Effect of pipe inclination on deposition-limit velocity and slip velocity of heterogeneous slurries

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Heterogeneous slurry flow exhibits flow stratification and asymmetrical velocity and concentration profiles. At flow velocities below the deposition limit, a stationary granular bed develops and this significantly affects slurry flow behavior. The deposition-limit and slip velocities are important parameters of heterogeneous slurry flow; they affect energy dissipation and pressure drop. A systematic experimental and theoretical investigation of these velocities has not been done yet. The project focuses on the effect of pipe inclination, slurry velocity and concentration on deposition-limit and slip velocities, local concentration distribution, and experiments. The deposition-limit will be determined by flow visualization and concentration profile measurements, the slip velocity will be determined from measured delivered and spatial concentrations. Pressure differences will be sensed in horizontal, vertical and inclined sections of and experimental pipe loop. Project goals The main goal of the project is a development of a mathematical model for a prediction of the deposition-limit velocity, the mean slip velocity, and the pressure drop in heterogeneous slurry flows in inclined pipes. The model will be calibrated and validated by results of own experiments.