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Patent US2121157A successfully refreshed from Google Patents.
US3656313A
Expired / Lapsed
US
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Helium refrigerator and method for decontaminating the refrigerator
Assignee: National Aeronautics and Space Administration
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Filing: 1971-02-05
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Granted: 1972-04-18
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Expires: 1991-02-05
Abstract
Abstract For use in a multi-stage refrigeration system an improved heat exchanger of a type having an hermetically sealed housing and including therewithin a pair of chambers defining a pair of concentrically related countercurrent passages extending therethrough. A particular feature of the invention is embodied in a decontaminating system which includes a circuit pneumatically coupled with a given heat exchanger and adapted to vent the heat exchanger to atmosphere and to flush the vented heat exchanger with a gas delivered under pressure and at ambient temperature so that frozen contaminants operatively are melted and simultaneously expelled from the system.
Inventors
- 👤 Ervin R Wiebe
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 23:04
CPC Classifications
F; F25; F25B; F25B9/00; F25B9/10
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
77 words
In a counterflow refrigeration system of the type including a plurality of series-connected heat exchangers, each having arranged therewithin a pair of concentric chambers defining a pair of countercurrent passages extending therethrough, the improvement comprising: A. an inlet and an outlet conduit extending from each of said chambers for simultaneously conducting through said chambers oppositely flowing streams of gas; and B. flushing means operatively associated with one chamber of said pair of chambers for flushing contaminants therefrom.
Claim 2
Dependent Claim
77 words
In a counterflow refrigeration system of the type including a plurality of series-connected heat exchangers, each having arranged therewithin a pair of concentric chambers defining a pair of countercurrent passages extending therethrough, the improvement comprising: A. an inlet and an outlet conduit extending from each of said chambers for simultaneously conducting through said chambers oppositely flowing streams of gas; and B. flushing means operatively associated with one chamber of said pair of chambers for flushing contaminants therefrom.
Claim 3
Dependent Claim
190 words
The improvement of claim 1 wherein the inlet conduit extending from said one chamber of said pair of chambers serves to deliver gas at ambient temperatures to the chamber while the outlet conduit extending from the other chamber of said pair of chambers serves to deliver gas from said other chamber, and said flushing means includes: A. a blow-down conduit coupled with the outlet conduit of said one chamber; B. an atmospheric vent communicating with said one chamber through said blow-down conduit; C. a first on-off valve operatively coupled within the blow-down conduit for controlling the delivery of gas between said one chamber and said atmospheric vent; and D. a second on-off valve associated with the outlet conduit extending from said other chamber for interrupting the delivery of gas flowing from said other chamber, whereby when said first valve is opened and said second valve is closed gas delivered at ambient temperature through the inlet conduit extending from said one chamber is discharged to atmosphere through said vent while gas flowing from the inlet conduit extending from said other chamber through said heat exchanger is interrupted at said second valve.
Claim 4
Dependent Claim
101 words
In a method of decontaminating a refrigeration apparatus of a type including a plurality of series-connected heat exchangers each including a pair of concentrically oriented countercurrent passages for cooling gases to cryogenic temperatures, the step of, interrupting the flow of gas through one of the chambers of a first-in-line one of said heat exchangers, and delivering gas at ambient temperatures through the other chamber of the heat exchanger and venting the delivered gas to atmosphere as it is discharged from said other chamber, whereby the temperature of said one heat exchanger is elevated for melting and dispelling frozen contaminants disposed therewithin.
Claim 5
Dependent Claim
101 words
In a method of decontaminating a refrigeration apparatus of a type including a plurality of series-connected heat exchangers each including a pair of concentrically oriented countercurrent passages for cooling gases to cryogenic temperatures, the step of, interrupting the flow of gas through one of the chambers of a first-in-line one of said heat exchangers, and delivering gas at ambient temperatures through the other chamber of the heat exchanger and venting the delivered gas to atmosphere as it is discharged from said other chamber, whereby the temperature of said one heat exchanger is elevated for melting and dispelling frozen contaminants disposed therewithin.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-04-18 | 1975-10-18 | 1976-04-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-04-18 | 1979-10-18 | 1980-04-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-04-18 | 1983-10-18 | 1984-04-18 | $7700.00 | Window Closed / Lapsed |