Optimisation of a Capsule Transporting Pipeline Carrying Spherical Capsules

Pipelines carrying fluids and slurries are very common. The third-generation pipelines carrying spherical or cylindrical capsules (hollow containers) filled with minerals or other materials including hazardous liquids are rather a new concept. These pipelines need to be designed optimally for commercial viability. Researchers, so far, have used rather simplified empirical and semi-empirical methods for optimisation purposes, the range and application of which is fairly limited. This study uses a rigorous approach to predict pumping cost based on Computational Fluid Dynamics (CFD) analysis and hence optimise capsule pipelines. A numerical solution has been obtained for pressure drop from the equations governing the turbulent flow around a concentric spherical capsule train consisting of 1–4 equal density capsules in a hydraulically smooth pipe section. The diameter of the pipe used in the analysis is 0.1m while the capsules’ diameters are in the range of 50 to 80% of the pipe diameter. The investigation was carried out in the practical range of 0.4 ≤bulk velocity≥ 1.6 m/sec. Obtained results of pressure gradient along the pipeline in presence of capsules were compared with the available experimental data to validate the model used. The results predicted by the model agree well with the experimental data. The computationally obtained data over a wide range of flow conditions has then been used to develop a rigorous model for pressure drop. The pressure drop along the pipe can be used to calculate the pumping requirements and hence design of the system. The least cost principle has been used for optimisation.