Process and apparatus for the elutriation of solids

Claim 1

A METHOD FOR THE CONVEYANCE AND ELUTRIATION OF GRANULAR SOLIDS CONTAINING SOLIDS FINES WHICH COMPRISES SUBMERGING THE INLET OF AN ELONGATED CONVEYANCE ZONE WITH A BED OF SAID SOLIDS TO BE CONVEYED, PASSING A CONVEYANCE FLUID THROUGH SAID BED AND THROUGH SAID CONVEYANCE ZONE AT A RATE SUFFICIENT TO CONVEY SAID SOLID THERETHROUGH, APPLYING A FORCE AGAINST THE SOLIDS DISCHARGING THEREFROM THEREBY MAINTAINING SAID SOLIDS DURING CONVEYANCE IN THE PRESENCE OF A CONCURRENT CONVEYANCE FLUID FLOW IN THE FORM OF A MOVING SUBSTANTIALLY COMPACT MASS OF SAID SOLIDS HAVING SUBSTANTIALLY THEIR AT-REST BULK DENSITY, FLOWING AT LEAST A PORTION OF THE DISCHARGING COMPACT MASS OF GRANULAR SOLIDS INTO AN ELUTRIATION ZONE AT AN INTERMEDIATE POINT TO FORM AND MAINTAIN A DOWNWARDLY MOVING ACCUMULATION OF SAID SOLIDS THEREIN BELOW SAID INTERMEDIATE POINT, PASSING AN ELUTRIATION FLUID UPWARDLY THROUGH SAID ACCUMULATION OF SOLIDS, CONTROLLING THE ELUTRIATION FLUID FLOW RATE AT A VALUE INSUFFICIENT TO FLUIDIZE SOLIDS BUT SUFFICIENT TO FORM AND MAINTAIN SAID ACCUMULATION OF SOLIDS AS AN EXPANDED BED OF NONFLUIDIZED SOLIDS HAVING A BULK DENSITY LESS THAN SAID AT-REST BULK DENSITY OF SAID SOLIDS AND TO ESTABLISH AND MAINTAIN A FLUIDIZED SUSPENSION OF SOLIDS FINES ABOVE SAID INTERMEDIATE POINT IN SAID ELUTRIATION ZONE WHEREBY AN ACTIVE CLASSIFYING TRANSFER OF SOLIDS EXISTS BETWEEN SAID EXPANDED BED AND FLUIDIZED SUSPENSION OF TIMES, REMOVING SOLIDS FINES FROM SAID AERATED SUSPENSION AT THE TOP OF SAID ELUTRIATION ZONE, AND SEPARATELY WITHDRAWING SUBSTANTIALLY FINES-FREE SOLIDS BY GRAVITY FROM THE BOTTOM OF SAID ELUTRIATION ZONE.

Claim 2

A METHOD FOR THE CONVEYANCE AND ELUTRIATION OF GRANULAR SOLIDS CONTAINING SOLIDS FINES WHICH COMPRISES SUBMERGING THE INLET OF AN ELONGATED CONVEYANCE ZONE WITH A BED OF SAID SOLIDS TO BE CONVEYED, PASSING A CONVEYANCE FLUID THROUGH SAID BED AND THROUGH SAID CONVEYANCE ZONE AT A RATE SUFFICIENT TO CONVEY SAID SOLID THERETHROUGH, APPLYING A FORCE AGAINST THE SOLIDS DISCHARGING THEREFROM THEREBY MAINTAINING SAID SOLIDS DURING CONVEYANCE IN THE PRESENCE OF A CONCURRENT CONVEYANCE FLUID FLOW IN THE FORM OF A MOVING SUBSTANTIALLY COMPACT MASS OF SAID SOLIDS HAVING SUBSTANTIALLY THEIR AT-REST BULK DENSITY, FLOWING AT LEAST A PORTION OF THE DISCHARGING COMPACT MASS OF GRANULAR SOLIDS INTO AN ELUTRIATION ZONE AT AN INTERMEDIATE POINT TO FORM AND MAINTAIN A DOWNWARDLY MOVING ACCUMULATION OF SAID SOLIDS THEREIN BELOW SAID INTERMEDIATE POINT, PASSING AN ELUTRIATION FLUID UPWARDLY THROUGH SAID ACCUMULATION OF SOLIDS, CONTROLLING THE ELUTRIATION FLUID FLOW RATE AT A VALUE INSUFFICIENT TO FLUIDIZE SOLIDS BUT SUFFICIENT TO FORM AND MAINTAIN SAID ACCUMULATION OF SOLIDS AS AN EXPANDED BED OF NONFLUIDIZED SOLIDS HAVING A BULK DENSITY LESS THAN SAID AT-REST BULK DENSITY OF SAID SOLIDS AND TO ESTABLISH AND MAINTAIN A FLUIDIZED SUSPENSION OF SOLIDS FINES ABOVE SAID INTERMEDIATE POINT IN SAID ELUTRIATION ZONE WHEREBY AN ACTIVE CLASSIFYING TRANSFER OF SOLIDS EXISTS BETWEEN SAID EXPANDED BED AND FLUIDIZED SUSPENSION OF TIMES, REMOVING SOLIDS FINES FROM SAID AERATED SUSPENSION AT THE TOP OF SAID ELUTRIATION ZONE, AND SEPARATELY WITHDRAWING SUBSTANTIALLY FINES-FREE SOLIDS BY GRAVITY FROM THE BOTTOM OF SAID ELUTRIATION ZONE.