Continuous moving bed ion exchange system

A continuous moving bed ion exchange apparatus, comprising:

• a resin cycling contactor assembly including means for contacting a feed aqueous composition with ion exchange resin, the feed aqueous composition and the ion exchange resin moving in a generally co-current direction within the resin cycling contactor assembly;
• a regeneration assembly having means for accepting spent resin from the resin cycling contactor assembly, for regenerating the spent resin by removing contaminant ions therefrom, and for transporting regenerated resin to the resin cycling contactor assembly;
• said resin cycling contactor assembly including an elongated contactor having an inlet, an outlet and a lengthy flow path of a relatively narrow cross-section;
• said resin cycling contactor assembly including at least two recycle resin reservoirs positioned in a generally parallel relationship with respect to each other;
• each of said recycle resin reservoirs including means for providing resin to means for combining said resin with a flow of feed aqueous composition into a feed slurry which flows into the inlet of said contactor;
• each of said recycle resin reservoirs and said regeneration assembly including means for receiving a slurry of cycled resin and treated aqueous composition from the outlet of said contactor;
• said recycle resin reservoirs being in alternating communication with said means for transferring regenerated resin from the regeneration assembly and being in alternating communication with said inlet and outlet of the contactor, said alternating communications being such that neither recycle resin reservoir is in communication with both the regenerated resin transfer means and the contactor outlet at the same time during operation of the apparatus;
• and
• means for transferring out of said apparatus an aqueous composition product which had passed through said resin cycling contactor assembly.

A continuous ion exchange method, comprising the steps of:

• contacting a feed aqueous composition with ion exchange resin within a moving bed resin cycling contactor assembly having a contactor with a lengthy flow path of a relatively narrow cross-section;
• said contacting step including moving the feed aqueous composition and ion exchange resin in a generally co-current manner through the narrow and lengthy flow path of the contactor;
• providing a regeneration assembly and accepting therewithin spent resin from the resin cycling contactor assembly after same has progressed through at least one of said co-current moving steps, and regenerating spent resin within the regeneration assembly by removing contaminant ions therefrom;
• transporting regenerated resin from the regeneration assembly to a first recycle resin reservoir of the resin cycling contactor assembly;
• combining resin from out of the first recycle resin reservoir with feed aqueous composition into a feed slurry which flows into the contactor to carry out said contacting step;
• passing said feed slurry from out of the contactor after said contacting step and into a second recycle resin reservoir of the resin contacting assembly;
• separating said slurry, after said passing step, into an aqueous composition product and cycled resin;
• combining cycled resin from out of the second recycle resin reservoir with feed aqueous composition to provide further feed slurry which flows into the contactor to further carry out said contacting step;
• and
• passing said further feed slurry from out of the contactor after said further carrying out of the contacting step and separating same into further aqueous composition product and the spent resin for the step of accepting spent resin by the regeneration assembly.