Intervention tools for the operation of electrolytic cells

Abstract

The invention relates to an intervention tool (2) which is movable and designed to reposition an anode assembly (38) of an electrolytic cell (3). The intervention tool (2) comprises a mounting (22) provided with one or more bearing surfaces (220) to allow the intervention tool (2) to be pressed against and stably supported directly on at least one element of the electrolytic cell (3), and an intervention unit designed to reposition the anode assembly (38).

Description

[0001] The present invention relates to an intervention tool designed to perform a predetermined intervention on an electrolytic cell and to an intervention device comprising the intervention tool. The present invention also relates to an electrolytic cell comprising the intervention device and an aluminum smelter comprising the electrolytic cell. The present invention also relates to a method of intervening on the electrolytic cell.

[0002] The industrial production of aluminum from aluminum oxide by electrolysis according to the Hall-Héroult process is well known. For this purpose, rectangular electrolytic cells are provided, such as Figure 1 As shown, it conventionally includes: a steel tank shell 31, in which a refractory coating is laid; a carbonaceous material cathode 33, which is traversed by a cathode conductor, and the cathode conductor is designed to collect the electrolysis current at the cathode 33 to conduct it to a cathode outlet passing through the bottom or side of the tank shell; and an electrolytic bath 35, in which alumina is dissolved.

[0003] The electrolytic cell comprises several anode assemblies 38, each comprising a substantially vertical anode rod 36 and an anode 37 formed by at least one anode block suspended from the anode rod 36 and immersed in the electrolytic bath 35. The anodes 37 are more particularly of the prebaked anode type with prebaked carbon blocks, i.e. baked before introduction into the electrolytic cell.

[0004] The electrolytic cell comprises an upper structure 30, which extends above the tank shell 31 to support and guide the anode frame 34 that moves vertically. The upper structure 30 is specifically composed of at least one beam that extends above the tank shell 31 in the longitudinal direction of the cell and is supported by legs arranged at the lateral edges of the tank shell 31. Typically, the upper structure 30 also includes a device for extracting cell gas and a device for supplying aluminum oxide. Anode assemblies 38 are suspended from the anode frame 34 along two rows at regular intervals by means of a removable connector 32 that presses the anode rod 36 against the anode frame 34. An electric conductor 39 for raising the electrolysis current that carries the electrolysis current from the cathode outlet of the previous electrolytic cell to the anode frame 34 extends obliquely upward from the longitudinal edge of the tank shell 31.

[0005] As the electrolysis reaction proceeds, the anode blocks are consumed and the anode assembly 38 is gradually lowered toward the cathode 33 to ensure that the distance between the lower surface of the anode 37 and the surface of the metal pool formed on the cathode 33 remains substantially constant.

[0006] The displacement of the anode assemblies 38 is collective, in that all anode assemblies 38 attached to the same anode frame 34 are displaced simultaneously due to the displacement of the anode frame 34 .

[0007] For operation of the electrolytic cell, it is generally necessary to position the anode assemblies 38 so that the lower surfaces of their anodes 37 are in a reference plane, in particular coincident with a plane containing the lower surfaces of the other anodes 37 of the electrolytic cell (also called anode plane).

[0008] However, sometimes it happens that when some anodes 37 are placed in the cell, they wear faster or slower than adjacent anodes 37, slip slightly or are improperly positioned so that their lower surface is no longer contained in the anode reference plane, causing electrolytic cell performance problems or creating adverse operating problems, such as short circuits. The corresponding anode assembly 38 must advantageously be repositioned so that the lower surface of the anode 37 is again in the anode reference plane. This individual repositioning of the anode assembly 38 is also referred to as anode height adjustment. The anode frame 34, which jointly supports and displaces a plurality of anode assemblies 38, does not allow such an adjustment.

[0009] To overcome this difficulty, a known solution is to equip each anode assembly 38 with an actuator or jack, allowing it to be moved individually. However, such individual motorized solutions are relatively expensive and not easily implemented in pre-existing aluminum smelters.

[0010] Another known solution is to use a handling crane (also called a tank management machine) that circulates in the potroom above the electrolytic cells and is guided by an operator to reposition an improperly positioned anode assembly. To this end, the electrolytic service machine that circulates in the potroom above the electrolytic cells includes a screw drive machine to tighten-loosen a removable connector that works with a clamping arm to allow clamping the anode rod, usually by its upper end, and repositioning the anode assembly by raising or lowering the anode assembly. However, the number of electrolytic service machines in an aluminum smelter is limited, and these machines are required for a variety of operations, so their availability is limited. In addition, the electrolytic service machine cannot traverse paths in the potroom. Therefore, the electrolytic service machine cannot be used as part of a process for continuous improvement of operations involving regular repositioning of anode assemblies.

[0011] In general, document FR3024466 discloses a vehicle for operating electrolytic cells that can be moved from one electrolytic cell to another to perform interventions therein. However, the vehicle circulates in a channel where other vehicles move for performing various operations on the cells, or in which pallets are temporarily stored for use in the operation of the cells, in particular for supporting new or used anode assemblies.

[0012] The present invention therefore aims to overcome all or part of these drawbacks by proposing an intervention tool designed to intervene in an electrolytic cell, in particular for repositioning the anode assembly quickly and at low cost without hampering the circulation of operators or other vehicles.

[0013] To this end, the subject of the invention is a movable intervention tool designed to reposition the anode assembly of an electrolytic cell, characterized in that the intervention tool comprises a mounting provided with one or more bearing surfaces allowing the intervention tool to be pressed against and stably supported directly on at least one element of the electrolytic cell, and an intervention unit designed to reposition the anode assembly.

[0014] The intervention tool according to the invention is suitable for being positioned on an electrolytic cell, in which occasional interventions are performed, and subsequently being moved, for example, by an electrolytic service machine, a vehicle moving in a channel or a handling device similar to that described below.

[0015] The intervention tool saves time, since the electrolysis service machine may only be needed to locate the tool before the intervention and to subsequently retrieve the tool after the intervention. In fact, the intervention is performed autonomously by the intervention tool and not by the electrolysis service machine.

[0016] Furthermore, the intervention tool allows the electrolytic cell to be the element that supports the weight of the intervention tool during the intervention. Thus, when the anode assembly is repositioned, this allows the weight of the anode assembly held by the intervention tool to be supported by the electrolytic cell.

[0017] Repositioning refers to adjusting the height of the anode of the anode assembly so that its lower surface is in a determined position.

[0018] According to one embodiment, the bearing surface is configured to allow the intervention tool to be supported by an element fixed relative to the anode frame of the electrolytic cell.

[0019] This element can be the anode frame itself, the connector, the connector shaft or a hook supporting the connector. This feature allows the intervention tool to be kept in a reference frame that is fixedly displaced relative to the anode frame, thus avoiding problems associated with continuous displacement of the anode frame and other cell elements attached to the anode frame. Thus, the repositioning of the anode assembly can be performed according to a determined position difference that is not affected by the duration of the intervention combined with continuous displacement of the anode frame.

[0020] Advantageously, the bearing surface defines a recess designed to engage a shaft of the electrolytic cell connector.

[0021] According to one embodiment, the mounting of the intervention tool comprises reversible fixing means adapted to create a reversible attachment between the mounting and the electrolytic cell element.

[0022] Thus, when the intervention tool is in the working position, pressed against at least one element of the cell, the intervention tool may also be attached to at least one element of the cell to further improve the stability of the intervention tool on the cell and to increase the level of stress that the intervention tool may be subjected to during interventions on the cell. This element may be the anode frame itself, the connector, the connector shaft or a hook supporting the connector.

[0023] Advantageously, the reversible fixing means comprise one or more locking tabs movable relative to the mounting between a retracted position and a deployed position, said locking tabs being configured to cooperate with an element of the electrolytic cell, more precisely with an element fixed relative to the anode frame, such as a connector, a connector shaft, an anode frame or a hook supporting the connector, when the intervention tool is in the working position. Thus, the locking tabs together with the bearing surface make it possible to attach the intervention tool to the electrolytic cell.

[0024] According to one embodiment, the intervention unit is configured to allow a vertical displacement of the anode assembly relative to the frame.

[0025] According to one embodiment, the intervention unit comprises a part movable relative to a frame, displacement means for moving said movable part in translation relative to the frame, said movable part comprising engagement means configured to engage an anode rod of an anode assembly of an electrolytic cell so as to fix the anode rod and the movable part in translation.

[0026] These features allow the intervention tool to reposition the anode assembly for which a possible optimization of the vertical positioning is detected, i.e. an individualized displacement of the anode assembly, in particular in order to reposition the lower surface of the anode assembly in the anode plane. Based on the desired positioning of the anode assembly, the movable part can be moved vertically, upwards or downwards, with the anode assembly in translation relative to the mounting.

[0027] This movable intervention tool, in particular along the superstructure, makes it possible to reposition all the anode assemblies of a cell individually, if necessary one after the other, with the aid of handling equipment facing the anode assemblies of each cell. The engaging means for fixing the anode rod and the movable part of the intervention tool in translation comprise conventional clamping means, such as a clamp or a vise that clamps the anode rod between two opposing jaw members.

[0028] According to one embodiment, the intervention unit comprises tightening / loosening means adapted to tighten / loosen a connector holding the anode assembly in place in the electrolytic cell.

[0029] These tightening / loosening means are advantageously screwdrivers engaging with the threaded rod of the connector when the intervention tool is in the working position.

[0030] According to one embodiment, the intervention tool, more particularly the mounting element, comprises gripping means complementary to the gripping means of the handling device.

[0031] Thus, the movable intervention tool can be brought into the working position by means of the handling device.

[0032] The gripping device may be configured to suspend a hoisting cable, allowing the tool to be lowered onto the electrolytic cell to perform a predetermined intervention or to be lifted to remove it from the electrolytic cell.

[0033] According to one embodiment, the intervention tool comprises position detection means. The position detection means may be of contact sensor or optical sensor type. Thus, the intervention tool can detect that it is pressing against an electrolytic cell element and thus actuate the intervention unit.

[0034] Advantageously, the intervention tool comprises a wire supply and an automatic reel designed to wind the wire supply. An automatic reel is a reel that applies a restoring force to the winding position of the wire, pipe or cable and allows the wire, pipe or cable to be unwound by a pulling force greater than the restoring force on the wire, pipe or cable.

[0035] According to a second aspect, the invention also relates to an intervention device comprising an intervention tool having the above characteristics and a handling device comprising a chassis carrying the intervention tool and a displacement device suitable for allowing displacement of the chassis, the displacement device being meant suitable for pressing against a superstructure.

[0036] Thus, the intervention tool can be brought by the handling device to various locations along the superstructure of the electrolytic cell in order to perform operations therein, without requiring intervention by the electrolytic service machine and without having to circulate in channels close to the electrolytic cell.

[0037] The superstructure refers to the structure supporting the anode frame and any fixed elements of the electrolytic cell attached to the anode frame, such as, for example, means for extracting cell gas and equipment for supplying alumina. For example, the superstructure comprises beams extending above the tank shell in the longitudinal direction of the cell and supported by feet arranged at the transverse edges of the tank shell. The superstructure against which the displacement devices are pressed supports these displacement devices and handling equipment.

[0038] The intervention device thus makes it possible in particular to use the same intervention tool for several anode assemblies arranged at regular intervals along the superstructure of the electrolytic cell, thereby reducing costs.

[0039] Thus, the intervention device provides the possibility to periodically reposition the anode assemblies individually and also increases the availability of the electrolysis service machine for other operations, also reducing the operating costs.

[0040] According to one embodiment, the handling device comprises a lifting device configured to raise or lower the intervention tool between a parking position and a working position, wherein the parking position can keep the intervention tool at a certain distance from the electrolytic cell, and the working position allows the intervention tool to be lowered to contact the electrolytic cell.

[0041] These lifting devices may consist of jacks or articulated arms, but advantageously, according to one embodiment of the invention, the lifting devices are cable lifting devices.

[0042] A cable lift refers to any lifting device comprising a long and flexible element designed to lower or tow a load from above, such as a cable, tether, strap, rope, chain or equivalent.

[0043] Since the chassis is positioned above the superstructure, that is to say above the intervention area of ​​the intervention tool, it is advantageous to use a cable lifting device which is essentially simple, reliable and inexpensive.

[0044] According to one embodiment, the lifting device comprises a mobile crane or a winch.

[0045] According to one embodiment, the lifting device comprises means for detecting the arrival of the intervention tool in the working position.

[0046] The height at which the intervention tool is in the working position depends on the height of the anode frame which varies with time. Thus, when the intervention tool contacts and presses against the anode frame or a cell element fixed relative to the anode frame, such as a connector, a connector shaft or a hook formed on the anode frame to support the connector, the lowering of the stopped intervention tool can be controlled. The detection device can be of contact sensor or optical sensor type.

[0047] According to one embodiment, the handling device comprises a guiding device configured to guide the intervention tool according to a predetermined path from the parking position to the working position.

[0048] This feature allows the intervention tool to be brought precisely to the intervention area.

[0049] According to one embodiment, the guiding means comprise two parallel flanges between which the intervention tool extends in the parking position, each flange comprising a groove designed to receive and guide an element attached to the intervention tool.

[0050] These flanges ensure robust and efficient guidance, preventing any tilting or awkward gaps.

[0051] According to one embodiment, the handling device comprises retaining members designed to prevent the chassis carrying the intervention tool from tilting on either side of the superstructure.

[0052] This allows the intervention tool to be lowered or raised in a safe manner.

[0053] According to one embodiment, the handling apparatus carries two intervention tools arranged on opposite sides of the chassis.

[0054] This makes it possible to balance the masses at the handling equipment and to have two intervention tools available per electrolytic cell, each intervention tool being designed to intervene in half of the electrolytic cell. Thus, the operating efficiency of the electrolytic cells and the aluminium smelter is increased.

[0055] Alternatively, the handling apparatus carries a single intervention tool arranged on a rotating platform positioned on a chassis.

[0056] According to one embodiment, the displacement means allow the bottom plate to be displaced along the superstructure of the electrolytic cell.

[0057] According to one embodiment, the chassis moves over the superstructure.

[0058] Thus, the same tool can advantageously and easily intervene on both sides of the electrolytic cell.

[0059] According to a third aspect, the invention relates to an electrolytic cell comprising a superstructure, an anode frame supported by said superstructure, and an intervention device having the above-mentioned characteristics, wherein said superstructure comprises a surface against which the displacement means bear.

[0060] Therefore, the handling equipment designed to transport intervention tools moves over the electrolytic cells instead of in the channels serving the electrolytic cells. This reduces congestion in the pot room and improves safety.

[0061] All the cells of an aluminium smelter can be equipped with intervention equipment, allowing the intervention tools to be moved and perform interventions in different areas of each cell without creating harmful congestion in the working channels adjacent to the cells, or mobilising the pot service machines.

[0062] According to one embodiment, the surface against which the displacement device is pressed is an upper surface of the superstructure.

[0063] This embodiment is the simplest since the superstructure typically comprises a substantially flat upper surface extending the entire length of the electrolytic cell.

[0064] According to one embodiment, the superstructure and / or the displacement device forms a displacement path for the undercarriage at least over the entire length of the anode frame.

[0065] Thus, an intervention tool carried by the handling device can be moved and brought to an intervention position close to all anode assemblies supported by the anode frames.

[0066] According to one embodiment, the displacement path presents a parking track at one end of the electrolytic cell.

[0067] This allows the handling equipment to clear the space above the anode frames, for example for the passage or intervention of electrolysis service machines.

[0068] According to one embodiment, the displacement device comprises a guide device designed to guide the base pan translationally in the longitudinal direction of the electrolytic cell.

[0069] These guide means ensure precise positioning of the handling device on the superstructure and may in particular be rails forming a displacement path and cooperating with wheels arranged on the chassis.

[0070] According to one embodiment, the displacement means comprises drive means configured to move the chassis along the superstructure.

[0071] The handling equipment can move autonomously on the superstructure of the electrolytic cell.

[0072] According to a fourth aspect, the present invention relates to an aluminium smelter comprising at least one electrolytic cell having the above-described characteristics.

[0073] According to a fifth aspect, the subject of the invention is a method for intervention in an electrolytic cell by means of an intervention tool having the above-mentioned characteristics, comprising the following steps:

[0074] - bringing said intervention tool into the working position,

[0075] - performing the intervention using said intervention tool,

[0076] - Retrieve said intervention tool.

[0077] According to one particular embodiment, the intervention in the electrolytic cell is the repositioning of the anode assembly and comprises the following steps:

[0078] - engaging said intervention tool with the anode rod of the anode assembly to be repositioned,

[0079] - loosen the cell connector to release the anode rod,

[0080] - displacing the anode assembly so that the lower surface of the anode assembly is brought to a predetermined position,

[0081] - tighten the connector,

[0082] - Disengaging the intervention tool and the anode rod.

[0083] Other features and advantages of the invention will emerge clearly from the following detailed description of an embodiment thereof given by way of non-limiting example with reference to the accompanying drawings, in which:

[0084] [ Figure 1 ] Figure 1 is a cross-sectional view of an electrolytic cell according to the prior art,

[0085] [ Figure 2 ] Figure 2 is a perspective view of an intervention device according to an embodiment of the present invention,

[0086] [ Figure 3 ] Figure 3 is a side view of an intervention device and an electrolytic cell according to one embodiment of the present invention,

[0087] [ Figure 4 ] Figure 4 is a perspective view of a portion of an electrolytic cell according to one embodiment of the present invention,

[0088] [ Figure 5 ] Figure 5 is a perspective view of a portion of an intervention device according to an embodiment of the present invention,

[0089] [ Figure 6 ] Figure 6 is a perspective view of a portion of an intervention device and a portion of an electrolytic cell according to one embodiment of the invention,

[0090] [ Figure 7 ] Figure 7 is a side view of a portion of an electrolytic cell according to one embodiment of the present invention,

[0091] [ Figure 8 ] Figure 8 is a side view of an intervention tool according to one embodiment of the present invention,

[0092] [ Fig. 9 ] Fig. 9 yes Figure 8 A side view of the intervention tool after the vertical displacement of the movable part,

[0093] [ Fig.10 ] Fig.10 is a perspective view of a portion of an intervention tool of an intervention device according to an embodiment of the present invention,

[0094] [ Fig.11 ] Fig.11 is a perspective view of an intervention device and an electrolytic cell according to one embodiment of the present invention,

[0095] [ Fig.12 ] Fig.12 is a perspective view of an intervention device and an electrolytic cell according to one embodiment of the present invention,

[0096] [ Fig.13 ] Fig.13 is a side view of an intervention device and an electrolytic cell according to one embodiment of the present invention,

[0097] [ Fig.14 ] Fig.14 is a top view of an intervention device and an electrolytic cell according to one embodiment of the present invention.

[0098] Figure 2 An intervention tool 2 according to one embodiment of the invention is shown. The intervention tool 2 is designed to perform predetermined operations on the electrolytic cell 3, such as repositioning the anode assembly, as will be described in more detail below. The intervention tool 2 can be moved to the intervention area by means of an electrolysis service machine or preferably by means of a handling device 1 which together with the intervention tool 2 forms an intervention device.

[0099] refer to Figure 7 , the intervention tool 2 comprises a mounting 22 provided with one or more bearing surfaces 220 allowing the intervention tool 2 to be pressed against and supported directly in a stable manner on at least one element of the electrolytic cell 3, more precisely on an element fixed relative to the anode frame 34, such as the connector 32, the shaft 320 of the connector 32, the anode frame 34 or a hook 322 supporting the connector 32. For example, the mounting 22 comprises a bearing surface 220a designed to be pressed against the upper surface of the anode frame 34, and / or a bearing surface 220b designed to be pressed against the side of the anode frame 34, and / or a bearing surface 220c designed to be pressed against the shaft 320 of the connector 32, corresponding here to the bottom of the recess 222. The bearing surfaces 220 are configured to allow the intervention tool 2 to be pressed stably against the electrolytic cell 3 by gravity and, if necessary, to be fully supported by the electrolytic cell 3. As Figure 7 As shown, the support surface 220 may include two orthogonal support surfaces 220a, 220b, in particular a horizontal support surface 220a and / or a vertical support surface 220b. The support surface 220 may include a recess 222, the bottom of which forms one of the support surfaces 220.

[0100] The mounting 22 may also include reversible fixing means designed to create a reversible attachment between the mounting 22 and at least one element of the electrolytic cell 3. The reversible fixing means may include one or more locking tabs movable between a retracted position and an extended position relative to the mounting 22, the locking tabs being configured to cooperate with an element of the electrolytic cell 3, more precisely with an element fixed relative to the anode frame 34, such as the connector 32, the shaft 320 of the connector 32, the anode frame 34 or the hook 322 supporting the connector 32, when the intervention tool 2 is in the working position. Thus, the locking tabs together with the bearing surface 220 make it possible to attach the intervention tool 2 to the electrolytic cell 3.

[0101] The intervention tool 2 is designed to perform predetermined operations on the electrolytic cell 3, such as, for example, the repositioning of the anode. To this end, the intervention tool 2 includes an intervention unit designed to reposition the anode assembly 38. In this case, the intervention unit may include engaging means allowing the anode rod 36 of the anode assembly 38 of the electrolytic cell 3 to be clamped, and means for driving these engaging means in translation so as to vertically move the anode assembly 38. More specifically, the intervention unit includes a part 24 capable of translational movement relative to the mounting 22, and a driving means for driving the movable part 24 in translation along the vertical axis Z relative to the mounting 22, the movable part 24 supporting the engaging means. The movable part 24 and the mounting 22 may be connected by a sliding guide 26. These features make it possible to move the anode assembly 38 by raising or lowering it, a relatively short distance, typically about 100 mm, but sufficient to return the lower surface of the anode block of the anode assembly 38 to the desired position, for example in the anode plane.

[0102] refer to Fig.10 , the engagement device may be a clamping device that can clamp the anode rod 36 and includes a vertical screw 200 having a reverse pitch double thread, two cams 202, a pair of upper jaws 204, and a pair of lower jaws 206, each cam 202 being engaged with one of the threads of the vertical screw 200 so that the rotation of the vertical screw 200 brings the cam 202 closer or further away. Each upper jaw 204 is rotatably connected to one of the lower jaws 206. Each cam 202 is engaged in a cavity 208 of the upper jaw 204 or the lower jaw 206. Therefore, the tightening or widening of the upper jaw 204 and the lower jaw 206 is caused by the rotation of the vertical screw 200 in one direction or the other direction. The movable part 24 of the intervention tool 2 is fixed to the anode rod 36.

[0103] refer to Figure 8 and Fig. 9 The means for driving the movable part 24 relative to the mounting 22 may comprise one or more jacks 240 of the screw type (preferably trapezoidal) which may be actuated by an electric motor 242. Figure 8 In the embodiment, the jack 240 is in the retracted position, and in Fig. 9 In the embodiment, the jack 240 is in the deployed position. Prior to the step of engaging the anode rod 36 by the clamping device, the position of the jack 240 may depend on the displacement direction required to reposition the anode assembly 38, ie, the lifting or lowering of the anode assembly 38.

[0104] The intervention unit advantageously comprises means for tightening / loosening the connector 32 of the electrolytic cell 3. The connector 32 may be of the type comprising a rotating lever actuated by a threaded rod 324, as disclosed in patent document WO2013159218. The means for tightening / loosening the intervention tool 2 may comprise a screwdriver 28 designed to engage and pivot the threaded rod 324 of the connector 32 in one direction or the other so as to loosen or tighten the grip exerted on the anode rod 36 by the connector 32 and the anode frame 34. The tightening / loosening means are arranged on the mounting 22 so that the tightening / loosening means of the intervention tool 2 engage with the corresponding part of the connector 32 when the intervention tool 2 is positioned in the working position, and maintain this engagement during the intervention, in particular when the movable part 24 of the intervention tool 2 is displaced relative to the mounting 22.

[0105] Furthermore, the intervention tool 2 may comprise a wired supply of the cable or pneumatic hose type, in particular designed to supply the drive means, the engaging means and / or the tightening / loosening means of the intervention tool 2, and an automatic reel designed to wind the wired supply. Alternatively or additionally, the intervention tool 2 may carry one or more energy storage units, such as batteries.

[0106] refer to Figure 2 The invention also relates to an intervention device comprising one or more intervention tools 2 having the above-described characteristics, and a handling device 1 designed to transport the intervention tool or tools 2 . Figure 3 It is shown that the handling device 1 is advantageously designed to transport two intervention tools 2. Where appropriate, each intervention tool 2 is designed to intervene on half of an electrolytic cell 3.

[0107] refer to Figure 2 and Figure 3 The handling device 1 includes a chassis 10 and a displacement device for moving the chassis 10 along the upper structure 30 of the electrolytic cell 3 .

[0108] The chassis 10 extends longitudinally along the transverse axis X and is designed to extend parallel to the transverse direction of the electrolytic cell 3. The chassis 10 can be a support plate or a platform ( Figure 2 ) or even beam ( Figure 12 to Figure 14 ) in the form of.

[0109] When the handling device 1 carries two intervention tools 2 , these two intervention tools 2 are advantageously positioned along the transverse axis X on opposite sides of the chassis 10 .

[0110] The displacement device supports the chassis 10. The displacement device is configured to press on a surface 300, advantageously the upper surface of the superstructure 30, and is configured to allow the handling device 1 to translate in the longitudinal direction of the electrolytic cell 3 along a displacement path defined by the upper surface 300 of the superstructure 30.

[0111] refer to Figure 2 , Figure 3 , Figure 5 and Figure 12 to Figure 14 The displacement means may comprise wheels or rollers 12 rotatably mounted on the chassis 10 about a transverse axis X. The displacement means may also comprise guide means, such as rails 41 attached to, for example, the superstructure 30 , which are designed to cooperate with the wheels or rollers 12 .

[0112] The displacement means of the handling device 1 may comprise drive means, such as a motor which may be mounted on the chassis 10 to allow the handling device 1 to move along the superstructure 30 in the longitudinal direction Y of the electrolytic cell 3. Alternatively, as Figure 4 As shown, the displacement device may include a motor 42 arranged on the superstructure 30 and a transmission member 44, such as a chain actuated by the motor 42 and attached to the chassis 10. The motor 42 may be arranged at one end of the displacement path, for example in the storage rail 40.

[0113] refer to Figure 5 , the chassis 10 advantageously comprises one or more retaining members 14 designed to prevent the handling device 1 from tilting on one side or the other of the superstructure 30. The retaining members 14 may be L-shaped tabs or hooks designed to engage under the surface of the displacement device, for example, under the head of the guide rail 41, or under the surface of the superstructure, to prevent vertical lifting of the chassis 10 of the handling device 1 relative to the superstructure 30.

[0114] The handling device 1 may include a lifting device. The lifting device is configured to Figure 2 and Figure 3 on the right side; Fig.12 ; Fig.13 and Fig.14 left side) and working position ( Figure 2 and Figure 3 on the left side; Figure 6 ; Fig.13 and Fig.14The intervention tool 2 is individually moved between the bottom plate 10 and the bottom plate 10 (on the right side of the figure), in which the intervention tool 2 is at a distance from the electrolytic cell 3 to allow it to be conveyed along the electrolytic cell 3, and in which the intervention tool 2 is lowered to contact the electrolytic cell 3 in order to perform a predetermined operation, such as anode repositioning. In the parking position, the intervention tool 2 is close to or in contact with the bottom plate 10. In the working position, the intervention tool 2 is at a distance from the bottom plate 10, and the distance from the bottom plate is greater than when in the parking position.

[0115] refer to Figure 2 , Figure 3 , Figure 6 and Figure 12 to Figure 14 , for each intervention tool 2, the lifting device advantageously comprises a winch 100 with a motor, for example an electric motor, having a cable 102 designed to be connected to the intervention tool 2. The cable 102 may comprise a lifting beam 104. The lifting device may also comprise one or more return pulleys 106, which may be arranged above a horizontal plane containing the chassis 10. For example, the return pulley 106 is rotatably mounted around a longitudinal axis Y on a support arm 108 extending from and above the chassis 10. The winch 100 is advantageously positioned above the track defined by the displacement device, in the center of the chassis 10. Alternatively, the lifting device may consist of a jack or an articulated arm.

[0116] refer to Figure 2 , Figure 3 and Figure 6 For each intervention tool 2, the handling device 1 comprises a guiding device configured to guide the intervention tool 2 according to a predetermined path (for example an inverted L-shaped path) starting from a parking position towards a working position.

[0117] The guiding means may comprise grooves 16 designed to receive and guide the rotating shaft or roller 20 of the intervention tool 2. The grooves 16 may be formed on two parallel flanges 18 connected to the chassis 10 and defining between them a space designed to receive the intervention tool 2 in the parking position. Each groove 16 preferably comprises a lower portion 162 extending advantageously along a vertical axis Z orthogonal to the longitudinal axis Y and the transverse axis X, substantially below or flush with the horizontal plane containing the displacement means, and an upper portion 160 extending obliquely to the lower portion 162 at or above the horizontal plane containing the displacement means of the chassis 10 or the handling device 1. The upper portion 160 preferably extends outwards from the lower portion 162, that is to say away from the chassis 10 and the electrolytic cell 3. In the parking position, the rotation axis or roller 20 of the intervention tool 2 is located in the upper part 160 of the groove, while in the working position, the rotation axis or roller 20 of the intervention tool 2 is located in the lower part 162 of the groove. Preferably, each flange 18 comprises two similar and parallel grooves 16. These double grooves 16 prevent the intervention tool 2 from tilting around the rotation axis or roller 20 placed in the groove 16.

[0118] The handling device 1 may comprise means for supporting each intervention tool 2 in the parking position. Thus, the intervention tool 2 at least partially presses against these supporting means. The supporting means may be the side walls of the groove 16 of the flange 18.

[0119] The handling device 1 may comprise a wire supply of the cable or pneumatic hose type, and an automatic reel designed to supply a lifting device and / or a motor, making it possible to move the handling device 1 on the superstructure 30, and the automatic reel designed to wind up the wire supply. Alternatively or additionally, the handling device 1 may carry one or more energy storage units, such as batteries.

[0120] Each intervention tool 2 is connected to the handling device 1 by means of a cable 102 and the guiding means described above.

[0121] The handling device 1 and more particularly the lifting device advantageously comprises detection means, such as for example a contact or optical sensor 11, Figure 8 and Fig. 9 , so that the positioning of the intervention tool 2 in the working position and / or in the parking position can be ensured.

[0122] According to one embodiment, the intervention tool 2, more specifically the mounting 22, comprises a gripping device complementary to the gripping device of the handling device 1. The gripping device may be configured to allow the cable 102 to be used to lower the intervention tool 2 onto the electrolytic cell 3 to perform a predetermined intervention, or to be used to lift the intervention tool 2 to move it away from the electrolytic cell 3. Although not shown, the gripping device may, for example, comprise a loop or a hook that allows the cable 102 to pass through. The gripping device may be provided on the upper portion of the mounting 22, for example, opposite to a support surface 220 that may be provided on the lower portion of the mounting 22.

[0123] The invention also relates to an electrolytic cell 3 comprising a superstructure 30, an anode frame 34 supported by the superstructure 30, an anode assembly 38, a connector 32 for removably hanging the anode assembly 38 from the anode frame 34, and a handling device 1 as described above, the handling device 1 being able to carry one or more intervention tools 2.

[0124] refer to Figure 3 , Figure 6 , Fig.12 , the superstructure 30 has a surface 300, in particular an upper surface, against which the displacement device is pressed. The superstructure 30 and / or the displacement device form a displacement path for the chassis 10 of the handling device 1 at least over the entire length of the anode frame 34 or the tank shell of the electrolytic cell 3. The surface 300 extends in a horizontal plane XY. The displacement path is advantageously rectilinear, located in the center of the electrolytic cell 3, symmetrical with respect to the median plane YZ of the electrolytic cell 3.

[0125] The displacement path may extend beyond the vertical projection of the anode frame 34 or the tank shell of the electrolytic cell 3. Fig.11 As illustrated, the displacement path may include a storage rail 40 to store the handling device 1, for example in the absence of intervention, or to free up space above the electrolytic cell 3 for the passage or intervention of an electrolytic service machine. The storage rail 40 is located, for example, in a cantilevered manner, at one end of the displacement path and the electrolytic cell 3. Although not shown, the storage rail 40 may extend in a horizontal plane below the plane containing the surface 300 of the superstructure 30, so as to free up more space above the electrolytic cell 3.

[0126] The positioning of the handling device 1 on the storage rails 40 can, if necessary, allow the power batteries of different equipment, such as the displacement device, the lifting device and / or the intervention tool 2 to be recharged.

[0127] It should be noted that the electrolytic cell 3 or the handling device 1 may advantageously include means for controlling the position of the handling device 1, such as an encoder installed in a motor 42 designed to drive the handling device 1, and sensors for a zero point (e.g., a first end of a displacement path, such as a storage track 40) and an end of travel (such as a second opposite end of the displacement path).

[0128] Alternatively, the markings and associated detectors can precisely determine the stops of the chassis 10 facing the anode assembly 38, the positions of which always remain the same and at regular intervals, such as Fig.14 shown.

[0129] In addition, although not shown, the electrolytic cell 3, the handling equipment 1 or the intervention tool 2 may be equipped with a wired or wireless communication device known to those skilled in the art for communicating with a control unit arranged in the aluminum smelter and designed to control the displacement and operation of the handling equipment 1 and the intervention tool 2.

[0130] The invention also relates to an aluminium smelter comprising a plurality of electrolytic cells 3, including at least one electrolytic cell 3 as described above. Preferably, all aluminium smelter electrolytic cells 3 have the above-described features. The aluminium smelter may comprise one or more electrolytic service machines designed to transport intervention tools 2 or to move above handling equipment 1 present on the displacement path of the superstructure 30.

[0131] Furthermore, the aluminum smelter or electrolytic cell 3 advantageously comprises means for measuring the current circulating in each anode assembly 38, such as, for example, a Hall effect sensor, as disclosed in U.S. Pat. No. 6,136,177. The aluminum smelter may comprise a control unit designed to control the displacement and operation of the handling device 1 and the intervention tool 2 based on the measurement of the current circulating in each anode assembly 38 and based on the information received about the positioning and operation of the handling device 1 and / or the intervention tool 2 and / or the electrolysis service machine.

[0132] The invention finally relates to a method for intervening in an electrolytic cell 3 as described above. The method comprises the following steps:

[0133] - bringing the intervention tool 2 into the working position by means of the electrolysis service machine or the handling device 1,

[0134] - performing an intervention on the electrolytic cell 3 using the intervention tool 2,

[0135] - Retrieving the intervention tool 2 with the aid of the electrolysis service machine or handling device 1 .

[0136] The method may include an initial step of measuring an operating parameter of the electrolytic cell 3 , such as the intensity of the electric current circulating in each anode assembly 38 .

[0137] Lowering the intervention tool 2 to the working position may comprise pressing the intervention tool 2 against an element of the electrolytic cell 3 , more precisely against an element fixed relative to the anode frame 34 , such as the connector 32 , the shaft 320 of the connector 32 , the anode frame 34 or a hook 322 supporting the connector 32 .

[0138] The lowering of the intervention tool 2 to the working position may be followed by the following steps: attaching the intervention tool 2 to the electrolytic cell 3 in the working position, more precisely, to an element of the electrolytic cell 3 fixed relative to the anode frame 34, such as the connector 32, the shaft 320 of the connector 32, the anode frame 34 or the hook 322 supporting the connector 32.

[0139] Preferably, the step of intervention performed by means of the intervention tool 2 consists in repositioning the anode assembly, for example displacement of the anode assembly 38, so as to reposition the lower surface of the anode block in the anode reference plane. Repositioning the anode assembly 38 may comprise the following steps:

[0140] - moving the intervention tool 2 from the parking position to the working position,

[0141] - bringing the intervention tool 2 into engagement with the anode rod 36 of the anode assembly 38 to be repositioned, for example by clamping the anode rod 36 by the intervention tool 2,

[0142] - loosen the connector 32 of the electrolytic cell 3 to release the anode rod 36,

[0143] - displacing the anode assembly 38 so that the lower surface of the anode block of the anode assembly 38 is brought to a predetermined position,

[0144] - Tighten the connector 32,

[0145] - disengagement of the intervention tool 2 and the anode rod 36,

[0146] - Move the intervention tool 2 into the parking position.

[0147] Advantageously, the loosening step of the connector 32 is a partial loosening step, so that the connector 32 maintains the contact between the anode rod 36 and the anode frame 34. The tightening and loosening of the connector 32 is advantageously performed by tightening / loosening means of the intervention tool 2.

[0148] The repositioning of the anode assembly 38 may also comprise an initial displacement step in which the chassis 10 is displaced on the superstructure 30 until it faces the anode assembly 38 to be repositioned when the intervention tool 2 is transported by the handling device 1 .

[0149] The method may further comprise communicating information or control signals between the aluminium smelter control unit and the handling device 1 and / or the intervention tool 2 and / or the electrolysis service machine in order to control their respective displacements and operations.

[0150] Obviously, the invention is in no way limited to the embodiment described above, which is given only as an example. Modifications may be made, in particular in the composition of the various devices, or by substitution by technical equivalents, without departing from the scope of protection of the invention.

Claims

1. A movable intervention tool (2) designed to reposition an anode assembly (38) of an electrolytic cell (3), characterized in that The intervention tool (2) comprises a mounting (22) provided with one or more bearing surfaces (220) to allow the intervention tool (2) to be pressed against and stably supported directly on at least one element of the electrolytic cell (3), and an intervention unit designed to reposition the anode assembly (38); wherein the bearing surface (220) is configured to allow the intervention tool (2) to be supported by an element fixed relative to an anode frame (34) of the electrolytic cell (3), and wherein the intervention unit is configured to allow a vertical displacement of the anode assembly (38) relative to the mount (22); The support surface (220) is configured to allow the intervention tool (2) to be stably pressed against the electrolytic cell (3) by gravity and to be fully supported by the electrolytic cell (3).

2. An intervention tool (2) according to claim 1, wherein the mounting (22) of the intervention tool (2) comprises a reversible fixing device, which is suitable for creating a reversible attachment between the mounting (22) and an element of the electrolytic cell (3).

3. An intervention tool (2) according to claim 1 or 2, wherein the intervention unit includes a movable part (24) relative to the mounting member (22), a driving device for moving the movable part (24) translationally relative to the mounting member (22), and the movable part (24) includes a coupling device, which is configured to engage the anode rod (36) of the anode assembly (38) of the electrolytic cell (3) so as to fix the anode rod (36) and the movable part (24) in translation.

4. An intervention tool (2) according to claim 1 or 2, wherein the intervention unit comprises a tightening / loosening device suitable for tightening / loosening a connector (32) holding the anode assembly (38) in place in the electrolytic cell (3).

5. The intervention tool (2) according to claim 1 or 2, wherein the intervention tool (2) comprises a position detection device.

6. An intervention device, comprising an intervention tool (2) according to any one of the preceding claims and a handling device (1), the handling device (1) comprising a chassis (10) carrying the intervention tool (2) and a displacement device suitable for allowing the chassis (10) to be shifted, the displacement device being suitable for pressing against an upper structure (30), wherein the upper structure (30) refers to a structure supporting the anode frame and any fixed elements of the electrolytic cell attached to the anode frame.

7. An intervention device according to claim 6, wherein the handling device (1) includes a lifting device, which is configured to raise or lower the intervention tool (2) between a parking position and a working position, wherein the parking position is capable of keeping the intervention tool (2) separated from the electrolytic cell (3), and the working position allows the intervention tool (2) to be lowered to contact the electrolytic cell (3).

8. Intervention device according to claim 6 or 7, wherein the mounting (22) of the intervention tool (2) comprises gripping means complementary to gripping means of the handling device (1).

9. Intervention device according to claim 6 or 7, wherein the lifting device comprises a mobile crane or a winch (100).

10. Intervention device according to claim 7, wherein the lifting device comprises means for detecting the arrival of the intervention tool (2) in the working position.

11. Intervention device according to claim 7 or 10, wherein the handling device (1) comprises a guiding device configured to guide the intervention tool (2) according to a predetermined path from a parking position towards a working position.

12. An intervention device according to any one of claims 6, 7 and 10, wherein the guiding device comprises two parallel flanges (18), between which the intervention tool (2) extends in the parking position, each flange (18) comprising a groove designed to receive and guide an element attached to the intervention tool (2).

13. Intervention device according to any one of claims 6, 7 and 10, wherein the handling device (1) comprises retaining members designed to prevent the chassis (10) carrying the intervention tool (2) from tilting on either side of the superstructure (30).

14. Intervention device according to any one of claims 6, 7 and 10, wherein the handling device (1) carries two intervention tools (2) arranged on opposite sides of the chassis (10).

15. Intervention device according to any one of claims 6, 7 and 10, wherein the handling device (1) carries a single intervention tool (2) arranged on a rotating platform located on the chassis (10).

16. Intervention device according to any one of claims 6, 7 and 10, wherein the displacement means allow the chassis (10) to be displaced along the superstructure (30) of the electrolytic cell (3).

17. Intervention device according to any one of claims 6, 7 and 10, wherein the chassis (10) moves above the superstructure (30).

18. An electrolytic cell (3) comprising a superstructure (30), an anode frame (34) supported by the superstructure (30) and an intervention device according to any one of claims 6 to 17, wherein the superstructure (30) comprises a surface (300) against which the displacement device is pressed.

19. The electrolytic cell (3) according to claim 18, wherein the surface (300) against which the displacement device is pressed is the upper surface of the superstructure.

20. The electrolytic cell (3) according to claim 18 or 19, wherein the superstructure (30) and / or the displacement device form a displacement path for the chassis (10) at least over the entire length of the anode frame (34).

21. The electrolytic cell (3) according to claim 18 or 19, wherein the displacement path has a storage track (40) at one end of the electrolytic cell (3).

22. The electrolytic cell (3) according to claim 18 or 19, wherein the displacement device comprises a guide device designed to guide the bottom plate (10) in translation in the longitudinal direction of the electrolytic cell (3).

23. An electrolytic cell (3) according to claim 18 or 19, wherein the displacement means comprises drive means configured to move the chassis (10) along the superstructure (30).

24. A method for intervention in an electrolytic cell (3) by means of an intervention tool (2) according to any one of claims 1 to 5, comprising the following steps: - bringing the intervention tool (2) into the working position, - performing the intervention using said intervention tool (2), - Retrieving the intervention tool (2).

25. The intervention method according to claim 24, wherein the intervention on the electrolytic cell consists in repositioning the anode assembly and comprises the following steps: - engaging the intervention tool (2) with the anode rod (36) of the anode assembly (38) to be repositioned, - loosening the connector (32) of the electrolytic cell (3) to release the anode rod (36), - displacing the anode assembly (38) so that the lower surface of the anode assembly (38) is brought to a predetermined position, - tightening the connector (32), - Decoupling the intervention tool (2) and the anode rod (36).

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