CENTRIFUGAL FORCES-

A PROBLEM EXISTS IN DRYING HEAT-SENSITIVE DRUGS DURING THEIR BULK CHEMICAL PRODUCTION. THE PRESENTLY AVAILABLE EQUIPMENT IS BASED ON CONDUCTION AS THE PRIMARY HEAT- TRANSFER METHOD; HOWEVER, IN DRYING HEAT-SENSITIVE CHEMICALS, THE JACKET TEMPERATURE OF CURRENT PROCESS EQUIPMENT MUST BE REDUCED TO AVOID THERMAL DEGRADATION OF THE DRUG. THE REDUCTION OF CONDUCTIVE DRIVING FORCE RESULTS IN DECREASED PRESSURE GRADIENTS WITHIN THE MATERIAL BEING DRIED, GREATLY DECREASING VAPOR DIFFUSION WITHIN THE SOLID AND LENGTHENING DRYING TIMES TO 16 TO 24 H/BATCH. AUXILIARY EQUIPMENT SUCH AS VACUUM SYSTEMS, RECIRCULATING HEATING SYSTEMS, CON- DENSERS, ETC., MUST BE OPERATED DURING THIS LENGTHY TIME MAKING THE DRYING CYCLE EXTREMELY ENERGY EFFICIENT AS WELL AS THE LIMITING STEP IN MANY PRODUCTION BATCHES, WHERE RARELY MORE THAN FIVE BATCHES PER WEEK CAN BE PRODUCED. THIS PROGRAM WILL EXAMINE THE TECHNICAL FEASIBILITY AND ENERGY EFFICIENCY OF VACUUM DRYING IN A HIGH CENTRIFUGAL FORCE FIELD. THE INCREASED VAPOR VELOCITIES WITHIN THE CAPILLARIES CAUSED BY INCREASED PRESSURE GRADIENT AS WELL AS HIGH CENTRIFUGAL FORCES APPEAR TO OFFER A PROMISING METHOD TO ENERGY-EFFICIENT FAST DRYING OF HEAT-SENSITIVE CHEMICALS. THE PHASE I EFFORT WILL CONCENTRATE ON CENTRIFUGAL VACUUM DRYING WITH THE INTRODUCTION OF A PREHEATED DRYING GAS.