Space purification device

Abstract

To provide a space purifying device stably generating a desired amount of hypochlorous acid gas without supplying any aqueous solution including a chloride ion from outside for a long time.SOLUTION: An air purifying device 1 includes: an electrolysis tank 10 for storing a first aqueous solution L1; a supply tank 20 for storing a second aqueous solution L2 and supplying a chloride ion to the first aqueous solution L1; an electrolysis tank side positive electrode 11 and an electrolysis tank side negative electrode 12 provided to the electrolysis tank 10; a supply tank side negative electrode 21 provided to the supply tank 20; a negative ion exchange membrane 30 connecting the electrolysis tank 10 and the supply tank 20 so as to transmit the negative ion; and an electric current control part 40 supplying the chloride ion included in the second aqueous solution L2 to the first aqueous solution L1 through the negative ion exchange membrane 30 by controlling an electric current so as to compensate the chloride ion included in the first aqueous solution L1 reduced by electrolysis.SELECTED DRAWING: Figure 1

Description

Technical Field

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

Background Art

[0002] Patent Document 1 discloses an air purification device that removes bacteria, fungi, viruses, odors, etc. contained in the air by using hypochlorous acid generated by electrolyzing an aqueous solution containing chloride ions.

Prior Art Document

Patent Document

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] When a conventional space purification device is miniaturized, the tank for storing the aqueous solution used for electrolysis also becomes small. When the tank is miniaturized, the amount of the aqueous solution that can be stored decreases compared to the conventional space purification device. Therefore, when electrolysis is repeatedly performed in the miniaturized space purification device, there is a problem that the chloride ion concentration in the aqueous solution easily decreases and the generation amount of hypochlorous acid is not stable.

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

Means for Solving the Problems

[0006] The space purification device according to the present invention includes an electrolytic cell for storing a first aqueous solution containing chloride ions, a supply tank 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 tank side cathode provided in the supply tank, and an anion exchange membrane that connects the electrolytic cell and the supply tank so as to be permeable to anions based on a voltage applied between the electrolytic cell side anode and the supply tank side cathode, a diaphragm-free electrolysis unit provided in the electrolytic cell, which generates hypochlorous acid by diaphragm-free electrolysis of the first aqueous solution by passing a first current between the electrolytic cell side anode and the electrolytic cell side cathode, a diaphragm electrolysis unit provided across the electrolytic cell and the supply tank, which performs diaphragm electrolysis through the anion exchange membrane by passing a second current between the electrolytic cell side anode and the supply tank side cathode, and a current control unit that controls the second current so as to supplement the chloride ions contained in the first aqueous solution reduced by diaphragm-free electrolysis, and supplies the chloride ions contained in the second aqueous solution to the first aqueous solution through the anion exchange membrane.

Advantages of the Invention

[0007] According to the present invention, it is possible to provide a space purification device capable of stably generating a desired amount of hypochlorous acid gas without supplying an aqueous solution containing chloride ions from the outside for a long period of time.

Brief Description of the Drawings

[0008]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

[0009] Hereinafter, specific embodiments of the present invention will be described in detail with reference to the drawings.

[0010] Note that the right-handed xyz coordinates shown in the figures are for convenience in explaining the positional relationship of the components. Unless otherwise specified, the positive z-axis direction is vertically upward. Also, the xy plane is a horizontal plane and is common among the drawings. <Embodiment 1> FIG. 1 is a perspective view showing an overview of the space purification device 1 according to Embodiment 1. The space purification device 1 electrolyzes 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, etc. contained in the air in the external space of the space purification device 1 by causing the volatilized hypochlorous acid to flow out into the external space of the housing B constituting the space purification device 1.

[0011] The space purification device 1 is installed indoors. The installation location of the space purification device 1 is preferably a place where an air flow can occur. More specifically, the installation location of the space purification device 1 includes, for example, inside a so-called air conditioner which is an air conditioner, around a fan, around a circulator, around a ceiling fan, inside a humidifier, inside an air purifier, on a desk, etc.

[0012] The space purification device 1 includes a housing B, an electrolytic cell 10, a supply tank 20, an anion exchange membrane 30, and a current control unit 40.

[0013] The housing B stores the electrolytic cell 10, the supply tank 20, the anion exchange membrane 30, and the current control unit 40. That is, the space purification device 1 may be a unit integrated by the housing B. The shape of the housing B can be appropriately changed according to the location where the space purification device 1 is installed, and may be, for example, a rectangular parallelepiped shape or a cylindrical shape. The space purification device 1 has a small size that can be stored inside, for example, an air conditioner, and is about 10 cm × 7 cm × 4 cm, for example.

[0014] The electrolytic cell 10 is a tank for storing the first aqueous solution L1 containing chloride ions. The electrolytic cell 10 has, for example, a box-like shape. In FIG. 1, a state in which the first aqueous solution L1 is stored in the electrolytic cell 10 is shown. 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.

[0015] 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, for example, the mass percentage concentration of a dilute sodium chloride aqueous solution or a dilute potassium chloride aqueous solution may be 0.1% to 5%, or may be 1%. By setting the predetermined chloride ion concentration to the numerical range or value, it is possible to generate hypochlorous acid necessary for space purification while suppressing the generation of chlorine that may be generated at the same time.

[0016] 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 of the supply tank 20 permeate through the anion exchange membrane 30 and are supplied to the first aqueous solution L1 in the electrolytic cell 10.

[0017] The supply tank 20 is a tank for storing the second aqueous solution L2 containing chloride ions and supplying chloride ions to the first aqueous solution L1. In FIG. 1, the state where the second aqueous solution L2 is stored in the supply tank 20 is shown. 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. More specifically, the second aqueous solution L2 is, for example, a 10% - 27% sodium chloride aqueous solution, a 10% - 29% potassium chloride aqueous solution, or a 10% - 25% hydrochloric acid. 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.

[0018] When assuming continuous use for 8 hours every day for one year, the volumes of the electrolytic cell 10 and the supply tank 20 are preferably such that, for example, the volume of the supply tank 20 is about 12 times or more that of the electrolytic cell 10. By setting such a volume ratio, the supply tank 20 can store the second aqueous solution L2 containing a sufficient amount of chloride ions required for supplying the first aqueous solution L1 of the electrolytic cell 10. Therefore, chloride ions can be stably 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. The amount of the first aqueous solution L1 stored in the electrolytic cell 10 is, for example, about 2 - 10 mL.

[0019] The anion exchange membrane 30 is a membranous member that connects the electrolytic cell 10 and the supply tank 20 so as to be permeable to anions based on the voltage applied between the electrolytic cell 10 and the supply tank 20. More specifically, when a voltage is applied between the anode plate 11 on the electrolytic cell side and the cathode plate 21 on the supply tank side, which will be described later, diaphragm electrolysis is performed through the anion exchange membrane 30. By the diaphragm electrolysis using the anode plate 11 on the electrolytic cell side and the cathode plate 21 on the supply tank side, the chloride ions contained in the second aqueous solution L2 permeate through the anion exchange membrane 30 and are supplied to the first aqueous solution L1 (in the negative x-axis direction, indicated by the thick black arrow).

[0020] The anion exchange membrane 30 in the present embodiment is not the type of anion exchange membrane that allows anions to permeate by osmotic pressure without using electricity. Also, 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 through the anion exchange membrane 30 and are supplied to the first aqueous solution L1 by diaphragm electrolysis using the electrolytic cell side anode 11 and the supply tank side cathode 21, sodium ions, which are cations, do not permeate through the anion exchange membrane 30. The anion exchange membrane 30 is, for example, a hydrocarbon-based anion exchange membrane, and includes membranes having characteristics such as monovalent anion selective permeability, alkali resistance, and high temperature resistance.

[0021] The anion exchange membrane 30 is disposed between the electrolytic cell 10 and the supply tank 20. For example, the surface of the electrolytic cell 10 facing the supply tank 20 (the yz plane on the positive x-axis side) and the surface of the supply tank 20 facing the electrolytic cell 10 (the yz plane on the negative x-axis side) may each be formed of a frame member. When the surfaces of the electrolytic cell 10 and the supply tank 20 facing each other are formed of frame members, the anion exchange membrane 30 may be disposed so as to be fitted into the frame members.

[0022] The current control unit 40 controls the current used for both undivided electrolysis and diaphragm electrolysis. More specifically, the current control unit 40 controls the current used for undivided electrolysis performed using the pair of electrolytic cell side anode 11 and electrolytic cell side cathode 12 disposed in the electrolytic cell 10. Also, the current control unit 40 controls the current used for diaphragm electrolysis performed through the anion exchange membrane 30 using the pair of electrolytic cell side anode 11 and supply tank side cathode 21 across the electrolytic cell 10 and the supply tank 20. The electrolytic cell side anode 11 is used for both undivided electrolysis and diaphragm electrolysis. That is, the space purification device 1 according to the present embodiment includes one anode and two cathodes, and a total of three electrodes. Since the supply tank 20 includes only a cathode, chlorine is not generated by the chemical reaction described later.

[0023] Hereinafter, the details of each configuration will be described more specifically with reference to FIGS. 1 to 3.

[0024] As shown in FIG. 1, the electrolytic cell 10 includes an electrolytic cell side anode 11, an electrolytic cell side cathode 12, wiring 13, wiring 14, an inlet 15, a mixing space 16, and an outlet 17.

[0025] The electrolytic cell side anode 11 and the electrolytic cell side cathode 12 are a pair of electrodes used for electrolyzing the first aqueous solution L1. As shown in FIG. 1, there is no diaphragm such as an ion exchange membrane 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 electrolytic cell side anode 11 and electrolytic cell side cathode 12 is diaphragm-free electrolysis. Hypochlorous acid used for space purification is generated by the diaphragm-free electrolysis of the first aqueous solution L1 performed using the pair of electrolytic cell side anode 11 and electrolytic cell side cathode 12.

[0026] 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 11 having a plate-like shape, and the electrolytic cell side cathode 12 is an electrolytic cell side cathode plate 12 having a plate-like shape. The plate-like shape includes a rectangular shape and a rectangular shape. Hereinafter, the electrolytic cell side anode 11 is also referred to as the electrolytic cell side anode plate 11. Also, the electrolytic cell side cathode 12 is also referred to as the electrolytic cell side cathode plate 12.

[0027] As an example, the case where the plate-like shapes of the electrolytic cell side anode plate 11 and the electrolytic cell side cathode plate 12 are rectangular will be described. The electrolytic cell side anode plate 11 and the electrolytic cell side cathode plate 12 are arranged such that the short side direction of the rectangle is along the vertical direction (z-axis direction). By this arrangement, it is possible to suppress the adhesion of bubbles generated by a chemical reaction to both surfaces of the rectangle of each electrode. Further, compared with the case where the long side direction of the rectangle is arranged along the vertical direction (z-axis direction), when the short side direction is arranged along the vertical direction (z-axis direction), the bubbles generated at the lower part (z-axis negative side) of the electrolytic cell side anode plate 11 and the electrolytic cell side cathode plate 12 can be prevented from adhering to the upper part (z-axis positive side) of the electrolytic cell side anode plate 11 and the electrolytic cell side cathode plate 12.

[0028] In addition, the electrolytic cell side anode plate 11 and the electrolytic cell side cathode plate 12 are arranged such that the longitudinal direction in the rectangle is along the horizontal direction (y-axis direction). In other words, the electrolytic cell side anode plate 11 and the electrolytic cell side cathode plate 12 are arranged so that the rectangular planes (yz planes) they each have face each other with a predetermined interval. The predetermined interval is an interval suitable for electrolysis performed using a pair of the electrolytic cell side anode plate 11 and the electrolytic cell side cathode plate 12.

[0029] The electrolytic cell side anode plate 11 includes an electrolytic cell side anode plate immersion part 11a and an electrolytic cell side anode plate protruding part 11b. Similarly, the electrolytic cell side cathode plate 12 includes an electrolytic cell side cathode plate immersion part 12a and an electrolytic cell side cathode plate protruding part 12b.

[0030] The electrolytic cell side anode plate 11 and the electrolytic cell side cathode plate 12 are inserted from the outside to the inside of the electrolytic cell 10. In FIG. 1 as an example, the electrolytic cell side anode plate 11 and the electrolytic cell side cathode plate 12 are inserted in the horizontal direction (y-axis direction) from the side of the electrolytic cell 10 (the xz plane side on the negative y-axis side). The electrolytic cell side anode plate immersion part 11a and the electrolytic cell side cathode plate immersion part 12a inserted into the electrolytic cell 10 are arranged on the inner side of 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 entire electrolytic cell side anode plate immersion part 11a and the electrolytic cell side cathode plate immersion part 12a are 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 parts (the ends on the positive z-axis side) of the electrolytic cell side anode plate immersion part 11a and the electrolytic cell side cathode plate immersion part 12a.

[0031] The electrolytic cell side anode plate protruding part 11b and the electrolytic cell side cathode plate protruding part 12b are arranged on the outer side of the electrolytic cell 10 Wiring 13 and wiring 14 are lines through which current flows. The electrolytic cell side anode plate protruding part 11b is electrically connected to the current control unit 40 via the wiring 13, and the electrolytic cell side cathode plate protruding part 12b is electrically connected to the current control unit 40 via the wiring 14.

[0032] As the anode plate 11 and the cathode plate 12 on the electrolytic cell 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.

[0033] The inlet 15 is an opening for the air in the external space of the housing B to flow in. That is, the inlet 15 is an opening for the air in the external space of the space purification device 1 to flow in. In FIG. 1, as an example, the inlet 15 is provided on the upper surface (xy plane on the positive z-axis side) of the electrolytic cell 10, but it may be arranged above the liquid surface 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 cylindrical.

[0034] The mixing space 16 is a space formed above the electrolytic cell 10 (on the positive z-axis side) in a state where the first aqueous solution L1 is stored in the electrolytic cell 10. The mixing space 16 is a space for mixing hypochlorous acid generated by the diaphragm-free electrolysis of the first aqueous solution L1 performed using a pair of anode plates 11 and cathode plates 12 on the electrolytic cell side and the air in the external space flowing in from the inlet 15. The hypochlorous acid generated by the diaphragm-free electrolysis includes hypochlorous acid gas volatilized and gasified and hypochlorous acid dissolved in the first aqueous solution L1. The hypochlorous acid gas is contained in the air flowing in from the inlet 15 and flows out to the external space from the outlet 17 described later. The hypochlorous acid dissolved in the first aqueous solution L1 flows out to the external space from the outlet 17 described later by making gas-liquid contact with the air flowing in from the inlet 15.

[0035] The outlet 17 is an opening for the mixed air mixed with the air flowing in from the inlet 15 and hypochlorous acid generated by the diaphragm-free electrolysis of the first aqueous solution L1 to flow out to the external space of the housing B. That is, the outlet 17 is an opening for the mixed air to flow out to the external space of the space purification device 1. In FIG. 1, as in the case of the inlet 15, the outlet 17 is provided on the upper surface (xy plane on the positive z-axis side) of the electrolytic cell 10 as an example, but it may be arranged above the liquid surface of the first aqueous solution L1. The shape of the outlet 17 is the same as that of the inlet 15, and may be, for example, cylindrical as shown in FIG. 1, or rectangular cylindrical.

[0036] The inlet 15 and the outlet 17 may be provided with an openable or detachable lid (not shown). The lid may be in a closed state when transporting or moving the space purification device 1, and may be configured to be opened or removed when the space purification device 1 is in use. Also, although the inlet 15 and the outlet 17 are described as separate configurations, the inlet 15 and the outlet 17 may each serve as both the inlet and the outlet depending on the wind direction flowing into the space purification device 1.

[0037] The air containing hypochlorous acid that flows out from the outlet 17 to the external space of the space purification device 1 purifies the external space. That is, the air containing hypochlorous acid removes bacteria, fungi, viruses, odors, etc. contained in the air of the external space of the housing B.

[0038] The supply tank 20 includes a supply tank side cathode 21, a wiring 22, and an outlet 23. The supply tank side cathode 21 is an electrode used for electrolyzing the second aqueous solution L2 as a pair with the electrolytic cell side anode 11. 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 electrolytic cell side anodes 11 and the supply tank side cathode 21 is diaphragm electrolysis. That is, the electrolytic cell side anode 11 is used for both diaphragm-free electrolysis and diaphragm electrolysis. By the diaphragm electrolysis of the second aqueous solution L2 performed using the pair of electrolytic cell side anodes 11 and the supply tank side cathode 21, chloride ions are supplied from the second aqueous solution L2 to the first aqueous solution L1.

[0039] The supply tank side cathode 21 is a supply tank side cathode plate 21 having a plate shape. The plate shape includes a rectangular shape and a rectangular shape. Hereinafter, the supply tank side cathode 21 is also referred to as the supply tank side cathode plate 21.

[0040] As an example, similar to the anode plate 11 on the electrolytic cell side, the case where the cathode plate 21 on the supply tank side also has a rectangular plate shape will be described. As shown in FIG. 1, for the cathode plate 21 on the supply tank side, the short side direction in the rectangle is arranged along the vertical direction (z-axis direction). Further, for the cathode plate 21 on the supply tank side, the long side direction in the rectangle is arranged along the horizontal direction (y-axis direction).

[0041] The anode plate 11 on the electrolytic cell side and the cathode plate 21 on the supply tank side are each close to the anion exchange membrane 30. In this specification, "close" includes both the state where the anode plate 11 on the electrolytic cell side and the cathode plate 21 on the supply tank side approach the anion exchange membrane 30 with a predetermined interval, and the state where the anode plate 11 on the electrolytic cell side and the cathode plate 21 on the supply tank side are in contact with the anion exchange membrane 30.

[0042] Let the plane (yz plane on the positive x-axis side) of the rectangular plate on the anion exchange membrane 30 side of the anode plate 11 on the electrolytic cell side be plane P1. Let the plane (yz plane on the negative x-axis side) of the rectangular plate on the anion exchange membrane 30 side of the cathode plate 21 on the supply tank side be plane P2. Plane P1 and plane P2 are arranged to face each other with the anion exchange membrane 30 in between. By this arrangement, a uniform electric field can be generated between the anode plate 11 on the electrolytic cell side and the cathode plate 21 on the supply tank side.

[0043] The anode plate 11 on the electrolytic cell side is arranged between the cathode plate 12 on the electrolytic cell side and the anion exchange membrane 30. By this arrangement, the potential difference between the anode plate 11 on the electrolytic cell side and the cathode plate 12 on the electrolytic cell side, and the potential difference between the anode plate 11 on the electrolytic cell side and the cathode plate 21 on the supply tank side can be kept small.

[0044] The supply tank side cathode plate 21 includes a supply tank side cathode plate immersion part 21a and a supply tank side cathode plate protruding part 21b. The supply tank side cathode plate 21 is inserted from the outside to the inside of the electrolytic cell 10. In FIG. 1, as an example, the supply tank side cathode plate 21 is inserted horizontally in the y-axis direction from the side of the electrolytic cell 10 (the xz plane side on the negative y-axis side). The supply tank side cathode plate immersion part 21a inserted into the supply tank 20 is arranged on the inner side of 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 immersion part 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 z-axis side) of the supply tank side cathode plate immersion part 21a.

[0045] As shown in FIG. 1, the supply tank side cathode plate protruding part 21b is arranged on the outside of the supply tank 20. The wiring 22 is a line through which current flows. The supply tank side cathode plate protruding part 21b is electrically connected to the current control unit 40 via the wiring 22.

[0046] As the supply tank side cathode plate 21, for example, a platinum iridium titanium electrode, a platinum electrode, a ruthenium titanium electrode, or an iridium titanium oxide electrode may be used.

[0047] The discharge port 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 discharge port 23 may be, for example, a check valve. When a check valve is used as the discharge port 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, hydrogen gas accumulates inside the supply tank 20, and the internal pressure of the supply tank 20 increases. Due to this pressure, the check valve opens, and the hydrogen gas is discharged to the external space of the supply tank 20.

[0048] FIG. 2 is a front partial cross-sectional view showing the space purification device 1 of FIG. 1. In FIG. 2, the The housing B is omitted. As shown in FIG. 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 surface 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) at least the upper ends (the portions on the positive z-axis side) of the electrolytic cell side anode plate immersion part 11a, the electrolytic cell side cathode plate immersion part 12a, and the supply tank side cathode plate immersion part 21a.

[0049] The water supply unit 19 supplies water to the electrolytic cell 10 based on the position of the liquid surface S1 detected by the water level detection unit 18. More specifically, the water supply unit 19 supplies water to the electrolytic cell 10 so as not to fall below the upper ends (the portions on the positive z-axis side) of the electrolytic cell side anode plate immersion part 11a, the electrolytic cell side cathode plate immersion part 12a, and the supply tank side cathode plate immersion part 21a. The water supply unit 19 may be, for example, a Peltier element that can cool the moisture contained in the air and cause condensation to form water droplets, or a water tank capable of storing water. The water supply unit 19 may be disposed at a position where it can supply water to the electrolytic cell 10, and may be disposed on the upper side of the electrolytic cell 10, or may be disposed on the side or bottom side.

[0050] When the space purification device 1 includes the water level detection unit 18 and the water supply unit 19, the electrolytic cell side anode plate immersion part 11a and the electrolytic cell side cathode plate immersion part 12a can maintain a state of being immersed in the first aqueous solution L1. Therefore, the exposure of the electrolytic cell side anode plate immersion part 11a and the electrolytic cell side cathode plate immersion part 12a to air due to the decrease in the first aqueous solution L1 can be suppressed, and the electrolysis efficiency of the diaphragm-free electrolysis can be maintained.

[0051] As shown in FIG. 2, the space purification device 1 according to the present embodiment includes a diaphragm-free electrolysis unit E1 and a diaphragm electrolysis unit 20. The current control unit 40 can control the chemical reactions occurring in the diaphragm-free electrolysis unit E1 and the chemical reactions occurring in the diaphragm electrolysis unit E2 by controlling the first current flowing through the diaphragm-free electrolysis unit E1 and the second current flowing through the diaphragm electrolysis unit E2.

[0052] The diaphragm-free electrolysis section E1 is provided in the electrolytic cell 10. The diaphragm-free electrolysis section E1 generates hypochlorous acid by subjecting the first aqueous solution L1 to diaphragm-free electrolysis by passing a first current between the anode 11 on the electrolytic cell side and the cathode 12 on the electrolytic cell side. In other words, the diaphragm-free electrolysis section E1 includes the anode 11 on the electrolytic cell side and the cathode 12 on the electrolytic cell side.

[0053] The diaphragm electrolysis section E2 is provided across the electrolytic cell 10 and the supply tank 20. Diaphragm electrolysis is performed through the anion exchange membrane 30 by passing a second current between the anode 11 on the electrolytic cell side and the cathode 21 on the supply tank side. In other words, the diaphragm electrolysis section E2 includes the anode 11 on the electrolytic cell side, the cathode 21 on the supply tank side, and the anion exchange membrane 30.

[0054] Here, the details of the chemical reactions occurring in the diaphragm-free electrolysis section E1 provided in the electrolytic cell 10 and the chemical reactions occurring in the diaphragm electrolysis section E2 provided across the electrolytic cell 10 and the supply tank 20 will be described. The following describes the case where the first aqueous solution L1 and the second aqueous solution L2 containing chloride ions are aqueous sodium chloride solutions. [Diaphragm-free electrolysis section E1 (electrolytic cell 10)] Sodium chloride (NaCl) contained in the aqueous sodium chloride solution ionizes into Na + and Cl - in water. When a predetermined voltage is applied to the diaphragm-free electrolysis section E1, a current flows, electrons move, and the following chemical reactions occur. · Reaction formula (a): Anode 11 on the electrolytic cell side (chlorine generation)

[0055]

Chem.

[0056]

Chem.

[0057]

Chem.

[0058]

Chemical formula

[0059]

Chemical formula

[0060]

Chemical formula

[0061]

Chemical formula

[0062] Here, the amount of chloride ions (Cl - ) consumed by diaphragm-free 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 the condition that Cl - apparently does not increase or decrease in the electrolytic cell 10 is as follows. In this reaction, since hypochlorous acid (HClO) volatilizes as a gas, it is not included in the following formula. · Reaction formula (h): The condition that Cl - apparently does not increase or decrease

[0063]

Chemical formula

[0064]

Chemical formula

[0065]

Chemical formula

[0066]

Chemical formula

[0067] Also, since 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 so that it does not change. In the above reaction formula (k), hydroxide ions and hydrogen ions, which are factors causing changes in pH, react to form water and disappear from the reaction formula. Therefore, the amount of chloride ions (Cl - ) consumed by diaphragm-free electrolysis is supplied from the second aqueous solution L2 stored in the supply tank 20 to the first aqueous solution L1 stored in the electrolysis tank 10, and when the amount of Cl - in the electrolysis tank 10 does not apparently increase or decrease, the increase or decrease in pH can also be suppressed.

[0068] When the number of electrons flowing into the diaphragm-free electrolysis section E1 changes as described above, that is, when the ratio of the current flowing into the diaphragm-free electrolysis section E1 to the current flowing into the diaphragm electrolysis section E2 changes, the supply amount of chloride ions supplied from the supply tank 20 to the electrolysis tank 10 changes. For example, when the ratio of the current used for diaphragm-free electrolysis is larger than the ratio of the current under the condition that chloride ions (Cl - ) are supplied from the supply tank 20 and the amount of Cl - in the electrolysis tank 10 does not apparently increase or decrease (the following reaction formula (l)), the supply amount of Cl - supplied from the supply tank 20 to the electrolysis tank 10 decreases, and the amount of Cl - in the electrolysis tank 10 decreases. · Reaction formula (l)

[0069]

Chemical formula

[0070] On the other hand, when the amount of current used for diaphragm-free electrolysis is such that chloride ions (Cl - ) are supplied from the supply tank 20 and the amount of Cl -When it is greater than the current amount under the condition of seemingly no increase or decrease (the following reaction formula (m)), the supply amount of Cl - supplied from the supply tank 20 to the electrolytic cell 10 increases, and the Cl - in the electrolytic cell 10 increases. · Reaction formula (m)

[0071]

Chem.

[0072] Also, when the Cl - in the electrolytic cell 10 increases, the equilibrium of reaction formula (d) shifts to the left, and the generation amount of chlorine increases. In other words, by adjusting the current flowing through the diaphragm-free electrolysis section E1 and the current flowing through the diaphragm electrolysis section E2 so that the Cl - in the electrolytic cell 10 seemingly does not increase or decrease, hypochlorous acid can be generated while suppressing the generation of chlorine. [Diaphragm electrolysis section E2] The reaction in the supply tank 20 will be described. The electrode arranged in the supply tank 20 is only the supply tank side cathode 21. When a predetermined voltage is applied to the diaphragm electrolysis section E2, a current flows, electrons move, and the following chemical reaction occurs. · Reaction formula (n): Electrolytic cell side cathode 12 (hydrogen generation)

[0073]

Chem.

[0074] [Chemical formula] The above are the details of the chemical reactions that occur in the diaphragmless electrolysis section E1 provided in the electrolytic cell 10 and the chemical reactions that occur in the diaphragmed electrolysis section E2 provided across the electrolytic cell 10 and the supply tank 20.

[0075] The current control unit 40 controls the above chemical reactions. More specifically, the second current is controlled so as to supplement the chloride ions contained in the first aqueous solution L1 that has decreased due to diaphragmless electrolysis in the diaphragmless electrolysis section E1. By controlling the second current, the chloride ions contained in the second aqueous solution L2 are permeated through the anion exchange membrane 30 and supplied to the first aqueous solution L1. Hereinafter, the details will be described with reference to FIG. 3.

[0076] FIG. 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.

[0077] The voltage acquisition unit 41 acquires the voltage between the anode 11 on the electrolytic cell side and the cathode 12 on the electrolytic cell side. 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.

[0078] The current control unit 40 controls the first current flowing through the diaphragmless electrolysis section E1 and the second current flowing through the diaphragmed electrolysis section E2 shown in FIG. 3 so as to maintain the chloride ion concentration of the first aqueous solution L1 at a predetermined concentration. Hereinafter, three examples of the current control by the current control unit 40 will be described. [1. When flowing the first current and the second current simultaneously] When the current control unit 40 flows the first current and 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 current ratio of the first current and the second current is changed so that the amount of chloride ions permeating through the anion exchange membrane 30 from the second aqueous solution L2 and supplied to the first aqueous solution L1 increases. 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 of the first current and the second current is changed so that the amount of chloride ions permeating through the anion exchange membrane 30 from the second aqueous solution L2 and supplied to the first aqueous solution L1 decreases. 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 equal to a predetermined concentration: The current ratio of the first current and the second current is not changed. [2. When flowing the first current at a predetermined value and controlling the second current at the same time] When the current control unit 40 flows the first current at a predetermined value and controls the second current at the same time, 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 that the amount of chloride ions permeating through the anion exchange membrane 30 from the second aqueous solution L2 and supplied to the first aqueous solution L1 increases. (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 that the supply of chloride ions from the second aqueous solution L2 to the first aqueous solution L1 stops. (3) When the chloride ion concentration of the first aqueous solution L1 estimated by the estimation unit 43 is equal to a predetermined concentration: The first current and the second current are not changed. [3. When flowing the first current or the second current] When the current control unit 40 flows the first current or the second current, 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 first current is stopped and at the same time the second current is passed so that the amount of chloride ions permeating through the anion exchange membrane 30 from the second aqueous solution L2 and supplied to the first aqueous solution L1 increases. (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 at the same time the first current is passed so that the supply of chloride ions from the second aqueous solution L2 to the first aqueous solution L1 stops. (3) When the chloride ion concentration of the first aqueous solution L1 estimated by the estimation unit 43 is at a predetermined concentration: The first current and the second current are not changed.

[0079] As described above, by the current control unit 40 controlling the first current and the second current, a necessary amount of chloride ions can be supplied to the first aqueous solution L1 in the electrolytic cell 10, and the chloride ion concentration of the first aqueous solution L1 can be maintained at a predetermined concentration.

[0080] In the case of "1. When the first current and the second current are passed simultaneously" above, when there is an increase or decrease in the chloride ion concentration of the first aqueous solution L1, the current ratio of the first current and the second current is changed. Since 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 maintained at an optimal predetermined concentration. In the case of "2. When the first current is passed at a predetermined value and the second current is controlled", when there is an increase or decrease in the chloride ion concentration of the first aqueous solution L1, mainly the second current is passed or stopped. In the case of "3. When the first current or the second current is passed", when there is an increase or decrease in the chloride ion concentration of the first aqueous solution L1, one of the first current and the second current is passed and the other is stopped. Therefore, the chloride ion concentration of the first aqueous solution L1 can be maintained at a predetermined concentration. In the cases of 2 and 3 above, since either the first current or the second current can be controlled, the current control is easy.

[0081] As described above, since the chloride ions consumed by the first aqueous solution L1 can be appropriately supplied from the second aqueous solution L2, it is possible to provide the space purification device 1 that can stably generate a desired amount of hypochlorous acid gas. Therefore, for example, it is possible to provide the space purification device 1 that can stably generate a desired amount of hypochlorous acid gas without supplying an aqueous solution containing chloride ions from the outside over a long period such as one year.

[0082] Note that a plurality of current control units 40 may be provided to separately control the first current and the second current.

[0083] Also, in FIG. 2, the inlet 15 and the outlet 17 are arranged on the front left side (negative y-axis and negative x-axis) and the rear right side (positive y-axis and positive 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 as to be at the most distant positions on the xy plane. By arranging them in such a way, the time for the inflowing air and hypochlorous acid to be mixed in the mixing space 16 becomes longer, so that more hypochlorous acid can be contained in the mixed air.

[0084] Also, the plane P1 (yz plane on the positive x-axis side) in the plate-shaped rectangle on the anion exchange membrane 30 side of the electrolytic cell side anode plate 11 and the plate-shaped rectangle on the anion exchange membrane 30 side of the supply tank side cathode plate 21 The case where the plane P2 (yz plane on the negative x-axis side) in does not face each other will be described. When the planes in each rectangle are arranged parallel to the xy plane, a non-uniform electric field may be generated between the electrolytic cell side anode plate 11 and the supply tank side cathode plate 21. When a non-uniform electric field is generated between the electrolytic cell side anode plate 11 and the supply tank side cathode plate 21, the current distribution between the electrolytic cell side anode plate 11 and the supply tank side cathode plate 21 also becomes non-uniform.

[0085] When the current distribution between the anode plate 11 on the electrolytic cell side and the cathode plate 21 on the supply tank side becomes non-uniform, regions with high and low current densities occur. In the regions with high current density, the deterioration of the catalyst layer on the surfaces of the anode plate 11 on the electrolytic cell side and the cathode plate 21 on the supply tank side (hereinafter also referred to as each electrode plate) tends to progress, while in the regions with low current density, the deterioration of the catalyst layer on the surfaces of each electrode plate hardly progresses. That is, when a non-uniform electric field is generated between the anode plate 11 on the electrolytic cell side and the cathode plate 21 on the supply tank side, the current distribution becomes non-uniform, and regions with different current densities can coexist on the same electrode plate. Therefore, the deterioration of the catalyst layer due to the use of each electrode plate can occur non-uniformly. When the degree of deterioration of the catalyst layer on the surface of each electrode plate is different, when repeated electrolysis is performed, at a certain point in time, regions that can be used as electrodes and regions that can no longer be used due to advanced deterioration can coexist on each electrode plate. When electrolysis is performed using each electrode plate including regions that cannot be used as electrodes, there is a risk that the electrolysis efficiency will easily decrease.

[0086] In contrast, in the space purification device 1 according to the present embodiment, the plane P1 and the plane P2 are arranged to face each other with the anion exchange membrane 30 interposed therebetween. With this arrangement, the electric field between the anode plate 11 on the electrolytic cell side and the cathode plate 21 on the supply tank side can be made uniform, so that the current between the two electrodes is also uniformly distributed. Therefore, since the deterioration of the catalyst layer on the surface of each electrode plate occurs uniformly, even when repeated electrolysis is performed, the non-uniform deterioration of the catalyst layer on the surface of each electrode plate due to the non-uniform electric field can be suppressed. Therefore, a decrease in electrolysis efficiency can be suppressed. <Modification Example 1> Hereinafter, with reference to FIG. 4, Modification Example 1 of the electrolytic cell 10 and the supply tank 20 according to Embodiment 1 will be described. FIG. 4 is a front cross-sectional view showing Modification Example 1 of the electrolytic cell 10 and the supply tank 20 included in the space purification device 1 according to Embodiment 1. The same components as those of the electrolytic cell 10 and the supply tank 20 are denoted by the same reference numerals, and the description thereof is omitted.

[0087] First, the 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 substantially L-shaped configuration in a front view. The electrolytic cell 50 includes a first ceiling surface 51 and a second ceiling surface 52, which are two ceiling surfaces having different heights (in the z-axis direction). The first ceiling surface 51 is a ceiling surface having a lower height (in the z-axis direction) than the second ceiling surface 52. The electrolytic cell side anode plate 11 and the electrolytic cell side cathode plate 12 are inserted into the electrolytic cell 50 from the upper side (positive z-axis side) of the first ceiling surface 51 toward the interior direction (negative z-axis direction) of the electrolytic cell 50.

[0088] The electrolytic cell side anode plate immersion portion 11a and the electrolytic cell side cathode plate immersion portion 12a inserted into the electrolytic cell 50 are disposed 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 such that the entire electrolytic cell side anode plate immersion portion 11a and the electrolytic cell side cathode plate immersion portion 12a are immersed. That is, the first aqueous solution L1 is stored in the electrolytic cell 50 such that the liquid level S1 of the first aqueous solution L1 exceeds the upper ends (the ends on the positive z-axis side) of the electrolytic cell side anode plate immersion portion 11a and the electrolytic cell side cathode plate immersion portion 12a.

[0089] The electrolytic cell side anode plate protruding portion 11b and the electrolytic cell side cathode plate protruding portion 12b are disposed outside the electrolytic cell 50. The electrolytic cell side anode plate protruding portion 11b is electrically connected to the current control unit 40 via the wiring 13, and the electrolytic cell side cathode plate protruding portion 12b is electrically connected to the current control unit 40 via the wiring 14.

[0090] Here, the case where the electrolytic cell 50 shown in FIG. 4 includes the water level detection unit 18 and the water supply unit 19 will be described. Similar to the electrolytic cell 10, the water level detection unit 18 is disposed above (on the positive z-axis side) at least the upper ends (the portions on the positive z-axis side) of the electrolytic cell side anode plate immersion portion 1 1a and the electrolytic cell side cathode plate immersion portion 12a. The water supply unit 19 may be provided on the second ceiling surface 52 as an example, but any arrangement capable of supplying water to the electrolytic cell 50 is acceptable.

[0091] Next, a supply tank 60, which is a first modification example of the supply tank 20, will be described. As shown in FIG. 4, the supply tank 60 has a shape that is horizontally inverted with respect to the electrolytic tank 50 in a front view. The supply tank 60 includes a first ceiling surface 61 and a second ceiling surface 62, which are two ceiling surfaces with different heights (in the z-axis direction). The first ceiling surface 61 is a ceiling surface with a lower height (in the z-axis direction) than the second ceiling surface 62. The supply tank side cathode plate 21 is inserted from above the first ceiling surface 61 (in the positive z-axis direction) toward the inside of the supply tank 60 (in the negative z-axis direction).

[0092] The supply tank side cathode plate immersion part 21a inserted into the supply tank 60 is arranged on the inner side of 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 entire supply tank side cathode plate immersion part 21a is immersed. That is, the second aqueous solution L2 is stored in the supply tank 60 such that the liquid level S2 of the second aqueous solution L2 exceeds the upper end (the end on the positive z-axis side) of the supply tank side cathode plate immersion part 21a.

[0093] The supply tank side cathode plate protruding part 21b is arranged on the outer side of the supply tank 60. The supply tank side cathode plate protruding part 21b is electrically connected to the current control unit 40 via the wiring 22. <Modification Example 2> Next, with reference to FIG. 5, a second modification example of the electrolytic tank 10 and the supply tank 20 according to the first embodiment will be described. FIG. 5 is a front cross-sectional view showing a second modification example of the electrolytic tank 10 and the supply tank 20 included in the space purification device 1 according to the first embodiment. The same components as those of the electrolytic tank 10 and the supply tank 20 are denoted by the same reference numerals, and the description thereof will be omitted. As shown in FIG. 5, the electrolytic tank 70 and the supply tank 80 have a shape in which the electrolytic tank 50 and the supply tank 60 of the first modification example are inverted vertically.

[0094] First, the electrolytic cell 70, which is a modified example 2 of the electrolytic cell 10, will be described. As shown in FIG. 5, the electrolytic cell 70 has a shape obtained by inverting the shape of a substantially L-shaped figure when viewed from the front. The electrolytic cell 70 includes a first bottom surface 71 and a second bottom surface 72, which are two bottom surfaces with different heights (in the z-axis direction). The first bottom surface 71 is the bottom surface of the electrolytic cell 70 provided above (in the positive z-axis direction) the second bottom surface 72. The electrolytic cell side anode plate 11 and the electrolytic cell side cathode plate 12 are inserted into the electrolytic cell 70 from the lower side (negative z-axis side) of the first bottom surface 71 toward the inside (positive z-axis direction) of the electrolytic cell 70.

[0095] The electrolytic cell side anode plate immersion part 11a and the electrolytic cell side cathode plate immersion part 12a inserted into the electrolytic cell 70 are disposed 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 entire electrolytic cell side anode plate immersion part 11a and the electrolytic cell side cathode plate immersion part 12a are immersed. That is, the first aqueous solution L1 is stored in the electrolytic cell 70 such that the liquid level S1 of the first aqueous solution L1 exceeds the upper ends (ends on the positive z-axis side) of the electrolytic cell side anode plate immersion part 11a and the electrolytic cell side cathode plate immersion part 12a.

[0096] The electrolytic cell side anode plate protruding part 11b and the electrolytic cell side cathode plate protruding part 12b are disposed outside the electrolytic cell 70. The electrolytic cell side anode plate protruding part 11b is electrically connected to the current control unit 40 via the wiring 13, and the electrolytic cell side cathode plate protruding part 12b is electrically connected to the current control unit 40 via the wiring 14.

[0097] Next, the case where the electrolytic cell 70 includes a water level detection part 18 and a water supply part 19 will be described. Similar to the electrolytic cell 10, the water level detection part 18 is disposed above (in the positive z-axis side) at least the upper ends (parts on the positive z-axis side) of the electrolytic cell side anode plate immersion part 11a and the electrolytic cell side cathode plate immersion part 12a. The water supply part 19 may be disposed at a position where water can be supplied to the electrolytic cell 10, and may be disposed on the upper side of the electrolytic cell 70, or may be disposed on the side part or the bottom part.

[0098] Next, the supply tank 80, which is a second modification of the supply tank 20, will be described. The supply tank 80 has a shape that is horizontally inverted with respect to the electrolytic cell 70 when viewed from the front. The supply tank 80 includes a first bottom surface 81 and a second bottom surface 82, which are two bottom surfaces with different heights (in the z-axis direction). The first bottom surface 81 is the bottom surface of the supply tank 80 provided above (in the positive z-axis direction) the second bottom surface 82. The supply tank side cathode plate 21 is inserted from the lower side (negative z-axis side) of the first bottom surface 81 toward the inside of the electrolytic cell 70 (positive z-axis direction).

[0099] The supply tank side cathode plate immersion portion 21a inserted into the supply tank 80 is disposed 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 such that the entire supply tank side cathode plate immersion portion 21a is 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 portion (the end portion on the positive z-axis side) of the supply tank side cathode plate immersion portion 21a.

[0100] The supply tank side cathode plate protruding portion 21b is disposed outside the supply tank 80. The supply tank side cathode plate protruding portion 21b is electrically connected to the current control unit 40 via the wiring 22. <Embodiment 2> Next, the space purification apparatus 2 according to Embodiment 2 will be described with reference to FIGS. 6 and 7. Components having the same configuration as those in Embodiment 1 are denoted by the same reference numerals, and the description thereof will be omitted. Also, although the shapes of the components are different from those in Embodiment 1, since the functions of the components are the same as those in Embodiment 1, the description of the functions of the components will be omitted.

[0101] FIG. 6 is a front schematic view showing the space purification apparatus 2 according to Embodiment 2. FIG. 7 is a plan view showing the space purification apparatus 2 according to Embodiment 2. The hatching shown in FIG. 7 is shown for clarifying each component, and FIG. 7 is not a cross-sectional view.

[0102] As shown in FIG. 6, the space purification device 2 according to the present embodiment includes an electrolytic cell 10', a supply tank 20', an anion exchange membrane 30', and a current control unit 40. The electrolytic cell 10' and the supply tank 20' have a cylindrical shape with an open upper surface (xy plane on the positive z-axis side) and a bottom surface (xy plane on the negative z-axis side). The anion exchange membrane 30' has a cylindrical shape. The anion exchange membrane 30' is disposed between the electrolytic cell 10' and the supply tank 20'. As shown in FIG. 6, the electrolytic cell 10' is a portion on the inner diameter side of the anion exchange membrane 30'. The cylindrical shapes of the electrolytic cell 10', the supply tank 20', and the anion exchange membrane 30' include a cylindrical shape and a rectangular tube shape. Also, although not shown in FIGS. 6 and 7, a first aqueous solution L1 is stored in the electrolytic cell 10', and a second aqueous solution L2 is stored in the supply tank 20'.

[0103] As shown in FIG. 6, the electrolytic cell 10' includes an electrolytic cell side anode 11' and an electrolytic cell side cathode 12'. The electrolytic cell side anode 11' is an electrolytic cell side anode cylinder 11' having a cylindrical shape. The electrolytic cell side cathode 12' is an electrolytic cell side cathode cylinder 12' or an electrolytic cell side cathode bar 12' having a cylindrical or bar shape. The supply tank 20' includes a supply tank side cathode 21'. The supply tank side cathode 21' is a supply tank side cathode cylinder 21' having a cylindrical shape. The cylindrical shapes of the electrolytic cell side anode 11', the electrolytic cell side cathode 12', and the supply tank side cathode 21' include a cylindrical shape and a rectangular tube shape. The bar shape includes a columnar shape and a spiral shape. The electrolytic cell side anode 11', the electrolytic cell side cathode 12', and the supply tank side cathode 21' are each electrically connected to the current control unit 40 via wiring (not shown).

[0104] As shown in FIGS. 6 and 7, in the space purification device 2 according to the present embodiment, for example, each cylindrical component has a nested structure. More specifically, in order from the outside, the supply tank 20', the supply tank side cathode 21', the anion exchange membrane 30', the electrolytic cell 10', the electrolytic cell side anode 11', and the electrolytic cell side cathode 12' are arranged in this order. That is, the diameters of the respective components are such that the supply tank 20' > the supply tank side cathode 21' > the anion exchange membrane 30' = the electrolytic cell 10' > the electrolytic cell side anode 11' > the electrolytic cell side cathode 12 '. And each component is arranged with a predetermined interval from each other.

[0105] The entire electrolytic cell side anode cylinder 11' and the entire electrolytic cell side cathode cylinder 12' or the electrolytic cell side cathode rod 12' are immersed in the first aqueous solution L1. Also, the entire supply tank side cathode cylinder 21' is immersed in the second aqueous solution L2. As shown in FIG. 6, the space purification device 2 according to the present embodiment may further include a water level detection unit 18 and a water supply unit 19. The water level detection unit 18 is disposed above (on the positive z-axis side) the upper ends (the ends on the positive z-axis side) of the electrolytic cell side anode 11', the electrolytic cell side cathode 12', and the supply tank side cathode 21'. The water supply unit 19 may be disposed at a position where water can be supplied to the electrolytic cell 10', for example, above (on the positive z-axis side) the electrolytic cell 10'.

[0106] Note that the electrolytic cell side anode 11', the electrolytic cell side cathode 12', and the supply tank side cathode 21' may be formed of a plate-like member, a mesh-like member, or expanded metal.

[0107] The space purification device 2 according to the present embodiment includes the same current control unit 40 as in the first embodiment. By the current control unit 40 controlling the first current and the second current, a required amount of chloride ions can be supplied to the first aqueous solution L1 in the electrolytic cell 10', and the chloride ion concentration of the first aqueous solution L1 can be maintained at a predetermined concentration. Therefore, it is possible to provide a space purification device 2 capable of purifying a space by stably generating a desired amount of hypochlorous acid gas.

[0108] Furthermore, the space purification device 2 according to the present embodiment can accommodate the electrolytic cell 10' and the anion exchange membrane 30' inside the supply tank 20'. Therefore, it is possible to provide a space purification device 2 that is more space-saving and compact.

[0109] Note that the present invention is not limited to the above-described embodiment, and can be appropriately modified without departing from the spirit thereof.

[0110] The outline of one aspect of the present disclosure is as follows.

[0111] (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 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), An anion exchange membrane (30) that connects the electrolytic cell (10) and the supply tank (20) so that anions can permeate based on the voltage applied between the electrolytic cell side anode (11) and the supply tank side cathode (21), A diaphragmless electrolysis unit (E1) provided in the electrolytic cell (10) that generates hypochlorous acid by diaphragmless 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 electrolysis unit (E2) provided across the electrolytic cell (10) and the supply tank (20) that performs diaphragm electrolysis through the anion exchange membrane (30) by passing a second current between the electrolytic cell side anode (11) and the supply tank side cathode (21), A current control unit (40) that controls the second current so as to supplement the chloride ions contained in the first aqueous solution (L1) reduced by the diaphragmless electrolysis, and supplies the chloride ions contained in the second aqueous solution (L2) to the first aqueous solution (L1) through the anion exchange membrane (30). A space purification device (1).

[0112] (Item 2) 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. The space purification device (1) according to Item 1.

[0113] (Item 3) The current control unit (40) A voltage acquisition unit (41) that acquires the 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); An estimation unit (43) that estimates the concentration of the first aqueous solution (L1) based on the conductivity calculated by the calculation unit (42), and The current control unit (40) Simultaneously flows the first current and the second current, When the chloride ion concentration of the first aqueous solution (L1) is lower than a predetermined concentration, the current ratio of the first current and the second current is changed so that the amount of chloride ions permeating through the anion exchange membrane (30) from the second aqueous solution (L2) and supplied to the first aqueous solution (L1) increases; When the chloride ion concentration of the first aqueous solution (L1) is higher than the predetermined concentration, the current ratio of the first current and the second current is changed so that the amount of chloride ions permeating through the anion exchange membrane (30) from the second aqueous solution (L2) and supplied to the first aqueous solution (L1) decreases. The space purification device (1) according to item 1. (Item 4) When the chloride ion concentration of the first aqueous solution (L1) is equal to the predetermined concentration, the current ratio of the first current and the second current is not changed. The space purification device (1) according to item 3. (Item 5) A voltage acquisition unit (41) that acquires the 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); An estimation unit (43) that estimates the concentration of the first aqueous solution (L1) based on the conductivity calculated by the calculation unit (42), and The current control unit (40) Flows the first current at a predetermined value and simultaneously controls the second current, The control of the second current When the chloride ion concentration of the first aqueous solution (L1) is lower than a predetermined concentration, a second current is passed so that the amount of chloride ions permeating through the anion exchange membrane (30) from the second aqueous solution (L2) and supplied to the first aqueous solution (L1) increases. When the chloride ion concentration of 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. The space purification device (1) according to item 1. (Item 6) A voltage acquisition unit (41) that acquires the 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); Based on the conductivity calculated by the calculation unit (42), an estimation unit (43) that estimates the concentration of the first aqueous solution (L1); is provided. The current control unit (40) When the chloride ion concentration of the first aqueous solution (L1) is lower than a predetermined concentration, the first current is stopped and at the same time the second current is passed so that the amount of chloride ions permeating through the anion exchange membrane (30) from the second aqueous solution (L2) and supplied to the first aqueous solution (L1) increases. When the chloride ion concentration of the first aqueous solution (L1) is higher than a predetermined concentration, The second current is stopped and at the same time the first current is passed so that the supply of chloride ions from the second aqueous solution (L2) to the first aqueous solution (L1) is stopped. The space purification device (1) according to item 1. (Item 7) The electrolytic cell side anode (11), the electrolytic cell side cathode (12), and the supply tank side cathode (21) are respectively an electrolytic cell side anode plate (11), an electrolytic cell side cathode plate (12), and a supply tank side cathode plate (21) having a plate-like shape. The anode plate (11) on the electrolytic cell side and the cathode plate (12) on the electrolytic cell side are inserted into the electrolytic cell (10) from the outside of the electrolytic cell (10), and the cathode plate (21) on the supply tank side is inserted into the supply tank (20) from the outside of the supply tank (20). The anode plate (11) on the electrolytic cell side includes an anode plate immersion part (11a) disposed on the inner side of the electrolytic cell (10) and an anode plate protruding part (11b) disposed on the outer side of the electrolytic cell (10). The cathode plate (12) on the electrolytic cell side includes a cathode plate immersion part (12a) disposed on the inner side of the electrolytic cell (10) and a cathode plate protruding part (12b) disposed on the outer side of the electrolytic cell (10). The cathode plate (21) on the supply tank side includes a cathode plate immersion part (21a) disposed on the inner side of the supply tank (20) and a cathode plate protruding part (21b) disposed on the outer side of the supply tank (20). The entire anode plate immersion part (11a) on the electrolytic cell side and the entire cathode plate immersion part (12a) on the electrolytic cell side are immersed in the first aqueous solution (L1). The entire cathode plate immersion part (21a) on the supply tank side is immersed in the second aqueous solution (L2). The space purification device (1) according to item 1. (Item 8) The anode (11) on the electrolytic cell side and the cathode (21) on the supply tank side are an anode cylinder (11′) on the electrolytic cell side and a cathode cylinder (21′) on the supply tank side, each having a cylindrical or rectangular tube shape. The cathode (12) on the electrolytic cell side is a cathode cylinder (12′) or a cathode rod (12′) on the electrolytic cell side, having a cylindrical, rectangular tube shape or rod shape. The whole of the anode cylinder (11′) on the electrolytic cell side and the whole of the cathode cylinder (12′) or the cathode rod (12′) on the electrolytic cell side are immersed in the first aqueous solution (L1). The whole of the cathode cylinder (21′) on the supply tank side is immersed in the second aqueous solution (L2). The space purification device (1) according to item 1. (Item 9) A water level detection unit (18) for detecting the position of the liquid level in the first aqueous solution (L1); A water supply unit (19) for supplying water to the electrolytic cell (10) 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 plate immersion part (11a) and the electrolytic cell side cathode plate immersion part (12a), or the electrolytic cell side anode cylinder (11') or the electrolytic cell side cathode rod (12') and the electrolytic cell side cathode cylinder (12'); The space purification device (1) according to item 7 or 8. (Item 10) The electrolytic cell side anode plate (11) and the supply tank side cathode plate (21) are respectively close to the anion exchange membrane (30), The planes in the plate shape are arranged to face each other through the anion exchange membrane (30), The electrolytic cell side cathode plate (12) has the plane in the plate shape arranged to face the plane in the plate shape of the electrolytic cell side anode plate (11). The space purification device (1) according to item 7. (Item 11) The electrolytic cell side anode plate (11), the electrolytic cell side cathode plate (12) and the supply tank side cathode plate (21) have the plate shape being rectangular, (Item 11) The electrolytic cell side anode plate (11), the electrolytic cell side cathode plate (12) and the supply tank side cathode plate (21) have the plate shape being rectangular, The short side direction of the rectangle is arranged along the vertical direction, The long side direction of the rectangle is arranged along the horizontal direction. The space purification device (1) according to item 7. (Item 12) (Item 12) The diaphragm-free electrolysis part (E1) includes the electrolytic cell side anode (11) and the electrolytic cell side cathode (12), The diaphragm electrolysis part (E2) includes the electrolytic cell side anode (11), the supply tank side cathode (21) and the anion exchange membrane (30). The space purification device (1) according to item 1. (Item 13) The diaphragm-free electrolysis part (E1) includes the electrolytic cell side anode (11) and the electrolytic cell side cathode (12), The diaphragm electrolysis part (E2) includes the electrolytic cell side anode (11), the supply tank side cathode (21) and the anion exchange membrane (30). The space purification device (1) according to item 1. The space purification device (1) according to item 1. (Item 13) A housing (B) for housing the electrolytic cell (10) and the supply tank (20); An inlet (15) disposed above the liquid level of the first aqueous solution (L1) stored in the electrolytic cell (10) within the housing (B) and through which air from the external space of the housing (B) flows in; A mixing space (16) for mixing the volatilized hypochlorous acid and the air flowing in from the inlet (15); An outlet (17) through which the mixed air flows out to the external space, and comprising; The space purification device (1) according to item 1.

Explanation of symbols

[0114] 1,2 Space purification device 10 Electrolytic cell 11 Anode on the electrolytic cell side 11a Immersion part of the anode plate on the electrolytic cell side 11b Protrusion part of the anode plate on the electrolytic cell side 12 Cathode on the electrolytic cell side 12a Immersion part of the cathode plate on the electrolytic cell side 12b Protrusion part of the cathode plate on the electrolytic cell side 13,14 Wiring 15 Inlet 16 Mixing space 17 Outlet 20 Supply tank 21 Cathode on the supply tank side 22 Wiring 30 Anion exchange membrane 40 Current control unit B Housing E1 Diaphragmless electrolysis section E2 Diaphragm electrolysis section L1 First aqueous solution L2 Second aqueous solution 11 Anode plate on the electrolytic cell side 12 Cathode plate on the electrolytic cell side 21 Cathode plate on the supply tank side 50 Electrolytic cell 60 Supply tank 70 Electrolytic cell 71 First bottom surface 72 Second bottom surface 80 Supply tank 81 First bottom surface 82 Second bottom surface

Claims

1. An electrolytic cell for storing a first aqueous solution containing chloride ions, A supply tank 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, A housing for storing the electrolytic cell and the supply tank, An electrolytic cell side anode and an electrolytic cell side cathode provided in the electrolytic cell, A supply tank side cathode provided in the supply tank, An anion exchange membrane that connects the electrolytic cell and the supply tank so that anions can permeate based on a voltage applied between the electrolytic cell side anode and the supply tank side cathode, A diaphragm-free electrolysis unit provided in the electrolytic cell, which electrolyzes the first aqueous solution without a diaphragm by passing a first current between the electrolytic cell side anode and the electrolytic cell side cathode to generate hypochlorous acid, A diaphragm electrolysis unit provided across the electrolytic cell and the supply tank, which performs diaphragm electrolysis through the anion exchange membrane by passing a second current between the electrolytic cell side anode and the supply tank side cathode, A current control unit that controls the second current so as to supplement the chloride ions contained in the first aqueous solution reduced by the diaphragm-free electrolysis, and allows the chloride ions contained in the second aqueous solution to permeate through the anion exchange membrane and be supplied to the first aqueous solution, An inlet disposed above the liquid level of the first aqueous solution stored in the electrolytic cell within the housing, through which air from the external space of the housing flows in, A mixing space that mixes the volatilized hypochlorous acid gas and the air flowing in from the inlet, and brings the hypochlorous acid dissolved in the first aqueous solution into gas-liquid contact with the air flowing in from the inlet, An outlet through which the air mixed in the mixing space flows out to the external space, Comprising, The space purification is performed on the external space by the air containing hypochlorous acid flowing out from the outlet to the external space, Space purification device.

2. By flowing the first current and the second current at a predetermined ratio by the current control unit, The chloride ion concentration of the first aqueous solution is maintained at a predetermined concentration, which is the concentration of the first aqueous solution stored in the electrolytic cell before the diaphragm-free electrolysis, The predetermined ratio is a ratio at which the amount of chloride ions consumed by the diaphragm-free electrolysis is supplied to the first aqueous solution stored in the electrolytic cell, and the chloride ions in the electrolytic cell do not apparently increase or decrease, The space purification device according to Claim 1.

3. The current control unit is, A voltage acquisition unit that acquires the 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; An estimation unit that estimates the concentration of the first aqueous solution based on the conductivity calculated by the calculation unit, and The current control unit Simultaneously flows the first current and the second current, When the chloride ion concentration of the first aqueous solution is lower than a predetermined concentration which is the concentration of the first aqueous solution stored in the electrolytic cell before the diaphragm-free electrolysis, the current ratio of the first current and the second current is changed so that the amount of chloride ions permeating through the anion exchange membrane from the second aqueous solution and supplied to the first aqueous solution increases; When the chloride ion concentration of the first aqueous solution is higher than the predetermined concentration, the current ratio of the first current and the second current is changed so that the amount of chloride ions permeating through the anion exchange membrane from the second aqueous solution and supplied to the first aqueous solution decreases. The space purification device according to claim 1.

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

5. A voltage acquisition unit that acquires the 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; An estimation unit that estimates the concentration of the first aqueous solution based on the conductivity calculated by the calculation unit, and The current control unit Flows the first current and simultaneously controls the second current. The control of the second current When the chloride ion concentration of the first aqueous solution is lower than a predetermined concentration which is the concentration of the first aqueous solution stored in the electrolytic cell before the diaphragm-free electrolysis, the second current is flowed so that the amount of chloride ions permeating through the anion exchange membrane from the second aqueous solution and supplied to the first aqueous solution increases; When the chloride ion concentration of the first aqueous solution is higher than the predetermined concentration, the second current is stopped so that the supply of chloride ions from the second aqueous solution to the first aqueous solution stops. The space purification device according to claim 1.

6. A voltage acquisition unit that acquires the 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; An estimation unit that estimates the concentration of the first aqueous solution based on the conductivity calculated by the calculation unit, The current control unit When the chloride ion concentration of the first aqueous solution is lower than a predetermined concentration that is the concentration of the first aqueous solution stored in the electrolytic cell before the diaphragmless electrolysis, the first current is stopped and the second current is passed at the same time so that the amount of chloride ions permeating through the anion exchange membrane from the second aqueous solution and supplied to the first aqueous solution increases. When the chloride ion concentration of the first aqueous solution is higher than the predetermined concentration The second current is stopped and the first current is passed at the same time so that the supply of chloride ions from the second aqueous solution to the first aqueous solution is stopped. The space purification device according to claim 1.

7. The electrolytic cell side anode, the electrolytic cell side cathode, and the supply tank side cathode are an electrolytic cell side anode plate, an electrolytic cell side cathode plate, and a supply tank side cathode plate each having a plate shape, The electrolytic cell side anode plate and the electrolytic cell side cathode plate are inserted into the electrolytic cell from the outside of the electrolytic cell, and the supply tank side cathode plate is inserted into the supply tank from the outside of the supply tank. The electrolytic cell side anode plate includes an electrolytic cell side anode plate immersion part disposed on the inner side of the electrolytic cell and an electrolytic cell side anode plate protruding part disposed on the outer side of the electrolytic cell. The electrolytic cell side cathode plate includes an electrolytic cell side cathode plate immersion part disposed on the inner side of the electrolytic cell and an electrolytic cell side cathode plate protruding part disposed on the outer side of the electrolytic cell. The supply tank side cathode plate includes a supply tank side cathode plate immersion part disposed on the inner side of the supply tank and a supply tank side cathode plate protruding part disposed on the outer side of the supply tank. The entirety of the electrolytic cell side anode plate immersion part and the electrolytic cell side cathode plate immersion part Is immersed in the first aqueous solution, The entirety of the supply tank side cathode plate immersion part Is immersed in the second aqueous solution. The space purification device according to claim 1.

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

9. A water level detection unit that detects the position of the liquid level in the first aqueous solution; 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 part and the electrolytic cell side cathode plate immersion part, or the electrolytic cell side anode cylinder or the electrolytic cell side cathode rod and the electrolytic cell side cathode cylinder. The space purification device according to claim 7 or 8.

10. The water supply unit is a Peltier element that can cool the moisture contained in the air and turn it into water droplets. The space purification device according to claim 9.

11. The electrolytic cell side anode plate and the supply tank side cathode plate Are respectively close to the anion exchange membrane, The planes in the plate shape are arranged to face each other through the anion exchange membrane, The electrolytic cell side cathode plate The plane in the plate shape is arranged to face the plane in the plate shape of the electrolytic cell side anode plate. The space purification device according to claim 7.

12. The electrolytic cell side anode plate, the electrolytic cell side cathode plate, and the supply tank side cathode plate The plate shape is rectangular, The short side direction in the rectangle is arranged along the vertical direction, The long side direction in the rectangle is arranged along the horizontal direction. The space purification device according to claim 7.

13. The diaphragm-free electrolysis part The electrolytic cell side anode, The electrolytic cell side cathode, The diaphragm electrolysis part The electrolytic cell side anode, The supply tank side cathode, The anion exchange membrane. The space purification device according to claim 1.

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