A semi-empirical heat transfer model for core tube to gas–solid suspension flow in a CFB riser in terms of Nusselt and Reynolds numbers with effective suspension properties was also presented. The semi-empirical predicts the present experimental data within ±20% and when other published data was included, the deviation was ±30%. While the modeling approach seems satisfactory, it needs refinement to improve its accuracy and consolidate all data in a more comprehensive way.