CFD simulation of an oil-water skimmer tank

Abstract

Water recovery from oil wells is an environmental necessity. In order to achieve this goal, an air bubble technique is used to separate water from oil. This technique is being developed for usage in oil fields, and computational fluid dynamic (CFD) simulation is helping to improve the cleaning efficiency of the process. In this paper, the separation of an oil-water mixture using an air bubble stream in an open tank, skimmer tank, is implemented. The simulation was performed using commercial computational fluid dynamics software, CFD, Star CCM®. The separation of liquid mixtures with different densities is performed in this equipment using flotation along with drag forces created by fine air bubbles. The models required to simulate the process were deeply researched to secure the quality and the accuracy of the solution while making sure the time required for solution was manageable. The results show that 100-micron air bubbles are able to efficiently separate oil from water, reducing the time required for the process as long as the bubbles do not coalesce. The oil concentration at the over flow is close to 70%, and 0.5 litres of water per kilogram of oil are required in the cleaning process. [Received: May 22, 2016; Accepted: January 28, 2017]