JPH0431302A - Ozone generator - Google Patents

Abstract

PURPOSE:To surely prevent humidity from penetrating from a reacting vessel into an ozone generator by subjecting valves provided on inlet side and outlet side of the generator to closing operation when the ozone generator is stopped. CONSTITUTION:Air which is a raw material is collected by a blower 21 and cooled and dried by a dryer 22 and introduced through a piping 23 and valve 27 into an ozone generator 24 to generate ozone. Then the generated ozone is introduced through a lead pipe into a reacting vessel 26, where various reactions such as decolorization and sterilization are carried out. Then when the ozone generator 24 is stopped, two valves 27 are automatically subjected to closing operation and simultaneously a valve 31 is subjected to opening operation and pressurized air fed from a compressor 28 is dried by a dryer 30 and introduced into the ozone generator 24. Thereby deterioration of a conductive film in the generator 24 by the penetrated humidity is prevented and breakage of a discharge tube can be prevented.

Description

[Detailed description of the invention]

[Object of the Invention] (Industrial Field of Application) The present invention relates to improvements in ozone generators used in various fields such as, for example, urine treatment. (Prior art) In Europe, since 1906, 1. Ozone generators have been used for many purposes, and even today, ozone is used for a variety of purposes, including pre-ozonation, intermediate-ozonation, and post-ozonation. In addition, in Japan, ozone generators have been used in human waste treatment plants for the purpose of decolorization. In recent years, in Japan, mainly at water treatment plants in large cities,
The application of ozone generators as advanced treatment facilities for water purification is being considered. Furthermore, for the large-scale ozone generators used in these facilities, consideration has been given to using a cooling cylindrical multi-tube system from the standpoint of cooling efficiency. FIG. 3 is a sectional view showing an example of the internal configuration of this type of conventional ozone generator. In FIG. 3, an empty chamber 3 is created in a container 1 using two partition walls 2, and one side has a raw material gas population 4.
and an ozonized gas outlet 5 on the other side. Further, it is connected to a cylindrical metal tube 6 serving as a ground electrode or a partition wall 2 to form a cavity 7, with a cooling water port 8 at the bottom and a cooling water outlet 9 at the top. Furthermore, a cylindrical glass discharge tube 1
0 or is fixed concentrically inside the cylindrical metal tube 6 by a spacer (not shown). This discharge tube 10 has a conductive film 11 attached to the inner surface, and a conductor at the center of the conductive contact 2.
3 and is connected to a power supply (not shown) through a bushing 14 for insulation. Ozone is generated from the air passing between the cylindrical metal tube 6 and the discharge tube 10 by electrical discharge. In addition, in a large ozone generator, there are several cylindrical metal tubes 6 and discharge tubes which are ground electrodes. Stainless steel, Solus, ceramic, polyvinyl chloride, fluorocarbon resin, etc. are used as ozone-resistant materials, and under dry conditions, iron and aluminum may also be used as the lumber 4. Ru. Further, as the material for the conductive film 1 of the discharge tube 1, carbon paint or aluminum sprayed film has been conventionally used. However, when using such a large ozone generating KW in Japan, there are problems with the installation environment. From this, the conductive coating 11 inside the discharge tube]00 corroded, causing the discharge tube 10 to corrode.
The reason and 17 are as follows:
The opening of the discharge tube 10 is normally located on the feed air side, and this does not pose a problem during continuous operation, but due to changes in operating conditions or stoppages, the conductive coating 11 may come into contact with ozone, nitrogen oxides, etc. and corrode. This is considered to lead to deterioration 11 and destruction of the discharge tube 10. Incidentally, according to the experience in Europe, it is said that the number of such breakdowns of the discharge tubes 10 is 1 to 2% per j years. Therefore, the present inventors generated ozone using a 0.5 g/h ozone generator and raw air with a dew point of -40°C, and examined the amount of nitrogen oxide produced through an air washing bottle.
It is completely absorbed by the water in the air washing bottle with the mark, and has a resistance of about 1% to ozone.
It was found that 5% of nitric acid was produced. That is, when ozone is generated from raw air, active species are generated from nitrogen molecules due to discharge, and N and O are generated. NO is produced, which in turn becomes a high-grade nitrogen oxide. N20. adheres to the inside of the equipment and becomes nitric acid by reaction with moisture. Next, aluminum metal pieces were placed in a nitric acid solution and examined for corrosion and surface changes. The corrosion rate at various nitric acid concentrations was
As shown in the figure. As shown in Figure 4, the concentration is 60%, 40%,
Corrosion increases in the order of 20%. Aluminum, which forms a passive state against concentrated nitric acid, also
It can be seen that dilute nitric acid causes severe corrosion. (Problem to be solved by the invention) As mentioned above, in Japan, which is hotter and more humid than Europe, even during maintenance and inspection of ozone generators, N
For 20 s, nitric acid is produced by the humidity from the atmosphere,
It was found that general corrosion of the aluminum film occurred, leading to destruction of the discharge tube. The purpose of the present invention is to eliminate moisture intrusion from the reaction tank into the ozone generator, prevent deterioration of the conductive film, and thereby provide extremely reliable protection that can reliably prevent the destruction of the discharge tube. The purpose of the present invention is to provide a highly efficient ozone generator. [Configuration of the Invention (Means for Solving the Problem) In order to achieve the above object, the ozone generator according to the first invention collects raw material air, cools the collected raw material air, A raw air supply unit that supplies dry air; an ozone generator that receives dry air supplied from the raw air supply unit via a first pipe and generates ozone; and an ozone generator that leads the ozone through an ozone outlet pipe. a reaction tank in which ozonized air is reacted; a first valve that is provided in a first pipe on the inlet side of the ozone generator and an ozone outlet pipe on the outlet side and closes when the ozone generator is stopped; A compressor that produces pressurized air and a second
ozone according to the second invention; and a second valve that is provided in the second pipe and opens when the ozone generator is stopped. The generator includes a raw air supply section that collects raw material air, cools and dries the collected raw material air, and supplies dry air to the raw material air supply section through a first pipe. An ozone generator that generates received ozone, a reaction tank that reacts ozonized air led from the ozone generator via an ozone outlet pipe, and a first pipe on the inlet side and an ozone outlet pipe on the outlet side of the ozone generator. A first valve that closes when the ozone generator is stopped, a compressor that creates pressurized air, and a second valve that dries the air supplied from the compressor and connects it to the ozone generator through a second pipe. A second valve is provided in each of the second pipe and the third pipe that communicates the outlet side of the ozone generator with the compressor and opens when the ozone generator is stopped. are doing. (Function) Therefore, in the ozone generator of the first invention, the discharge is stopped by the ozone generator stop command, ozonized air is released, and then the supply of raw material air is stopped. Thereafter, the first valves provided in the inlet-side pipe and the outlet-side ozone outlet pipe of the ozone generator are automatically closed. Furthermore, at the same time, the second valve installed in the second pipe is automatically opened, and from then on, a small amount of dry gas at a constant pressure is intermittently supplied over a long period of time.
It is fed into the ozone generator from the compressor and dryer. As a result, it is possible to prevent moisture from entering the ozone generator from the reaction tank, thereby preventing deterioration of the conductive film and preventing destruction of the discharge tube. Furthermore, in the ozone generator of the second invention, at the same time as the first valve is automatically closed, the second valves provided in the second pipe and the third pipe are automatically closed. After that, intermittently over a long period of time, a small amount of dry gas at a constant pressure is fed into the ozone generator from the compressor and dryer, and the dry air from the ozone generator is returned to the compressor. It will circulate through the compressor dryer and ozone generator. This prevents moisture from entering the ozone generator from the reaction tank, prevents deterioration of the conductive film, prevents damage to the discharge tube, and reduces the burden on the dryer. This allows you to drive efficiently. (Example) Hereinafter, an example of the present invention will be described in detail with reference to the drawings. FIG. 1 is a diagram showing an example of the configuration of an ozone generator according to the present invention. As shown in FIG. 1, the ozone generator of this embodiment includes a blower 2/1 which serves as a raw material air supply section and collects raw material air, and the blower 21 cools and dries the collected raw material air. a dryer 22 that supplies the
An ozone generator 24 that receives dry air supplied from the dryer 22 via a first pipe 23 and generates ozone, and an ozone generator 24 that generates ozone from the ozone generator 24 via a first pipe 25.

A reaction tank 26 for reacting the ozonized air guided by [7], a first pipe 23 on the inlet side of the ozone generator 24, and an ozone outlet pipe 25 on the outlet side are provided respectively, and the ozone generator 24
A first valve 27 that automatically closes when the system is stopped, a compressor 28 that produces pressurized air, and a second pipe 29 that dries the air supplied from the compressor 28.
A dryer 30 that feeds into the ozone generator 24 via
and a second valve 31 which is provided in the second pipe 29 and opens automatically when the ozone generator 24 is stopped. Next, the operation of the ozone generator configured as above will be explained. In FIG. 1, when a command to operate the ozone generator 24 is given, raw air supplied from the blower 21 is cooled and dried by the dryer 22, and then supplied to the ozone generator 24 through the first pipe 23. After the ozone air is made into ozonized air by a discharge tube provided in the ozone generator 24, it is led to a reaction tank 26 through an ozone outlet tube 25 and reacted. On the other hand, when a command to stop the ozone generator 24 is given, the process starts by sequentially controlling the discharge, releasing the ozone air, and stopping the dryer 22 and the blower 2 in sequence. At this time, the first valves 27 provided in the first pipe 23 on the inlet side and the ozone outlet pipe 25 on the outlet side of the ozone generator 24 are similarly operated from the open state to the closed state by sequence control. Ru. As a result, even after the ozone generator 24 is stopped, moisture from the reaction tank 26 is shut off by the first valve 27 for a long period of time. At the same time, a second
Valve 3] is similarly operated from the closed state to the open state by sequence control. As a result, the air pressurized by the compressor 28 (the degree of pressurization of air may be about 0.1 to 0.2 higher than atmospheric pressure) is transferred to the dryer 3.
A small amount of dry air at a constant pressure is fed into the ozone generator 24 from its outlet side through the second pipe 29 and the second valve 31. As a result, even after the ozone generator 24 is stopped, the moisture from the reaction tank 26 remains in the first
The ozone generator 24 can be kept completely dry by the valve 27 for a long period of time. That is, when the distance of the ozone outlet pipe 25 is long or when the ozone generator 24 is stopped for a long period of time, moisture inevitably enters from the outside, but moisture enters the ozone generator 24 from the compressor 28 and the dryer 30. This can be prevented by supplying a small amount of constant pressure dry air. Note that when the ozone generator 24 is stopped, the ozone generator 24
By keeping the internal pressure high, closing the first valve 27, and thereafter supplying a constant amount of dry air into the ozone generator 24 from the compressor 28 and dryer 30, the dry state can be further improved. In this way, the ozone outlet pipe 25 or the first pipe 23
Intrusion from the gap between the connecting part and the first valve 271.
Regarding the generated moisture, dry air is supplied into the ozone generator 24 from the compressor 28 and the dryer 30, and the pressure is maintained at a constant level until the ozone generator 24 resumes operation, thereby preventing moisture from flowing back. I can do it. As described in [7] above, the ozone generator of this embodiment includes a blower 21 which serves as a raw material air supply unit and which collects raw material air, and a blower 21 that cools the raw material air collected by this blower 21.
Dryer 22 for drying and supplying dryer 22
an ozone generator 24 that receives dry air supplied from the ozone generator 24 via a first pipe 23 and generates ozone; and a reaction tank 26 that reacts ozonized air led from the ozone generator 24 via an ozone outlet pipe 25. , a first valve 27 which is provided in the first pipe 23 on the inlet side and the ozone outlet pipe 25 on the outlet side of the ozone generator 24, and which automatically closes when the ozone generator 24 is stopped; A compressor 28 that produces air, a dryer 30 that dries the air supplied from the compressor 28 and sends it into the ozone generator 24 via a second pipe 29, and a second pipe 2.
9, and a second valve 31 that is automatically opened when the ozone generator 24 is stopped. Therefore, in the past, the first valve 27 was not installed, or even if it was installed, it was a manual type for maintenance in most cases, and air containing a lot of moisture from the reaction tank 26 flows into the ozone generator 24. However, in response to a command to stop the ozone generator 24, the first valve 27 installed at the inlet and outlet sides of the ozone generator 24 was stopped by sequence control. Since it is in a closed state, it is possible to prevent continuous moisture from entering the ozone generator 24 from the reaction tank 26. Furthermore, the ozone outlet pipe 25 or the first pipe 23 connection part,
Regarding moisture entering through the gap between the first valve 27, the air compressed by the compressor 28 is dried by the dryer 30 and sent into the ozone generator 24, so the ozone generator 24 is not in operation. In this way, it is possible to maintain the inside of the ozone generator 24 in a completely dry state. Thereby, deterioration of the conductive film in the ozone generator 24 and destruction of the discharge tube can be reliably prevented. Particularly in Japan, where humidity is high, by keeping the conductive film in such a dry state, deterioration of the conductive film can be prevented, making it possible to more reliably prevent the destruction of expensive discharge tubes. As a result, it is possible to not only reduce the work of replacing discharge tubes, which was conventionally extremely time-consuming, but also to obtain an ozone generator that is easy to maintain and has excellent durability. Next, other embodiments of the present invention will be described. FIG. 2 is a diagram showing another example of the configuration of the ozone generator according to the present invention, in which the same elements as in FIG. 1 are denoted by the same reference numerals. As shown in FIG. 2, the ozone generator of this embodiment includes a blower 21 which serves as a raw material air supply section and collects raw material air, and a blower 21 that cools and dries the raw material air collected by this blower 21. A dryer 22 that supplies
An ozone generator 24 that receives dry air supplied from the dryer 22 via the first pipe 23 and generates ozone, and a reaction tank that reacts the ozonized air led from the ozone generator 24 via the ozone outlet pipe 25. 26, a first valve 27 which is provided in the first pipe 23 on the inlet side and the ozone outlet pipe 25 on the outlet side of the ozone generator 24, and which automatically closes when the ozone generator 24 is stopped; A compressor 28 that produces compressed air, a dryer 30 that dries the air supplied from the compressor 28 and sends it into the ozone generator 24 via a second pipe 29, a second pipe 29, and the ozone generator 24. The second valve 31 is provided in each third pipe 32 that communicates the outlet side of the ozone generator with the compressor 28, and is automatically opened when the ozone generator 24 is stopped. Next, the operation of the ozone generator configured as above will be explained. In FIG. 2, when a command to operate the ozone generator 24 is given, raw air supplied from the blower 21 is cooled and dried by the dryer 22, and then supplied to the ozone generator 24 through the first pipe 23. After the ozone air is made into ozonized air by a discharge tube provided in the ozone generator 24, it is led to a reaction tank 26 through an ozone outlet tube 25 and reacted. On the other hand, when a command to stop the ozone generator 24 is given, the process starts by sequentially stopping discharge, releasing ozone air, and stopping the dryer 22 and blower 21 by sequence control. At this time, the first valves 27 provided in the first pipe 23 on the inlet side and the ozone outlet pipe 25 on the outlet side of the ozone generator 24 are similarly operated from the open state to the closed state by sequence control. Ru. As a result, even after the ozone generator 24 is stopped, moisture in the reaction tank 26 is shut off by the first valve 27 for a long period of time. At the same time, the second valve 31 provided in the second pipe 29 and the third pipe 32 is similarly operated from the closed state to the open state by sequence control. As a result, the air pressurized by the compressor 28 is dried by the dryer 30, and a small amount of dry air at a constant pressure is sent into the ozone generator 24 from the outlet side through the second pipe 29 and the second valve 31. Furthermore, the dry air from the ozone generator 24 is returned to the compressor 28 through the third pipe 32 and the second valve 31, and the dry air is circulated through the compressor 28, the dryer 30, and the ozone generator 24. . As a result, even after the ozone generator 24 is stopped, moisture from the reaction tank 26 is shut off for a long period of time by the first valve 27, and the dry state inside the ozone generator 24 can be maintained even more completely. I can do it. In addition, since the dry air is circulated through the compressor 28,
Not only does the burden on the dryer 30 become lighter, but the flow of drying air is smoother, and the degree of dryness can be further increased. In the embodiment shown in FIG. 1 above, a case has been described in which pressurized dry air is fed into the ozone generator 24 from the outlet side from the compressor 28 and the dryer 30, but the present invention is not limited to this. 28
Alternatively, pressurized dry air may be sent from the dryer 30 into the ozone generator 24 from its inlet side. Furthermore, it goes without saying that the first valve 27 provided in the first pipe 23 can be omitted if the pipes between the ozone generator 24 and the dryer 22 are securely closed. Furthermore, in each of the above embodiments, the compressor 28 may be small, and the compressor 28 may be a small one, and the first valve 27, the second valve 3
It is also possible to use the compressed air source used for opening/closing in No. 1 in combination. On the other hand, in each of the above-mentioned embodiments, the dryer 30 may be a drying agent-packed tower or a system in which two units perform pressurized automatic regeneration. [Effects of the Invention] As explained above, according to the present invention, it is possible to prevent moisture from entering the ozone generator from the reaction tank and prevent deterioration of the conductive film, thereby preventing the destruction of the discharge tube. An extremely reliable ozone generator that can reliably prevent this can be provided.

[Brief explanation of drawings]

Fig. 1 is a block diagram showing one embodiment of the ozone generator according to the present invention, Fig. 2 is a block diagram showing another embodiment of the ozone generator according to the present invention, and Fig. 3 is an example of the internal configuration of the ozone generator. FIG. 4 is a schematic diagram for explaining the corrosion rate of aluminum at each nitric acid concentration. 1... Container, 2... Partition wall, 3... Vacant room, 4...
Raw material gas inlet, 5... Ozonated gas outlet, 6... Cylindrical metal tube, 7... Vacant room, 8... Cooling water population, 9...
- Cooling water outlet, 10... Discharge tube, 11... Conductive film, 12... Conductive contact, 13... Conductor, 14...
Bushing, 21... Blower, 22... Dryer 23... First Φ piping, 24... Ozone generator, 2
5... Ozone outlet pipe, 26... Reaction tank, 27...
First valve, 28... Compressor 29...
-Second piping, 30...Dryer 31...Second valve, 32...Third piping. Applicant's representative Patent attorney Takehiko Suzue Diagram Testing time (days) AI corrosion rate diagram

Claims (2)

[Claims] (1) A raw material air supply section that collects raw material air, cools and dries the collected raw material air, and supplies the collected raw material air; and dry air supplied from the raw material air supply section through a first pipe. an ozone generator that generates received ozone, a reaction tank that reacts ozonized air led from the ozone generator via an ozone outlet pipe, and a first pipe on the inlet side and ozone outlet side of the ozone generator. A first valve that is provided in each outlet pipe and closes when the ozone generator is stopped; a compressor that produces pressurized air; and a first valve that dries the air supplied from the compressor and supplies the air through a second pipe. An ozone generator comprising: a dryer that feeds into the ozone generator; and a second valve that is provided in the second pipe and opens when the ozone generator is stopped. (2) a raw air supply unit that collects raw air, cools and dries the collected raw air, and supplies dry air to the raw air supply unit through a first pipe; an ozone generator that generates received ozone, a reaction tank that reacts ozonized air led from the ozone generator via an ozone outlet pipe, and a first pipe on the inlet side and ozone outlet side of the ozone generator. A first valve that is provided in each outlet pipe and closes when the ozone generator is stopped; a compressor that produces pressurized air; and a first valve that dries the air supplied from the compressor and supplies the air through a second pipe. A dryer that feeds into the ozone generator, the second pipe, and a third pipe that communicates the outlet side of the ozone generator with the compressor, respectively, and are opened when the ozone generator is stopped. An ozone generator comprising: a second valve;