JP4738789B2 - Ozone water generator - Google Patents

Description

  The present invention relates to an ozone water generating apparatus that includes an electrolytic cell in which a solid polymer film is sandwiched between a cathode and an anode, and electrolyzes water to generate ozone water.

  Ozone is a substance having a very strong oxidizing power, and sterilization, decolorization, and deodorizing effects derived from the oxidizing power are applied in various fields. The sterilization method, decolorization method, etc. using ozone can be said to be a treatment method that does not cause the secondary contamination because ozone itself is naturally decomposed into oxygen. The oxidizing power of ozone dissolved in water is further improved and is generally used for sterilization and the like. For these purposes, development of a simpler and more efficient generation method than ozone gas or ozone water is required.

  As a method for generating gaseous ozone, an ultraviolet lamp method, a silent discharge method, and an electrolysis (electrolysis) method are known (for example, see Non-Patent Document 1). The ultraviolet lamp method generates a small amount of ozone and is often used to remove a small amount of bad odor sources such as deodorizing indoors and cars. The silent discharge method is a general method for generating ozone gas. For example, when air is used as a raw material, nitrogen oxides are also generated at the same time. In order to prevent this, it is necessary to use an accessory device that uses oxygen gas as a raw material or concentrates only oxygen in the air. In addition, mixing of metal impurities into the ozone gas due to consumption of the metal electrode is also a problem. Furthermore, ozone gas can also be obtained by electrolysis of water. According to this electrolysis method, high purity and high concentration ozone gas containing some water can be easily obtained, and ozone water can also be obtained directly as follows.

  As a technique for obtaining ozone water, a technique for dissolving the ozone gas obtained by the above technique in water and a technique for directly generating the ozone water by the electrolytic method are known. Ozone water can be obtained by dissolving ozone gas generated by a silent discharge method or an electrolytic method in water through a bubble column or an ejector, but this causes an increase in size and complexity of the apparatus.

On the other hand, an ozone water generating device is proposed in which an electrolytic cell is configured by sandwiching a solid polymer membrane between a porous or net-like anode and a cathode, and at least a water channel capable of passing water is provided on the surface of the anode. ing. In such an apparatus, tap water or pure water can be passed through the water channel and electrolyzed to generate ozone water directly, and the apparatus can be easily downsized (for example, Non-Patent Document 2). Patent Documents 1, 2, and 3).
Hidetoshi Sugimitsu "Basics and Applications of Ozone" Korin, February 1996 “Neo Heidi Electrolytic Ozone Water System” (catalog), BMC Corporation, March 2003 JP 2000-234191 A Japanese Patent No. 3297227 JP 2002-69679 A

  However, in the conventional ozone water generator, the generated ozone stays on the surface of the anode as a gas. And when this ozone gas is discharged | emitted with water as gas, without melt | dissolving in water, the process of making it melt | dissolve in water again through a bubble tower or an ejector is needed.

  In order to dissolve ozone generated on the anode surface well in water, the generated ozone is removed from the anode surface by a water flow (bubble sweep) before forming bubbles, and the solubility of ozone is increased by increasing the water pressure. However, none of them have been achieved sufficiently in the past. For example, in the device described in Non-Patent Document 2, since the cross-sectional area of the water channel in contact with the anode of the electrolysis cell is as thick as 3.6 mm × 3.6 mm, turbulent flow effective for bubble sweeping hardly occurs, and the water pressure is also the entire water channel It was almost 1 atm.

  Accordingly, an object of the present invention is to provide an ozone water generator capable of efficiently generating high-concentration ozone water by removing ozone on the anode surface and dissolving the ozone in water. As made.

The present invention has been made to reach a pre-Symbol object, comprising an electrolytic cell the polymer film formed by interposing between plate-shaped anode and a cathode, and a water passage provided so as to be passed through to the anode surface in the ozone water generation apparatus, wherein is disposed the comb-shaped barrier ribs that are combined as a spiral or comb teeth with each other over the entire surface of the anode is staggered, said anode in contact with portions of the waterway, the A partition wall is formed by adhering a flat wall to the opposite surface of the partition to the anode, and the cross-sectional area is converted into a circular tube with an inner diameter of 2 mm or less, and turbulence can be generated by the water flow. is characterized in that a has a smaller diameter portion.

In the present invention, the portion of the water channel that is provided on the anode surface of the electrolysis cell that sandwiches the solid polymer membrane between the anode and the cathode so as to be able to pass water is a small-diameter portion that can generate turbulent flow by passing water. It has become. For this reason, the ozone generated on the surface of the anode can be satisfactorily removed by turbulent flow before becoming bubbles. Moreover, when water is passed through the small diameter portion to generate turbulent flow, the water pressure (pressure loss) in the small diameter portion is also increased, and the solubility of ozone is increased. Therefore, in the present invention, ozone water generated by the anode can be dissolved in water satisfactorily by the synergistic effect of turbulent flow and water pressure to obtain ozone water. Therefore, in the present invention, it is possible to efficiently generate a high concentration of ozone water.

Moreover, production cross section of the small-diameter portion, since the inner diameter 2mm or less in terms of a circular tube, it is possible to generate a turbulent flow in the water flow rate of about 0.5 l / min, very efficiently ozone water can do.

Further, the water channel is provided with a comb-like partition that is spirally or combined so that the comb teeth are staggered over the entire surface of the flat plate-like anode, and further, the anode of the partition is by adhering the planar wall to the opposite side, since the small diameter portion is formed, additional effects such as the following may occur.

  In this case, since a plate-shaped electrolytic cell can be used, the configuration is simplified, and the small diameter portion is formed by disposing the partition wall on the surface of the anode, so that the small diameter portion having a small cross-sectional area is also easily formed. be able to. Therefore, in this case, the manufacturing becomes easier and the apparatus can be further downsized.

  In this case, when the partition walls are arranged in a spiral shape, the following further effects are produced. In this case, the small diameter portion is also formed in a spiral shape like the partition wall. Since the vortex has no corners and is smooth, the water flow is smooth and no extra pressure loss occurs. Therefore, in this case, ozone water can be generated more efficiently.

  Further, in the configuration using partition walls as described above, when the partition walls are made of titanium, the following further effects are produced. Titanium has excellent corrosion resistance because a titanium dioxide film is formed on the surface. Therefore, in this case, the durability of the ozone water generator can be further improved.

  Moreover, in the structure using a partition as mentioned above, when the said partition is comprised with silicone rubber, the following further effects will arise. Silicone rubber can be easily formed into various shapes. Accordingly, in this case, small-diameter portions having various shapes can be easily formed.

  Further, in the configuration using partition walls as described above, when the partition walls are integrally formed with the wall surface, the following further effects are produced. When the partition wall is integrally formed with the wall surface, the mechanical strength of the partition wall is improved. Therefore, in this case, the durability of the ozone water generator can be further improved.

  Next, embodiments of the present invention will be described with reference to the drawings. FIG. 1 (A) is a plan view showing a configuration of an ozone water generating apparatus 1 to which the present invention is applied, and FIG. 1 (B) is a cross-sectional view taken along the line AA. As shown in FIGS. 1 (A) and 1 (B), the ozone water generating apparatus 1 according to the present embodiment includes a flat solid polymer film 2 having a substantially square shape in plan view, like a disk-like anode 3. An electrolysis cell 5 sandwiched between plate-like cathodes 4 is provided.

  A spirally wound wire 7 is disposed on the surface of the anode 3, and a rubber spacer 8 having a circular hole fitted to the outer periphery of the anode 3 is fitted to the outer periphery of the anode 3 and the wire 7. Are combined. A flat wall surface 9a of an outer frame 9 made of a transparent resin is pressed against the surfaces of the spacer 8 and the wire 7, and a spiral shape on the anode side is placed in a space surrounded by the anode 3, the wire 7, the spacer 8, and the wall surface 9a. A water channel 10 is formed.

  The spiral water channel 10 is formed in a spiral shape along the shape of the wire 7, and water is supplied to the spiral water channel 10 at a position of the outer frame 9 facing the outer peripheral side end of the spiral water channel 10. A supply port 9b is formed. A discharge port 9 c for discharging water (ozone water as will be described later) from the spiral water channel 10 is formed at a position of the outer frame 9 facing the center side end of the spiral water channel 10.

  On the other hand, a rubber spacer 11 having a circular hole fitted to the outer periphery of the cathode 4 is disposed on the outer periphery of the cathode 4, and a mesh-like disc-shaped presser made of a transparent resin is provided on the surface of the cathode 4. A plate 13 is provided. Further, the outer surface 15 of a rectangular parallelepiped shape having a circular hole 15a fitted to the outer periphery of the presser plate 13 and thicker than the presser plate 13 is disposed on the surface of the spacer 11, and further, a substantially rectangular parallelepiped is provided on the surface thereof. A shaped outer frame 17 is provided. Thus, a cathode chamber 19 surrounded by the cathode 4 and the holding plate 13, the circular hole 15 a of the outer frame 15, and the outer frame 17 is formed on the surface of the cathode 4.

  The outer frame 17 is integrally provided with a supply port 17a for supplying the catholyte to the cathode chamber 19, a discharge port 17b for discharging the catholyte, and a rib 17c for pressing the presser plate 13. Molded. The ozone water generator 1 fastens the outer frame 9, the spacer 8, the solid polymer film 2, the spacer 11, the outer frame 15, and the outer frame 17 in the vertical direction of FIG. Is made up of. By this tightening, leakage of water (including ozone water or cathode water) from the spiral water channel 10 and the cathode chamber 19 is prevented.

  Here, when a direct current is passed between the anode 3 and the cathode 4 while passing water such as tap water through the spiral water channel 10, the water is electrolyzed, and the following reaction occurs on the surface of the anode 3. Arise. The following (1c) to (3c) are oxidation reactions, and (4c) and (5c) are dissolution equilibrium.

Both ozone generation (1c) and oxygen generation (2c) are competitive reactions due to water oxidation (electrolysis). The dissolved oxygen 0 ₂ (aq) generated by (2c) is further converted into bubbles 0 ₂ (g) by the shift of the dissolution equilibrium (5c) to the right side or further oxidized (3c), and dissolved ozone 0 ₃ (aq) is generated. Further, a part of the dissolved ozone 0 ₃ (aq) generated by (1c) or (3c) becomes bubbles by shifting the dissolution equilibrium (4c) to the right side.

Although the rates of (1c) and (2c), which are water oxidation reactions, are determined by the potential, there is little room for change, but (3c) varies depending on the concentration of dissolved oxygen 0 ₂ (aq). Therefore, in order to efficiently generate high-concentration ozone water, it is conceivable to shift the dissolution equilibrium (4c) and (5c) to the dissolution side (left side) by the following method.

One method is to increase the gas solubility by increasing the water pressure (equilibrium method), and the other is the dissolved oxygen O ₂ (aq) generated on the surface of the anode 3 and dissolved ozone. This is a method (kinetic method) that removes 0 ₃ (aq) quickly by turbulent flow and prevents the generation of bubbles due to local concentration increase.

  Subsequently, the effects of these methods were verified based on the calculation formula as follows. First, when water is flowed through a circular pipe having a length L (m) and an inner diameter d (m) at a water flow rate v (l / min), a differential pressure (pressure loss) ΔP between the inlet and outlet of the circular pipe is The following formulas (1m) to (3m) are obtained.

In the above (1 m) to (3 m), f is a coefficient of friction, ρ is a density of water (= 1000 kg / m ³ ), u is a flow velocity (= 4 v / πd ² ), and μ is a viscosity of water (= 0.0. 00089 Pa · s). Based on these (1 m) to (3 m), the relationship between the pressure loss ΔP and the water flow rate v when the length L of the circular pipe is 0.25 m and water is passed through the circular pipes having various inner diameters d (m). Was calculated. The results are shown in FIG. The legend in FIG. 2 represents the inner diameter d (m) of the circular tube.

  As shown in FIG. 2, when the inner diameter d of the circular tube is 0.002 m (= 2 mm) or less, the pressure loss ΔP increases rapidly. Therefore, when the cross-sectional area of the spiral water channel 10 in the ozone water generating apparatus 1 is converted into a circular tube and the inner diameter is 2 mm or less, the water pressure in the spiral water channel 10 can be increased satisfactorily. High concentration ozone water can be efficiently generated.

Next, in order to move the dissolved oxygen 0 ₂ (aq) and dissolved ozone 0 ₃ (aq) generated on the surface of the anode 3 into bulk water, it is effective to generate turbulence in the water. Turbulence occurs when the Reynolds number Re is 4000 or more. However, if d = 2 mm as described above, even if v = 0.5 (l / min), sufficient turbulence with Re≈6000. The calculation revealed that this occurred. On the other hand, when d = about 4 mm as in the conventional apparatus, when v = 0.5 (l / min), Re≈3000 (<4000), and no turbulent flow is generated. ₂ (aq) and dissolved ozone 0 ₃ (aq) cannot be removed well from the surface of the anode 3.

  The Sherwood number Sh representing mass transfer is obtained by the following equation (4m). Therefore, the relationship between the Sherwood number Sh and the water flow rate v when water was passed through circular pipes with various inner diameters d (m) under the same conditions as described above was calculated, and the results are shown in FIG.

In the above (4 m), Sc = μ / Dρ (D is a diffusion coefficient in water), and in the case of water, Sc≈890. As shown in FIG. 3, Sh is 91554 with respect to 3 l / min under the above conditions, and mass transfer is occurring as fast as mass transfer in air. Therefore, in this case, it can be seen that dissolved oxygen 0 ₂ (aq) and dissolved ozone 0 ₃ (aq) generated on the surface of the anode 3 can be quickly removed.

  For this reason, in the ozone water generating apparatus 1 of the present embodiment, the wire 7 is wound in a spiral shape at an appropriate interval, and the cross-sectional area of the spiral water channel 10 is converted into a circular tube so that the inner diameter is 2 mm or less. High-concentration ozone water can be generated efficiently.

  Then, the ozone water production | generation apparatus 1 was actually created as follows, and the performance evaluation was performed. First, as the solid polymer film 2, Nafion 324 (Nafion 117 may be used) manufactured by DuPont was used. As the anode 3 and the cathode 4, a platinum wire mesh (manufactured by Niraco, 0.08 mm, 80 mesh) was used to form a disc-shaped electrode having a diameter of 3 cm. As the wire 7, a titanium wire having a diameter of 1 mm was used, and the spiral water channel 10 was formed by winding it in a spiral shape with an interval of 1 to 3 mm. Further, the outer frames 9, 15, and 17 were formed of acrylic resin.

  The supply port 9b was directly connected to the water supply (distilled water may be continuously fed by a liquid feed pump), and an electrolysis experiment was conducted while a direct current was applied between the anode 3 and the cathode 4 at 5A. As the power source, a variable DC constant voltage / constant DC power source (PAD110-5L manufactured by Kikusui Electronics Co., Ltd.) was used and energized under constant current conditions. In this electrolysis experiment, a 0.1 M NaCl aqueous solution adjusted to a pH of about 4 by adding citric acid as a catholyte is placed in a tank (may be a bucket) and used via a supply port 17a and a discharge port 17b. Then, water was circulated through the cathode chamber 19.

The dissolved ozone concentration, etc. The results are shown in Table 1 was measured by a colorimetric method using ozone meter (Rika Ltd. O _3- 2Z Kasahara). Since a new Nafion membrane was used in the experiment, measurement was performed after continuous operation for 30 minutes or more until the ozone water concentration data settled. Table 1 shows the actual data obtained by purchasing the product shown in Non-Patent Document 2 as a conventional product.

  As shown in Table 1, in this example, highly concentrated ozone water could be generated very efficiently. In addition, in the said Example and embodiment of invention, the supply port 9b, the spiral water channel 10, and the discharge port 9c are equivalent to a water channel, Among these, the spiral water channel 10 is a small diameter part, The supply port 9b and a discharge port 9c corresponds to the large diameter portion. The wire 7 corresponds to a partition wall.

  Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and can be implemented in various forms without departing from the gist of the present invention. For example, in the above-described embodiment, the entire spiral water channel 10 is in contact with the anode 3, and the supply port 9 b and the discharge port 9 c are not in contact with the anode 3 at all. However, in the present invention, the entire small-diameter portion is not necessarily in contact with the anode. There is no need to be disposed in the portion, and it is not necessarily required to be disposed in the portion where the entire large diameter portion is not in contact with the anode. For example, even when 80% or more of the small-diameter portion is disposed in the portion in contact with the anode and 80% or more of the large-diameter portion is disposed in the portion not in contact with the anode, the same operation / effect is obtained to some extent. Arise.

  Moreover, in the ozone water generating apparatus 1, the spiral water channel 10 is formed by the titanium wire 7, but the partition wall can be configured by using various materials such as other metals, resins, and rubbers. However, when the partition wall is made of titanium as described above, titanium is excellent in corrosion resistance because a titanium dioxide film is formed on the surface, and the durability of the ozone water generating apparatus 1 can be further improved.

  Further, when the partition walls are made of silicone rubber, since the silicone rubber can be easily formed into various shapes, small-diameter portions having various shapes can be easily formed. Furthermore, the partition wall may be integrally formed with the wall surface 9a of the outer frame 9 or the like with a resin. In this case, the mechanical strength of the partition wall is improved, so that the durability of the ozone water generator can be further improved.

  Furthermore, various forms of water channels are also conceivable. For example, as shown in FIG. 4A, a pair of comb-shaped partition walls 27, 27 are combined so that the comb teeth 27a are alternated to form a twisted water channel 20 as a small diameter portion. Good.

  In this case, since both ends of the twisted water channel 20 are disposed at both ends of the surface of the twisted water channel 20, the supply port 27b and the discharge port 27c can also be disposed along the surface. However, since the spiral water channel 10 as described above has no corners and is smooth, the flow of water is also smooth and no extra pressure loss occurs. For this reason, in the above-mentioned ozone water production | generation apparatus 1, ozone water can be produced | generated more efficiently.

  Further, the supply port 9b and the discharge port 9c may be interchanged in the ozone water generator 1. However, it is predicted that a higher water pressure is generated in a portion where the radius of curvature of the spiral water channel 10 is smaller than a portion where the radius of curvature is large. Therefore, providing the supply port 9b at the outer peripheral side end of the spiral water channel 10 as described above makes the water pressure more uniform over the entire spiral water channel 10 (that is, the entire surface of the anode 3), thereby further improving the efficiency. There is a possibility that ozone water can be generated well.

  Furthermore, as shown in FIG. 4 (B), a double spiral water channel 30 as a small diameter portion may be configured by combining a pair of wires 37, 37 configured in a spiral shape. In the example of FIG. 4 (B), the supply port 39a and the discharge port 39b are provided perpendicularly to the surface of the double spiral water channel 30 as in the case of the ozone water generator 1, but in this example as well, the double spiral is provided. Since both ends of the water channel 30 are disposed at both ends of the surface of the double spiral water channel 30, the supply port and the discharge port can be disposed along the surface in the same manner as in FIG.

  Also, various forms are conceivable as materials and shapes of the anode 3 and the cathode 4. For example, various electrode materials such as zinc dioxide and porous diamond can be used as the anode and stainless steel can be used as the cathode, and the electrode shape can be a cylindrical shape, a square flat plate, a rectangular flat plate, or the like. When a cylindrical electrode is used, a form in which the partition wall is spirally arranged along the cylindrical surface is conceivable. However, in the above-mentioned ozone water generating apparatus 1, the configuration can be simplified because the flat electrolytic cell 5 can be used, and the spiral water channel 10 is formed by arranging the wire 7 on the surface of the anode 3. Therefore, the spiral water channel 10 having a small cross-sectional area can be easily formed. Therefore, the above-described ozone water generation apparatus 1 can be manufactured more easily and the apparatus can be further downsized.

  Moreover, in the said Example, although the outer frames 9,15,17 are shape | molded with the acrylic resin, it can comprise with various materials, such as other various plastics, aluminum, and SUS.

Further, tap water may be passed through the cathode chamber 19 or the cathode 4 may be opened to the atmosphere. In these cases, ozone water can be generated on the anode 3 side. However, in the above embodiment, since the catholyte is circulated through the cathode chamber 19, H ⁺ transported to the surface of the cathode 4 through the solid polymer membrane 2 can be released well with NaCl. Further, if the Ca or the like in tap water is carried to the surface of the cathode 4 in place of the H ⁺ is insufficient H ⁺ to be reduced at the cathode 4 can be compensated for by citric acid . Therefore, in this embodiment, the function of the cathode 4 can be secured and ozone water can be generated more efficiently. In addition, by forming the spiral water channel 10 and the twisted water channel 20 as described above on the cathode 4 side, the water pressure and the turbulent flow described above are used to bring the H ⁺ carried to the surface of the cathode 4. Etc. can be released more satisfactorily.

It is the top view and sectional drawing showing the structure of the ozone water production | generation apparatus to which this invention was applied. It is a graph showing the influence which the cross-sectional area of a water channel has on a pressure loss. It is a graph showing the influence which the cross-sectional area of a water channel has on mass transfer. It is a top view showing the modification of the water channel of the said ozone water production | generation apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Ozone water generator 2 ... Solid polymer film 3 ... Anode 4 ... Cathode 5 ... Electrolytic cell 7, 37 ... Wire 9 ... Outer frame 9a ... Wall surface 9b, 17a, 39a ... Supply port 9c, 17b, 39b ... Discharge port DESCRIPTION OF SYMBOLS 10 ... Spiral channel 19 ... Cathode chamber 20 ... Twist channel 27 ... Bulkhead 30 ... Double spiral channel

Claims (4)

An electrolysis cell comprising a solid polymer membrane sandwiched between a flat anode and a cathode;
A water channel provided on the anode surface so as to allow water to pass through;
In the ozone water generating apparatus provided with
Comb-like partition walls that are spirally or combined so that the comb teeth are staggered over the entire surface of the anode are disposed,
The portion of the water channel that is in contact with the anode is formed by partitioning the partition wall by bringing a flat wall surface into close contact with the surface opposite to the anode of the partition wall, and the cross-sectional area is converted to a circular tube and the inner diameter is 2 mm or less. in ozone water generation apparatus, characterized in that it is a possible small diameter portion turbulence by the water flow. The ozone water generating apparatus according to claim 1, wherein the partition wall is made of titanium . The partition wall according to claim 1 Symbol placement of the ozone water production apparatus characterized in that it is constituted by a silicone rubber. The partition wall according to claim 1 Symbol placement of the ozone water generation apparatus, characterized in that integrally molded with said wall.

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