Cooling apparatus employing a pressure actuated Joule-Thomson cryostat flow controller
US5974808A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 21, 1997 |
| Grant date | Nov 2, 1999 |
| Priority date | — |
| Expiry date | Nov 21, 2017 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG05D23/12
- WIPO fieldControl
- WIPO sectorInstruments
Abstract
A pressure activated flow controller for use with a Joule-Thomson valve having a diaphragm actuator that is located outside a dewar, and which is not cooled. The diaphragm actuator limits flow based on gas pressure supplied to the dewar from a gas supply, not temperature, and does not impede cooldown of a device coupled to the dewar. The diaphragm actuator comprises a diaphragm and load plate that exert a force to open the Joule-Thomson valve. A wave spring provides a force to close the Joule-Thomson valve, thus balancing the back pressure of the gas supply. The diaphragm actuator is compact, and limits flow based on gas supply pressure, not temperature. The present invention thus uses pressure regulation instead temperature regulation to achieve flow control.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.