Introduction to oil bearing turboexpander rotor dynamics

Turboexpanders are the ideal choice for processes with large pressure drops that require refrigeration or power recovery. Whereas a valve or orifice also can be used to effectively drop pressure, turboexpanders extract useful work from a flowing gas stream. Isentropic efficiencies as high as 90% are readily achieved with a turboexpander, resulting in much lower discharge temperatures. Turboexpanders were introduced in the mid-1930s when the first machine was designed and implemented for air separation. The first unit for a natural gas application was designed and installed in the early 1960s. Over the years, many technological advances in design and manufacturing have allowed these machines