JPH04337095A - Method and apparatus for producing ozonized water - Google Patents

Abstract

PURPOSE:To produce the ozonized water at a cost lower than the cost of the conventional ozonized water production which disperses an ozone-contg. gas through a filter into raw material water and with high dissolution efficiency. CONSTITUTION:The raw material water is converted to vortex flow by a liquid pump 9 when the ozone-contg. gas generated by an ozone-contg. gas generator 4 is supplied to the suction side of the liquid pump 9. The ozone-contg. gas is absorbed and dissolved in this vortex flow and the high-concn. ozonized water is obtd. Since the stirring effect of the pump 9 is utilized, the dissolution of the ozone in the ozone-contg. gas into the raw material water takes place surely and sufficiently and further the dissolution efficiency attains nearly 100% if the water pressure on the take-out side of the pump 9 is maintained at about 2kg/cm<2>G. The formed ozone-contg. gas is thus utilized efficiently for the ozonized water production.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention relates to a method and apparatus for producing ozonated water, and more particularly, it is possible to produce ozonated water suitable for various sterilizations, cleaning during semiconductor manufacturing, etc. at low cost and with high absorption efficiency of ozone-containing gas. The present invention relates to a method and apparatus for manufacturing.

0002

[Prior art and its problems] Ozone has attracted attention as a strong and clean oxidizing agent, and its decomposition product is oxygen, so compared to the conventionally used chlorine-based oxidizing agents, ozone is less exposed to residue. Its use in water treatment is increasing because it does not remain in the treated water, its decomposition rate is fast, ozone itself does not remain, and there is no problem of secondary pollution. In order to generate ozone-containing gas containing ozone, which is useful as an oxidizing agent, discharge methods and electrolytic methods have traditionally been mainly used, but electrolytic methods are currently mainstream due to the purity of the product and ease of operation. It becomes. In order to perform water treatment using the ozone-containing gas generated by this electrolysis method, the ozonated water obtained in a gas-liquid mixed state may be directly brought into contact with the water to be treated, or the water to be treated may be placed in the anode chamber of the electrolytic cell. However, in the former method, the ozone exists in the form of bubbles, so the contact efficiency with the water to be treated is poor, and the ozone water generated in the electrolytic tank is contaminated with electrode materials, etc., and the materials are exposed to the ozone. There is a problem that the treated water may be contaminated, and in the latter case, the electrodes may be contaminated by impurities in the water to be treated.

Therefore, in many cases, the ozone-containing gas generated in the anode chamber of the electrolytic cell in a gas-liquid mixed state is once supplied to a mixing tank containing raw water through a filter, and impurities are removed by the filter, and the filter Then, the ozone-containing gas in the gas-liquid mixed state is dispersed in the raw material water, and ozone is almost completely dissolved in the raw material water, thereby producing ozone water with a uniform concentration that does not contain gaseous ozone. However, with this ozonated water production method, it may be difficult to completely dissolve the ozone in the ozone-containing gas into the raw water with high absorption efficiency, which increases the cost of produced ozonated water and makes it economically uneconomical. It may become impossible to produce ozonated water.

0004

OBJECTS OF THE INVENTION An object of the present invention is to provide a method and apparatus for producing ozone water by dissolving ozone-containing gas in raw water with high absorption efficiency without using a filter or the like.

[0005]

[Means for Solving the Problems] The method of the present invention is to supply ozone-containing gas generated by an ozone-containing gas generator to the suction side of a liquid pump to which raw water is supplied, and to add the ozone-containing gas to the raw water. This is an ozonated water production method characterized by producing ozonated water by absorbing and dissolving ozone, and the apparatus of the present invention comprises an ozone-containing gas generator, a raw water supply means,
It comprises a liquid pump and a water pressure adjustment means, and the water pressure adjustment means supplies raw water to the liquid pump while maintaining the water pressure on the extraction side of the liquid pump within a predetermined range, and the ozone-containing gas generator. This ozone water production apparatus is characterized in that the generated ozone-containing gas is supplied to the suction side of the liquid pump, and the ozone-containing gas is dissolved in the raw material water in the pump to produce ozone water.

The present invention will be explained in detail below. The ozone water production method and apparatus according to the present invention utilizes the stirring power of a pump to efficiently disperse ozone-containing gas into raw water, instead of the conventional method of dispersing and dissolving ozone-containing gas in raw water through a filter. Depending on the conditions, ozone water can be produced by dissolving it with 100% absorption efficiency. The ozone-containing gas used in the present invention may be produced by an electrolytic method, a discharge method, or any other method, and accordingly, the ozone-containing gas generator may be an appropriate device such as an electrolytic cell or a discharge device. use. When producing ozone-containing gas using an electrolytic cell, the pressure in the anode chamber of the electrolytic cell where ozone-containing gas is generated is maintained at a positive pressure, and the hydrogen gas generated in the cathode chamber is passed through the anode chamber. It is desirable to prevent the liquid from being introduced into the liquid pump.

[0007] When making high-purity water into ozonated water, if the ozone-containing gas is dissolved in raw water to produce ozonated water and then purified, the dissolved ozone gas will dissipate and loss will occur. It is desirable to purify high purity water by distillation, ion exchange, etc. For example, when tap water is used as raw water, impurities in the tap water are removed to reduce the electrical conductivity, which is usually about 150 μS/cm, to 1μ.
It is preferable to reduce it to S/cm. A conventional type liquid pump can be used as is. The raw material water and ozone-containing gas are supplied from the suction side of the pump, a swirling flow of the raw water is formed by the pump, and the ozone-containing gas is efficiently absorbed into the raw water by the stirring force of the swirling flow. It is thought that it will dissolve. Note that ozone-containing gas produced by electrolysis is usually produced in a gas-liquid mixture, and gas-liquid separation is usually performed to separate the ozone-containing gas, but in the present invention, the ozone-containing gas is supplied to the pump in a gas-liquid mixture. Good too.

The dissolution efficiency is somewhat influenced by the water pressure on the take-out side of the liquid pump, and is approximately 90% when no pressure is applied to the take-out side.
%, and when a water pressure of about 2 kg/cm2g is applied, the dissolution efficiency increases to almost 100% (more than 5 ppm when converted to ozone concentration). However, if the water pressure is further increased to about 4 kg/cm2 g, the dissolution efficiency becomes 6
0 to 80% (approximately 3.5 to 4.0% when converted to ozone concentration)
5 ppm), and this is presumed to be because ozone decomposition in the ozone-containing gas occurs due to the increase in the number of rotations of the pump required to increase the water pressure. Therefore, it is desirable to maintain the water pressure on the extraction side of the pump in the range of 0 to 3 kg/cm2 g to dissolve ozone in the ozone-containing gas into the raw water with high dissolution efficiency. The present invention enables ozone water production, especially when the water pressure on the extraction side of the pump is reduced from 0 to 0.
By maintaining the concentration within the range of 3 kg/cm2 g, ozonated water can be produced with high dissolution efficiency from the beginning of the operation, and highly concentrated ozonated water can be produced in a short time and at low cost.

Next, an example of ozone water production according to the present invention will be explained based on the attached drawings, but the present invention is not limited to the illustrated example. FIG. 1 is a flowchart showing an example of a system for the ozonated water production method according to the present invention.

High-purity raw water produced by purifying relatively low-purity raw water such as tap water by distillation or ion exchange is supplied to the raw water storage tank 1 through a supply line 2, and the raw water 3 is stored in the storage tank 1. An electrolytic cell 4, which is an ozone-containing gas generator, is divided into an anode chamber 6 and a cathode chamber 7 by a diaphragm 5, and the anode chamber 6 is maintained at a higher pressure than the cathode chamber 7. When the raw water 8 for producing ozone-containing gas in the electrolytic cell 4 is electrolyzed, ozone-containing gas, which is a mixed gas of oxygen and ozone, is generated in the anode chamber 6. When the liquid pump 9 having the rotation speed control device 15 is driven, the raw water 3 stored in the storage tank 1 is guided to the suction side of the pump 9 through the line 10 and generates a swirling flow in the pump 9. let On the other hand, the ozone-containing gas generated in the anode chamber 6 of the electrolytic cell 4 is similarly introduced into the liquid pump 9 from the suction side through the line 11,
Ozone water is generated by absorbing and dissolving the raw material water into the swirling flow. The ozonated water is taken out from the extraction side of the pump 9 and supplied to the ozonated water storage tower 14 through the line 13 and stored therein.
If necessary, it is taken out via the control valve 12 and used for various purposes. Note that the water pressure on the extraction side of the pump 9 can be adjusted by adjusting the rotation speed using the rotation speed control device 15 and by finely adjusting the opening/closing degree of the control valve 12.

[0011]

[Example] Next, an example of ozonated water production according to the present invention will be described, but the present invention is not limited to this example. Ozone water was produced using the system shown in FIG. The following electrolytic cell, which is an ozone-containing gas generator, was used. As a solid electrolyte, β is an anode material on one side.
- Vertical 1 with lead dioxide coated with platinum, which is a cathode material, on the other side
Nafion (trade name) 11 with 0 cm, width 10 cm, thickness 0.18 mm and ion exchange capacity of 0.9 meq/g
7 was used to set the electrode area to 1 dm2. The solid electrolyte divided the electrolytic cell into an anode chamber and a cathode chamber each having a volume of 100 cm3 and 200 cm3. An anode power supply element made of a mesh-like titanium fine fiber sintered body and a cathode power supply element made of a stainless steel fine fiber sintered body were connected to the anode material and the cathode material, respectively. When this electrolytic cell was energized at 100 A and 3.2 V, ozone gas was 14% by weight and oxygen gas was 86% by weight.
An ozone-containing gas mixture of % by weight was produced at a rate of 30 g/h.

The storage tank contained raw water whose electrical conductivity was reduced to 1 μS/cm by removing impurities from tap water by ion exchange. When the control valve is completely opened, the water pressure on the outlet side of the vortex pump (liquid pump) is 0 kg/c.
m2 g, a stainless steel vortex pump connected to the anode chamber of the electrolytic cell and the storage tank is driven to introduce the ozone-containing gas and raw water into the pump, and the ozone water is directly converted into ozone water. It was taken out from the pump and stored in a storage tower. Ozone concentration (Qppm) and dissolution efficiency (η
%) over time was measured, and the results are shown in the graph of FIG. 2 with a circle. From this result, when the water pressure is 0 kg/cm2 g, the initial ozone concentration in ozonated water is about 4.6 ppm, which increases to about 5 ppm over time, and the dissolution efficiency increases from about 85% to about 90%. It can be seen that it increases to %. Ozone water was produced under the same conditions except that the rotation speed control device was adjusted so that the water pressure on the extraction side of the pump was 2 kg/cm2 g, and the ozone concentration and dissolution of the ozonated water extracted from the pump were determined. Changes in efficiency over time were measured, and the results are shown in the graph of FIG. 2 by △ marks. From this result, when the water pressure is 2 kg/cm2 g, the ozone concentration, that is, the dissolution efficiency increases, and the initial ozone concentration in ozonated water is about 5.3 ppm, and even with the passage of time, it remains ±0.1 ppm.
maintained within the pm range, and the initial dissolution efficiency was approximately 98%.
was maintained within a range of ±2% over time.

Furthermore, ozonated water was produced under the same conditions except that the rotational speed control device was adjusted so that the water pressure at the outlet side of the pump was 4 kg/cm2 g, and the ozonated water extracted from the pump was The changes over time in the ozone concentration and dissolution efficiency were measured, and the results are shown in the graph of FIG. 2 with ● marks. This result shows that when the water pressure is 4 kg/cm2 g, the ozone concentration, that is, the dissolution efficiency, decreases, and the initial ozone concentration in ozonated water is about 3.3 ppm, which increases to about 4.4 ppm with the passage of time. The initial dissolution efficiency was approximately 6
It was 0% and increased to 81% with the passage of time. Based on this result, the water pressure on the extraction side of the pump should be approximately 2 kg/cm2.
It can be seen that when ozone water is produced while maintaining the ozone water at 100 g, the dissolution efficiency reaches almost 100%, indicating that ozone-containing gas produced by electrolysis etc. can be used efficiently for ozonated water production.

[0014]

[Effects of the Invention] In the method for producing ozone water according to the present invention, ozone-containing gas generated by an ozone-containing gas generator is supplied to the suction side of a liquid pump sucking raw water,
Ozone-containing gas is absorbed and dissolved in the raw water by the stirring action of the pump that converts the raw water into a swirling flow, and ozone water can be efficiently produced. Unlike the conventional method of producing ozone water by dispersing ozone-containing gas into raw water using a filter, ozone-containing gas is dissolved using the strong stirring action of a pump in the method of the present invention. Therefore, ozone in the ozone-containing gas is reliably dissolved in the raw water, and highly concentrated ozonated water can be produced. Moreover, since only a pump is used, the cost is low, and ozonated water can be produced at low cost.

[0015] When a gas produced by an electrolytic method is used as the ozone-containing gas, since there are few impurities in the ozone-containing gas before dissolution, highly pure ozonated water can be produced. When producing ozone-containing gas using the electrolytic method described above, if the pressure on the anode chamber side of the electrolytic cell is kept higher than the pressure on the cathode chamber side, that is, maintained at a positive pressure, the hydrogen gas generated in the cathode chamber will be converted into ozone-containing gas. It is possible to produce ozone water with higher purity without contamination. Further, in the ozone water production apparatus of the present invention, when the ozone-containing gas generated by the ozone-containing gas generator is dissolved in the raw water by the liquid pump, the water pressure on the extraction side of the pump can be adjusted. The water pressure on the extraction side of this pump affects the ozone concentration (dissolution efficiency) of ozone water, and is 0 to 3 kg/cm.
When maintained in the range of 2 g, and especially 2 kg/cm2
g, it becomes possible to produce ozone water with almost 100% dissolution efficiency.

[Brief explanation of drawings]

FIG. 1 is a flowchart showing an example of a system for an ozone water production method according to the present invention.

FIG. 2 is a graph showing changes over time in the ozone concentration and dissolution efficiency of generated ozone water when the water pressure on the extraction side of the pump is changed in Examples.

[Explanation of symbols]

1... Storage tank 2... Supply line 3
...Raw material water 4...Electrolytic cell 5...Diaphragm 6.
...Anode chamber 7...Cathode chamber 8...Raw water for producing ozone-containing gas 9...Liquid pump 10, 11
... Line 12 ... Control valve 13 ... Line 14 ... Ozone water storage tower 1
5... Rotation speed control device

Claims (5)

[Claims] Claim 1: Ozone-containing gas generated by an ozone-containing gas generator is supplied to the suction side of a liquid pump to which raw water is supplied, and the ozone-containing gas is absorbed and dissolved in the raw water to produce ozone water. A method for producing ozone water characterized by the following. 2. The method according to claim 1, wherein the ozone-containing gas generator is an electrolytic cell, and the ozone-containing gas is generated by water electrolysis. 3. The method according to claim 2, wherein the anode chamber of the electrolytic cell is maintained at a positive pressure. 4. An ozone-containing gas generator, a raw material water supply means, a liquid pump, and a water pressure adjustment means, the water pressure adjustment means maintaining the water pressure on the extraction side of the liquid pump within a predetermined range while supplying the raw material. Water is supplied to the liquid pump, and ozone-containing gas generated by the ozone-containing gas generator is supplied to the suction side of the liquid pump, and the ozone-containing gas is dissolved in the raw water in the pump to produce ozonated water. An ozone water manufacturing device characterized by manufacturing. [Claim 5] Set the water pressure on the extraction side of the liquid pump to 0 to 3k.
5. The device according to claim 4, wherein the g/cm2 g is maintained.