Swirling flow of natural gas in supersonic separators

The supersonic swirling separator is a new apparatus for offshore and subsea natural gas separation, due to its lightweight and the viability of unmanned operation. A new supersonic swirling separator was designed for the numerical calculation, in which a central body was inserted based on the principle of conservation of angular momentum. Axial and radial distribution of the main parameters of natural gas flow was investigated with RNG K-ɛ turbulence model. The effects of the shock waves on the natural gas flow fields were analyzed in the supersonic separator. The results show that water and heavy hydrocarbons can be separated from natural gas due to the low temperature and high centrifugal field. The non-uniformity of radial distribution of the gas dynamic parameters significantly affects the gas/liquid separation. The position of the shock wave determines the distribution of the temperature, which has a great influence on the re-evaporation of liquid droplets.

► Low temperature of-93 °C with a centrifugal field of 720,000 g can be obtained in the supersonic separator.
► High gradients of gas dynamic parameters near the walls impair the natural gas separation.
► Shock wave shifts forward with the increase of the pressure recovery coefficient.