Patent ID: 7572359

Claim:
A fluid purification system, comprising: an electrical purification apparatus comprising circularly-shaped endblocks, a concentrating compartment disposed between the circularly-shaped endblocks, the concentrating compartment having concentrating subcompartments, and defined at least partially by a concentrating compartment spacer and an ion selective membrane, the concentrating compartment spacer having a concentrating compartment spacer rib at least partially defining at least one of the concentrating subcompartments, the concentrating compartment spacer rib at least partially extending substantially parallel a diametric axis of the concentrating compartment spacer, a depleting compartment disposed adjacent the concentrating compartment and having depleting subcompartments, and defined at least partially by a depleting compartment spacer and the ion selective membrane, the depleting compartment spacer having a depleting compartment spacer rib at least partially defining at least one of the depleting subcompartments, the depleting compartment spacer rib at least partially extending substantially parallel the concentrating compartment spacer rib, and a tie-rod coupling the circularly-shaped endblocks; and a pressure vessel having a circularly-shaped cylindrical wall at least partially surrounding the electrical purification apparatus, the circularly-shaped cylindrical wall comprising a non-metallic material.