Method of regenerating ion exchangers

Claim 1

IN THE OPERATION OF AN ION EXCHANGE SYSTEM HAVING A COLUMN OF ION EXCHANGE RESIN CONFINED BELOW A FREEBOARD SPACE AND IN THE LOWER PORTION OF A TANK HAVING UPPER AN DLOWER DISTRIBUTORS AT THE TOP AND BOTTOM OF THE TANK AND AN INTERMEDIATE DISTRUBUTOR AT THE LOWER END OF SAID FREEBOARD SPACE, THE METHOD OF REGENERATING SAID COLUMN AFTER A DOWNFLOW SERVICE CYCLE WHICH INCLUDES THE STEPS OF BACKWASHING SAID RESIN BY FLOWING WATER UPWARDLY THROUGHOUT THE FULL LENGHT OF SAID TANK TO EXPAND SAID BED INTO SAID FREEBAORD SPACE, INTERRUPTING THE BACKWASH FLOW TO LEAVE SAID TANK FILLED WITH WATER AND ALLOW THE RESIN TO SETTLE BELOW SAID INTERMEDIATE DISTRIBUTOR, INTRODUCING A SOLUTION FOR REGENERATING SAID RESIN INTO SAID TANK THROUGH SAID LOWER DISTRIBUTOR, SIMULTANEOUSLY FLOWING WATER INTO SAID TANK THROUGH SAID UPPER DISTRIBUTOR AND DOWN THROUGH SAID FREEBOARD SPACE, WITHDRAWING THE COMBINED STREAMS OF THE WATER AND THE SPENT REGENERATING SOLUTION FROM THE TANK THROUGH SAID INTERMEDIATE DISTRIBUTOR WHEREBY TO PREVENT SUBSTANTIAL EXPANSION OF SAID RESIN INTO SAID FREEBOARD SPACE, RINSING THE MAJOR PORTION OF THE REGENERATING SOLUTION OUT OF THE TANK BY FLOWING WATER UPWARDLY THROUGH THE BED WHILE CONTINUING THE FLOW OF WATER DOWN THROUGH SAID FREEBROARD SPACE AND OUT THROUGH SAID INTERMEDIATE DISTRIBUTOR, AND RINSING OUT THE LAST TRACES OF THE REGENERATING SOLUTION BY FLOWING WATER DOWNWARDLY THROUGH THE FULL LENGTH OF THE REGENERATING COLUMN.