System for producing a metal strip, control / regulating system of a secondary cooling device

Abstract

Plant (1) for the production of a metal strip (100), wherein the plant (1) comprises: a casting machine (10) configured to produce the metal strip (100) in the form of a casting strand and to transport it along a conveying direction (F); a secondary cooling device (20) comprising nozzle arrangements (21) configured to cool the metal strip (100) by applying a coolant, preferably a water / air mixture, in the area of ​​the casting machine (10); at least one sensor device (30) configured to detect an edge temperature Tedge and a center temperature Tcenter of the metal strip (100), wherein the edge temperature Tedge denotes a surface temperature of the metal strip (100) in a near-edge region (101) and the center temperature Tcenter denotes a surface temperature in the middle region (102) of the metal strip (100);and a control device (50) which communicates with the secondary cooling device (20) and the sensor device (30) and is configured to determine a secondary cooling fault FSecundary cooling from the edge temperature TEdge and the center temperature TCenter of the metal strip (100) and to control or regulate the secondary cooling device (20) depending on the secondary cooling fault FSecundary cooling.;

Description

Technical field

[0001] The invention relates to a plant for the production of a metal strip, comprising a casting machine with secondary cooling, and a method for controlling or regulating a secondary cooling device of a casting machine in a plant for the production of a metal strip. Background of the invention

[0002] During the continuous casting of metals, cracks can form in the material during cooling and solidification of the strand, leading to a reduction in quality or even scrap. In particular, edge cracks sometimes occur, often related to secondary cooling.

[0003] Analyzing the root causes of material defects in continuously cast products is difficult and time-consuming. Typically, after secondary cooling, the temperature of the strand surface is measured in the width direction. The primary goal of measuring and controlling the temperature is to prevent undercooling at the surface or near the edges of the cast strand, or to avoid temperatures falling below a critical level, which can lead to surface defects or cracking.

[0004] WO 2009 / 071236 A1 discloses a method for controlling or regulating the temperature of a casting strand in a continuous casting plant, in which a dynamic change to the target temperature of the casting strand is carried out. WO 2018 / 082883 A1 describes a system in which a temperature measurement is taken after rolling. Using the measurement signal, a control signal is generated for adjusting the secondary cooling.

[0005] The concepts described above use a measured temperature as a criterion to make statements about damage to the surface or near-edge of the casting strand. However, a single temperature measurement is often insufficient as a damage criterion. Description of the invention

[0006] One object of the invention is to improve the secondary cooling of a metal strip in a casting machine, in particular to increase the product quality.

[0007] The problem is solved by a system with the features of claim 1 and a method with the features of the dependent method claim. Advantageous embodiments follow from the dependent claims, the following description of the invention, and the description of preferred embodiments.

[0008] The plant is used to produce metal strips. Products made of a metal alloy, preferably steel, are cast and, if necessary, further processed. The plant is configured, for example, as a hot strip mill, CSP mill, or continuous strip mill.

[0009] The system includes a casting machine configured to produce the metal strip in the form of a cast strand and transport it along a conveying direction. The casting machine is preferably implemented as a vertical bending machine or arc caster.

[0010] The system includes a secondary cooling device comprising nozzle assemblies designed to cool the metal strip in the area of ​​the casting machine by applying a coolant, preferably a water / air mixture. The nozzle assemblies can be arranged in series and are preferably installed between opposing strand guide rollers of a strand guide.

[0011] The system further comprises at least one sensor device configured to detect an edge temperature Tedge and a center temperature Tcenter of the metal strip, wherein the edge temperature Tedge denotes a surface temperature of the metal strip in an area near the edge and the center temperature Tcenter denotes a surface temperature in the middle area of ​​the metal strip.

[0012] The system also has a control unit that communicates with the secondary cooling unit and the sensor unit and is set up to determine a secondary cooling fault F secondary cooling from the edge temperature T edge and center temperature T center of the metal strip and to control or regulate the secondary cooling unit depending on the secondary cooling fault F.

[0013] The sensor system measures the temperature not only across the width of the metal strip, as this is useful after secondary cooling but may not be sufficient to prevent surface errors and defects, but the sensor system is also designed to detect the area near the edges.

[0014] The use of this extended temperature measurement via suitable sensors leads to an improvement in the quality of the surface of the metal strip, in particular to the avoidance of cracking and other defects, as well as to homogeneous material properties of the end product.

[0015] Preferably, the sensor device is installed downstream of the secondary cooling device, for example directly at the outlet of the casting machine or in front of, inside or behind a rolling device, whereby the temperature measurement takes place essentially after the metal strip has solidified.

[0016] Spatial designations such as "downstream", "before", "behind", "after", etc. are clearly defined by the specification of the conveying direction and the intended use of the system.

[0017] Preferably, the sensor device comprises a camera, in particular a thermal imaging camera, which enables temperature measurement to be carried out in a structurally simple manner over a large area of ​​the metal strip, including areas near the edges. Alternatively or additionally, the sensor device can have several temperature sensors in order to measure the area near the edges and the middle area of ​​the metal strip separately.

[0018] Preferably, the control device is configured to increase the secondary cooling when the edge temperature Tedge is higher than the center temperature Tcenter. Alternatively or additionally, the control device is preferably configured to reduce the secondary cooling when the edge temperature Tedge is lower than the center temperature Tcenter. In this way, the secondary cooling can be easily adjusted via control, enabling quality optimization of the metal strip with minimal structural and process-related modifications.

[0019] Preferably, the control device is configured to determine the error of the secondary cooling Fsecondary cooling as the ratio of the edge temperature Tedge to the center temperature Tcenter of the metal strip. Furthermore, the control device is preferably configured such that the control or regulation of the secondary cooling device depends on how much Fsecondary cooling deviates from 1, thereby achieving fine-tuning of the secondary cooling with minimal structural and procedural modifications.

[0020] Preferably, the control unit is configured such that the determination of Tedge is carried out by averaging or determining the maximum value over a defined period, and / or, for example, over an edge width range of 5 to 300 mm. Alternatively or additionally, the control unit can be configured such that the determination of Tcenter is carried out by averaging or determining the maximum value over a defined period, and / or, for example, over a center width range of 5 to 1000 mm. In this way, the temperature measurement and the subsequent control of the secondary cooling can be further optimized.

[0021] The aforementioned problem is further solved by a method for controlling or regulating a secondary cooling device of a casting machine in a plant for the production of a metal strip. The method comprises: producing the metal strip in the form of a casting strand by means of the casting machine and conveying it along a conveying direction; cooling the metal strip in the area of ​​the casting machine by means of a secondary cooling device comprising nozzle arrangements which apply a coolant, preferably a water / air mixture, to the metal strip; detecting an edge temperature Tedge and a center temperature Tcenter of the metal strip by means of at least one sensor device, wherein the edge temperature Tedge denotes a surface temperature of the metal strip in a region near the edge and the center temperature Tcenter denotes a surface temperature in the middle region of the metal strip;wherein a control device, which communicates with the secondary cooling device and the sensor device, determines a secondary cooling fault F secondary cooling from the edge temperature T edge and center temperature T center of the metal strip and controls or regulates the secondary cooling device depending on the secondary cooling fault F.;

[0022] The technical effects, advantages and embodiments described in relation to the plant apply analogously to the process.

[0023] For the reasons mentioned above, the sensor device is preferably installed downstream of the secondary cooling device, in particular directly at the outlet of the casting machine or in front of, inside or behind a rolling device.

[0024] For the reasons mentioned above, the sensor device preferably includes a camera, in particular a thermal imaging camera.

[0025] Preferably, for the reasons mentioned above, the control device controls and / or regulates the secondary cooling device in such a way that the secondary cooling is increased if the edge temperature T edge is greater than the center temperature T center, and / or in the case that the edge temperature T edge is lower than the center temperature T center, the secondary cooling device in such a way that the secondary cooling is reduced.

[0026] Preferably, for the reasons mentioned above, the control device determines the error of the secondary cooling F secondary cooling as the ratio of the edge temperature T edge to the center temperature T center of the metal strip, wherein the control or regulation of the secondary cooling device depends in particular on how much F secondary cooling deviates from 1.

[0027] Preferably, for the reasons mentioned above, the control device determines the T edge by averaging or determining the maximum value over a defined period, and / or, for example, over a width range of the edge from 5 to 300 mm.

[0028] Preferably, for the reasons mentioned above, the control device determines Tcenter by averaging or determining the maximum value over a defined period, and / or, for example, over a width range of the center from 5 to 1000 mm.

[0029] Further advantages and features of the present invention will become apparent from the following description of preferred embodiments. The features described therein can be implemented individually or in combination with one or more of the features set out above, provided that the features do not contradict each other. The following description of preferred embodiments is given with reference to the accompanying drawings. Brief description of the characters

[0030] Preferred further embodiments of the invention are explained in more detail by the following description of the figures. These show: Figure 1 schematically shows a plant for the production of a metal strip, comprising a casting machine with secondary cooling; and Figure 2 schematically shows the cross-section of a metal strip with a central area and an edge area.

[0031] Detailed description of preferred embodiments

[0032] Preferred embodiments are described below with reference to the figures. Identical, similar, or equivalent elements in the figures are designated with identical reference numerals, and repeated descriptions of these elements are sometimes omitted to avoid redundancy.

[0033] The Figure 1 Figure 1 schematically shows a plant 1 for the production of metal strips 100, preferably steel strips. Plant 1 is configured, for example, as a hot wide strip mill, CSP or endless strip mill.

[0034] Plant 1 includes a casting machine 10 for producing a metal strip 100 in the form of a cast strand. The cast metal strip 100 can subsequently be further processed, in particular cut into slabs and formed by rolling.

[0035] The one in Figure 1The casting machine 10 shown has a ladle 11 in which liquid metal, in particular steel, is transported to an intermediate container 12 and poured into it. From the intermediate container 12, the liquid metal flows into a mold 13, at the edges of which the liquid metal is cooled by primary cooling, thereby forming a casting strand in the mold 13 with an initially liquid core but an already solidified, load-bearing strand shell.

[0036] After the metal strip 100 has left the mold 13 as a casting strand, it is guided along a conveying direction F by means of a strand guide such that the metal strip 100 is bent in the direction of gravity starting from the casting and then transported further in a horizontal line. For this purpose, the strand guide has several strand guide rollers 15, each opposite the other.

[0037] Casting machine 10 is implemented here as an example of a vertical bending system or bow caster. However, casting machine 10 can also be implemented in other ways.

[0038] The casting machine 10 further comprises a secondary cooling device 20, including nozzle assemblies 21, which are configured to cool the metal strip 100 by applying a coolant, preferably a water / air mixture, until the metal strip 100 has solidified. The nozzle assemblies 21 can be arranged in series and are preferably installed between the opposing strand guide rollers 15.

[0039] Following secondary cooling, the metal strip 100 is further processed, for example with a [missing information] in the Figure 1 The device (not shown) was divided into slabs and rolled in a roughing and finishing rolling mill.

[0040] Annex 1 further comprises one or more sensor devices 30 for measuring the temperature of the metal strip 100. Such a sensor device 30 can be, as shown in Figure 1 shown, installed at the outlet of the casting machine 10, i.e., at the end of the secondary cooling, or additionally or alternatively at other positions of the system 1, for example in front of, inside or behind a section of the Figure 1 rolling mill not shown.

[0041] The sensor device 30 can include a camera, in particular a thermal imaging camera, or one or more other sensors for temperature detection of the metal strip 100.

[0042] The sensor device 30 is configured to detect at least one edge temperature Tedge and at least one center temperature Tcenter. The edge temperature Tedge refers to the surface temperature of the metal strip 100 in an area 101 near the edge, while the center temperature Tcenter refers to a surface temperature in the central area 102 of the metal strip 100, cf. Figure 2 .

[0043] The system 1 also includes a control unit 50 which communicates with the various components of the system 1, actuators, sensors and the like, and is set up to control and / or regulate the process depending on process parameters.

[0044] The control unit 50 is connected via signal technology to the components of the system 1 to be controlled, regulated, and / or read out, in particular to the one or more sensor devices 30 and the secondary cooling device 20. Communication between the control unit 50 and the system components to be controlled, regulated, and / or read out can be wired or wireless, digital or analog. The control unit 50 can accordingly receive and / or send signals (control signals, data, etc.), whereby both unidirectional and bidirectional signal transmission fall under the term "communication" in this context. The control unit 50 does not necessarily have to be implemented by a central computer or electronic control system; rather, it includes decentralized and / or multi-stage systems, control networks, cloud systems, and the like.The controller can also be an integral part of a higher-level plant control system or communicate with one. The control unit 50 can also communicate with lower-level plant control systems, i.e., controllers assigned to the respective facilities.

[0045] The control unit 50 is configured to determine a secondary cooling error Fsecondary cooling from the ratio of the edge temperature Tedge to the center temperature Tcenter of the metal strip 100: Fsecondary cooling = Tedge / Tcenter. If the edge temperature Tedge is higher than the center temperature Tcenter, i.e., Fsecondary cooling > 1, the secondary cooling is increased by the secondary cooling unit 20 in the casting machine 10. If the edge temperature is lower than the center temperature, i.e., Fsecondary cooling < 1, the secondary cooling is reduced by the secondary cooling unit 20 in the casting machine 10. The control response can be made dependent on how much Fsecondary cooling deviates from 1.

[0046] The sensor device 30 does not only measure the temperature across the width B (cf. Figure 2The temperature of the metal strip 100 is approximately averaged, as this is useful after secondary cooling but may not yet be sufficient to prevent surface defects. Therefore, the sensor device 30 is additionally configured to separately detect the area 101 near the edge. For this purpose, the sensor device 30 can be equipped with additional sensors.

[0047] The use of this extended temperature measurement with suitable sensors leads to an improvement in the quality of the surface of the metal strip 100, in particular to the avoidance of cracking and other defects, as well as to particularly homogeneous material properties of the end product.

[0048] The determination of T edge can be carried out, for example, by averaging or determining the maximum value over a defined period, and / or preferably over a width range of the edge from 5 to 300 mm.

[0049] The determination of Tcenter can be carried out, for example, by averaging or determining the maximum value over a defined period, and / or preferably over a width range of the center from 5 to 1000 mm.

[0050] Where applicable, all individual features shown in the exemplary embodiments can be combined and / or exchanged without leaving the scope of the invention. Reference symbol list

[0051] 1 Plant for the production of a metal strip 10 Casting machine 11 Pan 12 Intermediate container 13 Mold 15 Strand guide roller 20 Secondary cooling device 21 Nozzle assembly 30 Sensor device 50 Control device 100 Metal band 101 Edge area 102 Middle area F Conveyor direction B Width of the metal belt

Claims

1. Plant (1) for producing a metal strip (100), wherein the plant (1) comprises: a casting machine (10) configured to produce the metal strip (100) in the form of a casting strand and to transport it along a conveying direction (F); a secondary cooling device (20) comprising nozzle arrangements (21) configured to cool the metal strip (100) by applying a coolant, preferably a water / air mixture, in the area of ​​the casting machine (10); at least one sensor device (30) configured to detect an edge temperature T Kante and a mean temperature T Mitte to detect the metal strip (100), whereby the edge temperature T Kante a surface temperature of the metal strip (100) in an area near the edge (101) and the center temperature T Mittea surface temperature in the middle region (102) of the metal strip (100); and a control device (50) which communicates with the secondary cooling device (20) and the sensor device (30) and is configured to detect a fault in the secondary cooling F Sekundärkühlung from the edge temperature T Kante and the mean temperature T Mitte to determine the metal strip (100) and the secondary cooling device (20) depending on the error F Sekundärkühlung to control or regulate.

2. Annex (1) according to claim 1, characterized by the fact that the sensor device (30) is installed downstream of the secondary cooling device (20), preferably directly at the outlet of the casting machine (10) or in front of, inside or behind a rolling device.

3. Appendix (1) according to claim 1 or 2, characterized by the fact that the sensor device (30) comprises a camera, preferably a thermal imaging camera.

4. Annex (1) according to any of the preceding claims, characterized by the fact thatthe control device (50) is set up to, in the event that the edge temperature T Kante greater than the mean temperature T Mitte is to control or regulate the secondary cooling device (20) in such a way as to enhance the secondary cooling, and / or in the event that the edge temperature T Kante lower than the mean temperature T Mitte is to control or regulate the secondary cooling device (20) in such a way as to reduce the secondary cooling.

5. Annex (1) according to any of the preceding claims, characterized by the fact that the control unit (50) is set up to detect the fault of the secondary cooling F Sekundärkühlung as a ratio of the edge temperature T Kante to the mean temperature T Mitte of the metal strip (100), wherein the control device (50) is preferably arranged such that the control or regulation of the secondary cooling device (20) depends on how strong F Sekundärkühlung differs from 1.

6. Annex (1) according to any of the preceding claims, characterized by the fact that the control device (50) is set up such that the determination of T Kante via averaging or determining the maximum value over a defined period, and / or via a width range of the edge from 5 to 300 mm.

7. Annex (1) according to any of the preceding claims, characterized by the fact that the control device (50) is set up such that the determination of T Mitte via averaging or determining maximum values ​​over a defined period, and / or via a width range of the center from 5 to 1000 mm.

8. Method for controlling or regulating a secondary cooling device (20) of a casting machine (10) in a plant (1) for the production of a metal strip (100), the method comprising: producing the metal strip (100) in the form of a casting strand by means of the casting machine (10) and conveying the same along a conveying direction (F); cooling the metal strip (100) in the area of ​​the casting machine (10) by means of a secondary cooling device (20), comprising nozzle arrangements (21) which apply a coolant, preferably a water / air mixture, to the metal strip (100); detecting an edge temperature T Kante and a mean temperature T Mitte of the metal strip (100) by means of at least one sensor device (30), wherein the edge temperature T Kante a surface temperature of the metal strip (100) in an area near the edge (101) and the center temperature T Mittea surface temperature in the middle region (102) of the metal strip (100); wherein a control device (50), which communicates with the secondary cooling device (20) and the sensor device (30), detects a fault in the secondary cooling F Sekundärkühlung from the edge temperature T Kante and mean temperature T Mitte of the metal strip (100) and the secondary cooling device (20) depending on the fault F Sekundärkühlung controls or regulates.

9. Method according to claim 8, characterized by the fact that the sensor device (30) is installed downstream of the secondary cooling device (20), preferably directly at the outlet of the casting machine (10) or in front of, inside or behind a rolling device.

10. Method according to claim 8 or 9, characterized by the fact that the sensor device (30) comprises a camera, preferably a thermal imaging camera.

11. Method according to any one of claims 8 to 10, characterized by the fact thatthe control device (50) in the event that the edge temperature T Kante greater than the mean temperature T Mitte is, the secondary cooling device (20) controls or regulates in such a way that the secondary cooling is enhanced, and / or in the case that the edge temperature T Kante lower than the mean temperature T Mitte is, the secondary cooling device (20) controls or regulates such that the secondary cooling is reduced.

12. Method according to any one of claims 8 to 11, characterized by the fact that the control unit detects the secondary cooling fault F Sekundärkühlung as a ratio of the edge temperature T Kante to the mean temperature T Mitte of the metal strip (100) is determined, wherein the control or regulation of the secondary cooling device (20) preferably depends on how strong F Sekundärkühlung differs from 1.

13. Method according to any one of claims 8 to 12, characterized by the fact that the control device (50) the determination of T Kanteby calculating an average or maximum value over a defined period, and / or over a width range of the edge from 5 to 300 mm.

14. Method according to any one of claims 8 to 13, characterized by the fact that the control device (50) the determination of T Mitte by calculating an average or a maximum value over a defined period, and / or over a width range of the center from 5 to 1000 mm.

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