In a centrifugal compressor, the two functional elements are which?

In a centrifugal compressor, the two functional elements are which?

• A. Impeller and diffuser
• B. Turbine and compressor
• C. Bucket and expander
• D. Stator and rotor

Answer: (A)

The main concept here is that a centrifugal compressor relies on two components to do the work: energy is added by a rotating element and then converted to pressure by a stationary diffusion path. The impeller is the rotating element that speeds up the gas, imparting kinetic energy to it. After leaving the impeller, the gas enters the diffuser, where the flow area broadens and the velocity decreases, converting that kinetic energy into an increase in static pressure. These two parts—impeller and diffuser—work together to achieve compression in this type of compressor. The other terms refer to components or concepts not representing the two functional elements that accomplish energy transfer and pressure rise in a centrifugal compressor.

The main concept here is that a centrifugal compressor relies on two components to do the work: energy is added by a rotating element and then converted to pressure by a stationary diffusion path. The impeller is the rotating element that speeds up the gas, imparting kinetic energy to it. After leaving the impeller, the gas enters the diffuser, where the flow area broadens and the velocity decreases, converting that kinetic energy into an increase in static pressure. These two parts—impeller and diffuser—work together to achieve compression in this type of compressor. The other terms refer to components or concepts not representing the two functional elements that accomplish energy transfer and pressure rise in a centrifugal compressor.