Patent ID: RE40733

Claim:
A helical electrodeionization apparatus which comprises an anion exchange membrane ( 18 ) and a cation exchange membrane ( 19 ), a central pipe ( 11 ), a plurality of main component parts, an outer crust ( 5 ) and covers( 2 , 2 ′), wherein: said central pipe ( 11 ) is a metal pipe that acts as an electrode and also as a water distributing or gathering pipe; said main component parts of said apparatus, which have a helical cylinder structure with said central pipe ( 11 ) as the helical axis, further comprising: i. at least one set of rolled membrane bags that are formed by positioning a net-separating wall ( 20 ) between an anion exchange membrane ( 18 ) and a cation exchange membrane ( 19 ), ii. metal strip or metal wire twined round the outside of said cylinder structure which forms a conductive crust, said conductive crust being used as another electrode; a first flow unit ( 8 ) of said main component parts, including the flow passage in said membrane bag being fitted tightly and communicating with said central pipe ( 11 ) along the axial direction; and a second flow unit ( 9 ) of said main component parts, including the flow passage between said adjacent membrane bags being formed by filling ion exchange resin.