A method for reducing the frequency of breakout prediction alarm of a continuous casting machine

Abstract

The application discloses a method for reducing the frequency of breakout prediction and alarm of a continuous casting machine, and belongs to the technical field of steel metallurgy continuous casting production, and comprises the following steps: S1, quality control is performed on the crystallizer copper plate and thermocouple, and it is ensured that the equipment state meets the production requirements; S2, the taper of the crystallizer is set differentially according to the solidification shrinkage characteristics of the cast steel grade; S3, quantitative control is performed on the argon gas parameters between the plates, and leakage prevention inspection is performed on the continuous casting medium pipeline; S4, at least one of the crystallizer cooling water quantity, the submerged entry nozzle insertion depth, the crystallizer liquid level, the ladle tonnage, the casting temperature and the state of the protective slag is controlled in detail; and S5, a normalized closed-loop management and control system is built: a standardized inspection and statistical system is formulated, and continuous tracking and rectification are performed on the equipment, the process and the alarm data. The application suppresses false alarms from the source, stabilizes the continuous casting production rhythm, and improves the identification accuracy of the breakout prediction system and the safety of the continuous casting production.

Description

Technical Field

[0001] This invention belongs to the field of continuous casting production technology in iron and steel metallurgy, and specifically relates to a method for reducing the frequency of steel leakage prediction alarms in continuous casting machines. Background Technology

[0002] The continuous casting machine crystallizer leakage prediction system is a core safety device for preventing continuous casting sticking and leakage accidents. It primarily relies on temperature data collected by thermocouples on the crystallizer copper plate and combines this data with changes in friction force curves to identify early signs of leakage. It has been widely used in continuous casting production lines in the steel industry. However, existing technology has the following drawbacks: 1. Equipment defects cause data distortion: After long-term use, the copper plate of the crystallizer will wear, deform and peel off, resulting in uneven copper plate thickness, abnormal local thermal resistance, and disruption of heat transfer law. This will cause disorder in the temperature gradient and temperature change data collected by the thermocouple, triggering a large number of false alarms in the system. At the same time, the aging and failure of thermocouple spare parts will also exacerbate the problem of abnormal temperature measurement.

[0003] 2. Poor taper matching of the crystallizer: Traditional continuous casting machine crystallizers uniformly adopt a fixed taper of 0.9% and 1.0%, without taking into account the different physical and chemical properties of different steel grades such as low carbon, medium carbon, and peritectic. If the taper is too small, air gaps will easily be generated between the billet shell and the copper plate, which will not only increase the risk of billet shell adhesion, but also deteriorate the lubrication and heat transfer effect of the crystallizer, further inducing false alarms of steel leakage prediction, and increasing the actual steel leakage risk.

[0004] 3. Non-standard gas supply and argon control: Argon gas in the on-site plate room is adjusted based on the experience of the staff, without a unified quantitative standard. Uncontrolled argon pressure, flow rate and back pressure parameters will cause crystallizer sealing failure, internal flow field disorder and uneven billet growth. In addition, there is a common gas leakage in the medium pipeline of the tundish car, which causes the crystallizer to absorb gas and the molten steel to oxidize and increase nitrogen, which disrupts the stability of the flow field. Under the dual effect, the alarm frequency is greatly increased.

[0005] 4. Lax control of process parameters: There are no refined control standards for process parameters such as primary cooling water volume of the crystallizer, insertion depth of the submerged nozzle, liquid level of the crystallizer, tonnage of the tundish, casting temperature of the tundish, and state of the protective slag. The parameters fluctuate greatly, resulting in uneven slag layer thickness and heat transfer imbalance in the crystallizer, which are important causes of frequent steel leakage warnings.

[0006] 5. Lack of management system: The rectification measures of each team are not targeted enough, and a normalized closed-loop management system has not been formed. After the frequency of alarms decreased in the early stage, they are prone to rebound. At the same time, there is a lack of standardized inspection, acceptance and assessment system, and problems recur.

[0007] The aforementioned problems collectively lead to a high frequency and strong randomness of alarms in the steel leakage prediction system, forcing the casting machine to frequently slow down, brake suddenly, or even stop casting unplanned, severely disrupting the production rhythm. The slabs corresponding to the alarms are prone to inclusion defects, requiring scrapping, increasing production costs and quality risks, and restricting the continuous production and economic benefits of continuous casting. Summary of the Invention

[0008] This invention addresses the problems of existing technologies by providing a method to reduce the frequency of steel leakage prediction alarms in continuous casting machines. By combining equipment modification, steel grade differentiation process optimization, standardized control of gas circuits, refined parameter adjustment, and routine management, false alarms are suppressed at the source, the continuous casting production rhythm is stabilized, and the recognition accuracy of the steel leakage prediction system and the safety of continuous casting production are improved.

[0009] A method for reducing the frequency of leak prediction alarms in continuous casting machines includes: S1. Rectification of crystallizer and temperature measuring equipment: Implement quality control on the copper plate and thermocouple of the crystallizer to ensure that the equipment condition meets production requirements; S2. Differentiated Adjustment of Crystallizer Taper: The crystallizer taper is set differently based on the solidification shrinkage characteristics of the steel being cast; specifically: When casting low-carbon or medium-carbon steel, set the crystallizer taper to 1.1%. When casting peritectic steel or low-alloy steel, set the crystallizer taper to 1.15%. S3. Standardized management and control of gas path and medium pipeline: Quantitative control of argon parameters between plates, controlling the inlet pressure of argon between plates to ≤0.4MPa, back pressure to ≤0.2MPa, and flow rate to ≤15L / min; and conducting leak prevention inspections on continuous casting medium pipelines; S4. Refined control of continuous casting process parameters: Refined control of at least one of the following: cooling water volume of the crystallizer, insertion depth of the submerged nozzle, liquid level of the crystallizer, tonnage of the tundish, casting temperature and state of the protective slag. S5. Establish a normalized closed-loop management and control system: formulate standardized inspection and statistical systems, and continuously track and rectify equipment, processes and alarm data.

[0010] Preferably, S1 includes: Regularly inspect and replace faulty thermocouples; Establish a system for accepting copper plates for crystallizers upon arrival at the factory, verify the ultrasonic flaw detection reports of the copper plates, and return any copper plates with defects. After each casting cycle, inspect and replace any deformed or peeling copper plates in the crystallizer.

[0011] Preferably, the defects in the copper plate of the crystallizer include at least one of the following: cracks, inclusions, porosity, wear deformation, and plating peeling.

[0012] Preferably, the specific parameters for the refined control are: The primary cooling water flow rate for the fixed crystallizer is 4200 / 600 L / min; The insertion depth of the submersible sprue should be controlled between 150mm and 180mm. The fluctuation of the liquid level in the crystallizer should be controlled within ±3mm; Control the tonnage fluctuation of the intermediate package within ±0.2 tons; The casting temperature of the molten steel in the intermediate ladle should be controlled at 15°C to 30°C above the target temperature. Replace the protective slag regularly to ensure a uniform thickness of the liquid slag layer inside the crystallizer.

[0013] Preferably, the standardized inspection and statistical system includes: Six standards were established for copper plate acceptance, taper inspection, argon gas verification, pipeline leak detection, temperature detection, and protective slag quality tracking, and the implementation frequency and responsible persons for each standard were clearly defined. Daily statistics on alarm data from each shift are compiled, and weekly analysis and corrective measures are developed.

[0014] Preferably, the execution frequency of each standard is as follows: copper plate acceptance is performed for each delivery; crystallizer taper inspection is performed for each casting; argon gas verification between plates and medium pipeline inspection are performed for each shift; tundish temperature detection is performed for each furnace; and protective slag quality tracking is performed monthly.

[0015] Preferably, the weekly analysis and formulation of corrective measures includes: Based on the daily alarm data, high-frequency alarm locations and alarm teams were identified, and specific rectification measures were formulated to suppress the rebound of alarm frequency.

[0016] Preferably, the execution priority among the steps is as follows: Equipment rectification, leak detection of medium pipelines, and control of argon parameters between plates are given the highest priority. Crystallizer taper adjustment and process parameter control are secondary priority. Routine inspections and data tracking are prioritized at level three.

[0017] Preferably, the leak prevention inspection of the continuous casting medium pipeline includes: A two-tiered inspection system was established, with each shift checking the medium hoses and the workshop conducting a comprehensive leak check on the medium pipelines of the intermediate packaging trucks every week, and promptly repairing any leaks.

[0018] Preferably, the leak prevention inspection is equipped with a reward and punishment assessment mechanism.

[0019] Beneficial effects This invention addresses the problems of frequent false alarms in continuous casting machine leakage prediction caused by defects in the copper plate of the crystallizer, improper taper matching, chaotic control of argon gas and pipelines, large fluctuations in process parameters, and lack of management in existing technologies. Through multi-dimensional collaborative optimization of equipment, process, gas path, and management, it quantifies all operating parameters, abandons manual experience-based operation, and effectively solves core problems such as distorted temperature measurement data, turbulent flow field in the crystallizer, and uneven billet shell growth. This invention can reduce the average monthly alarm frequency of continuous casting machine leakage prediction from 68.1 times to below 50 times, reducing unplanned casting machine shutdowns and scrap due to inclusion defects in the billet, stabilizing the continuous casting production rhythm, reducing production costs, and improving the identification accuracy of the leakage prediction system and the safety of continuous casting production. The method has a high degree of standardization and is suitable for widespread use in various slab continuous casting production lines. Attached Figure Description

[0020] Figure 1 In a preferred embodiment of the present invention, the slab alarm generates a joint mark. Detailed Implementation

[0021] The technical solutions in the embodiments of the present invention will be clearly and completely described below. 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 are within the scope of protection of the present invention.

[0022] To address the problems of frequent false alarms, inefficient equipment and process control, poor production stability, and high billet scrap rate in existing continuous casting machine leakage prediction systems, this invention provides a method to reduce the frequency of leakage prediction alarms in continuous casting machines. By combining equipment modification, steel grade differentiation process optimization, standardized gas path control, refined parameter adjustment, and routine management, false alarms are suppressed at the source, the continuous casting production rhythm is stabilized, billet scrapping costs are reduced, and the accuracy of leakage prediction system identification and the safety of continuous casting production are improved.

[0023] Please see Figure 1 , Figure 1 In the attached diagram, reference numeral 1 indicates the joint mark generated by the slab alarm; A method for reducing the frequency of leak prediction alarms in continuous casting machines includes: S1. Rectification of crystallizer and thermocouple equipment: Regularly inspect and replace abnormal thermocouples; establish a system for accepting incoming copper plates of crystallizers, verify the ultrasonic flaw detection report of copper plates, return copper plates with defects, and inspect and replace deformed or delaminating crystallizer copper plates after each casting stop. S2. Differentiated adjustment of crystallizer taper: Adjust the crystallizer taper according to the type of steel being cast. The taper for low carbon steel and medium carbon steel is set to 1.1%, and the taper for peritectic steel and low alloy steel is set to 1.15%. Check the taper dimension after each casting. S3. Argon gas and media pipeline management between plates: Limit argon gas parameters between plates: inlet pressure ≤ 0.4MPa, back pressure ≤ 0.2MPa, flow rate ≤ 15L / min; Establish a two-level inspection system, with each shift checking the media hoses and the workshop conducting a comprehensive leak check on the media pipelines of the central packaging truck every week, and promptly repairing any leaks. S4. Refined control of continuous casting process parameters: The primary cooling water flow rate of the crystallizer is fixed at 4200 / 600L / min; the insertion depth of the submerged entry nozzle is controlled at 150mm~180mm; the fluctuation of the liquid level in the crystallizer is controlled within ±3mm; the fluctuation of the tundish tonnage is controlled within ±0.2 tons; the casting temperature of the molten steel in the tundish is controlled at 15℃~30℃ above the target temperature; the protective slag is replaced regularly to ensure uniform thickness of the liquid slag layer, and the physical and chemical properties of the protective slag and the quality of the refractory material of the entry nozzle are optimized simultaneously. S5. Establish a normalized closed-loop management and control system: Formulate six standards for copper plate acceptance, taper inspection, argon gas verification, pipeline leak detection, temperature detection, and protective slag quality tracking, clarify the execution frequency and responsible persons, collect alarm data of each team daily, and analyze and rectify weekly.

[0024] To better understand the technical solution of the present invention, the following non-limiting explanation is provided: Defects in the copper plates used in crystallizers include cracks, inclusions, porosity, wear and deformation, and plating peeling. Copper plates with any of these defects are prohibited from being used in production.

[0025] In S3, a reward and punishment assessment mechanism is set up for the inspection of medium pipelines, and the personnel in charge of the inspection are assessed for inadequate inspection or failure to report gas leaks in a timely manner.

[0026] In S4, the thickness of the liquid slag layer inside the crystallizer is kept uniform, and heat transfer imbalance caused by abnormal slag conditions is avoided by changing the slag at regular intervals.

[0027] In S5, the execution frequency of each standard is as follows: copper plate acceptance is performed every time it arrives; crystallizer taper inspection is performed every time it is poured; argon gas verification between plates and medium pipeline inspection are performed every shift; tundish temperature detection is performed every furnace; and protective slag quality tracking is performed monthly.

[0028] This method prioritizes the following tasks: equipment rectification, leak detection of medium pipelines, and control of argon parameters between plates are first-level priorities and must be executed immediately; crystallizer taper adjustment and process parameter control are second-level priorities and must be completed on the same day; routine inspections and data tracking are third-level priorities and must be executed continuously in the long term.

[0029] In S5, based on the daily alarm data, high-frequency alarm locations and alarm teams are identified, and specific rectification measures are formulated to suppress the rebound of alarm frequency.

[0030] The technical solution of this invention mainly includes five modules: equipment modification, steel grade differentiated taper optimization, argon gas and pipeline management, refined control of process parameters throughout the entire process, and routine and standardized management. The specific steps are as follows: Step 1: Specific rectification of the crystallizer and thermocouple equipment: 1.1 Thermocouple Management: Regularly conduct comprehensive inspections and verifications of offline thermocouples, and promptly replace faulty or abnormally measuring thermocouples to ensure the accuracy of temperature measurement data.

[0031] 1.2 Control of Copper Plates in Crystallizers: Establish a joint acceptance mechanism for incoming copper plates. Workshop personnel will conduct acceptance in conjunction with outsourced manufacturers. Each batch of copper plates must be accompanied by an ultrasonic flaw detection report. Copper plates with defects such as cracks, slag inclusions, porosity, plating peeling, and deformation will be returned in the entire batch. After each casting cycle is stopped, the machine operator will inspect each crystallizer according to the standards. Copper plates that are worn, deformed, or have peeling plating will be replaced immediately to prevent temperature measurement distortion caused by copper plate defects.

[0032] Step 2: Differentiated adjustment of crystallizer taper based on steel type characteristics. Based on the solidification shrinkage characteristics of different steel types, the traditional fixed taper mode is abandoned, and the crystallizer taper is set according to steel type: the crystallizer taper of low carbon steel and medium carbon steel is adjusted to 1.1%, and the crystallizer taper of peritectic steel and low alloy steel is adjusted to 1.15%. Before pouring and after pouring, the taper size is checked for each pour to ensure that the taper is implemented in place, eliminate the air gap between the billet shell and the copper plate, optimize the billet shell growth quality, and reduce the risk of adhesion.

[0033] Step 3: Standardized management and control of argon gas and media pipelines between plates: 3.1 Quantitative control of argon gas between plates: Establish unified operating standards, with argon gas inlet pressure ≤0.4MPa, back pressure ≤0.2MPa, and flow rate ≤15L / min. All personnel must strictly follow the parameters and are prohibited from arbitrarily adjusting them based on experience to ensure the sealing effect of the crystallizer and the stability of the internal flow field.

[0034] 3.2 Leakage Prevention and Control of Medium Pipelines: A two-level inspection system has been established. Each work team checks the integrity of each medium hose before the preparation and baking operations. The workshop conducts a comprehensive leak inspection of all medium pipelines of the four medium-sized packaging machines every week. If a leak is found, it is repaired or replaced immediately. A corresponding reward and punishment assessment mechanism for leaks has been set up to strengthen job responsibilities and prevent the crystallizer from sucking in air.

[0035] Step 4: Fine-tuning and unifying the threshold values ​​of process parameters across the entire continuous casting process to minimize parameter fluctuations: 4.1 The primary cooling water flow rate of the crystallizer is fixed at 4200 / 600 L / min to ensure stable cooling intensity; 4.2 The insertion depth of the submersible nozzle should be controlled within the range of 150mm to 180mm; 4.3 The fluctuation of the liquid level in the crystallizer must be strictly controlled within ±3mm; 4.4 The tonnage fluctuation of the tundish should be controlled within ±0.2 tons to stabilize the liquid level in the tundish; 4.5 The temperature of the molten steel poured in the tundish should be controlled at 15℃~30℃ above the target temperature according to the requirements of the steel grade; 4.6 Replace the protective slag regularly to ensure a uniform thickness of the liquid slag layer inside the crystallizer and achieve balanced heat transfer; 4.7 Continuously optimize the physical and chemical properties of the protective slag and the quality of the refractory material at the nozzle to match the casting requirements of different steel grades.

[0036] Step 5: Establish a standardized and normalized closed-loop management system: Develop six fixed inspection standards, clarify the frequency of implementation and responsible persons, and form a long-term management mechanism. 5.1 Copper Plate Acceptance: Perform this procedure on each delivery, verifying the flaw detection report and appearance quality; 5.2 Crystallizer taper inspection: Check once before and after each pouring; 5.3 Argon gas parameter verification between plates: Regular inspection every shift; 5.4 Leak detection of media pipelines: daily inspections every shift + comprehensive leak detection of the workshop every week; 5.5. Tundish casting temperature check: Record the temperature of each heat of molten steel; 5.6. Tracking of mold flux and billet quality: Monthly summary and analysis, and continuous optimization of mold flux indicators.

[0037] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Any simple modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of the present invention shall fall within the scope of the technical solution of the present invention.

Claims

1. A method for reducing the frequency of steel leakage prediction alarms in continuous casting machines, characterized in that, include: S1. Rectification of crystallizer and temperature measuring equipment: Implement quality control on the copper plate and thermocouple of the crystallizer to ensure that the equipment condition meets production requirements; S2. Differentiated Adjustment of Crystallizer Taper: The crystallizer taper is set differently based on the solidification shrinkage characteristics of the steel being cast; specifically: When casting low-carbon or medium-carbon steel, set the crystallizer taper to 1.1%. When casting peritectic steel or low-alloy steel, set the crystallizer taper to 1.15%. S3. Standardized management and control of gas path and medium pipeline: Quantitative control of argon parameters between plates, controlling the inlet pressure of argon between plates to ≤0.4MPa, back pressure to ≤0.2MPa, and flow rate to ≤15L / min; and conducting leak prevention inspections on continuous casting medium pipelines; S4. Refined control of continuous casting process parameters: Refined control of at least one of the following: cooling water volume of the crystallizer, insertion depth of the submerged nozzle, liquid level of the crystallizer, tonnage of the tundish, casting temperature and state of the protective slag. S5. Establish a normalized closed-loop management and control system: formulate standardized inspection and statistical systems, and continuously track and rectify equipment, processes and alarm data.

2. The method for reducing the frequency of steel leakage prediction alarms in continuous casting machines according to claim 1, characterized in that, S1 includes: Regularly inspect and replace faulty thermocouples; Establish a system for accepting copper plates for crystallizers upon arrival at the factory, verify the ultrasonic flaw detection reports of the copper plates, and return any copper plates with defects. After each casting cycle, inspect and replace any deformed or peeling copper plates in the crystallizer.

3. The method for reducing the frequency of steel leakage prediction alarms in continuous casting machines according to claim 1, characterized in that, The defects in the copper plate of the crystallizer include at least one of the following: cracks, inclusions, porosity, wear and deformation, and plating peeling.

4. The method for reducing the frequency of steel leakage prediction alarms in continuous casting machines according to claim 1, characterized in that, The specific parameters for the refined control are as follows: The primary cooling water flow rate for the fixed crystallizer is 4200 / 600 L / min; The insertion depth of the submersible sprue should be controlled between 150mm and 180mm. The fluctuation of the liquid level in the crystallizer should be controlled within ±3mm; Control the tonnage fluctuation of the intermediate package within ±0.2 tons; The casting temperature of the molten steel in the intermediate ladle should be controlled at 15°C to 30°C above the target temperature. Replace the protective slag regularly to ensure a uniform thickness of the liquid slag layer inside the crystallizer.

5. The method for reducing the frequency of steel leakage prediction alarms in continuous casting machines according to claim 1, characterized in that, The standardized inspection and statistical system includes: Six standards were established for copper plate acceptance, taper inspection, argon gas verification, pipeline leak detection, temperature detection, and protective slag quality tracking, and the implementation frequency and responsible persons for each standard were clearly defined. Daily statistics on alarm data from each shift are compiled, and weekly analysis and corrective measures are developed.

6. The method for reducing the frequency of steel leakage prediction alarms in continuous casting machines according to claim 5, characterized in that, The execution frequency for each standard is as follows: copper plate acceptance is performed for each delivery; crystallizer taper inspection is performed for each casting; argon gas verification between plates and medium pipeline inspection are performed for each shift; tundish temperature detection is performed for each furnace; and protective slag quality tracking is performed monthly.

7. The method for reducing the frequency of steel leakage prediction alarms in continuous casting machines according to claim 5, characterized in that, The weekly analysis and development of corrective measures include: Based on the daily alarm data, high-frequency alarm locations and alarm teams were identified, and specific rectification measures were formulated to suppress the rebound of alarm frequency.

8. The method for reducing the frequency of steel leakage prediction alarms in continuous casting machines according to claim 1, characterized in that, Execution priority among steps: Equipment rectification, leak detection of medium pipelines, and control of argon parameters between plates are given the highest priority. Crystallizer taper adjustment and process parameter control are secondary priority. Routine inspections and data tracking are prioritized at level three.

9. The method for reducing the frequency of steel leakage prediction alarms in continuous casting machines according to claim 1, characterized in that, The leak-proof inspection of the continuous casting medium pipeline includes: A two-tiered inspection system was established, with each shift checking the medium hoses and the workshop conducting a comprehensive leak check on the medium pipelines of the intermediate packaging trucks every week, and promptly repairing any leaks.

10. The method for reducing the frequency of steel leakage prediction alarms in continuous casting machines according to claim 9, characterized in that, The leak prevention inspection is accompanied by a reward and punishment assessment mechanism.

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