DE3305611C1

DE3305611C1 - Scrap-charging basket for electric arc furnace

Info

Publication number: DE3305611C1
Application number: DE19833305611
Authority: DE
Inventors: Heinrich Jürgen Ing.(grad.) 4690 Herne Funk
Original assignee: Krupp Stahl AG
Current assignee: Krupp Hoesch Stahl AG
Priority date: 1983-02-18
Filing date: 1983-02-18
Publication date: 1984-08-16

Abstract

The basket of the invention has half-shells (5,6), which can tilt upwards, forming the floor. Several chambers (13,14,15) are arranged within the basket for lump lime, which is to be introduced into the furnace for the protection of the so-called hot spots during charging of the furnace. The chambers (13,14,15) have openings (16,17,18) externally on the lower edge of the basket casing (1), which are closed by a common closure (19). The closure (19) is coupled to the half-shells (5,6) by an opening mechanism (20,21), so that on the opening of the half-shells (5,6), the openings (16,17,18) are also opened. By the scrap introduced into the furnace after the opening of the half-shells (5,6), the lime next introduced into the furnace is kept at the desired places, the hot spots, and cannot become distributed in the furnace. The protective action is therefore optimum in relation to the quantity of lime used. <IMAGE>

Description

Mit dem erfindungsgemäßen Schrottchargierkorb für Elektro-Lichtbogenöfen ist es möglich, zum Schutz der Ofenwandung gegen Überhitzung durch die Lichtbögen gezielt Kalk an die zu schützenden Stellen der Ofenwandung zu bringen. Da nach Hochklappen der Halbschalen der Schrott auf den Boden des Ofens fällt, und auch beim vollständigen Öffnen der 1 lalbschalen und herausziehen des Schrottkorbes der Ofenboden auch nicht teilweise von Schrott wieder freigelegt wird, ist der aus den Öffnungen herausrieselnde Kalk daran gehindert, von der Ofenwandung weg in Richtung Ofenmitte sich zu verteilen. Deshalb leistet der gesamte, in den Ofen eingebrachte Kalk einen Antcil zum Schutz der gefährdeten Stellen der Ofenwandung. With the scrap charging basket according to the invention for electric arc furnaces it is possible to protect the furnace wall against overheating caused by the arcing to bring lime specifically to the areas of the furnace wall to be protected. There after folding up the half-shells the scrap falls to the bottom of the furnace, and even when opening the 1 half-shell completely and pulling out the scrap basket of the The furnace floor is also not partially exposed again by scrap, is the one from the Lime trickling out openings prevented it from moving away from the furnace wall in the direction To distribute oven center. That is why everything that is brought into the furnace works Lime a part to protect the endangered parts of the furnace wall.

Die Anordnung der Kammern an der Innenwandung des Mantels ist aus Raumgründen vorteilhaft. In diesem Fall kann die Außenwandung des Mantels eng an die Innenwandung des Ofens angepaßt werden. Die Abschnitte zwischen den im Innern des Mantels angeordnelen Kammern stehen dagegen für die Schrottaufnahme zur Verfügung. The arrangement of the chambers on the inner wall of the jacket is off Advantageous for reasons of space. In this case, the outer wall of the jacket can fit snugly the inner wall of the furnace can be adapted. The sections between the inside On the other hand, chambers arranged in the jacket are available for picking up scrap.

Von besonderem Vorteil sind auch die nur bei Bedarf einhängbaren Kammern. Wird kein Kalk benötigt, brauchen die Kammern nicht eingehängt zu werden, so daß der gesamte Querschnitt des Korbes für den Schrott zur Verfügung steht. Dies ist z. B. beim Nachchargieren der Fall. Those that can only be attached when required are also particularly advantageous Chambers. If no lime is required, the chambers do not need to be attached, so that the entire cross-section of the basket is available for the scrap. this is z. B. the case when recharging.

Besonders leicht sind die Verschüsse zu betätigen, wenn sie von einem gemeinsamen, um den Mantel verlaufenden, ringförmigen Schieber gebildet sind. In diesem Fall braucht nur ein Betätigungsorgan für die Verschlüsse vorgesehen zu sein. The locks are particularly easy to operate when they are operated by a common, around the jacket extending, annular slide are formed. In In this case, only one actuator for the closures needs to be provided.

Günstig ist es auch, wenn mit dem Kranhilfshub nicht nur die Halbschalen geöffnet werden können, sondern auch die Verschlüsse der Öffnungen. Dies läßt sich z. B. It is also beneficial if the auxiliary crane lift does not only cover the half-shells can be opened, but also the closures of the openings. This can be z. B.

dadurch verwirklichen, daß die Halbschalen und die Verschlüsse über ein Zugmittel miteinander verbunden sind. Die Folge der Betätigungen der Halbschalen und des bzw. der Verschlüsse läßt sich durch die Länge des Zugmittels bestimmen.thereby realize that the half-shells and the closures over a traction device are connected to one another. The consequence of the actuation of the half-shells and the lock or locks can be determined by the length of the traction means.

Bei einem Schrottchargierkorb, der Gegenstand eines älteren Patentes ist (DE-PS 32 16 102), wird der Boden von aufklappbaren Sektoren gebildet. Der Mantel des Chargierkorbes ist zur Aufnahme von Stückkalk doppelwandig ausgebildet. Außenseitig sind am unteren Rand des Mantels eine umlaufende Reihe von Öffnungen vorgesehen, die durch einen als Verschluß dienenden Außenring verschlossen sind. Mit einem solchen Chargierkorb ist es jedoch nicht möglich, gezielt an die zu schützenden Stellen Kalk zu bringen. Nach dem schlagartigen Öffnen der den Boden bildenden Kettenschürzen fällt der Schrott zwar auf den Boden des Ofens, stützt sich jedoch an den Kettenschürzen ab, so daß beim Herausziehen des Korbes die Schrottsäule leicht angehoben wird. Deshalb besteht die Gefahr, daß der sich zuvor zwischen der Schrottsäule und der Ofenwandung stauende Kalk sich zur Bodenmitte hin verteilt und von den Schrotteilen überdeckt wird, so daß er nicht mehr zum Schutze der Ofenwandung zur Verfügung steht. Die Wirksamkeit der eingesetzten Kalkmenge ist somit vergleichsweise klein. In the case of a scrap loading basket, the subject of an older patent is (DE-PS 32 16 102), the bottom is formed by hinged sectors. The coat of the charging basket is double-walled to accommodate lump lime. Outside a circumferential row of openings are provided at the lower edge of the jacket, which are closed by an outer ring serving as a closure. With such a However, it is not possible for the charging basket to target the areas to be protected Bring lime. After suddenly opening the chain aprons that form the bottom the scrap falls to the floor of the furnace but is supported by the chain aprons so that when you pull out the basket, the scrap column is raised slightly. Therefore, there is a risk that the before between the scrap column and the Lime accumulating on the furnace wall is distributed towards the center of the floor and from the scrap pieces is covered so that it is no longer available to protect the furnace wall. The effectiveness of the amount of lime used is therefore comparatively small.

Im folgenden wird die Erfindung anhand einer ein Ausführungsbeispiel darstellenden Zeichnung näher erläutert. Im einzelnen zeigt F i g. 1 einen Schrottchargierkorb mit geschlossenen, den Boden bildenden Halbschalen in Seitenansicht, F i g. 2 den Schrottchargierkorb gemäß F i g. 1 mit hochgeklappten Halbschalen in Seitenansicht, Fig. 3 den Schrottchargierkorb gemäß F i g. 1 im Querschnitt und F i g. 4 ein Detail des Schrottchargierkorbes im Schnitt nach der Linie 1-1 der F i g. 3. In the following the invention is based on an exemplary embodiment Illustrative drawing explained in more detail. In detail, FIG. 1 a scrap load basket with closed half-shells forming the bottom in a side view, FIG. 2 den Scrap loading basket according to FIG. 1 with folded up half-shells in side view, 3 shows the scrap loading basket according to FIG. 1 in cross section and FIG. 4 a detail of the scrap loading basket in section along the line 1-1 of FIG. 3.

Der in der Zeichnung dargestellte Schrottchargierkorb für Elektro-Lichtbogenöfen besteht aus einem zy- lindrischen Stahlmantel 1 mit gegenüberliegenden Tragzapfen 2,3 für ein Krangehänge 4 und aus zwei, den Boden bildenden, Stahlblech-Halbschalen 5, 6, die am Mantel 1 in Lagern 7, 8 auseinanderklappbar angelenkt sind. Dic beiden Halbschalen 5, 6 sind über Zugmittel 9, 10 an einer Travcrsc 11 angeschlagen, die an einem Kranhilfshub gehängt ist. Durch Anheben der Traverse 11 können somit die Halbschalen 5, 6 aus der in Fig. 1 gezeigten Stellung in die in F i g. 2 gezeigte Stellung für die Entleerung des Schrottkorbes gebracht werden. The scrap charging basket for electric arc furnaces shown in the drawing consists of a cy- Lindrian steel jacket 1 with opposing trunnions 2,3 for a crane suspension 4 and from two sheet steel half-shells forming the bottom 5, 6, which are hinged to the jacket 1 in bearings 7, 8 so that they can be folded apart. The two Half-shells 5, 6 are attached via traction means 9, 10 to a Travcrsc 11, which is hung on a crane auxiliary hoist. By lifting the cross member 11 can thus Half-shells 5, 6 from the position shown in FIG. 1 into the position shown in FIG. 2 shown Position for emptying the scrap basket.

An der Innenwandung des Mantels 1 sind um 1200 versetzt drei Kammern 13, 14, 15 zur Aufnahme von Stückkalk angcordnet, die sich über die Höhe des Schrottkorbes erstrecken. Die Kammern werden von hohlen, im wesentlichen rechteckigen Profilen gebildet. On the inner wall of the shell 1 are three chambers offset by 1200 13, 14, 15 angcorder to accommodate lump lime, which extends over the height of the scrap basket extend. The chambers are made of hollow, essentially rectangular profiles educated.

die an der Innenwandung angeschweißt sind. Am unteren Ende der Kammern 13 bis 15 sind in der Wandung Öffnungen 16, 17, 18 vorgesehen, denen als Verschluß ein gemeinsamer, um den Mantel herum verlaufender Ring 19 zugeordnet ist. Der Ring ist über Zugmittel, insbesondere Ketten 20, 21, mit den Halbschalen 5, 6 verbunden, so daß beim Hochklappen der Halbschalen 5,6 auch der Ring 19 aus seiner Verschließstellung in die in F i g. 4 dargestellte Öffnungsstellung hochgeschoben wird. Über die Wahl der Länge der Zugmittel 20, 21 kann bestimmt werden, in welcher Öffnungsstellung der Halbschalen 5, 6 der ringförmige Verschluß 19 hochgeschoben werden soll.which are welded to the inner wall. At the bottom of the chambers 13 to 15 openings 16, 17, 18 are provided in the wall, which as a closure a common ring 19 running around the jacket is assigned. The ring is connected to the half-shells 5, 6 via traction means, in particular chains 20, 21, so that when you fold up the half-shells 5, 6 and the ring 19 from its closed position in the in F i g. 4 shown open position is pushed up. About the choice the length of the traction means 20, 21 can be determined in which open position of the half-shells 5, 6 of the annular closure 19 is to be pushed up.

Mit einem solchen Schrottchargierkorb ist es möglich, entsprechend der Geometrie der Elektroden gezielt an die Stellen des Ofens Kalk zu bringen, wo die Wandung geschützt werden soll. Ein Wegrieseln des in den Ofen einbrachten Kalks zur Ofenmitte wird weitgehend dadurch ausgeschlossen, daß das Entleeren des Schrottes und das Einbringen des Kalkes aufeinander abgestimmt werden kann. Der auf den Boden des Ofens gefallene Schrott wird bei weiterem Öffnen der Halbschalen und Anheben des Schrottkorbes nicht wieder angehoben, so daß ein Verteilen des eingebrachten Kalkes zur Ofenmitte hin nicht stattfinden kann. Der einmal eingebrachte Kalk bleibt an den zu schützenden Stellen und kann deshalb seine Wirkung voll entfalten. With such a scrap loading basket it is possible to do this accordingly the geometry of the electrodes specifically to bring lime to the points of the furnace where the wall is to be protected. A trickle of the lime brought into the oven to the middle of the furnace is largely ruled out that emptying the scrap and the introduction of the lime can be coordinated. The one on the floor The scrap that has fallen in the furnace is released when the half-shells are opened further and lifted of the scrap basket not raised again, so that a distribution of the introduced Lime cannot take place towards the middle of the furnace. The lime that has been introduced remains in the areas to be protected and can therefore fully develop its effect.

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Claims

Claims: 1. Scrap charging basket for electric arc furnaces, consisting of a particularly cylindrical jacket, which is attached to a crane hanger can be suspended, and a base that can be folded apart by several on the coat hinged parts is formed, with the lower edge of the shell over its outer circumference distributed several openings of a common or several chambers intended for lime whose closures are coupled to one another via an opening mechanism, characterized in that the bottom parts are designed as two half-shells (5, 6) are connected to the closures (19) of the openings (16, 17, 18) via the opening mechanism (20, 21) are coupled to one another in such a way that only after the possibly partial When the half-shells (5, 6) are folded up, the openings (16, 17, 18) are released.

2. scrap charging basket according to claim 1, characterized in that the chambers (13, 14, 15) are arranged on the inner wall of the jacket (1).

3. scrap loading basket according to claim 1 or 2, characterized in that that the chambers (13, 14, 15) of open profiles with circular, elliptical or rectangular cross-section.

4. scrap loading basket according to one of claims 1-3, characterized in that that the chambers (13, 14, 15) are loosely suspended.

5. scrap loading basket according to one of claims 1-3, characterized in that that the chambers (13, 14, 15) are firmly connected to the jacket (1), in particular welded are.

6. scrap loading basket according to one of claims 1-5, characterized in that that the closures (19) of a common, around the jacket (1) extending annular Sliders are formed.

7. scrap loading basket according to one of claims 1-6, characterized in that that the opening mechanism (20, 21) consists of one or more traction means, via the or via which the closure or closures (19) with the half-shells (5, 6) are connected.

8. scrap loading basket according to claim 7, characterized in that the length of the traction device (s) 21) is adjustable.

The invention relates to a scrap charging basket for electric arc furnaces according to the preamble of the main claim.

Since the mid-30s, scrap has been fed into electric arc furnaces made by means of scrap loading baskets. With the scrap baskets that are common today These are cylindrical vessels welded from thick-walled boiler plate with lifting pin for a crane suspension. According to the current state of the art, it differs one between two types of scrap baskets.

In one type, the upper cylindrical vessel is downward completed by chain aprons, either by strong hemp ropes or a Special chain lock with bolt locking at the chain ends are held together. While the hemp rope when the basket is placed in the oven it burns and the bottom of the basket releases, the opening of the basket bottom takes place at the chain lock by the fact that after Inserting the basket into the oven the locking pin is pulled out.

The other type of basket is a folding basket or a bowl basket. Such a bowl basket on which the preamble of the main claim is based is described in the literature reference Stahleisen-Schriften, Issue 7, »Was der Elektrostahlwerker must know about his work «, Verlag Stahleisen, Düsseldorf, 1972, page 38. At Such a shell basket is the cylindrical upper shell at the bottom by two sheet steel half-shells completed, which are hinged on the upper part foldable. After insertion of the basket into the furnace by means of a crane, the half-shells are lifted via the crane auxiliary hoist pulled apart so that the scrap in the basket slide into the furnace vessel can.

In modern, large-volume, high-performance electric arc furnaces, The bowl basket is preferred for loading scrap because of its bulkiness of the scrap a single or repeated replenishment of scrap during the meltdown phase is required. The advantage of the latter type of basket is that the Repositioning of scrap in an already very liquefied bath in the furnace by slow When the trays are opened, the sliding in of the scrap can be better timed can.

Because high-performance arc furnaces with very much during the melting process high electrical power (specific transformer power up to 800 kVA / t), are formed between the three in the middle during the meltdown phase of the furnace circularly arranged electrodes at angles of 120C and the scrap pieces very "long" arcs. These arcs also radiate against the furnace wall, see above that in particular the wall parts that are directly opposite the individual electrodes, are endangered by arcing. To avoid these areas at risk of overheating (the so-called hot spots). it is common when loading the scrap basket bring a certain amount of lump lime into its inner circumference in order to empty it of the scrap to get a layer of lime in front of the hot spots, which are caused by melting down "intercepts" the arc. With this method it is possible to obtain a certain but not enough to bring the amount of lime in front of the overheated areas; the biggest Part of the lime is distributed within the entire furnace vessel and is thus ineffective for the protection of the overheated areas. In addition, therefore, lime by hand or by means of forklift boxes after the scrap loading is complete can be added to the desired locations.

The invention has the task of creating a bowl basket to develop further so that a targeted introduction of Lime is made possible to protect the furnace wall parts that are sensitive to overheating.

According to the invention, this object is achieved by the features of the claim 1 solved. Preferred embodiments of the invention are characterized in the subclaims.