A Novel Divergent Coalescence Separator for Superior Oil–Water Separation: Design and Computational Fluid Dynamics Analysis

Abstract The oil–water separator plays a critical role in ensuring both the economic viability and stability of oil production. Traditional corrugated plate gravity separators, however, suffer from issues such as large size and low efficiency. This study presents a novel divergent-type gravity separator featuring dual baffle plates and interconnected spherical coalescence elements. Computational fluid dynamics simulations are employed to evaluate its performance. The uniquely structured coalescence zone enhances oil droplet aggregation by promoting stable flow and reducing vortex formation, thereby accelerating separation and enabling more compact equipment design. Results indicate that the proposed configuration substantially outperforms conventional separators in oil–water separation efficiency. Furthermore, the study investigates the effects of the spatial configuration and length of the coalescence structures, providing valuable insights for future separator design. In situ tests confirm that the new separator reduces the average oil content in the water outlet to 173.12 mg/L, further demonstrating its effectiveness. Compared with the simulated effluent concentration of 195.54 mg/L, this represents an 11.2% improvement, indicating the robustness of the separator and validating the accuracy of the simulation approach.