Structure improvements and numerical simulation of supersonic separators with diversion cone for separation and purification

In the improved supersonic separator with the diversion cone, the reflow channel and the flush-type drain structure are adopted to overcome two shortcomings: the shock wave that easily appears in the diverging section of the nozzle and the swirling flow that occurs in subsonic conditions with poor efficiency, which makes the low-temperature section short and the cooling effect unsatisfactory. In this study, the distribution of the main parameters and the effects of the inlet temperature and outlet angle of the swirler were investigated by numerical simulation. The results indicated that the internal extension structure severely damaged the supersonic flow in the nozzle, while the flush type drainage port slightly influenced the fluid. The smaller outlet angle of the drainage port reduced its effect on the supersonic flow. Moreover, the improved device with the reflow enlarges the supersonic region and exhibits the better performance. In addition, it achieves a low temperature (221 K) and high centrifugal acceleration (2.2 × 10(7) m s(−2)). Moreover, the inlet temperature of 300–320 K and the outlet angle of 50°–60° are recommended for the improved supersonic separator based on the comprehensive consideration of good expansion characteristics and centrifugal separation performance.