Process for purifying polymers

Claim 1

PROCESS FOR PURIFYING A POLYMER CONTAMINATED WITH IMPURITIES, COMPRISING THE FOLLOWING STEPS; CONTINUOUSLY PASSING UPWARD IN A CONTACTING ZONE, COMPRISING AN ELONGATED COLUMN CONTAINING FLOW OBSTRUCTING MEANS AND HAVING A POLYMER EXIT, THE CONTAMINATED POLYMER TOGETHER WITH A FIRST LIQUID COUNTERCURRENT TO A CONTINUOUSLY DOWNWARDLY MOVING SECOND LIQUID, SAID SECOND LIQUID BEING HEAVIER THAN AND INCOMPLETELY MISCIBLE WITH SAID FIRST LIQUID; SIMULTANEOUSLY PULSATING THE CONTENTS OF THE CONTACTING ZONE, TO MAINTAIN THE POLYMER SUSPENDED IN THE LIGHTER LIQUID AND TO INSURE PASSAGE OF THE POLYMER IN THE DIRECTION OF SAID POLYMER EXIT WHEREBY THE IMPURITIES ARE TRANSFERRED TO THE DOWNWARDLY MOVING HEAVIER LIQUID; CONTINUOUSLY DISCHARGING FROM THE BOTTOM OF THE COLUMN A STREAM OF THE HEAVIER LIQUID CHARGED WITH IMPURITIES; CONTINUOUSLY CONTROLLING SAID DISCHARGE SO THAT THE INTERFACE BETWEEN THE LIGHTER AND THE HEAVIER LIQUIDS LIES IN THE BOTTOM SECTION OF THE COLUMN, WHEREBY THE LIGHTER LIQUID FORMS A CONTINOUS PHASE IN THE COLUMN; CONTINUOUSLY REMOVING THE POLYMER SUBSTANTIALLY FREE OF IMPURITIES FROM THE TOP OF THE COLUMN, TOGETHER WITH THE FIRST LIQUID AND THEREAFTER SEPARATING THE PURIFIED POLYMER FROM THE FIRST LIQUID.