US Patent 7763157 Electrodeionization device

An electrodeionization device for large-volume ultra-pure deionization of water is disclosed. The device comprises a plurality of alternating ion depletion and concentration compartments, interposed between an anode assembly and a cathode assembly, through which flows either a product stream or a waste stream. Each compartment contains several fluid-accessible channels packed with an appropriate ion-exchange medium. The flow of the waste and product streams among the compartments is “parallel” (i.e., contemporaneous). The flow of a stream through the compartments—i.e., through the channels therein—is “serial” (i.e., sequential). In an embodiment, electrical current is generated through the compartments using segmented electrodes—either in the anode and/or the cathode assembly—that are connected to a single multiple-outlet power source. The device is fast, efficient, robust, and its configuration is comparatively easy to scale upwards to accommodate larger water processing volumes.