Converter temperature real-time measuring device and converter smelting control method thereof

Abstract

The converter temperature real-time measuring device comprises a thermocouple, a thermocouple in-out driving part and a data collecting and processing system, the thermocouple is connected with the data collecting and processing system through a data transmission cable, and a protective shell is fixed outside the data transmission cable. The thermocouple in-out driving part comprises an upper limiting roller, a lower limiting roller, a gear and a rack, the upper limiting roller and the lower limiting roller are oppositely arranged on a mounting plate at an interval up and down, the mounting plate is fixed on the base through a supporting column, and the protective shell penetrates through the interval between the upper limiting roller and the lower limiting roller; the upper limiting rollers and the lower limiting rollers are arranged left and right at intervals, the rack is fixed to the bottom of the protective shell and located between the left lower limiting roller and the right lower limiting roller, the gear is meshed with the rack, and the center of the gear is connected with an output shaft of a motor fixed to the mounting plate. According to the measuring device, the temperature in the converter can be detected in real time, the influence of smoke pollution, molten steel splashing and thermal shock on measurement can be greatly reduced, and measured data are more accurate.

Description

Technical Field

[0001] This invention relates to the field of temperature detection and smelting technology, and particularly to a device for measuring the internal temperature of a converter and a method for controlling converter smelting thereby. Background Technology

[0002] In converter steelmaking, accurate measurement of molten steel temperature is crucial for controlling endpoint hit rate, ensuring product quality, and optimizing energy consumption. Currently, various technical solutions have been proposed for measuring molten steel temperature in converters, mainly categorized into direct contact temperature measurement and indirect non-contact temperature measurement. While the sublance technology, a typical example of contact temperature measurement, has played a key role in achieving automated steelmaking, it can only measure the carbon content and temperature (TSC) of molten steel at the end of the blowing process (when oxygen supply reaches approximately 85% of the total oxygen content), and the oxygen level and temperature (TSO) at the end of the blowing process. It cannot achieve continuous monitoring of molten steel temperature throughout the entire process. Therefore, current methods for measuring molten steel temperature in converters focus on indirect non-contact temperature measurement.

[0003] For example, patent document CN202510765930.4, entitled "A Method for Continuous Temperature Measurement in a Converter," discloses a scheme that combines the advantages of non-contact and contact temperature measurement. This scheme places the thermocouple on a thermocouple holder brick, preventing direct contact with molten steel during temperature measurement to avoid damage from erosion. It uses temperature measurement and calculation programs to calibrate heat flux density and temperature, achieving continuous temperature measurement and improving device lifespan and measurement accuracy. However, this method uses a fixed temperature measuring device, whose measurement position and response characteristics may be limited by complex furnace conditions (such as splashing and slag coverage). Furthermore, it primarily focuses on avoiding direct erosion by molten steel and does not address the mechanical operation and protection issues of the temperature measuring element (such as the thermocouple) actively and safely entering and exiting the measurement point in harsh flue gas environments.

[0004] Patent document CN201410226284.6, entitled "A Steel Temperature Measurement System and Method," proposes an indirect temperature measurement scheme. It collects flue gas temperature using a temperature acquisition device (such as a thermocouple) installed on the inner wall of the flue, and then establishes a correspondence between the flue gas temperature and the molten steel temperature through data processing. This method achieves non-contact measurement, avoiding direct contact between the temperature sensing element and the molten steel. However, the temperature measurement point is located inside the flue, far from the molten steel surface, resulting in significant signal lag. Furthermore, the complex and variable environmental factors within the flue, such as flue gas composition, flow rate, and dust concentration, significantly interfere with the accuracy and stability of the temperature measurement. More importantly, this method does not address how to deploy and operate the temperature sensing element in high-temperature, high-dust areas such as near the molten steel outlet, and particularly lacks a mechanism that allows the temperature sensing element to reliably extend to the measurement point and be safely retracted.

[0005] Furthermore, patent document CN202310186102.6, entitled "A Wireless Continuous Temperature Measurement System and a Method for Predicting Molten Steel Temperature in a Molten Steel Ladle," is mainly applied to processes such as molten steel ladle refining. It involves directly or indirectly measuring temperature by installing temperature sensors on the side wall of the molten steel ladle and predicting the temperature via wireless transmission. This method focuses on the construction of a process temperature drop model and data transmission. Its temperature measurement location and installation method are designed for the relatively static molten steel ladle and are not suitable for scenarios requiring frequent and rapid intervention inside the high-temperature, highly disturbed converter furnace (especially near the tapping spout) for measurement.

[0006] Another approach, such as "A Temperature Sampling Method Based on the Taphole of a Small Converter" (patent number CN202410527935.9), proposes a method for sending a temperature sampling unit into the molten pool inside the furnace for contact temperature measurement through the taphole. It also proposes a dedicated rotation and removal mechanism. However, its core objective remains to solve the problem of rapid temperature sampling in small converters without the need for furnace tilting. This method addresses how to overcome the adhesion, shielding, and corrosion effects of high-concentration dust in the molten steel area for temperature sensing elements (such as thermocouples) under continuous tapping or flue gas emission conditions, and how to design a matching clamping and control mechanism to ensure accurate thermocouple positioning, stable measurement, and safe withdrawal. However, it does not provide specific and optimized technical means.

[0007] In summary, the existing technology has the following shortcomings: 1) Fixed installation or remote indirect temperature measurement methods are difficult to reflect the real temperature of molten steel near the converter tapping port in real time and accurately, and are greatly affected by interference factors such as smoke and dust and splashing. 2) Existing portable temperature measurement solutions lack a complete clamping and control mechanism design specifically addressing the high-temperature, high-dust environment near the converter taphole. This mechanism must protect the temperature sensing elements (especially high-temperature thermocouples) from smoke and dust contamination and thermal shock, and ensure their accurate and safe insertion and retraction. Therefore, the industry urgently needs to develop a thermocouple temperature measurement system that can effectively eliminate smoke interference and has reliable clamping and motion control. This system would safely and accurately measure the flue gas temperature near the converter taphole, reliably converting it to the molten steel temperature, thereby achieving precise control of the converter smelting process. Summary of the Invention

[0008] The technical problem to be solved by the present invention is to overcome the defects of the prior art and provide a converter temperature real-time measurement device and a method for controlling converter smelting. It can detect the temperature inside the converter in real time, which can greatly reduce the impact of smoke pollution, molten steel splashing and thermal shock on the measurement, and the measurement data is more accurate. At the same time, the present invention also provides a control method for using the temperature measuring device in converter smelting.

[0009] The technical solution adopted by this invention to solve its technical problem is: A converter temperature real-time measurement device includes a thermocouple, a thermocouple inlet / outlet drive, and a data collection and processing system. The thermocouple is connected to the data collection and processing system via a data transmission cable. The thermocouple and the data transmission cable are installed and fixed inside a protective housing. The end of the protective housing is provided with a cover plate to close the steel outlet. The thermocouple inlet / outlet drive includes an upper limit roller, a lower limit roller, a gear, and a rack. The upper and lower limit rollers are arranged opposite each other at an interval on a mounting plate. The mounting plate is fixed to a base by a support column. Two sets of upper and lower limit rollers are arranged at an interval. The protective housing moves within the interval between the upper and lower limit rollers. The rack is fixed to the bottom of the protective housing. The gear meshes with the rack to form a transmission pair. The gear is driven by a motor, which is fixed to the mounting plate.

[0010] The aforementioned converter temperature real-time measurement device further includes a nitrogen purging mechanism. This mechanism comprises a first equalizing chamber, a second equalizing chamber, long blowpipes, short blowpipes, a gas pump, and a nitrogen storage tank. The first equalizing chamber, the second equalizing chamber, and the cover plate are all annular and integrated. The sidewall of the first equalizing chamber is fixed to the end of the protective shell. An air inlet is provided on the sidewall of the second equalizing chamber, connecting the first and second equalizing chambers. The pressure difference between the two chambers is adjusted by the diameter and number of the air inlet holes. A ring of long blowpipes is arranged on the cover plate, with evenly spaced intervals. A ring of short blowpipes is arranged inside the long blowpipes, with evenly spaced intervals along the circumference. The long blowpipes connect to the first equalizing chamber, and the short blowpipes connect to the second equalizing chamber. The first equalizing chamber is connected sequentially to the gas pump, a pneumatic ball valve, and the nitrogen storage tank via an air inlet. The thermocouple passes sequentially through the cover plate, the second equalizing chamber, and the first equalizing chamber, and is housed within the protective shell.

[0011] In the aforementioned real-time converter temperature measurement device, a dustproof ring is also provided on the outside of the thermocouple. One end of the dustproof ring is fixed to the cover plate and located in the inner ring of the short blowpipe. The dustproof ring has evenly distributed through holes with an inner diameter of 3-12mm. The dustproof ring further prevents furnace dust from covering the thermocouple surface, while the through holes ensure the accuracy of the temperature measurement.

[0012] In the aforementioned converter temperature real-time measurement device, the thermocouple and the data transmission cable are connected via an aviation plug, which facilitates disassembly and replacement and ensures accurate transmission of temperature data at high temperatures.

[0013] A method for controlling converter smelting using the above-mentioned measuring device is carried out according to the following steps: Step a: Before the converter blowing process, use the gear and rack assembly to insert the movable thermocouple, long blowing pipe and short blowing pipe into the converter's taphole, and seal the taphole with the cover plate. Step b: Start the gas pump. Nitrogen gas passes through the first and second equalization chambers continuously and is then blown out of the steel outlet by the long and short blow pipes to prevent slag from sticking to the thermocouple. Step c: During the blowing process, the temperature of the furnace gas inside the converter is continuously monitored in real time by thermocouples, and the measured temperature data is transmitted to the temperature data collection and processing system. Step d: The temperature data collection and processing system converts the furnace gas temperature into the molten steel temperature according to the following calculation model: GT = QT - Compensation Temperature Compensation temperature = 21.392 × S × (9 - Wco / Wco2) + 2.316 Wherein: GT—Temperature of molten steel; QT—Furnace gas temperature; S—Sound intensity index measured by the sonar slag removal system; Wco—The percentage of CO by mass as measured by the flue gas analysis system; W co2 — CO2 mass percentage measured by the flue gas analysis system; Step e: The temperature data collection and processing system and the converter PLC control system realize data exchange. The converter PLC control system transmits sonar slag treatment and flue gas analysis system data to the temperature data collection and processing system, and the temperature data collection and processing system transmits molten steel temperature data to the converter PLC control system, so that the converter PLC control system can optimize the blowing control such as oxygen lance position and charging in a timely manner. In step f, when tapping steel and tilting slag in the converter, first use the gear and rack assembly to move the thermocouple out of the tapping port to avoid interfering with the tapping and slag tilting operations.

[0014] In the method of controlling converter smelting with the above-mentioned measuring device, in step a, a thermocouple is inserted into the tap hole before the converter is blown, and the front end of the thermocouple is flush with the inner wall of the furnace lining.

[0015] In the method of controlling converter smelting with the above-mentioned measuring device, in step b, the pressure of nitrogen purging at the steel outlet is 3.0-5.0 kg.

[0016] The beneficial effects of this invention are: This invention incorporates a nitrogen purging mechanism. Before nitrogen is purged into the converter, it passes through a first and a second pressure equalization chamber for pressure equalization, resulting in a more stable nitrogen purging pressure. This ensures that the nitrogen purging pressure is evenly dispersed, preventing dust from adhering to the thermocouple surface, thus improving temperature measurement accuracy and reducing heat loss. The thermocouple is also surrounded by an inner ring of short blowpipes and an outer ring of long blowpipes, providing a wider purging range.

[0017] The protective shell installed on the outside of the data transmission cable uses upper and lower limit rollers to limit the movement, and the gear and rack assembly drives the cable to move steadily left and right, so as to realize the thermocouple entering and exiting the steel outlet with precise and reliable operation.

[0018] This invention can monitor the temperature of molten steel in the converter online in real time, and optimize the oxygen lance position, charging and blowing control in a timely manner, thereby obtaining high-quality molten steel, low energy consumption and high production efficiency. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the measuring device structure of the present invention; Figure 2 This is a schematic diagram of a partial structure of the temperature measurement purge end; Figure 3 Schematic diagram of the side structure of the temperature measurement and purging end.

[0020] In the diagram: 1. Thermocouple; 2. Data collection and processing system; 3. Data transmission cable; 4. Protective housing; 5. Upper limit roller; 6. Lower limit roller; 7. Gear; 8. Rack; 9. Mounting plate; 10. Support column; 11. Base; 12. First equalizing chamber; 13. Second equalizing chamber; 14. Long blowpipe; 15. Short blowpipe; 16. Air pump; 17. Nitrogen storage tank; 18. Cover plate; 19. Air inlet; 20. Pneumatic ball valve; 21. Air inlet; 22. Dustproof ring; 23. Aviation connector; 24. Steel tap; 25. Converter; 26. Converter PLC control system. Detailed Implementation

[0021] This invention addresses the technical challenges in measuring the temperature of molten steel inside a converter by proposing a non-contact device for detecting the temperature inside the converter. This device measures the temperature of the furnace gas inside the converter and then converts it into the temperature of the molten steel, thereby enabling control of the converter smelting process.

[0022] See Figures 1 to 3The converter temperature measuring device includes a thermocouple 1, a data transmission cable 3, a thermocouple entry / exit drive unit, a data collection and processing system 2, and a nitrogen purging mechanism. The thermocouple 1 is electrically connected to the data collection and processing system 2 through the data transmission cable 3. The thermocouple enters the converter 25 through the tapping port 24 and transmits the measured converter temperature data to the data collection and processing system through the data transmission cable. The data collection and processing system converts the furnace gas temperature into the temperature of the molten steel inside the furnace through a calculation model. The thermocouple and data transmission cable are installed inside the protective housing 4. A cover plate 18 is fixed to the end of the protective housing located at one end of the thermocouple. The thermocouple entry and exit drive part includes an upper limit roller 5, a lower limit roller 6, a gear 7, and a rack 8. The upper limit roller 5 and the lower limit roller 6 are arranged opposite each other on the mounting plate 9 through their respective rotating shafts. The mounting plate 9 is fixed to the base 11 by a support column 10. The protective housing 4 passes through the gap between the upper limit roller and the lower limit roller. The upper limit roller 5 and the lower limit roller 6 are each arranged in two sets at left and right intervals. The protective housing can move left and right along the upper and lower limit rollers. The rack 8 is fixed to the bottom of the protective housing 4 and is located between the two sets of lower limit rollers. The gear 7 meshes with the rack 8. The center of the gear 7 is connected to the output shaft of the motor (the motor is fixed on the mounting plate and is not shown) fixed on the mounting plate. The movement of the thermocouple entering and exiting the tapping spout is achieved through a gear and rack assembly. The rotation of the gears drives the thermocouple to move left and right. The length of the rack is set so that when the thermocouple enters the tapping spout to the left, its end is flush with the inner wall of the converter lining and then stops. When the protective shell 4 moves left and right, both the upper limit roller and the lower limit roller can rotate along their respective axes. This not only limits the upper and lower positions of the protective shell but also reduces friction during left and right transmission, ensuring smooth movement of the data transmission cable and the thermocouple.

[0023] After the thermocouple enters the converter, the nitrogen purging mechanism is activated simultaneously to purge the dust around the thermocouple in real time. The nitrogen purging mechanism includes a first equalizing chamber 12, a second equalizing chamber 13, a long blowpipe 14, a short blowpipe 15, a gas pump 16, and a nitrogen storage tank 17. One end of the outer wall of the first equalizing chamber 12 is fixedly connected to one end of the protective shell 4, and the other end of the first equalizing chamber 12 is fixedly connected to the cover plate 18. The side wall of the second equalizing chamber 13 is fixed on the cover plate 18 and located inside the first equalizing chamber 12. The thermocouple 1 passes through the first equalizing chamber, the second equalizing chamber and the cover plate in sequence. An air inlet 19 is provided on the side wall of the second equalizing chamber 13. Several long blowpipes 14 are provided and are fixedly fixed on the left side of the cover plate 18 at even intervals around the circumference, communicating with the first equalizing chamber. Several short blowpipes 15 are provided and are fixedly fixed on the outside of the cover plate 18 at even intervals around the circumference, located in the inner circle of the long blowpipes 14 and communicating with the second equalizing chamber. The air pump 16 is connected to the nitrogen storage tank 17 through a pipe. A pneumatic ball valve 20 is provided on the pipe. The air outlet of the air pump is connected to the air inlet 21 on the first equalizing chamber through a pipe. During nitrogen purging, the shell moves to the left, bringing the thermocouples, long blowpipe, and short blowpipe into the converter. The cover plate contacts the outer wall of the converter, sealing the taphole. The free end of the thermocouple is flush with the inner wall of the converter lining. The starting ball valve opens, the air pump starts, and nitrogen is continuously blown into the converter to prevent dust from adhering to the surface of the high-temperature thermocouples and affecting the accuracy of temperature measurement.

[0024] Before entering the converter, nitrogen gas passes through the first and second equalization chambers to ensure a smoother flow into the converter, preventing violent disturbances that could affect measurements. The equalization chambers smooth out the purging pressure between the long and short blowpipes, ensuring each pipe blows at the same pressure, preventing pressure imbalances due to distance from the inlet 21, and avoiding turbulence that could affect the purging effect. Furthermore, the use of long and short blowpipes, with the short blowpipes having a lower purging pressure than the long blowpipes, allows for the use of a lower purging pressure within the clean "channel" created by the long blowpipes to further disperse any weaker turbulence within that channel. This reduces disorder in the flow field and lessens the interference of turbulence on temperature measurement, resulting in more accurate temperature data.

[0025] A dustproof ring 22 is also provided on the outside of the thermocouple 1. One end of the dustproof ring 22 is fixed to the cover plate 18 and is located in the inner ring of the short blow pipe 15. The dustproof ring 22 has through holes evenly distributed on it. The function of the dustproof ring is to protect the thermocouple from contamination by smoke and slag. The purpose of the evenly distributed through holes is to prevent the dustproof ring from affecting the temperature measurement data.

[0026] The method for controlling converter smelting using the measuring device of the present invention is as follows: Step a: Before the converter blowing process, use the gear and rack assembly to insert the movable thermocouple, long blowing pipe and short blowing pipe into the converter's taphole, and seal the taphole with the cover plate. Step b: Start the gas pump. Nitrogen gas passes through the first and second equalization chambers continuously and is then blown out of the steel outlet by the long and short blow pipes to prevent slag from sticking to the thermocouple. Step c: During the blowing process, the temperature of the furnace gas inside the converter is continuously monitored in real time by thermocouples, and the measured temperature data is transmitted to the temperature data collection and processing system. Step d: The temperature data collection and processing system converts the furnace gas temperature into the molten steel temperature according to the following calculation model: GT = QT - Compensation Temperature Compensation temperature = 21.392 × S × (9 - W) CO / W CO2 +2.316 Wherein: GT—Temperature of molten steel; QT—Furnace gas temperature; S—Sound intensity index measured by the sonar slag removal system; W CO —The percentage of CO by mass as measured by the flue gas analysis system; W co2 — CO2 mass percentage measured by the flue gas analysis system; Step e: The temperature data collection and processing system and the converter PLC control system 26 realize data exchange. The converter PLC control system transmits sonar slag treatment and flue gas analysis system data to the temperature data collection and processing system, and the temperature data collection and processing system transmits molten steel temperature data to the converter PLC control system, so that the converter PLC control system can optimize the blowing control such as oxygen lance position and charging in a timely manner. In step f, when tapping steel and tilting slag in the converter, first use the gear and rack assembly to move the thermocouple out of the tapping port to avoid interfering with the tapping and slag tilting operations.

[0027] The temperature data collection and processing system is the process control level in the converter steelmaking automation control system. It uses mathematical models to perform process calculations, determine the optimal smelting process parameters, and provide operators with operational guidance and process monitoring.

[0028] The converter PLC control system can be one of the following: Siemens S7-1500R / H (redundant) series, Rockwell ControlLogix redundant series, or Schneider Quantum / M580 redundant series.

[0029] Sonar slag removal systems can be Siemens / VAI brands, such as the "LD-CB" sound control system, which outputs slag removal status curves or splash warning signals.

[0030] Refining process: 1) Initial blowing stage (start of blowing ~ approximately 1450℃): This stage mainly involves the intense oxidation of silicon (Si) and manganese (Mn), generating acidic slag (SiO2, MnO), while some iron (Fe) is also oxidized. Oxygen lance operation: A relatively high lance position is used, primarily employing "soft blowing." After the start of blowing, the first batch of slag-forming materials is quickly added, mainly lime (CaO) and lightly calcined dolomite (MgO·CaO). Inert gas is introduced throughout the process to stir the molten pool, homogenizing the composition and temperature, and enhancing the slag-metal reaction.

[0031] 2) Mid-stage of blowing (approximately 1450℃ ~ approximately 1550℃): The main task at this stage is to control the balance between the decarburization rate and the heating rate. Carbon begins to oxidize rapidly ("decarburization period"). "Hard blowing" is performed by lowering the oxygen lance position, and the oxygen stream directly impacts the molten pool, accelerating the decarburization reaction. Depending on the flame and furnace conditions, a second and third batch of lime and a small amount of ore or sinter are added in batches as coolant and oxidant, supplementing (FeO) to maintain slag foaming and reactivity.

[0032] 3) End-stage and endpoint control of blowing (approximately 1550℃ ~ target tapping temperature). The main task at this stage is to accurately hit the endpoint carbon content and temperature, and ensure that phosphorus and sulfur meet the standards. In the last few minutes of blowing, the real-time temperature and carbon content of the molten pool are measured using a secondary lance. Based on the measured temperature and carbon content, the model accurately calculates the amount of supplemental oxygen required to reach the target endpoint, and whether it is necessary to add a final fine-tuning coolant (such as a small amount of ore) or a heating agent (such as aluminum blocks or ferrosilicon). The lance is automatically raised and blowing stops according to the model's instructions, achieving "double hit" (simultaneously hitting the carbon temperature and carbon content).

[0033] The present invention will be further described below with reference to the embodiments. Example 1

[0034] The steel grade smelted in a certain heat of the converter is ultra-low carbon steel SPHETi-5. Before the converter blowing process, a movable high-temperature thermocouple, a long blowing pipe, and a short blowing pipe are inserted into the tap hole. The front end of the high-temperature thermocouple is flush with the inner wall of the furnace lining, and the cover plate on the shell is used to seal the tap hole. During the blowing process, the temperature of the furnace gas in the converter is continuously monitored in real time by the high-temperature thermocouple, and the measured temperature data is transmitted to the temperature data collection and processing system.

[0035] In the early stage of smelting, the thermocouple measured the furnace gas temperature at 1476℃. The flue gas analysis system measured the CO mass percentage in the furnace gas to be 31.39% and the CO2 mass percentage to be 29.94%. The sonar slag intensity index measured was 40%. The system calculated the compensation temperature using a model: 21.392 × 40% × (9 - 31.39% / 29.94%) + 2.316 = 70.36℃, and calculated the molten steel temperature as 1476 - 70.36 = 1405.64℃. The temperature data collection and processing system sent this temperature data to the converter PLC control system. It was found that the temperature control in the early stage of ultra-low carbon steel smelting was too high, which affected the dephosphorization efficiency. The converter PLC control system adjusted the blowing control in time, added an appropriate amount of coolant, and reasonably controlled the lance position to ensure that the C, temperature, and phosphorus content at the end of smelting were accurate. The final smelting temperature was measured at 1672℃ using a secondary lance, while the temperature measured by the device and method of this invention was 1669.22℃, with a deviation of 2.78℃. This demonstrates that the device and method of this invention can achieve continuous and accurate measurement of the molten steel temperature during converter smelting.

[0036] The entire blowing process utilizes nitrogen to purge the taphole, with a real-time nitrogen pressure of 3 kg to prevent slag from sticking to the thermocouples. This allows the thermocouples to be easily removed from the taphole during the tapping and slag removal stages, avoiding interference with the tapping and slag removal operations. Example 2

[0037] In a certain heat of the converter, the steel grade being smelted is low-carbon steel SPHC12. Before the converter blowing process, a movable high-temperature thermocouple, a long blowing pipe, and a short blowing pipe are inserted into the tap hole. The front end of the high-temperature thermocouple is flush with the inner wall of the furnace lining, and the cover plate on the shell is used to seal the tap hole. During the blowing process, the temperature of the furnace gas inside the converter is continuously monitored in real time by the high-temperature thermocouple, and the measured temperature data is transmitted to the temperature data collection and processing system.

[0038] During the mid-smelting process, the thermocouple measured the furnace gas temperature at 1481℃. The flue gas analysis system measured the CO mass percentage in the furnace gas to be 73.23% and the CO2 mass percentage to be 12.31%. The sonar slag intensity index measured was 20%. The system calculated the compensation temperature using a model: 21.392 × 20% × (9 - 73.23% / 12.31%) + 2.316 = 15.37℃. It also calculated the molten steel temperature as 1481 - 15.37 = 1465.63℃. The temperature data collection and processing system sent this temperature data to the converter PLC control system. This revealed that the temperature control during the mid-smelting of low-carbon steel in this furnace was too low. The converter PLC control system promptly adjusted the blowing control, appropriately lowered the oxygen lance position, and reduced the addition of cold materials, ensuring accurate reaching of the smelting endpoint. The final smelting temperature was measured at 1643℃ using a secondary lance. The temperature measured by the device and method of this invention was 1644.95℃, with a deviation of 1.95℃. This demonstrates that the device and method of this invention can achieve continuous and accurate measurement of the temperature of molten steel during converter smelting.

[0039] Nitrogen gas is used to purge the taphole throughout the smelting process, with a real-time nitrogen pressure of 5 kg to prevent slag from sticking to the thermocouples. The thermocouples are then smoothly removed from the taphole during the tapping and slag removal stages, avoiding interference with the tapping and slag removal operations. Example 3

[0040] The steel grade smelted in a certain heat of the converter is medium carbon steel SS400. Before the converter blowing, a movable high-temperature thermocouple and long and short blowing pipes are inserted into the tap hole. The front end of the high-temperature thermocouple is flush with the inner wall of the furnace lining, and the cover plate on the shell is used to seal the tap hole. During the blowing process, the temperature of the furnace gas in the converter is continuously monitored in real time by the high-temperature thermocouple, and the measured temperature data is transmitted to the temperature data collection and processing system.

[0041] During the mid-smelting process, the thermocouple measured the furnace gas temperature at 1517℃. The flue gas analysis system measured the CO mass percentage in the furnace gas to be 65.02% and the CO2 mass percentage to be 14.39%. The sonar slag intensity index measured was 15%. The system calculated the compensation temperature using a model: 21.392 × 15% × (9 - 65.02% / 14.39%) + 2.316 = 16.69℃. It also calculated the molten steel temperature as 1517 - 16.69 = 1500.31℃. The temperature data collection and processing system sent this temperature data to the converter PLC control system. This indicated that the mid-smelting temperature control of carbon steel in this furnace was appropriate, and no adjustment to the blowing control was required. The final smelting endpoint was accurately reached. The final smelting temperature was measured at 1635℃ using a secondary lance. The temperature measured by the device and method of this invention was 1636.56℃, with a deviation of 1.56℃. This demonstrates that the device and method of this invention can achieve continuous and accurate measurement of the temperature of molten steel during converter smelting.

[0042] Nitrogen gas is used to purge the taphole throughout the smelting process, with a real-time nitrogen pressure of 5 kg to prevent slag from sticking to the thermocouples. The thermocouples are then smoothly removed from the taphole during the tapping and slag removal stages, avoiding interference with the tapping and slag removal operations. Example 4

[0043] In a certain heat of the converter, the steel grade being smelted is high-carbon steel 55C. Before the converter blowing process, a movable high-temperature thermocouple, a long blowing pipe, and a short blowing pipe are inserted into the tap hole. The front end of the high-temperature thermocouple is flush with the inner wall of the furnace lining, and the cover plate on the shell is used to seal the tap hole. During the blowing process, the temperature of the furnace gas inside the converter is continuously monitored in real time by the high-temperature thermocouple, and the measured temperature data is transmitted to the temperature data collection and processing system.

[0044] During the later stages of smelting, the thermocouple measured the furnace gas temperature at 1663℃. The flue gas analysis system measured the CO mass percentage in the furnace gas to be 41.58% and the CO2 mass percentage to be 20.52%. The sonar slag intensity index measured was 43%. The system calculated the compensation temperature using a model: 21.392 × 43% × (9 - 41.58% / 20.52%) + 2.316 = 66.43℃. It also calculated the molten steel temperature as 1663 - 66.43 = 1596.57℃. The temperature data collection and processing system sent this temperature data to the converter PLC control system. This indicated that the temperature control was appropriate during the later stages of smelting high-carbon steel in this furnace, and no adjustment to the blowing control was required. The final smelting endpoint was accurately reached. The final smelting temperature was measured at 1631℃ using a secondary lance. The temperature measured by the device and method of this invention was 1630.03℃, with a deviation of 0.97℃. This demonstrates that the device and method of this invention can achieve continuous and accurate measurement of the temperature of molten steel during converter smelting.

[0045] Nitrogen gas is used to purge the taphole throughout the smelting process, with a real-time nitrogen pressure of 4 kg to prevent slag from sticking to the thermocouples. The thermocouples are then smoothly removed from the taphole during the tapping and slag removal stages, avoiding interference with the tapping and slag removal operations.

[0046] The above embodiments are only used to illustrate and not limit the technical solutions of the present invention. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the present invention without departing from the spirit and scope of the present invention. Any modifications or partial substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A converter temperature real-time measurement device, characterized in that: The measuring device includes a thermocouple (1), a thermocouple entry / exit drive section, and a data collection and processing system (2). The thermocouple (1) is connected to the data collection and processing system (2) via a data transmission cable (3). The thermocouple and the data transmission cable (3) are installed and fixed inside a protective housing (4). The end of the protective housing is provided with a cover plate (18) that closes the steel outlet. The thermocouple entry / exit drive section includes an upper limit roller (5), a lower limit roller (6), a gear (7), and a rack (8). The upper limit roller (5) and the lower limit roller (6) are connected to the data collection and processing system (2). The upper limit rollers (6) are arranged opposite each other on the mounting plate (9) at intervals. The mounting plate (9) is fixed to the base (11) by the support column (10). Two sets of upper limit rollers (5) and lower limit rollers (6) are arranged at intervals on the left and right. The protective shell (4) moves within the interval between the upper limit rollers and the lower limit rollers. The rack (8) is fixed to the bottom of the protective shell (4). The gear (7) meshes with the rack (8) to form a transmission pair. The gear (7) is driven by a motor, which is fixed on the mounting plate.

2. The converter temperature real-time measurement device according to claim 1, characterized in that: The measuring device is also equipped with a nitrogen purging mechanism, which includes a first equalizing chamber (12), a second equalizing chamber (13), a long blowing pipe (14), a short blowing pipe (15), an air pump (16), and a nitrogen storage tank (17). The first equalizing chamber (12), the second equalizing chamber (13), and the cover plate (18) are all annular and connected as one unit. The side wall of the first equalizing chamber (12) is fixed to the end of the protective shell (4). An air inlet (19) is provided on the side wall of the second equalizing chamber (13). The air inlet connects the first equalizing chamber (12) and the second equalizing chamber (13) and passes through the aperture of the air inlet. The pressure difference between the two is adjusted by the number of holes; a ring of long blowpipes (14) is set on the cover plate (18), and the long blowpipes are evenly spaced. A ring of short blowpipes (15) is set inside the long blowpipes, and the short blowpipes are evenly spaced along the circumference. The long blowpipes are connected to the first equalizing chamber (12), and the short blowpipes (15) are connected to the second equalizing chamber (13); the first equalizing chamber is connected to the air pump (16), the pneumatic ball valve (20) and the nitrogen storage tank (17) in sequence through the air inlet (21); the thermocouple (1) passes through the cover plate (18), the second equalizing chamber (13) and the first equalizing chamber (12) in sequence, and is placed in the protective shell (4).

3. The converter temperature real-time measurement device according to claim 2, characterized in that: A dustproof ring (22) is also provided on the outside of the thermocouple (1). One end of the dustproof ring (22) is fixed on the cover plate (18) and located in the inner ring of the short blow pipe (15). The dustproof ring (22) has through holes evenly distributed on it, and the inner diameter of the through holes is 3-12mm.

4. The converter temperature real-time measurement device according to claim 1, characterized in that: The thermocouple (1) is connected to the data transmission cable (3) via an aviation plug (23).

5. A method for controlling converter smelting using the measuring device as described in any one of claims 1-4, characterized in that: Follow these steps: Step a: Before the converter blowing process, use the gear and rack transmission pair to insert the movable thermocouple, long blowing pipe and short blowing pipe into the tap hole of the converter, and seal the tap hole with the cover plate. Step b: Start the gas pump. After nitrogen gas passes through the first and second equalization chambers, it is blown out of the steel outlet by the long and short blow pipes to prevent slag and flue gas from sticking to the thermocouple. Step c: During the blowing process, the temperature inside the converter is continuously monitored in real time by thermocouples, and the measured temperature data is transmitted to the temperature data collection and processing system. Step d: The temperature data collection and processing system converts the furnace gas temperature into the molten steel temperature according to the following calculation model: G T =Q T - Compensation temperature Compensation temperature = 21.392 × S × (9 - Wco / Wco2) + 2.316 Wherein: G T —Temperature of molten steel; Q T —Furnace gas temperature; S—Sound intensity index measured by the sonar slag removal system; Wco—The percentage of CO by mass as measured by the flue gas analysis system; Wco2 — CO2 mass percentage measured by the flue gas analysis system; Step e, the temperature data collection and processing system and the converter PLC control system (26) realize data exchange. The converter PLC control system transmits sonar slag and flue gas analysis system data to the temperature data collection and processing system. The temperature data collection and processing system transmits steel temperature data to the converter PLC control system, so that the converter PLC control system can optimize oxygen lance position and charging blowing control in a timely manner. In step f, when tapping steel and tilting slag in the converter, first use the gear and rack assembly to move the thermocouple out of the tapping port to avoid interfering with the tapping and slag tilting operations.

6. The method for controlling converter smelting with the measuring device according to claim 5, characterized in that: In step a, before the converter blowing process, the thermocouple is inserted into the tap hole, with the front end of the thermocouple flush with the inner wall of the furnace lining.

7. The method for controlling converter smelting using the measuring device according to claim 5, characterized in that: In step b, the pressure of nitrogen purging the steel outlet is 3.0-5.0 kg.

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