Process and apparatus for clay contacting in the refining of lubricating oil

Claim 1

IN THE PROCESS OF CONTINUOUSLY REFINING LUBRICATING OIL BY CONTACTING WITH CLAY WHEREIN QUANTITIES OF CLAY PRECISELY MEASURED WITH RESPECT TO THE OIL ARE DELIVERED TO A CONTACT TANK AT CONTROLLABLE RATE, THE IMPROVEMENT WHICH COMPRISES TRANSFERRING THE CALY FROM AN INITIAL STORAGE BIN TO THE CONTACT TANK IN SEPARATE STEPS, THE FIRST OF WHICH CONSISTS IN PNEUMATICALLY REMOVING AN EXCESS OF CLAY NOT TO EXCEED 150% OF THAT REQUIRED FOR THE CONTACTING OPERATION TO AN INTERMEDIATE ELEVATED CHAMBER, MAINTAINING A PREDETERMINED CLAY LEVEL IN SAID ELEVATED CHAMBER INDEPENDENT OF THE AMOUNT DRAWN OFF FROM THE CHAMBER, RETURNING ALL CLAY ABOVE THE PREDETERMINED LEVEL IN SAID CHAMBER TO THE STOREAGE BIN, DRAWING OFF CLAY FROM SAID CHAMBER THROUGH A SUBSTANTIALLY VERTICAL CONDUIT, AERATING THE CLAY IN SAID CONDUIT TO ASTABLISH A PREDETERMINED DENSITY THEREIN, APPLYING A GASEOUS MEDIUM TO THE LOWER END OF SAID CONDUIT TO DISCHARGE CLAY THEREFROM AND, THROUGH A CONNECTING CONDUIT INTO THE CONTACT TANK, CONTROLLING THE APPLICATION OF SAID GASEOUS MEDIUM BY DIFFERENTIAL OF PRESSURE TO MAINTAIN A UNIFORM RATE OF FLOW, SEPARATELY INTRODUCING CLAY FREE OIL TO THE CONTACT TANK, AND VARYING THE DISCHARGE RATE OF THE AERATED CLAY INTO THE CONNECTING CONDUIT IN ACCORDANCE WITH THE REFINING TREATMENT REQUIREMENTS OF THE OIL INTRODUCED TO THE CONTACT TANK.