Heating rate effect on the moisture clog while drying refractory castables: A neutron tomography perspective

Due to their great performance and ease of installation, refractory castables are common ground materials to enable high-temperature processes. However, their fully operational condition is slowed down by the gradual drying stage required. Therefore, better understanding of the moisture transport is essential to improve their efficiency and reduce the likelihood of explosive spalling events due to vapor pressurization. Neutron tomography provides a relevant inner view of the moisture distribution across a sample and its evolution over time. In this work, the effect of the heating rate on moisture clog was investigated and compared with available laboratory and industrial observations. It was found out that higher heating rates resulted in a faster and longer lasting water accumulation ahead of the drying front, in agreement with other macroscopic studies and explaining the common reasoning behind using slower heating rates and safer industrial operations. This study highlights the potential of neutron imaging for the ongoing effort to maximize the efficiency of the refractory castables drying process by controlling the moisture accumulation without exclusively relying on slower heating rates.