Thermal radiative properties of xonotlite insulation material

Abstract

This paper presents experimental results of thermal radiative properties of xonotlite-type calcium silicate insulation material. Transmittance spectra were first taken using Fourier transform infrared spectrometer (FTIR) for the samples with ρ=234 kg/m3. Specific extinction coefficient spectra were then obtained by applying Beer’s law. Finally, by using the diffusion approximation, the specific Rossland mean extinction coefficients and radiative thermal conductivities were obtained for various temperatures. The results show that the specific spectral extinction coefficient of xonotlite is larger than 7 m2/kg in the whole measured spectra, and diffusion approximation equation is a reasonable description of radiative heat transfer in xonotlite insulation material. The specific Rossland mean extinction coefficient of xonotlite has a maximum value at 400 K and the radiative thermal conductivity is almost proportional to the cube of temperature.