Predictable model for characteristics of one-dimensional solid-gas-liquid three-phase mixtures flow along a vertical pipeline with an abrupt enlargement in diameter

This paper treats the numerical analysis of the rising process of a solid-g as-liquid three-phase mixture along a vertical pipeline with an abrupt enla rgement in diameter. The system of governing equations used is based upon t he one-dimensional multifluid model and the transitions of gas flow pattern are taken into account irt the system of governing equations. For the case of a sudden enlargement in diameter in a coaxial pipeline, the procedure o f the numerical calculation to obtain the flow characteristics in the pipel ine section after a sudden change in diameter has been established here. Fu rthermore, in order to confirm the validity of the present theoretical mode l by the comparison between the calculated and experimental values, the exp eriments have been made using four kinds of lifting pipes, including the st raight one. Thereby, it has been found that the numerical model proposed he re gives good fit to the prediction of the flow rates of lifted water and s olid particles against that of air supplied for the case of a sudden change in diameter. In addition, the flowing process for each phase has been inve stigated from a photographic point of view. As a result, we found that the moving process of the solid particles depends strongly upon the volumetric flux of gas-phase as well as the submergence ratio.