Centrifugal separator

Claim 1

IN A CENTRIFUGAL SEPARATOR FOR SEPARATING SOLID PARTICLES FROM THE LIQUID PORTION OF A SLURRY COMPRISING A ROTATABLE BOWL INCLUDING AN IMPERFORATE TRUNCATED CONICAL INNER SURFACE CONNECTED AT ITS SMALLER END WITH THE INLET END OF A PORTION EXTENDING COAXIALLY THEREFROM HAVING AT LEAST ONE SCREEN IN ITS WALL AND HAVING A SOLIDS DISCHARGE END OPPOSITE SAID INLET END, SAID PORTION HAVING A DIAMETER AT ITS OUTLET END NO LESS THAN ITS DIAMETER AT ITS INLET END, A HELICAL CONVEYOR COAXIALLY MOUNTED FOR ROTATION WITHIN SAID BOWL, MEANS FOR INTRODUCING SAID SLURRY INTO SAID BOWL IN ADVANCE OF THE INLET END OF SAID SCREEN PORTION BY A DISTANCE, MESURED ALONG THE AXIS, EQUAL TO AT LEAST 15% OF THE DIAMETER OF THE LARGER END OF SAID CONICAL SURFACE, AND MEANS FOR ROTATING THE BOWL AND THE CONVEYOR IN THE SAME SENSE AT SLIGHTLY DIFFERENT SPEEDS TO CAUSE THE SOLIDS IN SAID SLURRY TO DEPOSIT ON THE INNER SURFACE OF THE BOWL AND TO ADVANCE THE SOLIDS DEPOSIT IN ONE DIRECTION ALONG SAID CONICAL SURFACE TOWARD THE DISCHARGE END OF SAID SCREEN PORTION, THE IMPROVEMENT WHICH COMPRISES MEANS FOR REMOVING THE LIQUID PORTION OF SAID SLURRY TO MAINTAIN THE DEPTH OF LIQUID WITHIN SAID BOWL AT SUCH A LEVEL THAT THE SURFACE OF THE LIQUID INTERSECTS THE CONICAL SURFACE AT A DISTANCE FROM THE INLET END OF SAID SCREEN PORTION, MEASURED ALONG THE AXIS, EQUAL TO AT LEAST 15% OF THE DIAMETER OF THE LARGER END OF SAID CONICAL SURFACE.