THE DEVELOPMENT OF A SOLVENT ABSORPTION FIBER OPTIC EXPLO- SIVE RANGE SENSOR

SOLVENT EVAPORATION IN INDUSTRIAL DRYING CHAMBERS IS AN ENERGY INTENSIVE PROCESS THAT CURRENTLY UTILIZES ENERGY IN A VERY INEFFICIENT MANNER. THIS IS DUE TO THE FACT THAT THESE DRYERS TYPICALLY OPERATE AT SOLVENT VAPOR CONCENTRATIONS ON THE ORDER OF 7% OF THE LOWER EXPLOSIVE LIMIT (LEL) IN ORDER TO ENSURE SAFE OPERATION. HOWEVER, IF A CONTINUOUS VAPOR CONCENTRATION MONITOR AND SAFETY INTERLOCKS WERE INSTALLED, THE SOLVENT CONCENTRATION COULD BE ALLOWED TO APPROACH 50% LEL. OPERATION AT HIGHER SOLVENTCONCENTRATIONS PRODUCES SIGNIFICANT, DIRECT ENERGY SAVINGS, AND IT RESULTS IN ADDITIONAL ECONOMIC BENEFITS OF IMPROVED DRYING EQUIPMENT PRODUCTIVITY AND REDUCTION OF SIZE AND COSTOF SOLVENT RECOVERY EQUIPMENT. THIS PROJECT ADDRESSES THE DEVELOPMENT OF A SOLVENT ABSORPTION FIBER OPTIC EXPLOSIVE RANGE (SAFER) SENSOR WHICH WOULD PROVIDE A SENSITIVE, REAL-TIME MEASUREMENT OF THE SOLVENT CONCENTRATION IN INDUSTRIAL DRYERS AND WHICH COULD BE USED IN A PROCESS/SAFETY CONTROL SYSTEM. THE SAFER INSTRUMENT WOULD USE AN INNOVATIVE COMBINATION OF A PROVEN SENSOR HEAD AND NEW IR FIBER OPTIC TECHNOLOGIES. THIS COMBINATION PERMITS THE SAFER SENSOR TO PERFORM ITS MEASUREMENTS DIRECTLY IN THE CONTAMINATING ENVIRONMENT OF THE SOLVENT DRYER, THEREBY ELIMINATING THE PROBLEMS OF FOULING AND SAMPLE LINE DELAYS THAT HAVE RESTRICTED THE UTILITY OF CURRENTLY AVAILABLE SENSORS. THE OBJECTIVE OF THE PROJECT IS THE DEVELOPMENT OF A COMMERCIAL SENSOR FOR MONITORING AND CONTROLLING THE CONCENTRATION OF SOLVENT VAPORS IN INDUSTRIAL DRYING CHAMBERS. AS A FIRST STEP TOWARD THIS GOAL, A LABORATORY BREADBOARD WILL BE CONSTRUCTED IN PHASE I TO INVESTIGATE THE SENSITIVITY AND DYNAMIC RANGE OF THE TECHNICAL APPROACH, AS WELL AS THE EFFECTS OF SAMPLE TEMPERATURE. IN PHASE II, A BRASSBOARD SAFER INSTRUMENT WILL BE CONSTRUCTED AND TESTED IN AN INDUSTRIAL SOLVENT DRYING CHAMBER.