JPH06312178A - Purified water sterilizing device and use thereof - Google Patents

Abstract

PURPOSE:To enhance the treatment capacity of raw water while ensuring the safety as drinking water and to inexpensively purify the raw water in an energy- saving manner by stepwise applying weak and high voltages across the electrodes selected from three electrodes provided to the adsorbing bed composed of conductive activated carbon arranged in a water tank. CONSTITUTION:A changeover signal is sent to a changeover switch 29 from a control unit 30 and voltage is applied across the electrodes selected from first, second and third electrodes 25-27. At a usual time, weak voltage is applied across the first and third electrodes 27 or the second and the third electrodes 26, 27 and bacteria in raw water are captured by an adsorbing part 20 to suppress the propagation of bacteria. At a time of the regeneration of the adsorbing part 20, a water supply valve 13 is closed by the operation signal from the control unit 30 on the basis of a time-up signal and a drain valve 15 is opened to drain the raw water in a water tank 10 and, thereafter, voltage is applied across the first and second electrodes 26 to allow the adsorbing part 20 to generate heat to sterilize bacteria captured at the usual time.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a water purification apparatus for purifying and sterilizing raw water such as tap water or ground water and supplying it as drinking water for general households and business and a method of using the same.

[0002]

2. Description of the Related Art Recent technical trends relating to sterilization of raw water in this type of water purification apparatus include an apparatus for sterilizing microorganisms such as bacteria by using a hollow fiber membrane module (commercially available product) to suppress breeding and to control bacteria. A device for sterilizing raw water by electrolysis and a device for sterilizing with an appropriate amount of chlorine are known.

Generally, in the case of a water purification device as a water treatment device, hypochlorous acid (C) contained in raw water such as tap water or ground water is used.
lO ^-) and residual chlorine components such as organic chlorine compounds, musty odor, trihalomethane, or general bacteria and the dye is adsorbed and removed by passing through an adsorbent or sterilizer. With the use over time, algae, bacteria, and microorganisms propagate due to the adsorbed substances adsorbed on the activated carbon and the wall surface of the storage tank in this manner, which increases the load on the filter and shortens the life of the device. Since the function of the adsorbent decreases depending on the adsorbed substance, the adsorbent is desorbed to regenerate the adsorbent, and various sterilization means are incorporated into the device to improve water purification efficiency and support maintenance and maintenance of the device. is doing.

[0004]

By the way, in the case of a sterilizer using a hollow fiber membrane module, the fiber membrane module is apt to be clogged with impurities in the raw water due to long-term use, and the treatment capacity is generally low. Electrolytic sterilizers have problems in terms of economy such as power consumption. Further, in the case of a sterilizer using chlorine, it is difficult to control and manage it in order to control it to a suitable chlorine concentration in consideration of safety. As described above, the conventionally known sterilization methods each have a problem to be solved.

An object of the present invention is to provide a water purification apparatus which secures safety as drinking water, enhances the treatment capacity of raw water, can save power, and is advantageous in terms of cost.

[0006]

In order to achieve this object, in the water purifying and sterilizing apparatus according to the first aspect of the present invention, an adsorbing section made of conductive activated carbon having a required shape is arranged in a water tank, and a water supply valve is provided. When purifying and sterilizing the raw water introduced into the water tank from the adsorber at the adsorption section before use, in normal times, the raw water passes through or stops at the adsorption section by repeated use and non-use. In a device that drains raw water in the water tank and in the adsorption section from the drain valve, a pouring tube inserted in the center of the adsorption section as a conductive tube section with a large number of water passage holes made of a conductive material, and adsorption during regeneration A pair of first and second electrodes to which a voltage is applied as a sterilization mode for sterilizing the bacteria in the raw water by sterilizing the parts, and the conductive pipe part of the spout pipe, which is normally provided in the raw water. As a bacteriostatic mode that captures and reproduces Pressure is applied between either the first electrode or the second electrode, a third electrode, a timer circuit that counts each execution time during normal and repetitive intervals, and a voltage in sterilization mode or Switching means for switching to the antibacterial mode, a power supply circuit for applying a voltage corresponding to the sterilization mode or antibacterial mode when switched by the switching means, a water supply valve, a drain valve and switching based on a time-up signal from a timer circuit And a control device for sending operation control signals to the respective means.

The method of using the water purification apparatus of claim 2 is that when normal time and regeneration are repeated at regular intervals,
Normally, there is a sterilization mode process in which a weak voltage is applied between the first electrode or the second electrode and the third electrode by the power supply circuit by switching the switching means with a control signal from the control device. . In addition, at the time of regeneration, the control signal from the control device based on the time-up signal indicating that the sterilization mode process has been completed closes the water supply valve to stop the introduction of raw water into the water tank, and opens the drain valve to open the water tank and The switching means is switched by a control signal from the control device based on a drainage process for discharging raw water in the adsorption part and a time-up signal indicating that the drainage process is completed, and the power supply circuit generates a voltage capable of generating heat in the adsorption part by the first electrode. And a sterilization mode process applied between the second electrodes.

In the method of use according to the third aspect, a weak DC voltage can be applied in the antibacterial mode, and an AC voltage or a DC voltage capable of generating heat in the adsorption section can be applied in the sterilization mode.

Similarly, in the case of the use method according to claim 4,
It is also possible to control the voltage application in the bacteriostatic mode to turn off the voltage when the raw water is flowing during normal use.

[0010]

In the purified water sterilizer according to the first aspect of the invention, the switching signal is sent from the control device to the switching means, and the first, second and third switching devices are provided.
A voltage is applied between the electrodes selected from among the electrodes.
By applying a weak voltage to the first electrode and the third electrode (or between the second electrode and the third electrode) at the normal stage,
Bacteria, etc. in the raw water are captured by the adsorption unit to suppress the reproduction. At the stage of regeneration, when the adsorption unit is regenerated, the water supply valve is closed by the operation signal from the control device based on the time-up signal to stop the raw water supply, and the drain valve is opened to drain the raw water in the water tank. Next, a voltage is applied between the first electrode and the second electrode to heat the adsorption portion, and the bacteria and the like trapped in the adsorption portion at the normal stage are sterilized. By adopting such a voltage application form, the power consumption is lower than that in the conventional device in which the raw water is directly electrolyzed to sterilize bacteria and the like in the raw water.

According to the use method of claims 2 and 3, when the normal time and the regenerating time are repeated at a constant interval, in the normal bacteriostatic mode process, a weak voltage is applied by the power supply circuit to cause adsorption. The part captures bacteria in raw water and suppresses the growth. At the time of regeneration, the drainage process is carried out as a preparation. That is, based on the time-up signal indicating that the bacteriostatic mode process has been completed, the water supply valve is closed to stop the introduction of raw water into the water tank and the drain valve is opened to discharge the raw water in the water tank and the adsorption section. When the process is completed, the switching means switches to the sterilization mode process, and in the sterilization mode process, the power supply circuit applies a voltage capable of generating heat in the adsorption unit.

Here, a weak DC voltage is used as an applied voltage in the bacteriostatic mode process, and the surface of microorganisms such as bacteria is generally tinged with weak anions due to energization of the adsorption section by the weak DC voltage. By utilizing this characteristic, the adsorbing part is made to capture bacteria and the like. The captured bacteria and the like are sterilized by applying a high voltage in the sterilization mode process.

In the method of use according to the third aspect, a weak DC voltage can be applied in the antibacterial mode, and an AC voltage or a DC voltage capable of generating heat in the adsorption section can be applied in the sterilization mode.

Further, when the raw water is flowing during normal use as in the method of use according to claim 4, from the viewpoint of bacteria and the like adhering to the adsorbing part and decreasing the capacity, the water is stopped. Bacteria and the like in the raw water flow more than in the inside, and it is still less likely that it will stay in the adsorption part. For this reason, the voltage application in the bacteriostatic mode can be turned off only in the passage of water as long as the bacteria and the like are allowed. This is a control that considers power consumption. However, it is desirable to control the capture of bacteria and the like by the application of a weak voltage and the suppression of reproduction throughout the normal process of repeating water supply and water stoppage.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of a water purification apparatus and a method of using the same according to the present invention will be described below with reference to the drawings.

FIG. 1 is a sectional view of the water purification and sterilization apparatus of the embodiment. The apparatus has a water tank 10, and raw water such as tap water is introduced from an inlet 11 provided at the bottom of the tank through a water supply pipe 12. The water supply pipe 12 is provided with a water supply valve 13 such as a solenoid valve that restricts the introduction of raw water.
A drain valve 15 that is a solenoid valve or the like is also provided in the drain pipe 14 that is branched off from the middle. By switching the pipeline, the raw water in the water tank 10 can be drained and discarded from the drain pipe 15. Of course, the water supply valve 13 is closed during drainage.

Inside the water tank 10, there is arranged an adsorption portion 20 which is formed into a cylindrical shape by using fibrous activated carbon which is electrically conductive and has a fixed shape. Filter members 21 and 22 are fitted on the cylindrical inner and outer peripheral surfaces of the suction portion 20. Between the cylindrical adsorption unit 20 and the water tank 10, the adsorption unit 2
0 is an annular passage 16 which surrounds 0, and the above-mentioned raw water inlet 11 communicates with this outer annular passage 16. Therefore, the raw water introduced from the introduction port 11 will not pass through the outer ring passage 16
Then, it is supplied to the adsorbing portion 20 through the filter member 21 on the outer peripheral side and can come into contact therewith.

A cylindrical outlet pipe 23 is provided so as to be fitted into the filter member 22 on the inner peripheral side from the inside so as to pass through the center of the suction portion 20. A part of the spout pipe 23 is a conductive pipe portion 23A formed of stainless steel or the like, and a large number of water passage holes 24 are provided therein.
A resin pipe portion 23B is joined to the conductive pipe portion 23A in the axial direction, and the spout pipe 23 is a joint pipe of two different materials. Further, the lower portion of the conductive pipe portion 23A is closed with a bottom, and the water purified by passing through the adsorbing portion 20 can be introduced into the spout pipe 23 through the water passage hole 24 through the filter member 22 on the inner peripheral side. is there. The water purification pipe 17 is connected to the upper resin pipe portion 23B, and a water injection plug (not shown) provided at the end of the water purification pipe 17
The tubular structure composed of the adsorbing part 20 and the inner and outer peripheral filter members 21 and 22 is a donut disc-shaped first and second upper and lower end formed of a pair of Yin and Yang. It is sandwiched between the electrodes 25 and 26, and from the upper part, for example, the first electrode 25 as an anode, the terminal rod 25
a is the terminal rod 26 from the second electrode 26 which is the lower cathode.
a is led out of the water tank 10 and connected to the power supply circuit 28. In addition, the extraction pipe 2 inserted into the suction unit 20
The third conductive tube portion 23A has a third outer surface on the lower bottom portion.
The electrode 27 is attached, and the terminal rod 27a of the third electrode 27 is attached.
Also goes out of the water tank 10 and is connected to the power supply circuit 28.

The power supply circuit 28 is a circuit capable of switching between alternating current and direct current, and is simply provided with both a direct current power supply 28A and an alternating current power supply 28B as in the embodiment, and is provided in the circuit, for example. Electromagnetic changeover switch (changeover means)
Switching of applying an alternating voltage between the first electrode 25 and the second electrode 26 or applying a direct voltage between the first electrode 25 (or the second electrode 26) and the third electrode 27 by means of 29. It is possible.

As shown in the block diagram of FIG. 2, the device of the present invention is automated by including a control device 30 such as a microcomputer. The control device 30 includes a central processing unit (CPU) 31, a memory 32 storing a control program, and an I / O port 3 for inputting / outputting to / from an external device to be controlled.
3 etc. are included. In addition, a timer circuit 34 is provided to send a time-up signal for each series of control processes to the control device 30. A control signal based on the time-up signal of the timer circuit 34 is sent from the control device 30 to the water supply valve 13 and the drain valve 15 as an operation signal. Further, a changeover signal is sent from the control device 30 to the changeover switch 29 of the power supply circuit 28 by the time-up signal,
Either the DC power supply 28A or the AC power supply 28B is used as a power supply circuit, and a DC voltage or an AC voltage is applied between selected electrodes of the first to third electrodes 25 to 26.

An appropriate number of dowel-shaped protrusions 25b and 26b are formed on the inner surfaces of the upper and lower first and second electrodes 25 and 26, respectively.
Are provided, and by making these stick out from the upper and lower end surfaces of the adsorption portion 20, the contact and electrical conductivity of the first and second electrodes 25, 26 with respect to the adsorption portion 20 are enhanced, and the positioning of the assembly is ensured.

Next, regarding the method of use and the operation of the embodiment of the water purification apparatus having the above structure, the operation flowchart of FIG. 3, the timing chart of FIG. 4, and the characteristic diagram of the correlation between the number of bacteria in the adsorbent section and the voltage of FIG. Will be described together.

The operation of the apparatus is controlled by repeating the normal time (1) and the reproduction time (2) at regular intervals.
That is, in the normal time (1), a flow occurs in the raw water while the purified water is being poured out as drinking water, and when the use is stopped, the flow of the raw water stagnates and water passing / stopping is repeated. This is a process of trapping the bacteria and the like in the adsorbing section 20 and suppressing the reproduction thereof, and hereinafter, this is referred to as a "bacteriostatic mode" process. On the contrary,
At the time of regeneration (2), the supply of raw water is stopped at the stage when the normal time is over, the raw water is discharged from the water tank 10, and then the adsorption unit 2
This is a process of sterilizing bacteria and the like adsorbed on 0, and at the time of regeneration, it is composed of this drainage process and the "sterilization mode" process.

As shown in the timing chart of FIG. 4, the interval from the normal antibacterial mode process time t ₁ to the regeneration drainage process, the end of the sterilization mode process, and the next sterilization. Let time be t ₄ . The supply of raw water is stopped at the time of regeneration, and the water tank 10 and the adsorption unit 20 are stopped.
The time of the drainage process of draining and discarding all the raw water stagnant therein is t ₂ , and the time of the sterilization mode process of finishing the drainage process and starting sterilization is t ₃ .

In the flow chart of FIG. 3, first, in the normal time (1), the drain valve 15 is closed by the control signal from the control device 30 when the device is started, the water supply valve 13 is opened, and the tap water which is the raw water is supplied to the water supply line. Enter the outer ring passage 16 from 12 once,
The water is introduced almost completely into the water tank 10 (step S ₁ ).

The introduced raw water is filtered by the filter member 2 on the outer peripheral side.
After being filtered by 1, the activated carbon of the adsorption unit 20 is contacted. By contact with the adsorption unit 20, dissolved substances in the raw water, for example, trace organic chlorine compounds, trace organic compounds, musty odor, etc. are adsorbed and removed. The purified water that has been purified is the inner filter member 2
It is filtered again at 2 and enters the outlet pipe 23 through a number of water passage holes 24. It is used for drinking water, etc. from this pouring pipe 23 through the water purification pipe 17. When the user opens the water tap at the end of the water purification pipe 17 and uses it for pouring, raw water flows in the water tank 10. On the other hand, the flow of raw water is naturally stagnant when the water tap is closed and not in use, or during long-term short-term absence.

The time period during which the passage / stopping of the raw water is repeated is set based on past data and empirical values, and this period is set as the normal time (1).
In the adsorption unit 20 in the water tank 10 at the normal time (1), the changeover switch 29 is switched to the circuit by the DC power supply 28A in the power supply circuit 28 by the switching signal from the control device 30. That is, the DC power source 28A causes the first upper side
The third electrode 27 of the dispensing tube 23 to the electrode 25 as a (+) pole (-) to apply a weak DC voltage between the electrodes to pole, weak current is applied to the suction unit 20 (Step S ₂ ). In the embodiment, the structure in which the voltage is applied between the first electrode 25 and the third electrode 27 is adopted, but a mode in which the voltage is applied between the lower second electrode plate 26 and the third electrode 27 is also possible. is there. Adsorption part 2 with normal time (1) as bacteriostatic mode process
The meaning of applying a weak DC voltage to 0 is for the following reason.

That is, by applying a weak direct current to the adsorbing portion 20 which is a conductor, the surface of microorganisms such as bacteria generally has a weak anion, and the adsorbing portion 20 traps bacteria and the like. In addition, the growth of bacteria is further suppressed in the adsorbing section 20 while the raw water is stagnant due to nonuse. In particular, when the user stays away for a long period of time, raw water is likely to stay in the adsorption unit 20 and promote bacterial growth. Therefore, it is also a treatment for suppressing this. The weak DC voltage applied between the first electrode 25 and the third electrode 27 in the bacteriostatic mode process is hereinafter referred to as bacteriostatic voltage E _AC .

The normal antibacterial mode process in the present invention is as follows.
This is a field that is being actively researched academically as part of the water sterilization method. For example, "Iron and Steel: 1976 (199
0) No. 9 ”," A New Sterilization Method Using Ion Exchange Membrane Electrodialysis Method "(Showa Pharmaceutical University Faculty of Pharmacy Toshio Sato, Yokohama National University Faculty of Engineering Professor Haruhiko Oya) has a chemical sterilization method and physics. It is said that it is necessary to solve the problems of the sterilization method and to develop a completely new sterilization method in principle.

The basis of the bacteriostatic mode process of the present invention is based on the common theory that the surface of microorganisms is anionized in a weakly charged state in the field of bacteriology, and therefore, according to the experiments by the inventors, for example, 5 volts is used. It has been confirmed that it is possible to prevent bacteria in the raw water from being captured by the adsorption unit 20 and flowing out into the pouring pipe 23 as they are, by allowing a certain amount of direct current to flow through the adsorption unit 20. Further, it is possible to sterilize the bacteria once captured by further increasing the voltage. The process for this sterilization is theoretically detailed in the article.

Now, in the normal time (1), the total time due to repeated use of water flow / stoppage is set as the bacteriostatic mode process from the empirical value to t.
_When set to ₁ , this set time t ₁ can be stored in the memory 32 of the control device 30 in advance. That is, in the control device 30, the timer circuit 3 measuring the set time t ₁
When the time-up signal from 4 is input (step S
₃ ), this signal is stored in the memory 32 and CP
The control unit in U31 determines and sends a command signal from the I / O port 33 to the water supply valve 13 and the drain valve 15 to be controlled in order to start the regeneration (2). The water supply valve 13 is closed by the operation signal to stop the introduction of raw water into the water tank 10, and in synchronization with this, the drain valve 15 is opened to discharge all the raw water accumulated in the entire water tank 10 from the drain pipe 14. Discard. The time of this drainage process is t ₂ (step S ₄ ).

The power supply circuit 28 is not related to the operation of the water supply valve 13 and the drain valve 15, and electromagnetic valves are used for both valves to turn them on and off with another power supply by a control signal from the control device 30. it can. As the operating voltage of both valves,
As shown in the time chart of FIG. 4, a voltage Ev that is considerably higher than the sterilization voltage E _AB in the next sterilization mode process is required.

The timer circuit 33 counts the completion of the drainage time t ₂ , the time-up signal is sent to the control device 30 (step S ₅ ), and the switching signal is sent from the control device 30 to the change-over switch 29. The AC power supply 28B of the power supply circuit 28 is closed. An AC voltage is applied between the first electrode 25 and the second electrode 26 by an AC power supply 28B. The AC voltage is higher than bacteriostatic voltage E _AC in the previous bacteriostatic mode, a sterilizing mode process bacteria or the like trapped in the suction unit 20 in bacteriostatic mode is applied as fungicidal voltage E _AB enough to sterilization by heat Start (step S ₆ ).
In the sterilization mode process, the first electrode 25 and the second electrode 26
The time during which the sterilization voltage E _AB is applied is t ₃ . As a result, an alternating current is caused to flow through the adsorbing portion 20 which is a conductor, and the amount of heat flowing out from the adsorbing portion 20 per unit time, that is, Joule heat is generated to sterilize and reduce the bacteria attached to the adsorbing portion 20. As is clear from the voltage characteristics of FIG. 5, the sterilization voltage E
_The higher the pressure of _AB , the smaller the number of bacteria held in the adsorption unit 20.

When the sterilization process is completed after the application time t ₃ has passed (step S ₇ ), the process in the bacteriostatic mode at the normal time (1) is resumed until the next sterilization start interval time t ₁ .

In the method of use in the apparatus of the above embodiment, in the normal time (1) in which the passage / stopping of the raw water is repeated.
The bacteriostatic voltage E _AC was applied between the first electrode plate 25 and the third electrode plate 27 during the entire process of passing water and stopping water. As a modification of this embodiment, in the present invention, it is possible to perform control in which it is not necessary to apply the bacteriostatic voltage E _AC during the passage of water.

Further, at the time of regeneration (2), when the raw water is drained to empty the water tank 10, the empty state is detected by, for example, a suitable means for detecting the water level, and this detection signal is detected. Can be sent to the control device 30 to shift to the sterilization process of the next step.

[0037]

As described above, the purified water sterilizing apparatus according to the first aspect of the present invention is selected from among the three electrodes for the adsorbing portion made of the conductive activated carbon disposed in the water tank, and the voltage is high from a weak voltage. By applying voltage stepwise, bacteria and other substances trapped in the adsorption part with a weak current are heated and sterilized at the next higher voltage and current, so that raw water is directly electrolyzed like this type of device. Compared with a device that sterilizes bacteria in raw water, it has the advantage of significantly reducing power consumption. Also,
It is not necessary to increase the size of the entire device in order to increase the treatment capacity of raw water, and it is possible to achieve compactness.

According to the method of use according to claims 2 and 3, the control unit causes the adsorption section to capture bacteria and the like in the raw water as a bacteriostatic mode process by repeating water flow and water stoppage during normal times. Suppress breeding and keep the antibacterial mode process for a certain period of time
A series of controls for sterilizing bacteria and the like adhering to the adsorbing portion in the sterilization mode process after passing the time can be efficiently performed at regular intervals.

[Brief description of drawings]

FIG. 1 is a sectional view of a water purification sterilizer according to an embodiment of the present invention.

FIG. 2 is a block diagram of a control mode of the water purification apparatus of the embodiment.

FIG. 3 is a flowchart of operations in the water purification apparatus and the sterilization method according to the embodiment.

FIG. 4 is a time chart of a purified water sterilizing apparatus and a sterilizing method according to an embodiment.

FIG. 5 is a characteristic graph showing the correlation between the number of bacteria and the voltage in the water purification apparatus of the embodiment.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 10 ... Water tank, 13 ... Water supply valve, 15 ... Drain valve, 17 ... Water purification pipe, 20 ... Activated carbon adsorption part, 23 ... Pour out pipe, 23A ... Conductive pipe part, 23B ... Resin pipe part, 25 ... First electrode, 26 … Second
Electrode, 27 ... Third electrode, 28 ... Power supply circuit, 28A ... AC power supply, 28B ... DC power supply, 29 ... Changeover switch, 30 ...
Control device.

Claims (4)

[Claims] 1. When the adsorbing part made of conductive activated carbon formed into a required shape is arranged in the water tank, and the raw water introduced into the water tank from the water supply valve is purified and sterilized by the adsorbing part before use,
In normal times, raw water passes through or stops water in the adsorption unit by repeating use and non-use, and when regenerating the adsorption unit, part of the water purification device that drains the raw water in the water tank and adsorption unit from the drain valve A conductive tube with a large number of water holes made of a conductive material, which is inserted in the center of the adsorption section, and a voltage as a sterilization mode that sterilizes bacteria in raw water by heating the adsorption section during regeneration. A pair of first and second electrodes to be applied, and a voltage as a bacteriostatic mode that is provided in the conductive tube part of the spout tube and normally suppresses and reproduces bacteria in raw water
A third electrode that is applied between either the electrode or the second electrode, a timer circuit that counts each execution time during normal time and regeneration that repeats at regular intervals, and the voltage is set to the sterilization mode or sterilization mode. Switching means for switching, a power supply circuit for applying a voltage corresponding to the sterilization mode or antibacterial mode when switched by the switching means, and a water supply valve, a drain valve, and the switching means, respectively, based on a time-up signal from the timer circuit. A control device for sending a control signal, and a water purification device. 2. The method of using the water purifying apparatus according to claim 1, wherein the normal time and the regenerating time are repeated at regular intervals, wherein in normal time, the switching means is switched by a control signal from the controller.
A bactericidal mode process in which a weak voltage is applied between the first electrode or the second electrode and the third electrode by the power supply circuit, and a time-up signal indicating that the bacteriostatic mode process has ended during regeneration. Based on the control signal from the control device based on this, the drainage process of closing the water supply valve to stop the introduction of raw water into the water tank and opening the drainage valve to discharge the raw water in the water tank and the adsorption unit, and the time of the completion of the drainage process The switching means is switched by a control signal from the control device based on the up signal, and a voltage capable of generating heat in the adsorption portion is set by the power supply circuit to the first electrode and the second electrode.
And a sterilization mode process applied between the electrodes. 3. The method according to claim 2, wherein a weak DC voltage is applied in the antibacterial mode, and an AC voltage or DC voltage capable of generating heat in the adsorption section is applied in the sterilization mode. 4. The voltage application in the bacteriostatic mode is turned off when the raw water is flowing during normal use.
How to use described.