Patent ID: 7591933

Claim:
An electrodeionization device comprising a generally cylindrical housing including a) a cylindrical inner core b) an inner electrode extending around the inner core c) a leaf arranged as a spiral winding about the inner electrode, wherein the leaf includes an anion exchange membrane sheet, a cation exchange membrane sheet and a spacer sheet between the anion exchange membrane sheet and the cation exchange membrane sheet; and d) an outer electrode extending about the spiral winding, wherein active treatment cells are defined by spaces within said spiral winding and by interleaf spaces thereof, wherein sealing bands secure the top edges of the anion exchange membrane sheet, cation exchange membrane sheet and spacer sheet together to define fluid flow, wherein sealing bands secure the bottom edges of the anion exchange membrane sheet, cation exchange membrane sheet and spacer sheet together to define fluid flow, and wherein sealing bands secure the portions of the anion exchange membrane sheet, cation exchange membrane sheet and spacer sheet together at locations between the top and bottom edges such that the fluid flow enters either the top or bottom of the spiral winding and exits from the other of the top or bottom of the spiral winding.