Strip casting plant

This is a continuation-in-part of application Ser. No. 09/202,036, filed Aug. 2, 1999 and now abandoned.

1. Field of the Invention

The invention relates to a strip casting plant, especially for the strip casting of steel.

2. Discussion of the Prior Art

When strip casting steel, it is largely possible to optimally select the casting thickness of the strip (e.g., approximately 10 mm) in keeping with the required thickness of the finish-rolled hot strip (1 to 3 mm) and for the purpose of attaining adequate material properties in light of the required heat deformation.

DE 31 42 099 discloses a device for the continuous casting of metal that has a supply device for molten metal, a carrying belt for molten and solidified metal, and side limits closely adjacent to the carrying belt. The side limits are attached to the carrying belt in the manner of a link chain.

Such a design is quite expensive technically. Moreover, it is basically suitable only for relatively small strip widths. The stress in the carrier due to the thermal load is substantially higher with larger strip widths than with narrow strips. Thus, the aforementioned side limit, which revolves in a chain-like fashion and acts as a reinforcement, cannot be used with large strip widths.

When side limits are used that remain stationary relative to the carrier or conveyance device of the cast strip, solidified steel occasionally sticks to a side limit during the casting process. This leads to massive defects in the strip and to operational disruptions or even interruptions in casting. Similar problems can occur in the supply device, since solidified steel occasionally sticks there as well, leading to similar difficulties.

The single FIGURE schematically illustrates the inventive device.

The object of the present invention is to provide a strip casting plant that reliably prevents the adhesion of solidified steel to the supply device or side limits.

This object is attained by embodying the supply device and/or side limits 1 so that they can vibrate on the plane of the carrying belt 2 and are connected to a device that produces vibrations. This measure prevents the adhesion of solidified material.

In a preferred embodiment, the vibrations of the supply device and/or side limits occur substantially perpendicular to the conveyance device of the strip. Thus, the vibrations occur on the plane of the carrying belt or the cast steel strip, but at a right angle to the conveyance device. Advantageously, this design is less expensive than one that vibrates in the conveyance direction, wherein the side limits would have to run exactly over the entire length. In addition, this embodiment advantageously allows the vibrations to be optimally adjusted in the region of the metallurgical length (from the pouring area to complete strip solidification). This is done, for example, by dividing the side limits in this region into individual sections with optimal frequencies and amplitudes.

In a further preferred embodiment, the side limits can be set at an angle relative to each other. This is true for side limits located across from each other as well as for sections located on one particular side. That is, the side limits located across from each other may be adjusted simultaneously for adjusting the thickness of the cast strip across the width of the cast strip or a section of the side limit on one particular side of the cast strip may be individually adjusted for adjusting the thickness at one side of the cast strip. As a result, the evenness of the strip thickness can be improved over the entire width of the cast strip.

In a preferred example, the side limits comprise water-cooled hollow profiles.

Preferably, the devices to produce the vibrations are eccentric drives. However, electric magnets or hydraulic cylinders can also be used. The vibrations can be sinusoidal, sawtoothed or trapezoidal in form, for example. The stroke frequency is, for example, 50 Hz at a stroke of 0.5 mm. The cooling water is supplied via flexible hoses. Over the cast strip, there is preferably a cover, in which a layer of temperature-stable sealing material, especially ceramic fiber felt, is arranged for the purpose of sealing between the side limits and the cover. A corresponding seal is also provided between the supply device and the carrying belt, whereby an aluminum sheet is preferably inserted between the carrying belt and the seal, so that when vibrations occur, relative movement takes place only between the felt layer and the aluminum sheet. The supply device and the side limits are preferably held by helical screws.

In a further preferred embodiment, the side limits can simultaneously vibrate both perpendicular and parallel to the strip movement (casting direction), so that all told a thrust force that also acts in the casting direction is exerted on the strip edge. Specifically, the vibration has components in all three spatial directions.

Furthermore, the vibrations can occur perpendicular to the strip surface.

In a another embodiment, the vibrations are generated by impacts in the longitudinal or transverse direction of the side limits. Shock-like longitudinal waves, with which adhesion can be effectively prevented, can be applied in this way.