Has anyone come across three stages compressor running under the same shaft and in separate casings...or it would be too impractical to have long shaft (i.e. optimum shaft to impeller diameter ration not to be more than 10)
Never seen such a thing or even rigid couplings put on the driven side. On top of this being very odd, lateral behavior (rotordynamics) would not be independent casing by casing due to absence of flexible couplings. What is the benefit?
Hi rotw, I totally agree with you, the rotodynamic loads on the shaft which is too long to accommodate three stages makes this configuration quite odd.