JPH052603B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an ozone generator (hereinafter referred to as an ozonizer).

In conventional ozonizers, a glass plate is interposed between parallel plate or parallel concentric cylindrical electrodes, and AC high voltage is applied to generate a silent discharge in the gap between the electrodes.
During this time, drying air or oxygen was passed through, and the oxygen was converted into ozone by the discharge chemical action unique to the silent discharge, thereby generating ozone. However, the power efficiency of ozone generation using this method was extremely low, remaining at a few percent of the theoretical value. In contrast, the inventor of the present application has another invention "Ozone generator" (filed on February 23, 1972; patent application filed in 1982-
21878) proposed a method to improve power efficiency by utilizing the effective ozone generation effect of creeping corona discharge, which generates extremely short pulses with extremely short pulse widths and high voltages. It had the disadvantage of overheating the body.

In order to improve these drawbacks, the present inventor first developed another prior invention, ``Ozone Generator (December 15, 1982).
(Japanese patent application No. 1983-219455) was completed.

The prior invention uses an extremely short pulsed high voltage with a significantly short pulse width, which is the same as the other invention, but it generates a strong streamer corona discharge in the gas space and suppresses the chemical action of the discharge. The purpose of the present invention is to provide an ozonizer that can be used to overcome the above problems and achieve a significant improvement in power efficiency.

The purpose of the present invention is to improve the drawbacks of the above-mentioned separate invention, which is the same as the above-mentioned prior invention, but the present invention has an additional purpose of solving the above-mentioned streamer corona discharge that may sometimes shift to spark discharge. The objective is to prevent this and ensure stable ozonizer discharge.

The space discharge type ozone generator of the present invention has a partition wall that partitions a gas inlet and a gas outlet inside the box, and a gas passage that passes through the partition wall and is provided between a silent discharge electrode, a counter electrode, and each of the electrodes. In a space discharge type ozonizer, each of the silent discharge electrodes of the plurality of pairs of counter electrodes is connected in series in sequence, and a gap between the silent discharge electrode and each counter electrode is provided. This is to connect an ultra-short high-voltage pulse power source to the

The pulse width of the ultra-short high voltage pulse used in the present invention is between 1 ns and several tens of μs, especially 1 ns.
It is preferable to select between 1000ns and 1000ns. When such an ultra-short pulsed high voltage is applied between opposing electrodes, an extremely strong silent discharge can be generated from one of the discharge electrodes without generating sparks, and its effective ozone generation effect can be enhanced. It becomes possible to use it stably. In this case, the opposing electrodes may be two cylindrical electrodes provided concentrically, or both may be flat discharge electrodes.
The silent discharge electrodes of the plurality of pairs of electrodes made up of these two electrodes are connected in series to increase their total length, and the pulse width of the extremely short pulse high voltage applied to one end of the silent discharge electrodes is significantly reduced. In this case, the pulsed high voltage propagates as a traveling wave along these elongated electrode pairs, and in the process, the pulsed high voltage becomes uniformly strong over the entire space of the gas passage provided between the two discharge electrodes. This generates silent discharge, and its ozone generation efficiency is further improved significantly. In this case, the speed of the traveling wave is ν
0.3 [m/ns], and its geometric wavelength is l=0.3τ [m] when the pulse width is τ [ns]. And, with respect to the total length L [m] of the elongated electrode pair, l
In other words, when the pulse width τ of the extremely short pulse high voltage is selected to be approximately τl/(0.3) [ns], the pulse high voltage behaves as a traveling wave in this way. In this way, the long and large electrode pair that causes the applied pulsed high voltage to behave as a traveling wave and generates a strong silent discharge unique to the traveling wave high voltage is formed as a silent discharge transmission line. The condition for making it such a silent discharge transmission line is to set its length L [m] to L0.3τ [m] for the pulse width τ [ns], but in reality, The properties of traveling waves remain even at L0.1τ [m], which is about /3, and the discharge chemical action that occurs here maintains the same level of activity. In this case, it is necessary that the air and oxygen used for ozone generation be sufficiently dry (for example, with a dew point of -40°C or less). Furthermore, it is preferable to sufficiently cool one or both electrodes by an appropriate method, thereby further improving the ozone yield.

In this way, the present invention utilizes a stable, uniform and strong silent discharge formed by a traveling wave ultra-short pulse high voltage, which is uniform over the entire cross-sectional area and length of the chemically active gas passage. It exhibits an excellent effect of being able to effectively generate ozone with significantly higher power efficiency than the above-mentioned ozonizer, and greatly improves the economic efficiency of ozone generation.

Furthermore, as the ultra-short pulse high voltage power supply to be used in the present invention, the present inventor has separately invented "Pulse power supply" (Patent application 1983-4183) and "Pulse power supply device" (Patent application 1986-4183).
109717), “Ultrashort pulse high voltage generator” (Special application
56-144399), “High-voltage ultra-short pulse power supply” (Special application
57-172797), etc., but the present invention is not limited thereto, and any ultrashort pulse high voltage power source of any suitable type and structure may be used.

To explain the present invention with reference to the embodiments shown in the accompanying drawings, in FIG. An inner cylindrical discharge electrode 3 is provided inside the electrode 2 via a dielectric layer 4 and a gas passage 5, and the outer cylindrical electrode 2 is grounded.
a, 1b... are arranged in parallel inside the box 14, and the inner cylindrical discharge electrodes 3, 3a, 3b... are sequentially connected in series as shown in the figure to form a long discharge transmission line 5. Conductor wires 7, 7a from short pulse high voltage power supply 6
Then, an extremely short pulse high voltage is applied to the input end 9 of the silent discharge transmission line 5 through the insulator tube 8 with a polarity such that the inner cylindrical discharge electrodes 3, 3a, . . . are negative. The peak value is V _p = when the distance between the electrodes is 20 [mm]
Approximately 30 to 40 [KV] is sufficient. Also,
The pulse width is L if the total length of the silent discharge transmission line 5 is
= 100 [m], τ = about 300 [ns] so as to satisfy the traveling wave formation condition L0.3τ (as already mentioned, L0.1τ may be set with L = 30 [m]).
Therefore, the pulsed high voltage is applied to the electrode pair as a traveling wave.
Propagates along -3→2a-3a→2b-3b,
During this period, a strong negative silent discharge is generated over the entire cross-sectional area and length of the gas passage 5, and finally reaches the open end 10, where it is reflected with the same polarity and proceeds in the opposite direction, thus producing the long silent discharge. The energy is finally consumed through multiple reflections on the transmission line 5, and the peak value V _p decreases, causing the silent discharge to disappear. Next, after a certain period, pulse high voltage is applied again from the ultra-short pulse high voltage power supply 6 and the same process is repeated, and the frequency can be arbitrarily selected between 50 [Hz] and several tens [KHz]. . In the figure, reference numerals 12 and 12a denote a grounded conductor partition for preventing gas from bypassing the outer cylindrical electrodes 2, 2a, 2b, . be. 15, 16... are conducting wires for connecting the two inner cylindrical discharge electrodes 3 and 3a, and 3a and 3b in series. Now gas inlet 17
When drying air or oxygen is introduced into the box 14 and allowed to flow through the outer cylindrical electrodes 2, 2a, 2b, etc., and placed under the action of the negative silent discharge, the strong chemical effects of the discharge occur. Ozone is generated with extremely high power efficiency, and the gas containing the generated ozone is supplied to the outside from the gas outlet 18.

FIG. 3 shows details of the electrode pair 1 described above in an enlarged sectional view, and the inner cylindrical electrode 3 is formed by adhering a metal foil film or the like to the inner surface of a dielectric layer 4 made of a glass tube or the like. It is something. Also, outer cylindrical electrode 2
A long silent discharge line 5 between the inner surface of the cylindrical dielectric layer 4 and the outer surface of the cylindrical dielectric layer 4 is used as a gas passage, and the above-mentioned air or oxygen is passed through this passage.

However, the electrode pair 1 of the present invention is not limited to such a structure, and its structure can be changed as appropriate.

For example, as shown in FIG. 4, the outer cylindrical electrode 2 is formed in close contact with the outer periphery of the outer cylindrical dielectric 11, and a gas passage is formed between the outer surface of the inner cylindrical electrode 3 and the inner surface of the outer cylindrical dielectric 11. It is also possible to form a long silent discharge transmission line 5.

Further, as shown in FIG. 5, the outer cylindrical electrode 2 is formed in close contact with the outer surface of the outer dielectric layer 11, and the inner cylindrical electrode 3 is formed in close contact with the inner surface of the inner cylindrical dielectric layer 4.
A gas passage may be formed between both dielectric layers 21 and 4, or two flat electrodes 22 and 4 may be formed as shown in FIG.
A flat dielectric layer 24 is interposed between the pair of flat electrodes 21 consisting of 23, and a silent long large discharge transmission line 5 serving as a gas passage is formed between this dielectric 24 and the aforementioned flat electrode 22. You can also

Furthermore, as shown in the figure, the electrode pair 1 in FIG.
2,33 One or both of the radii r ₁ and r ₂ are changed in the direction of travel of the traveling wave of the pulsed power supply, thereby increasing the capacitance (per unit length) between the two electrodes.
It is formed so that C=2πε ₀ ln (r ₂ /r ₁ ) decreases in the direction of travel.

In this case, the long electrode pair in FIG. 1 reflects the traveling wave of the pulsed high voltage at its final open end 10, while the one in FIG. Partial reflection is performed, and this reflected wave is superimposed on the input wave to compensate for the gradual decrease in the wave height of the pulse voltage due to ozonizer discharge, making it possible to utilize most of the energy of the pulse wave to generate silent discharge. .

Furthermore, instead of making the unit silent discharge transmission line 5 into a tapered shape so that the radii r ₁ and r ₂ gradually change according to the direction of the traveling wave and the capacitance C gradually decreases as shown in FIG. As in the embodiment shown in FIG. 8, one or both of radii r ₁ and r ₂ sequentially changes according to the direction of the traveling wave, and as a result, the capacitance C decreases. It is also possible to arrange a plurality of 41b in series to perform the above-described partial reflection of the traveling wave at each contact point of the unit electrode pair. In this case, compared to the one in FIG. 7, the electrode pairs 41, 41a,
41b is easy to work with. Although such partial reflection occurs, generally speaking, it is sufficient to increase the surge impedance Z ₀ =√ (where L is the inductance per unit length) of the transmission line in the traveling direction; It is also possible to use it once. In this figure, numeral 44 is a coil L for increasing the surge impedance of the long discharge transmission line 45 stepwise in the traveling direction, and it goes without saying that the value of L needs to be increased as it goes downstream.

Also, the parts in the drawings having the same reference numerals as those in FIG. 1 have the same functions.

As described above, the present invention forms a silent discharge transmission line for uniformly generating traveling wave silent discharge over the entire cross-sectional area and length, so that the ozone generation efficiency is extremely high.

Furthermore, since a dielectric layer is provided between both electrodes, it is possible to generate stable ozonizer discharge without generating spark discharge between the two electrodes.

Furthermore, by increasing the surge impedance of the long silent discharge transmission line continuously or stepwise along the traveling direction of the pulse traveling wave, the pulse wave head is partially reflected, thereby further improving the ozonizer efficiency. I can do it.

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional view of the ozone generator of the present invention,
Fig. 2 is a sectional view of the - line part in Fig. 1, Fig. 3 is an enlarged view of a part of Fig. 2, Fig. 4 is a sectional view of another embodiment of the part of Fig. 6 is a cross-sectional view of the portion shown in FIG. 3 or another embodiment, and FIG. 7 is a cross-sectional view of the portion shown in FIG. 1 according to another embodiment. 8 is a sectional view of another embodiment of the main part of FIG. 1. 1, 1a, 1b... electrode pair, 2, 2a, 2b...
...Electrode, 3, 3a, 3b... Electrode, 4... Dielectric layer, 5... Discharge transmission line, 6... Extreme pulse high voltage power supply.

Claims (1)

[Claims] 1. A gas inlet 17 and a gas outlet 18 are provided in the box 14.
A partition wall 12a, 12b is provided to partition the gap between the silent discharge electrode 3, the counter electrode 2, the gas passage 5 provided between the electrodes, and the planar dielectric layer 4. In a space discharge type ozonizer provided with a plurality of pairs of counter electrodes 1, the silent discharge electrodes 3 of the plurality of pairs of counter electrodes are sequentially connected in series, and a pulse width is set between the silent discharge electrode 3 and each counter electrode 2. A space discharge type ozone generator characterized by connecting an extremely short high voltage pulse power supply of several tens of microseconds or less, especially 1000ns or less. 2 A cylindrical silent discharge electrode and a counter electrode in which a counter electrode consisting of a silent discharge electrode, a counter electrode, a gas passage provided between each electrode, and a planar dielectric layer 4 are arranged concentrically. 2. The space discharge type ozone generator according to claim 1, wherein the counter electrodes are formed of a gas passage and a planar dielectric material concentrically formed between the respective electrodes. 3 Silent discharge electrodes and counter electrodes each having a flat plate shape, in which counter electrodes consisting of a silent discharge electrode, a counter electrode, a gas passage provided between these electrodes, and a planar dielectric layer 4 are arranged in parallel to each other. 2. The space discharge type ozone generator according to claim 1, further comprising: a plurality of counter electrodes comprising a gas passage and a planar dielectric material formed between and parallel to each of the electrodes. 4. The device according to any one of claims 1 to 3, characterized in that the surge impedance between the two electrodes is formed so as to increase continuously or stepwise along the traveling direction of the pulse traveling wave. Space discharge type ozone generator. 5. The space discharge type ozone generator according to claim 4, wherein the capacitance between the two electrodes decreases along the traveling direction of the pulse wave. 6 The two electrodes and the gas passage between them are connected in series with each silent discharge electrode of a plurality of ozonizers each composed of a planar dielectric layer, and a discharge voltage is applied downstream to the connecting portion of each silent discharge electrode. 5. The space discharge type ozone generator according to claim 4, wherein an inductance is inserted to increase the inductance.