Catalytic cracking of hydrocarbons

Claim 1

A METHOD FOR THE CATALYTIC CRACKING OF HIGH BOILING HYDROCARBON OIL FEEDS WHICH COMPRISES PASSING A MIXTURE OF HYDROCARBON OIL AND FRESHLY REGENERATED CATALYST PARTICLES AS AN UPWARDLY FLOWING CONFINED STREAM SUBMERGED IN A DENSE FLUIDIZED BED OF CATALYST PARTICLES IN A CRACKING ZONE AND DISCHARGING SAID MIXTURE OF OIL AND CATALYST PARTICLES UPWARDLY INTO SAID FLUIDIZED BED BUT AT A SHORT DISTANCE BELOW THE UPPER LEVEL OF THE DENSE FLUIDIZED BED, PASSING HYDROCARBON VAPORS UPWARDLY THROUGH THE DENSE FLUIDIZED CATALYST BED, REMOVING CRACKED HYDROCARBON VAPORS FROM ABOVE SAID DENSE FLUIDIZED CATALYST BED, CIRCULATING SPENT CATALYST FROM THE UPPER PORTION OF SAID FLUIDIZED CATALYST BED TO THE LOWER PORTION THEREOF BELOW THE REGION OF OIL-CATALYST MIXTURE DISCHARGE INTO A SOAKING ZONE IN THE ABSENCE OF ADDED OIL FEED TO INCREASE THE TIME OF SOAKING OF THE SPENT CATALYST PARTICLES AND TO INCREASE THE AMOUNT OF CRACKING OF RESIDUAL HIGH BOILING HYDROCARBONS ABSORBED ON SAID CATALYST PARTICLES, INTRODUCING HOT FRESHLY REGENERATED CATALYST PARTICLES INTO SAID SOAKING ZONE IN THE LOWER PORTION OF SAID FLUIDIZED CATALYST BED BELOW THE REGION OF OIL-CATALYST MIXTURE DISCHARGE TO INCREASE THE TEMPERATURE OF THE SPENT CATALYST PARTICLES IN SAID SOAKING ZONE TO EFFECT FASTER REMOVAL OF RESIDUAL HIGH BOILING HYDROCARBONS ABSORBED ON SAID CRACKING CATALYST, PASSING SPENT CATALYST PARTICLES FROM THE DENSE FLUIDIZED BED INTO AN ANNULAR STRIPPING ZONE SURROUNDING SAID CRACKING ZONE AND STRIPPING THE SPENT CATALYST PARTICLES TO REMOVE VOLATILE CRACKED HYDROCARBONS THEREFROM.