Global Patent Index - EP 0834601 B1

EP 0834601 B1 2000-04-26 - Process for controlling the bath temperature in an aluminium electrolysis cell

Title (en)

Process for controlling the bath temperature in an aluminium electrolysis cell

Title (de)

Verfahren zur Temperaturregelung eines Bades in einer Aluminium-Elektrolysewanne

Title (fr)

Procédé de régulation de la température du bain d'une cuve d'électrolyse pour la production d'aluminium

Publication

EP 0834601 B1 (FR)

Application

EP 97420174 A

Priority

FR 9611962 A

Abstract (en)

[origin: EP0834601A1] Thermal regulation of individual electrolysis cells for the production of aluminium comprises directly measuring the temperature of the bath at regular time intervals and modifying the distance between the anode and the metal as a function of the measured values of the resistance R of the cell w.r.t. a consigned resistance (Ro). During each cycle of thermal regulation of duration (Tr) corresponding to a working sequence incorporated in the duration (T) of the work cycle of the cell the following steps are taken: (a) at least one measurement of the bath temperature (θ ) is effected; (b) from the n latest measures a corrected average temperature (θ mc) representative of the medium state of the cell assembly and free from the variations in the time and space due to the periodic operations of exploitation is determined; (c) an additional resistance (RTH) is determined, this may be positive or negative and comprises two terms: (i) a prior correction term (RTHa), calculated in a manner to neutralise by anticipation the irregular but known and quantified perturbations such as the addition of solids to the bath; and (ii) a posterior correction term (RTHb), calculated as a function of the corrected average temperature (θ mc) and a consigned temperature (θ o); and (d) the additional resistance (RTH) is then applied to the consigned resistance (Ro) of the cell in order to maintain or correct the temperature of the cell.

IPC 1-7 (main, further and additional classification)

C25C 3/20

IPC 8 full level (invention and additional information)

C25C 3/20 (2006.01)

CPC (invention and additional information)

C25C 3/20 (2013.01)

Designated contracting state (EPC)

ES FR GB

EPO simple patent family

FR 2753727 A1 19980327; FR 2753727 B1 19981023; AU 3920097 A 19980402; AU 717983 B2 20000406; BR 9704860 A 19981229; BR 9704860 B1 20090113; CA 2215186 A1 19980325; CA 2215186 C 20030128; EG 20880 A 20000531; EP 0834601 A1 19980408; EP 0834601 B1 20000426; ES 2146967 T3 20000816; IN 192036 B 20040214; NO 317403 B1 20041025; NO 974304 A 19980326; NO 974304 D0 19970918; NZ 328743 A 19990128; US 5882499 A 19990316; ZA 9708544 B 19980511

INPADOC legal status


2011-11-30 [PG25 ES] LAPSED IN A CONTRACTING STATE ANNOUNCED VIA POSTGRANT INFORM. FROM NAT. OFFICE TO EPO

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2011-10-19 [REG ES FD2A] ANNOUNCEMENT OF LAPSE IN SPAIN

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2011-08-31 [PG25 GB] LAPSED IN A CONTRACTING STATE ANNOUNCED VIA POSTGRANT INFORM. FROM NAT. OFFICE TO EPO

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2011-07-29 [PG25 FR] LAPSED IN A CONTRACTING STATE ANNOUNCED VIA POSTGRANT INFORM. FROM NAT. OFFICE TO EPO

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2011-06-24 [REG FR ST] NOTIFICATION OF LAPSE

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2011-05-25 [GBPC] GB: EUROPEAN PATENT CEASED THROUGH NON-PAYMENT OF RENEWAL FEE

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2009-10-30 [PGFP ES] POSTGRANT: ANNUAL FEES PAID TO NATIONAL OFFICE

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2002-01-01 [REG GB IF02] EUROPEAN PATENT IN FORCE AS OF 2002-01-01

2001-04-11 [26N] NO OPPOSITION FILED

2000-08-16 [REG ES FG2A] DEFINITIVE PROTECTION

- Document: ES 2146967 T3

2000-06-28 [GBT] GB: TRANSLATION OF EP PATENT FILED (GB SECTION 77(6)(A)/1977)

- Effective date: 20000601

2000-04-26 [AK] DESIGNATED CONTRACTING STATES:

- Kind Code of Ref Document: B1

- Designated State(s): ES FR GB

1999-08-11 [17Q] FIRST EXAMINATION REPORT

- Effective date: 19990628

1999-02-04 [REG DE 8566] DESIGNATED COUNTRY DE NOT LONGER VALID

1998-12-23 [AKX] PAYMENT OF DESIGNATION FEES

- Free text: ES FR GB

1998-12-23 [RBV] DESIGNATED CONTRACTING STATES (CORRECTION)

- Designated State(s): ES FR GB

1998-10-07 [17P] REQUEST FOR EXAMINATION FILED

- Effective date: 19980811

1998-04-08 [AK] DESIGNATED CONTRACTING STATES:

- Kind Code of Ref Document: A1

- Designated State(s): ES FR GB