Numerical Simulation Of The Flow Characteristics In A Gravity-type Oil-water Separator

Corrugated plate separator has been widely applied in the field of oil and water separation.Under the premise of fully studying the internal flow field of corrugated plate,the suitable corrugated plate packing and corrugated plate’s specific way of building according to specific working conditions are decided.In this paper,the experimental and computational fluid mechanics methods are used to study the internal flow field of the interlaced corrugated plate,and the distribution characteristics and the influencing factors of the flow field.The experimental results show that with the increase of inlet flow,oil-water separation efficiency of separator decreased gradually.Holes in the corrugated plate can improve the separating efficiency and make the share of large oil droplets in water-phase outlet decrease.The separator has obvious separation effect on the oil droplets whose particle size is larger than 16 μm.The amount of large oil droplets above 16 μm in the outlet of the water phase increases first and then decreases and increase again with the increase of import flow.On the basis of the simulation verification,the computational fluid dynamics software Fluent was used to simulate the flow field in the separation of the corrugated plate.The results of numerical simulation show that:the angles of the corrugated plate have a great effect on the flow;and the flow dead zone will be formed due to the bending angles;the holes inside the corrugated plate will reduce the flow dead zone.In the corrugated plate without holes,the pressure drop in the flow path rises in a ladder like trend;In the corrugated plate with holes,the holes can reduce the influence of bending angles on the pressure drop along the path.Study on the distribution of oil droplet concentration by dispersion phase model(DPM)shows:Lower concentration of oil droplets occurs in the corrugated plate with holes;After the corrugated plate with holes,the oil droplet concentration has a concentrated distribution.Study on the oil-water phase interface using Mixture model shows:The holes in the corrugated plate provides a channel for the oil phase floating between the corrugated plates;The opening rate will affect the oil-water two phase interface after the corrugated plate;When the opening rate is about 10%,the existence range of the oil-water phase interface is narrow;With the increase of inlet flow rate,the existence range of the oil-water interface increases.