Method for estimating the drop position, method for operating a blast furnace, a blast furnace operation control device, and a blast furnace operation control program.

Abstract

To enhance estimation accuracy of a falling position of a blast furnace raw material falling onto a surface of a deposit in a furnace from a swing chute, in a radial direction of a blast furnace.SOLUTION: A falling position estimation method estimates a falling position of a blast furnace raw material falling onto a surface 20S of a deposit 20, in a radial direction of a blast furnace 10, on the basis of a charging condition of the blast furnace raw material, a surface shape of the deposit 20 in the blast furnace 10 before charging of the blast furnace raw material, and deposit state information of a deposit blast furnace raw material 22 deposited onto a surface 20S of the deposit 20 in the blast furnace 10, after charging of the blast furnace raw material, in a bell-less type blast furnace 10 for charging a blast furnace raw material into the blast furnace 10 by a swinging swing chute 40, and depositing the blast furnace raw material as the deposit 20 into the blast furnace 10.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The technology disclosed in the present application relates to a falling position estimation method, a blast furnace operation method, a blast furnace operation control device, and a blast furnace operation control program.

Background Art

[0002] In a bell-less blast furnace, iron ore and coke are charged into the furnace from a revolving chute, and an iron ore layer and a coke layer are alternately deposited in the furnace. In such a bell-less blast furnace, there is a measuring device for measuring the falling position of iron ore or coke that falls onto the surface of the deposit in the furnace from the revolving chute (see, for example, Patent Documents 1 to 3).

[0003] In Patent Document 1, blast furnace raw materials such as iron ore and coke that fall from the revolving chute are made to collide with an acceleration sensor that protrudes into the blast furnace from the furnace wall. And in Patent Document 1, based on the acceleration of the blast furnace raw materials measured by the acceleration sensor, the falling position of the blast furnace raw materials that fall onto the surface of the deposit in the radial direction of the blast furnace is estimated.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Patent Document 3

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, in Patent Document 1, the acceleration sensor is installed above the surface of the deposit in the furnace. Therefore, there is a possibility that the estimation accuracy of the falling position of the blast furnace raw materials that fall onto the surface of the deposit in the radial direction of the blast furnace may decrease.

[0006] The technology disclosed in this application aims to improve the accuracy of estimating the landing position of blast furnace raw materials falling from a swirling chute onto the surface of the deposits inside the blast furnace in the radial direction of the blast furnace. [Means for solving the problem]

[0007] The first embodiment of the method for estimating the drop position involves a bellless blast furnace in which blast furnace raw materials are charged into the blast furnace by a rotating chute and the blast furnace raw materials are deposited in the blast furnace, and the method estimates the drop position of the blast furnace raw materials that will fall onto the surface of the deposit in the radial direction of the blast furnace, based on the charging conditions of the blast furnace raw materials, the surface shape of the deposit in the blast furnace before the charging of the blast furnace raw materials, and information on the state of the blast furnace raw materials deposited on the surface of the deposit in the blast furnace after the charging of the blast furnace raw materials.

[0008] According to the first embodiment, the landing position of the blast furnace raw materials that fall onto the surface of the deposits is estimated in the radial direction of the blast furnace based on the charging conditions of the blast furnace raw materials, the surface shape of the deposits inside the blast furnace before charging of the blast furnace raw materials, and information on the deposit state of the blast furnace raw materials deposited on the surface of the deposits inside the blast furnace after charging of the blast furnace raw materials.

[0009] As a result, in this embodiment, the accuracy of estimating the fall position of the blast furnace raw materials can be improved compared to the case in which the fall position of the blast furnace raw materials is estimated based on the acceleration of the blast furnace raw materials measured by an acceleration sensor installed above the surface of the deposit.

[0010] The method for estimating the drop position according to the second embodiment is the method for estimating the drop position according to the first embodiment, wherein, after the blast furnace raw materials are charged, information on the deposition state of the blast furnace raw materials is obtained by measuring the surface shape of the blast furnace raw materials deposited on the surface of the deposits inside the blast furnace.

[0011] According to the second embodiment, after charging the blast furnace raw materials, information on the deposition state of the blast furnace raw materials is obtained by measuring the surface shape of the blast furnace raw materials deposited on the surface of the sediment inside the blast furnace. This makes it possible to further improve the accuracy of estimating the landing position of the blast furnace raw materials that fall onto the surface of the sediment in the radial direction of the blast furnace.

[0012] The third embodiment of the method for estimating the drop position is, in the first or second embodiment of the method for estimating the drop position, if the charging conditions for the blast furnace raw materials are the same over multiple rotations of the rotating chute, then after multiple rotations of the rotating chute, information on the deposition state of the blast furnace raw materials is obtained by measuring the surface shape of the blast furnace raw materials deposited on the surface of the deposits inside the blast furnace.

[0013] According to the third embodiment, when the charging conditions for blast furnace raw materials are the same over multiple rotations of the rotating chute, information on the deposition state of the blast furnace raw materials is obtained by measuring the surface shape of the blast furnace raw materials deposited on the surface of the deposits inside the blast furnace after multiple rotations of the rotating chute.

[0014] Here, if the charging conditions for the blast furnace raw materials are the same across multiple rotations of the rotating chute, the surface shape of the blast furnace raw materials deposited on the surface of the deposits inside the blast furnace will be roughly the same for each rotation of the rotating chute, and therefore the information on the deposit state will also be roughly the same.

[0015] Therefore, in this embodiment, when the charging conditions for blast furnace raw materials are the same over multiple rotations of the rotating chute, information on the deposition state of the blast furnace raw materials is obtained by measuring the surface shape of the blast furnace raw materials deposited on the surface of the sediment inside the blast furnace after multiple rotations of the rotating chute. This makes it possible to reduce the number of measurements of the surface shape of the blast furnace raw materials deposited on the surface of the sediment inside the blast furnace while ensuring the accuracy of estimating the landing position of the blast furnace raw materials that fall onto the surface of the sediment in the radial direction of the blast furnace.

[0016] The fourth embodiment of the method for estimating the drop position involves measuring the surface shape of the deposits inside the blast furnace for each rotation of the rotating chute, thereby obtaining information on the surface shape of the deposits inside the blast furnace before the charging of blast furnace raw materials, and information on the deposition state of the blast furnace raw materials deposited on the surface of the deposits inside the blast furnace after the charging of blast furnace raw materials.

[0017] According to the fourth embodiment, by measuring the surface shape of the deposits inside the blast furnace with each rotation of the rotating chute, information on the surface shape of the deposits inside the blast furnace before charging with blast furnace raw materials, and information on the deposition state of the blast furnace raw materials deposited on the surface of the deposits inside the blast furnace after charging with blast furnace raw materials, is obtained. By measuring the surface shape of the deposits inside the blast furnace with each rotation of the rotating chute in this way, the accuracy of estimating the drop position can be further improved.

[0018] The method for estimating the drop position according to the fifth embodiment is the method for estimating the drop position according to any one of the first to fourth embodiments, wherein the information on the deposition state of the blast furnace material includes the deposition width and apex position of the blast furnace material in the radial direction of the blast furnace.

[0019] According to the fifth embodiment, the information on the deposition state of the blast furnace material includes the deposition width and apex position of the blast furnace material in the radial direction of the blast furnace. Based on this information on the deposition state of the blast furnace material, the accuracy of estimating the deposition position can be improved by estimating the deposition position of the blast furnace material falling onto the surface of the deposit inside the blast furnace in the radial direction of the blast furnace.

[0020] The sixth embodiment of the method for estimating the drop position is the method for estimating the drop position according to any one of the first to fifth embodiments, wherein the blast furnace raw material charging conditions include the inclination angle of the swivel chute, the flow rate of the blast furnace raw material falling from the swivel chute, and the surface depth of the deposits in the blast furnace at which the charging of the blast furnace raw material begins.

[0021] According to the sixth embodiment, the blast furnace raw material charging conditions include the inclination angle of the swivel chute, the flow rate of the blast furnace raw material falling from the swivel chute, and the surface depth of the deposits inside the blast furnace at which the blast furnace raw material charging begins. Based on these charging conditions, the accuracy of estimating the landing position of the blast furnace raw material falling onto the surface of the deposits inside the blast furnace can be improved by estimating the landing position in the radial direction of the blast furnace.

[0022] The method for estimating the drop position according to the seventh embodiment involves estimating the drop position of the blast furnace raw material using the discrete element method, as described in the method for estimating the drop position according to any one of the first to sixth embodiments.

[0023] According to the seventh aspect, the dropping position of the blast furnace raw material is estimated using the discrete element method. Thereby, in the radial direction of the blast furnace, it is possible to easily improve the estimation accuracy of the dropping position of the blast furnace raw material that drops onto the surface of the deposit in the blast furnace.

[0024] In the predetermined dump for depositing a predetermined amount of deposit in the blast furnace by turning the swivel chute a plurality of times, the dropping position of the blast furnace raw material at the predetermined turning number of the swivel chute is estimated by the dropping position estimation method according to any one of the first to seventh aspects. In the subsequent dumps after the predetermined dump, the charging conditions of the blast furnace raw material are corrected so that the dropping position estimated in the predetermined dump approaches the target dropping position at the predetermined turning number of the swivel chute.

[0025] The blast furnace operation control device according to the ninth aspect includes a control unit that executes a process of estimating the dropping position of the blast furnace raw material at the predetermined turning number of the swivel chute by the dropping position estimation method according to any one of the first to seventh aspects in a predetermined dump for depositing a predetermined amount of deposit in the blast furnace by turning the swivel chute a plurality of times, and correcting the charging conditions of the blast furnace raw material so that the dropping position estimated in the predetermined dump approaches the target dropping position at the predetermined turning number of the swivel chute in the subsequent dumps after the predetermined dump.

[0026] The blast furnace operation control program according to the tenth aspect causes a computer to execute a process of estimating the dropping position of the blast furnace raw material at the predetermined turning number of the swivel chute by the dropping position estimation method according to any one of the first to seventh aspects in a predetermined dump for depositing a predetermined amount of deposit in the blast furnace by turning the swivel chute a plurality of times, and correcting the charging conditions of the blast furnace raw material so that the dropping position estimated in the predetermined dump approaches the target dropping position at the predetermined turning number of the swivel chute in the subsequent dumps after the predetermined dump.

[0027] According to the eighth to tenth embodiments, in a predetermined dump operation in which a predetermined amount of material is deposited into a blast furnace by rotating a swivel chute multiple times, the drop position of the blast furnace material at a predetermined number of rotations of the swivel chute is estimated by any one of the first to seventh embodiments. Then, in subsequent dump operations of the predetermined dump operation, the charging conditions for the blast furnace material are corrected so that the drop position estimated in the predetermined dump operation approaches the target drop position at a predetermined number of rotations of the swivel chute.

[0028] This allows the drop position of the blast furnace raw materials to be brought closer to the target drop position in subsequent dumps following a predetermined dump. As a result, the blast furnace raw materials can be deposited on the surface of the deposits inside the blast furnace with a predetermined layer thickness. Therefore, blast furnace operation can be stabilized. [Effects of the Invention]

[0029] The technology disclosed herein makes it possible to improve the accuracy of estimating the landing position of blast furnace raw materials falling from a swirling chute onto the surface of the deposits inside the blast furnace in the radial direction of the blast furnace. [Brief explanation of the drawing]

[0030] [Figure 1] This is a longitudinal cross-sectional view showing a blast furnace according to one embodiment. [Figure 2] This is a cross-sectional view showing an example of sediment deposited inside a blast furnace according to one embodiment. [Figure 3] This is a hardware configuration diagram of a blast furnace operation control device according to one embodiment. [Figure 4] This is a functional block diagram of a blast furnace operation control device according to one embodiment. [Figure 5] This graph shows the measurement results of the surface shape of the deposits inside the blast furnace and the surface shape of the deposited blast furnace raw materials, as measured by a profile meter, in an estimation test of the drop position of blast furnace raw materials according to one embodiment. [Figure 6] This flowchart shows an example of the initial processing of a blast furnace operation control process according to one embodiment. [Figure 7]This flowchart shows an example of a correction process for blast furnace operation control processing according to one embodiment. [Modes for carrying out the invention]

[0031] The following describes one embodiment of the technology disclosed in this application.

[0032] (blast furnace) Figure 1 shows a bellless blast furnace 10 according to this embodiment. Iron ore and coke, as blast furnace raw materials, are charged into the blast furnace 10 from the top 12 by a charging device 30, which will be described later. As a result, iron ore layers 20A and coke layers 20B are alternately deposited in layers within the blast furnace 10 as sediment 20.

[0033] Hot air and auxiliary fuel are blown into the blast furnace 10 from tuyeres (not shown) located at the bottom of the blast furnace 10. This causes the auxiliary fuel and coke to burn, generating rising high-temperature gas (reducing gas). This reducing gas heats and reduces the iron ore in the iron ore layer 20A formed inside the blast furnace 10 as it descends. The molten iron ore that descends is then discharged as pig iron through tapholes located in the side walls of the furnace bottom.

[0034] Note that the arrow R shown in Figure 1 indicates the radial direction of the blast furnace 10. In the following explanation, "radial direction of the blast furnace 10" will also be referred to as "blast furnace radial direction."

[0035] (Charging device) As described above, the charging device 30 charges iron ore and coke, etc., as blast furnace raw materials into the blast furnace 10 from the furnace top 12, and deposits iron ore layer 20A and coke layer 20B alternately in layers within the blast furnace 10 as deposits 20. A conveying device 32 is connected to this charging device 30. The charging device 30 also includes a switching chute 34, a pair of furnace top hoppers 36, a collection hopper 38, and a swirling chute 40.

[0036] The conveying device 32 is, for example, a belt conveyor, and conveys iron ore and coke, etc., as raw materials from a raw material tank (not shown) to a switching chute 34. The switching chute 34 is capable of switching the raw material supply destination between a pair of furnace hoppers 36. Through this switching chute 34, a predetermined amount of iron ore is supplied to one furnace hopper 36, and a predetermined amount of coke is supplied to the other furnace hopper 36.

[0037] The iron ore or coke stored in the pair of furnace top hoppers 36 is supplied to the swirling chute 40 via the collection hopper 38. The swirling chute 40 rotates around the central axis of the blast furnace 10, charging the iron ore or coke into the blast furnace 10 in layers.

[0038] Furthermore, by changing the inclination angle (tilting angle) θ of the swivel chute 40 with respect to the central axis of the blast furnace 10, the position (dropping position) of the iron ore or coke falling onto the surface 20S (see Figure 2) of the deposit 20 inside the blast furnace 10 in the radial direction of the blast furnace is adjusted. The inclination angle θ of the swivel chute 40 is controlled by a notch table (see Table 1), which will be described later.

[0039] In addition, charging a predetermined amount of iron ore and coke into the blast furnace 10 from the furnace top 12 using the charging device 30, and forming a set (two layers in total) of iron ore layer 20A and coke layer 20B throughout the entire blast furnace 10, is called one charge. Furthermore, the iron ore layer 20A and coke layer 20B can each be charged with blast furnace raw materials in multiple batches, and one operation of charging blast furnace raw materials is called one dump. The rotating chute 40 rotates multiple times during one dump.

[0040] (Overview of blast furnace operation control system) The blast furnace operation control device 50 (see Figure 4) controls the overall operation of the blast furnace 10. The blast furnace operation control device 50 also controls the charging device 30 so that, for each charge, the thickness ratio of the iron ore layer 20A and the coke layer 20B in the radial direction of the blast furnace (= thickness P2 of the iron ore layer 20A / thickness of one charge (thickness P1 of the coke layer 20B + thickness P2 of the iron ore layer 20A)) distribution becomes a predetermined target thickness ratio distribution.

[0041] Furthermore, as shown in Figure 2, when blast furnace raw materials (iron ore or coke, etc.) are charged into the blast furnace 10 from the top 12 by the charging device 30, the blast furnace operation control device 50 estimates the drop position (hereinafter referred to as "estimated drop position P") of the blast furnace raw materials that will fall from the swirling chute 40 onto the surface 20S of the deposits 20 inside the blast furnace 10. The blast furnace operation control device 50 then corrects the charging conditions of the charging device 30 that charges the blast furnace raw materials into the blast furnace 10 so that the estimated drop position P approaches a predetermined target drop position. This makes it possible to bring the layer thickness ratio distribution of the iron ore layer 20A and the coke layer 20B in the radial direction of the blast furnace closer to the target layer thickness ratio distribution.

[0042] In Figure 2, the symbol M indicates, as an example, the trajectory of the center in the radial direction of the blast furnace in the flow of blast furnace raw materials (iron ore or coke, etc.) falling from the swirling chute 40. The specific configuration and operation of the blast furnace operation control device 50 will be described later.

[0043] (Hardware configuration of blast furnace operation control system) Next, the hardware configuration of the blast furnace operation control device 50 will be described.

[0044] The blast furnace operation control device 50 is implemented, for example, by the computer 70 shown in Figure 3. The computer 70 includes a CPU (Central Processing Unit) 72, a memory 74 as a temporary storage area, and a non-volatile storage unit 76. The computer 70 also includes an input / output device 78. These CPU 72, memory 74, storage unit 76, and input / output device 78 are connected to each other via a bus 79. Note that the CPU 72 is an example of a control unit.

[0045] The storage unit 76 is implemented by, for example, an HDD (Hard Disk Drive), an SSD (Solid State Drive), or flash memory. The storage unit 76, as a recording medium, has a blast furnace operation control program pre-stored in it that enables the computer 70 to function as a blast furnace operation control device 50. The storage unit 76 is also provided with a storage area for storing various data, such as the estimated drop position P of the blast furnace raw materials.

[0046] The CPU 72 reads the blast furnace operation control program from the storage unit 76, loads it into the memory 74, and sequentially executes each process of the blast furnace operation control program. As a result, the computer 70 that executed the blast furnace operation control program functions as the blast furnace operation control device 50.

[0047] (Functions of blast furnace operation control system) Next, the functions of the blast furnace operation control device 50 will be described.

[0048] As shown in Figure 4, the blast furnace operation control device 50 uses the above-mentioned hardware resources to implement various functions when executing the blast furnace operation control program described above. Specifically, the blast furnace operation control device 50 functionally includes a charging condition acquisition unit 52, a weighing and conveying device control unit 54, a charging device control unit 56, a surface shape acquisition unit 58, a drop position estimation unit 60, and a charging condition correction unit 62.

[0049] (Charging condition acquisition department) The charging condition acquisition unit 52 acquires the charging conditions of the charging device 30 for charging blast furnace raw materials into the blast furnace 10. Specifically, the charging condition acquisition unit 52 acquires the charging conditions from, for example, the blast furnace raw material charging schedule table. The charging schedule table is a table that defines the charging conditions for the blast furnace raw materials to be charged into the blast furnace 10 for each dump, and is stored in advance in, for example, the aforementioned storage unit 76 (see Figure 3).

[0050] The charging conditions include, for example, the amount of blast furnace raw materials (coke or iron ore) charged per dump, the number of rotations of the swivel chute 40 per dump, and the flow rate of blast furnace raw materials falling from the swivel chute 40 (falling flow rate). In addition, for each rotation of the swivel chute 40, which rotates multiple times during one dump, the charging conditions include the notch of the swivel chute 40 and the surface depth L of the deposit 20 inside the blast furnace 10 at which the charging of blast furnace raw materials begins (charging stock level, see Figure 2).

[0051] The flow rate of blast furnace material falling from the rotating chute 40 is calculated, for example, based on the amount of blast furnace material charged per dump and the number of rotations of the rotating chute 40.

[0052] Furthermore, the notches of the swivel chute 40 are numbers that correspond to predetermined inclination angles θ of the swivel chute 40, as shown in the notch table in Table 1 below. This notch table is stored in advance, for example, the memory unit 76 (see Figure 3) mentioned above. Note that the inclination angles θ of the swivel chute 40 corresponding to the notches can be changed as appropriate.

[0053] [Table 1]

[0054] The charging schedule table registers, for example, the target drop position of the blast furnace raw materials for each rotation of the rotating chute 40. In addition, the charging condition acquisition unit 52 may acquire various charging conditions, not limited to the charging schedule table, but for example, input into the input / output device 78 (see Figure 3) by the blast furnace 10 manager.

[0055] (Weighing and conveying equipment control unit) The weighing and conveying device control unit 54 controls a weighing device (not shown) for each dump to weigh a predetermined amount of blast furnace raw materials (iron ore or coke, etc.) from the raw material tank. The weighing and conveying device control unit 54 also controls the conveying device 32 to transport the weighed blast furnace raw materials to the charging device 30 at the top of the furnace 12.

[0056] (Charging device control section) The charging device control unit 56 controls the rotation of the rotating chute 40 and charges blast furnace raw materials into the blast furnace 10 from the furnace top 12. At this time, the charging device control unit 56 controls the rotating chute 40 with each rotation based on the blast furnace raw material charging conditions acquired by the charging condition acquisition unit 52, and charges a predetermined amount of blast furnace raw materials into the blast furnace 10.

[0057] (Surface shape acquisition part) The surface shape acquisition unit 58 operates a profile meter (not shown) installed in the blast furnace 10 to measure the surface shape of, for example, the sediment 20 (iron ore layer 20A or coke layer 20B) deposited inside the blast furnace 10. The profile meter may be, for example, a microwave type, millimeter wave type, or optical type. The surface shape of the sediment 20 measured by this profile meter is output to the surface shape acquisition unit 58.

[0058] The surface shape of the deposit 20 refers to the shape of the surface 20S of the deposit 20 along the radial direction of the blast furnace. The surface shape of the deposit 20 may be measured at a specific cross section in the circumferential direction of the blast furnace 10, or it may be measured at multiple cross sections in the circumferential direction of the blast furnace 10. Furthermore, from the surface shape of the deposit 20 measured by the profile meter, the deposit width W in the radial direction of the blast furnace and the apex position T (see Figure 2) of the deposit 20 can be determined as information on the deposit state of the blast furnace raw materials.

[0059] (Falling position estimation part) As shown in Figure 2, the drop position estimation unit 60 estimates (calculates) the estimated drop position P of the blast furnace raw materials that will fall onto the surface 20S of the deposit 20, based on the blast furnace raw material charging conditions and the shape (surface shape) of the surface 20S of the deposit 20 before and after the charging of the blast furnace raw materials. In other words, the drop position estimation unit 60 estimates the estimated drop position P of the blast furnace raw materials that will fall onto the surface 20S of the deposit 20, based on the blast furnace raw material charging conditions, the surface shape of the deposit 20 before the charging of the blast furnace raw materials, and information on the deposition state of the blast furnace raw materials deposited on the surface 20S of the deposit 20 after the charging of the blast furnace raw materials.

[0060] For the sake of clarity, in the following explanation, blast furnace raw materials deposited on the surface 20S of the sediment 20 will be distinguished from the sediment 20 inside the blast furnace 10 and referred to as deposited blast furnace raw materials 22. However, deposited blast furnace raw materials 22 constitute a part of the sediment 20 (iron ore layer 20A or coke layer 20B).

[0061] Furthermore, the drop position of the blast furnace material (estimated drop position P) refers to the position (impact position) where the blast furnace material collides with the surface 20S of the deposit 20 in the radial direction of the blast furnace. Also, if the blast furnace material flow has width in the radial direction of the blast furnace, for example, it refers to the position (impact position) where the center of the blast furnace material flow in the radial direction collides with the surface 20S of the deposit 20.

[0062] The information regarding the deposition state of the blast furnace material 22 includes the deposition width W and apex position T of the blast furnace material 22 in the blast furnace radial direction. As mentioned above, these deposition width W and apex position T are determined from the surface shape of the blast furnace material 22 in the blast furnace radial direction, measured by a profile meter (not shown).

[0063] Furthermore, the deposition state information is not limited to the deposition width W and apex position T of the deposited blast furnace material 22, but may also be, for example, the inclination angle of the surface of the deposited blast furnace material 22 with respect to the blast furnace radial direction (inclination angle distribution). In addition, at least one of the deposition width W, apex position T, and surface inclination angle of the deposited blast furnace material 22 can be used as deposition state information.

[0064] The estimated drop position P of the blast furnace material is estimated, for example, by a simulation using the Discrete Element Method (DEM) for each rotation of the rotating chute. The method for estimating the drop position of the blast furnace material using the Discrete Element Method will be described later, along with the estimation test.

[0065] (Charging condition correction section) The charging condition correction unit 62 corrects the charging conditions for the blast furnace raw materials so that the estimated drop position P of the blast furnace raw materials, estimated by the drop position estimation unit 60, approaches a preset target drop position.

[0066] More specifically, the charging condition correction unit 62 corrects the inclination angle θ of the swivel chute 40 and at least one of the surface depth L (stock level) of the deposit 20 where the blast furnace raw material is charged, so that the estimated drop position P of the blast furnace raw material approaches the target drop position.

[0067] The inclination angle θ of the swivel chute 40 may be corrected by changing the notch of the swivel chute 40 (see Table 1), or it may be corrected by changing the inclination angle θ of the swivel chute 40 associated with the notch without changing the notch itself.

[0068] Furthermore, the target drop position for the blast furnace raw materials is predetermined for each rotation of the rotating chute 40, and may, for example, be pre-registered in the aforementioned blast furnace raw material charging schedule table.

[0069] (Estimation test of the drop location of blast furnace raw materials) Next, we will explain the estimation test for the drop location of blast furnace raw materials.

[0070] In this test, first, the surface shape of the deposit (iron ore) 20 accumulated inside the blast furnace 10 was measured using a profile meter in a test apparatus scaled down to 1 / 3 the size of the blast furnace 10. Next, blast furnace raw materials (coke) were dropped onto the surface 20S of the deposit 20 inside the blast furnace 10 from a swirling chute 40, and the accumulated blast furnace raw materials 22 were deposited on the surface 20S of the deposit 20. At this time, the landing position of the blast furnace raw materials was photographed using a high-speed camera.

[0071] Next, the shape (surface shape) of the surface 22S of the deposited blast furnace raw material 22, which is deposited on the surface 20S of the sediment 20 inside the blast furnace 10, was measured using a profile meter. In addition, the behavior of the blast furnace raw material particles when the blast furnace raw material is dropped onto the surface 20S of the sediment 20 inside the blast furnace 10 from a swirling chute 40 was simulated using the discrete element method.

[0072] The blast furnace raw material charging conditions are set according to the scale ratio of the test apparatus, as follows: The amount of blast furnace raw material charged per dump is 0.9 [t], and the number of rotations of the swivel chute 40 per dump is 10. The flow rate of the blast furnace raw material falling from the swivel chute 40 was calculated from the amount of blast furnace raw material charged per dump and the number of rotations of the swivel chute 40. The inclination angle θ of the swivel chute 40 is 48 degrees. The surface depth L of the deposit 20 before charging of blast furnace raw material is -0.075.

[0073] Figure 5 shows, as an example, the measurement results obtained by measuring the surface shape of the sediment 20 deposited inside the blast furnace 10 using a profile meter. Also, as an example, Figure 5 shows the measurement results obtained by measuring the surface shape of the deposited blast furnace raw material 22 deposited on the surface 20S of the sediment 20 using a profile meter.

[0074] In Figure 5, the horizontal axis is dimensionless, with the distance (radius) from the core (central axis) of the blast furnace 10 to the inner surface of the furnace wall 14 (see Figure 1) set to 1. The vertical axis of Figure 5 is dimensionless, with the radius of the blast furnace 10 as the reference point, relative to a predetermined level (reference level) of the blast furnace 10.

[0075] Furthermore, the stacking width W and apex position T of the stacked blast furnace material 22, which can be determined from the measurement results of the surface shape of the stacked blast furnace material 22 shown in Figure 5, are as shown in Table 2.

[0076] [Table 2]

[0077] Table 3 below shows the results of a discrete element method simulation of the behavior of blast furnace raw material particles when blast furnace raw material is dropped from a swirling chute 40 onto the surface 20S of the deposit 20 accumulated inside the blast furnace 10. Table 2 shows the simulation results for three patterns, 1 to 3.

[0078] [Table 3]

[0079] As shown in Table 2, the deposition width W (0.12) and apex position T (0.97) of the deposited blast furnace material 22, obtained from the measurement results of the surface shape of the deposited blast furnace material 22, approximate the estimated deposition width (0.120) and estimated apex position (0.968) of Simulation Result 2 shown in Table 3, respectively. From this, the estimated drop position P of the blast furnace material in the radial direction of the blast furnace is estimated to be 0.94 from Simulation Result 2.

[0080] Furthermore, the drop position of the blast furnace raw materials, as captured by the blast furnace camera, was 0.94, which matched the estimated drop position P(0.94) in this estimation test. Therefore, the validity of this estimation test was confirmed.

[0081] Furthermore, the estimated drop location P of the blast furnace raw materials can be estimated not only by the discrete element method, but also by mathematical modeling, AI (artificial intelligence), and machine learning.

[0082] (Blast furnace operation method) Next, we will explain an example of a blast furnace operation method while describing the operation of the blast furnace operation control device 50.

[0083] When blast furnace raw materials are charged into the blast furnace 10 from the furnace top 12, the blast furnace operation control device 50 executes a blast furnace operation process. The blast furnace operation process includes an initial process to obtain an estimated drop position P, and a correction process to correct the blast furnace raw material charging conditions based on the estimated drop position P. Note that the blast furnace operation process is an example of a blast furnace operation method.

[0084] (Initial processing) First, let's explain the initial processing. Initial processing is performed, for example, before each dump operation.

[0085] As shown in Figure 6, in the initial processing, first, in step S10, the CPU 72 obtains various loading conditions from the loading schedule table stored in the storage unit 76.

[0086] Next, in step S12, the CPU 72 operates a weighing device (not shown) based on the charging conditions to weigh a predetermined amount of blast furnace raw materials (coke or iron ore) from the raw material tank, and also operates a conveying device 32 to convey the weighed blast furnace raw materials to the charging device 30 at the top of the furnace 12.

[0087] Next, in step S14, the CPU 72 activates a profile meter (not shown) to measure the surface shape of the deposits 20 accumulated inside the blast furnace 10.

[0088] Next, in step S16, the CPU 72 sets a notch in the rotating chute 40 based on the charging conditions for a predetermined number of rotations (predetermined rotation number), and charges the blast furnace material into the blast furnace 10 from the rotating chute 40 while rotating the rotating chute 40 once. As a result, the deposited blast furnace material 22 is deposited on the surface 20S of the deposit 20 inside the blast furnace 10.

[0089] Next, in step S18, the CPU 72 activates a profile meter (not shown) to measure the surface shape of the blast furnace material 22 deposited on the surface 20S of the sediment 20 inside the blast furnace 10 before the charging begins with the next rotation of the rotating chute 40. Then, from the measured surface shape of the blast furnace material 22, the CPU 72 calculates the deposition width W and apex position T of the blast furnace material 22 in the radial direction of the blast furnace as information on the deposition state of the blast furnace material.

[0090] Next, in step S20, the CPU 72 estimates the estimated drop position P of the blast furnace material based on the charging conditions of the blast furnace material, the surface shape of the deposit 20 before charging the blast furnace material, and the information on the deposit state after charging the blast furnace material. The CPU 72 then stores the estimated drop position P in a predetermined storage area of ​​the storage unit 76, associating it with a predetermined number of rotations (predetermined rotation number) of the rotating chute 40.

[0091] Next, in step S22, the CPU 72 determines whether the collection hopper 38 is empty or not. If the CPU 72 determines that the collection hopper 38 is not empty, it returns to step S16. On the other hand, if the CPU 72 determines that the collection hopper 38 is empty, it terminates the process.

[0092] Through the above process, the estimated drop position P of the blast furnace raw material is estimated for each rotation of the rotating chute 40 in one dump truck, and the estimated drop position P is stored in a predetermined storage area of ​​the storage unit 76 in association with a predetermined number of rotations of the rotating chute 40.

[0093] (Correction process) Next, the correction process will be explained. The correction process is performed in subsequent dumps following a predetermined dump in which the drop position estimation was performed. Specifically, the correction process is performed, for example, in the second and subsequent dumps when multiple dumps are performed consecutively. Note that the correction process can be performed at least once in subsequent dumps following a predetermined dump in which the drop position estimation was performed.

[0094] As shown in Figure 7, in the correction process, first, in step S40, the CPU 72 obtains various loading conditions from the loading schedule table stored in the storage unit 76.

[0095] Next, in step S42, the CPU 72 operates a weighing device (not shown) based on the charging conditions to weigh a predetermined amount of blast furnace raw materials (coke or iron ore, etc.) from the raw material tank, and also operates a conveying device 32 to convey the weighed blast furnace raw materials to the charging device 30 at the top of the furnace 12.

[0096] Next, in step S44, the CPU 72 corrects the blast furnace material charging conditions for each rotation of the rotating chute 40 in one dump, based on the target drop position of the blast furnace material and the estimated drop position P of the blast furnace material estimated in the initial processing. Specifically, the CPU 72 obtains the target drop position of the blast furnace material and the estimated drop position P estimated in the initial processing from the storage unit 76 for each rotation of the rotating chute 40.

[0097] Next, the CPU 72 determines whether the target drop position and the estimated drop position P of the blast furnace material coincide for each rotation of the rotating chute 40. If the CPU 72 determines that the target drop position and the estimated drop position P of the blast furnace material coincide, it does not adjust the charging conditions for the blast furnace material.

[0098] On the other hand, if the CPU 72 determines that the target drop position of the blast furnace material and the estimated drop position P do not match, it corrects the charging conditions for the blast furnace material. Specifically, the CPU 72 corrects at least one of the inclination angle θ of the swivel chute 40 and the surface depth L of the deposit where the charging of the blast furnace material begins.

[0099] As mentioned above, the inclination angle θ of the rotating chute 40 may be corrected by changing the notch of the rotating chute 40 (see Table 1), or it may be corrected by changing the inclination angle θ of the rotating chute 40 associated with the notch without changing the notch itself.

[0100] Next, in step S46, the CPU 72 sets a notch in the rotating chute 40 based on the charging conditions for blast furnace raw materials during a predetermined number of rotations of the rotating chute 40, and charges the blast furnace raw materials into the blast furnace 10 from the rotating chute 40 while rotating the rotating chute 40 once. As a result, the deposited blast furnace raw materials 22 are deposited on the surface 20S of the deposit 20 inside the blast furnace 10.

[0101] Next, in step S48, the CPU 72 determines whether the collection hopper 38 is empty or not. If the CPU 72 determines that the collection hopper 38 is not empty, it returns to step S46. On the other hand, if the CPU 72 determines that the collection hopper 38 is empty, it terminates the process.

[0102] Through the above process, for subsequent dumps of a predetermined dump after the initial processing has been performed, the charging conditions for the blast furnace raw materials are corrected for each rotation of the rotating chute 40 based on the target drop position of the blast furnace raw materials and the estimated drop position P of the blast furnace raw materials estimated during the initial processing. This makes it possible to deposit blast furnace raw materials (iron ore layer 20A or coke layer 20B) of a predetermined layer thickness inside the blast furnace 10. Therefore, the layer thickness ratio distribution of the iron ore layer 20A and coke layer 20B in the radial direction of the blast furnace can be brought closer to the target layer thickness ratio distribution.

[0103] (effect) Next, the effects of this embodiment will be described.

[0104] According to this embodiment, as described above, based on the charging conditions for blast furnace raw materials, the surface shape of the deposits 20 inside the blast furnace 10 before charging the blast furnace raw materials, and the information on the deposition state of the deposited blast furnace raw materials 22 deposited on the surface 20S of the deposits 20 inside the blast furnace 10 after charging the blast furnace raw materials, the estimated landing position P of the blast furnace raw materials that will fall onto the surface 20S of the deposits 20 is estimated in the radial direction of the blast furnace 10.

[0105] As a result, in this embodiment, the accuracy of estimating the estimated drop position P of the blast furnace raw materials can be improved compared to, for example, estimating the drop position of the blast furnace raw materials based on the acceleration of the blast furnace raw materials measured by an acceleration sensor installed above the surface 20S of the deposit 20.

[0106] Furthermore, in this embodiment, information on the deposition state of the deposited blast furnace raw materials 22 is obtained by measuring the surface shape of the deposited blast furnace raw materials 22 deposited on the surface 20S of the sediment 20 inside the blast furnace 10. This makes it possible to further improve the accuracy of estimating the estimated drop position P of the blast furnace raw materials.

[0107] Furthermore, in this embodiment, the surface shape of the deposit 20 inside the blast furnace 10 is measured with each rotation of the rotating chute 40, thereby obtaining information on the surface shape of the deposit 20 before charging the blast furnace raw materials and the deposition state of the blast furnace raw materials 22 after charging the blast furnace raw materials. By measuring the surface shape of the deposit 20 inside the blast furnace 10 with each rotation of the rotating chute 40 in this way, the estimation accuracy of the estimated drop position P can be further improved.

[0108] Furthermore, the charging conditions for the blast furnace raw materials include the inclination angle θ of the swivel chute 40, the flow rate of the blast furnace raw materials falling from the swivel chute 40, and the surface depth L of the deposits 20 inside the blast furnace 10 before the charging of the blast furnace raw materials. By estimating the estimated drop position P of the blast furnace raw materials based on these charging conditions, the accuracy of the estimation of the estimated drop position P can be improved.

[0109] Furthermore, in this embodiment, the estimated drop position P of the blast furnace material is estimated using the discrete element method. This makes it easy to improve the accuracy of the estimation of the estimated drop position P of the blast furnace material.

[0110] Furthermore, in this embodiment, in a predetermined dump, the estimated drop position P of the blast furnace raw material is estimated for each rotation of the rotating chute 40. Then, in subsequent dumps of the predetermined dump, the charging conditions for the blast furnace raw material are corrected so that the estimated drop position P of the rotating chute 40 approaches the target drop position.

[0111] This allows the drop position of the blast furnace raw materials in the swivel chute 40 to be brought closer to the target drop position during subsequent dumps after a predetermined dump. As a result, the blast furnace raw materials can be deposited on the surface 20S of the deposit 20 inside the blast furnace 10 with a predetermined layer thickness. In other words, the layer thickness ratio distribution of the iron ore layer 20A and the coke layer 20B in the radial direction of the blast furnace can be brought closer to the target layer thickness ratio distribution. Therefore, blast furnace operation can be stabilized.

[0112] (modified version) Next, a modified example of the above embodiment will be described.

[0113] In the above embodiment, in the initial processing shown in Figure 6, the estimated drop position P of the blast furnace material was estimated for each rotation of the rotating chute 40. However, if the charging conditions for the blast furnace material are the same over multiple rotations of the rotating chute 40, the surface shape of the deposited blast furnace material 22 deposited on the surface 20S of the deposit 20 inside the blast furnace 10 will be approximately the same for each rotation of the rotating chute, and therefore the information on the deposit state will also be approximately the same.

[0114] Therefore, in this modified example, when the charging conditions for blast furnace raw materials are the same over multiple rotations of the rotating chute 40, the surface shape of the accumulated blast furnace raw materials 22 is measured not after one rotation of the rotating chute 40, but after multiple rotations of the rotating chute 40 to obtain information on the accumulation state. This makes it possible to reduce the number of measurements of the surface shape of the accumulated blast furnace raw materials 22 while ensuring the estimation accuracy of the estimated drop position P of the blast furnace raw materials that fall onto the surface 20S of the accumulated material 20 in the radial direction of the blast furnace.

[0115] Furthermore, in the above embodiment, the blast furnace operation control processing executed by the CPU 72 after reading the software (program) may also be executed by various processors other than the CPU 72. Examples of such processors include PLDs (Programmable Logic Devices) such as FPGAs (Field-Programmable Gate Arrays) whose circuit configuration can be changed after manufacturing, and dedicated electrical circuits that are processors with circuit configurations specifically designed to execute specific processing, such as ASICs (Application Specific Integrated Circuits). The blast furnace operation control processing may also be executed by one of these various processors, or by a combination of two or more processors of the same or different types (for example, multiple FPGAs, and a combination of a CPU and an FPGA). More specifically, the hardware structure of these various processors is an electrical circuit that combines circuit elements such as semiconductor elements.

[0116] Furthermore, in each of the above embodiments, the blast furnace operation control program is pre-stored in the storage unit 76. However, the blast furnace operation control program may also be provided in the form of a recording medium such as a CD-ROM (Compact Disk Read Only Memory), DVD-ROM (Digital Versatile Disk Read Only Memory), or USB (Universal Serial Bus) memory. Alternatively, the program may be downloaded to the blast furnace operation control device 50 from an external device via a network.

[0117] Although one embodiment of the technology disclosed in this application has been described above, the technology disclosed in this application is not limited to the above embodiment. Furthermore, the above embodiment and various modifications may be used in appropriate combinations, and it goes without saying that the technology disclosed in this application can be implemented in various ways without departing from the gist of the technology disclosed in this application. [Explanation of Symbols]

[0118] 10 blast furnace 14 Furnace wall 20 Sediment 20S surface 22. Deposited blast furnace material (blast furnace material deposited on the surface of sediment inside the blast furnace) 40. Swinging Shot 50 Blast Furnace Operation Control System 72 CPU (Control Unit) P Drop position (drop position of blast furnace raw materials) T: The vertex position of the blast furnace material deposits in the radial direction of the blast furnace. W: Width of the blast furnace material deposit in the radial direction of the blast furnace

Claims

1. In a bellless blast furnace, blast furnace raw materials are charged into the blast furnace by a rotating chute, and the blast furnace raw materials are deposited as sediment within the blast furnace, The charging conditions for blast furnace raw materials include the inclination angle of the swivel chute, the flow rate of blast furnace raw materials falling from the swivel chute, and the surface depth of the deposits in the blast furnace at which the charging of blast furnace raw materials begins. The surface shape of the deposits inside the blast furnace before charging the blast furnace raw materials, Information on the deposition state of blast furnace raw materials deposited on the surface of the deposits inside the blast furnace after the charging of blast furnace raw materials, including deposition state information including the deposition width and apex position of the blast furnace raw materials in the radial direction, Based on this, the landing position of the blast furnace raw materials falling onto the surface of the deposit is estimated in the radial direction of the blast furnace. Method for estimating the landing position.

2. After charging the blast furnace raw materials, information on the deposition state of the blast furnace raw materials is obtained by measuring the surface shape of the blast furnace raw materials deposited on the surface of the sediment inside the blast furnace. The method for estimating the fall position according to claim 1.

3. If the charging conditions for the blast furnace raw materials are the same throughout multiple rotations of the swivel chute, information on the deposition state of the blast furnace raw materials is obtained by measuring the surface shape of the blast furnace raw materials deposited on the surface of the deposits inside the blast furnace after multiple rotations of the swivel chute. The method for estimating the fall position according to claim 1.

4. By measuring the surface shape of the deposits inside the blast furnace with each rotation of the swivel chute, information is obtained regarding the surface shape of the deposits inside the blast furnace before charging with blast furnace raw materials, and the state of the blast furnace raw materials deposited on the surface of the deposits inside the blast furnace after charging with blast furnace raw materials. The method for estimating the fall position according to claim 1.

5. Estimating the drop position of the blast furnace material using the discrete element method, The method for estimating the fall position according to claim 1.

6. A predetermined dump in which a predetermined amount of material is deposited in the blast furnace by rotating the rotating chute multiple times, wherein the dropping position of the blast furnace material at a predetermined number of rotations of the rotating chute is estimated by the dropping position estimation method described in any one of Claims 1 to 5, In subsequent dumps following the predetermined dump, the blast furnace raw material charging conditions are adjusted so that the drop position estimated in the predetermined dump approaches the target drop position for the predetermined number of rotations of the rotating chute. Blast furnace operation methods.

7. In a predetermined dump that deposits a predetermined amount of material into the blast furnace by rotating the rotating chute multiple times, the dropping position of the blast furnace material at a predetermined number of rotations of the rotating chute is estimated by the dropping position estimation method described in any one of Claims 1 to 5. In subsequent dumps following the predetermined dump, the blast furnace raw material charging conditions are adjusted so that the drop position estimated in the predetermined dump approaches the target drop position for the predetermined number of rotations of the rotating chute. A blast furnace operation control system including a control unit that performs processing.

8. In a predetermined dump that deposits a predetermined amount of material into the blast furnace by rotating the rotating chute multiple times, the dropping position of the blast furnace material at a predetermined number of rotations of the rotating chute is estimated by the dropping position estimation method described in any one of Claims 1 to 5. In subsequent dumps following the predetermined dump, the blast furnace raw material charging conditions are adjusted so that the drop position estimated in the predetermined dump approaches the target drop position for the predetermined number of rotations of the rotating chute. A blast furnace operation control program that directs processing to a computer.

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