Sealing system for a turboexpander compressor

Abstract

A turboexpander compressor for use in a gas processing system has a seal system that avoids communication of gas with the oil being pumped through the bearings. The device has a shaft carried in a housing on bearings with a compressor wheel on one side and an expander wheel on the other side. Labyrinth seals seal the wheels from the interior of the housing and the bearings. Mechanical seals are located between the bearings and the labyrinth seals for preventing leakage of oil. The mechanical seals are located in a drainage chamber that allows any oil or gas leaked past the seals to be drained from the system, rather than dilute the oil. Gas is injected from the compressor discharge into a groove on the expander side of the shaft to provide a thermal barrier. The mechanical seals each have a rotating ring carried by the shaft and a nonrotating ring carried by the housing. The nonrotating ring is biased into the rotating ring by means of an O-ring. The O-ring is located in a groove in the bore and a recess formed in the nonrotating ring. The recess is offset to deform the ring and cause it to exert a force on the nonrotating ring against the rotating ring.

Dependencies are inferred from the claim text.