RU2699600C2 - System for performing operations associated with use of electrolytic cells in apparatus for producing aluminium by electrolysis - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: invention relates to a device for operation of an electrolytic cell of a plant for producing aluminium by fire electrolysis. Device configured to be mounted on movable module of installation and movement above electrolytic cell comprises support for its mounting on module, hinged manipulator mounted on support, device for gripping at least one cap, made with possibility of connection to first end of manipulator, and device for temporary storage of at least one cap, wherein the storage device mounted on the support is configured to receive at least one cap displaced by the handler provided with the gripping device, and removing at least one cap previously arranged in storage device, manipulator equipped with gripping device. Disclosed are a module for operation of electrolysis unit of an installation for production of aluminium by fire electrolysis, installation for production of aluminium by fire electrolysis and method of electrolysis unit for production of aluminium by fire electrolysis.

EFFECT: providing operational flexibility of the system under very good operating conditions.

20 cl, 16 dwg

Description

The present invention relates to a system for performing operations associated with the use of electrolyzers in a plant for the production of aluminum by flame electrolysis.

The invention also relates to a module for operating electrolyzers of such a plant, the module comprising a similar system, and to a plant for producing aluminum by means of fire electrolysis.

The invention also relates to a method for exposing an electrolyzer to such a plant.

Aluminum is produced industrially by firing electrolysis in electrolysis cells in accordance with the well-known Hall-Heroult process. French patent application FR 2 806 742 (corresponding to US Pat. No. 6,409,894) describes the installation of an aluminum electrolysis plant for the production of aluminum.

Electrolytic reactions, secondary reactions, and high operating temperatures result in gaseous effluents that contain mainly carbon dioxide and fluorinated products. The allocation of these effluents to the atmosphere is strictly controlled and regulated taking into account not only the surrounding atmosphere of the electrolysis shop for reasons related to the working conditions of personnel working near electrolysis cells, but also taking into account atmospheric pollution. Regulatory acts of a number of countries on environmental protection impose restrictions on the amount of emissions emitted into the atmosphere.

Currently, there are solutions that provide the ability to reliably and successfully retrieve, capture, and process data from outgoing streams. A widespread solution is to equip the electrolysers with a device for trapping the effluent. This device closes the electrolysis baths like a cap and contains retention means, which, in particular, include a closing venting means and means for suction and chemical treatment of the effluent.

The closing gas venting means includes removable caps that provide access to the inside of the cell, in particular when replacing the spent anode with a new anode. Access to the interior of the cell may also be necessary during other activities, such as removing molten metal, closing the bath, or various maintenance and repair operations.

According to the first known method, an operator standing on the ground removes the caps from the electrolyzer and replaces them manually one at a time. In this case, the operator is exposed to risks associated with the proximity of the cell and the presence of handling equipment. In particular, the position required to raise and lower the hoods requires the operator to tilt towards the electrolyzer. Since the caps rest on narrow surfaces, installing the cap in the wrong position can cause it to lean poorly on the cell, causing the operator to become unbalanced and possibly fall into the cell. On the other hand, the removal of the caps leads to a decrease in the efficiency of the catching device and exposes the operator to the effects of the streams leaving the cell, which requires wearing protective masks.

In a second known process, which is described, for example, in French Patent 2,879,582 (corresponding to US Pat. No. 8,273,223), the caps are removed from the cell and replaced by a system that contains:

- a support intended for its installation on a movable installation module so that it can move over the electrolyzers;

- and a first articulated arm mounted on a support and equipped with a device for gripping at least one cap.

Before placing the cap on the cell, the surface of the cells on which the cap will rest must be cleaned. Pieces of solidified melt could fall to a given surface during the anode replacement process, and the presence of these pieces would prevent the cap from being properly placed in a predetermined position. To perform this cleaning operation, the system of FR 2 879 582 comprises a second articulated arm mounted on a support and provided with a cleaning tool such as a brush. Thus, the cap in a predetermined position on the cell is removed with the first hand provided with a gripping device, then the second hand equipped with a cleaning tool performs a cleaning operation while the cap remains attached to the first hand, and then the first hand places the cap back on the cell .

Such a system is generally satisfactory. However, it has several disadvantages. In particular, it has a rather complex and cumbersome design, which can lead to negative consequences during its implementation and maintenance. In addition, this system is relatively fixed, which makes it difficult to adapt to various types of caps and electrolyzers and improve it so that it can perform other operations on electrolyzers.

The present invention is to overcome the disadvantages of the prior art mentioned above.

For this and in accordance with the first aspect, the invention relates to a system for performing operations associated with the operation of electrolytic cells of an aluminum production plant by means of fire electrolysis, including the operation of manipulating the caps of electrolytic cells, the system being designed for its installation on a movable module of the installation so that it can move over the electrolysers, while the system contains:

- a support intended for its installation on the module;

- articulated arm mounted on a support;

- a device for gripping at least one cap, made with the possibility of attaching to the first end of the hand;

- and, in addition, a device for temporary storage of at least one cap, wherein said storage device mounted on a support is configured to receive at least one cap moved by a hand provided with a gripping device, and is adapted to enable extraction of at least one cap previously housed in a storage device indicated by a hand provided with a gripper.

Due to the presence of a storage device mounted on a support, it is not necessary for the articulated arm to constantly hold the caps during operations requiring removal of the caps (in particular, replacing one or more anodes) and operations before putting the caps back in place (in in particular, cleaning certain areas of the cell). Consequently, an articulated arm free of caps can be used to perform other operations and then can remove caps placed in the storage device to place them back on the cell.

Thus, since this hand can perform various operations, the system can be more compact and less expensive to manufacture and operate.

In particular, in accordance with one possible embodiment, it may be provided that the system comprises a single articulated arm mounted on a support. Thus, an even greater gain is achieved in terms of compactness.

The hand may be specially designed for the operations of manipulating the caps and for cleaning the areas of the cell where the caps are placed. In addition, it can be designed to perform other operations, resulting in increased operational flexibility of the system while maintaining essentially unchanged compactness.

Alternatively, it can also be provided that the system will include an additional arm for operations other than the aforementioned handling of caps and cleaning, in particular if these other operations require special functionality or the design of the arm performing them.

In accordance with one possible embodiment, the system further comprises a device for storing tools, including at least a gripping device and a cleaning tool, the storage device mounted on a support configured to receive at least one tool, supplied by hand, and with the ability to capture one of the tools placed in the storage device specified by the hand.

With this design, the hand can only be equipped with the tool necessary to carry out the current operation, while the remaining tools during this time will be placed in the storage device. In particular, the cleaning can be carried out by hand, not bearing the gripping device, which makes it more practical and effective during the cleaning operation.

In addition, the availability of a storage device provides operational flexibility of the system under very good working conditions. Indeed, the tools remain in the system and are not located, for example, on the installation floor, as a result of which they save floor space and avoid unwanted movement of the tool and difficulties in determining its location so that the hand can remove it.

The support may comprise a base on which the following is fixedly mounted: a hand, a device for temporary storage of at least one hood and a device for storing tools, if any. Thus, the hand and both storage devices are located in the same “repository”, so that there is no need for the detection device to be able to correctly capture - or find / retrieve - one or more stored caps or a stored tool.

It may be provided that the first end of the arm will be provided with first connecting means and that the gripping device or any other tool that may be attached to the first end of the arm will be provided / equipped with second connecting means configured to interact with the first connecting means with the possibility of separation . In particular, the second connecting means may be identical on all instruments, so that a “universal” connection system is obtained. The connection provides holding the tool on the hand in terms of providing a mechanical connection, but also in terms of providing an electrical and / or pneumatic or hydraulic connection for transmitting energy and actuating commands.

The second connecting means is preferably accessible when the tool is placed in the storage device, so that the first end of the hand can approach them, and the second connecting means can interact with the first connecting means.

A device for temporarily storing at least one cap can be configured to receive a plurality of caps placed substantially in the same vertical plane with their substantially horizontal side edges, with the caps being arranged substantially continuously above each other in vertical direction. This creates the possibility that any gap that could exist between the caps before they are removed from the cell will be eliminated by gravity. Therefore, the overall size of the entire set of caps will be smaller than the space in which this set must be placed back, which facilitates the installation of caps back into place.

In one possible embodiment, a device for temporarily storing at least one cap comprises an element configured to move between an open position, allowing at least one cap to be inserted into said device for storing or removing at least one a cap from said storage device, and a closed position in which the cap (s) is held (s) in said storage device.

The system may further comprise a detection device configured to determine the exact position of the cap on the cell prior to hand grip and configured to detect an element near the location of the cell in which the cap must be reinstalled by hand in a predetermined position to allow proper reinstallation of the indicated cap in the set position. These two functions can be performed by the same detection device or by two separate elements of the detection device. For example, the detection device may include at least a telemetry system, such as a laser device for measuring distances.

The support may contain at least one component that is configured to move in a substantially vertical direction during operation and on which the arm is mounted. This component, movable with respect to the module on which the support is mounted, as a rule, can be a base. The arm is fixed, for example, by means of its second end on the lower part of the support.

Thus, the indicated movable component of the support can be raised so that the system and, in particular, the hand will not interfere with other operations that must be performed on the cell, and / or so that they will not touch the cell component (anode / positive »Riser, top of the structure, etc.) when the module must be moved.

In accordance with a second aspect, the invention relates to a module for operating electrolyzers of a plant for producing aluminum by flame electrolysis, the module comprising:

- a mobile crane, which contains two beams extending in the transverse direction, and which is configured to move in the longitudinal direction above the electrolysers;

- a carriage mounted to move in the transverse direction on two beams of a mobile crane;

- and a system similar to that described above, while the support of the system is mounted on the carriage.

In accordance with a third aspect, the invention relates to a plant for the production of aluminum by flame electrolysis, comprising:

- a structure in which a plurality of electrolyzers are placed, wherein each electrolyzer extends in the transverse direction, wherein the electrolyzers are located next to each other in the longitudinal direction;

- a module similar to that described above, while the mobile crane is mounted with the possibility of moving in the longitudinal direction on the longitudinal rails provided near two transverse end walls of the structure.

In accordance with a fourth aspect, the invention relates to a method for exposing a cell to an aluminum production plant by means of fire electrolysis, comprising, in this order, the following steps:

a) to capture at least one cap available on the electrolyzer using an articulated arm mounted on a support and equipped with a device for gripping at least one cap;

b) using the specified hand, place the cap (s) in the device for temporary storage of at least one cap mounted on a support, then disconnect the gripper and cap (s) to release the hand;

c) by means of said hand, remove at least one cap previously placed in the storage device;

d) place the indicated (s) cap (s) back on the electrolyzer using the indicated hand.

Thus, after step b), the hand will be free of caps and may perform other operations.

The method may further include between steps b) and c) and, in this order, the following steps:

- using the specified hand, that is, the hand that performs operations a) -d) manipulating the caps, place the gripper in the tool storage device mounted on the support;

- attach to the specified hand a tool other than a gripping device available in the storage device;

- perform the operation with the specified tool;

- place the specified tool back in the storage device;

- attach the gripper back to the specified hand.

Typically, the specified tool, other than the gripping device, may be a cleaning tool, such as a brush, while the operation performed by the specified tool, therefore, is a cleaning operation of at least one area of the cell.

Hereinafter, an embodiment of the invention will be described as a non-limiting example with reference to the attached drawings in which:

figure 1 is a schematic view in section of a plant for the production of aluminum, which uses electrolysis of the melt and which contains a system in accordance with the invention;

figure 2 is a schematic view in section of an electrolyzer installation;

figure 3 shows in isometric view part of the electrolyzer of figure 2;

4 is an isometric view of a system in accordance with one embodiment of the invention;

5 and 6 are images of a device for temporarily storing the caps of electrolyzers belonging to the system of FIG. 4, respectively, in a perspective view and a top view, wherein the storage device is empty;

FIGS. 7 and 8 are views similar to FIG. 5, wherein the storage device receives one cap and three caps, respectively;

Figures 9-16 illustrate successive steps of a process for exposing an electrolytic cell in accordance with the invention using the system shown in Figure 4.

Figure 1 shows the installation 1 for the production of aluminum, which uses electrolysis of the melt, and, in particular, the electrolysis shop of such a installation 1.

The installation 1 comprises a structure 2 in which a plurality of electrolytic cells are placed 3. Each electrolytic cell 3 extends in the transverse direction Y, and the electrolytic cells 3 are located next to each other in the longitudinal direction X.

As illustrated in FIGS. 2 and 3, each cell 3 comprises an electrolysis bath 20, a support structure 30, called a “top of the structure”, and a plurality of anodes 40, 40 ′.

The electrolysis bath 20 contains a steel casing 21, an inner lining 22, which is usually formed by blocks made of refractory materials, and a cathode kit that contains blocks made of carbon material, called "cathode blocks" 23, and metal connecting busbars 24 to which conductors 45, 46, 47 are attached for supplying an electrolysis current.

Each anode 40 is provided with a metal rod 41, which, as a rule, is attached to the anode 40 by means of a multipode 42. The anodes 40 are removably attached to the movable metal frame 25, called the “anode frame”, by means of the movable connector 26. The anode frame 25 is supported on the upper part 30 of the structure and connected to conductors 47, called "anode /" positive "risers" used to supply the electrolysis current.

In fact, more than one hundred electrolysers 3 are arranged next to each other in rows or lines in the X direction. The electrolysers 3 of the same row are electrically connected in series by using connecting conductors 45, 46, 47. The electrolysers 3 are arranged so as to leave passage 48 for circulation along the installation 1 and the space 49 for access between the electrolytic cells 3.

Each cell 3 is equipped with a cap system. The system comprises a number of removable caps 33, which are typically made of metal and, more typically, are made of aluminum alloy. The cap system holds the effluents in the inner space 29 of the electrolyzer 3 and is connected to means (not shown) for discharging the effluents and directing them to the processing center.

Caps 33 are typically inserted into a guide groove 35 located along the electrolyser 3 (in the Y direction) and moved to a position in which they rest on the flange 31 of the upper structure portion 30. The caps 33 are located next to each other in the Y direction on the cell 3. Between the side edges 36 of the two adjacent caps 33 there may be a gap of about 2-5 mm. On the other hand, the caps may be located with an angular defect of several degrees with respect to the X and Y axes. For example, the caps 33 may be as follows: the width (along the Y axis) is 685 mm and the height is 1535 mm. Caps 33 may be substantially flat or curved. Caps 33 are held in position by their own weight without a locking device. For example, the weight of cap 33 may be about 12 kg. Caps 33 are typically provided with a handle 34 so that operators can manipulate them.

The rod 41 of the anodes 40, as a rule, protrudes from the cap system through the holes 32 made for this in the cap system.

In accordance with the most common technology, the anodes 40 are made of pre-sintered carbon material. The gradual consumption of the anodes 40 during the electrolytic reduction of aluminum requires work on the electrolysers 3, which includes, in particular, replacing the spent anodes 40 'with new anodes 40.

Installation 1 contains a module 4, the so-called "site for maintenance of electrolytic cells", designed to operate electrolytic cells 3, that is, to perform operations on electrolytic cells 3, such as replacing the anodes or funnels of electrolytic cells 3, designed to supply crushed electrolyte and AlF ₃ . Module 4 can also be used to perform loading and unloading and transport operations with various cargoes, such as elements of electrolysis baths, ladles with molten metal or anodes.

As illustrated in FIG. 1, module 4 comprises a mobile crane 5, which has two beams 6 extending in the transverse direction, and which is movable in the longitudinal direction X above the electrolysis cells 3. In particular, the mobile crane 5 is mounted for movement in the longitudinal direction on the longitudinal guides 7 or tracks that can be provided near two transverse end walls 8 of structure 2.

The module 4 further comprises a carriage 9 mounted for transverse movement on two beams 6 of the mobile crane 5. The carriage 9 is a component of the machine 10 for servicing electrolysis cells, which also includes a module 11 for servicing the electrolytic cells, equipped with a variety of handling and servicing devices 12. The electrolyzer maintenance machine 10 may also include a control cabin.

On machines 10 intended for servicing electrolyzers and used for anode replacement operations, these handling and servicing devices 12 include tools, namely, as a rule, a tool for breaking the surface crust, a bucket-shaped shovel, an anode gripping device (called a “clamp for anodes ”) and a funnel equipped with a retractable tube. The tool for the destruction of the surface crust is used to destroy the crust of aluminum oxide and hardened melt, which, as a rule, covers all or part of the anodes 40 of the electrolyzer 3; a bucket-shaped shovel is used to clean the location of the anode 40 — after removing the used anode — by removing the solid therein (such as pieces of crust and alumina); the anode clamp is used to grab the anodes 40 and manipulate the anodes 40 by means of their rod 41, in particular, to remove spent anodes from the electrolyzer 3 and to place new anodes 40 in the electrolyzer 3; a retractable tube is used to introduce aluminum oxide and / or crushed electrolyte into the cell 3 to form a coating layer after installing a new anode in a predetermined position. The surface crust breaking tool, bucket spade and anode clamp are typically attached to the lower end of a guide member such as a stand or telescopic arm.

In addition, the module 4 includes a system 50 for performing operations related to the operation of the electrolytic cells 3 of the installation 1, in particular, the operations of manipulating the caps 33 of the electrolytic cells 3 and cleaning at least one area of the electrolytic cell 3.

As illustrated in FIG. 4, the system 50 comprises a support 51 that is mounted on the module 4 and, more specifically, on the carriage 9 so that it can be moved above the electrolysers 3. The system 50 further comprises an articulated arm 52 mounted on the support 51. For example, the arm 52 comprises a first free end 53 and a second end 54 fixed to the lower part of the support 51. The arm may be a six-axis anthropomorphic robot. Arm 52 may be a single articulated arm mounted on a support 51.

Essentially speaking, the support 51 can be designed so that the arm 52 can move substantially vertically during operation. This makes it possible to transfer the arm 52 to the area adjacent to the cell 3, when the operation is to be performed on the cell 3, and hold the arm 52 in a raised position for the rest of the time so that it will not interfere with other maintenance operations, or so that any movement module 4 carrying the system 50 will not prevent the hand 52 from coming into contact with a part of the electrolyzer 3, such as the anode / “positive” riser 47 or the supporting structure 30. For this, it may be provided that the support 51 will comprise telescopic stand extending essentially in the vertical direction Z.

The system 50 further comprises a device 55 for temporary storage of at least one cap 33 mounted on a support 51, and in the shown embodiment, a tool storage device 56 also mounted on a support 51.

In the embodiment shown in FIG. 4, the support 51 comprises a base 57 on which the following are mounted to securely: a hand 52, a device 55 for temporarily storing at least one cap and a device 56 for storing tools. In particular, the base 57 can be mounted on the lower part of the support 51 and can be made with the possibility of movement in the vertical direction relative to the upper part of the support 51, while this vertical movement is carried out by the power cylinder 58. In addition, the base 57 may include a wing 65 on which the storage device 55 is mounted, and a wing 66 on which the tool storage device 56 is mounted.

In the tool storage device 56, various tools that the hand 52 can manipulate can be detected, and in particular:

- a device 60 for gripping at least one cap 33, for example, comprising a housing provided with branches carrying gripping devices 59, such as cup suction cups, actuated, for example, by means of a pneumatic system;

and a cleaning tool 63, such as a brush, scraper, or blower.

The tool storage device 56 is configured to receive at least one tool 60, 63 supplied by the hand 52, and to grip one of the tools 60, 63 placed in the storage device 56 indicated by the hand 52. In addition to the gripper 60 and a cleaning tool 63, the storage device 56 may receive, for example, a measuring sensor, measuring tools, brushes for other parts of the cell (anode frame, anode rods), tools for removing p alloy, etc.

For this, the first end 53 of the arm 52 may be provided with the first connecting means 61, while each of the tools configured to attach to the first end 53 of the arm 52, in particular the gripper 60 and the cleaning tool 63, may be provided with a second connecting means 62, configured to interact with the first connecting means 61 with the possibility of separation. In a preferred embodiment of the invention, the second connecting means 62 are identical for all of these tools, resulting in a universal connection system.

The connecting means 61, 62 are designed to provide a detachable connection between the first end 53 of the arm 52 and the tools, in particular the gripping device 60 and the cleaning tool 63, and to provide automatic connection between the hand 52 and the tools for supplying pneumatic and electrical energy. In the case of a universal connection system, the connecting means 61, 62 should preferably have sufficient connections for each tool to be connected to the arm 52. In addition, the connecting means 61, 62 are preferably configured to ensure that the tools are held in place in the event of a cutoff nutrition.

The functional purpose of the device 56 for storing tools is to provide the ability to store tools that are not used at a given point in time. These unused tools are preferably fixed on the storage device 56, for example, by means of power cylinders. The storage device 56 may comprise several elements 64 that are integral with the wing 66 attached to the base 57, each of these elements 64 serving as a base on which an unused tool can be placed or fixed.

The device 55 for temporary storage of at least one cap is configured to receive at least one cap 33 carried by a hand 52 provided with a gripping device 60, and is designed to enable retrieval of at least one cap 33, previously housed in a storage device 55, indicated by a hand 52 provided with a gripper 60.

A storage device 55 will now be described more specifically with reference to FIGS. 5-8.

In the shown embodiment, the storage device 55 comprises a substantially horizontal base 70, a first side post 71 and a second side post 73, substantially vertical and fixed relative to the base 70. The first and second side posts 71, 73 can be connected by a wing 65 connecting a storage device 55 with a base 57 of a support 51.

In addition, a substantially vertical shutter 72 is provided near the second side pillar 73. The shutter 72 is movable relative to the second side pillar 73 between the open position, allowing at least one cap 33 to be placed in said storage or removal device 55, at least one cap 33 from said storage device 55, and a closed position in which the cap (s) 33 are / are held in said storage device 55 in a storage position. In a non-illustrated embodiment, a movable shutter may also be provided near the first side post 71.

The storage device 55 preferably does not have a front panel for allowing one or more caps 33 to be inserted in front and also removed by the hand 52. Furthermore, the storage device 55 may not have an upper cross member: in other words, it is open from above. In addition, the storage device 55 may not have a solid rear panel, with the wing 65 forming a single element on the rear side of the storage device 55.

The shutter 72 can be offset from the second side post 73 or close to the second side post 73 so that one or more caps 33 can be caught between the second side post 73 and the shutter 72, in particular, the free end of the shutter 72. In this storage position, the caps 33 are thus held between two posts 71, 73 by means of a shutter 72.

Thus, when the shutter 72 is in a position away from the second rack 73, that is, when it is in the open position (FIGS. 5-8), it is possible to place at least one cap 33 in the storage device 55 or remove at least one cap 33 of the storage device 55. On the contrary, when the shutter 72 is moved to a position in which it is closer to the second pillar 73, that is, when it is in the closed position (FIG. 4), the cap (s) 33 are held / are held in the storage device 33.

In the shown embodiment, the storage device 55 comprises a drive element configured to allow movement of the movable element — namely, the shutter 72 — between its open and closed positions. As illustrated in FIG. 6, this drive element is made in the form of at least one actuator 75. The actuator 75 can be connected to an eyelet 76, which is integral with the shutter 72 and pivotally connected around a substantially vertical axis 77 and fixed relative to the second strut 73. Thus, moving the shutter 72 between its open and closed positions involves turning the shutter 72 about an axis 77. An end switch can also be provided on the actuator 75.

In addition, the first pillar 71 — and possibly the second pillar 73 and / or the shutter 72 — may / may have a substantially vertical groove 74 that is open toward the second pillar 73 — or more generally toward the opposite pillar and which should include one edge of at least one cap 33. Typically, the upper and / or lower edges of cap 33 are inserted into these one or more grooves 74, with the terms “upper” and “lower” referring to the position occupied cap 33 on the cell 3. In practice, this rack 71 can Met V-shaped cross section as shown in Figure 6. This design improves the quality of positioning and holding the caps 33 in the device 55 for storage.

When only one cap 33 is in the storage position in the storage device 55, it rests on the base 70 and is held between the two uprights 71, 73 by the shutter 72, as illustrated in FIG. 7, with its side edges 36 being substantially horizontal.

When several caps 33 (up to three in the embodiment illustrated in FIG. 8) are in the storage position in the storage device 55, the lower cap 33 rests on the base 70. In addition, the caps 33 are located essentially in the same vertical plane and are arranged one above the other essentially continuously along the vertical direction Z. In addition, when the caps 33 are placed on the electrolyzer 3, their side edges 36 are located essentially in the plane (X, Z), as shown in FIG. In contrast, in a storage position similar to that shown in FIGS. 7 and 8, the side edges 36 of the caps 33 are substantially horizontal, that is, they have been rotated 90 ° relative to the position they occupy when placed on the electrolyzer 3.

In addition, the system 50 may include means for detecting the presence of at least one cap 33 in the storage device 55. As can be seen, in particular, in Fig. 5, these detection means may comprise one or more finger-shaped protrusions 78 located on the base 70 of the storage device 55, while these finger-shaped protrusions 78 protrude and are pressed under the weight of one or more caps 33, housed in the storage device 55.

The device 55 for temporary storage of at least one cap 33 is preferably reliable, that is, configured to ensure that the caps 33 are held in place even in the event of a power failure, which prevents them from accidentally falling.

The arm 52 may be provided with a chain 80 that provides support for the cables (see, in particular, FIG. 9), in which all cables and hoses necessary for the functioning of the system 50 will be mounted. In addition, the system 50 contains one or more box-shaped ones elements 79 containing various computer and / or pneumatic control systems, in particular for controlling the locking system of the caps 33 in the storage device 55 (by moving the shutter 72 to its closed position and holding it in this position) and fixing the tools 60, 63 in mustache 56 for tool storage. The systems located in the box element 79, can also provide the ability to communicate with the programmable controller of the machine 10, designed to serve electrolyzers, for receiving commands and relaying information.

Figures 9-16 illustrate successive steps of the method of acting on the electrolyzer 3 of the installation 1, requiring removal and subsequent re-installation of the caps 33 of the electrolyzer 3. In particular, when replacing the spent anode 40 'with a new anode 40, the caps 33 located in front of the spent anode 40 'must be removed and then reinstalled after fixing a new anode 40.

As shown in FIG. 9, the support 51 carried by the module 4 is moved close to the electrolyser 3 for which the action is to be carried out by means of a mobile crane 5 and a carriage 9. After that, the arm 52 is moved downward by the power cylinder 58 of the telescopic support 51 in the shown an embodiment until the first end 53 of the arm 52 is located adjacent to the caps 33 to be removed. The gripping device 60 is attached to this first end 53. The tool storage device 56 includes at least a queue cleaning tool 63.

A hand 52 provided with a gripping device 60 captures at least one cap 33 present on the cell 3, as shown in FIG. 10. In particular, the gripping device 60 may be configured to simultaneously capture three caps or two caps and half a cap (half caps may be located, for example, at the transverse ends of the electrolytic cells 3). Essentially speaking, three or four grippers 59 per cap 33 can be provided.

To accomplish this, the system may include a sensor configured to determine the exact position of the cap 33 on the cell 3 before it is captured by the hand 52. Indeed, as indicated above, the caps 33 may be located with a varying gap between them and / or with an angular defect, constituting several degrees with respect to the X and Y axes. Determining the actual position of the cap 33 ensures excellent positioning of the gripping elements 59 on the cap 33 and, therefore, a reliable grip without the risk of falling.

The exact position of the cap 33 can be determined, for example, by detecting the handle 34 of the cap 33 by means of a detection device.

A hand 52 supporting the caps 33 by means of a gripping device 60 then provides for the placement of all the data of the caps 33 in the storage device 55, as illustrated in FIG. 11. For this, the caps 33 - in this case their number is three, and this is just one example - are rotated 90 ° relative to their position on the electrolyzer 3, while the side edges 36 will thus be essentially horizontal and placed by hand 52 in the storage device 55 through its open front.

Caps 33 are placed in the device 55 for storage between two racks 71, 73, while the shutter 72 is in the open position to allow input caps 33 (Fig.11).

Then, the shutter 72 is moved to its closed position, so that the caps 33 will be held between the posts 71, 73 and the shutter 72 (Fig.12). After that, the gripping device 60 can be disconnected from the caps 33 without the risk of them falling.

When the caps 33 are removed from the cell 3, the machine 10 for servicing the cells can act on the cell 3 to perform various operations, in particular, but not exclusively, to replace the anode. During these actions, the caps 33 are held in the retracted position and therefore do not interfere with these actions. More generally, the arms 52 and the entire system 50 are positioned so that they do not interfere with these effects. More specifically, the system 50 can be raised (by means of the telescopic support 51 in the described embodiment), and it will subsequently be lowered when it is again required to be used for other operations.

A hand 52, which should not support the caps 33, can be used to perform other operations, usually through other tools. Thus, first, the arm 52 is released from the gripping device 60 by placing it in the storage device 56, typically on the corresponding element 64.

Then, the arm 52 is connected to a tool — other than the gripper 60 — that is present in the storage device 56 through interaction between the first connecting means 61 provided on the first end 53 of the arm 52 and the second connecting means 62 provided on the tool. After that, the hand 52 can use this tool to perform operations associated with the operation of the electrolyzer 3, but different from the manipulation of the caps 33.

In the embodiment shown in FIG. 13, the tool is a cleaning tool 63 that is used to clean at least one area of the cell 3, as shown in FIG.

Specifically, after replacing the anode and before installing the caps 33 back to their predetermined position on the electrolyzer 3, the guide groove 35 must be cleaned along the entire length that is not closed when the caps 33 are removed to remove all pieces - i.e., solid melt and fragments of crushed electrolyte, which could fall during the replacement operation of the anode 40. To clean the guide groove 35, the cleaning tool 63 can typically place these pieces inside the electrolysis bath 20. The hand 52 should preferably be constructed with espechivayuschey opportunity to clean under the right and the left anode / "positive" struts 47 without turning back.

Once the cleaning operation is completed, the cleaning tool 63 can be placed back in the storage device 56 on the corresponding element 64, and then the arm 52 can be disconnected from the cleaning tool 63.

Then, the arm 52 can be connected to another tool available in the storage device 56 to perform another operation.

As illustrated in FIG. 15, the arm 52 can retrieve a gripper 60 that it previously housed in the temporary storage device 56 by interacting between the first connecting means 61 provided on the first end 53 of the arm 52 and the second connecting means 62 provided on gripper 60.

A hand 52, thus equipped with a gripping device 60, can then remove one or more caps 33 previously housed in the storage device 55. This operation does not require a device configured to determine the exact position of the caps 33, since they remained in the same basic position as the arm 52 from the moment they were placed in the storage device 55. This saves time and increases reliability.

Once the gripping elements 59 are appropriately connected to the caps 33, the shutter 72 of the storage device 55 can be moved to its open position to allow removal of the caps 33 from the storage device 55.

Then, as illustrated in FIG. 16, the arm 52 is moved so that it can re-install the cap (s) 33 that it holds on the electrolysis cell 3. To allow for appropriate re-installation of the caps 33 in a predetermined position, the system 50 may include a detection device made with the possibility of detecting an element adjacent to the place of the cell 3, in which the caps 33 must be re-installed in a predetermined position by the hand 52. This neighboring element may be, for example, the neighboring cap 33, already installed copulating in a predetermined position on the electrolytic cell 3 or the end wall of the cell 3 in the case where the caps to be re-installed in the predetermined position, caps are placed on the transverse end of the cell 3.

Hand 52 inserts the caps 33 into the guide groove 35, which has been previously cleaned, and places them on the edge 31 of the upper part 30 of the structure.

Since the caps 33 were held, being located on each other in the direction of the Z axis, with their substantially horizontal side edges 36, any gap that could exist between two adjacent caps 33 before they were removed from the electrolyzer 3 was corrected by gravity. Thus, the overall dimension — along the Y axis — of all caps 33 to be placed back on the cell 3 will be smaller than the overall dimensions of this set of caps 33 before being removed from the cell 3. In other words, the space on the cell 3 is available for re-installing the caps 33 , will be larger in size compared with the size of this set of caps 33 along the Y axis. Reinstalling the caps 33 on the cell is greatly facilitated.

The process described above can be performed automatically, while the system 50 will operate independently after the machine 10 for servicing the cells located above the cell 3, will issue a command to initiate a cycle.

Alternatively, in particular, a manual operation may be provided for making adjustments, the operation being performed by an operator acting on the controls available in the cab of the machine 10 for servicing electrolyzers.

Thus, the system in accordance with the invention provides the ability to manipulate the caps and perform other operations (cleaning, etc.) in a very "filled" environment surrounding the cells, and with the required accuracy.

Due to its modularity, the cycle time of the system can be significantly reduced, for example, it can be less than 100 seconds (grabbing caps, cleaning and reinstalling the caps).

Since the system is compact, it can perform certain operations as a background task, provided that they do not pose a risk of collision with an element of the machine for servicing electrolyzers. This, in particular, is true for replacing tools when replacing a gripping device with a cleaning tool and vice versa, which can be performed while the electrolyzer maintenance machine 10 acts on the electrolyzer 3 to destroy the surface crust of the melt, remove the spent anode, or install a new anode.

In addition to the effect on finances, reducing the cycle time is preferable from the point of view of safety and the environment, since the time during which the caps will be removed from the electrolysis cells is reduced.

It is obvious that the invention is not limited to the embodiment described above by way of example, but includes all technical equivalents and variations of the described means and their combinations.

Claims (38)

1. A device for manipulating the caps of the exhaust hood of the electrolysers of a plant for the production of aluminum by fire electrolysis and cleaning at least one zone of the cells , made with the possibility of its installation on a movable module of a plant for the production of aluminum by fire electrolysis with the possibility of moving above the cell, containing: - a support made with the possibility of mounting on said module, - articulated arm - a gripping device for gripping at least one cap made with the possibility of attaching to the first end of the articulated manipulator, characterized in that it comprises a device for temporary storage of at least one cap mounted on said support with the possibility of receiving at least one cap moved by a hinged manipulator with a gripping device, and the possibility of removing at least one cap previously placed in the device for storage. 2. The device according to p. 1, characterized in that it is additionally equipped with a device mounted on a support for storing tools, including at least a gripping device and a cleaning tool, configured to receive at least one tool supplied by the articulated manipulator, and capture one of the tools placed in the storage device specified by the articulated manipulator. 3. The device according to p. 1 or 2, characterized in that it contains a single articulated arm mounted on a support. 4. The device according to any one of paragraphs. 1-3, characterized in that the said support comprises a base on which a hinged manipulator, a device for temporary storage of at least one hood and, if necessary, an additional device for storing tools are mounted. 5. The device according to any one of paragraphs. 1-4, characterized in that the first end of the articulated manipulator is provided with first connecting means, the gripping device or any other tool that can be attached to the first end of the articulated manipulator is provided with second connecting means configured to interact with the first connecting means disconnect. 6. The device according to any one of paragraphs. 1-5, characterized in that the said device for temporary storage of at least one cap made with the possibility of receiving many caps placed essentially in the same vertical plane with essentially horizontal side edges, with the caps being located one above the other the other is substantially continuous in the vertical direction (Z). 7. The device according to any one of paragraphs. 1-6, characterized in that the said device for temporary storage of at least one cap contains an element configured to move between an open position to enter at least one cap in the specified storage device or to remove at least one cap from the specified storage device and a closed position in which the cap is held in the specified storage device (55). 8. The device according to p. 7, characterized in that the said storage device contains a drive element made with the possibility of moving the movable element between its open and closed positions. 9. The device according to any one of paragraphs. 1-8, characterized in that the said storage device comprises a horizontal base, first and second side racks made vertical and fixed relative to the base and near at least one of the two side racks, a vertical shutter made to move relative to the specified side racks between the open position, allowing at least one cap to be inserted into said device for storing or withdrawing at least one cap from said device va storage, and a closed position wherein said cap is held in a storage device in the storage position. 10. The device according to p. 9, characterized in that at least one of these racks has a groove made vertically and open towards the other rack, which should include one edge of at least one cap. 11. The device according to any one of paragraphs. 1-10, characterized in that it contains means for detecting the presence of at least one cap in the storage device. 12. The device according to any one of paragraphs. 1-11, characterized in that it contains a detection device configured to determine the exact position of the cap on the cell before it is captured by the manipulator and configured to detect an element near the location of the cell in which the cap must be re-mounted by the manipulator in a predetermined position to the ability to properly reinstall the specified cap in a predetermined position. 13. The device according to any one of paragraphs. 1-12, characterized in that the support contains at least one component configured to move in the vertical direction during maintenance and on which a pivot arm mounted on its lower end is mounted. 14. The device according to any one of paragraphs. 1-13, characterized in that the support comprises a telescopic stand extending in the vertical direction (2). 15. The device according to any one of paragraphs. 1-13, characterized in that the articulated arm is a six-axis anthropomorphic robot. 16. A module for manipulating the caps of the exhaust hood of the electrolysers of the installation for the production of aluminum by firing electrolysis and cleaning at least one zone of the electrolysis cells , containing: - a mobile crane containing two beams extending in the transverse direction, and configured to move in the longitudinal direction (X) above the cell, - a carriage mounted with the possibility of movement in the transverse direction on two beams of a mobile crane, characterized in that it further comprises a device according to any one of paragraphs. 1-15, wherein the support of said device is mounted on said carriage. 17. Installation for the production of aluminum by fire electrolysis, containing: - a structure in which electrolyzers are placed, each of which is located in the transverse direction (Y), and the electrolyzers are located next to each other in the longitudinal direction (X), - a module for manipulating the caps of the gas outlet cover of the electrolysers of the plant for the production of aluminum by fire electrolysis according to claim 16, wherein the mobile crane of the module is mounted with the possibility of moving in the longitudinal direction on the longitudinal rails provided near two transverse end walls of the structure. 18. The method of manipulating the caps of the exhaust hood of the electrolysers of the installation for the production of aluminum by fire electrolysis and cleaning at least one zone of the electrolyzers using the device according to one of claims. 1-3, comprising the following sequential steps: a) the capture of at least one cap available on the electrolyzer, by means of a pivoting arm mounted on a support and provided with a gripper for gripping at least one cap, b) placing by means of the specified manipulator in the device for temporary storage of at least one cap mounted on a support, and the subsequent separation of the device for gripping the cap and to release the manipulator, c) extracting by the manipulator at least one cap previously placed in the storage device (55), d) re-placing the specified cap on the cell through the specified manipulator. 19. The method according to p. 18, characterized in that it further includes between steps b) and c) the following steps: - by means of the manipulator, a gripping device is placed in a tool storage device mounted on a support, - attach to the specified manipulator a tool other than a gripper available in the storage device, - perform the operation with the specified tool, - put the specified tool back into the storage device, - attach the gripper back to the specified manipulator. 20. The method according to p. 19, characterized in that the specified tool, other than the gripping device, is a cleaning tool, and the operation performed by the specified tool is a cleaning operation of at least one area of the cell.

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