Patent ID: 7856834
Filing Date: 2010-12-28
Classification: F04D,F25B,Y10T

Abstract:
1. A mixed flow impeller for use in compressing refrigerant in a multistage centrifugal compressor assembly having a final stage compressor and a non-final stage compressor, said mixed flow impeller comprising: an impeller hub, an impeller shroud, and a plurality of impeller blades arranged for approximately constant relative diffusion in the mixed flow impeller, the mixed flow impeller having a nominal diameter less than a maximum diameter at a multistage centrifugal compressor assembly capacity and sized to meet a target flow and a target head such that the final stage compressor has a final stage specific speed within an optimum specific speed range for the final stage compressor and the non-final stage compressor has a non-final stage specific speed that exceeds the final stage specific speed.