Slab edge heating system and method

Abstract

The present invention discloses a slab edge heating system and method. The system includes at least one heating subsystem, comprising a first heating unit and a second heating unit symmetrically arranged on either side of the slab. Each heating unit includes a track, a movable frame, a rotating frame, a C-shaped inductor, a first linear drive mechanism, a second linear drive mechanism, a control module, and a power module. The control module controls the operation of the first linear drive mechanism based on the slab thickness, adjusting the vertical position of the C-shaped inductor so that the slab edge is located at the center of the C-shaped inductor's channel. The control module also controls the operation of the second linear drive mechanism based on the slab width, adjusting the horizontal position of the C-shaped inductor, thereby adjusting the heating dimension of the slab edge by the C-shaped inductor. The present invention protects the C-shaped inductor while reducing the risk of slab scratches, ensuring the stable operation and heating effect of the C-shaped inductor.

Description

Technical Field

[0001] The present invention belongs to the technical field of slab heating, and in particular relates to a slab edge heating system and method. Background Art

[0002] Hot rolling is a typical and common steel production process. Continuously cast ingots or slabs are heated in a walking beam furnace, dephosphorized with high-pressure water, and then sent to a roughing mill. After roughing, they undergo intermediate rolling and finally to a finishing mill. The most important process control parameter during rolling—the temperature of the slab being rolled—must fundamentally be controlled within the rolling temperature range. Excessively high slab temperatures can lead to decarburization, affecting the material's composition and, in severe cases, even melting. Excessively low slab temperatures can affect rolling efficiency, reduce the life of the rolls, and affect the quality of the finished product and metal yield.

[0003] During slab rolling, as the slab is transferred from the front end of the continuous casting line or from the outlet of the gas furnace to the rolling mill, the edges of the slab dissipate heat more rapidly across its width, resulting in lower edge temperatures. Furthermore, the longer the transfer path and the slower the speed, the greater the edge temperature loss. During roughing, the overall temperature maintains stable quality throughout the process. However, heat loss continues throughout the roughing process. After roughing, the slab enters intermediate rolling, where the temperature dissipates further, further decreasing the edge temperature. This can lead to edge cracking in crack-sensitive steel grades during intermediate rolling due to the low edge temperature. Especially during finishing rolling (the final step in the rolling process), the temperature difference between the slab edge and the center can reach over 100°C, significantly below the minimum rolling temperature of 900°C. For most steel grades, if edge heating is not performed, trimming the cracked edge areas after rolling is necessary to ensure acceptable finished products. First, the cutting process requires additional cutting equipment and equipment installation space, and the cutting of cracked edges reduces the yield of finished products. In addition, to ensure that the edges do not crack during finishing rolling, the overall slab discharge temperature must be increased, which will result in a significant waste of energy. Both methods significantly increase production costs.

[0004] Currently, slab heating methods prior to intermediate or finish rolling include gas baking, resistance wire heating, and electromagnetic induction heating. Resistance wire heating is not widely used due to limitations in heating speed, temperature control accuracy, heating range control, power efficiency, heating uniformity, and equipment life. Meanwhile, gas baking, due to national initiatives and strategies regarding carbon emissions and its own shortcomings in thermal energy efficiency, automation, temperature controllability, and equipment footprint, is poised to be replaced or superseded by newer heating methods.

[0005] Compared with traditional heating methods - resistance wire heating and gas baking heating, electromagnetic induction heating has certain advantages in heating efficiency, heating rate, temperature control accuracy, degree of automation, equipment service life and safety, energy economy and the space required for complete sets of equipment. Especially after the country advocates green manufacturing and promotes the two carbon tasks of "carbon peak" and "carbon neutrality", the green heating characteristics of electromagnetic induction heating are more prominent. This technology has become a favorable escort magic weapon for the steel industry's green production transformation.

[0006] At present, the application of electromagnetic induction in slab heating is classified into two types according to the magnetic field form during heating: longitudinal magnetic field heating and transverse magnetic field heating. The two magnetic field forms have different heating characteristics and application occasions.

[0007] The induction coil for longitudinal magnetic field heating is helically wound. When the heated billet is within the channel wound by the helical coil, a current is induced at the skin depth of its surface, forming a circulation current in the surface layer of the slab cross section. This induced current rapidly heats the surface layer, transferring heat toward the center of the slab. Therefore, longitudinal magnetic field heating is surface heating and affects the surface layer throughout the entire thickness of the slab. This also increases the temperature of the hotter areas in the middle of the slab, wasting energy in unneeded areas and potentially causing overheating in the middle of the slab. Longitudinal magnetic field heating cannot heat the colder areas at the edges of the slab. Furthermore, the closed, fixed channel wound by the coil imposes very strict requirements on the billet's dimensional deviation and shape regularity, which cannot be met by conventional continuous casting processes. Furthermore, the demand for controlled deformation at any location along the billet's length is extremely high. Deformation exceeding the channel dimensions can damage the equipment. Increasing the size of the closed, fixed channel significantly reduces heating efficiency and energy utilization. In addition, when the thickness of the heated slab is relatively thin, due to the large skin depth of the induced current, the use of ordinary medium-frequency power supply for heating will cause the current to form a circulation in the surface of the cross section, causing the upper surface current and the lower surface current to cancel each other out, seriously affecting the heating efficiency and the effective use of electrical energy. Therefore, an extremely expensive high-frequency induction power supply must be used to heat the thin plate, which greatly increases the requirements for power components and leads to a significant increase in power supply costs.

[0008] Transverse magnetic field heating of slabs usually involves symmetrically placing two "flat" inductors above and below the slab. The magnetic field generated by these two inductors penetrates along the thickness of the slab, and the current induced in the slab flows across the entire thickness section of the slab, so the entire thickness section is heated. This is considered overall heating - the temperature of the slab will increase throughout the thickness, the middle, and the edges. When the edge temperature needs to be increased to a greater extent, the edge effect of the current can be used to increase the temperature above that of the middle of the slab. This transverse magnetic heating method, in which the upper and lower inductors are symmetrically arranged on both sides of the slab, can increase the temperature of the slab edges, but the equipment debugging and control are extremely complex. In addition, when the temperature in the middle of the slab is high and does not need to be heated, but the temperature at the edge of the slab is low and needs to be heated, this method of heating is obviously not targeted enough and wastes a lot of energy. An induction heating system and heating method with alternating transverse and longitudinal magnetic fields (publication number CN111278182A) adopts alternating transverse and longitudinal magnetic fields to ensure the temperature uniformity of various parts of the slab after heating. However, due to the structure of the longitudinal magnetic field coil, the equipment is very likely to be damaged by the deformation of the slab.

[0009] On the other hand, when a single set of equipment needs to heat slabs of varying thicknesses, its adaptability is clearly insufficient. Most existing technologies primarily propose highly inventive equipment and heating solutions focused on ensuring temperature uniformity during slab heating. However, the use of C-type inductors solely for heating the low-temperature edges of slabs, along with the equipment's matching requirements and adaptability to varying slab thicknesses, requires further consideration and breakthroughs. Furthermore, domestic technology for heating slab edges with C-type inductors remains at the academic research and development stage, with no domestically developed equipment possessing independent intellectual property rights. Summary of the Invention

[0010] The purpose of the present invention is to provide a slab edge heating system and method to solve the problem that traditional heating methods cannot adapt to the heating of slabs of different thickness specifications and the heating has poor targeting, resulting in low heating efficiency.

[0011] The present invention solves the above-mentioned technical problems through the following technical solutions: a slab edge heating system, the system comprising at least one heating subsystem, the heating subsystem comprising a first heating unit and a second heating unit symmetrically arranged on both sides of the slab with the slab centerline as the symmetry axis; the first heating unit and the second heating unit each comprising:

[0012] Tracks located on one side of the slab;

[0013] a movable frame, the movable frame being slidably disposed on the track;

[0014] a rotating frame, the rotating frame being located on the mobile frame and having a first end rotatably connected to the mobile frame; the first end of the rotating frame being an end away from the slab;

[0015] A C-shaped inductor, which is fixed on the rotating frame and is used to heat the edge of the slab;

[0016] a first linear drive mechanism and a second linear drive mechanism, wherein a first end of the first linear drive mechanism is fixedly connected to the movable frame, and a second end of the first linear drive mechanism is fixedly connected to the back of the C-shaped inductor; a first end of the second linear drive mechanism is fixedly connected to the movable frame, and a second end of the second linear drive mechanism is fixed to the ground or a track; the back of the C-shaped inductor refers to the side away from the slab;

[0017] a control module, wherein the control module controls the operation of the first linear drive mechanism according to the thickness of the slab, and adjusts the vertical position of the C-shaped inductor so that the edge of the slab is located at the center of the channel of the C-shaped inductor; the control module also controls the operation of the second linear drive mechanism according to the width of the slab, and adjusts the horizontal position of the C-shaped inductor, thereby adjusting the heating dimension of the C-shaped inductor on the edge of the slab;

[0018] A power supply module is used to supply power to the C-type sensor.

[0019] Furthermore, a fixed frame is provided on the back of the C-shaped sensor, and the second end of the first linear drive mechanism is fixedly connected to the back of the C-shaped sensor through the fixed frame.

[0020] Furthermore, the power module is connected to the C-type inductor via a connecting copper bus.

[0021] Furthermore, the first heating unit and the second heating unit each include a cooling unit, and the cooling unit includes a first cooling water pipe and a second cooling water pipe; the first cooling water pipe is arranged in the power module, and the second cooling water pipe is arranged on the induction coil of the C-type inductor, and the first cooling water pipe is connected to the second cooling water pipe through a connecting water pipe.

[0022] Furthermore, a drag chain is provided on the mobile frame, and a water inlet pipe, a water outlet pipe and a cable are arranged in the channel of the drag chain; the water inlet pipe is connected to the first cooling water pipe, the water outlet pipe is connected to the second cooling water pipe, and the power module is connected to the external power supply through a cable.

[0023] Furthermore, the distance between the rotation connection between the rotating frame and the movable frame and the center of the heating end surface of the C-shaped inductor is at least 6 times the width of the heating end surface of the C-shaped inductor.

[0024] Furthermore, the first heating unit and the second heating unit both include a temperature measuring unit for detecting the temperature of the edge of the slab, and the control module is also used to adjust the output voltage of the power supply module according to the temperature collected by the temperature measuring unit, and then adjust the output power of the C-type sensor to increase the temperature of the edge of the slab and maintain it at the target temperature.

[0025] Based on the same concept, the present invention also provides a control method for the slab heating system as described above, the control method comprising the following steps:

[0026] Acquiring slab incoming material information, wherein the incoming material information includes slab thickness and width;

[0027] The first linear drive mechanism is controlled to move according to the thickness of the slab, and the vertical position of the C-shaped sensor is adjusted so that the edge of the slab is located in the center of the channel of the C-shaped sensor;

[0028] The second linear drive mechanism is controlled to move according to the slab width, and the horizontal position of the C-shaped sensor is adjusted, thereby adjusting the heating size of the slab edge by the C-shaped sensor.

[0029] Furthermore, before obtaining the slab incoming material information, the control method further includes constructing a slab-travel database through system debugging, and the specific implementation process is as follows:

[0030] For slabs of different thicknesses, the first linear drive mechanism is controlled to operate and the vertical position of the C-shaped sensor is adjusted. When the edge of the slab is located at the center of the channel of the C-shaped sensor, the stroke of the first linear drive mechanism is determined to obtain different slab thicknesses and their corresponding strokes;

[0031] For slabs of different widths, the second linear drive mechanism is controlled to move and the horizontal position of the C-shaped sensor is adjusted. When the heating size of the slab edge by the C-shaped sensor meets the heating requirements, the stroke of the second linear drive mechanism is determined to obtain different slab widths and their corresponding strokes.

[0032] Construct a slab-stroke database based on different slab thicknesses and their corresponding strokes, and different slab widths and their corresponding strokes;

[0033] After obtaining the incoming slab information, the stroke of the first linear drive mechanism is determined according to the slab thickness and the slab-stroke database, and the action of the first linear drive mechanism is controlled according to the stroke; the stroke of the second linear drive mechanism is determined according to the slab width and the slab-stroke database, and the action of the second linear drive mechanism is controlled according to the stroke.

[0034] Furthermore, the control method further includes:

[0035] Get the temperature collected by the temperature measuring unit;

[0036] The output voltage of the power module is adjusted according to the temperature collected by the temperature measuring unit, and the output power of the C-type sensor is further adjusted to increase the temperature of the edge of the slab and maintain it at the target temperature.

[0037] Furthermore, after controlling the second linear drive mechanism to move according to the slab width, the second linear drive mechanism is also controlled to retract according to the steel grade information of the slab;

[0038] When the slab is made of ultra-high crack-sensitive steel, the retraction stroke of the second linear drive mechanism is H-N1, and the actual stroke of the second linear drive mechanism is D1'-(H-N1);

[0039] When the slab is a high crack-sensitive steel grade, the retraction stroke of the second linear drive mechanism is H-N2, and the actual stroke of the second linear drive mechanism is D2'-(H-N2);

[0040] When the slab is a steel grade with medium crack sensitivity, the retraction stroke of the second linear drive mechanism is H-N3, and the actual stroke of the second linear drive mechanism is D3'-(H-N3);

[0041] When the slab is a low crack-sensitive steel grade, the retraction stroke of the second linear drive mechanism is H-N4, and the actual stroke of the second linear drive mechanism is D4'-(H-N4);

[0042] Wherein, H is the coil width of the C-type inductor, D1', D2', D3', and D4' are all the strokes before the second linear drive mechanism retracts, N1 is the projection width of the coil of the C-type inductor when it is completely located on the surface of the slab, N2 is the projection width of the coil of the C-type inductor when it is partially located on the surface of the slab, N3 is the projection width of the coil of the C-type inductor when it is partially located on the surface of the slab, and N4 is the projection width of the coil of the C-type inductor when it is partially located on the surface of the slab, and N1>N2>N3>N4.

[0043] Beneficial effects

[0044] Compared with the prior art, the advantages of the present invention are:

[0045] The present invention uses a first linear drive mechanism to adjust the up and down movement of the C-type sensor, thereby adjusting the position of the edge of the slab in the C-type sensor and positioning the edge of the slab at the center of the channel of the C-type sensor, thereby reducing the mutual scratching between the slab and the channel, thereby protecting the C-type sensor and reducing the risk of the slab being scratched; when the edge of the slab is located at the center of the channel of the C-type sensor, the working parameters of the upper and lower coils of the C-type sensor tend to be consistent, thereby ensuring the stable operation and heating effect of the C-type sensor.

[0046] The present invention uses a second linear drive mechanism to adjust the left and right movement of the C-type sensor, and controls the C-type sensor to be online (when heating is required) or offline (when heating is not required), thereby ensuring the safety of the system when no heating is required; at the same time, when heating is required, the heating size of the C-type sensor on the edge of the slab is changed by adjusting the left and right movement of the C-type sensor, thereby meeting the heating requirements of edges of different sizes, making the edge temperature reach the ideal temperature range for rolling, ensuring the quality of slab rolling, and reducing unnecessary energy waste while improving the metal yield of steel.

[0047] For special steel slabs (crack-sensitive steel grades), the present invention also uses a second linear drive mechanism to adjust the retraction of the C-type sensor, avoiding the problem of cracking on the edges of the slab and ensuring the rolling quality of special steel grades during the rolling process. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] In order to more clearly illustrate the technical solution of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only one embodiment of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0049] Figure 1 1 is a schematic structural diagram of a heating subsystem in an embodiment of the present invention;

[0050] Figure 2 is a schematic structural diagram of the first heating unit or the second heating unit in an embodiment of the present invention;

[0051] Figure 3 is a bottom view of the first heating unit or the second heating unit in an embodiment of the present invention;

[0052] Figure 4 is a bottom perspective view of the first heating unit or the second heating unit in an embodiment of the present invention;

[0053] Figure 5 Schematic diagram of an embodiment of the present invention in which the roller plane is parallel to the bottom surface of the channel when the slab thickness is a1;

[0054] Figure 6 Schematic diagram of the embodiment of the present invention when the thickness of the slab increases from a1 to a2 and the roller plane and the channel bottom surface are at θ2;

[0055] Figure 7 Schematic diagram of the embodiment of the present invention when the thickness of the slab increases from a1 to a3 and the roller plane and the channel bottom surface are at θ3;

[0056] Figure 8 Schematic diagram of the embodiment of the present invention when the thickness of the slab is reduced from a1 to a2 and the roller plane and the channel bottom surface are at θ2;

[0057] Figure 9 Schematic diagram of the embodiment of the present invention when the thickness of the slab is reduced from a1 to a3 and the roller plane and the channel bottom surface are at θ3;

[0058] Figure 10 is a flow chart of a control method according to an embodiment of the present invention;

[0059] Figure 11 Schematic diagram of a C-shaped inductor coil in an embodiment of the present invention when its projection is completely located on the slab surface and its projection width is N1;

[0060] Figure 12 This is a schematic diagram of the embodiment of the present invention in which the coil projection portion of the C-type inductor is located on the slab surface and the projection width is N2.

[0061] Figure 13 This is a schematic diagram of the coil projection of the C-type inductor in the embodiment of the present invention when the coil projection portion is located on the slab surface and the projection width is N3.

[0062] Figure 14 1 is a schematic diagram of an embodiment of the present invention in which the coil projection portion of the C-shaped inductor is located on the surface of the slab and the projection width is N4.

[0063] Among them, Ⅰ-first heating unit or second heating unit, Ⅱ-slab, 1-C-type inductor, 11-fixed frame, 12-housing, 13-iron core, 14-coil, 15-magnetic lines of force, 16-projection of the coil on the slab, 17-edge current concentration area, 2-power module, 21-connecting water pipe, 22-connecting copper busbar, 3-rotating frame, 31-long axis, 4-moving frame, 41-pulley, 5-second linear drive mechanism, 51-ear plate, 6-track, 7-first linear drive mechanism, 8-drag chain. DETAILED DESCRIPTION

[0064] The following is a clear and complete description of the technical solutions of the present invention in conjunction with the accompanying drawings of the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts are within the scope of protection of the present invention.

[0065] The following specific embodiments are used to describe the technical solution of the present application in detail. The following specific embodiments can be combined with each other, and the same or similar concepts or processes may not be described in detail in some embodiments.

[0066] A slab edge heating system provided by an embodiment of the present invention includes at least one heating subsystem. The number of heating subsystems can be determined based on the temperature required to be compensated at the edge (or both sides) of the slab and the slab length. The higher the required edge temperature compensation and the longer the slab, the more heating subsystems are required. If multiple heating subsystems are provided, they are arranged at equal intervals along the slab conveying direction (or along the slab length).

[0067] like Figure 1 As shown, the heating subsystem includes a first heating unit I and a second heating unit I symmetrically arranged on both sides of the slab II with the center line of the slab II in the longitudinal direction as the symmetry axis. Figures 2-4 As shown, the first heating unit and the second heating unit both include a track 6, a movable frame 4, a rotating frame 3, a C-type sensor 1, a first linear drive mechanism 7 and a second linear drive mechanism 5, a control module and a power supply module 2; the track 6 is arranged on one side of the slab, the movable frame 4 is slidably arranged on the track 6, the rotating frame 3 is located on the movable frame 4 and its first end is rotatably connected to the movable frame 4, wherein the first end of the rotating frame 3 refers to the end away from the slab; the C-type sensor 1 is fixed on the rotating frame 3 and is used to heat the edge of the slab; the first end of the first linear drive mechanism 7 is fixedly connected to the movable frame 4, the second end of the first linear drive mechanism 7 is fixedly connected to the back of the C-type sensor 1, the first end of the second linear drive mechanism 5 is fixedly connected to the movable frame 4, and the second end of the second linear drive mechanism 5 is fixed to the ground or the track 6, wherein the back of the C-type sensor 1 refers to the side away from the slab; the control module is connected to the first linear drive mechanism 7 and the second linear drive mechanism 5, the power supply module 2 is connected to the C-type sensor 1 and the power supply module 2 is arranged on the rotating frame 3.

[0068] In this embodiment, the track 6 includes two parallel steel rails, and a pulley 41 is provided at the bottom of the movable frame 4. The pulley 41 is located on the steel rail. When the second linear drive mechanism 5 is activated, the movable frame 4 slides on the steel rail through the pulley 41, thereby driving the rotating frame 3, the C-shaped sensor 1 on the rotating frame 3 and the power module 2 to move left and right or move horizontally, thereby adjusting the C-shaped sensor 1 to be online (heating the slab) or offline (not heating the slab). When the C-shaped sensor 1 is online, the heating size of the edge of the slab by the C-shaped sensor 1 is also adjusted.

[0069] The movable frame 4 adopts a square frame structure, and a connecting plate is provided on the movable frame 4. The movable end (i.e., the action end) of the second linear drive mechanism 5 is connected to the connecting plate through an ear plate 51. The fixed end of the second linear drive mechanism 5 is fixed to the track 6 or the ground, so that the second linear drive mechanism 5 is arranged in a horizontal direction. In this embodiment, the movable end of the second linear drive mechanism 5 is close to the slab, and the fixed end is away from the slab. When the movable end of the second linear drive mechanism 5 is extended or retracted, a thrust or a pull is applied to the movable frame 4, and the movable frame 4 slides on the track 6, thereby adjusting the C-type inductor 1 to move left and right or move horizontally, thereby adjusting the heating size of the edge of the slab by the C-type inductor 1. The projection size of the coil of the C-type inductor 1 on the surface of the slab is the heating size of the edge of the slab by the C-type inductor 1. Since the C-type inductor 1 moves left and right, what is adjusted is the projection width (the projection length remains unchanged), so the heating size refers to the heating width.

[0070] The rotating frame 3 has a rectangular structure. The C-shaped inductor 1 and power module 2 are both fixed to the rotating frame 3, with the C-shaped inductor 1 positioned close to the slab. A long axis 31 is provided at the end of the rotating frame 3 away from the slab. Both ends of the long axis 31 engage bearings fixed to the movable frame 4. When the first linear drive mechanism 7 extends or retracts, it applies a thrust or pull to the C-shaped inductor 1. Since the C-shaped inductor 1 is fixed to the rotating frame 3, it drives the rotating frame 3 to rotate about the long axis 31, thereby adjusting the C-shaped inductor 1 to move up and down or vertically. This in turn adjusts the position of the slab edge within the C-shaped inductor 1, aligning it with the center of the channel of the C-shaped inductor 1. The channel of the C-shaped inductor 1 refers to the gap between the upper and lower coils of the C-shaped inductor 1. When the C-shaped inductor 1 is used to heat the edge (or both sides) of the slab, the edge of the slab is placed between the upper and lower coils of the C-shaped inductor 1. Electromagnetic induction generates a current within the slab, thereby achieving heating. When the edge of the slab is centered within the C-shaped inductor's channel, the distance between the slab and the upper coil is equal to the distance between the slab and the lower coil. This reduces friction between the slab and coil, preventing scratches on the inductor and slab. Furthermore, the parameters of the upper and lower coils are consistent, ensuring a better heating effect. The C-shaped inductor's channel opening is more adaptable to slab sizes.

[0071] Both the first linear drive mechanism 7 and the second linear drive mechanism 5 can be configured as a motor + lead screw assembly, or as a hydraulic control unit + hydraulic cylinder assembly. A fixed frame 11 is secured to the back of the C-shaped inductor 1. The first end of the first linear drive mechanism 7 is fixedly connected to the fixed frame 11, while the second end of the first linear drive mechanism 7 is secured to the movable frame 4, placing the first linear drive mechanism 7 in a vertical orientation. Controlling the first linear drive mechanism 7 controls the rotation angle of the rotating frame 3, thereby controlling the vertical position of the C-shaped inductor 1.

[0072] The control module can be located in the control room and communicated with the production line control system. The production line control system sends slab incoming material information to the control module, or the slab incoming material information can be manually input into the control module. The slab incoming material information includes slab thickness, slab width, and slab steel grade information. The control module controls the operation of the first linear drive mechanism 7 based on the slab thickness, adjusting the vertical position of the C-shaped inductor 1 so that the edge of the slab is located in the center of the channel of the C-shaped inductor 1. The control module also controls the operation of the second linear drive mechanism 5 based on the slab width, adjusting the horizontal position of the C-shaped inductor 1, thereby adjusting the heating width of the slab edge by the C-shaped inductor 1.

[0073] The power module 2 is used to supply power to the C-shaped sensor 1 . Both the power module 2 and the C-shaped sensor 1 are fixed on the rotating frame 3 , and the power module 2 is connected to the power terminal of the C-shaped sensor 1 via a connecting copper bus 22 .

[0074] In one embodiment of the present invention, both the first heating unit and the second heating unit further include a cooling unit, each comprising a first cooling water pipe and a second cooling water pipe. The first cooling water pipe is located within the power module 2, and the second cooling water pipe is located on the induction coil of the C-type inductor 1. The first cooling water pipe is connected to the second cooling water pipe via a connecting water pipe 21. Cooling water is introduced into the power module 2 through the first cooling water pipe to cool the power module 2, then flows through the connecting water pipe 21 into the second cooling water pipe, where it cools the coil of the C-type inductor 1, before flowing out. This cycle continues, thereby cooling both the power module 2 and the C-type inductor 1.

[0075] In a specific embodiment of the present invention, a drag chain 8 is further provided on the mobile frame 4, one end of the drag chain 8 is fixed inside the mobile frame 4, and the other end is provided on the ground; a water inlet pipe, a water outlet pipe and a cable are arranged in the channel of the drag chain 8; the water inlet pipe is connected to the first cooling water pipe, and the water outlet pipe is connected to the second cooling water pipe, thereby forming a cooling circuit. The power module 2 is connected to the external power supply via a cable. When the first linear drive mechanism 7 and the second linear drive mechanism 5 adopt a linear drive mechanism composed of a hydraulic control unit + a hydraulic cylinder, the required hydraulic medium and lubricating medium can be introduced from the outside to the corresponding interface position of the first heating unit or the second heating unit through the drag chain 8. Similarly, the signal line can also be introduced from the outside through the drag chain 8. The water pipes, cables, etc. introduced from the drag chain 8 remain relatively stationary with the C-type sensor 1 and the power module 2.

[0076] In a specific embodiment of the present invention, the first heating unit and the second heating unit also include a temperature measuring unit for detecting the temperature of the edge of the slab (i.e., both sides of the slab), and the control module is also used to adjust the output voltage of the power supply module 2 according to the temperature collected by the temperature measuring unit, and then adjust the output power of the C-type sensor 1, so that the temperature of the edge of the slab is increased and maintained at the target temperature.

[0077] To ensure that the bottom surface of the C-shaped inductor's channel (i.e., the top surface of the lower coil) remains approximately horizontal during its vertical movement, the distance L from the pivoting connection between the rotating and movable frames (i.e., the long axis) to the center of the C-shaped inductor's heated end surface must be significantly greater than the width H of the C-shaped inductor's heated end surface. Both the lower surface of the upper coil and the upper surface of the lower coil serve as heated end surfaces. In this embodiment, the distance from the long axis to the center of the top surface of the C-shaped inductor's lower coil is L, and the width of the lower coil is H. L is at least six times H. This ensures that the C-shaped inductor rotates a very small angle as the rotating frame rotates, keeping the bottom surface of the C-shaped inductor's channel approximately horizontal.

[0078] Slabs of different thickness specifications are all conveyed on the roller plane, that is, the lower surface of the slab coincides with the roller plane. When the slab thickness changes, the height position of the roller plane will not change, so the distance between the upper surface of the slab and the lower surface of the C-type sensor channel (that is, the lower surface of the upper coil) will change. In order to make the slab located in the center of the channel, the vertical position of the C-type sensor needs to be adjusted. Figure 5 As shown, assuming that the distance from the long axis to the center of the upper surface of the lower coil of the C-shaped inductor is L, the width of the lower coil (i.e., the channel width or the width of the heating end surface) is H, and the spacing between the upper coil and the lower coil (i.e., the channel height) is B. When the thickness of the slab is a1, the first linear drive mechanism, the C-shaped inductor and the rotating frame are all in the initial position, and the roller plane is parallel to the channel floor. At this time, the distance b1 between the upper surface of the slab and the top surface of the channel (i.e., the lower surface of the upper coil) is equal to the distance c1 between the lower surface of the slab and the bottom surface of the channel (i.e., the upper surface of the lower coil), i.e., b1=c1.

[0079] like Figure 6 As shown, when the thickness of the slab changes from a1 to a2 (a2>a1), the distance b2 between the upper surface of the slab and the top surface of the channel is smaller than the distance c2 between the lower surface of the slab and the bottom surface of the channel. By controlling the extension of the first linear drive mechanism, the rotating frame is rotated by a very small angle (θ2), and then the C-type sensor is adjusted to move upward. Since the C-type sensor is away from the long axis, its upward movement distance is the largest, so that the distance b2 between the upper surface of the slab and the top surface of the channel is approximately equal to the distance c2 between the lower surface of the slab and the bottom surface of the channel, that is, b2≈c2, ensuring that the edge of the slab is in the center of the channel.

[0080] like Figure 7As shown, when the thickness of the slab changes from a1 to a3 (a3>a1), the distance b3 between the upper surface of the slab and the top surface of the channel is smaller than the distance c3 between the lower surface of the slab and the bottom surface of the channel. By controlling the extension of the first linear drive mechanism to rotate the rotating frame by a very small angle (θ3), the C-type sensor is adjusted to move upward, so that the distance b3 between the upper surface of the slab and the top surface of the channel is approximately equal to the distance c3 between the lower surface of the slab and the bottom surface of the channel, that is, b3≈c3, ensuring that the edge of the slab is in the center of the channel.

[0081] When the slab thickness changes from a1 to a small value, the distance between the upper surface of the slab and the top surface of the channel is greater than the distance between the lower surface of the slab and the bottom surface of the channel. By controlling the retraction of the first linear drive mechanism to rotate the rotating frame by a very small angle, the C-type sensor is adjusted to move downward so that the distance between the upper surface of the slab and the top surface of the channel is approximately equal to the distance between the lower surface of the slab and the bottom surface of the channel, ensuring that the edge of the slab is in the center of the channel.

[0082] When the thickness and width of the slab change, the C-type sensor, pushed by the first linear drive mechanism and the second linear drive mechanism, has both a height displacement, so that the slab is approximately located in the center of the channel, and a horizontal displacement. However, since H<<L, the height displacement will hardly cause the heated area to change. Even if the height displacement causes the heated area at the edge of the slab to change, the heated area can be adjusted by pushing the second linear drive mechanism.

[0083] When constructing the slab-stroke database, the thinnest slab corresponds to the zero stroke of the first linear drive mechanism (i.e., the rotation angle is 0). When the slab becomes thicker, the first linear drive mechanism pushes upward (the stroke increases) so that the heated area of the slab is approximately located in the center of the channel, such as Figures 5-7 On the contrary, the thickest slab corresponds to the maximum stroke of the first linear drive mechanism (i.e., the rotation angle is the maximum). When the slab becomes thinner, the first linear drive mechanism pushes downward (the stroke decreases), so that the heated area of the slab is approximately located in the center of the channel, as shown in FIG. Figures 8-9 shown.

[0084] like Figure 10 As shown, an embodiment of the present invention further provides a control method for the slab heating system as described above, comprising the following steps:

[0085] Step 1: Build the slab-stroke database through system debugging;

[0086] Step 2: Obtain slab incoming material information, including slab thickness and width;

[0087] Step 3: Control the action of the first linear drive mechanism according to the thickness of the slab, and adjust the vertical position of the C-type sensor so that the edge of the slab is located in the center of the channel of the C-type sensor; control the action of the second linear drive mechanism according to the width of the slab, and adjust the horizontal position of the C-type sensor, thereby adjusting the heating size of the C-type sensor on the edge of the slab.

[0088] In step 1, the width of the slab determines the stroke of the second linear drive mechanism, and the thickness of the slab determines the stroke of the first linear drive mechanism. Before using the slab edge heating system of the present invention to heat the slab edge, the system is debugged to build a slab-stroke database, which specifically includes:

[0089] For slabs of different thicknesses, the first linear drive mechanism is controlled to operate and the vertical position of the C-type sensor is adjusted. When the edge of the slab is located at the center of the channel of the C-type sensor, the rotation angle of the rotating frame can be determined, thereby determining the stroke of the first linear drive mechanism. Different slab thicknesses and their corresponding strokes are obtained, as shown in Table 1. The stroke is equal to L×sinθ.

[0090] Table 1 Correspondence between slab thickness and stroke

[0091] Slab thickness rotation angle Stroke of the first linear drive mechanism a1 θ1 h1=L×sinθ1 a2 θ2 h2=L×sinθ2 a3 θ3 h3=L×sinθ2 …… …… ……

[0092] For slabs of different widths, the second linear drive mechanism is controlled to move and the horizontal position of the C-type sensor is adjusted. When the heating size of the slab edge by the C-type sensor meets the heating requirements, the stroke of the second linear drive mechanism is determined, and different slab widths and their corresponding strokes are obtained, as shown in Table 2.

[0093] Table 2 Correspondence between slab width and stroke

[0094] Slab width Stroke of the second linear drive mechanism E1 D1 E2 D2 E3 D3 …… ……

[0095] The heating requirement refers to the required heating dimension of the slab edge. For example, if a 100mm area on the slab edge needs to be heated to increase the temperature, the required heating dimension is 100mm. Therefore, the projected width of the C-shaped inductor coil on the slab edge must be at least 100mm. The required heating dimension can be determined through on-site testing based on the rolling temperature range.

[0096] A slab-stroke database is constructed based on different slab thicknesses and their corresponding strokes, as well as different slab widths and their corresponding strokes. After obtaining the incoming slab information, the stroke of the first linear drive mechanism is determined based on the slab thickness and the slab-stroke database, and the first linear drive mechanism's movement is controlled accordingly. The stroke of the second linear drive mechanism is determined based on the slab width and the slab-stroke database, and the second linear drive mechanism's movement is controlled accordingly.

[0097] During the process of heating the edge of the slab, the control method also includes obtaining the temperature collected by the temperature measuring unit; adjusting the output voltage of the power module according to the temperature collected by the temperature measuring unit, and then adjusting the output power of the C-type sensor to increase the temperature of the edge of the slab and maintain it at the target temperature.

[0098] In addition to realizing the overall online and offline operation of the first heating unit or the second heating unit and adapting the heating unit to different slab widths, the second linear drive mechanism can also control the concentration of the magnetic field at the edge of the slab by fine-tuning the stroke, that is, adjusting the end effect of the current to further increase the edge temperature to meet the requirement of crack-sensitive steel grades to prevent the edges from cracking during rolling.

[0099] The C-type inductor includes a housing 12 , an iron core 13 and a coil 14 . The coil 14 generates current inside the slab through electromagnetic induction, thereby heating the slab. Figures 11-14 The figure shows four situations in which the C-type inductor adjusts the magnetic field concentration at the edge. In the first situation, the coil projection of the C-type inductor is completely located on the slab surface. In this case, the projection width of the C-type inductor on the slab surface (i.e., the heating width of the slab or the width of the heated area of the slab) is N1. Figure 11 As shown; the second case is that the coil projection of the C-type inductor is located on the slab surface. At this time, the projection width of the C-type inductor on the slab surface is N2, as shown Figure 12 As shown; the third case is that the coil projection of the C-type inductor is located on the slab surface. At this time, the projection width of the C-type inductor on the slab surface is N3. Figure 13 As shown; the fourth case is that the coil projection of the C-type inductor is located on the slab surface. At this time, the projection width of the C-type inductor on the slab surface is N4. Figure 14 As shown; and N1>N2>N3>N4. Figures 11-14 It can be seen that the width of the projection 16 of the coil of the C-shaped inductor on the slab is different, and the edge current concentration area 17 is different.

[0100] The alternating magnetic field causes the current generated on the heated slab to have an edge effect. The more the projection of the C-type inductor coil (the projection on the slab surface) exceeds the slab surface area (the fourth case exceeds the most), the more obvious the edge effect of the magnetic field is, that is, the greater the current gathered at the edge of the slab. Therefore, it can be seen that the current at the edge of the heated slab is I N1 <I N2 <I N3 <I N4 .

[0101] Therefore, when the edge temperature of the crack-sensitive slab needs to be further increased, after the second linear drive mechanism pushes the C-type sensor to a position adapted to the plate width (such as D1, D2, D3, ... in Table 2), it will continue to retreat a corresponding distance based on the required edge temperature.

[0102] The retraction stroke corresponding to the required edge temperature for different steel grades is determined during system commissioning. This retraction stroke, along with the actual stroke of the second linear drive mechanism, is added to the slab-stroke database, which is stored in the control module, as shown in Table 3. For different steel grades, when heating the edge area, the stroke of the second linear drive mechanism is adjusted and operated based on the data stored in the slab-stroke database.

[0103] Table 3 Retraction stroke and actual stroke of different steel grades

[0104]

[0105] The above disclosure is only a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any technician familiar with this technical field can easily think of changes or modifications within the technical scope disclosed in the present invention, and they should all be covered by the scope of protection of the present invention.

Claims

1. A slab edge heating system, characterized in that: The system includes at least one heating subsystem, which includes a first heating unit and a second heating unit symmetrically arranged on both sides of the slab with the center line of the slab as the symmetry axis; the first heating unit and the second heating unit each include: Tracks located on one side of the slab; a movable frame, the movable frame being slidably disposed on the track; a rotating frame, the rotating frame being located on the mobile frame and having a first end rotatably connected to the mobile frame; the first end of the rotating frame being an end away from the slab; A C-shaped inductor, which is fixed on the rotating frame and is used to heat the edge of the slab; a first linear drive mechanism and a second linear drive mechanism, wherein a first end of the first linear drive mechanism is fixedly connected to the movable frame, and a second end of the first linear drive mechanism is fixedly connected to the back of the C-shaped inductor; a first end of the second linear drive mechanism is fixedly connected to the movable frame, and a second end of the second linear drive mechanism is fixed to the ground or a track; the back of the C-shaped inductor refers to the side away from the slab; a control module, wherein the control module controls the operation of the first linear drive mechanism according to the thickness of the slab, and adjusts the vertical position of the C-shaped inductor so that the edge of the slab is located at the center of the channel of the C-shaped inductor; the control module also controls the operation of the second linear drive mechanism according to the width of the slab, and adjusts the horizontal position of the C-shaped inductor, thereby adjusting the heating dimension of the C-shaped inductor on the edge of the slab; A power supply module is used to supply power to the C-type sensor.

2. The slab edge heating system according to claim 1, characterized in that: A fixed frame is provided on the back of the C-shaped sensor, and the second end of the first linear drive mechanism is fixedly connected to the back of the C-shaped sensor through the fixed frame.

3. The slab edge heating system according to claim 1, characterized in that: The first heating unit and the second heating unit both further include a cooling unit, and the cooling unit includes a first cooling water pipe and a second cooling water pipe; the first cooling water pipe is arranged in the power module, and the second cooling water pipe is arranged on the induction coil of the C-type inductor, and the first cooling water pipe is connected to the second cooling water pipe through a connecting water pipe.

4. The slab edge heating system according to claim 3, characterized in that: A drag chain is also provided on the mobile frame, and a water inlet pipe, a water outlet pipe and a cable are arranged in the channel of the drag chain; the water inlet pipe is connected to the first cooling water pipe, the water outlet pipe is connected to the second cooling water pipe, and the power module is connected to the external power supply through a cable.

5. The slab edge heating system according to claim 1, characterized in that: The distance between the rotation connection between the rotating frame and the movable frame and the center of the heating end surface of the C-shaped inductor is at least 6 times the width of the heating end surface of the C-shaped inductor.

6. The slab edge heating system according to any one of claims 1 to 5, characterized in that: The first heating unit and the second heating unit both include a temperature measuring unit for detecting the temperature of the edge of the slab. The control module is also used to adjust the output voltage of the power module according to the temperature collected by the temperature measuring unit, and then adjust the output power of the C-type sensor to increase the temperature of the edge of the slab and maintain it at the target temperature.

7. A control method for a slab edge heating system according to any one of claims 1 to 6, characterized in that: The control method comprises the following steps: Acquiring slab incoming material information, wherein the incoming material information includes slab thickness and width; The first linear drive mechanism is controlled to move according to the thickness of the slab, and the vertical position of the C-shaped sensor is adjusted so that the edge of the slab is located in the center of the channel of the C-shaped sensor; The second linear drive mechanism is controlled to move according to the slab width, and the horizontal position of the C-shaped sensor is adjusted, thereby adjusting the heating size of the slab edge by the C-shaped sensor.

8. The control method of the slab edge heating system according to claim 7, characterized in that: Before obtaining the incoming slab information, the control method further includes building a slab-travel database through system debugging, and the specific implementation process is as follows: For slabs of different thicknesses, the first linear drive mechanism is controlled to operate and the vertical position of the C-shaped sensor is adjusted. When the edge of the slab is located at the center of the channel of the C-shaped sensor, the stroke of the first linear drive mechanism is determined to obtain different slab thicknesses and their corresponding strokes; For slabs of different widths, the second linear drive mechanism is controlled to move and the horizontal position of the C-shaped sensor is adjusted. When the heating size of the slab edge by the C-shaped sensor meets the heating requirements, the stroke of the second linear drive mechanism is determined to obtain different slab widths and their corresponding strokes. Construct a slab-stroke database based on different slab thicknesses and their corresponding strokes, and different slab widths and their corresponding strokes; After obtaining the incoming slab information, the stroke of the first linear drive mechanism is determined according to the slab thickness and the slab-stroke database, and the action of the first linear drive mechanism is controlled according to the stroke; the stroke of the second linear drive mechanism is determined according to the slab width and the slab-stroke database, and the action of the second linear drive mechanism is controlled according to the stroke.

9. The control method of the slab edge heating system according to claim 7, characterized in that: The control method further includes: Get the temperature collected by the temperature measuring unit; The output voltage of the power module is adjusted according to the temperature collected by the temperature measuring unit, and the output power of the C-type sensor is further adjusted to increase the temperature of the edge of the slab and maintain it at the target temperature.

10. The control method of the slab edge heating system according to any one of claims 7 to 9, characterized in that: After controlling the second linear drive mechanism to move according to the slab width, the second linear drive mechanism is also controlled to retract according to the steel grade information of the slab; When the slab is made of high alloy steel or high carbon steel, the retraction stroke of the second linear drive mechanism is H-N1, and the actual stroke of the second linear drive mechanism is D1'-(H-N1); When the slab is medium carbon steel, the retraction stroke of the second linear drive mechanism is H-N2, and the actual stroke of the second linear drive mechanism is D2'-(H-N2); When the slab is low carbon steel, the retraction stroke of the second linear drive mechanism is H-N3, and the actual stroke of the second linear drive mechanism is D3'-(H-N3); When the slab is pure iron, the retraction stroke of the second linear drive mechanism is H-N4, and the actual stroke of the second linear drive mechanism is D4'-(H-N4); Wherein, H is the coil width of the C-type inductor, D1', D2', D3', and D4' are all the strokes before the second linear drive mechanism retracts, N1 is the projection width of the coil of the C-type inductor when it is completely located on the surface of the slab, N2 is the projection width of the coil of the C-type inductor when it is partially located on the surface of the slab, N3 is the projection width of the coil of the C-type inductor when it is partially located on the surface of the slab, and N4 is the projection width of the coil of the C-type inductor when it is partially located on the surface of the slab, and N1>N2>N3>N4.

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