WO2012031973A1 - Charging device for a melting furnace of a melt-metallurgical plant - Google Patents

Abstract

A charging device (4) for a melting furnace (1) of a melt-metallurgical plant has a charging element (5), which can be filled with metal scrap (2) intended for the melting furnace (1) in a stockpiling area (6) of the melt-metallurgical plant, can be transferred from there into a charging area (7), can be tipped there about a horizontal tipping axis (7) for emptying and, in the emptied state, can be transferred back into the stockpiling area (6). The charging element (5) has a bottom plate (10) and side walls (11). At least one of the side walls (11) can be opened for emptying the charging element (1). This side wall (11) runs parallel to the tipping axis (9). A component of a respective local normal vector (N) that the bottom plate (10) defines by its contour varies in a horizontal direction (x), which extends orthogonally in relation to the tipping axis (9), in such a way over the locus on the bottom plate (10) that, when the charging element (5) is tipped about the tipping axis (9), the metal scrap (2) located in the charging element (5) does not fall out of the charging element (5) all at once but with a time lag.

Description

description

Feeding device for a melting furnace of a metallurgical plant

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 Beschickungsbe ^¬ rich can be transferred there tilted for emptying about a horizontal tilt axis and in the emptied state again in the storage area is convertible,

- wherein the loading element has a bottom plate and side walls ^¬ ,

- wherein at least one of the side walls for emptying the Be ^¬ schickungselements is obvious

- Where the apparent side wall ver ^¬ runs parallel to the tilting axis.

For preheating steel scrap, melting furnaces often use the process gases produced in the melting furnace. The process gases are often passed through the shaft-shaped Anordnun ^¬ gene in which the steel scrap by means of a return ^¬ retaining system - ^¬ like for example in the form of pivotable Fin - is maintained above the furnace vessel and is flowed through by the process gases of the furnace. The steel scrap is sozu- kept saying between the furnace vessel and exhaust system in a form that as much heat as the exhaust gas passes into the steel scrap or ^¬ in the scrap column. This approach as ^¬ improves the energy balance and thus lowers the Ener ^¬ energy requirement of the melting furnace.

The shaft is loaded in the prior art via a feed element, which is ausgebil ^¬ det in many cases as a chute. The chute is tilted over a pivot point to to let the steel scrap 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 thus given head of the scrap act on the Rückhal ^¬ tesystem high dynamic forces. High forces also act on the shaft wall. Due to the procedure of the prior art, high wear and deformation effects result. These reduce the operational reliability and the service ^¬ time of the melt metallurgical plant. They continue to increase the maintenance and repair costs considerably.

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

The object of the present invention is to provide opportunities by which the load on the rear can stop system reduced without having to take otherwise nen ^¬ nenswerte 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, trainees make the bottom plate of a Beschi ^¬ ckungseinrichtung of the aforementioned type characterized in that a portion of a respective local normal vector to the base plate defi ^¬ defined because of its course in a horizontal direction that is orthogonal to the tilting axis, in such a way over the Location on the bottom plate varies ^{¬ ¬} that when tilting of the loading element about the tilt axis of the metal scrap located in the feed element not abruptly but temporally offset falls out of the Beschi ^¬ ckungselement. Thus, the inventive solution is m a special shape of the bottom plate of the feed element, due to which the transition from static friction to sliding stages takes place and thus the fall of the scrap into the shaft of "all at once" to "continuous - piece by piece" is via ^¬.

Preferably, the apparent sidewall is pivotable about a horizontal pivot axis disposed in the vicinity of the end of the exposed sidewall remote from the bottom plate.

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

It is possible for the proportion of the respective local normal vector in the horizontal direction to vary seen 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 Hori zontalrichtung seen, but is constant in the direction of the tilt axis.

For example, it is possible for For the bottom plate such ^¬ make that before tilting the feed member about the tilt axis

 in a front edge area located near the apparent side wall, on which the apparent side wall slopes down,

- In a rear edge region which is located in the vicinity of one of the apparent side wall opposite the side wall, on the opposite side wall is to ^{abge ¬} schüssig and

 - Is substantially horizontal in a central region located between the front and the rear edge region.

In the latter embodiment, it is preferably provided that between the central region and the front edge A front transition region is arranged, that between the central region and the rear edge region, a rear transition region is arranged and that the transition regions are sloping down to the central region.

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 increases ^{vorzugswei ¬} se with increasing distance from the apparent 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 shows a melting metallurgical plant from the side,

 2 shows a section of the melt metallurgical plant of FIG. 1, FIG.

 3 shows the detail of FIG 2 in another operating state,

 4 shows a feed element in cross-section and

5 shows a bottom plate.

According to FIG. 1, a melting metallurgical plant has a melting furnace 1. The melting furnace 1 may be formed, for example, as an electric arc furnace. The melting furnace 1 is charged with scrap metal 2. In many cases - also in the illustration of FIG. 1 - a shaft 3 is arranged above the melting furnace 1. In this case, the metal scrap 2 is first poured into the shaft 3 and there preheated ^¬ by means of the heat generated during operation of the furnace 1 waste heat.

For feeding the melting furnace 1 (or previously the

Shaft 3) a charging device 4 is provided. The charging device 4 has a charging element 5 on. The feed element 5 is first of all melt metallurgical plant with the particular for scrap metal the melting furnace 1 2 is filled in a ^¬ Before ratungsbereich. 6 The feed element 5 is then transferred to a feed area 7 of the melt-metallurgical plant. The

Conversion of the loading element 5 takes place, for example, by moving on rails 8, which extend obliquely from bottom to top (inclined lift). FIG. 2 shows the charging region 7 of the melt-metallurgical plant with feed element 5 located therein.

In the loading area 7, the loading element 5 is tilted about a horizontally extending tilting axis 9. The course of the tilting axis 9 can be selected as needed, as long as the tilting axis 9 remains horizontal. As a rule, the tilting axis 9 is orthogonal to the direction of travel of the loading ^¬ elements 5. Due to the tilting of the feed element 5 about the tilt ^¬ axis 9 of the metal scrap 2 is tilted into the shaft 3, the loading element 5 thus emptied. FIG. 3 shows the charging region 7 of the melt-metallurgical plant with tilted charging element 5. After emptying the charging element 5, the charging element 5 is tilted back into its starting position and then transferred again into the storage area 6.

Alternatively, for example, a crane can be used which receives and transports the loading element 5 by means of cables. When tilting the loading element 5 is here inclined over a virtual horizontal tilting axis and the metal scrap 2 emptied into the shaft 3. The charging element 5 has - see in addition to FIG 4 - a bottom plate 10 and side walls 11. At least one of the side walls 11 is for emptying the loading element 5 apparently. This side wall 11 extends parallel to the tilting ^¬ axis 9.

The Öffenbarkeit the apparent side wall 11 can be achieved in belie ^¬ bige manner. In general, the apparent side wall 11 is pivotable about a horizontal pivot axis 12. The pivot axis 12 is arranged in this case in the vicinity of the end facing away from the bottom plate 10 of the apparent side wall 11. For a better understanding of the present invention, it is useful to define below first a Cartesian coordinate system ^¬. 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 run in the direction of the tilting axis 9. The x-axis should be orthogonal to the tilt axis 9. This ^axis is partially also referred to below as a horizontal ^axis . The following comments on the design of the base plate 10 relate to the untilted state of the charging element 5, that is, the state that is shown in Figures 1, 2 and 4 (and also in Figure 5). As can be seen particularly clearly from FIG. 4, FIG

Base plate 10 is not formed as a uniform, continuous horizontally extending bottom plate 10. A normal vector N on the bottom plate 10, ie a vector of length 1, which rises lo ^¬ kal orthogonal on the bottom plate 10, consequently does not show everywhere in the same direction. In particular vari ^¬ ated according to FIG 4, a fraction of the respective local normal vector N in the x-axis depending on the location on the bottom plate 10. This variation is chosen such that the tilt axis 9 of the located when tilting the feed member 5 in the feed element 5 Metal scrap 2 not abruptly, but temporally offset from the charging ^¬ 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 may be provided a recess which - based on the bottom plate 10 - is surrounded on all sides by increased Be ^¬ rich. Preferably, however, the proportion of the respective local normal vector N in the horizontal direction ^¬ x varies as seen in the direction of the horizontal direction x, in the direction of the tilt axis 9 is seen, however, constant. This embodiment is also taken in the present case. For this reason, the feed element 5 is shown in the figures only in side view or in section.

As shown in FIGS. 1 to 4, the bottom plate 10 has a front edge region 13, a rear edge region 14 and a middle region 15. The front edge portion 13 is located near the apparent side wall 11. The rear edge region 14 is located in the vicinity of that side wall 11 which lies opposite the apparent side wall 11. The middle region 15 lies between the front and the rear edge region 13, 14.

The front edge region 13 is on the apparent side wall 11 to slope. The rear edge region 14 is on the above-mentioned opposite side wall 11 to from ^¬ schüssig. The central region 15 extends substantially horizontally.

The edge regions 13, 14 have in the horizontal direction x respective longitudinal extensions 1, 1 '. Similarly, the By ^¬ telbereich 15 in the horizontal direction x a longitudinal extension 1 ". The longitudinal extents 1, 1 ', 1" are generally between 20% and 40% of a total extension L of the feeder element 5, this measured from the reveal side wall 11 to the opposite side wall 11th

Furthermore, according to the representation of FIGS. 1 to 4, between the central region 15 and the front ren edge region 13, a front transition region 16 is arranged. Furthermore, a rear transition region 17 is preferably arranged between the middle region 15 and the rear edge region 14. The two transitional areas 16, 17 are in this case down to the central area 15 down.

Alternatively to the above-described embodiment

(Keyword edge and middle regions 13, 14, 15), the Bo ^¬ denplatte 10 according to Figure 5, a plurality of waves or half-waves 18 - are shown in Figure 5 half-waves 18 - have. 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 half-waves 18 may be constant. However, according to the illustration of FIG. 5, the wavelength λ preferably increases with the distance a from the apparent side wall 11. The inventive design, in particular the bottom plate 10 of the loading element 5, results in different locations of the bottom plate 10, a different ratio of normal force to shear force when tilting the feed element 5. However, the static friction coefficient remains constant. The result is thus a time-shifted slipping of the metal scrap 2. This results in the introduction of the metal scrap 2 in the shaft 3 and thus the period in which dynamic forces acting on the Rückhal ^¬ system of the shaft 3, significantly extended.

The present invention has many advantages. Insbeson ^¬ particular to extend the service life and improves the reliability of the overall system. Also, the schmelzme ^¬ gical plant maintenance is not as vulnerable as a melt metallurgical installation of the prior art. Further ^¬ further design optimizations of ^{Rückhaltesys ¬} tems, the shaft 3, etc. are 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

claims 1. Feeding device for a melting furnace (1) of a metallurgical plant, - wherein the loading device has a feed element (5) which can be filled in a storage area (6) of the melt metallurgical plant with intended for the melting furnace (1) metal scrap (2), from there into a loading area (7) can be transferred there for emptying tiltable about a horizontal tilting axis (9) and in the emptied state again in the storage area (6) is movable,  - wherein the loading element (5) has a bottom plate (10) and side walls (11), - wherein at least one of the side walls (11) for emptying the loading element (5) is apparent,  - wherein the apparent side wall (11) is parallel to the tilting axis (9), - Wherein a proportion of a respective local normal vector (N), the bottom plate (10) defi ^¬ due to their course, in a horizontal direction (x), which is orthogonal to the tilting axis (9), so over the location on the bottom ^¬ plate (10) varies that when tilting the Beschickungsele ^¬ ment (5) about the tilt axis (9) of the feed element (5) located metal scrap (2) not abruptly, son ^¬ dern staggered from the feed element (5) ago ^¬ fails. 2. Feeding device according to claim 1, characterized in that the side wall of fenbare ^¬ (11) is pivotable about a horizontal pivot axis (12), the end of the reveal side wall (11) facing away in the vicinity of the bottom plate (10) is arranged. 3. Feeding device according to claim 1 or 2, characterized in that the tilting axis (9) runs orthogonal to a direction of travel of the loading element. 4. The feed arrangement of claim 1, 2 or 3, characterized in that the at ^¬ part of the respective local normal vector (N) in the horizontal direction (x) in the direction of the horizontal direction (x) varies seen looking in the direction of the tilt axis (9) however, it is constant. 5. Feeding device according to claim 4, that the bottom plate (10) around the tilting axis (9) before the tilting of the loading element (5)  in a front edge region (13), which is located in the vicinity of the apparent side wall (11), to which the apparent side wall (11) slopes downwards, - In a rear edge region (14) which is located in the vicinity of one of the apparent side wall (11) opposite side wall (11), on the opposite side ^¬ wall (11) is to slope and  - In a between the front and the rear edge region (13, 14) located central region (15) extends substantially horizontally. 6. Feeding device according to claim 5, There is no difference between the central area (15) and the front edge area (13) a front transition region (16) is arranged, that between the central region (15) and the rear edge region (14) a rear transition region (17) is arranged and that the transition regions (16, 17) to the central region (15) downhill. 7. Feeding device according to claim 4, characterized in that the Bo ^¬ denplatte a plurality of shafts or half-waves (18), which in the direction of the horizontal direction (x) seen before the tilting of the loading element (5) about the tilting axis (9) one behind the other. 8. Feeding device according to claim 7, That is, the wavelength (λ) of the waves or halfwaves (18) increases with increasing distance from the apparent sidewall (11).