US4642994A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Magnetic refrigeration apparatus with heat pipes
Assignee: United States Department of Energy
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Filing: 1985-10-25
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Granted: 1987-02-17
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Expires: 2005-10-25
Abstract
Abstract A magnetic refrigerator operating in the 4 to 20 K range utilizes heat pipes to transfer heat to and from the magnetic material at the appropriate points during the material's movement. In one embodiment circular disks of magnetic material can be interleaved with the ends of the heat pipes. In another embodiment a mass of magnetic material reciprocatingly moves between the end of the heat pipe of pipes that transmits heat from the object of cooling to the magnetic material and the end of the heat pipe or pipes that transmits heat from the magnetic material to a heat sink.
Inventors
- 👤 John A. Barclay
- 👤 F. Coyne Prenger, Jr.
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 12:19
CPC Classifications
F; F25; F25B; F25B21/00; F25B2321/00; F25B2321/002; F25B2321/0021; Y; Y02; Y02B; Y02B30/00; Y10; Y10S; Y10S505/00; Y10S505/825; Y10S505/888; Y10S505/89
Claims Analysis
Total Claims: 24
Claim 1
Independent Claim
166 words
An about 4 to about 20 K. refrigeration apparatus comprising: a magnetic field generating means; a fluid contactable magnetic material interacting with the magnetic field produced by said magnetic field generating means so as to be subjected to a cyclically time varying magnetic field; a fluid effective to transfer heat at temperatures between about 4 and about 20 K.; an external heat sink; and at least two directional heat pipes, one such pipe disposed between said fluid and the object of cooling whereby heat from the object of cooling is transmitted through said fluid to said magnetic material when said magnetic material absorbs heat, and another such pipe disposed between said fluid and said external heat sink whereby heat from said magnetic material when said magnetic material is rejecting heat is transmitted through said fluid to said external heat sink, and also whereby the heat from the hot ends of said directional heat pipes is minimally transmitted to the cold ends of said directional heat pipes.
Claim 2
Dependent Claim
166 words
An about 4 to about 20 K. refrigeration apparatus comprising: a magnetic field generating means; a fluid contactable magnetic material interacting with the magnetic field produced by said magnetic field generating means so as to be subjected to a cyclically time varying magnetic field; a fluid effective to transfer heat at temperatures between about 4 and about 20 K.; an external heat sink; and at least two directional heat pipes, one such pipe disposed between said fluid and the object of cooling whereby heat from the object of cooling is transmitted through said fluid to said magnetic material when said magnetic material absorbs heat, and another such pipe disposed between said fluid and said external heat sink whereby heat from said magnetic material when said magnetic material is rejecting heat is transmitted through said fluid to said external heat sink, and also whereby the heat from the hot ends of said directional heat pipes is minimally transmitted to the cold ends of said directional heat pipes.
Claim 3
Dependent Claim
36 words
The refrigeration apparatus of claim 1 wherein said magnetic field generating means is moved by a drive means in a cyclic manner to vary the position of the magnetic field in relation to said magnetic material.
Claim 4
Dependent Claim
34 words
The refrigeration apparatus of claim 1 wherein said magnetic material is moved by a drive means in a cyclic manner to vary the position of said magnetic material in relation to the magnetic field.
Claim 5
Dependent Claim
16 words
The refrigeration apparatus of claim 1 wherein said magnetic field is varied in strength through time.
Claim 6
Dependent Claim
16 words
The refrigeration apparatus of claim 1 wherein said magnetic field generating means is a superconducting magnet.
Claim 7
Dependent Claim
29 words
The refrigeration apparatus of claim 5 wherein said superconducting magnets are made with Nb 3 Sn and are maintained at superconducting temperatures by the cooling of said refrigeration apparatus.
Claim 8
Dependent Claim
16 words
The refrigeration apparatus of claim 1 wherein said magnetic field generating means is a permanent magnet.
Claim 9
Dependent Claim
18 words
The refrigeration apparatus of claim 1 wherein said magnetic material is in the form of a rotating wheel.
Claim 10
Dependent Claim
20 words
The refrigeration apparatus of claim 8 wherein said fluid and said magnetic material is contained in a hermetically sealed container.
Claim 11
Dependent Claim
19 words
The refrigeration apparatus of claim 8 wherein said heat pipes are disposed both above and below said rotating wheel.
Claim 12
Dependent Claim
36 words
The refrigeration apparatus of claim 8 wherein said rotating wheel is segmented into disks sufficiently spaced apart to allow said ends of the directional heat pipes to interleave, but not contact, the disks of magnetic material.
Claim 13
Dependent Claim
23 words
The refrigeration apparatus of claim 11 wherein a set of directional heat pipes is interleaved with more than two disks of magnetic material.
Claim 14
Dependent Claim
25 words
The refrigeration apparatus of claim 11 wherein said disks of magnetic material are spaced apart vertically but are joined together at a radially inward position.
Claim 15
Dependent Claim
34 words
The refrigeration apparatus of claim 11 wherein said disks are disposed vertically and are spaced apart horizontally, but are joined together at the face opposite from the direction of entry of said heat pipes.
Claim 16
Dependent Claim
25 words
The refrigeration apparatus of claim 1 wherein said directional heat pipes are disposed in tubular envelopes which are composed of a high thermal conductivity material.
Claim 17
Dependent Claim
25 words
The refrigeration apparatus of claim 15 wherein said magnetic material is disposed in a reciprocating mass that surrounds but does not touch said tubular envelopes.
Claim 18
Dependent Claim
18 words
The refrigeration apparatus of claim 16 wherein thermal regeneration is achieved between said magnetic material and said fluid.
Claim 19
Dependent Claim
20 words
The refrigeration apparatus of claim 15 wherein said fluid and said magnetic material are contained in a hermetically sealed container.
Claim 20
Dependent Claim
22 words
The refrigeration apparatus of claim 18 wherein said magnetic material is moved by a cable which is driven by a indirect coupler.
Claim 21
Dependent Claim
14 words
The refrigeration apparatus of claim 19 wherein said indirect coupler is a magnetic coupler.
Claim 22
Dependent Claim
12 words
The refrigeration apparatus of claim 1 wherein said fluid is gaseous helium.
Claim 23
Dependent Claim
39 words
The refrigeration apparatus of claim 1 wherein said directional heat pipe disposed between said fluid and the object of cooling contains helium and said another such heat pipe disposed between said fluid and said external heat sink contains hydrogen.
Claim 24
Dependent Claim
38 words
The refrigeration apparatus of claim 1 wherein a set of heat pipes is disposed between said fluid and the object of cooling and another set of heat pipes is disposed between said fluid and said external heat sink.
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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) | 1990-02-16 | 1990-08-18 | 1991-02-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-02-16 | 1994-08-18 | 1995-02-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-02-16 | 1998-08-18 | 1999-02-17 | $7700.00 | Window Closed / Lapsed |