DE102017117634A1 - Optimized continuous casting plant and process for the optimized alignment of components of a continuous casting plant - Google Patents

Abstract

The invention relates to a continuous casting plant comprising a continuous casting mold displaceable in oscillation by means of an oscillating device, to which a plurality of segments provided with strand guide rollers adjoin, which are arranged on a support structure and connected to the support structure at a plurality of bearing points, wherein at least one of the bearing points of the directly to the continuous casting mold subsequent segment is a floating bearing.

Description

The present invention relates to an optimized continuous casting plant and to a process for optimized alignment of components of a continuous casting plant, in particular for aligning the transition from the continuous casting mold into the downstream pairs of strand guide rolls combined in roll stands (segments) and / or the transition between the first two segments Continuous casting plant (Segment i and Segment i + 1).

State of the art

Continuous casting plants are known to consist of several components. The steel produced in a steelworks is given for the continuous casting process first by means of ladles in a distribution trough, which serves as an intermediate container for the liquid steel. From the distributor trough, the steel is then placed in a water-cooled copper mold. The water-cooled copper mold is usually stored in an oscillation unit and is operated in oscillation in order to avoid adhesion of the steel to the mold plates. The copper mold is followed by a segmented and roller support-based strand guide. The rollers are usually installed in several successively arranged segments, wherein the segments depict the entire strand guide.

The segments are arranged and fixed on a support structure made of steel. The support structure is in turn supported by a concrete, steel or reinforced concrete foundation.
It is immensely important that the transitions from the copper mold to the strand guide rollers of the adjoining segment, as well as the individual segments are aligned with each other exactly.

The copper mold is usually arranged on a support structure designated as a machine frame, while the adjoining segments are usually arranged on a supporting structure called a segment carrier.

Even with a slight offset between the individual components, surface defects occur in the completely or partially solidified steel strand, which can, for example, lead to the slabs produced not being suitable for rolling or to surface defects occurring during rolling. This disadvantageous change in the surface quality leads to an increased rejection of products and, of course, to a reduced profitability of the process. In addition to the mentioned quality and production losses and the concomitant impairment of the casting operation deviations from the optimal alignment of the components can also lead to damage of components of the continuous casting.

In the various phases of operation continuous casting plants are subjected to very different loads. These may be of a mechanical or thermal nature in particular. These different loads lead to various distortions of the overall structure, which is formed by the components of the continuous casting. The resulting relative movements of system components to each other can exceed a total of 10 mm and still be in the millimeter range with respect to adjacent strand guiding components. Particularly damaging are relative deformations of adjacent strand guiding components.

To counteract the occurrence of undesirable deformations of the strand guiding components, these are usually connected in four bearing points with the support structure, which bearings can be independently formed as a fixed bearing, sliding bearing or support.

In the definition of fixed bearing, sliding bearing and support is based on a local Cartesian component coordinate system (x, y, z), where x has tangential in the casting direction, y normal to the casting direction (perpendicular to the strand surface) and z horizontal transverse to the casting direction. A "local coordinate system" is understood to be a coordinate system that moves along with the strand guide. The directions x, y and z therefore vary with the changing slope (or slope) of the respective system.

Some corresponding local coordinate systems are in the following 5 and 6 a circular arc plant and a vertical bending plant for a better understanding:

Starting from this local Cartesian component coordinate system (x, y, z), the x-, y- and z-axes are bound in a fixed bearing. In a sliding bearing, either the x and y axes or the z and y axes are constrained, leaving either the z or x axis free. For a support, however, only the y-axis is tied, while the x- and z-axis are free.

As a rule, one of the four bearings, in which the strand guiding components are connected to the support structure, is formed as a fixed bearing in the prior art. Another is designed as a sliding bearing and the two remaining as a support. In the overall system, the rotations about the x and z axes are through the Co-operation of all four bearings tied up in the y-direction, while the rotation about the y-axis is bound by the interaction of fixed and sliding bearings. In special cases, more or less than four bearings are possible.

Since the alignment of the continuous casting mold and the segments has a great influence on the quality of the products, the positions of the individual components are precisely measured, for example by means of templates or laser technology, and the components are thereby precisely aligned.

The problem is, however, that the alignment of the individual components of a continuous casting takes place in the cold state, but this also in the production state, i. at temperatures of the cast product of 1000-1500 ° C should maintain their position to avoid the resulting from a thermal displacement of the components surface defects. This is very difficult to achieve because during the entire continuous casting process different expansion processes take place in the components of the plant and in the support structure, which are mainly due to temperature. For example, if the support structure is made of steel and the underlying foundation is made of reinforced concrete, these two materials result in different elongation behavior, because while the steel reaches the desired temperature comparatively quickly when the system starts up, the concrete takes longer for it, so that shifts occur during operation can. This temperature-dependent expansion of the support structure and the foundation naturally has a direct influence on the position of the components of the continuous casting plant and in particular on the alignment of the transitions from the continuous casting mold into the first segment and between the segments. Here, in order to avoid surface defects in the product, a deviation of the components from their optimally aligned position of less than 1.0 mm, preferably less than 0.2 mm, particularly preferably 0.0 mm is desirable.

Object of the invention

It is the object of the present invention to provide an optimized continuous casting plant and a method for optimized alignment of components of a continuous casting plant, wherein the components of the continuous casting differ less by temperature-dependent expansion processes of the support structure and the components themselves from their optimal orientation.

General description of the invention

The invention solves this problem with the features of the claims and in particular by providing a continuous casting plant, which comprises a vibratable continuous oscillating means by means of an oscillating continuous casting mold, followed by several provided with strand guide rollers segments arranged on a support structure and at each of several bearing points with the Support structure are connected, wherein at least one of the bearing points of the adjoining directly to the continuous casting mold segment is a floating bearing.

For the purposes of the invention, the continuous casting mold, which is preferably made of copper, as well as the individual segments or roll stands are understood to mean, in particular, a component of a continuous casting plant or under a strand guiding component.

A floating bearing refers to one of the three types of bearings (fixed bearing, sliding bearing or support) for the purposes of the invention, but in addition the degree of freedom in y-direction is released within defined limits.

The continuous casting mold and at least the first individual segments of the continuous casting plant according to the invention are e.g. arcuately arranged on a support structure, wherein the continuous casting mold forms the uppermost point of the arc and the subsequent, arranged on the support structure segment boxes are each arranged lower lying. However, the arrangement of the individual segments on the support structure is not necessarily arcuate, because the invention relates to all types of continuous casting, i. Horizontal, vertical, vertical and also circular arc systems.

The roll stand, which adjoins directly to the continuous casting mold, is also referred to as segment i, while the following roll stand is also referred to as segment i + 1 and the subsequent roll stands are accordingly continuously referred to as segment i + 2, segment i + 3 and so on , Overall, the continuous casting can have a plurality of segments depending on the casting performance.

The support structure, on which at least the first segments adjoining the continuous casting mold are arranged, is in particular made of concrete, steel and / or reinforced concrete.

Notwithstanding the usual practice in the prior art, the individual arranged on the support structure segments are not firmly connected in each of their connection points in the y-direction with the support structure, but at least the segment that connects directly to the continuous casting mold (segment i) is eg in addition to at least one fixed bearing in at least one floating bearing connected to the support structure. Because the segment i is connected to the support structure by means of at least one movable bearing, a relative displacement of the segment by a defined distance, for example by a maximum of 12 mm, or by a maximum of 5 to 10 mm, or by a maximum of 1 to 2 mm, or allowed by <1 mm, <0.2 mm or <0.1 mm in the radial direction perpendicular to the strand. Preferably, a shift in only one direction is allowed. For this purpose, the floating bearing preferably comprises a spring element which is adapted to allow the connection with the support structure in the connection point a certain margin, for example up to 12 mm, up to 5 to 10 mm, up to 1 to 2 mm, up to <1 mm, up to <0.2 mm or up to <0.1 mm. As a spring element is suitable for a hydraulic cylinder, a hydraulic spring, a leaf spring and in particular a plate spring and combinations of a plurality of the aforementioned springs, for example, a plurality of coupled plate springs. Also, a coil spring or a gas pressure / air spring can be used as a spring element. Alternatively, the non-locating bearing can also be designed as an elastomer bearing, as is known, for example, from bridge construction or for vibration compensation.

Preferably, the adjoining the copper mold segment is connected not only in a floating bearing, but in two or four loose bearings with the support structure.

Optionally, one or more of the remaining segments is or are in each case connected in at least one fixed bearing and at least one floating bearing with the support structure, in particular the segment i + 1.

According to a particularly preferred embodiment, each segment is connected in four connection points with the support structure, wherein each of two of the connection points is floating bearing and the other two bearings are independently selected from a fixed bearing, a sliding bearing, a support and a floating bearing.

More preferably, each of the two transverse to the casting direction (z-direction) on both sides of the casting strand opposite bearing designed as a floating bearing with spring element.

Equipped with the floating bearing pair according to the invention, the segment can adjust to a relative displacement to its neighbors within the design limit specified by the spring element to the new position, the adjustment movement is determined by the cast strand itself. On this then act only the restoring forces from the elastic coupling or the proportionate weight of the segment. Also, within the design limitation, alignment errors, e.g. when installing or changing the segments may be compensated.

The spring element is preferably selected such that the reaction forces acting on the casting strand as a result of the elastic coupling cancel out with the other external forces and upon deflection of the segment or component by a thermally and / or mechanically caused relative offset to the neighboring segment or component the reaction force acting on the strand are always smaller than in an embodiment of the floating bearing without spring element. This is e.g. permitted by spring forces of approx. 10% to 500% of the operating force to be expected at the bearing point. The travel is, for example, 0.5 to 3 times the permissible tolerance margin, wherein the spring element is adapted to transmit both tensile and compressive forces.

Since the adjoining the continuous casting mold segment i is subject to a particular stress, all four bearings, with which this segment is connected to the support structure, preferably designed as a floating bearing here.

The precisely aligned before commissioning the continuous casting components, in particular the individual segments including the strand guide rollers, which are aligned with the continuous casting mold, therefore, at the respective temperature changes during operation of the system their position to a small extent within the scope, the floating bearing according to the invention offers, change, with the segments thereby move transversely to the strand in the y direction against each other. The orientation of the components therefore remains wholly or at least for the most part even during the temperature changes and the associated material expansions, which is why the segments of the continuous casting machine according to the invention can also be referred to as self-centering components.

According to one embodiment, the continuous casting plant according to the invention also has a displacement sensor which is set up to determine the deviation of the position of at least one component of the continuous casting plant from its original position. The displacement sensor measures the deflection that the component on which it is located has traveled. The actual position of the component can then be determined from the measured deflection and its deviation from its original position can be determined.

The displacement sensor is preferably arranged on the segment adjoining the continuous casting mold (the segment i) or the subsequent segment (the segment i + 1). Optionally, the displacement sensor or an electrical component connected thereto can also be set up to compare the determined deviation from the original position with a predetermined desired value, and to emit a signal only when the setpoint is reached or exceeded, which can be perceived as an optical or acoustic warning signal, for example is. Thus, for example, a setpoint value can be determined which corresponds to a just tolerable deviation of the component of the continuous casting installation connected to the displacement sensor from its original position, whereby reaching the setpoint value is indicated by an emitted signal.

Optionally, the continuous casting plant according to the invention also has a control unit which is set up to detect an imminent breakthrough of the cast strand in a component, in particular a segment, of the continuous casting plant. For this purpose, the control unit is connected to the displacement sensor and / or to a force meter, which in particular measures the forces acting on a movable bearing according to the invention. From the deviation determined by the displacement sensor from the original position and / or the forces measured on the floating bearing according to the invention, the control unit thereupon determines the probability of a breakthrough in the relevant component. A breakthrough may be e.g. announce that the forces acting on a bearing point increase with time and, for example, exceed a predetermined limit, or also in that the measured by the displacement sensor deviation of a component from its original position stronger and / or faster than usual increases.

The invention also relates to a method for the optimized alignment of components of a continuous casting plant comprising a continuous casting plant comprising a continuous casting mold displaceable in oscillation by means of an oscillating device, to which a plurality of segments provided with strand guiding rolls adjoin, arranged on a support structure and at each of a plurality of bearing points are connected to the support structure, wherein at least one of the bearing points of the adjoining directly to the continuous casting mold segment is a movable bearing according to the invention.

The continuous casting plant provided for the method according to the invention can have all the features mentioned in connection with the description of the continuous casting plant according to the invention. In particular, not only the segment (segment i) adjoining the continuous casting mold but also the following segment (segment i + 1) as well as all other segments can be connected to the support structure by means of at least one movable bearing according to the invention. Preferably, each segment is connected in two fixed bearings and two movable bearings with the support structure.

Optionally, each non-locating bearing, by means of which the segments are fastened on the carrier structure, comprises at least, however, each movable bearing of the segment adjoining the continuous casting mold, a spring element. It is also possible to provide the fixed, sliding and / or supports with the optional spring elements. The inventive method therefore preferably has a step of equipping the at least one movable bearing with a spring element, wherein the spring element is adapted to grant the connection between the segment and support structure in at least one direction a predetermined margin, for example, up to 12 mm, up to 5 to 10 mm, up to 1 to 2 mm, up to <1 mm, up to <0.2 mm, up to <0.1 mm or up to 0.01 mm.

In the method according to the invention, the components of the continuous casting installation are optimally aligned before they are put into operation, for example the continuous casting mold and the segment i are aligned and the segments are mutually aligned e.g. aligned with the help of stencils or laser technology.

During or after commissioning, however, the individual components are practically self-aligning. The fact that the individual segments are not fixed completely rigidly on the support structure, but are fixed by means of at least one movable bearing according to the invention and preferably by means of two movable bearings according to the invention per segment on the support structure, the segments during the temperature-induced expansion processes within the by or Moving stored clearance according to the invention move, in which case the strand is performed without tension. Even with a component wear such. a roller wear, the inventive storage of the segments by means of at least one movable bearing according to the invention has a positive effect. For in particular in a component change is in an arrangement of the new (unworn) component instead of the old (worn) component, a self-centering of the new component with the adjacent components for both the quality of the product to be cast as well as for a longer life of the components very effective.

Optionally, the method according to the invention also has a step of determining the deviation of the position of at least one component the continuous casting from its original position by a displacement sensor. The displacement sensor or an electrical component connected thereto can be set up to compare the deviation of the component of the continuous casting plant from its original position with a predetermined limit value and to issue a warning signal when it is reached or exceeded.

Furthermore optionally, the method according to the invention can also have a step of recognizing an imminent breakthrough in a component of the continuous casting installation by a control unit. For this purpose, the control unit is preferably set up to receive signals from the odometer and / or a force gauge and to issue a warning signal in case of abnormalities. Abnormalities may be e.g. consist in a relatively large deviation of a component from its original position or in an increasing with time increasing acting on the movable bearing of a segment force.

Description of the invention

• 1 ein Segment einer Stranggießanlage in Seitenansicht,
• 2 ein Loslager mit Federelement,
• 3 in den Teilfiguren a) und b) zwei Segmentlagerungen gemäß dem Stand der Technik, einmal mit und einmal ohne elastische Koppelungen, und
• 4 in den Teilfiguren a) bis c) drei verschiedene erfindungsgemäße Segmentlagerungen,
• 5 und 6 schematisch eine Kreisbogenanlage bzw. Senkrechtabbiegeanlage mit lokalem Koordinatensystem.

The invention will now be described in greater detail by way of examples and with reference to the figures. It shows schematically:

• 1 a segment of a continuous casting plant in side view,
• 2 a floating bearing with spring element,
• 3 in the sub-figures a) and b) two segment bearings according to the prior art, once with and once without elastic couplings, and
• 4 in the subfigures a) to c) three different segment bearings according to the invention,
• 5 and 6 schematically a circular arc system or vertical bending plant with local coordinate system.

The 1 schematically shows a segment 4 a continuous casting plant with paired strand guide rollers 3 in side view. The line A denotes the casting radius which forms the lower edge of the cast product. The vector B denotes the weight of the segment 4 , which attacks in the center of gravity of the segment. At the camp 6 grabs the associated horizontal force (shown as a vector C ) at. The at the tangential floating bearing 7 attacking horizontal support force is shown as vector D.

The 2 shows a floating bearing 7 with spring element 8th as it can be used in a continuous casting plant according to the invention. The spring element 8th is adapted to transmit both tensile and compressive forces and comprises in the embodiment shown a combination of a plurality of coupled plate springs.

The radially movable floating bearing 7 is by means of a connector 11 with a segment 4 , eg the segment i adjoining the continuous casting mold, and by means of a further connecting piece 12 on the opposite side with the support structure 5 connected. So leaves the floating bearing 7 a movement in the direction transverse to the strand, wherein the additional degree of freedom by the spring element 8th is limited.

The 3a shows a storage of a segment 4 according to the current state of the art. The segment 4 is stored in four points, the bearing A as a fixed bearing and the bearing B are designed as a sliding bearing. Camps C and D are each supports.

The 3b shows a segment bearing according to the prior art, in which the bearings are designed as well as in the 3a shown embodiment, wherein the support C additionally has an elastic coupling.

In the 4 three inventive segment bearings are shown.

According to the in 4a embodiment shown are the bearings A and B each as a floating bearing and the bearings C and D each formed as a support. In the floating bearing A it is, for example, a floating bearing with fixed-bearing-side boundary and at the camp B it is, for example, a floating bearing with a slide-bearing-side boundary. In the embodiment shown, both movable bearings are elastically coupled, but it is also possible to use movable bearings without elastic coupling.

In the in 4b shown embodiment, all four bearings are designed as floating bearing with elastic coupling. It may be in the camp A For example, a floating bearing with fixed bearing side boundary and the camp B act around a floating bearing with slide-bearing-side limit, while the bearings C and D each floating bearing with Auflagerseitiger limitation. Such a segment storage according to the invention is particularly preferred for the segment i, which adjoins the continuous casting mold.

The 4c shows a preferred segment storage according to the invention for sheet and horizontal segments, in which the bearing A a permanent camp and the camp B a sliding bearing is. Camps C and D are each designed as floating bearing with preferably bearing-side boundary and have an elastic coupling.

The features of the invention disclosed in the foregoing description, in the figures and in the claims may be essential both individually and in any combination for the realization of the invention in its various embodiments.

LIST OF REFERENCE NUMBERS

1

oscillating

2

continuous casting

3

Strand guide rolls

4

segment

5

support structure

6

fixed bearing

7

movable bearing

8th

spring element

9

displacement sensor

10

control unit

11

first connector

12

second connector

Claims (11)

Continuous casting plant, comprising a continuous casting mold (2) which can be set in oscillation by means of an oscillating device (1), to which a plurality of segments (4) provided with strand guide rolls (3) adjoin, arranged on a support structure (5) and at a plurality of bearing points with the support structure (5), characterized in that at least one of the bearing points of the directly adjacent to the continuous casting mold (2) adjoining the segment (4) is a floating bearing (7). Continuous casting plant Claim 1 Characterized in that each of which then directly to the continuous casting mold segment (4) the following segments (4) is connected by at least one fixed bearing (6) and by at least one movable bearing (7) with the support structure (5). Continuous casting plant according to one of the Claims 1 or 2 , characterized in that each of the directly following the continuous casting mold subsequent segment (4) following segments (4) in two fixed bearings (6) and in two movable bearings (7) with the support structure (5) is connected, which is directly to the continuous casting mold (2) adjoining segment (4) in four movable bearings (7) with the support structure (5) is connected. Continuous casting plant according to one of the preceding claims, characterized in that the at least one loose bearing (7) comprises a spring element (8), which is arranged, the connection with the support structure (5) in this point up to 12 mm, up to 5 to 10 mm, up to 1 to 2 mm, up to <1 mm, up to <0.2 mm or up to <0.1 mm clearance. Continuous casting plant Claim 4 , characterized in that the spring element (8) comprises a plate spring, a hydraulic spring or a leaf spring or consists thereof. Continuous casting plant according to one of the preceding claims, characterized by a displacement sensor (9) which is set up to determine the deviation of the position of at least one component of the continuous casting plant from its original position. Continuous casting plant according to one of the preceding claims, characterized by a control unit (10) which is set up to detect an imminent breakthrough in a component of the continuous casting plant. Method for the optimized alignment of components of a continuous casting installation , characterized by a step of providing a continuous casting installation which comprises a continuous casting mold (2) which can be set in oscillation by means of an oscillating device (1), to which several segments (4) provided with strand guiding rolls (3) join , which are arranged on a support structure (5) and connected at a plurality of bearing points with the support structure (5), wherein at least one of the bearing points of directly to the continuous casting mold (2) adjoining the segment (4) is a floating bearing (7). Method according to Claim 8 , characterized in that the movable bearing (7) of the continuous casting mold (2) adjoining the segment (4) comprises a spring element (8). Method according to one of Claims 8 or 9 characterized by a step of determining the deviation of the position of at least one component of the continuous casting plant from its original position by a displacement sensor (9). Method according to one of the preceding claims, characterized by a step of detecting an imminent breakthrough in a component of the continuous casting plant by a control unit (10).

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