Method and apparatus for retorting oil shale

Claim 1

IN THE RETORTING OF OIL SHALE GRANULES BY PASSAGE DOWNWARDLY THROUGH A SHALE PREHEAT ZONE, A KEROGEN DECOMPOSITION ZONE, A COMBUSTION ZONE AND A SHALE COOLING ZONE COUNTERCURRENT TO RISING GASIFORM MATERIAL, THE IMPROVEMENT WHICH COMPRISES COOLING SHALE GRANULES IN SAID SHALE COOLING ZONE BY DIRECT COUNTERCOURRENT CONTACT WITH RISING GASIFORM MATERIAL IN A PLURALITY OF ELONGATED ADJACENTLY POSITIONED CONFINED JPASSAGEWAYS HAVING A LENGTH TO CROSS SECTIONAL RATIO KSUFFICIENT TO MAINTAIN A SUBSTANTIALLY UNIFORM GASIFORM MATERIAL PRESSURE DROP THROUGH THE SEPARATE PASSAGEWAYS SUBSTANTIALLY UNIFORM IN TEMPERATURE THROUGHOUT THE RETORT CROSS SECTION, PASSING GASIFORM MATERIAL PREHEATED IN SAID ELONGATED PASSAGEWAY COMBINED WITH COMBUSTION SUPPORTING GASEOUS MATERIAL INTRODUCED TO SAID RETORT UNWARDLY THROUGH A COMBUSTION SECTION COUNTERCURRENT TO DOWNWARDLY FLOWING SHALE GRANULES UNDER CONDITIONS TO HEAT SAID GASEOUS MATERIAL BY COMBUSTION, REMOVING FINELY DIVIDED SOLID PARTICLE MATERIAL MOVING UPWARDLY THROUGH SAID MID RETORT WITH SAID HEATED GASIFORM MATERIAL IN A FINES REMOVAL ZONE ADJACENT THE UPPER LEVEL OF SAID COMBUSTION SECTION, PASSING HEATED GASIFORM MATERIAL SUBSTANTIALLY FREE OF SOLID FINES UPWARDLY THROUGH THE KEROGEN DECOMPOSITION ZONE AND RECOVERING KEROGEN DECOMPOSITION PRODUCTS AND GASIFORM MATERIAL FROM THE UPPER PORTION OF SAID RETORT.