DE102010045948A1 - Fusion aggregate for steel plant, has device charger arranged on lateral charging opening for charging of insert material into furnace vessel equipped with electrode assemblies - Google Patents

Abstract

The fusion aggregate has a furnace vessel (11) equipped with a charging opening, a lid (12), and two electrode assemblies (13a,13b) comprising three electrodes for smelting the insert material such as steel scrap. A device charger (20) with a slider (22) is arranged on the lateral charging opening for charging of insert material. The electrode is formed of diameter of 700 mm or more. An independent claim is included for steel plant.

Description

The present invention relates to a melter, in particular to an electric arc furnace for steelmaking.

In the prior art, steel mills are known with electric arc furnaces. These arc furnaces are designed as three-phase arc furnaces (with three melting electrodes) or direct current arc furnaces (with melting electrodes and bottom electrode).

The material to be melted (feedstock) is usually steel scrap. There are several ways to charge the feed to the arc furnace for melting. It is possible to lift the lid and throw the steel into the oven jar. Furthermore, solutions with Chargiergutvorwärmern that are designed as a shaft, known for batch or continuous loading. The loading openings for the furnace vessel are, unless the lid is raised, formed either in the top of the lid or laterally on the furnace vessel.

Such arc furnaces are used for batch or continuous steelmaking. In batch steelmaking, a certain molten steel is usually poured (tapped) into a vessel (pan). For this purpose, the furnace vessel is often tilted. There are also solutions in which the steel is tapped without tilting the furnace vessel. It is important to make sure that no slag or possibly little slag gets into the pan when cutting off. An example of such a conventional technology is in the EP 0 385 434 A2 shown.

Furnaces for continuous melting have also been considered in the prior art (see, for example, US Pat DE-OS 1 937 839 ).

Typical oven sizes have tapping weights in the range of 100 to 250 tons. Since the time from tapping to tapping (tap-to-tap time) for large ovens in the range of one hour, so is the capacity per hour in the range of up to 250 tons per hour. This means that even if an oven were to run uninterrupted for a whole year, which is not possible due to maintenance times, etc., it would be possible to produce a maximum of 2.2 million tons of steel per year with such an oven.

In particular, if the capacity in existing steel mills is to be increased, one can set up either a larger furnace or two furnaces.

The object of the invention is to provide an improved smelting unit, in particular an improved electric arc furnace, which is suitable for large tapping weights.

This object is achieved by a smelting unit according to claim 1.

Further developments of the inventions are specified in the dependent claims.

The combination of two electrode sets and an oval furnace vessel allows the realization of a large furnace with high tapping weights.

By a lateral feed opening for the feedstock (steel scrap) can bring about an advantageous utilization of the two electrode sets.

With the smelting aggregate, it is also possible to increase the capacity of an existing steel mill without having to change the steelwork of the steelworks.

The use of two electrode sets allows the use of standard electrodes and standard transformers.

Further features and expediencies will become apparent from the description of an embodiment with reference to FIGS. From the figures show:

1 a melter according to one embodiment in a perspective oblique view of the side of the oval furnace vessel with the tap hole;

2 a plan view of the melter 1 ;

3 another perspective view of the melter 1 ;

4 another perspective view of the melter 1 ; and

5 a plan view of the melter 1 with weggeschwenkten electrode sets and cover halves.

In the figures, the same reference numerals are used for the same features.

In 1 . 3 . 5 is an embodiment of a trained as a three-phase arc furnace melter according to an embodiment shown in a perspective view. The smelting unit has an electric arc furnace 10 With a furnace vessel 11 and a lid 12 on. As in the plan views 2 and 5 It is best to see the furnace vessel 11 in plan view an oval shape with an eccentrically arranged tap hole 15 , The taphole 15 is located in a bay window 11 of the furnace vessel 11 , The taphole 15 is a Bodenabstichloch and in the embodiment, the bottom of the bay is 11 opposite the bottom of the remaining furnace vessel 11 elevated. This is used when parting to the tap hole 15 when tilting back the furnace vessel is no longer covered by the corresponding steel bath and the slag layer, as is known in the art.

The oval-shaped lid in plan view 12 has two lid halves 12a . 12b on. The furnace vessel has a lateral charging opening 14 on. To the charging opening 14 is a charging material preheater 20 the one from the WO 2005/052481 A1 known way about an approach 23 connected. The charging material preheater 20 has a shaft 21 and a slider 22 for quasi-continuous feeding of feedstock. The feedstock is usually steel scrap, preferably unsorted steel scrap.

The charging opening 14 is, relative to the bay window 111 on one side of the furnace vessel, which is offset by approximately 90 ° relative to the bay, formed.

The electric arc furnace 10 has two electrode arrangements 13a . 13b , each of which used for a three-phase operation three electrodes 133 have, on. That is, it is 2 times 3, so a total of 6 electrodes 133 intended. Each lid half 12a . 12b is an electrode assembly 13a . 13b assigned. Each lid opening has three openings through which the corresponding three electrodes 133 lowered through the lid in the oven vessel and can be pulled out of this. These are the electrodes 133 on each one electrode support and holding arm 131 appropriate. Each electrode arrangement 13a . 13b thus has three electrode arms 131 on, over a hoist 132 can be lifted and lowered.

In the embodiment shown, the lid half 12a together with the associated electrode arrangement 13a through the hoist 132 not only raised but also pivoted (see 5 ). The same applies to the other pair of cover half 12b and electrode assembly 13b with associated hoist 132 ,

The hoists 132 are on the charging opening 14 opposite side of the furnace vessel 11 arranged. This allows the lid halves 12a . 12b and electrode assemblies 13a . 13b are each pivoted away from the furnace center to the right or left side in the plan view (see 5 ).

The furnace vessel 11 is in a furnace cradle 16 held over which the oven vessel for tapping in a known manner is tilted.

Under the furnace vessel are rails 52 provided on which a pan car 51 is movable. A "pan" called vessel 50 serves to accommodate over the tap hole 15 From the furnace vessel discharged (tapped) molten (liquid) steel. As is apparent from the figures, the shaft can 20 for example, for maintenance of the furnace vessel 11 be withdrawn.

Such a furnace is particularly suitable for Abstichmassen in the range of 300 to 500 t. Thus, the production of a steelworks with one kiln can be increased to over 4 million tons of steel without having to use two furnaces. Two ovens mean a significantly increased investment and, above all, personnel and space requirements.

Alternatively, it would also be possible to make such a large oven with a single set of electrodes.

In the in the 1 to 5 shown solution allows the use of two sets of electrodes 13a . 13b the use of conventional electrodes with a diameter up to 700 mm for an oven with up to 500 t Abstichmasset be used.

Although not shown in the figures, separate transformers are preferably used for the two electrode sets. This means that one standard transformer can also be used per electrode set.

Particularly advantageous is the use of the conventional infrastructure of the steelworks, in particular the pans with the usual sizes of up to 250 tons of steel.

With the in the 1 to 5 The oven shown then only after filling a first pan 50 the oven tipped back so far that the taphole 15 again slag-free, then the second pan 50 move it under the tap hole, and then tamp the remainder until reaching the desired tapping mass.

In this way, in an existing steel plant with a furnace up to 250 t after upgrading to a furnace of up to 500 t existing steel construction and also the usual infrastructure continue to be used, which offers significant benefits.

As is conventional in the art, the filled pans can then be transported to a ladle furnace or otherwise used.

By the arrangement of the two electrode arrangements 13a . 13b in the in 2 As shown, a particularly advantageous utilization of the use of multiple electrodes is possible. Two of the three electrodes of each of the electrode assemblies 13a . 13b are arranged with their longitudinal axis substantially in a plane E, which is parallel to the charging opening 14 runs. The quasi-continuous through the slide 22 in the oven vessel 11 subsidized material is then melted particularly effective. Furthermore, the electrodes offer increased resistance to large scrap pieces.

It is expressly stated that all features disclosed in the specification and / or the claims are intended to be separate and independent of each other for the purpose of original disclosure and also for the purpose of limiting the claimed invention, independently of the composition of the features in the embodiments and / or the claims, to be disclosed. It is expressly stated that all ranges of values or indications of groups of entities disclose every possible intermediate value and every intermediate entity for the purpose of original disclosure and also for the purpose of limiting the claimed invention.

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• EP 0385434 A2 [0004]
• DE 1937839 [0005]
• WO 2005/052481 A1 [0023]

Claims (7)

Smelting unit, in particular three-phase arc furnace with a furnace ( 10 ) with a furnace vessel ( 11 ), which has an oval bottom in a plan view and a charging opening (in a side wall) ( 14 ), and a lid ( 12 ), two electrode arrangements ( 13a . 13b ) each with three electrodes ( 133 ), which melt the feedstock through the lid ( 12 ) in the furnace vessel ( 11 ) and a feedstock charging device ( 20 ) with a slider ( 22 ) located at the lateral charging opening ( 14 ) for charging feed through the port 14 is arranged. A smelting unit according to claim 1, wherein the six electrodes ( 133 ) each have a maximum diameter of 700 mm. A smelting unit according to claim 1 or 2, wherein each electrode arrangement ( 13a . 13b ) is powered by a separate transformer. Melting unit according to one of claims 1 to 3, wherein the oval furnace vessel ( 11 ) a tapping opening ( 15 ) in the bottom of a bay ( 111 ) having. Melting unit according to one of claims 1 to 4, wherein the furnace vessel ( 11 ) in a kiln cradle ( 16 ) is held. A melter according to any one of claims 1 to 5, sized to allow the furnace vessel to hold a tapping weight of from 300 to 500 t of liquid steel. Steel mill with a smelting unit according to one of claims 1 to 6, in which pans with a maximum capacity of 250 t of liquid steel, preferably a maximum of 200 t of liquid steel for receiving tapped, liquid steel under the furnace vessel ( 11 ) are movable.

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