EP2614178A1

EP2614178A1 - Handling tool, for secure handling of connectors of electrolysis cells intended for aluminium production

Info

Publication number: EP2614178A1
Application number: EP11761648.2A
Authority: EP
Inventors: Stéphane DAVID
Original assignee: ECL SAS
Current assignee: Fives ECL SAS
Priority date: 2010-09-08
Filing date: 2011-09-06
Publication date: 2013-07-17
Anticipated expiration: 2031-09-06
Also published as: CA2807888A1; AU2011300604B2; US8888156B2; CN103080383A; US20130181468A1; CA2807888C; RU2587103C2; EP2614178B1; AU2011300604A1; RU2013115288A; WO2012032234A1; ZA201301122B

Abstract

Handling tool (300) for handling a connector (200) in order to connect an anode rod onto the anode frame (5) of a cell (1) for producing aluminium by melt electrolysis, said connector being provided with two lateral journals (212, 212') capable of cooperating with bearing hooks (10, 10') fastened to said anode frame and placed on either side of the anode rod (9), so as to press said anode rod against said anode frame, said handling tool comprising at least one guiding member (30) having a groove (40) associated with each of said journals and intended to accommodate said journal, said handling tool being characterized in that it also comprises: at least one gripping member (31) having an open position and a closed position, said guiding member and said gripping member cooperating in such a way that, when said gripping member is in the open position, each journal may be inserted into said groove or extracted therefrom, and when said gripping member is in the closed position, each journal may undergo only a limited displacement in said groove, between what is called the "low" position corresponding to the contact between said gripping member and what is called a "high" position; an actuation system (311) associated with said gripping member, capable of moving said gripping member between said open and closed positions; and at least one locking system (32) having a locked position and an unlocked position, capable of blocking said gripping member when it is in the locked position and capable of switching from the locked position to the unlocked position when said journals are in the high position.

Description

SECURED HANDLING MEMBER OF ELECTROLYSIS CELL CONNECTORS FOR ALUMINUM PRODUCTION

The invention relates to handling equipment used in aluminum production plants by igneous electrolysis according to the Hall-Héroult process. It relates more particularly to the handling devices of the connectors which ensure the attachment and electrical contact of the anodes on the anode frame.

Aluminum metal is produced industrially by igneous electrolysis, namely by electrolysis of alumina in solution in a bath of molten cryolite, called electrolyte bath, according to the well-known Hall-Héroult process. The electrolyte bath is contained in tanks, called "electrolysis cells", comprising a steel box, which is coated internally with refractory and / or insulating materials, and a cathode assembly located at the bottom of the tank. Anodes, typically of carbonaceous material, are partially immersed in the electrolyte bath. The assembly formed by an electrolytic cell, its anodes and the electrolyte bath is called an electrolysis cell.

The anodes are provided with a metal rod for electrical and mechanical connection to a metal frame, called anode frame, which is movable relative to a fixed gantry disposed above the electrolytic cell. The anode rods are connected to the anode frame by using removable connectors capable of being deposited on support hooks disposed on either side of the anode rods and operable to press the anode rods against the anode rods. anodic frame. French patent FR 2 039 543 (corresponding to US Pat. No. 3,627,670) describes such devices, which have a clamping screw whose actuation makes it possible to place the connector in a tight configuration, where it plates the anode rod. against the anode frame thus ensuring the electrical contact, and in a loose configuration where it can be removed so as to allow the disconnection of the anode rod.

In operation, an electrolysis plant requires interventions on the electrolysis cells including, in particular, the replacement of spent anodes with new anodes. To carry out these interventions, factories are generally equipped with at least one lifting and handling unit comprising an overhead crane, which can be translated over and along the electrolysis cells, and a trolley equipped with several handling and intervention devices (often called "tools"). Such a lifting and handling unit may in particular be equipped with a device for the handling of the connectors, in particular their installation, removal and transport, such as the connector described in the French patent FR 2 039 543.

However, it may happen that the connectors are not well grasped by these handling devices, and this can lead to an accidental fall of the connector, typically during transport or when it is placed on the support hooks. In US Pat. No. 7,344,625, the Applicant has proposed a simple and compact anode connector handling device. This handling member is intended to set up, remove and transport an anode connector provided with two lateral journals and a clamping screw, such as that disclosed by US Pat. No. 7,344,625 and again illustrated in FIGS. 3A and 3B. . This handling member comprises a clamping member which cooperates with the clamping screw so as to modify the clamping state of the connector and a locking system which cooperates with said clamping member so as to keep the connector locked in a position determined in the handling member, when the connector is loosened with the aid of the clamping member. It further comprises two movable members having an open position and a closed position, and can serve as a support for the connector when in the closed position and that, by accident, the connector is not or is no longer retained by the blocking system.

In this device, the moving members move from one position to another under the effect of cams which cooperate with the upper surface of the support hooks during vertical downward movement of the handling member. In practice, these mobile members are subjected to frequent shocks and twist or bend easily, so that they are wedged or closed and that, their end no longer passing underneath the trunnions, they end up no longer able act as a safety support in case the connector is no longer held by the locking system. This requires many maintenance visits to this device that result in frequent replacements of said mobile members. To avoid these drawbacks, the applicant has decided to develop a connector handling member more solid and more reliable.

The subject of the invention is a handling device intended in particular to reliably and permanently ensure the transport of an electrolytic cell anode connector, the placing and fixing thereof on an anode frame for ensuring the electrical contact between the anode rod and the anode frame, or its removal, the handling member being arranged such that the risk of accidental fall of said connector during its handling is as low as possible. A first object of the invention is a connector handling member for connecting an anode rod to the anode frame of an igneous electrolysis aluminum production cell, said connector being provided with two lateral pins capable of cooperate with integral support hooks of said anode frame and placed on either side of the anode rod, so as to press said anode rod against said anode frame, said handling member comprising at least one anode member; guide having an indentation associated with each of said trunnions and intended to receive said trunnion, said handling member being characterized in that it also comprises:

at least one gripping member, having an open position and a closed position, said guide member and said gripping member cooperating so that, when said gripping member is in the open position, each pin can be inserted into said notch or when extracted, and when said gripping member is in the closed position, each pin can perform only a limited displacement in said notch, between a so-called "low" position corresponding to the contact with said gripping member and a so-called "position. high ";

an actuation system associated with said gripping member, able to move it between said open and closed positions,

- At least one locking system having a locked position and an unlocked position, adapted to block said gripping member when in the locked position, and adapted to move from the locked position to the unlocked position when said pins are in the up position .

The arrangement of the gripping member and the locking system is such that: a) when said handling member is provided with a connector and moves in order to deposit it on the support hooks of the anode frame, the locking system is in the locked position and blocks the gripper in the closed position, trapping the pins of the connector. By gravity, the pins are in the lower position, in contact with the gripping member, which is advantageously provided with concavities able to form a seat on which a pin can rest. Arrived above the support hooks, the handling member is lowered until the pins rest on said support hooks. Continuing the descent of the gripping member, the pins lose contact with said gripping member and move in the notch until they reach their upper position where, for example by driving a movable part integral with the locking system, they pass said locking system from its locked position to its unlocked position, thereby allowing said gripping member to move to its open position. Once the actuating system has been implemented to place the gripping member in the open position, the handling member, typically integral with a service machine, is animated with an upward vertical movement and released from the connector that he was carrying. b) when said handling member is empty and is moved to seize a connector resting on the support hooks of the anode frame and extract it from this position, the gripping member is held in the open position. Arrived above the connector, which rests on the support hooks, the handling member is lowered until the pins are introduced into said notches and reach their upper position where, for example by driving a movable piece secured to said locking system, they pass said locking system in the unlocked position, thereby allowing said gripping member to move from its open position to its closed position to imprison said trunnions. The handling member is raised so that the pins are in the low position, which corresponds to the contact with said gripping member. By continuing the upward movement, the connector is driven by the gripping member, the pins remaining in contact with the gripping member, typically by gravity, resting on concavities of said gripping member forming seats said trunnions.

Unlike the handling device described in US Pat. No. 7,344,625, the locking of the connector in the handling device does not depend on the clamping and unclamping device of the connector, and can thus be used for the handling of type connectors. different, for example that do not require the actuation of a clamping screw. However, the preferred embodiment of the invention for handling connectors provided with a clamping screw is also provided with a device for clamping / loosening the clamping screw of the connector, the latter not having to must be associated with the locking system of the connector.

The movable members of US Pat. No. 7,344,625, which serve as safety supports for the trunnions, are here replaced by a gripping member intended to serve as a "permanent" support for said trunnions when those are in the lower position in the indentations of said tread member. handling. The gripping member is moved between its open position and its closed position by means of an autonomous actuating system. In this way, the displacement of the gripping member, which is no longer dependent on the effect of cams cooperating with the upper surface of the hooks, can be performed regardless of the state, worn or deformed, of said member grasping. The gripping member is also associated with a locking system that can not unlock - to allow the handling member to move from its closed position to its open position - that if the pins of the connector, introduced into the notches, are in high position. The locking system comprises a movable part capable of moving between two positions: an unlocking position, where the gripping member is free to move and a locking position, where it prevents the movement of the gripping member, towards its open position if it is in the closed position and towards its closed position if it is in the open position. Advantageously, the locking position is reached by said movable part when it comes into contact with a journal and is driven by said journal in its stroke towards its upper position. This movable part can move by pivoting about an axis integral with the connector of the handling member or being guided in translation by a sliding type connection.

Advantageously, said locking system is associated with an actuator which, when said pin is not in the raised position, passes said movable part from its unlocking position to its locking position. Thus, as soon as the trunnion is no longer in the up position, the locking system is in its locked position, which prevents the unintentional opening or closing of the gripping member. Said actuator is an elastic means, typically a compression spring, whose stiffness is sufficiently small so that the movable portion of the locking system can be driven by said pin in its movement to its upper position.

In normal operation, the upper position of the trunnions can only be reached by moving down the handling member, the connector being fixed, typically resting on the support hooks of the anode frame.

Advantageously, the actuating system of the gripping member is a cylinder, typically pneumatic, comprising a rod whose two ends of the race respectively correspond to said open position and to said closed position. Advantageously, positioning sensors are provided to locate the position of the moving part of the locking system, so as to avoid the implementation of the actuating system when the locking system is in the locking position (redundant security).

In a preferred embodiment of the invention, the gripping member comprises two flanges, each associated with a pin and driven by the same actuating system. Similarly, the locking system advantageously comprises two locking devices, each associated with a trunnion. Said gripping member is advantageously a pivoting member, preferably a set of pivoting flanges, whose outer contour, in a plane perpendicular to the pivot axis, has a tenon or mortise type relief, which cooperates with a relief locking device, and a protrusion, which forms an obstacle to the entry of the notch, when said gripping member is in the closed position, and which typically has a concavity capable of forming a seat on which can rest the trunnion. The overall shapes in C or L are well adapted to this pivoting member but other more compact shapes, such as that presented in Example 4, may also be suitable.

The movable part of the locking system is advantageously provided with two walls which, when said movable part is in the locking position, form stops to move said relief of the gripping member: a stop wall at the opening which opposed to the movement of said relief when said gripping member has to move from its closed position to its open position and an abutment wall to the closure which opposes the displacement of said relief when said gripping member has to move from its open position to its position closed.

The invention also relates to a lifting and handling unit comprising at least one connector handling member according to the invention.

The invention also relates to the use of the handling device according to the invention in an aluminum production plant by igneous electrolysis.

The invention also relates to the use of the lifting unit and handling according to the invention in an aluminum production plant by igneous electrolysis.

The invention will be better understood from the detailed description of preferred embodiments thereof which are set forth below and are illustrated with the aid of the accompanying figures.

FIG. 1 illustrates a typical electrolysis cell, seen in perspective, intended for the production of aluminum.

Figure 2 illustrates, in cross sectional view, a typical electrolysis room for the production of aluminum.

Figure 3A illustrates, seen in perspective, an anode connector and support hooks of said connector (the anode frame to which they are attached is not shown). The figure 3B illustrates this same connector placed on the support hooks to press the anode rod (not shown) on said anode frame.

Figures 4a to 4d illustrate, in side views, a first connector handling member according to the invention, with its mounting plate.

Figures 5a to 5d illustrate, in side views, a second connector handling member according to the invention.

Figures 6a to 6d illustrate, in side views, a third connector handling member according to the invention.

Figures 7a to 7d illustrate, in side views, a fourth connector handling member according to the invention.

Electrolysis plants for the production of aluminum comprise one or more electrolysis rooms (100) having a large number of electrolysis cells (1) normally arranged in rows or rows (typically side by side or head to head ), each row or file typically having one or more hundreds of cells. As illustrated in FIG. 1, an electrolysis cell (1) comprises a tank (2), able to contain the liquid metal and the electrolyte bath, a superstructure (3) and anodes (8), typically precooked anodes. The superstructure (3) comprises a fixed gantry (4) and a moving metal anode frame (5). The anodes (8) are provided with a metal rod (9) for fixing and electrical connection of the anodes (8) to the anode frame (5). The superstructure (3) also comprises at least one jack (not shown) coupled to the anode frame (5) by connecting rods (6) and levers (7). The anode frame (5) can be moved vertically (upwards or downwards) under the action of the cylinder (s).

The anode rods (9) are fixed to the anode frame (5) by connectors such as that illustrated in FIG. 3A. This connector (200) comprises two levers (201, 202) able to articulate around a common axis (213), clamping means (205, 206, 210, 21 1) for articulating said levers (201, 202 ) and two lateral journals (212, 212 ') arranged on each side of the connector. The lateral journals (212, 212 ') generally form the common axis (213) and are typically constituted by the ends of a rod which passes through the connector from one side. Said journals (212, 212 ') are intended to rest in the recess (1 1, 1 1') of the hooks (10, 10 ') fixed to the anodic frame (5) and situated on either side of each rod of anode (9). A connector (200) has at least one first state, called a tight state, and a second state, called a loose state. When a connector (200) is installed in fixing hooks (10, 10 '), as shown in FIG. 3B, the tightening state allows either the anode rod (9) to be fixed to the frame anode (5), ie to release the anode rod (9): in the tightened state, the connector (200) applies pressure against the anode rod (9) and the plate on the anode frame (5) ; in the loosened state, the connector (200) no longer applies pressure against the anode rod (9), so that the connector and the anode can be removed.

A connector (200) can pass between the two tightening states by actuating the clamping means (205, 206, 210, 21 1). These means typically comprise a screw

(210) adapted to cooperate with an outer clamping member, generally attached to a handling member (300). The clamping screw (210) is typically provided with a head

(21 1) adapted to be inserted into the clamping member, which is actuated for clamping or loosening the connector (200). The clamping means also comprise nuts (205, 206) fixed to the levers (201, 202) of the connector, preferably movably, and adapted to cooperate with the screw (210) so as to allow the articulation of the levers ( 201, 202) and the tightening / loosening of the connector (200). The levers (201, 202) of a connector (200) generally comprise crosspieces (203, 204) intended in particular to communicate, directly or indirectly, the clamping pressure of the connector against the anode rods.

As illustrated in FIG. 2, the electrolysis rooms (100) generally comprise at least one lifting and handling unit, called a "service machine" (20), and subsequently designated under the symbol "MSE". ". Said unit (20) typically comprises a traveling crane (21) able to be moved along the electrolysis cells on treads (23, 23 '), a trolley (22) able to move on the crane ( 21), and handling and intervention members (30), often referred to as "tools", such as a handling member (300) for the anode connectors (200). The handling member (300) typically comprises a plate (301) fixed to the end of a movable vertical arm (24), for example the last segment of a telescopic arm, itself secured to a door turret tool pivoting about a vertical axis integral with the carriage (22).

Examples 1 to 4 illustrate four embodiments of the connector handling member according to the invention, which differ essentially by the shape given to the gripping member and by the locking system. EXAMPLE 1 (FIGS. 4a to 4d)

The first example is a connector handling member (300) which is mounted on the end of a telescopic arm via a mounting plate (301). Said handling member comprises a guide member (30) which has a notch (40) associated with each of said trunnions and wherein said trunnion is intended to move.

The handling member also comprises a gripping member (31), which has an open position and a closed position. The guide member (30) and the gripping member (30) cooperate such that:

when the gripping member (31) is in the open position, each pin can be inserted into or extracted from the notch (40),

when the gripping member (31) is in the closed position, each pin can make only a limited displacement in said notch, between a so-called "low" position corresponding to the contact with said gripping member and a so-called "high" position. ".

A pneumatic cylinder plays the role of the actuating system (31 1) associated with said gripping member, able to move it between said open and closed positions.

An L-shaped pivoting latch (320) is the movable part of the locking system (32). It has a locked position and an unlocked position, adapted to block the gripping member (31) when in the locked position. The pivot axis (322) of said latch is substantially at the intersection of the two branches of the L, the first leg (321) of the substantially horizontal L, being intended to come into contact with said pin when it moves from its lower position to its upper position and to be driven by said pin, pivoting the latch to its unlocked position. The second branch (325) of L, substantially vertical, is provided with a protrusion that cooperates, when said latch is in the locked position, with a raised portion (313) of the gripping member (31) so that it opposes any movement of said gripping member, regardless of its original position, open or closed: its bottom wall (324) forms a stop closure, its upper wall (323) forms stop at the opening .

When the handling member (300) is provided with a connector and moves in order to deposit it on the support hooks of the anode frame, the latch (320) is in the locked position and blocks the gripping member ( 31) in a closed position, imprisoning the connector pins. By gravity, the journals are in the low position, in contact with the gripping member (Fig. 4d). Arrived above the support hooks, the handling member is lowered until the pins rest on said support hooks. Continuing the descent of the gripping member, the journals move and reach their high position where, coming into contact with the horizontal portion of the latch, they rotate said latch by moving it from its locking position to its position of unlocking (Fig. 4c), thus allowing the gripping member to move to its open position (Fig. 4b) and the handling member to release from the connector it was carrying (Fig. 4a).

When the handling member (300) is empty and is moved to seize a connector resting on the support hooks of the anode frame and extract it from this position, the gripping member is held in the open position. At the top of the connector (Fig. 4a), which rests on the support hooks, the handling unit is lowered until the trunnions are introduced into the said notches and reach their upper position (Fig. 4b). wherein, in contact with the horizontal portion of the latch, they rotate said latch from its locked position to its unlocked position, thereby allowing the gripper to move from its open position to its closed position to imprison said trunnions (Fig. 4c). The handling member is then reassembled so that the pins arrive in the lower position, which corresponds to the contact with the gripping member. By continuing the upward movement, the connector is driven by the gripping member, the journals resting on said gripping member (Fig. 4d).

An actuator (34) moves the locking system (32) from its unlocked position to its locked position when the journal is not in the up position. Said actuator is a spring (340), connecting a fixed point of the handling member to a point of the substantially vertical leg L. The stiffness of the spring is low enough so that the latch can pivot when the pin comes into contact with the substantially horizontal part.

The gripping member (31) comprises two pivoting flanges, each associated with a trunnion and animated by a jack to move from the open position to the closed position and vice versa. Said flanges pivot about an axis (302). They have a C-shaped contour, with a tenon-like relief (313) which cooperates with the upper wall (323) and the lower wall (324) of the latch (320) and with a protuberance (314) which forms an obstacle to the inlet of the notch, when said gripping member is in position closed. The protrusion (314) has a concavity (312) adapted to form a seat on which can rest the trunnion.

EXAMPLE 2 (FIGS. 5a to 5d)

The second example differs from the first example essentially by the latch (320 '). The latter is also an L-shaped pivoting latch, with a very short vertical branch, connected to a compression spring (340 ') and a substantially horizontal branch provided with a notch having a stop wall (323') to the opening and provided at its end with a wall (324 ') of abutment closure.

The finger (313 ') of the flange (310') of the gripping system (31) cooperates with said stop wall at the opening to maintain the locking system (31) in the locked position, said flange being locked in the closed position . The finger (313 ') cooperates with said closing stop wall (324') to keep the locking system (31) in the locking position, the flange (310 ') of the gripping system (31) being locked in position opened.

EXAMPLE 3 (FIGS. 6a to 6d)

The third example differs from the first example also by the latch (320 "), which is not pivoting: it moves vertically, guided by a sliding connection (322"). Its high end is connected to a compression spring (340 ") which tends to push it to a low position, in which the stop wall at the opening (323") and the closing stop wall (324 ") play with the finger (313 ") of the flange (310") roles similar to those described in the previous example.

EXAMPLE 4 (FIGS. 7a to 7d)

The fourth example differs from the previous examples in the more compact shape of the flanges (310 "') of the gripping system (31) The latch (320"') is pivotable. A compression spring (340 "') tends to push it to a low position, in which the stop wall at the opening (323"') and the closing stop wall (324 "') play with the finger. (313 "') of the flange (310"') roles similar to those described in Examples 2 and 3 above.

In this example, the displacements of the flanges (310 "') of the gripping system (31) are less ample, the seat (312"') offered to the trunnions is less extensive but the associated protuberance (314 "') allows to trap said trunnions in the indentation.

Claims

1. Handling member (300) of an anode connector (200) for connecting an anode rod to the anode frame (5) of an igneous electrolysis cell (1), said connector being provided with two lateral trunnions (212, 212 ') adapted to cooperate with bearing hooks (10, 10') integral with said anode frame and placed on either side of the anode rod (9), so as to plating said anode rod against said anode frame, said handling member comprising at least one guiding member (30) having a notch (40) associated with each of said trunnions and intended to receive said trunnion, said handling member being characterized in what it also includes:

at least one gripping member (31), having an open position and a closed position, said guiding member and said gripping member cooperating so that, when said gripping member is in the open position, each pin can be inserted in said notch or being extracted from it, and when said gripping member is in the closed position, each pin can only make a limited displacement in said notch, between a so-called "low" position corresponding to the contact with said gripping member and a position called "high";

an actuation system (31 1) associated with said gripping member, able to move it between said open and closed positions,

- At least one locking system (32) having a locked position and an unlocked position, adapted to block said gripping member when in the locked position, and adapted to move from the locked position to the unlocked position when said pins are in high position.

2. handling member (300) according to claim 1, characterized in that said locking system comprises a movable part (320, 320 ', 320 ", 320"') capable of moving between two positions: an unlocking position , wherein said gripping member is free to move and a locking position, wherein said movable member prevents movement of said gripping member, said locking position being reached by said moving part when the latter comes into contact with a trunnion ( 212) and is driven by said pin in its stroke towards its high position.

3. handling member (300) according to claim 1 or 2, characterized in that it also comprises an actuator (34) which, when said pin is not in position high, moves said locking system from its unlocked position to its locked position.

4. handling member (300) according to claim 3, characterized in that said actuator is an elastic means, typically a compression spring (340, 340 ', 340 ", 340"'), whose stiffness is sufficiently low for that the movable part of said locking system can be driven by said pin in its movement to its upper position

5. handling member (300) according to any one of claims 1 to 4, characterized in that said gripping member (31) comprises two flanges (310, 310 ', 310 ", 310"'), each associated with a trunnion.

6. handling member (300) according to any one of claims 1 to 5, characterized in that it comprises two locking devices, each associated with a trunnion.

7. handling member (300) according to any one of claims 1 to 6, wherein said gripping member (31) has, perpendicular to the pivot axis, a contour comprising a relief (313, 313 ', 313 ", 313" ') which cooperates with said locking system and a protuberance (314, 314 "') which forms an obstacle to the entry of the notch (40), when said gripping member is in the closed position.

Handling device (300) according to claim 7, wherein said protuberance has a concavity (312) adapted to form a seat on which can rest the trunnion (212).

9. handling member (300) according to any one of claims 1 to 8, wherein said actuating system (31 1) is a jack, typically pneumatic, comprising a rod whose two ends of the race respectively correspond to said open position and said closed position.

The handling member (300) according to any one of claims 7 to 9, wherein said movable part (320, 320 ', 320 ", 320"') of the locking system (32) is provided with a wall (323, 323 ', 323 ", 323"') which, when said moving part is in the locking position, opposes the displacement of said relief (313, 313 ', 313 ", 313"') of the organ gripper (31) which allows to move from the closed position to the open position.

The handling member (300) according to any one of claims 7 to 10, wherein said movable part (320, 320 ', 320 ", 320'") of the locking system (32) is provided with a wall (324, 324 ', 324 ", 324"') which, when said movable part is in the locking position, opposes the displacement of said relief (313, 313 ', 313 ", 313"') of gripping member (31) for moving from the open position to the closed position.

12. Lifting and handling unit (20) comprising at least one connector handling member (200) according to any one of claims 1 to 1 1.

13. Use of a handling member (300) according to any one of w claims 1 to 1 1 in an igneous electrolysis aluminum production plant.

14. Use of a lifting and handling unit according to claim 12 in an igneous electrolysis aluminum production plant.