Fluid separation process and apparatus

Claim 1

AN IMPROVED MULTI-STAGE METHOD FOR CONTINUOUSLY PROGESSIVELY SEPARATING A PERMEABLE FLUID FROM A FLUID MIXTURE ACCORDING TO THE DIFFERENT PERMEATION RATES OF THE MIXTURE COMPONENTS THROUGH A PLURALITY OF PERMEABLE MEMBRANE STRUCTURES, SAID METHOD COMPRISING MAINTAINING, IN EACH OF A PLURALITY OF OPERATIVELY ASSOCIATED STAGES, A PLURALITY OF PERMEABLE MEMBRANE STRUCTURES OF POLYMERIC COMPOSITION AND COMPRISING HOLLOW FILAMENTS EXTENDING THROUGH AND PACKED IN A FLUID-TIGHT ENCLOSED ZONE, SAID PLURALITY OF STAGES COMPRISING A FIRST STAGE AND A FINAL STAGE, SAID METHOD FURTHER COMPRISING PASSING AN INLET STREAM OF AN INITIAL FLUID MIXTURE AT A GIVEN PRESSURE THROUGH THE INTERIOR OF THE HOLLOW FILAMENTS EXTENDING THROUGH THE ENCLOSED ZONE OF THE FIRST STAGE, REMOVING ANY PERMEATED FLUID FROM SAID FIRST STAGE ENCLOSED ZONE OUTSIDE SAID HOLLOW FILAMENTS IN A DIRECTION COUNTERCURRENT TO THE DIRECTION OF FLOW OF SAID INITIAL FLUID MIXTURE INSIDE SAID HOLLOW FILAMENTS IN SAID FIRST STAGE ZONE SAID METHOD FURTHER COMPRISING CONCURRENTLY PASSING AT LEAST A PORTION OF THE PERMEATED FLUID FROM A PRECEDING STAGE AS AN INLET STREAM TO AND THROUGH THE ENCLOSED ZONE OF SAID FINAL STAGE OUTSIDE SAID HOLLOW FILAMENTS IN SAID FINAL STAGE ZONE UNDER A GIVEN PRESSURE, WITHDRAWING AND COLLECTING PERMEATED FLUID FROM THE INTERIOR OF THE HOLLOW FILAMENTS EXTENDING THROUGH SAID FINAL STAGE ZONE AT A LOWER PRESSURE AND COUNTERCURRENTLY WITH RESPECT TO SAID INLET STREAM MOVING THROUGH SAID ENCLOSED ZONE OF SAID FINAL STAGE, SUPPLYING THE REMAINING PORTION OF THE SAID FLUID WHICH PASSES THROUGH SAID ENCLOSED ZONE OUTSIDE SAID HOLLOW FILAMENTS OF SAID FINAL STAGE AS A PORTION OF AN INLET FLUID STREAM TO AT LEAST ONE PRECEEDING STAGE.