Method for treating slight leakage of blast furnace top diffuser valve

Abstract

The present application relates to a kind of blast furnace top diffuser valve slight leakage processing method, steam plugging and furnace top pressure reduction form two-way cooperation, steam plugging is the pressure reduction operation to gain safety time, pressure reduction then slows down gas flow scouring, enhances the stability of plugging, effectively avoid the fluctuation of furnace condition caused by emergency shutdown, equipment damage, reduce production loss, with the advantages of safe and efficient, strong practicality, low cost.

Description

Technical Field

[0001] This invention relates to the field of metal smelting technology, and more specifically, to a method for dealing with minor leakage in the blast furnace top venting valve. Background Technology

[0002] The blast furnace top vent valve is a core piece of equipment for maintaining stable furnace pressure and ensuring production safety. Leaks can easily lead to safety and environmental accidents such as gas escape and high-temperature material splashing. Traditional solutions often involve emergency shutdowns. Existing technologies offer three main solutions: ① Leakage warning: This involves monitoring parameters such as charging time, temperature, and gas concentration to provide early warning of leaks, as exemplified by patent CN121430932A. However, this only addresses risk identification and does not cover post-leakage handling. ② Mechanical temporary sealing: This uses a dedicated locking device to temporarily seal the vent valve, as exemplified by patent CN208308896U. However, this relies on additional hardware modifications and cannot be implemented quickly in the early stages of a leak. ③ Valve structure improvement: This improves reliability by optimizing the vent valve's structure, as exemplified by patents CN2844588Y and CN202530096U. However, this cannot solve existing leaks and is considered preventative rather than reactive.

[0003] In addition, there are many drawbacks to using emergency shutdown to deal with blast furnace top vent valve leakage: it is difficult to restore the furnace condition, as the shutdown material was not put into the furnace before the emergency shutdown, and the furnace temperature was low and the furnace condition fluctuated greatly after the shutdown, resulting in a long recovery period; the risk of equipment failure is high, as shutdown when slag and iron in the furnace are not completely discharged can easily lead to slag filling in the tuyeres, causing the small sleeves in the tuyeres to burn out, resulting in a significant extension of the shutdown time and a sharp increase in the difficulty of restoring the furnace condition after the shutdown; and there is insufficient preparation time, as the emergency shutdown operation is rushed and can easily cause secondary safety hazards, making it difficult to guarantee the quality of the treatment.

[0004] None of the aforementioned existing technologies provide a systematic solution for "process intervention in the early stage of minor leakage + subsequent standardized shutdown". Therefore, the present invention fills the technical gap in this field. Summary of the Invention

[0005] To address the shortcomings of existing technologies, the present invention aims to provide a method for handling minor leakage in the blast furnace top vent valve. Steam plugging and top pressure reduction work in a two-way synergy. Steam plugging provides safe time for pressure reduction operations, while pressure reduction slows down the scouring of the gas flow and enhances the stability of the plugging. This effectively avoids furnace condition fluctuations and equipment damage caused by emergency shutdowns, reducing production losses. It has the advantages of being safe, efficient, practical, and low-cost.

[0006] The above-mentioned technical objective of the present invention is achieved through the following technical solution: A method for handling minor leakage in a blast furnace top venting valve includes the following steps: S1. Dust Adhesion Sealing Intervention: When a minor leak is detected, immediately introduce saturated steam into the furnace throat next to the furnace top riser pipe or turn on the furnace top atomization system to spray water on the furnace top material surface, so that the dust particles in the furnace are moistened and adhere to the leak gap, thus achieving temporary sealing. S2. Optimized adjustment of furnace top pressure: By setting the furnace top pressure, the set working pressure value of the furnace top is reduced by 10-15 kPa to slow down the scouring of the gas flow to the leaking part and prevent the leak from expanding. S3. Real-time monitoring of leakage status: Combine the pressure curve of the blast furnace top when the blast furnace is not being charged, keep monitoring and recording the leakage situation, track the sealing effect, and dynamically grasp the changes in risk. S4. Two to four hours after implementing the treatment according to steps S1-S3, confirm the sealing effect through the furnace top monitoring device and the online CO monitoring equipment near the furnace top. S5. After confirming that the original leak point of the furnace top vent valve has been successfully sealed, continue to process according to steps S1 and S2 for 2-3 hours. S6. After confirming the successful sealing, shut off the steam to the furnace top throat and gradually restore the furnace top working pressure to the level before the leak by adjusting the pressure value by ≤3kPa each time.

[0007] In one embodiment, in step S1, the pressure of the saturated steam is ≥0.3 MPa, and the flow rate of the saturated steam is ≥1200 m³ / s. 3 / h, duration ≥2 hours.

[0008] In one embodiment, in step S1, the leakage level is confirmed by combining an online gas concentration monitor with manual inspection. The criteria for determining minor leakage in the blast furnace top vent valve are as follows: The parameters for judging minor leaks are: the gas concentration CO within 2 meters of the leak point is ≤200ppm, there is a faint airflow sound or white mist, and the pressure fluctuation of the furnace top is within ±5 kPa when no material is discharged from the furnace top. Severe leakage criteria: CO concentration in the gas within 2 meters of the leakage point > 200 ppm, and the furnace top pressure shows a rapid downward trend when no material is being discharged from the furnace top.

[0009] In one embodiment, in step S3, the leakage situation is monitored and recorded every 15-30 minutes.

[0010] In one embodiment, in step S6, after the furnace top working pressure is gradually restored to the level before the leak, the online monitoring is adjusted to record once every 1-2 hours.

[0011] In summary, the present invention has the following beneficial effects: The technical steps of this invention are not simply superimposed, but form an organic whole that supports and promotes each other, producing a synergistic effect of 1+1>2, as detailed below: This invention breaks with conventional understanding, and through 120 sets of comparative experiments, it optimizes and obtains values ​​of 0.3-0.5 MPa and 1200-2000 m. 3 The combination of steam parameters of / h and ≥2 hours, and the precise selection of the furnace throat next to the gas riser pipe at the top of the blast furnace as the steam inlet location, combined with the steam phase change-heterogeneous nucleation-dust agglomeration and adhesion mechanism, achieves rapid and stable sealing of minor leaks; This invention avoids the drawbacks of emergency shutdown: steam plugging and furnace top pressure reduction form a two-way synergy. Steam plugging buys safe time for pressure reduction operation, while pressure reduction slows down the scouring of coal gas flow and enhances the stability of plugging, effectively avoiding furnace condition fluctuations and equipment damage caused by emergency shutdown, and reducing production losses. This invention has the advantages of safety and efficiency: multi-dimensional dynamic monitoring (recording every 30 minutes) provides a guarantee for steam plugging and pressure regulation, real-time feedback of abnormal parameters and triggering emergency interlocks, two on-site confirmations to ensure the plugging effect, gradual restoration of working conditions to reduce risks, and sufficient time for handling to improve safety and handling efficiency.

[0012] This invention has the advantages of being highly practical and low-cost: it can be implemented using existing blast furnace equipment without the need for additional complex devices, and its operation is simple and easy to master; it uses the dust from the coal gas itself as a sealing medium, eliminating the need for external materials, saving costs and meeting environmental protection requirements, and can be incorporated into scheduled maintenance to achieve root cause treatment and reduce the risk of subsequent leaks.

[0013] This invention is safe and environmentally friendly: it effectively suppresses the escape of coal gas, eliminates risks such as personnel poisoning, fire, and excessive levels of harmful gases, meets the safety and environmental protection production requirements of the blast furnace metallurgical industry, and achieves the disposal goal of "control first, then treat, and orderly eradicate". Detailed Implementation

[0014] The present invention will now be described in detail with reference to the embodiments.

[0015] This invention proposes a method for handling minor leakage in the blast furnace top vent valve, comprising the following steps: S1. Dust Adhesion Sealing Intervention: Upon detection of a minor leak, immediately introduce saturated steam into the furnace throat next to the riser pipe at the furnace top. The pressure of the saturated steam should be ≥0.3 MPa, and the flow rate of the introduced saturated steam should be ≥1200 m³ / h. 3 / h, duration ≥2 hours, or the furnace top atomization system can be turned on to spray water on the furnace top material surface, so that the dust particles such as ore powder, coke powder, and unburned coal powder in the furnace are moistened and adhere to the leak gaps to achieve temporary sealing; S2. Optimized adjustment of furnace top pressure: By setting the furnace top pressure, the set working pressure value of the furnace top is reduced by 10-15 kPa to slow down the scouring of the gas flow to the leaking part and prevent the leak from expanding. S3. Real-time monitoring of leakage status: Using a furnace top camera or drone, combined with the furnace top pressure curve when the blast furnace is not charging, the leakage status is monitored and recorded every 15-30 minutes to track the sealing effect and dynamically grasp the changes in risk. S4. After 2-4 hours (e.g., 3 hours) following the treatment in steps S1-S3, use the furnace top monitoring device in conjunction with the online CO monitoring equipment near the furnace top to determine that the original leak point of the blast furnace vent valve is no longer leaking. Then, organize professional maintenance personnel to go to the furnace top vent valve working platform, take protective measures, and confirm the sealing effect at close range. S5. After confirming that the original leak point of the furnace top vent valve has been successfully sealed, continue to maintain the above-mentioned state of saturated steam supply and slight reduction of top pressure for 2-3 hours, that is, continue to process according to steps S1 and S2, that is, further reduce the furnace top set working pressure on the basis of step S2; for example, the processing time is 2 hours. S6. Once again, organize professional maintenance personnel to go to the furnace top vent valve operating platform. After taking protective measures, confirm the successful sealing at close range, shut off the steam leading to the furnace top throat, and gradually restore the furnace top working pressure to the level before the leak by adjusting the pressure value by ≤3kPa each time. Adjust the original furnace top vent valve leakage online monitoring to record once every 1-2 hours. S7. Collaborative Promotion: Include the furnace top vent valve in the next scheduled maintenance project and take advantage of the blast furnace scheduled maintenance opportunity to thoroughly address the potential leakage hazards of the furnace top vent valve.

[0016] The principle of this invention, which utilizes steam-induced dust adhesion and sealing technology, is as follows: blast furnace gas contains a large amount of fine mineral powder and coal powder particles (concentration approximately 7-8 g / m³). 3These fine dust particles (with a particle size distribution of 1-10 μm) will continuously escape into the sealing gap of the vent valve under the influence of leakage pressure differential (pressure difference between the furnace interior and the outside environment), exacerbating the leakage. The core of this invention is to utilize the phase change characteristics of steam and the agglomeration and adhesion patterns of dust. By introducing saturated steam into the furnace throat next to the gas riser pipe at the top of the blast furnace, precisely targeting the sealing gap of the vent valve seat, an integrated sealing mechanism of "steam phase change—heterogeneous nucleation—dust agglomeration—adhesion layering" is constructed. Specifically, after high-temperature saturated steam is injected into the sealing gap, it rapidly exchanges heat with the low-temperature gas inside the gap, undergoing a cooling phase change and forming a supersaturated water vapor environment. Fine dust particles act as condensation nuclei, undergoing heterogeneous nucleation and condensation, forming uniform and viscous water on the particle surface. The water-containing film, under the combined action of airflow inertia, van der Waals forces, and liquid bridge forces, causes dust particles to collide and agglomerate, rapidly increasing in size (from 1-10μm to 50-100μm), losing their suspension ability, and gradually adhering to the sealing surface of the vent valve and the inner wall of the gap. As steam continues to flow in, the adhered dust particles accumulate and compact, eventually forming a dense, low-permeability wet powder adhesive layer, effectively filling the sealing gap, blocking the gas leakage channel, and achieving temporary controllable sealing of minor leaks, thus buying sufficient time for subsequent orderly ventilation shutdown and maintenance operations.

[0017] In step S1, the leakage level is confirmed by combining on-site online gas concentration monitoring with manual inspection. The criteria for judging minor leakage of the blast furnace top vent valve are as follows: The parameters for judging minor leaks are: the gas concentration CO within 2 meters of the leak point is ≤200ppm, there is a faint airflow sound or white mist, and the pressure fluctuation of the furnace top is within ±5 kPa when no material is discharged from the furnace top.

[0018] Severe leakage criteria: CO concentration in the gas within 2 meters of the leakage point > 200 ppm, and the furnace top pressure shows a rapid downward trend when no material is being discharged from the furnace top.

[0019] This invention focuses on the core logic of "control first, then treat, and synergistic control" for minor leaks, abandoning the conventional, crude handling model, as follows: Core sealing technology: This invention precisely selects the furnace throat next to the gas riser pipe at the top of the blast furnace as the steam inlet location. Combining the integrated sealing mechanism of "steam phase change - heterogeneous nucleation - dust agglomeration - bonding and layering", it utilizes the fine dust of the blast furnace gas itself as the sealing medium, without the need to add additional sealing materials, to achieve temporary and controllable sealing of minor leaks.

[0020] Optimal steam parameter combination: 0.3-0.5 MPa, 1200-2000 m³ / h were obtained through optimization via 120 sets of comparative experiments. 3The combined range of steam parameters, with a duration of ≥2 hours, breaks through the conventional understanding that "the higher the parameter, the better the sealing effect." It can achieve a gas concentration reduction rate of ≥88% and a sealing stability of ≥3 hours. This parameter combination cannot be obtained through conventional experiments or empirical derivation and is the core technical support for achieving effective sealing.

[0021] Two-way coordinated pressure regulation technology: It combines steam plugging with furnace top pressure regulation. By reducing the furnace top set working pressure by 10-15 kPa and controlling the pressure difference before and after the vent valve to 5-10 kPa, it slows down the scouring of the sealing surface by the gas flow. This not only buys safe time for steam plugging but also enhances the stability of the plugging and prevents leakage from expanding.

[0022] Multi-dimensional safety monitoring and interlocking technology: The monitoring mode adopts a combination of cameras / drones, online CO monitoring, and pressure curve linkage. Data is collected every 30 minutes, and clear emergency interlocking thresholds (gas concentration, steam parameters, and splashing conditions) are set to provide real-time warnings of sealing failure risks and ensure that the disposal process is safe and controllable.

[0023] Sealing consolidation and operating condition restoration technology: Through the process of "first confirmation after 3 hours of treatment - continued steam supply for 2 hours of consolidation - gradual pressure restoration after second confirmation", the sealing effect is ensured to be stable. During the restoration process, the pressure adjustment range is strictly controlled (≤3 kPa each time) to avoid operating condition fluctuations. At the same time, the leaking valve is included in the scheduled maintenance to achieve root cause treatment.

[0024] The technical solution of the present invention will be described below through specific embodiments.

[0025] In this invention, saturated steam pressure and flow rate directly affect the plugging effect. Experimental data and nonlinear relationship demonstration of steam parameters and plugging effect: To determine the optimal combination of steam parameters, this invention underwent 120 sets of comparative experiments (based on a 3000 m³ / h) 3 Under actual operating conditions of a blast furnace, simulating a minor leakage scenario (initial gas concentration 150 ppm, sealing gap 0.1-0.3 mm), 120 samples were divided into 10 groups, with 12 parallel experiments in each group. The effects of steam pressure (0.1-0.8 MPa) and steam flow rate (800-2500 m³ / h) were systematically studied. 3 The relationship between the gas concentration reduction rate ( / h), duration (0.5-4 hours), and sealing effect (with gas concentration reduction rate and sealing stability as the core evaluation indicators) is shown in Table 1 below. The experimental data and nonlinear laws are as follows: The 10 comparative experiments are divided into the following 10 groups based on the experimental conditions: Table 1. Experimental data on steam parameters and plugging effect

[0026] According to the data in Table 1, there is a nonlinear relationship between steam pressure and sealing effect: when the pressure is in the range of 0.1-0.4 MPa, as the pressure increases, the steam jet penetration increases, the water vapor saturation in the gap increases, the dust agglomeration and adhesion efficiency increases significantly, and the gas concentration reduction rate increases exponentially; when the pressure exceeds 0.4 MPa, if the pressure continues to increase, the steam impact force will exceed the bearing limit of the dust bonding layer, causing the already formed wet powder bonding layer to be washed away and loosened, the sealing stability decreases, and the gas concentration reduction rate shows a slow downward trend, forming a nonlinear curve of "rise-peak-fall", with the peak corresponding to a pressure of about 0.4 MPa.

[0027] Table 1 shows a non-linear relationship between steam flow rate and plugging effect: for flow rates between 800–1600 m³ / h... 3 Within the range of / h, increasing the flow rate can improve the water vapor renewal rate within the gap, ensuring that dust particles fully contact water vapor and form a water film. The agglomeration efficiency increases linearly with increasing flow rate, and the gas concentration reduction rate increases synchronously. When the flow rate exceeds 1600 m³ / h, 3 After a certain flow rate, further increases will lead to excessively high airflow velocity within the gap, interfering with the collision and aggregation of dust particles. This also easily causes the wet dust layer to detach, reducing the stability of the sealing layer. The rate of decrease in gas concentration tends to level off or even slightly decrease, exhibiting a non-linear characteristic of "linear increase—leveling off—decline." The optimal flow rate range is 1200-2000 m³ / h. 3 / h.

[0028] According to the data in Table 1, there is a non-linear relationship between the duration and the sealing effect: when the duration is in the range of 0.5-2 hours, as time increases, the wet powder binder layer accumulates and compacts, the sealing density gradually improves, and the rate of decrease in gas concentration increases logarithmically; when the duration reaches 2 hours, the wet powder binder layer reaches saturation, the density tends to stabilize, and the rate of decrease in gas concentration approaches its maximum value; if the time is further extended (more than 2 hours), the sealing effect does not improve significantly, the marginal benefit approaches 0, forming a non-linear curve of "rapid increase - tending to stabilize", and the optimal duration is more than 2 hours (with 2 hours as the critical value, taking into account both sealing effect and energy consumption).

[0029] As shown in Table 1, the innovative demonstration of the optimal parameter combination differs from the conventional understanding that "higher steam pressure, greater flow rate, and longer duration result in better sealing effects." This invention, through extensive experiments, has discovered that steam parameters and sealing effects are not simply linearly positively correlated, but rather exhibit a complex nonlinear relationship. Furthermore, there are synergistic effects between parameters (e.g., excessively high pressure negates the advantages of increased flow rate, and excessively long duration leads to energy waste without additional benefits). 0.3-0.5 MPa, 1200-2000 m 3The parameter combination of / h and 2 hours or more was optimized through multi-parameter cross-experiments and orthogonal experiments. This combination ensures both the sealing effect (gas concentration reduction rate ≥88%, sealing stability ≥3 hours) and avoids sealing surface erosion and energy waste caused by excessively high parameters, as well as sealing failure caused by excessively low parameters. It is easy to understand that this optimal steam parameter combination is the foundation for the synergistic effect of subsequent steps. Only when the steam sealing effect meets the standards can a safe premise be provided for pressure regulation, dynamic monitoring, and shutdown preparation, ensuring the effective operation of the entire synergistic system. Example 1

[0030] This embodiment is applied to 3000 m 3 A minor leak occurred in the top vent valve of the blast furnace. The initial gas concentration was 150 ppm, and the sealing gap was 0.2 mm. The specific handling process is as follows: Leakage Assessment and Emergency Control: Based on on-site gas detectors and manual inspection, a minor leak was confirmed (CO concentration within 2 meters of the leak point is 150 ppm, with a faint airflow sound, and pressure fluctuations of ±3 kPa at the furnace top without material discharge). The furnace top steam purging bypass valve was immediately opened, and 0.4 MPa, 1600 m³ / h steam was introduced into the furnace throat next to the blast furnace top gas riser pipe. 3 Saturated steam at a rate of / h was precisely applied to the sealing gap area of ​​the vent valve seat and continuously purged for 2 hours. During this period, steam parameters were monitored in real time to ensure stability. The steam-induced dust adhesion and plugging effect was good. After 2 hours, the gas concentration dropped to 7ppm, a reduction rate of 95%, and the plugging was stable.

[0031] Pressure regulation and gas flow rate suppression at the furnace top: The set working pressure at the furnace top is reduced from 260 kPa to 248 kPa to reduce the scouring of the gas flow to the leaking parts. The pressure difference between the furnace top pressure and the inlet pressure of the vent valve is monitored and stabilized at 4 kPa, which effectively reduces the scouring of the gas flow.

[0032] Multi-dimensional real-time monitoring and risk interlocking: Fixed industrial cameras are used to monitor the leak point. Combined with the pressure curve of the furnace top, the gas concentration and steam parameters are recorded every 30 minutes. There were no abnormalities throughout the process and no emergency interlocking was triggered.

[0033] Confirmation and consolidation of sealing effect: After handling the above steps for 3 hours, confirm that there is no leakage at the leak point through furnace top monitoring and online CO monitoring. Organize maintenance personnel to confirm the sealing effect at close range after taking protective measures. After confirming that the sealing is successful, continue to maintain steam supply and slightly reduce the top pressure for 2 hours to ensure the stability of the sealing layer.

[0034] Restoration of operating conditions and subsequent radical treatment: After confirming that the sealing was successful again, shut off the steam in the furnace throat and restore the furnace top pressure to 260 kPa at a rate of 3 kPa each time. Adjust the monitoring frequency to record once every 2 hours. Include the vent valve in the next scheduled maintenance project to thoroughly address the potential leakage hazard.

[0035] Results: The total time for handling this fault was 7 hours. The technical and economic indicators of the blast furnace were basically unaffected, and only a small amount of steam resources were consumed. Compared with the many hidden dangers that are easily caused by conventional emergency shutdown, the application of this technical method did not cause any fluctuations in furnace conditions, equipment damage, or safety and environmental hazards. The steam plugging parameters met the optimal combination requirements, and the plugging effect was stable, which verified the feasibility and superiority of the technical solution of this invention. Example 2

[0036] This embodiment is applied to 2000 m 3 A minor leak occurred in the top vent valve of the blast furnace. The initial gas concentration was 180 ppm, and the sealing gap was 0.15 mm. The specific handling process is as follows: Leakage Assessment and Emergency Control: Upon confirming a minor leak (CO concentration of 180 ppm within 2 meters of the leak point, faint white mist, and pressure fluctuation of ±4 kPa at the top of the furnace without charging), immediately open the top steam purging bypass valve and introduce 0.35 MPa, 1400 m³ / h steam into the furnace throat next to the blast furnace top gas riser. 3 Saturated steam at a rate of / h was precisely applied to the sealing gap area of ​​the vent valve seat and continuously purged for 2.2 hours. After 2.2 hours, the gas concentration dropped to 12ppm, a decrease rate of 93%, and the blockage was stable.

[0037] Pressure regulation and gas flow rate suppression at the furnace top: The set working pressure at the furnace top is reduced from 220 kPa to 210 kPa, which reduces the scouring of the gas flow to the leaking parts and stabilizes the pressure difference at 6 kPa, effectively suppressing the scouring of the gas flow.

[0038] Multi-dimensional real-time monitoring and risk interlocking: Drone-assisted monitoring is used, combined with the furnace top pressure curve, and data is recorded every 30 minutes. The steam parameters are stable, the gas concentration does not rise, and the emergency interlocking is not triggered.

[0039] Confirmation and consolidation of sealing effect: Three hours after the treatment, no leakage was confirmed by monitoring and online CO monitoring, and maintenance personnel confirmed the successful sealing at close range; steam supply and slight pressure reduction at the top were maintained for another 2 hours to consolidate the sealing effect.

[0040] Restoration of operating conditions and subsequent radical treatment: After confirming that the sealing was successful again, shut off the steam and restore the furnace top pressure to 220 kPa at a rate of 2.5 kPa each time. Adjust the monitoring frequency to record once every 2 hours. Include the vent valve in the next scheduled maintenance to completely eliminate the hidden danger.

[0041] Results: The total treatment time was 6.2 hours. The blast furnace condition was stable, with no equipment damage or economic loss. The steam plugging effect met expectations, further verifying the rationality of the optimal steam parameter combination and the practicality of the technical solution of this invention.

[0042] The above description is merely a preferred embodiment of the present invention. The scope of protection of the present invention is not limited to the above embodiments. All technical solutions falling within the scope of the present invention's concept are within the scope of protection of the present invention. It should be noted that for those skilled in the art, any improvements and modifications made without departing from the principles of the present invention should also be considered within the scope of protection of the present invention.

Claims

1. A method for handling minor leakage in a blast furnace top venting valve, characterized in that, Includes the following steps: S1. Dust Adhesion Sealing Intervention: When a minor leak is detected, immediately introduce saturated steam into the furnace throat next to the furnace top riser pipe or turn on the furnace top atomization system to spray water on the furnace top material surface, so that the dust particles in the furnace are moistened and adhere to the leak gap, thus achieving temporary sealing. S2. Optimized adjustment of furnace top pressure: By setting the furnace top pressure, the set working pressure value of the furnace top is reduced by 10-15 kPa to slow down the scouring of the gas flow to the leaking part and prevent the leak from expanding. S3. Real-time monitoring of leakage status: Combine the pressure curve of the blast furnace top when the blast furnace is not being charged, keep monitoring and recording the leakage situation, track the sealing effect, and dynamically grasp the changes in risk. S4. Two to four hours after implementing the treatment according to steps S1-S3, confirm the sealing effect through the furnace top monitoring device and the online CO monitoring equipment near the furnace top. S5. After confirming that the original leak point of the furnace top vent valve has been successfully sealed, continue to process according to steps S1 and S2 for 2-3 hours. S6. After confirming that the sealing is successful again, shut off the steam to the furnace top throat and gradually restore the furnace top working pressure to the level before the leak by adjusting the pressure value by ≤3kPa each time.

2. The method for handling minor leakage in the blast furnace top venting valve as described in claim 1, characterized in that, In step S1, the pressure of the saturated steam is ≥0.3 MPa, and the flow rate of the saturated steam is ≥1200 m³ / s. 3 / h, duration ≥2 hours.

3. The method for handling minor leakage in the blast furnace top venting valve as described in claim 1, characterized in that, In step S1, the leakage level is confirmed by combining on-site online gas concentration monitoring with manual inspection. The criteria for judging minor leakage of the blast furnace top vent valve are as follows: The parameters for judging minor leaks are: the gas concentration CO within 2 meters of the leak point is ≤200ppm, there is a faint airflow sound or white mist, and the pressure fluctuation of the furnace top is within ±5 kPa when no material is discharged from the furnace top. Severe leakage criteria: CO concentration in the gas within 2 meters of the leakage point > 200 ppm, and the furnace top pressure shows a rapid downward trend when no material is being discharged from the furnace top.

4. The method for handling minor leakage in the blast furnace top venting valve as described in claim 1, characterized in that, In step S3, the leakage situation is monitored and recorded every 15-30 minutes.

5. The method for handling minor leakage of the blast furnace top venting valve as described in claim 1, characterized in that, In step S6, after gradually restoring the furnace top working pressure to the level before the leak, the online monitoring is adjusted to record once every 1-2 hours.

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