Electrolytic water generation device, space purification device

Abstract

Provided is an electrolytic water generation device and a space purifying device that suppresses the collision of water with the membrane surface of an anion exchange membrane. An electrolysis tank (30) stores a first aqueous solution (L1) containing chloride ions, and a supply tank (40) stores a second aqueous solution (L2) containing chloride ions. An anion exchange membrane (50) is provided so as to connect the electrolysis tank (30) and the supply tank (40), and is permeable to anions including chloride ions. A protective membrane (70) is provided on the electrolysis tank (30) side of the anion exchange membrane (50). The electrolysis tank (30) electrolyzes the first aqueous solution (L1) without a separator to generate hypochlorous acid, and the supply tank (40) electrolyzes the second aqueous solution (L2) with a separator to supply the chloride ions contained in the second aqueous solution (L2) to the first aqueous solution (L1) through the anion exchange membrane (50) and the protective membrane (70). The protective membrane (70) includes a porous membrane (72) having a mesh-like fine pore.

Description

Technical Field

[0001] This disclosure relates to an electrolytic water generation device and a space purification device. Background Technology

[0002] Electrolyzed water containing hypochlorous acid is produced using an anion exchange membrane as a diaphragm and an electrolyzer in which the anode and the diaphragm are positioned close together. To prevent the anion exchange membrane from deteriorating due to chlorine gas generated at the anode surface, a protective membrane with multiple slit-like gaps is disposed between the anode and the anion exchange membrane (see, for example, Patent Document 1).

[0003] Prior art literature

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent Application Publication No. 2006-322053 Summary of the Invention

[0006] The technical problem that the invention aims to solve

[0007] Chlorine reacts with water to produce hypochlorous acid. Additionally, electrolysis can generate water flow towards the surface of the anion exchange membrane. Even with a protective membrane featuring multiple slits, it is difficult to prevent water from colliding with the membrane surface.

[0008] This disclosure was made in view of the above-mentioned problems, and provides a technique for suppressing the collision of water flow with the membrane surface of anion exchange membrane.

[0009] Technical means for solving technical problems

[0010] To address the aforementioned technical problems, one embodiment of the electrolytic water generation apparatus disclosed herein comprises: an electrolytic cell for storing a first aqueous solution containing chloride ions; a supply tank for storing a second aqueous solution containing chloride ions; an anion exchange membrane connected to the electrolytic cell and the supply tank, capable of permeating with anions containing chloride ions; and a protective membrane disposed on the electrolytic cell side of the anion exchange membrane. The electrolytic cell electrolyzes the first aqueous solution without a diaphragm to generate hypochlorous acid, while the supply tank electrolyzes with a diaphragm, allowing chloride ions contained in the second aqueous solution to permeate through the anion exchange membrane and the protective membrane to be supplied to the first aqueous solution. The protective membrane comprises a porous membrane with mesh-like micropores.

[0011] Other embodiments of this disclosure also include an electrolytic water generation apparatus. This apparatus comprises: an electrolytic cell for storing a first aqueous solution containing chloride ions; a supply tank for storing a second aqueous solution containing chloride ions; a buffer layer disposed between the electrolytic cell and the supply tank for storing the first aqueous solution; an anion exchange membrane disposed between the buffer layer and the supply tank, capable of permeating chloride-containing anions; and a diaphragm disposed between the electrolytic cell and the buffer layer. The electrolytic cell electrolyzes the first aqueous solution without a diaphragm to generate hypochlorous acid, while the supply tank, through diaphragm electrolysis, supplies chloride ions contained in the second aqueous solution to the first aqueous solution through the anion exchange membrane, the buffer layer, and the diaphragm.

[0012] Furthermore, any combination of the above-mentioned constituent elements, as well as any manner in which the present disclosure is transformed between methods, apparatus, systems, storage media, or computer programs, are also valid forms of the present disclosure.

[0013] Invention Effects

[0014] According to this disclosure, it is possible to suppress the collision of water flowing towards the membrane surface of the anion exchange membrane. Attached Figure Description

[0015] Figure 1 This is a front sectional view of the space purification device of Embodiment 1.

[0016] Figure 2 yes Figure 1 A magnified view of a portion of the anion exchange membrane and the porous membrane.

[0017] Figure 3 It means Figure 1 A graph showing the time-varying concentration of hypochlorous acid in a space purification device.

[0018] Figure 4 This is a front sectional view of the space purification device in Embodiment 2.

[0019] Figure 5 yes Figure 4 A magnified view of the anion exchange membrane, porous membrane, and water-permeable membrane.

[0020] Figure 6 This is a front sectional view of the space purification device in Embodiment 4.

[0021] Figure 7 yes Figure 6 A magnified view of the anion exchange membrane, buffer layer, and diaphragm.

[0022] Figure 8 It means Figure 6 A graph showing the time-varying concentration of hypochlorous acid in a space purification device.

[0023] Figure 9 This is a front sectional view of the space purification device in Embodiment 5. Detailed Implementation

[0024] The specific embodiments of this disclosure will now be described in detail with reference to the accompanying drawings. Furthermore, the xyz coordinates shown in the figures are for ease of illustrating the positional relationships of the constituent elements. Unless otherwise specified, the positive direction of the z-axis is vertically upward. Additionally, the xy plane is a horizontal plane, which is common across the figures.

[0025] (Example 1)

[0026] Figure 1 This is a front cross-sectional view of the space purification device 20. The space purification device 20 performs diaphragmless electrolysis of a first aqueous solution L1 containing chloride ions in an electrolytic cell 30 (described later), generating hypochlorous acid, which is then volatilized. The space purification device 20 removes bacteria, fungi, viruses, or odors from the air in the external space R of the space purification device 20 by discharging the generated hypochlorous acid into the external space R of the housing C constituting the space purification device 20. Alternatively, diaphragm electrolysis is performed. To replenish the chloride ions in the first aqueous solution L1 that are reduced due to diaphragmless electrolysis, chloride ions contained in a second aqueous solution L2 stored in a supply tank 40 are supplied to the first aqueous solution L1 stored in the electrolytic cell 30 through an anion exchange membrane 50 and a protective membrane 70.

[0027] The air purification device 20 is installed indoors. The preferred location for installing the air purification device 20 is a place where airflow can be generated. More specifically, the location for installing the air purification device 20 is indoors. Specific examples of locations for installing the air purification device 20 include the interior of an air conditioner, the interior of a bathroom heating dryer, around a fan, around a circulator, around a ceiling fan, inside a humidifier, inside a dehumidifier, inside an air purifier, and on a table.

[0028] In this specification, "external space R" refers to the exterior of the space purification device 20, i.e., the exterior of the housing C, such as an indoor space. When the space purification device 20 is installed inside the aforementioned air conditioner or other equipment, the exterior of the housing C and the interior of the equipment are also included in "external space R".

[0029] like Figure 1As shown, the space purification device 20 includes a housing C, an electrolytic cell 30, and a current control unit 60. The space purification device 20 may also include a supply tank 40, an anion exchange membrane 50, and a protective membrane 70. To continuously purify the external space R without supplying chloride ions from the external source to the electrolytic cell 30 for an extended period, the supply tank 40 and the anion exchange membrane 50 are used to supply chloride ions to the electrolytic cell 30 from the supply tank 40. Furthermore, the protective membrane 70 is used to protect the anion exchange membrane 50.

[0030] The housing C is a box-shaped component that houses the electrolytic cell 30, the supply tank 40, the anion exchange membrane 50, the current control unit 60, and the protective membrane 70. In other words, the space purification device 20 is an integrated unit formed by the housing C. The space purification device 20 has a small size; for example, it is approximately 10cm × 7cm × 4cm when the housing C is rectangular.

[0031] Electrolytic cell 30 is used to store a first aqueous solution L1 containing chloride ions, and to generate hypochlorous acid by diaphragm-free electrolysis of the first aqueous solution L1. Supply cell 40 is used to store a second aqueous solution L2 containing chloride ions, and to supply the first aqueous solution L1 with chloride ions contained in the second aqueous solution L2 through anion exchange membrane 50 and a protective membrane 70 via diaphragm electrolysis. The protective membrane 70 will be explained later, and therefore will be omitted in the following description. More specifically, chloride ions contained in the second aqueous solution L2 are supplied to the first aqueous solution L1 via diaphragm electrolysis through anion exchange membrane 50, which is provided in a manner connecting electrolytic cell 30 and supply cell 40. Anion exchange membrane 50 allows anions containing chloride ions to pass through. Current control unit 60 controls both diaphragm-free electrolysis and diaphragm electrolysis.

[0032] Assuming continuous use for 8 hours per day for one year, the volumes of the electrolyzer 30 and the supply tank 40 are preferably such that the volume of the supply tank 40 is approximately 12 times or more than the volume of the electrolyzer 30. With this volume ratio, the supply tank 40 can store a second aqueous solution L2 containing a sufficient amount of chloride ions required to supply the first aqueous solution L1 to the electrolyzer 30. Therefore, chloride ions can be stably supplied from the second aqueous solution L2 stored in the supply tank 40 to the first aqueous solution L1 stored in the electrolyzer 30.

[0033] When viewed from the front, the electrolytic cell 30 and the supply cell 40 are arranged sequentially from the negative x-axis side. An anion exchange membrane 50 is arranged between the electrolytic cell 30 and the supply cell 40 to connect them. For example, if the surfaces of the electrolytic cell 30 and the supply cell 40 facing each other are formed by a frame-like member, the anion exchange membrane 50 can be embedded within this frame-like member. The current control unit 60 is disposed at any position within the housing C, but is not limited to this; it can also be disposed outside the housing C and connected wirelessly or otherwise.

[0034] [Electrolytic Cell 30]

[0035] Electrolytic cell 30 is a tank used to store a first aqueous solution L1 containing chloride ions, and to perform diaphragm-free electrolysis of the first aqueous solution L1 to generate hypochlorous acid. The shape of electrolytic cell 30 may be, for example, box-shaped, but any shape suitable for storing the first aqueous solution L1 is acceptable. Figure 1 The diagram shows the state in which the first aqueous solution L1 is stored in the electrolytic cell 30. The first aqueous solution L1 stored in the electrolytic cell 30 is, for example, 2 mL to 10 mL. The first aqueous solution L1 is, for example, an aqueous solution containing a dissolved electrolyte that has electrical conductivity, i.e., an electrolyte, specifically a dilute chloride aqueous solution with a specified chloride ion concentration. More specifically, the first aqueous solution L1 is, for example, a dilute sodium chloride aqueous solution or a dilute potassium chloride aqueous solution.

[0036] The "prescribed chloride ion concentration" of the first aqueous solution L1 includes both a chloride ion concentration within a prescribed numerical range and a chloride ion concentration with a prescribed numerical value. More specifically, the chloride ion concentration of the first aqueous solution L1 can be, for example, 17 mmol / L to 1500 mmol / L, or it can be 171 mmol / L. In other words, the concentration of, for example, a dilute sodium chloride aqueous solution or a dilute potassium chloride aqueous solution can be 17 mmol / L to 1500 mmol / L, or it can be 171 mmol / L. By setting the prescribed chloride ion concentration to this numerical range or value, hypochlorous acid required for space purification of the external space R can be generated, and the generation of chlorine that may be generated simultaneously can be suppressed.

[0037] The electrolytic cell 30 includes an electrolytic cell-side anode 31, an electrolytic cell-side cathode 32, an air supply unit 33, an air supply duct 34, an internal space on the electrolytic cell side 35, a water recovery unit 36, and a discharge port 37. The electrolytic cell 30 may also include a water level detection unit 38.

[0038] The electrolytic cell-side anode 31 and electrolytic cell-side cathode 32 are a pair of electrodes used for the electrolysis of the first aqueous solution L1. Insoluble electrodes can also be used as the electrolytic cell-side anode 31 and electrolytic cell-side cathode 32. More specifically, for example, platinum-iridium-titanium electrodes, platinum electrodes, ruthenium-titanium electrodes, or iridium-titanium oxide electrodes can also be used. Furthermore, as the electrolytic cell-side cathode 32, titanium electrodes, iron electrodes, tin electrodes, nickel electrodes, or alloys of the aforementioned metals with oxide coatings formed on their surfaces can also be used. An example of the case where the electrolytic cell-side cathode 32 is a metallic alloy is a titanium electrode using a nickel-titanium alloy or tin oxide as a catalyst. Iron electrodes with oxide coatings contain both FeO and Fe2O3. The shapes of the electrolytic cell-side anode 31 and electrolytic cell-side cathode 32 can be any shape among plates, meshes, or rods.

[0039] There is no diaphragm, such as an ion exchange membrane, between the anode 31 and cathode 32 on the electrolytic cell side. That is, the electrolysis of the first aqueous solution L1 using a pair of anodes 31 and cathodes 32 on the electrolytic cell side is diaphragm-free electrolysis. By using the diaphragm-free electrolysis of the first aqueous solution L1 using a pair of anodes 31 and cathodes 32 on the electrolytic cell side, hypochlorous acid gas is generated for space purification of the external space R.

[0040] The air supply unit 33 is a blower, such as a blower, that introduces air from the external space R into the electrolytic cell 30.

[0041] The air supply duct 34 is a tubular component connecting the air supply unit 33 and the electrolytic cell 30. One end of the air supply unit 33 is disposed on the external space R side, and the other end is connected to the air supply duct 34 side. One end of the air supply duct 34 is connected to the air supply unit 33 side, and the other end is connected to the electrolytic cell 30 side. The end of the air supply duct 34 disposed on the electrolytic cell 30 side is connected to the electrolytic cell 30 at a position lower than the liquid surface S1 (negative z-axis side) of the first aqueous solution L1 stored in the electrolytic cell 30.

[0042] Air supply unit 33 supplies air from external space R to the first aqueous solution L1 stored in electrolytic cell 30 via air supply pipe 34. When the end of air supply pipe 34 is positioned below the liquid surface S1 (negative z-axis side) of the first aqueous solution L1 stored in electrolytic cell 30, the air introduced into the first aqueous solution L1 via air supply unit 33 and air supply pipe 34 is discharged as bubbles B in the first aqueous solution L1. Alternatively, a moisture-permeable and waterproof membrane (not shown) can be integrally disposed along the diameter of air supply pipe 34. The moisture-permeable and waterproof membrane allows the gas supplied from external space R, i.e., air, and the moisture (water vapor) contained in that air, to pass through, but does not allow the first aqueous solution L1, which is a liquid, to pass through. By arranging this moisture-permeable and waterproof membrane, backflow of the first aqueous solution L1 from electrolytic cell 30 to air supply pipe 34 can be prevented.

[0043] The internal space 35 on the electrolytic cell side is the space above the surface S1 of the first aqueous solution L1 (the space on the positive z-axis side) formed in the electrolytic cell 30 when the first aqueous solution L1 is stored in the electrolytic cell 30. In other words, when the first aqueous solution L1 is not stored on the inner upper surface of the electrolytic cell 30 (the xy plane on the positive z-axis side), the electrolytic cell 30 has the internal space 35 on the electrolytic cell side.

[0044] The water recovery unit 36 ​​circulates inside the space purification device 20 and recovers moisture contained in the air discharged from the electrolyzer 30 into the external space R as liquid back into the electrolyzer 30. The water recovery unit 36 ​​is, for example, a Peltier element capable of cooling and condensing moisture in the air into water droplets. When the water recovery unit 36 ​​is a Peltier element, the Peltier element has a heat dissipation surface and a heat absorption surface, and a cooling radiator is provided on the heat absorption surface. The cooling radiator is capable of cooling and condensing moisture in the air passing through it into water droplets.

[0045] To recover moisture contained in the air circulating inside the space purification device 20, a water recovery unit 36 ​​can also be disposed at the discharge port 37 through which the air is discharged to the external space R. With the water recovery unit 36 ​​disposed at the discharge port 37, moisture contained in the air circulating inside the space purification device 20 can be recovered efficiently. Furthermore, the water recovery unit 36 ​​can also be disposed at any location within the internal space 35 on the electrolyzer side.

[0046] The discharge port 37 is an opening for discharging the mixed air M, formed by mixing air flowing in from the air supply unit 33 with hypochlorous acid generated from the first aqueous solution L1 through diaphragm-free electrolysis, into the external space R of the housing C. Figure 1 As an example, a discharge port 37 is provided on the upper surface (xy plane on the positive z-axis side) of the electrolytic cell 30, as long as it is positioned above the liquid surface S1 of the first aqueous solution L1. The discharge port 37 is cylindrical in shape, such as a cylindrical or square tube. When the upper surface (face on the positive z-axis side) of the electrolytic cell 30 is close to the top surface of the shell C, the discharge port 37 may also be a hole-like opening provided on a part of the upper surface of the electrolytic cell 30. Alternatively, the discharge port 37 and the upper surface (face on the positive z-axis side) of the shell C may be integrally formed.

[0047] The discharge port 37 may also have an openable or detachable cover (not shown). The cover may be configured to be closed when transporting, moving or setting up the space purification device 20, and to be opened or removed when the space purification device 20 is in use.

[0048] Next, a series of processes (purification operation) for supplying hypochlorous acid gas generated by the space purification device 20 to the external space R will be described. In the space purification device 20 of this embodiment, air introduced from the external space R flows through the electrolytic cell 30 and is supplied to the external space R together with hypochlorous acid.

[0049] Figure 1 The hollow arrow and the arrow with an upward slant to the right, indicating airflow path A, represent a series of paths through which air supplied from the external space R to the space purification device 20 flows in the electrolytic cell 30 and is discharged as a mixture of hypochlorous acid-containing air M back into the external space R. Specifically, airflow path A represents the flow of air through the external space R, the air supply unit 33, the air duct 34, the first aqueous solution L1 stored in the electrolytic cell 30, the internal space 35 on the electrolytic cell side, the water recovery unit 36, the discharge port 37, and back to the external space R.

[0050] More specifically, in airflow path A, such as Figure 1 As shown, air supplied from the external space R to the electrolytic cell 30 via the air supply unit 33 and the air duct 34 is discharged as bubbles B in the first aqueous solution L1 stored in the electrolytic cell 30. In other words, bubbles B are generated by bubbling the first aqueous solution L1 using air introduced from the external space R. The discharged bubbles B mix with hypochlorous acid generated by the diaphragmless electrolysis of the first aqueous solution L1 to form mixed air M.

[0051] Here, the hypochlorous acid generated by the diaphragmless electrolysis of the first aqueous solution L1 includes both hypochlorous acid dissolved in the first aqueous solution L1 and hypochlorous acid gas that evaporates and vaporizes into the internal space 35 of the electrolytic cell. The hypochlorous acid dissolved in the first aqueous solution L1 mixes with bubbles B and is discharged as mixed air M through the water recovery unit 36 ​​from the discharge port 37 to the external space R. The hypochlorous acid gas that evaporates and vaporizes into the internal space 35 of the electrolytic cell mixes with bubbles B that are mixed with hypochlorous acid and is discharged as mixed air M through the water recovery unit 36 ​​from the discharge port 37 to the external space R.

[0052] When the space purification device 20 is equipped with a water recovery unit 36, hypochlorous acid gas (mixed with air M) flows through the water recovery unit 36, and the moisture contained in the hypochlorous acid gas is recovered to the electrolytic cell 30. Simultaneously with the recovery of this moisture by the water recovery unit 36, metal ions such as sodium ions contained in the moisture of the hypochlorous acid gas are also recovered to the electrolytic cell 30. Therefore, moisture is recovered, and hypochlorous acid gas with a reduced metal ion content can be supplied to the external space R. The metal ion components are contained in the electrolyte components. More specifically, the metal ions are sodium ions, potassium ions, calcium ions, or magnesium ions, etc.

[0053] By generating bubbles B within the first aqueous solution L1 through bubbling, hypochlorous acid comes into contact with the bubble B during its buoyancy as it rises to the liquid surface S1. In other words, compared to the gas-liquid contact between air and the liquid surface S1 of the first aqueous solution L1, the gas-liquid contact generated by bubbling within the first aqueous solution L1 allows more hypochlorous acid to be introduced into the bubble B, which is then discharged as mixed air M into the external space R. The mixed air M contains moisture evaporated from the first aqueous solution L1, but this moisture is recovered by the water recovery unit 36 ​​and returned to the first aqueous solution L1 as water droplets.

[0054] The external space R is purified by discharging a mixture of hypochlorous acid-containing air M from the discharge port 37 into the external space R of the space purification device 20. More specifically, the mixture of hypochlorous acid-containing air M removes bacteria, fungi, viruses, or odors contained in the air of the external space R of the housing C.

[0055] The electrolytic cell 30 may also include a water level detection unit 38. The water level detection unit 38 detects the position of the liquid level S1 in the first aqueous solution L1. The water level detection unit 38 is, for example, a water level sensor. The water level detection unit 38 is disposed at least above the upper end (positive z-axis side) of the electrolytic cell-side anode 31 and the electrolytic cell-side cathode 32.

[0056] When the space purification device 20 is equipped with a water level detection unit 38, the water recovery unit 36 ​​recovers moisture from the mixed air M and supplies water to the electrolytic cell 30 based on the position of the liquid level S1 detected by the water level detection unit 38. More specifically, the water recovery unit 36 ​​supplies water to the electrolytic cell 30 at a level not lower than the upper ends (positive z-axis portion) of both the electrolytic cell-side anode 31 and the electrolytic cell-side cathode 32. Furthermore, the water recovery unit 36 ​​supplies water to the electrolytic cell 30 at a level not lower than the upper end (positive z-axis portion) of the air supply duct 34 connected to the electrolytic cell 30.

[0057] When the space purification device 20 is equipped with a water recovery unit 36 ​​and a water level detection unit 38, the electrolytic cell-side anode 31 and the electrolytic cell-side cathode 32 can be kept immersed in the first aqueous solution L1. Therefore, the exposure of the electrolytic cell-side anode 31 and the electrolytic cell-side cathode 32 to the air as the first aqueous solution L1 decreases can be suppressed, and the electrolysis efficiency of diaphragm-free electrolysis can be maintained. In addition, the supply tank 40 may also be equipped with the same water recovery unit and water level detection unit as the electrolytic cell 30.

[0058] In order to continuously purify the electrolytic cell 30 without supplying chloride ions from the outside for an extended period of time, and to continue purifying the external space R, the supply tank 40 and the anion exchange membrane 50 described below are used to supply chloride ions to the electrolytic cell 30 from the supply tank 40.

[0059] [Supply Tank 40]

[0060] Supply tank 40 is used to store a second aqueous solution L2 containing chloride ions, and to supply the chloride ions contained in the second aqueous solution L2 to the first aqueous solution L1. Figure 1 The image shows the state in which the second aqueous solution L2 is stored in the supply tank 40.

[0061] To ensure safety in the event of a leak, the solute in the second aqueous solution L2 is preferably a substance with the same level of safety as sodium chloride according to the GHS (Globally Harmonized System of Classification and Labelling of Chemicals) classification. Specifically, the second aqueous solution L2 is an aqueous solution of metal chloride containing metal ions and chloride ions. The second aqueous solution L2 is subjected to membrane electrolysis via the anion exchange membrane 50 described later. The metal ions contained in the second aqueous solution L2 react with the hydroxide ions generated by the membrane electrolysis to form a precipitate of metal hydroxide. Preferably, the second aqueous solution L2 is a high-concentration magnesium chloride aqueous solution or a saturated magnesium chloride aqueous solution.

[0062] When using an aqueous solution of magnesium chloride as the second aqueous solution L2, the mass percentage concentration of the magnesium chloride aqueous solution is, for example, 1% to 35%. As an example, when the second aqueous solution L2 is an aqueous solution of magnesium chloride, through membrane electrolysis, the magnesium ions contained in the magnesium chloride aqueous solution react with hydroxide ions generated by the membrane electrolysis to form a precipitate of magnesium hydroxide. The "precipitate" of magnesium hydroxide can be hard and sandy, colloidal, slurry, or gel-like, including a turbid state in the aqueous solution.

[0063] The supply tank 40 includes a supply tank-side cathode 41, a supply tank-side internal space 42, and a discharge port 43. The supply tank-side cathode 41 is an electrode used in pair with the electrolytic cell-side anode 31 for membrane electrolysis via anion exchange membrane 50. Chloride ions are supplied from the second aqueous solution L2 to the first aqueous solution L1 through membrane electrolysis of the second aqueous solution L2 using a pair of supply tank-side cathodes 41 and electrolytic cell-side anodes 31.

[0064] As the feed cell side cathode 41, an insoluble electrode can be used. More specifically, it can also be, for example, a titanium electrode, a platinum-iridium titanium electrode, a platinum electrode, a ruthenium titanium electrode, or an iridium-titanium oxide electrode. The shape of the feed cell side cathode 41, like the shape of the electrolytic cell side anode 31 and the electrolytic cell side cathode 32, can be any of the following: plate-shaped, mesh-shaped, or rod-shaped.

[0065] The supply tank side internal space 42 is the space above the liquid surface S2 of the second aqueous solution L2 (the space on the positive z-axis side) formed in the supply tank 40 when the second aqueous solution L2 is stored in the supply tank 40. In other words, when the second aqueous solution L2 is not stored to the inner upper surface of the supply tank 40 (the xy plane on the positive z-axis side), the supply tank 40 is in a state where the supply tank side internal space 42 is present.

[0066] The outlet 43 is an opening for discharging hydrogen gas generated by the diaphragm electrolysis of the second aqueous solution L2 into the external space R of the housing C. The outlet 43 is, for example, a check valve. When a check valve is used as the outlet 43, hydrogen gas inside the supply tank 40 is discharged into the external space R, preventing the inflow of gases such as air from the external space R. If the diaphragm electrolysis of the second aqueous solution L2 is repeated, hydrogen gas accumulates in the internal space 42 of the supply tank, and the internal pressure of the supply tank 40 increases. The check valve at the outlet 43 opens due to this pressure, and hydrogen gas is discharged into the external space R of the supply tank 40.

[0067] Furthermore, if the supply tank 40 does not have an outlet 43, a ventilation path (not shown) connecting the internal space 35 on the electrolyzer side and the internal space 42 on the supply tank side can also be provided. If a ventilation path is provided between the electrolyzer 30 and the supply tank 40, hydrogen can be allowed to flow and be discharged in the order of the internal space 42 on the supply tank side, the ventilation path, the internal space 35 on the electrolyzer side, and the outlet 37.

[0068] The anion exchange membrane 50 is a membrane-like member that connects the electrolytic cell 30 and the supply cell 40, allowing anions to permeate based on a voltage applied between the electrolytic cell 30 and the supply cell 40. More specifically, if a voltage is applied between the anode 31 on the electrolytic cell side and the cathode 41 on the supply cell side, membrane electrolysis via the anion exchange membrane 50 is performed. Through membrane electrolysis using the anode 31 on the electrolytic cell side and the cathode 41 on the supply cell side, chloride ions contained in the second aqueous solution L2 are supplied to the first aqueous solution L1 through the anion exchange membrane 50 (indicated by a thick black arrow in the negative x-axis direction).

[0069] The anion exchange membrane 50 in this embodiment is not the type of anion exchange membrane that allows anions to permeate through osmotic pressure without the use of electricity. Furthermore, the anion exchange membrane 50 does not permeate magnesium ions, which are cations. More specifically, when chloride ions contained in the second aqueous solution L2 are supplied to the first aqueous solution L1 through the anion exchange membrane 50 using a membrane electrolysis with an anode 31 on the electrolytic cell side and a cathode 41 on the supply cell side, magnesium ions, which are cations, do not permeate the anion exchange membrane 50. The anion exchange membrane 50 is, for example, a hydrocarbon-based anion exchange membrane. Specific examples of hydrocarbon-based anion exchange membranes include membranes with properties such as selective permeability to monovalent anions, alkali resistance, or high-temperature resistance.

[0070] An anion exchange membrane 50 is disposed between the electrolytic cell 30 and the supply cell 40. When the opposing surfaces of the electrolytic cell 30 and the supply cell 40 are formed by a frame-like member, the anion exchange membrane 50 can also be embedded within this frame-like member. In other words, the electrolytic cell 30 and the supply cell 40 are connected in a manner that allows anions to pass through the anion exchange membrane 50.

[0071] In addition, the chloride ion concentration of the second aqueous solution L2 is the same as that of the first aqueous solution L1, and it may also be equipped with a high-concentration chloride aqueous solution supply tank for supplying high-concentration chloride aqueous solution to the second aqueous solution L2.

[0072] The current control unit 60 includes wiring 61, 62, and 63. Wiring 61, 62, and 63 are current flow lines. The electrolytic cell side anode 31 is electrically connected to the current control unit 60 via wiring 61, the electrolytic cell side cathode 32 is connected via wiring 62, and the supply cell side cathode 41 is connected via wiring 63.

[0073] The current control unit 60 controls the current used in diaphragmless electrolysis and diaphragm electrolysis. More specifically, it controls a first current used in diaphragmless electrolysis and a second current used in diaphragm electrolysis. In other words, the current control unit 60 controls the chemical reactions caused by diaphragmless electrolysis and diaphragm electrolysis by controlling the first current and the second current.

[0074] During purification operation, by performing diaphragm electrolysis to replenish the chloride ions contained in the first aqueous solution L1 that were reduced due to diaphragmless electrolysis, chloride ions contained in the second aqueous solution L2 stored in the supply tank 40 are supplied to the first aqueous solution L1 stored in the electrolysis tank 30 through the anion exchange membrane 50. Specifically, the current control unit 60 increases the amount of chloride ions supplied from the second aqueous solution L2 to the first aqueous solution L1, for example, by increasing the second current.

[0075] Furthermore, during purification operation, to replenish the chloride ions in the first aqueous solution L1 that are reduced due to diaphragm-less electrolysis, the current control unit 60 controls the first current to supply chloride ions in the second aqueous solution L2 through the anion exchange membrane 50 to the first aqueous solution L1. The current control unit 60 maintains the first current and the second current in a predetermined ratio to replenish the chloride ions reduced in the first aqueous solution L1 and to maintain the hypochlorous acid concentration in the first aqueous solution L1 at a predetermined concentration or within a predetermined concentration range. The predetermined concentration, for example, refers to the concentration of chloride ions in the electrolytic cell 30. - There is no apparent increase or decrease in concentration. That is, the so-called specified concentration, for example, refers to the concentration of Cl stored in the first aqueous solution L1. - The initial concentration of Cl stored in the first aqueous solution L1 is the concentration that appears to have not changed.- The specified concentration range refers to the degree to which hypochlorous acid gas can be stably supplied from electrolyzer 30. - The range of concentrations.

[0076] The following reaction equation 1 represents the equilibrium reaction for the formation of hypochlorous acid.

[0077] Cl2+H2O HCl + HClO ･･･(Reaction 1)

[0078] According to the Cl supplied from the second aqueous solution L2 to the first aqueous solution L1 - The increase or decrease of the concentration of the first aqueous solution L1 stored in the electrolytic cell 30 can cause the equilibrium state to shift to the right or to the left. The current control unit 60 controls the current to maintain the concentration of hypochlorous acid in the first aqueous solution L1 stored in the electrolytic cell 30 at a specified concentration, that is, the concentration of Cl in the electrolytic cell 30 is controlled. - There is no increase or decrease in appearance.

[0079] [Protective film 70]

[0080] If the water flow generated by electrolysis collides with the anion exchange membrane 50, the anion exchange membrane 50 will deteriorate. To suppress the deterioration of the anion exchange membrane 50, it is desirable to suppress the collision of water flow with the anion exchange membrane 50. Therefore, a protective membrane 70 is provided on the electrolysis cell 30 side of the anion exchange membrane 50 in the space purification device 20. That is, the anion exchange membrane 50 and the protective membrane 70 are arranged adjacent to each other, and the anion exchange membrane 50 arranged on the electrolysis cell 30 side is covered by the protective membrane 70. In particular, the protective membrane 70 is composed of only one layer of porous membrane 72.

[0081] Figure 2 This is a partially enlarged view of the anion exchange membrane 50 and the porous membrane 72. The porous membrane 72 is a semi-permeable membrane with mesh-like micropores 74. Although it has liquid retention properties due to the surface tension generated on the microporous surface, it has low water permeability and does not actively allow water to pass through. Therefore, the porous membrane 72 can inhibit the collision of ions or particles in water with the anion exchange membrane 50.

[0082] The porous membrane 72 can be any one of a microfiltration (MF) membrane, an ultrafiltration (UF) membrane, or a nanofiltration (NF) membrane. When the porous membrane 72 is a microfiltration membrane, the diameter of the micropores 74 is, for example, 100 nm to 10000 nm. When the porous membrane 72 is an ultrafiltration membrane, the diameter of the micropores 74 is, for example, 10 nm to 1000 nm. When the porous membrane 72 is a nanofiltration membrane, the diameter of the micropores 74 is, for example, 1 nm to 100 nm. Furthermore, the materials constituting the porous membrane 72, as examples, include PET (Polyethylene terephthalate), PTFE (Polytetrafluoroethylene), and PVDF (Polyvinylidene fluoride). Furthermore, the shape of the mesh-like micropores 74 can be either a symmetrical structure (such as a lattice) or an asymmetrical structure. To further improve the electrical conductivity between the electrolytic cell 30 and the supply cell 40, the surface of the porous membrane 72 can also be hydrophilized.

[0083] In the case of diaphragm-free electrolysis in electrolytic cell 30, hypochlorous acid ions are drawn to the anode 31 on the electrolytic cell side and do not actively move towards the porous membrane 72 and anion exchange membrane 50. Therefore, hypochlorous acid ions hardly come into contact with the anion exchange membrane 50. In addition, since the porous membrane 72 has liquid retention capacity through micropores 74, the contact between hypochlorous acid ions moving by water flow and the anion exchange membrane 50, as well as the physical load of water flow on the anion exchange membrane 50, are also reduced. Here, the water flow is either convection generated during diaphragm-free electrolysis or bubbling bubbles B generated from the air supply unit 33.

[0084] On the other hand, when no diaphragm-free electrolysis is performed in the electrolyzer 30, hypochlorite ions move towards the anion exchange membrane 50 side by natural diffusion. Figure 3 This represents the change in hypochlorous acid concentration over time in the space purification device 20. The horizontal axis represents the elapsed time after the diaphragm-free electrolysis was stopped, and the vertical axis represents the hypochlorous acid concentration. Figure 2 In the chart, the concentration of hypochlorous acid in electrolytic cell 30 is expressed as "hypochlorous acid concentration 80". If the diaphragmless electrolysis is stopped, hypochlorous acid ions diffuse naturally while undergoing volatilization, self-decomposition, etc., so the concentration of hypochlorous acid 80 in electrolytic cell 30 decreases over time. In addition, due to the liquid retention capacity of the porous membrane 72, hypochlorous acid ions have difficulty passing through the porous membrane 72.

[0085] exist Figure 2In the diagram, the concentration of hypochlorous acid on the surface of the anion exchange membrane 50 is expressed as "hypochlorous acid concentration 82". At the timing of stopping the diaphragmless electrolysis, very few hypochlorous acid ions reach the anion exchange membrane 50 due to the liquid retention capacity of the porous membrane 72. As the number of hypochlorous acid ions passing through the porous membrane 72 increases over time, the concentration of hypochlorous acid 82 on the surface of the anion exchange membrane 50 also increases. However, as the concentration of hypochlorous acid 80 in the electrolyzer 30 decreases, the concentration of hypochlorous acid 82 on the surface of the anion exchange membrane 50 also decreases. Furthermore, in the first aqueous solution L1, ionized and unionized hypochlorous acid exist in equilibrium. The above explanation concerns ionized hypochlorous acid, but the concentration of unionized hypochlorous acid reaching the surface of the anion exchange membrane 50 can also be reduced through the same mechanism.

[0086] The main body of the apparatus, system, or method disclosed herein includes a computer. The computer executes a program to realize the functions of the main body of the apparatus, system, or method disclosed herein. The computer has a processor as its main hardware structure, which operates according to the program. The type of processor is not limited as long as it can perform its functions by executing a program. The processor consists of one or more electronic circuits, including semiconductor integrated circuits (ICs) or LSIs (Large Scale Integration). Multiple electronic circuits can be integrated onto a single chip or disposed on multiple chips. Multiple chips can be integrated into a single device or disposed on multiple devices. The program is recorded in a non-transitory recording medium such as a computer-readable ROM, optical disk, or hard disk drive. The program can be pre-stored on the recording medium or supplied to the recording medium via a wide area communication network, including the Internet.

[0087] According to this embodiment, since the protective membrane 70 protects the anion exchange membrane 50, direct contact between the electrolyzed water containing hypochlorous acid ions generated in the electrolyzer 30 and the anion exchange membrane 50 can be suppressed. Furthermore, since direct contact between the electrolyzed water containing hypochlorous acid ions and the anion exchange membrane 50 is suppressed, degradation of the anion exchange membrane 50 can be suppressed. Additionally, since the protective membrane 70 protects the anion exchange membrane 50, physical influences such as water flow or bubbles can be suppressed. Furthermore, since physical influences such as water flow or bubbles are suppressed, degradation of the anion exchange membrane 50 can be suppressed. Furthermore, since degradation of the anion exchange membrane 50 is suppressed, hypochlorous acid gas can be stably supplied for extended periods without the need for external chloride supply. Furthermore, since degradation of the anion exchange membrane 50 is suppressed, the frequency of maintenance can be reduced.

[0088] Furthermore, since the protective membrane 70 is composed solely of a porous membrane 72, it possesses liquid retention properties due to the surface tension of the porous membrane 72. Additionally, since the porous membrane 72 is any one of a microfiltration (MF) membrane, ultrafiltration (UF) membrane, or nanofiltration (NF) membrane, it can protect the anion exchange membrane 50. Furthermore, since the surface of the porous membrane 72 is hydrophilically treated, its electrical conductivity is further improved. Moreover, to replenish the chloride ions contained in the first aqueous solution L1, which are reduced due to diaphragmless electrolysis, chloride ions contained in the second aqueous solution L2 stored in the supply tank 40 are supplied to the first aqueous solution L1. Therefore, purification operation can continue for an extended period without external supply of chloride ions to the electrolytic cell 30, and the external space R can continue to be purified. Furthermore, gas-liquid contact can be achieved by bubbling to generate bubbles B within the first aqueous solution L1, introducing more hypochlorous acid into the bubbles B, which are then discharged as mixed air M into the external space R. By discharging a mixture of hypochlorous acid-containing air M into the external space R, space purification of the external space R can be achieved.

[0089] One aspect of this disclosure is summarized below.

[0090] (Project 1)

[0091] An electrolytic water generating device, comprising:

[0092] An electrolytic cell (30) for storing a first aqueous solution (L1) containing chloride ions.

[0093] Supply tank (40) for storing a second aqueous solution (L2) containing chloride ions.

[0094] The electrolytic cell (30) and the supply cell (40) are connected in such a way that an anion exchange membrane (50) containing chloride ions can pass through.

[0095] A protective membrane (70) is disposed on the side of the electrolytic cell (30) of the anion exchange membrane (50).

[0096] The electrolytic cell (30) electrolyzes the first aqueous solution (L1) without a diaphragm to generate hypochlorous acid;

[0097] The supply tank (40) uses diaphragm electrolysis to supply the chloride ions contained in the second aqueous solution (L2) through the anion exchange membrane (50) and the protective membrane (70) to the first aqueous solution (L1).

[0098] The protective film (70) includes a porous membrane (72) with mesh-like micropores.

[0099] (Project 2)

[0100] The water electrolysis generator as described in Project 1

[0101] The protective membrane (70) is composed solely of the porous membrane (72).

[0102] (Project 4)

[0103] The water electrolysis generator as described in Project 1

[0104] The porous membrane (72) is any one of microfiltration (MF) membrane, ultrafiltration (UF) membrane, and nanofiltration (NF) membrane.

[0105] (Project 5)

[0106] The water electrolysis generator as described in Project 1

[0107] The surface of the porous membrane (72) is subjected to hydrophilic treatment.

[0108] (Project 6)

[0109] A space purification device (20).

[0110] It has an electrolytic water generation device as described in any one of items 1 to 5;

[0111] The space purification device (20) performs purification operation in which air introduced from the indoor space circulates in the electrolytic cell (30) and is discharged into the indoor space together with the hypochlorous acid;

[0112] In order to replenish the chloride ions contained in the first aqueous solution (L1) that are reduced due to the diaphragmless electrolysis, the chloride ions contained in the second aqueous solution (L2) stored in the supply tank (40) are supplied to the first aqueous solution (L1) stored in the electrolytic cell (30) through the anion exchange membrane (50) and the protective membrane (70).

[0113] (Project 7)

[0114] The space purification device (20) described in Project 6.

[0115] The air supplied to the electrolytic cell (30) is discharged as bubbles (B) in the first aqueous solution (L1);

[0116] The emitted bubbles (B) are mixed with the hypochlorous acid, and the resulting mixed air (M) is discharged into the indoor space.

[0117] (Example 2)

[0118] Example 2 also relates to a space purification device 20, similar to Example 1. The structure of the protective membrane 70 in Example 2 differs from that in Example 1. When multiple porous membranes 72 are arranged adjacently, i.e., stacked, undesirable air such as air bubbles may be mixed between the membranes, depending on the membrane arrangement. The arrangement of the porous membranes 72 that may introduce undesirable air bubbles refers to, for example, the case where a porous membrane 72 / porous membrane 72 / anion exchange membrane 50 is arranged as the protective membrane 70. The porous membrane 72 is a semi-permeable membrane with mesh-like micropores 74. It has liquid retention properties due to the surface tension generated on the fine porous surface, but low water permeability, and does not actively allow water to pass through. Therefore, when porous membranes 72 are arranged adjacent to each other, air bubbles mixed into the spaces between adjacent porous membranes 72 accumulate between the membranes, making it difficult to discharge them to the outside of the space purification device 20. If air (bubbles) exists between the membranes instead of as a liquid, the flow of electricity through the anion exchange membrane 50 for membrane electrolysis is hindered. This could potentially impede the supply of chloride ions from the supply tank 40 to the electrolytic cell 30. In Example 2, the aim is to suppress this obstruction of the supply of chloride ions from the supply tank 40 to the electrolytic cell 30. The following description focuses on the differences from Example 1.

[0119] Figure 4 This is a front cross-sectional view of the space purification device 20. The protective membrane 70 consists of two layers: a porous membrane 72 and a water-permeable membrane 76. The water-permeable membrane 76 is disposed on the electrolytic cell 30 side of the anion exchange membrane 50, and the porous membrane 72 is disposed on the electrolytic cell 30 side of the water-permeable membrane 76. That is, the water-permeable membrane 76 is disposed between the porous membrane 72 and the anion exchange membrane. The porous membrane 72 is a membrane with water permeability that allows the first aqueous solution L1 to pass through. That is, the anion exchange membrane 50 and the water-permeable membrane 76 are disposed adjacent to each other, and the anion exchange membrane 50 disposed on the electrolytic cell 30 side is covered by the water-permeable membrane 76. In addition, the water-permeable membrane 76 is disposed adjacent to the porous membrane 72, and the water-permeable membrane 76 disposed on the electrolytic cell 30 side is covered by the porous membrane 72.

[0120] Figure 5This is a partial enlarged view of the space purification device 20, the porous membrane 72, and the water-permeable membrane 76. By configuring the porous membrane 72 / water-permeable membrane 76 / anion exchange membrane 50, moisture is retained by the water-permeable membrane 76 disposed between the porous membrane 72 and the anion exchange membrane 50. Even if undesirable bubbles or the like are generated between the porous membrane 72 and the anion exchange membrane 50, the permeable membrane 76 ensures that the current flow for membrane electrolysis via the anion exchange membrane 50 is not easily obstructed. Furthermore, the supply of chloride ions from the supply tank 40 to the electrolysis tank 30 is not easily obstructed. Moreover, by configuring the protective membrane 70 as a double-layer structure of the porous membrane 72 and the water-permeable membrane 76, the durability of the protective membrane 70 is improved, and direct contact between the electrolyzed water containing hypochlorite ions generated in the electrolysis tank 30 and the anion exchange membrane 50 is suppressed, further inhibiting the deterioration of the anion exchange membrane 50. The protective membrane 70 can also be configured as a porous membrane 72 / water-permeable membrane 76 / water-permeable membrane 76 / anion exchange membrane 50 stacked together.

[0121] According to this embodiment, since the low-permeability porous membrane 72, the high-permeability permeable membrane 76, and the anion exchange membrane 50 are sequentially stacked as the protective membrane 70, i.e., the membranes are arranged adjacent to each other, the membrane thickness can be increased, thereby improving the durability of the protective membrane 70. Furthermore, since the low-permeability porous membrane 72, the high-permeability permeable membrane 76, and the anion exchange membrane 50 are sequentially stacked, the amount of water retained between the anion exchange membrane 50 and the porous membrane 72 can be increased. Additionally, since the amount of water retained between the anion exchange membrane 50 and the porous membrane 72 is increased, the electrical conductivity can be improved.

[0122] One aspect of this disclosure is summarized below.

[0123] (Project 3)

[0124] The water electrolysis generator as described in Project 1

[0125] The protective membrane (70) is composed of a double-layer structure consisting of the porous membrane (72) and a water-permeable membrane (76) that is permeable to the first aqueous solution (L1);

[0126] The permeable membrane (76) is disposed between the porous membrane (72) and the anion exchange membrane (50).

[0127] (Example 3)

[0128] Examples 1 and 2 are space purification devices 20. On the other hand, Example 3 relates to an electrolyzed water generating device within the space purification device 20. The electrolyzed water generating device... Figure 1 , Figure 4The device excludes the air supply unit 33, air duct 34, water recovery unit 36, and discharge port 37, and includes a discharge pipe for discharging the solution containing hypochlorous acid gas generated by diaphragm-free electrolysis (hereinafter referred to as "electrolyzed water") from the electrolytic cell 30. That is, the electrolyzed water generating device discharges electrolyzed water without discharging the mixed air M containing hypochlorous acid. The protective membrane 70 in Example 3 is constructed in the same manner as in Examples 1 and 2.

[0129] According to this embodiment, a protective membrane 70 is used to protect the anion exchange membrane 50 in the water electrolysis generating device, thus expanding the scope of application.

[0130] (Example 4)

[0131] Chlorine reacts with water to produce hypochlorous acid. Additionally, electrolysis can generate water flow towards the surface of the anion exchange membrane. Even when using a protective membrane with multiple slit-like gaps, it is difficult to prevent hypochlorous acid ions from contacting the membrane surface.

[0132] This disclosure addresses the aforementioned problems by providing a technique for suppressing the contact between hypochlorite ions and the membrane surface of anion exchange membranes. The following description focuses on the differences from previous techniques.

[0133] Figure 6 This is a front cross-sectional view of the space purification device 20. The space purification device 20 performs diaphragmless electrolysis of a first aqueous solution L1 containing chloride ions in an electrolytic cell 30 (described later) to generate hypochlorous acid, which is then volatilized. The space purification device 20 removes bacteria, fungi, viruses, or odors from the air in the external space R of the space purification device 20 by discharging the generated hypochlorous acid into the external space R of the housing C constituting the space purification device 20. Alternatively, diaphragm electrolysis is performed. To replenish the chloride ions in the first aqueous solution L1 that are reduced due to diaphragmless electrolysis, chloride ions contained in a second aqueous solution L2 stored in a supply tank 40 are supplied to the first aqueous solution L1 stored in the electrolytic cell 30 through anion exchange membrane 50, buffer layer 170, and diaphragm 172.

[0134] like Figure 1 As shown, the space purification device 20 includes a housing C, an electrolytic cell 30, and a current control unit 60. The space purification device 20 may also include a supply tank 40, an anion exchange membrane 50, a buffer layer 170, and a diaphragm 172. To ensure continuous internal purification operation without the electrolytic cell 30 receiving chloride ions from the outside for an extended period, the supply tank 40 and the anion exchange membrane 50 supply chloride ions to the electrolytic cell 30 from the supply tank 40. Furthermore, the buffer layer 170 and the diaphragm 172 protect the anion exchange membrane 50.

[0135] The housing C is a box-shaped component that houses the electrolytic cell 30, the supply tank 40, the anion exchange membrane 50, the current control unit 60, the buffer layer 170, and the diaphragm 172. In other words, the space purification device 20 is an integrated unit formed by the housing C. The space purification device 20 has a small size; for example, it is approximately 10cm × 7cm × 4cm when the housing C is rectangular.

[0136] Electrolytic cell 30 is used to store a first aqueous solution L1 containing chloride ions, and to generate hypochlorous acid by performing diaphragm-free electrolysis on the first aqueous solution L1. Supply cell 40 is used to store a second aqueous solution L2 containing chloride ions, and to supply the first aqueous solution L1 with chloride ions contained in the second aqueous solution L2 through anion exchange membrane 50, buffer layer 170, and diaphragm 172 via diaphragm electrolysis. The buffer layer 170 and diaphragm 172 will be described later, and therefore will be omitted in the following description. More specifically, chloride ions contained in the second aqueous solution L2 are supplied to the first aqueous solution L1 via diaphragm electrolysis through anion exchange membrane 50, which is provided in a manner connecting electrolytic cell 30 and supply cell 40. Anion exchange membrane 50 is permeable to anions containing chloride ions. Current control unit 60 controls both diaphragm-free electrolysis and diaphragm electrolysis.

[0137] [Supply Tank 40]

[0138] The anion exchange membrane 50 is, for example, a hydrocarbon-based anion exchange membrane made of hydrocarbon-based polymer materials. Hydrocarbon-based anion exchange membranes exist with various properties. As a specific example of the hydrocarbon-based anion exchange membrane 50 used in this embodiment, a membrane with properties such as selective permeability to monovalent anions, alkali resistance, or high temperature resistance is preferably used.

[0139] [Buffer layer 170 and diaphragm 172]

[0140] If a large number of hypochlorous acid ions reach and come into contact with the anion exchange membrane 50 after electrolysis stops, the anion exchange membrane 50 will deteriorate. To suppress the deterioration of the anion exchange membrane 50, it is desirable to suppress the large-scale arrival of hypochlorous acid ions at the anion exchange membrane 50. Therefore, a buffer layer 170 is provided on the electrolytic cell 30 side of the anion exchange membrane 50 in the space purification device 20, and a diaphragm 172 is provided between the buffer layer 170 and the electrolytic cell 30. That is, two layers, the buffer layer 170 and the diaphragm 172, are disposed between the electrolytic cell 30 and the anion exchange membrane 50.

[0141] Figure 7This is a partially enlarged view of the anion exchange membrane 50, the buffer layer 170, and the diaphragm 172. The buffer layer 170 is a hollow space, such as a tube, connecting the electrolytic cell 30 and the supply cell 40. The anion exchange membrane 50 is disposed at the opening where the buffer layer 170 connects to the supply cell 40, and the diaphragm 172 is disposed at the opening where the buffer layer 170 connects to the electrolytic cell 30. The shape of the buffer layer 170 is not limited thereto; for example, a portion of the electrolytic cell 30 may be divided by the diaphragm 172, and this divided portion of the electrolytic cell 30 may also serve as the buffer layer 170. A first aqueous solution L1 is stored in the buffer layer 170. Therefore, the first aqueous solution L1 stored in the electrolytic cell 30 and the first aqueous solution L1 stored in the buffer layer 170 are separated by the diaphragm 172.

[0142] The diaphragm 172 is a porous membrane. To elaborate further, the diaphragm 172 is a semi-permeable membrane with mesh-like micropores 74. It possesses liquid retention properties due to the surface tension generated on its fine porous surface, but has low water permeability and does not actively allow water to pass through. Therefore, the diaphragm 172 can inhibit collisions between ions or particles in water and the anion exchange membrane 50.

[0143] The membrane 172 can be any one of a microfiltration (MF) membrane, an ultrafiltration (UF) membrane, or a nanofiltration (NF) membrane. When the membrane 172 is a microfiltration membrane, the diameter of the micropores 74 is, for example, 100 nm to 10000 nm. When the membrane 172 is an ultrafiltration membrane, the diameter of the micropores 74 is, for example, 10 nm to 1000 nm. When the membrane 172 is a nanofiltration membrane, the diameter of the micropores 74 is, for example, 1 nm to 100 nm. Furthermore, the materials constituting the membrane 172, as examples, include PET (Polyethylene terephthalate), PTFE (Polytetrafluoroethylene), and PVDF (Polyvinylidene fluoride). Furthermore, the shape of the mesh-like micropores 74 can be either a symmetrical structure (such as a lattice) or an asymmetrical structure. To further improve the electrical conductivity between the electrolytic cell 30 and the supply cell 40, the surface of the diaphragm 172 can also be hydrophilicated.

[0144] In the case of diaphragmless electrolysis in electrolyzer 30, hypochlorous acid ions are drawn to the anode 31 on the electrolyzer side and do not actively move towards the diaphragm 172, buffer layer 170, and anion exchange membrane 50. Therefore, hypochlorous acid ions have almost no contact with the anion exchange membrane 50. In addition, since the diaphragm 172 has liquid retention capacity through micropores 74, the contact between hypochlorous acid ions moving by water flow and the anion exchange membrane 50, as well as the physical load of water flow on the anion exchange membrane 50, are also reduced. By providing the buffer layer 170 and the diaphragm 172, the influence of hypochlorous acid generated in electrolyzer 30 on the anion exchange membrane 50 and the influence of water flow generated by electrolysis are suppressed. As a result, the deterioration of the anion exchange membrane 50 is suppressed.

[0145] On the other hand, when no diaphragm-free electrolysis is performed in the electrolyzer 30, hypochlorite ions move towards the anion exchange membrane 50 side by natural diffusion. Figure 8 This represents the change in hypochlorous acid concentration over time in the space purification device 20. The horizontal axis represents the elapsed time after the diaphragm-free electrolysis was stopped, and the vertical axis represents the hypochlorous acid concentration. Figure 8 In the chart, the concentration of hypochlorous acid in electrolytic cell 30 is expressed as "hypochlorous acid concentration 180". If diaphragmless electrolysis is stopped, hypochlorous acid ions diffuse naturally while undergoing volatilization, self-decomposition, etc., so the concentration of hypochlorous acid 180 in electrolytic cell 30 decreases over time. In addition, due to the liquid retention capacity of diaphragm 172, hypochlorous acid ions have difficulty passing through porous membrane 72.

[0146] exist Figure 8 In the graph, the concentration of hypochlorous acid on the diaphragm 172 side of the buffer layer 170 is represented as "hypochlorous acid concentration 182". At the time of stopping diaphragmless electrolysis, fewer hypochlorous acid ions reach the buffer layer 170 due to the liquid retention capacity of the diaphragm 172. As the number of hypochlorous acid ions passing through the diaphragm 172 increases over time, the hypochlorous acid concentration 182 in the buffer layer 170 also increases. However, as the hypochlorous acid concentration 180 in the electrolytic cell 30 itself decreases, the hypochlorous acid concentration 182 in the buffer layer 170 also decreases.

[0147] exist Figure 8In the diagram, the concentration of hypochlorous acid on the anion exchange membrane 50 side of the buffer layer 170 is represented as "hypochlorous acid concentration 184". By providing the buffer layer 170, the time for hypochlorous acid ions to reach the anion exchange membrane 50 is delayed. As a result, before the hypochlorous acid ions reach the anion exchange membrane 50, diffusion of hypochlorous acid ions occurs within the buffer layer 170, thus the hypochlorous acid concentration 184 on the surface of the anion exchange membrane 50 becomes lower than the hypochlorous acid concentration 182 in the buffer layer 170. Consequently, the degradation of the anion exchange membrane 50 is suppressed. Furthermore, in the first aqueous solution L1, ionized hypochlorous acid and unionized hypochlorous acid exist in an equilibrium state. The above explanation concerns ionized hypochlorous acid, but for unionized hypochlorous acid, the concentration of hypochlorous acid reaching the surface of the anion exchange membrane 50 can also be reduced through the same mechanism.

[0148] Furthermore, by providing the diaphragm 172, the flow of bubbles (water flow) generated during diaphragmless electrolysis can be suppressed from reaching the buffer layer 170 side through the diaphragm 172. As a result, the influence of water flow that may be generated during diaphragmless electrolysis on the anion exchange membrane 50 is suppressed. That is, by providing the diaphragm 172 and the buffer layer 170, the degradation of the anion exchange membrane 50 caused by hypochlorous acid ions is suppressed. Therefore, the diaphragm 172 can be described as a porous membrane with mesh-like micropores 74, such that after diaphragmless electrolysis in the electrolyzer 30 stops, the concentration of hypochlorous acid ions reaching the anion exchange membrane 50 through the diaphragm 172 and the buffer layer 170 from the electrolyzer 30 does not exceed a threshold. Here, the "threshold" of hypochlorous acid ion concentration is the concentration that can suppress the degradation of the anion exchange membrane 50. For example, if the hypochlorite ion concentration in electrolyzer 30 is 1000 ppm and the anion exchange membrane 50 can be used for 10 years without deterioration, and the lifespan of the space purification device 20 is 5 years, then the threshold can be set to 2000 ppm. The "threshold" of hypochlorite ion concentration is a value determined in advance through experiments, etc., and can be appropriately changed according to the intended lifespan of the space purification device 20.

[0149] According to this embodiment, due to the presence of the buffer layer 170 and the diaphragm 172, the time it takes for hypochlorous acid ions generated in the electrolyzer 30 to reach the anion exchange membrane 50 can be delayed. Furthermore, because the time for hypochlorous acid ions to reach the anion exchange membrane 50 is delayed, contact between hypochlorous acid ions and the membrane surface of the anion exchange membrane 50 can be suppressed through self-decomposition or natural diffusion of the hypochlorous acid ions. Additionally, because the contact between hypochlorous acid ions and the membrane surface of the anion exchange membrane 50 is suppressed, the degradation of the anion exchange membrane 50 can be prevented. Furthermore, because the time for hypochlorous acid ions to reach the anion exchange membrane 50 is delayed, the increase in the concentration of hypochlorous acid in the anion exchange membrane 50 can be suppressed.

[0150] Furthermore, due to the presence of the buffer layer 170 and the diaphragm 172, physical loads such as water flow and bubbles generated in the electrolyzer 30 can be suppressed. Moreover, since the physical loads such as water flow and bubbles generated in the electrolyzer 30 are suppressed, the deterioration of the anion exchange membrane 50 can be suppressed. Furthermore, since the deterioration of the anion exchange membrane 50 is suppressed, the system can operate at a stable chloride ion concentration for extended periods without external chloride supply, ensuring a stable supply of hypochlorous acid gas. Additionally, since the deterioration of the anion exchange membrane 50 is suppressed, the frequency of maintenance can be reduced.

[0151] Furthermore, since the diaphragm 172 is any one of a microfiltration (MF) membrane, an ultrafiltration (UF) membrane, or a nanofiltration (NF) membrane, it can protect the anion exchange membrane 50. Additionally, because the surface of the diaphragm 172 is hydrophilically treated, it can be energized. Furthermore, to replenish the chloride ions in the first aqueous solution L1 that are reduced due to diaphragm-free electrolysis, chloride ions stored in the second aqueous solution L2 in the supply tank 40 are supplied to the first aqueous solution L1. Therefore, the electrolysis tank 30 can operate continuously without external chloride ion supply for extended periods, enabling continuous purification of the external space R. Furthermore, by bubbling, gas-liquid contact is achieved by generating bubbles B in the first aqueous solution L1, introducing more hypochlorous acid into the bubbles B, which are then discharged as mixed air M into the external space R. The external space R is purified by the hypochlorous acid-containing mixed air M discharged into the external space R.

[0152] One aspect of this disclosure is summarized below.

[0153] (Project 8)

[0154] An electrolytic water generation device, comprising:

[0155] An electrolytic cell (30) for storing a first aqueous solution (L1) containing chloride ions.

[0156] Supply tank (40) for storing a second aqueous solution (L2) containing chloride ions.

[0157] A buffer layer (170) is provided between the electrolytic cell (30) and the supply cell (40) to store the first aqueous solution (L1).

[0158] An anion exchange membrane (50) containing chloride ions is disposed between the buffer layer (170) and the supply tank (40), and is capable of passing through the membrane.

[0159] A diaphragm (172) is disposed between the electrolytic cell (30) and the buffer layer (170).

[0160] The electrolytic cell (30) electrolyzes the first aqueous solution (L1) without a diaphragm to generate hypochlorous acid;

[0161] The supply tank (40) uses diaphragm electrolysis to allow the chloride ions contained in the second aqueous solution (L2) to pass through the anion exchange membrane (50), the buffer layer (170), and the diaphragm (172) to be supplied to the first aqueous solution (L1).

[0162] (Project 9)

[0163] The water electrolysis generator as described in Project 8

[0164] The diaphragm (172) is a porous membrane with mesh-like micropores, such that after the diaphragmless electrolysis in the electrolytic cell (30) stops, the concentration of hypochlorite ions passing through the diaphragm (172) and the buffer layer (170) from the electrolytic cell (30) to the anion exchange membrane (50) does not exceed a threshold.

[0165] (Project 10)

[0166] The water electrolysis generator as described in Project 8

[0167] The diaphragm (172) is any one of a microfiltration (MF) membrane, an ultrafiltration (UF) membrane, or a nanofiltration (NF) membrane.

[0168] (Project 11)

[0169] The water electrolysis generator as described in Project 8

[0170] The surface of the diaphragm (172) is subjected to a hydrophilic treatment.

[0171] (Project 16)

[0172] A space purification device (20).

[0173] It has an electrolytic water generation device as described in any one of items 8 to 15;

[0174] The space purification device performs purification operation by introducing air from the indoor space into the electrolytic cell (30) and discharging it into the indoor space together with the hypochlorous acid;

[0175] In order to replenish the chloride ions contained in the first aqueous solution (L1) that are reduced due to the diaphragmless electrolysis, the chloride ions contained in the second aqueous solution (L2) stored in the supply tank (40) are supplied to the first aqueous solution (L1) stored in the electrolytic cell (30) through the anion exchange membrane (50) and the protective membrane (70).

[0176] (Project 17)

[0177] The space purification device (20) described in Project 16.

[0178] The air supplied to the electrolytic cell (30) is discharged as bubbles (B) in the first aqueous solution (L1);

[0179] The emitted bubbles (B) are mixed with the hypochlorous acid, and the resulting mixed air (M) is discharged into the indoor space.

[0180] (Example 5)

[0181] Next, Example 5 will be described. Example 5 relates to the same space purification device 20 as Example 4. In Example 4, in order to suppress the deterioration of the anion exchange membrane 50 caused by hypochlorous acid ions, a buffer layer 170 is provided on the electrolytic cell 30 side of the anion exchange membrane 50, and a porous membrane (septum 172) is provided between the buffer layer 170 and the electrolytic cell 30. After using the porous membrane for a certain period of time, the porous membrane may deteriorate due to hypochlorous acid ions. In this case, the protective effect on the anion exchange membrane 50 may be insufficient. To prevent this, if the area of ​​the porous membrane is reduced or the number of porous materials is increased, the protective effect increases. However, if the area of ​​the porous membrane is reduced or the number of porous materials is increased, the voltage used for electrolysis increases. In addition, as described in Example 4, the deterioration of the anion exchange membrane 50 can be suppressed by the porous membrane, but even before the porous membrane deteriorates as described above, the anion exchange membrane 50 may still deteriorate due to hypochlorous acid ions that diffuse through the porous membrane.

[0182] On the other hand, compared with porous membranes, anion exchange membranes offer higher protection, suppressing the rise in voltage used for electrolysis and protecting the anion exchange membrane 50. Therefore, in Example 5, to protect the anion exchange membrane 50, a protective anion exchange membrane (hereinafter referred to as the "protective anion exchange membrane") different from the original anion exchange membrane 50 is added to extend the lifespan of the anion exchange membrane 50. With the addition of the protective anion exchange membrane, compared to the case where only a porous membrane is provided, the time for hypochlorous acid ions to reach the anion exchange membrane 50 via the protective anion exchange membrane becomes longer. Therefore, through the natural decay of hypochlorous acid ions, the concentration of hypochlorous acid on the surface of the anion exchange membrane 50 decreases.

[0183] Figure 9This is a front cross-sectional view of the space purification device 20. A buffer layer 170 is provided on the electrolytic cell 30 side of the anion exchange membrane 50 in the space purification device 20, and a diaphragm 172 is provided between the buffer layer 170 and the electrolytic cell 30. Here, the diaphragm 172 includes a protective anion exchange membrane 176 and a porous membrane 178, with the porous membrane 178 disposed between the electrolytic cell 30 and the protective anion exchange membrane 176. The porous membrane 178 corresponds to the diaphragm 172 of Example 4. Therefore, the porous membrane 178 is a semi-permeable membrane with mesh-like micropores 74 (not shown), possessing liquid retention properties due to the surface tension generated on the fine porous surface, but with low water permeability, and does not actively allow water to pass through.

[0184] The protective anion exchange membrane 176 is an anion exchange membrane different from the anion exchange membrane 50. The protective anion exchange membrane 176 may also have the same level of oxidation resistance as the anion exchange membrane 50, but is more preferably made of a material with higher oxidation resistance than the anion exchange membrane 50. Materials with higher oxidation resistance than the anion exchange membrane 50 include, for example, fully fluorinated anion exchange membranes (perfluorinated anion exchange membranes) and partially fluorinated anion exchange membranes. The former is made of a polymer material with a fully fluorinated main chain, while the latter is made of a polymer material containing at least one fluorine atom in its main chain. That is, the protective anion exchange membrane 176 can be considered a fluorine-based anion exchange membrane. On the other hand, as described above, the anion exchange membrane 50 is a hydrocarbon-based anion exchange membrane. Here, the separator 172 may also exclude the porous membrane 178 and consist only of the protective anion exchange membrane 176.

[0185] According to this embodiment, since the diaphragm 172 includes a protective anion exchange membrane 176, the voltage rise during diaphragm electrolysis and the diffusion of hypochlorous acid ions can be suppressed compared to using only the porous membrane 178. Furthermore, since the diffusion of hypochlorous acid ions is suppressed, the degradation of the anion exchange membrane 50 can be further suppressed. Additionally, since the diaphragm 172 includes both the protective anion exchange membrane 176 and the porous membrane 178, the diffusion of hypochlorous acid ions into the buffer layer 170 caused by the degradation of the protective anion exchange membrane 176 can be suppressed. Furthermore, since the diffusion of hypochlorous acid ions into the buffer layer 170 caused by the degradation of the protective anion exchange membrane 176 is suppressed, the degradation of the anion exchange membrane 50 can be further suppressed. Moreover, since the oxidation resistance of the protective anion exchange membrane 176 is higher than that of the anion exchange membrane 50, the diffusion of hypochlorous acid ions into the buffer layer caused by the degradation of the protective anion exchange membrane 176 can be suppressed.

[0186] One aspect of this disclosure is summarized below.

[0187] (Project 12)

[0188] The water electrolysis generator as described in Project 8

[0189] The diaphragm (172) includes a protective anion exchange membrane (176) that is different from the anion exchange membrane (50).

[0190] (Project 13)

[0191] The water electrolysis generator as described in Project 12

[0192] The diaphragm (172) also includes a porous membrane (178) with mesh-like micropores.

[0193] The porous membrane (178) is disposed between the electrolytic cell (30) and the protective anion exchange membrane (176).

[0194] (Project 14)

[0195] The water electrolysis generator as described in Project 12

[0196] The protective anion exchange membrane (176) is made of a material with higher oxidation resistance than the anion exchange membrane (50).

[0197] (Project 15)

[0198] The water electrolysis generator as described in Project 13

[0199] The protective anion exchange membrane (176) is made of a material with higher oxidation resistance than the anion exchange membrane (50).

[0200] The present disclosure has been described above based on embodiments. Those skilled in the art should understand that the embodiments are merely illustrative, and the combination of the constituent elements or processing procedures can have various modifications, and such modifications are also within the scope of the present disclosure.

[0201] The space purification device 20 was described in Examples 4 and 5. However, it is not limited to this; for example, the electrolyzed water generating device in the space purification device 20 can also be used. The electrolyzed water generating device from Figure 6 The device, excluding the air supply unit 33, air duct 34, water recovery unit 36, and discharge port 37, includes a discharge pipe for discharging the solution containing hypochlorous acid gas generated by diaphragm-free electrolysis (hereinafter referred to as "electrolyzed water") from the electrolytic cell 30. That is, the electrolyzed water generating device discharges electrolyzed water without discharging the hypochlorous acid-containing mixed air M. The buffer layer 170 and diaphragm 172 are constructed in the same manner as in the embodiment. According to this modified example, since the buffer layer 170 and diaphragm 172 are used in the electrolyzed water generating device to protect the anion exchange membrane 50, the application scope of the embodiment can be expanded.

[0202] Explanation of reference numerals in the attached figures

[0203] 20 Space purification device, 30 Electrolytic cell, 31 Electrolytic cell side anode, 32 Electrolytic cell side cathode, 33 Air supply unit, 34 Air duct, 35 Electrolytic cell side internal space, 36 Water recovery unit, 37 Discharge port, 38 Water level detection unit, 40 Supply tank, 41 Supply tank side cathode, 42 Supply tank side internal space, 43 Discharge port, 50 Anion exchange membrane, 60 Current control unit, 61, 62, 63 Wiring, 70 Protective membrane, 72 Porous membrane, 74 Micropore, 76 Water-permeable membrane, 170 Buffer layer, 172 Diaphragm, 176 Protective anion exchange membrane, 178 Porous membrane, R External space.

Claims

1. An electrolytic water generating device, comprising: An electrolytic cell for storing the first aqueous solution containing chloride ions. A supply tank for storing a second aqueous solution containing chloride ions. The electrolytic cell and the supply cell are connected in such a way that an anion exchange membrane containing chloride ions can pass through. A protective membrane disposed on the electrolytic cell side of the anion exchange membrane; The electrolytic cell electrolyzes the first aqueous solution without a diaphragm to generate hypochlorous acid; The supply tank uses diaphragm electrolysis to allow the chloride ions contained in the second aqueous solution to pass through the anion exchange membrane and the protective membrane and be supplied to the first aqueous solution. The protective film comprises a porous membrane with mesh-like micropores.

2. The water electrolysis generating device as described in claim 1, The protective membrane is composed solely of the porous membrane.

3. The water electrolysis generating device as described in claim 1, The protective membrane is composed of a double-layer structure consisting of the porous membrane and a water-permeable membrane that allows water to pass through the first aqueous solution. The water-permeable membrane is disposed between the porous membrane and the anion exchange membrane.

4. The water electrolysis generating device as described in claim 1, The porous membrane is any one of microfiltration (MF) membrane, ultrafiltration (UF) membrane, or nanofiltration (NF) membrane.

5. The water electrolysis generating device as described in claim 1, The surface of the porous membrane is subjected to a hydrophilic treatment.

6. A space purification device, It is equipped with an electrolytic water generating apparatus as described in any one of claims 1 to 5; The space purification device purifies the air introduced from the indoor space by circulating it in the electrolytic cell and discharging it into the indoor space along with the hypochlorous acid. To replenish the chloride ions in the first aqueous solution that are reduced due to the diaphragmless electrolysis, the chloride ions in the second aqueous solution stored in the supply tank are supplied to the first aqueous solution stored in the electrolytic cell through the anion exchange membrane and the protective membrane.

7. The space purification device as described in claim 6, The air supplied to the electrolytic cell is released as bubbles in the first aqueous solution; The emitted bubbles are mixed with the hypochlorous acid, and the resulting mixed air is discharged into the indoor space.

8. An electrolytic water generating device, comprising: An electrolytic cell for storing the first aqueous solution containing chloride ions. A supply tank for storing a second aqueous solution containing chloride ions. A buffer layer is provided between the electrolytic cell and the supply cell to store the first aqueous solution. An anion exchange membrane containing chloride ions is disposed between the buffer layer and the supply tank, and is permeable to the membrane. A diaphragm is disposed between the electrolytic cell and the buffer layer; The electrolytic cell electrolyzes the first aqueous solution without a diaphragm to generate hypochlorous acid; The supply tank uses diaphragm electrolysis to allow the chloride ions contained in the second aqueous solution to pass through the anion exchange membrane, the buffer layer, and the diaphragm and be supplied to the first aqueous solution.

9. The water electrolysis generating apparatus as described in claim 8, The diaphragm is a porous membrane with mesh-like micropores, such that after the diaphragm-free electrolysis in the electrolytic cell stops, the concentration of hypochlorite ions passing through the diaphragm and the buffer layer to reach the anion exchange membrane from the electrolytic cell does not exceed a threshold.

10. The water electrolysis generating apparatus as described in claim 8, The membrane is any one of microfiltration (MF) membrane, ultrafiltration (UF) membrane, or nanofiltration (NF) membrane.

11. The water electrolysis generating apparatus as described in claim 8, The surface of the diaphragm was subjected to a hydrophilic treatment.

12. The water electrolysis generating apparatus as described in claim 8, The diaphragm includes a protective anion exchange membrane, which is different from the anion exchange membrane.

13. The water electrolysis generating apparatus as described in claim 12, The diaphragm also includes a porous membrane with mesh-like micropores; The porous membrane is disposed between the electrolytic cell and the protective anion exchange membrane.

14. The water electrolysis generating apparatus as described in claim 12, The protective anion exchange membrane is made of a material with higher oxidation resistance than the anion exchange membrane itself.

15. The water electrolysis generating apparatus as described in claim 13, The protective anion exchange membrane is made of a material with higher oxidation resistance than the anion exchange membrane itself.

16. A space purification device, It is equipped with an electrolytic water generating apparatus as described in any one of claims 8 to 15; The space purification device purifies the air introduced from the indoor space by circulating it in the electrolytic cell and discharging it into the indoor space along with the hypochlorous acid. To replenish the chloride ions contained in the first aqueous solution that are reduced due to the diaphragmless electrolysis, the chloride ions contained in the second aqueous solution stored in the supply tank are supplied to the first aqueous solution stored in the electrolytic cell through the anion exchange membrane, the buffer layer, and the diaphragm.

17. The space purification device as described in claim 16, The air supplied to the electrolytic cell is released as bubbles in the first aqueous solution; The emitted bubbles are mixed with the hypochlorous acid, and the resulting mixed air is discharged into the indoor space.

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