An energy-based model of gas-solids transport in a riser

Gas-solids transport in riser flows can be found in many industrial applications such as FCC in petrochemical industry, coal combustion in utility industry, and pneumatic conveying of drug powders in pharmaceutical industry. An energy-based mechanistic model for analyzing the partitions of the axial gradient of pressure by solids acceleration, collision-induced energy dissipation, and solids holdup in gas-solid riser flows was developed. Based on this model, the correct estimation of axial distributions of solids holdup and solid velocity were obtained. The impact of solids acceleration on the pressure drop can be significant in a range of moderate solids holdup whereas the effect of energy dissipation became important in the dense phase transport region. The combined energy partition of solid acceleration and energy dissipation in the solid acceleration and dense phase transport regimes was typically about 20% and can be as high as 50%. This is an abstract of a paper presented at the AIChE Spring Annual Meeting - The 5th World Congress on Particle Technology (Orlando, FL 4/23-27/2006).