US4448661A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Device for measuring the bath temperature in a fused salt electrolytic cell used for the production of aluminum
Assignee: SWISS ALUMINIUM Ltd A SWISS CORP
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Filing: 1983-03-18
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Granted: 1984-05-15
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Expires: 2003-03-18
Abstract
Abstract The temperature measuring device comprises a rod which passes approximately vertically through the anode block and terminates at the level of the working face of the anode. Fitted over the rod at the top is a light plug which provides an optical connection to the fiber bundles with the minimum of reflection. This optical connection is usefully in a coupling fluid which, like the rod and the bundle of fibers, is able to transmit infra-red radiation.
Inventors
- 👤 Rolf Roggen
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 19:14
CPC Classifications
G; G01; G01J; G01J5/00; G01J5/02; G01J5/08; G01J5/0818; G01J5/0821; C; C25; C25C; C25C3/00; C25C3/06; C25C3/20; G01J5/0037; G01J5/004; G01J5/0205; G01J5/04; G01J5/041; G01J5/042; G01J5/046; G01J5/048
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
191 words
Device for measuring the bath temperature in the pot of a reduction cell used for the fused salt electrolytic production of aluminum which comprises: at least one anode in combination with said cell; a rod running approximately vertically through said anode and made of a material which transmits infra-red radiation and dissolves in the molten electrolyte at approximately the same rate as the consumption of the anode, wherein said rod is made of a material which contains no components which would excessively contaminate the aluminum produced; an infra-red detector optically coupled to the rod; at least one bundle of fibers which transmit infra-red radiation communicating between the infra-red detector and the rod; means for optically connecting said rod and fibers including a light plug between the fibers and the rod for transmitting the signal from the rod to the fibers, wherein the light plug contains a coupling fluid which transmits infra-red radiation and has an index of refraction (n 2 ) approximately the same as that (n 1 ) of the rod; and a transmitter or connecting cable for communicating an electrical signal from the infra-red detector to the control system.
Claim 2
Dependent Claim
191 words
Device for measuring the bath temperature in the pot of a reduction cell used for the fused salt electrolytic production of aluminum which comprises: at least one anode in combination with said cell; a rod running approximately vertically through said anode and made of a material which transmits infra-red radiation and dissolves in the molten electrolyte at approximately the same rate as the consumption of the anode, wherein said rod is made of a material which contains no components which would excessively contaminate the aluminum produced; an infra-red detector optically coupled to the rod; at least one bundle of fibers which transmit infra-red radiation communicating between the infra-red detector and the rod; means for optically connecting said rod and fibers including a light plug between the fibers and the rod for transmitting the signal from the rod to the fibers, wherein the light plug contains a coupling fluid which transmits infra-red radiation and has an index of refraction (n 2 ) approximately the same as that (n 1 ) of the rod; and a transmitter or connecting cable for communicating an electrical signal from the infra-red detector to the control system.
Claim 3
Dependent Claim
13 words
A device according to claim 1 wherein said anode is a carbon anode.
Claim 4
Dependent Claim
15 words
A device according to claim 1 wherein said fibers are enclosed in a protective sheathing.
Claim 5
Dependent Claim
19 words
A device according to claim 1 wherein the infra-red detector is positioned in the upper region of the cell.
Claim 6
Dependent Claim
22 words
A device according to claim 1 wherein the rod is made of SiO 2 or of corundum capable of transmitting infra-red radiation.
Claim 7
Dependent Claim
14 words
A device according to claim 1 wherein the rod is round in cross section.
Claim 8
Dependent Claim
15 words
A device according to claim 6 wherein the diameter of the rod is 5-15 mm.
Claim 9
Dependent Claim
35 words
A device according to claim 1 wherein the rod is, at least in the region of the anode, embedded in a protective pipe which dissolves in the molten electrolyte and does not contaminate the electrolyte.
Claim 10
Dependent Claim
21 words
A device according to claim 8 wherein the protective pipe projects out some centimeters above the top surface of the anode.
Claim 11
Dependent Claim
16 words
A device according to claim 8 wherein the protective pipe is made of sintered aluminum oxide.
Claim 12
Dependent Claim
50 words
A device according to claim 1 wherein said anode is a pre-baked anode and including an anode pin and rod supporting said anode, wherein the rod, the light plug, the fiber bundle and the infra-red detector are secured to at least one of the anode pin, and the anode rod.
Claim 13
Dependent Claim
35 words
A device according to claim 1 wherein the lower end of the rod together with the bottom face of the anode dips into the molten electrolyte and is dissolved thereby at substantially the same rate.
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) | 1987-05-15 | 1987-11-14 | 1988-05-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-05-15 | 1991-11-14 | 1992-05-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-05-15 | 1995-11-14 | 1996-05-15 | $7700.00 | Window Closed / Lapsed |