A NOVEL COMPACT PROBE FOR NON-INTRUSIVE DIAGNOSTICS OF FINE PARTICULATES IN FLUE GAS STREAMS

THIS PROJECT DEALS WITH RESEARCH ON THE DEVELOPMENT OF A NEWPARTICLE DIAGNOSTIC TECHNIQUE TO INVESTIGATE THE DYNAMIC BEHAVIOR OF PARTICLES. THE NOVEL APPROACH USES TWO COAXIAL LASER BEAMS AND THE AMPLITUDE OF THE SIGNALS FROM THE LIGHT SCATTERED BY THE PARTICLES TRAVERSING THE PROBE VOLUME TO INFER THEIR SIZE AND VELOCITY. THE NEW TECHNIQUE HAS THE FOLLOWING ADVANTAGES OVER OTHER EXISTING ONES: (1) NONSHERICAL PARTICLES CAN BE MEASURED, (2) PARTICLE NUMBER DENSITY AND VOLUME FLUX CAN BE OBTAINED IN HIGH PARTICLE DENSITY FLOWS BECAUSE OF THE REQUIREMENT OF A BEAM DIAMETER RATIO OF ONLY 2 OR 3 TO 1 AND, (3) THE RANGE OF APPLICABILITY OF THE TECHNIQUE IS FROM 0.3 TO 400 MUM. THE RESEARCH AND DEVELOPMENT WORK ALSO ENCOMPASSES THE EVALUATION AND INTEGRATION OF SEMICONDUCTOR DEVICES SUCH AS DIODE LASERS AND AVALANCHE PHOTODIODES, ADVANCED SIGNAL PROCESSING, AND SENSOR-BASED TECHNOLOGY IN A PROBE COMPACT AND RUGGED ENOUGH TO BE USED IN HOT, DIRTY ENVIRONMENTS TYPICAL OF STACKS, COMBUSTOR EXHAUSTS, AND THE LIKE. PHASE I OF THE RESEARCH PROJECT INCLUDES THE FOLLOWING TASKS: (1) DEVELOPING THE MATHEMATICAL ANALYSIS AND THE NECESSARY SOFTWARE, (2) INVESTIGATING THE OPTICAL CONFIGURATION OF THESYSTEM, (3) DESIGN CALIBRATION AND PRELIMINARY TESTING, AND (4) EVALUATING SEMICONDUCTOR DEVICES FOR THE PRESENT APPLICATION. SUCCESSFUL COMPLETION OF THESE TASKS IN PHASE I WILL LEAD TO THE DEVELOPMENT OF A NEW DIAGNOSTIC TECHNIQUEFOR MEASURING NONSPHERICAL PARTICLES AND A PROTOTYPE INSTRUMENT IN PHASE II OF THIS RESEARCH EFFORT.