EP1013361B1 - Mould pipe and process for recalibrating a mould pipe - Google Patents

Description

On the one hand, the invention relates to a mold tube according to the features in the preamble of claim 1.

On the other hand, the invention is directed to a method for recalibrating an im Use of the mold tube.

Chill pipes for continuous casting are known to be used in cooling Water boxes tightly fixed. To withstand the high cooling water pressures, the mold tubes are stiffened at their upper ends so that they retain their shape maintained. In this context, it is especially with some Double-T-shaped cross-section with "beam-blank" or "dogbone" molds known, in the opposite outer channels at the upper ends Welding wedges, so that such mold tubes in the front view then one have largely rectangular cross-section. GB-A-2 117 293 shows one Similar mold construction with a round flange.

When recalibrating such mold tubes using explosive forming (Accumold method), however, the welded-in wedges proved to be a hindrance in the course of the reshaping. The weld seams also tore in part. Then that was associated with a no longer perfect seal. It also showed that the original shape at the top of the mold tubes is not or only was difficult to recalibrate.

Starting from the prior art, the invention is based on the object, on the one hand to create a mold tube that is perfectly sealed and dimensionally stable in one Water box can be fixed in position, and on the other hand a method for recalibration to introduce a mold tube that has been used, in which the The mold tube can be reworked several times without the reworking lead to sealing problems or damage to the mold material.

With regard to the part of this task relating to the mold tube, the solution becomes seen in the features listed in the characterizing part of claim 1.

The solution to the part of the task relating to the method consists in the features of claim 4.

Then, at a distance from the upper end face of the tube wall, a mold tube an outer circumferential groove, in particular rectangular in cross section, is provided. Furthermore, a circumferential shoulder on the mold tube is adjacent to the upper end face generated. This paragraph is used for precise and sealing definition a stiffening frame, which is also on the flange of the water tank supported. The stiffening frame is also sealed against the water tank. Below the stiffening frame are two U-shaped flanges with inner ones Locking bars, which from opposite sides in the circumferential groove on the Grasp the pipe wall. The radial extension of the locking bars is smaller than the depth of the Dimensioned circumferential groove. After the U-shaped flanges over the locking bars in the circumferential groove are oriented, the stiffening frame is on the heel pushed and then with the two U-shaped flanges by screws firmly connected. In this way, the upper end of the mold tube Sufficiently stabilized against cooling water pressures. Are welding work no longer necessary, so that there is no longer any risk that the mold material is damaged.

If a mold tube that has been in use is now to be recalibrated, all you need is the stiffening frame and the U-shaped flanges to be removed then restore the inner mold cavity to meet the requirements with continuous casting is sufficient. Is the mold cavity restored what? usually with a decrease in wall thickness at the top of the mold tube is connected, only the paragraph corresponding to the decrease in wall thickness reworked and put on a new stiffening frame adapted to it then bolted to the remaining U-shaped flanges. these can therefore remain because the radial extension of the locking webs is smaller than the depth the circumferential groove is dimensioned.

It is advantageous that this calibration can be repeated several times and only corresponding ones Stiffening frame must be provided.

According to an advantageous embodiment, the lowest is according to claim 2 of the paragraph facing inner edge of the stiffening frame with a recess to accommodate the sealing ring. This sealing ring is used when screwing of the stiffening frame with the U-shaped flanges in the corner area of the paragraph pressed and in this way ensures the seal.

The features of claims 1 and 2 are particularly advantageous in the case of a double T-shape configured mold tube according to claim 3 applicable, for example is known in the form of a "beam-blank" - or a "dogbone" mold. Conceivable is also used for billet and bloom formats.

Restoring the inner mold cavity of a mold tube can be done with all known methods are carried out. However, the is particularly advantageous Restoration of the mold cavity by explosive molding at one in the Mold tube inserted mandrel according to the features of claim 5.

Reworking after restoration of the inner mold cavity the paragraph at the upper end of the mold tube is advantageously according to claim 6 performed by a milling operation.

Figur 1

in der Perspektive das obere Ende eines "beam-blank"- Kokillenrohrs;

Figur 2

ebenfalls in der Perspektive das obere Ende des Kokillenrohrs der Figur 1 in Explosionsdarstellung und

Figur 3

in vergrößerter Darstellung im vertikalen Querschnitt das obere Ende des Kokillenrohrs der Figur 1 in eingebautem Zustand.

The invention is explained below with reference to an embodiment shown in the drawings. Show it:

Figure 1

in perspective the upper end of a "beam-blank" mold tube;

Figure 2

also in perspective the upper end of the mold tube of Figure 1 in an exploded view and

Figure 3

in an enlarged representation in vertical cross section the upper end of the mold tube of Figure 1 in the installed state.

1 to 3 is a mold tube made of copper with one in FIGS Designated double T-shaped cross section. Such a mold tube 1 is also called "beam-blank" mold.

Around such a mold tube 1 tightly and dimensionally stable in a not shown Fixing the water tank 2 in position (FIG. 3) is adjacent to the upper end face 3 of the Pipe wall 4 is provided a circumferential paragraph 5 rectangular in cross section. This paragraph 5 is used to hold a stiffening frame 6, the top 7 runs in one plane with the end face 3 of the tube wall 4. The stiffening frame 6 has a substantially rectangular outer contour with rounded Corner regions 8. In FIG. 2, the stiffening frame 6 is shown folded through 180 °.

At a distance below paragraph 5, which is approximately the vertical extent of the Paragraph 5 corresponds to an outer circumferential groove 9 is rectangular in the tube wall 4 Cross section provided. The circumferential groove 9 serves to accommodate two U-shaped ones Flanges 10 trained inner locking ridges 11. The radial extension the locking webs 11 is smaller than the depth of the circumferential groove 9. The corner regions 12 of the flanges 10 are also rounded.

After inserting the locking webs 11 into the circumferential groove 9, the stiffening frame 6 with one embedded in a recess 13 in the area of the inner edge 14 Sealing ring 15 placed on paragraph 5 and then over several itself extending along the contour of the mold tube 1 bolts 16 with the Flanges 10 braced.

The stiffening frame 6 is underpinned by holding plates 17 which are connected to the water tank 2 are screwed. A seal 21 between the stiffening frame 6 and the water box 2 serves to seal against the overlying Flange 18 of the water box 2. With 19 the water guide jacket is designated in FIG.

To recalibrate a mold tube 1, it is removed and it is then the stiffening frame 6 and the flanges 10 removed. After that the mold tube 1 with the introduction of a mandrel, not shown in the mold cavity 20 is calibrated by explosive molding. With this explosive forming the thickness of the tube wall 4 is reduced in the upper region. Based on these Subsequent to the reduction, paragraph 5 is then processed accordingly, in particular re-milled. The circumferential groove 9 does not need to be reworked because their depth is greater than the radial extent of the locking webs 11. After processing Paragraph 5, a new stiffening frame 6 is fitted to it and braced with the flanges 10.

With a decrease in wall thickness of approximately 0.7 mm per calibration, a Mold tube 1 can be recalibrated about three times.

REFERENCE NUMBERS

1 -

Mold pipe

2 -

cistern

3 -

Front of v. 4

4 -

Rohrwand v. 1

5 -

Paragraph on 4

6 -

stiffening frame

7 -

Top v. 6

8th -

Corner areas of 6

9 -

Circumferential groove in 4

10 -

U-shaped flanges

11 -

Locking bars at 10

12 -

Corner areas of 10

13 -

Recess on 6

14 -

Inner edge of 6

15 -

Sealing ring in 13

16 -

bolts

17 -

Haltebleche

18 -

Flange v. 2

19 -

Wasserleitmantel

20 -

mold cavity

21 -

poetry

Claims (6)

1. Mould pipe which can be sealingly immobilised in position by means of its upper end in a water chamber (2) and is stabilised in this area against cooling water pressures with a flange mounted externally on the mould pipe, characterised in that an external circumferential groove (9) is provided a distance from the upper end face (3) of the pipe wall (4), into which U-shaped flanges (10) engage from opposite sides with inner locking ledges (11) the radial extension of which is less than the depth of the circumferential groove (9), and in that a circumferential shoulder (5) is provided adjacent to the upper end face (3), on which a stiffening frame (6), which can be screwed with the U-shaped flanges (10) and is supported on a flange (18) of the water chamber (2), can be secured with a precise fit with sealing with respect to the pipe wall (4) and with respect to the flange (18) of the water chamber (2).
2. Mould pipe according to claim 1, characterised in that the inner edge (14) of the stiffening frame (6) facing the deepest part of the shoulder (5) is provided with a recess (13) for reception of a sealing ring (15).
3. Mould pipe according to claim 1 or 2, in the application to a mould pipe configured with a double T shape.
4. Method for recalibration of a mould pipe (1) which has been in use according to one of claims 1 to 3, in which after the restoration of the inner mould cavity (20), the shoulder (5) on the mould pipe adjacent to the upper end face (3) is reworked according to the reduction in the wall thickness during the restoration and a new stiffening frame (6) matched to this configuration is screwed with the U-shaped flanges (10).
5. Method according to claim 4, in which the restoration of the mould cavity (20) is carried out by explosive forming with a forming mandrel introduced into the mould pipe (1).
6. Method according to claim 4 or 5, in which the reworking of the shoulder (5) is carried out by milling.

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