INNOVATIVE SILICON CARBIDE FIBER COMPOSITE FILTERS

THE COMBUSTION OF COAL INTRODUCES HAZARDOUS EMISSION PRODUCTS, INCLUDING RESPIRABLE PARTICLES THAT ARE 10UM IN DIAMETER. THE REMOVAL OF THESE PARTICLES FROM THE COMBUSTION GAS STREAM IS DIFFICULT DUE TO THE HIGH TEMPERATURES AND CORROSIVE ENVIRONMENT. A CERAMIC FILTER HAS THE GRATST POTENTILA TO SURVIVE THE HARSH GAS ENVIRONMENT; HOWEVER, CERAMIC FILTER MATERIALS WHICH HAVE THUS FAR BEEN TESTED ARE LIMITED PRIMARILY BY CORROSION AND INFERIOR THERMAL PROPERTIES. MONOLITHIC SILICON CARBIDE (SiC) IN PARTICULAR HAS DEMONSTRATED SIGNIFICANT POTENTIAL BUT IS SUSCEPTIBLE TO THERMAL SHOCK AND SUBSEQUENT FAILURE. INNOATIVE HOLLOW SiC FIBERS HAVE BEEN DEVELOPED WHICH CAN BE UTILIZED AS FILTER ELEMENTS. CONTROL OF THEINSIDE DIAMETER TO MICRON SIZES IS POSSIBLE SO THAT COAL PARTICLES OF ULTRAFINE SIZES CAN BE EASILY SEPARATED. THE FIBERS HAVE VERY HIGH STRENGTH ( 4 GIGAPASCALS) WHICH SUGGESTS THAT THEY WILL BE MECHANICALLY STABLE IN THE COMBUSTION GAS STREAM ENVIRONMENT. FILTERS WILL BE FABRICATED FROM THESE HOLLOW SiC FIBER ELEMENTS IN PHASEI, AND SUBSEQUENTLY TESTED AT THE COAL FIRED FLOW FACILITY (CFFF) AT THE UNIVERSITY OF TENNESSEE SPACE INSTITUTE (UTSI).