KR20240058269A - Method for manufacturing sterilized water containing hypochlorous acid through pH adjustment - Google Patents

Abstract

The present invention includes the steps of (a) passing raw water through a filter unit including an H-type cation exchange resin filter to lower the pH of the water to 6 or less; and (b) electrolyzing the water having a pH of 6 or less prepared in step (a) in a diaphragmless electrolysis device.

Description

Method for manufacturing sterilized water containing hypochlorous acid through pH adjustment}

The present invention relates to a method for producing hypochlorous acid sterilizing water, and specifically, to a method of increasing the content of hypochlorous acid (HOCl) in sterilizing water by lowering the pH of raw water in advance.

As living standards improve, the number of people pursuing well-being is gradually increasing. Additionally, in accordance with this trend, interest in sterilization to keep living spaces clean is gradually increasing.

As a conventional sterilization method, a sterilization method using hypochlorous acid (HOCl) or chlorous acid (HClO ₂ ) is widely known. Hypochlorous acid (HOCl) or chlorous acid (HClO ₂ ) has a wide range of sterilization targets, has an immediate sterilizing effect, and is completely non-toxic in the appropriate pH range, so it can be used for a variety of purposes, from drinking water such as tap water to sterilizing food and medicine. It is being used. In particular, hypochlorous acid (HOCl) has excellent sterilizing power and is highly safe, so it is attracting attention in the sterilization field.

Recently, various sterilizing water production devices have become popular, improving the convenience of sterilization. The sterilizing water production device is a device that produces sodium hypochlorite (NaOCl) and/or hypochlorous acid (HOCl) water by electrolyzing salt in water. The sterilizing water production device can be classified into a diaphragm electrolysis device and a non-diaphragm electrolysis device. The diaphragm electrolysis device is characterized by a diaphragm that allows electronic ions to pass between the anode and the cathode, and is non-diaphragm. Compared to the formula, the device is complex and expensive.

In the case of a non-diaphragm electrolysis device, the device structure is simple and the price is low, so consumers can purchase and use it without burden, and it has the advantage of being easy to carry. However, when electrolysis is performed with salt in a non-diaphragm electrolysis device, sodium hypochlorite (NaOCl) is mainly produced as the pH rises. Sodium hypochlorite (NaOCl) has significantly greater sterilizing power compared to hypochlorous acid (HOCl). It has the disadvantage of being low. In addition, sodium hypochlorite (NaOCl) is known to be the main ingredient of bleach, which causes consumers to hesitate to use it regardless of its actual safety.

Therefore, in order to improve this disadvantage, a method of increasing the concentration of hypochlorous acid by adding a small amount of hydrochloric acid (HCl) during electrolysis of salt water to lower the pH is used. However, the reality is that hydrochloric acid is difficult for consumers to handle, and consumer awareness of the use of hydrochloric acid is not good.

Republic of Korea Patent No. 10-0853347

The present invention was devised to solve the above problems of the prior art,

As a method of producing sterilizing water by non-diaphragm electrolysis, it is possible to safely produce sterilizing water containing a high concentration of hypochlorous acid (HOCl) by lowering the pH of raw water before electrolysis without using acids such as hydrochloric acid. The purpose is to provide a manufacturing method and manufacturing device for hypochlorous acid sterilizing water.

In order to achieve the above object, the present invention

(a) passing raw water through a filter unit including an H-type cation exchange resin filter to lower the pH of the water to 6 or less; and

(b) electrolyzing the water with a pH of 6 or less prepared in step (a) in a diaphragmless electrolysis device; providing a method for producing hypochlorous acid sterilizing water, including the step.

In addition, the present invention

An electrolyzer containing a diaphragm-less electrolyzer; and

It includes a filter unit that is coupled to the electrolyzer and filters raw water flowing in,

The filter unit includes an H-type cation exchange resin filter, and the H-type cation exchange resin filter is provided to lower the pH of the incoming water to 6 or less.

The method for producing hypochlorous acid sterilizing water of the present invention does not use acids such as hydrochloric acid in non-diaphragm electrolysis, but lowers the pH of raw water before electrolysis by filtering an H-type ion exchange membrane, thereby producing hypochlorous acid (HOCl). It provides the effect of safely producing sterilizing water containing high concentrations.

In addition, the apparatus for producing hypochlorous acid sterilizing water of the present invention provides a device with a simple and efficient structure that can easily carry out the above method.

Figure 1 is a graph showing the HOCl and OCl ^- production rates according to pH in the electrolysis of water.
Figure 2 is a diagram schematically showing the ion exchange mode depending on the type of ion exchange resin.
Figures 3 to 5 are diagrams schematically showing the hypochlorous acid sterilizing water production apparatus of the present invention.

This invention

(a) passing raw water through a filter unit including an H-type cation exchange resin filter to lower the pH of the water to 6 or less; and

(b) electrolyzing the water with a pH of 6 or lower prepared in step (a) in a diaphragm-less electrolysis device.

In the above, the lower limit value of pH of the water passing through the filter unit can be set to 2, 3, 4, or 5, and this lower limit value is determined by the pH to be raised during the subsequent electrolysis process, the pH of the finally produced sterilizing water, etc. It can be decided by taking into account .

As a conventional method for producing sterilizing water, a method of producing sterilizing water by placing salt water in a non-diaphragm electrolyzer and performing electrolysis is known. In this case, as the pH of the electrolyte increases during the electrolysis process, hypochlorous acid (HOCl) formed by electrolysis exists in the electrolyte as sodium hypochlorite (NaOCl) (see Figure 1). Therefore, according to the conventional sterilizing water manufacturing method, this electrolyte is manufactured and used as sterilizing water.

However, sodium hypochlorite (NaOCl) has the disadvantage of having a significantly lower sterilizing power of 1/20 to 1/80 compared to hypochlorous acid (HOCl). In addition, sodium hypochlorite (NaOCl) is known to be the main ingredient in bleach, causing consumers to hesitate to use it regardless of its actual safety.

In the conventional sterilizing water production method, a method of adding hydrochloric acid is sometimes used to improve the above disadvantages. However, hydrochloric acid is undesirable because it is difficult for consumers to handle and consumer awareness of the use of hydrochloric acid is not good.

The present invention is characterized by employing a configuration that lowers the pH of raw water to solve this problem. That is, the present invention passes raw water through a filter unit containing an H-type cation exchange resin filter to lower the pH of the water to 6 or less in advance, and then performs electrolysis, so that even if the pH of the electrolyte solution increases during the electrolysis process, electrolysis is performed. The pH of the completed final electrolyte is maintained relatively low. When the pH of the final electrolyte solution is low, as shown in FIG. 1, the presence rate of HOCl in the electrolyte solution becomes overwhelmingly high. Therefore, the sterilizing water prepared by the production method of the present invention contains a high content of hypochlorous acid (HOCl), and thus provides significantly higher sterilizing power compared to the sterilizing water prepared by the conventional method.

The method of obtaining sterilizing water by electrolysis of water can be explained as follows:

Step 1: Chlorine anions in water are oxidized to Cl ₂ by electrical energy.

2Cl ^- → Cl ₂ + 2e ^-

Step 2: Cl ₂ meets water and hydrolyzes into HOCl

Cl ₂ + H ₂ O → HClO + HCl

Step 3: Depending on the pH, HOCl and OCl ^- exist in water in an equilibrium relationship.

HClO ↔ ClO ^- + H ⁺

In step (a), it is more preferable to lower the pH of the water to 5 or less by passing the raw water through a filter unit containing an H-type cation exchange resin filter, and even more preferably to 4 or less, especially when lowering it to 3.5 or less. , Even if the pH of the electrolyzed water increases during the electrolysis process, the pH of the electrolyzed water can be maintained relatively low, providing a more desirable effect. That is, at low pH, the content of hypochlorous acid contained in electrolyzed water (sterilizing water) increases, thereby providing a more desirable effect.

In the present invention, the filter unit may further include an H-type cation exchange resin filter, a filter for removing general impurities, and other cation exchange resin filters. Other cation exchange resin filters include Na type and the like. When using the H-type cation exchange resin filter in combination with other filters as described above, it can be easy to remove impurities, prevent scale generation, and adjust pH.

For example, if it is necessary to maintain the pH of the electrolyzed electrolyte solution at a slightly acidic level (5.0 to 6.5) after the H-type cation exchange resin filter, a small amount of H-type cation exchange resin may need to be used. However, in this case, the replacement cycle of the H-type cation exchange resin filter may be shortened and the hardness reduction rate may be low. Therefore, in this case, the amount of H-type cation exchange resin should be used according to the target exchange cycle, and the difficulty in controlling pH caused by the inclusion of a large amount of H-type cation exchange resin can be resolved by using a filter made by mixing Na-type cation exchange resin. This can be solved by using

As described above, when using a mixture of an H-type cation exchange resin and a Na-type cation exchange resin, the H-type cation exchange resin and the Na-type cation exchange resin can be mixed in a weight ratio of 3:1 to 1:3, It may be more appropriate to mix and use at a weight ratio of 2:1 to 1:2.

In step (b), electrolysis is more preferably carried out until the pH of the electrolyte is 7 or less, and especially more preferably is carried out until the pH is 6.5 or less.

In the above, the lower limit value of the pH of the electrolyte solution by electrolysis may be set to 3, 4, 5, or 6, and this lower limit value may be determined in consideration of the effect on the human body and sterilizing power.

As shown in Figure 1, when the pH of the electrolyte solution exceeds 7, the content of HOCl in the electrolyte solution decreases and the content of OCl ^- increases, so it is preferable to perform electrolysis only until the pH is 7 or less.

In the present invention, the pH of the sterilizing water prepared by electrolysis is preferably 5 to 7, and more preferably 5 to 6.5. When the pH of the sterilizing water is less than 5 or more than 6.5, as shown in FIG. 1, the content of HOCl in the electrolyte is lowered, which is not desirable because the sterilizing power is weakened.

In the present invention, the H-type cation exchange resin filter includes H-type cation exchange resin particles. The H-type cation exchange resin particles can form a filter by filling a certain space forming the H-type cation exchange resin filter. The particle size of the H-type cation exchange resin particles is not particularly limited, but for example, those with a particle size range of 0.1 mm to 2 mm can be used, and more preferably, those with a particle size range of 0.3 mm to 1.2 mm can be used.

As illustrated in Figure 2, ion exchange resin refers to a synthetic resin that exchanges ions in an aqueous solution with ions contained in the ion exchange resin. As a type of such ion exchange resin, a cation exchange resin is a resin that exchanges cations contained in an aqueous solution with its own cations, and an anion exchange resin is a resin that exchanges anions contained in an aqueous solution with its own anions.

As illustrated in Figure 1 (a), the H-type cation exchange resin used in the present invention is a resin that exchanges ions such as Ca ²⁺ and Mg ²⁺ contained in raw water with H ⁺ ions. Therefore, the pH of raw water can be lowered through this action.

On the other hand, Na-type cation exchange resin is a resin that exchanges ions such as Ca ²⁺ and Mg ²⁺ contained in raw water with Na ⁺ ions, as illustrated in (b) of Figure 1. Therefore, these resins cannot lower the pH of raw water.

In addition, the anion exchange resin is a resin that exchanges ions such as Cl ^- contained in raw water with OH ^- ions, as illustrated in Figure 1 (c). Therefore, these resins cannot lower the pH of raw water.

In one embodiment of the present invention, salt may be added to water with a pH of 6 or less prepared in step (a), or salt may be added before or during electrolysis in step (b). The reason for adding salt above is to increase the electrical conductivity of water and to generate more hypochlorous acid by Cl ^- ions.

However, the production method of the present invention is also possible to produce hypochlorous acid by performing electrolysis without adding salt. In this case, the concentration of hypochlorous acid is lower than when salt is added, but it may be suitable for use in applications that do not require strong disinfection power.

In addition, the present invention, as shown in Figures 3 to 5,

An electrolyzer (10) including a diaphragm-less electrolyzer (12); and

It includes a filter unit 20 that filters raw water flowing in while coupled to the electrolyzer 10,

The filter unit 20 includes an H-type cation exchange resin filter 22, and the H-type cation exchange resin filter 22 is provided to lower the pH of water to 6 or less. It relates to device 100.

In the electrolysis tank 10, the diaphragm-less electrolysis device 12 includes a power supply, an anode, and a cathode, and is characterized in that it is provided at the bottom of the electrolysis tank. The diaphragm-less electrolytic device 12 refers to an electrolytic device that does not have a diaphragm that allows electron ions to pass between the anode and the cathode.

The sterilizing water production device including the diaphragm-less electrolyzer 12 is simple, inexpensive, and suitable for portable manufacturing.

The electrolysis tank 10 may be further provided with a handle 14.

The filter unit 20 is detachably fixed to the upper end of the electrolysis tank 10, and includes an electrolysis tank coupling portion 26 formed in the lower portion, one or more raw water inlets 28 formed in the upper portion, and a hollow portion. It may include one or more filter installation units (not shown).

In particular, as shown in FIG. 4, the filter unit 20 has the feature of including an H-type cation exchange resin filter 22, and the H-type cation exchange resin filter 22 is a filter through which raw water flows. It can be installed in the filter installation part formed in the hollow part of the unit 20.

The H-type cation exchange resin filter includes H-type cation exchange resin particles, and the H-type cation exchange resin particles can be accommodated in a filter case provided in the filter installation portion. The filter case can be formed by fixing a porous sheet that allows water to pass through the hollow portion but does not allow H-type cation exchange resin particles to pass through. However, the shape of the filter case is not limited to this, and can be formed in various ways by applying conventional techniques.

In addition, the filter installation unit may further include one or more filters for removing impurities in addition to the H-type cation resin filter 22. Non-woven filters, mesh filters, etc. may be used as the filter for removing impurities, but are not limited thereto, and filters known in the art may be used without limitation.

The one or more filters 24 and 26 for removing impurities may be installed at the top and bottom of the H-type cation exchange resin filter, for example, as shown in FIG. 4, and may be installed only at the top or bottom. there is.

As shown in Figure 4, when the impurity removal filters 24 and 26 are installed at the upper and lower parts of the H-type cation exchange resin filter, these impurity removal filters can perform the function of the filter case. desirable. In addition, even when the impurity removal filters 24 and 26 are installed only at the bottom of the H-type cation exchange resin filter, they can perform the function of the filter case.

The particle size of the H-type cation exchange resin particles is not particularly limited, but for example, those with a particle size range of 0.1 mm to 2 mm can be used, and more preferably, those with a particle size range of 0.3 mm to 1.2 mm can be used.

The apparatus 100 for producing sterilizing water further includes a raw water inlet guide 30, wherein the raw water inlet guide 30 has a raw water inlet guide fixing member ( 32) may further be included.

The raw water inflow guide 30 has a tubular shape with upper and lower ends opened, has an upper end wider than the opening at the upper end of the electrolyzer, and may be tapered to become narrower toward the bottom. By having this form, raw water can flow in smoothly, and stagnant water can be prevented from flowing out even if the inflow speed of raw water is slowed by the filter unit 20.

In addition to the configuration described above, the hypochlorous acid sterilizing water production device of the present invention can employ conventional configurations known in the field without limitation.

Hereinafter, the present invention will be described in detail with reference to examples. However, the embodiments according to the present invention may be modified into various other forms, and the scope of the present invention should not be construed as being limited to the embodiments described in detail below. Examples of the present invention are provided to more completely explain the present invention to those with average knowledge in the art.

Example 1 and Comparative Example 1.

(1-1) Filtering raw water using H-type cation exchange resin

First, the pH of tap water (raw water) was measured.

Afterwards, an H-type cation exchange resin filter with a total weight of 30 g and a particle size range of 0.3 mm to 1.2 mm was installed in the hypochlorous acid sterilizing water production device of the type shown in Figure 3, and then the tap water was filtered through the H-type cation exchange resin filter. After passing through, the pH and hardness (ppm) of the tap water contained in the non-diaphragm electrolyzer were measured. At this time, the pH was measured with a pH meter using a glass electrode method, and the hardness (ppm) was measured with an EDTA titration method.

The pH and hardness measurements of tap water before and after passing the filter are shown in Table 1 below.

division pH Hardness (ppm) Tap water (before filter) 7.73 80.0 Tap water (after H type filter (w: 30g)) 4.83 48.0

From the experimental results in Table 1 above, it can be seen that the pH of tap water (raw water) was very significantly lowered by filtering with H-type cation exchange resin.

(1-2) Preparation of sterilizing water

Following the experiment of Example 1-1, (i) tap water with a pH of 4.83 (no salt added) filtered by an H-type cation exchange resin and (ii) unfiltered tap water with a pH of 7.73 (no salt added). Electrolysis was performed for 3 to 9 minutes in a sterilizing water production device equipped with a non-diaphragm electrolyzer.

Afterwards, the pH and residual chlorine (ppm) of the electrolyte solution were measured. At this time, the pH was measured in the same manner as in Example 1, and the residual chlorine (ppm) was measured by the DPD colorimetric method.

The measured pH and residual chlorine values of the sterilizing water after electrolysis are shown in Table 2 below.

tap water
(400 mL) Tap water pH salt
usage
(g) electrolysis
hour
(minute) manufactured sterilizing water Residual chlorine (ppm) pH Example 1-1 Tap water filtered with H-type cation exchange resin 4.83 0 3 2.0 5.05 Comparative Example 1-1 Unfiltered tap water 7.73 0 3 2.1 7.79 Example 1-2 Tap water filtered with H-type cation exchange resin 4.83 0 6 3.5 5.24 Comparative Example 1-2 Unfiltered tap water 7.73 0 6 3.5 7.90 Example 1-3 400 ml of tap water filtered with H-type cation exchange resin 4.83 0 9 5.6 5.47 Comparative Example 1-3 Unfiltered tap water 7.73 0 9 5.7 7.99

As seen in Table 2 above, in Examples 1-1 to 1-3, although electrolysis of tap water filtered with an H-type cation exchange resin filter was performed for 3 to 9 minutes, the electrolyzed sterilizing water The pH was confirmed to be below 5.47. Therefore, comparing these results with the graph of FIG. 1, it can be seen that almost no OCl ^- ions exist in the prepared sterilizing water, and most hypochlorous acid (HOCl) is present.

On the other hand, in Comparative Examples 1-1 to 1-3, after electrolysis of unfiltered tap water was performed for 3 to 9 minutes, the pH of the electrolyzed sterilized water was confirmed to be 7.79 or higher. Therefore, comparing these results with the graph of FIG. 1, it can be confirmed that OCl ^- ions are present in more than 70% of the prepared sterilizing water, while hypochlorous acid (HOCl) is present in less than 30%.

Example 2.

(2-1) Filtering raw water using H-type cation exchange resin

First, the pH of tap water (raw water) was measured.

Afterwards, an H-type cation exchange resin filter with a total weight of 120 g and a particle size range of 0.3 mm to 1.2 mm was installed in the hypochlorous acid sterilizing water production device of the type shown in Figure 3, and then tap water was filtered using the H-type cation exchange resin filter. After passage, the pH and hardness (ppm) of the tap water contained in the non-diaphragm electrolyzer were measured. At this time, the pH and hardness (ppm) were measured in the same manner as in Example 1.

The pH and hardness measurements of the tap water before and after passing the filter are shown in Table 3 below.

division pH Hardness (ppm) Tap water (before filter) 7.05 62.0 Tap water (after H type filter (w: 120g)) 3.16 4.0

From the experimental results in Table 3, it can be seen that the pH of tap water (raw water) was very significantly lowered by filtering with H-type cation exchange resin.

(2-2) Preparation of sterilizing water

Following the experiment of Example 2-1, 0.25 g to 0.5 g of salt was dissolved in tap water with a pH of 3.16 contained in a non-diaphragm electrolyzer of the hypochlorous acid sterilizing water production device, and electrolysis was performed for 1 minute to 1.5 minutes, respectively. It was carried out for minutes.

Afterwards, the pH and residual chlorine (ppm) of the electrolyte solution were measured. At this time, the pH and residual chlorine were measured in the same manner as in Example 1.

The measured pH and residual chlorine values of the sterilizing water after electrolysis are shown in Table 4 below.

Tap water (mL) Salt (g) electrolysis
Time (minutes) manufactured sterilizing water Residual chlorine (ppm) pH Example 2-1 400 0.25 One 28 3.20 Example 2-2 400 0.5 One 48 3.53 Example 2-3 400 0.5 1.5 71 5.52

As seen in Table 4 above, in Examples 2-1 to 2-3, even though salt was added and electrolysis was performed for 1 to 1.5 minutes, the pH of the electrolyzed sterilizing water was confirmed to be 5.52 or less. . Therefore, when comparing these results with the graph of FIG. 1, it can be seen that almost no OCl ^- ions exist in the electrolyte and most hypochlorous acid (HOCl) exists.

Example 3 and Comparative Example 2.

(3-1) Filtering raw water using H-type cation exchange resin

First, the pH of tap water (raw water) was measured.

Thereafter, the hypochlorous acid sterilizing water production device of the type shown in Figure 3 is equipped with (i) an H-type cation exchange resin filter with a total weight of 40 g and a particle size range of 0.3 mm to 1.2 mm, and (ii) a total weight of 40 g, After installing each Na-type cation exchange resin filter with a particle size range of 0.3 mm to 1.2 mm, tap water was passed through it and filtered, and the pH and hardness (ppm) of the tap water contained in the non-diaphragm electrolyzer were measured. At this time, the pH and hardness (ppm) were measured in the same manner as in Example 1.

The pH and hardness measurements of the tap water before and after passing the filter are shown in Table 5 below.

division pH Hardness (ppm) Tap water (before filter) 7.13 58.0 Example 3-1 Tap water (after H-type filter) 3.34 16.0 Comparative Example 2-1 Tap water (after Na type filter) 7.32 18.0

From the experimental results in Table 5, it can be seen that the pH of the tap water filtered by the H-type cation exchange resin filter of Example 3-1 was very significantly lowered compared to the pH of tap water (raw water).

On the other hand, it can be seen that the pH of the tap water filtered by the Na-type cation exchange resin filter of Comparative Example 2-1 has little difference compared to the pH of tap water (raw water).

(3-2) Preparation of sterilizing water

Following the above experiment, (i) tap water (no salt added) with pH 3.34 (filtered using H-type cation exchange resin) and (ii) pH 7.32 (Na-type) stored in the non-diaphragm electrolyzer of the hypochlorous acid sterilizing water production device. Electrolysis was performed on tap water (no salt added), which was filtered using a cation exchange resin, for 3 minutes each.

Afterwards, the pH and residual chlorine (ppm) of the electrolyzed electrolyte solution were measured in each sterilizing water production device. At this time, the pH and residual chlorine were measured in the same manner as in Example 1.

The measured pH and residual chlorine values of the sterilizing water after electrolysis are shown in Table 6 below.

tap water
(mL) salt
(g) electrolysis time
(minute) manufactured sterilizing water Residual chlorine
(ppm) pH Example 3-2 400 0 3 2.50 3.29 Comparative Example 2-2 400 0 3 2.80 7.55

As shown in Table 6 above, when electrolysis was performed on tap water filtered with an H-type cation exchange resin filter for 3 minutes (Example 3-2), the pH of the electrolyzed sterilized water was confirmed to be 3.29. .

On the other hand, when electrolysis was performed on tap water filtered through a Na-type cation exchange resin filter for 3 minutes (Comparative Example 2-2), the pH of the electrolyzed sterilized water was confirmed to be 7.55.

Therefore, comparing these results with the graph of FIG. 1, the sterilizing water prepared in Example 3-2 of the present invention contains significantly higher hypochlorous acid (HOCl) compared to the sterilizing water prepared in Comparative Example 2-2. You can check what is contained in the ratio.

10: Electrolyzer, 12: Non-diaphragm electrolyzer
14: handle, 20: filter unit
22: H-type cation exchange resin filter
24, 26: Filter for removing impurities
26: Electrolyzer coupling part
28: raw water inlet 30: raw water inlet guide
32: Raw water inlet guide fixing member
100: Hypochlorous acid sterilizing water manufacturing device

Claims (12)

(a) passing raw water through a filter unit including an H-type cation exchange resin filter to lower the pH of the water to 6 or less; and
(b) electrolyzing the water with a pH of 6 or lower prepared in step (a) in a diaphragmless electrolysis device. According to paragraph 1,
A method of producing hypochlorous acid sterilizing water, characterized in that the H-type cation exchange resin filter contains H-type cation exchange resin particles. According to paragraph 1,
Step (a) is a method of producing hypochlorous acid sterilizing water, characterized in that the pH of the water is lowered to 5 or less by passing the raw water through a filter unit including an H-type cation exchange resin filter. According to paragraph 1,
A method for producing hypochlorous acid sterilizing water, characterized in that electrolysis in step (b) is carried out until the pH of the electrolyte is 7 or less. According to paragraph 4,
A method for producing hypochlorous acid sterilizing water, characterized in that electrolysis in step (b) is carried out until the pH of the electrolyte is 6.5 or less. According to paragraph 1,
A method for producing hypochlorous acid sterilizing water, characterized in that salt is added to water with a pH of 6 or less prepared in step (a), or salt is added before or during electrolysis in step (b). An electrolyzer containing a diaphragm-less electrolyzer; and
It includes a filter unit that is coupled to the electrolyzer and filters raw water flowing in,
The filter unit includes an H-type cation exchange resin filter, and the H-type cation exchange resin filter is provided to lower the pH of the incoming water to 6 or less. In clause 7,
In the electrolysis tank, the non-diaphragm electrolysis device includes a power supply, an anode, and a cathode, and is provided at the bottom of the electrolysis tank. In clause 7,
The filter unit is a hypochlorous acid sterilizing water production device, characterized in that the filter unit further includes a filter for removing impurities at the top, bottom, or top and bottom of the H-type cation exchange resin filter. In clause 7,
The filter unit is detachably fixed to the upper end of the electrolysis tank, and includes an electrolysis tank coupling portion formed in the lower portion, one or more raw water inlets formed in the upper portion, and one or more filter installation portions formed in the hollow portion. Sterilizing water manufacturing device. According to clause 10,
The apparatus for producing sterilizing water further includes a raw water inflow guide, wherein the raw water inflow guide further includes a raw water inflow guide fixing member coupled to the upper end of the filter unit or the upper end of the electrolyzer at the lower end. Sterilizing water manufacturing device. According to clause 11,
The raw water inflow guide has a tubular shape with upper and lower ends opened, has an upper part wider than the upper opening of the electrolyzer, and is tapered to become narrower toward the lower part. A hypochlorous acid sterilizing water production device.