Thermal Conductivity and Infrared Opacity of Ceramic Fibres
topic
Ceramic fibre blanket thermal conductivity increases from 0.06 watts per metre kelvin at 200 degrees Celsius to 0.35 watts per metre kelvin at 1000 degrees Celsius due to increasing radiative heat transfer through the semi-transparent fibre matrix, with alumina particle addition as opacifier reducing radiative transmission and lowering high-temperature effective thermal conductivity by 20 to 30 percent in high-density boards.
Role
Quantifies the dominant high-temperature heat transfer mechanism through ceramic fibre insulation systems, guiding design of high-density opacified ceramic fibre products for applications requiring minimum heat flux through lining systems, and explaining the divergence of ceramic fibre thermal performance from that of dense refractory castables as furnace operating temperature increases above 800 degrees Celsius.