Space purification device

Abstract

To provide a space purification device stably generating a desired amount of hypochlorous acid gas for a long time.SOLUTION: A space purification device 1 includes: an electrolytic tank 10 storing a first aqueous solution L1 containing chloride ions; a supply tank 20 storing a second aqueous solution L2 containing hydroxide ions; a gas supply unit 1b supplying chlorine gas to the first aqueous solution L1; an anion exchange membrane 30 enabling permeation of negative ions on the basis of a voltage applied between an electrolytic tank-side anode 11 and a supply tank-side cathode 21; a diaphragm electrolytic part E1 subjecting the first aqueous solution L1 and the second aqueous solution L2 to diaphragm electrolysis via the anion exchange membrane 30 to generate a hypochlorous acid in the electrolytic tank 10 by flowing a first electric current between the electrolytic tank-side anode 11 and the supply tank-side cathode 21; and an electric current control part 50 controlling the first electric current in the diaphragm electrolytic part E1 so as to consume the chloride ions generated by dissolving the chlorine gas supplied from the gas supply unit 1b into the first aqueous solution L1.SELECTED DRAWING: Figure 1

Description

[Technical Field]

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

[0002] Patent Document 1 discloses an air purifier that uses hypochlorous acid produced by electrolyzing an aqueous solution containing chloride ions to remove bacteria, fungi, viruses, odors, and the like from the air. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2019-174032 Summary of the Invention [Problem to be solved by the invention]

[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 invention 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. [Means for solving the problem]

[0006] a gas supply unit for supplying chlorine gas to the first aqueous solution stored in the electrolytic cell; an electrolytic cell-side anode provided in the electrolytic cell; a supply cell-side cathode provided in the supply cell; an anion exchange membrane connecting the electrolytic cell and the supply cell to allow anions to pass therethrough based on a voltage applied between the electrolytic cell-side anode and the supply cell-side cathode; a diaphragm-equipped electrolysis unit provided between the electrolytic cell and the supply cell to generate hypochlorous acid in the electrolytic cell by performing membrane-equipped electrolysis of the first aqueous solution and the second aqueous solution via the anion exchange membrane by passing a first current between the electrolytic cell-side anode and the supply cell-side cathode; and a current control unit for controlling the first current in the diaphragm-equipped electrolysis unit so as to consume chloride ions generated when chlorine gas supplied from the gas supply unit dissolves in the first aqueous solution. [Effects of the Invention]

[0007] The present invention provides a space purification device that can stably generate a desired amount of hypochlorous acid gas over a long period of time. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a side cross-sectional view showing a space purification device according to a first embodiment of the present invention. [Figure 2] FIG. 2 is a top view showing the space purification device of FIG. [Figure 3] FIG. 3 is a diagram showing the chemical reaction formulas that occur in the membraneless electrolysis section and membrane-containing electrolysis section that are configured by the respective tanks of the space purification device. [Figure 4] FIG. 4 is a block diagram showing a current control unit that constitutes the space purification device. DETAILED DESCRIPTION OF THE INVENTION

[0009] (Embodiment 1) A space purification device 1 according to a first embodiment of the present invention will be described with reference to Figures 1 and 2. Figure 1 is a side cross-sectional view showing the space purification device 1 according to the first embodiment of the present invention. Figure 2 is a top view showing the space purification device 1 of Figure 1.

[0010] The space purification device 1 electrolyzes a first aqueous solution L1 containing chloride ions 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 space outside the space purification device 1 by discharging the volatilized hypochlorous acid into the space outside the housing (not shown) that constitutes 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 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, or on a desk.

[0012] As shown in FIGS. 1 and 2, the space purification device 1 mainly includes a hypochlorous acid water unit 1a, a gas supply unit 1b, and a current control unit 50. The hypochlorous acid water unit 1a, the gas supply unit 1b, and the current control unit 50 are housed in a housing (not shown). In other words, the space purification device 1 may be a unit integrated into the housing. The shape of the housing 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 housed inside an air conditioner, for example, approximately 10 cm x 7 cm x 4 cm.

[0013] The hypochlorous acid water unit 1a is a unit that electrolyzes a first aqueous solution L1 containing chloride ions in an electrolytic cell 10 to generate and volatilize hypochlorous acid, and the gas supply unit 1b is a unit that electrolyzes a third aqueous solution L3 containing chloride ions in a diaphragm-less electrolytic cell 40 to supply air containing chlorine gas to the hypochlorous acid water unit 1a. As will be described in detail later, the current control unit 50 controls the operations of the hypochlorous acid water unit 1a and the gas supply unit 1b.

[0014] (Hypochlorous acid water unit) The hypochlorous acid water unit 1 a includes an electrolytic cell 10 , a supply cell 20 , and an anion exchange membrane 30 .

[0015] The electrolytic bath 10 is a bath for storing a first aqueous solution L1 containing chloride ions. Fig. 1 shows a state in which the first aqueous solution L1 is stored in the electrolytic bath 10 up to the position of a liquid level S1. 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 within a predetermined 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 10 g / L. In other words, the mass percent concentration of the dilute sodium chloride aqueous solution or dilute potassium chloride aqueous solution may be, for example, 0.1% to 5%, or even 1%. By setting the predetermined chloride ion concentration within 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 hydroxide ions. Hydroxide ions contained in the second aqueous solution L2 in the tank 20 pass through the anion exchange membrane 30 and are supplied to the first aqueous solution L1 in the electrolytic tank 10. The electrolytic tank 10, the supply tank 20, and the anion exchange membrane 30 described below may be collectively referred to as a "membrane-equipped electrolytic tank."

[0018] The supply tank 20 stores a second aqueous solution L2 containing hydroxide ions and supplies the hydroxide ions to the first aqueous solution L1. FIG. 1 shows a state in which the second aqueous solution L2 is stored in the supply tank 20 up to the liquid level S2. The second aqueous solution L2 is, for example, an aqueous sodium hydroxide solution. More specifically, the second aqueous solution L2 may be, for example, an aqueous sodium hydroxide solution with a mass percent concentration of 0.1% to 5%, or even 1%. It is more preferable that the second aqueous solution L2 contains sodium chloride or potassium chloride so that the molar concentration is the same as that of the metal cations (sodium ions or potassium ions) contained in the first aqueous solution L1.

[0019] The anion exchange membrane 30 is a membranous member that connects the electrolytic cell 10 and the supply cell 20 in a manner that allows anions to pass therethrough, based on a voltage applied between the electrolytic cell 10 and the supply cell 20. More specifically, when a voltage is applied between the electrolytic cell-side anode 11 and the supply cell-side cathode 21 (described below), membrane-type electrolysis occurs via the anion exchange membrane 30. By the membrane-type electrolysis using the electrolytic cell-side anode 11 and the supply cell-side cathode 21, hydroxide ions contained in the second aqueous solution L2 permeate the anion exchange membrane 30 and are supplied to the first aqueous solution L1.

[0020] More specifically, the anion exchange membrane 30 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. That is, 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 the electrolytic cell-side anode 11 and the supply cell-side cathode 21, sodium ions, which are cations, do not permeate the anion exchange membrane 30. The anion exchange membrane 30 may be, for example, a hydrocarbon-based anion exchange membrane, and may include membranes that have monovalent anion-selective permeability, alkali resistance, and high-temperature resistance.

[0021] Hereinafter, the details of each tank (electrolytic tank 10, supply tank 20) ​​that constitutes the hypochlorous acid water unit 1a will be described in more detail.

[0022] (electrolytic cell) The electrolytic cell 10 includes an electrolytic cell-side anode 11 , a supply port 43 b , an upper space 13 , a discharge port 12 , and wiring 15 .

[0023] The electrolytic cell-side anode 11 is an electrode used in the electrolysis of the first aqueous solution L1, paired with the supply cell-side cathode 21 disposed in the supply cell 20. A main portion of the electrolytic cell-side anode 11 is disposed immersed in the first aqueous solution L1, facing the supply cell-side cathode 21. An anion-exchange membrane 30 is disposed between the electrolytic cell-side anode 11 and the supply cell-side cathode 21. That is, the electrolysis of the first aqueous solution L1 and the second aqueous solution L2 performed using the pair of the electrolytic cell-side anode 11 and the supply cell-side cathode 21 is membrane-operated electrolysis. Hypochlorous acid, which is used for space purification, is generated in the electrolytic cell 10 by the membrane-operated electrolysis of the first aqueous solution L1 performed using the pair of the electrolytic cell-side anode 11 and the supply cell-side cathode 21.

[0024] As the electrolytic cell-side anode 11, 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.

[0025] The supply port 43b is an opening for supplying air (air containing chlorine gas) supplied from the gas supply unit 1b (described later) as bubbles into the first aqueous solution L1. For this reason, the supply port 43b is provided near the bottom of the electrolytic cell 10. An air tube is connected to the supply port 43b. The air stone is a stone (for example, a stone made of porous ceramics or porous synthetic resin) that converts supplied air into fine bubbles and releases them into the first aqueous solution L1.

[0026] The upper space 13 is a space formed above the liquid level S1 in the electrolytic cell 10 when the first aqueous solution L1 is stored in the electrolytic cell 10. The upper space 13 is a space that mixes air that is supplied from the supply port 43b and rises to the surface as bubbles in the first aqueous solution L1, hypochlorous acid gas that is produced by dissolving chlorine gas supplied from the supply port 43b in the first aqueous solution L1 and then volatilizing and gasifying hypochlorous acid, and hypochlorous acid gas that is produced by membrane-equipped electrolysis of the first aqueous solution L1 using a pair of the electrolytic cell-side anode 11 and the supply cell-side cathode 21.

[0027] The discharge port 12 is an opening through which mixed air, which is a mixture of air supplied from the supply port 43b and floating up as bubbles in the first aqueous solution L1 and hypochlorous acid (hypochlorous acid gas) generated in the first aqueous solution L1, flows out to the space outside the housing. That is, the discharge port 12 is an opening through which the mixed air flows out to the space outside the space purification device 1. The shape (opening cross section) of the discharge port 12 may be, for example, cylindrical as shown in FIG. 2 or rectangular tubular.

[0028] The air containing hypochlorous acid that flows out from the outlet 12 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.

[0029] The wiring 15 is a line through which a current flows. The electrolytic cell anode 11 is electrically connected via the wiring 15 to a current control unit 50, which will be described later.

[0030] (supply tank) The supply tank 20 includes a supply tank-side cathode 21 , an outlet 22 , and wiring 25 .

[0031] The supply tank-side cathode 21 is an electrode paired with the electrolytic cell-side anode 11 and used in the electrolysis of the second aqueous solution L2. A major portion of the supply tank-side cathode 21 is immersed in the second aqueous solution L2, facing the electrolytic cell-side anode 11. As described above, an anion-exchange membrane 30 is disposed between the supply tank-side cathode 21 and the electrolytic cell-side anode 11. That is, the electrolysis of the second aqueous solution L2 performed using the pair of the supply tank-side cathode 21 and the electrolytic cell-side anode 11 is membrane-operated electrolysis. Hydroxide ions are generated by the membrane-operated electrolysis of the second aqueous solution L2 performed using the pair of the supply tank-side cathode 21 and the electrolytic cell-side anode 11, and the hydroxide ions are supplied from the second aqueous solution L2 to the first aqueous solution L1. Hydrogen is also generated by the membrane-operated electrolysis of the second aqueous solution L2 performed using the pair of the supply tank-side cathode 21 and the electrolytic cell-side anode 11.

[0032] As with the electrolytic cell side anode 11, for example, a platinum-iridium-titanium electrode, a platinum electrode, a ruthenium-titanium electrode, or an iridium-titanium oxide electrode may be used as the supply cell side cathode 21.

[0033] The outlet 22 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. The outlet 22 may be, for example, a check valve. When a check valve is used as the outlet 22, the hydrogen gas inside the supply tank 20 is discharged to the external space, but the inflow of gas 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. The shape (opening cross section) of the outlet 22 may be, for example, cylindrical as shown in FIG. 2. , or may be in the shape of a square tube.

[0034] The wiring 25 is a line through which a current flows. The supply tank side cathode 21 is electrically connected via the wiring 25 to a current control unit 50, which will be described later.

[0035] In the hypochlorous acid water unit 1a as described above, the electrolytic cell 10, the anion exchange membrane 30, and the supply tank 20 constitute a membrane-type electrolysis section E1.

[0036] The membrane-with-diaphragm electrolysis unit E1 is provided across the electrolytic cell 10 and the supply cell 20. The membrane-with-diaphragm electrolysis unit E1 performs membrane-with-diaphragm electrolysis via the anion exchange membrane 30 by passing a first current between the electrolytic cell-side anode 11 and the supply cell-side cathode 21 via wiring 15 and wiring 25. More specifically, the membrane-with-diaphragm electrolysis unit E1 performs membrane-with-diaphragm electrolysis of the first aqueous solution L1 to produce hypochlorous acid and performs membrane-with-diaphragm electrolysis of the second aqueous solution L2 to produce hydroxide ions and hydrogen by passing a first current between the electrolytic cell-side anode 11 and the supply cell-side cathode 21.

[0037] (gas supply unit) The gas supply unit 1 b includes a diaphragm-less electrolytic cell 40 , an air supply unit 42 , and a vent pipe 43 .

[0038] The diaphragm-less electrolytic cell 40 is a tank for storing the third aqueous solution L3 containing chloride ions. FIG. 1 shows the state in which the third aqueous solution L3 is stored in the diaphragm-less electrolytic cell 40 up to the liquid level S3. The chloride ion concentration of the third aqueous solution L3 is higher than the chloride ion concentration of the first aqueous solution L1. The third aqueous solution L3 is, for example, a high-concentration hydrochloric acid aqueous solution. More specifically, the third aqueous solution L3 is, for example, a hydrochloric acid aqueous solution with a mass percent concentration of 10% to 25%.

[0039] The air supply unit 42 is a pump that supplies air drawn in from an external space at high pressure into the diaphragm-less electrolytic cell 40. The air supply unit 42 is, for example, an air pump. The air supply unit 42 is disposed outside the diaphragm-less electrolytic cell 40 (for example, on the upper surface of the outer wall). The air supply unit 42 is connected wirelessly or by wire to be able to communicate with the current control unit 50, which will be described later, and is controlled by the current control unit 50.

[0040] The vent pipe 43 is a pipe for introducing air (air containing chlorine gas) from within the diaphragm-less electrolytic cell 40 into the first aqueous solution L1 of the electrolytic cell 10. The vent pipe 43 extends to communicate between an outlet 43a provided in the diaphragm-less electrolytic cell 40 and a supply port 43b provided in the electrolytic cell 10. It can be said that the vent pipe 43 has the role of sending air forced out of the diaphragm-less electrolytic cell 40 by operation of the air supply unit 42 from the supply port 43b of the electrolytic cell 10 into the first aqueous solution L1.

[0041] The details of the membraneless electrolytic cell 40 that constitutes the gas supply unit 1b will be described in more detail below.

[0042] (Diaphragmless electrolytic cell) The diaphragm-less electrolytic cell 40 includes a diaphragm-less electrolytic cell-side anode 41a, a diaphragm-less electrolytic cell-side cathode 41b, an inlet 42a, an upper space 44, an outlet 43a, a wire 45a, and a wire 45b.

[0043] The diaphragm-less electrolytic cell side anode 41a and the diaphragm-less electrolytic cell side cathode 41b are a pair of electrodes used in the electrolysis of the third aqueous solution L3. As shown in FIG. 1, no diaphragm such as an ion exchange membrane is provided between the diaphragm-less electrolytic cell side anode 41a and the diaphragm-less electrolytic cell side cathode 41b. In other words, the electrolysis of the third aqueous solution L3 performed using the pair of the diaphragm-less electrolytic cell side anode 41a and the diaphragm-less electrolytic cell side cathode 41b is diaphragm-less electrolysis. The chlorine gas to be supplied to the hypochlorous acid water unit 1a is generated by membraneless electrolysis of the third aqueous solution L3 using the hypochlorous acid water unit 1b.

[0044] As the membrane-less electrolytic cell side anode 41a and the membrane-less electrolytic cell side cathode 41b, 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.

[0045] The inlet 42a is an opening for introducing air from the space outside the housing into the diaphragm-less electrolytic cell 40 by operating the air supply unit 42. That is, the inlet 42a is an opening for air to flow into from the space outside the space purification device 1. In FIG. 1, the inlet 42a is provided on the top surface of the diaphragm-less electrolytic cell 40 as an example, but it need only be located above the liquid level S3 of the third aqueous solution L3. The shape (opening cross section) of the inlet 42a may be cylindrical, as shown in FIG. 2, or may be a rectangular tube.

[0046] The upper space 44 is a space formed above the liquid level S3 in the diaphragm-less electrolytic cell 40 when the third aqueous solution L3 is stored in the diaphragm-less electrolytic cell 40. The upper space 44 can also be called a mixing space, and is a space in which chlorine (chlorine gas) produced by diaphragm-less electrolysis of the third aqueous solution L3, which is performed using a pair of diaphragm-less electrolytic cell-side anodes 41a and diaphragm-less electrolytic cell-side cathodes 41b, is mixed with air from the external space that has flowed in through the inlet 42a. The mixed air (air containing chlorine gas) is forced out from the outlet 43a into the vent pipe 43 by the driving force of the air supply unit 42.

[0047] The outlet 43a is an opening for discharging the air mixed in the upper space 44 to the outside of the membraneless electrolytic cell 40. The outlet 43a is connected to one end of the vent pipe 43 in the upper space 44.

[0048] The wiring 45a is a line through which a current flows. The membraneless electrolytic cell side anode 41a is electrically connected to a current control unit 50 (described later) via the wiring 45a.

[0049] The wiring 45b is a line through which a current flows. The membraneless electrolytic cell side cathode 41b is electrically connected to a current control unit 50 (described later) via the wiring 45b.

[0050] In the gas supply unit 1b as described above, the diaphragm-less electrolysis cell 40 constitutes the diaphragm-less electrolysis section E2.

[0051] The diaphragm-free electrolysis unit E2 is composed of a diaphragm-free electrolytic cell-side anode 41a and a diaphragm-free electrolytic cell-side cathode 41b without a diaphragm, and performs diaphragm-free electrolysis by passing a second current between the pair of the diaphragm-free electrolytic cell-side anode 41a and the diaphragm-free electrolytic cell-side cathode 41b. More specifically, the diaphragm-free electrolysis unit E2 electrolyzes the third aqueous solution L3 without a diaphragm, producing chlorine, by passing a second current between the diaphragm-free electrolytic cell-side anode 41a and the diaphragm-free electrolytic cell-side cathode 41b.

[0052] (Current control section) The current control unit 50 controls the current used in the diaphragm-containing electrolysis and the diaphragm-less electrolysis. More specifically, the current control unit 50 controls the current used in the diaphragm-containing electrolysis performed via the anion exchange membrane 30 by the electrolytic cell-side anode 11 arranged in the electrolytic cell 10 and the supply cell-side cathode 21 arranged in the supply cell 20. The current control unit 50 also controls the current used in the diaphragm-less electrolysis performed by the diaphragm-less electrolytic cell-side anode 41a and the diaphragm-less electrolytic cell-side cathode 41b arranged in the diaphragm-less electrolytic cell 40.

[0053] More specifically, the current control unit 50 controls the first current to be applied to the membrane-containing electrolysis unit E1 and the second current to be applied to the membrane-less electrolysis unit E2. By controlling the second current flowing through E2, the chemical reaction occurring in the electrolysis section with a diaphragm E1 and the chemical reaction occurring in the electrolysis section without a diaphragm E2 are controlled.

[0054] As will be described in detail later, the current control unit 50 controls the first and second currents to flow at a predetermined ratio, thereby supplying the chloride ions consumed by the first aqueous solution L1 from the air containing chlorine produced by the third aqueous solution L3, thereby maintaining the chloride ion concentration of the first aqueous solution L1 at a predetermined concentration. In other words, the chloride ions produced by the chlorine gas (chlorine gas produced by the third aqueous solution L3) supplied from the gas supply unit 1b dissolves in the first aqueous solution L1 and consumes them to produce hypochlorous acid, thereby maintaining the chloride ion concentration of the first aqueous solution L1 at a predetermined concentration. This allows the space purification device 1 to stably generate a desired amount of hypochlorous acid gas. Therefore, a desired amount of hypochlorous acid gas can be stably generated over a long period of time, such as one year, without supplying an aqueous solution containing chloride ions from outside.

[0055] The current control unit 50 controls the supply operation of the air supply unit 42 and adjusts the amount of air supplied (airflow) by the air supply unit 42 into the membraneless electrolytic cell 40.

[0056] 1, the space purification device 1 may further include a water level detection unit 61 and a water supply unit 62. The water level detection unit 61 is installed in the electrolytic cell 10 and detects the position of the liquid level S1 of the first aqueous solution L1. The water level detection unit 61 is, for example, a water level sensor. The water level detection unit 61 is disposed at least above the upper end of the electrolytic cell-side anode 11.

[0057] The water supply unit 62 supplies water to the electrolytic cell 10 based on the position of the liquid level S1 detected by the water level detection unit 61. More specifically, the water supply unit 62 supplies water to the electrolytic cell 10 so that the water level does not fall below the upper end of the electrolytic cell-side anode 11. The water supply unit 62 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 62 may be located in any position that allows it to supply water to the electrolytic cell 10, and may be located above the electrolytic cell 10 or above the diaphragm-less electrolytic cell 40 as shown in Figure 1.

[0058] When the spatial purification device 1 is equipped with the water level detector 61 and the water supplier 62, the electrolytic cell anode 11 can be kept immersed in the first aqueous solution L1. This prevents the electrolytic cell anode 11 from being exposed to air due to a decrease in the first aqueous solution L1, and maintains the electrolysis efficiency of the membrane-type electrolysis.

[0059] The water supply unit 62 may also supply water to the diaphragm-less electrolytic cell 40. More specifically, the water supply unit 62 may also supply water to the diaphragm-less electrolytic cell 40 so that the water level does not fall below the upper ends of the diaphragm-less electrolytic cell-side anode 41a and the diaphragm-less electrolytic cell-side cathode 41b. This makes it possible to replenish the moisture lost from the third aqueous solution L3 when air introduced from the air supply unit 42 flows through the upper space 44. In other words, the diaphragm-less electrolytic cell-side anode 41a and the diaphragm-less electrolytic cell-side cathode 41b can be maintained immersed in the third aqueous solution L3. This prevents the diaphragm-less electrolytic cell-side anode 41a and the diaphragm-less electrolytic cell-side cathode 41b from being exposed to air due to a decrease in the third aqueous solution L3, thereby maintaining the electrolysis efficiency of the diaphragm-less electrolysis.

[0060] Here, with reference to Fig. 3, the chemical reactions occurring in the diaphragm-less electrolysis unit E2 and the diaphragm-containing electrolysis unit E1 provided between the electrolytic cell 10 and the supply cell 20 will be described in detail. Fig. 3 is a diagram showing the chemical reaction formulas occurring in the diaphragm-less electrolysis unit E2 and the diaphragm-containing electrolysis unit E1, which are constituted by the respective cells of the space purification device 1. The following description will be given for the case where the first aqueous solution L1 containing chloride ions is a sodium chloride aqueous solution, the second aqueous solution L2 containing hydroxide ions is a sodium hydroxide aqueous solution, and the third aqueous solution L3 containing chloride ions is a hydrochloric acid aqueous solution.

[0061] [Diaphragmless electrolytic section E2 (diaphragmless electrolytic cell 40)] The hydrochloric acid (HCl) contained in the third aqueous solution L3 is H + and Cl - When a predetermined voltage is applied to the membraneless electrolysis section E2, a current flows and one electron (e - ) moves, and the following chemical reaction occurs, as shown in Figure 3: Reaction formula (a): Hydrogen generation reaction at the cathode 41b on the membraneless electrolytic cell side Reaction formula (b): Chlorine generation reaction at the membraneless electrolytic cell anode 41a

[0062] [Diaphragm electrolysis section E1 (electrolytic cell 10)] The sodium chloride (NaCl) contained in the first aqueous solution L1 is + and Cl - When a predetermined voltage is applied to the membraneless electrolysis section E2, a current flows and one electron (e - ) moves, and one of the following chemical reactions occurs, as shown in Figure 3: Reaction formula (c): Hypochlorous acid generation reaction at the electrolytic cell anode 11 Reaction formula (d): Oxygen evolution reaction at the electrolytic cell anode 11

[0063] [Diaphragm electrolysis section E1 (supply tank 20)] The sodium hydroxide solution in the second aqueous solution L2 contains sodium hydroxide (NaOH) in water. + and OH - When a predetermined voltage is applied to the membraneless electrolysis section E2 in this ionized state, a current flows and electrons (e - ) moves, and the following chemical reaction occurs, as shown in Figure 3: Reaction formula (e): Generation reaction of hydrogen and hydroxide ions at the supply tank side cathode 21

[0064] On the other hand, in addition to the above-mentioned chemical reactions, the following phenomenon shown in FIG. 3 occurs in the electrolytic cell 10.

[0065] When air containing chlorine gas is supplied from the diaphragm-less electrolytic cell 40 through the vent pipe 43 to the electrolytic cell 10, the water (HO) in the first aqueous solution L1 stored in the electrolytic cell 10 changes to hydrochloric acid (HCl) and hypochlorous acid (HClO). That is, in the first aqueous solution L1 to which the air containing chlorine gas has been supplied, part of the water (HO) contained before the change changes to hydrochloric acid (HCl) and hypochlorous acid (HClO) after the change.

[0066] In the electrolytic cell 10, a voltage is applied to the diaphragm electrolysis section E1 and a current flows. When one electron (e - ) is lost from the first aqueous solution L1 stored in the electrolytic cell 10, hydroxide ions (OH - ) permeate through the anion exchange membrane 30 from the second aqueous solution L2 stored in the supply tank 20 and are supplied to the first aqueous solution L1 in the electrolytic cell 10. That is, in the electrolytic cell 10, it can be said that the electrons (e - ) before the change become hydroxide ions (OH - ) after the change.

[0067] Here, let the ratio of the current used in the hypochlorous acid generation reaction of reaction formula (c) be "x (0 < x < 1)", and the ratio of the current used in the oxygen generation reaction of reaction formula (d) be "1 - x". Also, let the first current used in the diaphragm electrolysis be represented by the number of electrons (e - ) and be "Y [mol]", and let the second current used in reaction formulas (a) and (b) of the diaphragm-free electrolysis be "W [mol]". Also, let the amount of chlorine (Cl2) generated in reaction formula (b) that dissolves in the first aqueous solution L1 in the electrolytic cell 10 be "Z [mol]", and the dissolution ratio be "α (0 < α ≤ 1)".

[0068] Based on the above premises, in the electrolytic cell 10, the amount (consumption amount) of chloride ions (Cl - ) consumed by the progress of reaction formula (c) is such that "Yx" of the chloride ions (Cl - ) on the left side are consumed, and "Yx / 2" of hydrochloric acid (HCl) on the right side is generated and remains as chloride ions (Cl - ), so it is calculated as "Yx / 2 (= Yx - Yx / 2)".

[0069] On the other hand, the amount (generation amount) of chloride ions (Cl ions (Cl - ) generated by the supply of chlorine gas (Cl2) from the diaphragm-free electrolytic cell 40 is "Z [mol]" because the amount of chlorine (Cl2) that dissolves in the first aqueous solution L1 in the electrolytic cell 10 is "Z [mol]".

[0070] Therefore, in order to maintain the chloride ion concentration in the first aqueous solution L1 at a predetermined concentration, the amount of chloride ions consumed and produced in the electrolytic cell 10 should be controlled to be equal. In other words, "Z=Yx / 2."

[0071] Next, attention will be paid to the amount of chlorine gas (Cl2) in the membraneless electrolytic cell 40.

[0072] Since the amount dissolved in the first aqueous solution L1 of the electrolytic cell 10 is "Z [mol]" and the dissolution ratio is "α", the amount (supply amount) of chlorine gas (Cl2) supplied from the membrane-less electrolytic cell 40 is calculated as "Z / α". On the other hand, the amount (production amount) of chlorine gas (Cl2) generated by the progress of reaction formula (b) in the membrane-less electrolytic cell 40 is calculated as "Z / α". - ) produces 1 / 2 chlorine gas (Cl2). Here, the amount of chlorine gas (Cl2) produced is the same as the amount supplied, so "W = 2Z / α". Substituting this with the above-mentioned "Z = Yx / 2", we get "W = Yx / α".

[0073] From the above, in the space purification device 1, to maintain the chloride ion concentration of the first aqueous solution L1 at a predetermined concentration, the current control unit 50 simply controls the first current "Y [mol]" used in the diaphragm-containing electrolysis unit E1 (diaphragm-containing electrolysis) to be equal to the second current "W = Yx / α [mol]" used in the diaphragm-free electrolysis unit E2 (diaphragm-free electrolysis). In other words, by flowing the first current and the second current at a predetermined ratio of "first current:second current = 1:x / α," the amount of chloride ions consumed by the first aqueous solution L1 can be replenished by supplying them from the air containing chlorine generated by the third aqueous solution L3. In other words, the amount of chloride ions resulting from chlorine generated and supplied by the third aqueous solution L3 can be consumed by the diaphragm-containing electrolysis in the diaphragm-containing electrolysis unit E1.

[0074] The above is a detailed description of the chemical reaction that occurs in the diaphragm-equipped electrolysis section E1 that is provided between the electrolytic cell 10 and the supply cell 20, and the chemical reaction that occurs in the diaphragm-less electrolysis section E2 that is provided in the diaphragm-less electrolytic cell 40.

[0075] The current control unit 50 controls the chemical reaction. More specifically, it controls the second current used in the membrane-less electrolysis in the membrane-less electrolysis unit E2 so as to replenish the chloride ions contained in the first aqueous solution L1 that have been reduced by the membrane-less electrolysis in the membrane-less electrolysis unit E1 using the first current. By controlling the second current, chloride ions contained in the third aqueous solution L3 are electrolyzed without a membrane, thereby supplying chlorine gas to the first aqueous solution L1. Details will be described below with reference to FIG. 4.

[0076] 4 is a block diagram showing the current control unit 50 that constitutes the space purification device 1. As shown in FIG. 4, the current control unit 50 includes a voltage acquisition unit 51, a calculation unit 52, and an estimation unit 53.

[0077] The voltage acquiring unit 51 acquires the voltage between a pair of electrodes (not shown) immersed in the first aqueous solution L1 of the electrolytic bath 10. The voltage acquiring unit 51 is, for example, a voltmeter. The calculation unit 52 calculates the conductivity of the first aqueous solution L1 based on the voltage acquired by the voltage acquiring unit 51. The estimation unit 53 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 52.

[0078] The current control unit 50 controls the first current passed through the diaphragm-equipped electrolysis unit E1 and the second current passed through the diaphragm-less electrolysis unit E2 shown in Fig. 4 so as to maintain the chloride ion concentration in the first aqueous solution L1 at a predetermined concentration. An example of current control by the current control unit 50 will be described below.

[0079] When the current control unit 50 simultaneously supplies the first current and the second current, it performs the following controls (A) to (C).

[0080] (A) When the chloride ion concentration of the first aqueous solution L1 estimated by the estimation unit 53 is lower than a predetermined concentration: The current ratio between the first current and the second current is changed so that the amount of chlorine gas supplied from the diaphragm-less electrolytic cell 40 to the first aqueous solution L1 increases. More specifically, the current ratio of the second current to the first current is increased. Alternatively, the current ratio between the first current and the second current is changed so that the amount of chloride ions consumed in the electrolytic cell 10 decreases. More specifically, the current ratio of the first current to the second current is decreased.

[0081] (B) When the chloride ion concentration of the first aqueous solution L1 estimated by the estimation unit 53 is higher than a predetermined concentration: The current ratio between the first current and the second current is changed so that the amount of chloride ions supplied from the diaphragm-less electrolytic cell 40 to the first aqueous solution L1 decreases. More specifically, the current ratio of the second current to the first current is decreased. Alternatively, the current ratio between the first current and the second current is changed so that the amount of chloride ions consumed in the electrolytic cell 10 increases. More specifically, the current ratio of the first current to the second current is increased.

[0082] (C) When the chloride ion concentration of the first aqueous solution L1 estimated by the estimation unit 53 is a predetermined concentration: the current ratio between the first current and the second current is not changed.

[0083] As described above, the current control unit 50 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.

[0084] If the chloride ion concentration in the first aqueous solution L1 increases or decreases, the current ratio of the second current to the first current is changed. Because the first and second currents are passed simultaneously, increases or decreases in the chloride ion concentration in the first aqueous solution L1 can be minimized and maintained at an optimal predetermined concentration.

[0085] As described above, the space purification device 1 according to the first embodiment can provide the following effects.

[0086] (1) The space purification device 1 includes an electrolytic cell 10 for storing a first aqueous solution L1 (aqueous sodium chloride solution) containing chloride ions, a supply tank 20 for storing a second aqueous solution L2 (aqueous sodium hydroxide solution) containing hydroxide ions and supplying hydroxide ions to the first aqueous solution L1, a gas supply unit 1b for supplying chlorine gas to the first aqueous solution L1 stored in the electrolytic cell 10, an electrolytic cell-side anode 11 provided in the electrolytic cell 10, a supply tank-side cathode 21 provided in the supply tank 20, and a cathode 22 for permeating anions based on a voltage applied between the electrolytic cell-side anode 11 and the supply tank-side cathode 21. the anion exchange membrane (30) connecting the electrolytic cell (10) and the supply cell (20); a membrane-equipped electrolysis unit (E1) provided across the electrolytic cell (10) and the supply cell (20) for generating hypochlorous acid in the electrolytic cell (10) by performing membrane-equipped electrolysis of the first aqueous solution (L1) and the second aqueous solution (L2) via the anion exchange membrane (30) by passing a first current between the electrolytic cell-side anode (11) and the supply cell-side cathode (21); and a current control unit (50) for controlling the first current in the membrane-equipped electrolysis unit (E1) so as to consume chloride ions generated when chlorine gas supplied from the gas supply unit (1b) dissolves in the first aqueous solution (L1).

[0087] With this configuration, the amount of chloride ions generated when chlorine gas supplied from the gas supply unit 1b dissolves in the first aqueous solution L1 is consumed by the diaphragm electrolysis in the diaphragm electrolysis section E1. In other words, the amount of chloride ions consumed by the first aqueous solution L1 can be replenished with chloride ions by the chlorine gas supplied from the gas supply unit 1b, so that the chloride ion concentration in the first aqueous solution L1 can be maintained at a predetermined concentration. This means that the space purification device 1 can stably generate a desired amount of hypochlorous acid gas for a long period of time.

[0088] (2) In the space purification device 1, the gas supply unit 1b includes a diaphragm-less electrolytic cell 40 for storing a third aqueous solution L3 (hydrochloric acid aqueous solution) containing a higher concentration of chloride ions than the first aqueous solution L1, and a pair of a diaphragm-less electrolytic cell-side anode 41a and a diaphragm-less electrolytic cell-side cathode 41b provided in the diaphragm-less electrolytic cell 40. Then, by passing a second current between the diaphragm-less electrolytic cell-side anode 41a and the diaphragm-less electrolytic cell-side cathode 41b, the third aqueous solution L3 is electrolyzed without a diaphragm to generate chlorine gas, which is supplied to the first aqueous solution L1.

[0089] Thus, by controlling the first current passed in the diaphragm-less electrolysis of the third aqueous solution L3 together with the first current passed in the diaphragm-less electrolysis of the diaphragm-less electrolysis section E1, it is possible to easily supply chlorine produced by the diaphragm-less electrolysis of the third aqueous solution L3 as chlorine gas supplied from the gas supply unit 1b.

[0090] (3) In the spatial purification device 1, the current control unit 50 controls the second current in the gas supply unit 1b. In this case, the current control unit 50 controls the first current and the second current at a predetermined ratio (first current:second current=1:x / α) to maintain the chloride ion concentration of the first aqueous solution L1 at a predetermined concentration. This allows the current control unit 50 to control the chloride ion concentration of the first aqueous solution L1 so as to maintain it with high precision.

[0091] (4) In the space purification device 1, the current control unit 50 simultaneously passes 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 chlorine gas supplied from the gas supply unit 1b (diaphragm-less electrolytic cell 40) to the first aqueous solution L1, and when the chloride ion concentration of the first aqueous solution L1 is higher than the predetermined concentration, changes the current ratio between the first current and the second current so as to decrease the amount of chlorine gas supplied from the gas supply unit 1b (diaphragm-less electrolytic cell 40) to the first aqueous solution L1.

[0092] This minimizes the increase or decrease in the chloride ion concentration in the first aqueous solution L1, and allows the concentration to be maintained at an optimum predetermined level.

[0093] (5) The space purification device 1 is provided with an air supply unit 42 that introduces air from the external space into the diaphragm-less electrolytic cell 40, an outlet 43a that is arranged above the liquid level S3 of the third aqueous solution L3 stored in the diaphragm-less electrolytic cell 40 and that discharges air containing chlorine gas generated by diaphragm-less electrolysis, a supply port 43b that supplies the air containing chlorine gas discharged from the outlet 43a into the first aqueous solution L1 stored in the electrolytic cell 10, and a discharge port 12 that is arranged above the liquid level S1 of the first aqueous solution L1 stored in the electrolytic cell 10 and that discharges air that is supplied from the supply port 43b and floats up in the first aqueous solution L1 into the external space.

[0094] With this configuration, the air from the external space introduced into the diaphragm-less electrolytic cell 40 from the air supply unit 42 flows through the upper space 44 of the diaphragm-less electrolytic cell 40, the vent pipe 43, the first aqueous solution L1, and the upper space 13 of the electrolytic cell 10, and can be released into the external space as air containing hypochlorous acid gas from the discharge port 12. This makes it possible to remove bacteria, fungi, viruses, odors, and the like contained in the air in the external space of the space purification device 1.

[0095] The present invention has been described above based on the embodiments, but the present invention is not limited to the above embodiments, and it can be easily inferred that various improvements and modifications are possible within the scope of the invention without departing from the spirit of the invention.

[0096] In the space purification device 1 according to the first embodiment, air from the external space supplied from the air supply unit 42 is introduced into the space 44 above the diaphragm-less electrolytic cell 40 via the inlet 42a. However, this is not limiting. For example, the air introduced from the air supply unit 42 may be released as bubbles into the third aqueous solution L3 stored in the diaphragm-less electrolytic cell 40. Specifically, the inlet 42a may be provided near the bottom of the diaphragm-less electrolytic cell 40 and connected to an air stone via an air tube, so that the air supplied from the air supply unit 42 is made into fine bubbles and released as bubbles into the third aqueous solution L3. This makes it possible to more reliably include chlorine gas in the air supplied from the gas supply unit 1b (diaphragm-less electrolytic cell 40).

[0097] Furthermore, in the space purification device 1 according to the first embodiment, the diaphragm-less electrolytic cell 40 is used as the gas supply unit 1b, and chlorine gas is generated by diaphragm-less electrolysis of stored chloride ions and supplied to the electrolytic cell 10. However, this is not limiting. For example, a small gas cylinder filled with chlorine gas may be used to introduce chlorine gas into the air in the external space supplied from the air supply unit 42. In this case, the amount of chlorine gas (supply amount) can be controlled by adjusting the opening state of the supply valve of the gas cylinder. This also achieves the above-described effects. [Industrial Applicability]

[0098] The air purifying device according to this embodiment can stably generate a desired amount of hypochlorous acid gas over a long period of time, and is therefore useful as a device for purifying or sterilizing indoor spaces, etc. [Explanation of symbols]

[0099] 1. Space Purification Device 1a Hypochlorous acid water unit 1b Gas supply unit 10 Electrolytic cell 11 Electrolyzer side anode 12 Outlet 13 Upper space 15 Wiring 20 supply tanks 21 Supply tank side cathode 22 outlet 25 Wiring 30 anion exchange membrane 40 diaphragmless electrolyzer 41a Anode side of electrolytic cell without diaphragm 41b Cathode side of electrolyzer without diaphragm 42 Air Supply Department 42a Inlet 43 pipe 43a Export port 43b Supply port 44 Upper Space 45a wiring 45b wiring 50 Current Control Unit 51 Electric pressure acquisition part 52 Calculation Department 53 Presumption 61 water level outlet 62 Water Supply Department E1 with diaphragm electrolysis unit E2 diaphragmless electrolysis unit L1 1st aqueous solution L2 Second aqueous solution L3 The third aqueous solution S1 liquid level S2 liquid level S3 liquid level

Claims

1. an electrolytic cell for storing a first aqueous solution containing chloride ions; a supply tank for storing a second aqueous solution containing hydroxide ions and supplying the hydroxide ions to the first aqueous solution; a gas supply unit for supplying chlorine gas to the first aqueous solution stored in the electrolytic cell; an electrolytic cell-side anode 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 cell so as to be permeable to anions based on a voltage applied between the electrolytic cell-side anode and the supply cell-side cathode; a membrane-equipped electrolysis section provided between the electrolytic cell and the supply cell, for generating hypochlorous acid in the electrolytic cell by electrolyzing the first aqueous solution and the second aqueous solution via the anion exchange membrane by passing a first current between the electrolytic cell-side anode and the supply cell-side cathode; a current control unit that controls the first current in the diaphragm electrolysis unit so as to consume chloride ions generated when the chlorine gas supplied from the gas supply unit is dissolved in the first aqueous solution; A space purification device comprising:

2. The gas supply unit includes: a membrane-free electrolytic cell for storing a third aqueous solution containing a chloride ion having a higher concentration than that of the first aqueous solution; A pair of a non-diaphragm electrolytic cell side anode and a non-diaphragm electrolytic cell side cathode provided in the non-diaphragm electrolytic cell; Equipped with a second current is passed between the non-diaphragm electrolytic cell side anode and the non-diaphragm electrolytic cell side cathode to electrolyze the third aqueous solution without a diaphragm to generate chlorine gas and supply the chlorine gas to the first aqueous solution; The space purification device according to claim 1 .

3. the current control unit controls the second current in the gas supply unit, the current control unit applies the first current and the second current at a predetermined ratio, thereby maintaining a chloride ion concentration of the first aqueous solution at a predetermined concentration. The space purification device according to claim 2.

4. an air supply unit for introducing air from an outside space into the membraneless electrolytic cell; an outlet that is disposed above a liquid level of the third aqueous solution stored in the membrane-less electrolytic cell and that outputs air containing chlorine gas generated by the membrane-less electrolysis; a supply port for supplying the air containing chlorine gas discharged from the outlet into the first aqueous solution stored in the electrolytic cell; a discharge port that is disposed above a liquid level of the first aqueous solution stored in the electrolytic cell and that discharges, to the external space, the air that is supplied from the supply port and floats in the first aqueous solution; The space purification device of claim 2 .

5. 5. The spatial purification device according to claim 4, wherein the air introduced from the air supply unit is released as air bubbles into the third aqueous solution stored in the diaphragm-less electrolytic cell.

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