06187162 is referenced by 45 patents and cites 39 patents.

First and second stages are used in electrodeionization to purify water including calcium and carbon dioxide and its hydrates. The diluting flow channels of the first stage include only anion exchange material or cation exchange material, and thus remove either carbon dioxide and its hydrates (and other anions) or calcium (and other cations) but not the other. The diluting flow channels of the second stage receive the diluting channel effluent from the first stage and include the other type of exchange resin (or a mixed resin) and remove the oppositely charged ions. The brine effluent from the concentrating flow channels in the first stage is isolated from the second stage, and calcium and total inorganic carbon tend to be removed in different stages so as to deter calcium carbonate precipitation in any of the concentrating flow channels. Also the concentrating channels can include cation exchange material next the anion membrane, with pH being lowered at the surface of the anion so as to limit calcium carbonate precipitation in the concentrating flow channel.

Title
Electrodeionization apparatus with scaling control
Application Number
9/395327
Publication Number
6187162 (B1)
Application Date
September 13, 1999
Publication Date
February 13, 2001
Inventor
Leon Mir
15 Hobart Rd., Newton
MA, US
Agent
Fish & Richardson P C
US
IPC
B01D 61/48
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