Method and apparatus for processes employing fluent solids

Claim 1

IN PROCESS WHEREIN FLUENT SOLID HYDROCARBON CONVERSION CATALYST CIRCULATES IN A SYSTEM COMPRISING A CONVERSION ZONE AND A REGENERATION ZONE, IN WHICH CONVERSION ZONE HYDROCARBONS CONTACT SAID CATALYST SO AS TO FROM CONVERSION PRODUCTS AND CONCOMITANTLY TO DEPOSIT COKE ON SAID CATALYST IN WHICH REGENERATION ZONE AN OXYGEN CONTAINING GAS CONTACTS CATALYST FROM THE CONVERSION ZONE UNDER COMBUSTION CONDITIONS SO AS TO REMOVE COKE DEPOSITED THEREON, THE IMPROVEMENT WHICH COMPRISES PASSING FLUENT SOLID HYDROCARBON CONVERSION CATALYST THROUGH SAID CONVERSION ZONE AS A CONTINUOUS DOWNWARDLY MOVING NONTURBULENT BED OF APPROXIMATELY EQUAL HORIZONTAL CROSS SECTIONAL AREA THROUGHOUT ITS VERITICAL EXTENT, WITHDRAWING FROM THE CONVERSION ZONE AS AT LEAST ONE COMPACT COLUMN A PORTION OF SAID CATALYST AT A POINT INTERMEDIATE OF THE VERTICAL EXTENT OF SAID BED PASSING HYDROCARBON THROUGH SUBSTANTIALLY THE COMPLETE VERTICAL EXTENT OF SAID BED, DISENGAGING HYDROCARBON VAPORS FROM THE PORTION OF CATALYST SO WITHDRAWN SUBSTANTIALLY AT THE POINT OF WITHDRAWAL, INTRODUCING TO THE COMPACT COLUMN OF CATALYST SO WITHDRAWN AT A POINT BEYOND THE CONVERSION ZONE AN UNREACTIVE GAS AT A PRESSURE GREATER THAN THE PRESSURE IN THE CONVERSION ZONE AT THE POINT OF WITHDRAWAL OF CATALYST TO PREVENT THE ESCAPE OF HYDROCARBON VAPORS FROM THE CONVERSION ZONE, WHEREBY THE MASS VELOCITY OF THE CATALYST IS GREATER IN THE PART OF THE CONVERSION ZONE ABOVE THE POINT OF WITHDRAWAL OF CATALYST THAN IN THE PART OF THE CONVERSION ZONE BELOW THE POINT OF WITHDRAWAL OF CATALYST.