Enhanced waste heat recovery from liquid silicon via dry centrifugal granulation: Improving heat transfer efficiency and operational safety

This study aims to recover waste heat from liquid industrial silicon using dry centrifugal granulation technology. A 2D model was developed to thoroughly investigate the heat transfer dynamics within silicon particle clusters, considering the physical parameter changes of industrial silicon with a focus on its phase change latent heat. The heat exchange process in the granulation chamber was extensively analysed, examining the temperature changes of silicon particles and the heat absorption distribution of water cooling and argon gas. It was found that flight trajectory, residence time, and edge wall argon velocity significantly affect the flow field distribution and heat exchange efficiency within the chamber. Additionally, the collision pressure of particles against the wall, which is much lower than the critical load of the spherical shell, was explored, analysing issues of particle agglomeration and adhesion on the chamber wall in actual production. Furthermore, the effectiveness of edge wall argon assistance measures was investigated, highlighting their importance for safe operation. Optimal conditions balancing effective heat transfer and energy consumption were identified.