Method for dynamically adjusting scrap steel loading amount based on converter mouth flame analysis system

Abstract

The invention discloses a method for dynamically adjusting the scrap steel loading amount based on a converter mouth flame analysis system, and relates to the technical field of scrap steel smelting. The method comprises the following steps: adding scrap steel slightly less than the original smelting mode, adding molten iron, carrying out lance descending blowing, monitoring the temperature condition of the converter smelting process in real time through a converter mouth flame analysis system, collecting the temperatures at the end of the smelting early stage and the end of the smelting middle stage, and comparing the temperatures with the standard temperature at the moment, and the amount of scrap steel needing to be added is calculated and is added through the overhead bunker, all surplus heat of the converter is used for scrap steel smelting to the maximum extent, and the dynamic adjustment of the scrap steel loading amount of the converter is achieved. The method has the beneficial effects that all surplus heat of the converter can be used for scrap steel smelting to the maximum extent, the converter can dynamically adjust the scrap steel loading amount, and powerful support is provided for green development of the iron and steel industry.

Description

Technical Field

[0001] The invention relates to the technical field of scrap steel smelting, and in particular to a method for dynamically adjusting the scrap steel charging amount based on a converter mouth flame analysis system. Background Art

[0002] As a clean and recyclable resource, scrap steel has significant energy-saving and emission-reduction advantages compared to steelmaking with ore and coking coal. Using scrap steel to produce 1 ton of steel can reduce carbon dioxide emissions by about 1.6 tons and solid waste emissions by about 3 tons. With the rapid development of China's steel industry, the accumulated amount of steel has increased significantly, and scrap steel resources have increased year by year, which is expected to reach 200 million tons / year and continue to rise. Domestic steelmaking is mainly based on the long process, and the output of electric furnace steel accounts for only about 9.7% of the total crude steel output. Scrap steel resources are in oversupply and low in price, which has a significant price advantage over molten iron. Therefore, increasing the use of scrap steel in long-process steelmaking can not only effectively reduce carbon dioxide and solid waste emissions, but also has important significance for improving the economic benefits of enterprises.

[0003] During converter smelting, the carbon in the molten pool is continuously oxidized, and the carbon content in the molten steel is continuously reduced. When carbon is oxidized, a large amount of high-temperature CO gas is generated and discharged from the furnace mouth. When it meets the surrounding air, it is immediately oxidized and burned to form a flame. The color, brightness, shape, and length of the flame at the furnace mouth are signs of the molten pool temperature and the amount of CO discharged per unit time. Therefore, the carbon content and furnace temperature in the furnace can be judged from the appearance of the flame. The converter furnace mouth flame analysis system obtains the real-time flame image of the converter furnace mouth through a high-definition camera and presents it in the client software. The system is connected to the PLC signal of the converter steelmaking site, collects PLC data, and uses the converter-specific temperature curve algorithm to calculate the real-time temperature curve that conforms to the converter steelmaking process. After each furnace of steelmaking is completed, the system automatically records the converter production data after receiving the end signal.

[0004] The conventional smelting process of the converter is to add a fixed amount of scrap steel and molten iron at one time and then lower the gun for smelting. Due to the influence of the temperature and composition of the molten iron entering the furnace and the complex chemical changes during the smelting process, the temperature between each furnace fluctuates greatly. The furnace master judges the temperature based on personal experience through the flame at the furnace mouth. In the smelting process, cold materials such as limestone and iron ore are added to adjust the temperature. The method of high carbon drawing and then supplementary blowing is adopted. After the furnace is turned over and the temperature is sampled, supplementary blowing is adjusted according to the composition and temperature. In the converter equipped with the converter mouth flame analysis system, the smelting is also carried out after adding a fixed amount of scrap steel and molten iron. During the smelting process, according to the terminal temperature predicted by the converter mouth flame analysis system, the converter temperature is regulated by adding limestone, dolomite and other cold materials near the converter smelting end point. Although the terminal temperature can meet the steel production requirements, the large amount of limestone, dolomite, etc. added not only wastes the excess heat of the converter, but also increases the loss of converter slag and steel materials.

[0005] Chinese patent CN 114959160 A discloses a converter steelmaking method and device for dynamically adjusting the scrap steel loading amount based on molten iron conditions. The patent uses the scrap steel loading amount calculation model to determine the maximum scrap steel loading amount of the current furnace by obtaining molten iron information, thereby realizing flexible adjustment of the scrap steel loading amount. However, the heat balance in the converter smelting process is affected by a variety of complex and variable factors, and the actual conditions of each furnace are different. Therefore, even with this method of adjusting the scrap steel loading amount based on a static calculation model, the end point temperature hit rate is still low, and even low-temperature pulling and blowing may occur.

[0006] Based on the above problems, the present invention proposes a method for dynamically adjusting the scrap steel charging amount based on a converter mouth flame analysis system. Summary of the invention

[0007] The purpose of the present invention is to address the shortcomings and defects in the prior art and provide a method for dynamically adjusting the scrap steel charging amount based on the converter mouth flame analysis system. Through this method, all surplus heat of the converter can be used for scrap steel smelting to the maximum extent, and the converter can dynamically adjust the scrap steel charging amount, providing strong support for the green development of the steel industry.

[0008] To achieve the above-mentioned purpose, the present invention adopts the following technical scheme: a method for dynamically adjusting the scrap steel charging amount based on the converter mouth flame analysis system, which includes the following process: first adding a slightly less amount of scrap steel than the original smelting mode, then adding molten iron, and then performing gun lowering and blowing, through the converter mouth flame analysis system, real-time monitoring of the converter smelting process temperature, collecting the temperature at the end of the early smelting and the end of the middle smelting and comparing it with the standard temperature at that moment, calculating the amount of scrap steel to be added, and adding it through the high-level silo, maximizing the use of all the surplus heat of the converter for scrap steel smelting, and realizing the dynamic adjustment of the scrap steel charging amount of the converter.

[0009] Furthermore, the high-level silo is specifically: by optimizing the materials in the original high-level silo of the converter, a high-level silo is vacated, and the high-level silo is modified to improve the wear resistance of the silo, wherein the scrap steel silo, like other silos, has anti-blocking and weighing functions, and can accurately control the added weight. The scrap steel prepared in advance can be loaded into the scrap steel silo through the converter feeding system.

[0010] Furthermore, there are two ways to add the scrap steel: one is to add the scrap steel bucket by crane, and there is no special requirement for this part of the scrap steel; the other is to add the scrap steel by converter high-level silo, and this part of the scrap steel is required to be pure steel bar cuttings.

[0011] Furthermore, when the scrap steel is added to the converter high-level silo, in order to prevent the scrap steel from being blocked during the unloading process and to ensure that the scrap steel added during the smelting process can be melted in time, as well as to reduce the adverse effects of scrap steel impurities on the quality of molten steel, the scrap steel used in the converter high-level scrap steel silo is pure steel bar cuttings, and the scrap steel length is ≤10cm and the diameter is ≤4cm.

[0012] Furthermore, when adding the scrap steel from the converter high-level silo, if the addition time is too early, the converter smelting has many influencing factors, which may easily lead to a low hit rate of the terminal temperature. If the addition time is too late, the scrap steel may not be completely melted, and continue to melt and absorb heat during the steel-making process, causing a low-temperature accident. Therefore, the scrap steel is added at the end of the early stage of smelting and the end of the middle stage of smelting, corresponding to smelting 4min (T4 标 ) and smelting 9min(T9 标 ).

[0013] Furthermore, since the requirements for the converter endpoint temperature are different when producing different steel grades, the heating curves when the converter endpoint temperature of different steel grades hits the target are obtained through big data analysis, and 4min (T4 标 ) and 9min (T9 标 ) standard temperature.

[0014] Furthermore, the furnace mouth flame analysis system is used to monitor the converter smelting process temperature in real time and dynamically adjust the amount of scrap steel added. Considering that the flame analysis system monitors the converter smelting process temperature, there is a certain error. Therefore, the amount of scrap steel added is adjusted dynamically twice. At 4 minutes, the temperature deviates from the standard value by more than 20°C, and the scrap steel is added at 9 minutes. The closer to the converter smelting end point, the fewer variable factors affect the converter end point temperature. Therefore, the 9-minute temperature deviation value is narrower, which can better ensure the smelting end point temperature hit rate.

[0015] Furthermore, the calculation of the amount of scrap steel added is as follows: the heat consumption of scrap steel melting includes not only the latent heat of melting, but also the oxidation of chemical elements in the steel will release some heat. However, considering the fluctuation of scrap steel composition and the low proportion of heat released by the oxidation of these elements, when only the latent heat of melting is considered, the empirical formula is used in the first month. For every 10°C increase in converter temperature, the amount of scrap steel added (W 初 ) is set at 2kg / t, but the heat balance of the converter is affected by many factors such as the converter condition and raw material changes. At different periods of the converter service, the amount of scrap steel added varies for every 10°C increase in the furnace temperature. Therefore, by continuously collecting all the production data of the converter for deep self-learning, the amount of scrap steel (W) that needs to be added for every 10°C increase in the converter temperature under the current conditions is obtained. 后 ), from the second month onwards, for every 10°C increase in converter temperature, the amount of scrap steel added (W后 ) is the weight derived from the system’s deep self-learning.

[0016] After adopting the above technical scheme, the beneficial effect of the present invention is: through this method, all surplus heat of the converter can be used for scrap steel smelting to the maximum extent, and the converter can dynamically adjust the scrap steel loading amount, providing strong support for the green development of the steel industry. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0018] Figure 1 It is a structural schematic diagram of the converter high-level silo system of the present invention.

[0019] Figure 2 It is a schematic diagram of a standard heating curve for smelting HRB400E converter in the present invention. DETAILED DESCRIPTION

[0020] The technical solution adopted in this specific implementation mode is: it includes the following process: first add a slightly less amount of scrap steel than the original smelting mode, then add molten iron, and then carry out lance blowing, and monitor the process temperature of the converter smelting in real time through the converter mouth flame analysis system, collect the temperature at the end of the early smelting period and the end of the middle smelting period and compare it with the standard temperature at that moment, calculate the amount of scrap steel that needs to be added, and add it through the high-level silo, so as to maximize the use of all surplus heat of the converter for scrap steel smelting, realize dynamic adjustment of the scrap steel loading amount of the converter, and provide strong support for the green development of the steel industry.

[0021] See also Figure 1 As shown, the high-level silo is specifically: by optimizing the materials in the original high-level silo of the converter, a high-level silo is vacated, and the high-level silo is modified to improve the wear resistance of the silo. Among them, the scrap steel silo, like other silos, has anti-blocking and weighing functions, and can accurately control the added weight. The scrap steel prepared in advance can be loaded into the scrap steel silo through the converter feeding system.

[0022] More specifically, the scrap steel is added in two ways:

[0023] One is to use a crane to transport the scrap steel bucket into the machine. There is no special requirement for this part of scrap steel.

[0024] The second is to use the high-level silo of the converter to add scrap steel. This part of scrap steel is not only required to be pure steel bar cutting heads (in order to prevent scrap steel from clogging during the unloading process and to ensure that the scrap steel added during the smelting process can be melted in time, as well as to reduce the adverse effects of scrap steel impurities on the quality of molten steel, the scrap steel used in the high-level scrap steel silo of the converter is pure steel bar cutting heads, and the scrap steel length is ≤10cm, and the diameter is ≤4cm), but also has requirements for the timing of adding (if the timing of adding is too early, due to the many factors affecting the converter smelting, it is easy to cause a low hit rate of the terminal temperature. If the timing of adding is too late, the scrap steel may not be completely melted, and continue to melt and absorb heat during the steelmaking process, causing a low-temperature accident. Therefore, the timing of adding scrap steel is at the end of the early stage of smelting and the end of the middle stage of smelting, corresponding to 100t converter smelting 4min (T4 标 ) and smelting 9min(T9 标 )).

[0025] More specifically, since the requirements for the converter endpoint temperature are different when producing different steel grades, the temperature rise curves when the converter endpoint temperature of different steel grades hits the target are obtained through big data analysis, and 4min (T4 标 ) and 9min (T9 标 ) standard temperature, taking HRB400E as an example, the standard heating curve can be found in Figure 2 As shown, its T4 标 =1400℃、T9 标 =1500℃, set T4 for each steel grade 标 and T9 标 .

[0026] More specific explanation. Through the furnace mouth flame analysis system, the temperature of the converter smelting process is monitored in real time, and the amount of scrap steel added is adjusted dynamically. Considering that the flame analysis system monitors the temperature of the converter smelting process, there is a certain error. Therefore, the amount of scrap steel added is adjusted dynamically twice. At 4 minutes, the temperature deviates from the standard value by more than 20°C, and the scrap steel is added; at 9 minutes, the temperature deviates from the standard value by more than 10°C, and the scrap steel is added. The closer to the end point of converter smelting, the fewer variable factors affect the end point temperature of the converter. Therefore, the temperature deviation value of 9 minutes is narrower, which can better ensure the hit rate of the smelting end point temperature.

[0027] More specifically, the calculation of the amount of scrap steel added is as follows:

[0028] The heat consumed in melting scrap steel includes not only the latent heat of melting, but also the oxidation of chemical elements in the steel will release some heat. However, considering the fluctuation of scrap steel composition and the low proportion of heat released by the oxidation of these elements,

[0029] When considering only the latent heat of melting, the empirical formula is used in the first month. For every 10℃ increase in converter temperature, the amount of scrap steel added (W 初) is set at 2kg / t, but the heat balance of the converter is affected by many factors such as the converter condition and raw material changes. At different periods of the converter service, the amount of scrap steel added varies for every 10°C increase in the furnace temperature. Therefore, by continuously collecting all the production data of the converter for deep self-learning, the amount of scrap steel (W) that needs to be added for every 10°C increase in the converter temperature under the current conditions is obtained. 后 ), from the second month onwards, for every 10°C increase in converter temperature, the amount of scrap steel added (W 后 ) is the weight derived from the system’s deep self-learning.

[0030] The system automatically collects the type of steel being smelted and other smelting data. According to the requirements in the following table, the system automatically adds the corresponding amount of scrap steel at 4 minutes and 9 minutes based on the comparison between the process temperature and the standard temperature:

[0031]

[0032] The following are relevant embodiments of the present invention:

[0033] Example 1: 100-ton converter, furnace number 247L0001, smelting steel grade HRB400E, tapping temperature requirement 1620℃~1630℃. W initial = 2kg / t, scrap steel loading 22t, molten iron loading 85t, molten iron temperature 1340℃, Si content 0.37%, then smelting directly under the gun, 4min, converter mouth flame analysis system monitors converter real-time temperature 1435℃, 35℃ higher than the standard temperature when smelting 4min, the system is 2W initial, i.e. 4kg / t, and adds 400kg scrap steel after weighing through the high-level silo. 9min, converter mouth flame analysis system monitors converter real-time temperature 1513℃, 13℃ higher than the standard temperature when smelting 9min, the system is 2W initial, i.e. 2kg / t, and adds 200kg scrap steel after weighing through the high-level silo, the converter terminal temperature is 1621℃, hitting the tapping requirement.

[0034] Example 2: 100-ton converter, furnace number 248L0019, smelting steel type 40CrMo, tapping temperature requirement 1590℃~1600℃. After self-learning in July, the system W = 1.88kg / t, scrap steel loading 22t, molten iron loading 85t, molten iron temperature 1298℃, Si content 0.24%, and then directly smelting. At 4 minutes, the converter mouth flame analysis system monitors the converter real-time temperature of 1414℃, which is 8℃ higher than the standard temperature when smelting for 4 minutes, and there is no need to add scrap steel through the high-level silo. At 9 minutes, the converter mouth flame analysis system monitors the converter real-time temperature of 1500℃, which is 15℃ higher than the standard temperature when smelting for 9 minutes. The system is based on W, which is 1.88kg / t. After weighing through the high-level silo, 188kg of scrap steel is added. The converter terminal temperature is 1598℃, hitting the tapping requirements.

[0035] Example 3: 100-ton converter, furnace number 249L0032, smelting steel type 35MnBH, tapping temperature requirement 1600℃~1610℃. After two months of self-learning in July and August, the system W = 1.93kg / t, scrap steel loading 22t, molten iron loading 85t, molten iron temperature 1312℃, Si content 0.30%, and then directly smelting. At 4 minutes, the converter mouth flame analysis system monitors the converter real-time temperature of 1423℃, which is 28℃ higher than the standard temperature when smelting for 4 minutes. The system is based on W, that is, 1.93kg / t, and 193kg of scrap steel is added after weighing through the high-level silo. At 9 minutes, the converter mouth flame analysis system monitors the converter real-time temperature of 1507℃, which is 6℃ higher than the standard temperature when smelting for 9 minutes. There is no need to add scrap steel through the high-level silo. The converter terminal temperature is 1605℃, which meets the tapping requirements.

[0036] The above examples are all based on the converter mouth flame analysis system. During the smelting process, scrap steel is added through the high-level silo to adjust the converter process temperature so that the converter terminal temperature meets the steelmaking temperature requirement. All the excess heat of the converter is used for scrap steel smelting, enabling the converter to dynamically adjust the scrap steel loading amount, providing strong support for the green development of the steel industry.

[0037] The above description is only used to illustrate the technical solution of the present invention rather than to limit it. Other modifications or equivalent substitutions made to the technical solution of the present invention by ordinary technicians in this field should be included in the scope of the claims of the present invention as long as they do not depart from the spirit and scope of the technical solution of the present invention.

Claims

1. A method for dynamically adjusting the amount of scrap steel charged based on a converter mouth flame analysis system, characterized in that: It includes the following processes: first add a slightly less amount of scrap steel than the original smelting mode, then add molten iron, and then perform lance lowering and blowing. Through the converter mouth flame analysis system, the temperature of the converter smelting process is monitored in real time. The temperatures at the end of the early smelting period and the end of the middle smelting period are collected and compared with the standard temperature at that moment. The amount of scrap steel that needs to be added is calculated and added through the high-level silo, so as to maximize the use of all surplus heat in the converter for scrap steel smelting and realize dynamic adjustment of the scrap steel loading amount in the converter.

2. The method for dynamically adjusting the scrap steel loading amount based on the converter mouth flame analysis system according to claim 1, characterized in that: The high-level silo is specifically: By optimizing the materials in the original high-level silo of the converter, a high-level silo was left vacant and the high-level silo was modified to improve the wear resistance of the silo. The scrap steel silo, like other silos, has anti-blocking and weighing functions, and can accurately control the added weight. The scrap steel prepared in advance can be loaded into the scrap steel silo through the converter feeding system.

3. The method for dynamically adjusting the scrap steel loading amount based on the converter mouth flame analysis system according to claim 1, characterized in that: There are two ways to add scrap steel: One is to use a crane to transport the scrap steel bucket into the machine. There is no special requirement for this part of scrap steel. The second method is to use the high-level silo of the converter to add this part of scrap steel, which is required to be pure steel bar cuttings.

4. The method for dynamically adjusting the scrap steel loading amount based on the converter mouth flame analysis system according to claim 3 is characterized in that: When adding the scrap steel using the converter high-level silo, in order to prevent the scrap steel from being blocked during the unloading process and to ensure that the scrap steel added during the smelting process can be melted in time, as well as to reduce the adverse effects of scrap steel impurities on the quality of molten steel, the scrap steel used in the converter high-level scrap steel silo is pure steel bar cuttings, and the scrap steel length is ≤10cm and the diameter is ≤4cm.

5. The method for dynamically adjusting the scrap steel loading amount based on the converter mouth flame analysis system according to claim 3 is characterized in that: When adding the scrap steel from the converter high-level silo, if the addition time is too early, the converter smelting has many influencing factors, which may easily lead to a low hit rate of the terminal temperature. If the addition time is too late, the scrap steel may not be completely melted, and continue to melt and absorb heat during the steel-making process, causing a low-temperature accident. Therefore, the scrap steel is added at the end of the early stage of smelting and the end of the middle stage of smelting, corresponding to 100t converter smelting 4min (T4 标 ) and smelting 9min(T9 标 ).

6. The method for dynamically adjusting the scrap steel loading amount based on the converter mouth flame analysis system according to claim 1, characterized in that: Because the requirements for the converter endpoint temperature are different when producing different steel grades, the temperature rise curves when the converter endpoint temperature of different steel grades hits the target are obtained through big data analysis, and 4min (T4 标 ) and 9min (T9 标 ) standard temperature.

7. The method for dynamically adjusting the scrap steel charging amount based on the converter mouth flame analysis system according to claim 1, characterized in that: Through the flame analysis system at the furnace mouth, the temperature of the converter smelting process is monitored in real time, and the amount of scrap steel added is adjusted dynamically. Considering that the flame analysis system monitors the temperature of the converter smelting process, there is a certain error. Therefore, the amount of scrap steel added is adjusted dynamically twice. At 4 minutes, the temperature deviates from the standard value by more than 20°C, and the scrap steel is added; at 9 minutes, the temperature deviates from the standard value by more than 10°C. The closer to the end point of converter smelting, the fewer variable factors affect the end point temperature of the converter. Therefore, the temperature deviation value of 9 minutes is narrower, which can better ensure the hit rate of the smelting end point temperature.

8. The method for dynamically adjusting the scrap steel charging amount based on the converter mouth flame analysis system according to claim 1, characterized in that: The calculation of the amount of scrap steel added is specifically as follows: The heat consumed in melting scrap steel includes not only the latent heat of melting, but also the oxidation of chemical elements in the steel will release some heat. However, considering the fluctuation of scrap steel composition and the low proportion of heat released by the oxidation of these elements, When considering only the latent heat of melting, the empirical formula is used in the first month. For every 10℃ increase in converter temperature, the amount of scrap steel added (W 初 ) is set at 2kg / t, but the heat balance of the converter is affected by many factors such as the converter condition and raw material changes. At different periods of the converter service, the amount of scrap steel added varies for every 10°C increase in the furnace temperature. Therefore, by continuously collecting all the production data of the converter for deep self-learning, the amount of scrap steel (W) that needs to be added for every 10°C increase in the converter temperature under the current conditions is obtained. 后 ), from the second month onwards, for every 10°C increase in converter temperature, the amount of scrap steel added (W 后 ) is the weight derived from the system’s deep self-learning.

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