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EP0447861A2 Expired / Lapsed EP ⏱️ 0.0 years remaining

Two-stage Joule-Thomson cryostat with gas supply management system, and uses thereof

Assignee: Raytheon Co
•
Filing: 1991-03-01
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Granted: —
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Expires: 2011-03-01
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Abstract

Abstract A two-stage Joule-Thomson cryostat (10) has a first-stage cryostat (12) with a helical-coil heat exchanger (14) and an isenthalpic gas expansion orifice (20) that discharges a mixture of cooled gas and cryogenic liquid into a liquid cryogen plenum (26). A second-stage cryostat (30) with a helical coil heat exchanger (32), wound to a larger diameter than the first-stage heat exchanger coil (14), is wound around and in thermal contact with the liquid cryogen plenum (26). This arrangement achieves a high degree of interstage heat transfer and cooling of the gas flowing in the second-stage heat exchanger coil (32) by the liquid cryogen in the first-stage liquid cryogen plenum (26). In operation, a gas flow management system (60), designed for rapid cooldown, initially passes a first gas of high specific refrigerating capacity through both stages (12 and 30). When the stages and structure are sufficiently cooled to the near-vicinity of the normal boiling temperature of the first gas, the flow of the first gas through the second-stage cryostat (30) is discontinued, and a flow of a second gas of lower normal boiling temperature than the first gas is passed through the second-stage cryostat (30). The flow of the first gas continues through the first-stage cryostat (30).

Inventors

  • 👤 Matthew M. Skertic
  • 👤 Joseph L. Hlava

Bibliographic Details

Application Number —
Jurisdiction EP
Data Source google_patents
Last Synchronized 2026-10-26 12:49
CPC Classifications
F; F42; F42B; F42B15/00; F42B15/34; F25; F25B; F25B9/00; F25B9/02; F25B9/10; F25B2309/00; F25B2309/02; F25B2309/023; F25D; F25D2400/00; F25D2400/28

Claims Analysis

Total Claims: 27
Claim 1
Independent Claim 156 words
A cooling apparatus, comprising: a first-stage cryostat having a first-stage heat exchanger coil of tubing, a first-stage Joule-Thomson orifice at a cold end of the first stage heat exchanger coil of tubing, and a liquid cryogen plenum at the cold end of the heat exchanger coil in which cooled and liquefied gas expanded through the orifice is received; and a second-stage cryostat having a thermally conducting second-stage support mandrel with an inner dimension greater than the outer dimension of the first-stage heat exchanger coil of tubing and overlying the first-stage heat exchanger coil of tubing, a second-stage heat exchanger coil of tubing wound upon the second-stage support mandrel, the second-stage heat exchanger coal of tubing extending beyond the liquid cryogen plenum and including a plurality of intercooler turns wound onto, and in thermal communication with, the liquid cryogen plenum, and a second-stage Joule-Thomson orifice at a cold end of the first-stage heat exchanger coil of tubing.
Claim 2
Dependent Claim 16 words
The apparatus of claim 1, wherein the heat exchanger tubing of the first-stage coil is finned.
Claim 3
Dependent Claim 24 words
The apparatus of claim 1, wherein the heat exchanger tubing of the second-stage coil is finned, except for the intercooler portion, which is unfinned.
Claim 4
Dependent Claim 28 words
The apparatus of claim 1, wherein the first-stage heat exchanger coil of tubing and the second-stage heat exchanger coil of tubing are each wound into a helical pattern.
Claim 5
Dependent Claim 20 words
The apparatus of claim 1, further including means for introducing gases into the first-stage cryostat and into the second-stage cryostat.
Claim 6
Dependent Claim 27 words
The apparatus of claim 5, wherein the means for introducing includes means for controlling the flow of gases into the first-stage cryostat and into the second-stage cryostat.
Claim 7
Dependent Claim 54 words
The apparatus of claim 1, further including a gas flow system controllable to provide a first gas to the first-stage cryostat and the second-stage cryostat under an initial operating condition, and controllable to provide the first gas to the first-stage cryostat and a second gas to the second-stage cryostat under a final operating condition.
Claim 8
Dependent Claim 16 words
The apparatus of claim 1, further including a thermal cooling load having a temperature sensor therein.
Claim 9
Dependent Claim 25 words
The apparatus of claim 8, wherein the means for controlling includes a temperature sensor that provides a control signal for controlling the flow of gases.
Claim 10
Dependent Claim 145 words
A cooling apparatus, comprising: a two-stage cryostat having a first-stage cryostat with a first heat exchanger coil and a first gas expansion orifice, and a second-stage cryostat with a second heat exchanger coil and a second gas expansion orifice; and a gas supply management system for supplying pressurized gas to the cryostat, the gas supply system including a first supply source of a first pressurized gas, a first gas supply line from the first supply source to the first-stage cryostat, a first gas supply valve in the first gas supply line, a second supply source of a second pressurized gas, a second gas supply line from the second supply source to the second-stage cryostat, a second gas supply valve in the second gas supply line, and means for controllably permitting the first pressurized gas to flow from the first supply source to the second-stage cryostat.
Claim 11
Dependent Claim 38 words
The apparatus of claim 10, wherein the means for controllably permitting includes a gas interconnect line from the first gas supply line to the second gas supply line, and a gas interconnect valve in the gas interconnect line.
Claim 12
Dependent Claim 79 words
The apparatus of claim 10, wherein the means for controllably permitting includes means for permitting the first pressurized gas to flow from the first supply source to the second-stage cryostat when no second gas is flowing from the second gas supply source to the second-stage cryostat, but not permitting the first gas to flow from the first supply source to the second-stage cryostat when the second gas is flowing from the second gas supply source to the second-stage cryostat.
Claim 13
Dependent Claim 37 words
The apparatus of claim 10, wherein the means for controllably permitting includes a normally open gas interconnect valve between the first gas source and the second-stage cryostat which closes when the second gas supply valve is opened.
Claim 14
Dependent Claim 35 words
The apparatus of claim 10, wherein the means for controllably permitting includes a check valve that permits gas to flow from the first gas source to the second-stage cryostat but not in the opposite direction.
Claim 15
Dependent Claim 23 words
The apparatus of claim 10, wherein the means for controllably permitting includes a temperature sensor that senses the temperature of a cooling load.
Claim 16
Dependent Claim 14 words
The apparatus of claim 10, wherein the means for controllably permitting includes a controller.
Claim 17
Dependent Claim 19 words
The apparatus of claim 10, wherein the first gas is selected from the group consisting of argon and freon-14.
Claim 18
Dependent Claim 24 words
The apparatus of claim 10, wherein the second gas is selected from the group consisting of nitrogen and a mixture of nitrogen and neon.
Claim 19
Dependent Claim 164 words
The apparatus of claim 10, wherein the two-stage cryostat includes a first-stage cryostat having a first-stage helical heat exchanger coil of tubing, a first-stage orifice at a cold end of the first stage helical heat exchanger coil of tubing, and a liquid cryogen plenum at the cold end of the first-stage helical coil in which cooled and liquefied gas expanded through the orifice is received; and a second-stage cryostat having a thermally conducting cylindrical second-stage support mandrel with an inner diameter greater than the outer diameter of the first-stage helical heat exchanger coil of tubing and overlying the first-stage helical heat exchanger coil of tubing, a second-stage helical heat exchanger coil of tubing wound upon the cylindrical second-stage support mandrel, the second-stage helical coil of tubing extending beyond the liquid cryogen plenum and including a plurality of intercooler turns wound and soldered onto the liquid cryogen plenum, and a second-stage orifice at a cold end of the first-stage helical heat exchanger coil of tubing.
Claim 20
Dependent Claim 134 words
A process for rapidly cooling a thermal cooling load to an operating temperature, comprising the steps of: furnishing a two-stage cryostat having a first-stage cryostat and a second-stage cryostat; passing a first gas through the first-stage cryostat and the second-stage cryostat to cool the thermal cooling load to an intermediate temperature less than the ambient temperature but greater than the operating temperature; discontinuing the flow of the first gas through the second-stage cryostat but continuing the flow of the first gas through the first-stage cryostat; and passing a second gas through the second-stage cryostat, after the flow of the first gas through the second-stage cryostat is discontinued, the first gas having a specific refrigerating capacity greater than the second gas, but the second gas having a normal boiling temperature less than the first gas.
Claim 21
Dependent Claim 19 words
The process of claim 20, wherein the first gas is selected from the group consisting of argon and freon-14.
Claim 22
Dependent Claim 24 words
The process of claim 20, wherein the second gas is selected from the group consisting of nitrogen and a mixture of nitrogen and neon.
Claim 23
Dependent Claim 24 words
The process of claim 20, wherein the step of discontinuing is performed when the thermal cooling load has been cooled to a preselected temperature.
Claim 24
Dependent Claim 153 words
A detector system, comprising: a two-stage cryostat having a first-stage cryostat with a first heat exchanger coil and a first gas expansion orifice, and a second-stage cryostat with a second heat exchanger coil and a second gas expansion orifice; a gas supply management system for supplying pressurized gas to the cryostat, the gas supply system including a first supply source o a first pressurized gas, a first gas supply line from the first supply source to the first-stage cryostat, a first gas supply valve in the first gas supply line, a second supply source of a second pressurized gas, a second gas supply line from the second supply source to the second-stage cryostat, a second gas supply valve in the second gas supply line, and means for controllably permitting the first pressurized gas to flow from the first supply source to the second-stage cryostat; and a sensor in thermal contact with the cryostat.
Claim 25
Dependent Claim 166 words
A detector system, comprising: a first-stage cryostat having a first-stage heat exchanger coil of tubing, a first-stage Joule-Thomson orifice at a cold end of the first stage heat exchanger coil of tubing, and a liquid cryogen plenum at the cold end of the heat exchanger coil in which cooled and liquefied gas expanded through the orifice is received; a second-stage cryostat having a thermally conducting cylindrical second-stage support mandrel with an inner dimension greater than the outer dimension of the first-stage heat exchanger coil of tubing and overlying the first-stage heat exchanger coil of tubing, a second-stage heat exchanger coil of tubing wound upon the second-stage support mandrel, the second-stage heat exchanger coil of tubing extending beyond the liquid cryogen plenum and including a plurality of intercooler turns wound onto, and in thermal communication with, the liquid cryogen plenum, and a second-stage Joule-Thomson orifice at a cold end of the first-stage heat exchanger coil of tubing; and a sensor in thermal contact with the second-stage cryostat.
Claim 26
Dependent Claim 186 words
A missile having an infrared detector, comprising: a missile having a control system that receives an electrical signal from an infrared sensor; a two-stage cryostat having a first-stage cryostat with a first heat exchanger coil and a first gas expansion orifice, and a second-stage cryostat with a second heat exchanger coil and a second gas expansion orifice; a gas supply management system for supplying pressurized gas to the cryostat, the gas supply system including a first supply source of a first pressurized gas, a first gas supply line from the first supply source to the first-stage cryostat, a first gas supply valve in the first gas supply line, a second supply source of a second pressurized gas, a second gas supply line from the second supply source to the second-stage cryostat, a second gas supply valve in the second gas supply line, and means for controllably permitting the first pressurized gas to flow from the first supply source to the second-stage cryostat; and an infrared sensor in thermal contact with the cryostat, the infrared sensor providing an electrical signal to the control system of the missile.
Claim 27
Dependent Claim 199 words
A missile having an infrared detector, comprising: a missile having a control system that receives an electrical signal from an infrared sensor; a first-stage cryostat having a first-stage heat exchanger coil of tubing, a first-stage Joule-Thomson orifice at a cold end of the first stage heat exchanger coil of tubing, and a liquid cryogen plenum at the cold end of the heat exchanger coil in which cooled and liquefied gas expanded through the orifice is received; a second-stage cryostat having a thermally conducting cylindrical second-stage support mandrel with an inner dimension greater than the outer dimension of the first-stage heat exchanger coil of tubing and overlying the first-stage heat exchanger coil of tubing, a second-stage heat exchanger coil of tubing wound upon the second-stage support mandrel, the second-stage heat exchanger coil of tubing extending beyond the liquid cryogen plenum and including a plurality of intercooler turns wound onto, and in thermal communication with, the liquid cryogen plenum, and a second-stage Joule-Thomson orifice at a cold end of the first-stage heat exchanger coil of tubing; and an infrared sensor in thermal contact with the second-stage cryostat, the infrared sensor providing an electrical signal to the control system of the missile.

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