Centrifugal Air Compressors

The figure shown here illustrates a multistage centrifugal air compressor.

Centrifugal air compressors work much like centrifugal pumps. Ambient air is accepted at the center of the rotor. The rotor imparts centrifugal energy to the air, which forces air to move toward the circumferential regions. In the circumferential regions, the kinetic energy of the air is converted to potential (pressure) energy.

In a multistage design, compressed air is moved through each of the stages in succession. The peripheral region of one stage feeds air into the eye of the succeeding stage. In each stage, the pressure is successively increased. For each stage, the direction of airflow is radial with respect to the axis of rotation.

Centrifugal compressors are mainly used for near-continuous industrial air service when the load is reasonably constant. These compressors also work well when oil-free air is required.