JP3804229B2 - Ozonizer - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an ozonizer for generating ozone used for water treatment and the like.
[0002]
[Prior art]
Ozonizers are widely used in water treatment facilities and the like in order to utilize the bactericidal, decolorizing and deodorizing power of ozone. 2A and 2B show the structure of an example of a single-side cooling ozonizer of an ozonizer according to the prior art. FIG. 2A is a longitudinal sectional view showing the entire structure, and FIG. 2B shows a part of an ozone generating tube. It is sectional drawing of the length direction shown in detail. The single-side cooling ozonizer is an ozonizer having a structure in which only the ground electrode of the ozone generating tube is cooled with cooling water.
[0003]
The housing of this ozonizer is composed of a cylindrical body 1 made of stainless steel having both ends open and two side plates 21 and 22 made of stainless steel fastened to both open ends. ing. Since the body 1 and the two side plates 21 and 22 need to be airtightly connected, screws (not shown) are connected to both ends of the opening through flat packings (simply packings in FIG. 2) 81 and 82, respectively. It is connected using a fastening means such as. On the inner surface side of the body portion 1, support plates 41 and 42 made of at least a pair of stainless steel for holding a large number of ozone generating tubes are fitted at appropriate intervals. On the tube wall of the body portion 1, there is a gas inlet 11 for supplying a raw material gas to an intermediate position between the side plate 21 and the support plate 41 on the side plate 21 side, and a side plate 22 on the opposite side and a support plate on the side plate 22 side. There is a gas outlet 12 for taking out the gas containing the generated ozone at a position intermediate with 42. Further, a cooling water inlet 13 for allowing cooling water to flow in and a cooling water outlet 14 for discharging the cooling water are provided substantially opposite to each other between the two support plates 41 and 42. Usually, the cooling water inlet 13 is provided in the lower part and the cooling water outlet 14 is provided in the upper part. In addition, a voltage introduction terminal 72 is mounted at a position near the side plate 21 of the body 1.
[0004]
The ozone generating tube supported by the support plates 41 and 42 is composed of a ground-side ground electrode 5 made of cylindrical stainless steel having both ends open, and a discharge gap having a substantially constant gap length inside the ground electrode 5. And a high-voltage electrode 6 disposed through 56. The ground electrode 5 includes a metal tube 51 made of stainless steel, and a lining (a glass tube is inserted inside the metal tube 51 and the glass is softened by induction heating in a state where internal pressure is applied. The glass dielectric layer 52 is formed by a technology for forming a glass layer on the glass dielectric layer 52. Near both ends of the lower portion of the outer surface of the high-voltage electrode 6, a protrusion 61 for holding the discharge gap 56 is formed by welding. The ozone generating tube is fitted into through holes formed in the support plates 41 and 42 and supported by the support plates 41 and 42, and the contact portion is not shown so that the cooling water does not leak. Sealed by a ring.
[0005]
The reason why stainless steel is used for the housing, the ozone generating tube, etc. is that stainless steel has resistance to the strong oxidizing action of ozone. One of the high-frequency voltages supplied from the high-frequency power source 73 to the ozone generator tube is supplied from the voltage introduction terminal 72 attached to the body 1 to the high voltage electrode 6 of each ozone generator tube via the lead wire 71. The other of the high-frequency voltages of the high-frequency power source 73 is connected to the ground potential point, and is simultaneously connected to the body 1 and is connected to the ground electrode 5 through a lead wire (not shown).
[0006]
The cooling water for cooling the ground electrode 5 of the ozone generating pipe is cooled by the heat exchanger 93 and pressurized by the pump 92, supplied to the water jacket 3 from the cooling water inlet 13 through the cooling pipe 91, and grounded electrode 5. Then, the cooling water exit 14 passes through the cooling pipe 91 and returns to the heat exchanger 93. This cooling system is a known industrial water supply system, and industrial water is often used as the cooling water.
[0007]
In such a single-sided cooling ozonizer, a source gas (such as air or oxygen) containing oxygen supplied from the gas inlet 11 flows into the discharge gap 56 from the opening of the ground electrode 5 on the side plate 21 side, and in the discharge gap 56. A part of oxygen is ozonized by silent discharge, and is extracted from the gas outlet 12 as a gas containing ozone. A pressure regulating valve (not shown) is mounted behind the gas outlet 12, and the pressure value of the gas is adjusted to, for example, 1.7 atm to supply a gas containing ozone to the consuming equipment.
[0008]
FIG. 3 shows the structure of an example of a double-sided cooling ozonizer in the conventional ozonizer. (A) is a longitudinal sectional view showing the entire structure, and (b) is a part of an ozone generating tube. It is a fragmentary sectional view of the length direction shown in detail. The double-sided cooling ozonizer is an ozonizer having a structure in which both the ground electrode and the high voltage electrode of the ozone generating tube are cooled with cooling water.
[0009]
The double-sided cooling ozonizer is different from the single-sided cooling ozonizer shown in FIG. 2 in that both ends of the high-voltage electrode 6a are closed and cooling pipes for introducing cooling water are attached to the cooling water. That is. Since the high voltage electrode 6a needs to be electrically insulated from the ground potential, high resistance ion exchange water is used as the cooling water. Further, the manifolds 95 and 96 for branching the cooling water provided in the body portion 1 and the cooling pipe are connected by an insulating tube 97 and are electrically insulated. Further, the cooling water system is equipped with an ion exchanger 94 for maintaining a high resistance value of the cooling water.
[0010]
4A and 4B show the structure of an example of a glass tube type ozonizer of conventional ozonizers. FIG. 4A is a longitudinal sectional view showing the entire configuration, and FIG. 4B is a vertical sectional view thereof. It is. The glass tube type ozonizer has a ground electrode 5a made of cylindrical stainless steel with both ends opened, and a metal film 6b2 made of aluminum or stainless steel formed by sputtering or vapor deposition on the inner surface of the glass tube 6b1 closed at one end. And an ozone generating tube comprising a high voltage electrode 6b having The glass tube 6b1 functions as a dielectric layer. The high voltage electrode 6b is held by a stainless steel spacer 62, and the discharge gap 56 is maintained. As described above, the structure of the glass tube ozonizer is similar to that of the single-side cooling ozonizer.
[0011]
The conventional ozonizer as described above is an ozonizer suitable for the supply of ozonized gas. However, due to the demand for processing technology, the conventional ozone concentration of 100 g / Nm3 is increased to a higher ozone concentration, for example, 150 to 200 g / Ozonized gas increased to Nm3 has become necessary. As a method for increasing the ozone concentration, it is known that the discharge gap 56 may be narrowed. However, it has been difficult to realize a uniform and narrow discharge gap 56 on an industrial scale because of the manufacturing accuracy of electrodes in manufacturing technology. For example, even if an attempt is made to hold the discharge cap 56 at 0.5 mm or less, since the electrode is curved, the discharge cap 56 varies in the longitudinal direction of the electrode, resulting in non-uniform discharge and gas flow in the electrode surface. The problem is that the yield of ozonizers that can produce ozonized gas containing high-concentration ozone is low.
[0012]
[Problems to be solved by the invention]
An object of the present invention is to provide an ozonizer that solves the above-described problems and obtains an ozonized gas containing high-concentration ozone, has a high yield rate, and is inexpensive.
[0013]
[Means for Solving the Problems]
In order to solve such a problem, in the present invention, a cylindrical ground electrode having both ends opened, a high voltage electrode disposed inside the ground electrode via a gap, and disposed between both electrodes In an ozonizer that includes an ozone generator tube made of a dielectric layer and a housing containing the ozone generator tube, and generates ozone by discharge of a source gas containing oxygen introduced into the housing, a high-voltage electrode The outer diameter in the vicinity of the terminal end in the gas flow direction is expanded.
[0014]
By expanding the vicinity of the terminal portion of the high voltage electrode, the fluid resistance of this portion is increased, and the nonuniformity of the gas flow due to the nonuniformity of the discharge gap in the previous portion is alleviated.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the ozonizer according to the present invention will be described using examples. Also in this invention, since the basic configuration is the same as that of the prior art, the same reference numerals are used for portions having the same functions as those of the prior art.
[0016]
FIG. 1 is a partial sectional view in the length direction showing a part of an ozone generating tube according to an embodiment of the present invention. Although this embodiment is shown as a structure of a single-side cooling ozonizer, it is also effective for an ozonizer having another structure.
[0017]
The high voltage electrode 6c of this embodiment includes a diameter enlarged portion 6c1 in which the diameter in the vicinity of the end portion in the gas flow direction is expanded. Since the gas flow path is throttled by the enlarged diameter portion 6c1, the fluid resistance in this portion is sufficiently larger than in other portions. As a result, the gas flow non-uniformity due to the variation in the gap length of the discharge gap on the upstream side is alleviated. In the example, as a result of setting the gap length of the terminal portion to 1/6 of the average gap length of the upstream portion, it was possible to increase the concentration of generated ozone.
[0018]
【The invention's effect】
According to the present invention, the ozone is composed of a cylindrical ground electrode having both ends opened, a high voltage electrode disposed inside the ground electrode via a gap, and a dielectric layer disposed between both electrodes. In an ozonizer comprising a generator tube and a housing containing an ozone generator tube, and generating ozone by discharge of a source gas containing oxygen introduced into the housing, the outside of the high voltage electrode near the end portion in the gas flow direction Since the diameter is expanded, the fluid resistance of this portion is increased, and the non-uniformity of gas flow due to the non-uniformity of the discharge gap in the previous portion is alleviated. Therefore, by slightly changing the electrode shape, an ozonizer with a small discharge gap and high concentration ozone can be obtained at a high yield rate, and an inexpensive material with low processing accuracy can be used. become.
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional view of an ozone generating tube showing the structure of an embodiment of an ozonizer according to the present invention. FIG. 2 shows the structure of an example of a single-side cooling ozonizer according to the prior art, and FIG. FIG. 3B is a longitudinal sectional view showing a part of an ozone generating tube in detail. FIG. 3 shows a structure of an example of a double-sided cooling ozonizer according to the prior art, and FIG. FIG. 4B is a partial cross-sectional view in the length direction showing a part of the ozone generating tube in detail. FIG. 4 shows a structure of an example of a conventional glass tube ozonizer, (A) is a longitudinal sectional view showing the entire configuration, (b) is a vertical sectional view thereof [Explanation of Symbols]
1 Body 11 Gas inlet 12 Gas outlet 13 Cooling water inlet 14 Cooling water outlet 21, 22 Side plate 3 Water jacket 41, 42 Support plate 5, 5a, 5b Ground electrode 51 Metal tube 52 Glass dielectric layer 56 Discharge gap 6, 6a , 6b, 6c, High voltage electrode 61 Projection body 62 Spacer 6b1 Glass tube 6b2 Metal film 6c1 Diameter enlarged part 63 Nut 71 Lead wire 72 Voltage introduction terminal 73 High frequency power supply 74 Connection member 81, 82 Packing 91 Cooling pipe 92 Pump 93 Heat exchange vessel

Claims (1)

An ozone generator tube composed of a cylindrical ground electrode open at both ends, a high voltage electrode disposed inside the ground electrode via a gap, and a dielectric layer disposed between both electrodes, and ozone generation And an ozonizer that generates ozone by discharge of a source gas containing oxygen introduced into the housing, and the outer diameter in the vicinity of the terminal portion in the gas flow direction of the high-voltage electrode is expanded. Ozonizer characterized by that.

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