Process for destructive distillation

Claim 1

A CONTINUOUS PROCESS FOR SEPARATING AND RECOVERING SHALE OIL FROM OIL SHALE WHICH COMPRISES: INTRODUCING OIL SHALE HAVING A PARTICLE SIZE OF 40 MESH AND SMALLER AND CONTAINING FROM 15 TO 90 GALLONS OF SHALE OIL PER TON INTO AN OIL SHALE PREHEATING ZONE AND THEREIN FORMING A FIRST FLUIDIZED OIL SHALE BED AND HEATING SAID OIL SHALE TO A TEMPERATURE NO GREATER THAN 450* F. BY DIREACTLY CONTACTING SAID OIL SHALE WITH FLUE GAS WITHDRAWN FROM A SECOND SEPARATION ZONE AS HEREINAFTER SET FORTH AND PASSED INTO THE LOWER PORTION OF SAID OIL SHALE PREHEATING ZONE; WITH DRAWING PREHEATED OIL SHALE FROM THE UPPER PORTION OF SAID FIRST FLUIDIZED OIL SHALE BED AND PASSING SAME IN DIRECT CONCURRENT CONTACT WITH HEATED STRIPPING GAS PRODUCED AS HEREINAFTER SET FORTH INTO THE OWER PORTION OF A SHALE OIL STRIPPING ZONE AND THEREIN FORMING A SCOND FLUIDIZED OIL SHALE BED AND STRIPPING SHALE OIL FROM SAID OIL SHALE AT A TEMPERATURE OF FROM 825 TO 1050* F.; WITHDRAWING A RESULTING MIXTURE OF SHALE OIL VAPORS AND STRIPPING GAS FROM THE UPPER PORTION OF SAID STRIPPING ZONE AND PASSING SAME INTO A FIRST INDIRECT HEAT EXCHANGE ZONE WHEREIN SAID MIXTURE IS INDIRECTLY PASSED IN HEAT EXCHANGE RELATION WITH AIR PASSED INTO SAID FIRST HEAT EXCHANGE ZONE THEREBY HEATING SAID AIRAND REMOVING HEAT FROM SAID MIXTURE; WITHDRAWING SAID MIXTURE FROM SAID HEAT EXHCHANGE ZONE AND SEPARATING SAME IN A FIRST SEPARATING ZONE INTO A LIQUID STREAM OF SHALE OIL AND A VAPOROUS PRODUCT GAS STREAM, EACH OF SAID STREAMS BEING A PRODUCT OF PROCESS; WITHDRAWING STRIPPED OIL SHALE FROM THE UPPER PORTION OF SAID SECOND FLUIDIZED OIL SHALE BED AND PASSIN SAME IN CONCURRENT DIRECT CONTACT WITH HEATED AIR WITHDRAWN A COMBUSTION ZONE AND THEREIN FORMING A FLUIDIZED STRIPPED OIL SHALE BED AND BURNING RESIDUAL CARBON FROM STRIPPED OIL SHALE; WITHDRAWING RESULTING HEATED SPENT OIL SHALE FROM THE UPPER PORTION OF SAID FLUDIZED STRIPPED OIL SHALE BED AND PASSING SAME INTO A STRIPPING GASHEATING ZONE AND THEREIN FORMING A FLUIDIZED SPENT OIL SHALE BED AND HEATING SAID STRIPPING GAS BY DIRECTLY CONTACTING AND HEATED SPENT OIL SHALE WITH SAID STRIPPING GAS WHICH IS PASSED INTO