US3768273A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Self-balancing low temperature refrigeration system
Assignee: Wickes Manufacturing Co
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Filing: 1972-10-19
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Granted: 1973-10-30
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Expires: 1992-10-19
Abstract
Abstract Extremely low temperatures, in the range of -40*F. to -300*F., are achieved in a single circuit compression refrigeration system which is capable of being operated by a conventional compressor without the aid of special start-up or stand-by equipment. The system relies upon a series of intermediate cooling stages in which each stage includes the steps of withdrawing a portion of the liquid condensate from a compressed vapor-liquid refrigerant mixture which enters that stage, throttling the withdrawn condensate to a lower pressure, mixing the throttled condensate with refrigerant being recycled to the compressor from the final evaporator and evaporating the throttled condensate to absorb heat from and at least partially condense the compressed unconcensed vapor in the compressed mixture.
Inventors
- 👤 D Missimer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 00:21
CPC Classifications
F; F25; F25B; F25B9/00; F25B9/002; F25B9/006
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
203 words
A compression refrigeration process employing a mixture of refrigerants having different boiling points, comprising the steps of: a. compressing a vaporous mixture of said refrigerants; b. partially condensing the compressed refrigerant vapor to form a mixture consisting of compressed condensate and compressed uncondensed vapor; c. subjecting the compressed mixture from step (b) to at least one intermediate, cooling stage, each said intermediate cooling stage including the steps of throttling a portion of said compressed condensate to a lower pressure, mixing said throttled condensate with the mixture of refrigerants being recycled to the compressing step from the final evaporator, evaporating said throttled condensate to absorb heat from and at least partially condense the compressed vapor in the remaining mixture of the compressed condensate and compressed vapor, returning the mixture of evaporated, throttled condensate and recycled refrigerant mixture to step (a), and passing said at least partially condensed compressed mixture to the next successive intermediate cooling stage; d. throttling said compressed mixture obtained from the last intermediate cooling stage to a lower pressure; e. at least partially evaporating the throttled condensate produced in step (d) to produce the final refrigerating temperature and recycling the at least partially evaporated mixture of refrigerants to said compressing step.
Claim 2
Dependent Claim
203 words
A compression refrigeration process employing a mixture of refrigerants having different boiling points, comprising the steps of: a. compressing a vaporous mixture of said refrigerants; b. partially condensing the compressed refrigerant vapor to form a mixture consisting of compressed condensate and compressed uncondensed vapor; c. subjecting the compressed mixture from step (b) to at least one intermediate, cooling stage, each said intermediate cooling stage including the steps of throttling a portion of said compressed condensate to a lower pressure, mixing said throttled condensate with the mixture of refrigerants being recycled to the compressing step from the final evaporator, evaporating said throttled condensate to absorb heat from and at least partially condense the compressed vapor in the remaining mixture of the compressed condensate and compressed vapor, returning the mixture of evaporated, throttled condensate and recycled refrigerant mixture to step (a), and passing said at least partially condensed compressed mixture to the next successive intermediate cooling stage; d. throttling said compressed mixture obtained from the last intermediate cooling stage to a lower pressure; e. at least partially evaporating the throttled condensate produced in step (d) to produce the final refrigerating temperature and recycling the at least partially evaporated mixture of refrigerants to said compressing step.
Claim 3
Dependent Claim
26 words
The process of claim 1 wherein the portion of compressed condensate throttled in each intermediate cooling stage is determined by the capacity of the throttling device.
Claim 4
Dependent Claim
22 words
The process of claim 1 wherein 10 to 95 percent of the compressed condensate entering each successive intermediate cooling stage is throttled.
Claim 5
Dependent Claim
13 words
The process of claim 2 wherein said throttling device is a capillary tube.
Claim 6
Dependent Claim
14 words
The process of claim 2 wherein said throttling device is a thermal expansion valve.
Claim 7
Dependent Claim
13 words
The process of claim 1 including 2 to 6 successive intermediate cooling stages.
Claim 8
Dependent Claim
15 words
The process of claim 1 wherein said refrigerant mixture comprises 2 to 7 individual refrigerants.
Claim 9
Dependent Claim
27 words
The process of claim 7 wherein the difference in boiling point between each refrigerant and the closest boiling other refrigerant in said mixture is 50*F. to 180*F.
Claim 10
Dependent Claim
15 words
The process of claim 7 wherein said refrigerant mixture includes at least two halocarbon refrigerants.
Claim 11
Dependent Claim
31 words
The process of claim 7 wherein said refrigerant mixture includes at least two halocarbon refrigerants and at least one inert gas selected from the group consisting of argon, nitrogen and neon.
Claim 12
Dependent Claim
50 words
The process of claim 1 wherein only a portion of the cooling effect produced by evaporating said throttled condensate in an intermediate cooling stage is employed to absorb heat from and at least partially condense the compressed uncondensed vapor and the remainder is employed to produce an external refrigeration effect.
Claim 13
Dependent Claim
79 words
The process of claim 1 wherein the compressed mixture obtained from the last intermediate cooling stage is divided into first and second streams, throttling said first stream to a low pressure, evaporating said throttled first stream to absorb heat from and sub-cool said second stream, mixing said throttled, evaporated first stream with refrigerant being recycled to the compressor from the final evaporator, throttling said second stream to a lower pressure, and passing said throttled second stream to step (e).
Claim 14
Dependent Claim
117 words
The process of claim 1 wherein said refrigerant mixture further includes a compressor lubricating oil and a separation fluid, said separation fluid having a boiling point which is 35* to 115*F. higher than the highest boiling refrigerant in said refrigerant mixture and being soluble in said lubriCating oil, separating the compressed mixture obtained in step (b) into liquid and vapor phases whereby said lubricating oil and a substantial portion of the separation fluid remains in said liquid phase, throttling said separated oil-laden separation fluid to a lower pressure, mixing said throttled oil-laden separation fluid with refrigerant being recycled to the compressor from the final evaporator and passing said compressed vapor phase to the first intermediate cooling stage.
Claim 15
Dependent Claim
37 words
The process of claim 13 wherein the separated compressed vapor phase is at least partially condensed by heat exchange with said mixture of throttled oil-laden separation fluid and recycled refrigerant prior to said first intermediate cooling stage.
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) | 1976-10-29 | 1977-04-30 | 1977-10-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-10-29 | 1981-04-30 | 1981-10-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-10-29 | 1985-04-30 | 1985-10-30 | $7700.00 | Window Closed / Lapsed |