Tailoring fibre lengths to fabricate a highly permeable SiC fibre porous medium for more efficient combustion

Abstract

Traditional ceramic foam and metal fibre media combustion were usually restricted owing to their intrinsic brittleness and easy corrosion, respectively. In order to obtain higher gas permeability, longer durability, and less noxious gas emissions for gas flame combustion, a novel SiC fibre porous medium (FPM) is investigated in this study. SiC fibre mat were firstly produced from chopped SiC fibres using solution dispersion and vacuum filtration, then a boron nitride interphase for antioxidation and subsequent SiC coating for rigidity were deposited by chemical vapor infiltration, resulted in the formation of self-supporting SiC FPM. Findings demonstrate that the microstructure, gas permeability, thermal physical and combustion properties of SiC FPM can be improved by tailoring fibre length. As the fibre length was 4.5 mm, the density of SiC FPM was 0.113 g/cm3, and it exhibited excellent properties in permeability and utilization of fuel gas, pollutant emissions and combustion temperature accompanied by slight reduction in thermal conductivity. Such ultra-light SiC FPM could respond fast during the heating process and help gas mixture burn off.