JP3790362B2 - Electrolytic sodium hypochlorite generator - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an electrolytic sodium hypochlorite generator, and more particularly to an electrolytic sodium hypochlorite generator that is compact and easy to install without the need to cool an electrolytic cell.
[0002]
[Prior art]
Conventionally, an electrolytic sodium hypochlorite generator is used for sterilization of waterworks, pools, and the like. From this electrolytic sodium hypochlorite generator, a sodium hypochlorite aqueous solution having a high concentration (effective chlorine concentration of about 1% by weight) is generated. Then, an appropriate amount is injected or added so as to have a concentration suitable for use in waterworks or a pool. In the present specification, L, which is a unit of volume, is represented by L.
[0003]
[Problems to be solved by the invention]
By the way, when such high-concentration sodium hypochlorite aqueous solution is used for sterilization washing water for hygiene management (hand washing, floors, containers, equipment, food), it cannot be used because it corrodes and dissolves. It is necessary to dilute to a concentration suitable for use. Accordingly, another supply water source is required for dilution, and concentration control is required in two steps before and after dilution.
[0004]
In addition, the conventional electrolytic sodium hypochlorite generator electrolyzes concentrated salt water at a high current density and a low flow rate, so that the electrolytic bath becomes high temperature, requires a cooling device, and has a drawback that the structure is complicated.
The present invention has been made in view of such conventional problems, and an object of the present invention is to provide an electrolytic sodium hypochlorite generator that is compact and easy to install without the need to cool the electrolytic cell.
[0005]
[Means for Solving the Problems]
In order to achieve the above object, the invention according to claim 1 of the present invention is an electrolytic sodium hypochlorite generator for electrolyzing salt water to produce sodium hypochlorite. Concentrated salt water storage section for generating or storing salt water of a concentration, salt water supply means for supplying salt water from the concentrated salt water storage section, and salt water supplied from the salt water supply means has a concentration of 8 to 30 g-NaCl / L. The first diluting means for diluting with water and the salt water diluted with the first diluting means are introduced and electrolyzed to form sodium hypochlorite, which is then released as an aqueous sodium hypochlorite solution. an electrolytic bath, diluted with water directly without storing the aqueous solution of sodium hypochlorite released from electrolytic bath, a second dilution means for discharging an effective chlorine concentration of 20 to 300 mg / L, Serial The electrolytic cell, characterized in that no cooling means for cooling the electrolytic bath.
[0006]
In the concentrated salt water storage unit, salt water of 100 g-NaCl / L to a saturated concentration is generated or stored. Here, the salt water is an aqueous solution of sodium chloride. The saturation concentration is about 310 g-NaCl / L. The reason for generating or storing is that salt water adjusted to a predetermined concentration may be stored in advance, or salt water having a predetermined concentration may be adjusted by dissolving solid salt in water. In the salt water supply means, salt water is supplied from the concentrated salt water reservoir.
[0007]
In the first dilution means, the salt water supplied from the salt water supply means is diluted with water so as to have a concentration of 8 to 30 g-NaCl / L. Thus, since concentrated salt water was diluted, a concentrated salt water storage part can be reduced in size.
Thereafter, the diluted salt water is electrolyzed after flowing into the electrolytic cell. As a result of the electrolysis, sodium hypochlorite is produced and released as an aqueous sodium hypochlorite solution.
[0008]
The reason for limiting the concentration of salt water flowing into the electrolytic cell to 8 to 30 g-NaCl / L is that the higher the concentration, the higher the chlorine generation current efficiency, but the lower the utilization rate of NaCl, the lower the flow rate. . Moreover, the utilization rate of NaCl increases as the concentration decreases, but the efficiency of chlorine generation current decreases, and the electrolytic cell needs to be enlarged. That is, when the concentration is high, the water temperature rises greatly, and a cooling device is required. On the other hand, when the concentration is low, the electrolytic cell becomes large and the versatility becomes poor. Therefore, by limiting the salt water concentration to 8 to 30 g-NaCl / L, the electrolytic cell can be operated without becoming high temperature without being cooled, and the entire apparatus can be downsized.
[0009]
In the second dilution means, the sodium hypochlorite aqueous solution released from the electrolytic cell is directly diluted with water without being stored , and discharged to the outside at an effective chlorine concentration of 20 to 300 mg / L, which is a concentration suitable for use. . For this reason, the discharged sodium hypochlorite aqueous solution can be used as it is without the need for concentration adjustment such as dilution work.
[0010]
The water supplied to the first diluting means and the second diluting means can be supplied from separate pipes, but as in the invention according to claim 2, the salt water is electrolyzed and sodium hypochlorite is obtained. In the electrolytic sodium hypochlorite generating device to be generated, a concentrated salt water storage section for generating or storing 100 g-NaCl / L to saturated salt water, a salt water supply means for supplying salt water from the concentrated salt water storage section, and the salt water First diluting means for diluting with salt water supplied from the supplying means to a concentration of 8 to 30 g-NaCl / L, and electrolyzing the salt water diluted with the first diluting means after flowing in. An electrolytic cell that generates sodium hypochlorite and then discharges it as an aqueous sodium hypochlorite solution, and an aqueous sodium hypochlorite solution released from the electrolytic cell is diluted with water to obtain an effective chlorine concentration of 20 to 300 mg / L. so A second dilution means for out, water supplied to the first dilution means and the second dilution means can also be supplied separately from the same water pipe. As a result, it can be used with only one supply water source, and versatility is expanded. Also, the installation work is simple.
[0011]
Further, the invention according to claim 3 is characterized in that the concentrated salt water storage part stores a mixture of solid salt and salt water, and has a water supply pipe having a water supply valve for supplying water to the concentrated salt water storage part, and the solid A salt water supply pipe that separates and discharges salt water from a mixture of salt and salt water, and a liquid level gauge that detects the liquid level of the concentrated salt water storage section. The water supply valve is opened when it reaches, and the water supply valve is closed when the liquid level rises and reaches a predetermined value. The present invention is applied when salt water is generated from solid salt in a concentrated salt water reservoir. Labor saving can be achieved by opening and closing the water supply valve based on the signal of the liquid level gauge.
[0012]
Furthermore, the invention described in claim 4 is characterized in that at least the salt water supply means, the first dilution means, the electrolytic cell, and the second dilution means are mounted as a unit. By mounting with a housing or the like, the apparatus can be miniaturized and easily transported, and installation work can be simplified.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings. A first embodiment of the present invention is shown in FIG. In FIG. 1, solid salt is stored in the concentrated salt water storage unit 1, and salt water close to a saturated concentration is generated by supplying water. From the concentrated salt water storage unit 1, salt water close to saturation concentration is pumped by a salt water supply pump 5 through a salt water supply pipe 3. Supply water is supplied to the salt water adding section 7 through a dilution supply water pipe 9 and an on-off valve 11, a salt water dilution supply water pipe 13 and a flow rate control valve 15. The salt water diluted in the salt water addition unit 7 is introduced into the electrolytic cell 19 through the salt water introduction pipe 17.
[0014]
The electrolytic cell 19 is provided with an anode 21 and a cathode 23 facing each other, and a DC power source 25 is connected to them. The sodium hypochlorite aqueous solution generated by electrolysis in the electrolytic bath 19 is discharged to the outside through the sodium hypochlorite aqueous solution discharge pipe 27. The sodium hypochlorite aqueous solution discharge pipe 27 and the sodium hypochlorite dilution supply water pipe 29 are connected by a sodium hypochlorite dilution water mixing section 31, and are diluted via a flow rate control valve 33. Supply water is supplied.
[0015]
The sodium hypochlorite dilution supply water pipe 29 and the salt water dilution supply water pipe 13 are connected to the dilution supply water pipe 9 by a supply water pipe connecting portion 35, and the supply water is a sodium hypochlorite dilution supply water pipe. 29 and the salt water dilution feed water pipe 13 are distributed by a predetermined flow rate. Further, in order to maintain the liquid level of the concentrated salt water storage unit 1, a liquid level adjustment supply water pipe 37 is provided, and a water supply valve 39 is provided in the middle of the liquid level adjustment supply water pipe 37. The liquid level adjusting supply water pipe 37 and the dilution supply water pipe 9 are connected by a supply water branching section 41.
Each component is housed in an integral housing 40 except for the liquid level adjusting supply water pipe 37, the water supply valve 39, the supply water branching section 41 and the concentrated salt water storage section 1.
[0016]
Next, the operation will be described.
In FIG. 1, solid salt is stored in the concentrated salt water storage unit 1, and by supplying water from a liquid level adjusting supply water pipe 37, salt water close to a saturated concentration is generated. And the salt water supply pump 5 pumps the salt water close | similar to the saturated density | concentration produced | generated in this concentrated salt water storage part 1. FIG. However, the installation location of the salt water supply pump 5 is not limited to the inside of the housing 40, and can be installed in the concentrated salt water storage unit 1, for example.
[0017]
In the salt water addition part 7, the density | concentration of salt water is diluted 3 to 40 times with the feed water sent from the feed water pipe 13 for salt water dilution. Thereby, the density | concentration of salt water is made into the density | concentration of 8-30 g-NaCl / L suitable for electrolysis. By reducing the supply amount of salt water close to the saturated concentration pumped from the salt water supply pipe 3 as much as possible, the concentrated salt water storage unit 1 can be downsized.
[0018]
Thereafter, this salt water is introduced into the electrolytic cell 19 through the salt water introduction pipe 17. In the electrolytic bath 19, the salt water is electrolyzed to produce a sodium hypochlorite aqueous solution. By adjusting the concentration of salt water to 8 to 30 g-NaCl / L, the utilization rate of NaCl can be improved and the generated heat can be suppressed as much as possible. For this reason, a cooling device is unnecessary and the electrolytic cell 19 can be comprised compactly.
The DC power supply 25 is preferably provided with a voltage forward / reverse switching function in order to prevent calcium salt deposition.
[0019]
The generated sodium hypochlorite aqueous solution is diluted 2 to 60 times in the sodium hypochlorite dilution water mixing unit 31 with the dilution supply water supplied through the sodium hypochlorite dilution supply water pipe 29. . As a result, the effective chlorine concentration discharged from the sodium hypochlorite aqueous solution discharge pipe 27 is diluted to a working concentration of 20 to 300 mg / L. Thus, since it is diluted so as to have a concentration suitable for use, the discharged sodium hypochlorite aqueous solution can be used as it is without the need for concentration adjustment such as dilution work. Moreover, the mistake of density adjustment at the time of dilution work is eliminated.
[0020]
Specific flow rates of the liquids in the apparatus of FIG. 1 include, for example, a flow rate of 6 mL / min in the salt water supply pipe 3, a flow rate of 200 mL / min in the salt water introduction pipe 17, and a flow rate in the sodium hypochlorite aqueous solution discharge pipe 27. An example is 5 L / min. As other examples, the flow rate of the salt water supply pipe 3 is 60 mL / min, the flow rate of the salt water introduction pipe 17 is 2 L / min, and the flow rate of the sodium hypochlorite aqueous solution discharge pipe 27 is 15 L / min.
[0021]
Supply water passes through a supply water pipe 9 for dilution, which is a single pipe, and is used for dilution of salt water (supply water pipe 13 for dilution of salt water) and aqueous sodium hypochlorite solution (dilution of sodium hypochlorite) at the supply water pipe connecting portion 35. Therefore, the apparatus is simple and the installation work is simple. The flow rate control valve 15 and the flow rate control valve 33 are configured by, for example, a venturi pipe, and supply water is distributed at a predetermined flow rate distribution ratio as described above.
In addition, when the liquid level of the concentrated salt water storage part 1 falls, in order to prepare salt water, the water supply valve 39 is opened and supply water is replenished.
[0022]
As described above, by setting the salt water supply method to a low concentration and high flow rate instead of a high concentration and low flow rate, the temperature increase of the electrolytic cell 19 can be prevented and the apparatus can be downsized.
The dilution supply water pipe 9 is provided with an opening / closing valve 11, and the opening / closing of the apparatus is started and stopped. In addition, when the operation is abnormal (for example, when the electrolytic cell voltage is detected and the normal range is exceeded, or when the flow rate detector is provided in the pipe and the normal range is exceeded), the on-off valve 11 is closed and the device is closed. The device can be safely operated by stopping or turning off the power.
[0023]
Next, a second embodiment of the present invention is shown in FIG.
In the second embodiment of the present invention, except for the concentrated salt water storage section 1, the components of the liquid level adjusting supply water pipe 37, the water supply valve 39, and the supply water branching section 41 are contained in an integrated housing 40. Stored. This makes installation easier than in the first embodiment of the present invention.
When using salt water having a concentration close to saturation, it is desirable to provide a level detector (not shown) in the concentrated salt water reservoir 1 so that the water supply valve 39 can be opened and closed automatically.
[0024]
Next, a third embodiment of the present invention is shown in FIG.
In the third embodiment of the present invention, all the components including the concentrated salt water storage unit 1 are housed in an integral housing 40. The present invention is particularly effective when, for example, the production capacity of an aqueous sodium hypochlorite solution is 10 L / min or less. Since the concentrated salt water storage unit 1 is also housed in the housing 40, the installation work can be omitted and the operation can be made more convenient.
[0025]
【The invention's effect】
As described above, according to the present invention, since the concentration of the salt water introduced into the electrolytic cell is limited, the electrolytic cell can be operated without cooling, and the entire apparatus can be downsized. Moreover, since the effective chlorine concentration of the sodium hypochlorite aqueous solution discharged from the electrolytic cell was adjusted to a concentration suitable for use by the second diluting means, the discharged sodium hypochlorite aqueous solution was adjusted for concentration during dilution work, etc. Can be used as it is.
[0026]
[Brief description of the drawings]
FIG. 1 is a block diagram of a first embodiment of the present invention. FIG. 2 is a block diagram of a second embodiment of the present invention. FIG. 3 is a block diagram of a third embodiment of the present invention.
DESCRIPTION OF SYMBOLS 1 Concentrated salt water storage part 3 Salt water supply pipe 5 Salt water supply pump 7 Salt water addition part 9 Dilution supply water pipe 11 On-off valve 13 Salt water dilution supply water pipe 15 Flow control valve 17 Salt water introduction pipe 19 Electrolysis tank 27 Discharge of sodium hypochlorite aqueous solution Pipe 29 Water supply pipe 31 for diluting sodium hypochlorite 31 Water mixing section 33 for diluting sodium hypochlorite Flow control valve 35 Supply water pipe connecting section 37 Supply water pipe 39 for adjusting the liquid level Water supply valve 40 Housing 41 Supply water branching section

Claims (4)

In an electrolytic sodium hypochlorite generating device that electrolyzes salt water to generate sodium hypochlorite, a concentrated salt water storage unit that generates or stores salt water of 100 g-NaCl / L to a saturated concentration, and the concentrated salt water storage unit A salt water supplying means for supplying salt water, a first diluting means for diluting the salt water supplied from the salt water supplying means with water so that the salt water has a concentration of 8 to 30 g-NaCl / L, and the first diluting means. An electrolytic cell that is electrolyzed after flowing in diluted salt water to generate sodium hypochlorite and then discharged as an aqueous sodium hypochlorite solution, and an aqueous sodium hypochlorite solution released from the electrolytic cell are stored. Without being diluted directly with water and having a second dilution means for discharging at an effective chlorine concentration of 20 to 300 mg / L ,
The electrolytic cell sodium hypochlorite generator, characterized in that the electrolytic cell does not have a cooling means for cooling the electrolytic cell . In an electrolytic sodium hypochlorite generating device that electrolyzes salt water to generate sodium hypochlorite, a concentrated salt water storage unit that generates or stores salt water of 100 g-NaCl / L to a saturated concentration, and the concentrated salt water storage unit A salt water supplying means for supplying salt water, a first diluting means for diluting the salt water supplied from the salt water supplying means with water so that the salt water has a concentration of 8 to 30 g-NaCl / L, and the first diluting means. An electrolytic cell that is electrolyzed after injecting diluted salt water to form sodium hypochlorite and then discharged as an aqueous sodium hypochlorite solution, and the aqueous sodium hypochlorite solution discharged from the electrolytic cell with water Second dilution means for diluting and discharging at an effective chlorine concentration of 20 to 300 mg / L,
The first dilution means and water supplied to the second dilution means to that electrostatic KaitsugiA sodium chlorate generator and supplying separated from the same water pipe.   The concentrated salt water storage part stores a mixture of solid salt and salt water, a water supply pipe having a water supply valve for supplying water to the concentrated salt water storage part, and separates salt water from the mixture of solid salt and salt water A salt water supply pipe that discharges and a liquid level meter that detects the liquid level of the concentrated salt water storage unit, and when the liquid level decreases to reach a predetermined value due to salt water discharge, the water supply valve is opened, The electrolytic sodium hypochlorite generator according to claim 1 or 2, wherein the water supply valve is closed when the liquid level rises and reaches a predetermined value.   The apparatus for producing electrolytic sodium hypochlorite according to claim 1, 2 or 3, wherein at least the salt water supply means, the first diluting means, the electrolytic cell, and the second diluting means are integrally mounted.

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