LU88807A1 - Charge preheater - Google Patents

Description

Charge preheater

The present invention relates to a charge preheater for preheating charge for a metallurgical melting unit, such as an electric arc furnace.

Such a batch preheater is described, for example, in US-A-5,153,894 (EP-A-0 385 434). It comprises a loading shaft which is installed above the crucible of an arc furnace and the interior of which is connected to the interior of the arc furnace by a connecting opening. This loading shaft has a supporting structure which is independent of the crucible and to which a vessel lid for the crucible is also fastened, so that the crucible on the one hand and the vessel lid with the loading shaft on the other hand can be moved relative to one another. In the lower area of the loading shaft, opposite, pivotally mounted retaining fingers are arranged, which are actuated by actuators from a closed position, in which they close the connection opening with the interior of the electric arc furnace and hold back the cargo in the loading shaft, down to a release position are pivotable. In this release position, they open the connection opening to the interior of the electric arc furnace, so that the charge material preheated in the loading shaft by exhaust gases from the melting process can be emptied into the crucible below. The retaining fingers are arranged on two opposite horizontal bearing rollers, which are rotatably mounted in the loading shaft. Forces that act on the restraining fingers are introduced into the loading shaft via the horizontal bearing rollers and dissipated via its supporting structure. Shock loads that act on the retaining fingers when the cargo is being introduced into the loading chute are dampened by shock absorbers installed between the bearing rollers and the charging chute.

In US-A-4547099 (WO-A-84/00947) it is proposed to store the restraining fingers individually in the support structure of the loading shaft and to assign elastic supports on the support structure of the loading shaft to them at the entry points into the loading shaft. These elastic supports are intended to absorb shock loads that act on the retaining fingers when the cargo is introduced into the loading shaft.

WO 95/04910 proposes a toggle lever mechanism which is intended to allow shock forces to be introduced directly into the supporting structure of the loading shaft using large shock absorbers.

The impact loads and forces which act on the retaining fingers when the goods to be loaded into the loading shaft are thus only absorbed by the supporting structure of the loading shaft in the case of the aforementioned goods preheaters. This means that this support structure must be designed accordingly, which of course makes the shaft construction very expensive. It also remains to be seen that even the damped impact loads, the supporting structure with the loading shaft and the vessel lid still put a relatively high load, which of course has a negative effect on the service life of the system.

The present invention is therefore based on the object of largely relieving the load-bearing structure of the loading chute from the load caused by shock loads.

This object is achieved by a charge preheater according to claim 1. The charging material preheater according to the invention differs from the known charging material preheaters essentially by a frame in which a plurality of retaining fingers are mounted, this frame being mounted in the supporting structure of the loading chute in such a way that it has vertical freedom of movement and, when the retaining fingers are in the closed position, they can be transferred the forces acting on the fingers are supported on a support that is statically independent of the support structure of the loading chute. Shock forces when introducing the cargo into the

Feed chute essentially act vertically on the retaining fingers, are thus introduced via the frame that is vertically movable in the supporting structure of the charging chute into the support that is statically independent of the supporting structure of the charging chute and no longer into the supporting structure of the charging chute. In addition, the assembly of the retaining fingers in a frame facilitates the dismantling of the retaining fingers, so that they can be replaced quickly and easily, thereby avoiding a long standstill of the device.

Another object of the present invention is to increase the useful volume of the loading chute. This problem is solved in a charge preheater with a loading chute for receiving the charge, which has a loading opening in its upper area and a junction in the melting unit at its lower end, and retaining fingers in the lower area of the loading chute that pass through at least one actuator from a closed position, in which they close the confluence with the melting unit for charge goods and thus retain this charge in the loading shaft, can be swiveled downwards into a release position in which the loading material can empty out of the loading shaft into the melting unit, these retaining fingers can be raised relative to the loading shaft.

With such a device, the retaining fingers can be arranged in their closed position much deeper in the loading shaft than in the known charge preheaters. In fact, in the known charge preheaters, the retention fingers are arranged relatively high in the loading shaft, so that the tips of the retention fingers after the furnace has been charged, if the charge column still extends into the feed shaft, are above the charge column and the Retaining fingers are pivotable from the release position into the closed position. In the present invention, the retention fingers can be arranged at the lower end of the loading shaft, since they can be raised relative to the loading shaft 14 after being pivoted into the release position. The tips of the retaining fingers, which are still within the charge goods column after being pivoted into the release position, are thereby lifted up out of the charge goods, so that the retention fingers are again pivoted into their closed position. The retaining fingers are then lowered again, returning to their basic position at the bottom of the loading shaft. In the present invention, due to the deep arrangement of the retaining fingers in their basic position, the usable volume of the loading chute increases, so that it can be dimensioned smaller for the same usable volume than a conventional charge preheater, or has a larger capacity with the same dimensions than a conventional batch preheater.

In a possible embodiment of the invention, the individual retaining fingers are pivotally mounted in the frame, the individual retaining fingers each having their own pivot drive for pivoting from the closed position into the release position and back. The rotary actuator can e.g. comprise a hydraulic cylinder which is arranged on the frame and which can pivot the retaining finger over a lever system between the two positions and lock it in the respective end position.

In an alternative embodiment, the frame is pivotally mounted in the support structure of the loading shaft in such a way that in a first position the retaining fingers are in the closed position and in a second position the retaining fingers are in the release position. This is achieved, for example, in that the frame is rotatably mounted on the supporting structure in its upper region by means of trunnions, and extends essentially vertically downwards in the first position. The retaining fingers are then arranged in the lower region of the frame, and they extend laterally through an opening in the wall of the loading shaft with a slight inclination down into the loading shaft, so that they close the mouth of the loading shaft. If the lower part of the frame is deflected laterally from its first position, the retaining fingers release the mouth of the loading chute and the cargo can slide into the electric arc furnace. It should be noted that in this embodiment the retaining fingers do not have to be driven individually, so that no individual drives for the retaining fingers have to be provided. Of course, this results in a significant simplification of the entire device, since only one drive is required for the restraint device. In addition, the installation of the restraining fingers in the frame is simplified, so that they can be easily replaced if necessary, for example in the case of heavy wear.

As described above, the device preferably has means for lifting the frame relative to the loading chute. Here, the frame is preferably mounted in a guide in the support structure of the loading shaft. The lifting devices are, for example, a hydraulic cylinder that is mounted on the support structure of the loading chute and that e.g. engages the frame by means of a suitable lever arrangement. In a preferred embodiment, these are the hydraulic cylinders which are provided for lifting the furnace cover and the loading shaft. In this case, a special unlocking device is provided, which allows switching between the operating modes of the drive - lifting the loading shaft and the cover or simply lifting the frame.

It should be noted that the frame is supported on the supporting structure in the raised position, but in this position the retaining fingers are in their release position, so that no vertical impact forces are dissipated via the retaining fingers and the frame on the supporting structure. In fact, when the loading chute is filled with cargo, the retaining fingers are in their lowered closed position, in which the frame is supported on its statically independent support.

In a preferred embodiment, the charge preheater comprises means for deflecting a lifting movement of the frame into a pivoting movement of the frame, such that the lifting of the frame relative to the loading shaft simultaneously causes a pivoting movement of the frame from the first position to the second position. These means include e.g. on

Cam gear with a cam member fixedly mounted on the support structure and an engagement member mounted in the lower region of the frame, which is guided in the cam member in a certain path. The track is preferably designed in such a way that after unlocking the closed position the frame first experiences a rapid lateral deflection and then swivels back into its vertical position when approaching the uppermost point of the track. The retaining fingers therefore return to their closed position before the frame is lowered again, so that the frame is lowered into its basic position at the lower end of the loading shaft without the tips of the retaining fingers again immersing themselves in the charge column.

In a first, space-saving variant, the support for the frame can be formed by the melting unit. In this case, the frame is supported by a passage in the furnace lid on the wall of the furnace vessel and thus dissipates the vertical forces that occur when filling the loading shaft via the wall of the furnace into the furnace cradle. Alternatively, the support for the frame is formed by a separate support element. This frame is then arranged to the side of the furnace vessel and transfers the forces directly into the furnace cradle or, if applicable, directly into the furnace foundation.

Regardless of the type of support, this preferably comprises shock-absorbing means, so that impacts which occur are dampened before being discharged into the furnace cradle. In another advantageous embodiment, the frame comprises shock-absorbing means by means of which the retaining fingers are held in their position relative to the frame. When the cargo hits the retaining fingers, the forces that occur are dampened before they are introduced into the frame, so that the support is subjected to less stress.

An embodiment of the invention will now be described below with reference to the accompanying figures. There are:

1 shows a cross section through an arc furnace with a first configuration of a charge preheater according to the invention, the retaining fingers being shown in their closed position;

2 shows a cross section through the arc furnace of FIG. 1, the retaining fingers being shown in their release position;

3: the sequence of movements of the retaining fingers of the device according to FIG. 1 when pivoting from the closed position into the release position and back again into the closed position;

4 shows a cross section through an electric arc furnace with a second embodiment of a charge preheater according to the invention, the retaining fingers being shown in their closed position;

5 shows a cross section through the electric arc furnace of FIG. 4, the retaining fingers being shown in their release position;

6: the sequence of movements of the retaining fingers of the device according to FIG. 4 when pivoting from the closed position into the release position and back again into the closed position;

7: an advantageous embodiment of the support for the frame;

Fig.8: a front view (shaft side) of the frame with attached retaining fingers;

9 shows a cross section through a charge preheater with swivel frame with a particularly advantageous drive device for swiveling the frame into its release position;

Fig. 10: the operation of the drive device for pivoting the frame in Fig. 9

Fig. 11: an enlargement of Fig. 10.a.

In Fig. 1, a cross section through an arc furnace 2 with charging material preheater 4 is shown schematically. The arc furnace 2 essentially comprises a furnace vessel 6, which is lined with a heat-resistant cladding 8 in its lower region, a cover 10 which closes the vessel 6 at the upper end, and at least one electrode 12, the lower end of which can be inserted into the vessel 6 through a corresponding opening in the lid 10. The furnace vessel 6 is generally supported in one

Furnace frame 11 (only partially shown), so that the arc furnace 2 can be tilted when tapping the molten metal over a cradle or by means of a hydraulic cylinder.

The charge material preheater 4 comprises a loading shaft 14 which is arranged above the furnace vessel 6 in such a way that the loading shaft 14 and the furnace vessel 6 can be moved relative to one another. For this purpose, the feed chute 14 is carried by an independent support structure (not shown) which is statically independent of the furnace vessel 6 and to which the lid 10 of the furnace vessel 6 is preferably also attached. It should be noted that the loading chute 14 shown is somewhat widened in its upper region in order to increase the volume.

The feed chute 14 forms an opening in the cover 10 so that it is connected to the furnace vessel 6. In the area of this mouth, the retaining device 16 for the charge is arranged. This comprises a plurality of spaced-apart skirt holding fingers 20 which, in their closed position, extend through a lateral opening 22 into the loading chute 14. The retaining fingers 20 are inserted into the feed chute 14 in such a way that they extend in the direction of the center of the furnace, whereby they incline slightly downwards in this direction. Opposite the retaining fingers 20, substantially shorter fingers 24 are arranged, which interact with the retaining fingers 20 in order to retain cargo in the loading chute 14. Due to the small length of the auxiliary fingers 24, the moments which are transmitted to the supporting structure when the loading shaft 14 is filled are very small, so that the auxiliary fingers 24 are conventionally arranged on the loading shaft 14 by means of a bearing journal 26 and by means of a pivot drive from a closed position (FIG. 1) can be swiveled into a release position (FIG. 2). It should be noted that the different lengths of the retaining fingers 20 and the auxiliary fingers 24 cause the charge material to be guided towards the center of the furnace when the retaining fingers 20 are released.

The retaining fingers 20 are mounted according to the invention in the lower region of a frame 28 which is arranged laterally on the loading shaft 14 within a housing 29 such that it has freedom of vertical movement. For this purpose, the frame 28 is preferably mounted in its upper region with lateral bearing journals 30 in a backdrop which is attached to the supporting structure of the loading shaft 14. In its closed position shown in FIG. 1, the frame 28 is supported downward on a support 32 which is statically independent of the supporting structure of the loading shaft 14 and which rests on the furnace cradle or the foundation of the furnace 2. The frame 28 is thus decoupled from the loading chute 14 and its supporting structure in such a way that vertical impacts from falling cargo do not enter the supporting structure, but rather via the support 32 directly into the foundation.

In order to dampen the shocks that occur before being introduced into the foundation, the support 32 preferably has a fixed support element 34 and a rocker 36, which can be tilted thereon, on the front arm of which the frame 28 rests and the rear arm with a damping element 38, e.g. a spring, is connected to a cantilever 40 of the support element 34 in such a way that the rocker 36 is horizontal in the west. In addition, the frame 28 includes damping elements 42, by means of which the retaining fingers 20 are held resiliently in their relative position with respect to the frame 28. Due to this resilient mounting of both the retaining fingers 20 in the frame 28 and the frame 28 on the support 32, occurring impacts are substantially damped, so that the support 32 is exposed to less great loads and consequently has a longer service life.

In the embodiment of a charge preheater 4 shown in FIG. 1, the retaining fingers 20 can only make a slight rotation with respect to the frame 28 in order to dampen impacts. In order to pivot the retaining fingers 20 out of the mouth of the loading chute 14, the frame 28 is therefore pivotally mounted in the backdrop in this embodiment in such a way that it is in its lower region, in which the retaining fingers 20 are mounted. can be deflected sideways. As a result, the retaining fingers 20 are inclined downward and withdrawn from the mouth. 2, the frame 28 and the retaining fingers 20 are shown in their release position. It should be noted that the auxiliary fingers 24 are pivoted into their release position at the same time as the retaining fingers 20, so that the mouth of the loading shaft 14 is released and the cargo can slide into the furnace vessel 6, initially starting from those still in the loading shaft 14 protruding longer retaining finger 20 is directed towards the center of the furnace.

The frame is then raised relative to the loading chute 14 until the tips of the retaining fingers 20 are above the surface of the charge. The lifting device can e.g. comprise a hydraulic cylinder which is mounted on the support structure of the loading shaft 14 and which engages the frame 28.

The complete sequence of movements of the frame 28 and the retaining fingers 20 is shown in FIG. 3. First, the frame 28 is locked in its closed position, in which it extends essentially vertically, so that the retaining fingers 20 protrude into the loading chute 14 and close the mouth of the charging chute 14 (FIG. 3.a). After unlocking, the lower end of the frame 28 is laterally deflected by the weight of the charging material resting on the retaining fingers 20 (FIG. 3.b), as a result of which the retaining fingers 20 are tilted downward and withdraw from the loading shaft 14. The frame 28 is then brought into its raised position (FIG. 3.c) in which the tips of the retaining fingers 20 are located above the surface of the charge. The frame 28 is now pivoted back into its vertical position (FIG. 3.d) and, after lowering into its lower position (FIG. 3.e), is locked in the closed position (FIG. 3.f).

It should be noted that the frame 28 is no longer supported on the support 32 in the deflected release position, but is supported on the supporting structure via the lifting device. However, this does not lead to impermissible

Loads on the supporting structure, since the retracted retaining fingers 20 cannot transmit any significant moments to the supporting structure.

FIG. 3 also shows an advantageous suspension of the retaining fingers 20 in the frame 28, which enables damaged retaining fingers 20 to be easily replaced. The retaining fingers 20 are rotatably supported at their rear end projecting beyond the frame 28 on an extension arm 44 of the frame 28, so that the front end can be pivoted in the vertical direction. In a central region, which lies within the frame 20, the skirt holding fingers 20 then have bearing pins 46 on both sides, with which they are suspended from a spring element 42 mounted in the frame 28. Due to this flexible suspension, impacts that act on the retaining fingers 20 are only transmitted to the frame in a damped form.

A further embodiment of a charge preheater according to the invention will now be described with reference to FIGS. 4 and 5. In this embodiment, each of the retaining fingers 20 has its own swivel drive 50, by means of which it can be swiveled from its closed position into its release position. For this purpose, the retaining fingers 20 are not mounted directly at their rear end on a fixed arm 44 of the frame 28, but via a toggle lever mechanism 52, which is actuated by means of a hydraulic cylinder 54 attached to the frame 28. By actuating the toggle mechanism 52, the rear end of the retaining fingers 20 is deflected upward, the retaining fingers 20 pivoting about the bearing pins 46. This allows the tips of the retaining fingers 20 to be lowered so that the mouth of the loading chute 14 is cleared (see FIG. 5). It is self-evident that the frame in this device does not have to be pivotable in order to pivot the retaining fingers 20 into their release position.

The frame 28 can then be raised similarly to the device according to FIGS. 1 to 3 in order to bring the front ends of the retaining fingers 20 above the surface of the charge. The complete sequence of movements of the frame 28 and the retaining fingers 20 is shown in FIG. 6. First, the retaining fingers 20 are in their closed position, in which their front ends protrude into the feed chute 14 and close the mouth of the feed chute 14 (FIG. 6.a). The locking takes place here by the toggle lever mechanism 52, the two struts of which lie in a straight line, so that a rigid connection between the arm 44 and the rear end of the retaining fingers 20 is created. By actuating the hydraulic cylinder 54, the retaining finger 20 is unlocked and pivoted into its release position. (Fig. 6.b). The frame 28 is then brought into its raised position (FIG. 6.c) in which the tips of the retaining fingers 20 are located above the surface of the goods to be charged. By actuating the hydraulic cylinder 54 again, the toggle mechanism 52 is pushed through again, so that the retaining finger 20 swings back into its closed position (FIG. 6.d) and is locked in this position (FIG. 6.e). The frame is then lowered and brought into its lower basic position so that the feed chute 14 can be refilled (Fig. 6.f).

7 shows a device similar to FIG. 1. In contrast to FIG. 1, the frame 28 is supported in this configuration in its closed position at the lower end not by a separate support element, but by the wall of the furnace on the foundation of the furnace. This means that the wall of the furnace 2 forms the support 32 and introduces the impact forces that occur into the foundation. Since the furnace cover 10 generally covers the wall of the furnace 2, e.g. a feedthrough is formed in the cover, in which a force transmitter 56 is arranged, which transmits the occurring forces from the frame 28 into the wall. The force transmitter 56 is preferably designed as a damping element which transmits the impact forces to the furnace vessel 6 only in a damped form.

FIG. 8 shows a front view (loading shaft side) of the frame 28. For a better illustration of the suspension of the restraining fingers 20 there is additionally a lateral one for each of the two types of suspension

Section shown. In the upper area one can see the bearing journals 30 attached on both sides, by means of which the frame 28 is mounted displaceably and pivotably in the backdrop on the supporting structure of the loading shaft 14. At its lower end, the frame 28 has comb-like, downwardly extending webs 58 which are separated from one another by indentations 60. In the upper area of the indentations 60, damping elements 42 are now mounted on both sides of the webs 58, into which retaining fingers 20 are hung in the manner described above. Above the retaining fingers 20, each indentation 58 on the furnace side is preferably covered with a cover plate 61 in order to protect the suspension device behind it from soiling. Through this configuration of the frame 28, the webs 58 which extend downward between the retaining fingers 20 and which are advantageously connected to one another at their lower end to reinforce the frame 28, form a support surface 62 which, in the basic position of the frame 28, rests on the support 32 rests.

9 shows a cross section through a charge preheater with a pivoting frame with a particularly advantageous drive device for pivoting the frame into its release position. The loading shaft 14 is suspended together with the furnace cover 10 in a support structure 64 which is statically independent of the furnace 2 and which can be moved with respect to the furnace 2 by means of a carriage 66 on rails 68. For this purpose, the loading chute 14 and the lid 10 are first raised by means of a hydraulic cylinder 70, which is mounted on the carriage 66 and which engages laterally on the supporting structure 64 via a transverse linkage 72 in order to subsequently be moved away laterally, so that they release the upper opening of the furnace vessel 6. The two transverse rods 72 are arranged on both sides of the loading shaft 14 in such a way that the ends facing the retaining device 16 each end laterally next to the frame 28.

In order to enable an advantageous drive device for lifting and pivoting the frame 28, each transverse linkage 72 comprises two parallel cross struts, which on the side of the retaining device 16 facing away from the retaining device 16

Feeding shaft 14 are rotatably mounted on the supporting structure 64. At the end of the two cross struts facing the retaining device 16, a guide element 74 is rotatably mounted such that it can be laterally displaced vertically from the frame 28. If the charging chute 14 with the cover 10 is to be removed from the arc furnace 2, a locking block 76 is inserted between the guide element 74 and the upper edge of the housing 29 fixedly mounted on the support structure 64 (see FIGS. 10 a and 11) ), which transmits the movement of the guide element 74 to the supporting structure 64. When the hydraulic cylinder 70 is actuated, each transverse linkage 72 is consequently raised uniformly on both sides, the upward movement of the cylinder piston being transmitted to the supporting structure 64. In this case, the frame 28 remains locked in its closed position and is raised together with the support structure 64 of the loading shaft 14.

The further structure of the restraint device 16 and the mode of operation of the drive device for lifting and pivoting the frame 28 can be seen in FIGS. 10 and 11. The frame 28 is rotatably mounted laterally in bearing bushings 78 with its two bearing journals 30. These bearing bushes 78 are in turn on the support structure 64 e.g. in a slide guide, vertically slidably arranged. In the closed position of the frame 28 (FIGS. 10 a and 11), the guide element 74 is arranged on each side at a distance below the bearing bush 78. In this position, the frame 28 is secured against pivoting by a locking mechanism 79 (FIG. 9). This comprises the frame 28 on each side of a locking cam 80, which is rotatably arranged behind the frame 28 (seen in the direction of deflection) in the housing 29 on a horizontal pivot 81 and which in its locking position against a laterally mounted on the frame 28 te guide roller 82 presses and thus prevents deflection of the frame 28. The locking cam 80 is secured against rotation by a locking linkage 84 which is composed of two struts which are rotatably connected to one another by means of a pivot pin 86, one of which is rotatably mounted on a lever arm above the pivot pin 81 on the locking cam 80 and the others in the rear area of the housing 29. In the locking position of the locking cam 80, the two struts in the swivel joint 86 are aligned on a line and form a rigid connection between the locking cam 80 and the housing 29.

In order to prevent the two struts of the locking linkage 84 from rotating relative to one another in the closed position, the pivot pin 86 advantageously has a laterally projecting end which is secured in a corresponding indentation 88 of a locking lever 90 against vertical displacement downward, a displacement towards is prevented at the top by a spring-loaded lever 89, which is mounted on the locking lever 90 and presses against a lateral cam 102 on the locking rod 84. The locking lever 90 is advantageously designed as a rocker arm which is mounted on the housing 29 on a swivel 92 so that it can be tilted vertically. At its end opposite the indentation, it has an elongated hole 94 into which a guide pin 96 of the guide element 74 engages. This guide pin 96 consequently prevents the locking lever 90 from tilting, since the guide element 74 cannot be moved relative to the support structure 64 due to the locking block 76 in the closed position of the frame 28.

If the frame 28 is to be pivoted into its release position, the locking block 76 is first removed from its position between the guide element 74 and the upper edge of the housing 29 (FIG. 10.b). This can be done by a hydraulic cylinder 98 which laterally shifts the locking block 76 out of its position. At the same time, the support structure 64 is supported by a further locking block 100 upwards against the rails 68, so that the support structure 64 is secured against lifting. When the hydraulic cylinder 70 is actuated, only the guide element 74 now executes an upward movement without the support structure 64 with the loading shaft 14 being raised. Due to the upward movement of the guide element 74, the guide pin 96 tilts the locking lever 90 and the pivot pin 86 is released. At the same time, the spring-loaded lever 89 exerts a force on the cam 102 arranged laterally on the locking linkage 84, so that the swivel joint 86 is deflected downward and the locking of the locking cam 80 is thereby released.

The frame 28 then experiences a lateral deflection due to the torque that the charging good exerts on the retaining fingers 20 and the spring force of a spring element 104 mounted on the support structure 64, the guide roller 82 tilting the locking cam 80. The guide roller 82 can thereby swing out to the rear and engage behind a cam member 106 which causes the frame 28 to deflect when it is raised. The locking cam 80 is then moved back into its locking position by a spring element 108 mounted on the housing, the locking rod 84 again taking up its locking position.

If the guide element 74 is now raised further by the hydraulic cylinder 70, the guide element 74 presses against the displaceable bearing bush 78 from below and the frame 28 is raised (FIG. 10.c). The guide roller 82 is guided along the cam member 106, so that the frame 28 is deflected further at its lower end and assumes its release position. When the frame 28 has reached its highest position, the guide roller 82 is released by the cam member 106 and the frame 28 is moved in the direction of the feed chute 14 by a guide roller 110 which is attached in the upper region of the housing 29 behind the frame 28. that the guide roller 82 engages on the front of the cam member 106.

The guide element 74 can then be lowered again by means of hydraulic cylinders 70, the bearing bushes 78 and the frame 28 also being moved down into their basic position. The cam member 106 and the locking cam 80 cause a simultaneous pivoting back of the frame 28 into its vertical position, so that the guide roller 82 again engages behind the locking cam 80. It should be noted that with the lowering of the guide element 74, the pin 96 is also moved downward, whereby it slides along in the elongated hole 94 of the locking lever 90 and rotates the locking lever 90 back into its locking position. The entire restraint device 16 is in turn locked and, after the locking block 76 has been inserted between the guide element 74 and the housing 29, the entire support structure 64 can be raised again by the hydraulic cylinder 70.

Claims (13)

1.Charging material preheater (4) for preheating charging material for a metallurgical melting unit (2), comprising a loading chute (14) for receiving the charging material, which has a loading opening in its upper region and an opening at the lower end into the melting unit ( 2) trains; a support structure (64) for supporting the feed chute (14) above the melting unit (2), so that the feed chute (14) and melting unit (2) can be moved relative to one another; Retaining fingers (20) in the lower area of the loading shaft (14), which are at least partially closed by at least one actuator from a closed position, in which they at least partially close the junction in the melting unit (2) for the cargo, and hold back cargo in the loading shaft (14) , can be moved into a release position in which the charge can be emptied from the loading shaft (14) into the melting unit (2), characterized by a frame (28) in which a plurality of retaining fingers (20) are mounted, this frame (28) is mounted in the support structure (64) of the loading shaft (14) such that it has vertical freedom of movement; and a support (32) which is statically independent of the support structure (64) of the loading shaft (14) and onto which the frame (28) which is vertically movable in the support structure (64) of the loading shaft (14) can be transferred when the retaining fingers (20) are in the closed position which supports forces acting on the fingers. 2. Chargiergutvorwärmer according to claim 1, characterized in that the individual retaining fingers (20) are pivotally mounted in the frame (28), the individual retaining fingers (20) each having its own pivot drive (54, 52) for pivoting from the closed position in have the release position and back. 3. Chargiergutvorwärmer according to claim 1, characterized in that the frame (28) is pivotally mounted in the supporting structure (64) of the loading shaft (14), such that in a first position the retaining fingers (20) in the closed position and in in a second position, the retaining fingers (20) are in the release position. 4. Chargiergutvorwärmer according to any one of claims 1 to 3, characterized by means (70, 72) for lifting the frame (28) relative to the feed chute (14). 5. Chargiergutvorwärmer according to claim 3 and 4, characterized by means (82, 106) for deflecting a lifting movement of the frame (28) in a pivoting movement of the frame (28), such that the lifting of the frame (28) relative to the loading chute (14) at the same time causes the frame (28) to pivot from the first position to the second position. 6. Chargiergutvorwärmer according to claim 4 or 5, characterized in that the means for lifting the frame (28) comprise a hydraulic cylinder. 7. Chargiergutvorwärmer according to any one of claims 3 to 6, wherein the device, a drive means (70) for lifting the support structure (64) of the loading shaft (14) relative to the melting unit (2), ge-characterized by a switching means (76, 98, 100) for switching the driving force of the drive means (70) between the supporting structure (64) and the frame (28), so that in a first position of the switching means (76, 98, 100) the supporting structure (64) with respect to the melting unit (2) is raised, and in a second position of the switching means (76, 98, 100) the frame (28) is raised with respect to the supporting structure (64). 8. Chargiergutvorwärmer according to any one of claims 3 to 7, characterized by a locking device (79) for locking the frame (28) in its closed position, wherein the locking device (79) by lifting the frame (28) with respect to the supporting structure (64) can be unlocked . 9. Chargiergutvorwärmer according to any one of claims 1 to 8, characterized by a link guide for the frame (28) in the supporting structure (64) of the loading shaft (14). 10. Chargiergutvorwärmer according to one of claims 1 to 9, characterized in that the support (32) for the frame (28) is formed by the melting unit (2). 11. Charge material preheater according to one of claims 1 to 9, characterized in that the support (32) for the frame (28) is formed by a separate support element (34, 36). 12. Charge material preheater according to one of claims 1 to 11, characterized in that the support (32) comprises shock absorbing means (38, 56). 13. Charge material preheater according to one of claims 1 to 11, characterized in that the frame (28) comprises shock absorbing means (42).