Dynamic Displacement Compressors

Dynamic displacement compressors work by increasing the velocity of the incoming gas and then restricting the air flow.  This restriction in the airflow causes the pressure to increase.

Dynamic displacement compressors are also known as oil free or oil-less compressors.  There are no seals and valves in dynamic displacement compressors.

Centrifugal compressors are the most common type of dynamic displacement compressors.  The operation is similar to that of a centrifugal pump.

Air is drawn into the centre of an impeller and then pushed out of the perimeter at high velocity.  Centrifugal compressors operate at high speeds of the order of 75000 rpm.  They are driven by gears.
They have higher efficiencies as compared to dynamic displacement compressors.  Changes in temperature and humidity will have a significant impact on  the operating characteristics of dynamic displacement compressors.