A method for on-line dust cleaning of a blast furnace forehearth dust removal pipeline

Abstract

This invention relates to an online ash removal method for dust removal pipelines in front of a blast furnace, comprising the following steps: S1, determining the locations with the most deposits on the dust removal pipelines in front of the furnace; S2, online cleaning. This invention utilizes real-time dynamic monitoring of temperature and deposits during the operation of the dust removal system, constructing a three-dimensional monitoring model. Using the method of this invention for cleaning effectively reduces the labor intensity of manual operations, enhances the safety of the cleaning operation, and achieves good cleaning results.

Description

Technical Field

[0001] This invention relates to the field of pipeline dust removal technology, and more specifically, to an online ash removal method for dust removal pipelines in front of a blast furnace. Background Technology

[0002] The dust collection pipeline in front of the blast furnace primarily draws in the flue gas and dust generated during the slag and iron tapping process. After filtration and sedimentation, the dust is finally discharged into a sealed ash silo. Once the ash reaches a certain storage capacity, it is centrally discharged for disposal. During the slag and iron tapping process, the flue gas and dust drawn into the blast furnace front dust collection pipeline are at high temperatures, sometimes exceeding 100°C. The dust collection process involves flue gas, particulate matter, toxic and harmful gases, and volatile gases from zinc and alkali metals. The composition drawn into the dust collection pipeline is complex, and due to long-term continuous operation, significant scaling and adhesion occur on the inner walls of the pipeline.

[0003] The dust removal system at the blast furnace taphole operates continuously for 365 days a year, with only a few days of shutdown. The dust removal pipelines at the blast furnace taphole can only be cleaned by professionals after the deposits inside have cooled down when the blast furnace is shut down. This cleaning process is extremely difficult and carries high safety risks.

[0004] The dust collection pipelines in front of blast furnaces are generally irregularly laid out, with numerous bends and inclines, further increasing the difficulty of cleaning and inspection. These pipelines are typically 2-3 meters in diameter, allowing ordinary personnel to stand and walk inside. However, due to the confined space, insufficient lighting, and uneven distribution of scale, manual cleaning is inefficient and prone to missing blind spots. Furthermore, the residual zinc vapor condensate inside the pipelines is highly corrosive, placing higher demands on the protective equipment and operating procedures of workers. Existing cleaning methods mostly rely on high-pressure water jets or mechanical scrapers, but repeated operations can damage the pipeline substrate and shorten equipment lifespan. Current methods for cleaning the internal deposits of dust collection pipelines generally include using mechanical scrapers, high-pressure gas purging, or hammering with steel chisels. Performing such operations in a confined space presents extremely high labor intensity and safety risks. Moreover, both high-pressure water washing and high-pressure gas purging consume significant amounts of energy, increasing production energy costs. Therefore, it is necessary to propose an online dust collection method for blast furnace dust collection pipelines. Summary of the Invention

[0005] To address the shortcomings of existing technologies, the present invention aims to provide an online ash removal method for dust removal pipelines in front of blast furnaces. This method involves real-time dynamic monitoring of temperature and adhering materials during the operation of the dust removal system, constructing a three-dimensional monitoring model, and using the method of the present invention to clean effectively reduces the labor intensity of manual operations, enhances the safety of the cleaning operation, and achieves good cleaning results.

[0006] The above-mentioned technical objective of the present invention is achieved through the following technical solution: A method for online dust removal of blast furnace front dust collection pipelines, comprising the following steps: S1. Identify the locations with the most adhesive residue in the dust removal pipes in front of the furnace: S11. Multiple measurement paths are evenly set along the circumferential side of the dust removal pipe. The measurement paths are parallel to the center line of the dust removal pipe, and the length of each measurement path is the same as the total length of the dust removal pipe. S12. Measure the temperature of the dust inside the dust removal duct within 1 m from the air inlet and at the end of the dust removal duct and calculate the temperature difference. Calculate the temperature loss per 1 m in the dust removal duct based on the temperature difference between the two ends and the length of the dust removal duct. Then, starting from the air inlet of the dust removal duct, calculate the temperature every 1 m in the dust removal duct. S13. For each measurement path, starting from a position 1 m away from the air inlet of the dust removal duct, measure the temperature of the outer wall of the dust removal duct every 1 meter. S14. For each measurement path, calculate the difference between the dust temperature and the outer wall temperature per 1 m along the measurement path, which is taken as the inner and outer wall temperature loss. Compare the inner and outer wall temperature loss per 1 m along all measurement paths. The point with the largest inner and outer wall temperature loss is the location where the adhesion inside the dust removal pipe is most prominent. S2. Online Cleanup: S21. Make a cleaning ball with the inside of the ball connected to an inflation hose. Multiple connection holes are evenly arranged on the surface of the ball, and a metal air valve is installed in each connection hole. S22. When the blast furnace taphole is discharging slag and iron, open the valve of the dust removal pipe in the direction where slag and iron are not being discharged. Place the ball and the air-filling hose into the dust removal pipe together. Under the action of huge suction, the ball and the air-filling hose are sucked into the dust removal system. According to the running distance of the air-filling hose, when the ball just runs to the point where the temperature loss between the inner and outer walls is the greatest, fix the position of the air-filling hose. Blow high-pressure nitrogen into the air-filling hose. The nitrogen fills the ball, and the high-pressure nitrogen is discharged from the metal vent valve on the ball. The ball bounces under the action of nitrogen, thereby cleaning the adhering material inside the dust removal pipe. S23. When the temperature loss at the cleaning point is reduced to the average temperature loss of the inner and outer walls of the entire dust removal pipe, stop cleaning and remove the ball and the inflation hose together from the dust removal pipe.

[0007] In one embodiment, in step S1, the number of measurement paths is ≥3.

[0008] In one embodiment, in step S21, starting from the connection between the air hose and the ball, the air hose is marked along its own length at the point where the maximum temperature loss between the inner and outer walls is equal to the distance between the air hose and the air inlet, so as to facilitate the identification of the running distance of the air hose in the dust removal pipeline.

[0009] In one embodiment, in step S21, the outer diameter of the ball is 300-500 mm, and the inner diameter of the connecting hole is 10 mm.

[0010] In one embodiment, in step S21, the outer diameter of the inflation hose is 20-50 mm.

[0011] In one embodiment, in step S22, the pressure of the high-pressure nitrogen gas is >0.8 MPa.

[0012] In summary, the present invention has the following beneficial effects: This invention enables real-time dynamic monitoring of temperature and adhering materials in the dust removal system during operation, constructs a three-dimensional monitoring model, and utilizes the cleaning method of this invention to effectively reduce the labor intensity of manual operations, enhance the safety of cleaning operations, and achieve good cleaning results. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of the present invention; In the picture: 1. Blast furnace, 2. Iron tap, 3. Iron tap dust hood, 4. Dust removal pipe, 5. Ball, 6. Gas filling hose. Detailed Implementation

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

[0015] It is worth noting that the directional terms such as "up" and "down" used in this article are all relative to the perspective of the attached figures and are only for the purpose of description. They should not be interpreted as limitations on the technical solutions.

[0016] This invention proposes an online ash removal method for dust removal pipelines in front of blast furnaces, the specific steps of which are as follows: S1. Identify the locations with the most adhesive residue in the dust removal pipes in front of the furnace: S11. Multiple measurement paths are evenly set along the circumferential side of the dust removal pipe. The measurement paths are parallel to the center line of the dust removal pipe, and the length of each measurement path is the same as the total length of the dust removal pipe. S12. Measure the temperature of the dust inside the dust removal duct within 1m from the air inlet and at the end of the dust removal duct and calculate the temperature difference. Calculate the temperature loss per meter in the dust removal duct based on the temperature difference between the two ends and the length of the dust removal duct. Then, starting from the air inlet of the dust removal duct, calculate the temperature every meter in the dust removal duct. S13. For each measurement path, starting from a position 1 m away from the air inlet of the dust removal duct, measure the temperature of the outer wall of the dust removal duct every 1 meter. S14. For each measurement path, calculate the difference between the dust temperature and the outer wall temperature per 1 m along the measurement path, which is taken as the inner and outer wall temperature loss. Compare the inner and outer wall temperature loss per 1 m along all measurement paths. The point with the largest inner and outer wall temperature loss is the location where the adhesion inside the dust removal pipe is most prominent. S2. Online Cleanup: S21. Make a cleaning ball with the inside of the ball connected to an inflation hose. Multiple connection holes are evenly arranged on the surface of the ball, and a metal air valve is installed in each connection hole. S22. When the blast furnace taphole is discharging slag and iron, open the valve of the dust removal pipe in the direction where slag and iron are not being discharged. Place the ball and the air-filling hose into the dust removal pipe together. Under the action of huge suction, the ball and the air-filling hose are sucked into the dust removal system. According to the running distance of the air-filling hose, when the ball just runs to the point where the temperature loss between the inner and outer walls is the greatest, fix the position of the air-filling hose. Blow high-pressure nitrogen into the air-filling hose. The nitrogen fills the ball, and the high-pressure nitrogen is discharged from the metal vent valve on the ball. The ball bounces under the action of nitrogen, thereby cleaning the adhering material inside the dust removal pipe. S23. When the temperature loss at the cleaning point is reduced to the average temperature loss of the inner and outer walls of the entire dust removal pipe, stop cleaning and remove the ball and the inflation hose together from the dust removal pipe.

[0017] like Figure 1 As shown in the diagram, the labels represent: 1. Blast furnace, 2. Taphole, 3. Taphole dust hood, 4. Dust collection pipe, 5. Ball, 6. Gas charging hose. The dust collection pipe's suction inlet is equipped with a taphole dust hood, located above the blast furnace taphole.

[0018] In step S1, the number of measurement paths is ≥3, preferably 4.

[0019] It is easy to understand that in step S12, when calculating the temperature per meter of the dust removal pipe based on the temperature difference between the two ends, when calculating the temperature per meter of the dust removal pipe, if the length of the dust removal pipe is not an integer multiple of 1 meter, the temperature calculation point adjacent to the end is less than 1 meter away from the end. The temperature calculation point in the dust removal pipe and the temperature measurement points at both ends are used as a scale, which corresponds to the position of measuring the outer wall temperature on each measurement path in step S13.

[0020] In step S14, the process proceeds to step S2 for online cleaning only when the maximum value of the temperature loss between the inner and outer walls exceeds the historical maximum value.

[0021] In step S2, when the ball cleans the adhesive inside the dust removal pipe, the impact of the ball on the inner wall of the dust removal pipe has a cleaning effect. At the same time, the high-pressure nitrogen gas sprayed from the ball also has the effect of impacting the adhesive.

[0022] In step S21, starting from the connection between the air hose and the ball, the air hose is marked along its own length at the point where the maximum temperature loss between the inner and outer walls is equal to the distance between the air hose and the air inlet, so as to facilitate the identification of the running distance of the air hose in the dust removal pipeline.

[0023] In step S21, the outer diameter of the ball is preferably 300-500 mm, and the inner diameter of the connecting hole is preferably 10 mm. The metal air valve has a structure similar to that of a basketball inflation needle.

[0024] In step S21, the outer diameter of the inflation hose is 20-50 mm.

[0025] In step S22, the pressure of the high-pressure nitrogen gas is >0.8 MPa.

[0026] The technical solution of the present invention will be described below through specific embodiments.

[0027] During operation, the dust collector at the furnace front continuously monitors the temperature of the flue dust carried by the high-temperature slag and iron in the taphole area and main trough. The temperature of the flue dust at the inlet of the dust collector pipe is generally between 150-350℃ (when there is significant slag and iron splashing at the taphole, the flue dust contains a large amount of iron sparks, resulting in a higher temperature). The flue dust temperature at the inlet of the dust collector pipe is set as T1. Simultaneously, the temperature of the flue dust at the very end of the dust collector pipe is measured, obtaining the temperature T2 at the pipe's end. T1-T2 represents the temperature drop of the flue dust inside the dust collector pipe. The length of the dust collector pipe is L meters, and (T1-T2) / L represents the temperature loss per meter within the dust collector pipe.

[0028] During the operation of the dust removal pipeline, the temperature of the outer wall of the dust removal pipeline is measured 1 meter away from the air inlet. The temperature of the outer wall of the pipeline at the first point (the air inlet is the zero position) is T3. α = T1 - T3 represents the temperature gradient between the inside and outside of the dust removal pipeline. Similarly, the temperature of the outer wall of the dust removal pipe is measured 1 meter from the end of the pipe, and the temperature of the outer wall of the pipe at the second point is T4 (the temperature measurement at 1 meter from the inner wall of the suction port is difficult to achieve on-site, as the suction port is the location with the fastest air velocity, and adhesion is unlikely to occur at this location. The temperature loss of the flue dust from the dust hood inlet to this point is very small. Therefore, the flue dust temperature at the suction port is basically the same as the flue dust temperature on the inner wall of the pipe within 1 meter of the suction port. The flue dust temperature measured within 1 meter of the suction port of the dust removal pipe is taken as the flue dust temperature at the zero point. Generally, the length of the dust removal pipe in front of the furnace is several hundred meters or even longer. The pipe has an irregular layout, and adhesion generally occurs more easily as the pipe path extends). The temperature gradient β between the inside and outside of the end of the dust removal pipe is obtained as β = T2 - T4. Following this procedure, multiple sets of temperatures T1, T2, T3, and T4 are measured to obtain data under different dust inlet flue gas temperature conditions. The temperature loss of the inner and outer walls of the dust removal pipeline under different dust suction temperature conditions is obtained and denoted as: X = (ɑ + β) / 2, which represents the average temperature loss of the inner and outer walls of the entire dust removal pipeline.

[0029] During the operation of the furnace-front dust removal system, a drone carrying an infrared thermal imaging scanning device performs a comprehensive scan and temperature measurement of the dust removal duct, obtaining a three-dimensional thermal image of the duct. The three-dimensional thermal image is used to mark the entire dust removal duct based on temperature distribution. Using the furnace-front dust removal air intake as the zero point and 1-meter intervals as scales, a model of the furnace-front dust removal energy distribution is created. The model displays the dust removal duct in three dimensions, with different colors used to distinguish high and low temperatures. Scanning the entire duct's outer wall temperature is primarily to avoid blind spots caused by measuring at 1-meter intervals, and also to construct a model of the duct's outer wall temperature distribution for easier daily monitoring.

[0030] The total length of the dust removal duct is L. Starting from point zero, the temperatures of the gas inside the dust removal duct are t0, t1, t2...t n , where t0, t n The measurements obtained from t1 to t2 inside the pipe were obtained through testing. n-1 The temperature loss per meter within the dust collection duct is calculated. The outer wall temperature corresponding to each graduation on the outer wall of the dust collection duct is directly measured, and is t. 外0 t 外1 t 外2 ...t 外n Calculate the temperature loss between the inside and outside of the dust removal pipe at the corresponding scale positions, denoted as X1, X2, X3...X nBecause the diameter of a typical furnace dust removal pipe is 2-3 meters, four measurement paths are evenly formed along the side of the pipe according to its layout. The direction (north, south, east, west) is marked at each scale position. That is, four directions are set along the circumference of the pipe, and each direction is marked as X. 1东 X 1西 X 1南 X 1北 ...X n东 X n西 X n南 X n北 .

[0031] Through calculation, X is obtained. 1东 X 1西 X 1南 X 1北 ...X n东 X n西 X n南 X n北 The point with the greatest temperature loss indicates that the adhesion inside the pipe is most pronounced at that point.

[0032] Online cleaning: Construct a cleaning ball with a diameter of 300-500mm. A hole is made in the ball, and an inflation hose is threaded through it and fixedly connected to the ball. The diameter of the inflation hose should be controlled between 20-50mm. Mark the coordinates of the location with the highest temperature loss to obtain the distance L1 from the dust collection inlet to that point. Make 8 small holes evenly spaced around the ball, each approximately 10mm in diameter, and fix metal vent holes (similar to a basketball inflation needle) to each hole.

[0033] When the blast furnace taphole is tapping slag and iron, open the valve of the dust removal branch pipe in the direction where slag and iron are not being tapped (usually, multiple tapholes in the blast furnace tap iron in turn). Place the rubber ball and the charging hose together into the dust removal pipeline. Under the strong suction, the rubber ball and charging hose are drawn into the dust removal system. Based on the hose's travel distance, fix the charging hose position when the rubber ball reaches the point of greatest temperature loss. Blow nitrogen gas at a pressure greater than 0.8 MPa into the charging hose. The nitrogen fills the rubber ball, and the high-pressure nitrogen gas exits from the outlet on the rubber ball. The rubber ball bounces under other forces, thus cleaning the deposits inside the dust removal pipeline.

[0034] As online cleaning progresses, the temperature loss at the cleaning points gradually decreases. When the temperature loss at the cleaning points decreases to the average temperature loss of the entire dust collection duct, cleaning is stopped, and the rubber ball and inflation hose are removed from the dust collection duct together.

[0035] 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 online ash removal of dust collection pipelines in front of a blast furnace, characterized in that, The steps are as follows: S1. Identify the locations with the most adhesive residue in the dust removal pipes in front of the furnace: S11. Multiple measurement paths are evenly set along the circumferential side of the dust removal pipe. The measurement paths are parallel to the center line of the dust removal pipe, and the length of each measurement path is the same as the total length of the dust removal pipe. S12. Measure the temperature of the dust inside the dust removal duct within 1 m from the air inlet and at the end of the dust removal duct and calculate the temperature difference. Calculate the temperature loss per 1 m in the dust removal duct based on the temperature difference between the two ends and the length of the dust removal duct. Then, starting from the air inlet of the dust removal duct, calculate the temperature every 1 m in the dust removal duct. S13. For each measurement path, starting from a position 1 m away from the air inlet of the dust removal duct, measure the temperature of the outer wall of the dust removal duct every 1 meter. S14. For each measurement path, calculate the difference between the dust temperature and the outer wall temperature per 1 m along the measurement path, which is taken as the inner and outer wall temperature loss. Compare the inner and outer wall temperature loss per 1 m along all measurement paths. The point with the largest inner and outer wall temperature loss is the location where the adhesion inside the dust removal pipe is most prominent. S2. Online Cleanup: S21. Make a cleaning ball with the inside of the ball connected to an inflation hose. Multiple connection holes are evenly arranged on the surface of the ball, and a metal air valve is installed in each connection hole. S22. When the blast furnace taphole is discharging slag and iron, open the valve of the dust removal pipe in the direction where slag and iron are not being discharged. Place the ball and the air-filling hose into the dust removal pipe together. Under the action of huge suction, the ball and the air-filling hose are sucked into the dust removal system. According to the running distance of the air-filling hose, when the ball just runs to the point where the temperature loss between the inner and outer walls is the greatest, fix the position of the air-filling hose. Blow high-pressure nitrogen into the air-filling hose. The nitrogen fills the ball, and the high-pressure nitrogen is discharged from the metal vent valve on the ball. The ball bounces under the action of nitrogen, thereby cleaning the adhering material inside the dust removal pipe. S23. When the temperature loss at the cleaning point is reduced to the average temperature loss of the inner and outer walls of the entire dust removal pipe, stop cleaning and remove the ball and the inflation hose together from the dust removal pipe.

2. The online dust removal method for blast furnace front dust removal pipelines as described in claim 1, characterized in that, In step S1, the number of measurement paths is ≥3.

3. The online ash removal method for blast furnace front dust removal pipelines as described in claim 1, characterized in that, In step S21, starting from the connection between the air hose and the ball, the air hose is marked along its own length at the point where the maximum temperature loss between the inner and outer walls is equal to the distance between the air hose and the air inlet, so as to facilitate the identification of the running distance of the air hose in the dust removal pipeline.

4. The online ash removal method for blast furnace front dust removal pipelines as described in claim 1, characterized in that, In step S21, the outer diameter of the ball is 300-500 mm, and the inner diameter of the connecting hole is 10 mm.

5. The online dust removal method for blast furnace front dust removal pipelines as described in claim 1, characterized in that, In step S21, the outer diameter of the inflation hose is 20-50 mm.

6. The online ash removal method for blast furnace front dust removal pipelines as described in claim 1, characterized in that, In step S22, the pressure of the high-pressure nitrogen gas is >0.8 MPa.

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