SU377093A1 - INSTALLATION FOR ELECTROSLAG FIBER - Google Patents

Description

one

The invention relates to the field of electrothermal and can be used for electroslag remelting of steels and alloys in mosh multielectrode installations.

Known multi-electrode installation, powered by a multiphase network, in which the electrodes are arranged in a circle and divided into groups, the number of which is equal to the number of phases of the furnace. The electrodes of each group are located next to each other and interconnected by conductive jumpers. Such a coupling scheme simplifies the short circuit and reduces its reactance. However, when using such a setup for electroslag remelting, due to the absence of voltage between adjacent electrodes of each group, the slag bath is not evenly heated and the electrode melting rates are effectively self-leveling. In addition, the known installation does not provide for the electrical supply of an additional central electrode, which is used in the smelting of solid large-tonnage ingots.

The purpose of the invention is to eliminate these drawbacks and is achieved by connecting electrodes diametrically opposed by conductive bridges. At the same time various

options for connecting transformer leads to these jumpers using current leads.

FIG. 1 depicts a seven-electrode installation powered by three single-phase transformers connected by primary windings to a three-phase system connecting the secondary windings into a star, the zero point of which is located on the electrode holder on the axis of symmetry of the electrode system; in fig. 2 - six-electrode installation with the connection of the secondary windings of transformers in a "triangle on the electrode holder, with the ends of the windings connected to the midpoints of current-carrying jumpers between the diametral electrodes; in fig. 3 - six-electrode installation, which is powered by one three-phase transformer, the secondary windings of which are assembled in a "triangle on the transformer; in fig. 4 - electrode installation, in which the phase terminals of each of the three windings are connected directly to adjacent electrodes, each electrode being connected only to

one phase output; in fig. 5 shows a vector voltage chart on the electrodes.

The electrodes 1-6, arranged in a circle, and the central electrode 7 are fixed in the electrode holder 8. Diametrically opposite electrodes 1 and 4, 2 and 5, 3 and 6 are interconnected by a conductor using jumpers 9, which are connected to the power supply network 10, formed by three single-phase transformers 11. When the secondary windings are connected in a star diagram (Fig. 1), the zero point 12 of the star is located on the electrode holder along the axis of symmetry of the electrode system and is isolated from them or connected to the central electrode 7, if it exists. Electrode 7 is used in the smelting of solid section ingots to increase plant capacity.

The installation works as follows.

After applying voltage, remelting of consumable electrodes begins. As can be seen from FIG. 5, there is a linear voltage between all electrodes except diametrically opposite, and a phase voltage between the central electrode and the others. As a result, effective self-leveling of the rates of electrode melting, uniform distribution of the electromagnetic field in the slag bath, and uniform thermal field in it are provided.

In the absence of an electrode 7 in the case of melting ingots of a hollow section, the connection diagrams shown in FIG. 2-4, since using the circuit of FIG. 1, the current leads 10 have a larger cross-section needed to pass the currents of the two electrodes.

Current leads 10 to the jumpers 9 between the diametral electrodes are connected to the midpoints of these jumpers to ensure symmetry of the electric and thermal fields in the scale (diagrams of Figs. 1-3).

With a large decay diameter of the electrodes, to simplify the design of the current leads and reduce their length, the current conductors of the phases are connected directly to the adjacent electrodes of FIG. four.

If the capacity of the installation is less than 5000 kVa, it is more expedient to use one three-phase transformer with the connection of secondary windings into a “delta” (Fig. 3). With a greater installation power, circuits with three single-phase transformers are used (Figs. 1, 2, 4).

Subject invention

Claims (6)

1. Installation for electroslag remelting containing an axially symmetric system of electrodes insulated from each other, fixed fixed in an electrode holder and connected in pairs by conductive bridges, a current lead connecting the bridges to the secondary windings of the supply transformers forming a multiphase symmetrical power supply system, number the phases of which are equal to the number of pairs of electrodes, characterized in that, in order to increase the efficiency of self-leveling of the rates of electrode melting and the uniformity of the temperature in the slag bath, electrodes diametrically opposed are connected by bridges. 2. Installation on n. 1, characterized in that the jumpers are within the contour of the polygon, at the vertices of which the electrodes are located and do not pass through its center. 3. Installation under item 1, characterized in that when connecting the secondary windings of the supply transformers to the "star their phase the leads are connected to the jumpers, and the zero point is located on the electrode holder on the axis of symmetry of the electrode system. 4. Installation on n. 3, characterized in that with the presence of an additional central electrode, the zero point is connected to it. 5. Installation according to claim 1, characterized in that the terminals of the secondary windings of the supply transformers are connected to the central parts of the jumpers. 6. Installation under item 1, characterized in that when the secondary windings of the supply transformers are connected in a "triangle", the phase terminals of each of the windings are connected directly to adjacent electrodes, each electrode being connected to only one phase terminal. V 1. LxAJ eleven VuZ 2