Process for comminuting grit in pigments and supersonic fluid energy mill therefor

Claim 2

IN A PROCESS FOR COMMINUTING GRIT IN A PIGMENT THE STEPS COMPRISING (1) INJECTING A GASEOUS FLUID TANGENTIALLY AND AT SUPERSONIC VELOCITY INTO THE PERIPHERY OF AN ENCLOSED, CIRCULAR SPACE HAVING ONLY AN AXIAL OUTLET, WHEREBY TO ESTABLISH IN SAID CIRCULAR SPACE A DISC-SHAPED VORTEX OF SAID GASEOUS FLUID INWARDLY SPIRALING TO SAID OUTLET, (2) INJECTING GRIT-CONTAINING PIGMENT INTO SAID VORTEX AT A LOCUS REMOTE FROM SAID OUTLET, WHEREBY THE GRIT IS COMPLETELY COMMINUTED IN THE VORTEX, AND (3) DISCHARGING THE GASEOUS FLUID, PIGMENT, AND COMMINUTED GRIT THROUGH THE OUTLET WHILE MAINTAINING THE PRESSURE THEREIN AT 2 TO 30 P.S.I.A.

Claim 3

IN AN IMPROVED APPARATUS FOR COMMINUTING PULVERULENT SOLIDS, IN COMBINATION, A CIRCULAR, DISC-SHAPED CHAMBER HAVING A PERIPHERAL WALL THROUGH WHICH SAID CHAMBER IS IN CLOSED COMMUNICATION WITH A SOURCE OF PRESSURIZED GASEOUS FLUID THROUGH A MULTIPLICITY OF CONVERGING-DIVERGING NOZZLES, EACH NOZZLE HAVING INLET BORE, THROAT BORE, AND EXIT BORE PORTIONS, ALL OF CIRCULAR CROSS SECTION AND HAVING A COMMON AXIS, THE INLET BORE CONVERGING THROUGH A NECK TO A CYLINDRICAL THROAT HAVING A DIAMETER ABOUT ONE-THIRD THAT OF THE INLET BORE, SAID THROAT OPENING INTO A TAPERED OUTLET BORE OF DIAMETER INCREASING LINEARLY IN THE DIRECTION OF A DISCHARGE OUTLET IN SAID EXIT PORTION, THE TAPER ANGLE BETWEEN THE WALL AND AXIS OF THE OUTLET BORE BEING ABOUT 2 TO 14*, SAID EXIT PORTION HAVING A TRUNCATED EXIT FACE, THE ANGLE BETWEEN THE TRUNCATING PLANE FORMING THE EXIT FACE AND A PLANE PERPENDICULAR TO THE AXIS OF THE OUTLET BORE BEING ABOUT FROM 19 TO 42*, AND THEREBEING IN THE TRUNCATED FACE IN INSET FACE AROUND THE DISCHARGE OPENING OF THE OUTLET BORE, PERPENDICULAR TO THE AXIS THEREOF AND EXTENDING OUT FROM SAID DISCHARGE OPENING A DISTANCE OF FROM 1/2 TO 3 RADII OF SAID OPENING, THE OPENING DEFINED BY SAID INSET FACE TAPERING OUTWARDLY FROM THE PERIPHERY OF SAID FACE TO THE TRUNCATED FACE AT AN ANGLE OF AT LEAST ABOUT 6* FROM THE AXIS OF THE OUTLET BORE, SAID NOZZLES BEING MOUNTED IN SAID PERIPHERAL WALL AT SUBSTANTIALLY EQUALLY SPACED POINTS THEREIN, WITH THE TRUNCATED FACE OF EACH NOZZLE SUBSTANTIALLY FLUSH WITH SAID WALL AND THE AXIS OF THE NOZZLE BORE BEING TANGENT TO A CIRCLE CONCENTRIC WITH SAID CHAMBER, OF A RADIUS FROM 1/3 TO 2/3 THE RADIUS OF SAID CHAMBER, THE CHAMBER HAVING AN AXIAL DISCHARGE PORT CONCENTRIC WITH ITS PERIPHERY, MEANS COMMUNICATING WITH SAID CHAMBER FOR FEEDING PULVERULENT SOLIDS INTO IT BETWEEN ITS PERIPHERY AND THE DISCHARGE PORT, AND MEANS COMMUNICATING WITH THE DISCHARGE PORT FOR SEPARATING EFFLUENT SOLIDS FROM GASEOUS FLUIDS.

Claim 4

IN AN IMPROVED APPARATUS FOR COMMINUTING PULVERULENT SOLIDS, IN COMBINATION, A CIRCULAR, DISC-SHAPED CHAMBER HAVING A PERIPHERAL WALL THROUGH WHICH SAID CHAMBER IS IN CLOSED COMMUNICATION WITH A SOURCE OF PRESSURIZED GASEOUS FLUID THROUGH A MULTIPLICITY OF CONVERGING-DIVERGING NOZZLES, EACH NOZZLE HAVING INLET BORE, THROAT BORE, AND EXIT BORE PORTIONS, ALL OF CIRCULAR CROSS SECTION AND HAVING A COMMON AXIS, THE INLET BORE CONVERGING THROUGH A NECK TO A CYLINDRICAL THROAT HAVING A DIAMETER ABOUT ONE-THIRD THAT OF THE INLET BORE, SAID THROAT OPENING INTO A TAPERED OUTLET BORE OF DIAMETER INCREASING LINEARLY IN THE DIRECTION OF A DISCHARGE OUTLET IN SAID EXIT PORTION, THE TAPER ANGLE BETWEEN THE WALL AND AXIS OF THE OUTLET BORE BEING ABOUT 2 TO 14*, SAID EXIT PORTION HAVING A TRUNCATED EXIT FACE, THE ANGLE BETWEEN THE TRUNCATING PLANE FORMING THE EXIT FACE AND A PLANE PERPENDICULAR TO THE AXIS OF THE OUTLET BORE BEING ABOUT FROM 19 TO 42*, AND THEREBEING IN THE TRUNCATED FACE IN INSET FACE AROUND THE DISCHARGE OPENING OF THE OUTLET BORE, PERPENDICULAR TO THE AXIS THEREOF AND EXTENDING OUT FROM SAID DISCHARGE OPENING A DISTANCE OF FROM 1/2 TO 3 RADII OF SAID OPENING, THE OPENING DEFINED BY SAID INSET FACE TAPERING OUTWARDLY FROM THE PERIPHERY OF SAID FACE TO THE TRUNCATED FACE AT AN ANGLE OF AT LEAST ABOUT 6* FROM THE AXIS OF THE OUTLET BORE, SAID NOZZLES BEING MOUNTED IN SAID PERIPHERAL WALL AT SUBSTANTIALLY EQUALLY SPACED POINTS THEREIN, WITH THE TRUNCATED FACE OF EACH NOZZLE SUBSTANTIALLY FLUSH WITH SAID WALL AND THE AXIS OF THE NOZZLE BORE BEING TANGENT TO A CIRCLE CONCENTRIC WITH SAID CHAMBER, OF A RADIUS FROM 1/3 TO 2/3 THE RADIUS OF SAID CHAMBER, THE CHAMBER HAVING AN AXIAL DISCHARGE PORT CONCENTRIC WITH ITS PERIPHERY, MEANS COMMUNICATING WITH SAID CHAMBER FOR FEEDING PULVERULENT SOLIDS INTO IT BETWEEN ITS PERIPHERY AND THE DISCHARGE PORT, AND MEANS COMMUNICATING WITH THE DISCHARGE PORT FOR SEPARATING EFFLUENT SOLIDS FROM GASEOUS FLUIDS.