Patent US5595065A successfully refreshed from Google Patents.
US5595065A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Closed cycle cryogenic refrigeration system with automatic variable flow area throttling device
Assignee: Azenta Inc
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Filing: 1995-07-07
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Granted: 1997-01-21
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Expires: 2015-07-07
Abstract
Abstract An integral combination of expansion valve and evaporator in a cryostat using a single support member. The valve includes two flow orifices, one orifice being used primarily for steady-state operation and the other orifice being used only during cool-down. An actuator having a high coefficient of thermal expansion moves a needle positioned in the cool-down orifice such that a large orifice flow area at the start of cool-down is automatically and continuously reduced as the actuator temperature decreases as refrigerant is throttled through the orifice. Within a range of approximately 30 K from the desired steady-state evaporator temperature, the needle completely blocks the cool-down orifice. Then, refrigerant flows through the steady-state orifice which has a remotely adjustable needle. In the final stage of cool-down, the refrigerant system is entirely controlled by the steady-state orifice and its associated needle. In other embodiments, the steady-state orifice and adjusting needle, are replaced with a fixed restrictor, such as a capillary tube, that is positioned in parallel with the cool-down orifice and needle. The fixed restrictor is sized to satisfy the desired steady-state operating conditions.
Inventors
- 👤 Michael Boiarski
- 👤 Ralph C. Longsworth
- 👤 Boris Yudin
- 👤 Dennis H. Hill
- 👤 Lawrence A. Klusmier
- 👤 Ajay N. Khatri
- 👤 Anthony L. Owoc
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 06:03
CPC Classifications
F; F17; F17C; F17C3/00; F17C3/02; F17C3/08; F17C3/085; F25; F25B; F25B41/00; F25B41/30; F25B41/31; F25B41/325; F25B41/33; F25B41/36; F25B9/00; F25B9/02; G; G05; G05D; G05D23/00; G05D23/01; G05D23/02; G05D23/021; G05D23/022; F17C2205/00; F17C2205/03; F17C2205/0302; F17C2205/0323; F17C2205/0326; F17C2205/0329; F17C2223/00; F17C2223/01; F17C2223/0146; F17C2223/0153; F17C2223/0161; F17C2227/00; F17C2227/03; F17C2227/0337; F17C2227/0341; F17C2227/0353; F17C2227/0355; F17C2250/00; F17C2250/06; F17C2250/0605; F17C2250/0631; F17C2250/0636; F25B2309/00; F25B2309/02; F25B2309/022; F25B2400/00; F25B2400/12
Claims Analysis
Total Claims: 44
Claim 1
Independent Claim
247 words
In a closed cycle cryogenic refrigeration system using a mixed refrigerant, said system including an evaporator operating in a range from 70 K to 150 K for absorbing heat from a load, a refrigerant compressor receiving low pressure refrigerant and compressing said refrigerant to a high pressure, and first heat exchanger means for rejecting heat including compressor heat from said system, and second heat exchanger means for exchanging heat between a flow of low pressure refrigerant leaving said evaporator and entering said compressor, and a flow of high pressure refrigerant leaving said first heat exchanger means, the improvement therein comprising: an automatic restrictor valve for receiving said high pressure refrigerant from said second heat exchanger, means for throttling said refrigerant to reduce pressure and temperature of said refrigerant, and delivering said reduced temperature refrigerant to an inlet of said evaporator, said valve including: a first orifice for refrigerant flow therethrough to throttle said refrigerant and reduce said pressure and temperature; first needle means for obstructing a flow area of said first orifice; an actuator connected to said first needle means, said actuator being responsive to changes in temperature and moving said first needle means to reduce said first orifice flow area when said actuator temperature drops, said first orifice flow area in operation diminishing from a start of cool-down toward a steady-state operating temperature, said first orifice flow area no longer decreasing and remaining substantially constant in a predetermined range of temperature above said steady-state operating temperature.
Claim 2
Dependent Claim
247 words
In a closed cycle cryogenic refrigeration system using a mixed refrigerant, said system including an evaporator operating in a range from 70 K to 150 K for absorbing heat from a load, a refrigerant compressor receiving low pressure refrigerant and compressing said refrigerant to a high pressure, and first heat exchanger means for rejecting heat including compressor heat from said system, and second heat exchanger means for exchanging heat between a flow of low pressure refrigerant leaving said evaporator and entering said compressor, and a flow of high pressure refrigerant leaving said first heat exchanger means, the improvement therein comprising: an automatic restrictor valve for receiving said high pressure refrigerant from said second heat exchanger, means for throttling said refrigerant to reduce pressure and temperature of said refrigerant, and delivering said reduced temperature refrigerant to an inlet of said evaporator, said valve including: a first orifice for refrigerant flow therethrough to throttle said refrigerant and reduce said pressure and temperature; first needle means for obstructing a flow area of said first orifice; an actuator connected to said first needle means, said actuator being responsive to changes in temperature and moving said first needle means to reduce said first orifice flow area when said actuator temperature drops, said first orifice flow area in operation diminishing from a start of cool-down toward a steady-state operating temperature, said first orifice flow area no longer decreasing and remaining substantially constant in a predetermined range of temperature above said steady-state operating temperature.
Claim 3
Dependent Claim
17 words
A restrictor valve as in claim 1, wherein said predetermined range of temperature is approximately 30 K.
Claim 4
Dependent Claim
23 words
A restrictor valve as in claim 1, wherein said actuator is at least one of plastic, metal, bi-metal, and a gas filled bellows.
Claim 5
Dependent Claim
60 words
A restrictor valve as in claim 1, wherein said first orifice flow area in said predetermined range is substantially zero, said first needle means entirely blocking said first orifice, and further comprising: a steady-state refrigerant flow path bypassing said first orifice and said first needle means, said steady-state flow path including one of a fixed restriction and a variable restriction.
Claim 6
Dependent Claim
15 words
A restrictor valve as in claim 4, wherein said fixed restriction is a capillary tube.
Claim 7
Dependent Claim
30 words
A restrictor valve as in claim 4, wherein said variable restriction is a second orifice and a second needle means positioned to obstruct a flow area of said second orifice.
Claim 8
Dependent Claim
44 words
A restrictor valve as in claim 6, wherein said second needle means is adjustable in its setting to vary said flow area of said second orifice, steady-state evaporator temperature being settable by selective positioning of said second needle means relative to said second orifice.
Claim 9
Dependent Claim
23 words
A restrictor valve as in claim 1, further comprising means for remotely controlling relative positions of said first orifice and first needle means.
Claim 10
Dependent Claim
55 words
A restrictor valve as in claim 8, wherein said means for remotely controlling include a valve stem connected to said first needle means via said actuator and threadably engaged with said restrictor valve, said first needle means moving relative to said first orifice to vary said first orifice flow area when said stem is rotated.
Claim 11
Dependent Claim
23 words
A restrictor valve as in claim 6, further comprising means for remotely controlling relative positions of said second orifice and second needle means.
Claim 12
Dependent Claim
52 words
A restrictor valve as in claim 10, wherein said means for remotely controlling include a valve stem connected to said second needle means and threadably engaged with said restrictor valve, said second needle means moving relative to said second orifice to vary said second orifice flow area when said stem is rotated.
Claim 13
Dependent Claim
19 words
A restrictor valve as in claim 11, wherein said threadable engagement is in a cold region of said valve.
Claim 14
Dependent Claim
44 words
A restrictor valve as in claim 11, further comprising a seal between said stem and said valve to prevent refrigerant escape at said stem, said seal being in one of said cold region of said valve and a warm region remote from said valve.
Claim 15
Dependent Claim
247 words
A closed cycle cryogenic refrigeration system using a mixed refrigerant, comprising: an evaporator operating in a range from 70 K to 150 K for absorbing heat from a load; a refrigerant compressor receiving low pressure refrigerant and compressing said refrigerant to a high pressure; first heat exchanger means for rejecting heat including compressor heat from said system; second heat exchanger means for exchanging heat between a flow of low pressure refrigerant leaving said evaporator and entering said compressor, and a flow of high pressure refrigerant leaving said first exchanger means; an automatic restrictor valve for receiving said high pressure refrigerant from said second heat exchanger means, and for throttling said refrigerant to reduce the pressure and temperature of said refrigerant, and for delivering said reduced temperature refrigerant to an inlet of said evaporator, said valve including: a first orifice for refrigerant flow therethrough to throttle said refrigerant and reduce said pressure and temperature; first needle means for obstructing a flow area of said first orifice; an actuator connected to said first needle means, said actuator being responsive to changes in temperature and moving said first needle means to reduce said first orifice flow area when said actuator temperature drops, said actuator being cooled by refrigerant flow, said first orifice flow area in operation diminishing from a start of cool-down toward a steady-state operating temperature, said first orifice flow area no longer decreasing and remaining substantially constant in a predetermined range of temperature above said steady-state operating temperature.
Claim 16
Dependent Claim
247 words
A closed cycle cryogenic refrigeration system using a mixed refrigerant, comprising: an evaporator operating in a range from 70 K to 150 K for absorbing heat from a load; a refrigerant compressor receiving low pressure refrigerant and compressing said refrigerant to a high pressure; first heat exchanger means for rejecting heat including compressor heat from said system; second heat exchanger means for exchanging heat between a flow of low pressure refrigerant leaving said evaporator and entering said compressor, and a flow of high pressure refrigerant leaving said first exchanger means; an automatic restrictor valve for receiving said high pressure refrigerant from said second heat exchanger means, and for throttling said refrigerant to reduce the pressure and temperature of said refrigerant, and for delivering said reduced temperature refrigerant to an inlet of said evaporator, said valve including: a first orifice for refrigerant flow therethrough to throttle said refrigerant and reduce said pressure and temperature; first needle means for obstructing a flow area of said first orifice; an actuator connected to said first needle means, said actuator being responsive to changes in temperature and moving said first needle means to reduce said first orifice flow area when said actuator temperature drops, said actuator being cooled by refrigerant flow, said first orifice flow area in operation diminishing from a start of cool-down toward a steady-state operating temperature, said first orifice flow area no longer decreasing and remaining substantially constant in a predetermined range of temperature above said steady-state operating temperature.
Claim 17
Dependent Claim
17 words
A refrigeration system as in claim 14, wherein said predetermined range of temperature is approximately 30 K.
Claim 18
Dependent Claim
23 words
A refrigeration system as in claim 14, wherein said actuator is at least one of plastic, metal, bi-metal and a gas filled bellows.
Claim 19
Dependent Claim
60 words
A refrigeration system as in claim 14, wherein said first orifice flow area in said predetermined range is substantially zero, said first needle means entirely blocking said first orifice, and further comprising: a steady-state refrigerant flow path bypassing said first orifice and said first needle means, said steady-state flow path including one of a fixed restriction and a variable restriction.
Claim 20
Dependent Claim
15 words
A restrictor valve as in claim 17, wherein said fixed restriction is a capillary tube.
Claim 21
Dependent Claim
30 words
A restrictor valve as in claim 17, wherein said variable restriction is a second orifice and a second needle means positioned to obstruct a flow area of said second orifice.
Claim 22
Dependent Claim
44 words
A restrictor valve as in claim 19, wherein said second needle means is adjustable in its setting to vary said flow area of said second orifice, steady-state evaporator temperature being settable by selective positioning of said second needle means relative to said second orifice.
Claim 23
Dependent Claim
19 words
A refrigeration system as in claim 14, further comprising means for controlling said first orifice and first needle means.
Claim 24
Dependent Claim
54 words
A refrigeration system as in claim 21, wherein said means for controlling include a valve stem connected to said first needle means via said actuator and threadably engaged with said restrictor valve, said first needle means moving relative to said first orifice to vary said first orifice flow area when said stem is rotated.
Claim 25
Dependent Claim
20 words
A refrigeration system as in claim 20, further comprising means for remotely controlling said second orifice and second needle means.
Claim 26
Dependent Claim
52 words
A refrigeration system as in claim 23, wherein said means for remotely controlling include a valve stem connected to said second needle means and threadably engaged with said restrictor valve, said second needle means moving relative to said second orifice to vary said second orifice flow area when said stem is rotated.
Claim 27
Dependent Claim
19 words
A refrigerant system as in claim 24, wherein said threadable engagement is in a cold region of said valve.
Claim 28
Dependent Claim
44 words
A refrigerant system as in claim 24, further comprising a seal between said stem and said valve to prevent refrigerant escape at said stem, said seal being in one of said cold region of said valve and a warm region remote from said valve.
Claim 29
Dependent Claim
177 words
A restrictor valve for operation in a closed cycle cryogenic refrigeration system using a mixed refrigerant, said system operating in a range from 70 K to 150 K for absorbing heat from a load, said restrictor valve comprising: an inlet for receiving high pressure refrigerant; a first orifice for flow of high pressure refrigerant therethrough to throttle said refrigerant and reduce said pressure, said refrigerant becoming cooler as its pressure decreases; first needle means for obstructing a flow area of said first orifice; an actuator connected to first needle means, said actuator being responsive to changes in temperature and moving said first needle means to reduce said first orifice flow area when actuator temperature drops, said actuator being cooled by refrigerant flow, said first orifice flow area in operation diminishing from a start of cool-down toward a steady state operating temperature, said first orifice flow area no longer decreasing and remaining substantially constant in a predetermined range of temperature above a temperature selected as a steady-state operating temperature in said range of 70 K to 150 K.
Claim 30
Dependent Claim
177 words
A restrictor valve for operation in a closed cycle cryogenic refrigeration system using a mixed refrigerant, said system operating in a range from 70 K to 150 K for absorbing heat from a load, said restrictor valve comprising: an inlet for receiving high pressure refrigerant; a first orifice for flow of high pressure refrigerant therethrough to throttle said refrigerant and reduce said pressure, said refrigerant becoming cooler as its pressure decreases; first needle means for obstructing a flow area of said first orifice; an actuator connected to first needle means, said actuator being responsive to changes in temperature and moving said first needle means to reduce said first orifice flow area when actuator temperature drops, said actuator being cooled by refrigerant flow, said first orifice flow area in operation diminishing from a start of cool-down toward a steady state operating temperature, said first orifice flow area no longer decreasing and remaining substantially constant in a predetermined range of temperature above a temperature selected as a steady-state operating temperature in said range of 70 K to 150 K.
Claim 31
Dependent Claim
17 words
A restrictor valve as in claim 27, wherein said predetermined range of temperature is approximately 30 K.
Claim 32
Dependent Claim
23 words
A restrictor valve as in claim 27, wherein said actuator is at least one of plastic, metal, bi-metal, and a gas filled bellows.
Claim 33
Dependent Claim
60 words
A restrictor valve as in claim 27, wherein said first orifice flow area in said predetermined range is substantially zero, said first needle means entirely blocking said first orifice, and further comprising: a steady-state refrigerant flow path bypassing said first orifice and said first needle means, said steady-state flow path including one of a fixed restriction and a variable restriction.
Claim 34
Dependent Claim
15 words
A restrictor valve as in claim 30, wherein said fixed restriction is a capillary tube.
Claim 35
Dependent Claim
30 words
A restrictor valve as in claim 30, wherein said variable restriction is a second orifice and a second needle means positioned to obstruct a flow area of said second orifice.
Claim 36
Dependent Claim
44 words
A restrictor valve as in claim 32, wherein said second needle means is adjustable in its setting to vary said flow area of said second orifice, steady-state evaporator temperature being settable by selective positioning of said second needle means relative to said second orifice.
Claim 37
Dependent Claim
23 words
A restrictor valve as in claim 27, further comprising means for remotely controlling relative positions of said first orifice and first needle means.
Claim 38
Dependent Claim
55 words
A restrictor valve as in claim 34, wherein said means for remotely controlling include a valve stem connected to said first needle means via said actuator and threadably engaged with said restrictor valve, said first needle means moving relative to said first orifice to vary said first orifice flow area when said stem is rotated.
Claim 39
Dependent Claim
23 words
A restrictor valve as in claim 32, further comprising means for remotely controlling relative positions of said second orifice and second needle means.
Claim 40
Dependent Claim
52 words
A restrictor valve as in claim 36, wherein said means for remotely controlling include a valve stem connected to said second needle means and threadably engaged with said restrictor valve, said second needle means moving relative to said second orifice to vary said second orifice flow area when said stem is rotated.
Claim 41
Dependent Claim
19 words
A refrigerant system as in claim 37, wherein said threadable engagement is in a cold region of said valve.
Claim 42
Dependent Claim
44 words
A refrigerant system as in claim 37, further comprising a seal between said stem and said valve to prevent refrigerant escape at said stem, said seal being in one of said cold region of said valve and a warm region remote from said valve.
Claim 43
Dependent Claim
166 words
A restrictor valve for operation in a closed cycle cryogenic refrigeration system using a mixed refrigerant, said system operating in a range from 70 K to 150 K for absorbing heat from a load, said restrictor valve comprising: an inlet for receiving high pressure refrigerant; a first orifice for flow of high pressure refrigerant therethrough to throttle said refrigerant and reduce said pressure, said refrigerant becoming cool as its pressure decreases; first needle means for obstructing a flow area of said first orifice; an actuator connected to said first needle means, said actuator being responsive to changes in temperature and moving said first needle means to reduce said first orifice flow area when actuator temperature drops, said actuator being cooled, said first orifice flow area in operation diminishing from a start of cool-down toward a steady state operating temperature, said first orifice flow area no longer decreasing and remaining substantially constant at a preselected steady-state operating temperature in said range of 70 K to 150 K.
Claim 44
Dependent Claim
166 words
A restrictor valve for operation in a closed cycle cryogenic refrigeration system using a mixed refrigerant, said system operating in a range from 70 K to 150 K for absorbing heat from a load, said restrictor valve comprising: an inlet for receiving high pressure refrigerant; a first orifice for flow of high pressure refrigerant therethrough to throttle said refrigerant and reduce said pressure, said refrigerant becoming cool as its pressure decreases; first needle means for obstructing a flow area of said first orifice; an actuator connected to said first needle means, said actuator being responsive to changes in temperature and moving said first needle means to reduce said first orifice flow area when actuator temperature drops, said actuator being cooled, said first orifice flow area in operation diminishing from a start of cool-down toward a steady state operating temperature, said first orifice flow area no longer decreasing and remaining substantially constant at a preselected steady-state operating temperature in said range of 70 K to 150 K.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2000-01-21 | 2000-07-22 | 2001-01-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2004-01-21 | 2004-07-22 | 2005-01-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2008-01-21 | 2008-07-22 | 2009-01-21 | $7700.00 | Window Closed / Lapsed |