Patent · US Expired

Gas mixture for cryogenic applications

US6074572A · kind A · utility

9Cited by
6References
2Claims
0Family size

Assignee

Inventors

Key dates

Filing dateApr 6, 1999
Grant dateJun 13, 2000
Priority date
Expiry dateApr 6, 2019

Classification

  • Technology area (CPC C)Chemistry; Metallurgy
  • CPC primaryC09K2205/13
  • WIPO fieldBasic materials chemistry
  • WIPO sectorChemistry

Abstract

An optimum gas mixture formulated from a group of component fluids, for use in a miniature mixed gas refrigeration system. The gas mixture has appropriate components, in appropriate concentrations, to optimize refrigeration power and heat transfer capacity, and to minimize plugging of the Joule-Thomson expansion element. The gas mixture is pressurized by a compressor to a pressure less than 750 psia, and preferably less than 420 psia, for safety reasons, and supplied to a heat exchanger. The high pressure outlet of the heat exchanger is connected to a Joule-Thomson expansion element where the high pressure gas is expanded isenthalpically to a lower temperature at least as low as 183K. This low temperature gas cools a heat transfer element mounted in the distal end of the probe, to cool an external object. Return gas flows back through the heat exchanger to pre-cool the incoming high pressure gas mixture.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.