Anode Assembly

Abstract

Anode assembly (100) comprising an anode (3) and an anode support (4) for the production of aluminium, characterized in that the anode assembly (100) comprises an electrical connecting element (1) to electrically connect the anode support (4) with the anode (3), and at least one thermally insulating element (6) arranged to reduct heat transfer between the anode (3) and the anode support (4) during the production of aluminium.

Claims

1. Anode assembly production of aluminum comprising an anode, an anode support, and an electrical connecting element having a sealing portion and a non-sealing portion for electrically connecting the anode support to the anode, wherein the anode comprises a recess in which is located the sealing portion of the electrical connecting element and wherein a seal formed of an electrically conductive material holds the electrical connecting element, characterized in that at least one thermally insulating element is arranged between two walls facing each other belonging to the non-sealing portion of the electrical connecting element and/or to the anode support to reduce heat transfer between the anode and the anode support during the production of aluminum.

2. Anode assembly according to claim 1, wherein the two walls facing each other are electrically and mechanically connected by means of a bead of electrically conductive material.

3. Anode assembly according to claim 1, wherein the electrical connecting element extends in a direction of extension between the anode and the anode support and wherein at least one thermally insulating element extends in a plane transverse to the direction of extension.

4. Anode assembly according to claim 1, wherein at least one thermally insulating element is arranged between one wall of the electrical connecting element and one wall of the anode support.

5. Anode assembly according to claim 1, wherein the anode assembly further comprises a bead of electrically conductive material arranged to electrically and mechanically connect the electrical connecting element and the anode support.

6. Anode assembly according to claim 1, wherein the non-sealing portion of the electrical connecting element defines a housing wherein at least one thermally insulating element is arranged.

7. Anode assembly according to claim 6, wherein the housing is formed by a notch in the non-sealing portion of the electrical connecting element.

8. Anode assembly according to claim 7, wherein the notch opens out laterally from the non-sealing portion of the electrical connecting element.

9. Anode assembly according to claim 1, wherein the non-sealing portion of the electrical connecting element comprises a first portion and a second portion, the first and second portions being separated by at least one thermally insulating element.

10. Anode assembly according to claim 9, wherein an additional bead of electrically conductive material is arranged to cover at least a portion of said at least one thermally insulating element and to electrically and mechanically connect the first portion and the second portion.

11. Anode assembly according to claim 9, wherein the first portion is arranged on a side of the anode support and has a smaller cross section reduced relative to that of the second portion, the second portion being arranged on the side of the anode, and wherein an electrical conductivity component arranged to electrically connect the second portion and the anode support.

12. Anode assembly according to claim 1, wherein the electrically conductive material comprises a substantially cylindrical shape, such as a steel stub.

13. Anode assembly according to claim 1, wherein at least one thermally insulating element comprises a plate shape, formed from a sintered powder, a film or a fiber mat including at least one refractory material.

Description

[0023] Other aspects, objects and advantages of the invention will appear more clearly on reading the following description of embodiments thereof, given as non-limiting examples and with reference to the accompanying drawings. The figures are not necessarily to scale for all the elements shown in order to improve readability. In the following description, for simplicity, elements that are identical, similar or equivalent to the various embodiments have the same reference numbers.

[0024] FIG. 1 shows an anode assembly according to a first embodiment of the invention.

[0025] FIG. 2 shows an anode assembly according to an alternative embodiment of the invention.

[0026] FIG. 3 shows an anode assembly according to a second embodiment of the invention.

[0027] FIG. 4 shows an anode assembly according to yet another embodiment of the invention.

[0028] As illustrated in FIG. 1, the anode assembly 100 includes an anode 3, typically made of carbon, and an anode support 4 for the production of aluminum by electrolysis according to the Hall-Hroult process. Anode 3 is suspended from the anode support 4 by an electrical connecting element 1 having a sealing portion 21 for fixing to anode 3 and providing electrical conductivity to anode 3, and a non-sealing portion 22 which provides the mechanical suspension of anode 3.

[0029] Anode 3 comprises in its upper part a recess 7 in which the sealing portion 21 of the electric connecting element 1 is housed and fixed by a seal 8 made of an electrically conductive material, for example cast iron. The sealing portion 21 is therefore the lower part of the electrical connecting element 1 which is caught in the seal 8, in contrast to the non-sealing portion 22 which extends above the seal 8. It is understood in the present document that any other material suitable for the seal 8 can be used, including adhesive carbonaceous paste. This seal 8 covers all the surfaces of the recess 7 and the sealing portion 21 of the electrical connecting element 1 housed in recess 7. Seal 8 may alternatively extend along the side walls of the sealing portion 21 and not on the underside.

[0030] The anode assembly also comprises a bead 9 of electrically conductive material, arranged to provide electrical and mechanical connection between the anode support 4 and the electrical connecting element 1, especially in the upper part of the non-sealing portion 22 of electrical connecting element 1. Electrical connecting element 1 is typically made of steel and has the shape of a cylinder. Bead 9 can be formed by a weld based on cupro-type copper, arranged laterally at the interface between the electrical connecting element 1 and the anode support 4.

[0031] FIG. 1 also illustrates, in the non-sealing portion 22, a thermally insulating element 6 which extends in a plane transverse to the direction of extension of the electrical connecting element 1 between the anode 3 and the anode support 4. This configuration effectively reduces heat transfer from the anode 3 to the anode support 4. More precisely, the electrical connecting element 1 comprises a housing 5, formed from a notch opening out laterally, in which a thermally insulating element 6 is arranged. This thermally insulating element 6 may be made of any suitable refractory materials, such as sintered powder, a film or a fiber mat, including at least one refractory material.

[0032] In the embodiment illustrated in FIG. 2, non-sealing portion 22 of the electrical connecting element 1 comprises a first portion 11 and a second portion 12 separate from the first portion 11 between which a thermally insulating element 6 is arranged. Conduction heat transfer is significantly decreased by the fact that the entire cross section of electrical connecting element 1 is covered by the thermally insulating element 6. Electrical conductivity is then provided by an additional bead 13 of an electrically conductive material arranged laterally in relation to thermally insulating element 6 so as to electrically and mechanically connect the first portion 11 and the second portion 12.

[0033] The embodiment shown in FIG. 3 differs from the two previous embodiments particularly in that the thermally insulating element 6 is arranged at the interface between the electrical connecting element 1 and the anode support 4. As with the embodiment illustrated in FIG. 1, bead 9 is arranged laterally in relation to insulating element 6 so as to ensure electrical and mechanical connection between electrical connecting element 1 and anode support 4. It was observed that electrical conductivity between the anode and the anode support mainly occurred via the weld bead 9 and not by the opposite surfaces being brought into contact so that a thermally insulating element may advantageously be inserted between the electrical connecting element and the anode support without detriment to overall electrical conductivity. Heat loss by radiation can be limited between the electrical connecting element and the anode support.

[0034] According to the embodiment illustrated in FIG. 4, the non-sealing portion 22 of electrical connecting element 1 comprises a first portion 11 arranged on the side of anode support 4 and a second portion 12 arranged on the side of anode 3. The cross section of the first portion 11 is smaller in relation to that of the second portion 12 so as to limit heat transfer. Furthermore, the anode assembly comprises a thermally insulating member 6 arranged between electrical connecting element 1 and anode support 4 and further includes a thermally insulating member 6 arranged between the first portion 11 and second portion 12. An electrical conductivity component 14, such as a copper plate, is arranged to provide an electrical connection between the second portion 12 and the anode support 4 and rests against a part of the first portion 11. In this configuration, heat transfer is very much limited by the presence of two thermally insulating elements 6 and the smaller cross section of the first portion 11. Furthermore, electrical connection is provided by bead 9 and additional bead 13 as well as the highly conductive copper plate. As the section of the copper plate is small, thermal conductivity through it is very limited.

[0035] So the present invention proposes an anode assembly 100 making it possible to effectively reduce heat loss between anode 3 and the anode support 4 by reducing heat transfer while also maintaining a very good electrical conductivity.

[0036] It goes without saying that the invention is not limited to the embodiments described above by way of example, but includes all technical equivalents and variants of the means described and combinations of these.