JP2938815B2 - Method for displaying pH value of electro-generated water and pH display device for electro-generated water - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to tap water, well water,
Raw water such as seawater is electrolyzed through a diaphragm, and a method and apparatus for producing acidic water from the anode side and alkaline water from the cathode side, and accurately determine the pH of the acidic water or alkaline water produced from the anode side. And a method for real-time display.

[0002]

2. Description of the Related Art The present inventors have disclosed a method and an apparatus for producing an acidic water from the anode side and an alkaline water from the cathode side by electrolyzing raw water, and have already disclosed Japanese Patent Application No. 63-3790.
No. (JP-A-1-180293), Japanese Patent Application No. 63-517.
No. 65 (Japanese Patent Application Laid-Open No. 1-228589), Japanese Patent Application No. 63-1
According to Japanese Patent No. 49861 (JP-A-1-317592), the inside of an electrolytic cell is partitioned by a diaphragm into an anode chamber and a cathode chamber, and raw water such as tap water introduced into the bipolar chambers is electrolyzed to produce aseptic treated water. That was invented.

[0003]

However, the production of this type of conventional treated water requires the production of acidic water and alkaline water having a stable pH value. During its formation, its pH
It was difficult to measure the value. That is, in order to measure the pH value, it is general to use a pH meter such as an ion electrode method. In this measurement, the measurement target must always be performed in an electric field. In the case of electrolysis where
The value itself could not be measured. In particular, measuring its pH value in real time has been unsuccessful.

The present invention has been made in view of the above-mentioned conventional circumstances, and raw water is flowed into an electrolytic cell in which an anode and a cathode are partitioned by a diaphragm to form an anode chamber and a cathode chamber, and electrolysis is performed. Find the difference between the electric conductivity of raw water before electrolysis and the electric conductivity of treated water after electrolysis, measure the pH of electrolyzed water in real time according to a predetermined procedure, and display the pH value of electrolyzed water to be displayed It is an object of the present invention to provide a method and a pH indicator for electrolytically produced water.

[0005]

According to the present invention, in order to achieve the above-mentioned object, according to the present invention, raw water is contained in an electrolytic cell in which an anode chamber and a cathode chamber are formed by partitioning an anode and a cathode with a diaphragm. And a method for producing treated water having a desired pH value by measuring the difference (EC difference) between the electric conductivity of the raw water before electrolysis and the electric conductivity of the treated water after electrolysis. The pH value of the electrolyzed water is calculated by the following equations (A) and (B) and displayed. pH value of 4.1
Y = 5.43-0.94X (A) [Y = log (EC difference), X = pH value] If the pH value is 4.11 or more, Y = 2.84-0.31X (B) [Y = log (EC difference), X = pH value]

According to a second aspect of the present invention, there is provided an apparatus used in the method for displaying the pH value of the electrolytically produced treated water according to the first aspect, wherein the anode and the cathode are separated by a diaphragm. And a cathode chamber formed therein, raw water supply means for supplying raw water to the anode chamber and cathode chamber of the electrolytic cell, power supply means for applying a voltage between the anode and cathode of the electrolytic cell, and an inlet for raw water Means for measuring the difference between the side electric conductivity and the electric conductivity of the treated water on the outlet side of the anode chamber, calculating the pH value of the electrolytically produced treated water by the following formulas (A) and (B), and displaying the pH value.
It is characterized by having . When the pH value is less than 4.11, Y = 5.43-0.94X (A) [Y = log (EC difference), X = pH value] When the pH value is 4.11 or more, Y = 2. 84-0.31X (B) [Y = log (EC difference), X = pH value]

[0007]

According to the above configuration, instead of directly measuring the pH value of the generated acidic water and alkaline water, the difference in electric conductivity between the entrance and the exit is detected, and the pH value is displayed in real time based on the difference. can do.

[0008]

Embodiments of the present invention will be described below with reference to the accompanying drawings. In FIG. 1 (a), reference numeral 1 denotes an electrolytic cell, which is partitioned by a diaphragm 2 into an anode chamber 3 and a cathode chamber 4, and the anodes 5 and the cathodes 6 are provided integrally with or separately from the inner walls of the chambers 3, 4, respectively. Raw water supply means 7 for supplying raw water such as tap water and well water is connected to the anode chamber 3 and the cathode chamber 4.
That is, the raw water supply pipe 8 is connected to the lower part of the cathode chamber 4,
The branch pipe 10 is connected to the lower part of the anode chamber 4 to form the raw water supply means 7.

A discharge pipe 11 for anodized water (acidic water) and a discharge pipe 12 for cathodically treated water (alkaline water) are connected to the upper portions of the anode chamber 3 and the cathode chamber, respectively. The anode 5 and the cathode 6 have a variable output voltage DC power supply 13 for electrolyzing raw water.
Is connected, and raw water is supplied from the raw water supply means 7 into the anode chamber 3 in the electrolytic cell 1 and into the cathode chamber 4, and a DC voltage is applied between the anode 5 and the cathode 6 from the DC power supply 13, raw water is electrolyzed, treated water acidity is drained from the anode exhaust water pipe 11, also alkaline treated water is drained from the cathode discharge pipe 12.

The raw water supply pipe 8 is provided with an EC electrode 14 for measuring the electric conductivity of the raw water, and the anodized water pipe 11 is provided with an EC electrode 14 for measuring the electric conductivity of the anodized water. In this embodiment, by providing these two EC electrodes 14 and 15, the electric conductivity of raw water supplied to the electrolytic cell and the electric conductivity of treated water discharged from the anode chamber are provided. It is intended to provide a method and an apparatus for displaying the pH value of generated acidic water or alkaline water in real time while electrolysis while measuring and comparing the pH values.

Next, the relationship between the pH value and the EC value when such an EC electrode is used will be described. Measure the electrical conductivity (EC) value of the raw water. When the raw water is electrolyzed in the electrolytic cell 1, the pH value of the treated water (acidic water) discharged from the anode chamber 3 after electrolysis is lower than the pH value of the raw water, and the EC value is the EC value of the raw water. More to rise. Therefore, focusing on this relationship, in the electrolytic treatment, the relationship between the pH value and the EC value can be converted into a pH value by deriving a related equation as follows. The relational expression between the EC value and the pH value in the raw water and the electrolyzed water is as follows. That is, the electric conductivity K of the raw water is represented by Expression 15.

[0012]

(Equation 1)

[0013] This is determined by the ion species generated by ionization of the electrolyte substance in the raw water and its concentration. Since the pH value of the raw water is in the so-called neutral range,
= OH = 10 ⁻⁷ M / l. Therefore, at this ion concentration, the EC value of the raw water can be said to be that of ions due to ionization of the electrolyte substance. Next, when raw water is electrolyzed, in this electrolysis, the amount of current Q (clone) required for electrolysis is represented by the product of current i and time t as shown in the following equation. Q = i · t (2) Further, the current i is also expressed by Expression 2.

[0014]

(Equation 2)

The relationship between the equivalent ionic conductivity λi and the ion mobility Ui is expressed by the following equation: Ui = λi / F (4) The electric conductivity K of the raw water is expressed by the following equation (1). Substitute,
Which can be expressed in equation 3,

[0016]

(Equation 3)

From the equations (3) and (5), the variable of the function K is

[0018]

(Equation 4)

Thus, the voltage is determined by the voltage and current between the electrodes. Further, of the variable 式 | Zi | Ci · λi, the cation portion (shown by equation 5) passes through the diaphragm,
On the cathode side, the anion portion (indicated by Equation 6) moves to the anode side, but the equivalent ion conductivity and ion mobility of various ions show slightly higher values for anions, but the raw water The ionic species considered to be contained in the above have substantially the same value when OH ions are excluded.

[0020]

(Equation 5)

[0021]

(Equation 6)

Therefore, it can be understood that the equation 7 holds, and the EC values before and after electrolysis are different due to changes in the concentration of H ⁺ on the anode side and the OH ⁺ concentration on the cathode side.

[0023]

Equation 7

Therefore, the EC value before electrolysis is defined as K1,
Assuming that the EC value after electrolysis is K2, Expression 8 holds.

[0025]

(Equation 8)

That is, assuming that K2-K1 is the EC difference, E
Equation 9 holds because the C difference and H have a correlation.

[0027]

[Equation 9]

As a result of several measurements, the difference between the EC difference between the treated water discharged from the anode chamber and the pH value is as follows.
We knew that there was a certain correlation. That is, using the electrolytic cell of FIG. 1, tap water (EC 68 μs / cm, pH
6.65) was electrolyzed, and the data of the EC difference and the pH value at that time are shown in Table 1, and this data is shown in the graph of FIG.

[0029]

[Table 1]

As a test method at this time, the EC of the tap water before the electrolysis was measured by a commercially available EC meter, and the value was used as the EC value of the raw water before the electrolysis. The pH value of the treated water discharged from the anode chamber 3 is measured with a commercially available pH meter, and the EC value of the generated treated water is measured by an EC meter (by varying the electrolytic current applied to the tank 1). And this value was taken as the EC value after electrolysis. Then, a value obtained by subtracting EC before electrolysis from EC after electrolysis was defined as EC difference. By deriving such a measurement and a predetermined relationship, it was found that there is a certain correlation between the pH value and the EC value.

Next, tap water (EC 68 μs / c)
m, pH 6.65), and the EC value and EC difference at each pH value were examined. That is, an electrolytic solution (for example, sulfuric acid or the like) was diluted with tap water, and the EC value and EC difference at each pH value were shown in Table 2, and this data is shown in a graph in FIG.

[0032]

[Table 2]

By comparing the data of Test Examples 1 and 2 above, what can be known is that the EC difference between tap water and electrolytic solution is p
It was found that between H3.0 and 2.0, the values were expressed by almost the same values with almost no difference, and that at pH 3.0 or higher, they were expressed by approximate values. It also electrolyzes tap water, well water, seawater (water containing salt, etc.), and produces a pH value of the generated water.
As for the value, it was found that the pH value of the produced water can be determined by measuring the EC value before electrolysis and the EC value after electrolysis.

In FIG. 3, when the straight line A and the straight line B are mathematically expressed, the straight line A is expressed by the equation (A), and the straight line B is expressed by the equation (B). Y = 5.43-0.94X (A) [Y = log (EC difference), X = pH value] The straight line B becomes Y = 2.84-0.31X (B). The intersection is (4.11, 1.57), and when calculating the pH value, the pH 4.11 is taken as the branch point, and when the pH is 4.11 or more, the approximate value is calculated using the above equation (B). By calculating log (EC difference), the EC value after electrolysis can be known. In addition, when the pH is less than 4.11, up to about pH 2.0, using the above formula (A),
og (EC difference) can be calculated, and the EC value after electrolysis can be known.

From the above, if the EC difference can be obtained by using the above equations (A) and (B), the p of the treated water after electrolysis can be obtained.
The H value can be easily calculated. Thus, using the above method of calculation, it is possible to determine the pH value of the treated water even during the electrolysis are easily generated.

Next, the difference in electric conductivity between raw water and treated water (EC
An apparatus for displaying the pH of the treated water from the difference will be described with reference to FIG. In FIG. 4, EC electrode 16 of raw water and EC of treated water are shown.
An AC bridge 21 connected to an oscillator 20 is formed by the electrode 17 and the output is input to a potential difference amplifier 22, and this potential difference is converted into a DC voltage by a DC current / voltage conversion circuit 23. The obtained output 24 is input to the control circuit 25. The control circuit 25 includes the test examples 1 and 2 described above.
Is calculated, the pH value is output from the obtained voltage value to the display circuit 26, and the pH value of the treated water at that time can be displayed by analog display or digital display.

[0037]

As described above, according to the present invention, by measuring the difference in electric conductivity (EC) between raw water and treated water, it is possible to measure pH in an electric field, and during electrolysis, Even if the pH of the generated treated water is real-time
Values can be displayed.

[Brief description of the drawings]

FIG. 1 is an apparatus diagram showing one embodiment of the present invention.

FIG. 2 is an explanatory diagram showing a relationship between a pH value of treated water and an EC value in the present invention.

FIG. 3 is an explanatory diagram showing a relationship between a pH value of treated water and an EC value in the present invention.

FIG. 4 is a power supply circuit diagram of a direct current according to the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Electrolyzer 2 ... Diaphragm 3 ... Anode chamber 4 ... Cathode chamber 5 ... Anode 6 ... Cathode 7 ... Raw water supply means 13. DC power supply 14, 15 ... EC electrodes 16, 17 ... EC measuring tank

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-1-180293 (JP, A) JP-A-51-82802 (JP, A) JP-A-58-131193 (JP, A) JP-A-57-131 57248 (JP, a) the actual public Akira 63-10867 (JP, Y2) "electrochemical", Vol. 11 (1943 November), pp. 324-329 (58) investigated the field (Int.Cl. ⁶ , DB name) G01N 27/06-27/10 C02F 1/46-1/469

Claims (2)

(57) [Claims] 1. A method for producing raw water having a desired pH value by flowing raw water into an electrolytic cell having an anode chamber and a cathode chamber formed by partitioning an anode and a cathode with a diaphragm to form electrolyzed water. The EC difference between the electric conductivity of the raw water before electrolysis and the electric conductivity of the treated water after electrolysis was measured, and the following equation (A) was obtained.
A method of calculating and displaying the pH value of the electrolytically generated treated water according to (B). When the pH value is less than 4.11, Y = 5.43-0.94X (A) [Y = log (EC difference), X = pH value] When the pH value is 4.11 or more, Y = 2 .84-0.31X (B) [Y = log (EC difference), X = pH value] 2. An electrolytic cell in which an anode chamber and a cathode chamber are formed by partitioning an anode and a cathode with a diaphragm, raw water supply means for supplying raw water to the anode chamber and the cathode chamber of the electrolytic cell, A power supply means for applying a voltage between the anode and the cathode; and E of the electric conductivity of the raw water at the inlet side and the electric conductivity of the treated water at the outlet side of the anode chamber.
Means for measuring the C difference and calculating and displaying the pH value of the electrolyzed treated water by the following formulas (A) and (B). When the pH value is less than 4.11, Y = 5.43-0.94X (A) [Y = log (EC difference), X = pH value] When the pH value is 4.11 or more, Y = 2 .84-0.31X (B) [Y = log (EC difference), X = pH value]