US3714004A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method and apparatus for cathodic protection
Assignee: ConocoPhillips Co
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Filing: 1970-12-02
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Granted: 1973-01-30
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Expires: 1990-12-02
Abstract
Abstract An improved apparatus and method for cathodically protecting surfaces exposed to a corrosive environment utilizing a predetermined number of anodes, each anode being connected to a power source adapted to supply a predetermined polarizing current thereto, and each anode being connected to a current controller adapted to supply an adjustingly, controlled polarizing current thereto. The polarizing current supplied by the current controller to any one anode is adjustingly controlled in response to the anode potential of that one anode with respect to the protected surface, the cathodic protection system being adapted to sequentially provide electrical continuity between each anode and the current controller and between the remaining anodes and the power source in such a manner that polarization of the system is obtained and maintained utilizing a minimum overall power consumption and in a manner maintaining a predetermined polarization over substantially the entire area of the protected surface.
Inventors
- 👤 O Riggs
- 👤 D Barnett
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 06:45
CPC Classifications
C; C23; C23F; C23F13/00; C23F13/02; C23F13/04
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
214 words
A cathodic protection apparatus for obtaining and maintaining polarization of a protected surface in a corrosive environment, the protected surface being maintained cathodic, comprising: a plurality of anode means, each anode means being disposed at a predetermined position with respect to the protected surface; a current controller means adapted to selectively provide an adjustingly controlled, polarizing current to one of said anode means; a power supply means adapted to selectively provide a predetermined polarizing current to the remaining of said anode means; a reference electrode means mounted in the vicinity of each of said anode means and generating an electrical control signal corresponding to the passivation condition of said protected surface, said current controller means being adapted to receive said electrical control signal and to adjustingly control the polarizing current provided by the current controller in response thereto; and a switch means in electrical communication with said plurality of anode means, said power supply means, said current controller means and said reference electrode means, whereby said switch means is adapted to selectively and sequentially provide electrical continuity between said remaining anode means and said power supply means and to provide electrical continuity between said one anode means, said reference electrode means in the vicinity of said one anode means and said current controller means.
Claim 2
Dependent Claim
214 words
A cathodic protection apparatus for obtaining and maintaining polarization of a protected surface in a corrosive environment, the protected surface being maintained cathodic, comprising: a plurality of anode means, each anode means being disposed at a predetermined position with respect to the protected surface; a current controller means adapted to selectively provide an adjustingly controlled, polarizing current to one of said anode means; a power supply means adapted to selectively provide a predetermined polarizing current to the remaining of said anode means; a reference electrode means mounted in the vicinity of each of said anode means and generating an electrical control signal corresponding to the passivation condition of said protected surface, said current controller means being adapted to receive said electrical control signal and to adjustingly control the polarizing current provided by the current controller in response thereto; and a switch means in electrical communication with said plurality of anode means, said power supply means, said current controller means and said reference electrode means, whereby said switch means is adapted to selectively and sequentially provide electrical continuity between said remaining anode means and said power supply means and to provide electrical continuity between said one anode means, said reference electrode means in the vicinity of said one anode means and said current controller means.
Claim 3
Dependent Claim
33 words
A system of claim 1 in which the reference electrode means is located within the area of the throwing power of its corresponding anode means for which the passivation condition is being measured.
Claim 4
Dependent Claim
40 words
A system of claim 1 in which the plurality of anode means, controller means and switch means are placed and cooperate such that the passivation condition encompasses substantially the entire area of the surface being protected in the corrosive environment.
Claim 5
Dependent Claim
39 words
A system of claim 1 in which the controller means and switching means are adapted to operate in a cyclic manner with the period of time for each step in the cycle being adjusted according to a predetermined program.
Claim 6
Dependent Claim
51 words
A system of claim 1 in which the controller means and switching means are adapted to operate in a cyclic manner with the period of time for each step in the cycle and the overall cycle being adjusted in response to a control signal indicative of parameters of the passivation system.
Claim 7
Dependent Claim
27 words
The apparatus of claim 1 which is adapted to maintain a minimum overall power consumption and passivation condition for a large complex surface in a corrosive environment.
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) | 1976-01-30 | 1976-07-31 | 1977-01-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-01-30 | 1980-07-31 | 1981-01-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-01-30 | 1984-07-31 | 1985-01-30 | $7700.00 | Window Closed / Lapsed |