Methods for counter current solidliquid material transfer

Claim 1

A METHOD OF REMOVING IMPURITIES CONTAINED IN A SUGAR SYRUP BY COUNTER-CURRENT SOLID-LIQUID CONTACT IN TWO VERTICAL ZONES FILLED WITH GRANULAR MATERIAL IN EACH OF WHICH ZONES COUNTER-CURRENT CONTACT IS EFFECTED BETWEEN THE UPWARD FLOW OF LIQUID AND THE GRANULAR MATERIAL, SAID METHOD COMPRISING UPWARDLY INTRODUCING SUGAR SYRUP INTO THE ZONES AT SUCH LEVELS AS TO RESPECTIVELY DIVIDE SAID ZONES INTO AN UPPER LAYER CONSTITUTED OF GRANULAR MATERIAL TO BE CONTACTED WITH THE SUGAR SYRUP AND A LOWER LAYER CONSTITUTED OF GRANULAR MATERIAL WHICH HAS COMPLETED CONTACT WITH THE SUGAR SYRUP, UPWARDLY PASSING THE SUGAR SYRUP THROUGH SAID UPPER LAYER IN WHICH COUNTERCURRENT CONTACT BETWEEN THE GRANULAR MATERIAL AND THE SUGAR SYRUP IS EFFECTED, DISCHARGING THE SUGAR SYRUP WHICH HAS COMPLETED THE CONTACT FROM THE TOP OF ZONES, DISCHARGING THE GRANULAR MATERIAL FROM SAID LOWER LAYERS FROM THE BOTTOM OF THE ZONES BY THE INTERNAL PRESSURE EXERTED BY THE PASSING OF THE SUGAR SYRUP THROUGH SAID UPPER LAYERS, AND THEN AFTER A PREDETERMINED PERIOD OF TIME STOPPING THE PASSAGE OF THE SUGAR SYRUP AND SIMULTANEOUSLY DISCHARGING A PART OF THE SUGAR SYRUP IN THE VICINITY OF SAID LEVELS TO CAUSE A REDUCTION OF INTERNAL PRESSURE AND THE SUBSEQUENT DECENT OF SAID UPPER LAYERS AND THE SUPPLY OF NEW GRANULAR MATERIAL FROM THE TOP OF THE ZONES TO FILL THE RESULTING SPACES ABOVE SAID UPPER LAYERS WITH A PREDETERMINED QUANTITY, SAID SUPPLY BEING TERMINATED UPON THE BEGINNING OF THE PASSING OF THE SUGAR SYRUP INTO THE ZONES, THE FIRST ZONE AND THE SECOND ZONE BEING CONNECTED IN SERIES TO TRANSFER THE TREATED SUGAR SYRUP FROM THE FIRST ZONE TO THE SECOND ZONE, THE FIRST ZONE BEING FILLED WITH ANION EXCHANGE RESIN AND THE SECOND ZONE BEING FILLED WITH CATION EXCHANGE RESIN.