JP6937005B2 - Water electrolyzer, method of manufacturing functional water - Google Patents

Description

The present invention relates to a water electrolyzer and a method for producing functional water.

Patent Document 1 discloses a configuration in which water is supplied to a water electrolysis cell using a metal mesh such as Pt (platinum) as an electrode to perform water electrolysis.

Japanese Unexamined Patent Publication No. 2006-175384

Here, a manufacturing method is known in which water is passed once through a water electrolysis cell to produce ozone water, oxygen water, or hydrogen water (hereinafter, these are collectively referred to as functional water). In this manufacturing method, in order to increase the concentration of functional water, for example, it is necessary to reduce the amount of water flow and increase the current density of the water electrolysis cell to increase the ratio of the generated gas to the amount of water flow. Become. Even if such an operation is performed, for example, ozone water having a concentration of more than 70 mg / L, hydrogen water having a concentration of 1.8 mg / L or more exceeding the saturation concentration, and oxygen water having a concentration of 60 mg / L or more can be produced. It's difficult to do.

In consideration of the above facts, an object of the present invention is to provide a water electrolyzer capable of producing high-concentration functional water that cannot be reached by one water flow.

The first aspect is a solid electrolyte membrane, a first electrode portion having a first terminal plate and a plate-shaped first mesh electrode, a second electrode portion having a second terminal plate and a plate-shaped second mesh electrode, and the like. The first mesh electrode is sandwiched between one surface of the solid electrolyte membrane and the first terminal plate, and water flows along the one surface between them. The water electrolysis cell in which the second mesh electrode is sandwiched between the other surface of the solid electrolyte membrane and the second terminal plate and water flows along the other surface between them, and the first electrode. A current is passed between the portion and the second electrode portion to store the power source for water electrolysis in the water electrolysis cell and the water flowing through the flow path between the one surface and the first terminal plate. It includes a storage unit and a pump that re-sends water from the storage unit to the flow path.

According to this configuration, in the first electrode portion of the water electrolysis cell, a plate-shaped first mesh electrode is sandwiched between one surface of the solid electrolyte membrane and the first terminal plate, and the space between them is formed on the one surface. Water circulates along. In the second electrode portion of the water electrolysis cell, a plate-shaped second mesh electrode is sandwiched between the other surface of the solid electrolyte membrane and the second terminal plate, and water flows along the other surface between them. .. Then, the power supply causes a current to flow between the first electrode portion and the second electrode portion to electrolyze the water in the water electrolysis cell. The gas generated by this water electrolysis dissolves in water flowing through the flow path between one surface and the first terminal plate, and functional water is produced.

The functional water that has flowed through the flow path is stored in the storage unit. The functional water in the reservoir is pumped back into the flow path.

As described above, in the configuration of the first aspect , since water can be passed through the flow path between one surface and the first terminal plate a plurality of times, water is electrolyzed each time the water is passed a plurality of times to increase the concentration of the functional water. Can be planned.

Further, in the configuration of the first aspect , since water flows between one surface and the first terminal plate along one surface, the finely foamed gas and water come into contact with each other in the first mesh electrode. It is possible to increase the concentration of functional water.

As described above, in the configuration of the first aspect , it is possible to produce high-concentration functional water that cannot be reached by one water flow.

In the second aspect , the first water previously stored in the storage section circulates between the storage section and the flow path by circulating the first water in the storage section and then storing the first water in the storage section again. The product is operated under operating conditions in which the product of the circulating water amount per unit time and the operating time is at least twice the amount of the first water stored in the storage unit in advance.

According to this configuration, the first water pre-stored in the storage section circulates in the flow path between one surface and the first terminal plate more than once, so that the concentration of the functional water can be increased. Can be planned.

In the third aspect , the second water flowing through the flow path between the other surface and the second terminal plate is sent back to the flow path to circulate the second water.

According to this configuration, since the second water circulates, the amount of the second water used can be reduced as compared with the case where the second water flowing through the flow path between the other surface and the second terminal plate is discarded. ..

The fourth aspect is included in the first water and the first water which are arranged between the water electrolysis cell and the storage portion and which have flowed through the flow path between the one surface and the first terminal plate. It is equipped with a gas-liquid mixer that mixes with gas.

According to this configuration, the gas that could not be completely dissolved in the water electrolysis cell can be dissolved in water in the gas-liquid mixer, and the concentration of the functional water can be increased.

A fifth aspect includes a cooling device for cooling the storage unit.

According to this configuration, since the cooling device cools the reservoir, Henry's law suppresses the transition of the generated gas from the liquid phase to the gas phase, and further, a high concentration of functional water can be achieved. ..

A sixth aspect includes an extraction unit capable of extracting the first water from the storage unit, and a replenishment unit for replenishing the storage unit from which the first water has been extracted by the extraction unit.

According to this configuration, the functional water extracted from the storage unit by the extraction unit can be used for, for example, disinfection, washing, drinking, and the like. Then, since the extracted water can be replenished to the storage unit by the replenishment unit, functional water can be continuously produced without reducing the water in the storage unit.

In the seventh aspect , when the first water is extracted from the storage unit by the extraction unit and the extracted amount of the first water is replenished to the storage unit by the replenishment unit, the first water is stored in the storage unit in advance. The product of the average residence time and the circulating water amount per unit time is the product of the average residence time and the value obtained by dividing the stored water amount of the first water by the amount of replenished water replenished in the storage unit per unit time as the average residence time. , It is operated under operating conditions that are more than twice the amount of stored water.

According to this configuration, the first water flows through the flow path between one surface and the first terminal plate more than once within the time when the first water replenished in the storage part stays in the storage part. Therefore, the concentration of the highly concentrated functional water can be maintained.

In the eighth aspect , the first water is circulated between the flow path between the one surface and the first terminal plate and the storage part without extracting the water from the storage part.

According to this configuration, water is circulated between the flow path of the water electrolysis cell and the storage portion without being extracted from the storage portion, so that the concentration of functional water can be increased in a short time.

In the ninth aspect , the first electrode portion is used as a cathode portion, and the first water is circulated in a flow path between the one surface and the first terminal plate to produce hydrogen water.

According to this configuration, water can be passed through the flow path between one surface on the cathode side and the first terminal plate multiple times, so that water is electrolyzed each time water is passed multiple times to obtain high-concentration hydrogen water. Can be manufactured.

The tenth aspect is a preparatory step for preparing the water electrolyzer of any one of the first to ninth aspects, and the first water and the second water are circulated a plurality of times to the water electrolyzer cell of the water electrolyzer. It has a water electrolysis step of producing functional water containing a gas generated from the water electrolysis by passing a current through the water electrolysis cell and performing water electrolysis in the water electrolysis cell.

According to this manufacturing method, while water is circulated through the water electrolysis cell of any one of the first to ninth aspects , a current is passed through the water electrolysis cell a plurality of times to electrolyze the water in the water electrolysis cell. , To produce functional water containing a gas generated from the water electrolysis.

As described above, in the production method of the tenth aspect , water can be passed through the water electrolysis cell a plurality of times, and water electrolysis can be performed each time the water is passed a plurality of times to increase the concentration of the functional water.

Further, in the manufacturing method of the tenth aspect , since water flows between one surface and the first terminal plate along one surface, the finely foamed gas and water are separated in the first mesh electrode. It can be brought into contact with each other, and the concentration of functional water can be increased.

As described above, in the production method of the tenth aspect , it is possible to produce high-concentration functional water that cannot be reached by one water flow.

Since the present invention has the above configuration, it is possible to provide a water electrolyzer capable of producing high-concentration functional water that cannot be reached by one water flow.

It is the schematic which shows the structure of the water electrolysis apparatus which concerns on 1st Embodiment. It is an exploded perspective view which shows the internal structure of the water electrolysis cell which concerns on 1st Embodiment. It is the schematic which shows the structure of the water electrolysis apparatus which concerns on 2nd Embodiment. It is a graph which shows the time-dependent change of the concentration of ozone water in Example 1. It is a graph which shows the time-dependent change of the concentration of ozone water and the water temperature of a storage part in Example 2. It is a graph which shows the simulation result under the production condition of the ultra-high concentration ozone water.

Hereinafter, an example of the embodiment according to the present invention will be described with reference to the drawings.

<< First Embodiment >>
<Water electrolyzer 100>
First, the configuration of the water electrolyzer 100 according to the first embodiment will be described. FIG. 1 is a schematic view showing the configuration of the water electrolyzer 100 according to the first embodiment.

The water electrolyzer 100 is a device that electrolyzes pure water (an example of water) to generate (manufacture) ozone water (an example of functional water). Specifically, as shown in FIG. 1, the water electrolysis apparatus 100 includes a water electrolysis cell 30, a first supply path 120, a first discharge path 170, a storage unit 112, and a second supply path 160. It has a second discharge passage 190, a gas-liquid mixer 196, a dissolved ozone concentration meter 168, an extraction unit 410, a replenishment unit 420, and a power supply 180.

The components of each part of the water electrolysis device 100 (for example, housing, tank, pump, piping, mixer, valve, joint, packing, water electrolysis cell, etc.) are made of a material having excellent ozone resistance, for example, Teflon (for example, Teflon (for example). It is composed of registered trademark), stainless steel, etc.

[Water electrolysis cell 30]
As shown in FIG. 2, the water electrolysis cell 30 includes a solid electrolyte membrane 32, an anode portion 40 (an example of a first electrode portion), a cathode portion 50 (an example of a second electrode portion), and a housing 38 (an example of a second electrode portion). (See FIG. 1) and.

As the solid electrolyte membrane 32, for example, a solid polymer electrolyte membrane such as a Nafion membrane (Nafion is a registered trademark) is used. The solid electrolyte membrane 32 is not limited to the Nafion membrane, and various solid electrolyte membranes can be used.

The anode portion 40 has a plate-shaped (flat) first mesh electrode 42, 431, 432, 433, and a plate-shaped first terminal plate 44 (terminal). The first mesh electrodes 42, 431, 432, and 433 are overlapped in the thickness direction and are arranged so as to be in contact with each other in the thickness direction. One surface 32A of the solid electrolyte membrane 32 is in contact with one surface 42A of the first mesh electrode 42. One surface 44A of the first terminal plate 44 is formed in a planar shape and is in contact with one surface 433B of the first mesh electrode 433. Specifically, the first terminal plate 44 has a flat plate shape, one surface 44A of the first terminal plate 44 does not have a groove for forming a water channel, and one surface 44A has an entire surface. It is formed in a plane.

The cathode portion 50 has a plate-shaped (flat) second mesh electrodes 52 and 53 and a plate-shaped second terminal plate 54 (terminal). The second mesh electrodes 52 and 53 are overlapped in the thickness direction and are arranged so as to be in contact with each other in the thickness direction. The other surface 32B of the solid electrolyte membrane 32 is in contact with one surface 52A of the second mesh electrode 52. One surface 54A of the second terminal plate 54 is formed in a flat shape and is in contact with one surface 53B of the second mesh electrode 53. Specifically, the second terminal plate 54 has a flat plate shape, one surface 54A of the second terminal plate 54 does not have a groove for forming a water channel, and one surface 54A has an entire surface. It is formed in a plane.

Therefore, the solid electrolyte membrane 32 is sandwiched between the first mesh electrodes 42, 431, 432, 433 and the second mesh electrodes 52, 53, and the sandwiched one is arranged between the first and second terminal plates 44, 54. Has been done. That is, in the water electrolysis cell 30, the first terminal plate 44, the first mesh electrode 433, the first mesh electrode 432, the first mesh electrode 431, the first mesh electrode 42, the solid electrolyte membrane 32, the second mesh electrode 52, and the second mesh electrode The two mesh electrodes 53 and the second terminal plate 54 are laminated in this order. Then, this laminated body is housed in the housing 38.

As the first and second terminal plates 44 and 54, for example, Ti or stainless steel is used. As the first and second mesh electrodes 42 and 52 that come into contact with the solid electrolyte membrane 32, for example, catalyst electrodes having excellent water electrolysis activity are used. Examples of the catalyst electrode include metals such as Pt, Ni, and stainless steel, oxides such as _{SnO 2} , IrO ₂ , Nb ₂ O _{5, and TaOx doped with PbO 2} , Ni, and Sb, and activated carbon and boron-doped diamond. Such as carbon electrodes are used.

As the first and second mesh electrodes 431, 432, 433, and 53 that do not come into contact with the solid electrolyte membrane 32, materials having excellent oxidation resistance such as Ti and stainless steel are used. As a result, deterioration of the water electrolysis cell 30 can be suppressed. Further, as the first and second mesh electrodes 42, 431, 432, 433, 52, and 53, for example, plate-like (flat) and mesh-like (net-like) electrodes such as plain weave and twill weave are used.

Further, the first and second mesh electrodes 42, 431, 432, 433, 52, and 53 have a plurality of irregularities on both the front and back surfaces (one surface and the other surface). As a result, the first terminal plate 44, the first mesh electrode 42, 431, 432, 433, the solid electrolyte membrane 32, the second mesh electrodes 52, 53, and the second terminal plate 54 are attached to the members adjacent to each other. A contacting portion and a portion having a gap are formed.

In the anode portion 40, the gap portion between each of the solid electrolyte membrane 32, the first mesh electrode 42, 431, 432, 433 and the first terminal plate 44, and the mesh portion of the first mesh electrode 42, 431, 432, 433. And, a flow path through which water flows is formed. Then, in the anode portion 40, between the solid electrolyte film 32 and the first terminal plate 44, pure along one surface 32A (the surface of the first mesh electrode 42, 431, 432, 433) of the solid electrolyte film 32. Water (anode water as the first water) flows through the flow path.

Further, in the cathode portion 50, water flows through the gap portion between each of the solid electrolyte membrane 32, the second mesh electrodes 52, 53 and the second terminal plate 54, and the mesh portion of the second mesh electrodes 52, 53. A flow path is formed. Then, in the cathode portion 50, between the solid electrolyte membrane 32 and the second terminal plate 54, salt water (second water) is formed along the other surface 32B (the surfaces of the second mesh electrodes 52 and 53) of the solid electrolyte membrane 32. (Cathode water as) circulates in the flow path. In FIG. 2, the directions in which the assault water and the cathode water flow in the water electrolysis cell 30 are indicated by arrows.

The size (area) of the first and second mesh electrodes 42, 431, 432, 433, 52, and 53 is defined by the flow rates of the assault water and the cathode water flowing in the water electrolysis cell 30. For example, when the flow rate is about 1 L / min, the first and second mesh electrodes 42, 431, 432, 433, 52, and 53 have a size of, for example, 10 mm in width and 20 mm in length. Further, for example, when the flow rate is about 4 to 6 L / min, the first and second mesh electrodes 42, 431, 432, 433, 52, and 53 have a size of, for example, a width of 30 mm and a length of 60 mm. Will be done. Further, for example, when the flow rate is about 10 L / min, the first and second mesh electrodes 42, 431, 432, 433, 52, and 53 have a size of, for example, 50 mm in width × 100 mm in length. .. Further, the sizes of the first and second mesh electrodes 42, 431, 432, 433, 52, and 53 are smaller than the size of the solid electrolyte membrane 32.

In any of the above cases, the aspect ratios of the first and second mesh electrodes 42, 431, 432, 433, 52, and 53 are 1: 2, and the aspect ratio of the water flow direction in the water electrolysis cell 30 is The length is longer than the width in the orthogonal direction orthogonal to the distribution direction. Further, the first and second mesh electrodes 42, 431, 432, 433, 52, and 53 may have a configuration in which the width in the orthogonal direction is wider than the length in the distribution direction.

In the water electrolysis cell 30, four first mesh electrodes 42, 431, 432, and 433 are arranged between the solid electrolyte membrane 32 and the first terminal plate 44, and the solid electrolyte membrane 32 and the second terminal plate 54 are arranged. Two second mesh electrodes 52 and 53 were arranged between the two, but the present invention is not limited to this. That is, the number of mesh electrodes arranged between the solid electrolyte membrane 32 and each of the first and second terminal plates 44 and 54 is the flow rate of pure water flowing in the water electrolysis cell 30 and the number of mesh electrodes in the water electrolysis cell 30. Specified by the pressure loss of.

By increasing the number of mesh electrodes, the gap between the solid electrolyte membrane 32 and each of the first and second terminal plates 44 and 54 becomes large, and the cross-sectional area of the flow path becomes large, so that the pressure loss can be suppressed. Therefore, when it is desired to suppress the pressure loss while increasing the flow rate of pure water flowing in the water electrolysis cell 30, it is arranged between the solid electrolyte membrane 32 and each of the first and second terminal plates 44 and 54. The number of mesh electrodes is increased.

For example, when the mesh electrode has a size of 30 mm in width and 60 mm in length and the flow rate of pure water flowing in the water electrolysis cell 30 is 4 L / min, the solid electrolyte membrane 32 and the first and second terminal plates 44 and 54 Six mesh electrodes (12 in total) are placed between each of the two mesh electrodes. The size of the housing 38 at this time is, for example, 56 mm in width × 95 mm in length × 31 mm in height.

[First supply path 120]
The first supply path 120 is a flow path for supplying cathode water (for example, salt water) to the cathode portion 50 of the water electrolysis cell 30. The downstream end of the first supply path 120 is connected to the cathode portion 50 of the water electrolysis cell 30, and the upstream end is connected to the storage portion 121 for storing the cathode water.

A pump 122 as a water supply unit is arranged in the first supply path 120. The pump 122 sends the cathode water stored in the storage section 121 to the cathode section 50 of the water electrolysis cell 30. Further, a flow rate adjusting valve 124 for adjusting the flow rate of the cathode water is arranged on the downstream side of the pump 122 in the first supply path 120.

When a metal electrode such as Pt is used as the first mesh electrode 42, oxidation / deterioration is likely to occur in the process of water electrolysis. Therefore, in the present embodiment, salt water is used as the cathode water to suppress the oxidation of the metal electrode and suppress the decrease in water electrolysis efficiency. The mechanism for suppressing the oxidation of the metal electrode is described in JP2012-107331A.

Incidentally, as the first mesh electrode 42, _PbO 2, Ni or _{SnO 2 · IrO 2 · Nb 2} O 5 · oxides such TaOx doped with Sb, if used, carbon electrodes, such as activated carbon, boron-doped diamond Since oxidation and deterioration are unlikely to occur in the water, it is not necessary to use salt water as the cathode water, and pure water or ion-exchanged water can be used as the cathode water.

[First discharge channel 170]
The first discharge passage 170 is a flow path through which the cathode water flowing through the cathode portion 50 of the water electrolysis cell 30 is discharged. The upstream end of the first discharge path 170 is connected to the cathode portion 50 of the water electrolysis cell 30. The cathode water that has passed through the cathode portion 50 of the water electrolysis cell 30 is discharged through the first discharge path 170. The cathode water discharged in the first discharge passage 170 may be supplied to the cathode portion 50 of the water electrolysis cell 30 again through the first supply passage 120. That is, the cathode water may be circulated. As a result, the amount of cathode water used can be reduced as compared with the configuration in which the cathode water is not circulated.

[Reservoir 112]
The storage unit 112 is composed of, for example, a container for storing anode water (pure water). The anode water stored in the storage unit 112 circulates with the water electrolysis cell 30 as described later.

Here, when the water temperature in the reservoir 112 rises, Henry's law promotes the transfer of ozone from the liquid phase to the gas phase, so that the rise in the concentration of ozone water is suppressed. Therefore, in the present embodiment, the storage unit 112 is installed in the cooling device 114. The cooling device 114 cools the storage unit 112 to, for example, 20 ° C. or lower, preferably 10 ° C. or lower. As a result, the transition of the generated ozone from the liquid phase to the gas phase is suppressed.

The cooling device may be a throw-in type cooler in which a cooling unit composed of a cooling coil or the like is inserted into the storage unit 112, or a normal heat exchanger type cooler may be installed in the second discharge path 190. It may be installed. Further, the storage unit 112 may be configured to contain ice together with the anode water and keep the water temperature in the storage unit 112 low by the heat of fusion of the ice. Further, in the replenishment unit 420 described later, the cooled anode water may be replenished to the storage unit 112 to keep the water temperature in the storage unit 112 low.

[Second supply path 160]
The second supply path 160 is a flow path for supplying the assault water stored in the storage section 112 to the anode section 40 of the water electrolysis cell 30. The upstream end of the second supply path 160 is connected to the storage portion 112, and the downstream end is connected to the anode portion 40 of the water electrolysis cell 30.

A pump 162 as a water supply unit is arranged in the second supply path 160. The pump 162 sends assault water to the anode portion 40 of the water electrolysis cell 30. Further, a flow rate adjusting valve 164 for adjusting the flow rate of the anode water is arranged on the downstream side of the pump 162 in the second supply path 160. Further, on the downstream side of the flow rate adjusting valve 164 in the second supply passage 160, a pressure gauge 166 for measuring the pressure of the anode water in the second supply passage 160 is arranged.

[Second discharge channel 190]
The second discharge passage 190 is a flow path for discharging the assault water (ozone water) flowing through the anode portion 40 of the water electrolysis cell 30 to the storage portion 112. The upstream end of the second discharge passage 190 is connected to the anode portion 40 of the water electrolysis cell 30, and the downstream end is connected to the storage portion 112. The anode water flowing through the second discharge channel 190 is stored in the storage unit 112. In this way, assault water circulates between the storage portion 112 and the anode portion 40 of the water electrolysis cell 30 through the second discharge passage 190 and the above-mentioned second supply passage 160. A flow rate adjusting valve 192 for adjusting the flow rate of the anode water is arranged in the second discharge path 190.

[Gas-liquid mixer 196]
The gas-liquid mixer 196 has a function of mixing a gas (ozone) with water. The gas-liquid mixer 196 is arranged on the downstream side of the flow rate adjusting valve 192 in the second discharge passage 190.

As the gas-liquid mixer 196, for example, 13 # 100 Ti meshes having a width of 40 mm and a length of 100 mm are stacked and arranged inside a Teflon-made can body (Teflon is a registered trademark). In this gas-liquid mixer 196, water and ozone flow along the mesh surface, and the mixing is promoted by increasing the contact area of the gas-liquid. As the gas-liquid mixer 196, for example, a static mixer (for example, CSM-12-5 manufactured by Noritake Co., Ltd.) may be used.

[Dissolved ozone concentration meter 168]
The dissolved ozone concentration meter 168 has a function of measuring the ozone concentration dissolved in the sword water. The dissolved ozone concentration meter 168 is arranged in a branch path 167 branching from the second supply path 160 between the pump 162 and the flow rate control valve 164 in the second supply path 160. An on-off valve 169 for opening and closing the branch path 167 is arranged in the branch path 167. When the on-off valve 169 opens the branch path 167, the assault water sent by the pump 162 flows into the dissolved ozone concentration meter 168 from the second supply path 160, and the ozone concentration dissolved in the assault water is changed to the dissolved ozone concentration. A total of 168 measures.

[Extractor 410]
The extraction unit 410 has a function of extracting the sword water (ozone water) stored in the storage unit 112. The extraction unit 410 has an extraction path 412 connected to the storage unit 112 and an on-off valve 414 arranged in the extraction path 412. In the extraction unit 410, the on-off valve 414 opens the extraction path 412, so that the anode water stored in the storage unit 112 is extracted through the extraction path 412. The extraction of the anode water is performed after, for example, the dissolved ozone concentration meter 168 confirms that the concentration of the anode water in the reservoir 112 has reached a predetermined concentration. When extracting ozone water in a pressurized state, a branch pipe (tea, etc.) may be attached to the pipe (branch path 167) of the dissolved ozone concentration meter 168 to extract the ozone water pressurized by the pump 162. can. The sword water (ozone water) extracted by the extraction unit 410 is used for, for example, sterilization, disinfection, cleaning, and the like.

[Replenishment unit 420]
The replenishment unit 420 has a function of replenishing the storage unit 112 with anode water (pure water). Specifically, the replenishment unit 420 includes, for example, a storage unit 422 for storing the anode water for replenishment, a replenishment path 424 connected to the storage unit 422 and the storage unit 112, and a pump arranged in the replenishment path 424. It has 426 and. In the replenishment unit 420, the replenishment anode water stored in the storage unit 422 is replenished to the storage unit 112 by the pump 426.

[Power supply 180]
The power supply 180 is connected to the first terminal plate 44 of the anode portion 40 and the second terminal plate 54 of the cathode portion 50. A DC power supply is used for the power supply 180. The power supply 180 is operated in a constant current mode by, for example, operating a personal computer 182 (PC).

The current density of the current flowing through the water electrolysis cell 30, 0.1 A / cm ² or more 3.5A / cm ² or less. This is because if the current density is ^{less than 0.1 A / cm 2} , the electrolytic reaction of water is not promoted and the concentration of ozone water does not increase. If the current density ^{exceeds 3.5 A / cm 2} , the electrodes of the anode portion 40 and the cathode portion 50 are deteriorated and consumed, and the life of the water electrolyzer 100 is shortened. Further, when the current density ^{exceeds 3.5 A / cm 2} , the water temperature in the storage portion 112 rises. As a result, Henry's law promotes the transfer of ozone from the liquid phase to the gas phase, thus suppressing the increase in the concentration of ozone water.

Then, by passing a DC current through the water electrolysis cell 30, the assault water and the cathode water flowing through the water electrolysis cell 30 are electrolyzed. When the assault water and the cathode water are electrolyzed, hydrogen is generated in the cathode portion 50 and ozone is generated in the anode portion 40.
[Operating conditions of water electrolyzer 100]
The water electrolyzer 100 is operated under operating conditions in which the product of the circulating water amount and the operating time is at least twice the amount of the anode water previously stored in the storage unit 112. That is, the anode water previously stored in the storage unit 112 is operated under operating conditions in which the water electrolysis cell 30 is circulated twice or more. The amount of circulating water is the amount of circulating water per unit time, which is the amount of water sent from the storage unit 112 to the water electrolysis cell 30 and returned to the storage unit 112 again.

[Amount of circulating water in the water electrolyzer 100]
In the water electrolysis apparatus 100, it is preferable that the amount of circulating water of the anode water circulating in the second supply path 160, the water electrolysis cell 30, and the second discharge path 190 is large. The reason is that the ozone bubbles generated in the water electrolysis cell 30 can be efficiently discharged from the first mesh electrodes 42, 431, 432, 433 of the water electrolysis cell 30. As the concentration of ozone water increases, the amount of ozone that cannot be completely dissolved in water during electrolysis and forms bubbles increases. As a result, air bubbles will accumulate in the water electrolysis cell 30. These bubbles reduce the effective area of the first mesh electrodes 42, 431, 432, and 433 of the anode portion 40, and reduce the electrolysis efficiency.

Therefore, by increasing the amount of circulating water to suppress the decrease in the effective area of the first mesh electrodes 42, 431, 432, and 433, and by increasing the number of times of water electrolysis per unit time, the concentration of ozone water can be increased. Try.

In particular, in the configuration in which the anode water is circulated along one surface 32A (the surface of the first mesh electrode 42, 431, 432, 433) of the solid electrolyte membrane 32 in the anode portion 40 as in the present embodiment. Bubbles generated in the first mesh electrodes 42, 431, 432, and 433 can be flushed out, and the effect of suppressing the influence of bubbles is high.

[Method for producing ozone water using the water electrolyzer 100]
This manufacturing method includes a preparatory step and a water electrolysis step. In the preparation step, the water electrolyzer 100 described above is prepared.

In the water electrolysis step, the water electrolysis device 100 is operated under operating conditions in which the product of the circulating water amount and the operating time is at least twice the amount of the anode water stored in the storage unit 112 in advance. As a result, while assault water was circulated a plurality of times through the anode portion 40 of the water electrolysis cell 30 of the water electrolysis apparatus 100, a current was passed through the water electrolysis cell 30 to perform water electrolysis in the water electrolysis cell 30, and the water electrolysis was generated. Produce ozone water containing ozone (an example of gas).

Specifically, the water electrolysis step is performed as follows. That is, the assault water stored in the storage section 112 of the water electrolysis device 100 is supplied to the anode section 40 of the water electrolysis cell 30, and a current is passed through the water electrolysis cell 30 by the power supply 180 to perform water electrolysis in the water electrolysis cell 30. Will be. The ozone generated by the water electrolysis is dissolved in the assault water in the water electrolysis cell 30, and further, in the gas-liquid mixer 196, the ozone that could not be completely dissolved in the water electrolysis cell 30 is dissolved in the assault water. Then, the anode water is returned from the gas-liquid mixer 196 to the storage unit 112. This process (cycle) is repeated a plurality of times to produce ozone water.

In the present embodiment, the produced ozone water is extracted from the storage unit 112 by the extraction unit 410 and used. Specifically, in the extraction section 410, the on-off valve 414 opens the extraction path 412, so that the ozone water stored in the storage section 112 is extracted through the extraction path 412. Assorted water (pure water) is replenished by the replenishment unit 420 as much as the ozone water is extracted. By replenishing the storage unit 112 with sword water while extracting ozone water from the storage unit 112, ozone water can be continuously used.

At this time, the time (average residence time) at which the replenished water replenished in the storage unit 112 stays in the storage unit 112 is defined as follows, and the water is electrolyzed twice or more within this average residence time.

Average residence time [min] = stored water amount [L] ÷ replenishment water amount [L / min]

The stored water amount is the amount of water stored in advance in the storage unit 112. The replenishment water amount is the amount of water replenished to the storage unit 112 per unit time.

When the water is electrolyzed twice or more within the average residence time, the relationship between the amount of circulating water circulating per unit time and the amount of stored water is as follows.

Average residence time [min] x circulating water amount [L / min] ≥ stored water amount [L] x 2

That is, in the present embodiment, the operation is performed under operating conditions in which the product of the average residence time and the circulating water amount per unit time is twice or more the stored water amount. The amount of circulating water is the amount of water that is sent from the storage unit 112 to the water electrolysis cell 30 and returned to the storage unit 112 again per unit time.

The produced high-concentration ozone water has extremely strong oxidizing / decomposing power, sterilizing power, and detergency, and can be used for sterilization, disinfection, cleaning, and the like. Further, the produced high-concentration ozone water can be used, for example, in a photoresist peeling step. Therefore, ozone water can replace the acid or alkaline aqueous solution currently used in the photoresist stripping step or the like. In addition, the ozone water after use returns to water and oxygen, which leads to a reduction in the environmental load.

<Action and effect according to this embodiment>
Next, the action and effect according to the present embodiment will be described.

According to the configuration of the present embodiment, as described above, in the anode portion 40 of the water electrolysis cell 30, the first mesh electrodes 42 and 431 are located between one surface 32A of the solid electrolyte film 32 and the first terminal plate 44. 432 and 433 are sandwiched, and the anode water flows along one surface 32A between them. Then, the power supply 180 passes a current between the anode portion 40 and the cathode portion 50 to perform water electrolysis in the water electrolysis cell 30. Ozone generated by this water electrolysis is dissolved in water flowing through the flow path between one surface 32A and the first terminal plate 44, and ozone water is produced.

The sword water (ozone water) that has flowed through the flow path is stored in the storage unit 112. The anode water is sent again by the pump 162 to the flow path of the water electrolysis cell 30, and water electrolysis is performed again.

As described above, in the configuration of the present embodiment, since water can be passed through the flow path between one surface 32A and the first terminal plate 44 a plurality of times, water is electrolyzed each time the water is passed a plurality of times to increase the ozone water level. It is possible to increase the concentration.

In particular, the water electrolyzer 100 is operated under operating conditions in which the product of the circulating water amount and the operating time is at least twice the amount of the anode water previously stored in the storage unit 112. As a result, the assault water previously stored in the storage unit 112 is circulated through the water electrolysis cell 30 twice or more, so that the concentration of ozone water can be increased.

Further, in the present embodiment, since the assault water flows between the one surface 32A and the first terminal plate 44 along the one surface 32A, fine bubbles are formed in the first mesh electrodes 42, 431, 432 and 433. The converted ozone can be brought into contact with water, and the concentration of ozone water can be increased.

Further, in the present embodiment, the anode water (ozone water) flowing between one surface 32A and the first terminal plate 44 passes through the gas-liquid mixer 196. Therefore, ozone that could not be completely dissolved in the water electrolysis cell 30 can be dissolved in water in the gas-liquid mixer 196, and a high concentration of ozone water can be achieved.

Further, in the present embodiment, the storage unit 112 is installed in the cooling device 114, and the storage unit 112 is cooled to, for example, 20 ° C. or lower. As a result, according to Henry's law, the transition of the generated ozone from the liquid phase to the gas phase is suppressed, and a high concentration of ozone water can be achieved.

As described above, in the configuration of the present embodiment, it is possible to produce high-concentration ozone water that cannot be reached by one water flow.

Further, in the present embodiment, the ozone water extracted from the storage unit 112 by the extraction unit 410 can be used for sterilization, disinfection, cleaning and the like. Then, since the extracted water can be replenished to the storage unit 112 by the replenishment unit 420, ozone water can be continuously produced without reducing the water in the storage unit 112.

Further, in the present embodiment, the replenished water replenished in the storage unit 112 is electrolyzed twice or more within the time (average residence time) in which the replenishment water is replenished in the storage unit 112, so that the ozone water has a high concentration. Can maintain the concentration of. As described above, in the present embodiment, ozone water having a constant concentration can be continuously produced by continuously extracting the ozone water from the storage unit 112 and continuously replenishing the water.

<Modification example of water electrolyzer 100>
In the water electrolyzer 100 described above, pure water is used as the sword water, but the present invention is not limited to this, and for example, ion-exchanged water may be used.

Further, when salt water is used as the cathode water, tap water may be used as the sword water. In the configuration in which salt water is used as the cathode water, NaOH is generated by electrolysis of the salt water in the cathode portion 50, so that the pH of the cathode water rises from 11 to 12. _{In that pH range, the particles of the electrolytic product (CaCO 3} , Mg (OH) _2, etc.) of the mineral component contained in the tap water are negatively charged, so that the electrolytic product is electrostatically repelled by the cathode portion 50. Precipitation is suppressed. In this way, the precipitation of the electrolytic product is suppressed, so that tap water can be used as the anode water.

Further, in the above-mentioned water electrolyzer 100, the produced ozone water is extracted from the storage unit 112 and used, but the present invention is not limited to this. For example, the sword water is circulated in a batch manner without extraction, and the produced ozone water is stored in the storage unit 112. Then, the operation of the water electrolyzer 100 may be stopped, the storage unit 112 may be removed from the water electrolyzer 100, and then the produced ozone water may be used. In this case, the concentration of ozone water can be increased in a short time.

Further, as the water electrolyzer 100 described above, it is preferable that the storage unit 112 has a pressure resistance, a pressure control device is installed, and the water electrolyzer 100 is operated under pressure. When water electrolysis is performed under a pressure of several atmospheres, Henry's law increases the solubility of the gas from the gas phase to the liquid phase, so that high-concentration functional water can be obtained.

<Modification example of using the water electrolyzer 100 for producing oxygenated water>
The water electrolyzer 100 described above was configured as an apparatus for producing ozone water, but may be configured as an apparatus for producing oxygen water (an example of functional water). In this case, as the first mesh electrode 42 of the anode portion 40, a mesh electrode having a catalyst layer (IrO ₂ ) having a function of reducing oxygen overvoltage in water electrolysis and suppressing ozone generation is used. As the mesh electrode, for example, a Ti mesh is used.

Further, in the case of producing oxygenated water, since there is little risk of oxidation / deterioration of the anode portion 40, it is not necessary to use salt water as the cathode water, and pure water or ion-exchanged water may be used as the cathode water. Further, the material of each part of the water electrolyzer 100 does not need to have ozone resistance.

<< Second Embodiment >>
<Water electrolyzer 10>
First, the configuration of the water electrolyzer 10 according to the second embodiment will be described. FIG. 3 is a schematic view showing the configuration of the water electrolyzer 10 according to the second embodiment.

The water electrolyzer 10 is a device that electrolyzes pure water (an example of water) to generate hydrogen water. Specifically, as shown in FIG. 3, the water electrolyzer 10 includes a water electrolysis cell 30, a first supply path 20, a first discharge path 70, a storage unit 12, and a second supply path 60. It has a second discharge passage 90, a dissolved hydrogen concentration meter 68, an extraction unit 210, a replenishment unit 220, and a power supply 80.

[Water electrolysis cell 30]
In the water electrolysis cell 30, as the first mesh electrode 42 of the anode portion 40, a mesh electrode having a catalyst layer (IrO ₂ ) having a function of reducing oxygen overvoltage in water electrolysis and suppressing the generation of ozone is used. As the mesh electrode, for example, a Ti mesh is used. Other points are the same as in the case of the water electrolyzer 100 for producing ozone.

In the water electrolyzer 10, the cathode portion 50 is an example of the first electrode portion, the second mesh electrodes 52 and 53 are examples of the first mesh electrode, and the second terminal plate 54 is an example of the first terminal plate. The other surface 32B functions as an example of one surface. Further, the anode portion 40 is an example of the second electrode portion, the first mesh electrode 42, 431, 432, 433 is an example of the second mesh electrode, and the first terminal plate 44 is an example of the second terminal plate 54. Surface 32A functions as an example of the other surface.

[First supply path 20]
The first supply path 20 is a flow path for supplying the anode water (pure water) as the second water to the anode portion 40 of the water electrolysis cell 30. The downstream end of the first supply path 20 is connected to the anode portion 40 of the water electrolysis cell 30, and the upstream end is connected to, for example, a storage portion for storing the anode water.

A pump 22 as a water supply unit is arranged in the first supply path 20. The pump 22 sends assault water to the anode portion 40 of the water electrolysis cell 30. Further, a flow rate adjusting valve 24 for adjusting the flow rate of the anode water is arranged on the downstream side of the pump 22 in the first supply path 20. As the sword water, ion-exchanged water may be used.

[First discharge channel 70]
The first discharge passage 70 is a flow path through which the anode water (oxygen water) that has passed through the anode portion 40 of the water electrolysis cell 30 is discharged. The upstream end of the first discharge path 70 is connected to the anode portion 40 of the water electrolysis cell 30. The downstream end of the first discharge passage 70 is connected to, for example, a storage portion (not shown) to which the first supply passage 20 is connected. The anodic water flowing through the first discharge path 70 is stored in a storage section (not shown), oxygen is removed from the storage section, and the water electrolysis cell 30 is again connected from the storage section through the first supply path 20. It is supplied to the anode portion 40. In this way, the anodic water is circulated (recycled).

[Reservoir 12]
The storage unit 12 is composed of, for example, a container for storing cathode water (pure water) as the first water. The cathode water stored in the storage section 12 circulates with the cathode section 50 of the water electrolysis cell 30 as described later. As the cathode water, ion-exchanged water may be used.

[Second supply path 60]
The second supply path 60 is a flow path for supplying the cathode water stored in the storage section 12 to the cathode section 50 of the water electrolysis cell 30. The upstream end of the second supply path 60 is connected to the storage portion 12, and the downstream end is connected to the cathode portion 50 of the water electrolysis cell 30.

A pump 62 as a water supply unit is arranged in the second supply path 60. The pump 62 sends the cathode water to the cathode portion 50 of the water electrolysis cell 30. Further, a flow rate adjusting valve 64 for adjusting the flow rate of the cathode water is arranged on the downstream side of the pump 62 in the second supply path 60. Further, on the downstream side of the flow rate adjusting valve 64 in the second supply passage 60, a pressure gauge 66 for measuring the pressure of the cathode water in the second supply passage 60 is arranged.

[Second discharge channel 90]
The second discharge passage 90 is a flow path for discharging the cathode water (hydrogen water) that has passed through the cathode portion 50 of the water electrolysis cell 30 to the storage portion 12. The upstream end of the second discharge passage 90 is connected to the cathode portion 50 of the water electrolysis cell 30, and the downstream end is connected to the storage portion 12. The cathode water flowing through the second discharge channel 90 is stored in the storage unit 12. In this way, the cathode water circulates between the storage portion 12 and the cathode portion 50 of the water electrolysis cell 30 through the second discharge passage 90 and the above-mentioned second supply passage 60. A flow rate adjusting valve 92 for adjusting the flow rate of the cathode water is arranged in the second discharge passage 90.

[Gas-liquid mixer 96]
The gas-liquid mixer 96 has a function of mixing a gas (hydrogen) with water. The gas-liquid mixer 96 is arranged on the downstream side of the flow rate adjusting valve 92 in the second discharge passage 90. The gas-liquid mixer 96 is configured in the same manner as the gas-liquid mixer 196 in the water electrolyzer 100.

[Dissolved hydrogen concentration meter 68]
The dissolved hydrogen concentration meter 68 has a function of measuring the concentration of hydrogen dissolved in the cathode water. The dissolved hydrogen concentration meter 68 is arranged in a branch path 67 branching from the second supply path 60 between the pump 62 and the flow rate adjusting valve 64 in the second supply path 60. An on-off valve 69 for opening and closing the branch path 67 is arranged in the branch path 67. When the on-off valve 69 opens the branch passage 67, the cathode water sent by the pump 62 flows into the dissolved hydrogen concentration meter 68 from the second supply passage 60, and the hydrogen concentration dissolved in the cathode water is changed to the dissolved hydrogen concentration. A total of 68 measures.

[Extract 210]
The extraction unit 210 has a function of extracting the cathode water (hydrogen water) stored in the storage unit 12. The extraction unit 210 has an extraction path 212 connected to the storage unit 12 and an on-off valve 214 arranged in the extraction path 212. In the extraction section 210, the on-off valve 214 opens the extraction path 212, so that the cathode water stored in the storage section 12 is extracted through the extraction path 212. The cathode water is extracted, for example, after it is confirmed by the dissolved hydrogen concentration meter 68 that the concentration of the cathode water in the reservoir 12 has reached a predetermined concentration. When extracting hydrogen water in a pressurized state, a branch pipe (tea, etc.) may be attached to the pipe (branch path 67) of the dissolved hydrogen concentration meter 68, and the hydrogen water pressurized by the pump 62 may be extracted. can. The cathode water (hydrogen water) extracted by the extraction unit 210 is used as, for example, washing water.

[Replenishment unit 220]
The replenishment unit 220 has a function of replenishing the storage unit 12 with cathode water (pure water). Specifically, the replenishment unit 220 includes, for example, a storage unit 222 for storing the cathode water for replenishment, a replenishment path 224 connected to the storage unit 222 and the storage unit 12, and a pump arranged in the replenishment path 224. It has 226 and. In the replenishment unit 220, the replenishment cathode water stored in the storage unit 222 is replenished to the storage unit 12 by the pump 226.

[Power supply 80]
The power supply 80 is connected to the first terminal plate 44 of the anode portion 40 and the second terminal plate 54 of the cathode portion 50. A DC power supply is used for the power supply 80. Then, the power supply 80 is operated in the constant current mode by, for example, operating the personal computer 82 (PC).

The current density of the current flowing through the water electrolysis cell 30, 0.1 A / cm ² or more 3.5A / cm ² or less. This is because if the current density is ^{less than 0.1 A / cm 2} , the electrolytic reaction of water is not promoted and the concentration of hydrogen water does not increase. If the current density ^{exceeds 3.5 A / cm 2} , the electrodes of the anode portion 40 and the cathode portion 50 are deteriorated and consumed, and the life of the water electrolyzer 10 is shortened.

Then, by passing a DC current through the water electrolysis cell 30, the assault water and the cathode water flowing through the water electrolysis cell 30 are electrolyzed. When the assault water and the cathode water are electrolyzed, hydrogen is generated in the cathode portion 50 and oxygen is generated in the anode portion 40.
[Operating conditions of water electrolyzer 10]
The water electrolyzer 10 is operated under operating conditions in which the product of the circulating water amount and the operating time is at least twice the amount of the cathode water previously stored in the storage unit 12. That is, the cathode water previously stored in the storage unit 12 is operated under operating conditions in which the water electrolysis cell 30 is circulated twice or more.

Further, it is preferable that the amount of circulating water of the cathode water is large. The reason is that the hydrogen bubbles generated in the water electrolysis cell 30 can be efficiently discharged from the first mesh electrodes 42, 431, 432, 433 of the water electrolysis cell 30. As the concentration of hydrogen water increases, the amount of hydrogen that cannot be completely dissolved in water during electrolysis and forms bubbles increases. As a result, air bubbles will accumulate in the water electrolysis cell 30. These bubbles reduce the effective area of the first mesh electrodes 42, 431, 432, and 433 of the anode portion 40, and reduce the electrolysis efficiency.

Therefore, by increasing the amount of circulating water to suppress the decrease in the effective area of the first mesh electrodes 42, 431, 432, and 433, and by increasing the number of times of water electrolysis per unit time, the concentration of hydrogen water can be increased. Try.

[Method for producing hydrogen water using the water electrolyzer 10]
This manufacturing method includes a preparatory step and a water electrolysis step. In the preparatory step, the water electrolyzer 10 described above is prepared.

In the water electrolysis step, the water electrolysis device 10 is operated under operating conditions in which the product of the circulating water amount and the operating time is at least twice the amount of the cathode water previously stored in the storage unit 12. As a result, while the cathode water was circulated to the cathode portion 50 of the water electrolysis cell 30 of the water electrolysis device 10 a plurality of times, a current was passed through the water electrolysis cell 30 to electrolyze the water in the water electrolysis cell 30, and the water electrolysis was generated. Produce hydrogen water containing hydrogen (an example of gas).

Specifically, the water electrolysis step is performed as follows. That is, the cathode water stored in the storage section 12 of the water electrolysis device 10 is supplied to the cathode section 50 of the water electrolysis cell 30, and a current is passed through the water electrolysis cell 30 by the power supply 80 to perform water electrolysis in the water electrolysis cell 30. Will be. Hydrogen generated by water electrolysis is dissolved in the cathode water in the water electrolysis cell 30, and further, hydrogen that could not be completely dissolved in the water electrolysis cell 30 is dissolved in the cathode water in the gas-liquid mixer 96. Then, the cathode water is returned from the gas-liquid mixer 96 to the storage unit 12. This process (cycle) is repeated a plurality of times to produce hydrogen water.

In the present embodiment, the produced hydrogen water is extracted from the storage unit 12 by the extraction unit 210 and used. Specifically, in the extraction section 210, the on-off valve 214 opens the extraction path 212, so that the hydrogen water stored in the storage section 12 is extracted through the extraction path 212. The cathode water (pure water) is replenished by the replenishment unit 220 as much as the hydrogen water is extracted. By replenishing the storage unit 112 with cathode water while extracting hydrogen water from the storage unit 112, hydrogen water can be continuously used.

At this time, the time (average residence time) at which the replenished water replenished in the storage unit 112 stays in the storage unit 112 is defined as follows, and the water is electrolyzed twice or more within this average residence time.

Average residence time [min] = stored water amount [L] ÷ replenishment water amount [L / min]

The stored water amount is the amount of water stored in advance in the storage unit 112. The replenishment water amount is the amount of water replenished to the storage unit 112 per unit time.

When the water is electrolyzed twice or more within the average residence time, the relationship between the amount of circulating water circulating per unit time and the amount of stored water is as follows.

Average residence time [min] x circulating water amount [L / min] ≥ stored water amount [L] x 2

That is, in the present embodiment, the operation is performed under operating conditions in which the product of the average residence time and the circulating water amount per unit time is twice or more the stored water amount. The amount of circulating water is the amount of water that is sent from the storage unit 112 to the water electrolysis cell 30 and returned to the storage unit 112 again per unit time.

The produced hydrogen water is used, for example, for cleaning parts. Specifically, for example, a cleaning method using hydrogen water for removing fine particles of silica and alumina adhering to the semiconductor substrate while also irradiating ultrasonic waves can be considered. In particular, in this cleaning method, when 1 mg / L of ammonia was added to hydrogen water having a dissolved hydrogen concentration of 0.9 mg / L or more and cleaning was performed in combination with ultrasonic irradiation, it adhered to the semiconductor substrate. It is known that nearly 100% of alumina fine particles can be removed. The produced hydrogen water can also be used for drinking and agriculture.

<Action and effect according to this embodiment>
Next, the action and effect according to the present embodiment will be described.

According to the configuration of the present embodiment, as described above, in the cathode portion 50 of the water electrolysis cell 30, the second mesh electrodes 52 and 53 are located between the other surface 32B of the solid electrolyte film 32 and the second terminal plate 45. Is sandwiched and the cathode water flows along the other surface 32B between them. Then, the power supply 80 passes a current between the anode portion 40 and the cathode portion 50 to perform water electrolysis in the water electrolysis cell 30. The hydrogen produced by this water electrolysis dissolves in water flowing through the flow path between the other surface 32B and the second terminal plate 54, and hydrogen water is produced.

The cathode water (hydrogen water) flowing through the flow path is stored in the storage unit 12. The cathode water is sent again by the pump 62 to the flow path of the water electrolysis cell 30, and water electrolysis is performed again.

As described above, in the configuration of the present embodiment, water can be passed through the flow path between the other surface 32B and the second terminal plate 45 a plurality of times. It is possible to increase the concentration.

In particular, the water electrolyzer 10 is operated under operating conditions in which the product of the circulating water amount and the operating time is at least twice the amount of the cathode water previously stored in the storage unit 12. As a result, the cathode water previously stored in the storage unit 12 circulates in the water electrolysis cell 30 twice or more, so that the concentration of hydrogen water can be increased.

Further, in the present embodiment, since the cathode water flows between the other surface 32B and the second terminal plate 45 along the other surface 32B, the hydrogen foamed in the second mesh electrodes 52 and 53 is formed. Can be brought into contact with water, and the concentration of hydrogen water can be increased.

Further, in the present embodiment, the cathode water (hydrogen water) flowing between the other surface 32B and the second terminal plate 45 passes through the gas-liquid mixer 96. Therefore, hydrogen that could not be completely dissolved in the water electrolysis cell 30 can be dissolved in water in the gas-liquid mixer 96, and a high concentration of hydrogen water can be achieved.

As described above, in the configuration of the present embodiment, it is possible to produce high-concentration hydrogen water that cannot be reached by one water flow.

Further, in the present embodiment, the hydrogen water extracted from the storage unit 12 by the extraction unit 210 can be used as the washing water. Then, since the extracted water can be replenished to the storage unit 12 by the replenishment unit 220, hydrogen water can be continuously produced without reducing the water in the storage unit 12.

Further, in the present embodiment, the replenished water replenished in the storage unit 112 is electrolyzed twice or more within the time (average residence time) in which the replenishment water is replenished in the storage unit 112, so that the ozone water has a high concentration. Can maintain the concentration of. As described above, in the present embodiment, hydrogen water having a constant concentration can be continuously produced by continuously extracting the hydrogen water from the storage unit 112 and continuously replenishing the water.

<Modification example of water electrolyzer 10>
In the water electrolyzer 10 described above, the produced hydrogen water is extracted from the storage unit 12 and used, but the present invention is not limited to this. For example, the cathode water is circulated in a batch manner without extraction, and the produced hydrogen water is stored in the storage unit 12. Then, the operation of the water electrolyzer 10 may be stopped, the storage unit 12 may be removed from the water electrolyzer 10, and then the produced hydrogen water may be used. In this case, the concentration of hydrogen water can be increased in a short time.

Further, as the water electrolyzer 10 described above, it is preferable that the storage unit 12 has a pressure resistance, a pressure control device is installed, and the water electrolyzer 10 is operated under pressure. When water electrolysis is performed under a pressure of several atmospheres, Henry's law increases the solubility of the gas from the gas phase to the liquid phase, so that high-concentration functional water can be obtained.

Further, similarly to the water electrolyzer 100, the storage unit 12 may be cooled. By cooling the storage unit 12, the transition of the generated hydrogen from the liquid phase to the gas phase is suppressed.

<Example>
Hereinafter, the present invention will be specifically described with reference to examples, but the present invention is not limited to these examples.

[Example 1]
In Example 1, the water electrolyzer 100 was used to circulate the sword water in a batch manner without extracting the water by the extraction unit 410 to produce ozone water.

In the anode portion 40, a Pt mesh of # 80 was used as the first mesh electrode 42, and a Ti mesh of # 100 was used as the first mesh electrodes 431, 432, and 433. In the cathode portion 50, a Pt mesh of # 80 was used as the second mesh electrode 52, and a Ti mesh of # 100 was used as the second mesh electrode 53. Each of the mesh electrodes has a width of 30 mm and a length of 60 mm, and is a plain weave mesh. The amount of water in the storage unit 112 was 2.0 L, the circulating water amount of the anode water was 1.36 L / min, and the operation time was 30 minutes.

Further, a current of 27 A was passed through the water electrolysis cell 30. As the cathode water, salt water having a concentration of 0.5 M was used, and the cathode water was flowed at a flow rate of 30 mL / min. Further, 2 L of ice water was put into the storage portion 112 and passed through the anode portion 40 of the water electrolysis cell 30 as sword water to produce ozone water. During production, 3 mL of ozone water was taken out at 1-minute intervals, and the concentration of ozone water was measured by spectroscopy.

The result is shown in FIG. As shown in this figure, 6 minutes after the start of water electrolysis, ozone water having a high concentration of 140 mg / L could be produced.

[Example 2]
In Example 2, in the configuration of Example 1, ozone water was produced by constantly extracting ozone water from the storage unit 112 at 0.1 L / min by the extraction unit 410 and replenishing the same amount with the replenishment unit 420. .. The concentration of the extracted ozone water was measured by spectroscopy, and the temperature of the storage unit 112 during operation was also measured.

The result is shown in FIG. As shown in this figure, although ozone water is constantly extracted, 60 mg / L ozone water is produced 5 minutes after the start of operation, and 90 mg / L ozone water is produced 15 minutes later. did it. Further, it was clarified that when the temperature of the storage unit 112 rises to around 20 ° C., the concentration of ozone water decreases.

In addition, the present inventor repeated experiments for producing ozone water under various conditions, created a mathematical model for predicting a change in the concentration of ozone water in the storage unit 12, and predicted it by simulation. This prediction result was in agreement with the results of Examples 1 and 2.

As a result of searching for conditions for continuously producing ultra-high concentration ozone water of 150 mg / L using this mathematical model, if sword water can be circulated at 7 L / min and the water temperature can be maintained at 0 ° C, a current of 27 A and storage can be achieved. It was clarified that an ultra-high concentration ozone water of 150 mg / L can be continuously produced at 0.1 L / min under the condition of the water volume of Part 12 of 2 L. The simulation result is shown in FIG. In this simulation, the concentration of ozone water increases with the start of operation and reaches 150 mg / L after 30 minutes.

[Example 3]
In the third embodiment, in the configuration of the first embodiment, the first mesh electrode 42 is changed from the Pt mesh of # 80 _{to the Ti mesh on which the catalyst layer (IrO 2} ) is formed, and the extraction is not performed by the extraction unit 410. Assorted water was circulated in a batch system to produce oxygenated water. In Example 3, the storage unit 112 was not cooled.

As a result, 2 L of supersaturated oxygenated water of 60 mg / L could be produced 7 minutes after the start of operation.

[Example 4]
In Example 4, the water electrolyzer 10 was used to circulate the cathode water in a batch manner without extracting the water by the extraction unit 210 to produce hydrogen water. _{A Ti mesh having a catalyst layer (IrO 2} ) formed was used as the first mesh electrode 42, and a # 80 Pt mesh was used as the second mesh electrode 52. The amount of water in the storage unit 12 was 2 L, the current was 30 A, and the cathode water was circulated at a flow rate of 3 L / min. The anode water was circulated at 1 L / min.

As a result, hydrogen water having a high concentration of 2.1 mg / L could be produced 3 minutes after the start of operation. After 9 minutes from the start of operation, the concentration of hydrogen water decreased as the water temperature of the storage unit 12 increased.
[Example 5]
In Example 5, in the configuration of Example 4, hydrogen water was produced by constantly extracting hydrogen water from the storage unit 12 at 0.1 L / min by the extraction unit 210 and replenishing the same amount with the replenishment unit 220. ..

As a result, hydrogen water having a high concentration of 1.9 mg / L could be produced 6 minutes after the start of operation. After 13 minutes from the start of operation, the concentration of hydrogen water decreased as the water temperature of the storage unit 12 increased.

The present invention is not limited to the above-described embodiment, and various modifications, changes, and improvements can be made within a range that does not deviate from the gist thereof. For example, the above-mentioned modified examples may be configured by combining a plurality of them as appropriate.

10, 100 Water electrolyzer 12, 112 Reservoir 30 Water electrolysis cell 32 Solid electrolyte film 40 Anode (an example of the first electrode in the water electrolyzer 100, an example of the second electrode in the water electrolyzer 10)
42, 431, 432, 433 First mesh electrode (an example of the first mesh electrode in the water electrolyzer 100, an example of the second mesh electrode in the water electrolyzer 10)
44 Terminal 1 plate (an example of the first terminal plate in the water electrolyzer 100, an example of the second terminal plate in the water electrolyzer 10)
50 Cathode part (an example of the second electrode part in the water electrolyzer 100, an example of the first electrode part in the water electrolyzer 10)
52, 53 Second mesh electrode (an example of the second mesh electrode in the water electrolyzer 100, an example of the first mesh electrode in the water electrolyzer 10)
54 Second terminal plate (an example of the second terminal plate in the water electrolyzer 100, an example of the first terminal plate in the water electrolyzer 10)
62, 162 Pump 80, 180 Power supply 96, 196 Gas-liquid mixer 114 Cooling device 210, 410 Extraction part 220, 420 Replenishment part

Claims (7)

A solid electrolyte film, a first electrode portion having a first terminal plate and a plate-shaped and plain-woven or twill-woven first mesh electrode, and a second terminal plate and a plate-shaped and plain-woven or twill-woven second mesh electrode. A water electrolysis cell having a second electrode portion and a plurality of first mesh electrodes stacked in the thickness direction between one surface of the solid electrolyte membrane and the first terminal plate. The first water flows along the one surface between the plurality of first mesh electrodes, and the second mesh electrode is formed in the thickness direction between the other surface of the solid electrolyte membrane and the second terminal plate. The water electrolysis cell, which is arranged in a plurality of layers and in which the second water flows between the plurality of second mesh electrodes along the other surface,
A power source that allows a current to flow between the first electrode portion and the second electrode portion to electrolyze water in the water electrolysis cell,
A storage unit for storing the first water flowing through the flow path between the one surface and the first terminal plate, and
A pump that re-sends the first water in the reservoir to the flow path,
A water electrolyzer equipped with. Disposed between the front Symbol water electrolysis cell and the reservoir, mixing the gas contained in the first water and said first water flows through the flow path between said one surface and said first terminal plate Gas-liquid mixer ,
The water electrolyzer according to claim 1. An extraction unit capable of extracting the first water from the storage unit,
A replenishment unit that replenishes the storage unit from which the first water has been extracted by the extraction unit, and a replenishment unit.
The water electrolyzer according to claim 1 or 2. The first water previously stored in the storage section flows through the flow path and is stored again in the storage section, so that the first water circulates between the storage section and the flow path.
The product is operated under operating conditions in which the product of the circulating water amount per unit time and the operating time is at least twice the amount of the first water stored in the storage unit in advance.
The water electrolyzer according to any one of claims 1 to 3. The second water flowing through the flow path between the other surface and the second terminal plate is sent back to the flow path to circulate the second water.
The water electrolyzer according to any one of claims 1 to 4. The water electrolyzer according to any one of claims 1 to 5, further comprising a cooling device for cooling the storage unit. The preparatory step for preparing the water electrolyzer according to any one of claims 1 to 6.
While recirculating the first water and the second water that have flowed through the water electrolysis cell of the water electrolysis apparatus, a current is passed through the water electrolysis cell to electrolyze the water in the water electrolysis cell, and the gas generated from the water electrolysis. And the water electrolysis process to produce functional water including
A method for producing functional water having.

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