Comparison Between Centrifugal Compressors and Centrifugal Blowers

       Centrifugal compressors are a sub-class of dynamic axisymmetric work-absorbing turbomachinery. The idealized compressive dynamic turbo-machine achieves a pressure rise by adding kinetic energy/velocity to a continuous flow of fluid through the rotor or impeller. This kinetic energy is then converted to an increase in potential energy/static pressure by slowing the flow through a diffuser.

       Centrifugal compressors are also similar to centrifugal blowers as they both increase pressure with the benefit of increasing radius. In contrast to centrifugal blowers, compressors operate at higher speeds to generate greater pressure rises. In many cases the engineering methods used to design centrifugal blowers are the same as those to design centrifugal compressors. As a result, they can at times look very similar.

This relationship is less true in comparison to a squirrel-cage fan. For purposes of generalization and definition, it can be said that centrifugal compressors often have density increases greater than 5 percent. Also, they often experience relative fluid velocities above Mach number 0.3 when the working fluid is air or nitrogen. In contrast, fans or blowers are often considered to have density increases of less than 5 percent and peak relative fluid velocities below Mach 0.3.