JPS61223485A - Molten metal vessel - Google Patents

Abstract

1. An electric arc furnace comprising - a furnace vessel upper casing portion which at least partially comprises a lining with water-cooled wall elements, and - a furnace vessel lower casing portion with a refractory lining, wherein the furnace vessel casing has vertical ribs on its outer cylindrical surface, characterised in that - the lining of the furnace vessel lower casing portion (3) comprises refractory bricks with a high degree of heat transmission, and - only the furnace vessel lower casing portion (3) has ribs (7) which are suitable for air cooling in that they form completely or partially closed cooling passages (8) which are extended to below the furnace charging floor (5), - that funnel-shaped guide plates (10) are provided for directing the flow of air, with an annular gap (6) between the tippable furnace charging floor (5) and the furnace vessel (1), and - the ribs (7) are welded to the furnace vessel casing (3) or are produced in one piece therewith.

Description

DETAILED DESCRIPTION OF THE INVENTION FIELD OF INDUSTRIAL APPLICATION The present invention relates to melt vessels, in particular electric arc furnaces, having a partial lining with a refractory lining or water-cooled wall elements.

[Conventional technology]

Arc furnaces with tap taps are now operated with high power and short charging times. This mode of furnace operation requires the use of high wear linings or water-cooled wall elements and water-cooled lids. The linings present in the melt vessel, in particular in the area directly above the slag zone and in the heating zone, are subjected to high loads and as a result wear out prematurely and the worn parts have to be replaced frequently.

In order to improve the service life of linings in the critical range, special quality bricks, such as carbon-containing bricks, have been developed. This brick quality provides a long service life due to high heat transfer.

High heat transfer results in heating the jacket plate over a large area rather than locally. For metal plates that are prevented from expanding in the radial direction, the effects of this high temperature load can lead to deformation of the metal plate, which can lead to destruction not only of the metal plate itself but also of the supporting rods of the molten metal container.

[The problem that the invention is trying to solve]

The object of the present invention is to develop a bathtub construction that allows the use of bricks of the above-mentioned optimized quality, without the above-mentioned drawbacks.

Means for Solving Problem C] In order to solve this problem, according to the present invention, within the range of the refractory lining, the cylindrical outer surface of the vessel jacket of the furnace vessel has vertical fins,
It is enlarged by protrusions etc.

The provision of vertical fins, protrusions, etc. in the area of the refractory lining provides a large heat dissipating surface and thus prevents heat buildup in the container envelope.

Good convection provides a oriented natural airflow;
in that the radial thermal expansion of the container envelope is unimpeded;
A vertical arrangement of the fins, projections, etc. is particularly advantageous.

The fins, protrusions, etc. are welded to the container envelope over their entire surface, which means a welded connection over the entire end surface of the fin that contacts the container envelope. On the other hand, the fins, projections, etc. are preferably welded to the vessel jacket of the furnace vessel in continuous or interrupted fillet welds.

A series of embodiments are possible as fins, protrusions, etc. The fins, projections, etc. can be manufactured from sheet metal strips, steel profiles, for example, T- or U-shaped profiles. Copper, cast steel, gray cast iron, non-ferrous metals or composite metals are used as materials for manufacturing fins, protrusions, etc.

However, the container jacket with fins, protrusions, etc. consists of multiple jacket pieces, each of which is made of TSU or L-shaped profiles, and is vertically welded to form the container jacket with fins, protrusions, etc. Also manufactured to form.

It is particularly advantageous if the fins, projections, etc. provided on the container envelope are configured in such a way that, depending on their shape, they form vertical cooling channels that are completely or partially closed.

In order to improve the natural air flow through the resulting cooling passages, an annular gap between the furnace control table, e.g. The dimensions should preferably match the dimensions of the cooling passages to be formed. The air flow that improves the convection on the Wg hot water vessel wall is further improved by forced air blowing by a blower.

〔Example〕

Embodiments of the present invention will be described based on schematic diagrams.

The furnace vessel according to FIG. 1 has an upper vessel envelope 2 and a lower vessel envelope 3. The upper part of the container envelope and the lower part of the container envelope are separated in the transition area between the wall element and the lining to ensure mutually independent movement between the sections during temperature loads. At the disassembly point, the upper part of the container envelope and the lower part of the container envelope are separably connected by a connecting screw (not shown).

Vertical fins 7 (or protrusions, etc.) are recognized in the lower container envelope 3 and these fins 7 are arranged around the lower container envelope. The fins 7 serve to increase the heat dissipation surface, thereby avoiding heat buildup in the container envelope.

The columns of the furnace support frame are shown at 4. A reinforcing ring ll is provided around the lower vessel envelope 3 and is connected to the furnace support frame 4 .

The part of the reactor vessel envelope according to FIG. 2 shows on the right a fin 7 which is welded to the vessel envelope 3 over its entire surface. On the other hand, the left fin 7 is not entirely welded but by fillet welding. In this case, it is possible to carry out a complete or partially continuous ll1I-f9 connection.

FIG. 3 shows fin shapes such as I, L, and T profiles and fins formed as half-tubes.

FIG. 4 shows a part of the lower container envelope 3 with fins 7, the fins being in one piece.

Its manufacture can take place from thick-walled stock by forging, casting, pressing or other machining.

According to diagram N5, the lower container envelope 3 is produced by welding T-shaped copper, thereby forming a finned container envelope.

2 L-shaped profiles (on the left in Figure 7), 2 T each
A closed vertical cooling channel 8 is produced by welding a profile (center in FIG. 7) or a U-shaped profile (right side in FIG. 7).

FIG. 6 shows an embodiment in which the lower container envelope 3 consists of a metal plate with fins 7 which are used in pieces. The metal plate is r! It is in contact with the furnace support frame 4 only via the partition Ii 9. The vertical gaps between the metal plates facilitate radial thermal expansion.

The encircled enlarged area of FIG. 1 shows the extent of the annular gap 6 between the tilting table 5 and the lower container envelope 3. In FIG. A hopper-like surrounding guide plate 10 located below the tilting table 5 serves to guide the cooling air flow reaching from the bottom to the top into the cooling channels 8 formed by the fins 7 .

[Brief explanation of the drawing]

゛ Figure 1 is a side view of the arc furnace vessel, Figures 2 to 7
The figure is a horizontal sectional view of a portion of the reactor vessel envelope. l... Furnace vessel, 3... Container jacket, 7... Fin.

Claims (1)

[Scope of Claims] 1. Partial lining with refractory lining or water-cooled wall elements, in which the furnace vessel (1
), characterized in that the cylindrical outer surface of the container jacket (3) is enlarged by vertical fins, protrusions, etc. (7). 2. Molten metal container according to claim 1, characterized in that the fins, protrusions, etc. (7) are welded on the entire surface to the container jacket (3). 3. Molten metal according to claim 1, characterized in that the fins, projections, etc. (7) are welded to the vessel jacket (3) of the furnace vessel (1) by continuous or interrupted fillet welding. container. 4. Molten metal vessel according to claim 1, characterized in that the fins, protrusions, etc. (7) are manufactured from sheet metal strips, molded copper, tubular or hollow profiles. 5. A patent claim characterized in that the container jacket (3) with fins, protrusions, etc. (7) is integral and is manufactured from thick-walled material by forging, casting, pressing or other mechanical processing. The molten metal container according to item 1. 6 Item 1, characterized in that the container jacket (3) with fins, protrusions, etc. (7) is composed of a plurality of jacket pieces, which are joined by welding of T-, U- or L-shaped profiles. 4. The molten metal container according to any one of items 4 to 4. 7. Patent claim characterized in that the sheathing pieces used separately as the vessel envelope (3) are supported on the support frame (4) of the furnace vessel (1) via spacing pieces (9). The molten metal container according to item 6. 8. One of claims 1 to 6, characterized in that the fins, protrusions, etc. (7) are configured to form a completely or partially closed cooling passage (8). Molten metal container described in . 9 The cooling passage (8) is extended to the bottom of the operation hearth (5),
9. Molten metal vessel according to claim 8, characterized in that it is provided with a hopper-shaped guide plate (10) for directing the air flow. 10 An annular gap (
10. Molten metal vessel according to claim 8 or 9, characterized in that the width of the annular gap is at least equal to the width of the cooling channel (8). 11. Molten metal container according to claim 1, characterized in that a forced air device is provided for generating an air flow at the lower part of the finned container envelope (3). 12. Claims characterized in that the container envelope upper part (2) is separated from the container envelope lower part (3) in the transition area between the wall element and the lining The molten metal container according to item 1. 13. Claim 1, characterized in that the container envelope upper part (2) is connected to the container envelope lower part (3) at the separation point by means of screws, keys or other removable connecting pieces.
The molten metal container according to item 2.