CN211128270U

CN211128270U - Composite electrode device of electric arc furnace

Info

Publication number: CN211128270U
Application number: CN201921913798.3U
Authority: CN
Inventors: 吴兴培; 黄健康; 刘玉龙; 刘世恩; 管志忱
Original assignee: Lanzhou University of Technology
Current assignee: Lanzhou University of Technology
Priority date: 2019-11-07
Filing date: 2019-11-07
Publication date: 2020-07-28
Anticipated expiration: 2029-11-07

Abstract

The utility model belongs to electric arc furnace equipment, in particular to a composite electrode device for an electric arc furnace; the composite electrode device of the electric arc furnace comprises a concave connector element, a prefabricated hole graphite electrode element and a tungsten rod screw element. The tungsten rod penetrates through a bottom flat-bottom counter bore of the connector element, taps into a prefabricated hole of the graphite electrode element, and enables the connector element and the graphite electrode to form a complete lower section electrode, and finally the tungsten rod is screwed into a metal water cooling section of the upper section through threads on the inner wall of the connector element to form a complete enhanced composite electrode. The utility model has the advantages that: the current density of the composite electrode is increased by utilizing the good conductivity and high temperature resistance of the tungsten rod, so that the current carrying capacity of the composite electrode with the same diameter is obviously increased compared with that of a pure graphite electrode, the surface temperature of the graphite electrode is reduced, the side oxidation loss is reduced, the probability of electrode breakage is reduced, the available volume in the furnace is relatively increased, the electric arc is concentrated compared with that of the pure graphite electrode, and the smelting efficiency is improved.

Description

Composite electrode device of electric arc furnace

Technical Field

The utility model relates to the technical field of metal smelting equipment, in particular to a device for increasing electrode current density and reducing graphite electrode consumption of an electric arc furnace.

Background

Graphite electrodes are important devices in steelmaking electric arc furnaces. In recent years, the price of graphite electrodes is increasing internationally and domestically, the cost ratio of the graphite electrodes to electric furnace steel is increased from 5% to 15%, and the supply and demand of the graphite electrodes are short with the increase of the steel yield. Therefore, it is a particular concern to try to reduce graphite electrode consumption to reduce the cost of electric steel. Electrode consumption can be divided into 4 forms, namely end consumption, side oxidation, stub detachment and breakage. The first two are continuous consumptions, accounting for about 50% to 70% of the total consumption of the electrode. The latter two are intermittent consumptions, commonly referred to as breakage losses, which are also an important cause of their consumption.

The existing graphite electrode improvement measures mainly include the following three measures: 1. water-cooling the graphite electrode: the water spraying technology is adopted, namely an annular water spraying device is used below the electrode holder to play the roles of isolating air and preventing the air from oxidizing and corroding the side surface of the electrode; 2. coating an anti-oxidation layer on the surface of the graphite electrode: has obvious high-temperature oxidation resistance effect; 3. water-cooling the composite electrode: the electrode consists of an upper section and a lower section, wherein the upper section is a metal water-cooled electrode, and the lower section is a graphite electrode, so that the conductivity of the electrode is ensured, and the cost of the graphite electrode is reduced. Although the composite electrode is complex in technology, the upper section of the composite electrode does not participate in graphite consumption due to the adoption of the metal water-cooling electrode, and the ultimate goal of saving graphite is achieved, so that the scheme is better. However, the graphite section at the lower part of the graphite has larger consumption, and has certain gap with the foreign technical level.

Disclosure of Invention

The utility model aims at providing a novel combined electrode device suitable for large-scale electric arc furnace reduces the consumption of graphite electrode, improves the benefit.

Another object of the present invention is to provide a method for increasing the current density of the graphite electrode without increasing the diameter of the electrode.

The novel composite electrode device of the electric arc furnace is characterized in that the upper section of the novel composite electrode device also adopts a metal water-cooling electrode, the lower section graphite electrode comprises a concave connector, a prefabricated hole graphite electrode and a tungsten rod screw.

The connector is cylindrical in appearance, has the same outer diameter as the water-cooling electrode and the graphite electrode, and is used for reliably connecting the water-cooling electrode and the graphite electrode.

The diameter and the number of the inner holes of the prefabricated hole graphite electrode are related to the carried current density, and the larger the current density is, the larger the number of the holes is, and the larger the diameter is. The connector and the graphite electrode can be conveniently connected into a whole by the tungsten rod screw through the prefabricated hole.

The tungsten rod screws serve to secure the connector to the graphite electrode, the number of which is related to the current density of the electrode. The tungsten rod screw has small resistivity and bears most of the electrode current.

The utility model has the advantages that: 1. the current density of the composite electrode is increased by utilizing the good conductivity and high temperature resistance of the tungsten rod, so that the diameter of the electrode required by the same current density can be obviously reduced compared with that of a pure graphite electrode, and the tungsten electrode can be repeatedly utilized, thereby reducing the loss of the graphite electrode; 2. the graphite area on the surface of the composite electrode is reduced, so that the side oxidation loss can be reduced; 3. the strength of the tungsten reinforced graphite electrode is increased, and the probability of electrode breakage is reduced; 4. the available volume in the furnace can be relatively increased; 5. the electric arc is more concentrated than a pure graphite electrode, so that the smelting efficiency can be improved.

Description of the drawings:

FIG. 1 is a schematic structural view of a composite electrode assembly according to an embodiment of the present invention;

fig. 2 is a schematic view of the female connector 1 of the water cooling section 4 and the graphite section 2 of the present invention;

fig. 3 is a cross-sectional view of the graphite electrode segment 2 of the present invention;

fig. 4 is a schematic view of a tungsten rod screw 3 according to the present invention;

FIG. 5 is a cross-sectional view of a graphite electrode segment of a tungsten rod screw of the present invention

FIG. 6 is a cross-sectional view of two tungsten rod screw graphite electrode segments of the present invention

FIG. 7 is a cross-sectional view of the graphite electrode section of the screw with three tungsten rods

FIG. 8 is a cross-sectional view of the graphite electrode section of four tungsten rod screws of the present invention

FIG. 9 is a cross-sectional view of the graphite electrode section of the five tungsten rod screws of the present invention

Detailed description of the preferred embodiments.

Example 1

As shown in fig. 1, the composite electrode device of the electric arc furnace comprises a concave connector 1, a graphite electrode 2 with a prefabricated hole and a tungsten rod screw 3; wherein the concave connector 1 is connected with the graphite electrode 2 of the prefabricated hole through a tungsten rod screw, and then the electrode water cooling section 4 is screwed in through the screw thread on the inner wall of the concave connector 1 to be connected into an integral electrode.

As shown in fig. 2, the groove wall of the concave connector 1 is provided with threads for connecting with the electrode water cooling section 4; the bottom of the groove is provided with a plurality of counter bores, and tungsten rod screws 3 are inserted into the counter bores and can be connected with the graphite electrode sections 2;

as shown in fig. 3, the upper end of the graphite electrode segment 2 is pre-opened with a plurality of blind holes with equal length, the number depends on the density of the current passing through the electrode, the reliable connection of the tungsten rod screw 3 and the graphite electrode 2 is ensured, and the accidental breakage of the electrode is prevented;

as shown in fig. 4, a tungsten rod screw 3 is used to securely integrate the female connector 1 with the graphite electrode 2.

Examples 2, 3 and 4

As shown in fig. 5, 6 and 7, the present embodiment is different from embodiment 1 in that: the graphite electrode of the embodiment has small current density, the number of the tungsten rods is less than or equal to 3, the tungsten rods in other 2 forms are all arranged on the outer layer of the inner part of the graphite electrode except for a single tungsten rod, the strength of the electrode is good, and the graphite electrode is suitable for direct current arc welding.

Examples 5 and 6

As shown in fig. 8 and 9, the present embodiment is different from

embodiments

2, 3 and 4 in that: the number of the tungsten rods is more than or equal to 4, one tungsten rod is arranged in the center of the graphite electrode to form a double-layer arrangement, and when the tungsten rod is used for alternating current arc welding, the current distribution can be uniform, so that the influence of skin effect is eliminated.

The technical idea of the present invention is not limited to the above-mentioned embodiment, and can also be according to the present invention, a plurality of different specific schemes can be obtained, for example, with the continuous improvement of the arc current, the required number of the tungsten rod electrode can be increased, when the number is large, the electrode can be arranged as single layer in example 1, 2, 3, 4, or as double layer in example 5, 6, the inner and outer layers can be arranged, and the multilayer arrangement can be performed if necessary, so that the current is uniformly distributed in the graphite electrode, thereby improving the current carrying capacity of the graphite electrode.

Claims

1. Composite electrode device of electric arc furnace, its characterized in that: the graphite electrode comprises a concave connector element, a prefabricated hole graphite electrode element and a tungsten rod screw element which are connected into a whole to form a composite graphite electrode lower section.

2. The composite electrode assembly for an electric arc furnace of claim 1, wherein: the cross section of the connector is in a concave shape, internal threads are formed on the inner side wall of the connector and can be tightly connected with external threads on the lower part of a metal water cooling section element, a stepped flat-bottom counter bore is formed in the bottom of the connector, the upper part of the connector is large and the lower part of the connector is small, the size of the upper part of the connector is matched with that of the head of a tungsten rod, the lower part of the connector is matched with a rod body of the tungsten rod, and a prefabricated hole.

3. The composite electrode assembly for an electric arc furnace of claim 2, wherein: the connector element is made of metal, and the outer diameter of the connector element is the same as that of the metal water cooling section and the graphite electrode section.

4. The composite electrode assembly for an electric arc furnace of claim 2, wherein: the number of the prefabricated holes of the graphite electrode depends on the current density carried by the electrode, and the number of the prefabricated holes can be more than 1, and the depth of the prefabricated holes is matched with the length of a tungsten rod screw.

5. The composite electrode assembly for an electric arc furnace of claim 2, wherein: the tungsten rod screw is provided with self-tapping threads and can be manually or electrically driven to tap a prefabricated hole of the graphite electrode.

6. The composite electrode assembly for an electric arc furnace of claim 5, wherein: the tungsten rod screw penetrates through a bottom flat-bottom counter bore of the concave connector element and taps into a prefabricated hole of the graphite electrode, the head of the tungsten rod is sunk into the flat-bottom counter bore and is parallel and level with the bottom of the concave connector element, and after all tungsten rods are connected and completed, the connector and the graphite section form an enhanced graphite electrode lower section without obvious gaps, shaking and deflection.

7. The composite electrode assembly for an electric arc furnace of claim 6, wherein: the lower section of the enhanced graphite electrode can be tightly connected to the external thread at the lower end of the metal water-cooling section through the internal thread of the concave connector to form the water-cooling combined electrode.