Fluid coking reactor

Claim 1

IN A FLUIDIZED SOLIDS HYDROCARBON CONVERSION PROCESS WHEREIN HYDROCARBONS ARE CONVERTED IN A LOWER PORTION OF A CONVERSION ZONE BY CONTACT WITH HIGH TEMPERATURE FLUIDIZED SOLIDS, VAPORS THEREFROM ARE UPWARDLY REMOVED AND ENTRAINED SOLIDS ARE SEPARATED FROM SAID VAPORS IN A CYCLONE SEPARATING ZONE IN THE UPPER PORTION OF SAID CONVERSION ZONE, THE IMPROVEMENT WHICH COMPRISES MAINTAINING A SEAL IN THE UPPER PORTION OF SAID CONVERSION ZONE TO PREVENT ACCESS OF VAPORS AND SOLIDS TO STAGNANT ZONES IN THE AREA OF SAID CYCLONE SEPARATING ZONE AND TO REDUCE VAPOR RESIDENCE TIME, SAID SEAL FORMING AN UPWARDLY CONVERGING CONFINED PASSAGE FOR SAID VAPORS TO THE INLET OF SAID CYCLONE SEPARATING ZONE, AND INTRODUCING AN INERT GAS AS A PURGE INTO SAID STAGNANT ZONES.