Circulation of granular solids through a process system

Claim 1

IN A PROCESS WHICH COMPRISES CIRCULATING THROUGH A PROCESS SYSTEM GRANULAR CONTACT MATERIAL COMPRISING RELATIVELY FINE AND RELATIVELY COARSE GRANULES AND WHICH INCLUDES THE STEPS OF GRAVITATING A RELATIVELY CONSTRICTED SEAL LEG STREAM OF GRANULAR CONTACT MATERIAL FROM A RELATIVELY ENLARGED SUPPLY ZONE AS A COMPACT MASS THROUGH A SUBSTANTIAL VERTICAL DISTANCE AND OF INTRODUCING A PORTION OF THE CONTACT MATERIAL IN SAID SYSTEM AS AN ELUTRIATOR STREAM INTO AN ELUTRIATING ZONE, THE IMPROVEMENT WHICH COMPRISES: PASSING CONTACT MATERIAL DOWN IN SAID SUPPLY ZONE AS A DOWNWARDLY CONVERGING FRUSTOCONICAL STREAM AND THENCE INTO A SEAL LEG STREAM; PASSING A SMALL PORTION OF THE CONTACT MATERIAL IN SAID FRUSTOCONICAL STREAM DOWN FROM THE UNDER SURFACE OF SAID FURSTOCONICAL STREAM INTO A DOWNWARDLY CONVERGING SECOND FRUSTOCONICAL STREAM HAVING LESSER VOLUMETRIC FLOW RATE OF SOLIDS THAN SAID FIRST-NAMED FRUSTOCONICAL STREAM AND THENCE INTO AN ELUTRIATOR STREAM; AND SEPARATELY REMOVING SAID ELUTRIATOR STREAM AND SAID SEAL LEG STREAM FROM A LOWER PORTION OF SAID SUPPLY ZONE, SAID ELUTRIATOR STREAM AND SAID SEAL LEG STREAM BEING REMOVED FROM SAID SUPPLY ZONE THROUGH OUTLETS THE HORIZONTAL DISTANCE BETWEEN THE CENTERS OF WHICH IS LESS THAN ONE-HALF THE MAJOR DIMENSION OF THE HORIZONTAL CROSS-SECTION OF THE SUPPLY ZONE AT THE LEVEL OF THE OUTLET FROM WHICH SAID SEAL LEG STREAM IS REMOVED.