Roller assembly and optimization method

Abstract

The invention relates to a roller arrangement (10, 10a, 10b) for the horizontal section (20) of a casting plant (30), in particular a thin slab casting plant, a horizontal section (20) with such a roller arrangement (10, 10a, 10b), a casting plant (30) with such a horizontal section (20), and a method (100) for optimizing a roller arrangement (10, 10a, 10b). The roller arrangement (10, 10a, 10b) has a plurality of roller pairs (12, 12a) arranged one behind the other in a transport direction (T). Each roller pair (12, 12a) comprises two rollers (14, 14a) arranged opposite each other. According to the invention, the distance (d1, d2) between each pair of identical roller pairs (12) within the roller arrangement (10, 10a, 10b) varies.

Description

field of technology

[0001] The invention relates to a roller arrangement for the horizontal section of a casting plant, in particular a thin slab plant, a horizontal section with such a roller arrangement, a casting plant with such a horizontal section and a method for optimizing a roller arrangement. State of the art

[0002] Casting systems for casting metal strands typically feature a mold into which liquid metal is continuously fed from an intermediate reservoir, creating a liquid level within the mold. A curved section, which may also include a bending section, adjoins the mold and consists of numerous rollers. This section guides the strand emerging vertically from the mold into a horizontal position via a straightening section. The curved section then leads into a horizontal section (also including a straightening section), which again contains numerous rollers. After passing through the horizontal section, the strand is sufficiently cooled and stable to allow for further processing. The curved and horizontal sections together form the so-called strand guide of the system.

[0003] A problem that arises with such casting systems is fluctuations in the fill level of the mold, i.e., a constant, and especially periodic, rise and fall of the liquid level. These fluctuations are caused by bulging of the still-molten strand as it passes through the curved and horizontal sections. Between adjacent coils, the thin strand sheath surrounding the still-liquid core can bulge. The associated volume changes in the strand lead to an oscillating flow of metal in the liquid core and thus ultimately to the fill level fluctuations. This effect is self-reinforcing, meaning that the fill level fluctuations, or rather the oscillating flow of metal, can lead to even greater bulging.

[0004] Fluctuations in the fill level can negatively impact strand quality, particularly the surface quality of the cast strand, and can complicate or even prevent stable casting operations. The bulging associated with these fluctuations can also lead to the formation of internal cracks in the strand and to mid-segregation. Furthermore, there is a risk that the strand will not have a consistent thickness after solidification. While this can generally be mitigated by reducing the casting speed, this decreases the plant's productivity.

[0005] Therefore, other approaches have been developed to prevent strand bulging or fluctuations in fill level. For example, the cooling of the strand directly below the mold or in the curved section can be intensified or improved, such as through optimized cooling patterns. The resulting thicker and thus more stable strand shell counteracts bulging. However, this approach is only sufficiently effective at low speeds and strand thicknesses. It is therefore unsuitable for use in thin slab casting at casting speeds of approximately 6 m / min, i.e., when casting slabs with a thickness of 120 mm or less.

[0006] Alternatively, fluctuations in the fill level can be at least partially compensated for by regulating the metal flow into the mold. This is usually achieved by periodically reducing or even stopping the outflow from the intermediate reservoir. However, due to technical limitations, this is only possible up to frequencies of approximately 0.6 Hz. Faster fluid oscillations in the core of the strand, which typically occur at casting speeds above approximately 2 m / min, cannot be counteracted in this way.

[0007] Another approach is to influence the metal flow from the mold by dynamically varying the gap in the bend section (bender gap oscillations). For example, the distance between opposing rollers in the bend section can be changed periodically. This can potentially compensate for high-frequency fluctuations in fill level; however, such gap variation systems are complex, maintenance-intensive, and expensive. Summary of the invention

[0008] Against this background, it is an object of the present invention to improve the avoidance or at least the reduction of fluctuations in fill level or bulges in continuous casting.

[0009] This problem is solved by a roller arrangement for a horizontal section of a casting plant, in particular a thin slab plant, a horizontal section with such a roller arrangement, a casting plant with such a horizontal section and a method for optimizing a roller arrangement according to the independent claims.

[0010] Preferred embodiments are the subject of the dependent claims and the following description.

[0011] A roller arrangement for a horizontal section of a casting plant, in particular a thin slab plant, according to a first aspect of the invention, comprises a plurality of roller pairs arranged one behind the other in a transport direction, in particular horizontally. Each roller pair comprises two rollers arranged opposite each other, in particular vertically. According to the invention, the distance between any two identical (adjacent) roller pairs varies within the roller arrangement.

[0012] In the context of the invention, the distance between two pairs of rollers is preferably the distance between the connecting lines, which expediently run parallel, through the axis of rotation of the two rollers of each of these two pairs of rollers. The distance is therefore not a tangential distance between the outer surfaces of the rollers, but an axial distance.

[0013] Similar pairs of rollers within the meaning of the invention are preferably pairs of rollers whose rollers are of a similar design, i.e., for example, have the same diameter.

[0014] It has been shown that the dynamics of bulges occurring during continuous casting, particularly self-reinforcing effects, are largely determined by the roller spacing in the horizontal section of a casting machine, especially at high casting speeds of around 6 m / min. Comprehensive studies have revealed that the majority of fill level fluctuations in the mold of the casting machine are caused by uniformly arranged rollers or roller pairs in the horizontal section.

[0015] One aspect of the invention is therefore based on the approach of distributing the rollers or roller pairs of a roller arrangement in the horizontal section of a casting machine not uniformly, but unevenly. A (horizontally) uneven distribution of the rollers or roller pairs in the horizontal section is advantageously achieved by varying the (horizontal) distances between adjacent rollers of the roller pairs. It is advantageously provided that the distance between any two (adjacent) identical roller pairs changes at least once within the roller arrangement. For example, a first distance can be provided between two adjacent identical roller pairs in one section of the roller arrangement, and a second distance, different from the first, can be provided in another section. Advantageously, further different distances can also be provided between other adjacent roller pairs.

[0016] It has been found that varying the spacing between identical pairs of rollers within the roller arrangement reliably suppresses fluctuations in the mold fill level and the growth of bulges in the casting strand. Ultimately, this leads to improved strand quality, particularly surface quality, and more stable casting operations. Specifically, the occurrence of internal cracks and mid-segregation can be avoided or at least reduced.

[0017] A particularly advantageous aspect of varying the distances between identical pairs of rollers within the roller arrangement is that it provides a passive measure for stabilizing the liquid level in the mold and for suppressing or at least reducing strand bulges. This measure is effective over a wide range of casting speeds, especially at high casting speeds of around 6 m / min, as occur in thin-slab casting plants. Consequently, when using at least one roller arrangement according to the invention, there is little or, ideally, no need to actively compensate for bulges or fluctuations in the fill level – with the associated effort and costs.

[0018] Preferred embodiments of the invention and their further developments are described below. These embodiments can be combined with each other and with the aspects of the invention described below, unless expressly excluded.

[0019] Particularly reliable prevention or at least reduction of bulging and the associated fluctuations in fill level can be achieved by providing at least three different distances between each pair of adjacent rollers within the roller arrangement. For example, two or more adjacent roller pairs can be arranged at the first distance, two or more adjacent roller pairs at the second distance, and two or more adjacent roller pairs at a third distance different from the first and second. Such a large variation in the distances between adjacent roller pairs within the roller arrangement can effectively prevent or at least reduce regular, uniform bulging of the strand between adjacent rollers and the associated amplification of fill level fluctuations.

[0020] It can be particularly advantageous if the roller arrangement has a predetermined distribution of the distances between adjacent roller pairs. The various distances between adjacent roller pairs within the roller arrangement can, for example, be distributed such that the greatest distance is provided in a central region of the roller arrangement. This allows, in particular, the arrangement in the central region of at least one driver roller pair consisting of two opposing rollers with a roller diameter that is larger than the roller diameter of rollers arranged outside the central region.

[0021] Accordingly, based on the spacing distribution, in a forward region of the roller arrangement relative to the transport direction, the distance between at least two pairs of rollers is advantageously smaller than in the central region of the roller arrangement. For example, in the forward region, three consecutive pairs of rollers can each be arranged at a first distance from one another. The last of these pairs of rollers, viewed in the transport direction, is then advantageously arranged at a third, larger distance from another pair of rollers, in particular the driver roller pair consisting of rollers with an increased roller diameter.

[0022] Alternatively or additionally, according to the spacing distribution, the distance between at least two pairs of rollers in a region of the roller arrangement further back in the direction of transport is also smaller than in the central region of the roller arrangement. For example, three consecutive pairs of rollers can be arranged at a second distance from each other in the rear region. The first of these pairs of rollers, viewed in the direction of transport, is then advantageously arranged at the third, larger distance to the next pair of rollers, in particular the driver roller pair.

[0023] Regardless, it can be provided that, according to the spacing distribution, the distance between at least two pairs of rollers in the front area is smaller than in the rear area, meaning that the at least two pairs of rollers in the front area are arranged closer together than in the rear area. For example, on the "input side" (viewed in the direction of transport), three consecutive pairs of rollers, each arranged at the first distance from each other, can be provided. On the "output side," three consecutive pairs of rollers, each arranged at the second distance from each other, can then be provided. The second distance is advantageously larger than the first distance.

[0024] An effective reduction in bulging dynamics and the corresponding fluctuations in fill level can be achieved, for example, by arranging at least two adjacent pairs of rollers in the front section at least 5 mm closer together or further apart than at least two adjacent pairs of rollers in the rear section, i.e., for example, the first spacing being 5 mm smaller or larger than the second spacing. At the same time, it is advantageous to arrange the at least two adjacent pairs of rollers in the front section at most 50 mm closer together or further apart than at least two adjacent pairs of rollers in the rear section, i.e., for example, to make the first spacing 50 mm smaller or larger than the second spacing.

[0025] Generally speaking, with regard to suppressing or at least reducing oscillations of different wavelengths while maintaining stable support of the strand, it has proven advantageous to have different distances between each pair of identical rollers stepped by at least 5 mm and / or at most 50 mm. In other words, the "jumps" between different distances provided between each pair of adjacent, preferably identical, roller pairs within the roller arrangement are preferably at least 5 mm and / or at most 50 mm.

[0026] The horizontal section of a casting plant, in particular a thin slab casting plant, according to a second aspect of the invention, comprises a plurality of roller assemblies arranged one behind the other in a transport direction, in particular horizontally, wherein at least one of the roller assemblies is designed according to the first aspect of the invention. By means of such a horizontal section, fluctuations in the fill level in the mold caused by the dynamics of the bulges between each pair of rollers can be passively avoided or at least reduced. As a result, improved strand quality and / or more stable casting conditions can be achieved with minimal effort.

[0027] To achieve an even more reliable avoidance or at least reduction of fluctuations in the fill level in the mold, or to at least largely reduce the self-reinforcing effect during strand bulging, a second roller arrangement is preferably also designed according to the first aspect of the invention. Advantageously, the variation of the distance in the at least one first roller arrangement differs from the variation of the distance in the at least one second roller arrangement.

[0028] Such a second roller arrangement allows for a greater number of different distances between any two identical pairs of rollers within the horizontal section. If the first and second roller arrangements are also essentially identical in construction, i.e., structurally interchangeable, the additional second roller arrangement can also be used to achieve variations in the sequence of different distances between the roller pairs. For example, different arrangements or sequences of the first and second roller arrangements are conceivable.

[0029] Of course, it is also advantageous to provide further roller arrangements with other, different variations in spacing.

[0030] To enable the structural interchangeability of at least one first and at least one second roller assembly, and optionally also the subsequent roller assemblies, it is advantageous for the at least one first and at least one second roller assembly to have the same length in the transport direction, i.e., to be built to the same length. In particular, all roller assemblies can be structurally identical except for the spacing between at least some of the roller pairs. For this purpose, all roller assemblies of the horizontal section can have the same frame. The length of the roller assembly is expediently defined as the distance from the first roller to the last roller of the assembly. The structural interchangeability of the roller assemblies, especially the first and second roller assemblies, allows for considerable flexibility and variation in the design of the horizontal section.

[0031] Particularly effective prevention of fill level fluctuations or reduction of bulging dynamics in the horizontal section can be achieved by arranging several, i.e., at least two, first roller assemblies and several, i.e., at least two, second roller assemblies alternately. In other words, a sequence of first and second roller assemblies is preferably provided in an alternating manner in at least one section of the horizontal section.

[0032] In principle, other arrangements or sequences of multiple first and second roller assemblies are also conceivable. For example, two second roller assemblies can always be provided between each first roller assembly. In another variant, two second roller assemblies can always follow two first roller assemblies. Likewise, variants are conceivable in which further roller assemblies designed according to the first aspect of the invention are arranged, for example, alternately or in another manner with the first and second roller assemblies.

[0033] The casting plant, in particular the thin slab casting plant, according to a third aspect of the invention, has a horizontal section according to the second aspect of the invention. In such a casting plant, fluctuations in the fill level in the mold caused by the dynamics of the bulges between each pair of rollers in the horizontal section can be passively suppressed or at least mitigated. As a result, improved strand quality and / or more stable casting conditions can be achieved with minimal effort.

[0034] Fluctuations in the fill level of the mold in a casting plant, or oscillations of the liquid metal occurring in the strand cast by the casting plant, are caused not only by the spacing of the rollers in the horizontal section, but also, for example, by the rollers in the curved section. Furthermore, if, in addition to conventional roller arrangements with uniformly spaced pairs of rollers in the horizontal section, for example alongside the arrangement according to the invention, this can also amplify the fluctuations in the fill level or the bulging dynamics.

[0035] To counteract this, it is advantageous that the variation in the distance between each pair of identical rollers in a roller arrangement according to the first aspect of the invention is also predetermined with regard to these "external" contributions, i.e., contributions made outside of the roller arrangements according to the invention, to the fill level fluctuations or the bulging dynamics. In other words, it is advantageous to adapt the roller arrangement according to the invention to the entire casting system or at least the entire horizontal section, particularly to predetermined casting conditions.

[0036] This can be achieved with the method, particularly computer-implemented, for optimizing a roller arrangement for the horizontal section of a casting plant, in particular a thin slab plant, according to a fourth aspect of the invention.This method comprises: i) a simulation step in which fluctuations in the fill level of a mold of a casting plant are simulated on the basis of a plant model in which a horizontal section of the casting plant has a roller arrangement with a plurality of roller pairs arranged one behind the other in a transport direction, in particular horizontally, each consisting of two rollers facing each other, in particular vertically; ii) an association step in which the simulated fluctuations in the fill level, in particular the magnitude of these fluctuations, are associated with distances between each pair of identical rollers of the roller arrangement; and iii) the simulation step and the association step are repeated for at least one changed distance between at least two identical pairs of rollers of the roller arrangement and iv) all simulated fluctuations in the fill level, in particular their magnitude, are compared with each other.In this way, the optimal distribution of the distances between the roller pairs of the roller arrangement, in which the fill level fluctuations are the smallest, can be determined.

[0037] A plant model according to the present invention is preferably a thermomechanical dynamic model of the entire casting plant, in particular the mold, the arc section and the horizontal section. Using this model, the bulging behavior of the casting strand can be comprehensively analyzed and an optimized roller arrangement can be determined.

[0038] The simulation of fill level fluctuations expediently includes determining a wavelength and / or a frequency of strand bulges in the casting system. Preferably, the contribution of each roller pair in the horizontal section, and preferably also in the curved section, to the fill level fluctuations or the bulge dynamics is also determined and taken into account when determining the spacing of the roller pairs. Short description of the drawings

[0039] The properties, features, and advantages of this invention described above, as well as the manner in which they are achieved, will become clearer and more readily understandable in connection with the following description of an exemplary embodiment, which is explained in more detail in conjunction with the drawings. These drawings show: FIG 1 an example of a roller arrangement; FIG 2 an example of a casting system; FIG 3 an example of an alternative configuration of the horizontal section of the casting system. FIG 2 ; and FIG 4 an example of a method for optimizing a roller arrangement.

[0040] Where appropriate, the same reference numerals are used in the figures for the same or corresponding elements of the invention. Description of the embodiments

[0041] FIG 1 Figure 1 shows an example of a roller arrangement 10 for the horizontal section of a casting plant, in particular a thin slab plant, with a plurality of roller pairs 12 arranged one behind the other in a transport direction T. Each of these roller pairs 12 consists of two rollers 14 arranged opposite each other transversely to the transport direction T. A gap D is thus formed between the rollers 14 of each pair 12, in which a casting strand can be guided.

[0042] The roller pairs 12 are spaced apart from each other along the transport direction T at different distances d1, d2, and d3. These distances d1, d2, and d3 are measured between the axes of rotation R of adjacent rollers 14 in the transport direction T, within each pair of roller pairs 12. The rollers 14 are arranged by means of a support 16 within a length L, defined as the distance between the first and last roller pair 12 of the roller arrangement 10 in the transport direction T.

[0043] For the sake of clarity, in FIG 1 Only one of the roller pairs 12 is highlighted by a dotted oval and provided with a reference symbol. For the same reason, only two of the rotation axes R and only two of the rollers 14 are also provided with a reference symbol.

[0044] In particular, in a forward region V of the roller assembly 10, viewed in the transport direction T, adjacent pairs of rollers 12 are arranged at a first distance d 1 from each other. These pairs of rollers 12 are identical to the pairs of rollers 12 in a rear region H of the roller assembly 10, viewed in the transport direction T. That is, the rollers 14 of these pairs of rollers 12 in the forward and rear regions V, H are identical to each other, in particular having the same diameters. Adjacent pairs of rollers 12 in the rear region H are arranged at a second distance d 2 from each other, which differs from the first distance d 1.

[0045] Generally speaking, the distance d 1 , d 2 between any two identical pairs of rollers 12 within the roller arrangement 10 varies.

[0046] In a central region M of the roller arrangement 10, a roller pair 12a can be provided, the rollers 14a of which have a larger diameter than the rollers 14 in the front and rear regions V, H. Unlike the rollers 14 in the front and rear regions V, H, the rollers 14a in the central region M expediently serve as drive rollers, i.e., they can be actively rotated by means of a drive device (not shown). The roller pair 12a in the central region M is arranged at a third distance d3 from the adjacent roller pairs 12 in the front and rear regions V, H, which may differ from the first and second distances d1, d2.

[0047] Advantageously, the third distance d3 is larger than the first and second distances d1, d2. This simplifies the arrangement of the driver rollers 14a between the rollers 14 in the front and rear areas V, H.

[0048] The second distance d2 can be larger than the first distance d1. However, it is also possible that the second distance d2 is smaller than the first distance d1.

[0049] By distributing the distances between the roller pairs 12, in particular by providing different distances d1, d2 between identical roller pairs 12, the dynamics of bulges in the casting strand occurring between adjacent rollers 14 in the transport direction T can be positively influenced when a partially solidified casting strand is guided by the roller arrangement 10 in a horizontal area of ​​a casting plant. In particular, the oscillation of these bulges, which occurs with a consistently regular spacing of identical roller pairs in conventional roller arrangements, can be prevented or at least reduced. This also results in a reduction of fill level fluctuations in a mold of the casting plant.It has been shown that these positive effects cannot be achieved – or at least not to this extent – ​​solely by different distances between the roller pairs 12 in the front and rear areas V, H and the driver roller pair 12a in the middle area M (i.e., when the first and second distances d 1 , d 2 are the same).

[0050] The aforementioned positive effects can also be achieved, in principle, by a different spacing distribution of the roller pairs 12 than the one described above. For example, according to another, equally advantageous spacing distribution, the first spacing d1 can be greater than the second spacing d2. Alternatively or additionally, further (different) spacings between other similarly configured roller pairs 12 can also be provided.

[0051] FIG 2 Figure 30 shows an example of a casting plant 30, in particular a thin-slab casting plant, for casting a strand 40. The casting plant 30 comprises a mold 32, which can be continuously filled with liquid metal 42 from an intermediate tank 34, so that a liquid level 44 forms in the mold 32. The strand 40 emerging from the mold 32, which still has a liquid core, can be transferred from the vertical to the horizontal position by means of a plurality of support rollers 36a arranged along an arc. The support rollers 36a form an arc section 36 of the casting plant 30. A horizontal section 20 adjoins the arc section 36, which is formed from several roller arrangements 10a, 10b, indicated by dashed rectangles, arranged one behind the other in a transport direction T.Each of these roller arrangements 10a, 10b has a plurality of roller pairs 12 arranged in the transport direction T, wherein each roller pair 12 is formed from two rollers 14 arranged opposite each other.

[0052] For clarity, only one of the roller pairs 12 is highlighted by a dotted oval and marked with a reference symbol. For the same reason, only one of the support rollers 36a and two of the rollers 14 are marked with a reference symbol.

[0053] The distances between adjacent, identical pairs of rollers 12 vary within the respective roller arrangement 10a, 10b. That is, at least two adjacent pairs of rollers 12 are arranged at a first distance from each other and at least two further adjacent, identical pairs of rollers 12 are arranged at a second distance different from the first distance (cf. FIG 1 ).

[0054] The arrangement of the first roller assemblies 10a with respect to the spacing of adjacent, identical roller pairs 12 is expediently different from the arrangement of the second roller assemblies 10b. For example, the difference between the spacing of identical roller pairs 12 in a front section of the first roller assemblies 10a and in a rear section of the first roller assemblies 10a can be smaller than the difference between the spacing of identical roller pairs 12 in a front section of the second roller assemblies 10b and in a rear section of the second roller assemblies 10b. Alternatively or additionally, the spacing distribution can also differ between the first and second roller assemblies 10a, 10b, i.e.,for example, whether the distance between adjacent, similar pairs of rollers 12 within the respective roller arrangement 10a, 10b increases or decreases.

[0055] The roller assemblies 10a and 10b expediently have the same length L and are therefore structurally interchangeable. In particular, all roller assemblies 10a and 10b can be connected using identical frames (see...). FIG 1 ), between which the rollers 14 are, for example, rotatably mounted, in the horizontal section 20. This allows for a large number of possible configurations of the horizontal section 20 to be implemented with minimal effort and flexibility, as exemplified below in connection with FIG 3 described.

[0056] Advantageously, the frames are also designed in the same manner as frames of conventional roller arrangements (not shown), which have a constant spacing between identical roller pairs 12. This allows existing casting plants to be retrofitted with roller arrangements 10a, 10b, which have varying distances between identical roller pairs 12, in a cost-effective and low-effort manner.

[0057] In principle, the casting system 30 can, in addition to the two first and two second roller arrangements 10a, 10b shown, also have further first and second roller arrangements 10a, 10b, which are expediently arranged alternately in the transport direction T. Alternatively or additionally, one or more conventional roller arrangements with a constant distance between identical roller pairs 12 can also be provided before and / or after the four roller arrangements 10a, 10b shown.

[0058] FIG 3 shows an example of an alternative configuration of the horizontal section 20 of the casting plant FIG 2 In this configuration, the two second roller assemblies 10b are arranged between the two first roller assemblies 10a. This pattern can be continued in the transport direction T if further second and / or first roller assemblies 10b, 10a are provided.

[0059] In a further alternative not shown, it may also be provided that two first roller arrangements 10a and two second roller arrangements 10b are provided alternately.

[0060] FIG 4 shows an example of a method 100, particularly a computer-implemented method, for optimizing a roller arrangement for the horizontal section of a casting plant, in particular a thin slab plant.

[0061] In simulation step S1, fluctuations in the fill level of a casting mold are simulated based on a model of the casting plant. This model, in particular a thermomechanical dynamic model of the casting plant, expediently describes (among other things) a horizontal section of the casting plant with a roller arrangement comprising multiple pairs of rollers arranged one behind the other in a transport direction, each pair consisting of two opposing rollers. To simulate the fill level fluctuations, parameters such as the wavelength and / or frequency of strand bulges occurring in the cast strand and the resonance of these bulges can be determined, for example, through a thermomechanical simulation of the strand's solidification. Possible input parameters for the model include, among others: the initial position of the liquid level in the mold, i.e.,the filling level of the mold; the casting speed; the chemical composition of the liquid metal supplied to the mold; the material properties of the mold; the roller geometry, in particular the positions of the support rollers in the arc section and / or the rollers in the horizontal section; the dimensions of the strand (thickness and width) and the cooling of the strand.

[0062] In an association step S2, the simulated fill level fluctuations are associated with distances between each pair of identical rollers in the roller arrangement. This allows the respective contribution of each roller pair in the horizontal section to the fill level fluctuations to be determined. This is expediently done on the basis of an elasticity model of the strand based on beam theory.

[0063] In a further process step S3, the simulation step S1 and the association step S2 are preferably repeated for at least one changed distance between at least two identical pairs of rollers in the horizontal section. This allows a comparison of all simulated fill level fluctuations in a further process step S4. Advantageously, the configuration of the roller arrangement with the smallest fill level fluctuations (for example, the lowest standard deviation of the fluctuations) can be determined based on this comparison.

[0064] In this way, new casting plants with an optimized roller arrangement or a horizontal section featuring one or more optimized roller arrangements can be designed. The 100 roller arrangements optimized using the described method can suppress or reduce strand bulging and the corresponding fill level fluctuations so effectively that, in a casting plant designed in this way, further measures to suppress or at least reduce strand bulging and the corresponding fill level fluctuations are either unnecessary or only required to a reduced extent. If necessary, the optimized roller arrangements can also be used in existing casting plants to create more stable casting conditions and enable the casting of higher-quality strands.

[0065] Although the invention has been further illustrated and described in detail by the preferred embodiments, the invention is not limited by the disclosed examples and other variations can be derived from them by the person skilled in the art without leaving the scope of protection of the invention. List of reference symbols

[0066] 10, 10a, 10b Roller arrangement 12 Roller pair 12a Driver roller pair 14 Roller 14a Driver roller 16 Frame 20 Horizontal section 30 Casting plant 32 Mold 34 Intermediate container 36 Bow section 36a Support roller 40 Strand 42 Liquid metal 44 Liquid mirror 100 Procedure S1 Simulation of fill level fluctuations S2 Association of fill level fluctuations with distances between each pair of identical rollers S3 Repeating the simulation step and the association step S4 Comparing the simulated fill level fluctuations TTransport direction LLength DSpat d1 first distance d2 second distance d3 third distance MMiddle area Vfront area Hrear area RRotation axis

Claims

1. Roller arrangement (10, 10a, 10b) for the horizontal section (20) of a casting plant (30), in particular a thin slab plant, with a plurality of roller pairs (12, 12a) arranged one behind the other in a transport direction (T), each consisting of two rollers (14, 14a) arranged opposite one another, wherein the distance (d1, d2) between each two identical roller pairs (12) within the roller arrangement (10, 10a, 10b) varies.

2. Roller arrangement (10, 10a, 10b) according to claim 1, wherein within the roller arrangement (10, 10a, 10b) at least three different distances (d1, d2, d3) are provided between each two adjacent pairs of rollers (12, 12a).

3. Roller arrangement (10, 10a, 10b) according to one of the preceding claims, comprising a predetermined distribution of the distances (d1, d2, d3) between adjacent roller pairs (12, 12a), wherein according to the distribution in a central region (M) of the roller arrangement (10, 10a, 10b) the greatest distance (d3) is provided.

4. Roller arrangement (10, 10a, 10b) according to one of the preceding claims, comprising a predetermined distribution of the distances (d1, d2, d3) between adjacent roller pairs (12, 12a), wherein according to the distribution in a front region (V) of the roller arrangement (10, 10a, 10b) with respect to the transport direction (T) the distance (d1) between at least two roller pairs (12) is smaller than in a central region (M) of the roller arrangement (10, 10a, 10b).

5. Roller arrangement (10, 10a, 10b) according to one of the preceding claims, comprising a predetermined distribution of the distances (d1, d2, d3) between adjacent roller pairs (12, 12a), wherein according to the distribution in a rear region (H) of the roller arrangement (10, 10a, 10b) with respect to the transport direction (T) the distance (d2) between at least two roller pairs (12) is smaller than in a central region (M) of the roller arrangement (10, 10a, 10b).

6. Roller arrangement (10, 10a, 10b) according to one of the preceding claims, wherein at least two identical roller pairs (12) are arranged more closely together in a front region (V) of the roller arrangement (10, 10a, 10b) with respect to the transport direction (T) than in a rear region (H) of the roller arrangement (10, 10a, 10b) with respect to the transport direction (T).

7. Roller arrangement (10, 10a, 10b) according to one of the preceding claims, wherein different distances (d1, d2) between each two identical roller pairs (12) are stepped by 5 mm to 50 mm.

8. Horizontal section (20) of a casting plant (30), in particular a thin slab plant, with a plurality of roller arrangements (10, 10a, 10b) arranged one behind the other in a transport direction (T), wherein at least a first of the roller arrangements (10a) is designed according to one of claims 1 to 7.

9. Horizontal section (20) according to claim 8, wherein at least a second of the roller assemblies (10b) is designed according to one of claims 1 to 7 and the variation of the distance (d1, d2) in the at least one first roller assembly (10a) differs from the variation of the distance (d1, d2) in the at least one second roller assembly (10b).

10. Horizontal section (20) according to claim 9, wherein the at least one first and the at least one second roller arrangement (10a, 10b) have the same length (L) in the transport direction (T).

11. Horizontal section (20) according to claim 9 or 10, wherein a plurality of first roller assemblies (10a) and a plurality of second roller assemblies (10b) are arranged alternately.

12. Casting plant (30), in particular thin slab plant, with a horizontal section (20) according to one of claims 8 to 11.

13. Method (100) for optimizing a roller arrangement (10, 10a, 10b) for the horizontal section (20) of a casting plant (30), in particular a thin slab plant, comprising: - in a simulation step (S1), simulating fill level fluctuations in a mold (32) of a casting plant (30) on the basis of a plant model in which a horizontal section (20) of the casting plant (30) has a roller arrangement (10, 10a, 10b) with a plurality of roller pairs (12, 12a) arranged one behind the other in a transport direction (T), each comprising two rollers (14, 14a) arranged opposite one another; - in an association step (S2), associating the simulated fill level fluctuations with distances (d1, d2) between two identical roller pairs (12) of the roller arrangement (10, 10a, 10b);- repeating (S3) the simulation step (S1) and the association step (S2) for at least one changed distance (d1, d2) between at least two similar roller pairs (12) of the roller arrangement (10, 10a, 10b); and - comparing (S4) all simulated fill level fluctuations;

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