JP2006110512A - Electrolytic water production device and method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electrolytic water production device and an electrolytic water production method which can control the temperature rise of an electrolytic cell during operation. <P>SOLUTION: The electrolytic water production device 1 generates electrolytic water by electrolysis of raw material water in the electrolytic cell 40. The electrolytic cell 40 is a continuous electrolytic cell through which the raw material water passes, while keeping the flow from the inlet 41 to outlet 42 of the electrolytic cell 40. A volumetric water supply means 25 for supplying the raw material water to the electrolytic cell 40 at a fixed flow rate is installed upstream of the electrolytic cell 40, and a suction mean 60 for sucking the inside of the electrolytic cell 40 is installed downstream of the electrolytic cell 40. It is preferable that the internal pressure of the electrolytic cell 40 is maintained at a negative pressure of less than -0.04 MPa during operation. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an electrolyzed water production apparatus and method for producing electrolyzed water such as hypochlorous acid water and chlorine water by electrolyzing raw water to which hydrochloric acid or the like is added.

Electrolyzed water is produced by electrolyzing raw water containing chloride ions, such as saline (sodium chloride) and aqueous hydrochloric acid, in an electrolytic cell. The electrolyzed water contains chlorine, hypochlorous acid, hypochlorite and the like produced by anodic oxidation of chloride ions, and the electrolyzed water has effects such as sterilization and disinfection.
Moreover, what is obtained by electrolysis in the non-diaphragm electrolysis tank of the diluted hydrochloric acid aqueous solution as electrolysis water which has little sodium salt content and exhibits slight acidity (pH 4-6) is known. This type of electrolyzed water, for example, has a high effect of sterilization and disinfection even at a low chlorine concentration, compared to the case where sodium hypochlorite is added to water, and a fine concentration every time it is used. It is excellent in that no adjustment is required.

In general, in the production of electrolyzed water, it is considered desirable in terms of efficiency that the amount of chlorine generated is higher than the amount of electrical energy applied to the electrolytic cell. The efficiency in this case is represented by the amount (mg) of chlorine generated per 1 Wh of the electric power supplied to the electrolytic cell, and is referred to as “power efficiency”.
It goes without saying that such power efficiency is preferably as high as possible. On the other hand, regarding the consumption of the electrolyte as a raw material, the consumption of the electrolyte necessary for generating a predetermined amount of chlorine is acceptable. It can be said that the smaller the number, the more efficient the operation.
In the following description, such high and low power efficiency, consumption of electrolyte as a raw material, and the like may be collectively expressed as “electrolysis efficiency”.

  In the actual process, the electrolyzed water is used for various purposes such as sterilization, cleaning, and freshness maintenance. In this case, if the effective chlorine concentration of the electrolyzed water used varies, Effects such as cleaning and maintaining freshness will also vary. Therefore, the operation of the electrolyzed water production apparatus is preferably an operation in which the amount of generated chlorine does not vary as much as possible, that is, the effective chlorine concentration of the obtained electrolyzed water is preferably maintained within a predetermined range. The For this reason, when operating the electrolyzed water production apparatus, it is preferable to set and control the operating conditions so that the effective chlorine concentration of the electrolyzed water to be generated is as constant as possible.

As a conventional electrolyzed water manufacturing apparatus, there exists a thing of patent document 1, for example. The electrolyzed water production apparatus described in Patent Literature 1 includes an ejector that sucks saline using the venturi effect of the liquid flow of clean water in order to smoothly mix salt water for promoting electrolysis with clean water. In addition, clean water mixed with saline by an ejector is supplied to an electrolytic cell and electrolyzed to produce electrolytic water.
Further, in Patent Document 2, for the purpose of electrolytic sterilization of raw water such as tap water flowing through a supply pipe, a jet bottle is provided in the supply pipe, the upstream side and the downstream side of the jet pipe are connected by a branch pipe, A water electrolysis disinfection device is described in which a diffusion salt addition device and an electroless electrolytic cell are provided in the middle of the tube. This water electrolysis disinfection device uses the pressure difference that occurs before and after the spout so that part of the raw water that flows through the supply pipe is naturally branched into the branch pipe, so that the salt is continuously diffused into the branch raw water that flows through the branch pipe. The metering pump or the pressurizing pump and / or the metering pump or the pressurizing pump forcibly supplying the saline solution to the diaphragm type electrolytic cell are not used at all.
JP-A-9-253648 JP 2001-113278 A

In conventional electrolyzed water production equipment, it is required to increase the power efficiency as much as possible, and it is also required to operate efficiently with the consumption of the electrolyte as a raw material as low as possible. Therefore, there has been a long-awaited device capable of satisfying such a desire.
On the other hand, in the conventional electrolyzed water production apparatus, the temperature of the electrolytic cell may rise while the operation is continued. When the temperature of the electrolytic cell rises, there is a problem that the life of the apparatus is shortened due to deterioration of electrodes and the like over time. In addition, as the material of the electrolytic cell, a vinyl chloride-based material is often used as a material that resists corrosion such as chlorine. However, if the temperature of the electrolytic cell is excessively high, it is not preferable because of the heat resistance. .

  The present invention has been made in view of the above circumstances, has higher power efficiency, consumes less electrolyte as a raw material, and is capable of suppressing an increase in the temperature of an electrolytic cell during operation and electrolysis It is an object to provide a method for producing water.

In order to solve the above-mentioned problem, the present invention is an electrolyzed water production apparatus that electrolyzes raw water in an electrolytic cell to generate electrolytic water, and the electrolytic cell has an internal raw material water inlet to the electrolytic cell. A continuous electrolytic cell that is passed while maintaining a flow from the outlet to the outlet, and a quantitative water supply means for supplying the raw water to the electrolytic cell at a constant flow rate is provided upstream of the electrolytic cell, Provided is an electrolyzed water production apparatus characterized in that suction means for sucking the inside of the electrolytic cell is provided downstream of the electrolytic cell.
In the electrolyzed water production apparatus of the present invention, a flow path for diluting water for diluting electrolyzed water discharged from the electrolyzer is joined downstream of the electrolyzer, and the suction means is connected to the diluted water flow path. It is preferable that the ejector is provided at the merging point and uses the dilution water as a driving fluid.
It is preferable that a mixer is provided downstream of the suction means.
It is preferable that the outlet of the electrolytic cell is opened at the top of the electrolytic cell.
In the electrolytic cell, the electrodes are preferably installed so that a flow path formed between the electrodes communicates in the vertical direction.

The present invention is also a method for producing electrolyzed water by electrolyzing raw water in an electrolyzer to produce electrolyzed water so as to keep the flow from the inlet to the outlet of the electrolyzer inside the electrolyzer. Provided is a method for producing electrolyzed water, wherein the raw water is passed and the internal pressure of the electrolytic cell is maintained at a negative pressure of less than -0.04 MPa.
In the method for producing electrolyzed water of the present invention, a quantitative water supply means is provided on the inlet side of the electrolytic cell to supply the raw water to the electrolytic cell at a constant flow rate, and a suction means is provided on the outlet side of the electrolytic cell. It is preferable to provide and suck the inside of the electrolytic cell.

  According to the present invention, the raw water is supplied from the inlet of the electrolytic cell to the electrolytic cell at a constant flow rate, and the raw water is continuously electrolyzed while maintaining the flow of the raw water inside the electrolytic cell. Since the inside of the electrolytic cell is sucked on the outlet side of the cell, the inside of the electrolytic cell is maintained in a state where the negative pressure is smaller than the atmospheric pressure. As a result, insoluble gas such as hydrogen gas generated in the electrode can be sucked and quickly discharged out of the electrolytic cell, and the efficiency of electrolysis can be improved. Thereby, since the electric power converted into heat can be suppressed, the temperature rise of the electrolytic cell can be suppressed, and inconveniences such as deterioration over time of the electrode and the electrolytic cell can be suppressed.

The present invention will be described below based on the best mode.
In the present invention, the raw water that is electrolyzed in the electrolytic cell is one containing an electrolyte that generates chloride ions by ionization, such as hydrogen chloride or sodium chloride. Such raw material water is preferably used by diluting an aqueous electrolyte solution such as an aqueous hydrochloric acid solution or a saline solution to an appropriate concentration with dilution water.
Dilution water used for diluting raw material water is tap water, groundwater, underground water, desalted water, distilled water, purified water (RO water, membrane treated water), mixed water thereof, and the like, which are substantially sodium chloride. Water containing no is preferred. Here, “substantially no sodium chloride” means that there is no artificial addition of sodium to the raw water and the sodium ion concentration is 200 ppm or less.

It is a preferred embodiment that only a hydrochloric acid aqueous solution is used as the raw material water. In this case, hypochlorous acid water that does not substantially contain a sodium salt can be produced. Moreover, when salt water is used as raw material water, strongly acidic hypochlorous acid water (so-called strong electrolyzed water) can be produced.
Hypochlorous acid water substantially containing no sodium salt can be diluted with dilution water after electrolysis as necessary, to prepare slightly acidic hypochlorous acid water exhibiting slightly acidic (pH 4 to 6). Can be used. Slightly acidic hypochlorous acid water has good sterilization and disinfection effects even if the effective chlorine concentration is relatively low, and has properties close to natural water because it is slightly acidic. Are better. Therefore, in this invention, it is preferable to use hydrochloric acid aqueous solution as raw material water in the state which does not contain sodium chloride substantially.

Here, the meaning of “in a state containing substantially no sodium chloride” means that sodium chloride is not artificially added before passing through the electrolytic cell. In this case, a small amount of sodium chloride naturally contained in diluted water or hydrochloric acid is not considered.
The fact that sodium chloride has not been artificially added means that the sodium ion concentration of the aqueous hydrochloric acid solution passed through the electrolytic cell does not exceed the sodium ion concentration contained in the original diluted water or hydrochloric acid. Means. In general, since diluted water or hydrochloric acid has a sodium ion concentration of 200 ppm or less, the diluted hydrochloric acid aqueous solution also has a sodium ion concentration of 200 ppm or less.
The hydrogen chloride concentration of the diluted hydrochloric acid aqueous solution is desirably 0.01% (mass%, hereinafter the same unless otherwise specified) in order to cause an appropriate reaction in the electrolytic cell. .1% or more is recommended. However, when pursuing economic efficiency and stable progress of the reaction, the hydrogen chloride concentration is preferably 1.0% or more and 21.0% or less.

The raw material water as described above is supplied to the electrolytic cell and electrolyzed by passing between the cathode and the anode.
In the present invention, as the electrolytic cell, a continuous electrolytic cell is used in which the raw material water is passed while maintaining the flow from the inlet side to the outlet side. In addition, a constant water supply means is provided on the inlet side (upstream side) of the electrolytic cell to supply raw water to the electrolytic cell at a constant flow rate, and a suction means is provided on the outlet side (downstream side) of the electrolytic cell. Aspirate the liquid.

The electrolytic cell is preferably a non-diaphragm electrolytic cell having no diaphragm between the cathode and the anode, for example. The diaphragm electrolytic cell may be a monopolar type, but is preferably a bipolar type electrolytic cell.
In general, there are two types of methods for connecting a plurality of electrodes in a non-diaphragm electrolytic cell: a monopolar type and a bipolar type. The monopolar type is a system in which all of the electrodes are connected to the positive electrode or negative electrode of the power source, and the multipolar type has, for example, a structure in which a plurality of electrodes are stacked at a constant interval and insulated from each other. In this method, there is at least one intermediate electrode that is not connected to any pole between the anode (that is, the anode) connected to the positive electrode of the power source and the cathode (that is, the cathode) connected to the negative electrode of the power source. .

In the electrolysis, the voltage per pair of electrodes is preferably 1.5 V or more and 4.0 V or less. In the case of a bipolar electrodeless membrane electrolytic cell, an intermediate electrode exists between the cathode and the anode as described above, but the “voltage per pair of electrodes” refers to the cathode, anode, and intermediate electrode. It is a term that means a voltage between two adjacent electrodes.
In general, when the voltage per pair of electrodes is increased, chlorine starts to be generated at 1.3 V or higher and reaches the maximum generation amount at 1.5 V or higher. Therefore, the voltage per pair of electrodes is desirably 1.5 V or more. When the voltage exceeds 4.0V, oxygen starts to be generated, and when it exceeds 5.0V, ozone starts to be generated. Since generation of ozone is not desirable, the voltage is desirably 5.0 V or less. Further, since the generation of oxygen is a waste of electric power, the voltage is particularly preferably 4.0 V or less. The voltage is preferably 3.0 V or less from the economical viewpoint. At least, since generation of ozone is not preferable in terms of the working environment, the voltage is desirably 5.0 V or less, and the electrolyzed water to be used is particularly preferably electrolyzed water without ozone.

When the raw water is electrolyzed in the electrolytic cell, chloride ions in the raw water are oxidized to generate chlorine, and hydrogen is generated by reduction of hydrogen ions derived from water or hydrogen chloride. Chlorine is easily dissolved in water and reacts with water to produce hypochlorous acid. On the other hand, since hydrogen gas has low water solubility, it exists as bubbles in the liquid phase.
In the present invention, a suction means is provided on the outlet side of the electrolytic cell to suck the liquid in the electrolytic cell, so that the internal pressure of the electrolytic cell is maintained at a negative pressure. Thereby, the gas phase in the electrolytic cell is easily discharged out of the electrolytic cell quickly. At this time, the liquid phase as well as the gas phase is discharged out of the electrolytic cell, but since the supply flow rate of raw material water to the electrolytic cell is kept constant by the quantitative water supply means, the amount of liquid phase in the electrolytic cell must be maintained. And the efficiency of electrolysis can be improved.

That is, a continuous electrolytic cell is used as an electrolytic cell, a fixed water supply means for supplying raw material water to the electrolytic cell at a constant flow rate is provided upstream of the electrolytic cell, and suction for sucking the inside of the electrolytic cell downstream of the electrolytic cell The electrolyzed water production apparatus provided with the means is suitable for operating while generating a high negative pressure inside the electrolytic cell and maintaining the negative pressure stably.
During operation, the internal pressure of the electrolytic cell is preferably maintained below -0.04 MPa. In this case, electrolysis can proceed extremely efficiently. It is considered that a stable gas-liquid mixed phase flow is obtained in the electrolytic cell, and the discharge of the gas phase is promoted. If the internal pressure of the electrolytic cell is in a high vacuum range of about −0.0999 MPa or less, the equipment cost may be expensive.
A particularly preferable electrolytic cell internal pressure is −0.099 MPa or more and −0.05 MPa or less, and within this range, the effect of improving the electrolysis efficiency can be obtained more reliably.

The outlet of the electrolytic cell is preferably opened at a position above the electrolytic cell as much as possible. Thereby, the gas generated on the surface of the electrode can be easily discharged from the outlet, and the stay in the electrolytic cell can be suppressed.
Moreover, it is preferable to install an electrode in an electrolytic cell so that the flow path formed between electrodes may communicate with a perpendicular direction. Thereby, the flow of the fluid in an electrolytic cell can be made smooth, and it can suppress that gas retains in the space between electrodes and narrows a flow path.

As the suction means, an ejector, a suction pump or the like can be used. The suction means may be an electric pump using electric power energy, but it is preferable to use an ejector using dilution water as a driving fluid in view of economy and downsizing of the apparatus. When the ejector is used, not only can the kinetic energy of the dilution water be used effectively, but also the mixing of the electrolyzed water and the dilution water can be performed effectively in the ejector.
As the quantitative water supply means, a quantitative pump, a pressure pump, or the like can be used. When using an aqueous electrolyte solution diluted with dilution water as the raw material water, a method of maintaining a constant flow rate of the raw material water obtained by diluting the aqueous electrolyte solution with the dilution water can be used.
When the flow rate of the aqueous electrolyte solution is sufficiently small with respect to the flow rate of the dilution water, the same effect can be obtained even by using a method of keeping the flow rate of the dilution water constant by quantitative water supply.

After the electrolyzed water is discharged from the electrolytic cell, electrolyzed water is obtained. In addition, you may acquire after diluting the electrolyzed water discharged | emitted from the electrolytic vessel. In general, in the production of electrolyzed water, it is desirable in terms of economy to produce only a small amount of water having a high chlorine concentration and then dilute and use it. Therefore, after electrolysis, it is preferable to collect electrolyzed water after dilution.
Dilution water used for diluting the electrolyzed water is tap water, ground water, underground water, desalted water, distilled water, purified water (RO water, membrane treated water), mixed water thereof, and the like, which are substantially sodium chloride. Water containing no is preferred.

The degree of dilution of the electrolyzed water is preferably such that the pH is 4.0 or more, preferably not deviating from the range of 4.5 to 7.0, and the effective chlorine concentration is in the range of 10 to 30 ppm. .
The effective chlorine concentration is determined by the orthotolidine method (edited by the Japan Pharmaceutical Association, “Hygiene Test Method / Comment 1980”, page 746, Kanehara Publishing Co., Ltd., March 20, 1980) or the iodine titration method (Japan Water Works Association). , “Water supply test method, 1993 edition”, pages 218 to 219, November 15, 1993).

It is preferable to provide a mixer downstream of the suction means. Thereby, dissolution of chlorine in water can be promoted. When diluting the electrolyzed water discharged from the electrolyzer, the mixing of the electrolyzed water and the diluted water can be further promoted.
The mixer is preferably a static mixer such as a static mixer, but may be a dynamic mixer such as rotating a stirrer or a stirring blade. Moreover, it is also possible to employ | adopt the instrument with which the suction means and the mixer were provided integrally.

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

Next, an embodiment of the electrolyzed water production apparatus of the present invention will be described with reference to the drawings.
FIG. 1 is a schematic configuration diagram showing an embodiment of the electrolyzed water production apparatus of the present invention. The electrolyzed water production apparatus 1 shown in FIG. 1 dilutes into a first diluting water flow path 10 through which diluting water flowing from the diluting water inlet 11 is passed, and the first diluting water flow path 10 and dilutes into the electrolytic cell 40. The second dilution water flow path 20 for supplying water, the hydrochloric acid flow path 30 through which the hydrochloric acid aqueous solution stored in the hydrochloric acid tank 31 is passed, the electrolytic bath 40 for electrolyzing the raw material water, and the electrolytic bath 40 are discharged. And an electrolyzed water discharge passage 51 through which the electrolyzed water is passed.

  In the first dilution water flow path 10, a strainer 12 that separates dust in the dilution water flowing from the dilution water inlet 11, a flow meter 13 that measures the flow rate of the dilution water on the downstream side of the strainer 12, and this flow rate A solenoid valve 14 that opens and closes the dilution water flow path 10 on the downstream side of the meter 13, a first pressure gauge 15 that measures the pressure of the dilution water in the dilution water flow path 10 on the downstream side of the electromagnetic valve 14, and a first pressure A constant flow valve 16 that adjusts the flow rate of the dilution water to be constant downstream of the total flow meter 15; a second pressure gauge 17 that measures the pressure of the dilution water in the dilution water flow channel 10 downstream of the constant flow valve 16; A check valve 18 is provided on the downstream side of the second pressure gauge 17 to prevent the reverse flow of the dilution water. Further, a drain 10a for discharging dilution water is branched downstream of the check valve 18 as necessary, and the drain 10a can be opened and closed by an on-off valve 10b. As the on-off valve 10b, for example, a solenoid valve that opens a flow path when energized is used, and is closed during normal operation.

The second dilution water flow path 20 is branched from between the strainer 12 and the flow meter 13 of the first dilution water flow path 10 and is disposed up to the electrolytic cell 40. In the case of the electrolyzed water production apparatus 1 shown in FIG. 1, a dilution water tank 21 for storing dilution water is provided in the middle of the second dilution water flow path 20. The dilution water tank 21 includes a level switch 22 that detects the level of dilution water in the tank. On the upstream side and downstream side of the dilution water tank 21, on-off valves 23 and 24 for opening and closing the second dilution water flow path 20 are provided. Further, a drain 20a including an on-off valve 20b is branched from between the dilution water tank 21 and the on-off valve 24 on the downstream side.
On the downstream side of the on-off valve 24, a dilution water pump is provided as a quantitative water supply means 25 that supplies dilution water to the electrolytic cell 40 at a constant flow rate. A check valve 26 for preventing backflow is provided.

  The hydrochloric acid tank 31 is provided with a level switch 32 for detecting the level of the hydrochloric acid aqueous solution in the tank. The hydrochloric acid channel 30 includes an on-off valve 33 that opens and closes the hydrochloric acid channel 30 on the downstream side of the hydrochloric acid tank 31, a hydrochloric acid pump 34 that supplies the aqueous hydrochloric acid solution in the hydrochloric acid tank 31 to the electrolytic bath 40, and a downstream side of the hydrochloric acid pump 34. And a check valve 35 for preventing the back flow of the hydrochloric acid aqueous solution.

The electrolytic cell 40 is a continuous electrolytic cell through which raw material water is passed while maintaining a flow from the inlet 41 side to the outlet 42 side. The illustrated electrolytic cell 40 includes an anode 44 (anode) connected to the positive electrode of the power supply 43, a cathode 45 (anode) connected to the negative electrode of the power supply 43, and an intermediate electrode installed between the anode 44 and the cathode 45. 46. These electrodes 44, 45, 46 are accommodated in an electrolytic cell body 47 made of vinyl chloride or the like. The inlet 41 of the electrolytic cell 40 is provided with a merging device 48 that joins the dilution water supplied via the second dilution water channel 20 and the hydrochloric acid aqueous solution supplied through the hydrochloric acid channel 30. .
The inlet 41 of the electrolytic cell 40 is provided at the lower part of the electrolytic cell main body 47, the outlet 42 is provided at the upper part of the electrolytic cell main body 47, and the electrodes 44, 45 and 46 are arranged so as to rise in the vertical direction.

A suction means 60 is connected to the outlet 42 side of the electrolytic cell 40 through an electrolytic water discharge path 51. The suction means 60 sucks electrolyzed water together with gas from the electrolyzer 40 and maintains the internal pressure of the electrolyzer 40 at a negative pressure.
In the embodiment shown in FIG. 1, the suction means 60 is an ejector provided at the junction of the electrolyzed water discharge path 51 and the first dilution water flow path 10, and the dilution water supplied from the first dilution water flow path 10. As a driving fluid, the electrolyzed water is sucked, and the electrolyzed water is diluted by mixing the electrolyzed water and the diluted water.

  In FIG. 2, an example of the ejector 60 which can be used with the electrolyzed water manufacturing apparatus of this invention is shown. The ejector 60 generates a negative pressure by injecting the driving fluid flowing in from the driving fluid inlet 61 from an injection port 62 formed therein, and uses the negative pressure to cause the driven fluid to enter the driven fluid inlet. The suction fluid is sucked from 63 and the driving fluid and the driven fluid are discharged from the outlet 64. Here, the driving fluid is dilution water supplied from the first dilution water flow path 10, and the driven fluid is a mixture of electrolytic water and gas discharged from the electrolytic cell 40.

  The structure of the ejector 60 will be described in more detail. The ejector 60 includes a first member 65 having a drive fluid inlet 61 formed at one end and an injection port 62 formed at the other end, and a receiving port facing the injection port 62. 66a and a second member 66 having an outlet 64 at an end opposite to the receiving port 66a, and a first member 65 and a third member 67 fitted so that the second member 66 faces each other. A side pipe portion 67 a having a driven fluid inlet 63 projects from the side portion of the third member 67. The outer surface of the end portion of the first member 65 on the injection port 62 side is tapered, and the inner diameter of the receiving port 66a of the second member 66 is smaller than the outer diameter of the end portion of the first member 65 on the injection port 62 side. The driven fluid can flow into the receiving port 66a through the gap 68.

  The outlet of the suction means 60 is connected to a dilute electrolyzed water flow path 52 through which electrolyzed water diluted with diluting water passes to the electrolyzed water outlet 53. The diluted electrolyzed water flow path 52 includes a mixer 54 provided on the downstream side of the suction means 60, a bypass pipe 55 that branches from the main flow of the diluted electrolyzed water flow path 52 on the downstream side of the mixer 54, and a bypass pipe. An open / close valve 56 for opening and closing the flow of 55 and a pH meter 57 for measuring the pH of the electrolyzed water flowing through the bypass pipe 55 are provided.

The operation of the electrolyzed water production apparatus 1 is as follows.
When the dilution water is introduced from the dilution water inlet 11, a part of the dilution water branches into the second dilution water channel 20 and is stored in the dilution water tank 21, while the remainder of the dilution water is the first dilution water channel. 10 is fed, adjusted to a constant flow rate by the constant flow valve 16, and flows into the drive fluid inlet 61 of the ejector 60. In the ejector 60, a negative pressure is generated by the flow of diluted water, and the inside of the electrolytic cell 40 is maintained in a negative pressure state.

The dilution water stored in the dilution water tank 21 is fed by the dilution water pump 25 through the second dilution water channel 20 at a constant flow rate.
Further, the aqueous hydrochloric acid solution stored in the hydrochloric acid tank 31 is sent through the hydrochloric acid flow path 30 at a predetermined flow rate by the hydrochloric acid pump 34. The aqueous hydrochloric acid solution and the diluting water are mixed by the confluencer 48, and the raw material water whose chloride ion concentration is appropriately adjusted is made and then flows into the electrolytic cell 40.

  The raw water flowing into the electrolytic cell 40 flows between the electrodes 44, 45, and 46 while flowing from the inlet 41 to the outlet 42 of the electrolytic cell 40, and is electrolyzed by applying a voltage. At this time, excess gas such as hydrogen gas generated from the electrodes 44, 45, and 46 is sucked together with the electrolyzed water by the ejector 60 and quickly discharged from the electrolytic cell 40.

  The electrolyzed water discharged from the electrolyzer 40 is mixed with the diluting water sent through the first diluting water flow path 10 in the ejector 60, mixed uniformly through the mixer 54, and then passed through the diluting electrolyzed water flow path 52. And discharged from the electrolyzed water outlet 53. If the mixing ratio of the electrolyzed water and the diluted water is appropriately adjusted, it is possible to obtain electrolyzed water suitable for use in the state discharged from the electrolyzed water outlet 53. The electrolyzed water obtained from the electrolyzed water outlet 53 can be diluted to an appropriate effective chlorine concentration, or the pH can be adjusted by adding a neutralizing agent, if necessary. If it is not necessary to use the electrolyzed water obtained from the electrolyzed water outlet 53 immediately, it may be temporarily stored in an electrolyzed water tank (not shown).

  As described above, according to the electrolyzed water production apparatus 1 of the present embodiment, the quantitative water supply means 25 is provided upstream of the continuous electrolyzer 40 and the inside of the electrolyzer 40 is sucked downstream of the electrolyzer 40. Since the suction means 60 is provided, it becomes easy to operate while maintaining the inside of the electrolytic cell 40 at a negative pressure, and an insoluble gas such as hydrogen gas generated in the electrolytic cell 40 is sucked to be used in the electrolytic cell 40. It can be discharged quickly to improve the efficiency of electrolysis. Thereby, since the electric power converted into heat can be suppressed, the temperature rise of the electrolytic cell can be suppressed, and inconveniences such as deterioration over time of the electrode and the electrolytic cell can be suppressed.

Since the ejector is provided as the suction means 60 at the junction of the first dilution water flow path 10 and the electrolyzed water discharge path 51, the kinetic energy of the dilution water supplied from the first dilution water flow path 10 can be used effectively. .
Since the mixer 54 is provided downstream of the suction means 60, the dissolution of chlorine in water and the mixing of electrolytic water and dilution water can be promoted.

Since the outlet 42 of the electrolytic cell 40 is opened in the upper part of the electrolytic cell main body 47, it becomes easy to discharge the gas generated on the surface of the electrode from the outlet 42, and the gas stays inside the electrolytic cell 40. Can be suppressed.
Since each electrode plate 44, 45, 46 of the electrolytic cell 40 is disposed so as to rise in the vertical direction, the space between the electrodes 44, 45, 46 is opened upward, and the gas is between the electrodes 44, 45, 46. It can suppress staying in the space.
Since the inlet 41 of the electrolytic cell 40 is provided on the anode 44 side and the outlet 42 is provided on the cathode 45 side, the residence time of the raw material water in the electrolytic cell 40 is ensured, and chloride ions contained in the raw material water are retained. Electrolytic oxidation can proceed efficiently and the yield of chlorine and hypochlorous acid can be improved.
Since the dilution water mixed with the hydrochloric acid aqueous solution can be temporarily stored in the dilution water tank on the upstream side of the electrolytic cell and then sent to the electrolytic cell, the dilution on the upstream side of the dilution water pump 25 (quantitative water supply means) The flow of water can be made more stable, the flow rate can be controlled more reliably, and even if the flow rate of the dilution water from the dilution water inlet 11 is temporarily reduced, The flow rate of the dilution water on the second dilution water channel 20 side can be reliably maintained.

In the electrolyzed water production apparatus of the present invention, the dilution water tank 21 can be omitted as shown in FIG. 3, the same reference numerals as those shown in FIG. 1 indicate the same or similar configurations as those shown in FIG. 1, and redundant description may be omitted.
In the electrolyzed water production apparatus 1A according to the modified example shown in FIG. 3, the second dilution water flow path 20 is branched from between the check valve 18 of the first dilution water flow path 10 and the drain 10a. It has a dilution water pump as means 25 and a check valve 26 provided downstream thereof.

According to the electrolyzed water production apparatus 1A, like the electrolyzed water production apparatus 1 shown in FIG. 1, it becomes easy to operate while maintaining the inside of the electrolyzer 40 at a negative pressure. The generated insoluble gas such as hydrogen gas can be sucked and quickly discharged out of the electrolytic cell 40 to improve electrolysis efficiency. Thereby, since the electric power converted into heat can be suppressed, the temperature rise of the electrolytic cell can be suppressed, and inconveniences such as deterioration over time of the electrode and the electrolytic cell can be suppressed.
In addition, since the configuration of the electrolyzed water production apparatus 1A can be simplified by omitting the dilution water tank and the like, the installation space and the like of the electrolyzed water production apparatus 1A can be saved.

Since the test example was implemented in order to confirm the effect of this invention, it demonstrates below.
First, the measurement method used when measuring various physical properties of raw water and / or electrolyzed water in each test example described below is shown below.

(Measurement method of pH)
The measurement was performed using a pH meter (model number PH81 No. 62852) manufactured by Yokogawa Electric Corporation or a pH meter (model number B-211 No. 8010214) manufactured by Horiba, Ltd.

(Measurement method of hardness)
Total hardness was measured using a drop test reagent (model number WAD-TH) manufactured by Kyoritsu Riken.
(Measurement method of flow rate of dilution water)
It measured using the Yokogawa Electric Corporation electromagnetic flowmeter (AXF050G, No. S5D603536 431).
(Used hydrochloric acid)
Pure Starmate 21 (hydrogen chloride 21%) manufactured by Clean Chemical Industry Co., Ltd. was used.

(Measurement method of effective chlorine concentration of electrolyzed water by iodine titration method)
[Reagents]
・ 0.01 mol / L sodium thiosulfate normal solution for titration ・ Potassium iodide aqueous solution (2 teaspoons dissolved in 100 mL water and stored in brown bottle)
・ Acetic acid aqueous solution (diluted in half with water and stored in brown bottle)
・ Aqueous soluble starch solution (1 tablespoon dissolved in 100 mL of hot water and refrigerated)
[Equipment]
・ Bullet (Simple pipette or syringe can be used instead)
・ Erlenmeyer flask (Nominal volume 300 mL or 500 mL)
-Three droppers (dedicated for potassium iodide aqueous solution, acetic acid aqueous solution, and soluble starch aqueous solution, respectively)
・ Measuring cylinder (capable of weighing 200 mL)
[Operating procedure]
1. Using a graduated cylinder, measure 200 mL of electrolyzed water.
2. Transfer the measured electrolyzed water to an Erlenmeyer flask.
3. Add 1 drop of potassium iodide aqueous solution to electrolyzed water using a dropper and stir (present yellow after mixing).
4). Add 1 drop of acetic acid aqueous solution to electrolyzed water using a dropper and stir.
5. Turn the flask to mix.
6). Put the sodium thiosulfate normal solution in the burette and record the liquid level reading (the reading at this time is a mL).
7). Gradually open the cock of the burette, and drop the sodium thiosulfate normal solution while stirring the Erlenmeyer flask (the yellow color of the liquid gradually becomes thinner).
8). When the yellow color of the liquid becomes thin, add 1 drop of starch aqueous solution using a dropper and stir (present purple after mixing)
9. The dropwise addition of the sodium thiosulfate normal solution is continued until the purple color of the liquid disappears, and the reading of the liquid level when the purple color disappears is recorded (the reading at this time is b mL).
10. The effective chlorine concentration [ppm] is calculated by the formula (ba) × 1.77.

(Test Example 1)
The electrolytic water production apparatus 1A having the configuration of FIG. 3 is used to adjust the flow rate of dilution water flowing from the dilution water inlet to 1200 L / h and adjust the internal pressure of the electrolytic cell to be maintained at −0.05 MPa. Water was produced. Prior to electrolysis, a pressure gauge for measuring the internal pressure of the electrolytic cell 40 was installed near the inlet 41 of the electrolytic cell 40. When the hardness and pH of the dilution water used were measured, the hardness was 90 and the pH was 7.36.
The electrolyzed water production apparatus was continuously operated with an electrolysis voltage of 42 V and an electrolysis current of 1.6 A. The electrolyzed water discharged from the electrolyzed water outlet was obtained every 30 minutes over 7 hours from 9:30 to 16:30, and the effective chlorine concentration and pH of the electrolyzed water were measured.
Further, the level of the hydrochloric acid tank was measured after the start of operation and before the end of operation, and the consumption of hydrochloric acid used during the operation was calculated based on this. During 6 hours and 23 minutes, 0.69 kg of hydrochloric acid was consumed, and the consumption of aqueous hydrochloric acid in the hydrochloric acid tank was 0.108 kg per hour.
The results of Test Example 1 are shown in Table 1. FIG. 4 is a graph showing the changes over time in the effective chlorine concentration and pH of the electrolyzed water in Test Example 1.

(Test Example 2)
Using a conventional electrolyzed water production apparatus in which an ejector is not provided at the junction of the first diluting water flow path and the electrolyzed water discharge path, the flow rate of diluting water flowing from the diluting water inlet is set to 1200 L / h. Manufactured. When the hardness and pH of the dilution water used were measured, the hardness was 80 and the pH was 7.05. The concentration of the aqueous hydrochloric acid solution used is the same as in Test Example 1.
The electrolyzed water production apparatus was continuously operated with an electrolysis voltage of 42 V and an electrolysis current of 1.7 A. The electrolyzed water discharged from the electrolyzed water outlet was obtained every 30 minutes over 7 hours from 9:30 to 16:30, and the effective chlorine concentration and pH of the electrolyzed water were measured.
Further, the level of the hydrochloric acid tank was measured after the start of operation and before the end of operation, and the consumption of hydrochloric acid used during the operation was calculated based on this. During 7 hours and 30 minutes, 1.59 kg of hydrochloric acid was consumed, and the consumption of aqueous hydrochloric acid in the hydrochloric acid tank was 0.212 kg per hour.
The results of Test Example 2 are shown in Table 2. FIG. 5 is a graph showing the changes over time in the effective chlorine concentration and pH of the electrolyzed water in Test Example 2.

(Contrast of the results of Test Example 1 and Test Example 2)
Comparing the results of Test Example 1 and Test Example 2, the amount of hydrochloric acid required to produce electrolyzed water having an effective chlorine concentration of about 15 ppm is about half that of Test Example 2 in Test Example 1. I understand. From this, it was confirmed that the electrolyzed water production apparatus of the present invention provided with an ejector has extremely good electrolysis efficiency as compared with the conventional electrolyzed water production apparatus.

(Test Example 3)
The electrolytic water production apparatus 1A having the configuration of FIG. 3 is used to adjust the flow rate of dilution water flowing from the dilution water inlet to 1200 L / h and adjust the internal pressure of the electrolytic cell to be maintained at −0.05 MPa. Water was produced. Prior to electrolysis, a pressure gauge for measuring the internal pressure of the electrolytic cell 40 was installed near the inlet 41 of the electrolytic cell 40. When the hardness and pH of the dilution water used were measured, the hardness was 85 and the pH was 7.13. The concentration of the aqueous hydrochloric acid solution used is the same as in Test Example 1.
The electrolyzed water production apparatus was continuously operated with an electrolysis voltage of 42 V and an electrolysis current of 2.6 A. The electrolyzed water discharged from the electrolyzed water outlet was obtained every 30 minutes over 7 hours and 30 minutes from 9:00 to 16:30, and the effective chlorine concentration and pH of the electrolyzed water were measured.
Further, the level of the hydrochloric acid tank was measured after the start of operation and before the end of operation, and the consumption of hydrochloric acid used during the operation was calculated based on this. During 7 hours and 45 minutes, 1.42 kg of hydrochloric acid was consumed, and the consumption of aqueous hydrochloric acid in the hydrochloric acid tank was 0.183 kg per hour.
The results of Test Example 3 are shown in Table 3. FIG. 6 is a graph showing changes in the effective chlorine concentration and pH of electrolyzed water in Test Example 3 over time.

  According to the results of Test Example 3, the amount of hydrochloric acid required for producing electrolyzed water having an effective chlorine concentration of about 30 ppm by the electrolyzed water producing apparatus of the present invention is approximately equal to the effective chlorine concentration by the conventional electrolyzed water producing apparatus. The amount was slightly less than the amount of hydrochloric acid consumed to produce 15 ppm electrolyzed water. From this, it was confirmed that the electrolyzed water production apparatus of the present invention provided with an ejector has extremely good electrolysis efficiency as compared with the conventional electrolyzed water production apparatus.

(Test Example 4)
In the electrolyzed water producing apparatus 1A having the configuration of FIG. 3, electrolyzed water was produced 6 times with the flow rate of diluting water flowing from the diluting water inlet being 1200 L / h (test numbers 4-1 to 4-6 and I will call it). Prior to electrolysis, a pressure gauge for measuring the internal pressure of the electrolytic cell 40 was installed near the inlet 41 of the electrolytic cell 40.
While measuring the internal pressure of the electrolytic cell, it was operated by changing the internal pressure of the electrolytic cell, and the effective chlorine concentration and pH of the electrolytic water discharged from the electrolytic water outlet were measured.
During the operation of Test Example 4, the hardness of the dilution water was in the range of 80 to 85, and the pH of the dilution water was in the range of 6.4 to 7.2.
The results of Test Example 4 are shown in Table 4 and Table 5. FIG. 7 is a graph showing the relationship between the internal pressure of the electrolytic cell and the effective chlorine concentration of the electrolyzed water in Test Example 4. FIG. 8 is a graph showing the relationship between the internal pressure of the electrolytic cell and the pH of the electrolyzed water in Test Example 4.

  When operating with the internal pressure of the electrolytic cell lowered to a pressure of less than -0.04 MPa, the effective chlorine concentration is reduced even when the electrolytic current and the electrolytic voltage are the same as compared with the case of operating at -0.04 MPa or more. It is increasing and the pH value is also decreasing. That is, it is clear that the electrolysis efficiency is improved if the internal pressure of the electrolytic cell is lowered to a pressure of less than -0.04 MPa. In order to obtain the effect of improving the efficiency of electrolysis more reliably, it is preferable to operate by reducing the internal pressure of the electrolytic cell to −0.05 MPa or less.

(Test Example 5)
In the electrolyzed water production apparatus 1A having the configuration of FIG. 3, electrolyzed water was produced four times with the flow rate of the diluting water flowing from the diluting water inlet set to 10000 L / h (each of test numbers 5-1 to 5-4 and I will call it). Prior to electrolysis, a pressure gauge for measuring the internal pressure of the electrolytic cell 40 was installed near the inlet 41 of the electrolytic cell 40.
Measure the effective chlorine concentration and pH of the electrolyzed water discharged from the outlet of the electrolyzed water while measuring the internal pressure of the electrolyzer and changing the internal pressure of the electrolyzer to -0.03 MPa and -0.09 MPa. did.
During the operation of Test Example 5, the hardness of the dilution water was in the range of 85 to 100, and the pH of the dilution water was in the range of 6.5 to 6.7.
The results of Test Example 5 are shown in Table 6. FIG. 9 is a graph showing the relationship between the internal pressure of the electrolytic cell in Test Example 5 and the effective chlorine concentration of the electrolyzed water.

  When operating with the internal pressure of the electrolytic cell lowered to -0.09 MPa, the effective chlorine concentration of the electrolyzed water is about 1.5 times that of operating at -0.03 MPa, in other words It is clear that the power efficiency has increased by about 1.5 times, and the electrolysis efficiency is high. That is, the result of Test Example 4 that the electrolysis efficiency is improved if the internal pressure of the electrolytic cell is lowered to a pressure of less than −0.04 MPa was confirmed even in the case of a dilution water flow rate of 10,000 L / h.

(Test Example 6)
In the electrolyzed water production apparatus 1A having the configuration of FIG. 3, electrolyzed water was produced with the flow rate of the diluting water flowing from the diluting water inlet set to 10000 L / h. Prior to the electrolysis, a pressure gauge for measuring the internal pressure of the electrolytic cell 40 was installed in the vicinity of the inlet 41 of the electrolytic cell 40, and a thermometer for measuring the temperature of the anode 44 and the cathode 45 was installed in the electrolytic cell 40. .

Test number 6-1 was adjusted and operated so that the internal pressure of the electrolytic cell was maintained at -0.03 MPa, and the pH and effective chlorine concentration of the electrolyzed water discharged from the electrolyzed water outlet, and the temperatures of the anode and the cathode Was measured.
In addition, when the hardness and pH of the dilution water were measured during the operation of Test No. 6-1, the hardness of the dilution water was 75 and the pH of the dilution water was 6.4.
The results of test number 6-1 are shown in Table 7. FIG. 10 is a graph showing the changes over time in the effective chlorine concentration and pH of the electrolyzed water and the electrode temperature in Test No. 6-1.

Test number 6-2 was adjusted and operated so that the internal pressure of the electrolytic cell was maintained at -0.09 MPa. The pH and effective chlorine concentration of the electrolyzed water discharged from the electrolyzed water outlet, and the temperatures of the anode and the cathode Was measured.
In addition, when the hardness and pH of the dilution water were measured during the test No. 6-2, the dilution water hardness was 65 and the dilution water pH was 6.4.
The results of test number 6-2 are shown in Table 8. FIG. 11 is a graph showing the changes over time in the effective chlorine concentration and pH of the electrolyzed water and the electrode temperature in Test No. 6-2.

As can be seen from the comparison between the test number 6-1 and the test number 6-2, when the internal pressure of the electrolytic cell was lowered to -0.09 MPa, the operation was performed at -0.03 MPa. It is clear that the electrolysis efficiency is high because the effective chlorine concentration of the electrolyzed water is large.
Further, regarding the temperature of the electrode, when the internal pressure is -0.03 MPa, the temperature rises to 55 ° C. or more when one hour or more has elapsed from the start of the operation, whereas when the internal pressure is −0.09 MPa. It rises only to about 32-37 ° C. Moreover, when operated at an internal pressure of -0.09 MPa, the anode temperature increased by + 3.0 ° C. and the cathode temperature increased by + 3.5 ° C. in 20 minutes from 9:55 to 10:15, whereas 10:15 From 30 to 10:45, the anode temperature was only + 0.6 ° C. and the cathode temperature was only + 1.1 ° C., and the temperature increase tended to slow down as the operation continued. That is, it is clear that the temperature rise of the electrolytic cell is suppressed by using the method for producing electrolyzed water of the present invention.
Therefore, according to the present invention, the life of the electrode, which is considered to be greatly affected by the temperature, is greatly extended, and the maintenance work cost and cost burden can be reduced.

It is a schematic block diagram which shows the example of 1 form of the electrolyzed water manufacturing apparatus of this invention. (A) Longitudinal sectional view showing an example of an ejector in the electrolyzed water production apparatus of the present invention, (b) an end view on the driving fluid inlet side, (c) an end view on the driven fluid inlet side, (d) an end face on the outlet side FIG. It is a schematic block diagram which shows the modification of the electrolyzed water manufacturing apparatus of this invention. 6 is a graph showing changes in effective chlorine concentration and pH of electrolyzed water in Test Example 1 over time. 6 is a graph showing changes in effective chlorine concentration and pH of electrolyzed water in Test Example 2 over time. 6 is a graph showing changes over time in effective chlorine concentration and pH of electrolyzed water in Test Example 3. 6 is a graph showing the relationship between the internal pressure of an electrolytic cell and the effective chlorine concentration of electrolytic water in Test Example 4. 6 is a graph showing the relationship between the internal pressure of an electrolytic cell and the pH of electrolyzed water in Test Example 4. 10 is a graph showing the relationship between the internal pressure of an electrolytic cell and the effective chlorine concentration of electrolytic water in Test Example 5. It is a graph which shows the time-dependent change of the effective chlorine concentration of electrolytic water and pH in the test number 6-1 of the test example 6, and the temperature of an electrode. It is a graph which shows the time-dependent change of the effective chlorine concentration of electrolytic water and pH in the test number 6-2 of Test Example 6, and the temperature of an electrode.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1,1A ... Electrolyzed water manufacturing apparatus, 10 ... Dilution water flow path, 25 ... Fixed quantity water supply means (dilution water pump), 40 ... Electrolyzer, 41 ... Inlet of electrolyzer, 42 ... Outlet of electrolyzer, 44, 45, 46 ... Electrode, 54 ... Mixer, 60 ... Suction means (ejector).

Claims (7)

An electrolyzed water production apparatus that electrolyzes raw water in an electrolyzer to generate electrolyzed water,
The electrolytic cell is a continuous electrolytic cell through which raw water is passed while maintaining a flow from the inlet to the outlet of the electrolytic cell, and the raw material water is flowed at a constant flow rate upstream of the electrolytic cell. An apparatus for producing electrolyzed water, characterized in that a quantitative water supply means for supplying the electrolyzer is provided, and a suction means for sucking the inside of the electrolyzer is provided downstream of the electrolyzer.   A flow path for dilution water for diluting the electrolyzed water discharged from the electrolysis tank is joined downstream of the electrolysis tank, and the suction means is provided at a junction with the dilution water flow path, and the dilution water is provided. The electrolyzed water manufacturing apparatus according to claim 1, wherein the electrolyzed water manufacturing apparatus is an ejector that uses as a driving fluid.   The electrolyzed water production apparatus according to claim 1 or 2, wherein a mixer is provided downstream of the suction means.   The electrolyzed water production apparatus according to any one of claims 1 to 3, wherein an outlet of the electrolytic cell is opened at an upper part of the electrolytic cell.   5. The electrolyzed water production apparatus according to claim 1, wherein an electrode is installed in the electrolytic cell so that a flow path formed between the electrodes communicates in a vertical direction. A method for producing electrolyzed water in which raw water is electrolyzed in an electrolytic cell to produce electrolyzed water,
The raw water is passed through so as to keep the flow from the inlet to the outlet of the electrolytic cell inside the electrolytic cell, and the internal pressure of the electrolytic cell is maintained at a negative pressure of less than -0.04 MPa. A method for producing electrolyzed water.   A fixed amount water supply means is provided on the inlet side of the electrolytic cell to supply the raw water to the electrolytic cell at a constant flow rate, and a suction means is provided on the outlet side of the electrolytic cell to suck the inside of the electrolytic cell. The method for producing electrolyzed water according to claim 6.

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