WO2004052574A1 - Impact pad for tundishes - Google Patents

Abstract

The invention relates to an impact pad for protecting the impact surface against which a pouring stream strikes in a metallurgical vessel, particularly in a tundish for strand casting, with delimiting walls, which surround the impact area and which, together with the impact surface, form a tub. The impact pad (4, 104, 204, 304, 404) has a covering (4d, 104d, 204d, 304d, 404d, 6, 7, 8) that closes the tub at the top. Said covering can be partially destroyed by the pouring stream (3, 503) arriving inside the impact pad (4, 104, 204, 304, 404).

Description

Insert body for intermediate container

The present invention relates to an insert body for protecting the impact surface of a cast steel in a metallurgical vessel, in particular an intermediate container for continuous casting, with the boundary walls surrounding the impact area, which together with the impact surface form a trough.

A generic insert body is known from DE 2643009. This insert body has an impact area, which is formed by a grate, to protect the impact surface of an intermediate container from an impacting cast steel. However, the boundaries forming the grate only insufficiently prevent the casting steel from splashing.

Various insert bodies of the generic type are known from US Pat. No. 5,169,591, each of which has an impact area which is surrounded by boundary walls. For example, it is proposed to design the boundary walls obliquely outwards or concave so that the impact Casting steel does not spray out of the insert body in an uncontrolled manner. The boundary walls should therefore form a circumferential roof, which forms an inlet opening for the pouring cast steel and should throw back the cast steel which sprays upwards. In a further exemplary embodiment of an insert body disclosed by US Pat. No. 5,169,591, the impact area is oriented obliquely to the base of the intermediate container, as a result of which the cast steel striking it is to be deflected to the side. For this purpose, this insert body has no boundary wall on one side, towards which the pouring jet is deflected. It has been found that the insert bodies disclosed in US Pat. No. 5,169,591 do not reliably prevent the casting steel from spraying out in an uncontrolled manner. This is due to the fact that the upper inlet opening for the casting steel formed by the boundary walls must be kept larger than the diameter of the pouring jet, so that it can always get safely into the insert body without hitting the boundary walls, which means that the casting steel even more from the intermediate housing would inject.

A baffle plate for an intermediate vessel made of refractory material is also known from European patent EP 0 790 873, the baffle plate having a baffle surface which is surrounded by side walls which in turn form an upper surface which forms the inlet opening for the pouring cast steel. It is essential in this baffle plate that a right angle is formed between the side walls and the baffle surface and between the side walls and the upper surface and / or the inlet opening has a rectangular shape. This baffle also has the problem that the inlet opening is larger than the diameter of the incoming pouring jet must be chosen so that it is reliably prevented that the pouring jet does not miss the inlet opening.

The object of the present invention is therefore to develop a generic insert body in such a way that the inlet opening is the same size or only slightly larger than the cross section of the pouring stream flowing in, so that an uncontrolled splashing of the casting steel out of the insert body is reliably avoided.

This object is achieved with an insert body according to the features of claim 1. Further advantageous embodiments of the insert body according to claim 1 result from the features of the dependent subclaims.

The idea on which the invention is based is that the insert body has a closed cover which is only partially destroyed or opened only by the impacting cast steel, so that the cast steel can get into the insert body. By this measure, the beam of the cast steel can in principle strike any point on the cover of the insert body, so that no special measures have to be taken for a precise pouring of the cast steel and the filling of the intermediate container is made simpler overall. For this purpose, the lid is advantageously of thin-walled design. As an alternative or in addition, it can be perforated and / or have predetermined breaking points so that it only breaks open where the cast steel hits. In principle, the predetermined breaking points can be arranged as desired. So it is possible to use the predetermined breaking points as Arrange transverse and longitudinal lines. At the same time, the predetermined breaking points can form concentric circles, ellipses, right or polygons. The same naturally applies to the perforations, which can be formed, for example, by means of small holes. The holes are advantageously dimensioned so small in diameter that the cast steel spraying upward from the impact surface cannot get outside through the holes remaining in the cover.

The lid area, which has not been torn into the insert body by the cast steel, advantageously remains in existence until the insert body is almost or completely filled. The lid is advantageously melted during or after completion of the filling process of the insert body, so that the cast steel can run out over the edge of the insert body. The basic idea here is that the cast steel is no longer sprayed when it is poured into an already filled container. At the same time, however, it is also possible that the lid is not completely melted, but is broken away from the cast steel pressing from below, so that the path for the cast steel is cleared upwards out of the insert body.

In any case, at least the cover material of the insert body should be of the same or at least similar type and nature as the cast steel itself, so that it does not contaminate the cast steel. However, due to the small dimensions and the thin-walled design of the lid, there will be no decisive contamination if a completely different material is used for the lid. It is of course possible to design the inner walls and the baffle surface of the insert body as desired in order to achieve a specific flow of the cast steel.

The lid can be bent around the upper edges of the side walls so that it is secured against loss. However, it is also possible to fasten the lid using fastening means, e.g. to attach in the form of screws to the insert body or its side walls.

It is also possible for a closed container to lie in the pot-shaped insert body, the outer walls of which are supported on the inner walls of the insert body. The upper wall of the container forms the lid of the insert body. The container can be inserted easily from above and is in particular thin-walled, so that it melts while the insert body is being filled and mixes with the cast steel. It is also possible to fill the container with a fluid, in particular a gas, such as e.g. Fill argon so that the cast steel does not come into contact with oxygen and thus there is no undesired oxidation of the steel. The shape of the insert body and the container can in principle be chosen as desired.

Exemplary possible embodiments of the insert body according to the invention are explained in more detail below with reference to drawings.

Show it:

Fig. 1: An intermediate container with an inserted insert body; 2: cross section through an insert body according to the invention in the not yet completely filled state;

Fig. 3: cross section through the insert body acc. Fig. 2 in the almost completely filled state;

Fig. 4: cross section through an overflowing insert according to. of Figures 2 and 3;

Fig. 5: insert body with screwed on lid;

6: insert body with cover bent over the end faces of the side walls;

Fig. 7: Insert body with the lid inserted from the side into a slot;

8: insert body with inserted closed container;

9: cross section through a first embodiment of a cover for an insert body;

10: cross section through a second embodiment of a cover for an insert body;

11: top view of the lid acc. Figure 10;

12: top view of a third possible embodiment of a cover;

13: cross section through a further embodiment with enclosed container and collar directed inwards and downwards; 14: cross section through an insert according to. Figure 13 shortly after the start of the inflow.

Figure 1 shows a perspective view of an intermediate container 1, as it e.g. is used in continuous casting. The intermediate container has an upper opening la, via which the cast steel 3 reaches the insert body 4 lying in the intermediate container 1 by means of a trunk 2. The insert body 4 according to the invention has a cover 4d, which is partially destroyed by the beam of the cast steel 3 when it hits the cover 4d. As soon as the insert body 4 is completely filled, the cast steel 3 flows over the edges of the side walls of the insert body 4 and reaches the bottom 1b of the intermediate container 1. The cast steel 3 then reaches openings or molds, not shown, through tools 1c.

FIG. 2 shows a cross section through an insert body 4 according to the invention, as has already been shown in FIG. 1. The insert body 4 has a bottom 4e which forms the baffle surface 4f for the impacting cast steel 3. The impact surface 4f is delimited by the side walls 4a of the insert body 4. The insert body 4 is closed at the top by the cover 4d. Only the area of the cover 4d, which the beam of the cast steel 3 strikes, is destroyed, so that the steel 3c splashing away from the baffle 4f can reach the side walls 4c and the cover 4d, but not out of the insert body. The cavity 4b of the insert body 4 is filled relatively quickly with the cast steel 3b, so that the surface 3a of the cast steel collecting in the insert body rises quickly and, as shown in FIG. 3, reaches the cover 4d. The cover is made of a similar or identical material to the cast steel 3, so that the cover 4d melts due to the hot cast steel 3 and clears the way for the cast steel from the insert body, as shown in FIG. The cast steel then flows over the side edges 4g of the side walls 4a of the insert body 4 and reaches the intermediate container (not shown).

FIG. 5 shows an alternative embodiment of an insert body 104 according to the invention, with an impact surface 104f, side walls 104a and cavity 104b. The in particular thin-walled cover 104d is fastened on the end faces 104g of the side walls 104a by means of screws.

FIG. 6 also shows an alternative embodiment of an insert body 204 with a bottom 204e, which forms the arched baffle 204f, which has an elevation in the middle that drops towards the side walls 204a, through which the cast steel striking it is diverted to the side walls 204a. The end faces 204g of the side walls 204a are shown rounded by way of example. You can of course also be angular. The cover 204d is bent around the end faces 204g and positively engages behind the outwardly directed side walls, as a result of which it is held securely on the insert body.

FIG. 7 shows a further possible embodiment of an insert body 304 according to the invention, in which case the cover 304d is inserted laterally into its slot 304m with its outer edges 304n, which is incorporated into the inwardly directed end faces 304g of the side walls 304a. The side walls 304a are curved or concave, so that the on the inner walls Casting steel 304c is deflected or thrown back in particular from the upper part of the side walls 304a.

FIG. 8 shows an embodiment in which a vessel or closed container 404p lies in the insert body 404, which forms the lid 404d of the insert body 404 with its upper wall. The container 404q is supported with its outer walls on the inner walls 404c, 404f of the insert body 404. The side walls 404a are directed outwards, so that the container 404p can be easily inserted into the insert body 404 from above. The container 404p can be filled with a gas 404q for corrosion protection. The container 404p can be made thin-walled, in particular in the lid region 404d, so that it can melt relatively easily.

FIGS. 9 to 12 show possible configurations of covers for insert bodies according to the invention. Thus, FIG. 9 shows a cross section through a cover 6, the region 6b of which the casting steel is intended to pierce is thin-walled, the region surrounding the region 6b being somewhat thicker. The transition from area 6a to area 6b can in principle be designed as desired, is shown here in a simplified manner.

FIG. 10 shows a cross section through a further possible embodiment of a cover 7 which has perforations in the form of blind holes or recesses 7b. FIG. 11 shows a possible arrangement of the perforations 7b, the area 7c to be broken through by the cast steel being surrounded by perforations 7b arranged in a circle. If the cast steel hits area 7c, the lid is broken along the line formed by the perforations 7b, whereby only the areas 7a of the lid remain intact. At the same time, the isolated perforations can also be replaced by continuous predetermined breaking lines or combined with these.

FIG. 12 shows an embodiment of a cover 8, in which perforations 8b are arranged in rows and columns. The incident beam 3a of a cast steel 3 is shown in a circle. The beam 3a will break out the area 8c of the cover 8 along the line 8d, which connects the perforations 8b closest to the beam, from the cover 8, so that only the areas 8a remain which have an optimally large reflection surface for the user forms highly spraying cast steel from the impact surface of the insert body.

FIGS. 13 and 14 show a further possible embodiment of an insert body 504 according to the invention. The insert body 504 has a base plate 504e, which is adjoined by a peripheral boundary wall 504a which extends vertically upwards. On the upper edge of the boundary wall 504a, an inwardly and downwardly directed collar 504g is formed, which forms a kind of funnel with its upper side surface 504g ', so that a possibly incorrectly oriented pouring jet is nevertheless directed into the insert body 504. The insert body can be designed as a circular vessel, and the cover 504d can be designed as a cone. The cover can be cast into the collar, for example, during the manufacturing process of the insert body 504. In a preferred embodiment, however, the funnel-shaped or conical lid is part of a container 504p, which is made of the same or similar material as the cast steel. The container is then used to produce the insert body as an internal shape. The free ends 504g ″ of the side wall 504a can be formed as tips, as a result of which the funnel, which is formed by the collar 504g, is enlarged. Due to the interaction of the circumferential inward and downward collar 504g and the funnel-shaped cover 504d, the cast-in casting steel 503 is again directed downward and towards the center of the insert body. The cover 504d melts after a while, in which case the cast steel continues to be directed from the side wall and its molded collar in the direction of the pouring stream (arrows). As in the previously described embodiments, the container can also be filled with a gas. The cover, in particular the tip of the cone or funnel, can also have perforations, for example in the form of holes, so that the cover is only partially destroyed by the impinging pouring jet and a defined opening is formed. Instead of perforations, one or more circumferential material weakenings, for example in the form of at least one groove, can also be provided. A groove has the advantage that the container remains closed and can therefore be filled with a gas.

As already mentioned, it is of course possible to adapt the shape and geometry of the insert body, along with its cover and its side walls and impact surface, to the prevailing framework conditions, always paying attention to an upper closure by means of the open or stuck cover.

Claims

Patent claims 1. insert body to protect the impact surface of a cast steel in a metallurgical vessel, in particular an intermediate container for continuous casting, with the boundary walls surrounding the impact area, which together with the impact surface form a trough, characterized in that the insert body (4, 104, 204, 304, 404, 504) has a ceiling (4d, 104d, 204d, 304d, 404d, 504d, 6, 7, 8) which closes the trough, the ceiling being inserted into the insert body (4, 104, 204, 304 , 404, 504) casting steel (3, 503) is partially destructible. 2. Insert body according to claim 1, characterized in that the impact surface and the boundary walls are made of a refractory material, and that the ceiling is made of a same or similar material to the cast steel. 3. insert body according to claim 1 or 2, characterized zei chnet that the ceiling is thin-walled. 4. insert body according to one of the preceding claims, characterized gekennzei chne t that the ceiling (6, 7, 8) is perforated and / or has predetermined breaking points. 5. Insert body according to one of the preceding claims, characterized in that the cover has at least one, in particular small, window-like opening. 6. Insert body according to one of the preceding claims, characterized in that the blanket melts after or during the filling of the insert body (4, 104, 204, 304, 404) or is broken open by the cast steel. 7. Insert body according to one of the preceding claims, characterized gekennz ei chnet that the ceiling is formed by a particularly thin-walled plate which rests on the upper end faces of the boundary walls. 8. Insert body according to claim 7, characterized in that the plate (104d) on the boundary walls (104a), in particular on the end faces (194g), is fastened by means of fastening means (105). 9. insert body according to one of claims 7 or 8, d a d u r c h g e k e n n z e i c h n e t that the The plate on its side areas has at least one collar, in particular molded on, which at least partially encompasses at least one of the boundary walls from the inside and / or outside. 10. insert body according to one of claims 1 to 6, d a d u r c h g e k e n n z e i c h n e t that in Insert body a container (404p, 504p) from a Cast steel is the same or similar material that forms the ceiling of the insert body (4, 104, 204, 304, 404, 504). 11. Insert body according to claim 10, characterized in that the container (404p) is closed and rests on the impact surface (404f) and the edge (404c) of the insert body (4, 104, 204, 304, 404) at least in regions , in particular the surface shape of the container being adapted to the shape of the impact surface and / or the boundary walls. 12. insert body according to claim 10 or 11, characterized zei chnet that the container has at least one molded or welded outward collar which at least partially surrounds at least one of the boundary walls. 13. Insert body according to one of claims 10 to 12, characterized gekennz ei chnet that in the Container (404p) is a gas or gas mixture (404q), which comes into contact with the incoming cast steel. 14. Insert body according to one of the preceding claims, characterized in that the impact surface is curved, honeycomb-shaped and / or shaped obliquely with respect to the horizontal. 15. Insert body according to claim, characterized in that the boundary walls to the top of the insert body (4, 104, 204, 404) diverge outwards. 16. insert body according to one of the preceding claims 1 to 14, characterized marked that the boundary walls (303a) are in particular concave ', whereby the boundary walls (304a) form part of the ceiling of the insert body (304). 17. Insert body according to one of the preceding claims 1 to 14, characterized in that the boundary walls (504a) extend vertically upwards, wherein they have an inwardly directed collar (504g) at their upper end. 18. Insert body according to claim 17, characterized in that the collar additionally extends downward in the direction of the baffle 504f. 19. insert body according to claim 17 or 18, characterized in that the insert body with its inwardly facing collar (504g) and / or its cover (504d) forms a funnel. 20. Insert body according to claim 19, characterized in that the lateral boundary walls (504a) with their free ends (504g '') form a section of the funnel. 21. Insert body according to one of claims 17 to 20, characterized in that the Lid is conical, bowl-shaped or flat. 22. Insert body according to one of claims 17 to 21, characterized in that the Cover held by the collar, in particular is covered by this. 3. insert body according to one of claims 17 to 22, characterized in that the Insert body has a container (504p), which is made of the same or similar material as the cast steel, the container having an in particular flat, flat bottom with adjoining boundary walls, the container (504p) having a lid (504d) which is conical is formed inwards and downwards.