Hydrocarbon conversion in pebble heaters

Claim 1

IN A PROCESS OF CONVERTING HYDROCARBONS TO MORE DESIRABLE HYDROCARBONS AT ELEVATED TEMPERATURES TO DESIRABLE PRODUCTS WHEREIN A FLUENT CONTIGUOUS MASS OF REFRACTORY PEBBLES IS CIRCULATED BY GRAVITY THRU A SERIES OF ZONES COMPRISING A PEBBLE HEATING ZONE AND A CONVERSION ZONE COMMUNICATING THRU A RELATIVELY NARROW ELONGATED ZONE AND PERMITTING RELATIVELY FREE FLOW OF PEBBLES THERETHRU, SAID ZONES BEING SUBSTANTIALLY FILLED WITH SAID MASS OF PEBBLES; WHEREIN THAT PORTION OF SAID MASS OF PEBBLES FLOWING THRU SAID PEBBLE HEATING ZONE IS CONTINUOUSLY CONTACTED WITH A STREAM OF HOT COMBUSTION GAS TO HEAT SAID PEBBLES TO A TEMPERATURE SUBSTANTIALLY ABOVE A PREDETERMINED CONVERSION TEMPERATURE IN THE RANGE OF 1500 TO 3000*F. AND THAT PORTION OF SAID MASS OF PEBBLES FLOWING THRU SAID CONVERSION ZONE IS CONTINUOUSLY CONTACTED WITH A STREAM OF HYDROCARBONS TO HEAT AND CONVERT THE SAME TO DESIRABLE HYDROCARBON PRODUCTS; AND WHEREIN CARBONACEOUS MATTER IS DEPOSITED ON SAID PEBBLES IN SAID CONVERSION ZONE; THE IMPROVEMENT WHICH COMPRISES FLOWING SAID MASS OF PEBBLES FROM SAID CONVERSION ZONE THRU A PEBBLE COOLING ZONE SEPEARTED FROM SAID CONVERSION ZONE AND THERE CONTINOUSLY CONTACTING SAID MASS OF PEBBLES AT AN INITIAL PEBBLE TEMPERATURE IN THE RANGE OF 1300 TO 2600*F. WITH A STREAM OF STEAM AT A TEMPERATURE AND FLOW RATE REGULATED TO INSURE SUBSTANTIALLY COMPLETE REMOVAL OF SAID CARBONACEOUS MATTER FROM SAID PEBBLES BY THE WATER GAS REACTION AND SUBSTANTIALLY COOLING OF SAID PEBBLES TO A TEMPERATURE IN THE RANGE OF 500 TO 900*F.