Automatic tapping method for heating furnace

Abstract

The invention relates to the technical field of steel rolling, in particular to an automatic tapping method for a heating furnace, which comprises the following steps of: loading plate blanks on a walking beam of the heating furnace, and recording identifiers and sizes of the plate blanks by a data acquisition system in a program; the stepping beam sequentially ascends, advances, descends and retreats the plate blank so as to heat the plate blank, and in the ascending and advancing process, the control system monitors the action of a laser signal; moving the heated plate blank to a tapping position, calculating the theoretical distance from the head of the rear plate blank to a laser detector based on the size of the rear adjacent plate blank, and calculating the actual measurement distance of the head of the rear plate blank based on the actual displacement of the stepping beam; the difference value between the theoretical distance and the actual distance is calculated, and when the difference value is within a preset range, it is judged that the position of the slab sequence is normal, and automatic tapping is executed; and if the difference value exceeds the preset tolerance range, an alarm is triggered, and the automatic tapping process is interrupted. The device can rectify and position wrong slabs to prevent furnace collision and slab falling accidents.

Description

Technical Field

[0001] This invention relates to the field of steel rolling technology, and more particularly to a method for automatic steel tapping from a heating furnace. Background Technology

[0002] In the hot rolling process of the steel industry, the heating furnace is a key piece of equipment for heating slabs. The walking beam furnace gradually moves the slab to the discharge end through the positive circulation motion of the walking beam. Precise control of the discharge position directly affects production safety and efficiency. Traditional control methods use a through-beam laser detection device as the position signal source. When the slab triggers the laser signal, the system records the displacement of the walking beam past the laser beam and calculates the subsequent stroke of the discharge machine to achieve automated discharge operation. This position detection and control method has high reliability during the initial equipment installation phase.

[0003] However, as the aging of components due to long-term operation of equipment becomes increasingly prominent, the frequency of signal malfunctions in laser detection systems has increased significantly. In existing technologies, when a laser signal is falsely triggered, the recorded over-laser displacement will deviate, but an effective real-time verification mechanism is lacking. If operators fail to detect such anomalies in time, it can lead to errors in the calculation of the tapping machine's stroke, potentially causing serious accidents such as slabs falling or impacting the furnace wall. This is particularly problematic on equipment like the Ansteel Bayuquan 5500 thick plate heating furnace, which has been in service for over ten years; the shortcomings of relying solely on a single laser signal for detection are even more pronounced, severely restricting the success rate of automatic tapping and production safety. Summary of the Invention

[0004] To address the aforementioned technical problems arising from inaccurate position calculations due to false laser signal triggering and the lack of a real-time verification mechanism, which can easily lead to billet dropping and furnace wall collisions, this invention provides a method for automatic steel tapping in a heating furnace. This invention primarily utilizes a combination of program logic optimization and dual-path position verification techniques to achieve real-time diagnosis and correction of tapping position calculation errors, significantly reducing production accidents caused by single signal failures. This invention increases the success rate of automatic steel tapping to over 98% and constructs a dual safety barrier consisting of automatic verification and manual confirmation, fundamentally improving the safety and reliability of the heating furnace steel tapping process.

[0005] The technical means employed in this invention are as follows: A method for automatically tapping steel from a heating furnace includes the following steps: The slabs are loaded onto the walking beam of the heating furnace, and the data acquisition system in the program records the identification and dimensions of each slab. The walking beam sequentially raises, advances, lowers, and retracts the slab to heat it. During the raising and advancing processes, the control system monitors the laser signal action. During the advancing process, the slab is moved along the steel output direction by a fixed pitch. The heated slab is moved to the tapping position. Based on the size of the adjacent slab behind, the theoretical distance from the head of the slab behind to the laser detector is calculated. Based on the actual displacement of the walking beam, the measured distance from the head of the slab behind is calculated. The difference between the theoretical distance and the actual distance is calculated. If the difference is within a preset threshold, the slab sequence position is determined to be normal, and automatic steel tapping is executed. If the difference exceeds the preset threshold, an alarm is triggered and the automatic steel tapping process is interrupted.

[0006] Furthermore, the dimension of the rear slab on which the theoretical distance is calculated is the width of the rear slab, and the theoretical distance is calculated using the following formula: Theoretical distance = width of the slab in front - position of laser + slab spacing.

[0007] Furthermore, the measured distance is calculated based on the actual displacement feedback of the walking beam, and the measured distance is calculated using the following formula: Measured distance = number of steps the slab moves behind × single-step horizontal displacement of the walking beam + horizontal position value of the walking beam when the laser signal is triggered.

[0008] Furthermore, the preset threshold is less than or equal to 150mm.

[0009] Furthermore, after triggering the alarm and interrupting the automatic steel tapping process, the following steps are also included: An alarm message is generated on the human-machine interface, and the automatic steel feeding control logic is locked; the alarm message is reset after manual confirmation by the operator.

[0010] Furthermore, the method also includes adding a slab counting function to the program, the slab counting function including: Adjacent slabs are marked as 1 and 2 respectively, and their position data is stored in the corresponding registers for comparison and alarm judgment.

[0011] Compared with the prior art, the present invention has the following advantages: This invention improves the automatic steel tapping rate to over 98% by optimizing program logic and adding a dual-path verification mechanism for slab position. The system can accurately identify slabs with abnormal steel tapping position calculations and promptly alert operators to intervene, thereby effectively preventing major safety accidents such as slab dropping and furnace door collisions caused by incorrect positioning, and significantly improving the automation level and inherent safety of the production process. Based on the above reasons, this invention can be widely applied in fields such as steel rolling. Attached Figure Description

[0012] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0013] Figure 1 This is a schematic flowchart of a method for automatic steel tapping from a heating furnace according to the present invention.

[0014] Figure 2 This is a schematic diagram of the laser verification of the steel tapping position in the heating furnace in an embodiment of the present invention. Detailed Implementation

[0015] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0016] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0017] like Figure 1 As shown, the present invention provides a method for automatic steel tapping from a heating furnace, the specific steps of which are as follows: S1. Load the slabs onto the walking beam of the heating furnace, and the data acquisition system in the program records the identification and dimensions of each slab.

[0018] S2. The walking beam sequentially raises, advances, lowers, and retracts the slab to heat it. During the raising and advancing processes, the control system monitors the laser signal action. During the advancing process, the slab is moved one fixed pitch along the steel output direction.

[0019] Specifically, the laser signal activates during the lifting of the stepping beam, while the program normally calculates that the laser signal activates when the stepping beam is horizontally displaced. By optimizing the program, the phenomenon of laser signal activation during the lifting of the stepping beam is included in the normal calculation range, which greatly reduces the phenomenon of laser position calculation errors and reduces the occurrence of accidents.

[0020] S3. Move the heated slab to the tapping position. Based on the dimensions of the adjacent slab behind, calculate the theoretical distance from the head of the slab behind to the laser detector. Based on the actual displacement of the walking beam, calculate the measured distance from the head of the slab behind.

[0021] When the walking beam moves, falling iron oxide scale or heat-resistant materials can affect the laser signal, causing incorrect laser positioning. Therefore, a laser position calibration function has been added after the two slabs are in place.

[0022] The theoretical distance is based on the width of the rear slab, and is calculated using the following formula: Theoretical distance = width of the front slab - position through the laser + slab spacing.

[0023] The measured distance is calculated based on the actual displacement feedback of the walking beam. The measured distance is calculated by the following formula: Measured distance = number of steps the slab moves behind × single-step horizontal displacement of the walking beam + horizontal position value of the walking beam when the laser signal is triggered.

[0024] The position verification function is crucial because the accuracy of the tapping position directly determines the movement stroke of the tapping machine. If the tapping position information is incorrect, the tapping machine will position itself in the wrong place to lift the billet, which can easily lead to the billet falling off the machine due to the billet not landing smoothly.

[0025] S4. Calculate the difference between the theoretical distance and the actual distance. If the difference is within the preset threshold, the slab sequence position is determined to be normal, and automatic steel tapping is executed. If the difference exceeds the preset threshold, an alarm is triggered and the automatic steel tapping process is interrupted.

[0026] S5. An alarm message is generated on the human-machine interface, and the automatic steel feeding control logic is locked; the alarm message is reset after manual confirmation by the operator.

[0027] In a preferred embodiment of the present invention, the preset threshold is less than or equal to 150mm, and the fixed spacing is 600mm.

[0028] The method of the present invention also includes adding a slab counting function to the program, the slab counting function including: Adjacent slabs are marked as 1 and 2 respectively, and their position data is stored in the corresponding registers for comparison and alarm judgment.

[0029] like Figure 2As shown, slabs A and B are sequentially loaded onto the walking beam of the heating furnace (slab A is the front slab, and slab B is the rear slab). The process data acquisition system (PDA) records that the width of slab A is 1450 mm and the width of slab B is 1450 mm. Simultaneously, the following fixed parameters are preset in the PLC program: slab spacing is 309 mm, single-step horizontal displacement of the walking beam is 600 mm, laser detector over-laser position is 435.78 mm, and the position verification alarm threshold is set to 130 mm.

[0030] The walking beam is activated, performing a cyclical motion of rising, advancing, lowering, and reversing to transport and heat the slab. During this process, the control system monitors the laser signal and performs key program optimizations: regardless of whether the walking beam is rising or advancing horizontally, whenever the laser detector signal is activated, the signal and the precise position value of the walking beam at that moment are acquired and recorded, and incorporated into the subsequent slab position calculation logic. This resolves calculation errors caused by false triggering of the signal during non-horizontal movement phases due to equipment aging.

[0031] When slab A moves to the tapping position in preparation for tapping, the system automatically activates the laser position calibration function for slab B, performing cross-verification through dual-path calculation: Path 1: Calculate the theoretical distance Based on the known fixed parameters, calculate the theoretical distance from the head of slab B to the laser detector.

[0032] The theoretical distance is: 1450mm - 435.78mm + 309mm = 1323.22mm Path 2: Calculate the measured distance Based on the actual operating data of the walking beam, the measured distance from the head of slab B to the laser detector is calculated.

[0033] In this embodiment, slab B moves in 2 steps. The horizontal position of the stepping beam is 110mm at the time of laser triggering. Substituting into the formula: The measured distance is: 2 steps × 600mm / step + 110mm = 1310mm The absolute difference between the theoretical distance and the measured distance is calculated as: |1323.22mm-1310mm|=13.22mm.

[0034] The alarm threshold here is set to 130mm. Since 13.22mm < 130mm, the system determines that the slab sequence position is normal and automatically executes the operation of lifting slab A to the steel discharge roller table.

[0035] If the gap exceeds the limit, an alarm will be triggered during HMI switching, prompting the operator to confirm the billet position via the in-furnace television. This improves the accuracy of manual operation, avoids situations where the operator fails to see the billet or makes a mistake, and further reduces the occurrence of steel tapping accidents.

[0036] Once this solution is finalized, a slab counting function will be added to the program. Two consecutive slabs will be marked as 1 and 2 respectively, and their position data will be stored in two registers. The difference will be compared, and if it exceeds a set value, an HMI alarm will be triggered. After the alarm, the laser position will be blocked, and the operator will need to manually confirm before the screen returns to normal and the steel can be unloaded.

[0037] By implementing an optimized method for the automatic tapping position of the heating furnace, the automatic tapping rate was improved, accidents caused by manual misoperation were reduced, and the occurrence of major accidents such as billet dropping and furnace wall collisions was effectively decreased. The two heating furnaces protected in this optimization have four tapping stages. Based on the calculation of avoiding one furnace wall collision accident per year, the following benefits can be derived: The annual savings in furnace shutdown and repair costs is: 1 × 200,000 = 200,000 yuan The annual savings in emergency repair costs is: 20 hours, 16 people × 25 yuan = 8,000 yuan. Based on a single furnace operating for 5 days: Normal production capacity: 6000 tons / day - 4500 tons / furnace × 5 = 7500 tons Based on a profit of 45 yuan per ton: 7500 × 45 = 337,500 yuan Total: 20 + 0.8 + 33.75 = 54.55 million yuan In the above embodiments of the present invention, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions of other embodiments.

[0038] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for automatically tapping steel from a heating furnace, characterized in that, Includes the following steps: The slabs are loaded onto the walking beam of the heating furnace, and the data acquisition system in the program records the identification and dimensions of each slab. The walking beam sequentially raises, advances, lowers, and retracts the slab to heat it. During the raising and advancing processes, the control system monitors the laser signal action. During the advancing process, the slab is moved along the steel output direction by a fixed pitch. The heated slab is moved to the tapping position. Based on the size of the adjacent slab behind, the theoretical distance from the head of the slab behind to the laser detector is calculated. Based on the actual displacement of the walking beam, the measured distance from the head of the slab behind is calculated. Calculate the difference between the theoretical distance and the actual distance. When the difference is within a preset threshold, it is determined that the slab sequence position is normal and automatic steel tapping is executed. If the difference exceeds the preset threshold, an alarm will be triggered and the automatic steel tapping process will be interrupted.

2. The method for automatic steel tapping from a heating furnace according to claim 1, characterized in that, The theoretical distance is based on the width of the rear slab, and is calculated using the following formula: Theoretical distance = width of the slab in front - position of laser + slab spacing.

3. The method for automatic steel tapping from a heating furnace according to claim 1, characterized in that, The measured distance is calculated based on the actual displacement feedback of the walking beam, and the measured distance is calculated using the following formula: Measured distance = number of steps the slab moves behind × single-step horizontal displacement of the walking beam + horizontal position value of the walking beam when the laser signal is triggered.

4. The method for automatic steel tapping from a heating furnace according to claim 1, characterized in that, The preset threshold is less than or equal to 150 mm.

5. The method for automatic steel tapping from a heating furnace according to claim 1, characterized in that, After triggering the alarm and interrupting the automatic steel tapping process, the following is also included: An alarm message is generated on the human-machine interface, and the automatic steel feeding control logic is locked; the alarm message is reset after manual confirmation by the operator.

6. The method for automatic steel tapping from a heating furnace according to claim 1, characterized in that, The method further includes adding a slab counting function to the program, the slab counting function including: Adjacent slabs are marked as 1 and 2 respectively, and their position data is stored in the corresponding registers for comparison and alarm judgment.

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