Low-profile aluminum cell potshell and method for increasing the production capacity of an aluminum cell potline

Patent metadata

Field	Value
Publication number	US-10889906-B2
Application number	US-201515528357-A
Country	US
Kind code	B2
Filing date	Nov 20, 2015
Priority date	Nov 21, 2014
Publication date	Jan 12, 2021
Grant date	Jan 12, 2021

Abstract

An aluminum reduction cell having a shell structure with a pair of longitudinally extending sidewalls, a pair of transversely extending endwalls, a bottom wall, and an open top having an upper edge. The aluminum reduction cell also has a transverse support structure with transverse bottom beams located under the shell structure and extending transversely between the sidewalls, each of the transverse bottom beams having a pair of opposed ends. The aluminium reduction cell also has compliant binding elements fixed to the transverse support structure, each extending vertically along an outer surface of one of the sidewalls for applying an inwardly directed force said sidewall. The compliant binding elements are in the form of cantilever springs. Each spring has a metal member with a lower end which is secured to the transverse support structure, and a compliant, upper free end which is movable inwardly and outwardly in response to expansion and contraction of the shell structure.

First claim

What is claimed is:

1. An aluminum reduction cell comprising:
(a) a shell structure including a pair of longitudinally extending sidewalls, a pair of transversely extending endwalls, a bottom wall, and an open top having an upper edge;
(b) a transverse support structure including a plurality of transverse bottom beams located under the shell structure and extending transversely between the sidewalls, each of the transverse bottom beams having a pair of opposed ends; and
(c) a plurality of compliant binding elements fixed to the transverse support structure, each extending vertically along an outer surface of one of the sidewalls, for applying an inwardly directed force to said sidewall;
wherein the compliant binding elements are in the form of cantilever springs, each including:
a metal member having a lower end, which is secured to the transverse support structure; and
a compliant, upper free end, which is movable inwardly and outwardly in response to expansion and contraction of the shell structure.

2. The aluminum reduction cell according to claim 1 , wherein the ends of the transverse bottom beams do not substantially extend beyond the sidewalls of the shell structure.

3. The aluminum reduction cell according to claim 2 , wherein the lower end of each of the compliant binding elements is rigidly secured to one of the ends of one of the transverse bottom beams.

4. The aluminum reduction cell according to claim 1 , wherein each of the compliant binding elements extends vertically along an outer surface of one of the sidewalls.

5. The aluminum reduction cell according to claim 4 , wherein each of the compliant binding elements is in contact with the outer surface of the sidewall along at least a portion of its length.

6. The aluminum reduction cell according to claim 1 , wherein the compliant, upper free end of each compliant binding element is located at or below the upper edge of the shell structure.

7. The aluminum reduction cell according to claim 6 , wherein at least some of the compliant binding elements are attached, rigidly or flexibly, over parts of their length, to the sidewall.

8. The aluminum reduction cell according to claim 6 , wherein each of the compliant binding elements is of a length that allows for a majority of load transfer to the sidewalls to be directed to a top half of cathode blocks lining the bottom wall of the aluminum reduction cell.

9. The aluminum reduction cell according to claim 1 , wherein each of the compliant binding elements comprises a metal plate.

10. The aluminum reduction cell according to claim 9 , wherein the metal plate has a thickness, width and composition that allows:
the compliant, upper free end of each compliant binding element to be compliant; and
each compliant binding element to maintain an inwardly directed compressive force on the shell structure during outward dilation and inward contraction of the shell structure.

11. The aluminum reduction cell according to claim 10 , wherein the thickness and/or width of each of the compliant binding elements is varied along its length, with the upper end of the compliant binding element being reduced in width and/or thickness relative to the lower end, such that the upper end is more compliant than the lower end.

12. The aluminum reduction cell according to claim 1 , wherein each of the compliant binding elements is designed in a manner that allows each of the compliant binding elements to receive:
during normal operation of the aluminum reduction cell, a first applied load; and
in response to an expected reduction in process temperature, a second load the second load being greater than a minimum binding load, wherein the minimum binding load is a load at which forces opposing contraction of a lining of the aluminum reduction cell are overcome, thereby preventing formation of gaps in the lining during contraction in response to a thermal cycle comprising a deviation of about +/−100-150° C. from a normal operating temperature of the aluminum reduction cell.

13. The aluminum reduction cell according to claim 1 , wherein the compliant binding elements comprise a mild or low-alloy steel.

14. The aluminum reduction cell according to claim 1 , wherein the compliant binding elements have a depth of no more than about 200 mm.

15. The aluminum reduction cell according to claim 14 , wherein the compliant binding elements have a depth from about 50 mm to about 200 mm.

16. The aluminum reduction cell according to claim 1 , wherein the compliant binding elements are adjustable, and wherein the adjustability of the compliant binding elements is effected by disposition of an adjustment device between the upper ends of the compliant binding elements and the shell structure.

17. A method for improving the productivity of an aluminum reduction cell potline housed in an enclosure having a length and a width; wherein the potline comprises a plurality of existing aluminum reduction cells, each of said existing cells including an existing potshell and an existing support structure and having a first footprint defined by an area of the existing potshell and the existing support structure, wherein the existing potshell and the existing support structure each have a length extending across the width of the enclosure, and the length of the existing support structure is greater than the length of the existing potshell; the method comprising:
(a) removing one or more of said existing aluminum reduction cells from the potline; and
(b) inserting one or more new aluminum reduction cells with a potshell according to claim 1 into the potline, wherein each of the new cells comprises a new potshell and a new base structure and is inserted into a space vacated by one of the existing cells;
wherein each of the new cells has a second footprint which is substantially the same as the first footprint, and wherein the new potshell has a length which is substantially the same as a length of the new support structure, such that the area of the new potshell is greater than an area of the existing potshell.

18. The method according to claim 17 , whereupon increasing the width of the cells results in an increase in the operating current of the cells, so that the current density of the cathode remains substantially the same as before the capacity increase.

19. An aluminum reduction potline, comprising aluminum reduction cells connected in series, where the aluminum reduction cells are furnished with aluminum reduction cells according to claim 1 .

20. The aluminum reduction cell according to claim 16 , wherein:
the upper end of each of the compliant binding elements is shaped such that a slot is provided between the sidewall of the shell structure and an upper portion of the compliant binding element; and
the adjustment device includes a wedge, wherein the wedge is at least partly received in the slot, and displaceable within the slot for adjusting the inwardly directed compressive force applied to the shell by the compliant binding elements.

21. The aluminum reduction cell according to claim 20 wherein the wedge is drivable downwardly within the slot to increase an outward deflection of the upper end of the compliant binding element.

22. The aluminum reduction cell according to claim 21 wherein the wedge is downwardly drivable by a screw threadingly received in an aperture of a bracket secured to the sidewall above the upper end of the compliant binding element and the wedge.

23. The aluminum reduc

Assignees

• Hatch Ltd

Inventors

• Richard Daniel
• Pearen Dale
• Shaw John Andrew Ferguson
• Wasmund Bert O
• Jastrzebski Maciej Urban

Classifications

• C25C3/10 Primary

  External supporting frames or structures · CPC title

• C25C3/08

  Cell construction, e.g. bottoms, walls, cathodes · CPC title