example was shown. Here, a porous insulator 12 is provided inside the box 11 so as to be perpendicular to the flow direction of the raw material gas 7, and inside this porous insulator 12, a plurality of high voltage electrodes 13 and a ground electrode 14 are provided. are arranged alternately at regular intervals on a straight line perpendicular to the flow of gas 7. A high voltage power source 15 is installed between the high voltage electrode 13 and the ground electrode 14.

The high-voltage power supply 15 can use any waveform such as alternating current (commercial frequency to several KHz), direct current, pulsating current, pulsed voltage, etc., but from the viewpoint of power efficiency, pulsed voltage is most desirable.

Further, the electrodes 13 and 14 may be made of metals such as stainless steel, conductive plastics, etc. as long as they are not chemically attacked by the generated ozone.

The shape of the electrode is generally divided into unequal electric field type (those with a small radius of curvature) and uniform electric field type (those with a large radius of curvature). Since the discharge occurs in the minute voids in the electrode, a stable discharge can be obtained regardless of the size of the curvature of the electrode, and is not limited by the shape and size of the electrode.

As the material for the porous insulator 12, any material that is physically, chemically, and thermally safe against discharge can be used as long as it has insulating properties.

As will be explained in detail in the section on effects below, since the ozone production reaction takes place mostly within the insulating materials 1 and 2, C! has a catalytic effect on the oxidation reaction. uzo, V2O5゜Mo5s
It is desirable to use a material containing components such as , MnO2, Oo2eg, platinum, and silver.

Porous insulators have many pores (micro discharge voids) inside them.
Since it is important to have the following characteristics, its structure may be a so-called bulk porous insulator (ceramic foam, etc.), a packed layer of powder or granules, a spiral-shaped object, etc. In addition, in the second embodiment shown in FIG. 3 (1), the electrode 13
．． 14 is installed near the surface of the porous insulating material 12 on the source gas side.

In this case, discharge will occur not only in the internal micropores of the porous insulator but also on the surface of the insulator.

Further, in the third embodiment shown in FIG. 3(C), the electrode 13.
14 are arranged in a plurality of rows inside the porous insulating material 12, and the high voltage electrodes 16 and the ground electrodes 14 are arranged in a so-called staggered pattern. In this case, discharge occurs between all adjacent high-voltage electrodes 16 and ground electrodes 14, so the range in which discharge occurs becomes wider, and as a result, the amount of ozone produced increases.

In the above configuration, the principle of ozone generation and the power efficiency improvement effect of the apparatus according to the present invention will be explained based on the embodiment shown in FIG. 3(a).

When a high voltage is applied between the electrodes 13 and 14 from the high-voltage power supply 15, a discharge occurs between the electrodes, more precisely, in the minute voids in the porous insulating material 12 between the electrodes. Due to the action of electrons generated by this discharge, oxygen molecules in the source gas are dissociated according to formula (Fl), producing oxygen atoms.

These oxygen atoms react with oxygen molecules mainly within the micropores in the porous insulating material on the downstream side of the surface containing the electrode (F2).
Ozone is produced by the formula.

In the conventional ozone generator shown in Figures 1 and 2,
Since electrons are generated throughout the discharge gap in the gas flow direction, only the reaction of the formula (Fl) occurs on the gas upstream side, but the reaction of the formula (Dl) as well as the reaction of the (Fl) formula occurs on the downstream side, so the reaction due to the discharge Ozone production and decomposition reactions occur simultaneously.

On the other hand, according to the present invention, in the downstream part of the surface including the electrode where ozone is generated according to the equation (F2), since there are almost no electrons, the reaction of the equation (Dl) hardly occurs, and therefore ozone decomposition Reactions can be suppressed.

Furthermore, the presence of the sixth object M is important in the ozone production reaction shown in equation (F2). In conventional ozone generators, oxygen molecules and nitrogen molecules are important as M, but in this embodiment, in addition to these oxygen molecules and nitrogen molecules, the surface of the porous insulator is effective as the third object. It acts on

This is because the porous insulating material 12 has an extremely large specific surface area (surface area per unit volume). Thus, in this method, the ozone production reaction according to equation (F2) is promoted.

Furthermore, the porous insulating material 12 is a material having a catalytic effect on oxidation reactions (Cu20.σ205, Mo5s).

If a material containing MnO2, Co20a, platinum, silver, etc.) is used, the ozone generation efficiency will be significantly improved in conjunction with the increase in the specific surface area.

Next, the discharge that occurs in the discharge region, that is, near the surface containing the electrode, takes the form of a microgap discharge, so it is easy to achieve "reducing the discharge gap," which is desirable in conventional ozone generators. This means that it has been done.

In this embodiment, since such microdischarges occur in an extremely large number of locations, the dissociation (Fl) equation of oxygen molecules is also promoted. On the other hand, since the voltage applied to each microgap is low, the discharge energy is also small. Therefore, the ozone decomposition reaction (Dl) equation, which is caused by an increase in gas temperature due to discharge energy, is also suppressed.

In this way, the ozone generation process (Fl
, F2, DI, Dl), the ozone generation efficiency can be dramatically increased by promoting the reaction (Fl, F2) related to ozone production and suppressing the ozone decomposition reaction (DI, Dl). I can do it.

The above-mentioned phenomenon does not depend on the applied voltage waveform, so it is
Although it is possible to use a high-voltage power source having any voltage waveform, such as DC, pulsating current, or pulsed voltage (0 to several KHz), it is most desirable to use pulsed voltage from the viewpoint of improving efficiency.

By using a pulsed voltage, it is possible to create a high electric field for an extremely short period of time, making it difficult for the transition to a high-energy discharge (spark, arc, etc.). Not only can electrons be supplied, but wasteful power consumption due to ion current can be suppressed.

These descriptions regarding the operation similarly apply to the embodiments shown in FIGS. 6(b) and 6(C).

Effects of the Invention The embodiment of the ozone generator according to the present invention is as described above, and the following effects can be achieved.

By promoting reactions involved in ozone production and suppressing reactions involved in ozone decomposition, it is possible to dramatically improve ozone production efficiency.

Furthermore, from the standpoint of device manufacturing, manufacturing costs are reduced because the electrodes are simply inserted into the porous insulator.

[Brief explanation of drawings]

Figures 1 and 2 are structural diagrams showing the conventional example, Figure 3 (a)
, (b) and (C) are embodiment diagrams showing the structure of an ozone generator according to the present invention. 1. High voltage electrode, 2. Ground electrode, 3. Dielectric, 4.
・AC high voltage power supply, 5..Discharge gap, 6..Silent discharge, 7.
... Raw material gas, 8... Ozonated gas, 11... Box, 1
2. Porous insulating material, 13. High voltage side electrode, 14.
Ground side electrode, 15... High voltage power supply. Figure 1 (a) Figure 2 Figure 3 (b) (C)

Claims (1)

[Claims] A box through which the raw gas flows, a porous insulator provided in a direction perpendicular to the flow of the raw gas inside the box, and a porous insulator provided within or on the surface of the insulator and perpendicular to the flow of the raw gas. a plurality of high voltage electrodes and ground electrodes arranged alternately in the direction;
An ozone generator equipped with a high voltage power supply that applies a high voltage between these two electrodes.