JP2001321778A - Method and apparatus for producing sterilized water - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide sterilized water having a desired sodium hypochlorite concentration and pH safely, easily, at low cost and easily, and as a raw water for dilution for preparing sterilized water. Provided is a method and apparatus for producing sterilized water that can use a wide range of raw water for dilution, such as infiltration water (R / O water), tap water, well water, or seawater. SOLUTION: A predetermined sodium hypochlorite concentration and p
The method of producing sterilized water of H is that sodium hypochlorite and an acid are each separately diluted and mixed with raw water to obtain a sodium hypochlorite diluent and an acid diluent, respectively, and the sodium hypochlorite diluent is used. The concentration of sodium hypochlorite and the acid are monitored and / or the amounts added are adjusted based on the electric conductivity (d1, d2, d3) of the solution, the acid diluent and the raw water, and the sodium hypochlorite diluent And the acid diluent are mixed to obtain sterilized water.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention generally relates to sterilizing water which can be used to sterilize and disinfect microorganisms contaminating various devices or foodstuffs in various fields such as food processing, agriculture and fisheries, and medicine. Regarding the generation method and apparatus,
In particular, the present invention relates to a method and apparatus for producing sterilized water, which activates sodium hypochlorite used as a sterilizing agent and enhances sterilizing power.

[0002]

2. Description of the Related Art Conventionally, for example, in the medical field, an aqueous solution of sodium hypochlorite (NaOCl) has been used for sterilization and disinfection of hemodialysis equipment. Usually, sodium hypochlorite is provided at a concentration of about 6% w / w, and this stock solution is diluted to a concentration of 500 to 1000 ppm when used and used as sterilizing water.

[0003] However, after disinfecting and disinfecting various devices and the like with such sodium hypochlorite-containing sterilizing water, it is necessary to sufficiently wash the apparatus with fresh water so that sodium hypochlorite does not remain. Equipment cleaning wastewater containing sodium hypochlorite is discharged into the environment. Therefore, when a large amount of sterilized water containing sodium hypochlorite is used at a high concentration of 500 to 1000 ppm as described above, there is a problem that the effect on the environment is large. Also, if a washing waste liquid containing a high concentration of sodium hypochlorite is introduced into a wastewater treatment facility using an activated sludge method, it may cause considerable damage to sludge (microorganisms) and even become impossible to treat. .

[0004] On the other hand, in view of the above problems, there has recently been proposed an apparatus capable of reducing the amount of sodium hypochlorite used by increasing the sterilizing power of the sodium hypochlorite-containing sterilizing water (Japanese Patent Application Laid-Open No. H11-157572). JP-A-10-182325). or,
For example, as a method for washing and disinfecting hemodialysis equipment, the sterilization and disinfection ability of a method using sodium hypochlorite active water containing sodium hypochlorite and acetic acid has been demonstrated (for example, "sodium hypochlorite activity"). "Water cleaning and disinfecting effect", "Functional Water Medical Research Society Vol. 1, No. 2," p. 101-
104 (1999)).

That is, the main component of the sterilizing power of the sterilized water containing sodium hypochlorite is hypochlorous acid (HOCl), and the existence ratio of hypochlorous acid (HOCl) in the sterilized water is determined by It was found to be pH dependent. FIG.
Indicates the abundance of hypochlorous acid according to pH in sterilized water containing sodium hypochlorite. As can be understood from FIG. 5, sodium hypochlorite itself is strongly alkaline, and the content of hypochlorous acid (HClO) increases to about pH 4.5 as the pH decreases. Also, if the pH becomes too low below about 3.0, the content of hypochlorous acid (HClO) decreases.

That is, conventional sterilized water obtained by simply diluting sodium hypochlorite with water is strongly alkaline (about pH 8.5 to 8.5).
pH 10), and 500 ppm to 1000 in sterile water.
Even if sodium hypochlorite is diluted at a high concentration such as ppm, only about 5% of the contained sodium hypochlorite is present as hypochlorite (HClO) having a strong bactericidal activity.

Therefore, in the above-mentioned apparatus for enhancing the sterilizing power of sodium hypochlorite (JP-A-10-182325), the pH of the sterilizing water containing sodium hypochlorite is adjusted to pH3.
Adjust to a range of 0 to 6.0. As a result, almost 100% of sodium hypochlorite contained in the sterilized water can exist as hypochlorite (HClO) effective for sterilization, so that hypochlorous acid required for obtaining a strong sterilizing power is obtained. The amount of sodium can be reduced, for example, the concentration of sodium hypochlorite can be reduced to 10-20 ppm. Hereinafter, the sterilized water containing sodium hypochlorite prepared using this principle will be referred to as “sodium hypochlorite activated water” or simply “activated water”.

[0008]

As described above, in order to prepare sodium hypochlorite activated water having a reduced concentration of sodium hypochlorite and enhanced bactericidal activity, it is necessary to prepare activated sodium hypochlorite. It is essential that the sodium acid concentration and the pH are exactly adjusted to the desired settings, which only guarantees a strong bactericidal activity. Further, if sodium hypochlorite is added more than necessary, there is a problem when the disinfecting and sterilizing waste liquid is discharged into the environment as described above.

Conventionally, as a method for adjusting the concentration and pH of sodium hypochlorite in active water, a flow rate of raw water for diluting sodium hypochlorite and / or acid is detected and a predetermined ratio is determined with respect to this flow rate. There is a method of adding sodium hypochlorite or an acid.

However, in such a method, for example, when an undiluted solution of sodium hypochlorite or acid runs out (when it is used up) or an abnormality occurs in a chemical pump for supplying sodium hypochlorite or acid. In such cases, the concentration and pH of sodium hypochlorite do not conform to the set values.
As the abnormality of the chemical pump, a mechanical failure (damage of the diaphragm, etc.) or an electrical failure (fuse of the fuse, etc.) can be considered. It is also conceivable that an airlock occurs in the diaphragm type pump, or a problem such as a disconnection of the chemical solution piping tube occurs. Further, it is conceivable that the hypochlorous acid concentration and the pH of the activated water deviate from the set values due to a shortage of raw water for dilution, water cutoff, and the like.

Therefore, it is necessary to deal with such various events,
Always maintain a predetermined sodium hypochlorite concentration and pH to prepare sodium hypochlorite active water with always strong bactericidal power, or when there is a possibility that desired active water may not be obtained It is very important to monitor the concentration and pH of sodium hypochlorite to stop the preparation of activated water and to issue an alarm, and to adjust the amount of sodium hypochlorite and acid to increase reliability. Is important.

As a method for detecting the concentration of sodium hypochlorite in active water, it is conceivable to use a so-called polarographic concentration detection sensor (residual chlorine concentration detector) using a polarograph. For example, adjust the injection amount of sodium hypochlorite manually until the concentration of sodium hypochlorite reaches a predetermined value while watching the instructions of this hypochlorous acid concentration meter, or Can be automatically adjusted by using the detected value of. Further, it is considered that the pH of the activated water is detected using a pH meter, and the amount of the acid added is adjusted based on the detected value.

However, a hypochlorous acid concentration detection sensor using a polarograph is relatively expensive, and in order to maintain the detection accuracy, maintenance such as maintenance of the electrodes is expensive and operation is complicated. Also, as is well known, the pH meter needs to periodically perform standard calibration,
In order to maintain the detection accuracy of H, the standard calibration must be performed frequently, and the operation becomes complicated. As described above, the method using the hypochlorous acid concentration detection sensor and the pH meter has problems in cost, maintenance of the sensor, and reliability.

For example, when sodium hypochlorite activated water is used for disinfection and sterilization of equipment in the field of food processing, if a pH meter using a normal glass electrode is used, the glass electrode may be damaged. This is a problem because glass fragments may be mixed into food. Although there is a so-called methoxy-electrode type pH meter that does not use a glass electrode, hypochlorous acid contained in activated water is not suitable for use because it is a strong oxidizing agent.

As described above, there is a need for a method and an apparatus which can monitor the concentration and pH of hypochlorous acid in a safe, low-cost, and simple manner, and always accurately and accurately prepare active water of a predetermined concentration and pH.

In addition, it would be desirable for such a method and apparatus to be applicable to a wide range of use of raw water for dilution.
That is, for example, in preparing sodium hypochlorite active water used for sterilization and disinfection of hemodialysis equipment, it is necessary to use reverse osmosis water (R / O water) substantially free of dissolved ions as raw water for dilution. . A reverse osmosis water generation (R / O) device is relatively expensive and further requires running costs such as replacement of membranes and resins. However, for example, food processing, agricultural and marine products,
Sterilization and disinfection in the industrial production field such as sterilization and disinfection of equipment such as production lines, pipes, tanks, and semiconductor substrates in the livestock industry, sterilization and disinfection in the waste treatment and sewage treatment fields, or pool water For sterilization, tap water, well water, and the like can be used as raw water for dilution, which can significantly reduce costs.

In some cases, it is desirable to use seawater as raw water for dilution in addition to tap water and well water. That is,
In the field of fisheries, harmful microorganisms contained in seawater (eg, Vibrio parahaemolyticus, which can cause food poisoning) can be obtained by converting seawater used for washing and thawing fish into sodium hypochlorite activated water having a strong bactericidal activity. The effects of sterilization, propagation prevention, and washing can be obtained, and at the same time, since the raw water for dilution is seawater, adverse effects such as discoloration of fish can be prevented.

Accordingly, an object of the present invention is to provide a method and an apparatus for producing sterilized water capable of obtaining sterilized water with a desired concentration and pH of sodium hypochlorite safely, easily and at low cost. is there.

Another object of the present invention is to provide a reverse osmosis water (R / O) as a raw water for dilution for preparing sterilized water.
Water), tap water, well water or seawater can be used for a wide range of raw water for dilution, and it is safe, low-cost and simple, and always has the desired sodium hypochlorite concentration and pH.
It is an object of the present invention to provide a method and an apparatus for producing sterilized water capable of obtaining sterilized water.

[0020]

The above objects are achieved by the method and apparatus for producing sterilized water according to the present invention. In summary,
According to a first aspect of the present invention, there is provided a method for producing sterilized water having a predetermined sodium hypochlorite concentration and pH, wherein sodium hypochlorite and an acid are each independently diluted and mixed with raw water to obtain the following. A sodium chlorite diluent and an acid diluent are obtained, and the electric conductivity (d1, d2, d3) of each of the sodium hypochlorite diluent, the acid diluent and the raw water is obtained.
Monitoring the concentration of sodium hypochlorite and the acid and / or adjusting the amount of addition based on the above, and mixing the diluted sodium hypochlorite and the diluted acid to obtain sterilized water. A method for producing water is provided.

In the first aspect of the present invention, according to one embodiment, the electric conductivity (d1, d2, d3) of each of the diluted sodium hypochlorite solution, the acid diluted solution, and the raw water is determined at the time of producing sterilized water. To detect.

In the first embodiment of the present invention, according to another embodiment, when the electric conductivity of raw water is constant, the electric conductivity of each of the diluted sodium hypochlorite solution and the acid diluted solution ( d1 and d2) are detected at the time of producing sterilized water, and the electric conductivity (d3) of the raw water uses a predetermined value obtained in advance.

In the first aspect of the present invention, according to another embodiment, the difference between the previously determined electrical conductivity (d1-d3) of the diluted sodium hypochlorite solution and the raw water is sodium hypochlorite. Based on the relationship of the concentration and the relationship of the acid concentration to the difference (d2-d3) between the electric conductivity of the acid diluent and the raw water, the concentration of sodium hypochlorite and the acid are monitored and / or the amount added is adjusted.

According to a second aspect of the present invention, there is provided an apparatus for producing sterilized water having a predetermined sodium hypochlorite concentration and pH; raw water supply means for supplying raw water; and sodium hypochlorite as raw water. First mixing means for obtaining a sodium hypochlorite diluent by adding and mixing; and second diluting mixing means for adding and mixing an acid to raw water to obtain an acid diluent; Mixing means for mixing the sodium diluent and the acid diluent; and the electric conductivity (d1, d2, d) of each of the sodium hypochlorite diluent, the acid diluent and the raw water
3) first, second, and third electric conductivity measuring means for measuring; and, based on signals from the first, second, and third electric conductivity measuring means, sodium hypochlorite and acid. And a control means for monitoring the concentration and / or adjusting the amount of addition.

In a second aspect of the present invention, according to one embodiment, the apparatus comprises a raw water supply passage as the raw water supply means; and a branch from the raw water supply passage as the first dilution and mixing means. A flow path, comprising: means for adding sodium hypochlorite to raw water flowing in the flow path; and a first mixer for mixing and stirring the liquid after the sodium hypochlorite has been added. A first dilution / mixing flow path; a means for adding an acid to raw water flowing in the flow path as a flow path branched from the raw water supply flow path as the second dilution / mixing means;
A second dilution / mixing flow path including a second mixer for mixing and stirring the liquid after the acid has been added; and the mixing means includes a liquid from the first and second dilution / mixing flow paths. A mixing channel provided with a third mixer for mixing and stirring the liquid from the first dilution mixing channel and the liquid from the second dilution mixing channel. Have. According to one embodiment, the first electric conductivity measuring means is provided on the downstream side of the first mixer in the first dilution mixing channel, and the second electric conductivity measuring means is provided in the first dilution mixing channel. The second mixing passage is provided downstream of the second mixer, and the third electric conductivity measuring means is provided in the raw water supply passage.

In a second aspect of the present invention, according to another embodiment, the apparatus further comprises an electrical conductivity input means for inputting a predetermined value of the electrical conductivity of the raw water to the control means. If the electrical conductivity of raw water is constant,
The control means uses a signal input from the electric conductivity input means instead of a signal from the third electric conductivity measurement means as the electric conductivity (d3) of the raw water.

In a second aspect of the present invention, according to another aspect, the control means is configured to determine the difference (d1) between the previously determined electrical conductivity of the diluted sodium hypochlorite solution and raw water.
-D3) the relationship between the concentration of sodium hypochlorite and the difference between the electric conductivity of the acid diluent and the raw water (d2-d3)
The concentration of sodium hypochlorite and the acid are monitored and / or the amounts added are adjusted based on the relationship of the acid concentration with respect to.

In a second aspect of the present invention, according to another embodiment, the control means monitors the sodium hypochlorite concentration of the sodium hypochlorite diluent and the acid concentration of the acid diluent. The addition amount of sodium hypochlorite and the addition amount of acid are adjusted so that the sodium hypochlorite concentration of the sodium hypochlorite diluent and the acid concentration of the acid diluent have predetermined values. I do. According to another embodiment, the control means monitors the sodium hypochlorite concentration of the sodium hypochlorite diluent and the acid concentration of the acid diluent, and controls the sodium hypochlorite and / or When the concentration of the acid deviates from the set value, a predetermined alarm, a predetermined information display, and a predetermined device abnormal operation including a stop of raw water supply are performed.

According to one embodiment of the present invention, the raw water is tap water, well water, seawater or reverse osmosis water (R / O water).

According to one embodiment of the present invention,
Preferably, the concentration of sodium hypochlorite in the sterilizing water is in the range of 0.5 ppm to 1000 ppm, and the pH is p.
H is in the range of 3.0 to 7.5.

[0031]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a method and an apparatus for producing sterilized water according to the present invention will be described in more detail with reference to the drawings.

In this embodiment, the method and apparatus for producing sterilized water of the present invention will be described on the assumption that tap water is used as raw water for dilution. FIG. 1 shows a schematic configuration of an embodiment of an apparatus embodying the method for producing sterilized water of the present invention.

First, the basic configuration of the sterilizing water generator (active water generator) of the present embodiment will be described. As shown in FIG. 1, the sterilizing water generator 100 of the present embodiment takes in tap water from the supply port 1 of the raw water for dilution and activates sodium hypochlorite to increase the sterilizing power. Water (sodium hypochlorite activated water) can be prepared and taken out of the apparatus from the outlet 13. According to this embodiment, as will be described in detail later, sodium hypochlorite and the acid are each independently diluted and mixed with the raw water for dilution, and then the sodium hypochlorite diluent stream and the acid diluent stream are used. To obtain sodium hypochlorite active water. According to this embodiment, it is possible to continuously supply raw water for dilution to continuously generate active water. Further, for example, when an active water storage tank (not shown) is connected to the outlet 13 and the active water is stored therein and used, the active water in the storage tank becomes lower than a predetermined level every time. It is also possible to control the generation of active water intermittently, such as by starting the generation of active water.

A raw water supply flow path L1 as raw water supply means provided in the apparatus 100 is connected to a tap (not shown) of a general tap water supply pipe through a supply port 1. An electromagnetic valve 14 is provided in the raw water supply passage L1, and the supply of raw water is controlled by opening and closing the electromagnetic valve 14. The opening and closing of the solenoid valve 14 is normally performed by an instruction of the control means 20 according to a user's operation in the device operation unit 24 or the like. Further, as described later in detail, when the control means 20 detects an abnormality in the apparatus, the electromagnetic valve 14 is closed, and the supply of the raw water for dilution is stopped. Further, the supply port 1 of the raw water supply passage L1 and the solenoid valve 1
4, a pressure switch 15 can be provided.
Accordingly, the apparatus can be operated when a predetermined pressure is applied near the supply port 1, and when water is cut off or the amount of water is insufficient, a configuration in which sodium hypochlorite or an acid described later is not supplied can be provided.

The downstream side of the raw water supply flow path L1 is the first and second
And a sodium hypochlorite dilution mixing flow path as first and second dilution mixing means via first and second constant flow valves 2 and 3 as raw water flow rate control means, respectively. (First dilution mixing channel) L2, acid dilution mixing channel (second
Tap water is supplied to the dilution mixing flow path) L3. In the present embodiment, the first and second constant flow valves 2 and 3 supply the same flow rate of dilution raw water to the first dilution / mixing flow path L2 and the second dilution / mixing flow path L3.

The supply of raw water to the first dilution mixing flow path L 2 is maintained at a constant flow rate by the first constant flow valve 2. The first dilution mixing channel L2 is provided with a first injection section 6 located downstream of the first constant flow valve 2. In the first injection section 6, as a sodium hypochlorite adding means, from the first stock solution tank 4 via the first pump 5,
A stock solution of sodium hypochlorite is injected into the dilution water stream. The first pump 5 is operated under the control of the control means 20 as described later in detail, and the injection amount of sodium hypochlorite is adjusted. In this example, the concentration of the sodium hypochlorite stock solution was 6% w / w, and its pH was 12.4.
It is.

The sodium hypochlorite injected into the raw water for dilution is sufficiently stirred and mixed with the raw water for dilution in the first mixer 7 provided downstream of the first injection section 6.

The supply rate of the raw water for dilution from the raw water supply path L1 to the acid dilution path L3 is maintained at a constant flow rate by the second constant flow valve 3. A second injection section 10 is provided in the second dilution / mixing flow path L3 at a position downstream of the second constant flow valve 3. In the second injection section 10, as an acid adding means, a second pump 9
, The acid stock solution is injected into the liquid stream of the stock water for dilution.
Like the first pump 5, the second pump 9 operates under the control of the control means 20 as described later, and adjusts the acid injection amount.

In this embodiment, the concentration of the acid stock solution is 30 watts.
/ W% acetic acid was used. As the acid for adjusting the pH, acetic acid is preferred in terms of cost and non-toxicity, but the present invention is not limited to this, and any acid suitable for the purpose of adjusting the pH of the activated water may be appropriately selected. Can be done. For example, citric acid, hydrochloric acid, or a mixed acid of acetic acid and hydrochloric acid can be used instead of acetic acid.

The acetic acid injected into the raw water for dilution is sufficiently stirred and mixed with the raw water for dilution in the second mixer 11 provided downstream of the second injection section 10.

The sodium hypochlorite diluent stream and the acid diluent stream that have passed through the mixers 7 and 11 are joined further downstream, and introduced into a mixing channel L4 as a means for mixing the two diluents. And in the third mixer 12.

First, second and third mixers 7, 11, 1
As 2, any mixer having a sufficient stirring capacity can be used. For example, a device provided with a stirring means such as an appropriate stirrer or a baffle plate member that impedes water flow can be used.

As described above, in order for the sodium hypochlorite added to the raw water to exist as hypochlorous acid (HClO) having almost 100% sterilizing power, the pH must be 3.0 to 3.0.
It is preferably in the range of 7.5, more preferably
pH 3.0-6.5, most preferably pH 4.0-5.
0.

By setting the pH of the activated water within the above range, sodium hypochlorite can exert an effective sterilizing and disinfecting power at a relatively low concentration. Considering the effect of sodium hypochlorite on the environment, it is preferable that sodium hypochlorite has a lower concentration, but the sterilizing power of active water is stronger when the concentration of sodium hypochlorite is higher. Therefore, the concentration of sodium hypochlorite can be appropriately selected in consideration of the desired bactericidal activity and the effect on the environment. Preferably, the sodium hypochlorite concentration is 0.5
ppm to 1000 ppm.

In this embodiment, the active water finally produced by mixing the sodium hypochlorite diluent and the acid diluent, each of which is diluted and mixed in the raw water for dilution as described above, is used. Sodium hypochlorite concentration is 10pp
m and pH are set to be 5.0.

Next, a method of adjusting the concentration and pH of the sodium hypochlorite in the sterilizing water will be further described. As described above, it is extremely important to monitor the concentration and pH of sodium hypochlorite in the activated water so as to always obtain appropriate values in order to exert a strong sterilizing power.

First, the principle of the present invention will be described.
Is the amount (μL) of sodium hypochlorite (6 w / w%) added to tap water (200 mL) and the electric conductivity of the diluted sodium hypochlorite solution [μS / cm; × 10 ^-4 S
/ M] (about 17 ° C.). The electric conductivity is measured using an electric conductivity sensor (CP916, manufactured by Toa Denpa).
It measured using A). As shown in the figure, it can be seen that there is a certain correlation between the amount of sodium hypochlorite added to tap water, that is, the concentration and the electrical conductivity of the sodium hypochlorite dilution. Similarly, FIG. 3 shows the amount of acetic acid aqueous solution (5M) added to tap water (200 mL) and the electric conductivity of the acid diluent [μS / cm; × 10 ⁻⁴ S / m] (about 15 ° C.). An example of the relationship with is shown. As in the case of the sodium hypochlorite diluent, it can be seen that there is a certain correlation between the amount of acetic acid added to tap water, that is, the acid concentration and the electrical conductivity of the acid diluent.

The pH of the activated water produced by mixing the sodium hypochlorite diluent and the acid diluent is as follows: (1) the pH of the diluent raw water, and the buffer action (2) the sodium hypochlorite. And (3) an acid addition amount. FIG. 4 shows tap water (200 m) containing sodium hypochlorite at a concentration of 30 ppm.
L), that is, an example of the relationship between the amount (μL) of the aqueous acetic acid solution (5 M) added to the dilute sodium hypochlorite solution and the pH of the mixed solution. As shown in the figure, the amount of acid added to the sodium hypochlorite diluent obtained by diluting sodium hypochlorite at a predetermined concentration in a predetermined diluting raw water, that is, the concentration and the activated water finally generated. Has a certain correlation with pH.

As described above, by determining the correlation between the concentration of the sodium hypochlorite diluent and the electrical conductivity, the sodium hypochlorite diluent generated in the first dilution mixing channel L2 is obtained. From the electric conductivity value of the above, the concentration of sodium hypochlorite can be detected. Similarly, by obtaining the correlation between the concentration of the acid diluent and the electric conductivity, the acid concentration is detected from the electric conductivity of the acid diluent generated in the second dilution mixing channel L3. be able to.

Finally, the first and second dilution mixing channels L
2. Activated water is prepared by introducing the sodium hypochlorite diluent and the acid diluent from L3 into the mixing channel L4 at a predetermined ratio (flow rate) and mixing them. Therefore, by monitoring the concentration of the sodium hypochlorite diluent in the first dilution / mixing flow path L2 and the concentration of the acid diluent in the second dilution / mixing flow path L3, the activated water finally prepared is monitored. Hypochlorous acid and acid concentrations can be monitored. And, as described above, since there is a certain correlation between the acid concentration in the solution containing sodium hypochlorite and the pH of this solution, the acid concentration in the prepared activated water is set to a predetermined value. The pH can be set to a predetermined value.

However, when tap water is used as the raw water for dilution as in the present embodiment, the water quality is not constant depending on the passage of time (for example, seasonal change or difference between morning and evening), place and region, and in many cases, the electric conduction Rates also vary greatly. Generally, the electric conductivity of tap water is 200 to 250 [μS / c.
m; × 10 ^-4 is a S / m] of about, 140 to 250 and in some cases this electric conductivity [μS / cm; × 10 ^-4
S / m].

In the case of using the raw water for dilution having an inconstant electric conductivity as described above, the electric conductivity of the diluted sodium hypochlorite solution and the electric conductivity of the acid diluted solution greatly fluctuate along with the fluctuation of the electric conductivity of the raw water for dilution. Therefore, it becomes impossible to monitor fluctuations in the sodium hypochlorite concentration and the acid concentration itself.

Therefore, according to the present invention, in addition to the electric conductivity of the sodium hypochlorite diluent and the acid diluent, the electric conductivity of raw water is also used. The configuration is such that the sodium hypochlorite and acid concentration can always be accurately detected by subtracting the rate fluctuation.

According to the present invention, first, a signal corresponding to the electric conductivity (d1) of the dilute sodium hypochlorite solution and the electric conductivity (d2) of the acid diluent solution are controlled according to the principle described above. First and second electric conductivity measuring means for inputting to the means 20 are provided. In the present embodiment, a first electric conductivity sensor D1 is disposed as a first electric conductivity measuring unit downstream of the first mixer 7 provided in the first dilution mixing channel L2. Further, the second electric conductivity measuring means may be a second electric conductivity measuring means.
The second electric conductivity sensor D2 is arranged downstream of the second mixer 11 provided in the dilution mixing channel L3.

The first electric conductivity sensor D1 detects the electric conductivity (d1) of the sodium hypochlorite diluent diluted and mixed in the first mixer 7, and outputs a corresponding signal to the control means 20. Send to Also, the second electric conductivity sensor D2
Detects the electrical conductivity (d2) of the acid diluent diluted and mixed in the second mixer 11, and outputs a corresponding signal to the control means 2.
Send to 0.

Further, according to the present invention, there is provided a third electric conductivity measuring means for inputting the electric conductivity (d3) of the raw water for dilution to the control means 20. In the present embodiment, a third electric conductivity sensor D3 is disposed as a third electric conductivity measuring unit on the raw water supply flow path L1 on the downstream side of the electromagnetic valve 14. Third
The electric conductivity sensor D3 detects the electric conductivity (d3) of the raw water for dilution, and transmits a corresponding signal to the control means 20.

First, second and third electric conductivity sensors D
1, D2 and D3 are not particularly limited, but CP916A manufactured by Toa Denpa can be used preferably.
It is obvious to those skilled in the art that the outputs of the electric conductivity sensors D1, D2, D3 can be amplified or A / D converted and input to the control means 20 in a predetermined manner. The signals corresponding to the electric conductivity (d1) of the sodium hypochlorite dilution water, the electric conductivity (d2) of the acid diluent, and the electric conductivity (d3) of the raw water are those electric conductivity (d1, d2). , D3), the signal includes an arbitrary form of signal input to the control means 20.

According to the present embodiment, the difference (d1-d3) between the previously determined electrical conductivity d1 of the sodium hypochlorite diluent and the electrical conductivity d3 of the diluting raw water is stored in the control means 20.
And an electrical conductivity (d1-d3) corresponding to the concentration of a sodium hypochlorite diluent for preparing active water having a predetermined sodium hypochlorite concentration based on the relationship between the concentration and the sodium hypochlorite concentration. ) Is set.

Similarly, the control means 20 gives the difference (d2−d3) between the electric conductivity d2 of the acid diluent and the electric conductivity d3 of the raw water for dilution determined in advance and the relationship between the acid concentration and the difference. The electric conductivity (d2-d3) corresponding to the concentration of the acid diluent for preparing the activated water having a predetermined pH is set.

The difference in electric conductivity (d1-d) for preparing active water having a predetermined concentration and pH of sodium hypochlorite.
3), a plurality of set values of (d2-d3) are provided, and for example, by appropriately selecting them in the device operation unit 24, a plurality of types of activated water having different concentrations and pHs of sodium hypochlorite can be generated. You can also.

For example, in the storage means 21 built in the control means 20, the relation between the electric conductivity (d1-d3) and the sodium hypochlorite concentration, and the relation between the electric conductivity (d2-d3) and the acid concentration are stored. By storing the relationship as a table, a mathematical expression, or the like, an active water having a sodium hypochlorite concentration of, for example, 0.5 ppm to 1000 ppm and a pH range of 3.0 to 7.5 is arbitrarily selected, and the corresponding hypochlorous acid is selected. The concentration of sodium diluent and acid diluent can be monitored.

Further, for example, while measuring the concentration and pH of sodium hypochlorite at the use site of the apparatus 100 using a hypochlorous acid concentration detection sensor and a pH meter,
The operation of the pumps 5 and 9 is controlled to manually adjust the amount of sodium hypochlorite added and the amount of acid added, and the difference in electric conductivity (d1-d3) at the time when the desired activated water is obtained. ),
(D2-d3) may be set and stored.

When generating the active water, the control means 20
The electric power of the input sodium hypochlorite dilution water (d
The sodium hypochlorite concentration of the dilute sodium hypochlorite solution is constantly monitored by comparing the electric conductivity (d1-d3) obtained by subtracting the electric conductivity (d3) of the raw water for dilution from 1) with a set value. can do. Control means 2
0 is a value obtained by subtracting the electric conductivity (d3) of the raw water for dilution from the electric conductivity (d2) of the input acid diluent, and comparing the electric conductivity (d2-d3) with a set value. Acid concentration can be constantly monitored.

As described above, the electric conductivity (d1) of the dilute sodium hypochlorite solution and the electric conductivity (d
By using a signal corresponding to the difference between 3) and a signal corresponding to the difference between the electric conductivity (d2) of the acid diluent and the electric conductivity (d3) of the dilution raw water, sodium hypochlorite, In addition, it is possible to extract and monitor a change in electric conductivity caused only by a change in the concentration of an acid.

According to this embodiment, the control means 20 sets the concentration of sodium hypochlorite or the concentration of acid monitored as described above to a set value, that is, continuously. First, second and third electric conductivity sensors D1, D2, D
3 so that the electric conductivity difference (d1-d3) and the electric conductivity difference (d2-d3) detected based on the electric conductivities d1 and d3 detected by 3 are set to predetermined values.
Controlling the operations of the first pump 5 and the second pump 9;
The amount of sodium hypochlorite added from the first stock solution tank 4 and the amount of acid added from the second stock solution tank 8 are adjusted.

More specifically, the germicidal water generator 100 of this embodiment has a sodium hypochlorite concentration of 10 ppm
H5.0 activated water can be prepared at a feed rate of about 20 L / min. The first and second constant flow valves 2 and 3 supply raw water for dilution to the first dilution mixing flow path L2 and the second dilution mixing flow path L3 at the same flow rate (about 10 L / min), respectively. . Therefore, the first pump 5 injects the sodium hypochlorite stock solution such that the concentration of sodium hypochlorite detected at the position of the first electric conductivity sensor D1 becomes 20 ppm. Acetic acid has a final concentration of 0.05 to 0.1 w / w.
%, That is, 0. 0% at the position of the second electric conductivity sensor D2.
The pH of the activated water is adjusted to 5.0 by injecting acetic acid to a concentration of 1 to 0.2 w / w%.

Further, according to the present invention, when there is a possibility that active water having a predetermined concentration cannot be generated, a predetermined device abnormality operation such as an alarm or a predetermined information display is performed, so that the user can be normally operated. It can be notified that no activated water is generated. In such a case, the operation of generating the activated water itself can be stopped.

In this embodiment, the control means 20 determines that the concentration of sodium hypochlorite or the concentration of acid monitored as described above deviates from the set value, that is, the difference in electric conductivity (d
1-d3) and the electric conductivity (d2-d3) deviate from a predetermined value set in advance, and a predetermined alarm is issued by the alarm device 23 when a predetermined time has elapsed. At the same time, the control means 20 stops the supply of the raw water for dilution by closing the electromagnetic valve 14. Further, the display means 22 may display information notifying the user that the device is not operating normally.

As described above, the generated active water p
H varies depending on parameters such as the pH of the diluted raw water and the buffer action. For example, water quality including tap water pH and buffer action changes with time (seasonal change, etc.), place, and region. According to the study of the present inventors, when the apparatus 100 is used at a specific use site, the change of the pH of the tap water and the buffer action does not show the effect to fluctuate the pH of the activated water in a short time. . However, if desired, at the use site of the apparatus 100, the pH of the active water is periodically checked using a pH meter, and the relationship between the pH of the active water and the set value of the electric conductivity difference (d2-d3) is stored or stored. The relationship between the electric conductivity difference (d2-d3) stored in the means 21 and the acid concentration of the acid diluent can be appropriately corrected.

As described above, according to the present invention, it is possible to always monitor the concentration fluctuations of sodium hypochlorite and the acid itself regardless of the electric conductivity fluctuation of the raw water for dilution.
For example, even when the water quality of the raw water for dilution such as tap water changes with the passage of time, and the electrical conductivity thereof greatly changes, the addition amounts of sodium hypochlorite and the acid are automatically adjusted, and a predetermined amount is always set. It is possible to obtain activated water of sodium hypochlorite concentration and pH. In addition, it is possible to always generate active water having a strong bactericidal power by issuing a warning when there is a possibility that predetermined active water may not be generated, or by stopping the operation of generating the active water, and furthermore than necessary. The use of sodium hypochlorite can also avoid problems such as effects on the environment and costs.

Further, according to the present invention, the electric conductivity of the raw water for dilution itself is subtracted from the electric conductivity of the solution obtained by diluting and mixing sodium hypochlorite and acid, respectively. 0 [μS / cm; × 10 ^-4 S / m] reverse osmosis water (R / O water), electric conductivity of about 250 [μS / c]
m; × 10 ^-4 S / m] of tap water and an electric conductivity of about 20
A wide range of raw water for dilution, such as seawater of [mS / cm; × 10 ^-1 S / m], can be used regardless of the fluctuation of the electric conductivity. Thus, the method and apparatus according to the present invention can be used for disinfection of hemodialysis equipment that requires reverse osmosis water (R / O water) as raw water for dilution, washing and disinfection in the field of food processing such as washing of cut vegetables, etc. Further, the present invention can be applied to the preparation of activated water used in a wide range of fields, from washing and sterilizing fish in the field of fisheries.

In the above embodiment, the apparatus 100 has been described as being directly connected to the tap water supply pipe. However, when reverse osmosis water (R / O water) is used as raw water for dilution, for example, Alternatively, the supply port 1 may be connected to a tap water supply pipe via a reverse osmosis water generation device, or reverse osmosis water may be supplied to the supply port 1 from a reverse osmosis water storage tank. When seawater is used as the raw water for dilution, the supply port 1 may be connected to a seawater supply device or the supply port 1 may be connected to a seawater storage tank as raw water supply means.

Further, since the electric conductivity sensor such as the electric conductivity sensor (CP916A manufactured by Toa Denpa Co., Ltd.) is generally made of metal and plastic, according to the present invention, a pH meter using a glass electrode is used. There is no danger that the broken pieces are mixed into the activated water due to the breakage of the glass electrode as in the case of using. In general, since the calibration cycle of the electric conductivity sensor can be considerably long, for example, about 80 months, handling is simple and accurate detection is always possible.
Also, there is no need to periodically replace the electrode parts unlike a hypochlorous acid concentration sensor (residual chlorine concentration detector), so that the maintenance work and cost are significantly reduced.

In the above embodiment, as a means for inputting the electric conductivity (d3) of the raw water for dilution to the control means, the electric conductivity sensor d3 for detecting the electric conductivity of the raw water for dilution at the time of generation of the sterilizing water is used. However, as an alternative method, for example, when preparing activated water used for sterilization and disinfection of hemodialysis equipment, it has been found that the water quality is constant as reverse osmosis water (R / O water) as raw water for dilution. In this case, as the electric conductivity input means, for example, by inputting a constant value of the electric conductivity d3 of the raw water for dilution from the operation unit 24 of the apparatus 100, a corresponding signal is input to the control means 20. Can be. In this case, the control means 20 can use the constant value of the electric conductivity value d3 of the input raw water for dilution instead of the detection signal of the third electric conductivity sensor D3 in the above-described embodiment. You. The electric conductivity d3 of a plurality of types of raw water for dilution may be stored in advance in the storage means 21 and appropriately selected and used.

[0075]

As described above, according to the present invention,
A method for producing sterilized water having a predetermined sodium hypochlorite concentration and pH is to dilute and mix sodium hypochlorite and an acid alone in raw water to obtain a sodium hypochlorite diluent and an acid diluent, respectively. At the same time, the electrical conductivity of each of the diluted sodium hypochlorite solution, the diluted acid solution and the raw water (d1,
d2, d3) based on the concentration of sodium hypochlorite and acid and / or adjustment of the addition amount, and mixing of the sodium hypochlorite diluent and the acid diluent to obtain sterilized water, Also, the prescribed sodium hypochlorite concentration and pH
A raw water supply means for supplying raw water; first dilution and mixing means for adding and mixing sodium hypochlorite to the raw water to obtain a sodium hypochlorite diluted solution; Second dilution mixing means for adding and mixing an acid to obtain an acid diluent; mixing means for mixing a sodium hypochlorite diluent and an acid diluent; sodium hypochlorite diluent, acid diluent And the electric conductivity of each of the raw water (d1, d
2, d3) first, second, and third electric conductivity measuring means; and sodium hypochlorite and acid based on signals from the first, second, and third electric conductivity measuring means. And a control means for monitoring the concentration of and / or adjusting the amount of addition, so that sterilized water having a desired sodium hypochlorite concentration and pH can always be obtained safely, at low cost and easily. . Further, as raw water for dilution for preparing sterilized water, a wide range of raw water for dilution such as reverse osmosis water (R / O water), tap water, well water or seawater can be used,
Moreover, it is possible to always obtain sterilized water with a desired sodium hypochlorite concentration and pH safely, at low cost and easily.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram showing one embodiment of an apparatus embodying a method for preparing sodium hypochlorite activated water according to the present invention.

FIG. 2 is a graph showing an example of the relationship between the amount of sodium hypochlorite added to tap water and electric conductivity.

FIG. 3 is a graph showing an example of the relationship between the amount of acetic acid added to tap water and electric conductivity.

FIG. 4 is a graph showing an example of the relationship between the amount of acetic acid added to an aqueous solution of sodium hypochlorite and pH.

FIG. 5 is a graph for explaining the hypochlorous acid existence ratio depending on pH.

[Explanation of symbols]

Reference Signs List 1 supply port 2 first constant flow valve 3 second constant flow valve 4 first stock solution tank (sodium hypochlorite stock solution tank) 5 first pump 6 first injection section 7 first mixer 8 2nd stock solution tank (acid stock solution tank) 9 2nd pump 10 2nd injection part 11 2nd mixer 12 3rd mixer 13 take-out 14 solenoid valve 15 pressure switch 20 control means 21 storage means 22 display Means 23 Alarm device 24 Device operation section (electric conductivity input means) 100 Germicidal water generator (Sodium hypochlorite activated water generator) D1, D2, D3 Electric conductivity sensor (Electric conductivity measuring means) L1 Raw water supply Channel L2 First dilution / mixing channel (sodium hypochlorite dilution / mixing channel) L3 Second dilution / mixing channel (acid dilution / mixing channel) L4 Mixing channel

Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat II (Reference) C02F 1/50 560 C02F 1/50 560Z A61L 2/18 A61L 2/18 (72) Inventor Hitoshi Mohri Kawagoe-shi, Saitama 175-9 Yamashiro (72) Inventor Kiyotaka Shima 175-1 Mizuno, Sayama-shi, Saitama F-term (reference) 4C058 AA12 BB07 JJ06 JJ08

Claims (15)

[Claims] 1. The method according to claim 1, wherein a predetermined sodium hypochlorite concentration and p
A method for producing sterilized water of H, wherein sodium hypochlorite and an acid are each separately diluted and mixed with raw water to obtain a sodium hypochlorite diluent and an acid diluent, respectively.
The concentration of sodium hypochlorite and the acid are monitored and / or the amount added is adjusted based on the electric conductivity (d1, d2, d3) of each of the diluted sodium hypochlorite solution, the diluted acid solution and the raw water, A method for producing sterilized water, comprising mixing a diluted sodium hypochlorite solution and the diluted acid solution to obtain sterilized water. 2. The electrical conductivity (d1, d2, d3) of each of the sodium hypochlorite diluent, the acid diluent and the raw water.
2. The method according to claim 1, wherein the detection is performed when sterilized water is generated. 3. When the electric conductivity of raw water is constant,
The electric conductivity (d1, d2) of each of the sodium hypochlorite diluent and the acid diluent is detected when sterilized water is generated, and the electric conductivity (d3) of raw water is determined using a predetermined value. The method of claim 1 wherein the method comprises: 4. The relationship between the sodium hypochlorite concentration and the difference (d1-d3) between the previously determined electrical conductivity of the sodium hypochlorite diluent and the raw water, and the electrical conductivity of the acid diluent and the raw water. 4. The method according to claim 1, wherein the concentration of sodium hypochlorite and the acid are monitored and / or the amount added is adjusted based on the relationship between the acid concentration and the difference (d2-d3) in the ratio. 5. The raw water is tap water, well water, seawater or reverse osmosis water (R / O water).
The method according to any of the above items. 6. The concentration of sodium hypochlorite in sterilized water is in the range of 0.5 ppm to 1000 ppm, and the pH is p.
The method according to any one of claims 1 to 5, wherein H is in the range of 3.0 to 7.5. 7. A predetermined sodium hypochlorite concentration and p
An apparatus for producing sterilized water of H, a raw water supply means for supplying raw water, a first dilution and mixing means for adding and mixing sodium hypochlorite to the raw water to obtain a sodium hypochlorite diluted liquid, A second dilution mixing means for adding and mixing an acid to the raw water to obtain an acid diluent; a mixing means for mixing the sodium hypochlorite diluent and the acid diluent; and the sodium hypochlorite. First, second, and third electric conductivity measuring means for measuring the electric conductivity (d1, d2, d3) of each of the diluent, the acid diluent, and the raw water; and the first, second, and third electric conductivity measuring means. A germicidal water generating apparatus, comprising: control means for monitoring the concentrations of sodium hypochlorite and acid and / or adjusting the amounts added based on a signal from the electric conductivity measuring means. 8. A raw water supply flow path as the raw water supply means, and a flow path branched from the raw water supply flow path as the first dilution / mixing means, wherein the raw water flowing through the flow path has a sub-aperture. A first dilution / mixing flow path including means for adding sodium chlorate, a first mixer for mixing and stirring the liquid after sodium hypochlorite is added, and the second dilution / mixing means A flow path branched from the raw water supply flow path, a means for adding an acid to the raw water flowing in the flow path, and a second mixer for mixing and stirring the liquid after the acid is added. A second dilution / mixing flow path provided, and a flow path through which liquids from the first and second dilution / mixing flow paths are merged and guided as the mixing means; A mixing channel provided with a third mixer for mixing and stirring the liquid and the liquid from the second dilution mixing channel; The apparatus of claim 7, comprising: 9. The first electric conductivity measuring means is provided downstream of the first mixer in the first dilution mixing channel,
The second electric conductivity measuring means is provided downstream of the second mixer in the second dilution mixing channel, and the third electric conductivity measuring means is provided in the raw water supply flow path. 9. The device of claim 8, wherein: 10. An electric conductivity input means for inputting a predetermined value of the electric conductivity of raw water obtained in advance to the control means, wherein the control is performed when the electric conductivity of the raw water is constant. 8. The method according to claim 7, wherein the means uses the signal input from the electric conductivity input means instead of the signal from the third electric conductivity measurement means as the electric conductivity (d3) of the raw water. The device of 8 or 9. 11. The control means includes: a relationship between a difference (d1-d3) between an electric conductivity of the dilute sodium hypochlorite solution and raw water obtained in advance and a concentration of sodium hypochlorite, and the acid diluent solution. And the difference in electric conductivity between raw water (d2-
The apparatus according to any one of claims 7 to 10, wherein the concentration of sodium hypochlorite and the acid are monitored and / or the amounts added are adjusted based on the relationship of the acid concentration to d3). 12. The control means monitors the sodium hypochlorite concentration of the sodium hypochlorite diluent and the acid concentration of the acid diluent, and controls the hypochlorous acid of the sodium hypochlorite diluent. The addition amount of sodium hypochlorite and the addition amount of acid are adjusted so that the sodium concentration and the acid concentration of the acid diluting solution are set to predetermined values. The device according to the item. 13. The control means monitors the sodium hypochlorite concentration of the sodium hypochlorite diluent and the acid concentration of the acid diluent, and the concentration of the sodium hypochlorite and / or acid is monitored. When the value deviates from the set value, a predetermined alarm,
The apparatus according to any one of claims 7 to 12, wherein the apparatus performs a predetermined apparatus abnormal operation including a predetermined information display and a stop of raw water supply. 14. The raw water is tap water, well water, seawater or reverse osmosis water (R / O water).
Item 13. The device according to any one of items 13. 15. The sterilizing water has a sodium hypochlorite concentration in a range of 0.5 ppm to 1000 ppm,
The device according to any one of claims 7 to 14, wherein pH is in the range of 3.0 to 7.5.