CFD-based optimization study on the inlet pipe structure of oily wastewater treatment device

In response to the increasingly severe problem of oily wastewater emulsification, the oily wastewater treatment device studied in this paper integrates multiple processes such as thermal treatment, sedimentation, and packing filtration to achieve two-phase separation of crude oil and water from emulsified petroleum. To improve the internal flow stability and oil-water separation efficiency of the device, a multi-stage optimization design of the inlet pipe structure was carried out based on the CFD method. Through extensive simulations of the inlet pipe alone and of the entire device, the effects of the outlet hole size, hole shape, and oil droplet diameter on the liquid flow characteristics and separation performance inside the container were systematically analyzed. The study shows that an inlet pipe structure with a large-diameter first circular hole and smooth transition in hole size is more conducive to enhancing internal flow stability and separation efficiency compared with traditional designs. Meanwhile, better separation results are achieved when processing larger oil droplets. The research findings can provide theoretical guidance and numerical support for the structural optimization and operating condition adjustment of oily wastewater treatment devices.