Conversion process and apparatus for use therein

Claim 1

AN IMPROVED METHOD FOR CONVERTING HYDROCARBONS IN A TRANSFER LINE CRACKING ZONE WHICH COMPRISES PASSING A MIXTURE OF FRESH HYDROCARBON FEED MATERIAL AND FINELY DIVIDED CATALYST AS A CONCURRENT SUSPENSION UPWARDLY THROUGH AN ELONGATED CONFINED CRACKING ZONE AT A VELOCITY IN THE RANGE OF FROM ABOUT 4 TO ABOUT 20 FEET PER SECOND UNDER SEVERE CRACKING CONDITIONS IN THE LOWER PORTION OF THE CRACKING ZONE AND LESS SEVERE CRACKING CONDITIONS IN THE UPPER PORTION OF SAID CRACKING ZONE, SEPARATELY INTRODUCING A CYCLE OIL TO THE UPFLOWING MIXTURE ENTERING THE UPPER PORTION OF THE CRACKING ZONE UNDER LESS SEVERE CRACKING CONDITIONS, DISCHARGING PRODUCTS OF SAID CRACKING REACTIONS AND CATALYST FROM THE TOP OF SAID CRACKING ZONE, SEPARATING REACTION PRODUCTS FROM CATALYST, STRIPPING THE SEPARATED CATALYST, REGENERATING THE STRIPPED CATALYST AND PASSING THE REGENERATED CATALYST AT AN ELEVATED TEMPERAURE TO SAID SEVERE CRACKING PORTION OF THE CRACKING ZONE.