Sustor2 provides deep cooling of a gas flow, practically total condensation of a vapor, and fast and effective removal of the condensed liquid with a significantly reduced pressure losses compared with the prior art. Sustor2 performs the said operations by developing a strong swirling flow starting from its entrance, followed by spiral flow convergence in the inlet disc-like part, and then in a converging-diverging nozzle, by centrifugal removal of droplets, and removal of the liquid film through slits, then by spiral flow divergence and leaving the vortex chamber through tangential outlet.A gas enters from a pipeline (see the arrow in the A-A cross-section shown in FIG. 7) connected to Sustor2 by a flange and the inlet transition pipe ITP in FIG. 7, spirally converged in the disc-like part, marked by A-A in FIG. 6, enters the converging-diverging nozzle (FIG. 6). The flow is high-speed and swirling even at the near-entrance region of the vortex chamber. This swirl results in the centrifugal force that presses the through-flow to the sidewall. The flow accelerates near the nozzle throat up to a supersonic velocity with subsonic axial and supersonic swirl velocity components. This acceleration results in the gas temperature drop down to 200K and even less values. The reduced temperature causes rapid condensation of vapor into droplets. The centrifugal force pushes the droplets to the sidewall where they are removed through slits. Next the dried gas spirally diverges and leaves the vortex chamber through the tangential outlet. This results in the pressure recovery and transformation of the swirl kinetic energy into the longitudinal kinetic energy of the gas. Both the effects decrease pressure losses which is the Sustor2 advantage compared with the prior art.