Patent US3986969A successfully refreshed from Google Patents.
US3986969A
Expired / Lapsed
US
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Thixotropic mixture and method of making same
Assignee: University of Delaware
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Filing: 1975-02-06
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Granted: 1976-10-19
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Expires: 1995-02-06
Abstract
Abstract A mixture for the storage of heat energy utilizing a heat of fusion material includes sodium sulfate decahydrate, borax as a nucleating agent, and hydrous magnesium aluminum silicate (attapulgus clay) as a homogenizing agent. This composition maintains the salt-hydrate in suspension during repeated heating and cooling cycles. A method is also disclosed for preparing the mixture which includes the steps of mixing water with the attapulgus clay, adding a nucleating agent to the initial mixture, and mixing the initial mixture, including the nucleating agent, with a heat of fusion material such as sodium sulfate decahydrate.
Inventors
- 👤 Maria Telkes
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 13:38
CPC Classifications
C; C09; C09K; C09K5/00; C09K5/02; C09K5/06; C09K5/063
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
50 words
A mixture for the storage of heat energy utilizing the heat of fusion of the composition comprising: a salt-hydrate having a heat of fusion of more than 50 BTU per pound, a nucleating agent, and a thixotropic agent, said thixotropic agent being an attapulgite-type clay substance that has lath-like particles.
Claim 2
Dependent Claim
50 words
A mixture for the storage of heat energy utilizing the heat of fusion of the composition comprising: a salt-hydrate having a heat of fusion of more than 50 BTU per pound, a nucleating agent, and a thixotropic agent, said thixotropic agent being an attapulgite-type clay substance that has lath-like particles.
Claim 3
Dependent Claim
19 words
A composition according to claim 1 wherein the thixotropic agent is a calcium silicate hydrate finer than 200 mesh.
Claim 4
Dependent Claim
18 words
A composition according to claim 1 wherein said salt-hydrate is a salt-hydrate eutectic for the storage of cold.
Claim 5
Dependent Claim
15 words
A composition according to claim 1 wherein said thixotropic agent is a hydrous magnesium silicate.
Claim 6
Dependent Claim
14 words
A composition according to claim 4 wherein said thixotropic agent includes an aluminum oxide.
Claim 7
Dependent Claim
13 words
A composition according to claim 1 wherein said thixotropic agent is attapulgite clay.
Claim 8
Dependent Claim
32 words
A composition according to claim 1 where said mixture consists of about 56 parts water, 7 to 10 parts attapulgite clay, 3 parts borax, 44 parts sodium sulfate decahydrate, all by weight.
Claim 9
Dependent Claim
25 words
A composition according to claim 1 wherein said lath-like particles are about 1 micron in length, 0.01 microns in width, and 50-100 Anstroms in thickness.
Claim 10
Dependent Claim
19 words
A composition according to claim 1 wherein said lath-like particles have a length to thickness ratio of about 1000.
Claim 11
Dependent Claim
19 words
A composition according to claim 1 wherein said lath-like particles have a length to width ratio of about 100.
Claim 12
Dependent Claim
21 words
A composition according to claim 1 wherein said salt-hydrate has a heat of fusion or more than 100 BTU per pound.
Claim 13
Independent Claim
68 words
A method of preparing a mixture for the storage of heat energy comprising the steps of: mixing water with an attapulgite-type clay substance having lath-like particles which exhibits thixotropy to form an initial mixture, with said substance dispersed in water, and mixing said initial mixture with a nucleating agent and a salt to maintain a salt-hydrate having a heat of fusion of more than 50 BTU per pound.
Claim 14
Independent Claim
68 words
A method of preparing a mixture for the storage of heat energy comprising the steps of: mixing water with an attapulgite-type clay substance having lath-like particles which exhibits thixotropy to form an initial mixture, with said substance dispersed in water, and mixing said initial mixture with a nucleating agent and a salt to maintain a salt-hydrate having a heat of fusion of more than 50 BTU per pound.
Claim 15
Dependent Claim
15 words
A method according to claim 12 wherein said clay-type substance is a hydrous magnesium silicate.
Claim 16
Dependent Claim
16 words
A method according to claim 12 wherein said clay-type substance is a hydrous magnesium aluminum silicate.
Claim 17
Dependent Claim
24 words
A method according to claim 12 wherein a dispersant is initially dissolved in said water prior to mixing the water with said clay-type substance.
Claim 18
Dependent Claim
13 words
A method according to claim 12 wherein said clay-type substance is attapulgite clay.
Claim 19
Dependent Claim
21 words
A method according to claim 12 wherein said salt-hydrate has a heat of fusion of more than 100 BTU per pound.
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) | 1979-10-19 | 1980-04-19 | 1980-10-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-10-19 | 1984-04-19 | 1984-10-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-10-19 | 1988-04-19 | 1988-10-19 | $7700.00 | Window Closed / Lapsed |