Periodic heat wave determination of thermal diffusivity of clays

Abstract

The responses of Ankaful, Tetegu (# 1 & 2) and Mamfe clays to periodic heat waves were analyzed to deter-mine the thermal diffusivity values. The temperature amplitude attenuated with depth of penetration, while the phase shift increased. The thermal diffusivity values ranged from 3.0 - 9.5 x 10P-7P mP2P/s by amplitude decay and phase lag calculations based on Fourier theory of heat conduction. The large variation in the thermal diffusivity was attributed to non-homogeneity of the clay samples. The damping depths, heating and cooling rates were evaluated to identify most suitable clay samples for construction of kilns and furnaces for high temperature ind-ustrial applications. Tetegu # 1 and Mamfe clays exhibited characteristics of high thermal diffusivity, heat rete-ntion and depth of penetration, and were considered as suitable processing refractory media.