Structural optimization and separation characteristic of a separating device for three phases: Oil, water and solid

Solid particles and water are widely used as lubricating oils. However, oil–water–solid separation is inefficient when conventional methods are used. Therefore, a device is proposed to simultaneously separate oil, water, and solids from one another. In this study, a numerical model was established by combining the mixture, Reynolds stress, population balance, and discrete-phase models to investigate the separation characteristics of a separating device. The effect of the structural parameters on the separation was investigated, and the important structural parameters were optimized using the response surface method. The results indicate that the optimal underflow pipe, certain pipe, and sideflow pipe diameters are 6.5, 13.49, and 7 mm, respectively; at this instant, the tangential velocity in the small cone section and certain structure is large, the oil volume fraction is low near the underflow pipe, and the number of solid particles separating from the sideflow outlet increases, and the deoiling rate and desolidification rate reach a maximum of 84.45% and 91.44%. This study can provide valuable guidance for the design of high-performance devices for lubricating oil purification using physical methods.