JP3843450B2 - Continuous diaphragm electrolyzer for producing weakly acidic electrolyzed water with electrode life indicator - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a continuous diaphragm electrolyzer equipped with an electrode life indicator, and more particularly, to a continuous diaphragm electrolyzer equipped with an electrode life indicator based on attenuation of an electrode current value.
[0002]
[Prior art]
Conventionally, the life of an electrode of an electrolysis device is determined by measuring a sample test of the generated electrolyzed water using a pH test paper, a reagent, a residual chlorine concentration meter, an electric conductivity meter, etc. Alternatively, the number of cycles of ON / OFF of the electric power applied to the electrode is counted, and when a certain number of times is exceeded, a display or an alarm is issued.
[0003]
[Problems to be solved by the invention]
However, the sample is extracted and the test paper and the test with the reagent are troublesome and not performed in a timely manner, and the residual chlorine concentration meter and the conductivity meter are expensive, and the number of ON and OFF cycles is as follows. Since the cycle ratio at the time of use, the quality of the raw water, and the like are different, there is a variation in the correlation with the life of the electrode, and each has a problem in practical use.
The present invention provides a continuous diaphragm electrolyzer equipped with a simple electrode life indicator that solves the above problems.
[0004]
[Means for solving problems]
In view of the above, as a result of intensive experimental research, the present inventors have made platinum plating in an electrolytic cell in which electrode wear is supplied in a cycle in which a constant voltage power is supplied by an ON-OFF operation and the OFF time is 20 seconds or more. The titanium plate electrode was found to have a correlation with the decay rate of the current value related to the electrode, and the problems were solved by the present invention having the following constitution.
(1) In a continuous diaphragm electrolyzer for producing weakly acidic electrolyzed water using saline, dilute hydrochloric acid or a mixed solution of saline and dilute hydrochloric acid as an electrolyte, constant-voltage power is turned on and off, and Electrode made of a platinum-plated titanium plate in an electrolytic cell supplied in a cycle with an OFF time of 20 seconds or more, and an electrode that displays the decay rate of the current value in the electrolytic cell in terms of the electrode life A continuous diaphragm electrolyzer for producing weakly acidic electrolyzed water having an electrode life indicator.
(2) The electrode life indicator displays the electrode life that has a correlation with the decay rate of the current value divided into (a) use area, (b) caution area, and (c) unusable area. A continuous diaphragmless electrolyzer for producing weakly acidic electrolyzed water comprising the electrode lifetime indicator as set forth in (1) above.
(3) The electrode life indicator is equipped with a memory circuit, and it is displayed over time that it is in one of the (a) use area, (b) caution area, or (c) unusable area. A continuous diaphragm electrolyzer for producing weakly acidic electrolyzed water comprising the electrode life indicator according to (1) or (2) above.
(4) When the electrode life display reaches (b) a sensitive area, the electrolyzed water generation mode of the electrolyzer is switched to the high concentration mode. Any one of (1) to (3) above A continuous diaphragm electrolyzer for producing weakly acidic electrolyzed water comprising the electrode life indicator according to claim 1.
(5) The electrode life indicator according to any one of (1) to (4) above, wherein an alarm is issued when the electrode life display reaches (c) the unusable region. A continuous diaphragm electrolyzer for producing weakly acidic electrolyzed water .
[0005]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the invention will be described below.
In general, platinum electrodes, ferrite, carbon, stainless steel, titanium, etc. are used as the electrodes of the electrolytic cell of the electrolysis device. In this case, a titanium plate is plated with platinum (plating thickness 0.45 μm) to form a coating. Take a case.
The life of the electrode is influenced by many factors, such as the thickness of the platinum film and the amount of current per effective unit area, the frequency of ON and OFF during use, the frequency during reverse voltage cleaning, and the water quality due to regional differences in raw water, According to experiments, the combination of a short ON (energization) time and a long OFF (stop) time in the ON / OFF cycle during use is largely related to the remaining plating thickness (electrode life), and the current It was found to be highly correlated with the quantity decay rate.
The life of the electrode can be observed visually, in addition to the measurement with a film thickness meter, such as the loss of gloss on the plated surface and uneven plating due to wear and peeling (exposed and bare metal). As a result, the residual chlorine concentration of the electrolyzed water decreases.
[0006]
【Example】
The experimental results will be described below with reference to the drawings.
FIG. 1 is an external perspective view of an electrolysis apparatus (sterilization washing water generator) used in this experiment, FIG. 2 is a basic configuration of the electrolysis apparatus, and a block diagram of a measuring instrument used. In the figure, 1 is an electrolysis apparatus, 2 is an operation switch, 3 is a water supply pipe, 4 is a discharge pipe, 5 is a chlorine concentration setting device, 6 is an ammeter (display), 7 is a power cord, 8 is an alarm, 9 is a constant voltage power supply, 10 is Power line 11, DC power source switch 12, control unit 12, voltmeter, 14 electrolyzed water, 14 ′ electrolyzer, 15, 15 ′ electrode, 16 raw water mixing inlet, 17 additive injection Inlet, 18 is additive liquid, 18 'is an additive liquid tank, 19 is an infusion pump, 20 is a solenoid valve for flow rate adjustment, 21 is an electromagnetic valve for additive liquid, 22 is an electromagnetic valve for water discharge, 23 is an outlet for electrolyte, 24 Is a diluted mixed solution, 24 'is a diluted mixed solution tank, 26 is a plating thickness measuring device (film thickness meter), and 27 is a residual chlorine concentration measurement. , 28 is washing water, and 43 is a raw water mixing port.
[0007]
The electrolysis apparatus 1 shown in FIG. 1 is a continuous 1 tank type diaphragmless electrolysis apparatus that mixes the saline and dilute hydrochloric acid and uses it as an electrolyte.
On the surface of the electrolysis apparatus 1, operation switches 2, a water supply pipe 3, a washing water discharge pipe 4, a chlorine concentration setting device 5, an ammeter (display) 6, a power cord 7 and an alarm device 8 are arranged. The discharge pipe 4 discharges weakly acidic water for cleaning (effective chlorine concentration of about 30 to 50 ppm, pH value of 5 to 7) at about 2 to 3 L / min.
[0008]
Next, based on the basic configuration of the electrolysis apparatus shown in FIG.
The elements of the experimental machine, the life test of the electrodes 15 and 15 'of the electrolytic cell 14' based on the elements, and data thereof will be described.
As shown in the figure, in the electrolyzed water 14, an additive solution (electrolyte: saline + dilute hydrochloric acid) 18 is sent out by the infusion pump 19 and diluted to a concentration of about 1/30 at the raw water mixing port 43. Then, it is supplied from the additive liquid inlet 17.
In addition, two electrodes 15, 15 ′ (width 65 × length 130 × thickness 1 mm) are arranged in the electrolytic cell at a parallel interval of 5 mm, and each electrode has a constant voltage power source 9 (80VA: constant voltage). (4, 5V) to supply electric power to generate electrolyzed water 14.
And the said electrolyzed water 14 is mixed with the raw | natural water (tap water) which was inject | poured from the feed water pipe 3 and passed through the flow volume adjustment solenoid valve 20, and is mixed by the raw | natural water mixing inlet 16, and is about 1/300 in dilution mixing tank 24 '. The diluted mixed solution 24 is obtained.
Thereafter, the water is discharged to the outside as the wash water 28 from the discharge pipe 4 via the water discharge electromagnetic valve 22.
[0009]
A measurement method for the life test of the electrodes 15 and 15 ′ in the experimental machine having the above configuration will be described below.
The applied voltage to the electrodes 15, 15 'is a voltmeter 13, the amount of current is an ammeter 6, the amount of residual chlorine in the cleaning water 28 is determined by an iodine titration method (JIS k-0102), and the remaining plating thickness is determined by a film thickness meter. Each was measured, the cycle time of ON and OFF of the voltage applied to the electrodes 15 and 15 ′ was set, and the number of times was counted.
[0010]
The following figure shows the current value, the remaining plating thickness, and the residual chlorine concentration in the vertical direction, with the horizontal axis representing the ON / OFF cycle (ON / OFF time ratio) of the voltage applied to the electrode and the number of cycles. A graph with axes is shown.
FIG. 3 is a graph showing the correlation of voltage, current, remaining plating thickness, and residual chlorine concentration with ON and OFF cycles set to ON 7 seconds and OFF 5 seconds, and the number of cycles set to 0 to 125,000.
As can be seen from FIG. 3, there is no correlation between the current value A, the residual chlorine concentration P and the residual plating thickness t in the set value and the number of cycles of this cycle, and therefore the electrode depends on the current value. The lifetime of can not be estimated.
[0011]
Next, FIG. 4 is a graph showing the correlation among voltage, current, remaining plating thickness, and residual chlorine concentration when the ON / OFF cycle is ON 7 seconds and OFF 20 seconds and the number of cycles is 0 to 20,000.
In this graph, there is a clear correlation between the current value A, the residual chlorine concentration P and the residual plating thickness t, and it is possible to replace the decay rate of the current value with the life of the electrode. (Where V is a constant voltage)
That is, as the number of cycles increases, the current value A attenuates, and when the residual chlorine concentration P (standard: 30 ppm) also attenuates to 20 ppm (caution), the electrode plating thickness t (standard 0.45 μm) Is reduced by half to 0.2 μm.
Furthermore, when the residual chlorine concentration P is 13 ppm or less (unusable region), the current is linearly attenuated by 1.8 A from the initial (8.5 A) to 6.7 A, and the plating thickness t of the electrode at this time is It has decreased to 0.08 μm (unusable, life span).
Further, according to the above, the number of cycles reaches 12,000 (caution) and reaches 17,500 (unusable).
[0012]
In order to consider the difference between FIG. 3 and FIG.
FIG. 5 is a graph showing the transition of voltage after the electrolysis is stopped, with the horizontal axis representing elapsed time and the vertical axis representing voltage.
As shown in the figure, when the ON time applied to the electrode is maintained at a voltage of 4.2 V for 5 seconds and then turned OFF, the voltage does not become 2 V or less for 5 seconds after the OFF.
This is because the electrolyzed water is filled between the electrode plates 15 and 15 'which are parallel to each other at the interval of 5 mm, and acts as a kind of capacitor, so that the voltage after the power supply 0FF rapidly decreases to around the half-value strength. However, the subsequent discharge time constant is long, and the half value is still maintained after 5 seconds.
The subsequent discharge time is long and gentle especially after 13 seconds, and about 0.3 V still remains after 50 seconds.
[0013]
FIG. 6 and FIG. 7 show the above-mentioned phenomenon recorded in an experiment in comparison with the graphs shown in FIG. 3 and FIG.
FIG. 6 is a voltage observation waveform diagram when the ON / OFF cycle is 7 seconds ON and 5 seconds OFF, and the cycle is the same as FIG.
The voltage is repeated between 2V and 4.2V (difference 2.2V).
FIG. 7 is a voltage observation waveform diagram when the ON / OFF cycle is 7 seconds ON and 20 seconds OFF, and the cycle is the same as FIG.
The voltage is repeated between 0.6V and 4.2V (difference 3.6V).
[0014]
From the above, it can be seen that the difference between the voltage observation waveforms in FIG. 6 and FIG. 7 is the waveform after the electrolysis stop and the magnitude of the discharge potential.
That is, when the potential difference between ON and OFF is small, the rise leading to ON is gentle, and when the potential difference is large, it becomes steep. The ratio of the rise of 2.2V in FIG. 6 to the rise of 3.6V in FIG. 7 is 1: 1.6.
At the time of transition from OFF to ON, if the electrode is regarded as a capacitor, it is charged to the maximum voltage at the rise time, and a large peak current flows in a short time.
However, when FIG. 6 is compared with FIG. 3, the influence of the peak current is small in the cycle of the potential difference of about 2.2 V in FIG. 6, and the remaining plating thickness t is decreased even with the number of cycles of 125,000 in FIG. 3. Therefore, there is no correlation with the current A.
[0015]
On the other hand, since FIG. 7 has a potential difference 1.6 times larger than that in FIG. 6, the peak current is also considerably large, and damage to the plating of the electrode, that is, loss of gloss on the plated surface, wear / peeling. The effect of the plating over time due to uneven plating (exposed to bare metal) is great,
When comparing FIG. 7 with FIG. 4, the number of cycles in FIG. 4 is 17,500, and the remaining plating thickness t is attenuated to 0.07 μm. Along with this, the current decays with a correlation up to 6.7A. The residual chlorine concentration P is also attenuated with a correlation.
From the above, practically, the OFF time of the cycle is often longer than 20 seconds, but FIG. 4 is adopted as a graph that is close to the actual and shows the correlation.
[0016]
Based on the measurement data described above, an example of the electrode life indicator will be described.
FIG. 8 is a front view of the display part of various displays. The indicator is disposed on the surface panel of the electrolysis apparatus 1 (FIG. 1).
8A is a front view of a rectangular electrode life indicator, FIG. 8B is a front view of a horizontal slide electrode life indicator, and FIG. 8C is a lamp-lit electrode life indicator. FIG. 4D is a front view of an electrode life indicator equipped with a memory circuit.
In the figure, 6 is a display (square life indicator), 29 is a pointer, 30 is a use area, 31 is a caution area, 32 is an unusable area, 33 is a lateral slide electrode life indicator, and 34 is a lamp lighting type. An electrode life indicator, 35 is a display lamp, 36 is a front view of an electrode life indicator provided with a memory circuit, and 37 is a reversible counter mechanism display.
[0017]
(B) The figure replaces the indication value of the square DC ammeter with the life of the electrode, and the area indicated by the pointer 29 is divided into a use area 30, a caution area 31, and an unusable area 32.
(B) The figure replaces the indicated value of the horizontal slide type DC ammeter with the life of the electrode, and the area indicated by the pointer 29 is divided into a use area 30, a caution area 31, and an unusable area 32. ,
(C) In the figure, the indication value of the DC ammeter is replaced with the lighting of the display lamp 35 sequentially, and the life of the electrodes is displayed in the same area as above,
(D) In the figure, the display of the reversible counter is provided with a memory circuit by a mechanical mechanism according to the DC current value, and the above-mentioned division display is always performed over time.
In addition, it is easy to see the above-described divided area by color-coded display, for example, dividing the use area 30 into white, the caution area 31 into yellow, and the unusable area 32 into red.
[0018]
FIG. 9 is a block diagram showing a configuration of an electrode life indicator equipped with a memory circuit.
In the figure, 38 is a current line, 39 is a current detector, 40a to 40c are reversible counters, 41a to 41c are detection circuits, and 42a to 42c are signal line switches.
The signal from the current detector 39 drives the reversible counter 40a via the signal line switch 42a, and displays the use area 30 on the display unit 37a.
When the signal from the current detector 39 decreases with time and reaches the lower limit of the use area 30, the value is detected by the detection circuit 41a, and the signal line switch 42a is turned OFF by the signal, The display unit 37a is reset to 0, the signal line switch 42b is turned on, the next-stage reversible counter 40b is driven, and the caution area 31 is displayed on the display unit 37b.
[0019]
When the signal from the current detector 39 further decreases with time and reaches the lower limit of the area 31 requiring attention, the current detector 41b detects the value, and the signal line switch 42b is turned off by the signal. The display unit 37b is reset to 0, the signal line switch 42c is turned on, the next-stage reversible counter 40c is driven, and the unusable area 32 is displayed on the display unit 37c.
When the power is turned off for electrode replacement, the detector 41c detects that the signal line switch 42c is turned off, and the life indicator is ready for restart.
If the display units 37a to 37c are, for example, a mechanical display holding type, the area display can be performed even when the main power is turned off.
[0020]
Next, switching of automatic residual chlorine concentration is described.
The effective concentration in the experimental machine is set by adjusting the amount of raw water (tap water) diluted to a certain concentration of electrolyzed water 14.
For example, the standard mode is about 30 ppm (water supply amount: 3.2 L / min) and the high concentration mode is about 50 ppm (water supply amount: 2.3 L / min), and the chlorine concentration setter 5 (FIGS. 1 and 2) The adjustment electromagnetic valve 20 is manually adjusted via the control unit 12.
Therefore, it is always used in the standard mode, and when the life of the electrodes 15 and 15 ′ reaches the caution area 31 (FIG. 8), the signal is detected and the high concentration mode is automatically set via the control unit 12. When the flow rate adjusting electromagnetic valve 20 is switched, the residual chlorine concentration P increases once, so that the wash water can be used for a long time.
However, electrode wear has already occurred even at the time of switching, and the value of the remaining plating thickness t does not change. For example, if the limit value is 20 ppm, the remaining plating thickness t at that time is 0.25 μm. (Fig. 4).
For this reason, even if the chlorine concentration is raised thereafter, the thickness of the remaining plating thickness t becomes the limit value of the lifetime.
From the graph of FIG. 4, the remaining plating thickness t at that point is estimated to be about 0.08 μm.
As mentioned above, plating damage is due to loss of gloss on the plated surface, uneven plating due to wear and peeling (exposed and exposed metal base), etc., so the thickness is reduced even to an extremely thin thickness. There is no going.
[0021]
Further, when the display of the electrode life indicator 6 reaches the unusable area 32, the alarm device 8 (FIG. 2), such as lighting of an alarm lamp and notification by voice through the controller 12 in conjunction with the notification by the display unit. Can issue an alarm and clearly communicate the replacement time to the user.
[0022]
【The invention's effect】
According to the present invention, the following excellent effects can be exhibited.
1. According to the invention of claim 1 of the present invention,
Attenuation of the current value in the electric power supplied to the electrode of an electrolytic cell in a continuous diaphragm electrolyzer for producing weakly acidic electrolyzed water using saline, dilute hydrochloric acid or a mixture of saline and dilute hydrochloric acid as an electrolyte Because it is equipped with an electrode life indicator that converts the rate into the life of the electrode, a conventional sample of washing water is extracted and the test with test paper and reagents is cumbersome and not performed in a timely manner. Furthermore, residual chlorine concentration meters and electrical conductivity meters are expensive, and the estimation based on the number of ON and OFF cycles varies in correlation with the life of the electrode. Measurement can be displayed.
2. According to the invention of claim 2,
The electrode life indicator replaces the current decay rate with a correlated electrode life and displays it in a use area, a caution area, and an unusable area. I can know.
[0023]
3. According to the invention of claim 3,
The electrode life indicator is equipped with a memory circuit to indicate that it is in the use area, caution area, or unusable area over time, so that the current area can be known even when the main power is turned off. it can.
4). According to the invention of claim 4,
When the life display of the electrode reaches a caution area, the generation of electrolyzed water in the electrolyzer switches to the high concentration mode, so that the period of use of the cleaning water can be extended.
5. When the life display of the electrode reaches the unusable area, an alarm such as lamp lighting and voice notification is issued in conjunction with the display, so that the replacement time can be clearly communicated to the user.
[Brief description of the drawings]
FIG. 1 is an external perspective view of an electrolysis apparatus used in this experiment,
FIG. 2 is a block diagram of a basic configuration of an electrolysis apparatus and a measuring instrument used;
FIG. 3 is a graph showing the correlation of voltage, current, remaining plating thickness, and residual chlorine concentration with ON and OFF cycles set to ON 7 seconds and OFF 5 seconds, and the number of cycles set to 0 to 125,000 times;
FIG. 4 is a graph showing the correlation of voltage, current, remaining plating thickness and residual chlorine concentration with ON and OFF cycles set to ON 7 seconds, OFF 20 seconds, and the number of cycles set to 0 to 20,000 times;
FIG. 5 is a graph showing the transition of voltage after electrolysis is stopped;
FIG. 6 is a voltage observation waveform diagram when the ON / OFF cycle is set to 7 seconds ON and 5 seconds OFF,
FIG. 7 is a waveform diagram of voltage observation when the ON / OFF cycle is 7 seconds ON and 20 seconds OFF,
FIG. 8 is a front view of the display part of various displays;
FIG. 9 is a block diagram showing a configuration of an electrode life indicator equipped with a memory circuit;
[Explanation of symbols]
1: Electrolyzer 2: Operation switches 3: Water supply pipe 4: Discharge pipe 5: Chlorine concentration setting device 6: Ammeter (display)
7: Power cord 8: Alarm device 9: Constant voltage power source 10: Power source line 11: DC power source switch 12: Control unit 13: Voltmeter 14: Electrolyzed water 14 ': Electrolyzer 15, 15': Electrode 16: Raw water mixed Inlet 17: Additive liquid inlet 18: Additive liquid 18 ': Additive liquid tank 19: Injection pump 20: Solenoid valve for flow rate adjustment 21: Electromagnetic valve for additive liquid 22: Solenoid valve for water discharge 23: Electrolyte delivery outlet 24: Diluted liquid mixture 24 ': Diluted liquid tank 26: Plating thickness measuring instrument 27: Residual chlorine concentration measuring instrument 28: Washing water 29: Pointer 30: Use area 31: Caution area 32: Unusable area 33: Horizontal slide electrode Life indicator 34: Lamp lighting type electrode life indicator 35: Display lamp 36: Front view of electrode life indicator provided with memory circuit 37: Reversible counter mechanism display unit 38: Current line 39: Current detectors 40a to 40c: reversible Counter 41a to 41c: detection circuit 42 a to 42 c: the signal line switcher 43: raw water mixed port

Claims (5)

In a continuous diaphragm electrolyzer for producing weakly acidic electrolyzed water using saline, dilute hydrochloric acid, or a mixture of saline and dilute hydrochloric acid as an electrolyte,
Equipped with an electrode made of platinum-plated titanium plate in an electrolytic cell supplied with a cycle in which a constant voltage power is turned on and off and the OFF time is 20 seconds or more, and the current value in the electrolytic cell is attenuated A continuous diaphragm electrolyzer for producing weakly acidic electrolyzed water having an electrode life indicator, characterized in that it comprises an electrode life indicator that displays the rate in terms of electrode life. The electrode life indicator displays the life of an electrode having a correlation with the decay rate of the current value divided into (a) use area, (b) caution area, and (c) unusable area. A continuous diaphragm electrolyzer for producing weakly acidic electrolyzed water comprising the electrode life indicator according to claim 1. The electrode life indicator is equipped with a memory circuit, and it is displayed over time to indicate that it is in one of (a) use area, (b) caution area, or (c) unusable area. A continuous diaphragmless electrolyzer for producing weakly acidic electrolyzed water comprising the electrode life indicator according to claim 1 or 2. 4. The method according to claim 1, wherein when the electrode life display reaches (b) a sensitive area, the electrolyzed water generation mode of the electrolyzer is switched to the high concentration mode. 5. A continuous diaphragm electrolyzer for producing weakly acidic electrolyzed water having an electrode life indicator. The weak acid electrolysis provided with the electrode life indicator according to any one of claims 1 to 4, wherein an alarm is issued when the electrode life indication (c) reaches an unusable region. A continuous diaphragm electrolyzer for producing water .

Images