Precooling system for joule-thomson probe
US5758505A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 7, 1996 |
| Grant date | Jun 2, 1998 |
| Priority date | — |
| Expiry date | Oct 7, 2016 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF25B2400/12
- WIPO fieldMedical technology
- WIPO sectorInstruments
Abstract
A miniature mixed gas refrigeration system and method of operation are disclosed. An optimum gas mixture is formulated from a group of component fluids, according to calculated thermodynamic properties of a group of candidate fluid mixtures. The gas mixture is pressurized by a compressor to a pressure less than 420 psia, for safety reasons. The compressed gas mixture is passed through a primary heat exchanger, and then through a primary-to-secondary heat exchanger, to precool the gas mixture. The secondary side of the primary/secondary heat exchanger is cooled by a secondary Joule-Thomson refrigeration system. Properly sized flow restrictions in the primary side of the primary/secondary heat exchanger can solidify and trap liquid contaminants that may be in the gas mixture. The gas mixture exiting the primary outlet of the primary/secondary heat exchanger passes to a primary 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 outer wall of the catheter, to cool an external object. Return gas flows back through the primary heat exc…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.