JP2003103261A - Electrolytic washing water and method and apparatus for making the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide electrolytic washing water having stable solubility and excellent washing power and usable safely because of low corrosiveness. SOLUTION: Raw water comprising tap water or pure water is softened by using a strong acidic type cation exchange resin and a sodium or potassium compound is added to the softened raw water as an additive. This raw water is electrolyzed in an electrolytic cell 1 and alkaline electrolytic water generated in a cathode chamber 1B is used as washing water.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the field of cleaning in general, and more particularly to electrolytic cleaning water suitable for industrial part cleaning and the food processing industry, and a method and apparatus for producing this cleaning water.

[0002]

2. Description of the Related Art In the fields of machinery, metal, electronics, etc., there are various cleaning steps in each production process. For example, the use of organic chlorine compounds (volatile organic compounds) such as CFCs and ethane is prohibited or restricted by legal regulations, and high cleanliness can be obtained in a short period of time, and it is safe for living things and the environment. The development of alternative cleaning agents has been sought.

Hydrocarbon-based cleaning agents that have appeared in place of the above-mentioned organic chlorine-based compounds are one of the alternative cleaning agents, but they have problems in terms of flammability and working environment. Further, in recent years, water-based cleaning using a surfactant has also attracted attention, and industrial detergents suitable for use have been commercially available and are being put into practical use. But,
In the water-based cleaning, chemicals such as a surfactant are used in order to improve the cleaning effect, but a rinse step of washing out the surfactant is required and a large amount of rinse water is required. In addition, since the surfactant is an organic substance, BOD and CO
It corresponds to D and required a large-scale wastewater treatment facility to meet the wastewater standards.

Therefore, for example, Japanese Patent Laid-Open No. 10-192860.
As can be seen in the publications, etc., it has been considered to use electrolyzed water (particularly cathode water) as washing water. However, when electrolyzed water is used as cleaning water, there are the following problems.

Problem 1 (Problem in which the cleaning effect is halved by metal ions in tap water) Generally, electrolyzed water or tap water is used as raw water in many cases, but tap water contains many metal ions such as calcium and magnesium. It is known that many areas are covered. When there are many metal ions such as calcium and magnesium, there is a problem that the cleaning effect is halved. Therefore, generally sold cleaning agents are chelates such as phosphoric acid and EDTA that have the function of blocking metal ions (chelating effect). By mixing an agent or a water softening agent such as edetic acid or aluminosilicate, the washing effect due to metal ions is prevented from being reduced by half. By the way, environmental problems are mentioned as a great necessity of using electrolyzed water for cleaning purposes. The above-mentioned chelating agents and water softeners are known as substances that adversely affect the environment, like surfactants, and the use of these harmful substances in electrolyzed water is not preferable considering the impact on the environment, It is preferred to use only inorganic salts such as sodium chloride / potassium chloride / sodium silicate.

Problem 2 (Regarding Solubility of Inorganic Salt) Solubility is generally the limit of solubility of a substance (solute) in another substance (solvent), and is represented by the concentration of the solute in a saturated solution. , Generally changes with temperature.
The electrolyte as referred to herein means the capacity, and the solvent means tap water. As a method for automatically dissolving a solid substance (electrolyte), it is preferable to use the saturated solubility of a substance. Sodium chloride, which is generally used as an electrolyte in the production of electrolyzed water, has little solubility in the solubility which is affected by temperature changes. However, the solubility of other electrolytes used for cleaning purposes, such as sodium carbonate, changes due to changes in temperature, so even if it was dissolved during the summer, the electrolyte will dissolve in the winter when the temperature drops. It may be recrystallized and the pipe may be clogged, or the solubility may be increased by increasing the water temperature, which may affect the electric conductivity during electrolysis and the properties of the produced water. The electrolyte used for generating the electrolyzed water preferably has a small solubility change range due to temperature change. When attempting to dissolve automatically or considering recrystallization, the change in solubility with temperature change of potassium chloride currently used as an electrolyte is the limit,
That is, a substance having a further change in solubility is not suitable as an electrolyte.

[0007]

From these facts, the substance most easily used as the electrolyte is sodium chloride. The characteristics of sodium chloride are that it is a highly safe substance, that it is easily available, that it is inexpensive, and that its solubility is stable against temperature changes. The stability of the solubility with respect to this temperature change is very important for the electrolyzed water generator. However, when the electrolyzed water obtained by using sodium chloride as the electrolyte is used as the cleaning water, some cleaning power may be required depending on the degree of contamination, and there is a concern that the cleaning material may be corroded. Regarding corrosion, the same applies when potassium chloride is used.

[0008] Therefore, a technical object of the present invention is to provide an electrolytic cleaning water which has stable solubility and excellent cleaning power and has a low corrosion degree and which can be safely used.

[0009]

[Means for Solving the Problems] Means for solving the above technical problems are as follows.

(1) Tap water or raw water consisting of pure water
Using a soft water treatment device containing a strong acid type cation exchange resin, it adsorbs and removes metal ions such as calcium and magnesium contained in the raw water to soften the water, and then a sodium compound or sodium compound is added to the softened raw water. To generate by electrolyzing in an electrolytic cell after adding a potassium compound as an additive. (Claim 1)

(2) Tap water or pure water is placed in advance in an electrolytic additive tank or container equipped with a filter having an opening diameter of at least 0.7 to 0.01 mm,
In the tap water or pure water, a substance whose saturated solubility is stable, such as a sodium compound or a potassium compound,
By adding so that the saturated concentration or more, an aqueous solution corresponding to the saturated solubility of the substance is produced by filtering through the filter, and the saturated aqueous solution is added to the softened raw water, and the raw water is separated by a diaphragm. To electrolyze in an electrolytic cell. (Claim 2)

(3) Soft water by adsorbing / removing metal ions such as calcium and magnesium contained in the raw water in the middle of the raw water introducing pipe for introducing the raw water consisting of tap water or pure water into the electrolytic cell A soft water treatment device accommodating a strong acid type cation exchange resin to be converted, and an addition device capable of adding an additive composed of a sodium compound or a potassium compound to the softened raw water. (Claim 3)

(4) An opening of at least 0.7-0.01 mm in the lower inner part of the electrolytic additive tank or container containing a substance having a stable saturated solubility such as a sodium compound or a potassium compound. A filter having a diameter is attached, and an aqueous solution corresponding to the saturated solubility number of the above substance produced in a filtered state through this filter is added,
It should be configured so that it can be freely added to the softened raw water in the raw water introducing pipe, and that the raw water added with the aqueous solution is fed to the diaphragm electrolyzer to be electrolyzed. (Claim 4)

(5) Softening water using a strong acid type cation exchange resin, and then introducing raw water consisting of tap water or pure water to which a saturated aqueous solution of potassium carbonate has been added into a diaphragm membrane electrolytic cell for electrolysis. Electrolytic cleaning water using alkaline generated water generated from the cathode side. . (Claim 5)

In each of the above means, the sodium compound means sodium chloride and sodium hydrogen carbonate, and the potassium compound means potassium carbonate, potassium chloride,
Refers to potassium sulfate.

Claims 1 and 3 described in (1) and (3) above.
According to the method for producing electrolytic cleaning water and the apparatus therefor, first, by using tap water or pure water, which is raw water, with a soft water treatment device containing a strong acid type cation exchange resin, metals such as calcium and magnesium are obtained. Water is softened by adsorbing and removing ions. However, softened water itself does not have detergency, so next, add an additive composed of sodium compounds and potassium compounds for the purpose of washing to this softened raw water, and then add these. By electrolyzing the softened raw water to which the agent is added, it is possible to provide an electric cleaning water having a very high cleaning rate.

According to the method for producing electrolytic cleaning water and the apparatus therefor according to claims 2 and 4 described in the above (2) and (4), a filter having an opening diameter of at least 0.7 to 0.01 mm is provided. Saturated substances with stable solubility such as sodium compounds or potassium compounds set in electrolytic additive tanks or containers, and in tap water or pure water that has been put in these tanks or containers in advance. When added so that the concentration is higher than the concentration, an aqueous solution corresponding to the saturated solubility number of the substance is automatically generated through the filter, so this saturated aqueous solution is added to the softened raw water, and then introduced into the diaphragm electrolyzer. If electrolyzed, the alkaline generated water generated from the cathode side is used as it is as electrolytic cleaning water with excellent cleaning power and solubility and low corrosion rate. To enable the door.

According to the electrolytic cleaning water according to claim 5 described in (5) above, it has stable solubility and excellent cleaning power,
In addition, it is possible to provide electrolytic cleaning water that has a low degree of corrosion and can be safely used.

[0019]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram showing an electrolytic cleaning water producing apparatus according to the present invention, in which reference numeral 1 generally indicates 3A and 3B are the anode chamber 1 with the diaphragm chamber 2 having the inside divided into the anode chamber 1A and the cathode chamber 1B.
A and cathode electrodes provided in A and cathode chamber 1B, 4
Shows a raw water introduction pipe for introducing raw water consisting of tap water or pure water into the above-mentioned electrolytic cell 1.

Reference numeral 5 denotes a soft water treatment device provided in the middle of the raw water introducing pipe 4, and by passing the raw water through the soft water treatment device 5 containing a strong acid type cation exchange resin,
It is designed to soften the raw water by adsorbing and removing metal ions such as calcium and magnesium contained in the raw water into the strong acid type cation exchange resin. In the examples, it is described that a weak acid type cation exchange resin is used alone as the ion exchange resin sealed in the soft water treatment apparatus 5, but it may be used in combination with a strong acid type cation exchange resin. Well, the choice is arbitrary.

Further, in the figure, 6 is an electrolytic additive tank, 7 is a regular amount, or by arbitrarily opening it in accordance with a switch operation, the required amount of raw water consisting of tap water or pure water is added to the electrolytic additive tank 6 described above. Solenoid valve, which can be incorporated into
6F is a filter having an opening diameter of at least 0.7 to 0.01 mm, which is provided at a lower position inside the electrolytic additive tank 6, and sodium is placed in the electrolytic additive tank 6 containing the raw water in advance. When a substance having a stable saturated solubility such as a compound or a potassium compound is added so as to have a saturated concentration or more, an aqueous solution corresponding to the saturated solubility of the substance is filtered through the filter 6F. ing.

Reference numeral 8 denotes an aqueous solution having a saturated solubility of the sodium compound or potassium compound produced in the electrolytic additive tank 6 as described above, and added as an additive into the raw water introducing pipe 4 in which the softened raw water flows. With a pump that
As described above, in the electrolytic cleaning water producing apparatus according to the present invention, raw water consisting of tap water or pure water is softened by the soft water treatment apparatus 5, and then the aqueous solution of the sodium compound or potassium compound is added to the softened raw water. After the addition, the raw water is sent to the diaphragm electrolyzer 1 described above to be electrolyzed, and as a result, alkaline generated water generated from the cathode chamber 1B side is used as cleaning water.

Next, the relationship between the metal ions and the electrolyzed water in the present invention, the structure relating to the ion exchange resin used in the present invention and the arrangement thereof, and the solubility and corrosion degree of the electrolysis cleaning water in the present invention will be described. To do.

1: Relationship between Metal Ions and Electrolyzed Water Table 1 shows the cleaning power of tap water and water obtained by softening tap water with a strong acid type cation exchange resin, and when potassium carbonate and sodium chloride are added. , Enter the data regarding the presence or absence of electrolysis. Detergency judgment is JIS K3362
Using the same type as the linac type described in (1998), the model stains made with beef tallow, chloroform and oil red are adhered to the glass pieces, and the model stains before cleaning are adhered to the glass stains. A method of determining the cleaning rate X of each positive cleaning aqueous solution for determining the cleaning power from the difference between the amount α and the amount β of dirt attached to the model dirty glass piece after cleaning was used. In addition, the detergency described below was performed by the above method.

[Table 1]

From this data, it is understood that tap water is first softened by passing it through a strong acid type cation exchange resin. Hardness notation, which is generally used as an index for judging the amount of calcium and magnesium in tap water, was used for judgment of water softening. However, this result shows that the softened water itself has no detergency. Further, it is found that even if the diaphragm water is electrolyzed in this state and the cathode water is taken out, there is no detergency.

Next, when potassium carbonate and sodium chloride were added to tap water or soft water, an improvement in detergency was observed only when potassium carbonate and sodium chloride were added to soft water. However, the difference in washing power between alkaline electrolyzed water produced from the cathode side by electrolysis in the diaphragm electrolyzer 1 is large, and the hardness of tap water during electrolysis greatly affects the washing power. It was suggested.
From these results, when using potassium carbonate for cleaning purposes, a means to reduce the hardness of tap water, which is raw water, is used.
It can be considered that the most important thing is to carry out electrolysis.

2: Ion Exchange Resin Next, the necessity of being a strong acid type cation exchange resin in softening water will be described. As the ion exchange resin, a strong acid type cation exchange resin having a sulfonic acid group (-SO3H) as a functional group, a weak acid type cation exchange resin having a carboxylic acid group (-COOH) as a functional group, and a quaternary ammonium group (≡ N + O
There are four types, a strong base type anion exchange resin having H-) as a functional group and a weak base type anion exchange resin having a primary 1, 2, 3 amine group as a functional group. First, regarding cation / anion selection, the cation exchange resin is selected for the purpose of removing Ca2 + and Mg2 + because the ion exchange resin has the property of exchanging ions of the same sign. Next, there are two types of cation exchange resins, strong acid type and weak acid type. The strong acid type has a high selectivity for hardness components such as Ca2 + and Mg2 + over the weak acid type, and the strong acid type has the characteristics that it is chemically more stable and has a higher heat resistance and a stronger ion-trapping force, so that it becomes softened. Therefore, it was considered preferable to use a strong acid type cation exchange resin.
However, the strong acid type cation exchange resin is characterized by having high selectivity for Ca 2+, and in the case of water with high hardness, there is an example of using it as a pretreatment of the strong acid type cation exchange resin.

3: Arrangement of Ion Exchange Resin Since the main purpose of the ion exchange resin is to remove the hardness component of raw water (tap water), it is usually arranged in front of the electrolyzer. According to the experimental result Table 2 in which the ion exchange resin is arranged on the cathode side where the diaphragm electrolysis is performed, according to the cleaning rate,
A slight decrease was observed as compared with the example in which it was arranged before electrolysis. It can be considered that this is because the cleaning component obtained by electrolysis was slightly lost by passing through the ion exchange resin. Therefore, the ion exchange resin is placed before electrolysis.

[Table 2]

4: Solubility In Table 3, sodium chloride / potassium chloride / potassium carbonate /
Solubility of sodium silicate at each temperature (saturated solution 10
The mass (g) of the anhydride contained in 0 g is shown.

[Table 3]

Sodium chloride has a substantially constant solubility regardless of temperature changes, but other compounds show an increase in solubility with temperature changes and are not stable solubilities. In particular, in the case of sodium carbonate, the difference in solubility between 0 ° C. and 100 ° C. is quite large, and sodium silicate cannot be used with confidence because there is no data. However, in potassium carbonate, the solubility difference from 0 ° C. to 100 ° C. is located between sodium chloride and potassium chloride, and potassium chloride, which is the limiting electrolyte of the solubility difference with temperature change, is important when used as an electrolyte. The solubility difference is smaller than that. In addition, recrystallization of potassium carbonate was not observed in the temperature change within daily living temperature. That is, when considering the solubility, potassium carbonate is more suitable as the electrolyte than potassium chloride.

Table 4 shows the cleaning rates of sodium chloride / potassium chloride / sodium carbonate / potassium carbonate / sodium silicate.

[Table 4]

Diaphragm electrolysis was carried out after water softening using the above-mentioned five kinds of electrolytes, and the electrolyzed water generated on the alkali side was used as washing water. As a result, the cleaning rate when using sodium chloride was 56.15%, and the cleaning rate when using potassium chloride was 5%.
0.16%, the cleaning rate when using sodium carbonate is 6
1.62%, the cleaning rate when using potassium carbonate was 71.
23%, the cleaning rate when using sodium silicate is 53.9.
It was 3%, and it was found that the washing water produced by using potassium carbonate had an excellent washing effect.

5: Corrosion Degree of corrosion was determined by the method described in JIS K0100 (1990) and expressed in mg (mdd) of corrosion weight loss per day per 1 dm 2 of surface area of the test piece. Table 4 shows the corrosion rates of sodium chloride / potassium chloride / sodium carbonate / potassium carbonate / sodium silicate. Diaphragm electrolysis was performed using the above five types of electrolytes, and the electrolyzed water generated on the alkaline side was used as test water. The degree of corrosion when using sodium chloride is 4.5 mdd, the degree of corrosion when using potassium chloride is 12.3 mdd, the degree of corrosion when using sodium carbonate is 0.4 mdd, and the degree of corrosion when using potassium carbonate The degree of corrosion was 0.2 mdd, the degree of corrosion when sodium silicate was used was 0.5 mdd, and the test water produced using potassium carbonate was found to be an aqueous solution that is unlikely to cause corrosion.

The procedure until the cleaning water is generated using potassium carbonate as the electrolyte is as follows. (1) Pour into an aqueous solution to dilute potassium carbonate. (2) It is produced by filtration using a filter having a substance diameter or less. In the case of potassium carbonate, since the substance diameter is about 0.8 mm, the opening diameter of the filter is preferably less than that, that is, 0.7 mm or less. As for the minimum diameter, the smaller the numerical value, the more the filtration resistance increases, and the production amount tends to decrease. Therefore, it is considered that the opening diameter of about 0.01 mm is practical. (3) A saturated aqueous solution of the substance is automatically generated by the above operation. (4) Tap water and raw water obtained by adding an aqueous potassium carbonate solution to pure water are electrolyzed in a diaphragm electrolytic cell. (5) The alkaline generated water generated from the cathode side is used as cleaning water.

[0035]

Industrial Applicability As described above, the present invention can provide an electrolytic cleaning water which has stable solubility and excellent cleaning power, has low corrosion rate and can be used safely. .

[Brief description of drawings]

FIG. 1 is a configuration diagram illustrating an entire electrolytic cleaning water generation device according to the present invention.

[Explanation of symbols]

1 diaphragm electrolyzer 1A Anode chamber 1B cathode chamber 2 diaphragm 4 Raw water introduction pipe 5 Soft water treatment equipment 6 Electrolytic additive tank (container) 6F filter

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Claims (5)

[Claims] 1. A tap water or pure water consisting of pure water is adsorbed and removed from metal ions such as calcium and magnesium contained in the raw water by using a soft water treatment device containing a strong acid type cation exchange resin. A method for producing electrolytic cleaning water, which comprises softening water to produce softened water, and then adding a sodium compound or a potassium compound as an additive to the softened raw water, followed by electrolysis in an electrolytic cell. 2. Tap water or pure water is placed in advance inside an electrolytic additive tank or container provided with a filter having an opening diameter of at least 0.7 to 0.01 mm, and the tap water or pure water is placed in the tap water or pure water. For example, a substance having a stable saturated solubility such as a sodium compound or a potassium compound is added so as to have a saturated concentration or more, and an aqueous solution corresponding to the saturated solubility number of the substance is generated through the filter so as to be filtered, The method for producing electrolytic cleaning water according to claim 1, wherein the saturated aqueous solution is added to the softened raw water, and the raw water is electrolyzed in a diaphragm electrolytic cell. 3. A metal ion such as calcium or magnesium contained in the raw water is adsorbed in the middle of the raw water introducing pipe for introducing the raw water consisting of tap water or pure water into the electrolytic cell.
A soft water treatment device containing a strong acid type cation exchange resin that removes and softens water, and an addition device that can add an additive composed of a sodium compound or a potassium compound to the softened raw water are provided. An apparatus for producing electrolytic cleaning water, which is characterized by: 4. An opening diameter of at least 0.7-0.01 mm in the lower inner part of an electrolytic additive tank or container containing a substance whose saturation solubility is stable, such as a sodium compound or a potassium compound. Is installed, and an aqueous solution corresponding to the saturated solubility of the substance produced in a filtered state through the filter is configured to be freely added to the softened raw water in the raw water introduction pipe, and the raw water added with the aqueous solution is attached to a diaphragm. The electrolytic cleaning water generating apparatus according to claim 3, wherein the electrolytic cleaning water is sent to an electrolytic cell and electrolyzed. 5. By softening water using a strong acid type cation exchange resin, and then introducing raw water consisting of tap water or pure water to which a saturated aqueous solution of potassium carbonate has been added into a diaphragm electrolyzer to perform electrolysis. , Electrolytic cleaning water using alkaline generated water generated from the cathode side.