Electric deionization device and electric deionization system

Abstract

To provide an electric deionization device and an electric deionization system capable of suppressing a volume of concentrate water and maintaining the concentration of the concentrated water at an appropriate level.SOLUTION: An electric deionization system comprising a plurality of electric deionization devices arranged in series, with an ion exchange membrane partitioning the concentrate chamber and the deionization chamber between the anode and cathode. Concentrated water flows through the concentrate chamber, while raw water flows as the feed water into the deionization chamber and is withdrawn as deionized water. An effluent from the deionization chamber of the upstream electric deionization device is fed into the deionization chamber of the downstream electric deionization device and the effluent from the concentrate chamber of the later-stage electric deionization device is passed through the concentrate chamber of the earlier-stage device. This electric deionization system is characterized by including return means that returns the effluent from the concentrate chamber of the foremost electric deionization back to the inlet side of the concentrate chamber of the last electric deionization device.SELECTED DRAWING: Figure 1

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