Centrifugal Air Compressors 101

Centrifugal air compressors are dynamically engineered compressors that use rotating elements called impellers.  Incoming, low velocity air or gas reaches an inlet guide vane that automatically adjusts itself to changes in system demand. (Pictured Below)  This regulates the incoming stream as it flows toward the first stage impeller with a “pre-swirl” effect.  These impellers spin at a high rate of speed, accelerating the air or gas while pushing it toward the center of the machine by centrifugal force; hence, centrifugal compressor.  The ambient air or gas is then forced through a diffuser, which is a much smaller area.  The diffuser’s job is to convert kinetic energy (high velocity) of the air or gas into pressure by gradually slowing (diffusing) the velocity.  This progression of speeding the air up and then slowing it down causes the pressure to increase.  Different applications call for different pressures.  When more pressure is required, a number of different stages can be arranged in a series to achieve the necessary pressure increases.

The pressurized air then flows through an intercooler, causing the moisture in the air to condense and separate from the lower velocity, cooled air.  The separated condensate is removed through a drain valve allowing the cooled air to exit the intercooler and travel into an inlet duct for the next stage of compression, in which the entire process is repeated.  From there, the compressed air or gas moves to an aftercooler where it is cooled and any remaining moisture is removed.

As you can see from this progression, the gear boxes on centrifugal compressors are integrated with the compressor assembly and completely isolated from the air path by buffered seals; making them ideal for applications that require 100% oil-free air.  This highly efficient process concludes with a steady supply of exceptionally clean, oil-free air that’s ready to power a wide array of industrial applications; all while giving manufacturers the peace of mind of lower maintenance costs and less downtime.If you would like to gain more insight on how centrifugal air compressors operate and the benefits they provide for a variety of different applications, contact C.H. Reed today to speak with a centrifugal compressed air specialist.


Sources:
“How Does a Centrifugal Compressor Work?” FS-Elliott Centrifugal Compressors. N.p., n.d. Web. 05 Apr. 2017.
Arfalk, Erik. “How it Works: Centrifugal Compressors | Compressed Air …” How it Works: Centrifugal Compressors. N.p., 23 Jan. 2014. Web. 5 Apr. 2017.