US4139441A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electrofiltration with bi-directional potential pretreatment
Assignee: Chevron USA Inc
•
Filing: 1978-02-10
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Granted: 1979-02-13
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Expires: 1998-02-10
Abstract
Abstract Electrofiltration, in which solids are removed from a liquid by adherence to surfaces of bodies maintained in an electrostatic field when the liquid is passed through the field, is improved by subjecting the liquid to pretreatment with an electrostatic field of oscillating intensity, especially a field of oscillating alternating polarity.
Inventors
- 👤 Phillip R. Bose
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 23:11
CPC Classifications
B; B03; B03C; B03C5/00; B03C5/02; B03C5/022; B03C5/024; B01; B01D; B01D35/00; B01D35/06
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
92 words
In a method for separating subdivided solids from a liquid having a low electrical conductivity by passing a mixture of the liquid and the solids through a separation zone, subjecting the mixture to an electrostatic field of unidirectional polarity in the separation zone whereby said solids adhere to a surface of at least one solid body in the separation zone, and recovering the liquid from the separation zone, the improvement comprising: subjecting said mixture to at least one electrostatic field of oscillating intensity before subjecting said mixture to said unidirectional electrostatic field.
Claim 2
Dependent Claim
92 words
In a method for separating subdivided solids from a liquid having a low electrical conductivity by passing a mixture of the liquid and the solids through a separation zone, subjecting the mixture to an electrostatic field of unidirectional polarity in the separation zone whereby said solids adhere to a surface of at least one solid body in the separation zone, and recovering the liquid from the separation zone, the improvement comprising: subjecting said mixture to at least one electrostatic field of oscillating intensity before subjecting said mixture to said unidirectional electrostatic field.
Claim 3
Dependent Claim
26 words
An improved method according to claim 1 wherein said field of oscillating intensity potential is provided by potential resulting from half-wave rectification of alternating polarity potential.
Claim 4
Dependent Claim
93 words
In a method for separating subdivided solids from a liquid having a low electrical conductivity by passing a mixture of the liquid and the solids through a separation zone, subjecting the mixture to an electrostatic field of unidirectional polarity in the separation zone whereby said solids adhere to a surface of at least one solid body in the separation zone, and recovering the liquid from the separation zone, the improvement comprising: subjecting said mixture to at least one electrostatic field of alternating bidirectional polarity before subjecting said mixture to said unidirectional electrostatic field.
Claim 5
Dependent Claim
93 words
In a method for separating subdivided solids from a liquid having a low electrical conductivity by passing a mixture of the liquid and the solids through a separation zone, subjecting the mixture to an electrostatic field of unidirectional polarity in the separation zone whereby said solids adhere to a surface of at least one solid body in the separation zone, and recovering the liquid from the separation zone, the improvement comprising: subjecting said mixture to at least one electrostatic field of alternating bidirectional polarity before subjecting said mixture to said unidirectional electrostatic field.
Claim 6
Dependent Claim
23 words
An improved method according to claim 3 wherein said electrostatic field of alternating polarity has a maximum potential of at least 500 volts.
Claim 7
Dependent Claim
23 words
An improved method according to claim 3 wherein said electrostatic field of alternating polarity oscillates polarity with a frequency of about 60 hertz.
Claim 8
Dependent Claim
32 words
An improved method according to claim 3 wherein said electrostatic field of unidrectional polarity is applied to said mixture in the presence of substantially nonconductive subdivided packing material in said separation zone.
Claim 9
Dependent Claim
15 words
An improved method according to claim 4 wherein said packing material comprises substantially spherical solids.
Claim 10
Dependent Claim
17 words
An improved method according to claim 7 wherein said spherical solids are formed from glass or ceramic.
Claim 11
Dependent Claim
14 words
An improved process according to claim 3 wherein said liquid is a hydrocarbonaceous liquid.
Claim 12
Dependent Claim
14 words
An improved process according to claim 9 wherein said subdivided solids comprise catalyst fines.
Claim 13
Dependent Claim
14 words
An improved process according to claim 9 wherein said subdivided solids comprise hydrocarbonaceous solids.
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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) | 1982-02-12 | 1982-08-14 | 1983-02-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-02-12 | 1986-08-14 | 1987-02-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-02-12 | 1990-08-14 | 1991-02-13 | $7700.00 | Window Closed / Lapsed |