JP2003010852A - Method for operating diaphragm-free electrolytic cell and method for making electrolytic water - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for operating a diaphragm-free electrolytic cell capable of ensuring constant power to enable the efficient use of the power and capable of independently regulating the effective chlorine concentration and pH of electrolytic water and a method for making electrolytic water. SOLUTION: In a process (a), a mixing ratio of hydrochloric acid and dilution water is regulated so that the concentration of hydrochloric acid passed through the diaphragm-free electrolytic cell becomes a predetermined set concentration. In a process (b), the value of the current applied to the diaphragm-free electrolytic cell is measured and the set concentration of the hydrochloric acid aqueous solution in the process (a) is adjusted up and down so that the current value becomes a predetermined value to regulate the concentration of effective chlorine of electrolytic water discharged from the diaphragm-free electrolytic cell. In a process (c), the passing amount of the hydrochloric acid aqueous solution to the diaphragm-free electrolytic cell is increased and decreased to regulate the pH of the electrolytic water discharged from the diaphragm-free electrolytic cell.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a method for operating a membraneless electrolytic cell and a method for producing electrolyzed water. More specifically, the present invention relates to a method for operating a membraneless electrolytic cell capable of independently adjusting the effective chlorine concentration and pH of electrolyzed water, and a method for producing electrolyzed water. In the present invention, percentages are values by weight unless otherwise specified, and ppm is mg / k.
means g.

[0002]

2. Description of the Related Art In recent years, electrolyzed water obtained by electrolyzing various solutions is known, and the establishment of an application technique for such electrolyzed water is urgently needed (Kiyoko Shiba et al., "Strong Electrolysis"). Water Handbook ", Medical Information Company, 1995).

Conventional electrolyzed water is disclosed in, for example, JP-A-1-18.
It was manufactured by the technique disclosed in No. 0293. In this technique, water to which salt is added is passed through an electrolytic cell with a diaphragm and electrolyzed to obtain strongly acidic water generated on the anode side as electrolyzed water. The pH of this conventional electrolyzed water is 1.5 or more and 3.2 or less,
It is said that the bactericidal effect is higher than that of a simple low pH liquid.
The electrolyzed water produced by the technique disclosed in Japanese Patent No. 2627100 is obtained by mixing sodium chloride-added water with an aqueous hydrochloric acid solution and electrolyzing the mixture with a diaphragmless electrolytic cell. In this case, sodium chloride is considered to be an indispensable additive for increasing electrolysis efficiency during electrolysis.

The present inventors previously invented a technique for producing electrolyzed water which is almost neutral and has a low sodium chloride content, and has already filed a patent application as Japanese Patent Application No. 7-63384 (hereinafter, this electrolysis). Water shall be simply referred to as "electrolyzed water"). Such electrolyzed water is obtained by diluting hydrochloric acid with diluting water without substantially adding sodium chloride, passing the diluted hydrochloric acid aqueous solution through the diaphragmless electrolytic cell, and energizing the diaphragmless electrolytic cell. It is manufactured by a procedure of electrolyzing a hydrochloric acid aqueous solution, discharging the electrolyzed hydrochloric acid aqueous solution as electrolyzed water from a diaphragmless electrolytic cell, and obtaining the electrolyzed water discharged.

This electrolyzed water has a high effect of sterilization even at a low chlorine concentration as compared with, for example, the case where soda hypochlorite is added to water, and it is finer each time it is used. It is excellent in that it is not necessary to adjust the density.

Generally, in the production of electrolyzed water, it is considered desirable that the amount of chlorine generated is high with respect to the amount of electric energy applied to the electrolytic cell in terms of efficiency. The efficiency in this case is represented by the amount (mg) of chlorine generated per 1 wh of electric power supplied to the electrolytic cell, and is referred to as "electric power efficiency".

During electrolysis, gases other than chlorine,
For example, when oxygen or ozone is generated, electric power is used for meaningless reaction, which is also not preferable in terms of efficient use of energy.

On the other hand, electrolyzed water is
For example, it is used for sterilization, washing, freshness preservation, etc.
In this case, when the effective chlorine concentration of the electrolyzed water used changes, the effects of sterilization, washing, freshness maintenance, etc. also change. Therefore, it is preferable that the operation of the electrolytic cell is an operation in which the amount of chlorine generated does not fluctuate as much as possible, that is, the effective chlorine concentration of the obtained electrolyzed water is maintained within a predetermined range. Therefore, when operating the membrane-less electrolytic cell, it is preferable to set and control the operating conditions so that the effective chlorine concentration of the electrolyzed water produced is as constant as possible.

The electrolyzed water is water in which chlorine is dissolved to form hypochlorous acid. Generally, in such water in which hypochlorous acid is dissolved, the bactericidal effect can be maximized.
The range of H is pH 4.0 or more and 7.0 or less, preferably 4.5 or more and 6.5 or less. Therefore, also in the production of electrolyzed water, it is preferable to operate the diaphragmless electrolyzer so that the electrolyzed water falls within such a pH range.

[0010]

However, in the method for operating the membraneless electrolytic cell or the method for producing electrolyzed water, the effective chlorine concentration and pH of the electrolyzed water discharged are influenced by various factors. However, conventionally, no technology has been known that can independently control the effective chlorine concentration and pH of electrolyzed water. Further, there is known a method of controlling the effective chlorine concentration and pH of the electrolyzed water independently, and having a power efficiency as high as possible, and an efficient power energy generation without generation of ozone or oxygen. There wasn't.

[0011]

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and an object of the present invention is to enable operation while ensuring a constant power efficiency, and to provide oxygen and ozone. Generation of electricity, efficient use of electric power energy is possible, and an industrial method for operating a diaphragmless electrolytic cell capable of independently adjusting the effective chlorine concentration and pH of electrolyzed water and the production of electrolyzed water Providing a method.

A first aspect of the present invention for solving the above-mentioned problems is to pass an aqueous hydrochloric acid solution prepared by diluting hydrochloric acid with diluting water through a diaphragmless electrolytic cell in a state containing substantially no sodium chloride. A method for operating a diaphragmless electrolytic cell in which a prescribed voltage is applied to the passed diaphragmless electrolytic cell, the hydrochloric acid aqueous solution is electrolyzed into electrolyzed water by the applied voltage, and the electrolytic water is discharged from the diaphragmless electrolytic cell. A) adjusting the mixing ratio of hydrochloric acid and diluting water so that the hydrochloric acid concentration of the hydrochloric acid aqueous solution to be passed through the diaphragmless electrolyzer is b), and energizing the diaphragmless electrolyzer The current value is measured, and the set concentration of the hydrochloric acid aqueous solution of a) is raised or lowered so that the current value becomes a predetermined value, thereby adjusting the effective chlorine concentration of the electrolyzed water discharged from the diaphragmless electrolytic cell, c) Amount of hydrochloric acid solution to be passed through the diaphragmless electrolytic cell It is possible to increase / decrease and adjust the pH of the electrolyzed water discharged from the non-diaphragm electrolyzer by this, and thereby to independently adjust the effective chlorine concentration and pH of the electrolyzed water discharged from the non-diaphragm electrolyzer. The operating method of the non-diaphragm electrolytic cell.

A second aspect of the present invention for solving the above problems is to dilute hydrochloric acid with diluting water, and to dilute the hydrochloric acid aqueous solution into a diaphragmless electrolytic cell in a state substantially containing no sodium chloride. After passing the liquid, a predetermined voltage is applied to the passed diaphragmless electrolytic cell, the hydrochloric acid aqueous solution is electrolyzed by the applied voltage, the electrolyzed electrolytic water is discharged from the diaphragmless electrolytic cell, and the discharged electrolytic water is discharged. In the method for producing electrolyzed water to be obtained, a) adjusting the mixing ratio of hydrochloric acid and diluting water so that the hydrochloric acid concentration of the hydrochloric acid aqueous solution to be passed through the diaphragmless electrolysis tank is adjusted to b) The current value applied to the cell is measured, and the effective concentration of the electrolytic water discharged from the diaphragmless electrolysis cell is increased or decreased by increasing or decreasing the set concentration of the hydrochloric acid aqueous solution of a) so that the current value becomes a predetermined value. Adjusting the concentration, c) In a non-diaphragm electrolytic cell To adjust the pH of the electrolyzed water discharged from the diaphragmless electrolyzer by increasing / decreasing the flow rate of the hydrochloric acid solution to be liquefied, thereby independently adjusting the effective chlorine concentration and pH of the electrolyzed water to be acquired. It is a method for producing electrolyzed water that enables the above.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION In the operating method of the present invention, an aqueous hydrochloric acid solution prepared by diluting hydrochloric acid with diluting water is passed through a diaphragmless electrolytic cell while substantially not containing sodium chloride. Then, in the diaphragmless electrolytic cell, a predetermined constant voltage is applied to electrolyze the hydrochloric acid aqueous solution, and the electrolyzed solution is discharged as electrolyzed water. That is, in the present invention, the value of the voltage applied to the diaphragmless electrolytic cell is a predetermined constant value.

In this case, if the voltage value is adjusted to increase or decrease the effective chlorine concentration of the electrolyzed water, the following problems occur. That is, when the voltage is changed,
Since the power efficiency of the diaphragmless electrolytic cell (chlorine generation amount mg per 1 Wh of electric power supplied to the diaphragmless electrolytic cell) fluctuates, there is a possibility that operating conditions with poor power efficiency, that is, operating conditions that are energetically disadvantageous, may occur. It was Further, when the voltage is changed, if the voltage becomes a certain value or more, oxygen and ozone may be generated in addition to chlorine, and in this case, the energy efficiency may be lowered.

In the present invention, these problems do not occur if the voltage value is fixed at a predetermined constant value. Further, in the present invention, the mixing ratio of hydrochloric acid and dilution water is adjusted so that the hydrochloric acid concentration of the hydrochloric acid aqueous solution which is passed through the diaphragmless electrolytic cell is a predetermined set concentration. in this case,
Automatic control is desirable.

On the other hand, regarding the current, when the voltage is fixed to a predetermined value, the value of the flowing current correlates with the degree of the chemical reaction in the diaphragmless electrolytic cell. Therefore, the value of the current flowing in the diaphragmless electrolytic cell will be correlated with the absolute amount of chlorine discharged from the diaphragmless electrolytic cell,
That is, it correlates with the effective chlorine concentration of the electrolyzed water discharged from the membraneless electrolytic cell.

The present invention focuses on this point,
One of the features is that the concentration of the hydrochloric acid aqueous solution passing through the diaphragmless electrolytic cell is increased or decreased so that the value of the current flowing in the diaphragmless electrolytic cell becomes a predetermined set value. In this case, the hydrochloric acid aqueous solution is adjusted in the mixing ratio of hydrochloric acid and dilution water so as to have a predetermined set concentration. By increasing or decreasing this set concentration, the concentration of the hydrochloric acid aqueous solution is increased or decreased.

As a phenomenon, when the concentration of the hydrochloric acid aqueous solution increases, the electric resistance in the diaphragmless electrolytic cell decreases, but since the voltage has a predetermined constant value, the current value increases accordingly. Therefore, the effective chlorine concentration of the electrolyzed water discharged from the diaphragmless electrolyzer eventually increases. Then, when the concentration of the hydrochloric acid aqueous solution decreases, the electric resistance in the diaphragmless electrolytic cell rises and the current value drops, and as a result, the effective chlorine concentration of the electrolyzed water discharged from the diaphragmless electrolytic cell falls.

In the present invention, the concentration of the aqueous hydrochloric acid solution passed through the diaphragmless electrolytic cell, that is, the set concentration is increased or decreased so that the current flowing in the diaphragmless electrolytic cell reaches a predetermined set value. As a result, the electrolyzed water discharged from the diaphragmless electrolyzer can be adjusted to a predetermined effective chlorine concentration.

In this case, "to make the current value a predetermined value" is not limited to the case where the predetermined value is one point, but is a range defined by an upper limit and a lower limit. May be. That is, the "predetermined value" includes a range. In other words, it is included in the term "so that the current value becomes a predetermined value" that the current value flowing in the membrane-less electrolytic cell is controlled to fall within a predetermined range.

On the other hand, the present invention, in addition to the above operation,
The second feature is that the pH of electrolyzed water discharged from the diaphragmless electrolyzer is adjusted. Specifically, in the present invention, in order to adjust the pH of the electrolyzed water discharged from the diaphragmless electrolyzer, the amount of hydrochloric acid aqueous solution to be passed through the diaphragmless electrolyzer is increased or decreased.

When the amount of the hydrochloric acid aqueous solution to be passed through the diaphragmless electrolytic cell is increased or decreased, the pH of the electrolyzed water discharged from the diaphragmless electrolytic cell also changes accordingly. That is, as the flow rate of the hydrochloric acid aqueous solution increases, the amount of hydrochloric acid that has not been used in the reaction in the diaphragmless electrolytic cell (that is, the amount of hydrochloric acid that has not been electrolyzed) increases, so that the pH of the discharged electrolytic water is descend. Further, when the passing amount of the hydrochloric acid aqueous solution is decreased, the hydrochloric acid that has not been used in the reaction in the diaphragmless electrolytic cell is decreased, and the pH of the discharged electrolyzed water is increased.

In this case, for example, if the amount of diluting water for diluting hydrochloric acid is increased, the amount of hydrochloric acid is also increased so that the concentration of the diluted hydrochloric acid aqueous solution is maintained at a predetermined concentration. Therefore, it is preferable to increase the total amount of the hydrochloric acid aqueous solution to increase the liquid flow rate.

As described above, according to the operating method of the present invention, the effective chlorine concentration and pH of the electrolyzed water discharged from the diaphragmless electrolytic cell are independently adjusted without being influenced by each other. It is possible to operate the diaphragm electrolyzer. In such an operating method, it goes without saying that it is desirable to continuously dilute hydrochloric acid with diluting water, pass through a diaphragmless electrolytic cell, electrolyze, and discharge electrolytic water.

Next, the method for producing electrolyzed water of the present invention will be described. In the present invention, it is desirable that the production of electrolyzed water is basically performed by the following procedure. That is, first
Dilute hydrochloric acid with dilution water. In this case, substantially no sodium chloride is added.

Here, "dilution water" means tap water, ground water, underground water, demineralized water, distilled water, purified water (RO water, membrane treated water),
It means water that is a mixture of these and that does not substantially contain sodium chloride.

After diluting the hydrochloric acid with the diluting water, the resulting aqueous hydrochloric acid solution is passed through the diaphragmless electrolytic cell while containing substantially no sodium chloride. The term "substantially free of sodium chloride" means that sodium chloride is not artificially added before the solution is passed through the diaphragmless electrolytic cell. In this case, the trace amount of sodium chloride naturally contained in dilution water and hydrochloric acid is not considered.

The fact that sodium chloride (chloride) was not artificially added means that the sodium ion concentration of the hydrochloric acid aqueous solution passed through the diaphragmless electrolytic cell was contained in the original dilution water or hydrochloric acid. This means that the sodium ion concentration is not exceeded. Generally, since the dilution water or hydrochloric acid has a sodium ion concentration of 200 ppm or less, the hydrochloric acid aqueous solution diluted in the present invention also has a sodium ion concentration of 200 ppm or less.

The concentration of hydrogen chloride in the aqueous hydrochloric acid solution is preferably 0.01% or more, and particularly recommended to be 0.1% or more, in order to cause an appropriate reaction.
However, when pursuing economic efficiency, the hydrogen chloride concentration is
It is preferably 1.0% or more and 21.0% or less.
That is, when the hydrogen chloride concentration is 1.0% or more, it is possible to obtain an industrially stable reaction, and 21.0%
This is because if it is the following, it does not emit smoke at room temperature and is desirable in terms of storage and handling.

Such a hydrochloric acid aqueous solution is passed through a non-diaphragm electrolytic cell, and the positive and negative electrodes are energized to be electrolyzed. The diaphragmless electrolytic cell is an electrolytic cell having no diaphragm. The non-diaphragm electrolytic cell may be a monopolar type, but is preferably a bipolar non-membrane type electrolytic cell.

In general, there are two types of methods for connecting a plurality of electrodes in a diaphragmless electrolytic cell: a monopolar type and a bipolar type. The unipolar type is a system in which all of the electrodes are connected to either the cathode or the anode of the power source, and the bipolar type is, for example,
It has a structure in which multiple electrodes are stacked at regular intervals and insulated from each other, and between the electrode connected to the anode of the power supply (that is, the anode) and the electrode connected to the cathode of the power supply (that is, the cathode). In addition, there is at least one intermediate electrode that is not connected to any of the electrodes.

During electrolysis, the voltage per pair of electrodes is preferably 1.5 V or more and 4.0 V or less. In the case of the bipolar electrodeless electrolytic cell, the intermediate electrode exists between the cathode and the anode as described above, but the "voltage per pair of electrodes" means the cathode, the anode, and the intermediate electrode. Including, it is a term meaning a voltage between two adjacent electrodes.

Generally, when the voltage per pair of electrodes is increased, chlorine starts to be generated at 1.3 V or higher, and reaches the maximum amount at 1.5 V or higher. Therefore, the voltage per pair of electrodes is preferably 1.5 V or more. When the voltage exceeds 4.0 V, oxygen starts to be generated, and when it exceeds 5.0 V, ozone starts to be generated. Since the generation of ozone is not desirable, the voltage is preferably 5.0 V or less. In addition, since the generation of oxygen wastes electric power, the voltage is particularly preferably 4.0 V or less. From the economical point of view, the voltage is preferably 3.0 V or less. At least, the generation of ozone is unfavorable from the viewpoint of the working environment. Therefore, the voltage is preferably 5.0 V or less, and the electrolyzed water used is preferably ozone-free electrolyzed water.

After discharging the electrolyzed water from the diaphragmless electrolytic cell,
Get electrolyzed water. The electrolytic water discharged from the membraneless electrolytic cell may be obtained after being diluted. This is because, in general, in the production of electrolyzed water, it is desirable from the economical standpoint to produce only a small amount of water having a high chlorine concentration and then dilute it for use. Therefore, after electrolysis, it is preferable to dilute and then collect electrolyzed water. The degree of dilution is such that the pH is 4.0 or more, preferably 4.5 to
It is preferable to dilute so that the effective chlorine concentration falls within the range of 10 to 30 ppm without deviating from the range of 7.0.

The effective chlorine concentration is determined by the orthotrizine method (edited by the Pharmaceutical Society of Japan, "Hygiene test method / Note 1980", No. 7).
46 pages, Kinbara Publishing Co., Ltd., March 20, 1980) or iodine titration method (Japan Waterworks Association, "Water test method 1993 edition", pages 218 to 219, 1993 1
It is possible to measure it by January 15).

The electrolyzed water may be neutralized with a neutralizing agent. As such a neutralizing agent, an alkaline chemical is preferable, and sodium hydroxide, potassium hydroxide, sodium bicarbonate, sodium carbonate and the like can be used, but sodium hydroxide is most preferable. When the electrolyzed water is neutralized in this way, the neutralizing agent may be added before or after the dilution, but is preferably added after the dilution.

The above operation can be carried out, for example, by using a commercially available electrolyzed water producing apparatus, Pure Star (trademark; manufactured by Morinaga Engineering Co., Ltd., hereinafter). A tank storing 21% hydrochloric acid is installed in this device. 21
It is possible to produce electrolyzed water by diluting% hydrochloric acid with water and then passing the solution through a non-diaphragm electrolytic cell for continuous electrolysis.

At this time, the obtained electrolyzed water has a pH of 4.0.
Above, preferably pH 4.5 to 6.8, effective chlorine concentration 1
The operating conditions of the diaphragmless electrolyzer are adjusted by using the first aspect of the invention and the electrolyzed water is diluted under the condition that the range is 0 to 30 ppm.

The electrolyzed water thus obtained is substantially free of sodium chloride and has a pH in the vicinity of neutrality, and is more natural than conventional electrolyzed water. It has similar physical properties.

In the method for producing electrolyzed water as described above,
The production method of the present invention can be carried out by applying the method for operating a diaphragmless electrolytic cell according to the first aspect of the present invention. That is, a) adjusting the mixing ratio of hydrochloric acid and diluting water so that the hydrochloric acid concentration of the hydrochloric acid aqueous solution to be passed through the diaphragmless electrolysis cell is adjusted to a predetermined set concentration, and b) the current value supplied to the diaphragmless electrolysis cell. Is measured so that the current value becomes a predetermined value.
Adjust the effective chlorine concentration of the electrolyzed water discharged from the diaphragmless electrolytic cell by raising or lowering the set concentration of the hydrochloric acid aqueous solution of
c) The amount of the hydrochloric acid aqueous solution to be passed through the diaphragmless electrolytic cell is increased or decreased to adjust the pH of the electrolytic water discharged from the diaphragmless electrolytic cell, whereby the electrolytic water discharged from the diaphragmless electrolytic cell is adjusted. The pH of the.

As described above, in the method for producing electrolyzed water of the present invention, electrolyzed water having a desired effective chlorine concentration and pH can be obtained.

[0043]

EXAMPLE 1 FIG. 1 is an explanatory view for explaining a schematic structure of an example of a diaphragmless electrolytic cell and an electrolyzed water producing apparatus to which the present invention is applied.

The Pure Star 100 is equipped with a hydrochloric acid tank 101 in which 21% hydrochloric acid is stored.
A hydrochloric acid solution sending pipe 102 is connected to 1. A hydrochloric acid metering pump 103 (diaphragm pump) is provided in the hydrochloric acid liquid supply pipe 102, and a diaphragmless electrolytic cell 1 is provided at the end.
04 is connected.

Electrodes 105 and 106 are provided in the diaphragmless electrolytic cell 104. In FIG. 1, the electrodes 105 and 106 are simplified and shown as a pair of electrodes.
In reality, the electrodes 105 and 106 are bipolar electrodes. The electrodes 105 and 106 are connected to a power source 107.

An electrolyzed water delivery pipe 108 is connected to the outlet 104a of the diaphragmless electrolyzer 104, and the end of the electrolyzed water delivery pipe 108 reaches the next step. Further, a diluting means 110 for diluting electrolyzed water is connected to the electrolyzed water delivery pipe 108.

This diluting means 110 is basically a water supply source 110a (water tap) and this supply source 110a.
It is constituted by a water supply pipe 111 connected to.
The water supply pipe 111 includes an automatic opening / closing valve 112 and a constant flow valve 1.
13 are provided. The end 111a of the water supply pipe 111
Joins the electrolyzed water delivery pipe 108.

Further, in the diluting means 110, a hydrochloric acid diluting pipe 114 is branched from a water supply pipe 111, a metering pump 115 is installed in the hydrochloric acid diluting pipe 114, and the end of the hydrochloric acid diluting pipe 114 is fed with the hydrochloric acid. It joins the liquid pipe 102.

It should be noted that it is desirable that only the hydrochloric acid tank 101 and the hydrochloric acid liquid feeding pipe 102 or only the hydrochloric acid diluting pipe 114 be disposed in the diaphragmless electrolytic cell 104. That is, it is preferable to pass an aqueous hydrochloric acid solution containing substantially no sodium chloride into the membraneless electrolytic cell 104.

In addition to the above basic structure, the present invention is provided with a current measuring means 200 for measuring the current passed through the diaphragmless electrolyzer 104, and further the electrolyzed water delivery pipe 1
08 is equipped with a pH meter 300 for measuring the pH of electrolyzed water.

As described above, the automatic opening / closing valve 112 and the metering pump 10
3, the metering pump 115, the power supply 107 of the diaphragmless electrolyzer, the current measuring means 200, and the pH meter 300 are respectively connected to the signal line 1
12a, 103a, 115a, 107a, 200a, and 300a are connected to the controller 400.

As the controller 400, a commercially available sequencer, personal computer or the like (for example, KZ series manufactured by Keyence Corporation, MELSE manufactured by Mitsubishi Electric Corporation) is used.
C (trademark), Omron's SYSMAC (trademark), etc.) can be exemplified.

The above device Pure Star 100 is operated as follows. That is, 21% hydrochloric acid is stored in the hydrochloric acid tank 101, and this hydrochloric acid is sent to the diaphragmless electrolytic cell 104 by the metering pump 103 via the hydrochloric acid sending pipe 102. At this time, the diluting water is sent by the metering pump 115 through the hydrochloric acid diluting pipe 114, and the diaphragmless electrolytic cell 1
The concentration of hydrochloric acid flowing into 04 is adjusted.

In the diaphragmless electrolytic cell 104, the electrode 10
5 and 106 are energized, hydrochloric acid is electrolyzed,
It becomes electrolyzed water. The electrolyzed water is discharged from the outlet 104a of the diaphragmless electrolyzer 104 and sent to the next step via the electrolyzed water delivery pipe 108.

In the diluting means 110, the water source 11
Water is supplied from 0a through the water supply pipe 111,
The amount of water in this case is kept constant by the constant flow valve 113. This water joins the electrolyzed water discharge pipe 108 at the end 111a via the water supply pipe 111, where the electrolyzed water is diluted and then sent to the next step.

The controller 400 uses the signal line 112
Through a, 103a, 115a and 107a, it has a function of operating and stopping the automatic opening / closing valve 112, the metering pumps 103 and 115, and the power supply 107 of the diaphragmless electrolytic cell.

In the above Pure Star 100, the effective chlorine concentration and pH of electrolyzed water are adjusted as follows.
The current measuring means 200 measures the current passed through the membraneless electrolytic cell 104, and inputs the measurement result to the controller 400 via the signal line 200a.

In the controller 400, the input measurement result is compared with a preset setting value or setting range, and if the measurement result is lower than the setting value or lower than the lower limit of the setting range, the diaphragmless membrane is used. A command is issued to increase the concentration of the hydrochloric acid aqueous solution that is passed through the electrolytic cell 104. Then, the flow rate of the metering pump 103 increases, the absolute amount of hydrochloric acid increases, and the concentration of the hydrochloric acid aqueous solution increases. If the hydrochloric acid concentration of the hydrochloric acid aqueous solution increases, the electric resistance decreases and the current value increases. In this case, the reaction inside the diaphragmless electrolytic cell 104 is promoted, and the effective chlorine concentration of the electrolytic water discharged from the diaphragmless electrolytic cell 104 increases.

On the contrary, when the current value measured by the current measuring means 200 is higher than the set value or exceeds the upper limit of the set range, the concentration of the hydrochloric acid aqueous solution passing through the diaphragmless electrolytic cell 104 is changed. Issue a command to lower. Then, the flow rate of the metering pump 103 decreases, and the absolute amount of hydrochloric acid decreases,
The concentration of the hydrochloric acid solution drops. When the concentration of the hydrochloric acid aqueous solution decreases, the electric resistance increases and the current value decreases. In this case, since the reaction inside the diaphragmless electrolytic cell 104 is suppressed, the effective chlorine concentration of the electrolyzed water discharged from the diaphragmless electrolytic cell 104 decreases.

Thus, the effective chlorine concentration of the electrolyzed water flowing through the electrolyzed water delivery pipe 108 can be controlled by appropriately setting the set value or the set range of the current in the controller 400.

On the other hand, when the pH of the electrolyzed water flowing through the electrolyzed water delivery pipe 108 is changed by such an operation,
The rotation speed of the metering pump 115 is adjusted to increase or decrease the flow rate of the dilution water. As a result, the hydrochloric acid concentration of the hydrochloric acid aqueous solution passing through the diaphragmless electrolytic cell 104 changes, but the mixing ratio of the hydrochloric acid and the diluting water (that is, the hydrochloric acid concentration becomes a predetermined concentration).
Since the flow rate ratios of the metering pumps 103 and 115 are adjusted, the flow rate of hydrochloric acid also fluctuates, and eventually the flow rate of the hydrochloric acid aqueous solution increases or decreases.

Thus, the pH of the electrolyzed water is maintained at a predetermined value or range by varying the flow rate of the hydrochloric acid aqueous solution.

That is, the pH of the electrolyzed water flowing through the electrolyzed water delivery pipe 108 can be freely adjusted by adjusting the rotational speed of the metering pump 115 to increase or decrease the flow rate of the diluting water.

In this case, the indicated value of the pH meter 300 is input to the controller 400 via the signal line 300a,
Is automatically controlled so that is a predetermined value, and similarly, the current value measured by the current measuring means 200 is automatically controlled so as to be a preset value.

As described above, in the pure star 100, the effective chlorine concentration and pH of the electrolyzed water flowing through the electrolyzed water delivery pipe 108 can be independently adjusted.

Example 2 Using the apparatus of FIG. 1, the non-diaphragm electrolytic cell 104 was operated,
Electrolyzed water was produced by the following procedure.

The 21% hydrochloric acid stored in the hydrochloric acid tank 101 was caused to flow through the hydrochloric acid feed pipe 102 at a flow rate of 100 ml / h by the constant volume pump 103. In addition, the diaphragmless electrolytic cell 1
The effective area of the bipolar electrode of No. 04 (105, 106, etc.) is 0.6 dm ² . From the hydrochloric acid dilution tube 114, 0.5l
Diluting water was flown at a flow rate of / h to dilute the hydrochloric acid to form an aqueous hydrochloric acid solution, which was passed through the diaphragmless electrolytic cell 104.

In the diaphragmless electrolytic cell 104, a total voltage of 24 V was applied to the bipolar electrodes 105 and 106 to electrolyze the hydrochloric acid aqueous solution, and as a result, electrolyzed water having an effective chlorine concentration of 15 ppm and a pH of 6.6 was discharged from the outlet 104a. Was discharged. still,
The current value under this condition was 1.5A.

When the rotational speed of the metering pump 103 was increased to increase the flow rate of hydrochloric acid and the current value was adjusted to 2.0 A, the effective chlorine concentration of the electrolyzed water at the outlet 104a increased to 21 ppm. However, the pH value is
There was no change, which was 6.6.

In this state, when the rotation speed of the metering pump 115 was lowered to decrease the flow rate of the diluting water, the pH of the electrolyzed water at the outlet 104a increased to 6.9, and the rotation speed of the metering pump 115 was further increased. , The pH of the electrolyzed water is
It fell to 5.9. However, the value of the available chlorine concentration remained at 21 ppm and did not change.

As described above, the effective chlorine concentration and pH of electrolyzed water could be adjusted independently.

[0072]

EFFECTS OF THE INVENTION According to the method for operating a diaphragmless electrolytic cell or the method for producing electrolyzed water according to the present invention, the diaphragmless electrolytic cell can be operated while ensuring a constant power efficiency, and oxygen and ozone are not generated. In addition, the effective chlorine concentration and pH of electrolyzed water can be independently adjusted while efficiently using electric power energy. Also, the effective chlorine concentration of electrolyzed water and p
It is also possible to automatically control H and H independently.

Therefore, it is suitable for industrial use as a method for operating an electrolytic cell and a method for producing electrolyzed water, and it is possible to promote the use of electrolyzed water for various industrial fields.

[Brief description of drawings]

FIG. 1 is an explanatory diagram for explaining a schematic structure of an example of a diaphragmless electrolytic cell and an electrolyzed water manufacturing apparatus to which the present invention is applied.

[Explanation of symbols]

100 Pure Star (electrolyzed water production equipment) 101 hydrochloric acid tank 102 Hydrochloric acid delivery pipe 103 Metering pump 104 diaphragmless electrolytic cell 108 Electrolyzed water delivery pipe 110 means of dilution 110a Water tap (water supply source) 200 Current measuring means 300 pH meter 400 controller

Claims (2)

[Claims] 1. A hydrochloric acid aqueous solution prepared by diluting hydrochloric acid with diluting water is passed through a diaphragmless electrolytic cell substantially without containing sodium chloride, and a predetermined voltage is applied to the passed diaphragmless electrolytic cell. A method for operating a diaphragmless electrolytic cell in which an aqueous hydrochloric acid solution is electrolyzed into electrolyzed water by an applied voltage and the electrolytic water is discharged from the diaphragmless electrolytic cell, comprising: a) hydrochloric acid passing through the diaphragmless electrolytic cell. The mixing ratio of hydrochloric acid and dilution water is adjusted so that the hydrochloric acid concentration of the aqueous solution reaches a predetermined set concentration, and b) the current value applied to the diaphragmless electrolytic cell is measured, and the current value becomes the predetermined value. As described above, the set concentration of the hydrochloric acid aqueous solution of a) is raised and lowered, thereby adjusting the effective chlorine concentration of the electrolyzed water discharged from the diaphragmless electrolytic cell, and c) the passage of the hydrochloric acid aqueous solution to be passed through the diaphragmless electrolytic cell. Increase / decrease the volume, which causes it to be discharged from the diaphragmless electrolytic cell A method for operating a non-diaphragm electrolyzer capable of adjusting the pH of electrolyzed water and thereby independently adjusting the effective chlorine concentration and pH of electrolyzed water discharged from the non-diaphragm electrolyzer. 2. A hydrochloric acid is diluted with diluting water, and the diluted aqueous hydrochloric acid solution is passed through a diaphragmless electrolytic cell substantially without containing sodium chloride, and a predetermined voltage is applied to the passed diaphragmless electrolytic cell. In the method for producing electrolyzed water, in which the aqueous hydrochloric acid solution is electrolyzed by the applied voltage, the electrolyzed electrolyzed water is discharged from the diaphragmless electrolysis tank, and the discharged electrolyzed water is obtained: a) passing through the diaphragmless electrolyzer The mixing ratio of hydrochloric acid and diluting water is adjusted so that the hydrochloric acid concentration of the liquid hydrochloric acid solution is a predetermined set concentration, and b) the current value applied to the diaphragmless electrolytic cell is measured, and the current value is set to a predetermined value. The above-mentioned a) hydrochloric acid aqueous solution concentration is adjusted so that the value becomes a value, thereby adjusting the effective chlorine concentration of the electrolyzed water discharged from the diaphragmless electrolytic cell, and c) the hydrochloric acid aqueous solution which is passed through the diaphragmless electrolytic cell. Increase or decrease the liquid flow rate of the A method for producing electrolyzed water, which makes it possible to adjust the pH of electrolyzed water discharged from an electrolyzer and thereby independently adjust the effective chlorine concentration and pH of the electrolyzed water to be obtained.