Catalytic conversion of hydrocarbons with finely divided catalyst in two stages

Claim 1

IN THE PYROLITIC CONVERSION OF HYDROCARBONS WHEREIN A CHARGE OIL IN VAPOR PHASE IS SUBJECTED TO CONVERSION TEMPERATURES IN THE PRESENCE OF A FINELY DIVIDED CATALYST, THE STEPS COMPRISING DELIVERING VAPORIZED CHARGE OIL WITH THE CATALYST SUSPENDED THEREIN TO AN INITIAL CONVERSION CHAMBER WHEREIN CONVERSION OF THE CHARGE OIL IS INITIATED AND A MAJOR PORTION OF THE CATALYST SEPARATED FROM THE VAPORS, WITHDRAWING THE VAPORS FROM AN UPPER ZONE OF THE CHAMBER AND PASSING THEM DIRECTLY WITH RESIDUAL CATALYST SUSPENDED THEREIN TO A LOWER ZONE OF A SECOND CONVERSION CHAMBER AND PASSING THE VAPORS UPWARDLY THROUGH SAID SECOND CHAMBER, WITHDRAWING CATALYST FROM A LOWER ZONE OF THE INITIAL CONVERSION CHAMBER AND PASSING THE WITHDRAW CATALYST TO