Ion exchange methods and systems incorporating regenerant recycling

An ion exchanger, comprising:

• a pressure vessel containing a resin bed, the vessel including a first port defining means for supplying water to be treated to the vessel during a production cycle and for supplying recycled regenerant to the vessel during a regenerant cycle, a second port defining means for removing treated water from the vessel during the production cycle and for supplying regenerant to the vessel during a regenerant cycle, a third port located intermediate of the first and second ports, said third port defining means for supplying recycled regenerant, and a fourth port located intermediate of the first and third ports, said fourth port defining means for draining collected regenerant;
• an upper in-bed distributor located in the vessel and connected to the fourth port and defining means for collecting regenerant to be drained from the vessel;
• a lower in-bed distributor located below the upper in-bed distributor and connected to the third port and defining means for collecting regenerant to be recycled to the first port;
• a first fluid conduit connecting the third port and the first port;
• a second fluid conduit connecting the fourth port to a drain;
• and
• pump means supported in the first fluid conduit for pumping collected regenerant from the third port to the first port and for performing, during the regenerant cycle, substantially cocurrent operation relative to the production cycle feed flow in the portion of the vessel located between the first port and the upper in-bed distributor and in the portion of the vessel located between the upper in-bed distributor and the lower in-bed distributor, and including means for performing substantially countercurrent operation relative to the production cycle feed flow in the portion of the vessel located between the lower in-bed distributor and the second port.