Adjustable Speed---A Tool for Saving Energy Losses in Pumps, Fans, Blowers, and Compressors

Petroleum and chemical plants today are effectively cutting energy use by thermally, electrically, and mechanically reducing losses in their process equipment. In rotating equipment such as pumps, fans, compressors, and blowers, much mechanical or fluid energy is being dissipated or thrown away by throttling valves, dampers, and adjustable guide vanes. Adjustable speed is an increasingly used feature in the search to reduce losses. Fluid mechanics is reviewed in lay terms in an effort to illustrate where losses may be found and how to determine how much may be saved by converting to or using adjustable speed. Other potential ways that adjustable speed may be used for process savings are also discussed.