Numerical Simulation of the Performance of the Skimmer Tank Existing in a Desalination Unit in order to Find the Suitable Position of the Baffle

In skimmer tanks, the reduction of oil pollution from wastewater is a function of the geometry and the location of baffles inside these systems. The performance of a skimmer tank, existing in a desalination plant, with a diameter of 8 meters and a height of 10 meters has been unsatisfactory at the time of its launch because of lack of proper design of the tank and its internal equipment and thus, it has been out of service. In order to improve its performance, its aspects and sizes must be considered as problem’s constraints, and the problem solution must only be solved by locating its internal equipment. In this study, the arrangement of the polygon baffle of this skimmer tank has been extracted using geometrical similarity of an existing tank’s geometry with suitable performance. After that, three-dimensional turbulent flow within the tank has been simulated numerically using Fluent package. In order to validate the results of numerical simulation of flow in the tank, the pressure at the inlet pipe has been examined, and it can be shown that this amount is consistent with hydrostatic pressure. The performance of the skimmer tank has been assessed by establishing baffle and changing the diameter of the outlet pipe of water and doing numerical simulation. The results show that the new design of the skimmer tank will lead to increase the resident time of oil particles as well as to increase oil particles’ path through the water outlet pipe. Therefore, by installing the polygon baffle inside the existing tank and changing the diameter of the water outlet pipe, this tank can be used for operational purposes.