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US3674674A Expired / Lapsed US ⏱️ 0.0 years remaining

Apparatus for controlling electrode adjustment during aluminum oxide reduction

Assignee: ALUMINIUM DELFZIJL NV
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Filing: 1969-12-22
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Granted: 1972-07-04
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Expires: 1989-12-22
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Abstract

Abstract An apparatus for controlling the electrolytic reduction of aluminum oxide by adjusting the depth of immersion of anode blocks suspended on an anode bridge in an electrolysis melt containing Al2O3, said apparatus being of the type comprising an electric voltage supply for generating a reference voltage which is proportionate with the momentary bath current, an adjusting device for the anode bridge, which adjusting device is controlled by the difference in voltage over the bath and the reference voltage, and a system for deriving, according to a chosen program, a command signal for the adjusting device from the aforementioned differential voltage and the periodic, short excitation of the adjusting device by means of this possible command signal, said apparatus characterized by the improvement that the apparatus comprises an integrator having an input and an output, a set of relays each preceded by a trigger circuit connectable to said output, and means for feeding the differential voltage of the bath voltage and the reference voltage to the integrator and for disconnecting the integrator from the set of relays in the non-excited condition of the adjusting device, and for disconnecting the feeding of said differential voltage to said integrator and connecting said integrator to said set of relays in the excited condition of the adjusting device, and means for feeding back to the input of the integrator the integrated signal from said output when the differential voltage is fed to said integrator.

Inventors

  • 👤 Mathieu Gerardus Henricus Arts
  • 👤 Jan Anna Antonius Lucker
  • 👤 Maarten Groenenboom

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-03 09:53
CPC Classifications
C; C25; C25C; C25C3/00; C25C3/06; C25C3/20

Claims Analysis

Total Claims: 3
Claim 1
Independent Claim 72 words
Apparatus as claimed in claim 1, further characterized in that the apparatus comprises means by which, in the period during which the integrator is connected with the set of relays, the output adjusting signal of the set of relays is fed back to the input of the integrating circuit in such a form that by this feed back a simulation of the correction of the bath voltage in the integrator is achieved.
Claim 2
Dependent Claim 84 words
Apparatus as claimed in claim 1, further characterized in that said set of relays comprises four relays, two relays exciting the adjusting device for an upward and downward movement respectively, provided the associated corresponding trigger circuit is presented a voltage of corresponding sign by the integrator, which voltage exceeds a first threshold value, and each of the two remaining relays blocking the movement mechanism if the associated trigger circuit is presented a positive and negative voltage respectively which exceeds a second, higher threshold value.
Claim 3
Dependent Claim 24 words
Apparatus as claimed in claim 1, further characterized in that the apparatus further comprises a highly insulating transductor for coupling the bath voltage thereto.

References Cited (Backward Citations)

US3434945A Cited
US3317413A Cited
US3455795A Cited
US3400062A Cited
US3539461A Cited
US3485727A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1975-07-04 1976-01-03 1976-07-04 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1979-07-04 1980-01-03 1980-07-04 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1983-07-04 1984-01-03 1984-07-04 $7700.00 Window Closed / Lapsed

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