Method for estimating the amount of coke layer collapse, method for estimating the thickness ratio distribution, blast furnace operation method, blast furnace operation control device, and blast furnace operation control program.

Abstract

To enhance estimation accuracy of a collapse amount of a coke layer, in a bell-less type blast furnace.SOLUTION: A collapse amount estimation method of a coke layer estimates a collapse amount of a coke layer 22, on the basis of an apparent thickness T1 of a deposited iron ore layer 24A formed after charging of an iron ore to a surface 20S of a deposit 20 before charging of the iron core, and a reference thickness T0 of the deposited iron ore layer 24A formed after charging of the iron ore to the surface 20S of the deposit 20 before charging of the iron ore, if it is assumed that the coke layer 22 does not collapse, in a bell-less type blast furnace 10 for charging a coke and an iron ore into the blast furnace 10 by a swinging swing chute 40, and alternately depositing the coke layer 22 and the iron core layer 24 as the deposit 20 into the blast furnace 10.SELECTED DRAWING: Figure 4

Description

Technical Field

[0001] The technology disclosed in the present application relates to a method for estimating the amount of collapse of a coke layer, a method for estimating the layer thickness ratio distribution, a blast furnace operation method, a blast furnace operation control device, and a blast furnace operation control program.

Background Art

[0002] There is an estimation method for estimating the layer thickness ratio distribution of the iron ore layer and the coke layer in the blast furnace in the radial direction of the blast furnace (see, for example, Patent Document 1).

[0003] Also, in a bell-type blast furnace, there is a coke collapse amount estimation method for estimating the amount of collapse of the coke layer due to the collision with iron ore when loading iron ore into the blast furnace and depositing an iron ore layer on the coke layer in the blast furnace (see, for example, Patent Document 2).

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0005] In the technology disclosed in Patent Document 2, before the batch of loading iron ore into the bell-type blast furnace, the surface shape of the coke layer in the blast furnace is measured, and after the batch, the surface shape of the iron ore layer deposited on the coke layer is measured. Thus, in a bell-type blast furnace, when loading iron ore in batches into the blast furnace, since an iron ore layer with a predetermined layer thickness is deposited on the coke layer in the blast furnace at once, it is difficult to accurately estimate the amount of collapse of the coke layer.

[0006] The technology disclosed in the present application aims to improve the estimation accuracy of the amount of collapse of the coke layer in a bell-less blast furnace. [Means for solving the problem]

[0007] The method for estimating the amount of coke layer collapse according to the first embodiment is a bellless blast furnace in which coke and iron ore are charged into the blast furnace by a rotating chute, and coke layers and iron ore layers are alternately deposited as sediments in the blast furnace, and the amount of coke layer collapse is estimated based on the apparent thickness of the iron ore layer formed after the charging of iron ore on the surface of the sediment before the charging of iron ore, and the reference thickness of the iron ore layer formed after the charging of iron ore on the surface of the sediment before the charging of iron ore, assuming that the coke layer does not collapse.

[0008] According to the first embodiment, the amount of coke layer collapse is estimated based on the apparent thickness of the iron ore layer formed after the charging of iron ore relative to the surface of the sediment before the charging of iron ore, and the reference thickness of the iron ore layer formed after the charging of iron ore relative to the surface of the sediment before the charging of iron ore, assuming that the coke layer does not collapse.

[0009] In this case, if the coke layer collapses as iron ore is charged into the blast furnace, the apparent thickness of the iron ore charging position becomes thinner than the reference thickness, depending on the amount of coke layer collapse. Therefore, the amount of coke layer collapse can be estimated from the apparent thickness of the iron ore layer and the reference thickness. Thus, the accuracy of estimating the amount of coke layer collapse can be improved.

[0010] The method for estimating the amount of coke layer collapse according to the second embodiment involves measuring the surface shape of the coke layer as a deposit, and measuring the surface shape of the iron ore layer formed on the coke layer after the rotating chute has rotated once, and determining the apparent thickness based on the measured surface shapes of the coke layer and the iron ore layer.

[0011] According to the second embodiment, the surface shape of the coke layer as a deposit is measured, and after the rotating chute has rotated once, the surface shape of the iron ore layer formed on the coke layer is measured, and the apparent thickness of the iron ore layer is determined based on the measured surface shapes of the coke layer and the iron ore layer.

[0012] In this case, if iron ore falls directly onto the surface of the coke layer, the amount of coke layer collapse tends to be large. Therefore, in this embodiment, as described above, the surface shape of the coke layer is measured, and after the rotating chute has rotated once, the surface shape of the iron ore layer formed on the coke layer is measured, and the apparent thickness of the iron ore layer is determined based on the measured surface shapes of the coke layer and the iron ore layer. This further improves the accuracy of estimating the amount of coke layer collapse.

[0013] The third embodiment of the coke layer collapse estimation method is the same as the first embodiment of the coke layer collapse estimation method, wherein when iron ore is charged into the blast furnace by the swirling chute, the surface shape of the deposit and the surface shape of the iron ore layer formed on the deposit are measured before and after the swirling chute has made multiple rotations, and the apparent thickness is determined based on the measured surface shapes of the deposit and the iron ore layer.

[0014] According to the third embodiment, when charging iron ore into a blast furnace by a rotating chute, the surface shape of the sediment and the surface shape of the iron ore layer formed on the sediment are measured before and after the rotating chute has rotated multiple times, and the apparent thickness of the iron ore layer is determined based on the measured surface shapes of the sediment and iron ore.

[0015] By measuring the surface shape of the sediment and the iron ore layer formed on the sediment before and after the swirling chute rotates multiple times, the apparent thickness of the iron ore layer can be easily determined while reducing the number of measurements required for the surface shape of the iron ore layer.

[0016] The fourth embodiment of the layer thickness ratio distribution estimation method estimates the amount of coke layer collapse using the coke layer collapse amount estimation method according to any one of the first to third embodiments, estimates the amount of coke layer inflow based on the apparent thickness and the reference thickness, and estimates the layer thickness ratio distribution of the coke layer and the iron ore layer in the radial direction of the blast furnace based on the estimated amount of collapse and the amount of inflow.

[0017] According to the fourth embodiment, the accuracy of estimating the thickness ratio distribution of the coke layer and the iron ore layer in the radial direction of the blast furnace can be improved.

[0018] The fifth embodiment of the layer thickness ratio distribution estimation method is the same as the fourth embodiment of the layer thickness ratio distribution estimation method, in which, when iron ore is charged into the blast furnace by the rotating chute that rotates multiple times, the surface shape of the coke layer is measured, and then, for each rotation of the rotating chute, the surface shape of the iron ore layer formed on the coke layer is measured, and the layer thickness of the iron ore layer is determined based on the measured surface shapes of the coke layer and the iron ore layer.

[0019] According to the fifth embodiment, the accuracy of estimating the thickness ratio distribution of the coke layer and the iron ore layer in the radial direction of the blast furnace can be further improved.

[0020] In the sixth embodiment of the blast furnace operation method, iron ore and coke are charged into the blast furnace by a rotating chute, and in a predetermined charge in which a set of iron ore layers and coke layers are sequentially deposited in the blast furnace, the layer thickness ratio distribution of the coke layer and the iron ore layer in the radial direction of the blast furnace is estimated by the layer thickness estimation method according to the fourth or fifth embodiment, and in subsequent charges after the predetermined charge, the charging conditions for iron ore or coke are corrected so that the layer thickness ratio distribution estimated in the predetermined charge approaches the target layer thickness ratio distribution of the coke layer and the iron ore layer in the radial direction of the blast furnace.

[0021] According to the sixth aspect, in the charge after the next charge of a predetermined charge, the layer thickness ratio distribution of the coke layer and the iron ore layer in the radial direction of the blast furnace can be made closer to the target layer thickness ratio distribution. Therefore, the blast furnace operation can be stabilized.

[0022] The blast furnace operation method according to the seventh aspect is the blast furnace operation method according to the sixth aspect, wherein the charging conditions include the inclination angle of the swivel chute, the number of revolutions of the swivel chute, the charging amounts of iron ore and coke, and the surface depth of the deposit in the blast furnace before starting the charging of iron ore or coke.

[0023] According to the seventh aspect, by correcting the above charging conditions, the layer thickness ratio distribution of the coke layer and the iron ore layer can be made closer to the target layer thickness ratio distribution. Therefore, the blast furnace operation can be stabilized.

[0024] The blast furnace operation control device according to the eighth aspect loads iron ore and coke into the blast furnace by a swiveling swivel chute, and in a predetermined charge in which a set of iron ore layer and coke layer are sequentially deposited in the blast furnace, estimates the layer thickness ratio distribution of the coke layer and the iron ore layer in the radial direction of the blast furnace by the layer thickness estimation method according to the fourth aspect or the fifth aspect, and in the charge after the next charge of the predetermined charge, corrects the charging conditions of iron ore or coke so that the layer thickness ratio distribution estimated in the predetermined charge approaches the target layer thickness ratio distribution of the coke layer and the iron ore layer in the radial direction of the blast furnace, and executes the process.

[0025] The blast furnace operation control program according to the ninth aspect causes a computer to execute a process of charging iron ore and coke into a blast furnace by a rotating rotary chute, and depositing a set of iron ore layers and coke layers in the blast furnace in order in a predetermined charge. By using the layer thickness estimation method according to the fourth aspect or the fifth aspect, the layer thickness ratio distribution of the coke layer and the iron ore layer in the radial direction of the blast furnace is estimated, and in the charge after the next charge of the predetermined charge, the iron ore or coke charging conditions are corrected so that the layer thickness ratio distribution estimated in the predetermined charge approaches the target layer thickness ratio distribution of the coke layer and the iron ore layer in the radial direction of the blast furnace.

[0026] According to the eighth and ninth aspects, in the charge after the next charge of the predetermined charge, the layer thickness ratio distribution of the coke layer and the iron ore layer can be made closer to the target layer thickness ratio distribution. Therefore, the blast furnace operation can be stabilized.

Effect of the Invention

[0027] According to the technology disclosed in the present application, as one aspect, in a bell-less blast furnace, the estimation accuracy of the amount of collapse of the coke layer can be improved.

Brief Description of the Drawings

[0028] [Figure 1] It is a longitudinal sectional view showing a blast furnace according to an embodiment. [Figure 2] It is a hardware configuration diagram of a blast furnace operation control device according to an embodiment. [Figure 3] It is a functional block diagram of a blast furnace operation control device according to an embodiment. [Figure 4] It is a cross-sectional view showing an example of deposits deposited in a blast furnace according to an embodiment. <"0000113"> [Figure 5] It is a graph showing the measurement results of the surface shapes of the coke layer and the deposited iron ore in the blast furnace measured by a profiler in an estimation test of the amount of collapse and the amount of inflow of the coke layer according to an embodiment. [Figure 6]This graph shows the measurement results of the surface shape of the coke layer and deposited iron ore inside the blast furnace, measured by a profile meter, in an estimation test of the amount of coke layer collapse and inflow according to one embodiment. [Figure 7] This graph shows the relationship between the collapse thickness of the coke layer according to one embodiment and the ratio of the apparent thickness and reference thickness of the sedimentary iron ore. [Figure 8] This graph shows the relationship between the inflow thickness of the coke layer according to one embodiment and the ratio of the apparent thickness and reference thickness of the sedimentary iron ore. [Figure 9] This flowchart shows an example of the estimation process for blast furnace operation control processing according to one embodiment. [Figure 10] This flowchart shows an example of a correction process for blast furnace operation control processing according to one embodiment. [Figure 11] This graph shows the test results of an estimation test of the layer thickness ratio distribution of the coke layer and iron ore layer according to one embodiment. [Modes for carrying out the invention]

[0029] The following describes one embodiment of the technology disclosed in this application.

[0030] (blast furnace) Figure 1 shows a bellless blast furnace 10 according to this embodiment. Coke and iron ore, etc., 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, layers of coke 22 and iron ore 24, which serve as deposits 20, are alternately deposited in layers inside the blast furnace 10.

[0031] 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 24 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.

[0032] 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."

[0033] (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 layers of coke 22 and iron ore 24 alternately in the blast furnace 10 as sediment 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.

[0034] The conveying device 32 is, for example, a belt conveyor, and conveys iron ore and coke 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, for example, 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.

[0035] 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.

[0036] 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 radial position (drop position) of the iron ore or coke falling onto the surface 20S of the deposit 20 inside the blast furnace 10 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.

[0037] 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 24 and coke layer 22 throughout the entire area of ​​the blast furnace 10, is called one charge. Furthermore, the iron ore layer 24 and coke layer 22 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.

[0038] (Overview of blast furnace operation control system) The blast furnace operation control device 50 (see Figure 3) controls the overall operation of the blast furnace 10. The blast furnace operation control device 50 also estimates the amount of collapse and flow of the coke layer 22 that constitutes the deposit 20 inside the blast furnace 10 when iron ore is charged into the blast furnace 10 by the charging device 30.

[0039] The blast furnace operation control device 50 then determines the layer thickness ratio distribution of the coke layer 22 and the iron ore layer 24 (= layer thickness P2 of the iron ore layer 24 / layer thickness of 1 charge (layer thickness P1 of the coke layer 22 + layer thickness P2 of the iron ore layer 24)) based on the estimated amount of coke layer collapse and flow rate of the coke layer 22, and corrects the charging conditions of the charging device 30 that charges blast furnace raw materials (coke or iron ore) into the blast furnace 10 so that the said layer thickness ratio distribution approaches a predetermined target layer thickness ratio distribution. This makes it possible to stabilize the operation of the blast furnace.

[0040] The specific configuration and operation of the blast furnace operation control device 50 will be described later.

[0041] (Hardware configuration of blast furnace operation control system) Next, the hardware configuration of the blast furnace operation control device 50 will be described.

[0042] The blast furnace operation control device 50 is implemented, for example, by the computer 70 shown in Figure 2. 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.

[0043] 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 amount of coke layer collapse and the amount of coke flowing into the coke layer 22.

[0044] 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.

[0045] (Functions of blast furnace operation control system) Next, the functions of the blast furnace operation control device 50 will be described.

[0046] As shown in Figure 3, 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 collapse amount estimation unit 60, an inflow amount estimation unit 62, a layer thickness ratio distribution estimation unit 64, and a charging condition correction unit 66.

[0047] (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 (coke and iron ore) 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 2).

[0048] 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 (drop rate) of the blast furnace raw materials falling from the swivel chute 40. 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 (charging stock level, see Figure 4) of the deposit 20 inside the blast furnace 10 at which the charging of blast furnace raw materials begins.

[0049] 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.

[0050] The notches on 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. The inclination angles θ of the swivel chute 40 corresponding to the notches can be changed as appropriate.

[0051] [Table 1]

[0052] Furthermore, the charging condition acquisition unit 52 may acquire not only the charging schedule table, but also various charging conditions input to the input / output device 78 (see Figure 2) by, for example, the manager of the blast furnace 10.

[0053] (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.

[0054] (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.

[0055] (Surface shape acquisition part) The surface shape acquisition unit 58 operates a profile meter (not shown) installed in the blast furnace 10 to measure, for example, the surface shape of the sediment 20 (coke layer 22 or iron ore layer 24) or the sedimented iron ore layer 24A described later, which is deposited inside the blast furnace 10. The profile meter may be 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.

[0056] 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. Furthermore, the surface shapes of the deposit 20 and the deposited iron ore layer 24A may be measured at a specific cross section in the circumferential direction of the blast furnace 10, or at multiple cross sections in the circumferential direction of the blast furnace 10.

[0057] (Collapse amount estimation unit) Iron ore, used as a blast furnace raw material, has a higher density and smaller particle size than coke. Therefore, as shown in Figure 4, when iron ore is dropped (collides) onto the coke layer 22 inside the blast furnace 10, the region of the coke layer 22 where the iron ore falls (hereinafter referred to as the "collapse region R1") collapses in the radial direction of the blast furnace and flows out toward the central axis of the blast furnace 10. This phenomenon is called the collapse of the coke layer 22, and the volume of coke that flows out from the collapse region R1 of the coke layer 22 is called the amount of coke layer 22 collapse.

[0058] The amount of coke layer 22 collapse can be determined, for example, by integrating the area of ​​the portion where the thickness of the coke layer 22 decreases in the collapse region R1 of the coke layer 22 in the circumferential direction of the blast furnace 10.

[0059] In addition, the symbol M shown in Figure 4, etc., indicates, as an example, the falling trajectory of the center in the blast furnace diameter direction in the flow of iron ore falling from the swirling chute 40.

[0060] When the coke layer 22 collapses, coke flows out in the collapsed region R1 of the coke layer 22, causing the thickness of the coke layer 22 to decrease. Therefore, simply measuring the surface shape of the coke layer 22 and the surface shape of the iron ore layer 24 deposited on the surface of the coke layer 22 after the swivel chute 40 has been rotated multiple times (after one dump) using a profile meter or the like does not allow for an understanding of the amount of collapse of the coke layer 22, and the accuracy of estimating the thickness ratio distribution of the iron ore layer 24 and the coke layer 22 decreases.

[0061] Here, as shown in Figure 6, the apparent thickness T1 is defined as the thickness (solid line) of the iron ore layer (hereinafter referred to as "sedimented iron ore layer 24A") formed on the surface 20S (dotted line) of the sediment 20 (including the coke layer 22) after the iron ore is charged, relative to the surface 20S (dotted line) of the sediment 20 before the iron ore is charged. Furthermore, assuming that the coke layer 22 does not collapse, the reference thickness T0 is defined as the thickness (dotted line) of the sedimented iron ore layer 24A formed on the surface 20S (dotted line) of the sediment 20 after the iron ore is charged, relative to the surface 20S (dotted line) of the sediment 20 before the iron ore is charged.

[0062] The apparent thickness T1 and reference thickness T0 of the sedimentary iron ore layer 24A are the thicknesses of the sedimentary iron ore layer 24A at any position in the radial direction of the blast furnace. Furthermore, the sedimentary iron ore layer 24A is a component of the iron ore layer 24, and the iron ore layer 24 is formed by stacking multiple sedimentary iron ore layers 24A. Figure 6 will be described later in the estimation test.

[0063] When a collapse occurs in the coke layer 22 within the sediment 20, the apparent thickness T1 of the sedimentary iron ore layer 24A at the iron ore charging position becomes thinner than the reference thickness T0 in the collapsed region R1 of the coke layer 22, depending on the amount of collapse of the coke layer 22. Therefore, the amount of collapse of the coke layer 22 can be estimated from the ratio of the apparent thickness T1 of the sedimentary iron ore layer 24A to the reference thickness T0. Accordingly, the collapse amount estimation unit 60 estimates the amount of collapse of the coke layer 22 based on the apparent thickness T1 of the sedimentary iron ore layer 24A and the reference thickness T0.

[0064] The apparent thickness T1 of the sedimentary iron ore layer 24A is determined from the surface shape of the sediment 20 and the surface shape of the sedimentary iron ore layer 24A, measured by a profile meter or the like before and after the charging of iron ore. Note that the apparent thickness T1 of the sedimentary iron ore layer 24A will be negative if there is a large amount of collapse of the coke layer 22.

[0065] The standard thickness T0 of the sedimentary iron ore layer 24A is calculated based on the surface shape of the sediment 20 measured by a profile meter, for example, and the amount of iron ore charged. Specifically, the standard thickness T0 of the sedimentary iron ore layer 24A is calculated from the thickness of the sedimentary iron ore layer 24A when a predetermined amount of iron ore is uniformly deposited on the surface shape of the sediment 20 measured by a profile meter, etc., before the iron ore is charged, and the weight and bulk density of the iron ore charged in one rotation of the swivel chute 40, or it can be determined by numerical calculation or simulation.

[0066] (Inflow rate estimation unit) As shown in Figure 4, when the coke layer 22 collapses, coke flows in from the collapse region R1 to the region on the central axis side of the blast furnace 10 (hereinafter referred to as the "inflow region R3"), causing the thickness of the coke layer 22 to increase. The volume of coke that flows from the collapse region R1 to the inflow region R3 of the coke layer 22 in this way is called the inflow amount of the coke layer 22.

[0067] The amount of coke layer 22 flowing in can be determined, for example, by integrating the area of ​​the portion where the thickness of the coke layer 22 increases in the coke layer 22 flow region R3 in the circumferential direction of the blast furnace 10.

[0068] Furthermore, the region between the collapse region R1 and the inflow region R3 of the coke layer 22 in the radial direction of the blast furnace (hereinafter referred to as the "intermediate region R2") will be described later in the estimation test.

[0069] As mentioned above, in the inflow region R3, coke flows in, causing the thickness of the coke layer 22 to increase. Therefore, simply measuring the surface shape of the coke layer 22 and the surface shape of the iron ore layer 24 deposited on the surface of the coke layer 22 after the swivel chute 40 has been rotated multiple times (after one dump) using a profile meter or the like does not allow for an understanding of the amount of coke layer 22 that has flowed in, and thus the accuracy of estimating the thickness ratio distribution of the iron ore layer 24 and the coke layer 22 decreases.

[0070] Here, as shown in Figure 6, when flow occurs into the coke layer 22 within the sediment 20, the apparent thickness T1 of the sedimentary iron ore layer 24A becomes thicker than the reference thickness T0 in the flow region R3, depending on the amount of coke layer 22 flowing in. Therefore, the amount of coke layer 22 flowing in can be estimated from the ratio of the apparent thickness T1 of the sedimentary iron ore layer 24A to the reference thickness T0. Accordingly, the collapse amount estimation unit 60 estimates the amount of coke layer 22 flowing in based on the apparent thickness T1 of the sedimentary iron ore layer 24A and the reference thickness T0.

[0071] (Thickness ratio distribution estimation section) The layer thickness ratio distribution estimation unit 64 estimates (calculates) the layer thickness ratio distribution of the coke layer 22 and the iron ore layer 24 in the radial direction of the blast furnace, based on the surface shape of the coke layer 22, the surface shape of the iron ore layer 24, and the amount of collapse and inflow of the coke layer 22 estimated by the collapse amount estimation unit 60.

[0072] (Charging condition correction section) The charging condition correction unit 66 corrects the charging conditions for blast furnace raw materials so that the layer thickness ratio distribution of the coke layer 22 and the iron ore layer 24 estimated by the layer thickness ratio distribution estimation unit 64 approaches the target layer thickness ratio distribution.

[0073] Specifically, the charging condition correction unit 66 corrects at least one of the following so that the layer thickness ratio distribution of the coke layer 22 and the iron ore layer 24 estimated by the layer thickness ratio distribution estimation unit 64 approaches the target layer thickness ratio distribution: the inclination angle θ of the swivel chute 40, the number of rotations of the swivel chute 40, the amount of blast furnace raw materials charged, and the surface depth L of the deposit 20 where the blast furnace raw materials are to be charged.

[0074] 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.

[0075] (Estimation test of coke layer collapse and inflow volume) Next, we will explain the estimation tests for the amount of coke collapse and flow in the coke layer 22.

[0076] As shown in Figures 5 and 6, in this test, first, the surface shape of the coke layer 22, which is the deposit 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, iron ore was charged into the blast furnace 10 while rotating the swivel chute 40 once, and the deposited iron ore layer 24A was deposited on the surface 22S of the coke layer 22 inside the blast furnace 10. Then, the surface shape (surface shape) of the deposited iron ore layer 24A was measured using a profile meter.

[0077] Next, multiple electrical resistance thickness gauges were inserted into the coke layer 22 and the deposited iron ore layer 24A inside the blast furnace 10 at predetermined intervals in the radial direction of the blast furnace, and the boundary between the coke layer 22 and the deposited iron ore layer 24A (thick solid line, surface 22S) after the iron ore was charged was measured.

[0078] Next, iron ore was charged into the blast furnace 10 while rotating the swivel chute 40 multiple times. This caused multiple layers of deposited iron ore 24A to be deposited in layers on the surface 22S of the coke layer 22, forming an iron ore layer 24. During this process, the surface shape of the deposited iron ore layer 24A was measured using a profile meter after each rotation of the swivel chute 40.

[0079] Figure 5 shows the surface shapes of the coke layer 22 and the sedimentary iron ore layer 24A as measured by a profile meter. Figure 6 shows the coke layer 22 as measured by a profile meter, represented by a dashed line. Figure 6 also shows the surface shape of the sedimentary iron ore layer 24A as measured by a profile meter after the first rotation of the swivel chute 40, represented by a solid line. Furthermore, Figure 6 shows the boundary between the coke layer 22 and the sedimentary iron ore layer 24A as measured by multiple electrical resistance thickness gauges after the first rotation of the swivel chute 40, represented by a thick solid line (surface 22S).

[0080] In Figures 5 and 6, 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 in Figures 5 and 6 is dimensionless, with the radius of the blast furnace as the reference point from a predetermined level (reference level) of the blast furnace 10. Furthermore, "0" on the vertical axis in Figures 5 and 6 indicates the reference level (reference stock level).

[0081] As shown in Figure 6, in the collapse region R1 of the coke layer 22, the surface height of the deposited iron ore layer 24A after the charging of iron ore (solid line) is almost unchanged from the surface height 22S (dotted line) of the coke layer 22 before the charging of iron ore, and the boundary between the coke layer 22 and the deposited iron ore layer 24A (thick solid line) is lower than the surface height 22S (dotted line) of the coke layer 22 before the charging of iron ore. From this, it can be seen that a collapse occurred in the coke layer 22.

[0082] In this case, in the collapse region R1 of the coke layer 22, the apparent thickness T1 of the deposited iron ore layer 24A after the first rotation of the rotating chute 40 becomes almost zero, which is much thinner than the standard thickness T0 that would be assumed if no collapse occurred in the coke layer 22. At this time, the coke that was in the position where the iron ore was charged is ejected towards the central axis of the blast furnace 10 due to the impact of the falling iron ore. Furthermore, the reduction in the thickness of the coke layer 22 (hereinafter referred to as "collapse thickness V1", see Figure 4) can be estimated from the ratio of the standard thickness T0 to the apparent thickness T1 of the deposited iron ore layer 24A.

[0083] On the other hand, in the inflow region R3 of the coke layer 22, the boundary (thick solid line) between the coke layer 22 after the charging of iron ore and the deposited iron ore layer 24A is higher than the surface 22S (dotted line) of the coke layer 22 before the charging of iron ore, and the deposited iron ore layer 24A is deposited on this surface 22S.

[0084] In this case, the apparent thickness T1 of the sedimentary iron ore layer 24A is greater than the reference thickness T0. From this, it can be seen that the coke that flowed out from the collapse region R1 of the coke layer 22 flowed into the inflow region R3. Furthermore, the increase in the thickness of the coke layer 22 (hereinafter referred to as "inflow thickness V2," see Figure 4) can be estimated from the ratio of the reference thickness T0 to the apparent thickness T1 of the sedimentary iron ore layer 24A.

[0085] Furthermore, in the intermediate region R2 between the collapse region R1 and the inflow region R3 of the coke layer 22, the boundary (thick solid line) between the coke layer after iron ore charging and the deposited iron ore layer 24A is in the same position as the surface 22S (dotted line) of the coke layer 22 before iron ore charging, and the deposited iron ore layer 24A is deposited on this surface 22S.

[0086] In this case, the apparent thickness T1 of the sedimentary iron ore layer 24A is the same as the reference thickness T0. From this, it can be seen that the coke that flowed out from the collapse region R1 of the coke layer 22 passed through the intermediate region R2 and flowed into the inflow region R3. In the intermediate region R2, similar to the collapse region R1 or the inflow region R3, the collapse thickness V1 or the amount of inflow V2 of the coke layer 22 can be estimated from the ratio of the reference thickness T0 to the apparent thickness T1 of the sedimentary iron ore layer 24A. Note that the intermediate region R2 may not be detected under certain conditions.

[0087] Figure 7 shows, as an example, a graph illustrating the relationship between the ratio of the collapse thickness V1 of the coke layer 22 to the reference thickness T0 of the sedimentary iron ore layer 24A (= collapse thickness V1 / reference thickness T0) and the ratio of the apparent thickness T1 of the sedimentary iron ore layer 24A to the reference thickness T0 (= apparent thickness T1 / reference thickness T0) in the collapsed region R1 and intermediate region R2 of the coke layer 22. From the graph shown in Figure 7, the collapse thickness V1 of the coke layer 22 and the amount of collapse can be estimated.

[0088] Furthermore, Figure 8 shows, as an example, a graph illustrating the relationship between the ratio of the inflow thickness V2 of the coke layer 22 to the reference thickness T0 of the sedimentary iron ore layer 24A (= inflow thickness V2 / reference thickness T0) and the ratio of the apparent thickness T1 of the sedimentary iron ore layer 24A to the reference thickness T0 in the inflow region R3 of the coke layer 22. From the graph shown in Figure 8, the inflow thickness V2 of the coke layer 22 and the inflow amount can be estimated.

[0089] In this embodiment, the surface shape of the sediment 20 (coke layer 22) inside the blast furnace 10 after the iron ore was charged was measured using multiple electrical resistance thickness gauges, and the graphs shown in Figures 7 and 8 were created. However, the surface shape of the sediment 20 inside the blast furnace 10 after the iron ore was charged may also be estimated, for example, by mathematical models or simulations using the discrete element method (DEM), or by machine learning or AI (artificial intelligence) methods.

[0090] (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.

[0091] 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 estimation process that estimates the layer thickness ratio distribution of the coke layer 22 and the iron ore layer 24, and a correction process that corrects the charging conditions of the blast furnace raw materials based on the estimated layer thickness ratio distribution of the coke layer 22 and the iron ore layer 24. Note that the blast furnace operation process is an example of a blast furnace operation method.

[0092] (Estimation process) First, let's explain the estimation process. The estimation process is performed, for example, during the first charge when multiple charges are performed consecutively.

[0093] As shown in Figure 9, in the estimation process, first, in step S10, the CPU 72 obtains the charging conditions for blast furnace raw materials (coke and iron ore) from the charging schedule table stored in the memory unit 76.

[0094] 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 and 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.

[0095] Next, in step S14, the CPU 72 rotates multiple swivel chutes 40 based on the coke charging conditions to charge coke into the blast furnace 10. As a result, a coke layer 22 as sediment 20 is deposited on top of an iron ore layer (not shown) inside the blast furnace 10.

[0096] Next, in step S16, the CPU 72 activates a profile meter (not shown) to measure the surface shape of the coke layer 22 as the deposit 20 inside the blast furnace 10.

[0097] Next, in step S18, 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 iron ore into the blast furnace 10 from the rotating chute 40 while rotating the rotating chute 40 once. As a result, a layer of deposited iron ore 24A is deposited on the surface 20S of the deposit 20 inside the blast furnace 10.

[0098] Next, in step S20, the CPU 72 activates a profile meter (not shown) to measure the surface shape of the sedimentary iron ore layer 24A as sediment 20 in the blast furnace 10 while charging is being completed by the next rotation of the swivel chute 40.

[0099] Next, in step S22, the CPU 72 estimates the amount of collapse of the coke layer 22. Specifically, first, the CPU 72 determines the apparent thickness T1 of the sedimentary iron ore layer 24A formed after the charging of the ore, relative to the surface 20S of the sediment 20 (coke layer 22 or sedimentary iron ore layer 24A) before the charging of the iron ore. The CPU 72 also determines the standard thickness T0 of the sedimentary iron ore layer 24A formed after the charging of the iron ore, assuming that the coke layer 22 does not collapse, relative to the surface 20S of the sediment 20 before the charging of the iron ore.

[0100] Next, the CPU 72 estimates the collapse thickness V1 and collapse amount of the coke layer 22 based on the apparent thickness T1 and reference thickness T0 of the sedimentary iron ore layer 24A, and stores them in a predetermined storage area of ​​the storage unit 76. The CPU 72 also estimates the inflow thickness V2 and inflow amount of the coke layer 22 based on the apparent thickness T1 and reference thickness T0 of the sedimentary iron ore layer 24A, and stores them in a predetermined storage area of ​​the storage unit 76.

[0101] Next, in step S24, 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 S18. On the other hand, if the CPU 72 determines that the collection hopper 38 is empty, it proceeds to step S26.

[0102] Through the above process, the accumulated iron ore layer 24A is sequentially deposited on the coke layer 22 inside the blast furnace 10 to form the iron ore layer 24. In addition, when forming the iron ore layer 24, the collapse thickness V1, collapse amount, inflow thickness V2, and inflow amount of the coke layer 22 are estimated for each rotation of the rotating chute 40 and stored in a predetermined storage area of ​​the storage unit 76. Note that as the charging of iron ore progresses, it will completely cover the coke layer 22 on the surface of the blast furnace 10. In this case, no collapse will occur in the coke layer 22, so the estimation process of the amount of coke layer 22 collapse may be interrupted.

[0103] Next, in step S26, the CPU 72 estimates the layer thickness ratio distribution of the coke layer 22 and the iron ore layer 24 in the radial direction of the blast furnace based on the surface shape of the coke layer 22, the surface shape of the iron ore layer 24, and the amount of collapse and inflow of the coke layer 22.

[0104] Furthermore, the charging of coke and iron ore in one charge may be divided into multiple dumps. The above treatment should be performed when charging iron ore onto the surface 22S of the coke layer 22, but it is not necessarily required for other charging operations. In addition, the estimation of the layer thickness ratio distribution of the coke layer 22 and the iron ore layer 24 should be performed after the completion of one charge, but this is not necessarily required. The layer thickness ratio distribution of the coke layer 22 and the iron ore layer 24 may be determined in advance when a dump that causes collapse of the coke layer 22 is completed, and then the layer thickness ratio of the coke layer 22 and the iron ore layer 24 may be corrected based on the profile measurement results when a dump that does not cause collapse of the coke layer 22 is completed.

[0105] (Correction process) Next, the correction process will be explained. The correction process is performed in subsequent charges following the predetermined charge in which the estimation process was performed. Specifically, the correction process is performed, for example, in the second and subsequent charges when multiple charges are performed consecutively. The correction process can be performed at least once in subsequent charges following the predetermined charge in which the estimation process was performed.

[0106] As shown in Figure 10, in the correction process, first, in step S40, the CPU 72 obtains various charging conditions from the charging schedule table stored in the memory unit 76. In this embodiment, the charging conditions for the first charge and subsequent charges are the same, but they may be different.

[0107] 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 and 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.

[0108] Next, in step S44, the CPU 72 determines whether the layer thickness ratio distribution of the coke layer 22 and the iron ore layer 24 estimated in the estimation process matches the target layer thickness ratio distribution. If the CPU 72 determines that the layer thickness ratio distribution of the coke layer 22 and the iron ore layer 24 matches the target drop position, it proceeds to step S46.

[0109] In step S46, the CPU 72 charges coke and iron ore into the blast furnace 10 based on the charging conditions for coke and iron ore, and sequentially deposits a coke layer 22 and an iron ore layer 24 as sediment 20 into the blast furnace 10.

[0110] On the other hand, in step S44, if the CPU 72 determines that the layer thickness ratio distribution of the coke layer 22 and the iron ore layer 24 estimated in the estimation process does not match the target drop position, it proceeds to step S48.

[0111] In step S48, the CPU 72 corrects the blast furnace raw material charging conditions so that the layer thickness ratio distribution of the coke layer 22 and the iron ore layer 24 estimated in the estimation process approaches the target drop position. Specifically, the CPU 72 corrects at least one of the following: the inclination angle θ of the swivel chute 40, the number of rotations of the swivel chute 40, the amount of blast furnace raw material charged, and the surface depth L of the deposit where the blast furnace raw material charging begins.

[0112] 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.

[0113] Next, in step S50, the CPU 72 charges coke and iron ore into the blast furnace 10 based on the corrected coke and iron ore charging conditions, and deposits the coke layer 22 and the iron ore layer 24 in sequence inside the blast furnace 10. This makes it possible to bring the layer thickness ratio distribution of the coke layer 22 and the iron ore layer 24 closer to the target layer thickness ratio distribution.

[0114] (effect) Next, the effects of this embodiment will be described.

[0115] As described above, in this embodiment, the amount of collapse and inflow of the coke layer 22 is estimated based on the apparent thickness T1 and reference thickness T0 of the sedimentary iron ore layer 24A. Therefore, the accuracy of estimating the amount of collapse and inflow of the coke layer 22 can be improved.

[0116] Furthermore, when iron ore falls directly onto the surface 22S of the coke layer 22, the amount of coke layer 22 collapse and the amount of inflow tend to increase. Therefore, in this embodiment, the surface shape of the coke layer 22 as a deposit 20 is measured, and after the swivel chute 40 has rotated once, and before the charging is completed by the next rotation of the swivel chute 40, the surface shape of the deposited iron ore layer 24A deposited on the coke layer 22 is measured, and the apparent thickness T1 of the deposited iron ore layer 24A is determined based on the measured surface shapes of the coke layer 22 and the deposited iron ore layer 24A. This makes it possible to further improve the accuracy of estimating the amount of coke layer 22 collapse and the amount of inflow.

[0117] Furthermore, in this embodiment, the layer thickness ratio distribution of the coke layer 22 and the iron ore layer 24 in the blast furnace radial direction is estimated based on the estimated amount of coke layer 22 collapse and the amount of inflow. This improves the accuracy of estimating the layer thickness ratio distribution of the coke layer 22 and the iron ore layer 24 in the blast furnace radial direction.

[0118] Furthermore, in this embodiment, after measuring the surface shape of the coke layer 22 inside the blast furnace 10, the surface shape of the deposited iron ore layer 24A deposited on the coke layer 22 is measured for each rotation of the swirling chute 40. Then, in this embodiment, the thickness of the iron ore layer 24 is determined based on the measured surface shapes of the coke layer 22 and the deposited iron ore layer 24A. This further improves the accuracy of estimating the thickness ratio distribution of the coke layer 22 and the iron ore layer 24 in the radial direction of the blast furnace.

[0119] Furthermore, in this embodiment, the charging conditions for iron ore or coke are corrected so that the layer thickness ratio distribution of the coke layer 22 and the iron ore layer 24 approaches the target layer thickness ratio distribution. This makes it possible to bring the layer thickness ratio distribution of the coke layer 22 and the iron ore layer 24 closer to the target layer thickness ratio distribution. Therefore, blast furnace operation can be stabilized.

[0120] (Estimation test of layer thickness ratio distribution) Next, we will describe the estimation test of the layer thickness ratio distribution of the coke layer and iron ore layer in the radial direction of the blast furnace.

[0121] In this test, using a test apparatus scaled down to 1 / 3 the size of a blast furnace 10, the surface shape of the coke layer 22 as a deposit 20 was first measured using a profile meter. Next, the swirling chute 40 was rotated multiple times to deposit the iron ore layer 24 on top of the coke layer 22 inside the blast furnace 10. During this process, the surface shape of the deposited iron ore layer 24A was measured using a profile meter after each rotation of the swirling chute 40 to estimate the amount of coke layer 22 collapse and the amount of iron ore flowing in. Furthermore, as an example, the thickness ratio distribution of the coke layer 22 and the iron ore layer 24 in the radial direction of the blast furnace was estimated based on the amount of coke layer 22 collapse and the amount of iron ore flowing in.

[0122] The amount of coke charged was 0.94 [t], and the average particle size of the coke was 18.3 [mm]. The amount of iron ore charged (total charge) was 5.3 [t], and the average particle size of the iron ore was 6.8 [mm]. The amounts of coke and iron ore charged, as well as the average particle size, were set according to the scale ratio of the test apparatus.

[0123] Furthermore, samples were taken at multiple locations in the radial direction of the blast furnace, taking care not to disturb the coke layer 22 and iron ore layer 24 deposited inside the blast furnace 10. Then, by separating each sample into coke and iron ore, the thickness ratio distribution of the coke layer 22 and iron ore layer 24 in the radial direction of the blast furnace was determined.

[0124] Furthermore, as a comparative example, the layer thickness ratio distribution of the coke layer 22 and the iron ore layer 24 in the radial direction of the blast furnace was determined based on the surface shape of the coke layer 22 measured by a profile meter and the surface shape of the iron ore layer 24 at the time the iron ore charging was completed.

[0125] Figure 11 shows graph G1, which shows the layer thickness ratio distribution of the coke layer 22 and the iron ore layer 24 calculated based on the estimated collapse and inflow amounts of the coke layer 22. Figure 11 also shows graph G0, which shows the layer thickness ratio distribution of the coke layer 22 and the iron ore layer 24 obtained from a sample. Furthermore, as a comparative example, Figure 11 shows graph G2, which shows the layer thickness ratio distribution of the coke layer 22 and the iron ore layer 24 obtained from the surface shape of the iron ore layer 24 at the time when the charging of the coke layer 22 and the iron ore was completed.

[0126] In Figure 11, the vertical axis (relative iron ore layer thickness ratio) is obtained by non-dimensionalizing the iron ore layer thickness ratio (= thickness of iron ore layer 24 / (thickness of iron ore layer 24 + thickness of coke layer 22) by the standard iron ore layer thickness ratio (= standard thickness of iron ore layer 24 / (standard thickness of iron ore layer 24 + standard thickness of coke layer 22)). The standard layer thicknesses of iron ore layer 24 and coke layer 22 are the layer thicknesses of coke layer 22 and iron ore layer 24 formed in one charge, and are determined from the set charging amounts of iron ore and coke per charge, respectively. In this case, the standard layer thickness of iron ore layer 24 is assumed to be that iron ore layer 24 is formed with a uniform thickness from the central axis of the blast furnace 10 to the furnace wall 14.

[0127] As shown in Figure 11, graph G2, which relates to the comparative example, deviates from graph G0, which is based on sampling, because it does not take into account the amount of coke that flowed towards the central axis side of the blast furnace 10 due to the collapse of the coke layer 22. On the other hand, graph G1, which relates to the example, approximates graph G0, which is based on sampling. From this, the effectiveness of the method for estimating the layer thickness ratio distribution of the coke layer 22 and the iron ore layer 24 based on the estimated amount of coke layer 22 collapse and the amount of flow in was confirmed.

[0128] (modified version) Next, a modified example of the above embodiment will be described.

[0129] In the above embodiment, in the initial processing shown in Figure 9, the amount of coke layer 22 collapse and flow rate were estimated for each rotation of the swivel chute 40 into which the iron ore is charged. However, the amount of coke layer 22 collapse and flow rate are not limited to each rotation of the swivel chute 40 into which the iron ore is charged, but may also be estimated at a predetermined number of rotations (a predetermined number of rotations). However, from the viewpoint of the accuracy of estimating the amount of coke layer 22 collapse and flow rate, it is preferable to estimate the amount of coke layer 22 collapse and flow rate by the second rotation of the swivel chute 40 into which the iron ore is charged.

[0130] Furthermore, in the above embodiment, the surface shape of the sediment 20 and the surface shape of the sedimentary iron ore layer 24A were measured before and after one rotation of the swivel chute 40 into which the iron ore is loaded, and the apparent thickness T1 of the sedimentary iron ore layer 24A was determined based on the measured surface shapes of the sediment 20 and the sedimentary iron ore layer 24A. However, for example, the surface shape of the sediment 20 and the surface shape of the sedimentary iron ore layer 24A may be measured before and after multiple rotations of the swivel chute 40 into which the iron ore is loaded, and the apparent thickness T1 of the sedimentary iron ore layer 24A may be determined based on the measured surface shapes of the sediment 20 and the sedimentary iron ore layer 24A.

[0131] By measuring the surface shape of the sediment 20 and the sedimentary iron ore layer 24A before and after the rotating chute 40 into which the iron ore is loaded rotates multiple times, the apparent thickness T1 of the sedimentary iron ore layer 24A can be determined while reducing the number of measurements required for the surface shape of the sedimentary iron ore layer 24A.

[0132] 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.

[0133] 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.

[0134] 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]

[0135] 10 blast furnace 20 Sediments 20S surface 22. Coke layer (sediment) 22S Surface (Surface of sediment) 24 Iron ore layer 24A Sedimentary iron ore (sediment) 40. Swinging Shot 50 Blast Furnace Operation Control System

Claims

1. In a bellless blast furnace, coke and iron ore are charged into the blast furnace by a rotating chute, and layers of coke and iron ore are alternately deposited as sediments within the blast furnace, When rotating the aforementioned rotating chute multiple times and adjusting the iron ore loading position with each rotation to form one layer of the iron ore, After measuring the surface shape of the coke layer before charging the iron ore, the surface shape of the iron ore layer formed on the coke layer is measured for each rotation of the rotating chute, and the apparent thickness of the iron ore layer relative to the surface of the coke layer is determined based on the measured surface shapes of the coke layer and the iron ore layer. Based on the obtained apparent thickness and the standard thickness of the iron ore layer formed after the charging of iron ore on the surface of the deposit before the charging of iron ore, assuming that the coke layer does not collapse, the amount of collapse of the coke layer is estimated. A method for estimating the amount of coke layer collapse.

2. The amount of coke layer collapse is estimated by the coke layer collapse amount estimation method described in Claim 1, the amount of coke layer inflow is estimated based on the apparent thickness and the reference thickness, and the thickness ratio distribution of the coke layer and the iron ore layer in the radial direction of the blast furnace is estimated based on the estimated amount of collapse and the amount of inflow. Method for estimating layer thickness ratio distribution.

3. After measuring the surface shape of the coke layer, the surface shape of the iron ore layer formed on the coke layer is measured for each rotation of the rotating chute, and the thickness of the iron ore layer is determined based on the measured surface shapes of the coke layer and the iron ore layer. The method for estimating the layer thickness ratio distribution according to claim 2.

4. In a predetermined charge in which iron ore and coke are charged into a blast furnace by a rotating chute, and a set of iron ore layers and coke layers are sequentially deposited in the blast furnace, the layer thickness ratio distribution of the coke layer and the iron ore layer in the radial direction of the blast furnace is estimated by the layer thickness ratio distribution estimation method described in Claim 2. In subsequent charges following the predetermined charge, the charging conditions for iron ore or coke are corrected so that the layer thickness ratio distribution estimated in the predetermined charge approaches the target layer thickness ratio distribution of the coke layer and the iron ore layer in the radial direction of the blast furnace. Blast furnace operation methods.

5. The charging conditions include the inclination angle of the swivel chute, the number of rotations of the swivel chute, the amount of iron ore and coke to be charged, and the surface depth of the deposits in the blast furnace at which the charging of iron ore or coke is to be started. The blast furnace operation method according to claim 4.

6. In a predetermined charge in which iron ore and coke are charged into a blast furnace by a rotating chute, and a set of iron ore layers and coke layers are sequentially deposited in the blast furnace, the layer thickness ratio distribution of the coke layer and the iron ore layer in the radial direction of the blast furnace is estimated by the layer thickness ratio distribution estimation method described in Claim 2. In subsequent charges following the predetermined charge, the charging conditions for iron ore or coke are corrected so that the layer thickness ratio distribution estimated in the predetermined charge approaches the target layer thickness ratio distribution of the coke layer and the iron ore layer in the radial direction of the blast furnace. A blast furnace operation control system including a control unit that performs processing.

7. In a predetermined charge in which iron ore and coke are charged into a blast furnace by a rotating chute, and a set of iron ore layers and coke layers are sequentially deposited in the blast furnace, the layer thickness ratio distribution of the coke layer and the iron ore layer in the radial direction of the blast furnace is estimated by the layer thickness ratio distribution estimation method described in Claim 2. In subsequent charges following the predetermined charge, the charging conditions for iron ore or coke are corrected so that the layer thickness ratio distribution estimated in the predetermined charge approaches the target layer thickness ratio distribution of the coke layer and the iron ore layer in the radial direction of the blast furnace. A blast furnace operation control program that directs processing to a computer.

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