Structure improvements and numerical simulation of supersonic separators

Abstract In the separation process of the conventional supersonic separator, the shockwave easily occurs in the nozzle expanding section before the cyclone, the low temperature section is short and the cooling effect is not satisfied, and the swirling flow occurs in subsonic conditions with poor efficiency. Based on this, structure improvement of the supersonic separator was carried out by reducing the nozzle expand angle and extending the length of expanding section, which helps to improve the refrigeration performance and separation efficiency of the separator. The flow characteristics of natural gas in the improved supersonic separator were obtained by three-dimensional numerical simulation. The results show that the shockwave occurs in the back of the cyclone and the improved supersonic separator can achieve a wider range of deep cooling. The shockwave moves back with the increase of the pressure loss ratio, when the pressure loss ratio increases to 70%, the position of shockwave moves back to the diffuser. The numerical results show that when the inlet pressure is 600 kPa and the pressure loss ratio is 47.5%, the improved supersonic separator has a good cooling and separation performance.