Patent ID: 8337686

Claim:
A method of producing demineralized water comprising: a) providing an apparatus comprising; i) a cation exchange chamber containing a cation exchange media; ii) an anion exchange chamber containing an anion exchange media; iii) a bipolar interface located between said cation exchange chamber and said anion exchange chamber; iv) a first electrode chamber located on a side of said cation exchange chamber opposite said bipolar interface, and containing a first electrode operative at least as a cathode; v) a second electrode chamber located on a side of said anion exchange chamber opposite said bipolar interface, and containing a second electrode operative at least as an anode; and, vi) a third electrode disposed in at least one of said anion exchange chamber and said cation exchange chamber; b) configuring said apparatus to receive filtered raw water having a hardness of at least 75 mg/L as CaCO 3 ; c) causing said first and second electrodes to be energized during a period of no water flow to at least partially regenerate said ion exchange media, and sizing said ion exchange chambers such that said apparatus is capable of providing at least about 700 liters of demineralized water containing less than 75 mg/L hardness as CaCO 3 from said raw water having a hardness of at least 75 mg/L as CaCO 3 over about 24 hours; d) causing said filtered raw water to flow through said cation exchange chamber and said anion exchange chamber to produce said demineralized water; and, e) periodically reducing the pH in said first electrode chamber to at least partially dissolve hardness scale therein.