Fluid flow control system for simulated moving bed processes

Claim 1

IN A CONTINUOUS FLUID-SOLID CONTACTING PROCESS FOR ALTERING THE COMPOSITION OF A FEED STREAM TO YIELD A PRODUCT STREAM WHEREIN A PUMPAROUND FLUID IS CONTINUOUSLY CIRCULATED THROUGH AN ELONGATED CONTACTING ZONE CONTAINING A SOLID CONTACTING MATERIAL WHICH EFFECTS SAID ALTERATION OF COMPOSITION, ONE END OF SAID CONTACTING ZONE COMMUNICATING WITH THE OTHER THROUGH A FLOW-REGULATING MEANS TO FORM A CLOSED FLOW PATH THERETHOUGH AND SAID CONTACTING ZONE HAVING A PLURALITY OR INTERMITTENTLY FLOWCONDUCTING TRANSFER POINTS SPACED ALONG THE LENGTH OF SAID FLOW PATH, AND WHEREIN $ FLUID PROCESS STREAMS INCLUDING SAID FEED AND PRODUCT STREAMS ARE SUBSTANTIALLY SIMULTANEOUSLY INTRODUCED TO AND WITHDRAWN FROM SAID CONTACTING ZONE THROUGH A SET OF CORRESPONDING INLET AND OUTLET POINTS SELECTED FROM SAID TRANSFER POINT, AND WHEREIN SAID PROCESS STREAMS ARE PERIODICALLY SHIFTED IN UNISON SUCCESSIVELY FROM ONE SET OF TRANSFER POINTS TO THE NEXT IN DOWNSTREAM DIRECTION WITH RESPECT TO THE FLOW OF SAID PUMPAROUND FLUID WHEREBY EACH OF SAID PROCESS STREAMS EVENTUALLY PASSES THROUGH EACH OF SAID TRANSFER POINTS, THE METHOD OF CONTROLLING THE FLOW RATE OF SAID PUMPAROUND FLUID EXISTING WITHIN THAT PORTION OF SAID CONTACTING ZONE WHICH LIES BETWEEN A SELECTED PAIR OF ADJACENT PROCESS STREAMS, IRRESPECTIVE OF THEIR INSTANTANEOUS PHYSICAL POSITION RELATIVE TO SAID FLOW-REGULATING MEANS, WHICH METHOD COMPRISES: SEPARATELY SENSING THE FLOW RATES OF AT LEAST R-1 PROCESS STREAMS AND PRODUCING A GROUP OF FLOW SENSATIONS CORRESPONDING THERETO; AUTHOMATICALLY PRODUCING FROM SAID GROUP OF FLOW SENSATIONS A SETPOINT SIGNAL IN ACCORDANCE WITH THE NUMBER, DIRECTION AND FLOW RATES OF THE PROCESS STREAMS PASSING THROUGH THOSE TRANSFER POINTS BETWEEN SAID FLOW-REGULATING MEANS AND THE ONE OF SAID PAIR OF ADJACENT PROCESS STREAMS WHICH IS MORE REMOTE FROM SAID FLOW-REGULATING MEANS; AND ADJUSTING SAID FLOW-REGULATING MEANS IN RESPONSE TO SAID SETPOINT SIGNAL.