Regeneration of service demineralizers

Claim 1

THE PROCESS OF REGENERATING A SERVICE UNIT INCLUDING A TANK HAVING AN INLET FOR THE WATER TO BE TREATED AND AN OUTLET FOR THE TREATED WATER AND CONTAINING ANION AND CATION EXCHANGE RESINS OPERATING ON THE MIXED BED PRINCIPLE FOR DEIONIZATION OF WATER, COMPRISING THE STEPS OF REMOVING THE EXHAUSTED SERVICE UNIT WHEN IT IS NO LONGER CAPABLE OF PURIFYING WATER TO THE DESIRED DEGREE, BACKWASHING THE EXHAUSTED UNIT TO REMOVE SUBSTANTIALLY ALL OF THE ANION AND A PORTION OF THE CATION RESINS FROM THE UNIT BY FLOWING WATER UPWARDLY THROUGH THE BED IN A DIRECTION REVERSE TO THAT OF THE FLOW DURING NORMAL SERVICE OPERATION TO THEREBY TRANSFER A SUBSTANTIAL PORTION OF THE MIXED BED OF RESINS INTO A SEPARATE VESSEL CONNECTED WITH THE INLET OF THE TANK, CLEANSE THE BED OF FOREIGN MATTER AND THEN HYDRAULICALLY CLASSIFY AND DIVIDE THE CLEANSED RESINS INTO THEIR RESPECTIVE LAYERS OF ANION AND CATION RESINS ACCORDING TO THEIR DENSITY, SELECTIVELY REGENERATING AND RINSING EXCESS REGENERANT FROM THE LAYERS OF THE HYDRAULICALLY SEPARATED ANION AND CATION EXCHANGE RESINS, COMBINING THE REGENERATED ANION AND CATION EXCHANGE RESINS IN THE VESSEL IN A FLUDIZED BED, REMOVING EXCESS WATER FROM THE VESSEL TO ADJUST THE FLUIDITY OF THE COMBINED RESINS, INTIMATELY MIXING THE REGENERATED ANION AND CATION RESINS IN THE VESSEL, REMOVING CONTAINED WATER FROM THE TANK, AND TRANSFERRING THE SLURRY OF MIXED REGENERATED RESINS TO THE TANK AFTER WHICH THE UNIT IS READY FOR SERVICE IN THE DEIONIZATION WATER.