Combined transient 3D simulation and experimental methods to assess a slow heat-up curve used to dry a refractory concrete

Abstract

Explosive spalling is a major concern when drying refractory concretes. For safety, empirically defined overestimated slow heat-up curves are used in industry. Polypropylene fibres reduce spalling; however, they are inconvenient for certain castables due to properties deterioration, such as slag penetration. There is neither a generally accepted methodology to define monolithic refractories dry-out schedules nor agreement about a mathematical model to predict spalling phenomena. This paper presents original numerical and experimental results of castable drying investigation using slow heating. Modifications in experimental methods were made to reproduce refractory lining boundary conditions. A conservative fully implicit finite volume method in three-dimensions was developed to predict pressure and moisture migration. The influence of the methods used to characterize the properties needed for the mathematical model was discussed. The combined analyses suggest that the first holding time used was not productive for drying; however, its effect on curing must be reviewed.