A method of coiling strip steel

Abstract

The application provides a coiling method of a strip steel. Firstly, the height of a coiling position of the strip steel is judged. When the height of the coiling position is greater than a preset height limit value, different positions of the coiling position of the strip steel are lifted, and the forward rotation of a conveying roller is controlled at the same time, so that the coiling position is loosened, the height of the coiling position is lowered, and then the strip steel is cold-coiled. The application uses the inherent equipment and tools in the production site, and cooperates with the operation, so that the production accident of the coiling of the strip steel can be quickly handled, the time of the production accident is greatly shortened, the flame gas cutting is avoided, the fire operation is not needed, and the application is safe, convenient, fast and easy to implement.

Description

Technical Field

[0001] This application relates to the field of hot rolling control in the metallurgical industry, specifically to a method for coiling strip steel. Background Technology

[0002] On hot rolling production lines, the coiler may become unavailable due to various malfunctions. Before the strip head even enters the coiler, the production control system generates a rapid stop signal. To ensure the strip is ejected from the finishing mill and evenly distributed on the transport rollers, the transport rollers cannot stop simultaneously. Furthermore, they typically stop sequentially from back to front. This causes the strip to fold and accumulate along the rolling direction, resulting in a large amount of strip being folded and stacked, with a considerable height. Height-limiting devices such as measuring instruments or bridges are installed before the coiler; if the strip is too high, it becomes difficult to... The strip steel has requirements for pre-treatment before reaching the coiler. However, in the existing technology, the conveyor rollers generally have 10 sets. These 10 sets of conveyor rollers can only rotate together in the same direction. It is not possible for one part to rotate in reverse while the other part rotates in the forward direction. Even if one part can rotate in reverse while the other part rotates in the forward direction, the starting part cannot be properly pulled apart because the starting part is pressed too tightly and the power of the conveyor rollers is limited. It can only be cut apart separately with an oxy-acetylene torch and then lifted away, which greatly prolongs the production accident time. In addition, the inner ring of the cold-coiled steel coil is generally relatively loose, which will lead to the whole coil becoming flat and the coiler having difficulty unloading the coil. Summary of the Invention

[0003] The purpose of this application is to provide a method for coiling strip steel, which can shorten the accident handling time of strip steel unwinding in the prior art, and solve the problems of flattened coils and difficulty in unwinding coils from coilers in the prior art.

[0004] To achieve the above objectives, this application provides a method for coiling strip steel, applied to a hot rolling production line. The hot rolling production line is provided with a finishing mill, multiple sets of transport rollers, and a coiler in sequence according to the running direction. The multiple sets of transport rollers have cooling guard plates on both sides. The coiler includes, in sequence according to the running direction of the hot rolling production line, a side guide plate, a pressure roller, an inlet pinch roller, a first auxiliary coiling roller, a second auxiliary coiling roller, a third auxiliary coiling roller, and a coil.

[0005] The strip has a starting section, and the strip head is located between the starting section and the inlet pinch roll. The starting section includes an intermediate section and a winding section located between the intermediate section and the strip head.

[0006] The method for coiling the strip steel includes the following steps:

[0007] Step S1: Compare the maximum height of the strip's starting point with the preset height limit value;

[0008] Step S2: If the maximum height of the strip's starting part is greater than or equal to the preset height limit, then proceed to step S3; if the maximum height of the strip's starting part is less than the preset height limit, then proceed to step S5.

[0009] Step S3: Lift the position where the winding part intersects with the middle part, release the winding part, and after lifting, control multiple sets of transport rollers to rotate forward at a preset speed to separate the winding part from the middle part. Lift the winding part again to loosen it, and continue to control multiple sets of transport rollers to rotate forward at a preset speed to flatten the winding part. Finally, lift the middle part to loosen it, and continue to control multiple sets of transport rollers to rotate forward at a preset speed, thereby reducing the maximum height of the middle part.

[0010] Step S4: Repeat step S3 multiple times until the maximum height of the strip's starting part is less than the preset height limit.

[0011] Step S5: Cold coil the strip steel.

[0012] In some embodiments of this application, the aforementioned scheme further includes: shutting off the cooling water of the multiple sets of transport rollers.

[0013] In some embodiments of this application, based on the aforementioned scheme, the number of coilers is three, and the three coilers are arranged sequentially along the running direction of the hot rolling production line, respectively denoted as the first coiler, the second coiler, and the third coiler. The distance between the side guide plate outlet of the first coiler and the inlet pinch roller of the first coiler is L1, the distance between the inlet pinch roller of the first coiler and the inlet pinch roller of the second coiler is L2, and the distance between the inlet pinch roller of the first coiler and the inlet pinch roller of the third coiler is L3. The strip coiling method further includes:

[0014] Before step S5, the length L of the strip head is obtained. If L1 < L ≤ L1 + L2, the first winding machine is used; if L1 + L2 < L ≤ L1 + L3, the second winding machine is used; if L > L1 + L3, the third winding machine is used.

[0015] In some embodiments of this application, based on the aforementioned scheme, the length of the strip is ≥30m, the thickness of the strip is ≤6.0mm, and the yield strength of the strip is ≤600MPa.

[0016] In some embodiments of this application, based on the aforementioned scheme, in step S3, the preset speed is 1-2 m / s and the lifting height is 2-5 m.

[0017] In some embodiments of this application, based on the aforementioned scheme, before lifting the position where the winding part intersects with the middle part, all transport rollers are rotated so that the intersection of the winding part and the middle part is located at the junction of two adjacent sets of transport rollers.

[0018] In step S3, controlling multiple sets of transport rollers to rotate forward at a preset speed includes:

[0019] The multiple sets of transport rollers located between the winding machine and the intersection of the winding section and the intermediate section are controlled to rotate forward at a preset speed.

[0020] In some embodiments of this application, based on the foregoing scheme, in step S3, the lifting tools include an overhead crane and a wire rope, wherein the length of the wire rope is greater than four times the width of the strip steel.

[0021] In some embodiments of this application, based on the foregoing scheme, step S5 specifically includes:

[0022] The rotational speed of the coil is controlled to be equal to the rotational speed of the inlet pinch roller and greater than the rotational speed of the transport roller. The strip head is fed into the coiler. After the strip head reaches the coil, there is a first preset time delay, and the coil diameter expands to the maximum. After a second preset time delay, the second auxiliary coil roller opens to the maximum position, the third auxiliary coil roller opens to the maximum position, and the first auxiliary coil roller opens to a roll gap equal to the total thickness of the strip coiled on the coil.

[0023] In some embodiments of this application, based on the foregoing scheme, the method further includes: before the strip head is fed into the coiler, opening the side guide plate to its maximum position, the roll gap of the inlet pinch roller being equal to the thickness of the strip, the roll gap of the first auxiliary coiling roller being 2-3 mm greater than the thickness of the strip, the roll gap of the second auxiliary coiling roller being 1-2 mm greater than the thickness of the strip, and the roll gap of the third auxiliary coiling roller being equal to the thickness of the strip; after the strip head is fed into the coiler, closing the side guide plate to a position 10-15 mm greater than the width of the strip.

[0024] In some embodiments of this application, based on the aforementioned scheme, the rotational speed of the drum and the rotational speed of the inlet pinch roller are 0.8 to 1 m / s, the rotational speed of the conveyor roller is 0.5 to 0.8 m / s, the first preset time is 8 to 10 s, and the second preset time is 4 to 6 s.

[0025] The technical solution of this application first determines the height of the strip's lifting section. When the height of the lifting section exceeds a preset height limit, different positions of the lifting section are lifted, while the conveyor rollers are rotated forward to loosen the lifting section and lower its height, thus allowing for cold coiling of the strip. This application utilizes existing equipment and tools on the production site, and with proper operation, can quickly resolve production accidents related to strip lifting, significantly shortening the time required for such accidents. It also avoids the use of flame cutting, eliminating the need for open flame operations, making it safe, convenient, quick, and easy to implement. Furthermore, it prevents severe flattening of the coil after cold coiling, which could cause difficulties in uncoiling. Attached Figure Description

[0026] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application. It is obvious that the drawings described below are merely some embodiments of this application, and those skilled in the art can obtain other drawings based on these drawings without any inventive effort. In the drawings:

[0027] Figure 1 This is a schematic diagram of the structure of a hot rolling production line for the strip coiling method of this application;

[0028] Figure 2 This is a schematic diagram of the hot rolling production line for the strip coiling method of this application. Figure 2 Three winding machines are shown in the image;

[0029] Figure 3 This is a flowchart of the strip coiling method of this application. Detailed Implementation

[0030] To make the objectives, technical solutions, and advantages of this application clearer, the technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0031] The following detailed description of some embodiments of this application will be provided in conjunction with the accompanying drawings. Unless otherwise specified, the following embodiments and features can be combined with each other.

[0032] This application provides a method for coiling strip steel, applicable to a hot rolling production line. Please refer to [link / reference]. Figure 1 and Figure 2The hot rolling production line is arranged in sequence along the operating direction X: a finishing mill 2, multiple sets of transport rollers (layer cooling rollers) 6, and a coiler 1. The multiple sets of transport rollers 6 have layer cooling guard plates 7 on both sides. The coiler 1, along the operating direction X of the hot rolling production line, includes a side guide plate 12, a pressure roller 13, an inlet pinch roller 14, a first auxiliary coiling roller 16, a second auxiliary coiling roller 17, a third auxiliary coiling roller 18, and a coil 19. The strip has a starting section 3, with the strip head 30 located between the starting section 3 and the inlet pinch roller 14. The starting section 3 includes an intermediate section 32 and a coiling section 31 located between the intermediate section 32 and the strip head 30. When the coil 19 contracts, its diameter is 727 mm; the first expansion diameter is 745 mm; and the second expansion diameter is a maximum of 762 mm.

[0033] like Figure 3 As shown, the strip coiling method includes the following steps:

[0034] Step S1: Compare the maximum height of the starting part 3 of the strip with the preset height limit value;

[0035] Step S2: If the maximum height of the strip's starting part 3 is greater than or equal to the preset height limit, then proceed to step S3; if the maximum height of the strip's starting part 3 is less than the preset height limit, then proceed to step S5.

[0036] Step S3: Lift the position where the winding part 31 intersects with the middle part 32, release the winding part 31, and after lifting, control multiple sets of transport rollers 6 to rotate forward at a preset speed to separate the winding part 31 from the middle part 32. Lift the winding part 31 again to loosen it, and continue to control multiple sets of transport rollers 6 to rotate forward at a preset speed to flatten the winding part 31. Finally, lift the middle part 32 to loosen it, and continue to control multiple sets of transport rollers 6 to rotate forward at a preset speed, thereby reducing the maximum height of the middle part 32.

[0037] Step S4: Repeat step S3 multiple times until the maximum height of the strip starting part 3 is less than the preset height limit.

[0038] Step S5: Cold coil the strip steel.

[0039] It should be noted that the multiple sets of transport rollers 6 rotate clockwise, driving the strip steel to move along the X-direction of the hot rolling production line. The maximum height (highest point) of the starting section 3 is the maximum height of the middle section 32. In actual production, a height limiting device 4 (such as a detection instrument or bridge) is usually installed between the finishing mill 2 and the entrance pinch roll 14. The preset height limiting value is the height limiting point 41 of the height limiting device 4. When the coiler 1 is unable to operate due to various malfunctions, the production control system generates a quick stop signal before the strip head 30 is fed into the coiler 1. Multiple sets of transport rollers 6 will stop sequentially from back to front (i.e., in the opposite direction to the running direction X). As a result, the strip will continuously fold and accumulate along the running direction X, creating a large amount of stripping and a certain height. Since a height limiting device 4 is installed in front of the coiler 1, if the maximum height of the stripping section 3 exceeds the height limit point 41, the strip will have difficulty passing through the height limit point 41 of the height limiting device 4. Furthermore, because the middle section 32 is too high, the coiling section 31 is compressed, making it difficult for the transport rollers 6 to drive the strip head 30 to rotate. Therefore, the strip cannot reach the coiler 1 for coiling. Also, since the strip head 30 has not reached the inlet pinch roller 14, the inlet pinch roller 14 cannot clamp and pull the strip head 30, and thus cannot flatten the stripping section 3. Based on this, step S3 of this application reduces the maximum height of the lifting part 3 by repeatedly lifting it to different positions, and makes the lifting part 3 loose, so that the transport roller 6 can easily drive the strip head 30 to the inlet pinch roller 14 for subsequent winding processing.

[0040] Specifically, in order to prevent the entire strip from running when all the transport rollers 6 rotate as a whole, all the transport rollers 6 are rotated before the position where the coiling part of the strip intersects with the middle part, so that the intersection of the coiling part 31 and the middle part 32 is located at the junction of two adjacent sets of transport rollers 6. Then, in step S3, controlling the multiple sets of transport rollers 6 to rotate forward at a preset speed includes: controlling the multiple sets of transport rollers 6 located between the coiler 1 and the intersection of the coiling part 31 and the middle part 32 to rotate forward at a preset speed. Figure 1 and Figure 2 In the example of 10 sets of transport rollers 6, the 10 sets of transport rollers 6 are numbered 61, 62, 63, 64, 65, 66, 67, 68, 69, and 610 respectively. Assuming that the intersection of the winding part 31 and the middle part 32 is the boundary between transport rollers 66 and 67, then in step S3, it is only necessary to control transport rollers 66, 67, 68, 69, and 610 to rotate forward at a preset speed.

[0041] Specifically, in step S3, the preset speed is 1-2 m / s, the lifting height is 2-5 m, and the lifting tools include a crane 9 and a wire rope 10. The length of the wire rope 10 is greater than four times the width of the strip steel. If the wire rope 10 is too short, it will cause inconvenience in lifting; if it is too long, it will limit the lifting height of the crane 9.

[0042] Specifically, the strip coiling method further includes: shutting off the cooling water of the multiple sets of transport rollers 6, the cooling water including side spray water, layer cooling water, etc., to prevent the strip temperature from dropping.

[0043] Specifically, the strip length is ≥30m. If the strip length is too short, there will be difficulties in uncoiling the strip after cold coiling. The strip thickness is ≤6.0mm, and the strip yield strength is ≤600MPa. If the strip is too thick or the yield strength is too high, it will be difficult to flatten the strip.

[0044] Specifically, step S5 includes:

[0045] The rotational speed of the drum 19 is controlled to be equal to the rotational speed of the inlet pinch roller 14 and greater than the rotational speed of the transport roller 6. The strip head 30 is fed into the coiler. After the strip head 30 reaches the drum 19, there is a first preset time delay, during which the diameter of the drum 19 expands to its maximum. After a second preset time delay, the inner ring of the coiled steel is relatively tight. The second auxiliary coiling roller 17 is opened to its maximum position, the third auxiliary coiling roller 18 is opened to its maximum position, and the first auxiliary coiling roller 16 is opened until the roll gap is equal to the total thickness of the strip coiled on the drum 19. This avoids severe flattening of the steel coil after cold coiling, which would make it difficult to unload the coil from the coiler 1.

[0046] Specifically, the strip winding method further includes: before the strip head 30 is fed into the coiler 1, opening the side guide plate 12 to its maximum position, the roll gap of the inlet pinch roller 14 being equal to the thickness of the strip, the roll gap of the first auxiliary winding roller 16 being 2-3 mm greater than the thickness of the strip, the roll gap of the second auxiliary winding roller 17 being 1-2 mm greater than the thickness of the strip, and the roll gap of the third auxiliary winding roller 18 being equal to the thickness of the strip; after the strip head 30 is fed into the coiler 1, closing the side guide plate 12 to a position 10-15 mm greater than the width of the strip.

[0047] Specifically, the rotational speed of the drum 19 and the inlet pinch roller 14 is 0.8–1 m / s, and the rotational speed of the conveyor roller 6 is 0.5–0.8 m / s, so that the strip head 30 is less likely to deviate during the winding process into the drum 19. The first preset time is 8–10 s, and the second preset time is 4–6 s.

[0048] In actual production process, such as Figure 2As shown, the number of coilers 1 is generally set to three. The three coilers 1 are arranged sequentially along the running direction X of the hot rolling production line, and are respectively denoted as the first coiler 110, the second coiler 120, and the third coiler 130. The distance between the outlet of the side guide plate 12 of the first coiler 110 and the inlet pinch roller 14 of the first coiler 110 is L1, and the distance between the inlet pinch roller 14 of the first coiler 110 and the inlet pinch roller 14 of the second coiler 120 is L2. The distance between the inlet pinch roller 14 of the first coiler 110 and the inlet pinch roller 14 of the third coiler 130 is L3. The strip coiling method further includes: before step S5, obtaining the length L of the strip head 30. If L1 < L ≤ L1 + L2, the first coiler 110 is used; if L1 + L2 < L ≤ L1 + L3, the second coiler 120 is used; if L > L1 + L3, the third coiler 130 is used.

[0049] In one embodiment of this application, L1 = 3m, L2 = 9m, L3 = 18m. After the strip head 30 is wound into the inlet pinch roller 14 of the coiler 1, the side guide plate 12 of the coiler 1 is closed. For example, if a second coiler 120 is used, the side guide plates 12 of the first coiler 110 and the second coiler 120 are closed.

[0050] Of course, since the coiler 1 causes significant damage to the surface of the inlet pinch roll 14 when processing strip steel with the take-off section 30, in order to save costs and protect the coiler 1, it is also possible to select the coiler 1 with the largest number of used coils of the inlet pinch roll 14. This is because the larger the number of used coils of the inlet pinch roll 14, the closer it is to its service life (approximately 300,000 tons), and the more likely it is to be replaced. Moreover, the selection of which coiler 1 to use can be determined according to actual production needs, as long as the selected coiler 1 is usable.

[0051] In summary, the strip coiling method provided in this application first determines the height of the strip's starting point. When the height of the starting point exceeds a preset height limit, different positions of the starting point are lifted, while the conveyor rollers are rotated forward to loosen the starting point and lower its height, thus enabling cold coiling of the strip. This application utilizes existing equipment and tools on the production site, allowing for rapid handling of strip starting point accidents, significantly reducing production time. It avoids the use of flame cutting and hot work, making it safe, convenient, quick, and easy to implement. Furthermore, it prevents severe flattening of the coil after cold coiling, which can cause difficulties in uncoiling.

[0052] Other embodiments of this application will readily conceive of by those skilled in the art upon consideration of the specification and practice of the embodiments disclosed herein. This application is intended to cover any variations, uses, or adaptations of this application that follow the general principles of this application and include common knowledge or customary techniques in the art not disclosed herein. It should be understood that this application is not limited to the precise structures described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. The scope of this application is limited only by the appended claims.

Claims

1. A method for coiling steel strip, characterized in that, Applied to a hot rolling production line, the hot rolling production line is provided with a finishing mill, multiple sets of conveyor rollers and a coiler in sequence according to the running direction. The multiple sets of conveyor rollers have cooling guard plates on both sides. The coiler includes a side guide plate, a pressure roller, an inlet pinch roller, a first auxiliary coiling roller, a second auxiliary coiling roller, a third auxiliary coiling roller and a coil in sequence according to the running direction of the hot rolling production line. The strip has a starting section, and the strip head is located between the starting section and the inlet pinch roll. The starting section includes an intermediate section and a winding section located between the intermediate section and the strip head. The method for coiling the strip steel includes the following steps: Step S1: Compare the maximum height of the strip's starting point with the preset height limit value; Step S2: If the maximum height of the strip's starting part is greater than or equal to the preset height limit, then proceed to step S3; if the maximum height of the strip's starting part is less than the preset height limit, then proceed to step S5. Step S3: Lift the position where the winding part intersects with the middle part, release the winding part, and after lifting, control multiple sets of transport rollers to rotate forward at a preset speed to separate the winding part from the middle part. Lift the winding part again to loosen it, and continue to control multiple sets of transport rollers to rotate forward at a preset speed to flatten the winding part. Finally, lift the middle part to loosen it, and continue to control multiple sets of transport rollers to rotate forward at a preset speed, thereby reducing the maximum height of the middle part. Step S4: Repeat step S3 multiple times until the maximum height of the strip's starting part is less than the preset height limit. Step S5: Cold coil the strip steel.

2. The method for coiling strip steel according to claim 1, characterized in that, Also includes: Shut down the cooling water supply to the multiple sets of transport rollers.

3. The method for coiling strip steel according to claim 1, characterized in that, The number of coiling machines is three, arranged sequentially along the operating direction of the hot rolling production line, and are respectively designated as the first coiling machine, the second coiling machine, and the third coiling machine. The distance between the side guide plate outlet of the first coiling machine and the inlet pinch roll of the first coiling machine is L1, the distance between the inlet pinch roll of the first coiling machine and the inlet pinch roll of the second coiling machine is L2, and the distance between the inlet pinch roll of the first coiling machine and the inlet pinch roll of the third coiling machine is L3. The strip coiling method further includes: Before step S5, the length L of the strip head is obtained. If L1 < L ≤ L1 + L2, the first winding machine is used; if L1 + L2 < L ≤ L1 + L3, the second winding machine is used; if L > L1 + L3, the third winding machine is used.

4. The method for coiling strip steel according to claim 1, characterized in that, The strip has a length ≥30m, a thickness ≤6.0mm, and a yield strength ≤600MPa.

5. The method for coiling strip steel according to claim 1, characterized in that, In step S3, the preset speed is 1-2 m / s and the lifting height is 2-5 m.

6. The method for coiling strip steel according to claim 1, characterized in that, Before lifting the section where the take-up section intersects with the middle section, rotate all the transport rollers so that the intersection of the take-up section and the middle section is located at the junction of two adjacent sets of transport rollers. In step S3, controlling multiple sets of transport rollers to rotate forward at a preset speed includes: The multiple sets of transport rollers located between the winding machine and the intersection of the winding section and the intermediate section are controlled to rotate forward at a preset speed.

7. The method for coiling strip steel according to claim 1, characterized in that, In step S3, the lifting tools include an overhead crane and a wire rope, wherein the length of the wire rope is greater than four times the width of the strip steel.

8. The method for coiling strip steel according to claim 1, characterized in that, Step S5 specifically includes: The rotational speed of the coil is controlled to be equal to the rotational speed of the inlet pinch roller and greater than the rotational speed of the transport roller. The strip head is fed into the coiler. After the strip head reaches the coil, there is a first preset time delay, and the coil diameter expands to the maximum. After a second preset time delay, the second auxiliary coil roller opens to the maximum position, the third auxiliary coil roller opens to the maximum position, and the first auxiliary coil roller opens to a roll gap equal to the total thickness of the strip coiled on the coil.

9. The method for coiling strip steel according to claim 8, characterized in that, Also includes: Before the strip head is fed into the coiler, the side guide plate is opened to its maximum position, the roll gap of the inlet pinch roller is equal to the thickness of the strip, the roll gap of the first auxiliary coiling roller is 2-3 mm greater than the thickness of the strip, the roll gap of the second auxiliary coiling roller is 1-2 mm greater than the thickness of the strip, and the roll gap of the third auxiliary coiling roller is equal to the thickness of the strip; after the strip head is fed into the coiler, the side guide plate is closed to a width 10-15 mm greater than the width of the strip.

10. The method for coiling strip steel according to claim 8, characterized in that, The rotational speed of the drum and the inlet pinch roller is 0.8 to 1 m / s, the rotational speed of the conveyor roller is 0.5 to 0.8 m / s, the first preset time is 8 to 10 s, and the second preset time is 4 to 6 s.

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