US4299704A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for removing polychlorinated biphenyls from contaminated transformer dielectric liquid
Assignee: General Electric Co
•
Filing: 1980-05-19
•
Granted: 1981-11-10
•
Expires: 2000-05-19
Abstract
Abstract Immiscibility between polychlorinated biphenyl (PCB) substances and retrofilled non PCB transformer dielectrics allows for the mechanical separation of the PCB substances from the retrofilled dielectrics. Sedimentation, filtration and centrifugation can be employed in the separation process.
Inventors
- 👤 Stephen D. Foss
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 23:48
CPC Classifications
H; H01; H01F; H01F27/00; H01F27/08; H01F27/10; H01F27/12; H01F27/14; H01B; H01B3/00; H01B3/18; H01B3/20; H01B3/24; C; C10; C10G; C10G2400/00; C10G2400/10; Y; Y10; Y10S; Y10S210/00; Y10S210/902; Y10S210/908; Y10S210/909
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
101 words
A method for removing polychlorinated biphenyl from transformer windings comprising the steps of: heating a transformer winding containing polychlorinated biphenyl in a transformer containing silicone fluid dielectric to a temperature range of 70° C. to 90° C. to promote the removal of said biphenyl from said winding and to increase the solubility of said biphenyl within said silicone fluid; removing a portion of said heated biphenyl-silicone fluid mixture from said transformer; cooling said removed biphenyl-silicone fluid mixture to less than 50° C. to cause some of said biphenyl to separate from said mixture; and removing said separated biphenyl from said mixture.
Claim 2
Independent Claim
101 words
A method for removing polychlorinated biphenyl from transformer windings comprising the steps of: heating a transformer winding containing polychlorinated biphenyl in a transformer containing silicone fluid dielectric to a temperature range of 70° C. to 90° C. to promote the removal of said biphenyl from said winding and to increase the solubility of said biphenyl within said silicone fluid; removing a portion of said heated biphenyl-silicone fluid mixture from said transformer; cooling said removed biphenyl-silicone fluid mixture to less than 50° C. to cause some of said biphenyl to separate from said mixture; and removing said separated biphenyl from said mixture.
Claim 3
Dependent Claim
18 words
The method of claim 1 wherein said polychlorinated biphenyl is separated from said mixture by means of gravity.
Claim 4
Dependent Claim
19 words
The method of claim 1 wherein said polychlorinated biphenyl is removed from said mixture by means of a centrifuge.
Claim 5
Dependent Claim
19 words
The method of claim 1 wherein said polychlorinated biphenyl is removed from said mixture by means of a filter.
Claim 6
Dependent Claim
34 words
The method of claim 1 wherein said first temperature provides a single-phase polychlorinated biphenyl dielectric liquid mixture and wherein said second temperature provides a two-phase dielectric liquid rich mixture and polychlorinated biphenyl rich mixture.
Claim 7
Dependent Claim
14 words
The method of claim 1 wherein said dielectric liquid mixture comprises silicone dielectric fluid.
Claim 8
Dependent Claim
34 words
The method of claim 1 wherein said part of said polychlorinated biphenyl and dielectric liquid mixture is removed to a separate cooling tank for cooling and settling said polychlorinated biphenyl from said dielectric liquid.
Claim 9
Independent Claim
89 words
A method for removing polychlorinated biphenyl from transformer dielectrics containing polychlorinated biphenyl as a contaminant comprising the steps of: attaching a cooling source to a transformer tank containing a mixture of polychlorinated biphenyl and silicone dielectric fluid at an elevated temperature of from 70° C. to 90° C.; removing a part of said mixture from said transformer to said cooling source for cooling said mixture to less than 50° C. for removing some of said polychlorinated biphenyl from said mixture; and extracting said polychlorinated biphenyl from said cooled mixture.
Claim 10
Independent Claim
89 words
A method for removing polychlorinated biphenyl from transformer dielectrics containing polychlorinated biphenyl as a contaminant comprising the steps of: attaching a cooling source to a transformer tank containing a mixture of polychlorinated biphenyl and silicone dielectric fluid at an elevated temperature of from 70° C. to 90° C.; removing a part of said mixture from said transformer to said cooling source for cooling said mixture to less than 50° C. for removing some of said polychlorinated biphenyl from said mixture; and extracting said polychlorinated biphenyl from said cooled mixture.
Claim 11
Dependent Claim
39 words
The method of claim 8 wherein said step of cooling said mixture includes the steps of forming a silicone rich phase and a polychlorinated biphenyl rich phase of said mixture and extracting said polychlorinated biphenyl phase from said mixture.
Claim 12
Dependent Claim
29 words
The method of claim 8 wherein said cooling source includes a sedimentation tank for providing the separation of said polychlorinated biphenyl rich phase to the bottom of said tank.
Claim 13
Dependent Claim
26 words
The method of claim 8 further including the steps of providing centrifuge means to said cooling source and separating said polychlorinated biphenyl by centrifuging said mixture.
Claim 14
Dependent Claim
28 words
The method of claim 8 further including the steps of providing filter means to said cooling source for separating polychlorinated biphenyl from said mixture by means of filtration.
Claim 15
Independent Claim
76 words
A method of removing polychlorinated biphenyl from silicone transformer dielectric liquids comprising: heating said liquids to from 70° C. to 90° C. to enhance the solubility between said biphenyl and said liquid; cooling a mixture of silicone dielectric liquid and polychlorinated biphenyl to less than 50° C. to form a two-phase separation consisting of a silicone rich phase and a polychlorinated biphenyl rich phase; and separating said polychlorinated biphenyl rich phase from said silicone rich phase.
Claim 16
Independent Claim
76 words
A method of removing polychlorinated biphenyl from silicone transformer dielectric liquids comprising: heating said liquids to from 70° C. to 90° C. to enhance the solubility between said biphenyl and said liquid; cooling a mixture of silicone dielectric liquid and polychlorinated biphenyl to less than 50° C. to form a two-phase separation consisting of a silicone rich phase and a polychlorinated biphenyl rich phase; and separating said polychlorinated biphenyl rich phase from said silicone rich phase.
References Cited (Backward Citations)
US2191490A
Cited
US3731802A
Cited
US3838056A
Cited
US4001118A
Cited
US4127598A
Cited
US4127598B1
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1984-11-09 | 1985-05-11 | 1985-11-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-11-09 | 1989-05-11 | 1989-11-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-11-09 | 1993-05-11 | 1993-11-10 | $7700.00 | Window Closed / Lapsed |