Method for regulating high top pressure and constant pressure difference of blast furnace

Abstract

The application discloses a kind of high top pressure and the regulation and control method of fixed pressure difference of blast furnace, comprising the following operating steps: S1: before implementing high top pressure, confirm that blast furnace system is stable and proceeds in order;Blast furnace fan air release line is adjusted to 30kpa~40kpa;S2: the blast furnace belongs to the blast furnace of control edge open center operation, after improving top pressure, the edge coke ring of blast furnace coke distribution reduces a ring, after adjustment, if the furnace condition reaction still tends to edge airflow development, then the ore coke angle is simultaneously increased 0.2°~0.3°;The blast furnace belongs to the blast furnace of balance two airflow operations, after improving top pressure, the edge coke ring of blast furnace coke distribution reduces a ring;After adjustment, if the furnace condition reaction still tends to edge airflow development, then the edge ore ring is increased a ring, center coke ring number: increase 0.2~0.5 rings.This method can smoothly transition to high top pressure production state, strengthen smelting process, improve blast furnace index.

Description

Technical Field

[0001] This invention relates to the field of blast furnace ironmaking technology, and in particular to a method for controlling the high top pressure and constant pressure difference of a blast furnace. Background Technology

[0002] Increasing the top pressure of a blast furnace is beneficial for intensifying the smelting process and improving blast furnace performance. However, the blast furnace blast system needs to be strong enough to meet the high top pressure requirements of the blast furnace. Forcibly increasing the top pressure can cause accidents in the blast furnace blast system. The blast furnace gas flow distribution and the pressure difference inside the blast furnace will change significantly. If the adjustment is not timely or the adjustment method is incorrect, it will cause abnormal gas loss and blast furnace malfunction. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to provide a method for regulating the high top pressure and constant pressure difference of a blast furnace to ensure stable operation.

[0004] To solve the above-mentioned technical problems, the technical solution adopted by the present invention includes the following steps: S1: Before implementing high top pressure, confirm that the blast furnace system is operating stably and smoothly; adjust the blast furnace blower venting line to 30kPa~40kPa; S2: The blast furnace is a blast furnace with controlled edge open center operation. After increasing the top pressure, the edge coke ring of the blast furnace coke distribution is reduced by one ring. If the furnace condition reaction still tends to develop towards the edge airflow after adjustment, the ore-coke angle is increased by 0.2° to 0.3° at the same time. The blast furnace is a type of blast furnace that operates by balancing two airflows. After increasing the top pressure, the number of coke rings at the edge of the blast furnace coke distribution decreases by one ring. If the furnace condition still tends to develop towards the edge airflow after adjustment, the number of ore rings at the edge increases by one ring, and the number of coke rings at the center increases by 0.2 to 0.5 rings. The blast furnace is a type of blast furnace that operates by stabilizing the center while guiding the edge. After increasing the top pressure, the angle of the ore and coke in the upper charging system of the blast furnace is increased by 0.2° to 0.5°, and the number of central coke rings is increased by 0.1 to 0.2 rings. If the furnace condition still tends to develop towards the edge airflow after the adjustment, the edge ore ring is increased by 1 ring, and the number of central coke rings is increased by 0.2 to 0.3 rings. S3: If step S2 has no effect, then the following adjustments will be made: The blast furnace is a type of blast furnace with controlled edge open center operation. The area of ​​the tuyere at the bottom of the blast furnace is reduced by 2% to 3%. If the furnace condition still tends to develop towards the edge airflow after adjustment, the tuyere at one-sixth of the circumference is uniformly lengthened by 50 to 100 mm. The blast furnace is a type of blast furnace that operates in a balanced manner with two airflows. The area of ​​the tuyere at the bottom of the blast furnace is reduced by 3% to 5%. After the adjustment, if the furnace condition reaction tends to develop towards the edge airflow, the quarter tuyere in the circumferential direction is uniformly lengthened by 50 to 100 mm. The blast furnace is a type of blast furnace that operates by stabilizing the center at the edge. The area of ​​the tuyere at the bottom of the blast furnace is reduced by 5% to 10%. If the furnace condition still tends to develop towards the edge airflow after the adjustment, the quarter tuyere in the circumferential direction is uniformly lengthened by 50 to 100 mm. S4: After the above steps S1 or S1+S2 are implemented, the blast furnace will operate smoothly. The blast furnace can then use the top pressure to implement constant pressure difference operation and control the pressure difference ΔP between the blast furnace hot blast pressure and the top pressure to be less than 185 kPa.

[0005] Furthermore, in step S4, the baseline production policy for each blast furnace is as follows: 1780m 3 Blast furnace: top pressure 235 kPa; pressure difference ΔP < 175 kPa, cold blast pressure 420 kPa, hot blast pressure 410 kPa; 2000m 3 Blast furnace: top pressure 225 kPa; pressure difference ΔP < 150 kPa, cold blast pressure 375 kPa, hot blast pressure 375 kPa; 3200m 3 Blast furnace: top pressure 245 kPa; pressure difference ΔP < 185 kPa, cold blast pressure 440 kPa, hot blast pressure 430 kPa.

[0006] Furthermore, in step S4, the furnace condition is as follows: the feeding ruler moves normally, the gas flow distribution is normal, the top pressure is normal, and the hot air pressure is stable.

[0007] Furthermore, in step S4, if the following situations occur during production operation, it is determined that the constant pressure difference operation is not met: the material gauge stops for 20 seconds and collapses by more than 0.5m, the static pressure fluctuates by more than 20kPa, the hot air pressure suddenly increases by more than 5kPa, or the top pressure suddenly increases by more than 5kPa.

[0008] The beneficial effects of adopting the above technical solution are as follows: First, the blast furnace air supply system and gas system have the conditions for high-pressure operation; second, to adapt to high-pressure operation, the upper and lower parts of the blast furnace should be adjusted to ensure uniform and smooth gas flow, thereby achieving high top pressure operation; finally, on the basis of stable and smooth high-pressure operation, the blast furnace can implement constant pressure difference operation by utilizing the top pressure, thereby improving the blast furnace performance.

[0009] This invention enables blast furnace production to smoothly transition to a high top pressure production state, strengthens the smelting process, and improves blast furnace indicators. In addition, during blast furnace production, the blast furnace utilizes top pressure to implement constant pressure difference operation on the basis of stable operation under high pressure, which can stabilize the pressure difference level, make the blast furnace operation more stable, reduce small fluctuations in blast furnace operation, avoid the phenomenon of blast furnace blast reduction, and reduce production losses. Detailed Implementation

[0010] The present invention will now be described in further detail with reference to specific embodiments.

[0011] The invention patent for the method of controlling the high top pressure and constant pressure difference of a blast furnace includes the following steps: S1. Blast furnace air supply system parameter settings: S1.1: Before implementing high top pressure, the blast furnace is confirmed to be in a stable and smooth operating state, with smooth flow of gas and furnace charge, uniform and active operation of the hearth, and sufficient physical heat.

[0012] S1.2: The blast furnace blower venting line, i.e. the surge line, is adjusted from 40kpa~50kpa to 30kpa~40kpa. After the top pressure is increased, the blast furnace air pressure increases. Maintaining the original surge line can easily cause abnormal blast furnace venting and disrupt normal production order.

[0013] S1.3: During maintenance, the pressure of the furnace top charging system equipment and gas system is increased. The furnace top charging equipment and corresponding sealing gaskets, gas system corrugated compensators, and various maintenance manholes are inspected, replaced, and modified to meet the pressure increase requirements.

[0014] S2. Adjustment of Blast Furnace Charging System: After increasing the top pressure, the blast furnace gas flow tends to develop towards the edges. The initial adjustment principle of the charging system is to control the edge gas flow, with the adjustment intensity in the order of coke ring - ore ring - angle, gradually increasing the intensity. However, during the process of increasing the edge pressure, care should be taken to prevent the central gas flow from being blocked, causing excessive weight in the center. Therefore, the principle for adjusting the charging system is: high-pressure operation will cause the blast furnace edge gas flow to develop; adjust the upper charging system of the blast furnace to control the edge gas flow and stabilize the central gas flow.

[0015] S2.1: For blast furnaces operating with controlled edge open center: After increasing the top pressure, based on the baseline charge system, the edge coke ring of the upper part of the blast furnace is reduced by one ring, i.e., the outer ring coke ring is reduced by one ring. For example, the edge coke ring ③-② is adjusted to ②-③. If the furnace condition still tends to develop towards the edge airflow after the adjustment, the ore and coke charging angles are increased by 0.2° to 0.3° simultaneously.

[0016] S2.2: For blast furnaces operating with balanced two-stream airflow: After increasing the top pressure, based on the baseline charge system, the outer coke ring of the upper charging system is reduced by one ring, i.e., the outer coke ring is reduced by one ring. For example, the outer coke ring ③-② is adjusted to ②-③. If the furnace condition still tends to favor the edge airflow after the adjustment, the outer ore ring is increased by one ring, i.e., the outer ore ring is increased by one ring. For example, the outer ore ring ②-③ is adjusted to ③-②, and the number of central coke rings can be increased by 0.2 to 0.5 rings depending on the situation.

[0017] S2.3: For blast furnaces operating with a stable center and peripheral edge: After increasing the top pressure, based on the baseline charge system, the ore-coke angle in the upper part of the blast furnace should be increased by 0.2° to 0.5° as needed, and the number of central coke rings should be increased by 0.1 to 0.2 rings. If the furnace condition still tends to develop towards the edge airflow after adjustment, the edge ore ring should be increased by one ring, that is, the outer ring ore ring should be increased by one ring. For example, if the edge ore ring ②-③ is adjusted to ③-②, the number of central coke rings should be increased by 0.2 to 0.3 rings.

[0018] The adjustment of the charging system varies from furnace to furnace due to individual differences in the quality of raw materials and equipment for each blast furnace. The adjustment amount is determined based on the specific circumstances.

[0019] If the furnace conditions are normal after step S2 is implemented, then step S4 is implemented; if the furnace conditions are not normal after step S2 is implemented, then step S3 is implemented.

[0020] S3. Adjustment of the air supply system: High-pressure operation will cause the airflow at the edge of the blast furnace to develop. The technical route for adjusting the air supply system at the bottom of the blast furnace is to lengthen and narrow the tuyere. The order is to first lengthen the tuyere and then narrow the tuyere diameter, thereby increasing the wind speed and blast energy, so that the initial airflow distribution in the hearth is more reasonable and the activity level of the hearth is maintained.

[0021] S3.1: The blast furnace belongs to the type of blast furnace with controlled edge open center operation. Under the current furnace type benchmark blast area, the tuyere area at the bottom of the blast furnace is reduced by 2% to 3%. If the furnace condition still tends to develop towards the edge airflow after adjustment, the tuyere in the circumferential direction is uniformly lengthened by 50 to 100 mm.

[0022] S3.2: The blast furnace is a blast furnace that operates with two balanced airflows. Under the current furnace type and the standard blast area, the area of ​​the tuyere at the bottom of the blast furnace should be appropriately reduced by 3% to 5%. After the adjustment, if the furnace condition reaction tends to develop towards the edge airflow, the quarter tuyere in the circumferential direction should be uniformly lengthened by 50 to 100 mm.

[0023] S3.3: The blast furnace belongs to the type of blast furnace that operates with a stable center and a sparse edge. Under the current furnace type and the standard blast area, the area of ​​the tuyere at the bottom of the blast furnace should be appropriately reduced by 5% to 10%. If the furnace condition still tends to develop towards the edge airflow after the adjustment, the quarter tuyere in the circumferential direction should be uniformly lengthened by 50 to 100 mm.

[0024] In steps S2 and S3 above, the adjustment process for the upper and lower parts needs to be carried out gradually depending on the furnace condition. If the adjustment of the upper charging system promotes the two airflows to reach equilibrium, it is not necessary to adjust the air supply system. Conversely, if the effect is not good, the air supply system needs to be adjusted.

[0025] The charging system and the blast system are adjustments to the upper and lower parts of the blast furnace's high top pressure. The adjustment sequence is to first adjust the charging system, and then adjust the blast system if the adjustment of the charging system is ineffective.

[0026] If the furnace conditions of each furnace are in good order after step S3 is implemented, then step S4 is implemented.

[0027] S4. Using top pressure to implement constant pressure difference operation: After the above implementation, the blast furnace will operate smoothly and can use top pressure to implement constant pressure difference operation.

[0028] The conditions for implementing constant pressure differential operation using top pressure, i.e., the standard for smooth blast furnace operation, are as follows: the charging tip travels normally, i.e., no stopping or collapsing; the gas flow distribution is normal, i.e., static pressure and top temperature are within the normal range; the top pressure is normal, i.e., no sudden rise or fall, and the fluctuation range is <5 kPa; the hot blast pressure is stable, i.e., no sudden rise or fall, and the fluctuation range is <5 kPa. Under the above conditions, constant pressure differential operation using top pressure can be implemented. Since blast furnace pressure differential = blast pressure - top pressure, the constant pressure differential operation using top pressure is as follows: the blast pressure is relatively stable, and the pressure differential is controlled by adjusting the top pressure.

[0029] The baseline production guidelines for different blast furnace types are as follows: 1780m 3 The standard production guidelines for the blast furnace are: top pressure 235 kPa; pressure difference ΔP < 175 kPa, cold blast pressure 420 kPa, and hot blast pressure 410 kPa. 2000m 3 The standard production guidelines for the blast furnace are: top pressure 225 kPa; pressure difference ΔP < 150 kPa, cold blast pressure 375 kPa, and hot blast pressure 375 kPa. 3200m 3 The standard production guidelines for the blast furnace are: top pressure 245 kPa; pressure difference ΔP < 185 kPa, cold blast pressure 440 kPa, and hot blast pressure 430 kPa.

[0030] Ideally, the blast furnace automation air pressure and top pressure should be interlocked. The adjustment module should be designed with two operating scenarios: interlocking and de-interlocking. The following example uses a 3200m... 3 Let's take the blast furnace as an example: Interlocking: If the above conditions are met, implement interlocking using the top pressure difference. Based on a top pressure of 245 kPa, a pressure difference ΔP = 185 kPa, and a hot blast pressure of 440 kPa, increase the blast furnace hot blast pressure by 5 kPa to 445 kPa. Simultaneously, increase the top pressure interlocking by 5 kPa to 260 kPa, maintaining a stable ΔP = 185 kPa. Once the blast furnace interference factors are eliminated, the hot blast pressure slowly decreases to 440 kPa, and the top pressure interlocking is adjusted to 255 kPa, maintaining a stable ΔP = 185 kPa.

[0031] Chain release: The conditions for using top pressure to implement constant pressure difference operation during blast furnace production operation are not met if: the material gauge stops for 20 seconds and collapses by more than 0.5m, static pressure fluctuates by more than 20kPa, or the hot air pressure suddenly rises by more than 5kPa or the top pressure suddenly rises by more than 5kPa; if the above conditions occur, the top pressure constant pressure difference operation will not be carried out, and the chain between the air pressure and the top pressure will be released quickly.

[0032] After increasing the top pressure, the differential pressure level can be appropriately increased depending on the furnace condition. The differential pressure ΔP < 185 kPa can be adjusted to ΔP < 187 kPa. Example

[0033] A certain 1780m 3 The blast furnace is a type of blast furnace with controlled edge and open center operation. The blast furnace production policy is as follows: top pressure 235 kPa; pressure difference ΔP < 175 kPa; cold blast pressure 420 kPa; hot blast pressure 410 kPa.

[0034] Normally, the top pressure is 235 kPa. Starting in 2022, the above-mentioned high top pressure adjustment method was adopted, achieving an average top pressure of 245 kPa and a maximum of 250 kPa in the production mode. The blast furnace achieved very good technical indicators. The realization of high top pressure operation is a gradual process, including steps such as fan modification, gas system and air supply system modification, and blast furnace operation adjustment. S1: Before implementing high top pressure, the blast furnace is confirmed to be in a stable and smooth operating state, with smooth flow of gas and furnace charge, uniform and active operation of the hearth, and sufficient physical heat.

[0035] From February 5th to 8th, 2022, during scheduled maintenance, the blower was upgraded and its pressure increased, raising the unit's air pressure by 8-10%. The blower outlet air pressure reached 0.50 MPa, meeting the operational requirements of the blast furnace after the air pressure was increased. Two or more units can be used as backups for each other and can be switched normally.

[0036] Adjusting the blast furnace blower venting line (surge line) from 50 kPa to 30 kPa will increase the blast furnace air pressure after the top pressure is increased. Maintaining the original surge line will easily cause abnormal blast furnace venting and disrupt normal production.

[0037] Scheduled maintenance on March 17, 2022: Inspection, replacement and modification of the furnace top charging system equipment and gas system pressure enhancement, furnace top charging equipment and corresponding sealing gaskets, gas system corrugated compensators, and various maintenance manholes to meet the pressure enhancement requirements.

[0038] S2: After maintenance on March 19, 2022, the top pressure was gradually increased from 240 kPa to 245 kPa, and the air volume of blast furnace No. 3 was increased from 3850 m³ / h. 3 / min increased to 3900m 3 / min, corresponding to an actual wind speed of around 240m / s, making the initial gas flow distribution in the blast furnace more reasonable.

[0039] On March 19, 2022, the blast furnace upper charging system was adjusted from ③-② to ②-③, that is, the outer ring coke ring was reduced by one ring and the secondary outer ring coke ring was increased by one ring, in order to appropriately control the edge airflow. The furnace condition reaction still tended to develop towards the edge airflow. At the same time, the ore-coke angle was increased by 0.2°, from 37.5° to 37.7°, as shown in Tables 1 and 2.

[0040] Table 1: Before the adjustment of the blast furnace charging system

[0041] Table 2: Blast Furnace Charging System After Adjustment

[0042] In Tables 1 and 2, SL represents the material depth; α represents the fabric angle, and α1-α6 represent 6 angles respectively.

[0043] S3: After the charging system adjustment on the 19th, and after 5 smelting cycles, it was observed that the edge airflow still tends to develop towards the edge. On March 21, 2022, the scheduled maintenance adjustment of the blast furnace lower air supply system will be carried out, and the diameter of the tuyeres will be reduced: the 12 tuyeres of φ115mm×12 and φ120mm×12 will be adjusted to φ115mm×16 and φ120mm×8; the wind speed and blast energy will be increased to make the initial airflow distribution of the hearth more reasonable and maintain the activity level of the hearth.

[0044] On March 22, 2022, the blast volume of blast furnace No. 3 was increased from 3900 m³ / h. 3 / min increased to 3950m 3 / min, the corresponding top pressure is increased from 245kpa to 250kpa, and the actual wind speed is maintained at around 240m / s, making the initial gas flow distribution of the blast furnace more reasonable.

[0045] S4: At 21:15 on April 15, 2022, the coal injection rate of blast furnace No. 3 was increased from 32t to 34t. Due to the increase in injected materials, the amount of gas in the furnace belly increased, and the blast furnace pressure difference increased from 175kPa to 180kPa. The furnace condition was observed to be normal. The ruler movement was normal (no stopping or collapse), and the gas flow distribution was normal (static pressure and top temperature were within the normal range). The top pressure interlock was increased from 245kPa to 250kPa, maintaining the blast furnace constant pressure difference at 175kPa.

[0046] At 23:30, the pressure difference stabilized and dropped to 170 kPa. The top pressure was then adjusted back to 245 kPa, and the pressure difference was maintained at the baseline value of 175 kPa.

[0047] 3#1780m 3The process of increasing the blast furnace top pressure was smooth, the equipment operated reliably, and the furnace conditions remained stable throughout the entire process. The adjustments completed in April 2022 resulted in significant improvements in blast furnace indicators by June 2022 (see Table 3). The blast furnace top pressure increased from 225 kPa to 245 kPa, and the blast air volume increased from 3800 m³ / h. 3 / min increased to 4100m 3 The average daily output increased from 5400 t / d to 6000 t / d, the coal ratio increased from 130 kg / t to 150 kg / t, and the fuel ratio decreased from 530 kg / t to 522 kg / t. The blast furnace achieved better production indicators.

[0048] Table 3: Blast Furnace Indicators Before and After Increasing Top Pressure

[0049] Example 2: A certain 2000m 3 The blast furnace is a type of blast furnace that operates by balancing two airflows. The blast furnace production policy is as follows: top pressure 225 kPa; pressure difference ΔP < 150 kPa; cold blast pressure 375 kPa; hot blast pressure 375 kPa.

[0050] Starting in 2023, the above-mentioned high top pressure adjustment method was adopted, achieving an average top pressure of 235 kPa and a maximum of 240 kPa in the production mode. The blast furnace achieved very good technical indicators.

[0051] S1: Before implementing high top pressure, the blast furnace is confirmed to be in a stable and smooth operating state, with smooth flow of gas and furnace charge, uniform and active operation of the hearth, and sufficient physical heat.

[0052] From June 15th to 18th, 2023, the blower was upgraded and its pressure increased during scheduled maintenance, raising the unit's air pressure by 8%. The blower outlet air pressure reached 0.55 MPa, meeting the operational requirements of the blast furnace after the air pressure was increased. Two or more units can be used as backups for each other and can be switched normally.

[0053] Adjusting the blast furnace blower venting line (surge line) from 50 kPa to 30 kPa will increase the blast furnace air pressure after the top pressure is increased. Maintaining the original surge line will easily cause abnormal blast furnace venting and disrupt normal production.

[0054] Scheduled maintenance on July 12, 2023: Inspection, replacement and modification of the furnace top charging system equipment and gas system pressure enhancement, furnace top charging equipment and corresponding sealing gaskets, gas system corrugated compensators, and various maintenance manholes to meet the pressure enhancement requirements.

[0055] S2: After maintenance on July 15, 2023, the top pressure was gradually increased from 225 kPa to 235 kPa, and the air volume of blast furnace No. 3 was increased from 4000 m³ / h. 3 / min increased to 4150m3 / min, corresponding to an actual wind speed of around 240m / s, making the initial gas flow distribution in the blast furnace more reasonable.

[0056] S3: On July 15, 2023, the blast furnace upper charging system was adjusted from ③-② to ②-②, that is, the outer ring coke ring was reduced by one ring, while the secondary outer ring coke ring remained unchanged, in order to appropriately control the edge airflow. The furnace condition response still tended to develop towards the edge airflow. The edge ore ring was increased by one ring, that is, the outer ring ore ring was increased by one ring, and the edge ore ring ②-③ was adjusted to ③-②.

[0057] S4: The furnace operated smoothly from July 15th to July 16th, 2023, with the top pressure set at 235 kPa.

[0058] S5: On July 17, 2023, the furnace operation was observed to be normal. The charging guide moved normally, i.e., there was no stopping or collapse; the gas flow distribution was normal, i.e., the static pressure and top temperature were within the normal range; the top pressure was normal, i.e., there was no sudden rise or fall, and the fluctuation range was <5 kPa; the hot air pressure was stable, i.e., there was no sudden rise or fall, and the fluctuation range was <5 kPa. Under the above conditions, the furnace was operated using a constant top pressure difference of 170 kPa. Example

[0059] A certain 3200m 3 The blast furnace is a type of blast furnace that operates with a controlled edge and stable center. The standard production policy for the blast furnace is: top pressure 245 kPa; pressure difference ΔP < 185 kPa; cold blast pressure 440 kPa; hot blast pressure 430 kPa.

[0060] Starting in 2025, the above-mentioned high top pressure adjustment method was adopted, achieving an average top pressure of 255 kPa and a maximum of 260 kPa in the production mode. The blast furnace achieved very good technical indicators.

[0061] S1: Before implementing high top pressure, the blast furnace is confirmed to be in a stable and smooth operating state, with smooth flow of gas and furnace charge, uniform and active operation of the hearth, and sufficient physical heat.

[0062] From September 11th to 13th, 2025, during scheduled maintenance, the blower will be upgraded and its pressure increased, raising the unit's air pressure by 10%. The blower outlet air pressure will reach 0.52 MPa, meeting the operational requirements of the blast furnace after the air pressure is increased. Two or more units can be used as backups for each other and can be switched normally.

[0063] The blast furnace blower venting line (surge line) was adjusted from 50 kPa to 35 kPa. After the top pressure was increased, the blast furnace air pressure increased. Maintaining the original surge line could easily cause abnormal blast furnace venting and disrupt normal production.

[0064] Scheduled maintenance on September 17, 2025: The equipment of the furnace top charging system and the pressure-bearing capacity of the gas system will be increased. The furnace top charging equipment and corresponding sealing gaskets, the corrugated compensator of the gas system, and all maintenance manholes will be inspected, replaced, and modified to meet the pressure increase requirements.

[0065] S2: After maintenance on September 20, 2025, the top pressure was gradually increased from 245 kPa to 250 kPa, and the blast furnace air volume was increased from 5850 m³ / h. 3 / min increased to 6000m 3 / min, corresponding to an actual wind speed of around 240m / s, making the initial gas flow distribution in the blast furnace more reasonable.

[0066] S3: On September 21, 2025, the blast furnace was operating under a controlled edge-stabilized center operation: based on the baseline charge system, the ore-coke angle at the top of the blast furnace was increased by 0.3°, and the number of central coke rings increased by 0.2 rings. On September 23, the furnace condition continued to trend towards edge airflow development, and the edge ore ring increased by one ring, i.e., the outer ring ore ring increased by one ring, and the edge ore ring ②-③ was adjusted to ③-②. On September 24, the number of central coke rings increased by 0.2 rings.

[0067] S4: The furnace operated smoothly from September 24th to 25th, 2025, with a stable top pressure of 250 kPa.

[0068] S5: On September 27, 2025, the furnace operation was observed to be smooth. Under the above conditions, the top pressure was further increased to 255 kPa for operation. Because the blast furnace is a type of blast furnace that operates with a stable center at the edge, the tuyeres area at the bottom of the blast furnace was appropriately reduced from 0.4105 m² to 0.3933 m², based on the furnace type's baseline blast area. S6: On September 29, 2025, the feeding screed traveled normally, i.e., there was no stopping or collapse; the gas flow distribution was normal, i.e., the static pressure and top temperature were within the normal range; the top pressure was normal, i.e., there was no sudden increase or decrease, and the fluctuation range was <5 kPa; the hot air pressure was stable, i.e., there was no sudden increase or decrease, and the fluctuation range was <5 kPa. Under the above conditions, the operation was carried out with a constant pressure difference of 185 kPa.

[0069] S7: According to statistics, the 3200m mentioned in this embodiment 3 Table 4 compares the economic and technical indicators of blast furnaces using conventional methods and this control method. Table 4: 3200m 3 Blast Furnace Economic and Technical Indicators .

Claims

1. A method for controlling the high top pressure and constant pressure difference of a blast furnace, characterized in that, The following steps are included: S1: Before implementing high top pressure, confirm that the blast furnace system is operating stably and smoothly; adjust the blast furnace blower venting line to 30kPa~40kPa; S2: The blast furnace is a blast furnace with controlled edge open center operation. After increasing the top pressure, the edge coke ring of the blast furnace coke distribution is reduced by one ring. If the furnace condition reaction still tends to develop towards the edge airflow after adjustment, the ore-coke angle is increased by 0.2° to 0.3° at the same time. The blast furnace is a type of blast furnace that operates by balancing two airflows. After increasing the top pressure, the number of coke rings at the edge of the blast furnace coke distribution decreases by one ring. If the furnace condition still tends to develop towards the edge airflow after adjustment, the number of ore rings at the edge increases by one ring, and the number of coke rings at the center increases by 0.2 to 0.5 rings. The blast furnace is a type of blast furnace that operates by stabilizing the center while guiding the edge. After increasing the top pressure, the angle of the ore and coke in the upper charging system of the blast furnace is increased by 0.2° to 0.5°, and the number of central coke rings is increased by 0.1 to 0.2 rings. If the furnace condition still tends to develop towards the edge airflow after the adjustment, the edge ore ring is increased by 1 ring, and the number of central coke rings is increased by 0.2 to 0.3 rings. S3: If step S2 has no effect, then the following adjustments will be made: The blast furnace is a type of blast furnace with controlled edge open center operation. The area of ​​the tuyere at the bottom of the blast furnace is reduced by 2% to 3%. If the furnace condition still tends to develop towards the edge airflow after adjustment, the tuyere at one-sixth of the circumference is uniformly lengthened by 50 to 100 mm. The blast furnace is a type of blast furnace that operates in a balanced manner with two airflows. The area of ​​the tuyere at the bottom of the blast furnace is reduced by 3% to 5%. After the adjustment, if the furnace condition reaction tends to develop towards the edge airflow, the quarter tuyere in the circumferential direction is uniformly lengthened by 50 to 100 mm. The blast furnace is a type of blast furnace that operates by stabilizing the center at the edge. The area of ​​the tuyere at the bottom of the blast furnace is reduced by 5% to 10%. If the furnace condition still tends to develop towards the edge airflow after the adjustment, the quarter tuyere in the circumferential direction is uniformly lengthened by 50 to 100 mm. S4: After the above steps S1 or S1+S2 are implemented, the blast furnace will operate smoothly. The blast furnace can then use the top pressure to implement constant pressure difference operation and control the pressure difference ΔP between the blast furnace hot blast pressure and the top pressure to be less than 185 kPa.

2. The method for controlling the high top pressure and constant pressure difference of a blast furnace according to claim 1, characterized in that, In step S4, the baseline production policy for each blast furnace is as follows: 1780m 3 Blast furnace: top pressure 235 kPa; pressure difference ΔP < 175 kPa, cold blast pressure 420 kPa, hot blast pressure 410 kPa; 2000m 3 Blast furnace: top pressure 225 kPa; pressure difference ΔP < 150 kPa, cold blast pressure 375 kPa, hot blast pressure 375 kPa; 3200m 3 Blast furnace: top pressure 245 kPa; pressure difference ΔP < 185 kPa, cold blast pressure 440 kPa, hot blast pressure 430 kPa.

3. The method for controlling the high top pressure and constant pressure difference of a blast furnace according to claim 1, characterized in that, In step S4, the furnace condition is as follows: the feeding tape moves normally, the gas flow distribution is normal, the top pressure is normal, and the hot air pressure is stable.

4. A method for controlling the high top pressure and constant pressure difference of a blast furnace according to claim 1, 2, or 3, characterized in that, In step S4, if the following situations occur during production operation, it is determined that the constant pressure difference operation is not met: the material gauge stops for 20 seconds and collapses by more than 0.5m, the static pressure fluctuates by more than 20kPa, the hot air pressure suddenly increases by more than 5kPa, or the top pressure suddenly increases by more than 5kPa.

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