It is often referred to as a screw-type compressor. Air inlet and outlet ports are located on opposite sides of the casing.
Atmospheric air is drawn into the compressor through the filter-silencer.
Fresh water is injected into the airstream as it passes through the inlet port of the compressor casing. Most of the injected water is entrained into the airstream as it moves through the compressor. The compression cycle starts as the rotors unmesh at the inlet port. As rotation continues, air is drawn into the cavity between the male rotor lobes and into the grooves of the female rotor. The air is trapped in these grooves, or pockets, and follows the rotative direction of each rotor.