Method of and apparatus for sink and float separation of fine coal and the like

Claim 1

IN COMBINATION, A GENERALLY CYLINDRICAL VESSEL, ADAPTED TO CONTAIN A HEAVY MEDIUM BATH, A ROTOR ROTATABLE THEREIN ABOUT A HORIZONTAL AXIS, HAVING OUTWARDLY AND FORWARDLY INCLINDED ARCUATE FLIGHTS ADAPTED TO TRAVEL ALONG THE BOTTOM OF THE VESSEL, EACH FLIGHT BEING ADAPTED WHEN TRAVELING TO IMPEL A SEPARATE GENTLE CURRENT IN THE BATH UPWARDLY AND INWARDLY FROM THE BOTTOM THEREOF, A SINK DISCHARGE TROUGH PLATE CONCENTRIC WITH THE VESSEL HAVING ITS LOWER EXTREMITY BELOW THE LEVEL OF THE BATH AND DEFINING WITH THE VESSEL WALL A CHANNEL THROUGH WHICH SUCCESSIVE ROTOR FLIGHTS PASS UPWARDLY DEVELOPING A SLIGHT PUMPING HEAD ABOVE THE LEVEL OF THE BATH LIQUID, A BAFFLE WALL IN FRONT OF THE TROUGH PLATE EXTENDING DOWNWARDLY BELOW THE EXTREMITY OF THE ROTOR CHANNEL AND UPWARDLY TOWARD THE SURFACE OF THE BATH, MEANS ADJACENT THE BOTTOM OF THE VESSEL BUT ABOVE THE ROTOR FOR SUPPLYING MEDIUM TO THE VESSEL AND FOR DIRECTING THE MEDIUM FOR DOWNWARD FLOW TOWARD THE ROTOR, THE MEDIUM SUPPLY MEANS INCLUDING A MANIFOLD EXTENDING ACROSS THE BATH HAVING A DISCHARGE PORT ALONG THE UNDERSIDE THEREOF, A DRAINAGE APERTURE IN THE BOTTOM OF THE VESSEL IN OPPOSITION TO THE MEDIUM SUPPLY.