Improved swirl-vane designs: Development of low-pressure-drop tubular dynamic hydrocyclones for pre-dehydration

ABSTRACT Effective pre-dehydration is achieved to stabilize and improve oil production in high water cut oil fields. In order to reduce the pressure loss during the pre-dewatering process, a low-pressure-loss dynamic hydrocyclone (LPDH) was developed. And its swirler vane was designed which can not only drive liquid into circumferential rotational flow but also produce axial pressure. The axial pressure will compensate for the separation process pressure loss. The key parameters that affected the axial pressure were studied, the relative motion between the fluid and the vane was analyzed, and a pre-dehydration LPDH was designed (processing capacity is 1.0 m3/h). The changes in the separation efficiency and axial pressure of the LPDH with the operational and physical parameters were studied by the computational fluid dynamics (CFD) numerical simulation method. The results revealed that the pressure is increased during rotation-starting, and the pressure loss of LPDH was lower than the dynamic and compound hydrocyclones. Notably, low shear stress was generated using the designed vane when the fluid started rotating, and the separation efficiency increased under these conditions. When the speed of rotation of the swirler is 167.5 rad/s, the separation efficiency of the LPDH is greater than 99.8%.