Effect of immersed tubes configurations on mixing and heat transfer of mixed biomass and silica sand in a bubbling fluidized bed using CFD-DEM and statistical experimental design analysis

The presence of immersed tubes within fluidized beds enhances mixing efficiency and heat transfer. However, the influence of design parameters remains unexplored systematically. This study investigates the impact of design parameters on mixed biomass fluidized beds with immersed tubes employing a combined approach of CFD-DEM simulations and 2k factorial design analysis. Findings reveal that the angle between tubes and tube diameter are primary influential parameters, significantly influences particle mixing and heat transfer efficiency. Optimal conditions, identified through analyses of averaged mixing index and heat transfer coefficient, point to a staggered configuration with specific dimensionless of tube diameter per column width of 0.0515 and a tube spacing per tube zone height of 0.14. These insights offer valuable guidance for optimizing and emphasize the significance of design parameters incorporating immersed tubes, providing practical guidelines for enhancing mixing efficiency and heat transfer in various applications, especially those employing mixed biomass and silica sand.