DE3442769A1 - Electric-arc furnace or reduction furnace having a bifilar-encapsulated low-set-type electrode holder - Google Patents

Abstract

Published without abstract.

Description

The invention relates to an electric arc or reduction furnace with a deep electrode holder and a double-walled, hollow cylindrical cooling jacket for each electrode, which is coaxial with the electrode is arranged and the furnace cover penetrating power supply parts, in particular electrical conductors, protects.

DE-PS 21 25 773 is a deep electrode holder for Arc or reduction furnaces are known in which the power supply parts located in the furnace area, in particular current conductors, Socket parts and the like, are protected by a double-walled, water-cooled cooling jacket arranged coaxially to the electrode. In an advantageous embodiment, there is Cooling jacket made of interconnected segment parts.

With this so-called deep electrode holder, no measures are taken to prevent stray magnetic fields. The high electrical alternating currents flowing through the power tubes to the contact jaws form a magnetic field that is in the Cooling jacket induces an electric current. The through the Current flowing through the cooling jacket induces an electrical current in the cover surrounding it. Thereby big ones occur Loss and reactive power on, and the cooling jackets as well as the Furnace lids are heated inductively.

In the unpublished application P 34 00 186.7 is one Implementation for electrodes in a furnace cover of an electric arc or reduction furnace is proposed, in which the hollow cylindrical cooling jackets are each in the same plane lying end areas through made of electrically conductive material existing bridges connected in all phases of the alternating current are.

In this arrangement, the connection of the deep-hole cooling cylinder the bridges are exposed to increased wear due to the cable routing in the area of the cover, which leads to an increase in maintenance costs. In addition, in order to achieve maximum performance, the cooling jackets, which are designed as capsules, are closed Hollow cylinder required to keep the number of bridges between the deep sockets low. This eliminates the maintenance-related advantages of the cooling jacket formed in segments.

The object of the invention is to control the magnetic field of the conductor to remove the electrodes in the area of the cooling jacket of the deep sockets for arc or reduction furnaces and thus to increase the power factor of the AC system.

According to the invention is in an electric arc or reduction furnace with deep electrode holder and a double-walled, hollow cylindrical cooling jacket solved this problem at least one return conductor provided axially parallel to the respective electrode, which at its ends connects to the Cooling jacket is connected. The individual return conductors are surrounded by yokes made of dynamo sheets, which are perpendicular to the axial direction of the return conductor are arranged.

The high electrical currents flowing through the power tubes induce in the one surrounding the electrode and the power tubes Cooling cylinder a stream. This induced current is made to flow through the return conductor. The direction of the induced electric current is the direction of electric current opposite of the flow pipes. An influence of the magnetic field of the Return conductors whose current device is the same as that of the

Current pipes, is prevented by the magnet yokes. An induction of an electric current in the cylinder surrounding the cooling Cover is largely suppressed by the return of the current by means of the current return conductor. 5

The flow pipe / cooling cylinder system is opposed by the The flowing electrical currents of the biffilar laid high-current railway are comparable. By the back and forth flow of the electrical Currents cancel the magnetic changes and the current transmission system is magnetically encapsulated.

The inventive installation of the return conductors surrounded by yokes made of dynamo sheets reduces the inductance of the power line to the electrodes in the region of the passage through the furnace cover.

The return conductors made of copper or a similar material that conducts electrical current are designed as a hollow profile, for example a square profile, and can be connected to a cooling system. The return lines are preferred between the electrode and arranged the cooling jacket. The return lines are thus protected against the aggressive furnace atmosphere.

In a further embodiment, the return lines are provided in a cooling jacket separating cut which separates the cooling jacket in the direction of the central axis. The return lines in arranged in the area of the cooling jacket facing the neighboring electrodes. With this arrangement of the return lines will not only the inductive resistance of the associated electrode is reduced, but rather an influence is exerted on the magnetic field of the neighboring electrode.

The return conductors according to the invention can be retrofitted in existing cooling jackets with little effort. 35

An embodiment of the invention is shown in the drawings and explained below. Show it:

1 shows a vertical section and FIG

2 shows a horizontal section through the cooling jacket and a return conductor,

3 shows a section of a cooling jacket with return conductors separated in the central axis direction.

1 shows schematically the arrangement according to the invention of the return conductor 50 and its connection to the cooling jacket 40 via the current bridges 51. The cooling jacket 40 passes through the furnace cover 11, which is arranged above the furnace 10 (not shown further). The cooling jacket 40 surrounds the current-carrying parts 30, consisting of a current conductor (towards) 31 and a current conductor (back) 32 of the respective clamping jaw 33 and the electrode 20. The return conductor 50, designed as a hollow profile, has an Conclusions for a cooling medium 53, with which it is connected to the cooling water circuit of the cooling jacket can be connected. The return conductor 50 is surrounded by yokes made of dynamo sheets 52 from the inside of the cooling jacket 41 are spaced apart.

FIG. 2 shows section A-A of FIG. 1.

Fig. 3 shows the cooling jacket 40, which is separated in the center axis direction and has the separating edges 42 and 43, respectively. The distance 42 to 43 has a length which is greater than the length of a Dy namobleches 52. parallel to the respective separating edges 42, 43 return conductors 50 are arranged, which are connected at their ends via the current bridges 51 to the cooling jacket. The separating cut is between two pairs of current conductors 31, 32, which lead to the respective Guide jaw 33, arranged. The return conductors 50 are common sam surrounded by yokes made of dynamo sheets 52.

22630

Designation list

10 oven

11 lid

20 electrode

30 power supply parts

31 conductor (outward)

32 conductors (back)

33 jaw

40 cooling jacket

41 Inside of the cooling jacket

42 separating edge on the one hand

43 Separating edge on the other hand

50 return conductors

51 current bridge

52 dynamo sheet

53 Connection for cooling medium

Claims (8)

Mannesmann Aktiengesellschaft Mannesmannufer 2 22630 Düsseldorf Electric arc or reduction furnace with biffilar encapsulated deep electrode holder Patent claims 1. Electric arc or reduction furnace with the individual electrodes and its current-carrying parts surrounding, double-walled, hollow cylindrical cooling jacket with deep electrode holder, characterized, that axially parallel to the electrode (20) at least one return conductor (50) is arranged, which is connected at its ends via current bridges (51) to the cooling jacket (40), and that the return conductor (50) is surrounded by yokes made of dynamo sheets (52) arranged perpendicular to the axial direction of the return conductor (50) is. 2. Electric arc or reduction furnace according to claim 1, characterized, that the return conductor (50) is a closed hollow body, e.g. in the form of a square profile. 5 3. Electric arc or reduction furnace according to claim 2, characterized in that that the return conductor (50) has connections (53) for a cooling medium in the area of the stroke bridges (51). 10 4. Electric arc or reduction furnace according to one of the claims 1 to 3, characterized, that the return conductor (50) consists of a material with a high electrical conductivity, e.g. copper. 5. Electric arc or reduction furnace according to one of the claims 1 to 4, characterized, that the return conductor (50) is provided on the inside (41) of the cooling jacket (40) facing the electrode. 6. Electric arc or reduction furnace according to one of the claims 1 to 5, characterized, that in each case a return conductor (50) between two pairs of current conductors (31/32) is arranged. 7. Electric arc or reduction furnace according to one of the claims 1 to 4, characterized, that the cooling jacket (40) is separated in the center axis direction and these separating edges (42, 43) of the cooling jacket (40) are spaced apart that is greater than the length of a dynamo sheet (52). 35 22630 - 3 - 8. electric arc or reduction furnace according to claim 7, characterized in that the separating edges (42, 43) face the central axis of the Ufens (10) and at least one return conductor (50) of the respective electrode (20) is arranged between the separating edges (42, 43).