DE102010044984A1 - Feeding device for a melting furnace of a metallurgical plant - Google Patents

Abstract

A charging device (4) for a melting furnace (1) of a smelting metallurgical plant has a charging element (5) which can be filled with metal scrap (2) intended for the smelting furnace (1) in a storage area (6) of the smelting metallurgical plant, from there into a loading area (7) can be transferred, can be tilted about a horizontal tilting axis (9) for emptying and can be transferred back into the storage area (6) in the emptied state. The charging element 1). At least one of the side walls (11) can be opened for emptying the charging element (5). This side wall (11) runs parallel to the tilt axis (9). A portion of a respective local normal vector (N), which the base plate (10) defines on the basis of its course, varies in a horizontal direction (x) which runs orthogonally to the tilting axis (9) over the location on the base plate (10) such that When the loading element (5) is tilted about the tilting axis (9), the metal scrap (2) in the loading element (5) does not suddenly fall out of the loading element (5), but is staggered in time.

Description

• – wobei die Beschickungseinrichtung ein Beschickungselement aufweist, das in einem Bevorratungsbereich der schmelzmetallurgischen Anlage mit für den Schmelzofen bestimmtem Metallschrott füllbar ist, von dort in einen Beschickungsbereich überführbar ist, dort zum Entleeren um eine horizontale Kippachse kippbar und in entleertem Zustand wieder in den Bevorratungsbereich überführbar ist,
• – wobei das Beschickungselement eine Bodenplatte und Seitenwände aufweist,
• – wobei mindestens eine der Seitenwände zum Entleeren des Beschickungselements öffenbar ist,
• – wobei die öffenbare Seitenwand parallel zur Kippachse verläuft.

The present invention relates to a charging device for a melting furnace of a metallurgical plant,

• - wherein the charging device has a charging element which can be filled in a Vorratsungsbereich the melt-metallurgical plant with destined for the furnace metal scrap, from there into a loading area can be transferred, tilted there for emptying about a horizontal tilting axis and in the emptied state again in the storage area can be transferred .
• The loading element has a bottom plate and side walls,
• Wherein at least one of the side walls is openable for emptying the charging element,
• - The openable side wall is parallel to the tilt axis.

For preheating steel scrap, melting furnaces often use the process gases produced in the melting furnace. The process gases are often passed through shaft-like arrangements in which the steel scrap is held by means of a restraint system - for example in the form of swiveling fingers - above the furnace vessel and flows through the process gases of the furnace. The steel scrap is kept, so to speak, between the furnace vessel and the exhaust system in a form that transfers as much heat as possible of the exhaust gas into the steel scrap or into the scrap column. This procedure improves the energy balance and thus reduces the energy requirement of the melting furnace.

The shaft is loaded in the prior art via a feed element, which is formed in many cases as a chute. The chute is tilted over a fulcrum to allow the steel scrap to slip off the chute (dump truck principle). In the transition from static friction to sliding friction, the scrap located in the chute dissolves abruptly, so that the entire scrap practically as abruptly impinges on the finger. Due to the height of the shaft and the resulting drop height of the scrap, high dynamic forces act on the restraint system. High forces also act on the shaft wall. Due to the procedure of the prior art, there are high wear and deformation effects. These reduce the operational safety and service life of the smelting metallurgical plant. They continue to increase the maintenance and repair costs considerably.

The disadvantages associated with the prior art approach are readily accepted in the art.

The object of the present invention is to provide means by which the load on the restraint system can be reduced without otherwise having to incur appreciable disadvantages.

The object is achieved by a charging device having the features of claim 1. Advantageous embodiments of the charging device according to the invention are the subject of the dependent claims 2 to 8.

According to the invention, the bottom plate of a loading device of the type mentioned above is designed in such a way that a portion of a respective local normal vector, which the bottom plate defines on the basis of its course, varies in a horizontal direction, which is orthogonal to the tilt axis, in such a way over the location on the bottom plate, in that, when the loading element is tilted about the tilting axis, the metal scrap located in the loading element does not drop out of the loading element abruptly, but staggered in time.

The inventive solution is thus in a special shape of the bottom plate of the feed element, due to which the transition from static friction to sliding friction takes place in stages and thus the fall of the scrap into the shaft of "all at once" to "continuous - piecewise" is transferred.

Preferably, the openable side wall is pivotable about a horizontal pivot axis, which is arranged in the vicinity of the end facing away from the bottom plate end of the openable side wall.

Preferably, furthermore, the tilt axis runs orthogonal to a direction of travel of the feed element.

It is possible that the proportion of the respective local normal vector in the horizontal direction varies both in the direction of the horizontal direction and in the direction of the tilting axis. Preferably, however, said portion varies only in the direction of the horizontal direction, but is constant in the direction of the tilting axis.

• – in einem vorderen Randbereich, der in der Nähe der öffenbaren Seitenwand gelegen ist, auf die öffenbare Seitenwand zu abschüssig ist,
• – in einem hinteren Randbereich, der in der Nähe einer der öffenbaren Seitenwand gegenüber liegenden Seitenwand gelegenen ist, auf die gegenüber liegende Seitenwand zu abschüssig ist und
• – in einem zwischen dem vorderen und dem hinteren Randbereich gelegenen Mittelbereich im Wesentlichen horizontal verläuft.

For example, it is possible to design the bottom plate in such a way that before the tilting of the loading element about the tilting axis

• - in a front edge area located near the openable side wall, on the openable side wall is too steep,
• - in a rear edge area, which faces near one of the openable side wall lying side wall is located on the opposite side wall is too steep and
• - Is substantially horizontal in a central region located between the front and the rear edge region.

In the last-mentioned embodiment, provision is preferably made for a front transition area to be arranged between the middle area and the front edge area, for a rear transition area to be arranged between the middle area and the rear edge area, and for the transition areas to slope down to the central area.

Alternatively, it is possible that the bottom plate has a plurality of waves or half-waves, which are seen in the direction of the horizontal direction before tilting of the loading element about the tilt axis one behind the other. In this case, the wavelength of the waves or half-waves preferably increases with increasing distance from the openable side wall.

Further advantages and details will become apparent from the following description of exemplary embodiments in conjunction with the drawings. In a schematic representation:

1 schematically a melting metallurgical plant from the side,

2 a section of the melt metallurgical plant of 1 .

3 the clipping of 2 in another operating state,

4 a feed element in cross-section and

5 a bottom plate.

According to 1 For example, a smelting metallurgical plant has a smelting furnace 1 on. The smelting furnace 1 may be formed, for example, as an electric arc furnace. The smelting furnace 1 comes with metal scrap 2 fed. In many cases - as well as in the presentation of 1 - is above the melting furnace 1 a shaft 3 arranged. In this case, the metal scrap 2 first in the shaft 3 poured and there by means of the operation of the furnace 1 preheated waste heat.

For loading the furnace 1 (or previously of the shaft 3 ) is a feeder 4 intended. The loading device 4 has a loading element 5 on. The loading element 5 is initially in a storage area 6 the melting metallurgical plant with that for the melting furnace 1 certain metal scrap 2 filled. Then the charging element 5 in a loading area 7 transferred to the metallurgical plant. The transfer of the loading element 5 For example, by moving on rails 8th , which run obliquely from bottom to top (inclined lift).

2 shows the loading area 7 the melt metallurgical plant with therein feed element 5 ,

In the loading area 7 becomes the charging element 5 around a horizontal tilting axis 9 tilted. The course of the tilt axis 9 can be selected as needed, as long as the tilt axis 9 remains horizontal. As a rule, the tilt axis runs 9 orthogonal to the direction of travel of the feed element 5 ,

Due to tilting of the loading element 5 around the tilt axis 9 becomes the metal scrap 2 in the shaft 3 tilted, the loading element 5 so emptied. 3 shows the loading area 7 the melting metallurgical plant with tilted feed element 5 , After emptying the charging element 5 becomes the charging element 5 tilted back to its original position and then back into the storage area 6 transferred.

Alternatively, for example, a crane may be used, which is the loading element 5 picked up by ropes and transported. When tilting, the loading element 5 tilted here over a virtual horizontal tilt axis and the metal scrap 2 in the shaft 3 emptied.

The loading element 5 indicates - see supplementary 4 - a floor plate 10 and sidewalls 11 on. At least one of the side walls 11 is for emptying the feed element 5 openable. This sidewall 11 runs parallel to the tilt axis 9 , The openability of the openable side wall 11 can be achieved in any way. As a rule, the openable side wall 11 around a horizontal pivot axis 12 pivotable. The pivot axis 12 in this case it is close to the bottom plate 10 opposite end of the openable side wall 11 arranged.

For a better understanding of the present invention, it makes sense to first define a Cartesian coordinate system below. The Cartesian coordinate system has three coordinate axes x, y, z. The x-axis and the y-axis are horizontal. The z-axis is vertical. The y-axis should be in the direction of the tilt axis 9 run. The x-axis should be orthogonal to the tilting axis 9 run. This axis is sometimes referred to below as a horizontal axis.

The following comments on the design of the bottom plate 10 refer to the untilted state of the loading element 5 , that is, the condition in the 1 . 2 and 4 (and also in 5 ) is shown.

How very clear 4 is apparent, is the bottom plate 10 not as a uniform, consistently horizontal base plate 10 educated. A normal vector N on the bottom plate 10 , ie a vector of length l, which is locally orthogonal to the bottom plate 10 therefore, does not point in the same direction everywhere. In particular, varies according to 4 a proportion of the respective local normal vector N in the direction of the x-axis as a function of the location on the bottom plate 10 , This variation is chosen such that when tilting the feed element 5 around the tilt axis 9 in the charging element 5 located metal scrap 2 not abruptly, but temporally offset from the loading element 5 falls out.

It is possible that the proportion of the respective local normal vector N varies both in the direction of the x-axis and in the direction of the y-axis. For example, in the middle of the bottom plate 10 a depression may be provided which, based on the base plate 10 - Is surrounded on all sides by elevated areas. Preferably, however, the proportion of the respective local normal vector N in the horizontal direction x, although seen in the direction of the horizontal direction x, varies in the direction of the tilting axis 9 seen, however, constant. This embodiment is also taken in the present case. For this reason, the feed element 5 shown in the figures only in side view or in section.

According to the presentation of the 1 to 4 has the bottom plate 10 a front edge area 13 , a rear edge area 14 and a middle area 15 on. The front edge area 13 is near the openable side wall 11 located. The rear edge area 14 is near the side wall 11 located, the openable side wall 11 is opposite. The middle area 15 lies between the front and the rear edge area 13 . 14 ,

The front edge area 13 is on the openable side wall 11 too steep. The rear edge area 14 is on the above-mentioned opposite side wall 11 too steep. The middle area 15 runs essentially horizontally.

The border areas 13 . 14 have in the horizontal direction x respective longitudinal extensions l, l 'on. Likewise, the middle section 15 in the horizontal direction x a longitudinal extent l '' on. The longitudinal extents l, l ', l''are generally between 20% and 40% of a total extension L of the feed element 5 These are measured from the openable side wall 11 to the opposite side wall 11 ,

Preferably, according to the representation of 1 to 4 , between the middle section 15 and the front edge area 13 a front transition area 16 arranged. Furthermore, it is preferably between the middle region 15 and the rear edge area 14 a rear transition area 17 arranged. The two transition areas 16 . 17 are in this case the middle range 15 downhill.

Alternatively to the above-described embodiment (keyword edge and middle areas 13 . 14 . 15 ) can be the bottom plate 10 according to 5 a plurality of waves or half waves 18 - are shown in 5 half-wave 18 - exhibit. The waves or half waves 18 lie in this case in the direction of the horizontal direction x seen one behind the other.

The wavelength λ of the waves or halfwaves 18 can be constant. Preferably, the wavelength λ increases according to the representation of 5 however, with the distance a from the openable side wall 11 at.

Due to the inventive design, in particular the bottom plate 10 of the loading element 5 , results in different places of the bottom plate 10 a different ratio of normal force to lateral force when tilting the feed element 5 , The coefficient of static friction, however, remains constant. The result is thus a time-shifted slipping of the metal scrap 2 , This will introduce the metal scrap 2 in the shaft 3 and thus the period in which dynamic forces on the retention system of the shaft 3 act, significantly extended.

The present invention has many advantages. In particular, the service life is extended and the reliability of the overall system improves. Also, the melt metallurgical plant is not as maintenance prone as a prior art melt metallurgical plant. Furthermore, further design optimizations of the restraint system, the shaft 3 etc. possible.

The above description is only for explanation of the present invention. The scope of the present invention, however, is intended to be determined solely by the appended claims.

Claims (8)

Feeding device for a melting furnace ( 1 ) of a metallurgical plant, - wherein the charging device is a charging element ( 5 ) stored in a storage area ( 6 ) of the melting metallurgical plant with for the melting furnace ( 1 ) certain metal scrap ( 2 ) is filled, from there into a loading area ( 7 ), there for emptying about a horizontal tilting axis ( 9 ) tilted and in the emptied state back into the storage area ( 6 ), wherein - the loading element ( 5 ) a bottom plate ( 10 ) and side walls ( 11 ), wherein at least one of the side walls ( 11 ) for emptying the charging element ( 5 ) is openable, - whereby the openable side wall ( 11 ) parallel to the tilt axis ( 9 ), wherein - a portion of a respective local normal vector (N), the bottom plate ( 10 ) defined in terms of their course, in a horizontal direction (x) which is orthogonal to the tilt axis ( 9 ), so over the location on the bottom plate ( 10 ) varies, that when tilting the loading element ( 5 ) about the tilt axis ( 9 ) in the charging element ( 5 ) located metal scrap ( 2 ) not abruptly, but staggered from the loading element ( 5 ) falls out. Feeding device according to claim 1, characterized in that the openable side wall ( 11 ) about a horizontal pivot axis ( 12 ), which is close to that of the bottom plate ( 10 ) facing away from the end of the openable side wall ( 11 ) is arranged. Feeding device according to claim 1 or 2, characterized in that the tilting axis ( 9 ) runs orthogonal to a direction of travel of the feed element. Feeding device according to claim 1, 2 or 3, characterized in that the proportion of the respective local normal vector (N) in the horizontal direction (x), although seen in the direction of the horizontal direction (x) varies, in the direction of the tilt axis ( 9 ), however, is constant. Feeding device according to claim 4, characterized in that the bottom plate ( 10 ) before tilting the loading element ( 5 ) about the tilt axis ( 9 ) - in a front edge area ( 13 ) located near the openable side wall ( 11 ), on the openable side wall ( 11 ) is too steep, - in a rear edge area ( 14 ) located near one of the openable side walls ( 11 ) opposite side wall ( 11 ) is located on the opposite side wall ( 11 ) is too steep and - in one between the front and the rear edge region ( 13 . 14 ) ( 15 ) is substantially horizontal. Feeding device according to claim 5, characterized in that between the middle region ( 15 ) and the front edge area ( 13 ) a front transition area ( 16 ) is arranged that between the middle region ( 15 ) and the rear edge area ( 14 ) a rear transition region ( 17 ) and that the transition areas ( 16 . 17 ) to the middle area ( 15 ) are downhill. Feeding device according to claim 4, characterized in that the bottom plate a plurality of waves or half-waves ( 18 ), seen in the direction of the horizontal direction (x) before tilting of the loading element ( 5 ) about the tilt axis ( 9 ) lie one behind the other. Feeding device according to claim 7, characterized in that the wavelength (λ) of the waves or half-waves ( 18 ) with increasing distance from the openable side wall ( 11 ) increases.

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