Method and plant for producing a continuously cast metal product
A faster continuous casting model and active temperature control system address the inaccuracies in sump tip determination and slow response times, enhancing process efficiency and preventing whale formation in continuous casting.
Patent Information
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- SMS GROUP GMBH
- Filing Date
- 2026-01-15
- Publication Date
- 2026-07-23
AI Technical Summary
Existing continuous casting technologies fail to accurately and quickly determine the position of the sump tip, leading to inefficiencies and potential whale formation due to deviations in process conditions, and require costly and maintenance-intensive radar measurement systems with slow response times for temperature control.
Implementing a second continuous casting model that calculates faster than real time to determine the sump tip position based on current process conditions, and a third model for active temperature control to optimize cooling parameters, allowing for early warnings and adjustments to prevent whale formation.
Enables rapid and precise determination of the sump tip position, reducing the risk of whale formation and improving process efficiency by enabling timely adjustments to process parameters.
Smart Images
Figure EP2026050890_23072026_PF_FP_ABST
Abstract
Description
[0001] Process and plant for the production of a continuously cast metallic product
[0002] The invention relates to a method for producing a continuously cast metallic product in a continuous casting plant, in which a cast metal strand is guided in the conveying direction behind a mold in a strand guide and cools down, forming a bottom tip from which the metal strand is completely solidified, wherein the continuous casting process is calculated and / or controlled or regulated in real time by means of a first continuous casting model (the first continuous casting model can also optimize process parameters, such as the amount of water required for cooling, in order to achieve predetermined setpoints such as target temperatures). The invention further relates to a plant for producing a continuously cast metallic product.
[0003] A process of this type is well known in the prior art. A continuous casting plant of this type produces the strand from liquid metal and diverts it from the vertical to the horizontal; during this process, the strand solidifies more and more until it is completely solidified. The point where complete solidification occurs across the entire thickness of the strand is marked by the tip. The strand is guided by a strand guide, which carries the gradually solidifying strand into the horizontal position. It is important that complete solidification occurs at the end of the strand guide to prevent bulging of the cast strand in the area no longer supported by the strand guide; this bulging is also known as "whale formation."
[0004] It is also known to monitor, control, and regulate the continuous casting process using a continuous casting model. In this process, the process is observed, calculated, and controlled or regulated in real time.
[0005] Page 1. From EP 2 346 631 B1, it is already known for a continuous casting process of this type to use a second calculation model that calculates faster than real time. In this model, the temperature is calculated in such a way that a correction factor for optimizing the casting speed is determined using the second, faster model. The correction factor is then provided to the first, real-time model to control the casting process so that the end of the casting is located in the desired position.
[0006] To measure the strand thickness behind the strand guide, EP 3 628 416 B1 proposes radar measurement. This serves to prevent the formation of porpoises. If the measured strand thickness is greater than a predefined value, casting parameters are adjusted so that the porpoise head is moved back in the conveying direction.
[0007] From EP 2 222 426 B1 it is known to use a temperature control system that changes the spray water volume flows of the continuous casting plant in small steps, taking into account the deviation between a currently calculated temperature and a target temperature specified for the current material.
[0008] However, the previously known solutions have certain disadvantages:
[0009] Since the previously known, faster calculation models optimize the casting speed, they do not take the current process conditions into account. As a result, the calculated position of the sump tip deviates from the actual position and is therefore only of limited use for process monitoring.
[0010] The installation of the previously known radar measurement system requires not only relatively high investment costs but also constant maintenance and cleaning of the optics. The casting powder carried away by the spray water causes the optics to become dirty relatively quickly, leading to measurement errors.
[0011] Page 2 With the previously known temperature control system for the spray water supply, fluctuations in the water flow rates are to be avoided. For this purpose, the water flow rates are always changed slowly. However, this leads to long response times in the event of significant changes in process conditions (i.e., for example, a drastic change in casting speed, different materials, an emergency stop, or a "tail out"). Therefore, in these cases, the temperature control is deactivated internally, and the water flow rates are used according to a predefined spraying schedule.
[0012] In light of previously known solutions and their disadvantages, the invention is based on the objective of designing a generic method and a corresponding system in such a way that it becomes possible to quickly and reliably determine the position of the sump tip and to ensure that the information thus obtained can be used as quickly as possible to optimize the casting process (for this purpose, the second continuous casting model described below is used in particular). Furthermore, the temperature control of the process should be able to be carried out actively and as precisely as possible (for this purpose, the third continuous casting model described below is used in particular).
[0013] The solution to this problem by the invention is characterized by the method in that the position of the sump tip is calculated using a second continuous casting model, wherein the calculation is performed faster than in real time, wherein the calculation of the position of the sump tip is based on current process conditions, and wherein a warning is issued to a plant operator when the expected position of the sump tip approaches or reaches an impermissible range.
[0014] The calculation using the second continuous casting model is preferably performed at least 5 times, and particularly preferably at least 10 times, faster than in real time.
[0015] A first warning signal (i.e., a warning W) can be issued if the swamp tip falls below a target position for the swamp tip by a certain amount.
[0016] Page 3. Then a second warning signal (i.e., an alarm A) can be issued if the swamp tip is behind the target position for the swamp tip by a second amount that is greater than the first amount.
[0017] When a warning signal is issued, the watering rate can be reduced as a measure.
[0018] As a measure, the process parameters for cooling the cast metal strand can also be changed if a warning signal is issued.
[0019] Furthermore, it can be provided that the thickness of the cast metal strand is reduced when a warning signal is issued.
[0020] The measures mentioned can be automated or carried out by the operator of the system.
[0021] A particularly preferred embodiment of the invention provides that an optimization calculation for at least one operating parameter is performed using a third continuous casting model (i.e., an additional continuous casting model besides the first and second), with the calculation being performed faster than real time. This optimization allows target values for the operating parameters to be achieved more effectively. In this case, the operating parameter preferably relates to the cooling of the cast metal strand. The third continuous casting model also preferably enables the calculation of the position of the sump tip.
[0022] The invention further relates to a system for producing a continuously cast metallic product, in particular for carrying out the process described above, comprising a mold for dispensing molten metal, a strand guide for guiding the cast metal strand, and means for cooling the cast metal strand, wherein a first continuous casting model is arranged with which the continuous casting process can be calculated and / or controlled or regulated in real time. According to the invention, it is provided that a second
[0023] Page 4 continuous casting model is arranged with which the position of the sump tip of the cast metal strand can be calculated based on current process conditions, wherein the second continuous casting model can perform the calculation faster than in real time, wherein means are arranged with which a warning signal can be given to a plant operator when the expected position of the sump tip approaches or reaches an impermissible range.
[0024] In a preferred embodiment, a third continuous casting model is provided, which is configured for an optimization calculation for at least one operating parameter, with the calculation being performed faster than real time. Again, this third continuous casting model is capable of calculating the position of the forming sump tip.
[0025] Finally, the invention also relates to a computer program for carrying out the method described above.
[0026] The proposed solution therefore relies on the continuous casting model always being used at least one additional, faster computational model. These additional models do not perform calculations in real time, as the first model (the continuous casting model) does, but rather as quickly as the available computing power allows. The calculation in the second additional model is performed using the existing process conditions; the calculation in the third additional model is performed using optimized process conditions.
[0027] This allows for improved determination of the developing sump length. The system checks whether this sump length, predicted by the rapid model, exceeds a warning or alarm threshold (see the aforementioned "Warning" or "Alarm"). If so, the system operator receives an early notification, enabling them to react more effectively.
[0028] Page 5: In active temperature control, the additional, fast third calculation model provides the water flow rates required to reach the target temperature for each control loop and transmits this information to the first, real-time calculation model. This model also calculates the position of the sump tip and, if necessary, sends a warning to the system operator. As a possible countermeasure, a modified setpoint (for example, a colder temperature curve) can then be selected.
[0029] Thus, the proposed method provides parallel calculation models for monitoring the sump tip (specifically through the aforementioned second continuous casting model). Furthermore, improved temperature control can be achieved (specifically through the aforementioned third continuous casting model).
[0030] The proposed procedure ensures that if the additional, fast second calculation model detects an excessively long sump tip, the operator can take countermeasures early on. In particular, they can reduce the casting speed, specify a different injection molding plan or target temperature curve, or reduce the strand thickness (for example, by activating "LCR - Liquid Core Reduction").
[0031] When the first real-time calculation model issues a warning or alarm, the operator has significantly less time to take countermeasures. In the case of large changes in process conditions, sometimes only an emergency stop (i.e., briefly setting the casting speed to 0 m / min) can prevent whale formation. However, since data communication from the calculation model to the casting computer and from the casting computer to the HMI (Human-Machine Interface) already takes several seconds, and the operator also needs additional time to read the warning, make a decision, and initiate the emergency stop, whale formation may then no longer be preventable.
[0032] Page 6. Major changes in process conditions can be caused, for example, by:
[0033] - Production of a composite casting with a different material (high carbon instead of low carbon);
[0034] - Production with a different strand thickness (LCR was not switched on or only partially switched on);
[0035] - When the casting speed is reduced, the system switches to a warmer injection schedule or a warmer temperature curve to achieve a high furnace inlet temperature. If the injection speed is subsequently increased, the system does not switch back to the required cold injection schedule or corresponding temperature curve beforehand.
[0036] - Failure of the mold cooling system.
[0037] Within the scope of the present invention, the following can also be provided as a complementary or alternative method:
[0038] With active temperature control, the additional fast calculation model (especially the aforementioned third model) very quickly calculates the required water flow rates to achieve a predefined target temperature curve. Based on the water flow rates from the additional model, the first model calculates the temperatures and the position of the sump tip for the current state of the system. In the event of a material change, the position of the material change within the system is calculated in the first model.
[0039] In this case, several additional models can calculate water volume flows for the different materials.
[0040] Page 7: The water volume flows of the additional models are only used by the first model in the cooling zones where the corresponding material is located.
[0041] If a significant increase in the watering rate coincides with a switch to a colder temperature curve, the sump length can become too long without the use of an additional model. The temperature control requires a certain amount of time to calculate and adjust for the new, higher water flow rates. This can result in the first section of the line, operating at the higher watering rate, receiving insufficient spray water. This is prevented by using the third, additional, faster calculation model.
[0042] Another advantage of the additional, fast third calculation model is that the operator can see how the water volumes will change compared to the current settings even before activating temperature control. For this to work, the third fast calculation model must always operate in control mode, such as temperature control, even if the water volumes in the system have been determined differently.
[0043] Since the third model calculates the swamp length with different amounts of water than those switched on the system, the calculated swamp length does not match that of the system, which is why the third model cannot be used for warnings or alarms of an excessively long swamp length.
[0044] Therefore, in a specific embodiment of the invention, in addition to the first model (in real time) and the second model, a third model is also used. The second model quickly calculates with the current (same) process values (in particular with the current water volumes of the system), while the third model quickly calculates with optimized process values (in particular with water volumes from a control mode). The sump length thus determined can be used for warnings and alarms.
[0045] For clarification, the following should be noted.
[0046] Page 8 In the context of the preceding and following explanations, the “first continuous casting model” (synonymously the terms “calculation mode H” or “model” are also used instead of “continuous casting model”) is referred to as the calculation model which calculates in real time; this model is also referred to as “Model A”.
[0047] The “second continuous casting model” is the one that calculates faster than “Model A” and processes the current process values in the plant; this model is also referred to as “Model B”.
[0048] The “third continuous casting model” is the one that calculates faster than “Model A” and processes optimized process values; this model is also referred to as “Model C”.
[0049] The drawing shows an embodiment of the invention. It depicts:
[0050] Fig. 1 schematically shows the course of the strand temperature (measured in the middle of the strand) over the length of the strand guide during continuous casting of a material with a low carbon content,
[0051] Fig. 2 schematically shows the process according to Figure 1, wherein a material with a high carbon content is now cast in a composite,
[0052] Fig. 3 schematically shows the process according to Figures 1 and 2, whereby an alarm message is now issued.
[0053] Fig. 4 shows an example of the calculation of the location of the swamp tip using a second fast calculation model.
[0054] Fig. 5 schematically illustrates the operating concept for continuous casting according to the state of the art.
[0055] Page 9, Fig. 6 schematically shows the operating concept for continuous casting according to the state of the art in a slightly modified way.
[0056] Fig. 7 schematically shows the operating concept for continuous casting according to a preferred embodiment of the invention.
[0057] Fig. 8 schematically illustrates the operating concept for continuous casting according to a further embodiment of the invention and
[0058] Fig. 9 schematically shows the operating concept for continuous casting according to a further embodiment of the invention.
[0059] Figure 1 illustrates the temperature profile T along the strand guide in a continuous casting plant, as well known in the aforementioned prior art. The cast strand moves along the strand guide in the conveying direction F and is cooled, causing the temperature T to decrease until the strand is completely solidified. The casting speed is 4.4 m / min. A low-carbon steel is used. The position of the sink point is marked S; at this point, the cast steel in the strand has completely solidified (the core temperature falls below the solidus temperature). The end of the strand guide is reached at E. 1.0 m before reaching the end E of the strand guide, a warning W is issued if the strand is not yet completely solidified.The point at which alarm A is triggered is 0.5 m before reaching the end E of the strand, provided the strand is not yet fully solidified; in this case, there is a risk of whale formation. In the present case, as shown in Figure 1, the marsh tip S is located 2.0 m before the end E of the strand.
[0060] Figure 2 illustrates how the situation changes when high-carbon steel is cast in composite casting (immediately following low-carbon steel) without changing the casting speed.
[0061] Page 10. Due to the higher carbon content in the steel, the melting point of the material decreases. Figure 2 shows that the material change point is still located in the front section of the strand guide (at position WE). Consequently, the position of the current sump tip S has not (yet) changed.
[0062] The second, faster model, however, calculated the casting process for the entire strand (and specifically the strand temperature) shortly after the time shown in Figure 2 for real-time, and arrived at the result shown in Figure 3: The calculation showed that, under unchanged process conditions, the slump point S would only be located shortly after the end E of the strand due to the lowered melting point of the material. Based on this result, an alarm was issued to the operator, as whale formation was expected.
[0063] The second, faster model calculated the swamp lengths shown in Figure 4. This shows that in real time, only about 14 seconds elapse between the warning calculation and the formation of the whale (1,073.0 s - 1,059.5 s = 13.5 s). Without using the second, faster model, the operator would therefore have virtually no chance of preventing the formation of the whale.
[0064] Assume the second calculation model computes 10 times faster than the first model (the latter calculating in real time). Further assume the material change point WE is located 24.4 m before the end E of the strand. In this case, the second model delivers its result at the point 2.44 m (24.4 / 10) behind the material change point WE, i.e., 24.4 m - 2.44 m = 21.96 m before the end E of the strand. Therefore, the operator has approximately 24.4 m - 2.44 m = 21.96 m remaining until the actual whale formation (i.e., in real time).
[0065] 22 m, which at a pouring rate of 4.4 m / min means that 22 m / 4.4 m / min = 5 min time remains for the operator to react, in particular to change the pouring rate.
[0066] Page 11. This shows that the proposed method for operating the continuous casting plant provides the possibility of reacting in a simplified and timely manner to changes that can be predicted by the calculation results of the second, faster model. In particular, a casting interruption can be prevented, which has correspondingly significant economic advantages.
[0067] Figures 5 to 9 schematically illustrate operating concepts used in continuous casting, with figures 5 and 6 showing previously known solutions, while figures 7 to 9 show embodiments of the invention.
[0068] In all the figures mentioned, the upper section of the diagrams, referring to the nomenclature above, shows that three continuous casting models can generally be used: "Model A," "Model B," and "Model C." To recap, "Model A" is the "first" calculation model, which performs calculations in real time. "Model B" is the "second" calculation model, which calculates faster than "Model A" and processes current process values from the plant. "Model C" is the "third" calculation model, which also calculates faster than "Model A" but processes optimized process values.
[0069] According to Figure 5, there is no temperature control and models B and C are not used. According to Figure 6, there is temperature control, but models B and C are not used here either.
[0070] Figure 7 shows that, according to the invention, both model A and model B are used. While there is no temperature control in model B, the fast-calculating model B determines the position of the sump tip based on the current process parameters, so that a warning W or an alarm A can be issued as described above.
[0071] Page 12 Figure 8 illustrates the concept whereby, in addition to model A, the fast-calculating model C is also used, thus enabling temperature control; however, model B is not used here.
[0072] Finally, Figure 9 shows that all three models A, B and C are used, thus enabling both the rapid prediction of the position of the swamp tip (using model B) and the temperature control (using model C).
[0073] Page 13
Claims
Patent claims:
1. A method for producing a continuously cast metallic product in a continuous casting plant, in which a cast metal strand is guided in the conveying direction behind a mold in a strand guide and cools down, forming a sump tip from which the metal strand is completely solidified, wherein the continuous casting process is calculated and / or controlled or regulated in real time by means of a first continuous casting model. characterized by that a second continuous casting model is used to calculate the position of the sump tip, whereby the calculation is faster than in real time, wherein the calculation of the position of the sump tip is based on current process conditions, wherein a warning (W, A) is issued to a plant operator if the expected position of the sump tip approaches or reaches an impermissible range.
2. Method according to claim 1, characterized in that the calculation using the second continuous casting model is performed at least 5 times, preferably at least 10 times, faster than in real time.
3. Method according to claim 1 or 2, characterized in that a first warning signal (W) is given when the sump tip is behind a target position for the sump tip by a first amount. Page 144. Method according to claim 3, characterized in that a second warning signal (A) is given when the sump tip is behind the target position for the sump tip by a second amount which is greater than the first amount.
5. Method according to one of claims 1 to 4, characterized in that the casting speed is reduced when a warning signal (W, A) is issued.
6. Method according to one of claims 1 to 5, characterized in that, upon output of a warning signal (W, A), the process parameters for cooling the cast metal strand are changed.
7. Method according to one of claims 1 to 6, characterized in that the thickness of the cast metal strand is reduced when a warning signal (W, A) is issued.
8. Method according to one of claims 1 to 7, characterized in that an optimization calculation for at least one operating parameter is carried out using a third continuous casting model, wherein the calculation is performed faster than in real time.
9. Method according to claim 8, characterized in that the operating parameter relates to the cooling of the cast metal strand.
10. Plant for the production of a continuously cast metallic product, in particular for carrying out the process according to one of claims 1 to 10. Page 159, comprising a mold for dispensing metallic molten metal, a strand guide for guiding the cast metal strand and means for cooling the cast metal strand, wherein a first continuous casting model is arranged with which the continuous casting process can be calculated and / or controlled or regulated in real time, characterized by that a second continuous casting model is arranged with which the position of the sump tip of the cast metal strand can be calculated based on current process conditions, wherein the second continuous casting model can perform the calculation faster than in real time, wherein means are arranged with which a warning signal (W, A) can be given to a plant operator when the expected position of the sump tip approaches or reaches an impermissible range.
11. Plant according to claim 10, characterized in that a third continuous casting model is arranged which is designed for an optimization calculation for at least one operating parameter, wherein the calculation is performed faster than in real time.
12. Computer program comprising program commands for carrying out the first and second continuous casting model when carrying out the method according to any one of claims 1 to 9. Page 16