Contacting solids and gases

Claim 1

IN A CYCLIC METHOD OF CONTACTING A GAS WITH GRANULAR SOLID MATERIAL COMPRISING PREDOMINANTLY SOLIDS HAVING AN AVERAGE DIAMETER OF ABOUT 0.5 MM. TO ABOUT 10 MM. BY FLOWING SAID GAS THROUGH THE INTERSTICES OF A MASS OF GRANULES OF SAID SOLIDS IN A CONTACT ZONE, WITHDRAWING GRANULAR CONTACT MATERIAL FROM CONTACT WITH SAID GAS AT A LOW POINT IN SAID CONTACT ZONE AND RETURNING SAID GRANULAR CONTACT MATERIAL TO A HIGH POINT IN SAID CONTACT ZONE, THE IMPROVEMENT WHICH COMPRISES, MIXING SAID WITHDRAWN GRANULAR SOLID MATERIAL WITH A RELATIVELY MORE FINELY-DIVIDED SOLID MATERIAL OF SUBSTANTIALLY SMALLER AVERAGE PARTICLE SIZE THAN SAID GRANULAR SOLID IN SUFFICIENT AMOUNT TO FORM A FLUIDIZABLE MIXTURE, PASSING SAID MIXED SOLIDS INTO A SECOND GAS TO FORM A FLUIDIZED SUSPENSION OF SAID MIXED SOLIDS IN SAID GAS, PASSING SAID SUSPENSION TO AN ELEVATED POINT, SEPARATING SAID GRANULAR SOLIDS FROM SAID SECOND GAS AND SAID MORE FINELY-DIVIDED SOLID MATERIAL AT AN ELEVATED POINT, AND DISCHARGING SAID LAST-MENTIONED SEPARATED GRANULAR SOLID AT AN ELEVATED POINT INTO A CONTACT ZONE WHEREIN SAID GRANULAR SOLIDS ARE CONTACTED WITH A GAS IN THE ABSENCE OF SAID FINELY DIVIDED SOLID MATERIAL.