DRINKING WATER TREATMENT BY DIRECTIONAL FREEZE CRYSTALLIZATION

SMALL WATER SYSTEMS ARE INCREASINGLY CHALLENGED TO COMPLY WITH THE SAFE DRINKING WATER ACT. EXISTING TECHNOLOGIES IMPOSE HEAVY OPERATIONAL BURDENS ON SMALL SYSTEMS AND PROVIDE ONLY NARROWLY FOCUSED SOLUTIONS. POLAR SPRING CORPORATION PROPOSES TO DEMONSTRATE THE FEASIBILITY OF DIRECTIONAL FREEZE CRYSTALLIZATION (DFC) TO SIGNIFICANTLY REDUCE THE CONCENTRATION OF DISSOLVED SOLIDS, ORGANIC CHEMICAL AND PARTICULATES. THE DFC METHOD IS EXPECTED TO BE ESPECIALLY SUITABLE FOR SMALL WATER SYSTEMS BECAUSE OF ITS MODULARITY, LOW MAINTENANCE, NO EXPENDABLE FILTERS OR MEMBRANES, AND LONG LIFE-TIME. INNOVATIVE PROCESS SIMPLIFICATION AND THERMAL OPTIMIZATION WOULD MINIMIZE ENERGY CONSUMPTION. IT USES COMMERCIALLY AVAILABLE VAPOR COMPRESSION REFRIGERATION EQUIPMENT FOR COOLING, SO RELIABILITY IS ENHANCED AND FIELD DEPLOYMENT CAN BE ACCELERATED. THE DFC PROCESS IS EXPECTED TO REMOVE A BROAD SPECTRUM OF CONTAMINANTS, YET IT WORKS WITHOUT EXPENDABLE FILTERS OR MEMBRANES.WATER TO BE TREATED WOULD FILL A CYLINDER, AND BE COOLED THROUGH THE CYLINDER WALL BY A REFRIGERANT. CRYSTALS OF PURIFIED ICE WOULD FORM ON THE WALL, CONCENTRATING THE CONTAMINANTS WITHIN AN UNFROZEN CORE. TYPICALLY, ONE-HALF OR MORE OF THE WATER WOULD BE CRYSTALLIZED IN BATCHES. THE LIQUID CORE WOULD THEN BE DRAINED FROM THE VESSEL AND THE PURIFIED ICE MELTED USING HEAT REJECTED FROM THE REFRIGERANT CONDENSER.