CH643084A5 - Electrolysis cell short-circuiter - Google Patents

Description

643,084

2

1. Electrolytic cell short-circuiter having two current supply plates (1,2) and a frame (3,4) carrying these plates via insulators, as well as the bearings of a shaft control (5), characterized in that it is equipped with a special breaking contact (8) and several ordinary contacts (6), articulated on one of the current supply plates, all the electrical contacts of short-circuiting being ensured between silver or silver surfaces, except that of breaking proper which is carried out copper on copper, the articulation of the breaking contact on the current supply plate being shunted by a flexible conductor ( 21), the ordinary contacts and the breaking contact being driven by connecting rods (15,25) articulated on crank pins (14,24) fixed directly or indirectly on the control shaft with interposition of compression springs (18,28 ), the ma-neton of the breaking contact being angularly offset relative to the crank pins ordinary contacts so as to go far beyond neutral when these achieve this.

2. Short-circuiting device according to claim 1, characterized in that the breaking contact comprises (10,11) contact parts fixed by direct access screws so that they can be replaced easily.

3. Short-circuiting device according to claim 1, characterized in that the ordinary contacts are separated from the breaking contact by an insulating partition (33) which protects them from projections of copper droplets produced during cutting.

In certain electrolysis installations, for example those producing chlorine, each of the electrolysis cells of a group of cells supplied in series must be able to be inactivated by short-circuiting it, to allow its maintenance or its replacement, without suspending the production of other cells.

In these installations, a fixed short-circuiting system is sometimes provided for each of the cells in the group.

The direct current passing through said cells can reach more than 200,000 amperes; it is distributed among several anodes each receiving on average 10 to 15,000 amperes.

The cell short-circuiting system is then generally constituted by a set of contacts, arranged in each of the anode circuits, and controlled simultaneously by a mechanical system, often consisting of 1 or 2 pneumatic cylinders driving by connecting rods-cranks the anode contact control shafts, several of these contacts possibly having a common control shaft.

The short-circuiting system must be able to conduct the overall current of the installation, support it indefinitely and cut it off.

This current is distributed regularly between the anode contacts only if the simultaneity of the closing and breaking operations is well ensured and if the resistances offered to the passage of the current in the different contacts are comparable.

In practice, the anode contacts must be able to conduct and cut a current much higher than the average current of the anodes, without their average quality being deteriorated. The object of the present invention is to provide a short circuit for an electrolysis cell, not having the drawbacks mentioned.

This short-circuiter comprises, like other known devices, two current supply plates between which the short-circuit contacts must be established and a chassis on which said plates are fixed, by means of insulators. power supply, chassis which supports the bearings of a control shaft. The short-circuiter according to the invention is characterized by the characterizing part of claim 1. The control shaft can be common to several short-circuiters. In a particular embodiment of the short-circuiter according to the invention, the breaking contact comprises contact parts (fixed and mobile) fixed by screws and removable without any other disassembly, so that they can be easily replaced after wear.

In the short-circuiter according to the invention, the protection of ordinary contacts against projections of unavoidable copper droplets during cutting can be ensured by a simple insulating partition separating the ordinary contacts arranged side by side and the breaking contact.

The three figures of the appended drawing, relating to a particular embodiment of the invention, will make it clear.

Figure 1 is a partial schematic view of the short-circuit-cooker, the control shaft, as well as the crank pins, connecting rods and control springs of the movable contacts being assumed to be removed.

Figure 2 is a sectional view showing the breaking contact.

Figure 3 is a sectional view showing an ordinary contact.

25 We see in FIG. 1 the two current supply plates 1 and 2, fixed, by insulators not shown, on a frame whose flanges 4 carry the bearings, not shown, of the operating shaft 5 supposed to be cut , the 3 ordinary contacts 6 articulated on blocks 7, preferably insulating, assumed to be fixed by 30 screws on the plate 1, the movable breaking contact 8, articulated on the conducting block 9 and carrying the removable cutting piece 10, fixed by screws and cooperating with the removable part 11, fixed by screws on the current supply plate 2. We see on the contacts 6 and 7 the trace of the recesses 12 in which the contact compression springs are housed, as well as the sectional holes 13 for crossing the contact control rods, not shown. Finally, we see the insulating partition 33.

FIG. 2 is a section of the short-circuiter along a plane of trace aa in FIG. 1. This section shows the current supply plates 1 and 2, the chassis 3 and its flange 4, as well as the shaft 5. We can see the movable breaking contact 8, its articulation block 9, its removable contact piece 10 supposed to be fixed by two screws in threads 30 of 8, as well as 45 the removable fixed contact piece 11 supposed to be fixed by two screws in the threads 31 of the current supply plate 2. We see the control mechanism, constituted by the crank pin 14 articulated at 16 on the connecting rod 15, the connecting rod head 17, the spring 18 and its washer d support 19.

50 In the closed position of the short-circuiter, the crankpin exceeds the neutral position by 10 °, for a total operating angle of 45 °.

We can also see the articulation of the movable contact 8 in the block 9 assumed to be produced by means of two pins 20, 55 which are better visible in FIG. 1. Finally, we see the flexible connection 21 intended to ensure the protection of the contact 22 against deterioration at the time of opening of the breaking contact, when a significant effort must be exerted by the connecting rod head 17 on the breaking contact to take off the contacts 6010 and 11 which can be linked by a bad copper-copper soldering occurring at when the short circuiter is closed.

Figure 3, which is a section along the trace plane bb in Figure 1, shows the current supply plates 1 and 2, the 65 chassis 3 with its flange 4 and the operating shaft 5. We see there the insulating blocks 23 ensuring the fixing of the current supply plates to the chassis by means not shown, the ordinary contact 6 and its articulation block 7, preferably

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643,084

insulator, fixed to the plate 1 by means not shown. We can still see the contact control mechanism with its crank pin 24 hinged at 26 on the connecting rod 25, the spring 28, the washer 29 and the connecting rod head 27 which drives the movable contact. The short-circuiter is shown in the Closed position, while the crankpin 24 is in neutral.

The angular offset of the crank pin of the breaking contact with respect to the crank pins of ordinary contacts makes it possible to maintain correct operation of the breaking contact,

despite the inevitable wear of the breaking parts 10 and 11. This offset further reduces the maximum operating torque since the torque due to the breaking contact is already weakened when the ordinary contacts are contacted.

Note in FIG. 2 that the accesses to the 2 fixing screws of the part 10 on the part 8, on the one hand, and the access to the 2 fixing screws of the part 11 on the plate 2, on the other hand , are clear in the direction of arrow 32, which allows parts 10 and 11 to be replaced by means of a screwdriver.

VS

1 sheet of drawings