A calculation method for setting the re-feeding of hot continuous rolling mill finishing mill

Abstract

This invention provides a hot strip mill finishing mill re-feeding setting calculation device, including a roughing mill, a roughing mill post-width gauge, a roughing mill post-high temperature gauge, a flying shear, a secondary descaling device, and a finishing mill. The roughing mill post-width gauge is located to the right of the roughing mill, the roughing mill post-high temperature gauge is located to the right of the roughing mill post-width gauge, an operating area is located to the right of the roughing mill post-high temperature gauge, a finishing mill pre-high temperature gauge is located to the right of the operating area, the flying shear is located to the right of the finishing mill pre-high temperature gauge, and the secondary descaling device is located to the right of the flying shear. This design uses the temperature of the strip head to be re-collected during the re-feeding of the strip for model setting calculation, ensuring that the predicted data such as roll gap, speed, and rolling force of each stand in the finishing mill match the actual strip conditions. This keeps the difference between the strip head thickness and the target finished product thickness within the allowable process accuracy range, solving the problem of process parameters exceeding the range caused by the inconsistency between the low re-feeding head temperature and the model setting temperature in the original hot strip mill production line.

Description

Technical Field

[0001] This invention is a calculation method for setting the re-feeding of hot strip finishing mill, belonging to the field of hot strip rolling production technology. Background Technology

[0002] In actual production, hot strip mill production lines sometimes experience temporary malfunctions in the finishing mill, coiler, or laminar flow cooling system after the strip passes through the pyrometer at the finishing mill inlet. If the malfunction can be resolved quickly, the operator needs to move the strip towards the roughing mill to the waiting area. After the malfunction is resolved, the strip needs to be re-entered for re-rolling. However, by this time, the strip temperature has already dropped, and the model does not collect the strip temperature again. The roll gaps and speeds of the finishing mill stands are still set according to the initial model calculations, resulting in the strip head thickness being too thick, exceeding the allowable tolerance range for finished product thickness, and producing defective products. There is an urgent need for a hot strip mill finishing mill re-entry setting calculation device to solve the above-mentioned problems. Summary of the Invention

[0003] To address the shortcomings of existing technologies, the present invention aims to provide a calculation method for setting the re-feeding of hot strip in finishing mills, thereby solving the problems mentioned in the background. The present invention has a reasonable structure and uses the temperature of the strip head to be re-collected during the re-feeding of the strip for model setting calculation, so as to ensure that the predicted data such as roll gap, speed, and rolling force of each stand in the finishing mill are consistent with the actual strip conditions, and that the difference between the thickness of the strip head and the thickness of the target finished product is within the allowable accuracy range of the process.

[0004] To achieve the above objectives, the present invention provides the following technical solution: a hot continuous rolling mill finishing mill re-feeding steel setting calculation method, comprising a roughing mill, a roughing mill post-width measuring instrument, a roughing mill post-high temperature gauge, an operating area, a finishing mill pre-high temperature gauge, a flying shear device, a secondary descaling device, and a finishing mill. The roughing mill is equipped with a roughing mill post-width measuring instrument on its right side, a roughing mill post-high temperature gauge on its right side, an operating area on its right side, a finishing mill pre-high temperature gauge on its right side, a flying shear device on its right side, a secondary descaling device on its right side, and a finishing mill on its right side.

[0005] Furthermore, the operating area is equipped with a waiting area and a scrap removal area.

[0006] Furthermore, the finishing mill is provided in seven groups, and the seven groups of finishing mills are of the same specifications and are arranged in an equidistant structure.

[0007] Furthermore, if the strip does not reach the secondary descaling stage after passing the pre-finishing high-temperature meter, the head temperature of the strip is collected when it passes the pre-finishing high-temperature meter and continues to the flying shear equipment. After passing the flying shear equipment, it reaches the secondary descaling equipment. When the strip reaches the secondary descaling equipment, the descaling water will automatically turn on, causing the head temperature of the strip to drop. If the strip is then reversed and re-entered for rolling, the head temperature will drop significantly, and the rolling conditions will not be met. Forced rolling will damage the equipment. Therefore, the judgment condition is determined to be that the strip has not reached the secondary descaling equipment before the re-entry model setting calculation function can be activated.

[0008] Furthermore, if the temperature detected by the high-temperature gauge before finishing mill disappears for more than 5 seconds, and the finishing mill experiences a temporary abnormality that can be recovered in a short time, the strip can be withdrawn towards the roughing mill to the position of the high-temperature gauge before finishing mill, waiting to be fed again. When the detected temperature disappears for more than 5 seconds, the presence of iron oxide scale or water on the surface of the strip during actual production can also cause the temperature detected by the high-temperature gauge before finishing mill to disappear. Therefore, a judgment condition is set for the high-temperature gauge before finishing mill to disappear for more than 5 seconds.

[0009] Furthermore, after the strip exits, while waiting inside the operating area, it comes into contact with air, and the surface temperature of the strip decreases through natural cooling. Under normal circumstances, the temperature drops by at least 1°C per second. This is used for the calculation of the temperature control model. In order to control the damage to the equipment caused by low-temperature rolling, the waiting time is also set to not exceed 50 seconds. Once the waiting time exceeds the set time, the setting to re-feed the strip will not be activated.

[0010] The beneficial effects of this invention are as follows: This invention provides a hot continuous rolling mill re-feeding steel setting calculation device. Because it incorporates a roughing mill, a post-roughing width measuring instrument, a post-roughing pyrometer, an operating area, a pre-finishing pyrometer, a flying shear, a secondary descaling device, and a finishing mill, this design uses the re-collection of strip head temperature during re-feeding for model setting calculations. This ensures that the predicted data on roll gaps, speeds, and rolling forces for each stand in the finishing mill match the actual strip conditions, keeping the difference between the strip head thickness and the target finished product thickness within the allowable process accuracy range. This solves the problem of process parameters exceeding the range caused by the low re-feeding head temperature and inconsistency with the model setting temperature in existing hot continuous rolling production lines, thus improving the practicality of this invention. Attached Figure Description

[0011] Other features, objects, and advantages of the present invention will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings:

[0012] Figure 1 This is a schematic diagram of the field equipment layout for the calculation method of re-feeding steel in hot continuous rolling finishing mill according to the present invention.

[0013] Figure 2 This is a schematic diagram of the waiting state for re-feeding of steel in a hot continuous rolling mill finishing mill re-feeding calculation method according to the present invention.

[0014] Figure 3 This is a schematic diagram of the scrap removal process in the calculation method for the re-feeding of hot continuous rolling mill in the finishing mill according to the present invention.

[0015] In the diagram: 1-Roughing mill, 2-Width gauge after roughing, 3-Temperature gauge after roughing, 4-Operating area, 5-Temperature gauge before finishing, 6-Flying shear equipment, 7-Secondary descaling equipment, 8-Finishing mill. Detailed Implementation

[0016] To make the technical means, creative features, objectives and effects of this invention easier to understand, the invention will be further described below in conjunction with specific embodiments.

[0017] Please see Figures 1-3 This invention provides a technical solution: a hot continuous rolling mill finishing mill re-feeding steel setting calculation device, including a roughing mill 1, a roughing mill post-width measuring instrument 2, a roughing mill post-temperature pyrometer 3, an operating area 4, a finishing mill pre-temperature pyrometer 5, a flying shear device 6, a secondary descaling device 7, and a finishing mill 8. The roughing mill post-width measuring instrument 2 is located to the right of the roughing mill 1, the roughing mill post-width measuring instrument 2 is located to the right of the roughing mill post-width measuring instrument 2, the roughing mill post-temperature pyrometer 3 is located to the right of the roughing mill post-temperature pyrometer 3, the operating area 4 is located to the right of the operating area 4, the finishing mill pre-temperature pyrometer 5 is located to the right of the operating area 4, the flying shear device 6 is located to the right of the finishing mill pre-temperature pyrometer 5, the secondary descaling device 7 is located to the right of the flying shear device 6, and the finishing mill 8 is located to the right of the secondary descaling device 7. This design uses the temperature of the strip head to be re-collected when the strip is re-feeded for model setting calculation, so as to ensure that the predicted data such as the roll gap, speed, and rolling force of each stand in the finishing mill are consistent with the actual strip conditions, and that the difference between the strip head thickness and the target finished product thickness is within the allowable accuracy range of the process.

[0018] The operating area 4 is equipped with a waiting area and a scrap removal area.

[0019] There are seven sets of finishing mills 8, and the seven sets of finishing mills 8 are of the same specifications and are arranged at equal intervals.

[0020] If the strip does not reach the secondary descaling stage before passing the high temperature meter 5, the head temperature is collected when the strip passes the high temperature meter 5 and continues to the flying shear equipment 6. After passing the flying shear equipment 6, it reaches the secondary descaling equipment 7. When the strip reaches the secondary descaling equipment 7, the descaling water will be turned on automatically, causing the head temperature of the strip to drop. If the strip is reversed and re-entered for rolling at this time, the head temperature will drop significantly, and the rolling conditions will not be met. Forced rolling will damage the equipment. Therefore, the judgment condition is set to not reach the secondary descaling equipment 7 before the re-entry model setting calculation function can be activated.

[0021] If the temperature detected by the high temperature gauge 5 before finishing milling disappears and lasts for more than 5 seconds, and if there is a temporary abnormality in the finishing mill 8 that can be restored in a short time, the strip can be withdrawn towards the roughing mill 1 to the position of the high temperature gauge 5 before finishing milling, and wait to be fed again. If the detected temperature disappears and lasts for more than 5 seconds, the temperature detected by the high temperature gauge 5 before finishing milling will also disappear due to the presence of iron oxide scale or water on the surface of the strip during actual production. Therefore, a judgment condition of the high temperature gauge 5 before finishing milling disappearing for more than 5 seconds is also set.

[0022] After the strip exits and waits inside operating area 4, it comes into contact with air. The surface temperature of the strip will drop naturally through cooling, typically by at least 1°C per second. This temperature is used for calculations in the temperature control model to control the damage to the equipment caused by low-temperature rolling. The waiting time is also set to be no more than 50 seconds. If the waiting time exceeds the set time, the re-feeding setting will not be enabled.

[0023] As an embodiment of the present invention: the various devices are assembled and connected to form a hot continuous rolling mill finishing production line. When the strip steel is rolled from the roughing mill 1 to the finishing mill 8, the head of the strip steel reaches the position of the pre-finishing high temperature meter 5. The system collects the temperature of the strip steel head for the model setting calculation. If the finishing mill 8 experiences a temporary fault at this time, it is handled in two ways: 1. If the signal does not reach the secondary descaling equipment 7 and the fault can be handled quickly, the operator of the finishing mill 8 needs to move the strip steel back to the waiting position inside the operating area 4 and wait for the fault to be handled before re-entering the mill for rolling. The conditions to be met at this time are that the head of the strip steel has exited the position of the pre-finishing high temperature meter 5 and the time without temperature is greater than 5 seconds. At the same time, the maximum waiting time cannot exceed 50 seconds. When the head of the strip steel re-enters the mill and passes the pre-finishing high temperature meter 5, the system re-collects the real-time temperature of the strip steel head for the model's re-entry setting. 1. The calculation is set and the first-level automated control system is issued for execution. If the waiting time of the strip in the waiting position exceeds 50 seconds, rolling cannot be carried out at this time, and the strip can only be moved to the scrap removal area for scrap removal. 2. If the strip has reached the secondary descaling equipment 7, the operator of the finishing mill 8 needs to retreat the strip to the scrap removal area inside the operating area 4. It cannot be fed into the rolling mill again because once it reaches the secondary descaling equipment 7, the strip head will be sprayed with high-pressure water, causing the strip head to blacken and the temperature to drop sharply, which does not meet the rolling conditions. If rolling is forced, the process indicators will not be hit at best, and the finishing mill 8 and other equipment will be damaged at worst. Therefore, it is determined that when the strip reaches the secondary descaling equipment 7, the setting calculation for feeding into the rolling mill cannot be executed, and rolling cannot be carried out. This design can significantly improve the hit rate of strip head thickness, control the process indicators within the accuracy range, and has a significant effect, improving the first-pass yield of finished products.

[0024] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered illustrative and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

[0025] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A method for setting the re-feeding of hot continuous rolling mill into the finishing mill, comprising a roughing mill, a width measuring instrument after roughing, a pyrometer after roughing, an operating area, a pyrometer before finishing, a flying shear, a secondary descaling device, and a finishing mill, characterized in that: A roughing mill width gauge is installed on the right side of the roughing mill. A roughing mill pyrometer is installed on the right side of the roughing mill width gauge. An operating area is installed on the right side of the roughing mill pyrometer. A finishing mill pyrometer is installed on the right side of the operating area. A flying shear is installed on the right side of the finishing mill pyrometer. A secondary descaling device is installed on the right side of the flying shear. A finishing mill is installed on the right side of the secondary descaling device. The device is configured such that when the strip passes the finishing mill pyrometer but does not reach the secondary descaling device, if the finishing mill experiences a temporary malfunction and can be restored in a short time, the strip is controlled to return to the waiting area in the operating area. After the malfunction is restored, the strip is fed again, and when its head passes the finishing mill pyrometer, the real-time temperature of the strip head is collected again for the model's re-feeding setting calculation. The judgment condition for activating the re-feeding setting calculation function includes: the duration for which the finishing mill pyrometer detects the disappearance of the strip temperature is greater than 5 seconds.

2. The calculation method for setting the re-feeding of hot continuous rolling mill as described in claim 1, characterized in that: The operating area is divided into a waiting area and a waste removal area.

3. The calculation method for setting the re-feeding of hot continuous rolling mill finishing mill according to claim 1, characterized in that: The finishing mill is provided in seven groups, and the seven groups of finishing mills are of the same specifications and are arranged at equal intervals.

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