Kuldip Ubbi

A Study on Optimal Sizing of Pipeline Transporting Equi-sized Particulate Solid-Liquid Mixture

Pipelines transporting solid-liquid mixtures are of practical interest to the oil and pipe industry throughout the world. Such pipelines are known as slurry pipelines where the solid medium of the flow is commonly known as slurry. The optimal designing of such pipelines is of commercial interests for their widespread acceptance. A methodology has been evolved for the optimal sizing of a pipeline transporting solid-liquid mixture. Least cost principle has been used in sizing such pipelines, which involves the determination of pipe diameter corresponding to the minimum cost for given solid throughput. The detailed analysis with regard to transportation of slurry having solids of uniformly graded particles size has been included. The proposed methodology can be used for designing a pipeline for transporting any solid material for different solid throughput.

Pressure Drop in Capsule Transporting Bends Carrying Spherical Capsules

One of the most important parameters in designing a capsule transporting pipeline is the pressure drop in the pipes carrying capsules and associated pipe fittings such as bends etc. Capsules are hollow containers with typically cylindrical or spherical shapes flowing in the pipeline along with the carrier fluid. The dynamic behavior of a long train of capsules depends on the behavior of each capsule in the train and the hydrodynamic influence of one capsule on another. Researchers so far have used rather simplified empirical and semi-empirical correlations for pressure drop calculations, the range and application of which are fairly limited. Computational Fluid Dynamics (CFD) based techniques have been used to analyze the effect of the presence of solid phase in hydraulic bends. A steady state numerical solution has been obtained from the equations governing turbulent flow in pipe bends carrying spherical capsule train consisting of one to four capsules. The bends under consideration are of 45° and 90° with an inner diameter of 0.1m. The investigation was carried out in the practical range of 0.2 ≤Vb≥ 1.6 m/sec. The computationally obtained data set over a wide range of flow conditions has been used to develop a rigorous model for pressure drop calculations. The pressure drop along the pipe bends, in combination with the pressure drop along the pipes, can be used to calculate the pumping requirements and hence design of the system.

Effect of the Length and Diameter of a Cylindrical Capsule on the Pressure Drop in a Horizontal Pipeline

Capsule pipeline research involves the study of the flow in a pipe of a long train of spherical or cylindrical capsules (hollow containers) filled with minerals or other materials including hazardous liquids. The behavior of the capsule train will depend upon the behavior of each capsule in the train and the hydrodynamic influence of one capsule on another. Designers are in need of a general correlation to calculate pressure drop in a capsule pipeline. Researchers, so far, have used rather simplified empirical and semi-empirical correlations for pressure drop calculations, the range and application of which is fairly limited. A mathematical correlation developed for pressure drop in cylindrical capsule of equi-density as its carrying medium is presented here. Based on Computational Fluid Dynamics (CFD) a numerical solution has been obtained from the equations governing the turbulent flow around a concentric cylindrical capsule in a hydraulically smooth pipe section. The diameter of the pipe used in present study is 0.1m while that of capsules are in the range of 50-80% of the pipe diameter. The investigation was carried out in the practical range of 0.2 ≤Vb≥ 1.6 m/sec. The computationally obtained data set over a wide range of flow conditions have then been used to develop a rigorous model for pressure drop. Using this model the pressure drop along the pipeline can be computed which then can be used to calculate pumping requirements.

Optimisation of a Horizontal Capsule Transporting Pipeline carrying Cylindrical Capsules

Pipelines carrying fluids and slurries are quite 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. An optimal design of such a pipeline results in minimum pressure drop in the pipeline. This corresponds to minimum head loss and hence minimum pumping power required to drive the capsules and the transporting fluid. This study uses a rigorous approach to predict pumping cost based on Computational Fluid Dynamics (CFD) and hence optimize the design of the capsule transporting pipelines. Pressure drop relationship developed has been incorporated to calculate the pumping requirements for the system. Based on the least-cost principle, a methodology has been developed for the determination of the optimal diameter of cylindrical capsule carrying hydraulic pipeline. This procedure can be applied to obtain the optimal size of the capsule pipeline for minimum pumping and capital costs.

Optimal Design of Capsule Transporting Pipeline carrying Spherical Capsules

A capsule pipeline transports material or cargo in capsules propelled by fluid flowing through a pipeline. The cargo may either be contained in capsules (such as wheat enclosed inside sealed cylindrical containers), or may itself be the capsules (such as coal compressed into the shape of a cylinder or sphere). As the concept of capsule transportation is relatively new, the capsule pipelines need to be designed optimally for commercial viability. An optimal design of such a pipeline would have minimum pressure drop due to the presence of the solid medium in the pipeline, which corresponds to minimum head loss and hence minimum pumping power required to drive the capsules and the transporting fluid. The total cost for the manufacturing and maintenance of such pipelines is yet another important variable that needs to be considered for the widespread commercial acceptance of capsule transporting pipelines. To address this, the optimisation technique presented here is based on the least-cost principle. Pressure drop relationships have been incorporated to calculate the pumping requirements for the system. The maintenance and manufacturing costs have been computed separately to analyse their effects on the optimisation process. A design example has been included to show the usage of the model presented. The results indicate that for a specific throughput, there exists an optimum diameter of the pipeline for which the total cost for the piping system is at its minimum.