RU2290458C1 - Connection of bus with cathode rod of aluminum electrolyzer - Google Patents

Abstract

FIELD: non-ferrous metallurgy; structural members of electrolyzers used for production of aluminum by electrolysis.

SUBSTANCE: detachable fastener is made in form of two rigidly interconnected vertical plates provided with ports for passage of cathode rod and wedge pair located in between them; stop for wedge is swivel and wedge is provided with locking member. Besides that stop for wedge is made in form of cylinder with longitudinal shear for wedge; steel plate located between contact plate of cathode lead and wedge is rigidly connected with contact plate of cathode lead.

EFFECT: enhanced reliability and stability of electric contact of cathode with bus; reduction of labor input.

3 cl, 2 dwg

Description

The invention relates to the field of non-ferrous metallurgy, in particular to structural elements that ensure the operation of electrolytic cells for producing aluminum by electrolysis.

Currently, to connect the bus to the cathode rod, a flexible cathode descent made of aluminum tape is used, rigidly connected by welding to both the bus and the cathode rod. Welding of aluminum strips to a steel rod is carried out using a special butt welding machine (Metallurgical Guide to Non-ferrous Metals, Aluminum Production. Metallurgy Publishing House, 1971, p. 222).

If it is necessary to disconnect the electrolyzer equipped with such a connection, during overhaul, the cathode slopes are cut off from the cathode rod and from the bus and sent to remelting. Thus, approximately 1 ton of flexible expensive aluminum tapes (slopes) from each electrolyzer goes to remelting.

It is known to connect a tire to a cathode rod (Utility Model Certificate No. 15341, IPC C 25 C 3/16, 2000), adopted as a prototype. According to the description of the utility model, the connection of the bus to the cathode rod of an aluminum electrolysis cell, comprising a flexible cathode descent with contact plates associated with surfaces of the end of the cathode rod pretreated into electrical contact, is detachable in the form of fasteners: a pair of bolt and nut; or clamp; or a pair of wedge clamps.

The disadvantages of the proposed connection options include the following:

- the bolt-nut connection option, which is currently sometimes used, requires tightening the contacts during operation, especially in the post-launch period, when the cathode device of the electrolyzer is completely heated. At this time, the bolts passed through the holes in the steel rod are heated with it, are pulled out, the contact pressing to the rod is weakened, and the energy loss in the connection increases. To eliminate this, it is necessary to tighten the bolted connection. Such an operation is performed in real work several times during the operation of the cell "from repair to repair".

Another disadvantage is the need to make holes in the rods on drilling machines, which requires significant labor costs due to the length and weight of the rods;

- the option of connecting with a clamp or a pair of clamp-wedges cannot be taken into operation, because has the following disadvantages: when the rod is heated, the plate clamp is also stretched from the temperature and, in addition, the degree of stretching increases due to the straightening of the radii in the corners of the clamp under load. This will especially be manifested in the version with wedges.

Another disadvantage is the use of counter wedges, which must be manually hammered. The quality of contact in this case completely depends on each individual person and his physical capabilities. In addition, in the wedge installation area there is not enough space to work with the wedges, especially with the wedge, which must be hammered from the side of the wall of the cathode casing, since the end of the steel rod is 120-150 mm away from the wall.

An object of the invention is to provide a structure for connecting a cathode descent to a steel cathode rod, which allows both reliability in operation and reduction of labor costs in the manufacture and installation (dismantling) of the electrolyzer.

The stated technical problem is solved in that in the connection of the tire to the cathode rod of an aluminum electrolyzer, including a flexible cathode descent with contact plates connected to the surfaces of the end of the cathode rod previously processed under electrical contact by a detachable connection in the form of a wedge-shaped fastener, according to the claimed invention, the fastener is made in in the form of two vertical plates rigidly interconnected by ribs with windows for the passage of the cathode rod; and with fixed between the plates, on one side on the ribs, a wedge with a traction locking element; and mounted on a vertical plate emphasis for the wedge; the wedge and the stop for the wedge by the wedge surfaces are interconnected with the possibility of hard contact, and the stop for the wedge is made in the form of a cylindrical shaft with a slice along the length of the wedge.

The invention is complemented by private distinguishing features, also aimed at solving the problem.

The stop for the wedge is mounted on the plate with the possibility of rotation in the horizontal plane.

A steel plate is rigidly fixed to the contact plate of the cathode descent.

The proposed technical solution avoids making holes in the steel cathode rod, does not require contact maintenance during operation, simplifies the installation and dismantling of the cathode rod - descent during overhaul, and is reliable in operation.

The invention is illustrated by drawings, which depict:

figure 1 is a view of the connection in plan;

figure 2 is a section aa in figure 1.

The design of the connection of the bus with the cathode rod consists of two vertical plates 1 with windows for the passage of the cathode rod 2. The plates are welded together by ribs 3, 4 and 5 at a certain distance from each other, which is determined structurally. Plate 1 with ribs 3, 4, 5 form the body of the pads. A stop for the wedge 6 is installed between the plates 1. The stop for the wedge 6 is made in the form of a cylinder with a cutout along the length of the wedge 7. The wedge 7 is connected with a traction locking element consisting of a fixing screw 8 with a nut 9 mounted on the thread and a guide rod 10. Screw 8 and the rod 10 are installed in the holes made in the ribs 4 and 5, which are supports and guides during the movement of the wedge 7. Under the wedge 7 there is a tip 11 of the cathode descent 12 (copper, bimetal, etc.). A support (for a wedge) steel plate 13 is rigidly fixed on the tip 11. This tip with the plate makes electrical contact with one surface of the cathode rod 2. Another tip 14 of the cathode descent 12 makes electrical contact with the opposite surface of the rod and is located between the rod and the block body.

To make electrical contact between the bus and the cathode rod, you must:

- put the connection on the rod 2;

- insert the tip 11 with the plate 13 of the cathode descent 12 between the wedge 7 and the surface of the rod 2, and insert the tip 14 into the gap between the body of the device and the opposite surface of the rod (before inserting the tips, the wedge 7 should be in its extreme rear position);

- using the traction fixing screw 8 with nut 9, move the wedge 7 to the front position, in this case the axial force from the pair screw 8 - nut 9 with the help of a pair of wedges 7 - the stop for the wedge 6 with a cut is converted into a vertical force, pressing the tips 11 and 14 to the surfaces of the cathode rod 2, while fixing the wedge 7 with a nut 9. To reduce the friction forces arising on the working surfaces when the wedge 7 is moving, a steel plate 13 is installed on the tip 11, the working surface of which is machined according to a high class of shear Ovate and subjected to heat treatment. The surface of the cutout on the stop for the wedge 6 is also processed.

A pair of traction screw 8 - nut 9 with an M27 thread develops an axial force (for steel material 40X) up to 7400 kg, and a wedge pair (wedge 7 and an emphasis for wedge 6) at a wedge angle of 7 ° gives a contact pressing force of up to 14 tons. the efforts are sufficient to ensure reliable electrical contact with minimal loss of electricity in the contacts.

The advantage of this design is that during operation of the electrolyzer, the contacts do not require pulling, because the wedge is fixed by a nut 9 in a predetermined position, in addition, there are no elements that would stretch under load and under the influence of temperature, as is the case with bolt contacts.

In this case, when the steel rod is heated, the contacts become even more denser.

Thus, the proposed design is simple to manufacture, reliable in operation, provides quick inclusion and shutdown of the electrolyzer in the electrical circuit (during overhaul), reduces labor costs for this operation.

Claims (3)

1. The connection of the bus with the cathode rod of an aluminum electrolyzer, including a flexible cathode descent with contact plates connected to the surfaces of the end of the cathode rod pretreated for electrical contact by a detachable connection in the form of a wedge-shaped fixing element, characterized in that the fixing element is made in the form of two rigidly connected between by means of ribs of vertical plates with windows for the passage of the cathode rod, with fixed between the plates, on one side on the ribs, a wedge with ovym fixing member and mounted on the vertical plate abutment for the wedge, the wedge and the abutment to wedge the wedge surfaces are conjugate to each other to form a rigid contact and abutment for the wedge is made as a cylindrical shaft with a cut along the length of the wedge. 2. The compound according to claim 1, characterized in that the emphasis for the wedge is mounted on the plate with the possibility of rotation in a horizontal plane. 3. The compound according to claim 1, characterized in that a steel plate is rigidly fixed to the contact plate of the cathode descent.

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