Patent US4793940A successfully refreshed from Google Patents.
US4793940A
Expired / Lapsed
US
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Absorbent composition for refrigeration and heating systems
Assignee: Ben Gurion University of the Negev Research and Development Authority Ltd
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Filing: 1988-02-11
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Granted: 1988-12-27
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Expires: 2008-02-11
Abstract
Abstract The invention provides a working fluid for an absorption refrigeration, cooling or heating system comprising a mixture of dimethyl formamide and N-methyl-2-pyrrolidone as the absorbent therein.
Inventors
- 👤 Irena Borde
- 👤 Michael Jelinek
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 05:55
CPC Classifications
C; C09; C09K; C09K5/00; C09K5/02; C09K5/04; C09K5/047
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
30 words
A working fluid for an absorption refrigeration system comprising a mixture of about 30-70 w/w% dimethyl formamide and about 70-30 w/w% N-methyl-2-pyrrolidone as the absorbent therein, and difluoromonochloromethane as refrigerant.
Claim 2
Dependent Claim
30 words
A working fluid for an absorption refrigeration system comprising a mixture of about 30-70 w/w% dimethyl formamide and about 70-30 w/w% N-methyl-2-pyrrolidone as the absorbent therein, and difluoromonochloromethane as refrigerant.
Claim 3
Dependent Claim
33 words
A working fluid for an absorption refrigeration cooling or heating system comprising a mixture of about 40-60 w/w% dimethyl formamide and about 60-40 w/w% N-methyl-2-pyrrolidone as the absorbent therein, and difluoromonochloromethane as refrigerant.
Claim 4
Dependent Claim
33 words
A working fluid for an absorption refrigeration cooling or heating system comprising a mixture of about 40-60 w/w% dimethyl formamide and about 60-40 w/w% N-methyl-2-pyrrolidone as the absorbent therein, and difluoromonochloromethane as refrigerant.
References Cited (Backward Citations)
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US4557850A
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US4413479A
Cited
JPS5861172A
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EP0124079A2
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JPS6040183A
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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) | 1991-12-27 | 1992-06-27 | 1992-12-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-12-27 | 1996-06-27 | 1996-12-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-12-27 | 2000-06-27 | 2000-12-27 | $7700.00 | Window Closed / Lapsed |