US3590597A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Cooling apparatus employing the joule-thomson effect
Assignee: The Hymatic Engineering Co Ltd
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Filing: 1969-08-06
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Granted: 1971-07-06
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Expires: 1989-08-06
Abstract
Abstract The second stage in a miniature cryogenic two-stage cooler, working on the Joule-Thomson principle, is supplied with gaseous refrigerant which passes from a supply under pressure through one path of a tubular heat exchanger, to an expansion nozzle, after which the expanded gas returns through the other path of the heat exchanger to cool the incoming second stage gas. In the first stage, a precooling refrigerant in liquid form is supplied to a metering nozzle which, having no heat exchanger, is accommodated within the heat exchanger of the second stage, and this refrigerant evaporates to precool the second stage refrigerant. The nozzle of each stage is automatically controlled to vary the flow of refrigerant in accordance with the demand for cooling.
Inventors
- 👤 David Neil Campbell
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 16:08
CPC Classifications
F; F25; F25B; F25B9/00; F25B9/02; F25B2309/00; F25B2309/02; F25B2309/022; F25B2309/023
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
165 words
Cooling apparatus of the type in which cooling is produced by expansion, through a nozzle, of a refrigerant in gaseous form under pressure, which before expansion at the nozzle is at a temperature below its inversion temperature, including two stages in the second of which a second stage refrigerant from a supply in gaseous form is passed through one path of a heat exchanger, expanded through an expansion nozzle and passed back through the other path of the heat exchanger to cool the incoming second stage refrigerant, a precooling first stage in which a precooling refrigerant is supplied in liquid form under pressure through a metering nozzle to a space at reduced pressure where it evaporates to cool the second stage refrigerant before the latter passes through the heat exchanger, and means for automatically controlling the effective area of the nozzle of each stage so that the amount of refrigerant flowing through each nozzle may be governed by the requirement of cooling at that stage.
Claim 2
Dependent Claim
165 words
Cooling apparatus of the type in which cooling is produced by expansion, through a nozzle, of a refrigerant in gaseous form under pressure, which before expansion at the nozzle is at a temperature below its inversion temperature, including two stages in the second of which a second stage refrigerant from a supply in gaseous form is passed through one path of a heat exchanger, expanded through an expansion nozzle and passed back through the other path of the heat exchanger to cool the incoming second stage refrigerant, a precooling first stage in which a precooling refrigerant is supplied in liquid form under pressure through a metering nozzle to a space at reduced pressure where it evaporates to cool the second stage refrigerant before the latter passes through the heat exchanger, and means for automatically controlling the effective area of the nozzle of each stage so that the amount of refrigerant flowing through each nozzle may be governed by the requirement of cooling at that stage.
Claim 3
Dependent Claim
72 words
Cooling apparatus as claimed in claim 1 in which the apparatus is generally of tubular form, the heat exchanger comprising a finned tube wound to helical form with the second stage refrigerant flowing through it in one direction and past its outside in the opposite direction, the second stage expansion nozzle being at the cold end of the heat exchanger while the first stage metering nozzle is enclosed within its warm end.
Claim 4
Dependent Claim
53 words
Cooling apparatus as claimed in claim 2 in which the second stage expansion nozzle includes a needle valve controlled by a bellows the pressure upon which is determined by said automatic control means which includes a sensor comprising a vapor bulb with an extended tail extending down to a pool of liquefied refrigerant.
Claim 5
Dependent Claim
78 words
Cooling apparatus as claimed in claim 3 in which the first stage metering nozzle includes a needle valve controlled by a bellows the pressure upon which is determined by said automatic control means which also includes a sensor bulb secured to a curved plate fitting within the body of the heat exchanger at about the level of the metering nozzle so as to respond primarily to the temperature of the heat exchanger at that part of the apparatus.
Claim 6
Dependent Claim
85 words
Cooling apparatus as claimed in claim 4 in which a cup is secured to the inside of the body of the heat exchanger, just below the metering nozzle, to collect liquid refrigerant formed by the first stage refrigerant, and at the corresponding part of the length of the heat exchanger the helical finned tube is not finned and is soldered to the outer surface of the heat exchanger tube so as to transmit heat from the second stage refrigerant in the cup within the body.
Claim 7
Dependent Claim
22 words
Cooling apparatus as claimed in claim 5 wherein the refrigerant is Freon in liquid form supplied under pressure and at atmospheric temperature.
References Cited (Backward Citations)
US3431750A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-07-05 | 1975-01-04 | 1975-07-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-07-05 | 1979-01-04 | 1979-07-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-07-05 | 1983-01-04 | 1983-07-06 | $7700.00 | Window Closed / Lapsed |