DE2303399A1 - CONTINUOUS CASTING DEVICE - Google Patents

Description

Alcan. Research and Development Limited, Montreal,

Quebec '' Canada

S tranggielB device

The invention relates to a continuous casting device with a vertically movable table with a horizontal one bearing surface, which is used to carry at least one approach head receiving a block on a predetermined location on top of the supporting surface is appropriate, with the table at this point has a flat surface to allow lateral sliding movement of the starting head and a starting head

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is arranged at this point on the table, which has a substantially uniform surrounding surface for support by the table, it relates in particular to continuous casting by means of permanent molds.

In a continuous caster, the bottom of the mold is usually closed with a starter head or plug at the start of casting to allow the mold to be filled with molten metal to a desired height. If this height is achieved, the table on which the dummy bar is mounted, is lowered by a certain pre-measure and coolant to the surface ^is: - "height of the growing block around the boundary of the bottom of the mold is applied, and the metal mirror within the mold is maintained by pouring additional molten metal. When the molds have a small cross-section, it is common practice to cast a substantial number of ingots at the same time.

The mechanical inaccuracies inherent in the caster have been found to make it very difficult make to ensure that an approach head, which is firmly attached to the supporting table, exactly with a mold is aligned. When a number of approach heads on a single table to cooperate with a number individual chill molds is stored, so it is customary to store the starting heads loosely on the table and each starting head to align by hand with the appropriate mold when the table is lifted into position. This is done by inserting a rod through the top of the mold and connecting the approach head to the The mold is levered into alignment. However, if the mold is provided with a fragile heat-resistant upper part is, it no longer remains a practicable one

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Working method because of the risk of damaging the heat-resistant top is extremely large.

There were various forms of self-centering approach heads tried it, but usually the friction between the approach head and the table was too great to achieve a complete to achieve satisfactory work. In US-PS 3 j5 £ A 152 has also been proposed a Provide a spring-loaded approach head, which effectively seals against the bottom of the mold, but a beveled one Has section to enter the mold so as to achieve a certain self-centering. However, because the attachment for the lower end of the compression spring is not correctly aligned with the axis of the mold is ~, such an arrangement can not become a complete result in a satisfactory seal between the approach head and the mold, as there are some lateral force components between Start-up head and mold occur. So there is always the danger that molten metal at the beginning the casting passes and ^ or cooling water penetrates into the space above the start-up head.

The invention is based on the object of a device to create of the type mentioned, which makes it possible that a starting head freely attached to the table satisfactorily can be actuated in a self-aligning manner.

This task is achieved according to the invention in that the starting head at least in the horizontal and vertical direction a limited freedom of movement with respect to the table includes means for supplying pressurized fluid through the table to the underside of the approach head are provided at one point,

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which within the substantially uniform surrounding surface. So that a laterally exiting fluid layer between the table and the approach head can be produced for lifting the approach head out of contact with the table, vias a lateral one Allows sliding movement of the approach head without tilting with respect to the table.

This solution is based on the knowledge that the Desired self-alignment can be achieved when the friction particularly decreases over time can be when the approach head is introduced into the mold. During the rest of the time of pouring will be it is preferred instead that the starter head remain firmly supported by the table.

Thus, the table of a continuous casting device of the present type is provided with at least one approach head, which has a limited degree of freedom for lateral sliding movement with respect to the table. The table is provided with means for supplying a pressurized fluid to the underside of the approach head, to create a cushion of fluid between the table and the starting head, creating the starting head can be moved with respect to the table with a very small lateral force. The top of the approach head is preferably slightly rounded so that the approach head can enter the mold when the table is raised. Provided that pressurized fluid is supplied, the desired lateral movement will be achieved of the approach head is very easily brought about automatically when the approach head enters the mold.

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The table is preferably designed so that its entire top surface is flat. It is only essential, however, that there be a flat area for each approach head sufficient expansion is available to allow essential lateral freedom of movement. Of the The approach head or heads can be solid or hollow on the inside. Ss is necessary for the bottom of the approach head, that it has a substantially flat surface surrounding the opening for the supply of fluid in the upper surface of the table so that a substantially uniform flow of fluid can emerge laterally under the start-up head, when the fluid supply is on, so that the starter head or heads during the upward movement of the table are not in direct contact with it in order to move the approach head or the approach heads into a Bring sealing position in the mold or the molds. It's easy to see that after aligning of a starting head with the corresponding mold a random lateral movement of the starting head the table would be extremely undesirable during the lowering of the table in the course of the casting process. the end For this reason, suitable measures are preferably taken, e.g. the bottom of the approach head is roughened, to prevent the starter head from moving on the table when the fluid supply is turned off is. While the fluid may be a liquid such as water, the most common practice is Use compressed air.

In contrast to the construction of U.S. Patent 3 Jiok 152, the self-centering floating starter head of the present invention can enter the mold to form a seal with the peripheral wall rather than a seal against the bottom of the mold.

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In a preferred embodiment, the table is a continuous caster with multiple approach heads Provided in positions which correspond to the layers of several molds in which metal is poured at the same time by pouring it from a holding furnace into a common channel system, from which metal is fed to the individual molds via dip tubes in a manner known to those skilled in the art. Of the The table itself preferably consists of a layer structure in which passages are formed lead from a fluid inlet to the start-up head section.

In the following the invention with reference to the Drawing explained in more detail. Show it:

Fig. 1 is a partial section through one with the floating Starting head according to the present invention equipped table, and

Fig. 2 is a schematic plan view of the table.

In Fig. 1, a starting head provided with a holding part 2 is shown. The holding part is within an opening j5 for a supporting fluid included in the table 4 so that the starting head 1 limited a Has freedom of movement both vertically and laterally with respect to the table 4 and with respect to the table can float on a cushion or film of air or water, which is supplied through the opening 3 under pressure will.

E) he approach head 1 has a rounded edge 5 to the entrance to support the approach head in the mold 6.

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However, an additional centering effect can be created by pin 7, which has a conical Touch surface 8 at the bottom of the mold, as shown in FIG. Although to simplify the Representation of four pins 7 are shown, three pins are preferably at the same angular intervals on the Extensive use of the approach head. With this arrangement there will be no contact at all between the approach head and the mold, so there is no risk of damage the mold are avoided by the approach head. The conical surface δ and the pin 7 are not absolutely necessary, but allow in their use that the radius of the rounded edge to one very small value is decreased.

During operation, it has proven necessary to switch on a supply of compressed air for only 10 to 15 seconds, when the approach head penetrates the mold. This is sufficient to move the start-up head by a few fiftieths Raising millimeters (thousandths of an inch) on a cushion of air. It turned out that a pressure of 2.8 up to 4.2 kg / cm (40 to 60 psi) is sufficient to support approach heads of conventional weight. At the end of this short one The approach head was allowed to fall back onto the table 4 for a period of time. The lower end of the approach head is preferred roughened or knurled to increase the friction between it and the table when actually with each other stand in touch.

The supply of air through the openings 3 can in the in Fig. 2 schematically shown manner can be achieved. Air can pass through a flexible hose 10 and through a Shut-off valve 11 are fed to a distributor pipe 12, from which branch pipes 14 lead to the openings 3.

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Claims (2)

C claims 1. Continuous caster with a vertically movable table with a horizontal supporting surface, which is suitable for supporting at least one block receiving approach head at a predetermined location on the top of the supporting surface, the table at this point has a flat surface to a lateral To enable sliding movement of the approach head and an approach head is arranged at this point on the table, which has a substantially uniform surrounding surface for support by the table, characterized in that the approach head (1) at least in the horizontal and vertical direction a limited freedom of movement in with respect to the table (4) comprises means {~ 5, 10-14) for supplying pressurized fluid through the table (4). are provided on the underside of the approach head (1) at a point which lies within the substantially uniform surrounding area, so that a laterally exiting fluid layer between the table (4) and the approach head (1) to lift the approach head (1) out of contact can be produced with the table, which enables a lateral sliding movement of the approach head (1) without tilting with respect to the table (4). 2. Stranggießvorrxchtung according to claim 1, characterized in that the starting head (1) is designed for insertion into a mold (6) and sealing with the side walls of the same, and the starting head (1) is provided with laterally projecting elements (7) for engagement with a conical ring (8), which is arranged below and concentrically to the mold. 3098 3 2/04 5 Blank page