Design of floating pad journal bearings for a cryogenic turboexpander

摘要

Expansion turbine is the heart of most modern liquefaction and separation systems. These turbines, specially those used in small cryogenic plants such as laboratory liquefiers often run at speeds exceeding 1,00,000 r/min imposing stringent constraints on the bearing designer. Gas bearings, by the use of process gas as the lubricant sometimes provide the best answer to the problem The floating pad journal bearings have come up as a very reliable solution. This paper presents the methodology adopted for the design of this type of bearings for the turboexpander under development at IIT Kharagpur.