JPH07223805A - Double pipe type ozone-generator - Google Patents

Abstract

PURPOSE:To obtain highly concentrated ozone by disposing an inner electrode- cooling pipe in an inner electrode to improve the cooling efficiency for the inner electrode, in a double pipe type ozone-generator coaxially having a cylindrical outer electrode and the cylindrical inner electrode. CONSTITUTION:In a double pipe type ozone-generator in which an outer electrode 1 and an inner electrode 2 are coaxially disposed through an electric discharge gap 3, an inner electrode-cooling pipe 8 is coaxially attached in the inner electrode 2. Cooling water 7 flows from one end of the inner electrode 2 into a space 10a, proceeds to places near to the inner wall of the inner electrode through plural holes 11 formed in the part of the inner electrode-cooling pipe 8 between a sealing plate 9 and the inner wall of the inner electrode 2, reaches the flowing-out end of the inner electrode 2, and subsequently flows out from plural holes 11 on the outside of the inner electrode 2 through a flowing-out side space 10b. The width of the flow passage and the flow rate of the cooling water 7 are preferably controlled to <<=3mm and <=3X10<-2>m/s, respectively, in order to raise the cooling efficiency.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ozone generator used for water treatment, sterilization and the like.

[0002]

2. Description of the Related Art The structure of a conventional double-tube ozone generator is shown in the schematic sectional view of FIG. In FIG.
In this device, a cylindrical outer electrode 1 and an inner electrode 2 are concentrically arranged with a discharge gap 3 in between, and glass, for example, as a dielectric layer 4 is adhered to the inner surface of the inner electrode 2.

When air or oxygen gas is introduced from one end of the discharge gap 3 of this device and an AC voltage is applied between the outer electrode 1 and the inner electrode 2 by an AC power source 5, silent discharge is generated and the discharge gap is generated. Ozone can be generated from the other end of 3. At this time, in order to prevent the ozone from thermally decomposing due to the temperature rise of the external electrode 1 and the internal electrode 2 and the high concentration ozone not being obtained, the internal wall of the external electrode cooling pipe 6 provided outside the external electrode 1 is prevented. Cooling of the external electrode 1 is performed by supplying the cooling water 7 indicated by the dotted arrow 7 so that the cooling water 7 flows through the gap between the external electrode 1 and the outer wall, and letting the cooling water 7 flow out from the outlet located away from the inlet. To do. On the other hand, the internal electrode 2 is cooled by cooling water 7
Is made to flow in and is made to flow out from the other end.

[0004]

The problem is the cooling state of the internal electrode 2. That is, the flow direction of the cooling water 7 inside the internal electrode 2 is, as shown by the dotted arrow in FIG.
The center part of the internal electrode 2 has a high flow velocity and has a good flow, but the corner part has a low flow velocity and thus becomes a spiral, and the cooling water 7 stays there. Therefore, the internal electrode 2
However, there is a problem in that it is difficult to obtain high-concentration ozone because the cooling effect is not sufficient.

The present invention has been made in view of the above points, and an object thereof is to improve the cooling efficiency of internal electrodes,
An object is to provide an ozone generator capable of increasing the ozone concentration.

[0006]

An internal electrode cooling pipe for forming a cooling water flow path is installed between the inner wall of an internal electrode and a cooling water flow path having a width of 3 mm or less. ^Is at least 3 × 10 ⁻² m / s.

[0007]

Since the internal electrode cooling pipe described above can be provided to determine the flow width and flow rate of the cooling water regardless of the amount of the cooling water, the cooling efficiency is high and the cooling water is the same as the conventional one. It does not stay in the corners of the internal electrode and is always flowing, and the large cooling capacity suppresses the temperature rise of the internal electrode, preventing ozone from being thermally decomposed, and preventing high concentration of ozone. Can be generated.

[0008]

EXAMPLES The present invention will be described below based on examples. FIG. 1 is a schematic cross-sectional view showing the configuration of a double-tube ozone generator of the present invention, FIG. 1 (a) is the entire device, and FIG. 1 (b).
Shows only the internal electrodes and the cooling means therefor according to the present invention. In both figures, the same parts as in FIG. 4 are represented by the same reference numerals.

The overall structure of the ozone generator of the present invention is as follows.
Since it is basically the same as the case of FIG. 4 already described, the description thereof will be omitted. Therefore, mainly in FIG.
This will be described with reference to (b). The difference of the device of the present invention from the conventional one is that, as shown in FIG.
This is because the internal electrode cooling pipe 8 is attached concentrically with the internal electrode 2. Although both ends of the internal electrode cooling pipe 8 are open, the internal electrode 2 is provided in the vicinity of the inner wall of the internal electrode 2 at both ends thereof.
By the sealing plate 9 provided in the direction perpendicular to the
Space portion 10a on the inlet side of the cooling water 7 indicated by an arrow
And the space portion 10b on the outlet side is formed. Cooling water 7
Flows according to the flow path formed by the inner wall of the inner electrode 2 and the outer wall of the inner electrode cooling pipe 8. First, it flows in from one end of the inner electrode 2 and enters the inflow side space 10a, and then the sealing plate 9 and While passing through the plurality of holes 11 formed in the portion of the internal cold electrode cooling pipe 8 located between the inner electrode 2 inner wall and the inner electrode 2 inner wall, the inner electrode 2 reaches the outflow end of the inner electrode 2. Also here, the cooling water 7 can flow out of the internal electrode 2 through the plurality of holes 11 formed in the same manner as the inflow side, through the space portion 10b on the outflow side.

Next, FIG. 2 is a schematic cross-sectional view showing the structure of the double-tube type ozone generator of the present invention, as shown in FIG.
2 shows the entire device, and FIG. 2 (b) shows only the internal electrodes according to the present invention and the cooling means therefor. In both figures, the same parts as those in FIG. 4 are represented by the same reference numerals. Shows a case where one end of the internal electrode is in a closed state, and here also, description will be made mainly with reference to FIG.

In the ozone generator shown in FIG. 2 (a), the portion corresponding to the outflow end of the cooling water 7 of the internal electrode 2 of FIG. 1 is closed, so that the internal electrode cooling attached to the internal electrode 2a is cooled. The pipe 8a also has a corresponding portion closed, so that the cooling water 7 flowing from one end of the internal electrode cooling pipe 8a passes through the hole 11a formed in the closed portion of the internal electrode cooling pipe 8a, It flows through the flow path formed by the gap between the inner wall of the inner electrode 2a and the outer wall of the inner electrode cooling pipe 8a so as to run backwards toward the inflow end, and finally the cooling water 7
Follows a path of flowing out from the outlet 12 on the opening side of the internal electrode 2a.

Here, regarding the cooling effect of the internal electrodes 2 and 2a cooled as described above, the gap size between the inner wall of the internal electrode 2 and the outer wall of the internal electrode cooling pipe 8 , that is, the flow path of the cooling water 7 The width and the width of the cooling water passage between the inner electrode 2a and the outer wall of the inner electrode cooling pipe 8a are used as parameters to investigate the relationship between the amount of cooling water and the temperature rise of the inner electrode, and the obtained results are shown in the diagram of FIG. Shown in. The curve (a) in FIG. 3 indicates that the width dimension of the cooling water flow channel is 3 mm, the curve (b) indicates that the width dimension of the cooling water flow channel is 6 mm, and the curve (c) indicates that the width dimension of the cooling water flow channel is 10 mm. The flow rate of the cooling water 7 at this time is 3 × 10 ⁻² m / s or more.

From the diagram of FIG. 3, in order to suppress the temperature rise of the internal electrodes 2 and 2a to 5 ° C. or less, the cooling water should be at least 3 × 10 ⁻² m / irrespective of the amount of the cooling water 7.
It can be seen that the width dimension of the cooling water flow path formed by the internal electrode and the cooling pipe thereof should be set to 3 mm or less by flowing at a speed of s. In this way, the cooling water does not stay in the corners of the internal electrode and is constantly flowing, and as a result, the temperature rise of the internal electrode is suppressed, so this internal electrode cooling pipe was used. The double-tube ozone generator of the present invention can generate high-concentration ozone.

[0014]

In order to increase the ozone concentration obtained by the double tube type ozone generator, it is effective to cool the electrodes, but conventionally, regarding cooling of the internal electrodes, cooling water is simply passed inside. The cooling capacity was not sufficient, such as the cooling water staying at the four corners, but in the device of the present invention, the internal electrode cooling pipe that forms a cooling water flow path between itself and the inner wall of the internal electrode. Is installed and the dimension of the flow width of the cooling water and the flow velocity are appropriately set regardless of the amount of the cooling water, so that the cooling effect of the internal electrode can be improved. Therefore, the ozone generator of the present invention having such an internal electrode cooling pipe prevents the ozone from being thermally decomposed due to the temperature rise of the electrode, and can obtain high-concentration ozone.

[Brief description of drawings]

FIG. 1 is a schematic cross-sectional view showing the structure of a double-tube ozone generator of the present invention, in which (a) is the entire device and (b) is an internal electrode and its cooling means.

2 is a schematic cross-sectional view showing the structure of a double-tube ozone generator of the present invention, in which (a) is the entire device and (b) is an internal electrode different from FIG. 1 and its cooling means.

FIG. 3 is a diagram showing the relationship between the amount of cooling water and the temperature rise of internal electrodes with the flow width of cooling water as a parameter.

FIG. 4 is a schematic cross-sectional view showing the configuration of a conventional double-tube ozone generator.

[Explanation of symbols]

 1 External Electrode 2 Internal Electrode 2a Internal Electrode 3 Discharge Gap 4 Dielectric Layer 5 AC Power Supply 6 External Electrode Cooling Pipe 7 Cooling Water 8 Internal Electrode Cooling Pipe 8a Internal Electrode Cooling Pipe 9 Sealing Plate 10a Space 10b Space 11 Hole 11a Hole 12 exit

Claims (4)

[Claims] 1. A cylindrical external electrode having an inner surface closely contacted with a dielectric material, and a cylindrical internal electrode concentrically arranged with the external electrode with a discharge gap formed between the external electrode, and between these electrodes. A double-tube ozone generator for applying an AC voltage to ozone a raw material gas supplied from a discharge gap. The double-tube ozone generator is inserted into an internal electrode, and a cooling water flow path is formed between the internal wall of the internal electrode and the internal electrode. A double-tube type ozone generator, comprising a cylindrical internal electrode cooling tube to be formed. 2. The double-tube ozone generator according to claim 1, wherein the internal electrode cooling pipe is provided concentrically with the internal electrode. 3. The double-tube ozone generator according to claim 1 or 2, wherein the flow rate of the cooling water is at least 3 × 10 ⁻² m / s. 4. The double-tube ozone generator according to claim 1, wherein the width of the cooling water passage is 3 mm or less.