JP2009219984A - Process for producing sterilized water - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve the problem that sterilized water cannot be produced with a high accuracy at a low cost due to an unsatisfactory chemical mixing function and a low pH measuring accuracy, in a process for producing sterilized water by mixing acetic acid and sodium hypochlorite into water. <P>SOLUTION: Sodium hypochlorite is first introduced into a water tank with a circulation pump. Stirring is satisfactorily performed with a circulation pump, and a primary concentration is regulated with a pH meter. Next, acetic acid is introduced and dispersed into the water tank. The mixture is satisfactorily stirred with the circulation pump, and the concentration of a completed product is regulated with the pH meter to produce sterilized water. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

The present invention relates to a method and an apparatus for producing sterilizing water using sodium hypochlorite.

Conventionally, an apparatus for adjusting the acidity (pH) of chlorinated sterilized water to produce sterilized water having strong sterilizing power has been provided. (For example, Patent Document 1) In this sterilizing water production apparatus, an acidic liquid such as hydrochloric acid for adjusting pH is mixed into a water stream as a stock solution, and an aqueous sodium hypochlorite solution serving as a sterilizing water stock solution is mixed. Sterilized water is produced. The sterilized water produced in this way is widely used for various purposes such as washing in order to prevent the growth of microorganisms in the food industry and for disinfecting hospitals.
JP 2006-305428 A

In such a conventional sterilizing water production apparatus, since the chemicals are mixed in the flow path pipe, the mixing action is not sufficient, the measurement accuracy is low in pH measurement for concentration control, and hypochlorous acid is used as a stock solution of the chlorinated aqueous solution When a high concentration stock solution of sodium is used, there is a problem in that it is difficult to make uniform and highly accurate sterilized water because it is not possible to correct the concentration variation due to deterioration of the stock solution or unstable mixing operation.
An object of the present invention is to solve the above problems.

The reason why it is difficult to produce stable sterilized water is that the substantial concentration of sodium hypochlorite decreases during use and deteriorates (deactivates). First, sodium hypochlorite is added and sufficiently stirred with a circulation pump, and the primary concentration is controlled with a pH meter. Next, acetic acid, hydrochloric acid or citric acid is charged into the main tank and sufficiently stirred with a circulation pump. The pH meter was used as a means for controlling the finished product concentration to produce highly accurate sterilized water.

To introduce sodium hypochlorite into the water in the main tank, the chemical pressurized by the pump installed in the drain of the chemical container containing the sodium hypochlorite stock solution is passed through the transfer pipe. Gradually throwing water into the water in the main tank from the dispersion nozzle installed at the tip of this chemical transfer pipe, sodium hypochlorite is dispersed into the water in the main tank to create high-precision sterilizing water. .

In order to put acetic acid, hydrochloric acid or citric acid into the water in the main tank, the chemicals pressurized by the pump installed in the drain of the chemical container B containing these stock solutions are passed through the transfer pipe, Dispersion was charged into the water in the main tank from the dispersion nozzle installed at the tip of the chemical transfer pipe to create highly accurate sterilization water.

Circulating the liquid stored in the main tank from the drain of the main tank through the circulation pump, mixing pipe, three-way branch valve, and transfer pipe into the main tank through the dispersion nozzle installed at the tip In addition to providing a water channel, a pressure relief valve was provided in a part of this circulation channel so that sodium hypochlorite, acid and water could be sufficiently stirred and mixed.

In the present invention, a method for producing sterilizing water in which acetic acid, hydrochloric acid or citric acid and sodium hypochlorite are mixed in water, and first sodium hypochlorite is placed in a main tank equipped with a circulation pump. The concentration is accurately controlled by a pH meter, and then an acid such as acetic acid is charged into the main tank and the concentration is accurately controlled by the pH meter. Chlorine stock solution and acid stock solution are evenly mixed in water with higher accuracy than pH measurement in, so even if the chlorine stock solution has begun to deactivate, chlorine that should be properly mixed in sterilized water The supply amount of the system stock solution can be determined.

In addition, this configuration can be realized at a relatively low cost by controlling the concentration of acetic acid and sodium hypochlorite mixed in water using one pH sensor, and the pH sensor is appropriately Since it has a function that can be washed with injected water, it can produce sterilized water with high accuracy, and since the pH sensor is always operating, it can prevent generation of chlorine gas due to large liquidity and acidity. In the unlikely event that gas is generated and the internal pressure of the main tank rises abnormally, the pressure relief valve operates to ensure safety.

Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings.
FIG. 1 shows a schematic configuration of a sterilizing water production apparatus 1 according to an embodiment of the present invention. Reference numeral 2 denotes a cubic body case made of sheet metal, which has a leg 32 at the bottom and an operation display panel 11 on one side. The other side is penetrating the water supply pipe 14 and the drainage pipe 39, 25 is a main tank made of stainless steel having a lid 8 at the upper end and a drain outlet 26 at the lower end. This water supply pipe 14 is a water supply solenoid valve A41 and a water supply solenoid valve B42 are connected, one end is connected to a general water pipe, and the other end is piped through the lid 8 so that water can be supplied into the main tank 25. From the middle of the solenoid valve B42, the sensor cleaning pipe
The tip of the sensor cleaning pipe 43 extends through the lid 8 to the water in the main tank 25, and the pH sensor 24 is disposed in the pipe at the tip.

27 is a circulation pump installed at the drain port 26 at the lower end of the main tank 25. The discharge port connects the different diameter sections from the circulation pipe 28 to cause turbulence in the liquid, and uniformly mixes different kinds of liquids. A circulation path that extends through the mixing pipe 29 having the function of passing through the three-way branch valve 4 and the return pipe 44 and further through the lid 8 into the main tank 25 is formed above the return pipe 44. The installed pressure relief valve 5 provides protection against an abnormal pressure increase in the main tank 25. The three-way branch valve 4 manually switches the liquid in the main tank 25 that has passed through the mixing pipe 29 through the drain pipe 39. 6 is a water level gauge that is made of a thin non-magnetic pipe and is attached to the lid 8 of the main tank 25. A number of reed switches 3 are fixed to the pipe, and a floating float 7 with a magnet 9 is fixed to the outer periphery of the pipe. To have.

16 is a cubic chemical container A formed by blow molding a chemical-resistant resin, and has a lid 17 at the upper end and a drain port A23 at the lower end, and 22 is a chemical container A16 by a pump A22 installed at the drain port A23. The chemical contained in (sodium hypochlorite) can be gradually injected into the main tank 25 from the dispersion nozzle installed at the tip of this chemical transfer pipe through the chemical transfer pipe 21, 45 is non-magnetic A water level gauge 18 made of a thin body pipe and attached to the top lid 46 of the chemical container A16. A plurality of reed switches 47 are fixed at the water level detection position in the pipe, and a magnet 20 is attached to the outer periphery of the pipe. A fixed sliding donut-shaped float 19 is loosely fitted.

36 is a cubic chemical container B constructed by blow molding a chemical-resistant resin. It has a lid 38 at the top and a drain B41 at the bottom. 31 is a pump B31 installed at this drain B41. The charged chemical (acetic acid, hydrochloric acid or citric acid) can be injected into the main tank 25 from the dispersion nozzle installed at the tip of this chemical transfer pipe through the chemical transfer pipe 30, 37 is a thin non-magnetic material It is a water level gauge made of a pipe and attached to the top lid 56 of the chemical container B36. A plurality of reed switches 35 are fixed to the water level detection position in the pipe, and a magnet 33 is fixed to the outer periphery of the pipe and slides. A donut-shaped float 34 is loosely fitted.

Next, the dispersion nozzle 45 installed at the tip of the chemical transfer pipe described above will be described with reference to FIG. 2 for three embodiments. Fig. 2-1 is a cross-sectional view of the dispersion nozzle. Fig. 2-1 has a hole 51 in a part of the dispersion nozzle body formed by spherically opening open cell foams. The liquid sent from the chemical container configured as described above enters the dispersion nozzle body from the tip of the chemical transfer pipe, is diffused with the foam, and can be gradually injected into the main tank 25.
Fig. 2-2 shows a product made by machining a round bar of chemical-resistant resin (for example, vinyl chloride). A large number of through holes 49 are provided around the hole 53 in the center, and a hole 50 is also provided in the lower part. The liquid sent from the chemical container, which is configured by slidingly fitting the tips of the chemical transfer pipes 21 and 30 into the holes 53, enters the dispersion nozzle 45 from the tips of the chemical transfer pipes and through the through holes 49 and 50. Fig.2-3 is formed by drawing a sheet metal, and a projection 60 having a hole 48 in the center is formed in the cylinder 55. A large number of fine holes 59 are formed on the outer periphery of the cylinder. 61 is a bottom plate having a large number of holes 61 and is fixedly fitted to the lower surface of the cylinder 55. The dispersion nozzle 45 enters from the tip of the pipes 21 and 30 and is diffused through the fine holes 59 and 61 and can be gradually injected into the main tank 25.

The method of using the sterilizing water production apparatus according to the present embodiment will be described with reference to the flowchart of FIG. 3. When the power supply in the operation display panel 11 is turned on, a power lamp and a stop lamp (not shown) are lit. When the water supply electromagnetic valve B42 is opened, water from a general water pipe starts to be supplied into the main tank 25 via the water supply pipe 14, the water supply electromagnetic valve A41 and the water supply electromagnetic valve B42, and the water level starts to rise gradually. The float 7 with buoyancy slides on the outer circumference of the pipe 6 following the change in the water level. The magnet 9 fixed to the float 7 turns on the reed switch 3 in the water level detection position one after another, and the water level signal in the main tank 25 When the water level reaches the upper limit in the main tank 25, the water supply electromagnetic valve A41 and the water supply electromagnetic valve B42 are closed to stop the water supply. Next, when the circulation pump 27 is turned on, the main tank 25 The water in the discharge port 26, circulation pie The mixing tube 29 from the street way branch valve 4 to 28 via the return pipe 44 is circulated in a path back to the main tank 25.

Next, when the pump A22 of the chemical container A16 is turned on, the water level gauge 18 of the chemical container A16 operates. If the amount of liquid is insufficient, the lamp flashes and the chemical (sodium hypochlorite) is added to the chemical container A16. When the lid 17 is opened, the lamp stops blinking and the pump A22 starts to drive, and the chemical in the chemical container A16 is diffused and injected into the main tank 25 from the dispersion nozzle 45 through the chemical transfer pipe 21. The pH sensor 24 in the main tank 25 is constantly monitored, and when the specified value (in this case, pH 9.5) is reached, the pump A22 is stopped and first an aqueous solution in which the chemical A (sodium hypochlorite) is uniformly mixed. Is completed.

Next, when the pump B31 of the chemical container B36 is turned on, the water level gauge 37 of the chemical container B26 works, and if the amount of liquid is insufficient, the lamp blinks. When the container is opened and filled, the lamp stops blinking and the pump B31 starts to be driven, and the medicine in the medicine container B36 is injected little by little into the main tank 25 from the dispersion nozzle 45 through the medicine transfer pipe 30. The pH sensor 24 of the inside constantly monitors and when the specified value (in this case, pH 6.5) is reached, the pump B31 is stopped and chemical A (sodium hypochlorite) and chemical B (acetic acid) are mixed uniformly. The sterilized water is completed in the main tank 25.

Next, the process of taking out the sterilized water produced as described above will be explained. When the three-way branch valve 4 is switched to the discharge side, the sterilized water in the main tank 25 passes from the discharge port 26 and the circulation pipe 28 through the mixing pipe 29. The three-way branch valve 4 passes through the drainage pipe 39, exits from the drainage port 40, and is discharged to the outside from the sterilizing water production apparatus 1, and is subdivided as needed for each use.

When the water level gauge 6 in the main tank 25 gives a lower limit signal, the control unit informs with a lamp, turns off the circulation pump 27 that has been operating until now, returns the three-way branch valve 4 to the circulation side, and turns off the power supply. As a result, the power lamp and the stop lamp are extinguished to complete the manufacturing process.

During use, the sensing part of the pH sensor 24 in the main tank 25 may be contaminated with residual chemicals and the like, and the detection accuracy may deteriorate. At that time, during the water supply process to the main tank 25, the water supply electromagnetic valve B42 When the tap is closed, tap water from the water supply pipe 14 passes directly through the water supply electromagnetic valve A17 and the sensor cleaning pipe 43 and directly hits the pH sensor 24, so that the residual chemicals adhering to the surface of the pH sensor 24 can be washed away and the accuracy is maintained. .

These show the schematic structure of the sterilizing water manufacturing apparatus by one Embodiment of this invention. These are sectional drawings which showed each structure of 3 Example of a dispersion | distribution nozzle. FIG. 2 is a flowchart showing how to use the sterilizing water production apparatus of FIG.

Explanation of symbols

2 ... Body case 4 ... Three-way branch valve 11 ... Operation display panel 16 ... Chemical container A
18 ... Water level gauge 24 ... pH sensor 25 ... Main tank 27 ... Circulation pump 29 ... Mixing pipe 36 ... Chemical container B
45 ... Dispersing nozzle

Claims (4)

First, sodium hypochlorite is introduced into the water in the main tank equipped with a circulation pump. This is a method for producing sterilized water by mixing acetic acid, hydrochloric acid or citric acid and sodium hypochlorite into water. A method for producing sterilizing water, characterized in that the primary concentration is controlled by a pH meter, and then acetic acid, hydrochloric acid or citric acid is gradually introduced into the main tank, and the finished product concentration is controlled by the pH meter. In order to introduce sodium hypochlorite into the water in the main tank, the chemical pressurized by the pump installed at the drain of the chemical container containing the stock solution of sodium hypochlorite is transferred to the transfer pipe. The method for producing sterilized water according to claim 1, wherein the water is gradually introduced into the water in the main tank from a dispersion nozzle installed at the tip of the chemical transfer pipe. In order to put the acetic acid, hydrochloric acid or citric acid into the water in the main tank, the chemicals are pressurized by a pump installed in the drain of the chemical container in which these stock solutions are stored, and then passed through the transfer pipe. The method for producing sterilizing water according to claim 1, wherein the sterilizing water is gradually poured into the water in the main tank from a dispersion nozzle installed at the tip of the chemical transfer pipe. A circulation pump, a mixing pipe, and a three-way branch valve are connected to the main tank, and a circulation water passage for the mixed liquid in the main tank is provided, and a pressure relief valve is provided in a part of the circulation water passage. The method for producing sterilized water according to claim 1.