OA17791A - Electrolysis device and anode assembly intended for the production of aluminum, electrolysis cell and installation comprising such a device - Google Patents

Abstract

An electrolysis device comprising a casing (3) and an inner lining (5) delimiting an opening (16) through which an anode block (15) suspended from an anode support (13, 17) forming an anode assembly (12 ) moves vertically with the aid of an anode receiver (25), said anode receiver being disposed outside a space defined by the top of said anode block (15), said anode receiver comprising a contact surface (27) cooperating with the anode support (13, 17) to establish with the latter an electrical contact and a mechanical contact for vertically moving the anode assembly (12). An anode assembly (12). An electrolysis cell and an electrolysis installation comprising such an anode assembly

Description

ELECTROLYSIS DEVICE AND ANODIC ASSEMBLY FOR THE PRODUCTION OF ALUMINUM, ELECTROLYSIS CELL AND INSTALLATION INCLUDING SUCH A DEVICE

Field of the invention

The invention relates to the production of aluminum by igneous electrolysis. The invention relates more particularly to an electrolysis device associated with an electrolysis cell using at least one anode assembly displaced vertically during electrolysis, and supplied electrically by anode conductors.

State of the art

Aluminum metal is produced industrially by igneous electrolysis, namely by electrolysis of alumina in solution in a bath of molten cryolite, called an electrolyte bath, according to the well-known process of Hall Hérault. The electrolyte bath is contained in tanks, called "electrolysis tanks", each tank comprising a steel box having an interior lining generally made from refractory and / or insulating materials. An electrolysis cell comprises cathode assemblies located at the bottom of the cell, each cathode assembly comprising a cathode made of carbonaceous material. Anodes are partially immersed in the electrolyte bath. The anodes are more particularly of the prebaked anode type with prebaked carbonaceous anode blocks, that is to say, cooked before introduction into the electrolysis cell. The anode blocks are often suspended from an anode support to form with said blocks what is often referred to as the anode assembly. The anode assembly is generally mobile relative to the box and can move vertically using displacement means in order to compensate for the consumption of the anode blocks during electrolysis and the variations in the level of aluminum accumulating on the cathode.

The electrolytic cell can generally receive several anode assemblies distributed along a longitudinal direction of the cell and its box, the anode support of said anode assemblies extending (e along a transverse direction of the cell and its casing). The assembly formed by an electrolysis cell, its anodes and the electrolyte bath is often referred to as an electrolysis cell An electrolysis plant may comprise a series of several cells extending along the length of the cell. transverse direction of the tank and its box

The anode assemblies and the cathode assemblies of an electrolytic cell are electrically connected by a network of electrical conductors. Cathode conductors are connected to the cathode assemblies to collect electrolysis current at the cathode and to conduct it to cathode outputs passing through the bottom or sides of the well. The cathode outputs, in turn, are electrically connected, through routing conductors, to anode conductors electrically supplying the anode assemblies of the next tank. These 5 routing conductors generally extend in a substantially horizontal direction. The anode conductors are, for their part, electrically connected to the anode assemblies of the following tank. The electrolysis current is thus routed from the cathode of one electrolytic cell to the anode blocks of the following electrolytic cell, via cathode conductors, routing conductors, anode conductors and of the anode support of the anode assemblies.

The anode assemblies can be moved vertically using the displacement means, in order to compensate for the consumption of the anode blocks. The anode assemblies can also be moved vertically during anode change maneuvers by other means, such as handling tools. During these vertical movements of the anode assemblies, the anode blocks are moved through an opening delimited by the interior lining of the electrolytic cell casing. The vertical movements of the anode assemblies during the anode change maneuvers can be limited by the presence of equipment 20 of the electrolysis cell arranged above this opening.

For example, French patent published under number 2,694,945 describes a cell superstructure comprising a rigid beam arranged above the electrolysis cell and extending in the longitudinal direction of the box of said cell, the beam supporting a anode frame to which are connected on the one hand current rises and on the other hand anode rods. The rigid beam of the superstructure also supports mechanisms for raising-lowering the anodes making it possible to vertically move the anode frame and the anodes fixed to said anode frame. Such an arrangement of the superstructure, of the anode frame and of the current rises above the electrolytic cell tends to reduce the space available above the casing of said cell, and to limit the vertical displacement of the anodes. during anode change maneuvers.

American patent published under the number 3,575,827 describes an electrolysis cell with an anode assembly comprising a metal plate surmounted by a gateway secured to said plate and an anode block suspended from said plate, said anode assembly being adjusted upward or downward to using jacks fixed to the outer face of the walls of a box of said cell on which the anode assembly rests.

In the electrolysis cell described in the US patent cited above, a flexible conductor is used to bring the electrolysis current to a conductor integral with the anode assembly, the latter conductor being fixed on the top of the metal plate from which the anode block is suspended. It follows that, during the anode change maneuvers, the disassembly of the anode assembly seems to require first of all to disconnect the flexible conductor from the anode assembly, and secondly to separate the anode assembly. jacks. Likewise, the assembly of the anode assembly appears to be done in two stages, first securing the anode assembly to the jacks and then connecting the flexible conductor to the anode assembly. In addition, during the anode change maneuvers, the disconnection of the flexible conductor can leave the end of this conductor in the passage of the anode block or of the anode assembly, which can lead to mechanical interactions with said conductor and lead to its wear or damage. In addition, in the absence of an anode assembly in the electrolysis cell, during maintenance operations, the disconnected end of the flexible conductor risks coming into contact with the electrolyte inside the cell. electrolysis, which could lead to damage to said conductors or to other problems associated with the operation of said tank.

Description of the invention

The present invention relates to an electrolysis device associated with an electrolysis cell aimed at facilitating the anode change maneuvers and at promoting the accessibility of the tools for handling and intervention in the electrolysis cell. The invention also aims to make it possible to perform the anode change maneuvers without stopping the production of aluminum in the tank. The invention also aims to limit the wear and damage of the anode conductors during anode change maneuvers.

The invention relates to an electrolysis device intended for the production of aluminum comprising a casing comprising an interior lining defining an opening through which is intended to be moved at least one anode block, said at least one anode block being suspended from an anode support forming with said at least one anode block an anode assembly movable relative to the casing, said device further comprising displacement means comprising at least one anode receiver intended to cooperate with said anode support to move the anode assembly according to a substantially vertical direction, said anode support being intended to be connected to anode conductors to bring an electrolysis current to said at least one anode block, said electrolysis device being characterized in that said at least one anode receiver is arranged outside a space defined by the top of said at least one anode block during its displacement ment through the opening, said at least one anode receiver comprising a contact surface cooperating with a corresponding anode contact surface of the anode support to establish with said anode support an electrical contact for conducting the electrolysis current between said at least one anode support. at least one anode receiver and the anode assembly, and a mechanical contact for moving said anode assembly in the substantially vertical direction.

According to the invention, said at least one anode receiver is disposed outside of a space defined by the top of the at least one anode block as it moves through the opening. In other words, said at least one anode receiver is not placed in line with the at least one anode block during its movement through the opening, or else said at least one anode receiver is placed outside a. vertical projection of the translation path of the at least one anode block during its movement through the opening.

The invention thus makes it possible to facilitate the anode change maneuvers, and to promote the accessibility of handling and intervention tools in the electrolysis cell 20. The invention also makes it possible to limit wear and damage to the anode conductors during anode change maneuvers. The invention further makes it possible to perform the anode change maneuvers without stopping the production of aluminum in the electrolytic cell.

Preferably, the electrolysis device according to the invention is intended to receive several anode assemblies distributed along a longitudinal direction of the box, the anode support of said anode assemblies extending along a transverse direction of said box, said device further comprising compensation means cooperating with the displacement means to absorb the expansion of said anode support along the transverse direction and / or the longitudinal direction.

Indeed, during the mounting of the anode assembly in the box, the anode support of said assembly rises in temperature, which causes expansion of said support which is particularly important in the transverse direction. This expansion has the effect of generating mechanical stresses on the anode receptor of the displacement means, which can lead to blocking or damage to these displacement means. These mechanical stresses can not only deform the receiver but also the anode assembly and thus generate flatness and therefore electrical contact defects. In general, the compensation means make it possible to tolerate any defect in flatness to ensure good electrical contact by allowing a certain range of deformation, which makes it possible to release the mechanical stresses linked to thermal expansion or possible torsion of the anode support during of its handling.

By "means of compensation cooperating with the means of movement" is meant that there is established between the means of compensation and the means of movement at least functional cooperation, but not necessarily physical cooperation, that is to say that the means of compensation act directly or indirectly on the means of movement. In other words, the compensation means can interact directly with, or be integrated into, the displacement means, in particular the anode receiver of said displacement means. Alternatively, the compensation means may not have any direct interactions with the displacement means, for example by being integrated into the anode support of the anode assembly.

Preferably, the contact surface of the at least one anode receiver is arranged above said at least one anode receiver to support the anode assembly. In this way, the electrical contact between the anode receiver and the anode support is improved.

Preferably, the at least one anode receiver comprises a drive part guided in translation in the substantially vertical direction and an electrically conductive part. In this way, it is possible to optimize the anode receiver by decoupling the displacement function, and possibly support, from the conduction function of electricity, at least over a large part of the anode receiver. The drive part can be made of steel. The drive part cooperates with motor means and guide means. The conductive part can, for its part, be made of copper. This configuration makes it possible in particular to limit the electrical resistance.

Preferably, the contact surface of the at least one anode receiver is provided on the conductive part of said anode receiver. Thus, the decoupling between the displacement function and the conduction of electricity function is achieved on a major part of the anode receiver, but not on the whole of said anode receiver. In fact, it is only at the level of the contact surface of the anode receiver that the conductive part alone allows the dual function of displacement and conduction of electricity to be performed.

According to one embodiment of the present invention, the contact surface is substantially horizontal, the compensation means being essentially formed by said contact surface and the anode contact surface of the anode support cooperating with said contact surface, the expansion of the support anodic along the transverse direction being absorbed by sliding said anodic contact surface on said contact surface in the transverse direction and / or in the longitudinal direction of said support surface.

In order to ensure good electrical contact between the anode receiver and the anode assembly, the contact surface of the at least one anode receiver and the corresponding anode contact surface of the anode support generally have complementary shapes.

Preferably, the contact surface of the at least one anode receiver and the corresponding anode contact surface of the anode support are flat and horizontal.

Alternatively, the contact surface of at least one anode receiver and the corresponding anode contact surface of the anode support can have various shapes, in particular to maximize the extent of these surfaces and thus promote the electrical conductivity between the anode receiver and the support. anodic.

According to one embodiment, the contact surface of the at least one anode receiver may include a chute or groove passing through the whole of said contact surface and the main axis of which extends parallel to the transverse direction of the box. This embodiment makes it possible to promote the sliding of the anode contact surface of the anode support on the corresponding contact surface of the anode receiver in the transverse direction of the box. In this case, the corresponding anode contact surface has an oblong projecting part intended to cooperate with the chute. Preferably, the chute and the corresponding oblong projecting part have a transverse profile in the form of an arc of a circle, for example a semicircle.

In the preferred case of an anode support comprising at least two anode contact surfaces intended to be supported on two corresponding surfaces of anode receivers arranged on each longitudinal edge of the casing, the main directions of the chute and of the corresponding oblong protruding part can be oriented in the transverse direction of the box for the contact surfaces on one longitudinal edge of the box and oriented in the longitudinal direction for the surfaces on the other longitudinal edge of the box.

Preferably, the sliding of the anode contact surface of the anode support on the contact surface is facilitated by the use of an electrically conductive grease applied to one of said surfaces.

According to another embodiment of the present invention, the compensation means are arranged in said at least one anode receiver. The anode support can then be advantageously fixed to the anode receiver so that the anode contact surface of the anode support is in compression against the contact surface of the anode receiver, without risking damage to the displacement means.

Preferably, the compensation means are arranged between an upper part of the at least one anode receiver carrying the contact surface and the drive part.

According to a variant, the compensation means comprise at least one connecting element between the upper part and the driving part making it possible to absorb the expansion of said anode support along the transverse direction or the longitudinal direction, such as a connecting rod type connecting element.

Preferably, the displacement means are equipped with at least two anode receivers per anode assembly, arranged on either side of the box relative to the transverse direction, a first connecting element of one of the anode receivers making it possible to 'absorbing any expansion of said anode support along the transverse direction, and a second connecting member of the other anode receptor for absorbing any expansion of said anode support along the longitudinal direction.

According to another variant, the compensation means comprise at least one connecting element between the upper part and the driving part making it possible to absorb the expansion of said anode support along the transverse direction and the longitudinal direction, such as a ball joint type connecting element.

According to one embodiment of the present invention, the drive part of the anode receiver comprises a lifting mat driven in translation and a sole connected to said lifting mat by means of the connecting element, the conductive part comprising at least one side conductor and one conductive plate disposed on said sole electrically connected to said side conductor.

According to another embodiment of the present invention, the driving part comprises a hoop surrounding the electrically conductive part with sufficient clearance to allow said conductive part to deform inside said hoop and to absorb thus the expansion of the anode support along the transverse direction and / or the longitudinal direction.

Preferably, the displacement means are equipped with at least two anode receivers per anode assembly, said anode receivers being respectively arranged along each longitudinal wall of the box, outside of said box.

Preferably, the at least two anode receivers per anode assembly are associated with separate motorization means.

Preferably, the electrolysis device comprises guide means arranged along the longitudinal walls of the box, on the outside of said box, said guide means being arranged in a welded structure forming said box.

Preferably, the opening delimited by the interior lining of the box and the anode assembly is covered by a removable cover.

According to yet another embodiment of the invention, the compensation means are arranged in the anode support.

The invention also relates to an anode assembly intended to be installed in an electrolysis device for the production of aluminum, said anode assembly comprising an anode support and at least one anode block suspended from said anode support, said anode support being intended to be connected to anode conductors to bring an electrolysis current to said at least one anode block, said at least one anode block being intended to be moved in a substantially vertical direction through an opening delimited by a box and its interior coating of said electrolysis device using at least one anode receiver for moving means of said electrolysis device cooperating with said anode support, said anode assembly being characterized in that the anode support comprises at least one surface of anode contact cooperating with a corresponding contact surface of said at least one anode receiver to establish with the edit at least one anode receiver, an electrical contact for conducting the electrolysis current between said at least one anode receiver and the anode assembly, and a mechanical contact for moving said anode assembly in the substantially vertical direction, the at least one surface contact of the anode support being disposed outside a space defined by the top of said at least one anode block.

According to the invention, the at least one anode contact surface of the anode support is disposed outside a space defined by the top of said at least one anode block. In other words, the at least one anode contact surface is not disposed in line with the at least one anode block.

As described above more fully, such a configuration makes it possible in particular to receive the anode assemblies on anode receivers of the electrolysis device which are arranged outside the vertical translation path of the anode blocks.

Preferably, the anode support of the anode assembly extends along a main direction corresponding to a transverse direction of the box when the anode assembly is received in the electrolysis device, and said anode support comprises means of compensation for absorbing the expansion of said anode support along said main direction and / or a secondary direction of said anode support corresponding to a longitudinal direction of said well when the anode assembly is installed in said electrolysis device.

In general, the compensation means make it possible to correct any defect in flatness to ensure good electrical contact and to compensate for thermal expansion or possible torsion of the anode support.

Preferably, the anode support comprises a frame, supporting the at least one anode block, and an electrically conductive part, the at least one anode contact surface of said anode support being provided in said conductive part.

According to one embodiment, the means for compensating the anode support comprise at least one connecting element, such as a connecting element of the connecting rod type or a connecting element of the sliding type, arranged between the at least one anode contact surface. and a main part of the frame, to absorb any expansion of said anode support along the main direction or the secondary direction.

Preferably, the anode support comprises two anode contact surfaces arranged on each side of said anode support relative to the main direction, a first connecting element arranged between one of the anode contact surfaces and the main part of the frame allowing to absorb any expansion of said anode support along the main direction and a second connecting member disposed between the other anode contact surface and the main part of the frame making it possible to absorb any expansion of said anode support along the secondary management.

Preferably, at least one connecting element allows to absorb the expansion of the anode support along the main direction and the secondary direction, such as a ball-and-socket type connecting element.

The invention also relates to an electrolysis cell, said cell being characterized in that it comprises an electrolysis device as described above, said electrolysis cell further comprising an electrolysis cell formed by the casing and the internal coating of said electrolysis device, an electrolyte bath contained in said tank and at least one anode assembly comprising at least one anode block partially immersed in said electrolyte bath.

The invention will be better understood with the aid of the detailed description of preferred embodiments thereof which are set out below, in a nonlimiting manner, and which are illustrated with the aid of the appended figures.

Figure 1 shows in section, two neighboring electrolysis cells according to the invention, along a cross section A-A of Figure 2 described below.

Figure 2 shows in section, one of the electrolysis cells of Figure 1, along a longitudinal section B-B.

Figure 3 shows a side view of the same electrolysis cell of Figure 1, along a plane defined by a longitudinal section C-C.

FIG. 4 shows in section two neighboring electrolysis cells according to another embodiment of the invention.

FIG. 5 shows in section, for one of the electrolysis cells of FIG. 4, an anode receiver of the displacement means comprising a connecting rod-type connecting element and a jack cooperating with said anode receiver.

FIG. 6 represents in section, the anode receiver of FIG. 5, along a longitudinal section D-D.

FIG. 7 shows in section, for one of the electrolysis cells of FIG. 4, an anode receiver of the displacement means comprising a connecting element of the ball joint type and a jack cooperating with said anode receiver.

FIG. 8 represents, in section, the anode receiver of FIG. 7, along a longitudinal section E-E.

Figure 9 shows in section, two neighboring electrolysis cells according to yet another embodiment of the invention.

FIG. 10 shows in section an anode receiver of the means for moving the anode assembly of one of the electrolysis cells of FIG. 9 and a jack cooperating with said anode receiver.

FIG. 11 represents in section, the anode receiver of FIG. 10, according to a longitudinal section F-F.

FIG. 12 represents in section, the anode receiver of FIG. 10, according to a longitudinal section G-G.

FIG. 13 shows in section an anode assembly according to one embodiment.

Figure 14 shows in section, the anode support of Figure 13, along a longitudinal section l-1.

FIG. 15 represents in section, part of the anode support and of the compensation means of FIG. 13, according to a longitudinal section K-K.

FIG. 16 represents, in section, an anode assembly according to another embodiment.

Figure 17 shows in section, the anode support of Figure 16, along a longitudinal section L-L.

FIG. 18 represents in section, part of the anode support and of the compensation means of FIG. 16, according to a longitudinal section N-N.

Figure 1 shows two adjacent electrolysis cells 1 intended for the production of aluminum by electrolysis, each of said cells being associated with an electrolysis device 1 according to a first embodiment of the invention.

The description below is made with respect to a Cartesian frame of reference, shown in FIG. 1, which is linked to each electrolytic cell 1, the axis X being oriented in a transverse direction of the electrolytic cells, the axis Y being oriented in a longitudinal direction of the electrolytic cells, and the Z axis being oriented in a vertical direction of the electrolytic cells. The orientations, directions, planes and longitudinal, transverse and vertical displacements are thus defined in relation to this reference frame.

With reference to Figure 1 and to the Cartesian coordinate system shown in this same figure, the electrolysis cell 1 is arranged perpendicular to the length of a row of electrolysis cells to which it belongs. Thus, it extends lengthwise in the longitudinal direction Y, while the line of electrolytic cells extends lengthwise in the transverse direction X.

Each of the electrolysis cells 1 comprises a casing 3, which may be metallic, for example steel, and an inner lining 5, typically made of refractory materials. Box 3 is generally equipped with reinforcing cradles.

Each of the electrolysis cells 1 comprises at least one cathode assembly arranged at the bottom of the box 3, each cathode assembly comprising at least one cathode 7, which may be formed of several cathode blocks made of carbonaceous material, as well as cathode conductors 9 intended to collect. the electrolysis current to conduct it to cathode outputs 11 passing through well 3.

Each of the electrolytic cells 1 also comprises anode assemblies 12 comprising an anode support 13 and at least one anode block 15 or anode supported by the anode support 13. The anode support 13 comprises a support bar 17 which can extend from substantially horizontal way between two opposite longitudinal edges of the electrolytic cell and the logs 19. The anode block 15 is hung on the anode support 13 by means of the logs 19 sealed with cast iron in holes provided for this purpose in the anode block 15. The anode block 15 can be made of carbonaceous material. The anode block 15 is often of the pre-baked type. In operation, the anode block 15 is immersed in an electrolytic bath 21 contained in each electrolysis tank 1 to be consumed there. The anode assemblies 12 are intended to be removed and replaced periodically when the anode blocks 15 are largely consumed. Due to the consumption of the anode blocks 15, each of the electrolysis cells 1 comprises displacement means 23 for vertically translating the anode assemblies 12 downwards. In this way, the anode blocks 15 are lowered, as and when of their consumption, through an opening 16 delimited by the box 3 and its interior lining 5.

The displacement means 23 comprise, for each electrolytic cell 1, at least two anode receivers 25 intended to cooperate with the anode support 13, 17 to drive the anode assembly 12. The anode receivers 25 can be actuated by jacks 39. More precisely, each anode receiver 25 comprises a contact surface 27 cooperating with an anode contact surface 29 of the anode support 13, 17 to establish with said anode support a mechanical contact making it possible to drive the anode assembly 12 vertically. Occurrence, the contact surface 27 of the anode receivers 25 is arranged above said anode receivers, so that the anode assembly is supported on these anode receivers. Consequently, it is not necessary to have fixing means to fix the anode support 13, 17 on the anode receivers 25. As explained in what follows, the absence of fixing means makes it possible to compensate for the losses. transverse or longitudinal expansions of the anode support 13, 17.

From an electrical point of view, the anode assemblies and the cathode assemblies of each electrolysis cell are electrically supplied by a network of electrical conductors. The cathode outputs 11 of the electrolytic cells 1 are connected to routing conductors 31 to conduct the electrolysis current collected by the cathode conductors 9 to anode conductors electrically supplying the anode blocks 15 of the electrolytic cell. next. These routing conductors 31 generally extend in a substantially horizontal direction. The anode conductors are, for their part, electrically connected between the routing conductors 31 and the anode assemblies 12. The anode conductors are intended to conduct the electrolysis current to the anode assemblies 12 and comprise flexible electrical conductors 33 for s 'adapt, by their flexibility, to the vertical translational movement of the anode assemblies 12 and thus make it possible to maintain the electrical connection during the displacement of the anode assemblies 12. The flexible electrical conductors 33 can be formed by a superposition of electrically conductive flexible sheets. The cathode conductors 9, the cathode outputs 11 and the routing conductors 31 can be formed by metal bars, for example of aluminum, copper or steel.

According to one aspect of the invention, the contact surface 27 of each anode receiver 25 makes it possible to establish with the anode support 13, 17 not only a mechanical contact for vertically moving the anode assembly 12, but also a contact. electrical to conduct the electrolysis current between each anode receiver and said anode support.

To do this, each anode receiver 25 has a drive part 35 which is guided in vertical translation and an electrically conductive part. The drive part 35, which is often made of steel, is driven by the jacks 39 and guided in vertical translation by guide means 51 which can be formed against the box and by the upper part of the box and, where appropriate, by part of a tank superstructure. The conductive part can, for its part, be formed by rigid electrical conductors, non-deformable, for example, formed by a metal bar, in particular of steel, copper, aluminum or a steel / copper composite. The conductive part is one of the anode conductors described above, and thus makes it possible to conduct the electrolysis current to an anode assembly 12. More precisely, the conductive part is electrically connected between, on one side, the flexible electrical conductors 33 , and on the other side, the anode contact surface 29 of the anode support 13, 17. In FIG. 1, only the upper end of the conductive part 37 has been shown, that is to say the part of the anode receiver 25 carrying the contact surface 27. The transport of the electrolysis current in the anode support 13, 17, between the anode contact surface 29 of said support and the anode blocks 15, takes place using electrical conductors 40 , shown in black, integrated into said anode support. The transport of the electrolysis current in the anode support 13, 17 is also done by means of the logs 19. The contact surfaces 27 of the anode receivers 25 being arranged so as to support the anode assembly 12, the weight of this anode. anode assembly thus makes it possible to strengthen the electrical contact between the anode receiver and the anode support. As a result, the conduction of the electrolysis current is improved.

According to another aspect of the invention, the anode receivers 25 of the displacement means 23 are arranged outside a space defined by the top of the anode blocks 15 during their displacement through the opening 16. In fact, during the displacements vertical of the anode assembly 12, whether by means of the displacement means 23 in order to compensate for the consumption of the anode blocks 15, or whether it is using handling tools in the changeover operations anode, the anode receivers 25 do not lie in the vertical translation path of the anode blocks 15. Likewise, the anode conductors are also disposed outside the space defined by the top of the anode blocks 15 during their displacement at through the opening 16. In fact, the end of the anode conductors, which are in contact with the anode support 13, 17, is included in the conductive part 37 of the anode receivers 25, the latter itself being me outside the space defined by the top of the anode blocks 15. It follows that the anode change maneuvers are facilitated. This configuration also makes it possible not to hinder the accessibility of the operating tools in the electrolysis cell. With the exception of a removable cover described below, no equipment is placed above the opening 16 which could impede the accessibility in each electrolysis cell 1.

According to another preferred aspect of the invention, compensation means cooperating, at least functionally, with the displacement means are often necessary to absorb the expansion of the anode support 13, 17.

In the embodiment shown in Figure 1, the contact surface 27 of the anode receiver 25 is flat and horizontal, which makes it possible to absorb any expansion of the anode support 13, 17 by sliding the anode contact surface 29 of this anode support on said contact surface of the anode receiver. It follows that, in this embodiment, the compensation means are essentially formed by the contact surface 27 of the anode receiver 25 and the anode contact surface 29 of the anode support 13, 17. This sliding of the contact surface Anode 29 of the anode support 13, 17 on the contact surface 27 can be facilitated by the use of an electrically conductive grease applied to one of said surfaces.

Each of the electrolysis cells 1 comprises a containment chamber 41 intended for the confinement of the gases generated during the electrolysis reaction. This containment enclosure defines a closed volume above the opening 16 through which the anode assembly 12 is moved vertically. It will be noted that the anode assemblies 12 are fully contained in the confinement enclosure 41. This confinement enclosure is formed, at least in part, by the box 3 and by a removable cover 43. The confinement enclosure 41 may include a superstructure receiving the removable cover 43 and disposed above the box 3. In the embodiment shown, the removable cover 43 rests on a fixed part 45 of a superstructure or an extension of the box 3. The removable cover 43 allows extract and introduce anode assemblies 12, from above, into each electrolysis cell 1, using handling tools. It also facilitates any intervention in the electrolysis cell 1.

The anode receivers 25 of the displacement means 23 are partly in the confinement enclosure 41. An upper part of the anode receivers 25 carrying the contact surface 27 is disposed inside the confinement enclosure 41. A lower part of these same anode receivers 25, fixed to each jack 39 and electrically connected to the flexible conductors 33, is arranged outside the confinement enclosure 41. The flexible electrical conductors 33 and the jacks 39 are arranged outside of the confinement enclosure 41. The upper part of the anode receivers 25 carrying the contact surfaces 27 extends inside the confinement enclosure 41, so that the electrical connection with the anode support 13, 17 is made inside the confinement enclosure 41. Thus, the anode assembly 12 is free from any interaction with the box 3, the removable cover 43, and, where appropriate, the superstructure which form the enclosure confinement inte 41. In this way, the confinement enclosure 41 does not risk being affected, either by the replacement of the anode assembly, or by the displacement of the anode assembly downwards as and when consumption of anode blocks 15.

Dynamic seals are arranged around the anode receptors 25 at the level of the passage of the containment enclosure 41 by the anode receptor in order to prevent the gases generated during the electrolysis reaction from leaving the enclosure. 41. To improve the tightness of the containment 41, more particularly at the junction between the removable cover 43 and the fixed part 45, it can be provided that each electrolysis cell 1 comprises gaskets 'Sealing 47 interposed between the removable cover 43 and the fixed part 45 on which said removable cover 43 rests.

Figures 2 and 3 show that the removable cover 43 can include a plurality of adjacent covers 53 substantially longitudinal and parallel to each other, extending in a direction X substantially transverse, between two opposite longitudinal edges of each electrolytic cell 1 In the embodiment shown in Figures 4, 5, 6, 7 and 8, the compensation means are arranged in the anode receivers 125, 126 of the displacement means 123 associated with each electrolytic cell 101, that is, to say more precisely between the upper part of the anode receivers 125, 126 carrying the contact surfaces 127, 128 and the drive part 135, 136 of these same anode receivers guided in vertical translation. The compensation means comprise connecting elements 161 arranged in the anode receivers 125 arranged to the left of each electrolytic cell and connecting elements 171 of another type arranged in the anode receivers 126 arranged to the right of each electrolytic cell. electrolysis 101. The connecting elements 161 are of the connecting rod type, while the connecting elements 171 are of the ball joint type. The connecting elements 161, 171 of the compensation means are arranged between the upper part and the drive part 135, 136 of the anode receivers 125, 126.

Unlike the embodiment shown in Figure 1, the anode support 13, 17 of the anode assemblies 12 shown in Figure 4 is fixed to the anode receivers 125, 126 by means of fixing means comprising two complementary threads whose cooperation allows the fixing of the anode support 13, 17 by simple screwing using the screws 181. The fixing means could comprise any type of connector, for example screw, making a plating and a compression of the anode support 13, 17 against the anode receivers 125, 126.

Referring to Figures 5 and 6, showing in more detail the anode receivers 125 arranged to the left of each electrolytic cell 101, the drive part 135 comprises a lifting mast 163 driven in vertical translation by the jack 39. The drive part also comprises a steel sole 165 connected to the lifting mast 163 by means of the connecting element 161 of the rod type. The conductive part 137 comprises, for its part, two rigid lateral conductors 167 which are connected in their lower part to the flexible conductors 33 shown in FIG. 4. The conductive part 137 further comprises a conductive sole 169 made of copper disposed on the sole 165 and electrically connected to the two lateral conductors 167. The lateral conductors 167 are mechanically fixed to the steel sole 165 and welded to the conductive sole 169.

Referring to Figures 7 and 8, showing in more detail the anode receivers 126 arranged to the right of each electrolytic cell 101, the configuration of the anode receivers 126 is similar to the anode receivers 125, except that the connecting element 171 is ball joint type. The driving part 136 comprises a lifting mast 173 driven in vertical translation by the cylinder 39. The driving part also comprises a steel sole 175 connected to the lifting mast 173 via the link member 171. ball joint type. The conductive part 138 comprises, for its part, two rigid lateral conductors 177 which are connected in their lower part to the flexible conductors 33 shown in FIG. 4. The conductive part 138 further comprises a conductive plate 179 made of copper which is arranged. on the sole 175 and which is electrically connected to the two lateral conductors 177. The lateral conductors 177 are mechanically fixed to the steel sole 175 and welded to the conductive sole 179.

The connecting rod type 161 and ball joint type connecting elements thus make it possible to absorb any expansion of the anode supports 13, 17. The connecting rod type connecting element 161 is mounted with its axes of rotation oriented in the longitudinal direction Y, which makes it possible to absorb any expansion of the anode support 13, 17 along the transverse direction. If the axes of rotation of the connecting rod-type linkage had been oriented in the transverse direction X, compensation would be applied to absorb any expansion of the anode support along the longitudinal direction. The ball-and-socket-type connecting element 171, for its part, absorbs any expansion of the anode support 13, 17 along the transverse direction and the longitudinal direction.

According to an embodiment not shown, the displacement means are equipped with at least two anode receivers per anode assembly, arranged on either side of the box relative to the transverse direction, a first connecting element of the connecting rod type being mounted on one of the anode receptors so as to absorb any expansion of said anode support along the transverse direction, and a second connecting rod-type connecting member being mounted on the other anode receptor so as to absorb any expansion of said anode support along the longitudinal direction.

For each anode assembly, it is also possible to envisage having at least one connecting element arranged on at least one anode receiver arranged on only one side of the cell of the electrolytic cell.

In the embodiment shown in Figures 9, 10, 11 and 12, the compensation means are, as in the embodiment of Figure 4, arranged in the anode receivers of the displacement means associated with each electrolytic cell 201.

Unlike the embodiment shown in Figure 1, the anode support 13, 17 of the anode assemblies 12 shown in Figure 9 is fixed to the anode receivers 225 by means of fixing means comprising two complementary threads whose cooperation allows the fixing of the anode support 13, 17 by simple screwing using screws 281.

Referring to Figures 10, 11 and 12, showing in more detail the anode receivers 225, the drive part 235 of the anode receiver 225 comprises a ring 283 or casing surrounding the conductive part of this same anode receiver. The strapping 283 is made of rigid steel and constitutes the main part of the drive part 235 of the anode receiver 225. The strapping is driven in vertical translation by means of the jack 39. As can be seen in Figures 11 and 12, a clearance is left between the conductive part 237 and the strapping 283, so that said conductive part can move to take up the thermal expansion or any other defect in the flatness of the anode support 13, 17. A sliding pivot 285 is arranged in the lower part of the anode receiver 225 to support the conductive part 237. The sliding pivot 285 could also be arranged perpendicular to that shown in Figures 10 and 11, for example on the anode receiver 225 supporting the same anode assembly and placed on the other side of the box.

The compensation means can also be arranged in the anode support of the anode assembly. Anode assemblies 301, 401 incorporating such anode supports have been shown, by way of example, in Figures 13 to 18.

Referring to Figures 13 and 16, the anode support 303, 403 of the anode assemblies 301, 401 extends along a main direction corresponding to the transverse direction X when the anode assembly is installed in the electrolysis device. A Cartesian coordinate system has been shown in Figures 13 and 16, as an indication, to show the positioning of these anode assemblies with respect to the electrolytic cells. The expansion of the anode supports 303, 403 takes place essentially along the main direction. The expansion takes place, to a lesser extent, along a secondary direction of the anode supports 303, 403 corresponding to the longitudinal direction Y when the anode assembly is installed in the electrolysis device.

The anode supports 303, 403 of the anode assemblies 301, 401 comprise reinforcements 305, 405 supporting several anode blocks 307, 407 by the intermediary of logs 309, 409. The anode supports 303, 403 also comprise a conductive part 311, 411 formed. by flexible electrical conductors. Each of the anode supports 303, 403 comprises two anode contact surfaces having the form of soles 313, 413 intended to cooperate with corresponding contact surfaces of the anode receivers to establish an electrical contact and a mechanical contact. The anode contact surfaces 313, 413 are arranged outside a space defined by the top of the anode blocks 307, 407, which allows these anode assemblies to be supported on anode receivers of an electrolysis device which are arranged in outside the vertical translation path of the anode blocks. The anode contact surfaces 313, 413 are arranged in the conductive parts 311, 411 and are essentially constituted by copper flanges of said conductive parts. Thus, the electrical contact between the anode receivers and the anode carriers is improved.

As can be seen in FIGS. 14 and 17, the reinforcements 305, 405 comprise beams the profile of which has a shape and a dimension which makes it possible to reduce the bending of said beams under the weight of the anode blocks. The conductive parts 311, 411 can be formed by copper plates or strips which are not continuously mechanically linked with the reinforcements 305, 405 of the anode support. As can be seen in FIGS. 13 and 16, the conductive parts 311, 411 are more particularly linked to the reinforcements 305, 405 only at the level of the anodic contact surfaces 313, 413 and the logs 309, 409. The conductive parts 311, 411 can be combined. deform slightly on the sections not linked to the reinforcements 305, 405 so as to absorb any thermal expansion of the anode support 303, 403.

Referring to Figures 13, 14 and 15, the compensation means of the anode support 301 comprise a connecting rod type connecting element 321 disposed between the anode contact surface 313 to the right of the anode assembly 301 and a main part of the reinforcement 305. The means for compensating the anode support 303 comprise another ball joint type connecting element 322 disposed between the anode contact surface 313 to the left of the anode assembly and a main part of the reinforcement 305. More precisely, the connecting elements 321, 322 are arranged between the beam of the frame 305 and the steel flanges 325 supporting the copper flanges forming the anodic contact surfaces 313.

The connecting rod-type connecting element 321 is mounted with its axes of rotation oriented in the secondary direction Y, which makes it possible to absorb any expansion of the anode support 303 along the main direction X. The connecting element of the type connecting rod can be called a connecting rod for taking up the longitudinal thermal expansion of the beam constituting the anode support. If the axes of rotation of the connecting rod-type linkage had been oriented in the primary direction X, compensation would be applied to absorb any expansion of the anode support along the secondary direction Y. The link element 322 of type ball joint makes it possible to absorb any expansion of the anode support along the transverse direction and the longitudinal direction. The ball joint type connecting element can be called a ball joint for taking up torsional defects of the beam constituting the anode support.

Referring to Figures 16, 17 and 18, the compensation means of the anode support 301 comprise two connecting elements of sliding type 421 or of sliding type, each of said connecting elements being arranged between one or the other of the surfaces of anode contact 413 of the anode assembly and a main part of the frame 405. More specifically, the connecting elements 421 are arranged between the beam of the frame 405 and steel flanges 425 supporting the copper flanges forming the surfaces of anode contact 413. The sliding-type connecting elements 421 are formed on one side by the beam of the frame 405, the profile of which forms a slide, and on the other side by slides mounted to slide in the slide, each said slides carrying the copper sole of each anode contact surface 413. The connecting element 421 thus makes it possible to absorb any expansion of the anode support 403 along the main direction X. By ail their sliding type connecting elements 421 can further allow a slight rotation or pivot of the flanges 425 about an axis parallel to the main direction X, due to the substantially cylindrical shape of the slides. The connecting element 421 thus makes it possible to absorb any expansion of the anode support 403 along the secondary direction Y.

According to an embodiment not shown, the compensation means of the anode assembly could comprise a single connecting element on one side or the other of the anode support. The connecting means could also include a ball or pivot type connecting element on one side of the anode support and a sliding type connecting element on the other side of said anode support.

An advantage of the present invention is to facilitate access for handling and intervention tools in the box, in particular for anode change maneuvers, by proposing a configuration in which the space above the opening delimited by the interior lining of the box is clear.

Another advantage of the present invention is to facilitate the assembly and disassembly of the anode assembly.

Yet another advantage of the present invention is to limit the mechanical interactions with the anode conductors during the anode change operations, which makes it possible to reduce their wear and prevent their damage.

Yet another advantage of the present invention is that it allows the anode change maneuvers to be carried out without stopping the production of aluminum in the vessel.

An advantage of a preferred embodiment of the present invention is to allow any expansion of the anode support to be absorbed, in particular during anode change operations, and this without affecting the operation of the means for moving the anode assembly.

Claims (25)

1. An electrolysis device intended for the production of aluminum comprising a box (3) comprising an internal coating (5) defining an opening (16) through which at least one anode block (15) is intended to be moved, said at least one anode block being suspended from an anode support (13, 17) forming with said at least one anode block an anode assembly (12) movable relative to the box, said device further comprising movement means (23) comprising at least one anode receiver (25; 125, 126; 225) intended to cooperate with said anode support to move the anode assembly (12) in a substantially vertical direction (Z), said anode support (13, 17) being intended to be connected to anode conductors to bring an electrolysis current to said at least one anode block (15), characterized in that said at least one anode receiver (25; 125, 126; 225) is arranged outside of 'a space defined by the top of said at least one anode block (15) as it moves through the opening (16), said at least one anode receiver (25; 125, 126; 225) comprising a contact surface (27; 127, 128) cooperating with a corresponding anode contact surface (29) of the anode support (13, 17) to establish with said anode support, an electrical contact to conduct the electrolysis current between said at least one anode receiver (25; 125, 126; 225) and the anode assembly (12), and a mechanical contact for moving said anode assembly (12) in the substantially vertical direction. 2. Device according to claim 1, characterized in that it is intended to receive several anode assemblies (12) distributed along a longitudinal direction (Y) of the box (3), the anode support (13, 17) of said anode assemblies (12) extending along a transverse direction (X) of said box, said device further comprising compensation means (27, 29; 161, 171) cooperating with the displacement means (23) to absorb expanding said anode support (13, 17) along the transverse direction (X) and / or the longitudinal direction (Y). 3. Device according to claim 2, characterized in that the contact surface (27; 127, 128) of the at least one anode receiver (25; 125, 126; 225) is arranged above said at least one anode receiver to support the anode receiver. 'anode assembly (12). 4. Device according to one of claims 2 and 3, characterized in that the at least one anode receiver (25; 125, 126; 225) comprises a drive part (35; 135, 136; 235) guided in translation. in the substantially vertical direction (Z) and an electrically conductive part (37; 137, 138; 237). 5. Device according to claim 4, characterized in that the contact surface (27; 127, 128) of the at least one anode receiver (25; 125, 126; 225) is arranged on the conductive part of said at least one anode receiver (37; 137, 138; 237). 6. Device according to claim 5, characterized in that the contact surface (27) is substantially horizontal, the compensation means being essentially formed by said contact surface (27) and the anode contact surface (29) of the anode support (13, 17) cooperating with said contact surface (27), the expansion of the anode support (13, 17) along the transverse direction (X) being absorbed by sliding of said anode contact surface (29) on said surface contact contact (27) in the transverse direction (X) and / or in the longitudinal direction (Y) of said support surface. 7. Device according to claim 6, characterized in that the sliding of the anode contact surface of the anode support (13, 17) on the contact surface (27) is facilitated by the use of a conductive grease of the electricity applied to one of said surfaces. 8. Device according to claim 5, characterized in that the compensation means (161, 171) are arranged in the at least one anode receiver (125, 126; 225). 9. Device according to claim 8, characterized in that the compensation means (161, 171) are arranged between an upper part of the at least one anode receiver (125, 126; 225) carrying the contact surface (127, 128) and the driving part (135, 136). 10. Device according to claim 9, characterized in that the compensation means comprise at least one connecting element (161) between the upper part and the drive part (135, 136) making it possible to absorb the expansion of said anode support. (13, 17) along the transverse direction (X) or the longitudinal direction (Y), such as a connecting rod type connecting member. 11. Device according to claim 10, characterized in that the displacement means (23) are equipped with at least two anode receivers (125, 126) per anode assembly (12), arranged on either side of the box ( 3) with respect to the transverse direction (X), a first connecting element (161) of one of the anode receptors (125) making it possible to absorb any expansion of said anode support (13, 17) along the transverse direction (X), and a second connecting element (171) of the other anode receiver (126) making it possible to absorb any expansion of said anode support (13, 17) along the longitudinal direction (Y). 12. Device according to claim 9, characterized in that the compensation means comprise at least one connecting element (171) between the part. 5 upper and the driving part (135, 136) for absorbing the expansion of said anode support (13, 17) along the transverse direction (X) and the longitudinal direction (Y), such as an element ball joint type. 13. Device according to any one of claims 10 to 12, characterized in that the drive part (135, 136) of the at least one anode receiver (125, 126) comprises 10 a lifting mast (163, 173) driven in translation and a sole (165, 175) connected to said lifting mast (163, 173) via the link member (161, 171), the part conductor (137, 138) comprising at least one side conductor (167, 177) and a conductor plate (169, 179) disposed on said sole (165, 175) electrically connected to said at least one side conductor (167,177). 14. Device according to claim 8, characterized in that the driving part (235) comprises a band (283) surrounding the electrically conductive part (237) with sufficient clearance to allow said conductive part (237). ) to deform inside said strapping (283) and thus absorb the expansion of the anode support (13, 17) along the transverse direction (X) and / or the longitudinal direction (Y). 15. Device according to any one of claims 1 to 14, characterized in that the displacement means (23) are equipped with at least two anode receivers (25; 125, 126; 225) per anode assembly (12). , said anode receivers being respectively arranged along each longitudinal wall of the box (3), outside of said box (3). 25 16. Device according to claim 15, characterized in that the at least two anode receivers (25; 125, 126; 225) per anode assembly (12) are associated with separate motorization means (39). 17. Device according to any one of claims 15 or 16, characterized in that it comprises guide means arranged along the longitudinal walls of the box 30 (3), outside of said box (3), said means guide being arranged in a welded structure forming said box (3). 18. Device according to any one of claims 2 to 17, characterized in that the opening (16) delimited by the internal coating (5) of the box (3) and the anode assembly (12) is covered by a cover removable (43). 19. Anode assembly (12; 301; 401) intended to be installed in a device 5 electrolysis for the production of aluminum, said anode assembly comprising an anode support (13, 17; 303; 403) and at least one anode block (15; 307; 407) suspended from said anode support, said anode support being intended to be connected to anode conductors to supply an electrolysis current to said at least one anode block (15; 307; 407), said at least one anode block being intended to be moved in a substantially vertical direction ( Z) through an opening (16) delimited by a box (3) and its interior coating (5) of said electrolysis device using at least one anode receiver (25; 125, 126; 225) means for moving (23) said electrolysis device cooperating with said anode support, characterized in that the anode support (13, 17; 303; 403) has at least one anode contact surface (29; 313; 413) cooperating with a corresponding contact surface (27; 127, 128) of said at least one receptacle eur anode (25; 125, 126; 225) to establish with said at least one anode receiver, an electrical contact to conduct the electrolysis current between said at least one anode receiver (25; 125, 126; 225) and the anode assembly (12; 301; 401) , and a mechanical contact for moving said anode assembly (12; 301; 401) in the substantially vertical direction, the at least one anode contact surface (29; 313; 413) of the anode support (13, 17; 303; 403). ) being disposed outside a space defined by the top of said at least one anode block (15; 307; 407). 20. Anode assembly according to claim 19, characterized in that the anode support (303; 403) of the anode assembly (301; 401) extends along a main direction corresponding to a transverse direction (X). of the well (3) when the anode assembly is received in the electrolysis device, and in that said anode support (303; 403) comprises compensation means for absorbing the expansion of said anode support (303; 403) along of said main direction and / or of a secondary direction of said anode support (303; 403) corresponding to a longitudinal direction (Y) of said well when the anode assembly is installed in said electrolysis device. 21. Anode assembly according to claim 20, characterized in that the anode support (303; 403) comprises a frame (305; 405), supporting the at least one anode block (307; 407), and a conductive part (311; 411) of electricity, the at least one anode contact surface (313; 413) of said anode support being provided in said conductive part (311; 411). 22. Anode assembly according to one of claims 20 or 21, characterized in that 5 the compensation means of the anode support comprise at least one connecting element, such as a connecting rod-type connecting element (321) or a sliding-type connecting element (421), disposed between the at least one contact surface anode (313; 413) and a main part of the frame, to absorb any expansion of said anode support (301; 401) along the main direction or the secondary direction. 10 23. Anode assembly according to claim 22, characterized in that the anode support (303) comprises two anode contact surfaces (313) arranged on each side of said anode support with respect to the main direction, a first connecting member (321) disposed between one of the anodic contact surfaces and the main part of the frame (305) for absorbing any expansion of said anode support along the main direction and a second link member (322) disposed between the another anode contact surface and the main part of the frame (305) making it possible to absorb any expansion of said anode support along the secondary direction. 24. Anode assembly according to one of claims 22 or 23, characterized in that at least one connecting element (322) makes it possible to absorb the expansion of the anode support 20 (303) along the main direction (X) and the secondary direction (Y), such as a ball joint type connecting member. 25. Electrolysis cell characterized in that it comprises an electrolysis device according to any one of claims 1 to 18, said electrolysis cell further comprising an electrolysis cell (1; 101; 201; 201 ) formed at least in part by the box 25 (3) and the inner coating (5) of said electrolysis device, and at least one anode assembly (12) comprising at least one anode block (15) intended to be partially immersed in an electrolyte bath (21) contained in said tank. 26. Electrolysis plant for the production of aluminum comprising a plurality of electrolysis devices according to any one of claims 1 to 18.