SE434310B - DC arc furnace having at least one arc electrode and a bottom terminal, and also a crown roof comprising material resistant to thermal shock - Google Patents

Abstract

The invention relates to a DC arc furnace having at least one arc electrode and a bottom terminal. The crown roof 3, at least near to the electrodes 1, consists of a material 4, 6 resistant to thermal shock, such as plate- lined tile and/or graphite containing tile or mass and/or water-cooled elements 9, whereby the roof is electrically insulated from the melt in the furnace 7. <IMAGE>

Description

w 15 20 25 8100782-5 Uppfimhpn is based on a solution of these and other related problems and are due to the fact that the thermo shock resistant material is made of sheet metal bricks or MgO-Cwbegel or graphite, enbrafçta next to The electrode (s), and that the vault next to the gas wall consists of the electrode risk insulating bricks, for example alumina or basic bricks, It is true that between these bricks and the thermo-shock-resistant material rialot lr arranged basic bricks with or without sheet metal, MgO-C bricks, graphite- Jil 1110: pulp, Al oxide or combinations of the above. You have fu ll fifi normally sucks only one electrode or several electrodes with the same potential, why there is no risk of overturning between electrodes, and man can thus utilize said thermo shock resistant materials and thus use. Igxen at high power, ie if you simultaneously isolate the vault from smlltan. The latter can be done by arranging electrical insulation bricks at the outermost part of the vault (silicate bricks, Al-oxide bricks or basic brick, not electrically conductive). It also prevents splashing at oven the wall card closes 'the arc voltage' Traditionally, sheet metal bricks have been used in the upper part of the arc suction wall to cope with the temperature changes during arc switching on and off. Electrode- hollow bricks and arch parts with high wear can advantageously be masonry with a sheet metal clad basic brick. Peripheral to the arch and soil, where wear is most common lowest, as mentioned, the vault can be turned on. conventional way with electrical insulation Al-oxide bricks or alkaline bricks.

In the case of cooling panels in the furnace wall can in the transition to the hot., Bricked the slag line magnesite carbon brick or graphite brick is used to cope with it lccaftiga temperature gradient. These MgO-C bricks can be used in DC arc furnaces are used in arches in the same manner as those described above; sheet metal basic the tile. However, it may be advantageous in connection with this to use aqueous electrodes. hole seal to reduce the decarburization of the MgO-C bricks.

On. In the same way as for MgO-C bricks, the electrode hole box can be made of graphite. in the case of water pulp next to the electrode / electrode, the size of it is determined the water-cooled part and the combination with basic bricks (with or without sheet zaäasel) - nagneit carbon brick, grerite brick and Al-oxia brick of elite profile and vault lifting capacity. IN i. fgšçea startsar i 10 15 20 25 8100782-5 By means of the aqueous charge closest to the electrode, as in the case of the embodiment, the shape according to the above reduced arch and electrode wear, as well as savings in refractory material cost and at the same time increased operational availability. And dy- water cooling enables the use of advanced electrode sealing technology nik.

The invention is exemplified in the accompanying figure, which shows a furnace vault to a DC arc suction wxx with thermochoke resistant material.

The figure shows a direct current arc suction with an electrode 1, drawn in one bushing 2 in an oven arch 5. A ring 4 of is arranged next to the electrode 1 sheet metal bricks, Mgo-c-tege1, _gfafitte¿e1 or -maasa etc, electric leading. At 5 a water-cooled electrode seal is provided.

Arranged within the annular area 6 are oasis bricks with or without sheet metal, MgO-C brick or graphite, ie electrically conductive material. You can also in this field consider Al oxide bricks or combinations of the above standing conductive lining material. The dashed line 11 shows the vault wear profile and thus the motive for the extent of zone 6. Within the next to the furnace wall 8, a number of rings of electrical insulation are arranged. bricks, for example Al-oxide or basic bricks, and the intention is wise to isolate the leading delenzza. of the vault from the enamel in the ugx. Thus, peripheral to the vault ring and soil, where wear is usually lowest, is bricked on conventionally electrically insulating rings of, for example, Al oxide bricks or alkaline brick.

The DC arc furnace can also be equipped with several electrodes, but in between there is no risk of short circuits as they always have the same. potential.

The invention can be varied within the scope of the following claims.

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Claims (1)

8100782-s_ z ATEIT KRAV. DC arc eye with at least one arc electrode and bottom contact and a furnace vault (S), at least next to the electrode (s) (1) consisting of thermochock resistant material (4, 6), characterized in that it is shock shock resistant. the material (4, 6) consists of sheet metal clad bricks or MgO-C bricks or graphite, placed next to the electrode (s), and that the vault next to the oven wall consists of electrical. insulating bricks (7), for example alumina or basic bricks, and that any basic materials may be arranged between these bricks and the thermo-shock-resistant material. bricks with or without sheet metal, MgO-C bricks graphite bricks or pulp., Al-oxide or combinations of the above (6).