HIGH SPEED METHOD OF PRIMER DRYING

A NOVEL IDEAL TO DRAMATICALLY REDUCE DRYING TIME OF PRIMER PELLETS IS PROPOSED. CURRENT FORCED AIR CONVECTION DRYING IS LIMITED BY LOW CONDUCTIVE HEAT TRANSFER TO THE PELLET INTERIOR AND INADEQUATE WATER DIFFUSIVITY TO THE PELLET SURFACE. EMPLOYMENT OF ELECTROMAGNETIC RADIATION (EMR) CYCLES CAN SUBSTANTIALLY INCREASE THE DRYING RATE BY INCREASING PELLET INTERNAL TEMPERATURE, THEREBY IMPROVING HEAT TRANSFER AND MASS DIFFUSIVITY. THE COMBINED EMR-CONVECTION TECHNIQUE HAS PROVEN EFFECTIVE IN REDUCING DRYING TIMES FOR A NUMBER OF MATERIALS, INCLUDING HEAT-SENSITIVE SUBSTANCES. FURTHERMORE, IT AVOIDS THE DANGERS OF DECOMPOSITION AND AUTOIGNITION ATTENDANT WITH OPERATING PURE FORCE-AIR CONVECTION AT FREE-STREAM TEMPERATURES. THE UNDERLYING OBJECTIVE OF PHASE I IS TO EVALUATE THE FEASIBILITY OF COMBINED EMR-CONVECTION DRYING OF PRIMER PELLETS. THE PROPOSED WORK PLAN IS DIVIDED INTO FOUR TASKS: DESIGN AND CONSTRUCTION OF A VERSATILE LABORATORY TEST APPARATUS, MEASUREMENT OF DRYING CURVES UNDER PURE FORCED CONVECTION, DRYING STUDIES ON COMBINED EMR-CONVECTION AT A SINGLE FREQUENCY AND, IF NEEDED, EVALUATION OF ALTERNATIVE EMR FREQUENCIES. THE MEASURE OF PHASE I SUCCESS WILL BE TO ACHIEVE AN AVERAGE PRIMER PELLET DRYING TIME OF LESS THAN FIVE MINUTES, IN A LABORATORY-SCALE CHAMBER. IF FEASIBILITY IS PROVEN, PHASE II R&D WILL LEAD TO PROTOTYPE DEVELOPMENT, SCALE-UP AND PHASE III COMMERCIALIZATION.