JP5425007B2 - Water sterilization method, water sterilizer, and air conditioner, hand dryer and humidifier using water sterilizer - Google Patents

Description

  The present invention relates to a water sterilization method, a water sterilizer, and an air conditioner, a hand dryer, and a humidifier using the water sterilizer.

  2. Description of the Related Art In recent years, devices and methods for sterilizing water by applying a high voltage pulse between electrodes and discharging between the electrodes have been known. By discharging to the water surface or in the water, the water molecules and floating molecules can be separated / aggregated / decolored / sterilized / chemically decomposed. As such a conventional sterilization apparatus, when the high voltage pulse application electrode and the counter electrode are arranged close to, for example, 1 to 10 cm, and a high voltage pulse of 10 to 15 kV / cm or more is applied to the application electrode, for example, 50 ns or more, There has been proposed a technique in which a discharge due to a short circuit occurs between electrodes and a sterilization treatment can be performed using a shock wave due to the discharge (see, for example, Patent Document 1). In addition, for example, as such a conventional sterilization apparatus, bubbles are formed in water, plasma is generated in the air, and active ionic species are excessively permeated and diffused in the water by the plasma. Proposals have been made to decompose, sterilize, and decolorize substances to be decomposed (hazardous substances, bacteria, microorganisms, dyes, etc.) (see, for example, Patent Document 2).

JP 2001-252665 A JP 2007-207540 A

  However, in the conventional sterilization apparatus and sterilization method using high voltage pulse discharge, the sterilization effect is exhibited during the discharge by the high voltage pulse. However, there is a problem that if fungi / molds remain, they grow. In addition, when bubbles are formed in water as in the sterilization apparatus described in Patent Document 2, it is necessary to inject gas such as air or oxygen, and energy other than voltage application must be input. It was.

  The present invention has been made to solve the above-described problems, and a water sterilization method, a water sterilization apparatus, and a water sterilization method that can maintain a sterilization effect even after the sterilization treatment by discharge is completed. It is a first object to provide an air conditioner, a hand dryer, and a humidifier using the apparatus. Also provided are a water sterilizing method, a water sterilizing device, an air conditioner using the water sterilizing device, a hand dryer and a humidifier that can obtain a high sterilizing effect without applying energy other than voltage application. This is the second purpose.

  The method for sterilizing water according to the present invention includes at least one high-voltage electrode portion having a metal electrode formed of a sterilizing metal, and at least one grounding disposed with a predetermined gap from the high-voltage electrode portion. And a first voltage power source for applying a voltage between the metal electrode and the ground electrode portion, and a negative high-voltage pulse between the metal electrode immersed in water and the ground electrode portion. Is applied to generate a discharge to sterilize the water, and a positive voltage is applied between the metal electrode immersed in the water and the ground electrode portion to dissolve the metal ions in the water. And a step of sterilizing the water.

The water sterilization apparatus according to the present invention includes at least one high-voltage electrode portion having a metal electrode formed of a sterilizing metal, and at least one high-voltage electrode portion disposed through a predetermined gap. And a first voltage power source for applying a negative high voltage pulse and a positive voltage between the metal electrode and the ground electrode unit, the metal electrode and the ground electrode unit being underwater In the state immersed in the metal electrode, a negative high voltage pulse is applied between the metal electrode and the ground electrode part to generate a discharge, so that water is sterilized and the metal electrode and the ground electrode part are immersed in water. In this state, a positive voltage is applied between the metal electrode and the ground electrode portion, and metal ions are dissolved in water to sterilize the water .

  Moreover, the air conditioner which concerns on this invention is provided with said water sterilizer and the drain pan which stores drain water, and performs the sterilization process to the water stored by the drain pan with this sterilizer.

  Moreover, the hand dryer which concerns on this invention is equipped with said water sterilizer and the drain pan which stores drain water, and performs the sterilization process to the water stored by the drain pan with this sterilizer.

  Moreover, the humidifier which concerns on this invention is equipped with said water sterilizer, and sterilizes humidified water with this sterilizer.

  In the present invention, the water to be treated is sterilized by the discharge in the water to be treated by the negative high voltage pulse and the sterilizing action of the metal ions dissolved in the water to be treated by the positive voltage. For this reason, the sterilizing effect is maintained even after the sterilization treatment by the discharge is completed, and it is possible to prevent the bacteria / molds from growing after the sterilization treatment by the discharge is completed.

It is a schematic sectional drawing which shows the sterilizer which concerns on Embodiment 1 of this invention. It is explanatory drawing which shows the colon_bacillus | E._coli survival rate in to-be-processed water at the time of performing the sterilization process by discharge with the sterilizer which concerns on Embodiment 1 of this invention. It is explanatory drawing which shows the colon_bacillus | E._coli survival rate in to-be-processed water at the time of performing the sterilization process by silver ion with the sterilizer which concerns on Embodiment 1 of this invention. It is explanatory drawing which shows an example of a time-dependent change of the to-be-processed water amount in the processing tank which concerns on Embodiment 1 of this invention. It is explanatory drawing which shows the example of a voltage application to the high voltage electrode part-ground electrode part in the sterilizer which concerns on Embodiment 1 of this invention. It is explanatory drawing which shows the relationship between the length of the high voltage electrode which concerns on Embodiment 1 of this invention, and the response time of an ultrasonic wave. It is explanatory drawing which shows the relationship between the discharge electrode part which concerns on Embodiment 1 of this invention, and the water surface of to-be-processed water. It is explanatory drawing which shows the relationship between the discharge electrode part and the water surface of to-be-processed water following FIG. FIG. 6 is an explanatory diagram showing an experimental result of Example 1. It is explanatory drawing which shows the example of a voltage application between the high voltage electrode part-ground electrode part in the sterilizer which concerns on Embodiment 2 of this invention. FIG. 6 is an explanatory diagram showing an experimental result of Example 2. It is a schematic sectional drawing which shows the sterilizer which concerns on Embodiment 3 of this invention. It is a schematic sectional drawing which shows the sterilizer which concerns on Embodiment 4 of this invention. It is a schematic sectional drawing which shows the sterilizer which concerns on Embodiment 5 of this invention. It is explanatory drawing which showed an example of the image which the lifetime measuring apparatus which concerns on this Embodiment 5 obtains. It is a schematic sectional drawing which shows the air conditioner which concerns on Embodiment 6 of this invention. It is explanatory drawing which shows the amount of drain water in the drain pan in the air conditioner which concerns on Embodiment 6 of this invention. FIG. 10 is an explanatory diagram showing an experimental result of Example 3. It is a schematic sectional drawing which shows the hand dryer which concerns on Embodiment 7 of this invention. It is a schematic sectional drawing which shows the humidifier which concerns on Embodiment 8 of this invention.

Embodiment 1 FIG.
1 is a schematic cross-sectional view showing a sterilizer according to Embodiment 1 of the present invention. FIG. 1 shows a state in which the tip of the discharge electrode unit 6 (the high voltage electrode unit 5 and the ground electrode unit 3) of the sterilizer 1 is immersed in the water to be treated 10 in the treatment tank 11.

  As shown in FIG. 1, the sterilization apparatus 1 applies a high voltage pulse between the high voltage electrode unit 5 and the ground electrode unit 3, and between the high voltage electrode unit 5 and the ground electrode unit 3. A power supply 7 is provided. The high voltage electrode unit 5 includes a high voltage electrode 2 that is a silver electrode (an electrode using silver as an electrode material), an insulator 4 that covers the high voltage electrode 2, and the like. The high voltage electrode portion 5 and the ground electrode portion 3 are arranged in a state where they are immersed in the water to be treated 10 in the treatment tank 11 with a predetermined gap.

First, the high voltage electrode unit 5 will be described.
First, the shape of the high voltage electrode 2 of the high voltage electrode unit 5 will be described.
In order to cause discharge in the water 10 to be treated, it is necessary to concentrate the electric field in order to cause dielectric breakdown. For this reason, the high voltage electrode 2 of the high voltage electrode part 5 has a preferable needle electrode shape. The diameter of the high voltage electrode 2 is preferably 1.0 mm or less. More desirably, the diameter of the high-voltage electrode 2 is preferably 0.2 mm or less so that plasma can be generated even at a low frequency (about 100 Hz).

The shape and material of the insulator 4 of the high voltage electrode portion 5 will be described.
The high voltage electrode portion 5 needs to be insulated while leaving the tip portion (discharge portion) of the high voltage electrode 2 in order to apply a strong electric field to the tip of the high voltage electrode 2. When a high voltage pulse is applied between the high voltage electrode 2 of the high voltage electrode part 5 and the ground electrode part 3 to generate a discharge therebetween, heat is generated and the insulator covering the high voltage electrode 2 4 becomes hot. For this reason, it is desirable that the insulator 4 covering the high voltage electrode 2 can withstand the heat generated by the discharge of the high voltage pulse and has heat resistance. In particular, when the high voltage pulse is a high frequency (for example, 1 kHz to 30 kHz), the temperature of the high voltage electrode 2 is 1000 ° C. For this reason, as for the insulator 4, what is the material which has the heat resistance whose lower one of a softening temperature or a decomposition temperature is 300 degreeC or more is more desirable. Further, the insulator 4 immersed in the water to be treated 10 is suitable to have a low water absorption rate and good thermal conductivity. Examples of the material of the insulator 4 that satisfies such conditions include polyimide resin, fluororesin, ceramics, and glass.

Moreover, it is preferable that the thickness of the insulator 4 shall be 1 mm or less, for example. By setting the thickness of the insulator 4 to, for example, 1 mm or less, the heat dissipation is improved, and deformation and deterioration can be suppressed even when a resin is used as the insulator 4.
Moreover, the insulator 4 desirably has a thermal expansion coefficient close to that of the material of the high-voltage electrode 2 (silver in the first embodiment). Thereby, when the insulator 4 is coated and formed on the high voltage electrode 2, both materials are solidified while shrinking at the same speed, and the adhesion between the high voltage electrode 2 and the insulator 4 can be improved. It is possible to reduce the stress accompanying the temperature rise and to expect stable operation.

Next, the ground electrode portion 3 will be described.
As will be described later, in the sterilization apparatus according to the first embodiment, the discharge in the water 10 to be treated by the negative high voltage pulse and the sterilization action of the silver ions dissolved in the water to be treated 10 by the positive voltage pulse. Thus, the water to be treated 10 is sterilized. For this reason, when the electrode material of the ground electrode portion 3 is the same silver as that of the high voltage electrode 2, electrode anodization represented by Formula 2 described later occurs even during discharge by the negative high voltage pulse, and silver ions are generated in the water to be treated. It will dissolve. As a result, the dissolution of silver ions cannot be restricted, so that the electrode material of the ground electrode portion 3 is a material that does not corrode or dissolve during discharge other than silver.

Further, in the ground electrode portion 3, electrolysis occurs, and hydrogen ions (H ⁺ ) according to the following formula 1 are generated. For this reason, the pH in the vicinity of the ground electrode portion 3 drops to around 3.
2H ₂ O → O ₂ + 4H ⁺ + 4e ⁻ (Formula 1)
Further, in the state where the ground electrode portion 3 is a positive electrode, anions (halogen ions such as Cl ⁻ , SO ₄ ²⁻ , NO ²⁻ ) in the water to be treated 10 aggregate near the ground electrode portion 3. For this reason, it is preferable to use a metal such as platinum (Pt) or gold (Au) that is resistant to a pH 1 environment, halogen ions, or the like as the material of the ground electrode portion 3. Of course, the ground electrode portion 3 may be formed by plating platinum or the like on titanium (Ti) having low resistance.

  The shape of the ground electrode portion 3 can be various shapes such as a flat plate shape, a disk shape, a rod shape, or a linear shape. Similarly to the high voltage electrode portion 5, the side surface of the ground electrode portion 3 (in other words, the range excluding the discharge portion) may be covered with the insulator 4. Further, the size of the ground electrode portion 3 is not particularly limited. Further, when titanium or the like having low resistance is used for the ground electrode portion 3, it is desirable to use a material having a large surface area such as a mesh shape.

  In general, in sterilization by dissolving silver ions, a silver material is used for both electrodes to which a voltage pulse is applied. And it is the structure which dissolves silver actively from both electrodes, applying a positive voltage pulse and a negative voltage pulse alternately between both electrodes. However, in the sterilization apparatus 1 according to the first embodiment, the silver ions are dissolved only when a positive voltage pulse is applied to the high voltage electrode unit 5 (more specifically, the high voltage electrode 2). Therefore, the ground electrode portion 3 uses a material other than silver.

  Here, the ground electrode portion 3 is an electrode portion that is grounded as the name suggests. For this reason, the polarity of the voltage applied to the high voltage electrode unit 5 and the ground electrode unit 3 shown in the first embodiment and the following embodiments indicates the polarity with respect to the ground electrode unit 3.

  The gap between the high voltage electrode portion 5 (more specifically, the high voltage electrode 2) and the ground electrode portion 3 may be 1 to 50 mm, and preferably 5 to 20 mm. The treatment tank 11 is preferably an insulator, and for example, acrylic resin or glass can be used.

  Next, the operation principle of the sterilization method using the sterilizer 1 according to the first embodiment will be described with reference to FIG.

  In the sterilization apparatus 1 according to the first embodiment, the water to be treated 10 is placed in the treatment tank 11, and the high voltage electrode unit 5 (more specifically, the high voltage electrode 2) and the ground electrode unit 3 are connected by the power source 7. A negative high voltage pulse is applied between them. And the to-be-processed water 10 is sterilized by the discharge which generate | occur | produces between the high voltage electrode part 5 (more specifically, the high voltage electrode 2) and the ground electrode part 3. FIG. In addition, the sterilization apparatus 1 according to the first embodiment performs the sterilization process by the discharge with the negative high voltage pulse, and then the high voltage electrode unit 5 (more specifically, the high voltage electrode 2) and the ground electrode unit 3 A positive voltage is applied during the period. As a result, the silver ions released from the high voltage electrode 2 are dissolved in the water to be treated 10, and the microorganisms and fungi contained in the water to be treated 10 can be efficiently removed by the antibacterial action of the silver ions even after the sterilization treatment by discharge. And it becomes possible to sterilize continuously. Here, the destruction and extinction of microorganisms, molds, bacteria, etc. is referred to as sterilization treatment.

First, the sterilization treatment by applying a negative high voltage pulse between the high voltage electrode portion 5 and the ground electrode portion 3 and discharging in the treated water 10 will be described. In the first embodiment, the negative high voltage pulse condition is
-Electric field strength: -2 kV / cm to -50 kV / cm,
・ Frequency: 100 Hz to 20,000 Hz
-Pulse width: 500 μsec or less,
It is said.

Microorganisms and bacteria floating in the water to be treated 10 are activated by OH, H, O, O ₂ ⁻ , O ⁻ , H ₂ O _2, etc. formed by plasma generation in the vicinity of the high voltage electrode portion 5 during discharge. It is processed by seeds, heat generation in the discharge region, and shock waves generated by the discharge. Note that silver is not dissolved from the high voltage electrode 2 because a negative high voltage pulse is applied.

FIG. 2 is an explanatory diagram showing the survival rate of Escherichia coli in the water to be treated when the sterilization treatment by discharge is performed by the sterilization apparatus according to Embodiment 1 of the present invention. The horizontal axis in FIG. 2 represents the sterilization time, and the vertical axis in FIG. 2 represents the number of E. coli in the water to be treated 10. FIG. 2 shows the conditions of the negative high voltage pulse applied between the high voltage electrode portion 5 and the ground electrode portion 3.
-Applied voltage: -4 kV
・ Pulse width 3μs,
・ Frequency: 130Hz, 1kHz, 7kHz,
-Distance between the high voltage electrode part 5 and the ground electrode part 3: 10 mm,
The survival rate of E. coli in the treated water 10 is shown.

As can be seen from FIG. 2, when discharge is performed at a frequency of 130 kHz in the water to be treated 10 in which 10 ⁶ CFU / ml (CFU: colony forming unit) of Escherichia coli is present, E. coli is reduced to 10 ⁵ CFU / ml. It can also be seen that E. coli decreases faster as the processing time and frequency increase. For example, when discharge is performed at a frequency of 7 kHz in the water to be treated 10 in which 10 ⁶ CFU / ml of E. coli is present, the E. coli in the water to be treated 10 is reduced to 10 ⁴ CFU / ml in 1 hour. From FIG. 2, the water to be treated 10 can be sterilized by applying a negative high voltage pulse between the high voltage electrode portion 5 and the ground electrode portion 3 and discharging in the water 10 to be treated. It can be seen (in other words, it can be understood that Escherichia coli in the treated water 10 can be sterilized).

Next, the dissolution operation of silver ions from the high voltage electrode 2 of the high voltage electrode unit 5 into the water to be treated 10 and the sterilization treatment of the water to be treated 10 with silver ions will be described. When electricity is applied using the metal as an anode (positive electrode), the metal is oxidized to cations and dissolved in the water to be treated 10. Using this property, the sterilizer 1 according to the first embodiment dissolves silver ions in the water to be treated 10. That is, when a positive high voltage is applied to the high voltage electrode 2 using silver as an electrode material, electrode anodization represented by the following formula 2 occurs.
Ag⇒Ag ⁺ + e ⁻ (Formula 2)

FIG. 3 is an explanatory diagram showing the survival rate of Escherichia coli in the water to be treated when sterilization with silver ions is performed in the sterilizer according to Embodiment 1 of the present invention. The horizontal axis in FIG. 3 represents the sterilization time, and the vertical axis in FIG. 3 represents the number of E. coli in the water to be treated 10. FIG. 3 shows the conditions of silver ions dissolved in the water to be treated 10.
Concentration: 1-2 ppb, 20-30 ppb, 50 ppb, 100 ppb,
The survival rate of E. coli in the treated water 10 is shown.

For example, when silver ions having a concentration of 50 ppb are dissolved in the treated water 10 so that 10 ⁵ CFU / ml of E. coli is present, the E. coli in the treated water 10 decreases to 10 ⁴ CFU / ml after 6 hours. doing. It can also be seen that the greater the amount of silver ion dissolved, the faster E. coli decreases. When silver ions having a concentration of 100 ppb were dissolved in the water to be treated 10 so that 10 ⁵ CFU / ml of E. coli was present, the number of E. coli in the water to be treated 10 decreased to 1/10 after 3 hours. Yes. From FIG. 3, it can be seen that when the amount of silver ions dissolved in the water to be treated 10 is increased, the bactericidal effect is improved.

  Here, the sterilization treatment by the high voltage pulse discharge described above is compared with the sterilization treatment by silver ions. Comparing the two, it can be seen that the sterilization treatment with silver ions has a lower sterilization effect than the sterilization treatment with high voltage pulse discharge. However, unlike the sterilization treatment using high voltage pulse discharge, the sterilization treatment using silver ions can be performed continuously while the silver ions are dissolved in the water 10 to be treated even after the voltage application is stopped. There are advantages.

  On the other hand, when the concentration of silver ions in the water to be treated 10 is 200 ppb or more, white precipitates are generated by reaction with chloride ions, and further blackening due to ultraviolet reaction of the white precipitates and reaction with quinone. A reddish brown precipitate is formed, causing problems. Moreover, if high concentration silver ions are dissolved in the water to be treated 10, the high voltage electrode 2 is significantly consumed. In order to prevent problems related to the concentration of silver ions in the water to be treated 10 and extend the life of the high-voltage electrode 2, the amount of silver ions dissolved in the water to be treated 10 should be 200 ppb or less. For this reason, in this Embodiment 1, the dissolution amount of the silver ion to the to-be-processed water 10 is made into the range of 1-200 ppb.

The amount of silver ions dissolved in the water to be treated 10 can be calculated from the theoretical formula (Faraday's law) shown in the following formula 3. For example, when it is desired to dissolve 100 μg / L of silver ions in 0.5 liter (L) of water to be treated 10, assuming that the current value flowing through the high voltage electrode 2 is 1 mA, the current to the high voltage electrode 2 is about 45 seconds. It can be seen that a positive voltage may be applied between the high voltage electrode portion 5 (more specifically, the high voltage electrode 2) and the ground electrode portion 3 so that.
A = I × M × t × 1000 / Z / U (Formula 3)
A: Silver ion concentration to elute (μg / L), I: Current flowing between electrodes (mA), Z: Faraday constant (9.65 × 10 ⁴ C / mol), M: Silver atomic weight (108), t: Time (s) for energizing current, U: 10 amount of treated water (L).
That is, the dissolution of silver ions in the water to be treated 10 depends on the application conditions of the positive voltage, such as the voltage value of the positive voltage (current value flowing between the electrodes) and the application time of the positive voltage (the time during which the current is applied). The amount can be in the range of 1 to 200 ppb.

  In the first embodiment, the silver ions are dissolved in the water to be treated 10 after the sterilization treatment by discharge, but the timing of dissolving the silver ions in the water to be treated 10 is arbitrary. For example, you may change the timing which melt | dissolves a silver ion in the to-be-processed water 10 according to the inflow amount and outflow amount of the to-be-processed water 10 to the processing tank 11. FIG.

FIG. 4 is an explanatory diagram showing an example of a change over time in the amount of water to be treated in the treatment tank according to Embodiment 1 of the present invention. FIG. 4 shows four examples in (a) to (d). In FIGS. 4A to 4D, the vertical axis represents the amount of water to be treated 10 stored in the treatment tank 11, and the horizontal axis represents elapsed time.
The amount of treated water 10 stored in the treatment tank 11 is constant when the inflow water amount and the inflow / outflow water amount are equal {FIG. 4 (a), FIG. 4 (c)}. Further, when the inflow water amount and the inflow / outflow water amount are different, the amount of the water to be treated 10 stored in the treatment tank 11 changes {FIG. 4 (b), FIG. 4 (d)}.

  When the water to be treated 10 flows into the treatment tank 11 and the amount of the water to be treated 10 in the treatment tank 11 is constant (FIG. 4A), the water to be treated 10 always flows out of the treatment tank 11. doing. In addition, when the water to be treated 10 flows into the treatment tank 11 and the water to be treated 10 in the treatment tank 11 regularly decreases {FIG. 4 (b)}, the water to be treated 10 is also treated with the treatment tank. 11 is always flowing out. In such a case, even if silver ions are dissolved in the water to be treated 10, the silver ions are also discharged from the treatment tank 11 together with the water to be treated 10. For this reason, even if it uses the sterilization process by silver ion as the sterilization process of the to-be-processed water 10 in the processing tank 11, it is not effective. On the other hand, since the sterilization treatment by high voltage pulse discharge can obtain an effect in a short time as shown in FIG. 2, the sterilization treatment effect can be effectively obtained even in such a case. Therefore, when the to-be-processed water 10 has flowed out of the processing tank 11, fundamentally, it is desirable to perform the sterilization process by a high voltage pulse discharge. As shown in FIG. 4 (a), even when the amount of water to be treated 10 in the treatment tank 11 is constant, if the water to be treated 10 in the treatment tank 11 is constantly changing, sterilization by high voltage pulse discharge is performed. The treatment is more effective than the sterilization treatment with silver ions.

  On the other hand, when the to-be-processed water 10 is not flowing out from the processing tank 11, {FIG.4 (c), FIG.4 (d)}, the to-be-processed water 10 will remain in the processing tank 11. FIG. In such a case, since the silver ions dissolved in the water to be treated 10 can remain in the treatment tank 11 for a long time, they can be sterilized efficiently by the silver ions. Of course, the sterilization treatment by the high-voltage pulse discharge is effective even in such a case because it is sterilized at the moment of discharge. Therefore, when the water to be treated 10 can be sterilized batchwise without flowing out of the treatment tank 11, it is effective to perform sterilization by combining sterilization by high voltage pulse discharge and sterilization by silver ions. .

  From the above, when the water to be treated 10 flows out of the treatment tank 11, the sterilization treatment by high-voltage pulse discharge is basically performed, and the water to be treated 10 does not flow out of the treatment tank 11. It is desirable to sterilize with silver ions.

FIG. 5 is an explanatory diagram showing an example of voltage application between the high-voltage electrode unit and the ground electrode unit in the sterilization apparatus according to Embodiment 1 of the present invention. The vertical axis in FIG. 5 represents the application state between the high voltage electrode portion 5 (more specifically, the high voltage electrode 2) and the ground electrode portion 3. Further, the horizontal axis of FIG. 5 represents the elapsed time. Further, in FIG. 5, the positive polarity means that a positive voltage is applied to the high voltage electrode portion 5 (more specifically, the high voltage electrode 2). The negative polarity means that a negative voltage is applied to the high voltage electrode portion 5 (more specifically, the high voltage electrode 2). The ground indicates 0 kV at the high voltage electrode portion 5 (more specifically, the high voltage electrode 2), and indicates the voltage at the ground electrode portion 3.
Note that the voltage values 4 kV and −4 kV shown on the vertical axis in FIG. 5 are merely examples, and the magnitude of the voltage is not a problem. Of course, the applied voltage values of the positive polarity and the negative polarity may be different.

  When the water to be treated 10 flows out of the treatment tank 11, a voltage is applied between the high voltage electrode portion 5 (more specifically, the high voltage electrode 2) and the ground electrode portion 3, as shown in FIG. do it. That is, while the to-be-processed water 10 is flowing out from the processing tank 11, a negative high voltage pulse is applied between both electrode parts, and the sterilization process by a high voltage pulse discharge is performed. And when the outflow of the to-be-processed water 10 from the processing tank 11 stops, a positive voltage is applied between both electrode parts, and the sterilization process by silver ion is performed. Thus, by applying a voltage between both electrode parts, it is possible to perform sterilization by high voltage pulse discharge and sterilization by silver ions while suppressing dissolution of useless silver ions in the water to be treated 10. .

  Further, when the water to be treated 10 does not flow out of the treatment tank 11, for example, as shown in FIG. 5B, a voltage is generated between the high voltage electrode portion 5 (more specifically, the high voltage electrode 2) and the ground electrode portion 3. May be applied. That is, a negative high voltage pulse is applied between both electrode parts, and a positive voltage is applied between both electrode parts in the middle. Since the silver ions are dissolved during the sterilization treatment by the high voltage pulse discharge, the sterilization treatment by the silver ions can be performed simultaneously with the sterilization treatment by the high voltage pulse discharge, and the sterilization speed is increased. As a result, the application time of the negative high voltage pulse can be shortened by the antibacterial action (sterilization effect) of silver ions, and the sterilization efficiency is improved. In order to make maximum use of the antibacterial action (sterilization effect) of silver ions, the silver ions need to stay in the treatment tank 11 for a long time. For this reason, it is effective to apply a positive voltage at the initial time (such as when the outflow of the water to be treated 10 from the treatment tank 11 stops). In addition, the application interval and application time of the positive voltage performed during the sterilization process by high voltage pulse discharge are not limited to the application timing and application time shown in FIG. For example, when it is desired to improve the bactericidal effect, a positive voltage may be applied between the high voltage electrode portion 5 (more specifically, the high voltage electrode 2) and the ground electrode portion 3.

  Since the sterilizer 1 according to the first embodiment dissolves silver ions from the high voltage electrode 2, the high voltage electrode 2 becomes shorter (smaller) with use time. If the high voltage electrode 2 is shorter than a certain length (predetermined length), the effect of the sterilization treatment with silver ions cannot be obtained sufficiently. For this reason, when the high voltage electrode 2 becomes shorter than a certain length, the high voltage electrode 2 needs to be replaced. For this reason, it is desirable that the length of the high voltage electrode 2 can be measured. It is also desirable to notify that the high voltage electrode 2 has become shorter than a certain length (in other words, to notify the replacement timing of the high voltage electrode 2).

  Therefore, as shown in FIG. 1, the sterilization apparatus 1 according to the first embodiment is provided with a life measuring apparatus 8 that measures the length of the high-voltage electrode 2. In addition, the sterilization apparatus 1 according to the first embodiment is provided with a notification device 9 that notifies that the high voltage electrode 2 is shorter than a certain length (in other words, notifies the replacement timing of the high voltage electrode 2). Yes.

  The lifetime measuring apparatus 8 according to the first embodiment includes an ultrasonic generator 8a and a measuring instrument 8b. For example, the ultrasonic generator 8a is preferably a device that generates an ultrasonic wave by applying an AC voltage or a magnetic field to ceramic. Of course, other ultrasonic generators may be used as the ultrasonic generator 8a. For example, the measuring instrument 8b recognizes the output of the monostable multivibrator circuit, the monostable multivibrator circuit that operates according to the output signal of the circuit that amplifies the received ultrasonic wave, and the response time (T) described later. The circuit etc. which computes are provided. The notification device 9 includes, for example, a light emitting diode that emits light when the high voltage electrode 2 becomes shorter than a certain length (in other words, emits light when it is time to replace the high voltage electrode 2). Instead of the light emitting diode, the notification device 9 may be provided with a buzzer that sounds when the high voltage electrode 2 becomes shorter than a certain length.

  A method for measuring the length of the high voltage electrode 2 in the lifetime measuring apparatus 8 according to the first embodiment will be described below.

Ultrasound is a “high-frequency sound wave that cannot be captured by the human auditory organ” and means a sound wave of about 20 kHz or higher. When an ultrasonic wave is incident on a different medium, a part of the ultrasonic wave is reflected on the boundary surface due to a difference in the intrinsic acoustic impedance of the medium, and the remaining part is transmitted (incident) on a different medium. For this reason, the ultrasonic wave incident on the high voltage electrode 2 (ultrasonic signal input to the high voltage electrode 2) hits the water to be treated 10 and then directly enters the water to be treated 10, and the water to be treated 10. Some of them come back from you. Then, the response time of the ultrasonic wave incident on the high voltage electrode 2 (the time from when the ultrasonic wave is incident on the high voltage electrode 2 until it bounces back on the treated water 10) and the length of the high voltage electrode 2 This relationship is expressed by the following equation 4 and can be shown as shown in FIG.
L = VT / 2 (Formula 4)
L is the length (mm) of the high voltage electrode 2, V is the speed of sound (m / s), and T is the response time (s) of the ultrasonic wave incident on the high voltage electrode 2.

  From Equation 4 and FIG. 6, it can be seen that the shorter the length of the high voltage electrode 2, the shorter the response time. For this reason, if the measurement formula of the length and response time of the high voltage electrode 2 is calculated in advance, the measuring time of the ultrasonic wave incident on the high voltage electrode 2 is monitored by the measuring instrument 8b capable of measuring the response time. The voltage electrode 2 can be estimated. In addition, by setting a response time when the high voltage electrode 2 reaches the life length (when the high voltage electrode 2 becomes shorter than a certain length), the high voltage electrode 2 reaches the life length, It is possible to notify the outside of the supply stop of the high voltage pulse to the high voltage electrode unit 5 and the replacement timing of the high voltage electrode unit 5 by a buzzer, a light emitting diode or the like of the notification device 9 linked to the measuring instrument 8b. Become.

  Next, determination on whether or not a high voltage application to the high voltage electrode unit 5 is possible will be described.

7 and 8 are explanatory diagrams showing the relationship between the discharge electrode unit and the water surface of the water to be treated according to Embodiment 1 of the present invention.
The amount of the water to be treated 10 stored in the treatment tank 11 varies depending on the amount of inflow and outflow of the water to be treated 10. That is, the water surface of the water to be treated 10 in the treatment tank 11 moves up and down (fluctuates) depending on the amount of inflow and outflow of the water to be treated 10. As shown in FIG. 7A, when the water surface 12 of the water to be treated 10 is above both the front end portion of the high voltage electrode 2 and the front end portion of the ground electrode portion 3, the high voltage electrode 2 has a high negative polarity. When a voltage pulse is applied, an unequal electric field is generated in the vicinity of the tip of the high voltage electrode 2, a discharge is generated in the vicinity of the tip of the high voltage electrode 2, and the microorganisms in the water to be treated 10 are sterilized. Further, when a positive voltage is applied to the high voltage electrode 2, silver ions are dissolved, and the microorganisms in the water to be treated 10 are sterilized by the silver ions.

  As shown in FIG. 7B, the tip of the high voltage electrode 2 is above the water surface 12 of the water to be treated 10 and the tip of the ground electrode part 3 is below the water surface 12 of the water to be treated 10. When a negative high voltage pulse is applied to the high voltage electrode 2, the ground water 3 is immersed in the conductive water 10 to be treated, so that the water 10 becomes an electrode. For this reason, air discharge occurs from the high voltage electrode 2 toward the water to be treated 10. In the air discharge, since the discharge occurs only between the high voltage electrode 2 and the water surface 12 of the water to be treated 10, the sterilization in the water to be treated 10 cannot be performed. For this reason, the sterilization effect by air discharge is remarkably small compared with the sterilization effect at the time of discharging in the to-be-processed water 10. FIG. Therefore, it is desirable not to cause such air discharge.

  In order to prevent air discharge, it is effective to monitor the current flowing through the high voltage electrode 2 and stop the discharge depending on the value. This is because when the air discharge is compared with the discharge in the water to be treated 10, the discharge current flowing in the air discharge is smaller than the discharge in the water 10 to be treated. Therefore, as shown in FIG. 1, the sterilizer 1 according to the first embodiment is provided with an ammeter 13 that measures the current flowing through the high voltage electrode 2. And the sterilizer 1 which concerns on this Embodiment 1 makes the control apparatus (for example, control part of the power supply 7) the electric current value which flows into the high voltage electrode 2 at the time of normal operation (when discharging in the to-be-processed water 10). An input is made, and the value (hereinafter referred to as an input value) is compared with the measured value of the ammeter 13. More specifically, the sterilization apparatus 1 according to the first embodiment determines that an air discharge has occurred when the measured value of the ammeter 13 is, for example, 50% or more smaller than the input value, and the high The supply of the high voltage pulse to the voltage electrode 2 is stopped. Thus, by monitoring the current flowing through the high voltage electrode 2 and determining whether discharge is possible, invalid discharge can be stopped and the highly efficient sterilization apparatus 1 can be realized. .

  In addition, as shown in FIG.8 (c), when the to-be-processed water 10 surface is lower than both the front-end | tip part of the high voltage electrode 2, and the front-end | tip part of the ground electrode part 3, it exists in the air. A negative high voltage pulse and a positive voltage are applied to the voltage electrode 2. In this case, when the value of the voltage is increased, dielectric breakdown occurs in the space and discharge occurs. However, this discharge cannot sterilize microorganisms in the water to be treated 10 at all. In other words, a completely meaningless discharge is occurring. Therefore, the distance between the high voltage electrode 2 (that is, the high voltage electrode portion 5) and the ground electrode portion 3 needs to be sufficiently large so that such discharge does not occur. In the first embodiment, the high-voltage electrode 2 (that is, the high-voltage electrode 2 (that is, the high-voltage electrode portion 5) and the high-voltage electrode 2 (that is, the distance between the ground electrode portion 3 and the ground-electrode portion 3) is set at a distance such that A high voltage electrode part 5) and a ground electrode part 3 are arranged.

  Below, the Example which performed the sterilization process using the sterilizer 1 which concerns on this Embodiment 1 is described.

[Example 1]
In Example 1, in order to confirm the bactericidal effect with respect to the microbe and microorganisms of the sterilizer 1, E. coli was put into the water to be treated 10 of the treatment tank 11, and the effect of the sterilization treatment by the sterilizer 1 was examined.
FIG. 9 is an explanatory diagram showing the experimental results of Example 1. FIG. In FIG. 9, the experimental results of the comparative condition 1 (A) and the comparative condition 1 (B) are shown together with the experimental results of the experimental condition 1 (A) and the experimental condition 1 (B) showing the effect of the sterilization treatment by the sterilizer 1. Show.

The experimental conditions 1 (A), the experimental conditions 1 (B), the comparative conditions 1 (A), and the comparative conditions 1 (B) are the following experimental conditions.
High voltage electrode part 5: As the high voltage electrode 2, a silver (Ag) wire having a diameter of 0.2 mm and a length of 50 mm was used. Further, an epoxy resin was used as the insulator 4, and the periphery of the high voltage electrode 2 was covered with an epoxy resin having a diameter of 10 mm by injection molding.
Ground electrode portion 3: A 5 mm rod-shaped electrode obtained by plating platinum (Pt) onto a titanium wire having a wire diameter of 1 mm at a support density of 0.6 mg / cm ² by electroless plating.
The gap between the high voltage electrode portion 5 and the ground electrode portion 3 was 10 mm.
-The processing tank 11 was made of glass, and 50 ml of treated water 10 to which 10 ⁶ CFU / ml of Escherichia coli was added was placed therein (CFU: Colony Forming Unit). The depth of the to-be-processed water 10 at this time is 10 mm.

Further, in each of the experimental condition 1 (A), the experimental condition 1 (B), the comparative condition 1 (A), and the comparative condition 1 (B), the high voltage electrode portion 5 (more specifically, the high voltage electrode 2) and the ground electrode A voltage was applied to the part 3 under the following application conditions, and then allowed to stand.
○ Experimental condition 1 (A)
Negative polarity high voltage pulse: voltage -4 kV, repetition period 130 Hz, pulse width 4 μs, application time 30 minutes.
Positive polarity voltage: current 1 mA flowing through the high-voltage electrode 2, application time 11 sec.
○ Experimental condition 1 (B)
Negative polarity high voltage pulse: voltage -4 kV, repetition period 130 Hz, pulse width 4 μs, application time 30 minutes.
Positive polarity voltage: current 1 mA flowing through the high voltage electrode 2, application time 22 sec.
○ Comparison condition 1 (A)
Negative polarity high voltage pulse: voltage -4 kV, repetition period 130 Hz, pulse width 4 μs, application time 30 minutes.
-Positive voltage: not applied.
○ Comparison condition 1 (B)
・ Negative high voltage pulse: Not applied.
Positive polarity voltage: current 1 mA flowing through the high-voltage electrode 2, application time 11 sec.

  In the experimental condition 1 (A) and the experimental condition 1 (B), Escherichia coli decreased by one digit or more in one hour after the start of discharge by the negative high voltage pulse. In experimental condition 1 (A), about 1 digit of E. coli was further reduced 6 hours after the start of discharge by the negative high voltage pulse. In addition, in experimental condition 1 (B) where the amount of silver ions dissolved was higher than in experimental condition 1 (A), about 1 digit of E. coli was further reduced 3 hours after the start of discharge by the negative high voltage pulse. Under experimental condition 1 (A) and experimental condition 1 (B), no increase in E. coli was confirmed throughout the experiment.

  On the other hand, in Comparative condition 1 (A), E. coli decreased by one digit or more in one hour after the start of discharge by the negative high voltage pulse. However, an increase of about one digit in E. coli was confirmed 6 hours after the start of discharge by the negative high voltage pulse. In Comparative Condition 1 (B), no increase in E. coli was observed, but the number of E. coli was maintained at a relatively high concentration.

  From these facts, in the experimental condition 1 (A) and the experimental condition 1 (B), after being sufficiently sterilized by the discharge of the negative high voltage pulse, the sterilization state is maintained by the sterilization effect of silver ions, and the number of bacteria is It can be seen that a small amount is maintained and that sterilization of microorganisms is performed effectively and in the long term. On the other hand, under comparative condition 1 (A), it is sufficiently sterilized by the discharge of the negative high voltage pulse, but it can be seen that the growth of microorganisms has occurred thereafter. In other words, it can be seen that under the comparison condition 1 (A), the sterilization effect cannot be maintained after the discharge of the negative high voltage pulse is finished, and further, the sterilization treatment by the discharge of the negative high voltage pulse needs to be performed. Under comparative condition 1 (B), sterilization with silver lasts for a long time, but a sufficient effect cannot be obtained, and it is necessary to perform sterilization treatment by discharge and discharge of negative polarity high voltage pulse.

  In addition, as a result of leaving the to-be-treated water 10 sterilized under the experimental condition 1 (A) and the experimental condition 1 (B) for several tens of days, E. coli did not proliferate without further sterilization.

  As described above, in the sterilization apparatus 1 configured as described above, the discharge due to the negative high voltage pulse and the water to be treated 10 are sterilized by the silver ions dissolved by the positive voltage. The sterilizing effect is maintained even after the sterilization treatment by the sterilization is completed, and it is possible to prevent the bacteria / molds from growing after the sterilization treatment by the discharge is completed. Moreover, since the sterilization apparatus 1 according to the first embodiment can exhibit a sufficiently effective sterilization effect, it is not necessary to add bubbles to the sterilization apparatus, and it is not necessary to input energy other than voltage application.

  Moreover, the sterilizer 1 which concerns on this Embodiment 1 has set the application condition of the positive voltage so that the dissolution amount of the silver ion to the to-be-processed water 10 may become predetermined amount (range of 1-200 ppb). Therefore, the problem regarding the concentration of silver ions in the water to be treated 10 can be prevented and the life of the high voltage electrode 2 can be extended.

  Moreover, since the sterilizer 1 according to the first embodiment includes the lifetime measuring device 8, it is possible to estimate the lifetime of the high voltage electrode unit 5 (that is, the high voltage electrode 2). Further, when the high voltage electrode unit 5 reaches the end of its life (when the high voltage electrode 2 reaches the end of its life), the notification device 9 stops the supply of the high voltage pulse to the high voltage electrode unit 5 or the high voltage The replacement timing of the electrode unit 5 can be notified to the outside.

  In the first embodiment, silver is used as the material of the high voltage electrode 2, but the material of the high voltage electrode 2 is not limited to silver. Since metal ions having bactericidal properties only need to be dissolved, a metal having bactericidal properties such as copper, zinc, and aluminum may be used as the material of the high voltage electrode 2.

  In the first embodiment, the discharge electrode unit 6 including one pair of the high voltage electrode unit 5 and the ground electrode unit 3 is shown. However, the discharge electrode unit 6 is not limited to this configuration. For example, it is good also as the discharge electrode part 6 provided with multiple pairs of the high voltage electrode part 5 and the ground electrode part 3. FIG. By configuring the discharge electrode portion 6 in this manner, the sterilization capability can be improved. Alternatively, for example, the discharge electrode unit 6 may be provided with one ground electrode unit 3 (common ground electrode unit 3) for a plurality of high voltage electrode units 5. Further, for example, the ground electrode portion 3 and the high voltage electrode portion 5 may have the same shape, or the high voltage electrode portion 5 and the ground electrode portion 3 may be integrally formed.

Embodiment 2. FIG.
The positive voltage applied between the high-voltage electrode unit 5 (more specifically, the high-voltage electrode 2) and the ground electrode unit 3 is not limited to the method described in the first embodiment, and is applied as follows, for example. May be. In the second embodiment, the difference from the first embodiment will be mainly described, and the same functions and configurations will be described using the same reference numerals.

  The configuration of the sterilizer 1 according to the second embodiment is the same as that of the sterilizer 1 (FIG. 1) shown in the first embodiment. However, the sterilization apparatus 1 according to the second embodiment has a positive voltage application method (dissolution of silver ions) applied between the high voltage electrode unit 5 (more specifically, the high voltage electrode 2) and the ground electrode unit 3. Method) is different from the first embodiment.

  FIG. 10 is an explanatory diagram showing an example of voltage application between the high-voltage electrode unit and the ground electrode unit in the sterilizer according to Embodiment 2 of the present invention. Note that the vertical axis of FIG. 10 represents the application state between the high voltage electrode portion 5 (more specifically, the high voltage electrode 2) and the ground electrode portion 3. Further, the horizontal axis of FIG. 10 represents the elapsed time.

  Some power sources that apply high voltage pulses employ various methods such as a switching method and an igniter method. In any power source, when an attempt is made to apply a negative voltage, the positive voltage is applied slightly by hunting. For this reason, in general, the positive voltage application is removed by rectification using a diode. In the second embodiment, silver ions are eluted using this hunting action. The application time of the positive voltage applied by the hunting action necessary for dissolving the required amount of silver ions is obtained from the current flowing through the high voltage electrode 2 by the application of the positive voltage by the hunting action and the above-described equation 3. be able to. For example, when a negative voltage pulse is applied at 1 kHz, −4 kV, 5 μs, a current of 50 mA, 1 μs flows through the high voltage electrode 2 after each negative voltage pulse due to a positive voltage applied by a hunting action. . In this case, a voltage may be applied for 15 minutes in order to dissolve 100 μg / L of silver ions in 0.5 liter (L) of water to be treated 10.

  In addition, since the mechanism of the sterilization of the sterilizer 1 according to the second embodiment is the same as that of the first embodiment, the description thereof is omitted.

  Below, the Example which performed the sterilization process using the sterilizer 1 which concerns on this Embodiment 2 is described.

[Example 2]
In Example 2, in order to confirm the bactericidal effect of the sterilizer 1 against bacteria and microorganisms, Escherichia coli was put into the water 10 to be treated in the treatment tank 11 and the effect of the sterilization treatment by the sterilizer 1 was examined.
FIG. 11 is an explanatory diagram showing experimental results of Example 2. In FIG. 11, the experimental result of the comparative condition 2 (A) and the comparative condition 2 (B) is also shown with the experimental result of the experimental condition 2 which shows the effect of the sterilization process by the sterilizer 1. FIG.

The experimental conditions 2, the comparative conditions 2 (A), and the comparative conditions 2 (B) are the following experimental conditions.
High voltage electrode part 5: As the high voltage electrode 2, a silver (Ag) wire having a diameter of 0.2 mm and a length of 50 mm was used. Further, an epoxy resin was used as the insulator 4, and the periphery of the high voltage electrode 2 was covered with an epoxy resin having a diameter of 10 mm by injection molding.
Ground electrode portion 3: A 5 mm rod-shaped electrode obtained by plating platinum (Pt) onto a titanium wire having a wire diameter of 1 mm at a support density of 0.6 mg / cm ² by electroless plating.
The gap between the high voltage electrode portion 5 and the ground electrode portion 3 was 10 mm.
-The processing tank 11 was made of glass, and 50 ml of treated water 10 to which 10 ⁶ CFU / ml of Escherichia coli was added was placed therein (CFU: Colony Forming Unit). The depth of the to-be-processed water 10 at this time is 10 mm.

Further, in each of the experimental condition 2, the comparative condition 2 (A), and the comparative condition 2 (B), the following is provided between the high voltage electrode portion 5 (more specifically, the high voltage electrode 2) and the ground electrode portion 3. A voltage was applied under application conditions, and then allowed to stand.
○ Experimental condition 2
Negative polarity high voltage pulse: 25 mA, 1 µs negative polarity high voltage pulse with hunting action. Application time 30 minutes.
○ Comparison condition 2 (A)
・ Negative high voltage pulse: Negative high voltage pulse without hunting. Voltage −4 kV, repetition period 130 Hz, pulse width 4 μs, application time 30 minutes.
-Positive voltage: not applied.
Comparative condition 1 (B) {same condition as experimental condition 1 (A) of Example 1}
・ Negative high voltage pulse: Negative high voltage pulse without hunting. Voltage −4 kV, repetition period 130 Hz, pulse width 4 μs, application time 30 minutes.
Positive polarity voltage: current 1 mA flowing through the high-voltage electrode 2, application time 11 sec.

Under experimental condition 2, E. coli decreased by 1.1 to 1.2 digits in 1 hour after the start of discharge. In addition, E. coli decreased by about an order of magnitude 6 hours after the start of discharge. Throughout the experiment, no increase in E. coli was observed.
On the other hand, under comparative condition 2 (A), one-digit E. coli decreased 1 hour after the start of discharge. However, an increase of about 1 digit in E. coli was confirmed 6 hours after the start of discharge. Under comparative condition 2 (B), single-digit E. coli decreased 1 hour after the start of discharge. In addition, about 1 digit decrease in E. coli was confirmed 6 hours after the start of discharge.

  Therefore, in the experimental condition 2, in the state where the negative high voltage pulse is applied, the bactericidal effect is improved by the effects of both the bactericidal treatment by discharge of the negative high voltage pulse and the sterilization treatment of silver ions. I understand that In addition, it can be seen that even after the application of the negative high voltage pulse is completed, a state in which the number of bacteria is small is maintained due to the sterilization effect of silver ions, and the sterilization of microorganisms is performed effectively and in the long term. On the other hand, under comparative condition 2 (A), it is sufficiently sterilized by the discharge of the negative high voltage pulse, but it can be seen that the growth of microorganisms has occurred thereafter. In other words, it can be seen that under the comparison condition 1 (A), the sterilization effect cannot be maintained after the discharge of the negative high voltage pulse is finished, and further, the sterilization treatment by the discharge of the negative high voltage pulse needs to be performed. Under comparative condition 2 (B), it is sufficiently sterilized by the sterilization treatment by the discharge of the negative high voltage pulse and the sterilization by silver ions lasts for a long time, but it is understood that the sterilization effect as in experimental condition 2 cannot be obtained.

  In addition, as a result of leaving the to-be-treated water 10 sterilized under the experimental condition 2 for several tens of days, the growth of E. coli did not occur without further sterilization.

  As described above, also in the sterilization apparatus 1 configured as described above, since the water to be treated 10 is sterilized by the discharge by the negative high voltage pulse and the silver ions dissolved by the positive voltage, the discharge by the negative high voltage pulse The sterilizing effect is maintained even after the sterilization treatment by the sterilization is completed, and it is possible to prevent the bacteria / molds from growing after the sterilization treatment by the discharge is completed. In addition, since the sterilization apparatus 1 according to the second embodiment can also exhibit a sufficiently effective sterilization effect, it is not necessary to add bubbles to the sterilization apparatus, and it is not necessary to input energy other than voltage application.

  Further, in the sterilization apparatus 1 according to the second embodiment, it is not necessary to distinguish between the application of the negative high voltage pulse and the application of the positive voltage unlike the sterilization apparatus 1 of the first embodiment. For this reason, sterilization by dissolution of silver ions can be used in combination with sterilization by application of a negative high voltage pulse. For this reason, the remarkable effect that the to-be-processed water 10 can be disinfected more efficiently can be expected.

Embodiment 3 FIG.
In the first and second embodiments, a silver electrode is used as the high voltage electrode 2. The present invention is not limited to this, and the present invention can also be implemented by forming the high voltage electrode 2 with a metal electrode other than a silver electrode and using a silver electrode separately from the high voltage electrode 2. In the third embodiment, differences from the first and second embodiments will be mainly described, and the same functions and configurations will be described using the same reference numerals.

  FIG. 12 is a schematic cross-sectional view showing a sterilizer according to Embodiment 3 of the present invention. FIG. 12 shows a state in which the discharge electrode portion 6 (the high voltage electrode portion 5 and the ground electrode portion 3) of the sterilizer 1 and the tip of the silver electrode 2 a are immersed in the water to be treated 10 in the treatment tank 11.

  As shown in FIG. 12, the sterilizer 1 according to Embodiment 3 uses a metal other than silver as the material of the high voltage electrode 2 of the high voltage electrode unit 5. As a material for the high-voltage electrode 2, for example, a metal such as titanium, platinum, or gold having excellent corrosion resistance is used. Moreover, the sterilizer 1 according to the third embodiment is provided with, for example, a bar-shaped silver electrode 2 a separately from the high voltage electrode 2 of the high voltage electrode unit 5. The silver electrode 2a is disposed with a predetermined distance from the ground electrode portion 3. Since the silver electrode 2a is not provided for sterilization by electric discharge (because it is an electrode for dissolving silver ions as described later), it is not necessary to cover the periphery with the insulator 4. Further, in the sterilization apparatus 1 according to the third embodiment, the power source 7a that applies a positive voltage between the silver electrode 2a and the ground electrode unit 3 is replaced with the power source 7 (the high voltage electrode unit 5 and the ground electrode unit 3). And a power source for applying a negative high-voltage pulse between them. Further, in the sterilization apparatus 1 according to the third embodiment, the life measuring device 8 connected to the high voltage electrode 2 in the first and second embodiments is connected to the silver electrode 2a. Other configurations of the sterilizer 1 according to the third embodiment are the same as those in the first embodiment.

The sterilization apparatus 1 configured in this way performs sterilization as follows.
First, as in the first embodiment, a negative high-voltage pulse is applied from the power source 7 between the high-voltage electrode unit 5 (more specifically, the high-voltage electrode 2) and the ground electrode unit 3 to treat the water to be treated. Sterilize by discharging in 10. Thereafter, a positive voltage is applied from the power source 7a between the silver electrode 2a and the ground electrode portion 3, and silver ions are released from the silver electrode 2a into the water to be treated 10 (the silver ions are dissolved in the water 10 to be treated). ) By performing the sterilization process in this way, the same sterilization effect as in the first embodiment can be obtained. Moreover, in the sterilizer 1 according to the third embodiment, the high voltage electrode 2 is not dissolved, and the silver electrode 2a is dissolved. For this reason, there exists an effect that replacement | exchange of the silver electrodes 2a is easy, ie, a maintenance becomes easy. During dissolution of silver ions in the water to be treated 10 (application of positive voltage between the silver electrode 2a and the ground electrode part 3), sterilization treatment by discharge (high voltage electrode part 5 and ground electrode part) Of course, it may be performed in the middle of applying a negative high-voltage pulse to 3.

  As described above, in the sterilization apparatus 1 configured as described above, unlike the sterilization apparatus 1 according to the first embodiment, the negative high voltage pulse and the positive voltage are applied between the high voltage electrode unit 5 and the ground electrode unit 3. It is not necessary to apply them separately. For this reason, the sterilization apparatus 1 according to the third embodiment can independently perform the sterilization treatment by discharge and the sterilization treatment by silver ions, and can sterilize the water to be treated 10 more efficiently. A remarkable effect can be obtained.

Embodiment 4 FIG.
In the first to third embodiments, the ultrasonic generator 8 a and the measuring instrument 8 b are provided as the lifetime measuring device 8. The life measuring device 8 is not limited to this, and may be the following, for example. In the fourth embodiment, differences from the first to third embodiments will be mainly described, and the same functions and configurations will be described using the same reference numerals.

FIG. 13: is a schematic sectional drawing which shows the sterilizer which concerns on Embodiment 4 of this invention.
In the sterilization apparatus 1 according to Embodiment 1, the ammeter 13 is used to determine the discharge state. In the sterilization apparatus 1 according to the fourth embodiment, the ammeter 13 is also used for measuring the length of the high voltage electrode 2 that is a silver electrode. That is, the sterilizer 1 according to the fourth embodiment determines the life of the high voltage electrode 2 based on the measurement value of the ammeter 13. Other configurations of the sterilization apparatus 1 according to the fourth embodiment are the same as those in the first and second embodiments.
When the silver electrode is provided separately from the high voltage electrode 2 as in the third embodiment, an ammeter for measuring the current flowing through the silver electrode is provided, and the length of the silver electrode is determined based on the measured value of the ammeter. What is necessary is just to measure.

The sterilizer 1 configured as described above measures the length of the high voltage electrode 2 that is a silver electrode as follows.
The resistivity of a metal such as an electric wire is expressed by the following formula 5.
ρ = RA / L (Formula 5)
Here, ρ is the electrical resistivity (Ω · m), R is the electrical resistance (Ω), A is the cross-sectional area (m ² ), and L is the length (m).

  That is, if the cross-sectional area of the electric wire is the same, the resistivity of the electric wire changes with the length of the electric wire. For this reason, the shorter the wire length, the smaller the resistance value of the wire and the greater the current measured by the ammeter. Using this principle, in the sterilization apparatus 1 according to the fourth embodiment, the current value when the high voltage electrode 2 reaches the lifetime (hereinafter referred to as the lifetime current value) is measured in advance, and the ammeter When the measured value of 13 is equal to or greater than the lifetime current value, it is determined that the high-voltage electrode 2 has a lifetime.

  The comparison between the measured value of the ammeter 13 and the lifetime current value (that is, the lifetime determination of the high-voltage electrode 2) may be performed by a person or a control device or the like. Further, when the control device determines the life of the high voltage electrode 2, the alarm device 9 shown in the first embodiment is connected to the control device, so that the high voltage electrode 2 (high voltage electrode unit 5) is connected to the high voltage electrode 2. It is possible to notify the outside of the supply stop of the voltage pulse and the replacement timing of the high voltage electrode unit 5.

  As described above, in the sterilization apparatus 1 configured as described above, it is possible to obtain a remarkable effect that the life of the high-voltage electrode 2 that is a silver electrode can be easily confirmed as compared with the sterilization apparatus 1 according to the first embodiment. .

  In the fourth embodiment, the lifetime of the high voltage electrode 2 is determined based on the voltage flowing through the high voltage electrode 2 that is a silver electrode. However, the lifetime of the high voltage electrode 2 is determined based on the resistance value of the high voltage electrode 2. May be judged. That is, a resistance measurement value for measuring the resistance value of the high voltage electrode 2 may be provided, and the life of the high voltage electrode 2 may be determined based on the measurement value of the resistance measurement value. As can be seen from Equation 5, if the cross-sectional area of the wire is the same, the resistivity of the wire varies with the length of the wire. For this reason, the resistance value of an electric wire becomes small, so that electric wire length becomes short. Using this principle, the life of the high voltage electrode 2 can be determined (the length of the high voltage electrode 2 can be measured).

Embodiment 5 FIG.
Moreover, you may judge the lifetime of a silver electrode as shown below. That is, the lifetime of the silver electrode may be determined by the lifetime measuring device 8 as described below. In the fifth embodiment, differences from the first to fourth embodiments will be mainly described, and the same functions and configurations will be described using the same reference numerals.

FIG. 14 is a schematic cross-sectional view showing a sterilizer according to Embodiment 5 of the present invention.
The lifetime measuring device 8 of the sterilizer 1 according to the fifth embodiment includes an X-ray generator 8c and a measuring instrument 8d instead of the ultrasonic generator 8a and the measuring instrument 8b shown in the first embodiment. . Other configurations of the sterilization apparatus 1 according to the fifth embodiment are the same as those in the first and second embodiments.

A high voltage of several tens to several hundreds kV is applied between the anode 8c1 (metal such as tungsten or molybdenum) and the cathode 8c2 (filament), and the generated thermoelectrons collide with the anode 8c1, Generate. The X-rays are incident on the high voltage electrode unit 5. When this incident X-ray is baked and imaged on a film coated with a photosensitive agent in the measuring instrument 8d, as shown in FIG. 15, the portion where the high voltage electrode 2 which is a silver electrode is present and the high voltage electrode 2 due to dissolution are present. It is clearly distinguished from the missing part. The measuring instrument 8d can measure the length of the high voltage electrode 2 from this image and estimate (determine) the life of the electrode. Further, according to this measurement method (lifetime measuring device 8 according to the fifth embodiment), water penetration due to minute cracks generated around the high voltage electrode 2 can be confirmed, and deterioration of the high voltage electrode 2 is also estimated. it can.
When the silver electrode is provided separately from the high voltage electrode 2 as in the third embodiment, the anode 8c1 and the cathode 8c2 may be arranged so that the silver electrode is sandwiched through a predetermined gap.

  As described above, in the sterilization apparatus 1 configured as described above, it is possible to determine the deterioration of the high voltage electrode unit 5 in addition to the life determination of the high voltage electrode 2. For this reason, the sterilization apparatus according to the fifth embodiment can obtain a remarkable effect that the life of the high voltage electrode 2 can be determined with higher accuracy.

Embodiment 6 FIG.
The sterilizer 1 shown in the first to fifth embodiments may be provided, for example, in an air conditioner. In addition, this Embodiment 6 demonstrates the case where the sterilizer 1 which concerns on Embodiment 1 is provided in the air conditioner.

  FIG. 16 is a schematic cross-sectional view showing an air conditioner according to Embodiment 6 of the present invention. When the air conditioner 100 is operated (cooling operation or heating operation), water vapor in the air is cooled and condensed by a heat exchanger (indoor heat exchanger or outdoor heat exchanger) functioning as an evaporator. It becomes water. Since the surface of the heat exchanger is hydrophilized, when a certain amount or more of condensed water adheres, it starts to fall spontaneously and is collected as drain water 22 in the drain pan 23.

  Therefore, the air conditioner 100 according to the sixth embodiment uses the sterilizer 1 to sterilize the drain water 22 stored in the drain pan 23. That is, the air conditioner 100 according to the sixth embodiment uses the sterilizer 1 to remove mold, bacteria, and the like in the drain water 22.

FIG. 17 is an explanatory diagram showing the amount of drain water in the drain pan in the air conditioner according to Embodiment 6 of the present invention. The vertical axis in FIG. 17 indicates the amount of drain water in the drain pan, and the horizontal axis in FIG. 17 indicates time.
During the operation of the air conditioner 100, the drain water 22 in the drain pan 23 is discharged from the drain pan 23 by the drain pump 24 so that the drain water 22 in the drain pan 23 becomes a constant amount. And with the stop of the air conditioner 100, the drain pump 24 stops and the drain water 22 in the drain pan 23 becomes a fixed quantity. Since the air conditioner 100 according to the sixth embodiment sterilizes microorganisms, molds, bacteria, and the like in the drain water 22 stored in the drain pan 23, generation of mold and bacteria on the drain pan 23 surface, slime Generation | occurrence | production of (mold and bacteria which became slime form) can be suppressed. For this reason, the air conditioner 100 according to the sixth embodiment can obtain an unprecedented remarkable effect that the clogging of the drain pump 24 can be suppressed.

  Below, the Example which confirmed the bactericidal treatment effect of the air conditioner concerning this Embodiment 6 is described.

Example 3
FIG. 18 is an explanatory diagram showing the experimental results of Example 3. FIG. 18 shows the experimental results of the comparative condition 3 (A) and the comparative condition 3 (B) together with the experimental result of the experimental condition 3.

In Example 3, the experiment was performed under the following setting conditions.
When the air conditioner 100 is operated (cooling operation or heating operation), water vapor in the air is cooled and condensed by a heat exchanger (indoor heat exchanger or outdoor heat exchanger) functioning as an evaporator. It becomes water. Since the surface of the heat exchanger is hydrophilized, when a certain amount or more of condensed water adheres, it starts to fall spontaneously and is collected as drain water 22 in the drain pan 23. As shown in FIG. 17, the drain water 22 always flows into the drain pan 23 while the air conditioner 100 is in operation. When the drain water 22 in the drain pan 23 exceeds 400 ml, the drain pump 24 starts to move, and the drain water 22 is discharged from the drain pan 23 to the outside of the air conditioner 100. For this reason, the total amount of drain water 22 in the drain pan 23 is kept at 400 ml. Thereafter, when the operation of the air conditioner 100 is finished, the drain pump 24 is stopped and 400 ml of drain water 22 remains in the drain pan 23. The drain water 22 in the drain pan 23 gradually decreases due to drying, but when the operation is resumed, the drain water 22 flows into the drain pan 23 and increases.

In such a condition that the amount of the drain water 22 in the drain pan 23 fluctuates, the experiment condition 3, the comparison condition 3 (A), and the comparison condition 3 (B) are set as follows, and the sterilization effect under each condition is obtained. confirmed. In Example 3, an experiment was performed using the sterilizer according to Embodiment 1. Further, E. coli 10 ⁵ CFU / ml was grown in the drain water 22, and the change in the number of E. coli cells was measured. The material of the drain pan 23 was made of the same glass as that of the treatment tank 11 of Example 1.

Experimental condition 3: The gap between the high voltage electrode portion 5 and the ground electrode portion 3 was 10 mm. Further, while the drain pump 24 was operated and the drain water 22 was periodically discharged, discharge by negative high voltage pulse at −4 kV and 130 Hz was performed. After the drain pump 24 stopped, a positive voltage was applied under the condition that the current flowing through the high voltage electrode portion 5 (more specifically, the high voltage electrode 2) was 1 mA and 90 sec.
Comparative condition 3 (A): The gap between the high voltage electrode portion 5 and the ground electrode portion 3 was 10 mm. Further, while the drain pump 24 was operated and the drain water 22 was periodically discharged, discharge by negative high voltage pulse at −4 kV and 130 Hz was performed. After the drain pump 24 stopped, it was left without applying a positive voltage.
○ Comparison condition 3 (B): The battery was left without being discharged at all times.

Under the experimental condition 3, the bacteria gradually decreased while the drain pump 24 was operated and the drain water 22 was periodically discharged. More specifically, in the first 5 hours from the start of the experiment, E. coli that was originally 10 ⁵ CFU / ml could be sterilized by about one digit. Further, even when the drain pump 24 was stopped and the drain water 22 was allowed to stand still, E. coli continued to decrease, and E. coli decreased to about 10 ¹ CFU / ml 24 hours after the start of the experiment. On the other hand, in the comparative condition 3 (A), as in the experimental condition 3, the bacteria gradually decreased while the drain pump 24 was operated and the drain water 22 was periodically discharged. More specifically, in the first 5 hours from the start of the experiment, E. coli that was originally 10 ⁵ CFU / ml could be sterilized by about one digit. However, when the drain pump 24 was stopped and the drain water 22 was allowed to stand, the E. coli increased, and the E. coli increased to about 10 ⁵ CFU / ml 24 hours after the start of the experiment. Under comparative condition 3 (B), while the drain pump 24 was operated and the drain water 22 was periodically discharged, the number of E. coli was not changed so much, but then increased, and 24 hours after the start of the experiment. The number of E. coli increased to about 10 ⁷ CFU / ml. From this, the bactericidal effect by the experimental condition 3 is recognized.

In addition, the number of Escherichia coli in the drain water 22 and the generation state of slime when the above operation was performed for 30 cycles was described. Under experimental condition 3, the number of Escherichia coli, which was 10 ⁵ CFU / ml at the beginning of the experiment, gradually decreased and remained at 1 to 10 CFU / ml. Even after 30 cycles (30 days later), generation of slime was not confirmed. On the other hand, in the comparison conditions 3 (A) and 3 (B), after the start of the experiment, the number of cells changed at 10 ⁵ to 10 ⁷ CFU / ml, and slime was observed from around 14 cycles (around 14 days). I started.
Thus, by sterilizing the drain water 22 as in the experimental condition 3, it was confirmed that the generation of mold and bacteria in the drain pan 23 can be suppressed and the slime generation can also be suppressed.

Embodiment 7 FIG.
Moreover, you may provide the sterilizer 1 shown in Embodiment 1-Embodiment 5 in the hand dryer, for example. In addition, this Embodiment 7 demonstrates the case where the sterilizer 1 which concerns on Embodiment 1 is provided in the hand dryer.

FIG. 19 is a schematic sectional view showing a hand dryer according to the seventh embodiment of the present invention.
The hand dryer 110 according to the seventh embodiment is provided with a sterilizer 1 for sterilizing the drain water 22 collected in the drain pan 23.

  When the wet hand 25 is inserted into the hand dryer 110, the water droplets 27 adhering to the hand 25 are blown off at a stretch by the jet wind 26 blown on both sides of the hand 25 to become drain water 22 and collected in the drain pan 23. The The drain water 22 collected in the drain pan 23 is sterilized by the sterilizer 1 (mold, bacteria, etc. in the drain water 22 are removed).

  As described above, in the hand dryer provided with the sterilization apparatus 1, the drain water 22 collected in the drain pan 23 by the sterilization treatment with silver ions after the discharge sterilization treatment by the negative high voltage pulse is finished. It can remove microorganisms, molds, bacteria, etc. For this reason, even after the discharge sterilization treatment by the negative high-voltage pulse is completed, it is possible to obtain an unprecedented remarkable effect that there is an effect that the off-flavor generated from the drain pan 23 can be suppressed.

Embodiment 8 FIG.
Moreover, you may provide the sterilizer 1 shown in Embodiment 1- Embodiment 5 in the humidifier, for example. In addition, this Embodiment 8 demonstrates the case where the sterilizer 1 which concerns on Embodiment 1 is provided in the air conditioner.

FIG. 20 is a schematic cross-sectional view showing a humidifier according to Embodiment 8 of the present invention.
The humidifier 120 according to the eighth embodiment includes a water storage tank 28 that stores water for humidifying air, a humidifying element 29, a drain pan 23 that collects drain water 22 that is excess water in the humidifying element 29, and a drain pan. 23, a pipe 30 for sending drain water 22 from the water storage tank to the water storage tank, a pipe 31 for supplying water in the water storage tank 28 to the humidifying element 29, and the like. Further, the humidifier 120 according to the eighth embodiment is provided with a sterilizer 1 for sterilizing the drain water 22 collected in the drain pan 23.
In the eighth embodiment, water used for humidification such as water in the water storage tank 28, drain water 22 and the like is referred to as humidified water.

  In the humidifier 120 according to the eighth embodiment, the microorganisms and mold in the drain water 22 collected in the drain pan 23 are sterilized by silver ions even after the discharge sterilization by the negative high voltage pulse is completed. And bacteria can be removed. For this reason, the humidified water can be kept in a sterilized state at all times even after the discharge sterilization process by the negative high voltage pulse is completed. Accordingly, not only the water storage tank 28 but also the humidification element 29, the drain pan 23 and the like are prevented from generating mold.

  Further, in general, a humidifier has a problem that mold tends to occur in a portion where humidified water is likely to accumulate (particularly a humidifying element, a drain pan, etc.). However, in the humidifier 120 according to the eighth embodiment, since the humidified water sprayed with the humidifier is sterilized even after the discharge sterilization process by the negative high voltage pulse is finished, microorganisms, molds and bacteria It is possible to obtain an unprecedented remarkable effect such as the effect of suppressing the occurrence of the above.

  In the eighth embodiment, the sterilizer 1 is provided in the drain pan 23, but the sterilizer 1 may be provided in the water storage tank 28.

  DESCRIPTION OF SYMBOLS 1 Sterilizer, 2 High voltage electrode, 2a Silver electrode, 3 Ground electrode part, 4 Insulator, 5 High voltage electrode part, 6 Discharge electrode part, 7 Power supply, 7a Power supply, 8 Life measuring apparatus, 8a Ultrasonic generator, 8b Measuring instrument, 8c X-ray generator, 8c1 anode, 8c2 cathode, 8d measuring instrument, 9 alarm device, 10 treated water, 11 treatment tank, 12 water surface, 13 ammeter, 22 condensed water (drain water), 23 drain pan , 24 Drain pump, 25 hands, 26 Jet wind, 27 Water droplets, 28 Water storage tank, 29 Humidifier, 30, 31 piping, 100 Air conditioner, 110 Hand dryer, 120 Humidifier.

Claims (17)

At least one high voltage electrode portion having a metal electrode formed of a sterilizing metal;
At least one ground electrode portion disposed with a predetermined gap from the high voltage electrode portion;
A first voltage power source for applying a voltage between the metal electrode and the ground electrode portion;
With
A step of sterilizing water by applying a negative high voltage pulse between the metal electrode immersed in water and the ground electrode portion to generate a discharge;
Applying a positive voltage between the metal electrode immersed in water and the ground electrode part, dissolving metal ions in water and sterilizing the water;
A method for sterilizing water, comprising: At least one high voltage electrode section;
At least one ground electrode portion disposed with a predetermined gap from the high voltage electrode portion;
At least one voltage electrode portion having a metal electrode formed of a metal having a sterilizing property and disposed between the ground electrode portion and a predetermined gap;
A first voltage power source for applying a negative high voltage pulse between the high voltage electrode portion and the ground electrode portion;
A second voltage power source for applying a positive voltage between the metal electrode and the ground electrode portion;
With
A step of sterilizing water by applying a negative high voltage pulse between the high voltage electrode part immersed in water and the ground electrode part to generate a discharge;
Applying a positive voltage between the metal electrode immersed in water and the ground electrode part, dissolving metal ions in water and sterilizing the water;
A method for sterilizing water, comprising:   The method for sterilizing water according to claim 1 or 2, wherein the metal forming the metal electrode is silver, copper, zinc or aluminum. At least one high voltage electrode portion having a metal electrode formed of a sterilizing metal;
At least one ground electrode portion disposed in the high voltage electrode portion with a predetermined gap;
A first voltage power source for applying a negative high voltage pulse and a positive voltage between the metal electrode and the ground electrode portion;
Equipped with a,
In a state where the metal electrode and the ground electrode portion are immersed in water, a negative high voltage pulse is applied between the metal electrode and the ground electrode portion to generate a discharge, thereby sterilizing the water. Done
In a state where the metal electrode and the ground electrode portion are immersed in water, a positive voltage is applied between the metal electrode and the ground electrode portion to dissolve metal ions in water and sterilize the water. Water sterilizer characterized by that. At least one high voltage electrode section;
At least one ground electrode portion disposed with a predetermined gap from the high voltage electrode portion;
At least one voltage electrode portion having a metal electrode formed of a metal having a sterilizing property and disposed between the ground electrode portion and a predetermined gap;
A first voltage power source for applying a negative high voltage pulse between the high voltage electrode portion and the ground electrode portion;
A second voltage power source for applying a positive voltage between the metal electrode and the ground electrode portion;
Equipped with a,
In a state where the high voltage electrode part and the ground electrode part are immersed in water, a negative high voltage pulse is applied between the high voltage electrode part and the ground electrode part to generate a discharge. Sterilize
In a state where the metal electrode and the ground electrode portion are immersed in water, a positive voltage is applied between the metal electrode and the ground electrode portion to dissolve metal ions in water and sterilize the water. Water sterilizer characterized by that.   The application condition of a positive voltage applied between the metal electrode and the ground electrode portion is determined so that a predetermined amount of metal ions dissolved in water to be sterilized is determined. 4. The water sterilizer according to 4.   The application condition of a positive voltage applied between the metal electrode and the ground electrode portion is determined so that a predetermined amount of metal ions dissolved in water to be sterilized is determined. 5. The water sterilizer according to 5. As a positive voltage applied between the metal electrode and the ground electrode part,
Using a positive voltage applied between the metal electrode and the ground electrode part by hunting that occurs when a negative high voltage pulse is applied between the metal electrode and the ground electrode part. The water sterilizer according to claim 4 or 6, characterized by the above.   The water sterilizer according to any one of claims 4 to 8, further comprising a lifetime measuring device that measures the length of the metal electrode. The lifetime measuring device is:
An ultrasonic generator for generating an ultrasonic wave incident on the metal electrode;
A measuring instrument for measuring a response time until the ultrasonic wave incident on the metal electrode returns;
The water sterilizer according to claim 9, comprising: The lifetime measuring device is:
The water sterilizer according to claim 9, further comprising an ammeter for measuring a current flowing through the metal electrode or a resistance measuring device for measuring a resistance value of the metal electrode. The lifetime measuring device is:
An X-ray generator for generating X-rays incident on the metal electrode;
A detection device for detecting the X-rays after passing through the metal electrode;
The water sterilizer according to claim 9, comprising:   The water sterilizer according to any one of claims 9 to 12, further comprising a notification device that notifies the outside that the length of the metal electrode is shorter than a predetermined length.   The metal which forms the said metal electrode is silver, copper, zinc, or aluminum, The water sterilizer as described in any one of Claims 4-13 characterized by the above-mentioned. The water sterilizer according to any one of claims 4 to 14,
A drain pan for storing drain water;
With
An air conditioner that performs sterilization on water stored in a drain pan by the sterilizer. The water sterilizer according to any one of claims 4 to 14,
A drain pan for storing drain water;
With
A hand dryer that performs sterilization on water stored in a drain pan by the sterilizer. The water sterilizer according to any one of claims 4 to 14, comprising:
A humidifier that performs sterilization treatment on humidified water by the sterilizer.

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