Patent ID: 6991716

Claim:
A device for the electrodeionization (EDI) in the de-mineralization of aqueous solutions, comprising: a) several cation and anion-exchanger membranes ( 1 ; 2 ) arranged alternately and in spaced relationship and being assembled to form a stack, with the spaces between the membranes forming compartments through which the aqueous solution can be conducted, b) a cathode ( 3 ) and an anode ( 4 ) disposed at opposite end membranes ( 1 , 2 ) of said stack for establishing an electrical DC voltage across said stack, c) a mixed bed of cation and anion exchanger resin particle fractions ( 9 , 8 ) disposed in at least some of said compartments, that is the demineralization compartments ( 18 ), in which, upon application of said DC voltage to the cathode ( 3 ) and anode ( 4 ), ions are enriched by permeation from the adjacent compartments, the concentration compartments ( 17 ), through the respective exchanger membranes into the demineralization compartments ( 18 ), d) liquid supply means ( 5 ) and discharge means ( 6 , 7 ) at opposite ends of said stack for supplying the aqueous solution to, and removing the solutions separately from, said compartments, e) said ion exchanger resin particles of one of said fractions including a magnetic material so as to provide them with magnetic properties, and f) means ( 15 , 16 ) for generating a magnetic field with field lines which extend essentially normal to said ion exchanger membranes for orienting the magnetic resin particles and arranging them in mutually repelling chains between said ion exchanger membranes orienting themselves at the largest possible spacing from one another in the compartments and the compartment spaces between the chains being filled with ion exchanger particles of the other fraction.