Roll heating device for preheating at least two rolls, rolling mill having a roll heating device, method for preheating at least two rolls

Abstract

The invention relates to a roll heating device (100) for preheating at least two rolls (10), wherein each roll (10) is held rotatably mounted about the respective longitudinal axis thereof in two chocks (20), wherein the roll heating device (100) has a fastening device (21) for holding the chocks (20) of the rolls (10), a number of drive devices (30) corresponding to the number of rolls (10) to be heated, a number of induction heating devices (40) corresponding to the number of rolls (10) to be heated, and a control device (50), wherein each drive device (30) can be brought into operative connection with a roller (10) in such a way that the respective roller (10) can be set in rotation about its longitudinal axis by means of the drive device (30) assigned thereto, and wherein the control device (50) is data-coupled to the induction heating devices (40) and to the drive devices (30) for transmitting control signals.

Description

[0001] Page 1 / 49

[0002] Applicant: SMS group GmbH

[0003] Our reference number: P80995WO

[0004] September 17, 2024

[0005] Roll heating device for preheating at least two rolls, rolling mill with a roll heating device, method for preheating at least two rolls

[0006] The present invention relates to a roll heating device and a method for preheating at least two rolls of a rolling mill.

[0007] Rolling mills are used for the mechanical forming of a typically metallic workpiece by reducing its cross-section. During the rolling process, the workpiece is formed into a semi-finished product, such as a metal strip, between two or more rotating rolls, also known as work rolls, under appropriate pressure. To achieve a desired rolling result, such as a specific surface quality and / or surface structure of the semi-finished product, the rolls in contact with the workpiece or semi-finished product must operate at a predetermined temperature.

[0008] The rolls of a rolling mill are subject to considerable wear during operation, so they must be replaced with new or refurbished rolls at regular intervals. To heat the newly installed rolls to their operating temperature, it is common practice to roll one or more strips of material until the rolls reach their operating temperature. When this procedure is followed, the rollers used to heat up are shown on page 2 / 49.

[0009] P80995WO

[0010] At operating temperatures, semi-finished products exhibited reduced quality, particularly in terms of surface quality, rendering them unmarketable and often necessitating remelting. This approach consequently presents significant cost and environmental disadvantages, as substantial amounts of energy are required for remelting, resulting in an overall increase in carbon dioxide emissions during production.

[0011] To circumvent this problem, it is known from the prior art to heat work rolls in their installed position within a rolling mill stand. Various heating methods are used for this purpose. For example, the rolls are exposed to heated rolling oil or a heated emulsion. Such heating systems have the disadvantage of requiring significant design effort for their integration into the rolling mill stand. Furthermore, these heating systems exhibit reduced flexibility, as they can only be used to heat the rolls of a specific rolling mill stand.

[0012] The present invention is based on the objective of providing a roller heating device for preheating rollers that eliminates the disadvantages described above.

[0013] The problems underlying the present invention are solved by a roller heating device with the features of claim 1. Advantageous embodiments are described in the dependent claims.

[0014] More precisely, the problem underlying the present invention is solved by a roller heating device for preheating at least two rollers, wherein each roller is rotatably mounted in two mounting blocks about their respective longitudinal axis, wherein the roller heating device includes a fastening device for holding the mounting blocks (page 3 / 49)

[0015] P80995WO

[0016] The device comprises rollers, at least one, preferably one number of drive devices corresponding to the number of rollers to be heated, one number of induction heating devices corresponding to the number of rollers to be heated, and a control device, wherein the at least one drive device can be brought into operative connection with the rollers to be heated in such a way that the at least one roller can be rotated about its longitudinal axis by means of the at least one drive device, and wherein the control device is data-coupled with the induction heating devices and with the drive devices for transmitting control signals.

[0017] If each roller is assigned a drive device, then the roller heating device is to be described as follows: Roller heating device for preheating at least two rollers, wherein each roller is rotatably mounted in two mounting blocks about their respective longitudinal axes, wherein the roller heating device comprises a fastening device for holding the mounting blocks of the rollers, a number of drive devices corresponding to the number of rollers to be heated, a number of induction heating devices corresponding to the number of rollers to be heated, and a control device, wherein each drive device can be brought into operative connection with a roller in such a way that the respective roller can be set in rotation about its longitudinal axis by means of the drive device assigned to it.and wherein the control device is data-coupled with the induction heating devices and with the drive devices for transmitting control signals.

[0018] The roller heating device according to the invention has the advantage that a rolling mill is structurally simpler, since the heating devices for heating the rollers are not integrated into the rolling mill stand itself. Furthermore, the roller heating device according to the invention allows the following (page 4 / 49)

[0019] P80995WO

[0020] The utilization of a rolling mill can be increased because the heating does not take place in the rolling stand. Thus, the rolling mill can continue to operate with other rolls while the rolls are being heated. Furthermore, after changing rolls that have been preheated by means of the roll heating device according to the invention, a rolling mill is immediately ready for use again without any reduction in the quality of the rolled semi-finished products.

[0021] The mounting blocks, by means of which each roll is rotatably mounted about its respective longitudinal axis, are mounting blocks of a rolling mill stand into which the rolls remain installed after heating by the roll heating device. Consequently, the roll heating device according to the invention has the advantage that the rolls do not have to be labor-intensively and therefore time-consumingly mounted onto the mounting blocks after heating. After heating, the rolls, together with the mounting blocks holding them, can be installed in a designated rolling mill stand in a shorter time. Due to the shortened time interval between the completion of the heating process of the rolls by means of the roll heating device according to the invention and their installation in a rolling mill stand and subsequent commissioning, the rolls cool down less.Thus, the roller heating device according to the invention allows the rollers to be heated to a lower temperature, as they can be put back into operation more quickly and therefore cool down less after heating. Consequently, the roller heating device according to the invention has a reduced energy requirement.

[0022] Preferably, each of the at least two rollers is assigned an induction heating device. Thus, each of the at least two rollers can be heated to the desired temperature by exactly one induction heating device, so that the at least two rollers can be heated individually and particularly quickly. Page 5 / 49

[0023] P80995WO can be heated to a desired temperature. Such an arrangement of the induction heating devices allows the at least two rollers to be heated to different temperatures.

[0024] The roller heating device is preferably designed such that the heating of the respective rollers to be heated is controlled by the control device in such a way that the surface temperature of the rollers does not exceed a predetermined maximum temperature in the range between 90°C and 150°C, preferably in the range between 95°C and 145°C, more preferably in the range between 100°C and 140°C, more preferably in the range between 105°C and 135°C, more preferably in the range between 110°C and 130°C, and more preferably in the range between 115°C and 125°C. The fully preheated, thermalized rollers preferably have a temperature in the range between 80°C and 130°C, more preferably in the range between 85°C and 125°C, more preferably in the range between 90°C and 120°C, more preferably in the range between 95°C and 115°C, more preferably in the range between 100°C and 110°C.In the thermalized state of the rollers, the temperature difference between a surface temperature of a roller and a core temperature of the roller is preferably less than 20 K (20 Kelvin), more preferably less than 15 K, and even more preferably less than 10 K. The temperatures at the surface of the roller and in the core of the roller (i.e., on the longitudinal axis) are determined after a predetermined period following the heating of the rollers.

[0025] The roller heating device can also be called a roller preheating device, since it preheats rollers to their operating temperature. Page 6 / 49

[0026] P80995WO

[0027] The fastening device may have a frame or be designed as a frame.

[0028] The induction heating device can have a longitudinal field inductor for generating a longitudinal magnetic field in the roller to be heated and / or a transverse field inductor for generating a transverse magnetic field in the roller to be heated.

[0029] The respective drive devices preferably include an electric motor.

[0030] The drive systems can be designed such that each roller has its own dedicated drive. Alternatively, it can be provided that one drive drives more than one roller, e.g., by coupling the drive transmission or by frictional engagement between the rollers.

[0031] The control device is preferably designed as an electronic control device with a memory and at least one processor.

[0032] Preferably, the roller heating device is designed such that each induction heating element is positionally adjustable between an installation position and a working position relative to the roller assigned to the induction heating element, wherein in the installation position the respective induction heating elements have a greater lateral distance to the rollers assigned to them than in their working position, wherein the roller heating device has a number of first position adjustment devices corresponding to the number of induction heating elements, and wherein each induction heating element is positionally adjustable between its installation position and its working position by means of its assigned first position adjustment device. Page 7 / 49

[0033] P80995WO

[0034] The adjustable position of the induction heating devices offers the advantage that they can be mounted particularly easily in the roller heating device according to the invention in the installed position and operated comparatively efficiently in the operating position. These advantages are enhanced by the greater lateral distance that the induction heating devices have from the rollers associated with them in the installed position compared to the operating position. Furthermore, the greater lateral distance allows for comparatively easy maintenance of the induction heating devices in the installed position, whereas the roller heating device with induction heating devices enables improved coupling of the generated magnetic field into the rollers in the operating position.

[0035] The first position adjustment devices allow the respective induction heating units to be positioned particularly user-friendly between the installation position and the operating position. Furthermore, the position adjustability of the induction heating unit allows the roller heating device to be used advantageously for rollers with different diameters, so that a large number of different rollers can be heated or preheated.

[0036] Preferably, the first position adjustment devices for the induction heating devices each have a slide. It can be provided that each of the first position adjustment devices has a slide or is designed as a slide. Within the scope of the invention, a slide is understood to be a part of an assembly that has a mechanical guide element comprising a linear guide, by means of which the first position adjustment devices designed as slides are moved translationally along a straight line against another component, for example, a frame. Page 8 / 49

[0037] P80995WO can be used. The assembly consists of a stationary part, for example the frame, and a movable part, the carriage. The respective induction heating units can thus be moved particularly easily and with comparatively little resistance between the installation position and the operating position with respect to the roller assigned to the respective induction heating unit via the first position adjustment devices, which have a carriage. It can be provided that the first position adjustment devices have a drive and / or that the movement of the first position adjustment devices is controlled by the control device. Furthermore, it can be provided that the first position adjustment devices are moved manually.

[0038] In an alternative embodiment, the position adjustment device can be designed as a pivoting mechanism that pivots the induction heating devices to the intended working position. Such a pivoting mechanism would preferably be hydraulically actuated.

[0039] Preferably, the control device is configured to control the respective first position adjustment devices such that a predetermined target distance is set between at least one induction heating device and a surface of the roller associated with it. Further preferably, the control device is configured to control the respective drive devices such that a predetermined target rotational speed of the roller associated with the respective drive device is set.

[0040] The predefined target distance allows for precise lateral adjustment between the induction heating units and their corresponding rollers, enabling the roller heating device to be specifically configured for an individual heating process. (Self-page 9 / 49)

[0041] P80995WO understandably, when heating multiple rollers, several target distances can be set for both a single roller and multiple rollers. By setting one or more target distances, the roller heating device heats the rollers particularly efficiently.

[0042] Preferably, the control device is data-coupled with the respective first position adjustment devices for transmitting control signals.

[0043] Data coupling allows information regarding the current position and / or other information, such as speed or acceleration data or error messages, to be transmitted from the respective first position adjustment devices, and thus indirectly from the respective induction heating devices, to the control unit particularly easily and relatively quickly. Conversely, the aforementioned information can be transmitted from the control unit to the first position adjustment devices in the form of commands. Data coupling thus enables a beneficial exchange of information and / or commands between the control unit and the first position adjustment devices.

[0044] Data transmission can be achieved via a cable connection, with each cable connection linked to the control unit and the first position adjustment devices via an interface, and the cable connection being, for example, a LAN cable connection. Alternatively, data transmission can be achieved wirelessly using a local wireless network, for example, via WLAN.

[0045] The control device is preferably designed such that a data coupling for the transmission of data between the control device and other components of the roller heater is possible. Page 10 / 49

[0046] P80995WO measurement device in the same way as the previously described data coupling between the control device and the first position adjustment devices.

[0047] Preferably, each drive unit is positionally changeable between a receiving position and a drive position with respect to a roller assigned to the drive unit, wherein in the drive position the at least one drive unit is in operative connection with the roller(s) assigned to it, wherein the roller heating device has a number of second position adjustment devices corresponding to the number of drive units, and each drive unit is positionally changeable with respect to the roller assigned to the drive unit by means of the second position adjustment device assigned to it, such that the drive unit can be brought into operative connection with the roller assigned to it.

[0048] If each roller is assigned a drive device, then the roller heating device is to be described as follows: Each drive device is positionally changeable between a receiving position and a drive position with respect to a roller assigned to the drive device, wherein in the drive position the respective drive devices are in operative connection with the rollers assigned to them, wherein the roller heating device has a number of second position adjustment devices corresponding to the number of drive devices and each drive device is positionally changeable with respect to the roller assigned to the drive device by means of the second position adjustment device assigned to it, such that the drive device can be brought into operative connection with the roller assigned to it.

[0049] By means of the second position adjustment device, the respective drive unit can be moved along the longitudinal axis of this page 11 / 49

[0050] The roller assigned to P80995WO is moved translationally. The drive unit is spaced apart from the respective roller in the receiving position so that the roller can first be positioned in the roller heating device according to the invention. This spacing allows the roller heating device to heat rollers with different diameters as well as rollers with different lengths, and is therefore versatile in its application.

[0051] Preferably, the respective drive unit has a greater axial distance to the associated roller in a receiving position than in the driving position. In the receiving position, this spacing allows for the loading of the roller heating device. Additionally, maintenance or repair work can be carried out on both the drive unit and the corresponding roller. In the driving position, however, the drive unit is in operative contact with the associated roller and can drive it rotationally. The rotation allows the roller to be heated relatively uniformly along its circumferential surface when an induction heating device associated with this roller heats it in a working position.

[0052] Of course, other positions between the receiving position and the drive position, for example a maintenance position, can also be assumed by means of the positioning of the drive device using the second position adjustment devices.

[0053] Preferably, the second position adjustment devices for the drive devices each have a slide. It can be provided that each of the second position adjustment devices has a slide or is designed as a slide. Within the scope of the invention, a slide is understood to be a part of an assembly that has a mechanical guide element comprising a linear guide (page 12 / 49).

[0054] P80995WO enables the translational movement of the second position adjustment devices, designed as slides, against another component, for example, a frame, along a straight line. The assembly consists of a stationary part, for example, the frame, and a movable part, the slide. The respective drive unit can thus be moved in a particularly simple and comparatively low-resistance manner relative to the roller associated with the drive unit via the second position adjustment devices, so that the drive unit can be brought into operative contact with the roller associated with it. It can be provided that the second position adjustment devices have a drive and / or that the movement of the second position adjustment devices is controlled by the control unit.Furthermore, it may be provided that the second position adjustment devices are operated manually.

[0055] Preferably, the roller heating device has at least one temperature sensing device for determining a surface temperature of at least one of the rollers to be heated, and the at least one temperature sensing device is data-coupled with the control device and / or at least one of the induction heating devices for transmitting temperature measurement data.

[0056] The temperature sensing device allows the surface temperature of the roller to be heated to be advantageously determined before, during, and after a roller heating process, thus enabling near-continuous surface temperature monitoring. Knowing the roller's surface temperature allows for a particularly energy-efficient roller heating process, as excessive heating of the roller can be counteracted in a timely manner, for example, by switching off the heating element. (Page 13 / 49)

[0057] P80995WO

[0058] The roller is equipped with an induction heating device. This leads, on the one hand, to savings in energy costs generated by heating and, on the other hand, to protection of the roller surface, as it is not subjected to unnecessary thermal stress. The temperature measurement device can, for example, include a temperature sensor with which the surface temperature of the roller to be heated can be determined contactlessly and relatively easily. The surface temperature can be determined at individual points as well as at predefined areas of the roller.

[0059] Data can be recorded, stored and / or further processed from the temperature sensing device via the data coupling of the temperature sensing device with the control device and / or at least one of the induction heating devices.

[0060] Data coupling thus enables an advantageous exchange of information and / or commands between the temperature sensing device and the control device and / or induction heating device. This data coupling can be established via a wired connection, with each connection having an interface to the temperature sensing device and the control device and / or the induction heating device, and the wired connection being, for example, a LAN cable connection. Alternatively, data coupling can be established wirelessly using a local wireless network, such as WLAN.

[0061] Preferably, the control device is designed to determine, based on the determined surface temperature of the at least one roller to be heated, a heating power of the induction heating device assigned to the roller to be heated - Page 14 / 49

[0062] P80995WO to control that the surface temperature of the roller to be heated does not exceed a predetermined maximum temperature.

[0063] The temperature sensing device first determines the surface temperature of the roller to be heated. Subsequently, the heating power of the induction heating device assigned to the roller is determined and activated by the control unit to heat the corresponding roller. Heating can be carried out with a constant heating power output from the induction heating device or with successive and varying heating powers. The control unit is designed to regulate the heating power in such a way that the surface temperature of the roller to be heated does not exceed the predetermined maximum temperature.

[0064] In this context, maximum temperature refers to a limit value for the surface temperature, the exceeding of which should be avoided, for example, to reduce thermally induced damage to the roll or its surface. Alternatively, the maximum temperature can also represent the required surface temperature of the roll for the subsequent rolling process. In other words, the control unit regulates the heating power of the induction heating device up to a predetermined temperature limit of the roll being heated. In this way, undesirable thermal stresses and overheating of the roll being heated can be reduced.

[0065] Furthermore, the control device can be designed to regulate the heating power in such a way that it gradually decreases as the surface temperature of the roller being heated approaches, but does not exceed, the maximum temperature. Undesirable thermal stresses caused by an excessively high surface temperature of the roller being heated are thus prevented. Page 15 / 49

[0066] P80995WO partially avoids, so that the roller heating device heats the rollers in a particularly gentle manner. The rollers heated with the roller heating device according to the invention are thus heated particularly sustainably.

[0067] The roller heating device according to the invention is comparatively energy-efficient due to the design of the control device described above, since the control device can control the heating power of the induction heating device in such a way that exceeding the predetermined maximum temperature, which increases energy consumption, can be advantageously avoided.

[0068] The heating power can be adjusted by changing the current or the voltage.

[0069] Naturally, the control device can also set different predetermined maximum temperatures or target temperatures as limit values. With a control device designed in this way, for example, several rollers can be heated sequentially by a roller heating device according to the invention for different rolling mills. The roller heating device according to the invention can thus be advantageously used for several rolling mills or for a rolling mill with rollers to be heated with different temperature requirements. The heating of the rollers is therefore particularly energy- and cost-efficient.

[0070] Preferably, the control device is designed to reduce the heating power of the induction heating device associated with the roller being heated, or to switch off the induction heating device, if the measured surface temperature exceeds a predetermined maximum value. This makes the roller heating device particularly reliable. Page 16 / 49

[0071] P80995WO

[0072] Preferably, the control device is designed to control the drive device associated with the roller to be heated, based on the determined surface temperature of at least one of the rollers to be heated, in such a way that the rotational speed of the roller to be heated is controlled so that the surface temperature of the roller to be heated does not exceed a predetermined maximum temperature.

[0073] With this type of control device, the rotational speed of the roller to be heated can be adjusted to the heat output from the induction heating device and thus to the surface temperature of the roller. The rotation at this speed is driven by the drive mechanism of the respective roller. If the roller to be heated rotates at a low speed, for example, its surface will heat up comparatively faster with a constant heat output from the induction heating device compared to a rotation at a higher speed.

[0074] The control unit is designed such that the data recorded by the temperature sensing device for determining the surface temperature are received, stored, and processed by the control unit as needed. In response to the surface temperature data, the control unit then regulates the rotational speed of the drive unit.

[0075] Preferably, the control device can also be designed such that the drive device is controlled in such a way that the rotational speed of the roller to be heated is controlled in such a way that a target temperature of the roller to be heated is set. The target temperature can, for example, be a desired final temperature. Page 17 / 49

[0076] P80995WO temperature to which the roller to be heated is finally to be heated and the roller heating device thus heats the roller particularly precisely .

[0077] Preferably, the roller heating device has at least one distance measuring device for determining a distance between a surface of at least one of the rollers to be heated and the associated induction heating device, wherein the at least one distance measuring device is data-coupled with the control device and / or with at least one of the induction heating devices for transmitting distance measurement data.

[0078] The distance measuring device can be arranged on one of the induction heating devices, from which the distance to the roller to be heated and the roller associated with that induction heating device is to be determined. The distance measuring device can, for example, be a laser distance meter or an ultrasonic distance meter that determines the distance between the surface of the roller to be heated and the associated induction heating device with an accuracy in the millimeter range.

[0079] By determining the distance between the roller surface and the associated induction heating device, data is obtained which can be used to avoid collisions between the roller surface and the induction heating device and to optimize the heating process of the roller.

[0080] Depending on the roller material, the surface of the roller to be heated is particularly well-suited for heating within a specific temperature range. Page 18 / 49

[0081] P80995WO

[0082] The heating of the roller can be adjusted via the heating power and / or the heating duration of the induction heating device, as well as via the distance between the roller surface and the active induction heating device. The shorter this distance is selected, the more intensively the roller is heated by the induction heating device.

[0083] By linking the distance measuring device with the control unit, a target distance between the roller and the induction heating device can be directly adjusted to the respective heating process, thus enabling comparatively energy-efficient heating. Naturally, distance measurement can also be performed on rollers with different diameters.

[0084] The data connection between the distance measuring device and the induction heating device enables information exchange and can relatively easily reduce the risk of collision. It can be designed so that if a minimum distance, determined by the distance measuring device, is not maintained between the roller surface and the induction heating device, the induction heating device is switched off for safety reasons, thus protecting the roller surface from thermal damage. The roller heating device is therefore designed to be particularly safe.

[0085] Naturally, the distance measuring device for the design of a safe and at the same time energy-efficient roller heating device can be data-coupled with the control device as well as alternatively or simultaneously with at least one induction heating device.

[0086] Preferably, the roller heating device has at least one rotational speed measuring device for determining a page 19 / 49

[0087] P80995WO

[0088] Rotational speed of at least one of the rollers to be heated, wherein the at least one rotational speed measuring device is data-coupled with the control device and / or with at least one of the drive devices for transmitting rotational speed measurement data.

[0089] The rotational speed measuring device can, for example, be designed as part of the drive unit and be integrally installed in or on it, and / or it can include a speed measuring device that determines the rotational speed of the roller to be heated by means of the reflection of an LED or laser light beam or by means of a light barrier, and determines the rotational speed of the roller to be heated by means of information about its circumferential area. The rotational speed measuring device is also suitable for rollers with different diameters.

[0090] By coupling the rotational speed measuring device with the control device, rotational speed data from the roller to be heated can be transmitted to the control device. This data can then be stored, processed, or read out, allowing for future optimization of the heating process. Preferably, the control device is designed to control the respective drive devices in such a way that a predetermined target rotational speed is set for the rollers assigned to the respective drive device.

[0091] By coupling the data between the rotational speed measuring device and at least one of the drive devices, a comparatively simple shutdown of the drive devices can be achieved by means of a rotational speed limit value, according to which the corresponding drive device reduces or switches off the drive of the roller to be heated when the rotational speed limit value is exceeded. The roller according to the invention - page 20 / 49

[0092] The P80995WO heating device is therefore designed to be comparatively safe.

[0093] By data-linking the rotational speed measuring device with the control unit and the drive unit, a type of control loop can be established. The control unit can receive data and, based on this, send commands to the also data-linked drive unit, according to which the rotational speed of the roller to be heated is adjusted, i.e., increased or decreased. Since the control unit can also be data-linked with the induction heating device associated with the roller to be heated, the control loop can furthermore take into account the heating power and / or the heating duration of the induction heating device during a heating process.

[0094] For example, it can be provided that at low rotational speeds the roller is heated with a high heating power, and at high rotational speeds the roller is heated with a low heating power. The heating of the roller can thus be carried out relatively efficiently and, for example, adapted to a specific roller diameter. Preferably, the heating takes into account the temperature of the roller surface, which is determined by means of the temperature sensing device.

[0095] Because the control unit preferably offers several settings for heating the roller surface, roller heating can be carried out particularly efficiently and precisely. By selectively influencing the heating power, the angle of inclination, and / or the rotational speed, the most suitable setting or combination of settings can be selected. Page 21 / 49

[0096] P80995WO

[0097] Preferably, the control device is designed to control at least one, preferably all, induction heating devices in such a way that they heat the roller assigned to the at least one induction heating device with a predetermined first heating power for a predetermined first heating interval.

[0098] The surface temperature of the roller to be heated is primarily determined by the heating power and heating duration provided by the induction heating device. Alternatively, the surface temperature can also be adjusted by changing the distance between the induction heating device and the roller or by changing the roller's rotational speed. For the sake of simplicity, the following discussion focuses on the heating power without excluding the alternative settings. By controlling this parameter, the duration of the heating process and a target surface temperature of the roller can be set, which is reached after the roller has cooled down. Furthermore, by controlling and adjusting the heating power and heating interval, the roller heating device can be used for rollers with different diameters.

[0099] Basically, the heating process can be roughly divided into four successive stages:

[0100] 1. Starting from an ambient temperature, the roller to be heated is heated by means of at least one induction heating device with the predetermined first heating power for the predetermined first heating interval.

[0101] 2. At the end of the heating process, a target temperature of the roller surfaces is reached and the heating is stopped.

[0102] 3. After the heating process is complete, the surface of the roller cools down and reaches a working temperature. Page 22 / 49

[0103] P80995WO

[0104] 4. After the roller has cooled to the operating temperature, it continues to cool and approach the ambient temperature again, but remains in an operating temperature interval for a comparatively long period of time.

[0105] As long as the surface temperature of the heated roller is within the operating temperature range, the roller can be installed in a rolling mill and put into operation.

[0106] Preferably the first heating output is between 200 kW and 600 kW, further preferably between 250 kW and 550 kW, further preferably between 300 kW and 500 kW, and again further preferably 400 kW.

[0107] Preferably the first heating interval is between 1300 s and 2300 s, more preferably between 1500 s and 2100 s, and even more preferably between 1700 s and 1900 s.

[0108] By means of a predetermined initial heating power output for a predetermined initial heating interval, the surface temperature of the roller to be heated can be precisely set within a preferred timeframe via the induction heating device. Heating with this initial power output allows the surface temperature to be set relatively quickly, making the roller ready for use comparatively rapidly.

[0109] Preferably, the control device is configured to control at least two induction heating devices such that each heats the roller to be heated with the predetermined initial heating power for the predetermined initial heating interval. The roller to be heated can thus be... (page 23 / 49)

[0110] The P80995WO can be heated up and brought to operating temperature particularly quickly.

[0111] Preferably, the control device is designed to control at least one, preferably all, induction heating devices in such a way that they heat the roller assigned to the at least one induction heating device with a predetermined second heating line for a predetermined second heating interval, wherein the second heating interval is temporally subsequent to the first heating interval.

[0112] The second heating power and the second heating interval allow the heating process to be designed more complexly compared to heating with only the first heating power for the predetermined first heating interval.

[0113] The second heating interval allows the roller to be reheated after the first, for example, back to the target temperature. There can be a time interval between the first and second heating intervals, but this interval is not long enough to allow the surface of the heated roller to cool back down to ambient temperature. In other words, the second heating cycle reheats or additionally heats the already heated roller.

[0114] The reheating takes place during the previously described step 1 and offers the advantage that the heated roller is supplied with heat energy again, so that the surface of the roller can be reheated to a predetermined maximum or target temperature after cooling. This ensures that, in order to achieve a predetermined average temperature of the roller, the surface temperature does not exceed a predetermined maximum temperature. By heating the roller with the second heating interval and the second heating element (page 24 / 49)

[0115] P80995WO increases the total heat energy introduced into the roller, resulting in a comparatively higher average temperature of the entire roller.

[0116] By using the second predetermined heating power for the predetermined second heating interval, a comparatively more uniform average temperature of the roll to be heated can be advantageously achieved (step 4), without first having to heat the roll to a comparatively higher surface temperature. The higher operating temperature or average temperature of the heated roll is thus achieved under comparatively low thermal loads, and the heated roll can advantageously be used in a rolling mill with the correspondingly more uniform average temperature.

[0117] Preferably, the second heating output is between 50 kW and 350 kW, more preferably between 100 kW and 300 kW, and more preferably between 150 kW and 250 kW.

[0118] Preferably, the second heating interval is between 100 s and 1500°s, more preferably between 300°s and 1300°s, and particularly preferably between 500 s and 1100 s.

[0119] Preferably, the control device is designed to determine the surface temperature and / or a core temperature and / or an average temperature of at least one of the rollers to be heated by means of a temperature model.

[0120] Surface temperature refers to the temperature measured at the surface of the roller being heated or the heated roller. Core temperature is the temperature inside the roller, in other words, in the area of ​​a central axis of the cylindrical roller. Average temperature describes the

[0121] Temperature of the roller averaged over its cross-sectional area. Page 25 / 49

[0122] P80995WO

[0123] The temperatures refer specifically to the area of ​​the roller ball.

[0124] The temperature model for the roller to be heated can be created, for example, using finite element method simulation software such as Ansys or COMSOL Multiphysics, where the roller is modeled as a multi-mesh grid. From predefined input data, a temporal and / or spatial profile of the surface temperature and / or the core temperature and / or the average temperature can then be generated with respect to the model as output and preferably displayed graphically in the form of the temperature model of the roller to be heated.

[0125] The temperature model allows for the advantageous modeling of the surface temperature, core temperature, and / or average temperature under predefined conditions and / or boundary conditions. This enables, for example, the determination of the heating power and heating intervals required to heat the roller to a predetermined target surface temperature. The surface of the roller to be heated can thus be heated to the target surface temperature particularly quickly and efficiently.

[0126] By determining the surface temperature of the roller to be heated or the heated roller, the cooling behavior of the roller can also be determined. Thus, the temperature model can be used to model or predict after what time the heated roller will have a suitable surface temperature, so that the roller can be used for a subsequent work step after the cooling process.

[0127] This step, in addition to the regular operation of the roller, can also include, for example, the mechanical or manual transport of the cooled roller to maintenance, testing, or insertion (page 26 / 49).

[0128] P80995WO for purposes of rung. By predicting the surface temperature in relation to a cooling process, occupational safety is increased when using the heated roll, and the dwell time until the start of transport of the cooled roll is advantageously reduced.

[0129] By predicting the average and core temperatures using the temperature model, stress profiles generated by heating within the roll can be identified and simulated. This allows for advantageous inferences about the stress profiles of the actual heated roll based on the temperature model, enabling an assessment of the roll's condition. Therefore, the temperature model allows for a prediction regarding the service life of a repeatedly heated real roll.

[0130] Preferably, the control device is designed such that the temperature model performs the determination of the surface temperature and / or the core temperature and / or the average temperature using data representing the first and / or second heating power of at least one induction heating device, and / or the first heating interval and / or the second heating interval of at least one induction heating device, and / or the rotational speed of at least one of the rollers to be heated.

[0131] By using such input data, the temperature model is particularly accurate and can be specifically used for different heating processes with, for example, variable heating power.

[0132] Furthermore, the input data, data on the current ambient temperature, the geometric dimensions, the material, the rotational speed and the specific surface temperature can be found on page 27 / 49.

[0133] P80995WO of the roller to be heated and the distance between the surface of the roller to be heated and the induction heating device associated with it.

[0134] The input data for the temperature model can also include data from past heating processes. The more data the temperature model uses, the more accurately the temperature profile can be determined.

[0135] Preferably, the control device is designed such that the temperature model, using data representing the first and / or second heating power of at least one induction heating device, and / or data representing the first heating interval and / or the second heating interval of at least one induction heating device, and / or data representing the rotational speed of at least one of the rollers to be heated, determines a prediction of the development of the surface temperature and / or the core temperature and / or the average temperature of at least one roller to be heated.

[0136] When forecasting the development of the temperature of the roller to be heated, the future temperature of the roller is calculated using data from the past and / or current data of a heating process. This forecast allows prediction of when the heated roller will reach a specific limit or target temperature, such as a target surface temperature or a maximum core temperature (maximum temperature or limit temperature).

[0137] Based on the predicted time, a further work step, such as installing the heated roll in a rolling mill at a desired target surface temperature, can then be initiated, planned and / or carried out. Page 28 / 49

[0138] P80995WO

[0139] By predicting the temperature profile of the heated roller, the roller heating device can be operated advantageously in an energy-efficient manner, since the prediction makes it known at what time the respective temperature of the roller will be reached and the respective induction heating devices can be adjusted accordingly taking this time into account.

[0140] Furthermore, the roller heating device can be advantageously used with a rolling mill, as times in which the heated roller in the rolling mill does not yet have the required target surface temperature are advantageously avoided.

[0141] Preferably, the roller heating device has a human-machine interface for displaying at least one current temperature of the surface of at least one of the rollers to be heated and / or a target temperature of the surface of at least one of the rollers to be heated and / or a maximum temperature of the surface of at least one of the rollers to be heated and / or a rotational speed of at least one of the rollers to be heated and / or a position of at least one of the drive devices and / or a position of at least one of the induction heating device and / or a power supplied to at least one of the induction heating device, wherein the control device is data-coupled with the human-machine interface for transmitting control signals and wherein the control device is designed such that the roller heating device can be controlled via the human-machine interface.

[0142] The actual surface temperature can be determined, for example, by the temperature measuring device or read from a temperature model. The target temperature corresponds to a setpoint temperature value that the surface of the roller to be heated will reach, at least temporarily, after the heating process (page 29 / 49).

[0143] P80995WO exhibits [this]. In this context, maximum temperature refers to a limit value for the surface temperature, the exceeding of which should be avoided as far as possible to prevent thermally induced damage to the roller or the roller surface. The heating power of the induction heating device, and thus the heating of the roller surface, is influenced by the power supplied to at least one of the induction heating devices.

[0144] The human-machine interface, also called the user interface, allows an operator not only to operate the roller heating device but also to observe different states, intervene in the heating process, and view information and data. Intervention and the provision of information or data are achieved, for example, via a control panel with a touchscreen, indicator lights, display fields, and buttons, and / or via software through a visualization system, which is operated, for example, on a terminal equipped with at least one screen.

[0145] The human-machine interface and data link with the control unit provide the user with advantageous access to the necessary information and allow for particularly user-friendly control, monitoring, and control of the heating process, including its preparation and follow-up. Preparation and follow-up of the heating process can include, for example, moving an induction heating device and / or a drive device to a target position or determining the rotational speed of the drive devices.

[0146] The human-machine interface can, for example, include a control panel, such as a touchscreen, and / or be connected to the control device via cable in close proximity, or be a portable terminal, for example page 30 / 49

[0147] The P80995WO can be configured as a tablet and / or be data-linked to the control unit via a wireless connection, such as a WLAN connection. Depending on the application, the roller heating device can thus be controlled from a control room or from the immediate vicinity of the roller heating device.

[0148] According to a further aspect of the invention, the problem is solved by a rolling mill comprising: a rolling stand; at least two rolls, wherein each roll is rotatably mounted in two mounting pieces about their respective longitudinal axis, wherein the at least two rolls can be fastened in the rolling stand by means of their end pieces in which the respective roll is rotatably mounted; wherein the rolling mill comprises a roll heating device according to the first aspect of the invention.

[0149] The rolling mill according to the invention offers the advantage that, compared to rolling mills of the prior art, its rolls can be brought up to the desired operating temperature and ready for use quickly and with minimal effort. Depending on the application requirements, the rolls used can be repeatedly heated outside the rolling stand and / or gradually heated to different temperature levels.

[0150] Furthermore, the rollers can be changed relatively easily via the mounting pieces and replaced with other rollers, so that the rolling plant according to the invention is designed to be relatively simple in construction.

[0151] Further advantages, details, and features of the invention will become apparent from the exemplary embodiments described below. Page 31 / 49

[0152] P80995WO

[0153] Specifically, they show:

[0154] Figure 1: schematic three-dimensional view of the roller heating device;

[0155] Figure 2a: schematically a front view of a roller heating device with an induction heating unit in an installation position;

[0156] Figure 2b: schematically a front view of a roller heating device with an induction heating unit in a working position;

[0157] Figure 3a: Diagram showing the temperature profiles of a roller to be heated, which are established during a first heating interval;

[0158] Figure 3b: Diagram showing the temperature profiles of a roller being heated, which are established during a first and a second heating interval;

[0159] Figure 3c: Diagram showing further temperature profiles of a roller to be heated, which occur during a first and a second heating interval.

[0160] In the following description, identical reference numerals denote identical components or identical features, so that a description given for a component in relation to one figure also applies to the other figures, thus avoiding repetitive descriptions. Furthermore, individual features described in connection with one embodiment can also be used separately in other embodiments.

[0161] Fig. 1 shows a roller heating device 100, which has a fastening device 21 for holding several mounting pieces 20, wherein two mounting pieces 20 each hold a roller 10 rotatably about its longitudinal axis. The fastening device 21 has a frame. Each roller 10 can be brought into operative contact by means of an associated drive device 30, so that the respective roller 10 can be rotated by means of page 32 / 49

[0162] P80995WO of its associated drive unit 30 is rotatable about the longitudinal axis of the corresponding roller ze 10. In other words, each drive unit 30 drives one roller ze 10 rotationally.

[0163] Furthermore, the roller heating device 100 has a number of induction heating devices 40 corresponding to the number of rollers 10 to be heated. In the illustrated embodiment, the roller heating device 100 has two induction heating devices 40. In the view shown in Fig. 1, one induction heating device 40 is shown in a working position in which the respective distances between the induction heating devices 40 and the rollers 10 to be heated by them are smaller than in an installation position shown in Fig. 2a.

[0164] The induction heating devices 40 are positionally adjustable between their respective operating position and their respective installation position by means of first position adjustment devices 41. The positioning of the induction heating devices 40 via the first position adjustment devices 41, which have several slides, is effected by a rotation of a rotary wheel arranged in a rear area of ​​the roller heating device 100, as shown in Fig. 1. However, it is of course also possible for the respective position adjustment devices 41 to be driven by a motor.

[0165] Each drive unit 30 has a second position adjustment device 31, also comprising a slide. The drive units 30 can be moved translationally via this device, so that they can be moved between a receiving position shown in Fig. 2a and a drive position shown in Fig. 2b. Page 33 / 49

[0166] P80995WO

[0167] The roller heating device 100 further comprises a control unit 50, which is data-coupled with the induction heating units 40 and the drive units 50 for transmitting control signals. A human-machine interface 80 in the form of a touchscreen is arranged on the control unit 50, via which the elements of the roller heating device 100 that are data-coupled with the control unit 50 can be controlled and, for example, real-time data of a heating process can be displayed. The control unit 50 also has another screen on which, for example, a temperature model of the heating process or other data relating to the heating process can be displayed.

[0168] Fig. 2a shows a first frontal view of the roller heating device 100, in which one of the induction heating units 40 is in the installation position in which the distance of the induction heating unit 40 to the surface of the roller 10 associated with it is greater than in the operating position of the induction heating unit 40 shown in Fig. 2b. The induction heating unit 40 is vertically movable via the first position adjustment device 41, so that the distance to the roller is adjustable. In the view shown, the roller 10 is received by the mounting pieces 20. The mounting pieces 20 are held by the mounting device 21, which is designed as a frame. The drive unit 30 is in a receiving position in which the drive unit 30 is spaced apart from the roller 10 and is not in operative connection.

[0169] Furthermore, the illustrated embodiment includes a temperature sensing device 60 for recording temperature data of the roller ze 10 to be heated and a distance measuring device 70 for measuring a lateral distance between the induction heating device 40 and the ball surface of the roller ze 10 to be heated. Naturally, further details can be found on pages 34 / 49.

[0170] P80995WO according to the design, the temperature detection device 60 and the distance measuring device 70 can also be arranged at other locations of the roller heating device 100.

[0171] Fig. 2b also shows a frontal view of the roller heating device 100, with the induction heating device 40 in its operating position, in which the distance of the induction heating device 40 to the surface of the roller 10 associated with it is smaller than in the installation position of the induction heating device 40. Furthermore, the drive device 30 is in its drive position, in which the drive device 30 is in operative communication with the roller 10 associated with it.

[0172] The change of position of the drive device 30 between its drive position and its receiving position is effected via the second position adjustment device 31, which enables a translational movement of the drive device 30.

[0173] In the present embodiment, the functional connection is created by a contact which forms a form-fit / force-fit connection with a corresponding counter-contour of the roller journal.

[0174] Fig. 3a shows a diagram illustrating the surface temperature TI, average temperature T2, and core temperature T3 of the roller 10 heated by the roller heating device 100 over time. The control device 50 is configured to control at least one, preferably all, induction heating devices 40 such that they heat the roller 10 assigned to the at least one induction heating device 40 with a predetermined initial heating power for a predetermined initial heating interval. Page 35 / 49

[0175] P80995WO

[0176] According to the diagram shown in Fig. 3a, the duration of the first heating interval is 1800 s, with a heating power of 400 kW during this interval. As a result, the surface temperature TI of the roller 10 being heated increases from 20 °C to a maximum temperature of approximately 170 °C during the first heating interval. During this same interval, the average temperature T2 rises to approximately 100 °C and the core temperature T3 to approximately 50 °C.

[0177] After the first heating interval, the surface temperature TI of roller 10 decreases, with the surface temperature TI, the average temperature T2, and the core temperature T3 gradually equalizing over time, so that after 4000 s the surface, core, and average temperatures are approximately 100 °C. Within the following 3200 °C, the surface, core, and average temperatures decrease to approximately 90 °C.

[0178] The surface of the heated roller 10 thus exhibits only a slightly decreasing surface temperature over a comparatively long period after the end of the heating interval, so that the heated roller can be installed in a rolling mill after the heating process and the mill can be operated directly with the still warm roller.

[0179] Figure 3b shows a diagram with the time profiles of the surface temperature TI, the average temperature T2, and the core temperature T3 of the roller 10 heated by the roller heating device 100 when the roller 10 is heated using a heating strategy different from that illustrated in Figure 3a. In the heating strategy illustrated in Figure 3b, the first heating interval with a duration of 1800 s and a heating power of 400 kW is followed by a second heating interval with a heating duration of 900 s and a heating power of 200 kW. Figure 3b shows that (page 36 / 49)

[0180] P80995WO the surface temperature TI of roller 10 initially cools down slightly during the second heating interval, while the average temperature T2 and the core temperature T3 continue to increase.

[0181] Approximately 4000 seconds after the start of the entire heating process, the surface of the roller has a temperature of approximately 118 °C, with a core temperature of approximately 115 °C and an average temperature of 120 °C. Within the following 3200 seconds, the surface temperature TI, the average temperature T2, and the core temperature T3 decrease slightly to a temperature range between 105 °C and 115 °C.

[0182] The additional heating of the roll through the shorter second heating interval thus increases the surface temperature of the roll for a comparatively longer period. The heated roll can now be used in a rolling mill that requires a roll with a higher surface temperature compared to a heating process according to Fig. 3a.

[0183] Fig. 3c shows the previously mentioned temperature profiles, also obtained using two heating intervals, with the difference that the first heating interval lasts approximately 2000 s and the second approximately 1600 s, with the power of the second heating interval again being about half that used in the first. After the resulting total heating time of approximately 3600 s, the surface temperature, which again initially corresponds to the maximum temperature of the heated roller, is approximately 185 °C, while the average temperature is approximately 150 °C and the core temperature is approximately 115 °C.

[0184] Subsequently, approximately 4000 s after the start of the entire heating process, the surface of the roller has a temperature of approximately 155 °C, while the core temperature is approximately 125 °C, the average temperature is 150 °C, and the maximum temperature is [page 37 / 49].

[0185] P80995WO exhibits a temperature of approximately 158 °C. Within the following 3200°s, the temperatures initially diverge slightly, so that 7200°s, i.e. 2 hours, after the start of the first heating interval, the surface temperature is still approximately 138 °C, the average temperature approximately 130°C, and the surface temperature approximately 125 °C.

[0186] By controlling the heating power and duration according to Fig. 3c, a higher surface temperature of the heated roller can be maintained over a comparatively long period compared to the heating processes shown in Figs. 3a and 3b. A particular advantage is that the roller heated in this way never reaches temperatures above 200 °C at any point, thus effectively reducing unwanted thermal stress on the roller.

[0187] The roller heated in this way can therefore be used in a rolling mill that requires a roller with an increased surface temperature for rolling processes.

[0188] Page 38 / 49

[0189] P80995WO

[0190] Reference symbol list

[0191] 100 roller heating device

[0192] 10 rollers 20 mounting pieces (these are the mounting pieces)

[0193] 21 Fastening device

[0194] 30 Drive unit

[0195] 31 Second position adjustment device

[0196] 40 Induction heating device 41 First position adjustment device

[0197] 50 Control unit

[0198] 60 Temperature measuring device

[0199] 70 Distance measuring device

[0200] 80 Human-Machine Interface

Claims

Page 39 / 49 Applicant: SMS group GmbH Our reference number: P80995WO Patent claims 1. Roll heating device (100) for preheating at least two rolls (10), wherein each roll (10) is rotatably mounted in two mounting blocks (20) about their respective longitudinal axes, the roll heating device (100) comprising the following: a fastening device (21) for holding the mounting blocks (20) of the rolls (10); at least one, preferably one number corresponding to the number of rolls (10) to be heated, drive devices (30), wherein the at least one drive device (30) can be brought into operative connection with at least one roll (10) such that the rolls (10) to be heated can be rotated about their longitudinal axis by means of the at least one drive device (30); a number of induction heating devices (40) corresponding to the number of rolls (10) to be heated;and a control device (50) which is data-coupled with the induction heating devices (40) and with the drive devices (30) for transmitting control signals.

2. Roller heating device (100) according to claim 1, characterized by the following features: each induction heating device (40) is positionally changeable between an installation position and a working position with respect to the roller (10) assigned to the induction heating device (40); in the installation position, the respective induction heating devices (40) point towards the roller (10) assigned to them. Page 40 / 49 P80995WO neten rolls (10) have a larger lateral distance than in their working position; the roll heating device (100) has a number of first position adjustment devices (41) corresponding to the number of induction heating devices (40); and each induction heating device (40) is positionally adjustable between its installed position and its working position by means of the first position adjustment device (41) assigned to it.

3. Roller heating device (100) according to one of the preceding claims, characterized by the following feature: the control device (50) is data-coupled with the respective first position adjustment devices (41) for transmitting control signals.

4. Roll heating device (100) according to one of the preceding claims, characterized by the following features: each drive unit (30) is positionally changeable between a receiving position and a drive position with respect to a roll (10) assigned to the drive unit (30); in the drive position, the at least one drive unit (30) is in operative connection with the roll(s) (10) assigned to it; the roll heating device (100) has a number of second position adjustment devices (31) corresponding to the number of drive units (30); and each drive unit (30) is positionally changeable with respect to the roll (10) assigned to the drive unit (30) by means of the second position adjustment device (31) assigned to it, such that -40- Page 41 / 49 P80995WO the drive unit (30) can be brought into operative contact with the roller (10) associated with it.

5. Roller heating device (100) according to one of the preceding claims, characterized by the following features: the roller heating device (100) has at least one temperature sensing device (60) for determining a surface temperature of at least one of the rollers (10) to be heated; and the at least one temperature sensing device (60) is data-coupled with the control device (50) and / or at least one of the induction heating devices (40) for the transmission of temperature measurement data.

6. Roller heating device (100) according to claim 5, characterized by the following feature: the control device (50) is designed to control, based on the determined surface temperature of the at least one roller (10) to be heated, a heating power of the induction heating device (40) associated with the roller (10) to be heated in such a way that the surface temperature of the roller (10) to be heated does not exceed a predetermined maximum temperature.

7. Roller heating device (100) according to claim 5 or 6, characterized by the following feature: the control device (50) is configured to control the drive device (30) associated with the roller (10) to be heated, based on the determined surface temperature of at least one of the rollers (10) to be heated, such that a rotational speed of the roller (10) to be heated is controlled such that the surface temperature of the -41 - Page 42 / 49 P80995WO heating roller (10) does not exceed a predetermined maximum temperature.

8. Roller heating device (100) according to one of the preceding claims, characterized by the following features: the roller heating device (100) has at least one distance measuring device (70) for determining a distance between a surface (12) of at least one of the rollers (10) to be heated and the induction heating device (40) associated therewith; and the at least one distance measuring device (70) is data-coupled with the control device (50) and / or with at least one of the induction heating devices (40) for transmitting distance measurement data.

9. Roll heating device (100) according to one of the preceding claims, characterized by the following features: the roll heating device (100) has at least one rotational speed measuring device for determining a rotational speed of at least one of the rolls (10) to be heated; and the at least one rotational speed measuring device is data-coupled with the control device (50) and / or with at least one of the drive devices (30) for transmitting rotational speed measurement data.

10. Roller heating device (100) according to one of the preceding claims, characterized by the following feature: the control device (50) is configured to control at least one, preferably all, induction heating devices (40) such that these control the at least one induction heating device- Page 43 / 49 P80995WO tung (40) assigned roller (10) is heated with a predetermined first heating power for a predetermined first time heating interval.

11. Roller heating device (100) according to claim 10, characterized by the following features: the control device (50) is configured to control at least one, preferably all, induction heating devices (40) such that they heat the roller (10) assigned to the at least one induction heating device (40) with a predetermined second heating line for a predetermined second heating interval; and the second heating interval is temporally subsequent to the first heating interval.

12. Roller heating device (100) according to one of the preceding claims, characterized by the following feature: the control device (50) is designed to determine the surface temperature and / or a core temperature and / or an average temperature of at least one of the rollers (10) to be heated by means of a temperature model.

13. Roller heating device (100) according to claim 12, characterized by the following feature: the control device (50) is configured such that the temperature model determines the surface temperature and / or the core temperature and / or the average temperature using data representing the first and / or second heating power of at least one induction heating device (40), and / or Page 44 / 49 P80995WO performs the first heating interval and / or the second heating interval representing data of at least one induction heating device (40), and / or the rotational speed representing data of at least one of the rollers (10) to be heated.

14. Roller heating device (100) according to claim 12 or 13, characterized by the following feature: the control device (50) is designed such that the temperature model determines a prediction of the development of the surface temperature and / or the core temperature and / or the average temperature of at least one roller (10) to be heated using the data representing the first and / or second heating power of at least one induction heating device (40), and / or the data representing the first heating interval and / or the second heating interval of at least one induction heating device (40), and / or the data representing the rotational speed of at least one of the rollers to be heated.

15. Roller heating device (100) according to one of the preceding claims, characterized by the following features: the roller heating device (100) has a human-machine interface (80) for displaying at least one actual temperature of the surface of at least one of the rollers (10) to be heated and / or a target temperature of the surface of at least one of the rollers (10) to be heated and / or -44- Page 45 / 49 P80995WO a maximum temperature of the surface of at least one of the rollers (10) to be heated and / or a rotational speed of at least one of the rollers (10) to be heated and / or a position of at least one of the drive devices (30) and / or a position of at least one of the induction heating device (40) and / or a power supplied to at least one of the induction heating device (40); the control device (50) is data-coupled with the human-machine interface (80) for transmitting control signals; and the control device (50) is designed such that the roller heating device (100) can be controlled via the human-machine interface (80).

16. Rolling mill (200) comprising: a rolling stand (210); at least two rolls (10), wherein each roll (10) is rotatably mounted in two mounting blocks (20) about their respective longitudinal axis, wherein the at least two rolls (10) can be fastened in the rolling stand by means of their end pieces (11), in which the respective roll (10) is rotatably mounted; wherein the rolling mill (200) is characterized in that it comprises a roll heating device (100) according to one of the preceding claims.

17. Method for preheating at least two rollers (10) wherein each roller (10) is rotatably mounted in two mounting pieces (20) about their respective longitudinal axis, wherein the method comprises the following process steps: -45- Page 46 / 49 P80995WO Holding the mounting pieces (20) of the rollers (10) in a fastening device (21) ; Driving the rollers (10) by means of at least one, preferably a number of drive devices (30) corresponding to the number of rollers (10) to be heated, wherein the at least one drive device (30) is operatively connected to at least one roller (10) in such a way that the rollers (10) to be heated can be rotated about their longitudinal axis by means of the at least one drive device (30); and heating the rollers () to be heated by means of a number of induction heating devices (40) corresponding to the number of rollers (10) to be heated.

18. The method of claim 17, characterized in that the method further comprises the following process steps: Determining at least one surface temperature of at least one of the rollers to be heated by means of at least one temperature sensing device (60); and based on the determined surface temperature of the at least one roller (10) to be heated, adjusting a heating power of the induction heating device (40) associated with the roller (10) to be heated such that the surface temperature of the roller (10) to be heated does not exceed a predetermined maximum temperature.

19. Method according to one of claims 17 to 18, characterized in that the method further comprises the following process steps: Determining at least one surface temperature of at least one of the rollers to be heated by means of Page 47 / 49 P80995WO at least one temperature sensing device (60); and based on the determined surface temperature of the at least one roller (10) to be heated, controlling a rotational speed of the drive device (30) associated with the roller (10) to be heated such that the surface temperature of the roller (10) to be heated does not exceed a predetermined maximum temperature.

20. A method according to any one of claims 17 to 19, characterized in that the method further comprises the following process step: Heating the at least one, preferably all of the rollers (10) to be heated by means of at least one, preferably all induction heating devices (40) with a predetermined first heating power for a predetermined first heating interval.

21. The method of claim 20, characterized in that the method further comprises the following process step: Heating the at least one, preferably all of the rollers (10) to be heated by means of at least one, preferably all induction heating devices (40) with a predetermined second heating power for a predetermined second heating interval, wherein the second heating interval is temporally subsequent to the first heating interval.

22. Method according to one of claims 17 to 21, characterized in that the method further comprises the following process step: Determining a surface temperature and / or a core temperature and / or an average temperature of at least one of the rollers to be heated (10) using a temperature model using -47- Page 48 / 49 P80995WO representing the first and / or second heating power of at least one induction heating device (40), and / or the first heating interval and / or the second heating interval of at least one induction heating device (40), and / or the rotational speed of at least one of the rollers (10) to be heated.

23. Method according to claim 22, characterized in that the method further comprises the following process step: Determining a forecast of the development of the surface temperature and / or the core temperature and / or the average temperature of at least one roller (10) to be heated by means of a temperature model using the data representing the first and / or second heating power of at least one induction heating device (40), and / or the data representing the first heating interval and / or the second heating interval of at least one induction heating device (40), and / or the data representing the rotational speed of at least one of the rollers to be heated. -48-

Images