JPH0714802B2 - Ozonizer - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ozonizer that obtains ozone by contacting oxygen or an oxygen-containing gas with a discharge field.

[0002]

2. Description of the Related Art Conventionally, as a representative example of this type of ozonizer, a so-called silent discharge type is widely used as shown in FIG. In this silent discharge type ozonizer, an electrode 2 is loosely inserted into a dielectric 1 made of a glass tube with a constant distance from its inner peripheral surface, and the outside of the dielectric 1 is covered with a cooling water tank 5a. A high voltage is applied between the electrode 2 and the back side of the dielectric 1 (usually, the opposite electrode 3 is laminated) by a high voltage alternating power supply device 9 (in the illustrated example, the cooling water tank 5a is made of a conductive material). , And is electrically connected to the counter electrode 3 through the cooling water in the cooling water tank 5a.) The raw material gas flowing in from the raw material gas inlet 7 is introduced from one end side of the dielectric 1 to the dielectric material. The gas is passed through the gas passage gap 4 between the electrode 2 and the electrode 2 in 1 to flow out from the other side outlet 8. Further, a cooling water inlet 10 is provided at one end of the cooling water tank 5a and another end is provided at the other end. A cooling water outlet 11 is provided on the side.

In the above-mentioned "FIG. 5", a silent discharge field is generated in the passage gap 4 between the electrode 2 and the inner peripheral surface of the dielectric 1, and the raw material gas passes through the passage gap 4. It is contacted with the silent discharge field and is ozoned. The heat generated by the discharge is exchanged with the cooling water outside the dielectric 1 so that the heat is not stored in the dielectric 1. In addition, "Fig. 5"
Inside, 21 is a partition which also serves to hold the dielectric 1.

The one shown in FIG. 6 has been proposed as a creeping discharge type. This creeping discharge type ozonizer has a structure in which an electrode plate 2 is provided on one surface of a dielectric plate 1 made of ceramics or the like.
Is laminated by a printing means or the like, and the opposite electrode 15 is laminated or embedded in the other surface of the dielectric plate 1 or in the dielectric plate 1, and a high voltage is applied between the electrode plate 2 and the opposite electrode 15. When a high voltage is applied by the alternating-current power supply device 9, a creeping discharge is generated along the surface of the dielectric plate 1 on which the electrode plates 2 are laminated, and the raw material gas comes into contact with this creeping discharge field to be ozoned. It has been done.

[0005]

However, it is widely known that the above-mentioned conventional apparatus is still unsatisfactory in ozone generation efficiency. That is, it is said that most of the energy consumed by the silent discharge method is consumed as heat and the electric energy actually used for ozonization is only a few percent. Further, the creeping discharge method has a higher discharge density and higher ozonization efficiency than the silent discharge method, but in reality, the efficiency is only several percent higher than that of the silent discharge method.

In both of the above conventional devices, it is known that the amount of ozone generated is improved by increasing the applied voltage.
Actually, in the silent discharge method, the ozone generation amount is substantially proportional to the applied voltage up to about 10 to 15 KV, but at a voltage higher than that, the ozone generation amount is hardly improved, and in the creeping discharge method, the voltage is up to about 8 KV. On the other hand, the ozone generation amount is proportional, but at a voltage higher than that, the ozone generation amount decreases. The cause of this is not always explained clearly, but the main cause is that heat generated by electric energy is not just energy waste, it reduces the ozonization efficiency of oxygen in a high-temperature atmosphere, and furthermore, it is once ozonized. It is said that these are thermally decomposed and, as a result, the ozone generation rate is lowered.

In particular, in the above-mentioned creeping discharge method, the vicinity of the electrode plate 2 is the portion having the highest discharge density and being easily turned into ozone.
On the other hand, since this portion also generates a large amount of heat and the electrode plate 2 usually has good thermal conductivity, the electrode plate 2, especially the corners of the electrode plate 2 are heated near the darkest part of the discharge electric field, The heat reduces the ozonization efficiency, and the generated ozone is more likely to be thermally decomposed, which is consistent with the above description.

That is, the problem of the conventional ozonizer is
Since proper heat dissipation / cooling to improve ozone generation efficiency has not been performed, especially the electrode to which the high-voltage side of the pair of electrodes is connected has the need to be electrically cut off from the viewpoint of safety. This electrical insulation hinders heat dissipation / cooling, and there has been almost no heat dissipation / cooling means in the past, or inefficient heat dissipation / cooling via an electrically insulating material 1 is cooled from the back side.).

Therefore, the present invention has been made in view of the above, and an object thereof is to provide a high-power ozonizer capable of directly cooling the electrode connected to the high-voltage side.

[0010]

In order to solve the above-mentioned problems, in order to solve the above-mentioned problems, in order to solve the above-mentioned problems, the structure of the present invention, which is based on the above-mentioned claims, is provided on the outer surface side of the dielectric plate 1. One side cooling water tank 6 having the dielectric plate 1 as a part of a hermetically sealed wall is continuously provided, and a water injection pipe 12a connected to a cooling water inlet 10 of the one side cooling water tank 6 and a cooling water outlet 11 are provided.
The drainage pipe 12b connected to each of the drainage pipes 12b is provided with thin insulating flow paths 13a and 13b formed of a thin and long insulating material.
An electrode plate 2 is provided on the inner surface side of the dielectric plate 1 so as to have a raw material gas passage gap 4, and the electrode plate 2 is formed on the outer surface side of the electrode plate 2 as a part of a sealing wall. The other side cooling water tank 5 is provided in series, and the cooling water in the electrode plate 2 or the other side cooling water tank 5 is connected to the ground side output end of the high-voltage alternating-current power supply 9 and the cooling water in the one side cooling water tank 6 or one side thereof. The technical means is provided by connecting the counterpart electrode 3 housed in the cooling water tank to the high-voltage side output end of the high-voltage alternating-current power supply device 9.

[0011]

Therefore, in the ozonizer of the present invention, a discharge field is generated in the passage gap 4, and the raw material gas passing through the ozonizer has the same action as that of the conventional one.

A major function of the present invention is a cooling function. [FIG. 5] As shown in the conventional example, the water-cooling type ozonizer is conventionally known, but the feature of the present invention is that both electrodes are directly water-cooled.

However, although there has been no proposal to cool the electrode itself, in reality, directly cooling the electrode on the side where the high voltage is applied requires electrical insulation, so that a refrigerant such as chlorofluorocarbon has hitherto been used. An electrical insulating material is interposed between the electrode and the electrode. That is, since an electric insulating material having a low thermal conductivity is interposed between the electrode and the coolant, a special coolant is required. However, if the coolant having a high thermal conductivity can be brought into direct contact with the coolant, the coolant can be sufficiently cooled even if ordinary water is used as the coolant.

However, since water (especially tap water) has conductivity, when it is brought into direct contact with the electrode on the side to which a high voltage is applied, the high voltage flows through the water as a passage, causing a discharge field. In addition to damping, it is also dangerous if the entire cooling water system is not insulated. Therefore, in the present invention, since the thin and long thin insulating paths 13a and 13b made of the insulating material are provided, the thin insulating paths 13a and 13b serve as a resistance and the high voltage portion is formed on both the small insulating paths 13a. , 13b, and the cooling water is limited to the electrode 2
Even if it is brought into direct contact with, the safety is maintained and an efficient cooling action is obtained.

[0015]

Embodiments of the present invention will now be described with reference to the accompanying drawings. In the figure, reference numeral 1 denotes a dielectric plate made of ceramic or the like, and one side cooling water tank 6 having the dielectric plate 1 as a part of a hermetically sealed wall is continuously provided on the outer surface side of the dielectric plate 1.

As the above-mentioned dielectric plate 1, conventionally known ones such as glass and ceramics can be used. In this embodiment, a ceramic plate having a thickness of 1 mm or less, actually 0.5 mm is used.

The one side cooling water tank 6 is provided with a cooling water inflow port 10 on one end side and a cooling water outflow port 11 on the other end side, and the cooling water flowing from the cooling water inflow port 10 is in the one side cooling water tank 6. Through the cooling water outlet 11.

A water injection pipe 12a connected to the cooling water inlet 10 of the one side cooling water tank 6 and the cooling water outlet 1
The drain pipe 12b connected to 1 is provided with small-diameter insulating flow paths 13a and 13b each formed of a thin and long insulating material.

The small-diameter insulating flow passages 13a, 13b maintain a sufficient electric resistance value by reducing the diameter of the flow passages to increase the electric resistance value of the cooling water and setting the length thereof to a predetermined dimension. A vinyl chloride pipe 7 m with an inner diameter of 4 mm was wound around a coil for convenience of storage, and both small-diameter insulating flow paths 1
Even if a high voltage of 20 KV is applied to the cooling water (tap water) between 3a and 13b, a current or a change in voltage is recognized in the cooling water communicating downstream or upstream from the cooling water flow passages 12a and 12b. I couldn't do it.

On the inner surface side of the dielectric plate 1, an electrode plate 2 is provided oppositely with a passage gap 4 for the raw material gas.
This electrode plate 2 is made of a conductive and corrosion-resistant thin plate metal, such as stainless steel, titanium, platinum, etc., and a thin plate-like one (preferably having a thickness of 1 mm or less) is used for good heat conduction. Titanium with a thickness of 1 mm is used. The electrode plate 2 is placed in parallel with the dielectric plate 1 at a predetermined interval, and a raw material gas passage gap 4 is formed at this interval, and the raw material gas inlet port shown in FIG. 1 is formed. The raw material gas introduced from 7 passes through the passage gap 4 and flows out from the ozone outlet 8.

It is needless to say that the thinner the electrode plate 2 is, the better the cooling efficiency is, and it is desirable to make it as thin as possible. However, if the thickness is made too thin in the embodiment of FIG. It is necessary to note that the internal water pressure causes flexure and the electrode interval cannot be maintained normally.

Therefore, in the example shown in FIG. 3, the electrode plate 2 is made thin so that it does not easily bend even if it is thin.
However, a part of it is formed by an uneven thin plate that contacts the inner surface of the dielectric plate 1. Specifically, in the example shown in FIG. 3, a triangular corrugated plate is used for the electrode plate 2. That is, by complicating the cross-sectional shape, the strength is increased and the occurrence of bending is prevented. In this embodiment, a creeping discharge is generated at the portion where the electrode plate 2 contacts the dielectric plate 1, and the discharge form is different from the silent discharge in the example of FIG. In this embodiment, the raw material gas passage gap 4 is composed of a large number of passages each having a triangular cross section surrounded by the lower surface of the electrode plate 2 and the upper surface of the dielectric plate 1.

Further, in the example of FIG. 4, a flat plate is used as the electrode plate 2, but a conductive body 20 for locally connecting the electrode plate 2 and the dielectric plate 1 is locally provided between the electrode plate 2 and the dielectric plate 1. It will be installed.
Specifically, in the example shown in FIG. 4, a wire mesh body is used as the conductive body 20. That is, the conductive body 20 is sandwiched between the dielectric plate 1 and the electrode plate 2, and in this embodiment, the passage gap 4 for the raw material gas is formed from the inside of one mesh of the wire mesh body by the inclined portion of the mesh to form the dielectric body. It will be constituted by a passage which is successively communicated with the adjacent meshes through a gap formed between the plate 1 or the electrode plate 2.

On the outer surface of the electrode plate 2, the other side cooling water tank 5 having the electrode plate 2 as a part of a hermetically sealed wall is continuously provided. The other side cooling water tank 5 is the one side cooling water tank 6 described above.
Similarly, the cooling water inlet 10 is provided on one end side and the outlet 1 is provided on the other end side.
1 is provided, and the cooling water that has flowed in from the cooling water inlet 10 flows through the other side cooling water tank 5 and flows out from the outlet 11.

Further, the cooling water in the electrode plate 2 or the other side cooling water tank 5 is stored at the grounding side output end of the high-voltage alternating-current power supply 9, the cooling water in the one side cooling water tank 6 or the one side cooling water tank. The opposite electrode 3 thus formed is connected to the high-voltage output terminal of the high-voltage alternating power supply device 9. Usually, at a voltage of several KV, cooling water, especially tap water, can be regarded as a conductive material, and it is possible to energize the electrode plate 2 through the cooling water. It is also possible to use cooling water as the counter electrode. However, when the cooling water in the one side cooling water tank 6 is used as the counter electrode, it may be accompanied by some variation in electrical resistance and local voltage. Therefore, in the present embodiment, the counter electrode is formed on the outer surface of the dielectric plate 1. 3 (a silver paste is used as a good conductive material in the example).

In the figure, 17 denotes a cooling water tank and 18 denotes a pump. A water injection pipe 12a is connected to an outlet of the pump 18, and a downstream side of the water injection pipe 12a has a small-diameter insulating flow path. The cooling water inlet 10 of the one side cooling water tank 5 is connected via 13a, and the downstream end of the branched water injection pipe 19a branched at the upstream side from the small-diameter insulating flow path 13a is the cooling water inlet of the other side cooling water tank 5. It is connected to 10. further,
The drain pipe 12b connected to the cooling water outlet 11 of the one side cooling water tank 5 returns its downstream end to the cooling water tank 17 via a small-diameter insulating flow path 13b, and is connected to the cooling water outlet 11 of the other side cooling water tank 6. The downstream end of the connected second drain pipe 19b is also returned to the cooling water tank 17. In addition, 16 is a screw, 1
Reference numerals 4 and 15 indicate packings.

[0027]

According to the present invention as described above, the cooling water is applied to one surface of the dielectric plate 1 (the outer surface of the mating electrode 3 in the illustrated example).
Since it comes into direct contact with the one surface of the electrode plate 2, the cooling efficiency is high, the ozone generation efficiency is correspondingly increased, and an efficient ozonizer can be provided.

Specifically, in the embodiment shown in FIG. 4, the area of the dielectric plate 1 (ceramic having a thickness of 0.5 mm) is 10
0 cm ² · Titanium plate having a thickness of 0.1 mm for the electrode plate 2 · 50-mesh titanium net for the conductive body 20, oxygen 2 liter / min was used as the source gas, and a voltage of 10 Kz was applied for measurement. However, the following happened. (1) If the circulation of cooling water is stopped, the voltage is 7KV and 3
Ozone of 0 g / m ³ was obtained and 35 g / m at a voltage of 8 KV.
^When ozone of ³ was obtained and the voltage was set to 8 KV or more, the ozone concentration / amount of generation decreased. (2) When chiller cooling water at 15 ° C. was used as cooling water at 2 liters / minute, 40 g / m ³ at voltage 7 KV, voltage 8
KV 50g / m ³ , voltage 9KV 60g / m ³ , voltage 10KV 72g / m ³ , voltage 15KV 102g / m
Ozone of ³ was obtained. (3) 2 liters of 4 ° C chiller cooling water as cooling water
As a result, the voltage is 7 KV, 48 g / m ³ , and the voltage is 8 K.
55 g / m ³ at V, 70 g / m ^{3 at} 9 KV, voltage 1
Ozone of 3 g / m ³ was obtained at 0 KV and ozone of 120 g / m ³ was obtained at a voltage of 15 KV.

As is clear from the above measured values, there is a remarkable improvement in ozone generation efficiency by cooling,
For example, in order to obtain 80 g / m ³ of ozone with a source gas of 2 liters of oxygen per minute in FIG.
00 cm ² · 10 liters / min of 4 ° C tap water for cooling water
A voltage of 20 KV is required. In this case, even if the voltage and the amount of cooling water were variously changed, no improvement in efficiency was observed. Therefore, the cooling efficiency can be improved by directly contacting the cooling water, which enables miniaturization. As a result, the cooling area is reduced, the cooling efficiency is further improved, and as a result, a compact and efficient ozonizer can be provided.

[Brief description of drawings]

FIG. 1 is a plan view showing an embodiment of an ozonizer of the present invention.

FIG. 2 is a sectional view taken along line AA.

FIG. 3 is a cross-sectional view of a main part showing another embodiment.

FIG. 4 is a cross-sectional view of a main part showing another embodiment.

FIG. 5 is a cross-sectional view of a main part of a conventional example.

FIG. 6 is a sectional view of a main part of another conventional example.

[Explanation of symbols]

 1 Dielectric Plate 2 Electrode Plate 3 Counter Electrode 4 Passing Gap 5 Other Side Cooling Water Tank 6 One Side Cooling Water Tank 9 High Voltage Alternating Power Supply Device 10 Cooling Water Inlet 11 Cooling Water Outlet 12a Water Injection Pipe 12b Drainage Pipe 13a Small Diameter Insulation Channel 13b Small diameter insulated flow path

Claims (4)

[Claims] 1. A one side cooling water tank having the dielectric plate as a part of a hermetically sealed wall is continuously provided on the outer surface side of a dielectric plate made of ceramic or the like, and is connected to a cooling water inlet of the one side cooling water tank. A small-diameter insulating flow path formed of a thin and long insulating material is interposed between the water injection pipe and the drain pipe connected to the cooling water outlet, and the raw material gas is provided on the inner surface side of the dielectric plate. Electrode plates are provided opposite to each other with a passage gap of, and on the outer surface side of the electrode plate, the other side cooling water tank in which the electrode plate is a part of a sealing wall is continuously provided, and the electrode plate or the other side cooling water tank is provided. The cooling water in the high-voltage alternating-current power supply is connected to the ground-side output end of the high-voltage alternating-current power supply, and the cooling water in the one-side cooling water tank or the counterpart electrode stored in the one-side cooling-water tank is connected to the high-voltage side output end of the high-voltage alternating-current power supply. An ozonizer connected to. 2. The ozonizer according to claim 1, wherein the electrode plate is a flat plate parallel to the dielectric plate. 3. The ozonizer according to claim 1, wherein the electrode plate is formed of an uneven thin plate, a part of which is in contact with the inner surface of the dielectric plate. 4. The ozonizer according to claim 1, wherein a conductive material that locally connects the electrode plate and the dielectric plate is interposed between the electrode plate and the dielectric plate.