Electrolysis vessel and apparatus for generating electrolyzed water

Abstract

Provided is an electrolysis cell and an electrolyzed water producing equipment which are each small in size, has excellent electrolysis efficiency and can reduce an anion concentration in acidic electrolyzed water. The electrolysis cell is equipped with electrolysis rooms 10a and 10b located opposite to each other via an ion permeable membrane 2, raw water supply units 11a and 11b, electrodes 3a and 3bdisposed with the membrane interposed therebetween, and electrolyzed water discharge units 12a and 12b. The membrane 2 is an anion permeable film. The electrodes 3a and 3b are formed so as to firmly adhere to both surfaces of the anion permeable membrane 2 and expose a portion of the anion permeable membrane 2. Only raw water fed to the electrolysis room 10b on the cathode side contains an electrolyte. The electrodes 3a and 3b are porous and they each has an electrode base material made of a powdery titanium compound such as TiC or TiN, a catalyst such as platinum black or iridium black and a binder such as PVA. The electrodes 3a and 3b may be mesh-shaped or comb-shaped. The electrodes 3a and 3b are formed by applying a conductive paste containing conductive powders onto the surfaces of the anion permeable membrane 2, followed by heating or pressurization.

Description

TECHNICAL FIELD [0001] The present invention relates to an electrolysis cell for electrolyzing raw water fed to a pair of electrolysis rooms located opposite to each other via an ion permeable membrane by applying a voltage to a pair of electrodes disposed in the electrolysis rooms, respectively, via the membrane; and an electrolyzed water producing equipment for generating electrolyzed water by using the electrolysis cell. BACKGROUND ART [0002] As an electrolyzed water producing equipment, known are equipments for producing electrolyzed water by using an electrolysis cell equipped with a pair of electrolysis rooms located opposite to each other via an ion permeable membrane and a pair of electrodes disposed in the respective electrolysis rooms with the membrane interposed therebetween. In the above-described electrolyzed water producing equipment, raw water containing an electrolyte is fed to each of the electrolysis rooms and a voltage is applied to the pair of electrodes to elect...

AI Technical Summary

Benefits of technology

[0013] According to the electrolysis cell of the present invention, the two electrodes forming a pair adhere firmly to the both surfaces of the anion exchange membrane, respectively and thus, they are formed integrally with the anion exchange membrane so that an electrical resistance between these two electrodes is small and an electrolysis efficiency is high relative to the applied power. In addition, according to the electrolysis cell of the present invention, the electrodes are formed integrally with the anion exchange membrane so that the number of parts used for the cell is small, which simplifies the circulation structure of the raw water.

[0014] As a result, a circulation resistance of the raw water decreases, and a production amount of electrolyzed water per hour increases, which enables reduction in the size of the equipment. Moreover, according to the electrolysis cell of the present invention, the electrical resistance between the two electrodes is small and a high electrolysis efficiency can be attained so that a load on a power supply is small, which makes it possible to reduce the capacity of the power supply.

[0019] Hypochlorous acid generated in the electrolysis room on the anode side is therefore derived from only the chlorine ions which have transferred from the electrolysis room on the cathode side and chlorine ions emitted to the acidic electrolyzed water relate to only the production of hypochlorous acid. As a result, it is possible to yield acidic electrolyzed water containing a large amount of hypochlorous acid effective for sterilization, disinfection, deodorization or the like and at the same time, capable of reducing a chlorine ion concentration, thereby suppressing corrosion or the like of metals by the chlorine ions.

[0022] The electrodes are each preferably a porous material having an electrode base material made of a powdery titanium compound, a catalyst dispersed in the electrode base material and a binder for binding the electrode base material with the catalyst and formed integrally with the membrane. The electrodes may each be a carbonaceous. When the electrode base material made of a powdery titanium compound and the catalyst dispersed in the electrode base material are bound via the binder, however, they are able to have excellent electrochemical stability.

[0025] In the conventional electrodes, flow of an electric current is concentrated on the end portions of the electrodes and charges are therefore frequently exchanged at these portions, which phenomenon is known as “edge effect”. The above-described mesh-shaped or comb-shaped electrodes, on the other hand, have many end portions so that they are advantageous in the exchange of charges, which leads to a better electrolysis efficiency.

[0037] As the electrode base material, for example, titanium compounds such as titanium carbide (TiC) and titanium nitride (TiN) can be used. The electrode base material may be a carbonaceous material, but the carbonaceous material sometimes elutes in raw water during electrolysis and decreases the lifetime of the electrode. The above-described titanium compound, on the other hand, has good electroconductivity and in addition, is electrochemically stable and is slightly soluble in raw water during electrolysis compared with carbon. Accordingly, the electrodes 3a and 3b using the titanium compound as its base material are able to have a sufficiently long lifetime.

Problems solved by technology

The above-described constitution however is accompanied by the problem that an electrical resistance between the electrodes is large owing to a wide space between the electrodes disposed with the membrane interposed therebetween and an electrolysis efficiency is therefore low relative to the applied power.

In the above-described electrolysis cell, however, a circulation resistance is high because the raw water is circulated inside of the porous electrode base material and an increase in the production amount of electrolyzed water per hour inevitably leads to a size increase of the equipment.

In addition, in the above-described electrolysis cell, an average electrolysis current density in the electrodes is from 20 to 30 mA / cm2 and an electrolysis efficiency relative to the applied voltage cannot be improved fully.

By this, however, a large amount of chlorine ions remains in the acidic electrolyzed water inconveniently.

Chlorine ions have a property of breaking a film formed on a metal surface, thereby promoting corrosion.

When acidic electrolyzed water having a large amount of chlorine ions remained therein is used for a long period of time, there is a possibility of causing corrosion of piping system of the electrolyzed water producing equipment, metal parts to be sprayed and the like.

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