LOW ENERGY PULVERIZING VIA A FLUIDIZED IMPACT MILL

MANY TECHNIQUES ARE USED TO PULVERIZE COAL AND OTHER MINERALS. ALL ARE ENERGY INTENSIVE AND RESULT IN HIGH WEAR RATES ON THE EQUIPMENT. MOST ARE SLOW PROCESSES AND REQUIRE RESIDENCE TIMES MEASURED IN MINUTES. THE FLUIDIZED IMPACT MILL USES THE KINETIC ENERGY DERIVED FROM THROWING FEED MATERIALS AGAINST STATIONARY ANVILS AT HIGH SPEED TO BREAK THE FEEDSTOCK DOWN INTO FINE PARTICULATES. A ROTARY ASSEMBLY ACTS AS A PUMP TO RAPIDLY ACCELERATE THE SPEED OF ENTERING FEED MATERIALS TO A HIGH IMPACT SPEED. THE ASSEMBLY IS CONSTRUCTED OF SEVERAL PARALLEL DISKS, SPACED AT DISTANCES THAT ARE GREATER THAN THE SIZE OF THE LARGEST FEED. EACH DISK HAS THREE RADIAL FLIGHTS RADIATING FROM ITS CENTER HOLE TO ITS OUTER EDGE. THE FEED ENTERS THROUGH THE HOLLOW SHAFT OF THE ROTATING ASSEMBLY AND PASSES DOWN THE CENTRAL CHAMBER FORMED BY THE HOLES IN THE PARALLEL DISKS. CENTRIFUGAL FORCES DRAW THE FEED RADIALLY OUTWARD, THROUGH A WINDOW IN THE SURROUNDING HOUSING. THE PUMPING ACTION OF THIS ROTARY ASSEMBLY, OR IMPELLER, DRAWS AIR IN TO FLUIDIZE THE SOLID FEED MATERIALS IN AN AIR STREAM, SUBSTANTIALLY DECREASING FRICTIONAL LOSSES AND WEAR RATES. THE ACCELERATED FEED BREAKS AGAINST THE STATIONARY ANVILS AND, STILL ENTRAINED IN THE AIR STREAM, ENTERS AN ADJACENT AIR SORTING CHAMBER. THERE, OVERSIZE PARTICULATES DROP OUT (BY GRAVITY) TO RETURN TO THE ORIGINAL HOLLOW SHAFT ENTRY WITH NEW FEED. THE RECYCLING PROCESS CONTINUES UNTIL THE FEED IS SMALL ENOUGH TO EXIT THE SYSTEM IN THE AIR STREAM. THIS LOW ENERGY METHOD USES ONLY A FEW KILOWATT-HOURS/TON OF FEED FOR MOST FEEDSTOCKS. IT ALSO REQUIRES RESIDENCE TIMES OF ONLY A FEW SECONDS FOR LARGE CHANGES IN SIZE AND HAS LOW WEAR RATES. PHASE I CONSISTS OF BUILDING AND TESTING A PILOT UNIT. TESTING WILL PRODUCE INFORMATION ON ENERGY CONSUMPTION FOR FEED PULVERIZATION, FEED SIZE REDUCTION, AND INTERNAL WEAR RATES OF THE MACHINE.