page_title: Gas compressor
section_title: Centrifugal compressors
hierarchical_section_title: Gas compressor / Types of compressors / Centrifugal compressors
caption_attribution_description: English: A single stage centrifugal compressor (left) driven by an electric motor (right) through a gearbox (center). A low-speed coupling connects the motor to the gearbox, and a high-speed coupling connects the gearbox to the compressor. Process gas enters the compressor through the flanged opening at left center and is discharged through the flange in the upper left corner of the photograph. The impeller can be seen just inside the inlet port.
context_page_description: A gas compressor is a mechanical device that increases the pressure of a gas by reducing its volume. Compression of a gas naturally increases its temperature. When the gas is air, the machine is called an air compressor.
  Compressors are similar to pumps: both increase the pressure on a fluid and both can transport the fluid through a pipe. As gases are compressible, the compressor also reduces the volume of a gas. Liquids are relatively incompressible, so the main action of a pump is to transport liquids.
context_section_description: Centrifugal compressors use a vaned rotating disk or impeller in a shaped housing to force the gas to the rim of the impeller, increasing the velocity of the gas. A diffuser (divergent duct) section converts the velocity energy to pressure energy. They are primarily used for continuous, stationary service in industries such as oil refineries, chemical and petrochemical plants and natural gas processing plants. Their application can be from 100 hp (75 kW) to thousands of horsepower. With multiple staging, they can achieve extremely high output pressures greater than 10,000 psi (69 MPa).
  Many large snow-making operations (like a ski resort) use this type of compressor. They are also used in internal combustion engines as superchargers and turbochargers. Centrifugal compressors are used in small gas turbine engines or as the final compression stage of medium-sized gas turbines.
caption: Figure 1: A single stage centrifugal compressor
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