RU2232958C1 - Method for preparing electrode column having at least one electrode for operating in electric arc furnace and special bed for performing the same - Google Patents

Abstract

FIELD: manufacture of steels in electric arc furnaces.

SUBSTANCE: bed for preparing electrode column for operation in electric arc furnace includes at least one flared tube arranged over floor level and mechanism for securing column to tube. Under floor level opposite relative to said tube hated chamber with gas burners is arranged; said chamber has in upper portion duct for discharging combustion products. Bed may have several tubes and single heated chamber having individual burner and arranged opposite relative to said tubes. Method for preparing electrode column comprises steps of storing vertically arranged column in bed and lengthening it due to adding at least one new electrode; storing column while blanketing and heating part of column arranged under floor level; providing raised electrode temperature as far apart from place of column mounting; rotating column relative to lengthwise axis periodically or continuously; water cooling from outside upper electrode part protruded over bed level; blanketing and heating column in neutral atmosphere.

EFFECT: lowered temperature drop along cross section of electrodes of column, reduced thermal cracking, slow rupture of electrodes.

12 cl, 5 dwg, 3 ex

Description

The invention relates to the production of steel in the steel industry in electric arc furnaces of constant and alternating currents.

The main source of thermal energy necessary for steelmaking in an electric arc furnace remains the electric arc between the charge and the electrode column. It is known that the cost of electrodes, especially graphite, is a significant cost item in electric steelmaking.

The consumption of electrodes in an electric arc furnace depends on many factors, a significant proportion of which is crack formation on the lower (relative to the furnace working space) electrodes of the electrode column and their destruction [see, for example, R.D. Klein, C. Wimmer (SGL Garbon AG) “Requirements for Technology, Production and Customer Service of DC Electrodes”, MPT International April 1999, No. 2, p.25 ... 30].

Cracking due to thermal stresses, while taking a decisive place in the causes of low resistance of the electrodes.

Thermal stresses, in turn, are always caused by a significant temperature difference over the cross section of the heated (cooled) body, and this conclusion fully relates to the formation of cracks on the electrodes of the electrode column.

Thus, measures that contribute to reducing the temperature drop across the cross section of the electrodes of the electrode column during their operation in the furnace and cooling outside the furnace, clearly contribute to the reduction of cracking on the body of the electrodes.

These measures can be implemented in the process of finding the electrode column outside the electric arc furnace, i.e. in the process of preparing the column for operation.

A known method of preparing an electrode column, including the use of a self-sintering Soderberg electrode and, accordingly, welding a new casing, stuffing a self-sintering mass into it, replacing the burnt electrodes with new ones, which is most often carried out outside the furnace [see, for example, I.V. Okorokov. “Electrofusion furnaces”. M.: Metallurgizdat, 1945, p. 46 ... 47].

The specified method of preparation and operation of the electrode column has certain advantages compared to carbon electrodes, but is significantly inferior to graphite electrodes, which have received the greatest use on modern electric arc steel-smelting furnaces.

A known method of preparing an electrode column containing at least one electrode for operation in an electric arc furnace, comprising temporarily storing the column on a specialized stand in a vertical position with fastening in the upper part of the column, if necessary, elongating the column in this position until the formation of a new column by adding at least one new electrode by screwing it up [see, for example, Technological Instructions TI 518-2012-ES-01-02 CJSC Moldavian Metallurgical Plant, p. 4 ... 6]. The specified operation of temporary storage of the electrode column and its accompanying operation to extend the column is carried out during repair of the furnace or as the electrode column wears.

A known method of preparing an electrode column for essential features is closest to the proposed method, therefore, taken as a prototype.

The main significant disadvantage of this method is the lack of measures (actions) to reduce the temperature drop across the cross section of the electrodes of the electrode column both in the initial process of its temporary storage and sudden cooling, and in the initial process (final in terms of temporary storage) of its operation in an electric arc furnace and sharp at the same time heating.

The specified disadvantage of the known method contributes to the increased formation of thermal cracks on the body of the electrode, the acceleration of its partial or complete destruction.

The proposed method of preparing the electrode column for operation in an electric arc furnace is free from the indicated drawback and its negative consequences for the performance of the electrodes in the electrode column due to the maximum reduction of the causes of thermal stresses and, as a result, thermal cracks.

These technical results are achieved due to the fact that in the method of preparing an electrode column containing at least one electrode for operation in an electric arc furnace, comprising temporarily storing the column on a specialized stand in a vertical position with fastening in the upper part of the column, if necessary, elongating the column in this position until the formation of a new column by adding at least one new electrode by screwing it, according to the proposal during the specified time When storing the column, at least a part of the electrode column located below the level of the specialized stand is insulated, and the insulated part of the column is heated at the most, and in both cases the temperature of the column electrodes is increased as it moves away from the place of its fastening. In addition, during the indicated temporary storage of the column, it is rotated relative to the longitudinal axis of the column. The column is rotated periodically. The column is rotated constantly, except for the time of its extension. Moreover, the upper part of the column, protruding above the level of a specialized rod, outside is cooled by water. In addition, the insulation and heating of the columns is carried out in a neutral atmosphere.

Known specialized stand for temporary storage of the electrode columns and the implementation while lengthening the column until the formation of a new column by screwing new electrodes. The stand contains at least one bell located above the floor level, passing into a cylindrical pipe, and a column fixing mechanism in the pipe opening [see, for example, the indicated technological instruction].

A well-known specialized stand for temporary storage of the electrode column and the implementation of the extension of the column for essential features is closest to the proposed, therefore, taken as a prototype.

A well-known specialized stand is characterized by a significant drawback consisting in the absence of means and devices for storing heat by the electrode column, to exclude its sharp cooling at the beginning of the process of temporary storage of the column, to create a temperature field in the body of the column, providing a decrease in temperature stresses in its body at the time of the start of work columns in an electric arc furnace.

The proposed specialized stand for temporary storage of the electrode column and preparing it for operation in an electric arc furnace is free from this drawback. It provides means to prevent sudden cooling of the electrode column after it is removed from the furnace and installed on a stand for temporary storage. It also provides devices for obtaining a certain temperature field in the body of the electrodes of the electrode column, which excludes and / or reduces the temperature period in the cross section (and length) of the electrodes. The latter eliminates and / or reduces the likelihood of thermal cracking, especially at the first moment of the start of operation of the electrode column installed in the electric arc furnace.

The above technical results are achieved due to the fact that in a specialized stand containing at least one socket extending above the floor level, passing into a cylindrical pipe, and the column fastening mechanism in the pipe hole, according to the proposal below the floor, opposite to the specified pipe, there is an insulated chamber with heating devices, which in the upper part is equipped with a channel for the removal of generated gases. In addition, the stand is equipped with several sockets with cylindrical pipes, the opposite of which is a single insulated chamber with heating devices. In addition, the heating devices are individual for each temporary storage on the stand of the electrode column. In addition, a bell with a column mounting mechanism is installed in the bearing assembly. Moreover, the bell with the column mounting mechanism is equipped with a rotation mechanism. The bell is equipped with a locking mechanism against rotation.

The method of preparing the electrode column for operation in an electric arc furnace and a specialized stand for its implementation are explained by the drawings.

Figure 1 shows a specialized stand on the example of a single bell, passing into a cylindrical pipe; figure 2 is the same as in figure 1, but for a new electrode column; figure 3 is one of the cross sections of a specialized stand containing three sockets, each passing into a cylindrical pipe, with a single insulated chamber; figure 4 is a picture of the stresses arising in the cross section of the electrode of the electrode column during the rapid cooling of the hot column after it is removed from the electric arc furnace and installed in temporary storage on a specialized stand that is not equipped with an insulated chamber; figure 5 is a similar picture of figure 4, but in the process of rapid heating of a cold column in the working space of an electric arc furnace after removing the column from a specialized stand, not equipped with a warming chamber with heating devices.

A specialized stand for temporary storage of the electrode column is used when repairing an electric arc furnace, if necessary, to extend the electrode column taken out of the furnace, as well as when forming a new electrode column.

A specialized stand is installed above and below floor level 1 (Figs. 1 and 2) and contains a bell 2 of a cylindrical pipe 3. Below the floor level, opposite to the opening of the pipe 3, a heat-insulated chamber 4 is installed, consisting of a metal casing 5 and a heat insulator 6. As a heat insulator for example, high-alumina chamotte (operating temperature up to 1600 ° C), kaolin lightweights (operating t up to 1500 ° C), lightweight dinas brick (operating t up to 1550 ° C), etc. can be used. The insulated chamber 4 is equipped with heating devices 7, completed form, such as gas burners. In the lower part of the chamber 4 is equipped with a side window 8 with a cover 9, the dimensions of which are sufficient to remove the whole electrode. In case of elongated temporary storage, the socket 2 is covered with a lid 10. The electrode column contains several electrodes 11-13, the minimum number of which is one electrode, the maximum depends on the parameters of the furnace and the length of the electrodes, but usually does not exceed three. An electrode column of electrodes 11-13 is formed by screwing a new electrode with nipples 14. In the upper part, the chamber 4 is equipped with a gas outlet channel 15. The socket 2, together with the cylindrical tube 3, can be installed in the bearing assembly 16, making it possible to rotate relative to the longitudinal axis 17. A rotation drive can be used for the indicated rotation 18. To lock the electrode column and suspend it in a vertical position, the specialized stand is equipped with a column fixing mechanism 19. Sos avnoy specialized stand part is a locking mechanism 20 of the socket 2 and the pipe 3 against rotation during the screwing of the new electrode. The chamber 4 is installed on the foundation 21. A specialized stand can be equipped with several sockets 2 (three for AC electric arc furnaces). In this case, opposite each cylindrical pipe 2 can be installed insulated chamber 4 according to the description of figure 1. However, in the same case, as opposed to each cylindrical pipe 3 (Fig. 3), a single insulated chamber 22 with heating devices 7 can be installed. In this case, the heating devices 7 are preferably individualized, i.e. individual for each electrode column installed for temporary storage. An integral part of the specialized stand is a spraying system 23 for supplying cooling water to the electrode 11, which is upper in the column. Moreover, since the height of the electrode 11 relative to floor 1 can vary, the spraying system 23 is equipped with a vertical movement mechanism (not shown conventionally in FIG. 2). A component of the stand is also a system for supplying nitrogen 24 to the chamber 4 to create a neutral atmosphere in it.

The need to use the proposed method of preparing the electrode column for operation in an electric arc furnace follows from the following patterns of thermal stress formation in the electrodes of the electrode column (Figs. 4 and 5).

It is known that due to the uneven distribution of temperature, the maximum temperature stresses in the electrode body are determined by the expressions:

- radial normal voltage

- tangential (circumferential) normal stress

axial normal stress

where E is Young's modulus;

ν is the Poisson's ratio;

α is the coefficient of linear expansion;

t is the average integral temperature over the cross section of the electrode;

t _R is the temperature at the surface of the cross section of the electrode;

where r is the current radius of the cross section of the electrode; R is the outer radius of the cross section of the electrode. On the electrode surface, ρ = 1, lnρ = 0, respectively:

In this case, E, ν and α for the material of the electrode of the electrode column under consideration at appropriate temperatures.

в поперечном направлении; α=(0,5...0,6)·(10^-6 К^-1 в продольном направлении и (1,4...1,6)·(10^-6 К^-1 в поперечном направлении. Эти данные имеют место при комнатной температуре] и принятие ν=0,5 и постоянным при высоких температурах.The relatively low E and α values for the electrode material should be taken into account [according to Ir Loh Fook Guan et al. “Utilization and Optimization of DC Furnace Electrodes at Southern Steel Malaysia”, p.20, table 2 (Materials from SGL Carbon AG), the following values are known : E = 9.3 ... Kn / mm ² in the longitudinal direction and 4.8 ... 5.2

in the transverse direction; α = (0.5 ... 0.6) · (10 ^-6 K ^-1 in the longitudinal direction and (1.4 ... 1.6) · (10 ^-6 K ^-1 in the transverse direction. These data take place at room temperature] and adoption ν = 0.5 and constant at high temperatures.

In total, the above allows us to consider [according to formulas (1) - (4)] that the thermal stresses arising in the body of the electrodes of the electrode column depend to a large extent on the temperature difference across the electrode cross section. Therefore, a decrease in this temperature difference will proportionally reduce the thermal stresses that occur in the electrode body and lead to cracking of the electrodes and their increased wear. The latter is additionally due to the fact that the cracks that appear are always inclined to propagate.

With reference to the cycle of operation of the electrodes in the electrode column in steelmaking with an electric arc furnace, the indicated temperature difference in the cross section of the electrodes is especially significant:

- firstly, at the beginning of operation of a new electrode column having a temperature of 20 ° C in an electric arc furnace (due to the low initial temperature of the column electrodes, the indicated temperature difference in the body of the electrodes at the initial moment of operation can reach about 2200 ... 2400 ° and due to their rapid heating);

- secondly, at the beginning of the operation of a previously operated electrode column (columns with reference to an alternating current electric arc furnace) installed on a specialized stand for temporary storage during furnace repair and cooled down to the workshop temperature (also because of the low initial temperature of the column electrodes the temperature difference in the electrode body at the initial moment of operation can reach about 2200 ... 2400 ° and is also due to the rapid heating of the electrode body);

- thirdly, at the beginning of the cooling of a previously operated electrode column mounted on a specialized stand for temporary storage; due to the high temperature of the electrodes (especially the lower one), reaching 2400 ° С and higher, at a workshop temperature of 20 ° С, the indicated temperature difference in the electrode body at the initial moment of cooling can also be at the level of 2200 ... 2400 °.

The aforesaid refers to a greater extent to the lower electrode of the electric arc furnace, although it is also inherent in the following electrode as the electrode column is lowered into the furnace.

Moreover, when the surface of the cold electrode of the electrode column is rapidly heated, the axial σ _z and tangential σ _t stresses arising in it are compressive. However, they are combined with significant tensile radial stresses (Fig. 5), which together can lead to the appearance of both longitudinal and transverse cracks in the subsurface layers of the electrode with their subsequent exit to its surface.

When the surface of the heated electrode of the electrode column is rapidly cooled in its cross section, in the surface layers, tangential tensile stresses are formed at radial compressive stresses (Fig. 4). Under these conditions, tensile stresses can lead to the appearance and development of surface longitudinal cracks that propagate into and over the body of the electrode.

Thus, if you ensure slow cooling of the electrode column after it is removed from the electric arc furnace and installed on a specialized stand, and if you provide a smaller temperature difference in the cross section of the electrodes of the electrode column, cooled during a stay on a specialized stand, at the initial moment of its operation in the furnace, there is every reason to believe that the likelihood of thermal cracking on the body of the electrode will also decrease.

The latter is the essence of the proposed method of preparing the electrode column for operation in an electric arc furnace and a specialized stand for its implementation.

The proposed method is implemented as follows.

After removing the heated electrode column from the electric arc furnace for temporary storage on a specialized stand (for example, to extend the electrode column, the column may consist of up to one upper electrode 11, or if the furnace is stopped for repair, the column may consist of one up to three electrodes 11-13) it is placed in a vertical position in an insulated chamber 4, fixing in the upper part of the electrode 11 in the pipe 3 using the mechanism 19.

Before installing the electrode columns, the chamber 4 is at least warmed up with burners 7 and insulated with a cover 10. For the most part, when it is assumed that the electrode columns are relatively long on a specialized stand (for example, during furnace repair), the columns are heated using devices 7 .

In this case, the frequency of arrangement of the heating devices 7 in the chamber 4 increases as it approaches the foundation 21, in addition, at least one device 7 is located at the bottom of the chamber 4 and provides heating of the end part of the electrode column (the end face of the first electrode 13 from the bottom). In addition, the heating device 7 can be located along the height of the chamber 4 in a checkerboard pattern.

For a more uniform heating of the cross sections of the column, it is rotated relative to the longitudinal axis 17. The indicated rotation of the column can be carried out periodically (for example, manually) or continuously using the drive 18. The rotation of the column is ensured by placing the bell 2 and the cylindrical pipe 3 with the mounting mechanism 19 in the bearing assembly 16.

The extension of the column is carried out in a known manner by screwing a new electrode into the prepared socket of the upper electrode 11 of the column. In this case, using the mechanism 20, the pipe 3 is preliminarily stopped and the heating devices 7 are temporarily turned off.

The formation of a new electrode column is carried out by performing operations similar to its extension, starting from the upper electrode, which becomes 13. By the end of the formation of the column, this being the case, unlike the extension of the electrode column, when the heating devices of the column 7 may not turn on due to the short duration of their stay columns at a specialized stand, after completion of the process of forming a new column, they are thoroughly heated using heating devices 7, providing quasi-uniform for each cross section The cross-section of the column is the temperature distribution.

In all cases, when the electrode column is on a specialized stand, thanks to the insulated chamber 4 and heating devices 7, they increase the temperature of the column electrodes as they move away from the place of its fastening, i.e. take into account the specifics of the electrode column in an electric arc furnace.

During a relatively long stay of the electrode column on a specialized stand, for example, when repairing the furnace or, if necessary, thoroughly warming up the electrodes of the new column, water is supplied to the upper electrode 11 using the sprayer 23 (Fig. 2). This cooling prevents the heating of this electrode above its temperatures operation in an electric arc furnace.

To exclude increased oxidation of the surface of the electrodes of the column while it is in the chamber 4 in the latter provide a neutral atmosphere. The latter is ensured, firstly, by creating a weakly oxidized atmosphere in the chamber 4 during operation of the plants 7, and secondly, by additional supplying, for example, nitrogen to the chamber through the device 24. Combustion products (gases) are removed from the chamber 4 through the channel 15; the number of channels can be more than one and they are evenly distributed around the circumference relative to the pipe 3, necessarily lower than its edge in order to maximize the elimination of gas entry into the socket 2. Moreover, for the same purpose, the application of the method and a specialized stand does not exclude the use of mulite-siliceous wool (for example, 130) in the gap, the pipe 3 is an electrode column.

Since when the method is implemented, it is possible to destroy part of the column and fall off the broken ends to the bottom of the chamber 4 (this is possible, and the destruction of the electrodes of the column during operation in an electric arc furnace is a cause of destruction), a side window 8 and a cover 9 are provided in the chamber 4 the dimensions correspond to falling off pieces of the electrode column, but usually do not exceed the sizes of one electrode. Opposite the side window 8 there is a mechanism for cleaning the pieces of the column that have fallen off (it is not shown conditionally in the drawings, since it does not change the essence of the method).

With regard to the operation of an electric arc furnace with several electrode columns (AC furnace, DC furnace with two electrodes), a specialized stand is equipped with several sockets 2 with cylindrical tubes 3.

The implementation of the method involves two versions of the insulated chamber 4 with heating devices 7: with an individual chamber for each electrode column mounted on a stand for temporary storage (full analogy with figures 1 and 2); with a single insulated chamber 22 (figure 3), covering all installed on the stand electrode columns. Moreover, in the second embodiment, i.e. when using a single insulated chamber 22, devices for heating 7 column electrodes are individual for each column (see Fig. 3), the upper part of the stand is also individual, i.e. bell 2, pipe 3, etc.

The maximum temperature of the lower electrode 13 of the electrode column (Figs. 1 and 2) achieved in the insulated chamber 4, especially the lower end of the electrode, when implementing this method is determined by the operating temperature of the heat insulators 6 used in the insulated chamber 4, and thus is on the order of 1500 ° C. When using heat insulators with a higher operating temperature, this value of the maximum temperature can be increased, the efficiency of the method will be proportionally increased in reducing the likelihood of thermal cracks in the electrodes of the column.

The minimum temperature of the upper electrode 11 of the electrode column, especially its upper end (FIGS. 1 and 2), when implementing the present method, is such that a free touch of the bare hand to the end of the electrode is allowed (see the requirements of the specified instruction TI 518-2012-ES-01 -02, p. 4, clause 3.4.1).

Thus, when implementing the method, a temperature difference in the cross section of the electrodes is ensured in all considered cases of the beginning of operation and the beginning of temporary storage of the electrode column at a level from (2200 ... 2400 ° C) to 1500 ° C, i.e. at the level of 700 ... 900 ° C. According to equation (4), ensuring the temperature difference in the cross section of the column electrodes at the specified level reduces the tangential stresses σ _t and axial σ _z , for example, in the surface layers of the electrodes by 2.7 ... 3 times. In the case of the implementation of higher maximum temperatures in the insulated chamber 4, the indicated values for reducing thermal stresses increase.

Example 1. In the process of operating an electrode column composed of electrodes with a diameter of 750 mm in an electric arc furnace and applying a current of 110 KA, the main part of the lower electrode is heated to 2307 ° C, in its end part and to 1935 ° C in its surface (side) layers [cm. SGL Carbon Group prospectus data “News and Recommendations for AC and DC Arc Furnace Applications”. 09.99 / 1 Printed in Germany, p. 4, Fig. 2).

A new column is installed in the electric arc furnace, which is heated in a heated chamber 4 of a specialized stand to a temperature at the end of the lower electrode of 1500 ° C with a gradual decrease in the body temperature of this electrode in height to 1400 ° C (and lower as it approaches the upper electrode 11). According to equation (4), when these modes are implemented in the surface layers of the electrodes at the initial moment of their operation, they obtained the stress state picture shown in Fig. 5, but unlike the known method, the tangential σ _t and axial σ _z thermal stresses in the end part were reduced the lower electrode is 2.7 times, in its lateral layers - 3.6 times.

Example 2. During the repair of the electric arc furnace, the electrode column was temporarily (for 8 hours) stored on a specialized stand in an insulated chamber 4, where the columns were heated by burners 7 in a neutral atmosphere with the lower end of the lower electrode heated to 1500 ° C with a gradual decrease in the temperature of this the electrode in height up to 1400 ° C (and lower as it approaches the upper electrode of the column).

At the initial moment of operation of the electrode column in an electric arc furnace, the electrodes received a picture of the stress state shown in Fig. 5 and a decrease in thermal stresses in the lower electrode, similar to Example 1.

Example 3. During operation of the electrode column with electrodes with a diameter of 750 mm in an electric arc furnace and the use of a current of 110 KA, they heated the lower electrode to the temperatures indicated in Example 1.

The electric arc furnace was stopped for several hours. Before repair, the electrode column (three columns for the AC furnace) was removed from the furnace and installed on a specialized stand equipped with a heat-insulated chamber 4 and heating burners 7 [in the case of an AC furnace, electric arc columns were placed, for example, in a heat-insulated chamber 22 (Fig. 3) ].

Before the indicated shutdown of the electric arc furnace, the insulated chamber was heated to 1500 ° C, creating and maintaining a neutral atmosphere in it.

Provided a decrease in thermal stresses in the body of the lower electrode, similar to example 1, but taking into account changes in the picture of the stress state (figure 4).

Thus, the method of preparing the electrode column for operation in an electric arc furnace and a specialized stand for its implementation allow several times to reduce the thermal stresses arising in the electrodes of the electrode column. These voltages are caused by a significant temperature difference along the cross section of the electrodes that is formed during operation of the electrode column in an electric arc furnace during temporary storage of the column on a specialized stand. When applying the method, the indicated temperature difference decreases several times, thermal stresses in the electrode decrease by approximately the same amount. Reducing the values of thermal stresses reduces the likelihood of the appearance and size of longitudinal and transverse cracks formed on the electrode body, and therefore reduces the likelihood of accelerated destruction of the electrodes. The latter improves the technical and economic performance of the electric arc furnace, since the consumption of electrodes during operation of the furnace makes a significant contribution to the cost of steel produced.

The application of the method and the specialized stand for its implementation is most effective when using electrodes with an aluminum insert in the nipples of the electrode column (application No. 2001108 391/06 (008890) from 03/30/01 and application No. 2002126383 from 04.10.02). The marked increase in efficiency is due, firstly, to a significant decrease in the heating of the nipple, respectively, to a decrease in its thermal expansion and the tangential tensile stresses arising in the electrode body (see said material of SGL Carbon Group “News ...”, p.4, fig. .2), secondly, by preliminary melting of aluminum in all the nipples of the electrode column before its operation in the electric arc furnace and, consequently, by the simultaneous participation of all the nipples of the electrode column from the very beginning of the operation of the column in the furnace in reducing the resistance to the flow of electric current through the joint electrode - nipple-electrode of the electrode column.

Claims (12)

1. A stand for preparing an electrode column containing at least one electrode for operation in an electric arc furnace, comprising at least one cylindrical pipe with a bell located above the floor and a mechanism for attaching the electrode column in a cylindrical pipe, characterized in that the stand is equipped with a cylindrical pipe located below the floor level with an insulated chamber with gas burners, which in the upper part is equipped with a channel for the removal of combustion products. 2. The stand according to claim 1, characterized in that it is equipped with several cylindrical pipes with sockets, opposite which there is a single insulated chamber with gas burners. 3. The stand according to claim 2, characterized in that each electrode column has individual gas burners. 4. The stand according to claim 1, characterized in that the cylindrical pipe with a bell is installed in the bearing assembly. 5. The stand according to claim 4, characterized in that the cylindrical pipe with a bell is equipped with a rotation mechanism. 6. The stand according to claim 4, characterized in that the cylindrical pipe with a bell is equipped with a locking mechanism against rotation. 7. A method of preparing an electrode column containing at least one electrode for operation in an electric arc furnace, comprising temporarily storing the electrode column in a vertical position and securing it in the upper part and, if necessary, lengthening the electrode column in a vertical position until the formation a new column by adding at least one new electrode by screwing it up, characterized in that the temporary storage of the electrode column is carried out on the stand according to claim 1 by at least insulation eniya part of the electrode column below the floor level, and further heating the insulated portion of the column, while the column electrodes provide increased temperature with increasing distance from the site of its binding. 8. The method according to claim 7, characterized in that during the temporary storage of the electrode column it is rotated relative to its longitudinal axis. 9. The method according to claim 8, characterized in that the electrode column is rotated periodically. 10. The method according to claim 8, characterized in that the electrode column is rotated continuously, except for the time of its extension. 11. The method according to claim 7, characterized in that protruding above the level of the stand part of the top in the column of the electrode outside is cooled by water. 12. The method according to claim 7, characterized in that the warming and heating of the electrode column located below the floor is carried out in a neutral atmosphere.

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