JP3648584B2 - Water purifier - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a water purifier, and more particularly to a water purifier provided with a detection unit for detecting residual chlorine concentration.
[0002]
[Prior art]
A water purifier that filters water using activated carbon, a hollow fiber membrane filter, or the like is provided with a detection unit that detects residual chlorine concentration. In this type of water purifier that can display the residual chlorine concentration after filtration, or display the residual chlorine concentration of both the water before filtration and the water after filtration, platinum is used as the detection unit. A method is used in which a pair of electrodes formed of silver or silver is immersed in water, and the residual chlorine concentration is obtained based on the current value flowing between the electrodes when a constant voltage is applied between the electrodes. This utilizes the fact that the residual chlorine concentration C and the current value I are approximately proportional (C = a × I a: constant), but the constant a varies depending on the state of the electrode. When the electrode becomes dirty due to the use of the period, the value of the residual chlorine concentration obtained from the detection unit greatly deviates from the original value.
[0003]
In Japanese Utility Model Laid-Open No. 62-114692 and Japanese Utility Model Laid-Open No. 62-109796, small spheres such as glass are placed in the flow path of the detector so that the small spheres come into contact with the electrode surface by the flow of the small spheres caused by the water flow. And the tip of the blade of a water turbine rotating in a water stream are in contact with the electrode. By the contact, mechanical polishing and cleaning of the electrode surface is performed.
[0004]
[Problems to be solved by the invention]
However, when the dirt on the electrode surface is removed by the mechanical polishing described above, the abrasion of the electrode becomes a problem, and the polishing effect is reduced by the abrasion of the small spheres and the blades of the water wheel. In addition, since there is no water flow, the electrode cannot be polished and washed, and therefore there is a problem that accurate residual chlorine concentration cannot be detected when water is passed after it has not been used for a while.
[0005]
This invention is made | formed in view of such a point, The place made into the objective is to provide the water purifier which can perform the detection display of the residual chlorine concentration stabilized over the long term.
[0006]
[Means for Solving the Problems]
Therefore, the present invention provides a water purification unit having a filtering means, a residual chlorine detection unit comprising a pair of electrodes that are arranged in the water channel and to which a predetermined voltage is applied, and a current value that flows between the electrodes of the residual chlorine detection unit. In a water purifier equipped with a control unit for determining the residual chlorine concentration based on the above and a display unit that performs display according to the output of the control unit, the residual chlorine detection unit is arranged before and after the water purification unit before and after filtration The residual chlorine is detected and both residual chlorine concentrations are displayed on the display unit, and the control unit has a negative voltage relative to the other electrode on one of the pair of electrodes of each residual chlorine detection unit. It has an operation mode for performing reverse current processing to apply reverse current, and performs reverse current processing by repeatedly applying an inrush current at the time of application by repeatedly applying a voltage to the electrode and non-application within a predetermined time. there are particularly characterized. The electrode is cleaned by electrical treatment.
[0007]
Here, the control unit enters an operation mode of reverse electric processing when the unused time reaches a certain time, or enters an operation mode of reverse electric processing when the flow rate detected by the flow rate detection unit falls below a predetermined amount. A thing can be used suitably .
[0008]
Further, the flow rate may be detected from an electrical variable between the electrodes of the residual chlorine detector.
Furthermore, it is good also as what was provided with the control switch which switches on and off of a main power supply according to the flow volume detected from a flow volume detection part while providing the flow volume detection part.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
An example of an embodiment of the present invention will be described. A water purifier 1 receives raw water such as tap water from a connection port 2 as shown in FIG. 1, and includes a filtration tank 3 and two for detecting residual chlorine concentration. It has a detector 4a, 4b, a controller 6, a display 7, and a discharge port 8. The filtration tank 3 is composed of an adsorbent such as activated carbon, ion exchange resin, zeolite, and a hollow fiber membrane. It is a cartridge type containing a filtration filter.
[0010]
Of the two detection units 4a and 4b, the detection unit 4a is disposed in a flow path between the connection port 2 and the filtration tank 3, and the detection unit 4b is a flow path between the filtration tank 3 and the discharge port 8. Both are arranged in such a manner that a plate-like platinum electrode 10 and a silver electrode 11 are arranged at predetermined intervals as shown in FIG. A constant voltage is applied between 10 and 11 by the output of the control unit 6. At this time, the control unit 6 calculates the residual chlorine concentration based on the value of the current flowing between the electrodes 10 and 11 and displays the calculated value on the display unit 7.
[0011]
Since the detection unit 4a detects the residual chlorine concentration in the raw water before filtration, and the detection unit 4b detects the residual chlorine concentration in the purified water after filtration, how much residual chlorine is removed by passing through the filtration tank 3 is used. Can know. In addition, the material of the electrodes 10 and 11 of the detection units 4a and 4b is not limited to the above, and for example, gold, carbon, copper, or the like may be used. Further, the shape of the electrodes 10 and 11 is not limited.
[0012]
By the way, the electrodes 10 and 11 in the detection units 4a and 4b adsorb oxides and gas components generated by the electrode reaction, or the calcium scale adheres and the surface becomes dirty. For this reason, even when the relationship between the current value flowing between the electrodes 10 and 11 and the residual chlorine concentration is initially in the state indicated by I in FIG. 2, the output is reduced as indicated by II in the figure. turn into.
[0013]
For this reason, the control unit 6 performs a regeneration to remove the dirt on the electrodes 10 and 11 by performing a reverse power treatment periodically or irregularly. The reverse electric treatment here is to hold the potential of the silver electrode 11 at a negative potential for a certain time with respect to the platinum electrode 10, for example. Further, as the negative potential, when the contamination of the electrodes 10 and 11 is due to the adsorption of the gas component, as shown in FIG. 3, a high regeneration efficiency of about −0.5 V to −5 V can be obtained. When the contamination of the electrodes 10 and 11 is caused by the adhesion of the scale, as shown in FIG. 4, a high regeneration efficiency can be obtained at about −5V to −10V. Note that the value of the negative potential is not limited to the above example. In any case, as a result of regeneration by reverse electricity, as shown by III in FIG.
[0014]
Another example is shown in FIGS. Here, a flow rate detection unit 5 that detects the flow rate of water passing through the water purifier 1 is provided, and the power of the control unit 6 and the display unit 7 is turned on and off by the output of the flow rate detection unit 5. As shown in FIG. 6, the control unit 6 measures the unused time, and performs the reverse power process according to the measurement result.
That is, if a flow rate of a predetermined flow rate (for example, 0.5 liter / min) or more is detected in the water purifier 1, the controller 6 and the display unit 7 are energized. If reverse electric processing is performed and then the flow rate falls below a predetermined flow rate, post reverse electric processing is performed and a standby state is entered. Further, if the waiting time (unused time) is 24 hours or more, the reverse power process is performed during the waiting time.
[0015]
If water flow to the water purifier 1 is started when the unused time is 12 hours or more, the reverse current treatment is performed first, and then the residual chlorine concentration is detected. In the case where the water is not passed for a long time, a reverse electric treatment is performed regardless of the water flow state, and the electrodes 10 and 11 are always kept clean.
[0016]
FIG. 7 shows still another example. This is provided with a switching valve 12 so that the residual chlorine concentration of the raw water before reaching the filtration tank 3 and the residual chlorine concentration of the purified water that has passed through the filtration tank 3 can be detected by a single detection unit 4. At the beginning of water flow, as shown in FIG. 8 (a), a part of the raw water going to the filtration tank 3 is guided to the detection unit 4, and then, as shown in FIG. 12 is switched, and a part of the purified water that has passed through the filtration tank 3 is guided to the detection unit 4. In the illustrated example, the water that has passed through the switching valve 12 and the detection unit 4 is discharged from the discharge port 13, but a separate switching valve that is linked to the switching valve 12 is provided so that the raw water flows into the raw water flow path. The purified water may be returned to the purified water flow path.
[0017]
The flow path switching of the switching valve 12 may be performed based on the output of the flow rate detection unit 5, but the flow rate detection unit 5 may use the residual chlorine concentration detection unit 4. Since the flow rate detection here does not require high accuracy, the output changes depending on the specific resistance value between the electrodes when the electrodes 10 and 11 are submerged or the flow rate of water. Even if the operation of the switching valve 12 or the above-described energization control is performed by the detected flow rate, no trouble occurs.
[0018]
FIG. 9 is a block diagram relating to energization control in this case, and the detection unit 4 is always supplied with power from the power supply block 15, but the detection unit is between the power supply block 15 and the control unit 6 or the display unit 7. 5 is provided with a control switch 14 that operates based on an electrical variable that varies depending on the flow rate output from the motor 5.
By the way, in the reverse electric processing for the detection units 4, 4 a, 4 b, a rectangular wave having a certain frequency as shown by B in FIG. 10 rather than holding the voltage between the electrodes constant for a predetermined time T as shown by B in FIG. 10. It is more effective to maintain the voltage that shows the sine wave for a certain period of time or to maintain the voltage that shows a sine wave of a certain frequency for a certain period of time as shown by C . As shown in FIG. 11, an inrush current is generated when a voltage is applied, and the reverse current regeneration reaction at the power source is greatly advanced by the inrush current. However, in the case of the voltage application indicated by (b) or (c) in the figure, the inrush current This is because it flows repeatedly.
[0019]
【The invention's effect】
As described above, in the present invention, the electrode is soiled by an electrical process in which a negative voltage is applied to one electrode of the pair of electrodes of the residual chlorine detection unit with respect to the other electrode. The electrode is regenerated and the electrode is worn and the electrode polishing member is not worn, and the residual chlorine concentration is detected and displayed stably for a long time with respect to the water before and after filtration. It is something that can be done. Moreover, since the reverse current treatment is performed by repeatedly applying an inrush current at the time of application by repeatedly applying and not applying a voltage to the electrode within a predetermined time, the contamination of the electrode due to the reverse current treatment is removed. It can be done more effectively.
[0020]
And if the unused time reaches a certain time and enters the operation mode of reverse current processing, the electrode can be prevented from being soiled when the unused time is long, and the flow rate detected by the flow rate detection unit If the operation mode of the reverse electric processing is entered when the value becomes equal to or less than the predetermined amount, the reverse electric processing is performed every time it is used .
[0021]
In addition, the flow rate may be obtained from an electrical variable between the electrodes of the residual chlorine detector, and in this case, it is not necessary to provide a separate flow rate detection member.
Furthermore, in the case of a device provided with a flow rate detection unit, useless power consumption can be reduced if a control switch for turning on and off the main power supply according to the flow rate detected by the flow rate detection unit is provided.
[Brief description of the drawings]
1A and 1B show an example of an embodiment of the present invention, in which FIG. 1A is a schematic block diagram, and FIG. 1B is a cross-sectional view of a detection unit;
FIG. 2 is a characteristic diagram showing the relationship between the residual chlorine concentration and the output current of the detection unit.
FIG. 3 is a characteristic diagram of the inter-electrode voltage and the regeneration efficiency during the reverse electric treatment.
FIG. 4 is a characteristic diagram of the interelectrode voltage and the regeneration efficiency during the reverse electric treatment.
FIG. 5 is a schematic block diagram of another example.
FIG. 6 is a flowchart showing the operation of the above.
FIG. 7 is a schematic block diagram of still another example.
8 shows the operation of the flow path switching portion indicated by A in FIG. 7, and (a) and (b) are both cross-sectional views.
FIG. 9 is a schematic block circuit diagram of the above.
FIG. 10 is a time chart of reverse power processing.
FIG. 11 is a time chart showing a change in current during reverse electric processing.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Water purifier 3 Filtration tank 4a Detection part 4b Detection part 6 Control part 7 Display part

Claims (5)

Residual chlorine concentration based on the value of the current flowing between the water purification unit provided with a filtering means, a pair of electrodes arranged in the water channel and a predetermined voltage applied to the residual chlorine detection unit, and the residual chlorine detection unit In a water purifier equipped with a control unit for obtaining a display and a display unit for performing display according to the output of the control unit, a residual chlorine detector is arranged before and after the water purification unit to detect residual chlorine before and after filtration. The display unit displays both residual chlorine concentrations, and the control unit applies a reverse voltage process in which a negative voltage is applied to one of the pair of electrodes of each residual chlorine detection unit with respect to the other electrode. In addition, the reverse current treatment is performed by repeatedly applying an inrush current at the time of application by repeatedly applying the voltage to the electrode and not applying the voltage within a predetermined time. Water purifier.   2. The water purifier according to claim 1, wherein the control unit enters an operation mode of reverse electricity treatment when the unused time reaches a certain time.   The water purifier according to claim 1, further comprising a flow rate detection unit, wherein the control unit enters an operation mode of reverse power treatment when a flow rate detected by the flow rate detection unit becomes a predetermined amount or less. The water purifier according to any one of claims 1 to 3, further comprising a flow rate detection unit for obtaining a flow rate from an electrical variable between the electrodes of the residual chlorine detection unit . The water purifier according to claim 1, further comprising a control switch that includes a flow rate detection unit and that turns on and off the main power according to the flow rate detected by the flow rate detection unit .

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