Dynamic modelling of a multiple hearth furnace for kaolin calcination with a sensitivity analysis with respect to reaction rates*

This paper is devoted to dynamic modeling of a multiple hearth kaolin calciner. The physical-chemical phenomena taking place in the six furnace parts, including the solid phase, gas phase, walls, cooling air, rabble arms and the central shaft, are described by the model. In particular, a mixing model is developed to describe the solid phase movement, dividing the solid bed in a hearth into volumes and considering the distribution of their contents after one full central shaft rotation. Step changes are introduced to the feed rate to study the responses of the gas phase temperature and solid bed component profiles in the multiple hearth furnace (MHF). In addition, the sensitivity analysis of the temperature profile with respect to the reaction kinetics is provided.