Crack Appearance during Drying of an Alumina Gel: Thermo-Hydro-Mechanical Properties

Abstract

Most heterogeneous catalyst supports used in refineries are composed of porous alumina ceramics. Drying has been identified as a critical process for final product mechanical strength. In the literature, numerous papers deal with drying-induced stresses, which can lead to crack initiation. However, there are few papers devoted to experimental study of drying conditions that promote cracking. The objective of this work is to enhance knowledge of cracking behavior, specifically by studying alumina gel drying. First, the relation between drying conditions and first crack initiation is studied experimentally. Then a complete thermo-hydro-mechanical characterization of the alumina gel is made, including moisture content as a parameter.

Two-Phase Shrinking Porous Media Drying: A Modeling Approach Including Liquid Pressure Gradients Effects

“…For such a media, Pourcel [10,30,31] has recently carried out an experimental campaign (a schematic representation of the experimental configuration is proposed in Fig. 1); all the exchange surfaces are impermeable to water (because they are grease-covered) except the top surface; furthermore, heat convective exchange with the environment occurs on each surface.…”