Influence on energy demand of thickness, thermal conductivity, and volumetric heat capacity of ladle working lining in secondary steel-making process

The secondary steel-making process involves several steps during which steel is kept in a
ladle, that is, a vessel made of an outer steel layer (carpentry), an intermediate refractory layer, and
an internal refractory layer. Unlike the intermediate layer, the internal layer undergoes a progressive
reduction in thickness and a periodic restoration. Traditionally, it is made of alumina or magnesite.
During the process, the ladle undergoes unsteady heating and cooling; therefore, heat transfer
depends on thermal conductivity and heat capacity. This study aims to identify the ladle internal layer
characteristics that affect the energy demand. This analysis investigates the effect of the internal layer
thickness S, volumetric heat capacity C, and thermal conductivity λ. Through the Design Of the
Experiments (DOE), different scenarios have been selected and analyzed by means of numerical
simulations performed on a numerical model defined in COMSOL Multiphysics. The energy demand
as a function of the internal layer properties has been estimated, and it has emerged that low thermal
conductivity and heat capacity values require a lower amount of energy.