| The hydrodynamics of multiphase flow in Liquid-Liquid Cylindrical Cyclone (LLCC©1) and Gas-Liquid-Liquid Cylindrical Cyclone (GLLCC ©2) compact separators have been studied experimentally and theoretically for evaluation of their performance as free water knockout devices. In both GLLCC and the LLCC configurations, no complete oil-water separation occurs. Rather, both separators perform as free water knockouts, delivering a clean water stream and an oil rich stream.; A new state-of-the-art, two-inch, three-phase, fully instrumented flow loop has been designed and constructed. Experimental data on oil-water separation efficiency in the LLCC and the GLLCC have been acquired.; A total of 260 runs have been conducted for the LLCC for water-dominated flow conditions. Four different flow patterns in the inlet have been identified, namely, Stratified flow, Oil-in-Water Dispersion - Water Layer flow, Double Oil-in-Water Dispersion flow and Oil-in-Water Dispersion flow. For all runs, an optimal split ratio exists, where the flow rate in the water stream is maximum with 100% water cut. The value of the optimal (maximum) split ratio depends upon the existing flow pattern. For the Stratified and Oil-in-Water Dispersion - Water Layer flow patterns, this maximum split ratio is about 60%. For the Double Oil-in-Water Dispersion and Oil-in-Water Dispersion flow patterns, the maximum split ratio ranges from 50% to 20%, decreasing with the increase of oil content in the inlet stream.; Experimental data on oil-water separation efficiency in the GLLCC have been acquired. A total of 220 experimental runs have been conducted, including the oil-water separation efficiency for different combinations of oil and water superficial velocities, and varying the split ratio for each combination. The GLLCC separation efficiency data reveal that it performs, in addition to the separation of the gas phase, also as a free water knockout. This occurs only for very low oil concentrations at the inlet, below 10%. Also, lower separation efficiencies are observed, as compared to the LLCC configuration.; Novel mechanistic models have been developed for the prediction of the complex flow behavior and the separation efficiency in the LLCC and GLLCC. The models consist of several sub-models, including inlet analysis, nozzle analysis, droplet size distribution model, and separation model based on droplet trajectories in swirling flow.; Comparisons between the experimental data and the LLCC and GLLCC model predictions show excellent agreement. The models are capable of predicting both the trend of the experimental data as well as the absolute measured values. The developed models can be utilized for the design and performance analysis of the LLCC and GLLCC.; 1LLCC - Liquid-Liquid Cylindrical Cyclone - Copyright, The University of Tulsa, 1998. 2GLLCC - Gas-Liquid-Liquid Cylindrical Cyclone - Copyright, The University of Tulsa, 2000. |
