Space purification device

Abstract

A space purification device (1) is provided with: an electrolysis tank (10) for storing a first aqueous solution (L1); a supply tank (20) for storing a second aqueous solution (L2) and supplying chloride ions to the first aqueous solution (L1); an electrolysis tank-side anode (11) and an electrolysis tank-side cathode (12) which are provided in the electrolysis tank (10); a supply tank-side cathode (21) which is provided in the supply tank (20); an anion exchange membrane (30) which is disposed between the electrolysis tank (10) and the supply tank (20) and through which anions can permeate on the basis of a voltage applied between the electrolysis tank-side anode (11) and the supply tank-side cathode (21); and a current control unit (40) which controls the current so as to compensate for chloride ions contained in the first aqueous solution (L1) and reduced by electrolysis, thereby allowing chloride ions contained in the second aqueous solution (L2) to permeate through the anion exchange membrane (30) and supply the chloride ions to the first aqueous solution (L1).

Description

Space Purification Device

[0001] The present disclosure relates to a space purification device.

[0002] Patent Document 1 discloses an air purifying device that removes bacteria, fungi, viruses, odors, and the like from the air using hypochlorous acid generated by electrolyzing an aqueous solution containing chloride ions.

[0003] Japanese Patent Application Laid-Open No. 2019-174032

[0004] When a conventional space purification device is downsized, the tank that stores the aqueous solution used for electrolysis also becomes smaller. This downsizing of the tank reduces the amount of aqueous solution that can be stored compared to conventional space purification devices. Therefore, when electrolysis is repeatedly performed in a downsized space purification device, the chloride ion concentration in the aqueous solution tends to decrease, resulting in an unstable amount of hypochlorous acid generated.

[0005] The present disclosure has been made in consideration of the above problems, and provides a space purification device that can stably generate a desired amount of hypochlorous acid gas for a long period of time without supplying an aqueous solution containing chloride ions from the outside.

[0006] The spatial purification device according to the present disclosure includes an electrolytic cell for storing a first aqueous solution containing chloride ions, a supply cell for storing a second aqueous solution containing chloride ions at a higher concentration than the first aqueous solution and supplying chloride ions to the first aqueous solution, an electrolytic cell-side anode and an electrolytic cell-side cathode provided in the electrolytic cell, a supply cell-side cathode provided in the supply cell, an anion exchange membrane disposed between the electrolytic cell and the supply cell and capable of transmitting anions based on a voltage applied between the electrolytic cell-side anode and the supply cell-side cathode, and an anion exchange membrane disposed in the electrolytic cell and between the electrolytic cell-side anode and the electrolytic cell-side cathode. The electrolysis system comprises a membrane-less electrolysis unit that generates hypochlorous acid by conducting membrane-less electrolysis of a first aqueous solution by passing a first current therethrough; a membrane-with-diaphragm electrolysis unit that is provided across the electrolytic cell and the supply cell and that performs membrane-with-diaphragm electrolysis via an anion exchange membrane by passing a second current between the electrolytic cell-side anode and the supply cell-side cathode; and a current control unit that controls the second current so as to replenish chloride ions contained in the second aqueous solution that have been reduced by the membrane-less electrolysis, thereby causing chloride ions contained in the second aqueous solution to pass through the anion exchange membrane and be supplied to the first aqueous solution.

[0007] The present disclosure provides a space purification device that can stably generate a desired amount of hypochlorous acid gas for a long period of time without supplying an aqueous solution containing chloride ions from the outside.

[0008] FIG. 1 is a perspective view showing a space purification device according to embodiment 1. FIG. 2 is a partial front cross-sectional view showing a space purification device according to embodiment 1. FIG. 3 is a block diagram showing a current control unit according to embodiment 1. FIG. 4 is a front cross-sectional view showing a first modified example of an electrolytic cell and a supply cell provided in the space purification device according to embodiment 1. FIG. 5 is a front cross-sectional view showing a second modified example of an electrolytic cell and a supply cell provided in the space purification device according to embodiment 1. FIG. 6 is a schematic perspective view showing a space purification device according to embodiment 2. FIG. 7 is a schematic plan view showing a space purification device according to embodiment 2.

[0009] Specific embodiments of the present disclosure will be described in detail below with reference to the drawings.

[0010] The right-handed xyz coordinate system shown in the drawings is for the convenience of explaining the positional relationships of the components. Unless otherwise specified, the positive direction of the z axis is vertically upward. The xy plane is a horizontal plane, and is common to all drawings.

[0011] 1 is a perspective view showing an outline of a space purification device 1 according to embodiment 1. The space purification device 1 performs electrolysis on a first aqueous solution L1 containing chloride ions in an electrolytic cell 10 (described later) to generate and volatilize hypochlorous acid. The space purification device 1 removes bacteria, fungi, viruses, odors, and the like contained in the air in the external space of the space purification device 1 by causing the volatilized hypochlorous acid to flow into the external space of a housing B constituting the space purification device 1.

[0012] The space purification device 1 is installed indoors. The installation location of the space purification device 1 is preferably a location where air flow can occur. More specifically, the installation location of the space purification device 1 includes, for example, inside an air conditioner, around an electric fan, around a circulator, around a ceiling fan, inside a humidifier, inside an air purifier, on a desk, etc.

[0013] The spatial purification device 1 includes a housing B, an electrolytic cell 10 , a supply cell 20 , an anion exchange membrane 30 , and a current control unit 40 .

[0014] The housing B houses the electrolytic cell 10, the supply cell 20, the anion exchange membrane 30, and the current control unit 40. That is, the space purification device 1 may be an integrated unit formed by the housing B. The shape of the housing B can be changed appropriately depending on the location where the space purification device 1 is installed, and may be, for example, a rectangular parallelepiped or cylindrical shape. The space purification device 1 has a small size that can be stored inside an air conditioner, for example, approximately 10 cm x 7 cm x 4 cm.

[0015] The electrolytic bath 10 is a bath for storing a first aqueous solution L1 containing chloride ions. The electrolytic bath 10 has, for example, a box-like shape. Fig. 1 shows a state in which the first aqueous solution L1 is stored in the electrolytic bath 10. The first aqueous solution L1 is, for example, a dilute sodium chloride aqueous solution or a dilute potassium chloride aqueous solution having a predetermined chloride ion concentration.

[0016] The "predetermined chloride ion concentration" of the first aqueous solution L1 includes both a chloride ion concentration having a predetermined numerical range and a chloride ion concentration having a predetermined numerical value. More specifically, the chloride ion concentration of the first aqueous solution L1 may be, for example, 1 g / L to 50 g / L, or may be 10 g / L. In other words, the mass percent concentration of a dilute sodium chloride aqueous solution or a dilute potassium chloride aqueous solution may be, for example, 0.1% to 5%, or may be 1%. By setting the predetermined chloride ion concentration to this numerical range or numerical value, it is possible to generate hypochlorous acid necessary for space purification while simultaneously suppressing the generation of chlorine, which may be generated at the same time.

[0017] The supply tank 20 is a tank for storing the second aqueous solution L2 containing chloride ions. The chloride ions contained in the second aqueous solution L2 in the supply tank 20 permeate through the anion exchange membrane 30 and are supplied to the first aqueous solution L1 in the electrolytic tank 10.

[0018] The supply tank 20 is a tank for storing a second aqueous solution L2 containing chloride ions and supplying the chloride ions to the first aqueous solution L1. FIG. 1 shows the second aqueous solution L2 stored in the supply tank 20. The chloride ion concentration of the second aqueous solution L2 is higher than that of the first aqueous solution L1. The second aqueous solution L2 is, for example, a saturated sodium chloride aqueous solution, a high-concentration sodium chloride aqueous solution, a saturated potassium chloride aqueous solution, a high-concentration potassium chloride aqueous solution, or a high-concentration hydrochloric acid solution. More specifically, the second aqueous solution L2 is, for example, a 10% to 27% sodium chloride aqueous solution, a 10% to 29% potassium chloride aqueous solution, or a 10% to 25% hydrochloric acid solution. Note that the second aqueous solution L2 may be in a state where sodium chloride or potassium chloride precipitates and settles at the bottom of the supply tank 20.

[0019] Assuming continuous use for eight hours every day for one year, the respective volumes of the electrolytic cell 10 and the supply cell 20 are preferably set, for example, such that the volume of the supply cell 20 is at least about 12 times the volume of the electrolytic cell 10. By setting such a volume ratio, the supply cell 20 can store the second aqueous solution L2 containing a sufficient amount of chloride ions required to be supplied to the first aqueous solution L1 of the electrolytic cell 10. Therefore, the supply cell 20 can stably supply chloride ions from the second aqueous solution L2 stored in the supply cell 20 to the first aqueous solution L1 stored in the electrolytic cell 10. The amount of the first aqueous solution L1 stored in the electrolytic cell 10 is, for example, about 2 to 10 mL.

[0020] The anion exchange membrane 30 is a membranous member disposed between the electrolytic cell 10 and the supply cell 20, and is permeable to anions based on a voltage applied between the electrolytic cell 10 and the supply cell 20. More specifically, when a voltage is applied between an electrolytic cell-side anode plate (electrolytic cell-side anode 11 in the first embodiment) and a supply cell-side cathode plate (supply cell-side cathode 21 in the first embodiment), which will be described later, membrane-operated electrolysis is carried out via the anion exchange membrane 30. By the membrane-operated electrolysis using the electrolytic cell-side anode plate and the supply cell-side cathode plate, chloride ions contained in the second aqueous solution L2 permeate the anion exchange membrane 30 and are supplied to the first aqueous solution L1 (indicated by a thick black arrow pointing in the negative direction of the x-axis in FIG. 1 ).

[0021] The anion exchange membrane 30 in this embodiment is not a type of anion exchange membrane through which anions permeate due to osmotic pressure without using electricity. Furthermore, the anion exchange membrane 30 does not allow sodium ions, which are cations, to permeate. More specifically, when chloride ions contained in the second aqueous solution L2 permeate the anion exchange membrane 30 and are supplied to the first aqueous solution L1 by membrane electrolysis using an electrolytic cell-side anode plate and a supply cell-side cathode plate, sodium ions, which are cations, do not permeate the anion exchange membrane 30. The anion exchange membrane 30 is, for example, a hydrocarbon-based anion exchange membrane, and includes membranes that have monovalent anion-selective permeability, alkali resistance, and high-temperature resistance.

[0022] The anion exchange membrane 30 is disposed between the electrolytic cell 10 and the supply cell 20. For example, the surface of the electrolytic cell 10 facing the supply cell 20 (the yz plane on the positive side of the x-axis) and the surface of the supply cell 20 facing the electrolytic cell 10 (the yz plane on the negative side of the x-axis) may each be formed by a frame-shaped member. When the opposing surfaces of the electrolytic cell 10 and the supply cell 20 are each formed by a frame-shaped member, the anion exchange membrane 30 may be disposed so as to be fitted into the frame-shaped member.

[0023] The current control unit 40 controls the current used in the diaphragmless electrolysis and the diaphragm-containing electrolysis. More specifically, the current control unit 40 controls the current used in the diaphragmless electrolysis, which is performed using a pair of electrolytic cell-side anode 11 and electrolytic cell-side cathode 12 arranged in the electrolytic cell 10. The current control unit 40 also controls the current used in the diaphragm-containing electrolysis, which is performed via the anion-exchange membrane 30 using a pair of electrolytic cell-side anode 11 and supply cell-side cathode 21, across the electrolytic cell 10 and the supply cell 20. The electrolytic cell-side anode 11 is used for both the diaphragm-less electrolysis and the diaphragm-containing electrolysis. That is, the space purification device 1 according to this embodiment includes one anode and two cathodes, for a total of three electrodes. Because the supply cell 20 includes only a cathode, chlorine is not generated within the supply cell 20 by a chemical reaction, which will be described later.

[0024] The details of each component will be described in more detail below with reference to FIGS.

[0025] As shown in FIG. 1 , the electrolytic cell 10 includes an electrolytic cell-side anode 11 , an electrolytic cell-side cathode 12 , a wire 13 , a wire 14 , an inlet 15 , a mixing space 16 , and an outlet 17 .

[0026] The electrolytic cell-side anode 11 and the electrolytic cell-side cathode 12 are a pair of electrodes used in the electrolysis of the first aqueous solution L1. As shown in Fig. 1 , no diaphragm such as an ion exchange membrane is disposed between the electrolytic cell-side anode 11 and the electrolytic cell-side cathode 12. That is, the electrolysis of the first aqueous solution L1 performed using the pair of the electrolytic cell-side anode 11 and the electrolytic cell-side cathode 12 is diaphragm-less electrolysis. Hypochlorous acid, which is used for space purification, is produced by the diaphragm-less electrolysis of the first aqueous solution L1 performed using the pair of the electrolytic cell-side anode 11 and the electrolytic cell-side cathode 12.

[0027] The electrolytic cell-side anode 11 and the electrolytic cell-side cathode 12 each have a plate-like shape. That is, the electrolytic cell-side anode 11 is an electrolytic cell-side anode plate having a plate-like shape, and the electrolytic cell-side cathode 12 is an electrolytic cell-side cathode plate having a plate-like shape. Plate shapes include rectangular and oblong shapes. Hereinafter, the electrolytic cell-side anode 11 will also be referred to as an electrolytic cell-side anode plate. Furthermore, the electrolytic cell-side cathode 12 will also be referred to as an electrolytic cell-side cathode plate.

[0028] As an example, a case will be described in which the plate shapes of the electrolytic cell-side anode plate and the electrolytic cell-side cathode plate are rectangular. The electrolytic cell-side anode plate and the electrolytic cell-side cathode plate are arranged such that the shorter side of the rectangle is aligned with the vertical direction (z-axis direction). This arrangement can prevent bubbles generated by chemical reactions from adhering to both sides of the rectangle of each electrode. Furthermore, compared to when the longer side of the rectangle is aligned with the vertical direction (z-axis direction), when the shorter side is aligned with the vertical direction (z-axis direction), bubbles generated at the lower part of the electrolytic cell-side anode plate and the electrolytic cell-side cathode plate (negative side of the z-axis) can be prevented from adhering to the upper part of the electrolytic cell-side anode plate and the electrolytic cell-side cathode plate (positive side of the z-axis).

[0029] The electrolytic cell-side anode plate and the electrolytic cell-side cathode plate are arranged such that the longitudinal direction of the rectangle is along the horizontal direction (y-axis direction). In other words, the electrolytic cell-side anode plate and the electrolytic cell-side cathode plate are arranged such that the planes (yz planes) of their respective rectangles face each other with a predetermined distance between them. The predetermined distance is a distance appropriate for electrolysis performed using a pair of electrolytic cell-side anode plate and electrolytic cell-side cathode plate.

[0030] The electrolytic cell-side anode plate has an electrolytic cell-side anode plate immersed portion 11a and an electrolytic cell-side anode plate protruding portion 11b. Similarly, the electrolytic cell-side cathode plate has an electrolytic cell-side cathode plate immersed portion 12a and an electrolytic cell-side cathode plate protruding portion 12b.

[0031] The electrolytic cell-side anode plate and the electrolytic cell-side cathode plate are inserted from the outside of the electrolytic cell 10 toward the inside. In FIG. 1 , as an example, the electrolytic cell-side anode plate and the electrolytic cell-side cathode plate are inserted horizontally (in the y-axis direction) from the side of the electrolytic cell 10 (the xz plane side on the negative side of the y-axis). The electrolytic cell-side anode plate immersed portion 11a and the electrolytic cell-side cathode plate immersed portion 12a inserted into the electrolytic cell 10 are positioned inside the electrolytic cell 10 and are entirely immersed in the first aqueous solution L1. In other words, the first aqueous solution L1 is stored in the electrolytic cell 10 so that the electrolytic cell-side anode plate immersed portion 11a and the electrolytic cell-side cathode plate immersed portion 12a are entirely immersed. That is, the first aqueous solution L1 is stored in the electrolytic cell 10 so that the liquid level S1 of the first aqueous solution L1 exceeds the upper end (the end on the positive side of the z-axis) of the electrolytic cell side anode plate immersed portion 11a and the electrolytic cell side cathode plate immersed portion 12a.

[0032] The electrolytic cell-side anode plate protrusion 11b and the electrolytic cell-side cathode plate protrusion 12b are disposed on the exterior side of the electrolytic cell 10. The wiring 13 and the wiring 14 are electric wires through which current flows. The electrolytic cell-side anode plate protrusion 11b is electrically connected to a current control unit 40 via the wiring 13, and the electrolytic cell-side cathode plate protrusion 12b is electrically connected to a current control unit 40 via the wiring 13.

[0033] As the electrolytic cell side anode plate and the electrolytic cell side cathode plate, for example, a platinum iridium titanium electrode, a platinum electrode, a ruthenium titanium electrode, an iridium titanium oxide electrode, or the like may be used.

[0034] The inlet 15 is an opening through which air from the space outside the housing B flows in. That is, the inlet 15 is an opening through which air from the space outside the space purification device 1 flows in. In FIG. 1 , the inlet 15 is provided on the top surface of the electrolytic cell 10 (xy plane on the positive side of the z axis) as an example, but the inlet 15 may be located above the liquid level S1 of the first aqueous solution L1. The shape of the inlet 15 may be, for example, cylindrical as shown in FIG. 1 or rectangular tubular.

[0035] The mixing space 16 is a space formed above the electrolytic cell 10 (positive side of the z-axis) when the first aqueous solution L1 is stored in the electrolytic cell 10. The mixing space 16 is a space where hypochlorous acid generated by membrane-less electrolysis of the first aqueous solution L1 using a pair of electrolytic cell-side anode plates and electrolytic cell-side cathode plates is mixed with air from the external space that flows in through the inlet 15. The hypochlorous acid generated by membrane-less electrolysis includes volatilized and gasified hypochlorous acid gas and hypochlorous acid dissolved in the first aqueous solution L1. The hypochlorous acid gas is contained in the air that flows in through the inlet 15 and flows out to the external space through the outlet 17, which will be described later. The hypochlorous acid dissolved in the first aqueous solution L1 flows out to the external space through the outlet 17, which will be described later, by gas-liquid contact with the air that flows in through the inlet 15.

[0036] The outlet 17 is an opening through which mixed air, which is a mixture of air flowing in from the inlet 15 and hypochlorous acid generated by the membraneless electrolysis of the first aqueous solution L1, flows out to the external space of the housing B. That is, the outlet 17 is an opening through which the mixed air flows out to the external space of the space purification device 1. In FIG. 1 , the outlet 17 is provided on the upper surface of the electrolytic cell 10 (the xy plane on the positive side of the z-axis) as an example, similar to the inlet 15, but the outlet 17 may be located above the liquid level S1 of the first aqueous solution L1. The shape of the outlet 17 is similar to that of the inlet 15, and may be, for example, cylindrical as shown in FIG. 1 or rectangular tubular.

[0037] At least one of the inlet 15 and the outlet 17 may be provided with an openable or detachable lid (not shown). The lid may be configured to be closed when the space purification device 1 is transported or moved, and to be opened or detached when the space purification device 1 is used. Furthermore, although the inlet 15 and the outlet 17 are described as having separate structures, the inlet 15 and the outlet 17 may each serve as both an inlet and an outlet depending on the direction of wind flowing into the space purification device 1.

[0038] The air containing hypochlorous acid that flows out from the outlet 17 into the space outside the space purification device 1 purifies the space. That is, the air containing hypochlorous acid removes bacteria, fungi, viruses, odors, and the like contained in the air in the space outside the housing B.

[0039] The supply tank 20 includes a supply tank-side cathode 21, wiring 22, and an outlet 23. The supply tank-side cathode 21 is an electrode paired with the electrolytic cell-side anode 11 and used for electrolysis of the second aqueous solution L2. As shown in FIG. 1 , an anion exchange membrane 30 is disposed between the electrolytic cell-side anode 11 and the supply tank-side cathode 21. That is, the electrolysis of the second aqueous solution L2 performed using the pair of the electrolytic cell-side anode 11 and the supply tank-side cathode 21 is membrane-less electrolysis. That is, the electrolytic cell-side anode 11 is used for both membrane-less electrolysis and membrane-with electrolysis. Chloride ions are supplied from the second aqueous solution L2 to the first aqueous solution L1 by the membrane-with electrolysis of the second aqueous solution L2 performed using the pair of the electrolytic cell-side anode 11 and the supply tank-side cathode 21.

[0040] The supply tank side cathode 21 is a supply tank side cathode plate having a plate shape. The plate shape includes a rectangular shape and an oblong shape. Hereinafter, the supply tank side cathode 21 will also be referred to as a supply tank side cathode plate.

[0041] As an example, a case will be described in which the feed tank side cathode plate is also rectangular in shape, similar to the electrolytic tank side anode plate. As shown in Fig. 1, the feed tank side cathode plate is arranged with its shorter side aligned vertically (z-axis direction) and its longer side aligned horizontally (y-axis direction).

[0042] The electrolytic cell side anode plate and the supply cell side cathode plate are each in close proximity to the anion exchange membrane 30. In this specification, "close proximity" includes both a state in which the electrolytic cell side anode plate and the supply cell side cathode plate are close to the anion exchange membrane 30 with a predetermined gap therebetween, and a state in which the electrolytic cell side anode plate and the supply cell side cathode plate are in contact with the anion exchange membrane 30.

[0043] 2 , the rectangular plane (yz plane on the positive x-axis side) of the plate-shaped electrolytic cell-side anode plate on the anion exchange membrane 30 side is designated as plane P1. The rectangular plane (yz plane on the negative x-axis side) of the plate-shaped supply cell-side cathode plate on the anion exchange membrane 30 side is designated as plane P2. Planes P1 and P2 are arranged opposite each other with the anion exchange membrane 30 interposed therebetween. This arrangement allows a uniform electric field to be generated between the electrolytic cell-side anode plate and the supply cell-side cathode plate.

[0044] The electrolytic cell-side anode plate is disposed between the electrolytic cell-side cathode plate and the anion exchange membrane 30. This arrangement makes it possible to maintain small potential differences between the electrolytic cell-side anode plate and the electrolytic cell-side cathode plate, and between the electrolytic cell-side anode plate and the feed cell-side cathode plate.

[0045] The supply tank-side cathode plate includes a supply tank-side cathode plate immersed portion 21a and a supply tank-side cathode plate protruding portion 21b. The supply tank-side cathode plate is inserted from the outside toward the inside of the supply tank 20. In FIG. 1 , as an example, the supply tank-side cathode plate is inserted horizontally (in the y-axis direction) from the side of the supply tank 20 (the xz plane side on the negative side of the y-axis). The supply tank-side cathode plate immersed portion 21a inserted into the supply tank 20 is positioned inside the supply tank 20 and is entirely immersed in the second aqueous solution L2. In other words, the second aqueous solution L2 is stored in the supply tank 20 so that the entire supply tank-side cathode plate immersed portion 21a is immersed. That is, the second aqueous solution L2 is stored in the supply tank 20 so that the liquid level S2 of the second aqueous solution L2 exceeds the upper end (the end on the positive side of the z-axis) of the supply tank-side cathode plate immersed portion 21a.

[0046] 1, the supply tank-side cathode plate protrusion 21b is disposed on the exterior side of the supply tank 20. The wiring 22 is an electric wire through which current flows. The supply tank-side cathode plate protrusion 21b is electrically connected to the current control unit 40 via the wiring 22.

[0047] As the cathode plate on the supply tank side, for example, a platinum-iridium-titanium electrode, a platinum electrode, a ruthenium-titanium electrode, an iridium-titanium oxide electrode, or the like may be used.

[0048] The outlet 23 is an opening for discharging the hydrogen gas generated by the diaphragm electrolysis of the second aqueous solution L2 to the external space of the housing B. The outlet 23 may be, for example, a check valve. When a check valve is used as the outlet 23, the hydrogen gas inside the supply tank 20 is discharged to the external space, but the inflow of gases such as air from the external space can be suppressed. When the diaphragm electrolysis of the second aqueous solution L2 is repeated, the hydrogen gas accumulates inside the supply tank 20, and the internal pressure of the supply tank 20 increases. This pressure opens the check valve, and the hydrogen gas is discharged to the external space of the supply tank 20.

[0049] Figure 2 is a partial front cross-sectional view showing the space purification device 1 of Figure 1. The housing B shown in Figure 1 is omitted from Figure 2. As shown in Figure 2, the space purification device 1 may further include a water level detection unit 18 and a water supply unit 19. The water level detection unit 18 detects the position of the liquid level S1 in the first aqueous solution L1. The water level detection unit 18 is, for example, a water level sensor. The water level detection unit 18 is disposed above (on the positive z-axis side) the upper ends (ends on the positive z-axis side) of at least the electrolytic cell-side anode plate immersed portion 11a, the electrolytic cell-side cathode plate immersed portion 12a, and the supply cell-side cathode plate immersed portion 21a.

[0050] The water supply unit 19 supplies water to the electrolytic cell 10 based on the position of the liquid level S1 detected by the water level detection unit 18. More specifically, the water supply unit 19 supplies water to the electrolytic cell 10 so that the water level does not fall below the upper ends (ends on the positive side of the z-axis) of the electrolytic cell-side anode plate immersed portion 11a, the electrolytic cell-side cathode plate immersed portion 12a, and the supply cell-side cathode plate immersed portion 21a. The water supply unit 19 may be, for example, a Peltier element that can cool and condense moisture contained in the air into droplets, or a water tank that can store water. The water supply unit 19 may be located at any position that allows it to supply water to the electrolytic cell 10, and may be located on the top side, side side, or bottom side of the electrolytic cell 10.

[0051] When the space purification device 1 is equipped with the water level detection unit 18 and the water supply unit 19, the electrolytic cell-side anode plate immersed portion 11a and the electrolytic cell-side cathode plate immersed portion 12a can be maintained immersed in the first aqueous solution L1. This prevents the electrolytic cell-side anode plate immersed portion 11a and the electrolytic cell-side cathode plate immersed portion 12a from being exposed to air due to a decrease in the first aqueous solution L1, thereby maintaining the electrolysis efficiency of diaphragm-less electrolysis.

[0052] 2, the space purification device 1 according to this embodiment includes a diaphragm-less electrolysis unit E1 and a diaphragm-containing electrolysis unit E2. The current control unit 40 controls the first current flowing through the diaphragm-less electrolysis unit E1 and the second current flowing through the diaphragm-containing electrolysis unit E2, thereby controlling the chemical reactions occurring in the diaphragm-less electrolysis unit E1 and the diaphragm-containing electrolysis unit E2.

[0053] The diaphragm-less electrolysis unit E1 is provided in the electrolytic cell 10. The diaphragm-less electrolysis unit E1 produces hypochlorous acid by electrolyzing the first aqueous solution L1 without a diaphragm by passing a first current between the electrolytic cell-side anode 11 and the electrolytic cell-side cathode 12. In other words, the diaphragm-less electrolysis unit E1 includes the electrolytic cell-side anode 11 and the electrolytic cell-side cathode 12.

[0054] The membrane-equipped electrolysis unit E2 is provided across the electrolytic cell 10 and the supply cell 20. A second current is passed between the electrolytic cell-side anode 11 and the supply cell-side cathode 21, thereby performing membrane-equipped electrolysis via the anion exchange membrane 30. In other words, the membrane-equipped electrolysis unit E2 includes the electrolytic cell-side anode 11, the supply cell-side cathode 21, and the anion exchange membrane 30.

[0055] Here, we will explain in detail the chemical reaction that occurs in the diaphragm-less electrolysis section E1 provided in the electrolytic cell 10 and the chemical reaction that occurs in the diaphragm-containing electrolysis section E2 provided between the electrolytic cell 10 and the supply cell 20. Below, we will explain the case where the first aqueous solution L1 and the second aqueous solution L2 containing chloride ions are sodium chloride aqueous solutions.

[0056] [Membraneless Electrolysis Unit E1 (Electrolytic Cell 10)] Sodium chloride (NaCl) contained in the sodium chloride aqueous solution ionizes into Na+ and Cl- in the water. When a predetermined voltage is applied to the membraneless electrolysis unit E1, a current flows between the electrolytic cell-side anode 11 and the supply cell-side cathode 21, electrons move, and the following chemical reaction occurs: Reaction formula (a): Electrolytic cell-side anode 11 (chlorine generation)

[0057]

[0058] Reaction formula (b): Electrolytic cell side cathode 12 (hydrogen generation)

[0059]

[0060] Reaction formula (c): Electrolytic cell side anode 11 (oxygen generation)

[0061]

[0062] Reaction formula (d): in the first aqueous solution L1 (generation of hypochlorous acid)

[0063]

[0064] Reaction formula (e): Hypochlorous acid generation reaction at the electrolytic cell-side anode 11 (formula (a) + formula (d))

[0065]

[0066] Reaction formula (f): Anion exchange membrane 30 When a voltage is applied to the membraneless electrolysis section E1, causing a current to flow, and the first aqueous solution L1 stored in the electrolytic cell 10 loses one electron (e−), chloride ions Cl− are supplied from the second aqueous solution L2 stored in the supply tank 20 to the first aqueous solution L1 in the electrolytic cell 10 through the anion exchange membrane 30.

[0067]

[0068] Here, the proportion of current used in the hypochlorous acid generation reaction of reaction formula (e) is represented by "x", and the proportion of current used in the oxygen generation reaction of reaction formula (c) is represented by "1-x". Furthermore, the proportion of current used in reaction formula (b) of membraneless electrolysis is represented by "y", and the proportion of current used in reaction formula (f) of membrane-containing electrolysis is represented by "1-y". Applying the above x and y to reaction formula (b) + (c) + (e) + (f) gives the following reaction formula (g). Reaction formula (g): Reaction formula (b) + (c) + (e) + (f)

[0069]

[0070] When membrane-free electrolysis is performed in the membrane-free electrolysis section E1, the chloride ions in the electrolytic cell 10 are consumed and therefore reduced, but in the space purification device 1 according to this embodiment, chloride ions are supplied from the second aqueous solution L2 stored in the supply tank 20 to the first aqueous solution L1 stored in the electrolytic cell 10.

[0071] Here, the conditions under which the amount of chloride ions (Cl-) consumed by membraneless electrolysis is supplied from the second aqueous solution L2 stored in the supply tank 20 to the first aqueous solution L1 stored in the electrolytic cell 10, and Cl- does not appear to increase or decrease within the electrolytic cell 10, are as follows: In this reaction, hypochlorous acid (HClO) volatilizes as a gas, and is therefore not included in the following equation. Reaction formula (h): Conditions under which Cl- does not appear to increase or decrease

[0072]

[0073] After transformation, the following reaction formula (i) is obtained. Reaction formula (i): Transformation of reaction formula (h)

[0074]

[0075] Substituting y into the above reaction formula (g) gives the following reaction formula (j): Reaction formula (g) + (i)

[0076]

[0077] After transformation, the following reaction formula (k) is obtained. Reaction formula (k): A transformation of reaction formula (j).

[0078]

[0079] According to the above reaction formula (k), for example, when two electrons flow into the diaphragm-less electrolysis unit E1, one hypochlorous acid (HClO) is generated. For example, when four electrons flow into the diaphragm-less electrolysis unit E1, one oxygen is generated. For example, when two electrons flow into the diaphragm-less electrolysis unit E1, one hydrogen is generated.

[0080] Furthermore, because the acid dissociation constant of hypochlorous acid (HClO) is approximately 7.5, it is necessary to maintain the pH of the first aqueous solution L1 unchanged. In the above reaction formula (k), hydroxide ions and hydrogen ions, which are the cause of the change in pH, react to form water and disappear from the reaction formula. Therefore, chloride ions (Cl-) in the amount consumed by diaphragm-less electrolysis are supplied from the second aqueous solution L2 stored in the supply tank 20 to the first aqueous solution L1 stored in the electrolytic cell 10, and changes in pH can also be suppressed under conditions where Cl- does not appear to increase or decrease in the electrolytic cell 10.

[0081] As described above, when the number of electrons flowing in the diaphragm-less electrolysis section E1 changes, that is, when the ratio of the current flowing in the diaphragm-less electrolysis section E1 to the current flowing in the diaphragm-less electrolysis section E2 changes, a change occurs in the amount of chloride ions supplied from the supply cell 20 to the electrolytic cell 10. For example, when the ratio of the current used for diaphragm-less electrolysis is greater than the ratio of the current under the condition that chloride ions (Cl-) are supplied from the supply cell 20 and Cl- does not appear to increase or decrease in the electrolytic cell 10 (reaction formula (l) below), the amount of Cl- supplied from the supply cell 20 to the electrolytic cell 10 decreases, and Cl- in the electrolytic cell 10 decreases. Reaction formula (l)

[0082]

[0083] The electrolysis efficiency of membrane-free electrolysis decreases when Cl- in the electrolytic cell 10 decreases. If membrane-free electrolysis is continued in a state where the electrolysis efficiency has decreased, Cl- in the electrolytic cell 10 gradually increases, and reaches a level where Cl- in the electrolytic cell 10 does not appear to increase or decrease.

[0084] On the other hand, when the amount of current used for membraneless electrolysis is greater than the amount of current under the condition that chloride ions (Cl-) are supplied from the supply tank 20 and Cl- does not appear to increase or decrease in the electrolytic tank 10 (reaction formula (m) below), the amount of Cl- supplied from the supply tank 20 to the electrolytic tank 10 increases, and Cl- in the electrolytic tank 10 increases. Reaction formula (m)

[0085]

[0086] An increase in Cl- in the electrolytic cell 10 increases the electrolysis efficiency of membrane-less electrolysis. If membrane-less electrolysis is continued in a state where the electrolysis efficiency has increased, the Cl- in the electrolytic cell 10 gradually decreases, and reaches a level where the Cl- in the electrolytic cell 10 does not appear to increase or decrease.

[0087] Furthermore, when Cl- in the electrolytic cell 10 increases, the equilibrium of reaction formula (d) shifts to the left, and the amount of chlorine generated increases. In other words, if the current passed through the diaphragm-less electrolysis unit E1 and the current passed through the diaphragm-containing electrolysis unit E2 are adjusted so that the Cl- in the electrolytic cell 10 does not appear to increase or decrease, hypochlorous acid can be produced while suppressing the generation of chlorine.

[0088] [Diaper membrane electrolysis section E2] The reaction in the supply tank 20 will be described. The only electrode arranged in the supply tank 20 is the supply tank side cathode 21. When a predetermined voltage is applied to the diaphragm membrane electrolysis section E2, a current flows, electrons move, and the following chemical reaction occurs. Reaction formula (n): Electrolyzer side cathode 12 (hydrogen generation)

[0089]

[0090] Reaction formula (o): Anion exchange membrane 30 When a voltage is applied to the membrane-containing electrolysis unit E2 and a current flows, chloride ions (Cl-) contained in the second aqueous solution L2 stored in the supply tank 20 permeate the anion exchange membrane 30 and are supplied to the first aqueous solution L1, and the second aqueous solution L2 gains one electron (e-).

[0091]

[0092] The above is a detailed description of the chemical reaction occurring in the membraneless electrolysis section E1 provided in the electrolytic cell 10 and the chemical reaction occurring in the membrane-containing electrolysis section E2 provided across the electrolytic cell 10 and the supply cell 20.

[0093] The current control unit 40 controls the chemical reaction. More specifically, the second current is controlled to replenish the chloride ions contained in the first aqueous solution L1 that have been reduced by the diaphragm-less electrolysis in the diaphragm-less electrolysis unit E1. By controlling the second current, the current control unit 40 causes the chloride ions contained in the second aqueous solution L2 to permeate through the anion exchange membrane 30 and be supplied to the first aqueous solution L1. Details will be described below with reference to FIG. 3.

[0094] 3 is a block diagram showing the current control unit 40 according to embodiment 1. As shown in FIG. 3, the current control unit 40 includes a voltage acquisition unit 41, a calculation unit 42, and an estimation unit 43.

[0095] The voltage acquisition unit 41 acquires the voltage between the electrolytic cell-side anode 11 and the electrolytic cell-side cathode 12. The voltage acquisition unit 41 is, for example, a voltmeter. The calculation unit 42 calculates the conductivity of the first aqueous solution L1 based on the voltage acquired by the voltage acquisition unit 41. The estimation unit 43 estimates the chloride ion concentration of the first aqueous solution L1 based on the conductivity of the first aqueous solution L1 calculated by the calculation unit 42.

[0096] The current control unit 40 controls the first current passed through the membraneless electrolysis unit E1 and the second current passed through the membrane-containing electrolysis unit E2 shown in Fig. 2 so as to maintain the chloride ion concentration in the first aqueous solution L1 at a predetermined concentration. Three examples of current control by the current control unit 40 will be described below.

[0097] [1. When the First Current and the Second Current are Simultaneously Passed] When the current control unit 40 simultaneously passes the first current and the second current, it performs the following controls (1) to (3). (1) When the chloride ion concentration of the first aqueous solution L1 estimated by the estimation unit 43 is lower than a predetermined concentration: The current ratio between the first current and the second current is changed so as to increase the amount of chloride ions that permeate from the second aqueous solution L2 through the anion exchange membrane 30 and are supplied to the first aqueous solution L1. More specifically, the current ratio of the first current is decreased and the current ratio of the second current is increased. (2) When the chloride ion concentration of the first aqueous solution L1 estimated by the estimation unit 43 is higher than a predetermined concentration: The current ratio between the first current and the second current is changed so as to decrease the amount of chloride ions that permeate from the second aqueous solution L2 through the anion exchange membrane 30 and are supplied to the first aqueous solution L1. More specifically, the current ratio of the first current is increased and the current ratio of the second current is decreased. (3) When the chloride ion concentration of the first aqueous solution L1 estimated by the estimation unit 43 is a predetermined concentration: the current ratio between the first current and the second current is not changed.

[0098] [2. Case where the first current flows at a predetermined value and the second current is controlled simultaneously] When the current control unit 40 flows the first current at a predetermined value and controls the second current simultaneously, the following controls (1) to (3) are performed. (1) When the chloride ion concentration of the first aqueous solution L1 estimated by the estimation unit 43 is lower than a predetermined concentration: the second current is flowed so as to increase the amount of chloride ions that permeate the anion exchange membrane 30 from the second aqueous solution L2 and are supplied to the first aqueous solution L1. (2) When the chloride ion concentration of the first aqueous solution L1 estimated by the estimation unit 43 is higher than a predetermined concentration: the second current is stopped so as to stop the supply of chloride ions from the second aqueous solution L2 to the first aqueous solution L1. (3) When the chloride ion concentration of the first aqueous solution L1 estimated by the estimation unit 43 is a predetermined concentration: the first current and the second current are not changed.

[0099] [3. When the First Current or the Second Current is Passed] When the current control unit 40 passes the first current or the second current, it performs the following controls (1) to (3). (1) When the chloride ion concentration of the first aqueous solution L1 estimated by the estimation unit 43 is lower than a predetermined concentration: The first current is stopped and the second current is passed simultaneously so as to increase the amount of chloride ions that permeate the anion exchange membrane 30 from the second aqueous solution L2 and are supplied to the first aqueous solution L1. (2) When the chloride ion concentration of the first aqueous solution L1 estimated by the estimation unit 43 is higher than a predetermined concentration: The second current is stopped and the first current is passed simultaneously so as to stop the supply of chloride ions from the second aqueous solution L2 to the first aqueous solution L1. (3) When the chloride ion concentration of the first aqueous solution L1 estimated by the estimation unit 43 is a predetermined concentration: The first current and the second current are not changed.

[0100] As described above, the current control unit 40 controls the first current and the second current, so that the required amount of chloride ions can be supplied to the first aqueous solution L1 in the electrolytic cell 10, and the chloride ion concentration in the first aqueous solution L1 can be maintained at a predetermined concentration.

[0101] In the above-mentioned "1. When the first current and the second current are passed simultaneously," the current ratio between the first current and the second current is changed when there is an increase or decrease in the chloride ion concentration of the first aqueous solution L1. Because the first current and the second current are passed simultaneously, the increase or decrease in the chloride ion concentration of the first aqueous solution L1 can be minimized, and the chloride ion concentration can be maintained at an optimal predetermined concentration.

[0102] In the case of "2. Flowing the first current at a predetermined value while simultaneously controlling the second current," the second current is mainly started or stopped when the chloride ion concentration of the first aqueous solution L1 increases or decreases, thereby maintaining the chloride ion concentration of the first aqueous solution L1 at a predetermined concentration.

[0103] In "3. When the first current or the second current is passed," when the chloride ion concentration of the first aqueous solution L1 increases or decreases, one of the first current and the second current is passed and the other is stopped, thereby maintaining the chloride ion concentration of the first aqueous solution L1 at a predetermined concentration.

[0104] In the above cases 2 and 3, it is only necessary to control either the first current or the second current, so that current control is easy.

[0105] As described above, the chloride ions consumed in the first aqueous solution L1 can be appropriately supplied from the second aqueous solution L2, thereby providing the space purification device 1 capable of stably generating a desired amount of hypochlorous acid gas. Therefore, the space purification device 1 can be provided that can stably generate a desired amount of hypochlorous acid gas for a long period of time, such as one year, without supplying an aqueous solution containing chloride ions from the outside.

[0106] It is also possible to provide a plurality of current control units 40 and control the first current and the second current separately.

[0107] In addition, in FIG. 1 , the inlet 15 and the outlet 17 are arranged on the far right side (positive side of the y-axis and positive side of the x-axis) and the near left side (negative side of the y-axis and negative side of the x-axis) when the electrolytic cell 10 is viewed in plan, but the arrangement is not limited to this. For example, the positions of the inlet 15 and the outlet 17 may be reversed, the inlet 15 and the outlet 17 may be at the same position on the x-axis, or the inlet 15 and the outlet 17 may be at the same position on the y-axis. However, when the inlet 15 and the outlet 17 are arranged, it is preferable to arrange them so that they are at the farthest positions on the xy plane. By arranging them in this way, the time for the inflowing air and hypochlorous acid to mix in the mixing space 16 is longer, and therefore, more hypochlorous acid can be contained in the mixed air.

[0108] Next, a case will be described in which the rectangular plane P1 (yz plane on the positive side of the x-axis) of the plate-shaped electrolytic cell-side anode plate on the anion exchange membrane 30 side and the rectangular plane P2 (yz plane on the negative side of the x-axis) of the plate-shaped supply cell-side cathode plate on the anion exchange membrane 30 side do not face each other. When the planes of each rectangle are arranged parallel to the xy plane, a non-uniform electric field may be generated between the electrolytic cell-side anode plate and the supply cell-side cathode plate. When a non-uniform electric field is generated between the electrolytic cell-side anode plate and the supply cell-side cathode plate, the current distribution between the electrolytic cell-side anode plate and the supply cell-side cathode plate also becomes non-uniform.

[0109] When the current distribution between the electrolytic cell-side anode plate and the supply cell-side cathode plate becomes uneven, regions of high and low current density are generated. The high current density regions are more likely to deteriorate the catalytic layer on the surfaces of the electrolytic cell-side anode plate and the supply cell-side cathode plate (hereinafter also referred to as each electrode plate), while the low current density regions are less likely to deteriorate the catalytic layer on the surfaces of each electrode plate. That is, when an uneven electric field occurs between the electrolytic cell-side anode plate and the supply cell-side cathode plate, the current distribution becomes uneven, and regions of different current densities may exist simultaneously on the same electrode plate. Therefore, uneven deterioration of the catalytic layer may occur due to the use of each electrode plate. If the degree of deterioration of the catalytic layer on the surface of each electrode plate differs, repeated electrolysis may result in the simultaneous existence of regions on each electrode plate that can be used as an electrode and regions that have deteriorated to the point where they become unusable. When electrolysis is performed using electrode plates that include regions that cannot be used as electrodes, the electrolysis efficiency may be reduced.

[0110] In contrast, in the spatial purification device 1 according to this embodiment, the planes P1 and P2 are arranged opposite each other with the anion exchange membrane 30 interposed therebetween. This arrangement allows a uniform electric field to be generated between the electrolytic cell-side anode plate and the supply cell-side cathode plate, resulting in a uniform distribution of current between the two electrodes. Therefore, deterioration of the catalyst layer on the surface of each electrode plate occurs uniformly, and uneven deterioration of the catalyst layer on the surface of each electrode plate due to an uneven electric field can be suppressed even when electrolysis is performed repeatedly. Therefore, a decrease in electrolysis efficiency can be suppressed.

[0111] <Modification 1> Hereinafter, Modification 1 of the electrolytic cell 10 and supply cell 20 according to Embodiment 1 will be described with reference to Fig. 4. Fig. 4 is a front cross-sectional view showing Modification 1 of the electrolytic cell 10 and supply cell 20 included in the space purification device 1 according to Embodiment 1. The same components as those in the electrolytic cell 10 and supply cell 20 are denoted by the same reference numerals, and descriptions thereof will be omitted.

[0112] First, an electrolytic cell 50, which is a first modification of the electrolytic cell 10, will be described. As shown in Fig. 4, the electrolytic cell 50 has a generally L-shaped configuration when viewed from the front. The electrolytic cell 50 has two ceiling surfaces with different heights (positions in the z-axis direction), namely, a first ceiling surface 51 and a second ceiling surface 52. The first ceiling surface 51 is a ceiling surface that is lower in height (positions in the z-axis direction) than the second ceiling surface 52. The electrolytic cell-side anode plate and the electrolytic cell-side cathode plate are inserted from above the first ceiling surface 51 (positive side of the z-axis) toward the interior of the electrolytic cell 50 (negative direction of the z-axis).

[0113] The electrolytic cell-side anode plate immersed portion 11a and the electrolytic cell-side cathode plate immersed portion 12a inserted into the electrolytic cell 50 are positioned inside the electrolytic cell 50 and are entirely immersed in the first aqueous solution L1. In other words, the first aqueous solution L1 is stored in the electrolytic cell 50 so that the electrolytic cell-side anode plate immersed portion 11a and the electrolytic cell-side cathode plate immersed portion 12a are entirely immersed. That is, the first aqueous solution L1 is stored in the electrolytic cell 50 so that the liquid level S1 of the first aqueous solution L1 exceeds the upper ends (ends on the positive side of the z-axis) of the electrolytic cell-side anode plate immersed portion 11a and the electrolytic cell-side cathode plate immersed portion 12a.

[0114] The electrolytic cell-side anode plate protrusion 11b and the electrolytic cell-side cathode plate protrusion 12b are disposed on the exterior side of the electrolytic cell 50. The electrolytic cell-side anode plate protrusion 11b is electrically connected to the current control unit 40 via wiring 13, and the electrolytic cell-side cathode plate protrusion 12b is electrically connected to the current control unit 40 via wiring 14.

[0115] 4 will be described. As in the electrolytic cell 10, the water level detection unit 18 is located above (on the positive z-axis side) the upper ends (the ends on the positive z-axis side) of at least the electrolytic cell-side anode plate immersed portion 11a and the electrolytic cell-side cathode plate immersed portion 12a. The water supply unit 19 may be located on the second ceiling surface 52, for example, but may be located in any position that allows water to be supplied to the electrolytic cell 50.

[0116] Next, a supply tank 60, which is a first modified example of the supply tank 20, will be described. As shown in FIG. 4 , the supply tank 60 has a shape that is a left-right inversion of the electrolytic tank 50 when viewed from the front. The supply tank 60 has two ceiling surfaces with different heights (positions in the z-axis direction), namely, a first ceiling surface 61 and a second ceiling surface 62. The first ceiling surface 61 is a ceiling surface that is lower in height (positions in the z-axis direction) than the second ceiling surface 62. The supply tank-side cathode plate is inserted from above the first ceiling surface 61 (positive direction of the z-axis) toward the interior of the supply tank 60 (negative direction of the z-axis).

[0117] The supply tank-side cathode plate immersed portion 21a inserted into the supply tank 60 is positioned inside the supply tank 60 and is entirely immersed in the second aqueous solution L2. In other words, the second aqueous solution L2 is stored in the supply tank 60 so that the supply tank-side cathode plate immersed portion 21a is entirely immersed. That is, the second aqueous solution L2 is stored in the supply tank 60 so that the liquid level S2 of the second aqueous solution L2 exceeds the upper end (the end on the positive side of the z-axis) of the supply tank-side cathode plate immersed portion 21a.

[0118] The supply tank side cathode plate protrusion 21b is disposed on the external side of the supply tank 60. The supply tank side cathode plate protrusion 21b is electrically connected to the current control unit 40 via a wiring 22.

[0119] <Modification 2> Next, Modification 2 of the electrolytic cell 10 and supply cell 20 according to Embodiment 1 will be described with reference to Fig. 5. Fig. 5 is a front cross-sectional view showing Modification 2 of the electrolytic cell 10 and supply cell 20 included in the space purification device 1 according to Embodiment 1. The same components as those in the electrolytic cell 10 and supply cell 20 are given the same reference numerals, and their description will be omitted. As shown in Fig. 5, the electrolytic cell 70 and supply cell 80 have a shape obtained by turning the electrolytic cell 50 and supply cell 60 of Modification 1 upside down.

[0120] First, electrolytic cell 70, which is a second modification of electrolytic cell 10, will be described. As shown in Fig. 5, electrolytic cell 70 has a shape that is a substantially L-shape in a front view, which is inverted upside down. Electrolytic cell 70 has two bottom surfaces with different heights (positions in the z-axis direction): a first bottom surface 71 and a second bottom surface 72. The first bottom surface 71 is the bottom surface of electrolytic cell 70 that is located above (in the positive z-axis direction) the second bottom surface 72. The electrolytic cell-side anode plate and the electrolytic cell-side cathode plate are inserted from the lower side (negative z-axis side) of first bottom surface 71 toward the interior of electrolytic cell 70 (positive z-axis direction).

[0121] The electrolytic cell-side anode plate immersed portion 11a and the electrolytic cell-side cathode plate immersed portion 12a inserted into the electrolytic cell 70 are positioned inside the electrolytic cell 70 and are entirely immersed in the first aqueous solution L1. In other words, the first aqueous solution L1 is stored in the electrolytic cell 70 so that the electrolytic cell-side anode plate immersed portion 11a and the electrolytic cell-side cathode plate immersed portion 12a are entirely immersed. That is, the first aqueous solution L1 is stored in the electrolytic cell 70 so that the liquid level S1 of the first aqueous solution L1 exceeds the upper ends (ends on the positive side of the z-axis) of the electrolytic cell-side anode plate immersed portion 11a and the electrolytic cell-side cathode plate immersed portion 12a.

[0122] The electrolytic cell-side anode plate protrusion 11b and the electrolytic cell-side cathode plate protrusion 12b are disposed on the exterior side of the electrolytic cell 70. The electrolytic cell-side anode plate protrusion 11b is electrically connected to the current control unit 40 via wiring 13, and the electrolytic cell-side cathode plate protrusion 12b is electrically connected to the current control unit 40 via wiring 14.

[0123] Next, a case will be described in which the electrolytic cell 70 is equipped with a water level detection unit 18 and a water supply unit 19. As with the electrolytic cell 10, the water level detection unit 18 is located above (on the positive z-axis side) the upper ends (ends on the positive z-axis side) of at least the electrolytic cell-side anode plate immersed portion 11a and the electrolytic cell-side cathode plate immersed portion 12a. The water supply unit 19 need only be located in a position that allows it to supply water to the electrolytic cell 10, and may be located on the top side of the electrolytic cell 70, or on a side or bottom side of the electrolytic cell 70.

[0124] Next, supply tank 80, which is a second modification of supply tank 20, will be described. Supply tank 80 has a shape that is a left-right inversion of electrolytic tank 70 when viewed from the front. Supply tank 80 has two bottom surfaces with different heights (positions in the z-axis direction), namely, a first bottom surface 81 and a second bottom surface 82. First bottom surface 81 is the bottom surface of supply tank 80 that is provided above second bottom surface 82 (positive direction of the z-axis). The supply tank-side cathode plate is inserted from the lower side (negative side of the z-axis) of first bottom surface 81 toward the interior of supply tank 80 (positive direction of the z-axis).

[0125] The supply tank-side cathode plate immersed portion 21a inserted into the supply tank 80 is positioned inside the supply tank 80 and is entirely immersed in the second aqueous solution L2. In other words, the second aqueous solution L2 is stored in the supply tank 80 so that the supply tank-side cathode plate immersed portion 21a is entirely immersed. That is, the second aqueous solution L2 is stored in the supply tank 80 so that the liquid level S2 of the second aqueous solution L2 exceeds the upper end (the end on the positive side of the z-axis) of the supply tank-side cathode plate immersed portion 21a.

[0126] The supply tank side cathode plate protrusion 21b is disposed on the external side of the supply tank 80. The supply tank side cathode plate protrusion 21b is electrically connected to the current control unit 40 via a wiring 22.

[0127] <Embodiment 2> Next, a space purification device 2 according to embodiment 2 will be described with reference to Figures 6 and 7. Note that the same components as those in embodiment 1 are given the same reference numerals and their description will be omitted. Furthermore, although the shape of each component differs from that of embodiment 1, the function of each component is the same as that of embodiment 1, and therefore the description of the function of each component will be omitted.

[0128] Fig. 6 is a schematic front view showing the space purification device 2 according to embodiment 2. Fig. 7 is a plan view showing the space purification device 2 according to embodiment 2. The hatching shown in Fig. 7 is shown to clarify each component, and Fig. 7 is not a cross-sectional view.

[0129] As shown in FIG. 6 , the space purification device 2 according to this embodiment includes an electrolytic cell 110, a supply cell 120, an anion exchange membrane 130, and a current control unit 40. The electrolytic cell 110 and the supply cell 120 each have a cylindrical shape with an open top (x-y plane on the positive side of the z-axis) and a bottom (x-y plane on the negative side of the z-axis). The anion exchange membrane 130 also has a cylindrical shape. The anion exchange membrane 130 is disposed between the electrolytic cell 110 and the supply cell 120. As shown in FIG. 6 , the electrolytic cell 110 is the inner diameter side of the anion exchange membrane 130. The cylindrical shapes of the electrolytic cell 110, the supply cell 120, and the anion exchange membrane 130 include a cylindrical shape and a rectangular cylindrical shape. Although not shown in FIGS. 6 and 7 , the electrolytic cell 110 stores a first aqueous solution L1, and the supply cell 120 stores a second aqueous solution L2.

[0130] As shown in FIG. 6 , the electrolytic cell 110 includes an electrolytic cell-side anode 111 and an electrolytic cell-side cathode 112. The electrolytic cell-side anode 111 is an electrolytic cell-side anode tube having a cylindrical shape. The electrolytic cell-side cathode 112 is an electrolytic cell-side cathode tube or an electrolytic cell-side cathode bar having a cylindrical or rod-like shape. The supply cell 120 includes a supply cell-side cathode 121. The supply cell-side cathode 121 is a supply cell-side cathode tube having a cylindrical shape. The cylindrical shapes of the electrolytic cell-side anode 111, electrolytic cell-side cathode 112, and supply cell-side cathode 121 include cylindrical and rectangular tube shapes. The rod shapes include cylindrical and spiral shapes. The electrolytic cell-side anode 111, electrolytic cell-side cathode 112, and supply cell-side cathode 121 are each electrically connected to the current control unit 40 via wiring (not shown).

[0131] 6 and 7 , the spatial purification device 2 according to this embodiment has, for example, a cylindrical structure in which each component is nested. More specifically, from the outside, the components are arranged in the following order: supply tank 120, supply tank-side cathode 121, anion exchange membrane 130, electrolytic cell 110, electrolytic cell-side anode 111, and electrolytic cell-side cathode 112. That is, the diameters of the components are as follows: supply tank 120 > supply tank-side cathode 121 > anion exchange membrane 130 = electrolytic cell 110 > electrolytic cell-side anode 111 > electrolytic cell-side cathode 112, and the components are arranged with a predetermined distance between them.

[0132] The entire electrolytic cell-side anode tube and the entire electrolytic cell-side cathode tube or the entire electrolytic cell-side cathode rod are immersed in the first aqueous solution L1. The entire supply cell-side cathode tube is immersed in the second aqueous solution L2. As shown in FIG. 6 , the space purification device 2 according to this embodiment may further include a water level detector 18 and a water supply unit 19. The water level detector 18 is disposed above (on the positive z-axis side) the upper ends (ends on the positive z-axis side) of the electrolytic cell-side anode 111, electrolytic cell-side cathode 112, and supply cell-side cathode 121. The water supply unit 19 may be disposed in any position that allows it to supply water to the electrolytic cell 110, and may be disposed above (on the positive z-axis side) the electrolytic cell 110, for example.

[0133] The electrolytic cell side anode 111, the electrolytic cell side cathode 112 and the supply cell side cathode 121 may be made of a plate-like member, a mesh-like member or an expanded metal.

[0134] The space purification device 2 according to this embodiment includes a current control unit 40 similar to that of Embodiment 1. The current control unit 40 controls the first current and the second current, thereby supplying a required amount of chloride ions to the first aqueous solution L1 in the electrolytic bath 110 and maintaining the chloride ion concentration in the first aqueous solution L1 at a predetermined concentration. Therefore, a space purification device 2 capable of stably generating a desired amount of hypochlorous acid gas for space purification can be provided.

[0135] Furthermore, the space purification device 2 according to this embodiment can accommodate the electrolytic cell 110 and the anion exchange membrane 130 inside the supply tank 120. Therefore, it is possible to provide a space purification device 2 that is more compact and takes up less space.

[0136] The present disclosure is not limited to the above-described embodiments and modifications, and can be modified as appropriate within the scope of the present disclosure.

[0137] An outline of one aspect of the present disclosure is as follows.

[0138] (Item 1) An electrolytic cell (10) for storing a first aqueous solution (L1) containing chloride ions; a supply tank (20) for storing a second aqueous solution (L2) containing chloride ions at a higher concentration than the first aqueous solution (L1) and for supplying chloride ions to the first aqueous solution (L1); an electrolytic cell-side anode (11) and an electrolytic cell-side cathode (12) provided in the electrolytic cell (10); a supply tank-side cathode (21) provided in the supply tank (20); and an anion exchange membrane (30) disposed between the electrolytic cell (10) and the supply tank (20), which is permeable to anions based on a voltage applied between the electrolytic cell-side anode (11) and the supply tank-side cathode (21). The space purification device (1) comprises: a diaphragm-less electrolysis unit (E1) provided in the electrolytic cell (10) for generating hypochlorous acid by performing diaphragm-less electrolysis of the first aqueous solution (L1) by passing a first current between the electrolytic cell-side anode (11) and the electrolytic cell-side cathode (12); a diaphragm-containing electrolysis unit (E2) provided between the electrolytic cell (10) and the supply cell (20) for performing diaphragm-containing electrolysis via the anion exchange membrane (30) by passing a second current between the electrolytic cell-side anode (11) and the supply cell-side cathode (21); and a current control unit (40) for controlling the second current so as to replenish chloride ions contained in the first aqueous solution (L1) that have been reduced by the diaphragm-less electrolysis, thereby causing chloride ions contained in the second aqueous solution (L2) to permeate through the anion exchange membrane (30) and supply them to the first aqueous solution (L1).

[0139] (Item 2) The space purification device (1) according to Item 1, wherein the current control unit (40) maintains the chloride ion concentration of the first aqueous solution (L1) at a predetermined concentration by flowing the first current and the second current at a predetermined ratio.

[0140] (Item 3) The current control unit (40) comprises: a voltage acquisition unit (41) that acquires a voltage between the electrolytic cell-side anode (11) and the electrolytic cell-side cathode (12); a calculation unit (42) that calculates the conductivity of the first aqueous solution (L1) based on the voltage acquired by the voltage acquisition unit (41); and an estimation unit (43) that estimates the concentration of the first aqueous solution (L1) based on the conductivity calculated by the calculation unit (42); wherein the current control unit (40) simultaneously applies the first current and the second current, and when the chloride ion concentration of the first aqueous solution (L1) is lower than a predetermined concentration, changes the current ratio between the first current and the second current so as to increase the amount of chloride ions that permeate the second aqueous solution (L2) through the anion exchange membrane (30) and are supplied to the first aqueous solution (L1); Item 3. The space purification device (1) according to item 1 or 2, wherein, when the chloride ion concentration of the first aqueous solution (L1) is higher than the predetermined concentration, the current ratio between the first current and the second current is changed so as to reduce the amount of chloride ions that permeate the anion exchange membrane (30) from the second aqueous solution (L2) and are supplied to the first aqueous solution (L1).

[0141] (Item 4) The space purification device (1) according to Item 3, wherein the current ratio between the first current and the second current is not changed when the chloride ion concentration of the first aqueous solution (L1) is the predetermined concentration.

[0142] (Item 5) The current control unit (40) comprises: a voltage acquisition unit (41) that acquires a voltage between the electrolytic cell-side anode (11) and the electrolytic cell-side cathode (12); a calculation unit (42) that calculates the conductivity of the first aqueous solution (L1) based on the voltage acquired by the voltage acquisition unit (41); and an estimation unit (43) that estimates the concentration of the first aqueous solution (L1) based on the conductivity calculated by the calculation unit (42), wherein the current control unit (40) controls the second current while causing the first current to flow at a predetermined value, and in controlling the second current, when the chloride ion concentration of the first aqueous solution (L1) is lower than a predetermined concentration, causes the second current to flow so as to increase the amount of chloride ions that permeate the anion exchange membrane (30) from the second aqueous solution (L2) and are supplied to the first aqueous solution (L1), 3. The space purification device (1) according to item 1 or 2, wherein, when the chloride ion concentration in the first aqueous solution (L1) is higher than the predetermined concentration, the second current is stopped so that the supply of chloride ions from the second aqueous solution (L2) to the first aqueous solution (L1) is stopped.

[0143] (Item 6) The current control unit (40) comprises: a voltage acquisition unit (41) that acquires a voltage between the electrolytic cell-side anode (11) and the electrolytic cell-side cathode (12); a calculation unit (42) that calculates the conductivity of the first aqueous solution (L1) based on the voltage acquired by the voltage acquisition unit (41); and an estimation unit (43) that estimates the concentration of the first aqueous solution (L1) based on the conductivity calculated by the calculation unit (42), wherein the current control unit (40) stops the first current and simultaneously applies the second current so as to increase the amount of chloride ions that permeate from the second aqueous solution (L2) through the anion exchange membrane (30) and are supplied to the first aqueous solution (L1) when the chloride ion concentration of the first aqueous solution (L1) is lower than a predetermined concentration; 3. The space purification device (1) according to item 1 or 2, wherein the second current is stopped and the first current is simultaneously applied so as to stop the supply of chloride ions from the second aqueous solution (L2) to the first aqueous solution (L1).

[0144] (Item 7) The electrolytic cell-side anode (11), the electrolytic cell-side cathode (12), and the supply cell-side cathode (21) are electrolytic cell-side anode plates, electrolytic cell-side cathode plates, and supply cell-side cathode plates, each having a plate-like shape, the electrolytic cell-side anode plates and the electrolytic cell-side cathode plates being inserted into the electrolytic cell (10) from the outside, and the supply cell-side cathode plate being inserted into the supply cell (20) from the outside, the electrolytic cell-side anode plates comprising an electrolytic cell-side anode plate immersion portion (11a) arranged inside the electrolytic cell (10) and an electrolytic cell-side anode plate protrusion portion (11b) arranged outside the electrolytic cell (10), Item 7. The space purification device (1) according to any one of items 1 to 6, wherein the electrolytic cell-side cathode plate comprises an electrolytic cell-side cathode plate immersed portion (12a) arranged inside the electrolytic cell (10) and an electrolytic cell-side cathode plate protruding portion (12b) arranged outside the electrolytic cell (10); the supply cell-side cathode plate comprises a supply cell-side cathode plate immersed portion (21a) arranged inside the supply cell (20) and a supply cell-side cathode plate protruding portion (21b) arranged outside the supply cell (20); the electrolytic cell-side anode plate immersed portion (11a) and the electrolytic cell-side cathode plate immersed portion (12a) are entirely immersed in the first aqueous solution (L1), and the supply cell-side cathode plate immersed portion (21a) is entirely immersed in the second aqueous solution (L2).

[0145] (Item 8) The space purification device (1) according to claim 7, wherein the electrolytic cell-side anode plate and the electrolytic cell-side cathode plate are inserted into the electrolytic cell (10) from a side of the electrolytic cell (10), and the supply cell-side cathode plate is inserted into the supply cell (20) from a side of the supply cell (20).

[0146] (Item 9) The space purification device (1) according to claim 7, wherein the electrolytic cell-side anode plate and the electrolytic cell-side cathode plate are inserted into the electrolytic cell (10) from above, and the supply cell-side cathode plate is inserted into the supply cell (20) from above.

[0147] (Item 10) The space purification device (1) according to claim 7, wherein the electrolytic cell-side anode plate and the electrolytic cell-side cathode plate are inserted into the electrolytic cell (10) from below the electrolytic cell (10), and the supply cell-side cathode plate is inserted into the supply cell (20) from below the supply cell (20).

[0148] (Item 11) The space purification device (2) according to any one of Items 1 to 6, wherein the electrolytic cell side anode (111) and the supply cell side cathode (121) are an electrolytic cell side anode tube and a supply cell side cathode tube, respectively, having a cylindrical or rectangular tube shape, the electrolytic cell side cathode (121) is an electrolytic cell side cathode tube having a cylindrical or rectangular tube shape, or an electrolytic cell side cathode bar having a rod shape, the electrolytic cell side anode tube and the electrolytic cell side cathode tube or the electrolytic cell side cathode bar are entirely immersed in the first aqueous solution (L1), and the supply cell side cathode tube is entirely immersed in the second aqueous solution (L2).

[0149] (Item 12) The space purification device (2) according to claim 11, wherein the electrolytic cell (110) and the anion exchange membrane (130) are housed inside the supply tank (120).

[0150] (Item 13) The space purification device (1) according to Item 7, further comprising: a water level detection unit (18) that detects the position of the liquid level in the first aqueous solution (L1); and a water supply unit (19) that supplies water to the electrolytic cell (10) so that the liquid level detected by the water level detection unit (18) does not fall below the upper ends of the electrolytic cell-side anode plate immersed portion (11 a) and the electrolytic cell-side cathode plate immersed portion (12 a).

[0151] (Item 14) The space purification device (2) according to Item 11 or 12, further comprising: a water level detection unit (18) that detects the position of the liquid level in the first aqueous solution (L1); and a water supply unit (19) that supplies water to the electrolytic cell (110) so that the position of the liquid level detected by the water level detection unit (18) does not fall below the upper ends of the electrolytic cell-side anode cylinder, the electrolytic cell-side cathode cylinder, or the electrolytic cell-side cathode rod.

[0152] (Item 15) The space purification device (1) according to any one of Items 7 to 10, wherein the electrolytic cell-side anode plate and the supply cell-side cathode plate are each located close to the anion exchange membrane (30), with flat surfaces of the plate shapes facing each other across the anion exchange membrane (30), and the electrolytic cell-side cathode plate is located with a flat surface of the plate shape facing the flat surface of the plate shape of the electrolytic cell-side anode plate.

[0153] (Item 16) The space purification device (1) according to any one of Items 7 to 10, wherein each of the electrolytic cell-side anode plate, the electrolytic cell-side cathode plate, and the supply cell-side cathode plate has a rectangular plate shape, a shorter side of the rectangle is arranged along the vertical direction, and a longer side of the rectangle is arranged along the horizontal direction.

[0154] (Item 17) The space purification device (1, 2) according to any one of Items 1 to 16, wherein the diaphragm-less electrolysis unit (E1) comprises the electrolytic cell-side anode (11, 111) and the electrolytic cell-side cathode (12, 112), and the diaphragm-containing electrolysis unit (E2) comprises the electrolytic cell-side anode (11, 111), the supply cell-side cathode (21, 121), and the anion exchange membrane (30, 130).

[0155] (Item 18) The space purification device (1, 2) according to any one of Items 1 to 10, comprising: a housing (B) that houses the electrolytic cell (10) and the supply cell (20); an inlet (15) that is disposed within the housing (B) above the liquid level of the first aqueous solution (L1) stored in the electrolytic cell (10), and through which air flows in from an external space of the housing (B); a mixing space (16) that mixes the volatilized hypochlorous acid with the air that has flowed in from the inlet (15); and an outlet (17) through which the mixed air mixed in the mixing space flows out to the external space.

[0156] (Item 19) The space purification device (1) according to any one of Items 1 to 10, wherein the opposing surfaces of the electrolytic cell (10) and the supply cell (20) are each formed by a frame-shaped member, and the anion exchange membrane (30) is fitted into the frame-shaped member, thereby disposing the anion exchange membrane (30) between the electrolytic cell (10) and the supply cell (20).

[0157] 1, 2 Space purification device 10, 50, 70, 110 Electrolytic cell 11, 111 Electrolytic cell-side anode 11a Electrolytic cell-side anode plate immersion portion 11b Electrolytic cell-side anode plate protrusion portion 12, 112 Electrolytic cell-side cathode 12a Electrolytic cell-side cathode plate immersion portion 12b Electrolytic cell-side cathode plate protrusion portion 15 Inlet 16 Mixing space 17 Outlet 18 Water level detection portion 19 Water supply portion 20, 60, 80, 120 Supply cell 21, 121 Supply cell-side cathode 21a Supply cell-side cathode plate immersion portion 21b Supply cell-side cathode plate protrusion portion 30, 130 Anion exchange membrane 40 Current control portion 41 Voltage acquisition portion 42 Calculation portion 43 Estimation portion B Housing E1 Diaphragm-free electrolysis portion E2 Diaphragm electrolysis section L1 First aqueous solution L2 Second aqueous solution

Claims

1. An electrolytic cell for storing a first aqueous solution containing chloride ions; a supply cell for storing a second aqueous solution containing a higher concentration of chloride ions than the first aqueous solution and supplying chloride ions to the first aqueous solution; an electrolytic cell side anode and an electrolytic cell side cathode provided in the electrolytic cell; a supply cell side cathode provided in the supply cell; an anion exchange membrane disposed between the electrolytic cell and the supply cell and allowing anions to pass therethrough based on a voltage applied between the electrolytic cell side anode and the supply cell side cathode; a membrane-less electrolysis section provided in the electrolytic cell for generating hypochlorous acid by performing membrane-less electrolysis of the first aqueous solution by passing a first current between the electrolytic cell side anode and the electrolytic cell side cathode; and a membrane-containing electrolysis section provided between the electrolytic cell and the supply cell for performing membrane-containing electrolysis via the anion exchange membrane by passing a second current between the electrolytic cell side anode and the supply cell side cathode. a current control unit that controls the second current so as to replenish chloride ions contained in the first aqueous solution that have been reduced by the membrane-less electrolysis, thereby causing the chloride ions contained in the second aqueous solution to permeate through the anion exchange membrane and be supplied to the first aqueous solution.

2. The spatial purification device according to claim 1, wherein the current control unit maintains the chloride ion concentration of the first aqueous solution at a predetermined concentration by flowing the first current and the second current at a predetermined ratio.

3. The space purification device according to claim 1, wherein the current control unit comprises: a voltage acquisition unit that acquires a voltage between the electrolytic cell side anode and the electrolytic cell side cathode; a calculation unit that calculates the conductivity of the first aqueous solution based on the voltage acquired by the voltage acquisition unit; and an estimation unit that estimates the concentration of the first aqueous solution based on the conductivity calculated by the calculation unit, wherein the current control unit simultaneously flows the first current and the second current, and, when a chloride ion concentration of the first aqueous solution is lower than a predetermined concentration, changes a current ratio of the first current and the second current so as to increase an amount of chloride ions that permeate the anion exchange membrane from the second aqueous solution and are supplied to the first aqueous solution, and, when a chloride ion concentration of the first aqueous solution is higher than the predetermined concentration, changes a current ratio of the first current and the second current so as to decrease an amount of chloride ions that permeate the anion exchange membrane from the second aqueous solution and are supplied to the first aqueous solution.

4. The spatial purification device according to claim 3, wherein when the chloride ion concentration of the first aqueous solution is the predetermined concentration, the current ratio of the first current to the second current is not changed.

5. The space purification device according to claim 1, wherein the current control unit comprises: a voltage acquisition unit that acquires a voltage between the electrolytic cell side anode and the electrolytic cell side cathode; a calculation unit that calculates the conductivity of the first aqueous solution based on the voltage acquired by the voltage acquisition unit; and an estimation unit that estimates the concentration of the first aqueous solution based on the conductivity calculated by the calculation unit, wherein the current control unit controls the second current while flowing the first current at a predetermined value, and in controlling the second current, when the chloride ion concentration of the first aqueous solution is lower than the predetermined concentration, the second current is flowed so as to increase the amount of chloride ions that permeate the anion exchange membrane from the second aqueous solution and are supplied to the first aqueous solution, and when the chloride ion concentration of the first aqueous solution is higher than the predetermined concentration, the second current is stopped so as to stop the supply of chloride ions from the second aqueous solution to the first aqueous solution.

6. The space purification device according to claim 1, wherein the current control unit comprises: a voltage acquisition unit that acquires a voltage between the electrolytic cell side anode and the electrolytic cell side cathode; a calculation unit that calculates the conductivity of the first aqueous solution based on the voltage acquired by the voltage acquisition unit; and an estimation unit that estimates a concentration of the first aqueous solution based on the conductivity calculated by the calculation unit; and wherein, when a chloride ion concentration of the first aqueous solution is lower than a predetermined concentration, the current control unit stops the first current and simultaneously flows the second current so as to increase an amount of chloride ions that permeate through the anion exchange membrane from the second aqueous solution and are supplied to the first aqueous solution, and when a chloride ion concentration of the first aqueous solution is higher than the predetermined concentration, the current control unit stops the second current and simultaneously flows the first current so as to stop the supply of chloride ions from the second aqueous solution to the first aqueous solution.

7. The electrolytic cell side anode, the electrolytic cell side cathode, and the supply cell side cathode are an electrolytic cell side anode plate, an electrolytic cell side cathode plate, and a supply cell side cathode plate, each having a plate-like shape, the electrolytic cell side anode plate and the electrolytic cell side cathode plate being inserted into the electrolytic cell from the outside of the electrolytic cell, and the supply cell side cathode plate being inserted into the supply cell from the outside of the supply cell, the electrolytic cell side anode plate comprises an electrolytic cell side anode plate immersed portion arranged on the inside of the electrolytic cell and an electrolytic cell side anode plate protruding portion arranged on the outside of the electrolytic cell, the electrolytic cell side cathode plate comprises an electrolytic cell side cathode plate immersed portion arranged on the inside of the electrolytic cell and an electrolytic cell side cathode plate protruding portion arranged on the outside of the electrolytic cell, and the supply cell side cathode plate comprises a supply cell side cathode plate immersed portion arranged on the inside of the supply cell and a supply cell side cathode plate protruding portion arranged on the outside of the supply cell, The space purification device according to claim 1 , wherein the electrolytic cell side anode plate immersed portion and the electrolytic cell side cathode plate immersed portion are entirely immersed in the first aqueous solution, and the supply cell side cathode plate immersed portion is entirely immersed in the second aqueous solution.

8. The space purification device according to claim 1, wherein the electrolytic cell side anode and the supply cell side cathode are an electrolytic cell side anode tube and a supply cell side cathode tube, respectively, having a cylindrical or rectangular tubular shape, the electrolytic cell side cathode is an electrolytic cell side cathode tube having a cylindrical or rectangular tubular shape, or an electrolytic cell side cathode bar having a rod shape, the entirety of the electrolytic cell side anode tube and the entirety of the electrolytic cell side cathode tube or the electrolytic cell side cathode bar are immersed in the first aqueous solution, and the entirety of the supply cell side cathode tube is immersed in the second aqueous solution.

9. The space purification device as described in claim 7, comprising: a water level detection unit that detects the position of the liquid level in the first aqueous solution; and a water supply unit that supplies water to the electrolytic cell so that the position of the liquid level detected by the water level detection unit does not fall below the upper ends of the electrolytic cell side anode plate immersion portion and the electrolytic cell side cathode plate immersion portion.

10. The space purification device described in claim 7, wherein the electrolytic cell side anode plate and the supply cell side cathode plate are each adjacent to the anion exchange membrane, and the flat surfaces of the plate shapes are arranged opposite each other via the anion exchange membrane, and the flat surface of the plate shape of the electrolytic cell side cathode plate is arranged opposite the flat surface of the plate shape of the electrolytic cell side anode plate.

11. The space purification device according to claim 7, wherein each of the electrolytic cell side anode plate, the electrolytic cell side cathode plate, and the supply cell side cathode plate has a rectangular plate shape, the short side of the rectangle is arranged along the vertical direction, and the long side of the rectangle is arranged along the horizontal direction.

12. The spatial purification device according to claim 1, wherein the non-diaphragm electrolysis section comprises the electrolytic cell side anode and the electrolytic cell side cathode, and the diaphragm electrolysis section comprises the electrolytic cell side anode, the supply cell side cathode, and the anion exchange membrane.

13. The space purification device described in claim 1, comprising: a housing for housing the electrolytic cell and the supply cell; an inlet located within the housing above the liquid level of the first aqueous solution stored in the electrolytic cell, through which air flows in from an external space of the housing; a mixing space for mixing the volatilized hypochlorous acid with the air that has flowed in from the inlet; and an outlet through which the mixed air mixed in the mixing space flows out to the external space.

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