JP2641886B2 - Ozone generator - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial application field) The present invention relates to an ozone generator.

(Prior art) In general, some oxygen molecules are dissociated into an atomic state by energy due to silent discharge or photon energy of ultraviolet rays emitted from a mercury discharge tube, and this atomic oxygen is combined with oxygen molecules. To produce ozone with three atoms of oxygen.
As an example of an ozone generator using silent discharge, there is, for example, an apparatus shown in FIG. In this figure, a flat ground electrode (1a) is installed as a part of a water jacket (1) provided for cooling the same. Above the ground electrode (1a), a plate-like dielectric (2) is disposed in contact with the plate-like dielectric (2). The dielectric (2) is connected to the plate-like high-voltage electrode (4) via a discharge gap (3). A cooling fin (5) for cooling the high-voltage electrode (4) is provided in contact with the high-voltage electrode (4). The discharge gap (3) for generating ozone is formed between the lower surface of the high-voltage electrode (4) and the upper surface of the dielectric (2). The discharge gap (3) is connected to the source gas inlet (6) and the ozone gas. It is connected to the outlet (7). The water jacket (1) is provided with a cooling water inlet (8) and a cooling water outlet (9). These are all housed inside the housing (10).

And in the ozone generator of such a configuration,
A high voltage is supplied from a high voltage power supply (not shown) to the high voltage electrode (4) and the ground electrode (1a) to generate a silent discharge in the discharge gap (3). At this time, when a gas containing at least oxygen is supplied from the raw material gas inlet (6), a part of oxygen is activated in the discharge gap (3) to generate ozone.
The generated ozone is taken out from the ozone gas outlet (7). Generally, heat is generated by the discharge, and both electrodes and the inside of the discharge gap (3) become extremely hot. FIG. 5 is a graph showing the half life of the decomposition of ozone with temperature. As the temperature increases, the decomposition of ozone becomes remarkable. Therefore, in order to obtain a high concentration of ozone, the electrode and the discharge gap (3) are efficiently used.
Need to be cooled.

(Problems to be Solved by the Invention) However, in the above-mentioned conventional ozone generator, the ground electrode (1a) is sufficiently cooled by the cooling water, but in order to maintain insulation, the high-voltage electrode (4) is provided with the cooling fin (5). ), The temperature of the high-pressure electrode (4) was particularly high. Then, the temperature of the supplied oxygen rises due to the heat, and the decomposition of ozone is remarkably promoted by the rise in the temperature of the oxygen. The ozone generated by the discharge is decomposed again in the discharge gap (3) to generate ozone. There is a problem that efficiency is lowered and a desired high concentration of ozone cannot be obtained.

Here, although cooling with high efficiency can be strange by cooling the electrode with the cooling water, it is necessary to form a flow path through which the cooling water flows into a shape with good heat transfer without stagnation. As a result, it is difficult to reduce the size of the electrode cooling section, and there are many interlocks to prevent cooling water leakage or insulation due to having a flow path for cooling water near the electrodes. Operation and maintenance related to safety measures, such as alarms, were inevitable.

In the cooling of the electrodes by the cooling fins, high-efficiency cooling uses air as a cooling fluid, and therefore can be performed only by blowing air to the cooling fins by a high-output fan. It can be said that it is inevitable.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and provides a compact and simple ozone generator capable of improving ozone generation efficiency and obtaining high-concentration ozone.

[Configuration of the invention]

(Means for Solving the Problems) The present invention relates to an ozone generating apparatus for generating ozone by applying a voltage between electrodes arranged opposite to each other, comprising an apparatus main body provided in contact with the entire outer periphery of both electrodes. An electric insulating solid heat conductor to be constituted, a solid cooling block provided in contact with an outer surface of the solid heat conductor, a cooling device for circulating a cooling fluid to cool the solid cooling block, A temperature controller for detecting the temperature of the solid cooling block and controlling the cooling device.

(Function) The present invention is provided with a cooling mechanism comprising a heat conductor having electrical insulation in contact with the periphery of both electrodes arranged opposite to each other, and a cold heat source for integrally cooling the two electrodes via the heat conductor. Thereby, the electrode to which the voltage is applied can be directly cooled by the low-temperature heat conductor, so that the cooling capacity is significantly improved. And since it cools both electrodes using a solid heat conductor instead of liquid cooling, it is not necessary to form a flow path of the cooling liquid,
The apparatus can be made compact, and the manufacture, operation and maintenance of the apparatus are simplified.

Furthermore, since the electrical insulation between the two electrodes can be sufficiently ensured, it is possible to prevent the discharge between the electrodes due to the leakage of the liquid to the electrode surface or the like, and to suppress the occurrence of danger due to the short circuit. This makes it possible to improve the reliability of the entire equipment using the generator.

(Embodiment) An embodiment of the present invention will be described below with reference to the drawings.

For example, a plate-like high-voltage electrode (11) made of titanium, and a plate-like ground electrode (11) opposed to the high-voltage electrode (11) via a gap (13) adjusted by a spacer (12) and a ceramic dielectric (14). 16) is provided. A flat heat conductor (17) made of a material having good electrical insulation and good heat conductivity, for example, ceramics such as alumina, beryllia, and magnesia (17) is provided in contact with the outer periphery of both electrodes. Are integrated and joined to a cooling block (18) functioning as a cooling source having a sufficiently large amount of heat. This cooling block (18)
Cooling coil (19) for cooling the cooling block (18)
The cooling device (20) for circulating cooling water through the cooling coil (19) and the cooling block (18) are always kept at a predetermined temperature. A temperature control device (21) having a function of sending a control signal to the cooling device (20) is provided.

Then, the high-voltage electrode (11) and the ground electrode (1), which form a discharge region in opposition to the gap (13) via the dielectric (14), are formed.
6), a gas supply port (22) for supplying a gas containing at least oxygen is provided, and an oxygen supply source (24) is provided through the gas supply port (22) gas flow controller (23). )
It is connected to the. Further, a gas outlet (25) capable of discharging a gas containing at least ozone is provided at a portion facing the gas supply port (22). A high voltage power supply (26) is connected and installed so as to apply a voltage to the high voltage electrode (11) and the ground electrode (16). Thus, an ozone generator is configured.

Next, a method of generating ozone by the above-described ozone generator will be described.

First, the temperature of the cooling block (18) is controlled by a temperature control device (2
While monitoring by 1), cooling water or the like is circulated from the cooling device (20) into the cooling coil (19) to cool the cooling block (18) to a predetermined temperature. This cooling block (1
With the cooling of 8), high voltage electrode (11) and ground electrode (16)
The plate-like heat conductor (17) mounted on the outer periphery of is cooled.

Then, a high voltage of, for example, a frequency of about 1 to 10 KHz and a voltage of about 1 to 10 KV is applied to the high-voltage electrode (11) and the ground electrode (16) in a cooled state by a high-voltage power supply (26). At this time, the desired flow rate is set to, for example, 0.1 by the oxygen supply source (24) and the gas flow controller (23).
A gas containing at least oxygen of about 1 to 20 Sl / min flows from the gas supply port (22) to the gap (13). Here, ozone is generated by a silent discharge generated in a discharge region in which a dielectric (14) and a gap (13) are provided between the electrodes (11) and (16) to which a voltage is applied, and is shown from a gas outlet (25). A gas containing ozone is sent to a processing section or the like that uses ozone that is not used.

Note that the lifetime of the generated ozone depends on the temperature. As shown in FIG. 5, the higher the temperature is, the shorter the lifetime of the ozone becomes. For this reason, it is necessary to sufficiently lower the temperature in the vicinity of both electrodes (11) and (16), which are heating elements, and to set the cooling block (18) so that the temperature of the flat heat conductor (17) becomes, for example, 20 ° C. or less. It is desirable to control the temperature of (1).

Here, both electrodes (11) and (16) of the above-mentioned ozone generator
When the temperature of the cooling block (18) is reduced to about 1 to 2 ° C. by an electrically insulating heat conductor (17), and the air temperature is reduced to about 20 ° C. by cooling the high-voltage electrode (11) with a fan. The air flow rate is about 20Sl / min and the ground electrode (16) is liquid cooled with water, the water temperature is about 20 ° C and the cooling water flow rate is 0.5 / min.
FIG. 2 shows a comparison of the relationship between the supplied oxygen flow rate and the generated ozone concentration in the case of about the same. As can be seen from this characteristic example, when the oxygen flow rate is small, there is a remarkable difference in the concentration of generated ozone. This is the same as showing the difference in the ability to cool both electrodes (11) and (16). When a heat conductor (17) having electrical insulation is used, these electrodes (11) and (16) are cooled. 16) can be directly cooled at a low temperature, and the cooling capacity is significantly improved. Since the two electrodes (11) and (16) are cooled by using a solid heat conductor (17) instead of the cooling liquid, it is not necessary to form a flow path for the cooling liquid, and the apparatus is very compact. The operation and maintenance of the apparatus are simplified. Further, since the electrical insulation of the two electrodes (11) and (16) can be sufficiently ensured, the reliability of not only the ozone generator but also the entire equipment using the ozone generator can be improved.

FIG. 3 is a block diagram showing another embodiment of the apparatus of the present invention, which is capable of generating a large amount of ozone by increasing the scale by stacking a plurality of apparatuses shown in FIG. , Multiple electrodes in one cooling block (18)
As a result, it is possible to cool the apparatus, and as a result, it is possible to make the apparatus more compact and to use the space effectively.

Although the thermoelectric conductor of the above embodiment has been described using ceramics as a material having good electrical insulation and good thermal conductivity, the present invention is not limited to this. For example, metal oxides such as quartz and rutile, high alumina Any material, including bricks such as bricks and carbon bricks, may be used as long as the material has good electrical insulation and excellent thermal conductivity.

Further, the discharge between the electrodes (11) and (16) in the above embodiment is as follows.
Although the silent discharge in which the dielectric (14) and the air gap (13) are provided between the electrodes has been described, a discharge for generating ozone may be used, and a corona discharge or a glow discharge may be used.

As described above, according to this embodiment, a cooling system including an electrically insulating heat conductor that is in contact with the periphery of the opposed electrodes and a cooling source that cools the electrodes integrally through the heat conductor. By providing the mechanism, the electrode to which the voltage is applied can be directly cooled by the low-temperature heat conductor, so that the cooling capacity is significantly improved. Further, since both electrodes are cooled by using a heat conductor instead of liquid cooling, it is not necessary to form a flow path of a cooling liquid, and the apparatus can be compactly configured. Maintenance is simplified.

Furthermore, since the electrical insulation between the two electrodes can be sufficiently ensured, it is possible to prevent the discharge between the electrodes due to the leakage of the liquid to the electrode surface or the like, and to suppress the occurrence of danger due to the short circuit. It is possible to improve the reliability of the entire equipment using the generator.

〔The invention's effect〕

As described above, according to the present invention, the efficiency of ozone generation can be significantly improved by improving the cooling efficiency of the electrodes of the ozone generator, and a compact, simple, and highly reliable apparatus is provided. can do.
Further, a solid cooling block is provided in contact with the electrically insulating solid heat conductor provided in contact with the periphery of the electrode, and the solid cooling block is cooled by a cooling device, and the temperature of the solid cooling block is detected to activate the cooling device. By performing the control, the solid thermal conductor can also serve as the apparatus main body, and further, there is an effect that the temperature management is easy because the heat holding amount is large and the temperature change is small.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of an ozone generator for explaining an embodiment of the apparatus of the present invention, FIG. 2 is a curve diagram for explaining the effect of cooling in FIG. 1, and FIG. 3 is a diagram of FIG. FIG. 4 is a diagram showing the configuration of a conventional ozone generator, and FIG. 5 is a curve diagram showing the relationship between temperature and the half-life of ozone decomposition. 11 High voltage electrode, 16 Ground electrode, 17 Thermal conductor, 18 Cooling block, 20 Cooling device, 21 Temperature control device.

Claims (1)

(57) [Claims] 1. An ozone generator for generating ozone by applying a voltage between electrodes disposed opposite to each other, comprising: an electrically insulating solid heat constituting an apparatus main body provided in contact with the entire outer periphery of both electrodes. A conductor, a solid cooling block provided in contact with the outer surface of the solid thermal conductor,
An ozone generator comprising: a cooling device that circulates a cooling fluid to cool the solid cooling block; and a temperature control device that detects a temperature of the solid cooling block and controls the cooling device.