US4488117A
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Method of measuring backelectromotive forces of aluminum electrolysis cells
Assignee: RYOKA KEIKINZOKU KOGYO A CORP OF JAPAN KK
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Filing: 1982-04-21
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Granted: 1984-12-11
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Expires: 2002-04-21
Abstract
Abstract A backelectromotive force of an aluminum electrolysis cell is measured by the steps of: (a) repeatedly measuring voltage V and current I of the cell at a short interval; (b) forming groups of data each including measured values thus obtained within a relative short period; (c) calculating a constant e and its variance Ve with reference to each data group according to a linear regression expressed by an equation: V=r·I+e where r represents an internal resistance of the cell; (d) calculating a backelectromotive force E and its variance V E at a given time based on the constant e and its variance Ve calculated at the step (c), a backelectromotive force E' and its variance V' E with reference to a data group preceding the given time and a constant V T , and according to the following equations: P=(V'.sub.E +V.sub.T)/(Ve+V'.sub.E +V.sub.T) E=P·e+(1-P)·E' V.sub.E =P.sup.2 ·Ve+(1-P).sup.2 ·(V'.sub.E +V.sub.T); and (e) repeating the steps (b), (c) and (d) at a relatively short interval.
Inventors
- 👤 Yuzo Seo
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 02:49
CPC Classifications
G; G01; G01R; G01R19/00; C; C25; C25C; C25C3/00; C25C3/06; C25C3/20
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
171 words
A method of measuring a backelectromotive force of an aluminum electrolysis cell comprising the steps of: (a) repeatedly measuring voltage V and current I of said cell at a short interval; (b) forming groups of data each including measured values thus obtained within a relatively short period; (c) calculating a constant e and its variance Ve with reference to each data group according to a linear regression expressed by an equation V=r·I+e where r represents an internal resistance of said cell; (d) calculating a backelectromotive force E and its variance V E at a given time based on said constant e and its variance Ve calculated at said step (c), a backelectromotive force E' and its variance V' E with reference to a data group preceding said given time and a constant V T , and according to the following equations: P=(V'.sub.E +V.sub.T)/(Ve+V'.sub.E +V.sub.T) E=P·e+(1-P)·E' V.sub.E =P.sup.2 ·Ve+(1-P) .sup.2 ·(V'.sub.E +V.sub.T) where P represents a parameter; and (e) repeating said steps (a), (b), (c) and (d) at a relatively short interval.
Claim 2
Independent Claim
171 words
A method of measuring a backelectromotive force of an aluminum electrolysis cell comprising the steps of: (a) repeatedly measuring voltage V and current I of said cell at a short interval; (b) forming groups of data each including measured values thus obtained within a relatively short period; (c) calculating a constant e and its variance Ve with reference to each data group according to a linear regression expressed by an equation V=r·I+e where r represents an internal resistance of said cell; (d) calculating a backelectromotive force E and its variance V E at a given time based on said constant e and its variance Ve calculated at said step (c), a backelectromotive force E' and its variance V' E with reference to a data group preceding said given time and a constant V T , and according to the following equations: P=(V'.sub.E +V.sub.T)/(Ve+V'.sub.E +V.sub.T) E=P·e+(1-P)·E' V.sub.E =P.sup.2 ·Ve+(1-P) .sup.2 ·(V'.sub.E +V.sub.T) where P represents a parameter; and (e) repeating said steps (a), (b), (c) and (d) at a relatively short interval.
Claim 3
Dependent Claim
32 words
The method according to claim 1 wherein each of said data groups contains at least 10 measured values measured in continual measuring periods each having a length of 1 to 4 minutes.
Claim 4
Dependent Claim
25 words
The method according to claim 1 or 2 wherein the calculation of said backelectromotive force is repeated at an interval of less than 4 minutes.
Claim 5
Independent Claim
216 words
A method of measuring a backelectromotive force of an aluminum electrolysis cell comprising the steps of: (a) repeatedly measuring voltage V and current I of said cell at a short interval; (b) calculating, at a relatively short interval, a weighted mean value V0 and its variance V V of said cell voltage, a weighted mean value I0 and its variance V I of said cell current and their common variance C VI , based on the values of said voltage and current measured within a relatively short period at step (a); (c) calculating a constant e and its variance Ve in an equation V=r·I+e (where r represents an internal resistance of said electrolysis cell) according to the following equations: r=C.sub.VI /V.sub.I e=V-r·I Vε=V.sub.V -r.sup.2 V.sub.I Ve=Vε(1+I.sup.2 /V.sub.I); by utilizing the values calculated at step (b), (d) calculating a backelectromotive force E and its variance V E according to the following equations: P=(V'.sub.E +V.sub.T)/(Ve+V'.sub.E +V.sub.t) E=P·e+(1-P)·E' V.sub.E =P.sup.2 ·Ve+(1-P).sup.2 ·(V'.sub.E +V.sub.T) by utilizing the constant e and its variance Ve calculated at step (c) at a given time and a backelectromotive force E' and its variance V' E calculated at a time preceding said given time and a constant V T ; and (e) repeating the steps (a), (b), (c) and (d) at a relatively short interval.
Claim 6
Independent Claim
216 words
A method of measuring a backelectromotive force of an aluminum electrolysis cell comprising the steps of: (a) repeatedly measuring voltage V and current I of said cell at a short interval; (b) calculating, at a relatively short interval, a weighted mean value V0 and its variance V V of said cell voltage, a weighted mean value I0 and its variance V I of said cell current and their common variance C VI , based on the values of said voltage and current measured within a relatively short period at step (a); (c) calculating a constant e and its variance Ve in an equation V=r·I+e (where r represents an internal resistance of said electrolysis cell) according to the following equations: r=C.sub.VI /V.sub.I e=V-r·I Vε=V.sub.V -r.sup.2 V.sub.I Ve=Vε(1+I.sup.2 /V.sub.I); by utilizing the values calculated at step (b), (d) calculating a backelectromotive force E and its variance V E according to the following equations: P=(V'.sub.E +V.sub.T)/(Ve+V'.sub.E +V.sub.t) E=P·e+(1-P)·E' V.sub.E =P.sup.2 ·Ve+(1-P).sup.2 ·(V'.sub.E +V.sub.T) by utilizing the constant e and its variance Ve calculated at step (c) at a given time and a backelectromotive force E' and its variance V' E calculated at a time preceding said given time and a constant V T ; and (e) repeating the steps (a), (b), (c) and (d) at a relatively short interval.
Claim 7
Dependent Claim
23 words
The method according to claim 4 wherein measurements of said cell voltage and said cell current are performed continually at a predetermined interval.
Claim 8
Dependent Claim
57 words
The method according to claim 4 or 5 wherein said weighted mean values of said cell voltage and said cell current are calculated using a filtering time constant of from 0.5 to 2 minutes and a number of said measured voltage and current values in a period equal to said filtering time constant is larger than 5.
Claim 9
Dependent Claim
35 words
The method according to claim 4 or 5 wherein said weighted mean values of said cell current and cell voltage, their variances and common variances are calculated at an interval of less than 4 minutes.
References Cited (Backward Citations)
JPS524428A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1987-12-11 | 1988-06-11 | 1988-12-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-12-11 | 1992-06-11 | 1992-12-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-12-11 | 1996-06-11 | 1996-12-11 | $7700.00 | Window Closed / Lapsed |