JP2001327970A - Strongly acidic water generating method and device therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a strong acidic water generating method and its device, capable of preventing metal such as metallic calcium from precipitating onto each electrode thereby keeping electrolysis over a continuous long time and producing strongly acidic water having a high sterilizing effect. SOLUTION: Soft water and salt water are mixed, and the resultant mixed water is subjected to electrolysis to generate the strongly acidic water. This strongly acidic water generating device is provided with a water softener which generates soft water by using an ion exchange resin, a salt water tank which stores salt water for the regeneration of the ion exchange resin, and an electrolysis tank which electrolyzes the soft water from the water softener and the salt water from the salt water tank in the mixed state.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing strongly acidic water and an apparatus therefor.

[0002]

2. Description of the Related Art Conventionally, acidic water and alkaline water are produced by electrolyzing water. During the electrolysis, an anion (eg, a hydroxyl ion, a chlorine ion, etc.) is applied to a positive electrode. ) Is discharged, the hydroxyl ions are changed to water and oxygen gas, and the chloride ions are changed to chlorine gas. At the negative electrode, cations (hydrogen ions, calcium ions, etc.) are charged, hydrogen ions are changed to hydrogen gas, and calcium ions are precipitated as metal calcium. That is, oxygen gas and chlorine gas are generated at the positive electrode, and hydrogen gas and metal such as metallic calcium are generated at the negative electrode. Therefore, around the positive electrode, the amount of hydroxyl ions decreases, and chlorine gas is generated. In the vicinity of the negative electrode, hydrogen ions decrease, and the concentration of hydrogen ions decreases with respect to the concentration of hydroxyl ions, so that the water becomes alkaline water. The acidic water generated by the electrolysis of the water is used for disinfection as sterilizing water.

[0003]

When water is electrolyzed, acidic water and alkaline water can be obtained. However, in this case, scale is attached to the electrode, and the electrolysis cannot be maintained for a continuous long period. In addition, since the acidity of the acidic water cannot be maintained so high, the sterilizing effect cannot be expected so much. Therefore, in the present invention, in view of the above problems, a method capable of obtaining a highly acidic water having a high sterilizing effect without maintaining a continuous long-time electrolysis without attaching a metal such as metallic calcium to each electrode. It is intended to provide a device.

[0004]

Means for Solving the Problems The present invention has been made to solve the above problems, and the invention according to claim 1 is to mix soft water and salt water and electrolyze the mixed water. It is characterized by producing strongly acidic water.

Further, the invention according to claim 2 provides a water softener for generating soft water using an ion exchange resin, a salt water tank for storing the salt water for regenerating the ion exchange resin, and a soft water from the water softener. An electrolysis tank is provided for performing electrolysis in a state of being mixed with the salt water from the salt water tank.

[0006]

Next, an embodiment of the present invention will be described. INDUSTRIAL APPLICATION This invention can be implemented as the production | generation method and apparatus which produce | generate strongly acidic water. Here, this strongly acidic water is used, for example, for disinfection in a cafeteria or a hospital, and has a pH of about 2.5.
It is.

First, the method for producing strongly acidic water according to claim 1 is characterized in that soft water and salt water are mixed, and the mixed water is electrolyzed to produce strongly acidic water. Prevents scale adhesion and efficiently produces strongly acidic water continuously over a long period of time. Here, the soft water is generated using a water softener. This water softener uses a cation exchange resin, and the salt water is supplied by dissolving the salt to an appropriate concentration in a salt water tank. Then, soft water and salt water are supplied to the electrolysis tank, and the mixed water obtained by mixing both is electrolyzed to obtain strongly acidic water.

Next, a strongly acidic water generator according to a second aspect of the present invention includes a water softener for generating soft water using a cation exchange resin, a salt water tank for storing the salt water for regenerating the cation exchange resin, An electrolysis tank for performing electrolysis in a state in which soft water from the water softener and salt water from the salt water tank are mixed is provided, and salt water for regeneration of the water softener and generation of strongly acidic water is provided. Is generated in one salt water tank, and the salt water tank is shared, thereby making the configuration of the entire apparatus compact. Further, by disposing a water refilling port for the salt water tank above the salt and replenishing with a spray, the dissolution of the salt can be accelerated. Here, during the generation of strongly acidic water,
The salt water is constantly generated, and the soft water is generated by the water softener. On the other hand, in the regeneration step of the water softener, the soft water is not generated and supplied by the water softener, and accordingly, the generation of the strong acid water is not performed. In other words, the salt water generated in the salt water tank during the regeneration step must be supplied for regeneration of the water softener, not for the production of the strongly acidic water.

Further, the salt water tank is provided with a salt receiving plate for storing the salt, and the salt is replenished for dissolving the salt to maintain a constant water level. Produces saturated brine. Here, in order to maintain the water level in the salt water tank, a water level sensor is provided to perform water replenishment control. In addition, a salt water well is provided in the salt water tank, and water is replenished in the salt water well, or the salt water is supplied to the electrolysis tank by suction. The saturated salt water is maintained in the salt water line without being clogged by lump or garbage, and is supplied to the electrolysis tank.

Here, in order to electrolyze water to obtain strongly acidic water, it is necessary to add about 600 to 800 ppm of sodium chloride to soft water. Here, by using soft water, precipitation of a metal such as calcium metal on the electrode is prevented. Further, in general, soft water hardly contains chloride ions, and therefore does not show so strong acidity even when electrolysis is performed. Thus, by adding sodium chloride to water, not only hydroxyl ions but also chloride ions are present around the positive electrode. As a result, chlorine is generated around the positive electrode. The chlorine generated here dissolves in water and becomes hydrochloric acid and hypochlorous acid, so that acidic water is generated around the positive electrode. In addition, hydrogen ions and sodium ions exist around the negative electrode, and the conversion of hydrogen ions to hydrogen is preferentially performed. Then, as the hydrogen ions decrease, water is dissociated, and a reaction is performed to compensate for the decrease in the hydrogen ions, so that the hydroxyl ions also increase, so that the hydroxide ions and the sodium ions are present as sodium hydroxide. become. Therefore, alkaline water is generated around the negative electrode. Here, the salt water is generated in the salt water tank. Since the solubility of the saturated salt water reaches about 22%, it is necessary to dilute the salt water having a concentration suitable for electrolysis with soft water, and to use the diluted salt water concentration. , It is desirable that the saturated salt water concentration is also constant.

Further, in the water softener, the salt water for regenerating the cation exchange resin can be used freely except in the regeneration step. Therefore, the salt water tank for storing the salt water used for obtaining the strongly acidic water and the salt water tank for the water softener can be shared.

As described above, in the present invention, a strongly acidic water is generated by electrolyzing a diluted salt water produced by mixing salt water with soft water. Further, since soft water is used, adhesion of a metal such as metal calcium to the electrode can be eliminated. Further, in the strongly acidic water generating apparatus, the salt water tank can be shared and a compact configuration can be achieved.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A specific embodiment of the present invention will be described below with reference to FIG. The strongly acidic water production apparatus stores raw water in a resin tank 1 for storing a cation exchange resin (not shown), and a softener 2 for generating soft water by performing cation exchange. It comprises a salt water tank 4 for generating salt water while dissolving in raw water, and an electrolysis tank 5 for mixing and softening soft water supplied from the water softener 2 and salt water supplied from the salt water tank 4. .

First, the resin tank 1 accommodates the cation exchange resin and feeds raw water from a raw water line 6 to convert the hardness components such as calcium ions and magnesium ions into sodium ions by the cation exchange resin. And ion exchange hard water into soft water. Then, the soft water is supplied to the electrolysis tank 5 through the water supply line 7. Further, the resin tank 1 is provided with a drain line 8 for draining water during regeneration.
Is provided. Here, a water flow valve 10 is provided in the raw water line 6.

Next, the salt water tank 4 is provided with a salt receiving plate 11 for supporting the salt 3 therein, and a salt water well 12 for partitioning the salt water tank 4 so as to communicate with each other. Then, raw water is supplied from the water supply line 13 branched from the raw water line 6 into the salt water tank 4 to generate saturated brine. The saturated salt water is sucked from a salt water suction port 14 disposed below the salt water well 12 and supplied to the electrolysis tank 5 through a salt water line 15. The supply of the saturated salt water is performed by a pump 16 provided in the salt water line 15. Here, the salt water line 1
5 is configured to be connected to the electrolysis tank 5 by merging with the water flow line 7. That is, it merges with the water flow line 7 on the upstream side of the electrolysis tank 5, and an on-off valve 17 is provided between the junction and the electrolysis tank 5.

The salt water is generated in the salt water tank 4 by dissolving the salt 3 placed on the salt receiving plate 11 into raw water replenished via the water refilling line 13. The salt receiving plate 11 is provided at an appropriate height of the salt water tank 4, and the salt 3 placed on the upper surface is immersed in the salt water tank 4 by refilling. In order to keep the water level in the salt water tank 4 constant, a water level sensor 18 is provided in the salt water well 12 and the detected water level of the water level sensor 18 is controlled by a controller 19.
And the water refill valve 2 arranged in the water refill line 13
Water level control is performed by electromagnetically opening and closing 0. For this reason, the salt 3 of the salt receiving plate 11 maintains the immersion at a constant water depth, thereby reducing the precipitation and accumulation of the salt 3 on the bottom of the salt water tank 4. Here, a configuration in which the water level sensor 18 is provided in the salt water tank 4 is also suitable for implementation.

A water supply port 21 provided at the end of the water supply line 13 is opened above the inside of the salt water tank 4, and water is supplied from the water supply port 21 to the salt 3 in a spray form. Thereby, the dissolution of the salt 3 can be accelerated. On the other hand, the inside of the salt water well 12 is separated from the salt water tank 4, and even if there is undissolved salt precipitated in the salt water tank 4, the salt water suction port 1 is formed.
4, the salt 3 is not clogged in the salt water line 15, and the supply of the saturated salt water can be performed accurately.

Here, a description will be given of a modified example of the opening position of the water supply port 21. The opening position of the opening 21 is not limited to the upper part inside the salt water tank 4, but the inside of the salt water well 12 depending on the implementation. A configuration that opens upward is also suitable. According to this configuration, since the salt water suction port 14 of the salt water line 15 is opened below the inside of the salt water well 12, the salt water in the salt water tank 4 is not stirred, and the water is gently replenished. By causing the salt water to be supplied, the saturated salt water is generated, and the supply of the salt water to the electrolysis tank 5 can be stably performed.

In the electrolysis tank 5, the salt water diluted with the soft water (diluted salt water) is electrolyzed by energization between the positive electrode 22 and the negative electrode 23, and strong acid is supplied from the periphery of the positive electrode 22. Water is taken out, and strongly alkaline water is taken out from around the negative electrode 23.
Further, a diaphragm 24 is provided between the two electrodes 22 and 23, an acidic water line 25 is provided on the positive electrode 22 side with the diaphragm 24 as a boundary, and an alkaline water line 26 is provided on the negative electrode 23 side. I have.

Here, the strong acid water is generated by mixing the soft water of the water softener 2 and the salt water of the salt water tank 4 into the electrolytic bath 5 and mixing the supplied diluted salt water with the electric water. This is done by disassembly. By adding an aqueous solution of sodium chloride, that is, diluted saline, not only hydroxyl ions but also chloride ions are present around the positive electrode 22. As a result, in the vicinity of the positive electrode 22, the discharge of chlorine ions is prioritized over the discharge of hydroxyl ions, and chlorine is generated. Due to the chlorine generated here, a solution having a high acidity is generated around the positive electrode 22. Also,
Hydrogen ions and sodium ions are present around the negative electrode 23, and the conversion of hydrogen ions to hydrogen is preferentially performed. And with the decrease of hydrogen ions,
By dissociating water and making a reaction to compensate for the decrease in hydrogen ions, hydroxyl ions increase, and hydroxyl ions and sodium ions exist as sodium hydroxide. for that reason,
Around the negative electrode 23, alkaline water is generated.

Next, the operation of the above configuration will be described. Raw water is passed from the raw water line 6 to the resin tank 1, where it becomes soft water and supplied from the water flow line 7 to the electrolysis tank 5. Is done. The salt water tank 4
In the above, water is supplied into the salt water tank 4 via the water supply line 13 by the water supply valve 20 controlled by the water level detection of the water level sensor 18. Rehydration at this time,
Since the spraying is performed from above the salt 3, the salt concentration is improved early. And by this water replenishment control, the salt water level in the salt water tank 4 is always kept almost constant.

Further, even when water is supplied to the salt water well 12, the salt water level in the salt water tank 4 is always maintained substantially constant by the water supply control.

Now, the regeneration step of the cation exchange resin will be described. In the regeneration step, the on-off valve 17 is closed and the drain valve 9 is opened.
By driving the pump 16, the salt water is sucked from the salt water well 12 into the salt water line 15, and the salt water flows back through the water flow line 7 to be supplied to the upper portion of the resin tank 1. The salt water supplied to the upper part of the resin tank 1 regenerates the cation exchange resin while descending the cation exchange resin layer, and is discharged from the drain line 8 to the outside. Further, since the salt water is used for the regeneration of the cation exchange resin, the supply of the salt water to the electrolysis tank 5 is stopped. Accordingly, during the regeneration step, since the supply of the soft water and the supply of the salt water are not performed to the electrolysis tank 5, the production of the strongly acidic water is stopped.

The generated salt water is switched and supplied to the electrolysis tank 5 and the resin tank 1 by the on-off valve 17 so that the generation of the strongly acidic water and the regeneration step are performed without overlapping. Let it. In addition, even in a water passing step that does not require salt water, salt water is generated, and the salt water is supplied to the electrolysis tank 5 to generate strongly acidic water by electrolysis. Therefore, since the salt water is constantly generated, the saturated salt water can be supplied in a substantially continuous state, and the salt water concentration due to the dissolution of the salt 3 can be stabilized.

Further, since electrolysis is performed using the soft water generated in the water softener 2 in a state where the hardness component has been removed, a metal such as metal calcium does not adhere to the electrode, and high performance is achieved. Generation of strongly acidic water can be maintained.

[0026]

As described above, by mixing soft water and salt water and then performing electrolysis, it is possible to prevent the adhesion of metals such as metal calcium to the electrodes during the electrolysis, and to lengthen the strongly acidic water. It can be efficiently produced continuously over time. Further, since the salt water for regeneration of the water softener and the salt water for generating the strongly acidic water can be supplied from the same salt water tank, the salt water tank can be shared and the configuration of the entire apparatus can be made compact.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram of a block circuit of a strongly acidic water generating apparatus according to an embodiment of the present invention.

[Explanation of symbols]

 2 water softener 4 salt water tank 5 electrolysis tank

Claims (2)

[Claims] 1. A method for producing strongly acidic water, comprising mixing soft water and salt water, and electrolyzing the mixed water to produce strongly acidic water. 2. A water softener 2 for generating soft water using an ion exchange resin, a salt water tank 4 for storing the salt water for regenerating the ion exchange resin, a soft water from the water softener 2 and a soft water from the salt water tank 4. A strongly acidic water generator, comprising an electrolysis tank 5 for electrolyzing in a state of being mixed with salt water.