Slightly weak acidic hypochlorous acid water may be manufactured in such a way that diluted hydrochloric acid solution of 2˜6% is fed using a metering pump into a diaphragmless electrolytic bath wherein a cathode and an anode are arranged facing each other.
More specifically describing, a hydrogen generation reaction occurs at the cathode electrode as follows.2H2O—>2H2+4OH−  [Reaction Formula 1]
The following oxygen generation reaction occurs at the anode electrode.2H2O—>O2+4H+  [Reaction Formula 2]
At the same time, the chlorine ion of the hydrochloric acid solution is oxidized at the anode electrode as follows.2Cl−—>Cl2+2e  [Reaction Formula 3]
In addition, part of Cl2 generated at the anode electrode reacts with water as follows, thus generating hypochlorous acid.Cl2+H2O—>HOCl+HCl  [Reaction Formula 4]
As a result of the above reaction, high-density chlorine solution and hypochlorous acid solution are generated in the diaphragmless electrolytic bath, and the generated mixture liquid is properly diluted with water, and the chlorine solution and water are reacted, thus generating hypochlorous acid, and pH of the generated solution is regulated to 5.0 to 5.5, thus generating slightly weak acidic hypochlorous acid water wherein the chlorine contained in the generated water consists of only hypochlorous acid.
As compared with Cl2, NaOCl, etc. which are chlorine-based sterilizers and disinfectants, the hypochlorous acid has more than 80 times stronger in sterilizing powder, and stimulation smell seems to be weak, and the toxicity against humans and animals is less than 1/100, but the hypochlorous has instant sterilizing power against all kinds of microorganism such as bacteria, fungus, virus, etc. and is decomposed into harmless substances, so any environmental load becomes very low.
Thanks to the above-mentioned characteristics, the slightly weak acidic hypochlorous acid water containing hypochlorous acid water may be used for food sanitization, namely, for the disinfection of main ingredients or sub-ingredients of foods, and sterilization and disinfection of tools for food, container and facilities, and sterilization agricultural pesticides and substitutes for other disinfection agents in case of the growth of crop and livestock industry, and may be also widely used for the disinfection of medical tools, skin therapy of skin such as a cut, a pressure sore, etc., and a public disease prevention such as air sterilization and bad smell elimination based on spray into air. Therefore, the apparatus for producing slightly weak acidic hypochlorous acid water may be one of the very useful apparatuses in terms of industry.
The apparatus for producing slightly weak acidic hypochlorous acid water for industry in general has a production capacity per hour of 500 to 10,000 liters, and has a production capacity per hour of 50,000 liters for the large scale production. In addition to the above-mentioned large scale industrial purpose, there is a large demand for the apparatus which is capable of manufacturing a small amount of slightly weak acidic hypochlorous acid water, which corresponds to 50 to 200 liters production per hour for the economical use at home, small-scale restaurants, a small-scale cultivation under structure, a small-scale hospital, a dental hospital, an orphanage, a nursing home, etc.