Blast furnace uniform blasting equipment and method for changing angle of hot air branch pipe

Abstract

The invention belongs to the technical field of blast furnace blast, and relates to blast furnace uniform blast equipment and method for changing the inclination angle of a hot air branch pipe. The hot air branch pipes are evenly distributed in the circumferential direction of the bustle pipe, meanwhile, the inclined included angle alpha is formed between the axis of the straight pipe section of each hot air branch pipe and the radial plane of the bustle pipe, and due to the design, right-angle turning in the hot air flowing process is structurally reduced, pressure loss and vortex dissipation caused by the right-angle turning are reduced, and the heat exchange efficiency is improved. The main guide direction of the original tangential flow speed of hot air in the hot air bustle pipe is maintained, it is guaranteed that the air quantity entering all the branch pipes is basically consistent, the air quantity distribution uniformity of all the tuyeres of the blast furnace is remarkably improved, and good flow stability and adaptability are achieved. Numerical simulation verifies that the comprehensive blast uniformity is optimal under the working condition that the hot air branch pipe is inclined by 75 degrees. The blast furnace can effectively improve blast uniformity, reduce airflow deviation and energy loss and improve the stability and smelting efficiency of the blast furnace, and has good industrial application value.

Description

Technical Field

[0001] This invention belongs to the field of blast furnace blasting technology, specifically relating to a blast furnace uniform blasting device and method for changing the inclination angle of hot blast branch pipes. Background Technology

[0002] Blast furnace ironmaking is the most crucial process in modern steel production, and its stable and efficient operation largely depends on the performance of the blast furnace system. The blast furnace system typically consists of a hot blast stove, a main hot blast pipe, hot blast surround pipes, hot blast branch pipes, and tuyere sleeves. It supplies oxygen and heat to the blast furnace hearth by distributing high-temperature, high-pressure hot air along the hot blast surround pipes to each tuyere. In this process, the hot blast surround pipes arranged around the furnace not only perform the function of hot air transport but also largely determine the flow rate distribution of hot air at each tuyere, thus directly affecting the uniformity of the blast furnace system.

[0003] Uniformity of the blast system is one of the key parameters in blast furnace operation. Uneven blast can cause turbulent airflow distribution within the hearth, leading to a series of problems such as furnace temperature fluctuations, incomplete reduction, increased fuel ratio, and deteriorated burden distribution, ultimately affecting the blast furnace's smelting efficiency and lifespan. Studies have shown that maintaining a stable and uniform blast condition helps to form a good combustion zone distribution in the swirl zone and improve the permeability of the coke bed, promoting carbon-gas reaction and efficient burden reduction, thereby improving gas utilization and molten iron quality. Therefore, improving blast uniformity is an important technical path to achieving low-carbon, high-efficiency, and long-life operation of blast furnaces.

[0004] Currently, the main methods for achieving uniform blast furnace blast include adjusting the tuyere structure and blocking the tuyeres. However, these methods largely rely on feedback optimization of actual blast furnace operating parameters, resulting in limitations such as strong response lag, limited control precision, and high dependence on operators. Furthermore, these strategies cannot fundamentally solve the problem of uneven hot blast flow within the hot blast duct, especially with a large number of tuyeres or the trend towards larger blast furnaces, where the control capabilities of traditional methods become increasingly insufficient.

[0005] Therefore, starting from the blast furnace hot blast casing structure itself, systematic structural optimization and symmetry design are expected to fundamentally improve the flow distribution of hot blast within the casing, achieving a substantial improvement in blast uniformity. This not only reduces reliance on manual adjustment and intelligent control but also has broad engineering application value and profound industrial significance.

[0006] Chinese patent document CN222205298U (202421016089.6) discloses a blast furnace uniform air supply device. By setting up a hot blast gas collecting chamber, it buffers the hot blast from the hot blast stove, offsetting the unevenness of the hot blast airflow. Multiple hot blast downpipes divide the hot blast duct into multiple zones, ensuring uniform air intake at each tuyer inlet of the blast furnace and reducing the uneven distribution of the initial airflow, which is beneficial for the rational distribution and stable flow of the blast furnace gas stream. However, this technical solution does not consider the feasibility and economy of its actual layout. Because a large number of charging and blasting devices are installed above the blast furnace, there is no extra space for arranging the hot blast gas collecting chamber and hot blast downpipes. Furthermore, this technical solution requires the hot blast to be lifted above the blast furnace before distribution, greatly increasing production costs. Summary of the Invention

[0007] To address the uneven airflow distribution problem caused by structural asymmetry in traditional blast furnace systems, this invention arranges hot blast branch pipes uniformly along the circumference of the hot blast casing while simultaneously tilting the axis of the straight sections of each branch pipe at an angle α to the radial plane of the casing. This design structurally reduces right-angle turns in the hot blast flow, lowering pressure loss and eddy current dissipation, maintaining the dominant tangential velocity direction of the hot blast within the casing, and ensuring a relatively consistent airflow volume entering each branch pipe. This significantly improves the uniformity of airflow distribution at each tuyeres of the blast furnace, exhibiting excellent flow stability and adaptability. Numerical simulations have verified that the optimal overall blast uniformity is achieved when the hot blast branch pipes are tilted at 75°. This invention effectively improves blast uniformity, reduces airflow deviation and energy loss, enhances blast furnace stability and smelting efficiency, and possesses significant industrial application value.

[0008] To achieve the above objectives, the present invention adopts the following technical solution: a blast furnace uniform blasting device for changing the inclination angle of hot blast branch pipes, comprising a hot blast main pipe unit, a hot blast surrounding pipe, hot blast branch pipes, and tuyeres; The hot air main duct unit is connected to the hot air enclosure duct via a hot air inlet, and is used to send hot air into the hot air enclosure duct. Multiple hot blast branch pipes are evenly arranged along the circumference of the hot blast casing. The tuyeres are located at the ends of each hot blast branch pipe and communicate with the blast furnace hearth. Each tuyer faces the radial direction of the hot blast casing. The purpose of having each tuyer facing the radial direction of the hot blast casing is to ensure the uniformity of the combustion zone around the blast furnace circumference. The radial direction towards the hot blast casing is towards the centerline of the blast furnace, ensuring uniform charging. Each hot air branch pipe includes a straight pipe section connected to the hot air duct. The axis of the straight pipe section forms an inclined angle α with the radial plane of the hot air duct. The inclination direction of each hot air branch pipe is the same as the flow direction of the hot air within the hot air duct. The inclined design of the hot air branch pipes structurally reduces right-angle turns in the hot air flow, lowers the resulting pressure loss and eddy current dissipation, maintains the dominant direction of the original tangential flow velocity of the hot air, and ensures that the air volume entering each hot air branch pipe is basically consistent.

[0009] Preferably, in this invention, each hot air branch pipe has the same structural dimensions and the same tilt angle, with the tilt angle α ranging from 30 to 75°.

[0010] Preferably, the two hot air inlets are arranged symmetrically with respect to the central axis of the hot air duct.

[0011] Preferably, the hot air main unit of the present invention includes a first hot air main and a second hot air main; Both the first hot air main and the second hot air main are straight pipe structures; Both the first and second hot air mains are inserted tangentially to the hot air duct, and are centrally symmetrically distributed along the central axis of the duct. The straight lengths of the first and second hot air mains are greater than the radius of the hot air duct to ensure that the hot air entering the duct is tangentially directed, and that the angles at which the first and second hot air mains enter the duct are the same, thus reducing deviation. Simulation analysis revealed that this design is not only simple and low-cost, effectively improving the airflow uniformity caused by the non-centrally symmetrical structure of traditional hot air ducts, but also demonstrates good adaptability to dynamic changes in total airflow.

[0012] Preferably, in this invention, the inner diameters of the first hot air main pipe and the second hot air main pipe are the same, and the ratio of the inner diameter of the first hot air main pipe and the second hot air main pipe to the inner diameter of the hot air duct is [ratio missing]. The sum of the cross-sectional areas of the first and second hot air mains is made the same as the cross-sectional area of ​​the hot air enclosure. This ensures that when hot air enters the hot air enclosure from the first and second hot air mains, the air velocity will not fluctuate significantly, preventing changes in pressure and flow state (from laminar to turbulent) caused by changes in air velocity.

[0013] Preferably, the lengths of the first and second hot air mains are greater than the radius of the hot air enclosure. By limiting the lengths of the first and second hot air mains, they extend beyond the hot air enclosure, leaving sufficient space for pipe arrangement and enabling proper connection with the hot air main of the hot air furnace. Ensuring sufficient straight pipe sections in the first and second hot air mains allows for a stable distribution of hot air velocity, pressure, and flow state before the hot air enters the hot air enclosure.

[0014] Preferably, the tuyeres of this invention have the same diameter and length, with the tuyer diameter being 100-140 mm. The size of the hot blast casing varies depending on the size of the blast furnace, and the diameter of each tuyer also differs, generally ranging from 100 to 140 mm.

[0015] This invention also discloses a method for uniform blast furnace blowing by changing the inclination angle of the hot blast branch pipe, using the above-mentioned blowing equipment, and the steps are as follows: Hot air enters the hot air casing from the hot blast stove through the hot blast main pipe unit. The hot air forms a clockwise or counterclockwise circulating hot air flow inside the hot blast casing. Then the hot air moves along the hot blast casing. When passing through each hot blast branch pipe, the hot air continues to maintain its original tangential direction and enters the downward-sloping hot blast branch pipe section. Then the hot air flows to the tuyeres and enters the blast furnace, completing the blasting process.

[0016] Compared with the prior art, the beneficial effects of the present invention are: 1. Compared with the traditional hot blast casing structure, the blast furnace double hot blast main pipe uniform blowing device with adjustable hot blast branch pipe inclination angle reduces the problem of uneven air volume distribution caused by inconsistent relative distances between branch pipes and hot blast main pipe in the traditional hot blast casing, thereby significantly improving the uniformity of air volume distribution at each tuyer.

[0017] 2. The present invention has verified the air volume distribution at each tuyer using numerical simulation. The simulation results show that, compared with the traditional blast furnace hot blast pipe structure, under the condition that the total blast volume fluctuates by ±20%, the hot blast pipe structure corresponding to the present invention exhibits a lower standard deviation of air volume, indicating that it can significantly improve the uniformity of air volume distribution at each tuyer and has good adaptability and stability.

[0018] 3. This invention can achieve reasonable distribution of airflow within the hot blast duct, optimize the overall flow channel structure, and effectively avoid pressure loss and airflow deviation caused by right-angle turns, thereby ensuring the stability and smooth operation of the blast furnace. Attached Figure Description

[0019] Figure 1This is a schematic diagram of the blast furnace uniform blasting device with altered hot blast branch pipe angle according to Embodiment 5 of the present invention. Figure 2 This is a schematic diagram of the blast furnace uniform blast equipment with altered hot blast branch pipe angle according to Embodiment 4 of the present invention. Figure 3 This is a schematic diagram of the blast furnace uniform blasting equipment with altered hot blast branch pipe angle according to Embodiment 3 of the present invention. Figure 4 This is a schematic diagram of the blast furnace uniform blasting equipment with altered hot blast branch pipe angle according to Embodiment 2 of the present invention. Figure 5 This is a schematic diagram of the blast furnace uniform blast equipment with altered hot blast branch pipe angle according to Embodiment 1 of the present invention. Figure 6 This is a schematic diagram of a conventional hot air duct structure according to an embodiment of the present invention; In the diagram, 1 is the first hot air main pipe, 2 is the second hot air main pipe, 3 is the hot air enclosure pipe, 4 is the hot air branch pipe, 5 is the air outlet; 100 is the hot air inlet, 41 is the straight pipe section. Detailed Implementation

[0020] The technical solutions in the embodiments of the present invention will be clearly and completely described below.

[0021] The shapes of hot air ducts currently used by mainstream steel mills are as follows: Figure 6 As shown, when the main hot air duct is inserted vertically into the surrounding hot air duct, the two hot air branch inlets closest to the main duct are closest together. This causes most of the hot air to flow directly from the main duct into these two branch inlets, resulting in a larger outlet flow rate for these branch inlets. Conversely, for the branch inlets farther from the main duct, the hot air entering the corresponding branch inlet needs to flow along the main duct to the corresponding location. During this process, some airflow gradually decreases, resulting in a smaller airflow in most branch inlets farther from the main duct. In summary, this is a drawback of the traditional hot air duct structure: uneven airflow distribution caused by inconsistent relative distances between the branch inlets and the main duct.

[0022] like Figures 1-5 As shown, the present invention provides a blast furnace uniform blasting device for changing the inclination angle of hot blast branch pipes, including a hot blast main pipe unit, a hot blast surrounding pipe 3, hot blast branch pipes 4 and tuyeres 5.

[0023] The hot air main unit is connected to the hot air enclosure 3 via the hot air inlet 100, and is used to send hot air into the hot air enclosure 3.

[0024] Multiple hot blast branch pipes 4 are evenly arranged along the circumference of the hot blast casing 3 with equal spacing. The tuyeres 5 are located at the ends of each hot blast branch pipe 4 and communicate with the blast furnace hearth. Each tuyer 5 faces the radial direction of the hot blast casing 3. The hot blast branch pipes are evenly distributed along the circumference of the hot blast casing 3, with adjacent hot blast branch pipes differing by 10°, for a total of 36.

[0025] The hot air branch pipes 4 and air outlets 5 form an L-shaped structure. Each hot air branch pipe 4 includes a straight pipe section 41 connected to the hot air surrounding pipe 3. The axis of the straight pipe section 41 forms an inclined angle α with the radial plane of the hot air surrounding pipe 3. The inclined direction of each hot air branch pipe 4 is the same as the flow direction of the hot air within the hot air surrounding pipe 3. The inclination angle α in different embodiments is 30°, 45°, 60°, 75°, and 90°.

[0026] Each hot air branch pipe 4 has the same structural dimensions and the same tilt angle, with the tilt angle α ranging from 30 to 75°.

[0027] Two hot air inlets 100 are symmetrically arranged relative to the central axis of the hot air duct 3. In this embodiment, the hot air main duct unit includes a first hot air main duct 1 and a second hot air main duct 2.

[0028] Both the first hot air main duct 1 and the second hot air main duct 2 are straight pipe structures.

[0029] Both the first hot air main pipe 1 and the second hot air main pipe 2 are inserted along the tangent direction of the hot air enclosure pipe 3, and the first hot air main pipe 1 and the second hot air main pipe 2 are centrally symmetrically distributed along the central axis of the hot air enclosure pipe 3.

[0030] The first hot air main duct 1 and the second hot air main duct 2 have the same inner diameter, and the ratio of the inner diameter of the first hot air main duct 1 and the second hot air main duct 2 to the inner diameter of the hot air surrounding duct 3 is: For ease of geometric modeling, in this embodiment, the diameters of the first hot air main duct 1 and the second hot air main duct 2 are d1 = 840 mm. The radial diameter of the hot air duct 3 is 12264 mm, and the cross-sectional diameter is 1680 mm.

[0031] The lengths of the first hot air main duct 1 and the second hot air main duct 2 are greater than the radius of the hot air duct 3.

[0032] The air vent 5 has the same diameter and length, and the diameter of the air vent 5 is 120mm.

[0033] This embodiment also provides a method for uniform blast furnace blowing by changing the inclination angle of the hot blast branch pipe, using the blowing equipment described in this embodiment, and the steps are as follows: Hot air enters the hot air casing 3 from the hot blast stove through the hot blast main pipe unit. The hot air forms a clockwise or counterclockwise circulating hot air flow in the hot blast casing 3. Then the hot air moves along the hot blast casing 3. When passing through each hot blast branch pipe 4, the hot air continues to maintain its original tangential direction and enters the downward-sloping hot blast branch pipe 4. Then the hot air flows to the tuyeres 5 and enters the blast furnace, completing the blasting process.

[0034] In this embodiment, before the hot air enters the blast system from the hot blast stove, it is divided into two streams of hot air, which enter the hot blast enclosure pipe from the first hot blast main pipe 1 and the second hot blast main pipe 2, respectively. At this time, after the two streams of hot air enter the hot blast enclosure pipe tangentially, they begin to flow in the same direction along the wall of the hot blast enclosure pipe, forming a circulating hot air flow inside the hot blast enclosure pipe. Subsequently, the hot air moves along the hot blast enclosure pipe. When passing through each hot blast branch pipe, the projection of the hot air velocity on the plane of the hot blast enclosure pipe and the projection of the hot blast branch pipe axis on the plane of the hot blast enclosure pipe are in the same direction. The hot air continues to maintain its original tangential direction and enters the inclined hot blast branch pipe section. At this time, the component of the air velocity on the plane of the hot blast enclosure pipe is in the same direction as the axis of the hot blast branch pipe. Then it flows to the tuyeres and enters the blast furnace, completing the blasting process.

[0035] Example 1 like Figure 5 As shown, a blast furnace uniform blasting device that changes the angle of the hot blast branch pipe is used. The process is the same as described above. Numerical simulation is applied to study the effect on blast uniformity, and the results are as follows: The total hot blast stove of the blast furnace under standard operating conditions is 6944m³. 3 The hot air flow rate is [unspecified]. The diameters of the first hot air main duct 1 and the second hot air main duct 2 are 840 mm, and the diameter of the hot air surrounding duct is 1680 mm. The ratio of the diameter d1 of the hot air main duct to the diameter d2 of the hot air surrounding duct is 1:2. All 36 air outlets have identical parameters, with an outlet diameter d of 120 mm. All hot air branch ducts have the same structural dimensions, and their inclination direction is the direction along the tangent of the surrounding duct wall, with a uniform inclination angle α of 90°.

[0036] The influence of the symmetrical structure of the dual hot blast mains on the uniformity of blast is simulated. The hot blast flow can be known by calculating the standard deviation of the air volume at each tuyer in the blast furnace. The calculation results are shown in Table 1.

[0037] Formula for calculating standard deviation:

[0038] In the formula: This refers to the standard deviation of the airflow at the air outlet. Let m be the air volume at the i-th vent. 3 / min; The average total air volume, in meters. 3 / min; The number of wind vents; Numerical simulation and analysis showed that the standard deviation of the air volume at each tuyeres of the blast furnace was 0.364 m³ / s. 3 / min. The standard deviation of the airflow at each vent is related to the total blower volume. The total blower volume is the inlet airflow, and the airflow at each of the 36 vents is the outlet airflow. Changes in the total blower volume (inlet airflow) will correspondingly change the airflow at each vent (outlet). The total blower volume defined here is for standard operating conditions. Different total blower volumes correspond to different airflows at each vent, resulting in only one unique standard deviation. This indicates a single, specific total blower volume; therefore, its standard deviation is a fixed value.

[0039] Example 2 like Figure 4 As shown, to comprehensively compare the impact of varying hot air branch pipe tilt angles on airflow uniformity, this invention presents hot air duct structure models with different branch pipe tilt angles and performs numerical simulations. As a comparison under the same experimental conditions and hot air duct structure dimensions, the tilt angle α of the branch pipes in this comparative example is uniformly set to 75°, with all other conditions identical to Example 1. Numerical simulations show that the standard deviation of the airflow at each vent is 0.2766 m³ / s. 3 / min.

[0040] Example 3 like Figure 3 As shown, the method is the same as in Example 1, except that the tilt angle α of each hot air branch pipe is uniformly 60°. Numerical simulation calculations show that the standard deviation of the airflow at the air outlet is 0.4216 m³ / s. 3 / min.

[0041] Example 4 like Figure 2 As shown, the method is the same as in Example 1, except that the tilt angle α of each hot air branch pipe is uniformly 45°. Numerical simulation calculations show that the standard deviation of the airflow at the air outlet is 0.4457 m³ / s. 3 / min.

[0042] Example 5 like Figure 1 As shown, the method is the same as in Example 1, except that the tilt angle α of each hot air branch pipe is uniformly 30°. Numerical simulation calculations show that the standard deviation of the airflow at the air outlet is 0.4214 m³ / s. 3 / min.

[0043] Example 6 To comprehensively compare the effects of changing the inclination angle of the hot air branch pipe on the uniformity of airflow, this invention presents a traditional single hot air main pipe vertical hot air casing structure model of the same size, such as... Figure 6As shown, numerical simulations were performed as a control under the same experimental conditions and the same hot air duct structure dimensions. The numerical simulations showed that the standard deviation of the airflow at each vent was 0.6588 m³ / s. 3 / min.

[0044] Comparative Example 1-1 In actual production, to adapt to changes in total blast volume caused by variations in coke ratio and fluctuations in batch permeability, this invention compares the standard deviation of blast furnace tuyeres blast volume under different blast volumes in each embodiment, further illustrating the adaptability and robustness of the structure and equipment described in this invention, which alters the inclination angle of the hot blast branch pipe, under different total blast volumes. This comparative example is the same as Example 1, except that the total hot blast volume is increased by 20% based on the standard blast volume, reaching 8332.8 m³ / s. 3 / min. Numerical simulation calculations show that the standard deviation of the airflow at the vent is 0.9248m³ / min. 3 / min.

[0045] Comparative Examples 1-2 Same as Example 1, except that the total hot air volume is reduced by 20% from the standard air volume, to 5555.2 m³. 3 / min. Numerical simulation calculations show that the standard deviation of the airflow at the vent is 0.3418m³ / min. 3 / min.

[0046] Comparative Example 2-1 Same as Example 2, except that the total hot air volume is increased by 20% based on the standard air volume, to 8332.8 m³. 3 / min. Numerical simulation calculations show that the standard deviation of the airflow at the vent is 0.5587m³ / min. 3 / min.

[0047] Comparative Example 2-2 Same as Example 2, except that the total hot air volume is reduced by 20% from the standard air volume, to 5555.2 m³. 3 / min. Numerical simulation calculations show that the standard deviation of the airflow at the vent is 0.3635m³ / min. 3 / min.

[0048] Comparative Example 3-1 Same as Example 3, except that the total hot air volume is increased by 20% based on the standard air volume, to 8332.8 m³. 3 / min. Numerical simulation calculations show that the standard deviation of the airflow at the vent is 0.8104 m³ / min. 3 / min.

[0049] Comparative Example 3-2 Same as Example 3, except that the total hot air volume is reduced by 20% from the standard air volume, to 5555.2 m³. 3 / min. Numerical simulation calculations show that the standard deviation of the airflow at the vent is 0.5337m³ / min. 3 / min.

[0050] Comparative Example 4-1 Same as Example 4, except that the total hot air volume is increased by 20% based on the standard air volume, to 8332.8 m³. 3 / min. Numerical simulation calculations show that the standard deviation of the airflow at the vent is 0.7553m³ / min. 3 / min.

[0051] Comparative Example 4-2 Same as Example 4, except that the total hot air volume is reduced by 20% from the standard air volume, to 5555.2 m³. 3 / min. Numerical simulation calculations show that the standard deviation of the airflow at the vent is 0.5493m³ / min. 3 / min.

[0052] Comparative Example 5-1 Same as Example 5, except that the total hot air volume is increased by 20% based on the standard air volume, to 8332.8 m³. 3 / min. Numerical simulation calculations show that the standard deviation of the airflow at the vent is 0.9303m³ / min. 3 / min.

[0053] Comparative Example 5-2 Same as Example 5, except that the total hot air volume is reduced by 20% from the standard air volume, to 5555.2 m³. 3 / min. Numerical simulation calculations show that the standard deviation of the airflow at the vent is 0.6194m³ / min. 3 / min.

[0054] Comparative Example 6-1 Same as Example 6, except that the total hot air volume is increased by 20% based on the standard air volume, to 8332.8 m³. 3 / min. Numerical simulation calculations show that the standard deviation of the airflow at the vent is 1.0427m³ / min. 3 / min.

[0055] Comparative Example 6-2 Same as Example 6, except that the total hot air volume is reduced by 20% from the standard air volume, to 5555.2 m³. 3 / min. Numerical simulation calculations show that the standard deviation of the airflow at the vent is 0.6914 m³ / s. 3 / min.

[0056] Table 1. Comparison of standard deviations of blast furnace tuyeres air volume under different total blast volumes

[0057] Table 1 shows the numerical simulation results, indicating that when the total blower volume is 6944 m³ / s... 3 At a speed of / min, the standard deviation of airflow for the first five examples with inclined branch pipe angles was lower than that for Example 6 with a traditional hot air duct structure. Among them, Example 2 had the smallest standard deviation of airflow, that is, when the branch pipe inclination angle was 75°, it exhibited the smallest standard deviation of airflow at 0.2766m. 3 / min, which corresponds to the best blower uniformity, with an optimization effect of 58.013% compared to the blower uniformity optimization of Example 6.

[0058] When the total blower volume increases by 20%, it becomes 8332.8m³. 3 At / min, the standard deviation of air volume for the first 5 comparative examples was lower than that of comparative example 6-1 with traditional hot air duct structure. Among them, example 2-1 had the smallest standard deviation of air volume, that is, it still showed the best blower uniformity when the branch pipe tilt angle was 75°. Compared with comparative example 6-1, the blower uniformity optimization effect reached 46.4165%.

[0059] When the total blower volume decreases by 20% to 5555.2m³ 3 At / min, the standard deviation of air volume of the first 5 comparative examples is lower than that of the comparative example 6-2 with traditional hot air duct structure. The standard deviation of air volume of comparative example 1-2 is the smallest, and comparative example 2-2 is slightly higher than comparative example 1-2, but still much lower than comparative example 6-2. The optimization effect is still 47.4265% compared with comparative example 6-2.

[0060] In summary, under different total air volume, the standard deviation of air volume in comparative examples (1 to 5) with different hot air branch pipe angles is lower than that in comparative example 6 with traditional structure. Among them, Example 2, Comparative Example 2-1, and Comparative Example 2-2, that is, when the corresponding branch pipe tilt angle is 75°, show the best overall effect in optimizing air volume uniformity.

Claims

1. A blast furnace uniform blasting device that changes the inclination angle of hot blast branch pipes, characterized in that: It includes a hot air main duct unit, a hot air enclosure duct (3), hot air branch ducts (4), and an air outlet (5); The hot air main pipe unit is connected to the hot air enclosure pipe (3) through hot air inlets (100) evenly distributed around the central axis of the hot air enclosure pipe (3), and is used to send hot air into the hot air enclosure pipe (3) simultaneously in the counterclockwise or clockwise direction through the hot air inlets (100). Multiple hot air branch pipes (4) are evenly arranged along the circumference of the hot air surrounding pipe (3). The tuyeres (5) are located at the end of each hot air branch pipe (4) and are connected to the blast furnace hearth. Each tuyer (5) faces the radial direction of the hot air surrounding pipe (3). Each hot air branch pipe (4) includes a straight pipe section (41) connected to the hot air enclosure pipe (3). The axis of the straight pipe section (41) is inclined at an angle α with the radial plane of the hot air enclosure pipe (3). The inclination direction of each hot air branch pipe (4) is the same as the flow direction of hot air in the hot air enclosure pipe (3).

2. The blast furnace uniform blasting device for changing the inclination angle of the hot blast branch pipe according to claim 1, characterized in that: Each hot air branch pipe (4) has the same structural dimensions and the same tilt angle, with the tilt angle α ranging from 30 to 75°.

3. The blast furnace uniform blasting device for changing the inclination angle of the hot blast branch pipe according to claim 1, characterized in that: Includes two hot air inlets (100).

4. A blast furnace uniform blasting device for changing the inclination angle of hot blast branch pipes according to claim 1, characterized in that, The hot air main unit includes a first hot air main (1) and a second hot air main (2); Both the first hot air main pipe (1) and the second hot air main pipe (2) are straight pipe structures; The first hot air main pipe (1) and the second hot air main pipe (2) are both inserted along the tangent direction of the hot air enclosure pipe (3), and the first hot air main pipe (1) and the second hot air main pipe (2) are centrally symmetrically distributed along the central axis of the hot air enclosure pipe (3).

5. A blast furnace uniform blasting device for changing the inclination angle of hot blast branch pipes according to claim 4, characterized in that, The first hot air main pipe (1) and the second hot air main pipe (2) have the same inner diameter, and the ratio of the inner diameter of the first hot air main pipe (1) and the second hot air main pipe (2) to the inner diameter of the hot air surrounding pipe (3) is: .

6. A blast furnace uniform blasting device for changing the inclination angle of hot blast branch pipes according to claim 4, characterized in that: The lengths of the first hot air main pipe (1) and the second hot air main pipe (2) are greater than the radius of the hot air enclosure pipe (3).

7. A blast furnace uniform blasting device for changing the inclination angle of hot blast branch pipes according to claim 1, characterized in that: The diameter and length of the air vent (5) are the same, and the diameter of the air vent (5) is 100~140mm.

8. A method for uniform blasting in a blast furnace by changing the inclination angle of the hot blast branch pipe, characterized in that, The steps of using the blower equipment according to any one of claims 1-7 are as follows: Hot air enters the hot air casing (3) from the hot air stove through the hot air main pipe unit. The hot air forms a clockwise or counterclockwise circulating hot air flow in the hot air casing (3). Then the hot air moves along the hot air casing (3). When passing through each hot air branch pipe (4), the hot air continues to maintain its original tangential direction and enters the inclined downward hot air branch pipe (4). Then the hot air flows to the tuyeres (5) and enters the blast furnace to complete the blasting process.

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