To remove moisture from the gas it flows through the nozzle. In the nozzle the gas is accelerated and its potential energy is transformed into kinetic energy.
In the supersonic flow of gas temperature drops below the dew point of water vapor. With the help of induced swirling flow condensed water is separated from the rest of the gas stream by centrifugal forces.
The disadvantage of this economical method is sensitivity on inlet parameters (flow rate, temperature and pressure).
You can google it "Supersonic Separator"

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