Freeze-thaw valve that self-limits cryogenic agent usage
US7841190B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 16, 2005 |
| Grant date | Nov 30, 2010 |
| Priority date | — |
| Expiry date | Nov 4, 2026 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T137/6579
- WIPO fieldMechanical elements
- WIPO sectorMechanical engineering
Abstract
Methods and devices for the management of cryogenic agents within analytical systems using freeze thaw valving having an expansion chamber that limits the flow of the cryogenic agent. The expansion chamber is fitted with an expansion nozzle through which a cryogen flows and a porous frit that allows the cryogen to be exhausted. The porous frit initially allows a rapid flow of cryogen into the expansion chamber. This rapid flow lowers the temperature of the expansion chamber causing fluid contents within a freeze thaw segment to freeze. As the cryogen expands into the expansion chamber and turns into a solid, the porous frit is occluded causing the rapid flow to be restricted. The restriction of the cryogen flow by the occlusion of the porous frit allows the freeze thaw valve to use significantly less cryogen. Sublimation of the cryogen trapped within the porous frit provides sufficient cooling to maintain the valve in its closed position.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.