The gas enters through the inlet 1 . As it enters the side channel 2 , the rotating impeller 3 imparts velocity to the gas in the direction of rotation.
Centrifugal force in the impeller blades accelerates the gas outward and the pressure increases. Every rotation adds kinetic energy, resulting in further increase of pressure along the side channel. The side channel narrows to the rotor, by pushing the gas far from the impeller blades and discharging it through the outlet silencer 4 from which it gets outside.