FEASIBILITY OF AN ULTRA-CENTRIFUGE FOR DRYING COMMINUTED DEEP CLEANED COAL

THE DEEP CLEANING PROCESSES NOW UNDER INVESTIGATION FOR COAL MOST OFTEN INVOLVE PULVERIZING AND THE USE OF A LIQUID PROCESS MEDIUM. IF THE VERY FINE DEEP CLEANED COAL IS TO BE USED IN A DRY FORM, A SATISFACTORY DRYING TECHNOLOGY IS VITAL. PREVIOUS STUDIES HAVE INDICATED A SUBSTANTIAL PROBABILITY OF SUCCESS IF THE ULTRAHIGH LEVELS OF CENTRIFUGE GRAVITY ARE COMBINED WITH THE CENTRIFUGAL DECANTING/FILTRATION PROCESS DEVELOPED EARLIER. NEW METHODS HAVE BEEN DEVELOPED FOR OPERATING CENTRIFUGES, COMBINING DECANTING AND FILTRATION AT HIGH LEVELS OF GRAVITY AND WITHOUT BLINDING THE FILTERS. THE NEW BATCH TECHNOLOGY INCORPORATES COMPOSITES FOR THE BOWL AND AN ULTRAEFFICIENT VARIABLE FREQUENCY AC DRIVE SO THAT THE ENERGY CONSUMPTION IS HELD TO LOW LEVELS. THE PROCESS INVOLVES NO DETRIMENTAL ENVIRONMENTAL IMPACT. BOWL STRESS, VIBRATION DYNAMICS, AND FILTER PROCESS TECHNOLOGIES HAVE BEEN DEVELOPED AND PATENTED; THE LIMITS OF THEIR CAPABILITIES HAVE NOT YET BEEN EXPLORED. PHASE I COMPRISES AN IN-DEPTH STUDY OF GRAVITY LEVELS REQUIRED FOR DRYING ULTRAFINE DEEP CLEANED COAL TO ABOUT 10 TO 12% SURFACE MOISTURE. BY USING EXISTING HARDWARE, IN-HOUSE DEVELOPED SOFTWARE, AND APPROPRIATE CONSULTATIONS, DETERMINATION OF THE LIMITATIONS WITHIN WHICH THE ADVANCED CENTRIFUGES CAN BE DESIGNED WILL BE MADE. THE WORK IN PHASE I IS BEING SUPPLEMENTED BY DRAWING ON AN EXTENSIVE DATABASE DEVELOPED DURING PREVIOUS IN-HOUSE CENTRIFUGAL DRYER RESEARCH AND DEVELOPMENT, WHICH HAS YIELDED A SUCCESSFUL PROTOTYPE CENTRIFUGAL DRYER FOR CONVENTIONAL FROTH FLOTATION PRODUCTS.