Multistage centrifugal blower

Multistage centrifugal blower, the air or gas is sucked into the first stage through an inlet volute, every next single stage is linked to the former one through a return channel, and a discharge volute collects the gas from the exit of the last stage delivering it to the outlet pipe. The impellers are built with radial exit blades or backward-facing blades. The radial blades allow the achievement of a higher compression ratio. While the impellers with the backward-facing blades at a fixed speed of rotation and for the same differential pressure.