Lubrication of positive displacement expanders

摘要

A method and system for lubricating a positive displacement machine operating as an expander of a compressed gas, comprising introducing into an expansion chamber of the machine a lubricant whose pour point temperature is greater than the operating temperature of the machine in the expansion chamber as determined by the expanding gas, which thus causes the lubricant to freeze-adhere to the internal surfaces of the expansion chamber, to become fluid under increased pressure at a point of contact of the working surfaces of the expander and then to refreeze when the surfaces separate. Considerable reduction in the quantity of lubricant is realized with the attendant advantage that dis-entrainment of lubricant from the gas exhausted from the machine is largely avoided.

主权项

1. A method of lubricating a positive displacement machine operating as an expander of a compressed gas, comprising the steps of introducing into an expansion chamber of the machine a lubricant whose pour point temperature is greater than a reduced operating temperature of the machine in said expansion chamber, wherein the reduced operating temperature of the machine in said expansion chamber is determined by expansion of the compressed gas, wherein the lubricant is caused to freeze-adhere to the internal surfaces of the expansion chamber, and
wherein the temperature differential determined by the pour point of the lubricant and the operating temperature of the machine in the expansion chamber is such that the freeze-adhered lubricant becomes fluid under increased pressure at a point of contact of the working surfaces of the expander, then refreezes when the surfaces separate.