EP0192019B1 - Apparatus for introducing and changing a pouring tube - Google Patents

Description

The present invention relates to a device for supplying and exchanging a pouring tube with a movable attached plate for a closable steel or metallurgical container lined with a bottom plate of refractory material provided with a pouring orifice, by another pouring tube for the manufacture of blooms and small slabs, in particular in continuous casting distributors.

Most of the closing devices known to date with which the flow distributors can be fitted do not allow long casting sequences to be carried out, because of the need to replace one or the other refractory after a relatively short time. sensitive.

French patent No 2065592 (SCHLOEMANN AKTIENGESELLSCHAFT) describes a device making it possible to place interchangeable pouring tubes in the extension of a pouring orifice of a metallurgical container.

The pouring tubes intended to lead the molten metal into a mold or an ingot mold, are wear parts highly stressed. They are so so that their service life limits the casting time.

Due to erosion in the vicinity of the flow as well as inside the pouring tubes it becomes necessary to replace, after a relatively short time, one or the other sensitive refractory. These exchanges of pouring tubes have not so far made it possible to carry out long casting sequences.

To allow the tube to be changed, in a continuous casting installation, British Patent No. 1,563,966 (CONCAST AG) proposes a metallurgical container provided with a closure device and a pouring tube, through which the molten metal flows to an intermediate container or to a mold having only a small section opening for introducing the pouring tube there.

A handling machine comprising guide means making it possible to move the tube along a substantially horizontal path and to rotate it from a substantially horizontal position to a vertical position so as to allow placement in a casting line without having to raise the intermediate distributor.

The pouring tube is put in place by fitting the mouth of the tube onto an insert constituted by an outer rim of the inner nozzle. This operation requires the complete interruption of the pouring jet. The connection thus obtained has the drawback of adversely affecting the tightness of the pouring channel and consequently the quality of the metal. To protect the molten metal from oxidation, it is essential to provide, in the vicinity of the pouring orifice, an inerting device, for example with argon.

Document GB-A-1322761 describes a mechanism for actuating and loading pouring tubes with movable attached plate for casting container by the bottom of molten metal. The movable inserts along guides can be joined to each other by a perfectly united common transverse rim, so as to form a perfectly flat surface.

The closing device comprises a hydraulic cylinder with pressurized fluid comprising a pressure relief valve for bringing a tube by translation from a loading position to a service position in the pouring axis and a position for releasing the loading station to receive a new drawer, by moving said tube parallel to itself in a direction perpendicular to the axis of pouring of the tube.

This closing device has the drawback that the guides do not allow an upward thrust force to be transmitted. It also does not allow the plunging end of the tube to be inserted into or removed from a narrow neck of the continuous casting mold without lifting the distributor because of the small space available in height.

By French patent No 1 478 778 is known a shutter in refractory material for metallurgical containers intended for continuous casting. It comprises a movable refractory plate capable of sliding, under the action of a jack, along an upper plate fixed in a position for closing the pouring orifice. Guides subjected to an upward thrust by levers on which act at a first end of the springs apply the movable plate, in sealed contact, against the upper plate. Such a device makes it easy to replace the movable refractory plate with a sliding closure but does not allow the pouring tube to be replaced without raising the distributor.

Many other mechanical devices have been developed to replace pouring tubes mounted on the outlet orifice of a casting enclosure. Among other things, the applicant himself has protected, by his French patent application No 2 424 085, a device intended for the replacement, under a distributor, of refractory material pouring tubes. The tubes are loaded transversely in the upright position on intermediate devices consisting for example of support carriages brought into the casting position by sliding along a substantially horizontal linear path perpendicular to the casting axis.

The pouring tubes are applied tightly against the distributor by a lever arm articulated on a common carriage. Each lever is provided at its free end with a roller guided by a rail which is pushed down by a spring bearing against the casting enclosure.

In these known devices, the juxtaposition of two consecutive tubes is impossible. By construction of the support carriage, there is inevitably between the plates of the tubes a vacuum which does not allow to change the tube without interrupting the casting. Similarly, to unload a tube from the intermediate device and to load a new calf tube, the plunging end of the tube of which has been introduced into the continuous casting mold, it is essential to lift the distributor to carry out the transverse loading maneuver.

The present invention aims to avoid having to interrupt the casting due to the raising of the intermediate distributor.

It is intended to allow easy replacement of pouring tubes independently on each line, so as to ensure uninterrupted casting for a long period.

It relates to a device for supplying and exchanging a pouring tube with a movable attached plate for a closable steel or metallurgical container provided with a bottom plate of refractory material provided with a pouring orifice in which the plates attached to pouring tubes and / or closing plates are slidably mounted on guides and can be joined to each other by a perfectly transverse common transverse rim, so as to form a perfectly flat surface, characterized in that the guides are capable of transmitting an upward pushing force and in that the replacement tube is brought by pivoting into the well of the ingot mold, so as to allow the exchange of the tube without lifting the distributor.

The reference plate and the attached movable plate intended to slide along a rectilinear trajectory along the reference plate advantageously form an inclined plane determined by the above-mentioned trajectory constituting the straight line of greatest slope.

In a particular embodiment, the hydraulic cylinders ensuring the linear movement of the movable plates attached to the tubes and / or of obturation, are arranged parallel to the path of the plates, behind the guide rails.

Other particularities and details of the invention will appear during the following detailed description referring to the attached drawings which illustrate an embodiment of the invention, given by way of nonlimiting example.

• la figure 1 montre en plan un dispositif de chargement d'un tube de coulée suivant l'invention;
• la figure 2 est une vue en élévation latérale du dispositif montré à la figure 1;
• la figure 3 est une vue de bout partiellement arrachée du dispositif montré aux figures 1 et 2;
• la figure 4 illustre la face postérieure du dispositif montré aux figures 1 et 2;
• la figure 5 est une vue en coupe verticale d'un dispositif adapté à une plaque de référence oblique, et
• la figure 6 illustre le chargement d'un tube de coulée dans un dispositif muni d'un vérin actionnant le retrait d'un bras pousseur.

In these drawings:

• Figure 1 shows in plan a device for loading a pouring tube according to the invention;
• Figure 2 is a side elevational view of the device shown in Figure 1;
• Figure 3 is a partially broken away end view of the device shown in Figures 1 and 2;
• Figure 4 illustrates the rear face of the device shown in Figures 1 and 2;
• FIG. 5 is a vertical section view of a device adapted to an oblique reference plate, and
• FIG. 6 illustrates the loading of a pouring tube into a device provided with a jack actuating the withdrawal of a pusher arm.

In these figures, the same reference notations designate identical or analogous elements.

FIGS. 1 to 4 show a supply and loading device designated as a whole by the reference notation 1 of a reserve pouring tube 2 attached to a movable plate 3, replacing a worn tube 2 ′, attached to a movable plate 3 ', in the service position, and consisting of a main chassis 4 intended to be mounted under a tundish 5 in the vicinity of a tapping hole 7.

The distributor can possibly already be fitted with a sliding closure. This closure does not constitute an obstacle to the direct fixing of the device 1 according to the invention. In the continuous casting installation shown in Figure 3, the shutter is simply a stopper 7 '.

As illustrated in FIGS. 1 and 2, the pouring tubes 2, 2 ′, each attached to a movable plate 3, 3 ′, slide along a lower plate of the sliding closure device.

In this case, the reference plate 6 along which the supply and loading device 1 slides, is a bottom plate of the distributor 5 or of the ladle. The movable plate 3, 3 'attached to the pouring tube 2, 2' then serves to seal between the lower nozzle 8 and the reference plate 6 applied against the seat brick 8 'and the sealing collar.

The reference plate 6 is possibly formed of several independent refractory elements.

Two guide rails 9, 9 ′ having an inclined stroke relative to the reference plate 6, so as to approach the pouring orifice 7 make it possible to obtain a progressive tightening of the movable plate 3 of a tube of casting 2 against the reference plate 6.

The upward thrust is obtained by springs 10, 10 ', mounted at a respectable distance from the pouring orifice 7. As shown in FIG. 2, the guide rails 9, 9' are mounted at the end of levers 12, 12 'each subjected to the end opposite to the action of the springs 10, 10' moving the latter away from the enclosure 11 of the container 5. The force exerted by the guide rails 9, 9 'on each of the movable plates associated with a pouring tube 2 moving along said rails 9, 9 ′ suspended, increases as they approach the pouring orifice, 7. This upward push applies in a manner watertight, the movable plates 3, 3 'of the worn pouring tube 2' and respectively of the reserve tube 2 against the sliding plane of the reference plate 6.

The slope of the guide rails 9, 9 'causes the pressure to increase when any one of the pouring tubes 2, 2' approaches the pouring orifice and decreases when it moves away from it, allowing a easy removal of the above-mentioned plate in the standby position 14 away from the tap hole 7.

The linear movement of the mobile plates 3, 3 'is ensured by a pusher arm 15 actuated by a pair of hydraulic cylinders 16, 16' arranged in parallel in order to provide the force necessary to * allow rapid loading of the pouring tubes, making the best use of the small space available in height.

The reserve pouring tube 2 pushes the pouring tube into service 2 '.

The device 1 according to the invention makes it possible to replace a pouring tube 2 ′ in a continuous casting installation, without perceptibly interrupting the pouring jet.

When, during a casting operation, it becomes apparent that the dip tube 2 'is worn or defective, it is ensured that a replacement tube 2 is placed on the guide path determined by the guide rails 9 , 9 '.

By translation along the guide path, the used tube 2 'is loosened and moved away from the pouring zone towards a standby position 14 and the reserve tube 2 is brought simultaneously under the pouring channel.

The linear displacement of the two pouring tubes 2, 2 ′ can also be carried out using a device of the threaded rod-nut type.

The assembly of the pouring tube consists of a flat connection which has the property of having an excellent seal and of being able to be easily inertized.

As illustrated in FIG. 3, the supply device is a handling device which makes it possible to supply the reserve tube 2, cast horizontally. The plunging end 17 is introduced into a well 18 of an ingot mold 19 by rotating the pouring tube around a substantially horizontal axis. When the tube is arranged vertically, it is made to slide transversely along the opening of the mold well thanks to the two jacks 16, 16 ′ shown in FIG. 4, so as to align the neck of the pouring tube on the pouring orifice. The rails 9, 9 'under the action of the levers 12, 12' subjected to the springs 10, 10 'press the movable plate 3 to the pouring tube 2 against the reference plate 6.

In a particular embodiment of a continuous casting installation for small slabs, the reference plate 6 is arranged obliquely, so that its slope follows the path of supply of the tubes from their standby position to that of continuous casting.

When dealing with a small section mold, for example for small slabs as illustrated in FIG. 5, it is difficult to introduce the plunging end 17 of the tube 2 into the mold 19 and to tilt the tube 2 without deteriorate the tube or the walls of the mold 19, especially when the distance between the reference plate 6 and the mold 19 is restricted. The narrowness of the mold 19 in fact prevents the tube 2 from being tilted too much.

An inclined arrangement of the reference plate 6 aims to facilitate the introduction of the plunging end 17 of the tube because it allows the tube to occupy a higher position than if the plate 6 was arranged horizontally.

This tube is therefore less inclined than if it had been introduced into a conventional supply and exchange device comprising a horizontal reference plate 6.

As the tube 2, 2 'is slid into the mold 17, it straightens and allows its added plate 3, 3' to be applied in a sealed manner on the reference plate 6. The reasoning also applies to the withdrawal of tube 2 which gradually tilts as it rises.

It is thus possible to change the pouring tube without raising the distributor.

An inclined arrangement of the reference plate 6 also makes it possible to reduce the distance between the bottom of the distributor and the mold, without encroaching on the diving height of the tube.

The particular position of the thrust cylinders 16, 16 'arranged laterally set back from the path of supply of the pouring tubes 2, 2', makes it possible to load and / or unload the tubes 2, 2 'by tilting them in a vertical plane passing through the path of supply of the tube 2, 2 ′ in the pouring position, whereas previously the loading and unloading operations had to be carried out in a transverse direction, more inconvenient when the distributor has several lines of parallel casting.

In the particular case of an inclined arrangement illustrated in Figure 5, we proceed to the establishment and replacement of a worn tube as follows.

Care is taken to set up, in the first place, a closure plate 3 "on the supply and loading device and to bring it in front of the pouring orifice 7 by sliding it along the rails of guides 9, 9 '. As the shutter plate is brought towards the pouring orifice 7 under the action of the pusher arm 15, the levers 12 and the springs 10 push the plate upwards and apply it tightly against the reference plate 6.

When the closure plate 3 "is in place, the hydraulic cylinders 16, 16 'are again stretched and the pusher arm is removed laterally by an auxiliary cylinder 20. The feeding and loading device 1 is thus accessible to a pouring tube which is introduced into the free space at the end of the guide rails 9, 9 ′ by tilting the pouring tube on itself. When the loading of the tube on the guide rails is carried out, the arm is deployed -pusher 15 and the added plate 3 of the tube 2 is driven into the standby position 14 against the closure plate using the pusher arm 15 under the action of the jacks 16, 16 '.

The casting operation is started as soon as the pouring tube is moved towards the pouring orifice. Under the thrust of the pusher arm 15, a rim of the attached plate 3 of the tube 2 is applied sealingly against the juxtaposed rim of the shutter plate 3 ". The added plate 3 forms with the shutter plate 3" a united surface sealingly applied against the reference plate 6. It is therefore sufficient to put the pouring tube in place by sliding under the thrust of the jacks 16, 16 '.

When one realizes, during the casting operation, that the pouring tube 2 which has become 2 'is worn or defective and that it is necessary to replace it, one stops momentarily casting using the closure plate 3 ", hitherto held in the standby position 14 'on the guide rails 9, 9'.

The closing plate 3 "is brought in on the push of a second pusher arm 15 'rigidly fixed to the rods of the double-acting hydraulic cylinders 16,16'. The used tube 2 'is moved towards the position 14 under the thrust of the 3 "blanking plate.

Thanks to the constructive shape of the rails 9, 9 ′, the used tube 2 ′ is loose and can be easily removed from the supply device and be replaced by a new tube since the pusher arm 15 is retractable.

Once introduced into the supply and loading device 1, the new pouring tube 2 can be quickly put in place under the pouring channel.

The total duration of the operation for replacing a worn tube 2 'with a new tube is therefore very short. It does not exceed ten seconds for experienced operators. In addition, it can be carried out without being hindered by the other pouring lines connected to the same distributor, since it is carried out in the longitudinal direction, in the extension of the trajectory determined by the rails 9, 9 '.

Claims (4)

1. Means for the provision and replacement (1) of a pouring tube (2) with a separate movable plate for a steelmaking or metallurgical vessel (5) which can be obstructed by means of a baseplate (6) of refractory material provided with a pouring orifice (7) in which the movable plates (3, 3') associated with the pouring tubes and/or obstructing plates are slidably mounted on guides (9,9') and may be joined together into perfect union by means of a common transverse edge so as to form a perfectly plane surface, characterised in that the guides (9, 9') can transmit a thrust force upwards and in that the replacement tube (2) is directed by pivoting about a substantially horizontal axis into the well (18) of the ingot mould (19) so that the tube can be replaced without raising the distributor (5).

2. Means according to claim 1, characterised in that the reference plate (6) and the separate movable plate (3) which is designed to slide along the reference plate (6) in a straight trajectory form an inclined plane determined by the abovemen- tioned trajectory forming the straight line of greater slope.

3. Means according to any one of the foregoing claims, characterised in that the hydraulic jacks (16,16') responsible for linear displacement of the movable plates (3, 3') applied to the tubes (2, 2') and/or obstruction plates (3") are arranged parallel to the trajectory of the plates behind guide rails 9,9'.

4. Means according to any one of the foregoing claims, characterised in that a pusher arm (15) is retractable.

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