Experimental study on the design of light phase outlets for a novel axial oil-water separator

Abstract

Oil-water separation plays a serious role in oil exploitation to reduce the production cost. Centrifugal separation is one of the feasible methods due to its large capacity, high separation efficiency and low maintenance cost. Besides, the centrifugal separation equipment can be divided into tangential inlet separators and axial inlet separators. The ones with tangential inlet have received a large number of investigation on structure optimization but some shortcomings limit the further improvement of separation performance. In this paper, an axial separator with multiple-stage separation was introduced and investigated experimentally with water flow rate range from 3 to 7 m3/h and inlet oil fraction below 10%. Additionally, the schedule for Light Phase Outlets (LPOs) was studied experimentally and theoretically to ensure high separation efficiency and low split ratio. The results show that the multiple stage separator can keep high separation performance that the oil concentration in HPO is below 200 ppm while the split ratio ranged from 0.2 to 0.45 within experimental conditions. Besides, the reasonable schedule can lead an obvious drop in split ratio with high separation performance. Additionally, based on the analysis of flow field characteristic, the LPOs positioned in the two sides of the oil core can ensure the discharge of oil droplets in high swirl flow field and the LPO located downstream has better potential to separate small size droplets.