Intertube heat transfer characteristics of dilute semi-molten slag particles under gravity

Recovering waste heat from molten slag in the steel industry through centrifugal granulation assisted thermal energy recovery technology is a highly promising method. This study focuses on the issue of slow cooling rates of slag particles during their flight. By developing a two-dimensional comprehensive heat transfer model, we investigated the composite heat transfer characteristics of semi-molten dilute-phase slag particles between tube bundles. The results showed that air temperature, residence time, slag particle flow rate, initial velocity, and temperature significantly influence the cooling efficiency of slag particles. Additionally, we explored the effects of tube bundle structural parameters on slag particle cooling and established a dimensionless predictive correlation for heat transfer coefficients after correcting for structural parameters. This study offers new insights for enhancing the cooling of slag particles within the granulation chamber and provides important guidance for improving the efficiency of waste heat recovery from molten slag while ensuring the safe operation of the system.