FR2517502A1 - ELECTRODE SUPPLYING AND SUPPORTING DEVICE FOR ARC OVEN - Google Patents

Abstract

1. Arrangement for the supply of electrical energy to and for the support of the electrodes in an electric arc furnace comprising three electrodes fixed respectively in grips (14, 15, 16) placed at the respective ends of three support arms (8, 9, 10) extending horizontally from a vertical pillar, the said electrodes being connected by rigid electrical conductors to cables (13) for the supply of current, characterized in that the rigid conductors for the supply of electricity to the electrodes are constituted by the same horizontal support arms (8, 9, 10), the latter being constructed of non-magnetic metal and being provided, at their downstream ends opposite to the electrodes, with respective contact elements (11, 12) to which the cables (13) for the supply of current are connected.

Description

The present invention relates to a feeding device

  electrical energy and mechanical support of electrodes

  an electric arc furnace intended to equip a steelworks.

  In an electric arc melting furnace, the electric current

  The conductor is driven from the furnace transformer to the electrodes by flexible cables and rigid copper conductors. These conductors are generally cooled and are supported by the horizontal part, or arm, of each electrode holder. Each of these arms is constructed of

  steel and has a square or rectangular section.

  The conductors of each phase are arranged in such a way as to reduce and balance their electrical characteristics.

  what are reactances and resistances.

  In these known devices, the support functions (arms and electrical conductor (copper tubes) are always separated by the person skilled in the art, the electrical conduction of very high currents is always done by means of copper tubes. In contrast to the low resistivity of this metal, copper, because of its insufficient mechanical properties with the desired diameters to have a satisfactory implantation, is not used for the consti

electrode arms.

  The device according to the invention allows a simple manufacturing only for these known devices, as well as a reduction of the electrical x tance of this part of the furnace, which allows to have, for same power called network, a significant increase It is characterized in that it is equipped with non-magnetic metal electrode arms whose upstream end serves as a contact surface for the power supply cables. Preferably, the metal used is preferably also stainless steel, the arms are constructed so as to present, in the path of the current, no

  sharp angle both in their section and in their length.

  The invention will be better understood from the following description:

  a preferred example of embodiment, with reference to

annexed in which:

  FIG. 1 is a schematic side view of one of the arms

  te-electrode that is not framed by the other two

  FIG. 2 is a schematic side view of the support arm

  electrode which is flanked by the other two FIG. 3 is a schematic view from above of the device

of the invention.

  Referring to all of Figures 1 to 3, each of the three vertical poles (1, 2, 3) carries, in a conventional manner, a support piece

  (4,5,6) wider, provided with an electrically insulating portion 7.

  According to the invention, each support piece (4,5,6) carries a horizontal arm (8,9,10) made of stainless steel, whose upstream end (11,12) serves as contact pad for the cables 13, the downstream end of which is connected to the clamps C 14, 15, 16) intended for

enclose the electrodes.

  In order to avoid the phenomena of heating that would be due to

  accumulations of current, the arms (8,9,1 O) are constructed in such a way

  to present, on the path of the current, no sharp angle.

  tion is circular and they are, in the sense of the length, either

  1 is one of the two arms, such as the arm 8, which is not flanked by the other two. Such an arm is rectilinear and its

  support member (1,4) reaches the level of the lower part of the pin-

this associate 14.

  Figure 2 shows the central arm "9, which is framed

  the other two (8,10, Figure 3). For obvious reasons of clutter,

  its support member (2,5) arrives, in a conventional manner, at a

  calf situated above that of the lower part of the forceps,

  Mast 2 is thus higher than the other two.

  these (14,15,16) being preferentially at the same level, the arm 9 presents

  a gentle curvature, S-shaped as shown, so that its

  downstream part is at the same level as the others.

  For the realization of the invention, the use of a non-magnetic metal is indispensable because these metals exhibit a "skin effect" much less than that exhibited by non-magnetic metals, such as 251750

  that ordinary steel for example "Kelvin's skin" is in effect

  Thirty times thicker for stainless steel than for

  In addition, stainless steel leads to

  electrode arms which are especially well suited for

  S ted to the desired locations for electric furnaces; this

  It is therefore preferential for carrying out the invention.

Claims (3)

  1 Device for supplying electrical energy and sup-   mechanical port of an electric arc furnace, characterized in that it is   equipped with electrode arms (8,9,10) made of non-magnetic metal, the ex-   upstream tremity (11,12) serves as a contact area for the current supply cables (13).   2 Feeding device and support according to the claim   1, characterized in that said arms are constructed so as to present, on the path of the current, no sharp angle as well   in their section only on their length.   3 Supply and support device according to the claim   1 or 2, characterized in that said non-magnetic metal Tick is stainless steel.