Effect of solid particles on the slug frequency, bubble velocity and bubble length of intermittent gas–liquid two-phase flows in horizontal pipelines
Paolo Sassi, Gonzalo Fernández, Youssef Stiriba, Jordi Pallarès
Abstract
New experimental data are presented in this study for intermittent two and three-phase flows through horizontal pipelines involving air, water and polypropylene pellets of sizes ranging between 1 and 2 millimeters. Flow visualization and pressure measurements were performed and are explored in this work for intermittent flows. An automated image processing algorithm is developed to determine slug parameters of 59 flow conditions and compared with other measurements techniques. Correlations available in the literature for predicting slug frequency are tested with the new experimental data and curves of non-dimensional parameters are fitted to the data, the best fitting is obtained for the gas based Strouhal number against the input liquid or gas fraction. The influence of solid particles over the slug frequency is analyzed and reported. A decrease on the slug frequency is found when increasing solid concentrations. Finally, the influence of solid particles on the bubble length and velocity is investigated. A stronger influence of the gas flow rate on the velocity of the nose of the slug is observed for increasing solid concentration, together with more variability on the mean velocity. Also, longer bubbles are obtained with higher solid concentrations.