DE2052901A1 - Continuous casting facility - Google Patents

Description

ftl. - cLnp. sOe, (Zo ^ eltaetL i / CaeatetLt 9 Π S? 9 Ω 1

PATENT ADVOCATE

October 27, 1970 Application files: August 27, 1970

PATENT APPLICATION Applicant; The Babcock & Wilcox Company,

161 East 42nd Street, New York, N.Y. 10017, U.S.A.

¹¹ continuous casting device "

The invention relates to a continuous casting device in which the resulting strand is continuously drawn down from the bottom of a mold that is open on both sides.

When continuously casting metals, it is common to have one with open ends to use provided, essentially vertical, cooled mold, which is charged with molten metal at its upper end and from the lower end of which the resulting strand is withdrawn.

The strand emerging from the bottom of the mold has a relatively thin, solidified skin and a liquid core that usually at a temperature high enough to melt through the skin when not forced cooling the skin Was continued beyond the mold.

In practice, the cord skin is forced to cool in one zone provided, which extends over a considerable distance over the mold

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extends along the transport path of the strand and the usually referred to as "NachkUhlzone". In general, their length is chosen so that the strand when leaving the Post-cooling zone has a frozen skin of sufficient thickness to support itself over a given span, and a Cross-sectional temperature profile showing melting through the skin prevented through.

It is known to arrange guide devices, such as horizontal rollers or essentially, in the post-cooling zone continuous cooling plates to support the strand skin against breakage due to internal ferrostatic forces exerted by the liquid core. The skin area that is weakest and the one that needs most cooling and support is the one closest to the mold exit.

One of the problems with the continuously cast aftercoolers known per se with guide rollers is that because of the minimum roller diameter required for strength, the first set of rollers is not can be brought as close to the exit from the mold as it would be worth seeing for the support of the critical skin zone of the strand, since the thermal expansion of the mold in relation to the aftercooler construction requires a minimum distance to avoid interference between the mold and the closest group of rollers to exclude.

The well-known aftercooler in the form of continuous, massive Guide plates could support the strand closer to the mold than aftercoolers with guide rollers are able to do. at

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Guide plates, however, the heat transfer from the strand is much less than with the rollers, which are arranged so that they allowed direct contact water spray cooling of the skin.

The object of the present invention is to eliminate the shortcomings of the solid guide plates and the advantages of cooled ones Exploiting roles.

This object is achieved according to the invention in that on both sides of the strand cooling jaws at a distance from one another below the mold are arranged in several groups arranged in the longitudinal direction of the strand in such a way that they directly contact the solidified skin of the strand support after exiting the mold. Accordingly, the first group of cooling jaws is in the smallest possible minimum distance arranged to the lower edge of the mold.

According to the invention, the jaws are parallel to one another and to the strand transport path arranged. The cheeks themselves have beveled, possibly convex patches at the point where they touch the skin of the Touch the strand to avoid damaging the already solidified skin.

According to a further embodiment of the invention, the jaws are each Group so that they contact the skin of the strand along a common longitudinal dimension of the strand. the The jaws of each group are laterally spaced apart from one another and offset from one another with respect to the jaws of the adjacent groups.

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Another particular advantage of the device according to the invention is that coolant spray devices can be arranged so that they pass a coolant against the strand able to spray the spaces between adjacent jaws sindo

The invention makes it possible to use both the spray cooling as also to achieve the support of the cord skin close to the shape. This makes it possible to support the solidified skin of the resulting strand against breakage by internal ferrostatic forces and ^ To dissipate heat from the strand, so that the solidification of the strand is supported. The large number of cooling jaws enables targeted Heat dissipation. The distance between the KUhlbacken is adjusted so that no disturbance occurs which is related to the thermal expansion of the mold the neighboring group of cooling jaws is to be returned. The bevel of the cooling jaws on the face touching the strand The shoes also make it possible to improve the access to the spray cooling.

An exemplary embodiment of the invention is shown in the drawing and is described in more detail below. Show it:

Figure 1 is an elevation of the portion of the continuous casting device that is associated with an aftercooler arrangement is provided and

FIG. 2 shows a plan view in section of the aftercooler shown in FIG. 1 along the section line 2-2.

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Figures 1 and 2 show a simplified part of a continuous casting device 10, which has an open ended, substantially vertical, cooled shape Π, which at its The upper end is charged with molten metal to form a strand 12 which is withdrawn from the lower end 13 of the mold 11 will.

The strand 12 moves downward out of the mold 11 and slides along a substantially vertical transport path and through an aftercooler 14 aligned therewith.

When the resulting strand 12 reaches the lower end 13 of the mold 11, it will have formed a solidified skin of sufficient strength to hold the molten metal in it. One of them froze However, skin is relatively weak and is subject to deformation and possible breakage by internal ferrostatic Forces if not further cooled and supported until it is strong enough to withstand these forces. Usually forced cooling of the strand 12 is required over a considerable distance from the exit from the mold 11 along the transport path, because the cross-sectional temperature profile of the strand 12 iö near the mold 11 is still so high that melting through the Skin can be done through if only ambient air cooling would be provided.

In the aftercooler 14 of the continuous casting device according to the invention are several internally cooled jaws 15 are provided, which are arranged in three groups A, B, C, which in running order along the

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Strand transport route lie. All jaws 15 are parallel to Ab ^ ''''<- ■ stand each other and arranged to Strargfcransportweg And are ■ ■ '"■■■' ■ · so that they touch the solidified skin of the strand 12, by the same against fracture The use of jaws 15 which are hollow and connected to water supply pipes 16 and drainage pipes 17 removes heat from the Strong to help it solidify.

The jaws 15 of each group A, B, C are arranged in the longitudinal direction, around the skin of the strand 12 along a common, in a longitudinal row * - direction extending dimension to touch, and they are connected to a corresponding carrier 18 to be laterally spaced from one another. The carrier 18 in turn are through held any suitable and per se known device, such. B. a support structure, not shown.

The jaws 15 of group A are spaced with their front edges to the mold 11 and touch the strand 12 on one in the longitudinal direction extending dimension of the same downward from a given minimum distance D to the upper mold 11.

To provide greater support for the strand 12 through a given To obtain the number of jaws 15, jaws 15 become group B to the jaws 15 of the corresponding adjacent group A and C arranged offset.

By arranging the cooling jaws 15 at a distance, one can also additional cooling of the strand 12 can be achieved more easily, e.g. B.

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by a battery of nozzles 19 which are arranged to supply water or some other suitable liquid coolant through the spaces to spray between adjacent jaws 15 against the outer skin surface of the strand 12.

As shown in Figure 2, the portion of the jaws 15 contacting the skin of the strand 12 has beveled faces 20 to allow the coolant spray to sweep the skin, while at the same time the smaller contact surface tends to increase the friction of the strand reduce the downward movement and avoid injuries to the skin from sharp edges.

To the unsupported part of the strand 12 when exiting the To reduce the mold 11 to the smallest possible size, the jaws 15 of group A are brought as close as possible to the mold exit end 13, the minimum distance D is set so that interference between the mold 11 and the jaws 15 in groups A in the expected maximum relative thermal expansion between them is eliminated c

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Claims (7)

PATENT CLAIMS: SSSC = SSSSSSSSShS = SSS 1. Continuous casting device in which the resulting strand continuously downwards from the bottom of a mold that is open on both sides is withdrawn, characterized in that on both sides of the strand cooling jaws (15) at a distance from one another are attached below the mold (11) in several groups (A, B, C) arranged in the longitudinal direction of the strand (12), that they support the skin of the strand (12) immediately after exiting the mold. 2. Device according to claim 1, characterized in that the longitudinally arranged first group of KUhlbacken is arranged at a minimum distance from the lower edge of the mold. 3. Device according to claim 1 and / or 2, characterized in that the jaws (15) parallel to each other and are arranged to the strand transport path. 4. Device according to claim 1 and / or one of the following, characterized characterized in that the jaws (15) have beveled or convex surfaces (20) at the point where they the skin of the strand (12). 5. Device according to claim 1 and / or one of the following, characterized marked that the jaws (15) of each group - 9 -109885/1074 (A, B, C) lie so that they along the skin of the strand (12) touch a common, longitudinal part of the strand 6. Device according to claim 5, characterized in that that the jaws (15) of each group are arranged laterally spaced apart from one another and offset from the jaws of the adjacent groups are. 7. Device according to claim 1 and / or one of the following, characterized in that coolant spray devices (19) are provided to a cooling liquid against the strand (12) through the spaces between adjacent Spray baking (15). 109885/1074 Blank page