Rerate Of Centrifugal Process Compressors - Wider Impellers Or Higher Speed Or Suction Side Boosting?.
Impeller exchange, speed increase, and supercharging are the usual means to increase the capacity of existing industrial turbocompressors of the single shaft type. Replacing an existing rotor by a new one with wider impellers normally requires wider stationary flow channels as well and, therefore, necessitates some additional space that must be available within the compressor casing. Speed increase requires, besides the aerodynamics, careful consideration of rotordynamics and checking of mechanical components. Suction side boosting, on the other hand, leaves the existing compressor "almost" untouched since the booster forms a separate unit. One case study of a turbine driven hydrocarbon compressor in a fluid catalytic cracking (FCC) plant built in 1968, illustrates the complete exchange of the aero-package in combination with speed increase in two large steps to increase the volume flow from 100 percent to a spectacular value of 243 percent. The uprates included retrofitting bearings and shaft seals. In another example, a turbine driven air compressor in a terephthalic acid (PTA) plant built in 1980 is described, which was uprated to 164 percent of its original capacity by boosting.
Ludtke, Klaus (1997). Rerate Of Centrifugal Process Compressors - Wider Impellers Or Higher Speed Or Suction Side Boosting?.. Texas A&M University. Turbomachinery Laboratories. Available electronically from