Adsorption apparatus and method for drying gas streams having differential pressure control mechanism for vessels on adsorbing and desorbing cycles

Claim 1

IN A CYCLIC METHOD OF REMOVING A COMPONENT FROM A WET GAS STREAM WHEREIN A SUBSTANTIAL PORTION OF THE WET GAS STREAM IS PASSED THROUGH A FIRST DRYING AGENT FOR THE COMPONENT, A HOT REGENERATING FLUID IS PASSED THROUGH A SECOND DRYING AGENT PREVIOUSLY LOADED WITH SAID COMPONENT, AND ANOTHER PORTION OF THE WET GAS IS REMOVED FROM THE WET GAS LINE AT A POINT UPSTREAM OF SAID FIRST DRYING AGENT, DIRECTED THROUGH A THIRD FRESHLY REGENERATED DRYING AGENT TO COOL THE LATTER, AND THEN REINTRODUCED INTO THE DRY GAS LEAVING SAID FIRST DRYING AGENT AT A POINT DOWNSTREAM OF THE SAME, THE IMPROVED STEPS COMPRISING: SENSING THE PRESSURE OF THE WET GAS UPSTREAM AT THE POINT OF REMOVAL OF SAID OTHER PORTION OF GAS THEREFROM; SENSING THE PRESSURE OF THE DRY GAS DOWNSTREAM FROM THE POINT OF REINTRODUCTION OF SAID OTHER PORTION OF GAS INTO THE DRY GAS LEAVING SAID FIRST DRYING AGENT; AND MAINTAINING A PRESELECTED PRESSURE DIFFERENTIAL BETWEEN SAID POINTS BY VARYING THE QUANTITY OF GAS FLOWING THROUGH SAID FIRST DRYING AGENT IN ACCORDANCE WITH THE PRESSURE DROP ACROSS SAID THIRD DRYING AGENT.