Continuous Casting Device for Producing Slabs Made of Steel

Abstract

A continuous casting device for producing slabs of steel having a mold and a roller apron downstream of the mold which has frameworks with bottom frames and top frames at which are provided guide rollers whose gap width is continuously adjustable by means of adjusting elements which connect the frames. Cylinders controlled by switching valves are provided as adjusting elements. The advantages of position-regulated cylinders as adjusting elements are made use of, but at a reduced cost. To this end, the valves are constructed as fast switching valves, or the valves are provided with a control enabling a fast switching process.

Description

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention is directed to a continuous casting device for producing slabs of steel having a mold and a roller apron downstream of the mold, which has frameworks with bottom frames and top frames at which are provided guide rollers whose gap width is continuously adjustable by adjusting elements which connect the frames, wherein hydraulic cylinders controlled by switching valves are provided as adjusting elements.

The invention is directed further to a method for operation of the continuous casting device.

2. Prior Art

EP 980 295 B1 discloses a continuous casting device for producing slabs of steel having a mold and a roller apron downstream of the latter which has frameworks with bottom frames and top frames at which are provided guide rollers whose gap width is continuously adjustable by adjusting elements which connect the frames. Distance measuring devices and pressure transducers are provided for detecting the actuating force of the adjusting elements and the gap width of the guide rollers. Further, an oscillator is provided for exciting oscillation in the adjusting elements. In practice, the segments used for this purpose are known as CyberLink segments. Generally, the oscillation is described by specifying many discrete reference points per oscillation period. The reference points have a sinusoidal distribution, and the movement is enforced so as to be regulated with respect to position.

This device can be used to acquire certain information relevant to the process such as, for example, the position of the liquid crater tip.

The position-regulated adjusting units used for this purpose are relatively expensive. Therefore, it has already been proposed to replace them with cylinders controlled by switching valves.

This solution is inexpensive but has the drawback that the advantageous oscillation can no longer be carried out in the known manner.

SUMMARY OF THE INVENTION

An object of the invention is to provide a the continuous casting device such that the advantages of position-regulated cylinders as adjusting elements can be made use of, but at reduced cost.

This object is met according to one embodiment of the invention either by constructing the valves as fast switching valves or by providing the valves with a control unit enabling a fast switching process.

According to another embodiment, the valves have connections for optional arrangement of pressure measuring cells.

It is further proposed that:

• 1. the top frame is set in oscillatory motion by a fast toggling of the switching valves over a relatively short measurement time period—of a few seconds—so that the path signals and force signals are evaluated subsequently in a known manner; it is taken into account that a triangular motion that is eroded or slurred by the inertia of the system occurs instead of a sinusoidal motion such as was previously known; this has no effect on the precision or reliability of the evaluation;
• 2. the valves are provided with connections for arranging pressure measuring devices so that the latter can either be included with the valves when leaving the supplier or the valves can easily be retrofitted in case of an upgrade.

BRIEF DESCRIPTION OF THE DRAWING

FIG. 1 is a schematic description of the system according to one embodiment of the invention.

DETAILED DESCRIPTION OF THE DRAWINGS

Studies of measurements recorded in existing CyberLink segments with switching valves have shown that the deformation speeds that can be achieved when using slightly larger dies than are commonly used (1.8 mm-2.0 mm instead of 1.3 mm-1.5 mm) lie above the natural strand shell deformation rates according to the creep behavior of the cast materials and in the same order of magnitude as in the original CyberLink segments such that an evaluation is possible.

The motion occurring by means of this control is not necessarily sinusoidal is not critical for the methods of evaluation (hysteresis, phase response, bath level movement) to be taken into consideration.

The fact that the mean cylinder position is possibly not held constant during the measurement is accommodated by a measurement duration which is as short as possible.

Overload monitoring is made possible by the optional use of pressure measuring cells.

Even without the use of pressure measuring cells, the proposed procedure shows a way to implement the “auxiliary CyberLink functions” when the casting level signal is correlated with the top frame oscillation instead of evaluating hysteresis or phase displacement.

In addition, the use of (electronic) devices is advantageous for accelerating the switching processes.

Further, the installation of ventilators for improving convective heat removal in the area of the valves can also be advantageous.

According to one embodiment of the invention as shown schematically in FIG. 1, the device for continuous casting configured for producing slabs of steel includes a mold, a roller apron arranged downstream of the mold, the roller apron including a framework of at least one bottom frame and at least one top frame. A plurality of guide rollers are arranged in at least one of the at least one bottom frame and at least one top frame. At least one cylinder is configured as an adjusting element that connects the at least one bottom frame and at least one top frame, the at least one adjusting element configured to continuously adjust a gap width between the at least one bottom frame and at least one top frame. A fast switching valve configured to control the at least one cylinder is configured as an adjusting element. In one embodiment, a gap width of the plural guide rollers is continuously adjustable. At least heat sink is configured for convective heat removal from the fast switching valve.

Thus, while there have shown and described and pointed out fundamental novel features of the invention as applied to a preferred embodiment thereof, it will be understood that various omissions and substitutions and changes in the form and details of the devices illustrated, and in their operation, may be made by those skilled in the art without departing from the spirit of the invention. For example, it is expressly intended that all combinations of those elements and/or method steps which perform substantially the same function in substantially the same way to achieve the same results are within the scope of the invention. Moreover, it should be recognized that structures and/or elements and/or method steps shown and/or described in connection with any disclosed form or embodiment of the invention may be incorporated in any other disclosed or described or suggested form or embodiment as a general matter of design choice. It is the intention, therefore, to be limited only as indicated by the scope of the claims appended hereto.

Claims

1.-6. (canceled)

7. A continuous casting device configured for producing slabs of steel comprising: a mold;a roller apron arranged downstream of the mold, the roller apron comprising a framework of at least one bottom frame and at least one top frame;a plurality of guide rollers arranged in at least one of the at least one bottom frame and at least one top frame;at least one cylinder configured as an adjusting element that connects the at least one bottom frame and at least one top frame, the at least one adjusting element configured to continuously adjust a gap width between the at least one bottom frame and at least one top frame; anda fast switching valve configured to control the at least one cylinder configured as an adjusting element.

8. A continuous casting device for producing slabs of steel comprising: a mold;a roller apron arranged downstream of the mold, the roller apron comprising a framework of at least one bottom frame and at least one top frame;a plurality of guide rollers whose gap width is continuously adjustable;a plurality cylinders configured as adjusting elements connect the at least one bottom frame and at least one top frame;a plurality of switching valves configured to control respective ones of the plural cylinders; anda control configured to control the plural switching valves enabling a fast switching process.

9. The continuous casting device according to claim 7, wherein the fast switching valve has a connection configured for attaching at least one pressure measuring cell.

10. The continuous casting device according to claim 7, wherein at least one unit configured for convective heat removal is associated with the fast switching valve.

11. A method for the operation of a continuous casting device, the continuous casting device comprising: a mold;a roller apron arranged downstream of the mold, the roller apron comprising a framework of at least one bottom frame and at least one top frame;a plurality of guide rollers whose gap width is continuously adjustable;a plurality cylinders configured as adjusting elements connect the at least one bottom frame and at least one top frame;a plurality of valves configured to control respective ones of the plural cylinders; anda control configured to control the plural valves,

12. The method for the operation of a continuous casting device according to claim 11, wherein a measuring time for the oscillating of the top frame is as short as possible.

13. The continuous casting device according to claim 8, wherein at least one of the plural switching valves has a connection configured for attaching at least one pressure measuring cell.

14. The continuous casting device according to claim 8, wherein at least one unit configured for convective heat removal is associated with at least one of the plural switching valves.

15. The method for the operation of a continuous casting device according to claims 11, wherein the triangular signal is eroded.

16. The continuous casting device according to claim 10, wherein the at least one unit configured for convective heat removal is a ventilator.

17. The continuous casting device according to claim 14, wherein the at least one unit configured for convective heat removal is a ventilator.

18. The continuous casting device according to claim 7, further comprising dies wherein the dies are about 1.8 mm to about 2 mm.

19. The continuous casting device according to claim 8, further comprising dies wherein the dies are about 1.8 mm to about 2 mm.

20. The continuous casting device according to claim 8, wherein the control is configured to oscillate the top frame using a triangular signal.