Estimation method for slag discharge amount

Abstract

A slag discharge amount estimation method in which a slag flow, which flows out from an outlet of a refining vessel and has a wider width than upstream downstream, is imaged by one imaging device, and the width of the slag flow is determined on the basis of the imaged image, and the volume flow rate or the mass flow rate is determined. The amount of slag is estimated on the basis of the calculated volume flow rate or mass flow rate.

Description

Technical Field

[0001] The present disclosure relates to a method for estimating a slag discharge amount. Background Art

[0002] The following method is known: by tilting the converter after desiliconization and dephosphorization of molten iron in the converter, a part of the slag is discharged from the furnace mouth (intermediate slag discharge) while the molten iron remains in the converter, and then the converter is upright again and newly refined materials are added, and then refined. Compared with the method of discharging molten iron to the outside of the converter and separating it from the slag by tilting the converter after desiliconization and dephosphorization of molten iron, and performing decarburization and refining in another converter, such a method has less heat loss and is economically advantageous. However, since the discharge of flux is sandwiched in the middle, it is not advantageous in terms of the control accuracy of slag composition. In order to improve the control accuracy of slag composition, it is important to master the quantitative amount of intermediate slag discharge. As a quantitative evaluation method and estimation method of the intermediate slag discharge amount, Japanese Patent Publication No. 7-41813 and Japanese Patent Publication No. 2018-119195 are known.

[0003] The following method is disclosed in Japanese Patent Gazette No. 7-41813: slag is received by a slag pan installed on a slag discharge trolley, the amount of slag discharged from the converter (the amount of slag in the slag pan) is weighed by a scale installed on the ground, the slag discharge amount is estimated, and the amount of slag remaining in the furnace is calculated by subtracting the slag discharge amount from the estimated slag amount in the furnace.

[0004] The following method is disclosed in Japanese Patent Gazette No. 2018-119195: When discharging slag from a converter, the amount of residual slag in the furnace is calculated based on the tilting movement angle of the converter at the beginning and end of the slag outflow, and the value obtained by subtracting the amount of residual slag in the furnace from the theoretical slag amount is used as the intermediate slag discharge amount, and the operating conditions of the subsequent processes are adjusted. Summary of the invention

[0005] Technical problem to be solved by the invention

[0006] However, in Japanese Patent Application Laid-Open No. 7-41813, a weighing machine is used to obtain the intermediate slag discharge amount, and thus there are problems in the installation and maintenance of the weighing machine.

[0007] On the other hand, in Japanese Patent Application Publication No. 2018-119195, since the intermediate slag discharge amount is geometrically calculated, there are large deviations in the shape of the converter and the states of the slag and metal (molten iron), resulting in a problem of low estimation accuracy of the slag discharge amount.

[0008] An object of the present disclosure is to estimate the amount of slag discharged from a refining vessel at a lower cost than when a scale is used and with higher accuracy than when the amount of slag discharged is geometrically determined.

[0009] Technical solutions for solving technical problems

[0010] One solution of the present disclosure is a method for estimating slag discharge amount, comprising the following steps:

[0011] A slag flow flowing out of a refining vessel's outflow port and becoming wider upstream than downstream is photographed by a photographing device.

[0012] The width of the slag flow is calculated based on the captured image, and the volume flow rate or mass flow rate is calculated.

[0013] The slag discharge amount is estimated based on the obtained volume flow rate or mass flow rate.

[0014] Effects of the Invention

[0015] According to the present disclosure, the amount of slag discharged from the refining container can be estimated at a lower cost than when a scale is used and with higher accuracy than when the amount of slag discharged is geometrically determined. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1A It is a side view of the converter as the refining vessel according to the first embodiment.

[0017] Figure 1B yes Figure 1A A side cross-sectional view of a converter is shown.

[0018] Figure 2 This is a side cross-sectional view of the converter showing a state of a molten material remaining in the converter that is tilted when slag is discharged from the converter of the first embodiment.

[0019] Figure 3A This is a side cross-sectional view of the converter showing a state where oxygen is blown from a lance to molten iron charged into the converter of the first embodiment.

[0020] Figure 3B This is a side cross-sectional view of the converter showing a state in which slag is discharged from the converter that is moving tiltably.

[0021] Figure 4A The figure shows the direction from the spray gun to the Figure 3B A side sectional view of a converter in which oxygen is blown again into the molten iron remaining in the converter.

[0022] Figure 4B This is a side cross-sectional view of the converter showing a state in which molten steel is taken out through a tapping hole from the converter that is moving tiltably.

[0023] Figure 5 This is a plan view showing the arrangement of the imaging device relative to the converter when the converter in an upright state is viewed from above.

[0024] Figure 6This is a plan view showing the arrangement of the imaging device relative to the converter when the converter in a tilted moving state is viewed from the side.

[0025] Fig. 7A This is an enlarged front view showing a state where slag flows out from a furnace opening of a converter.

[0026] Figure 7B Yes means Fig. 7A The cross-sectional shape at a predetermined position of the slag flow in Fig. 7A Cross-sectional view along line 7B-7B as shown in FIG.

[0027] Figure 8 This is a graph showing the relationship between the slag removal volume based on image analysis and the slag removal volume based on geometric calculation.

[0028] Fig. 9 It is a diagram showing the configuration of a control device according to an embodiment.

[0029] Fig.10 It is a schematic diagram of an electric furnace.

[0030] Fig.11 This is a schematic diagram showing the state of slag removal by tilting movement of an electric furnace.

[0031] Fig.12 This is a schematic diagram showing a situation in which the estimation system senses the slag flow and estimates the outflow amount.

[0032] Fig.13 This is the measurement result of the slag outflow velocity (mass flow rate) of one of Test Examples 1 to 10.

[0033] Fig.14 This is the measurement result of the cumulative slag outflow amount of one of Test Examples 1 to 10.

[0034] Fig.15 The results show the relationship between the actual amount of slag outflow and the estimated amount of slag outflow obtained through the examples.

[0035] Fig.16 This is a front view of the refining vessel as seen from the front, showing a state in which the slag flow flowing out of the refining vessel is divided.

[0036] Fig.17 This is a front view of the refining vessel as seen from the front, showing a state in which the slag flow out of the refining vessel is not divided.

[0037] Fig.18 This is a graph showing the relationship between the actual slag discharge amount and the estimated slag discharge amount obtained by Examples and Comparative Examples.

[0038] Fig.19 This is a side view of the refining vessel as seen from the side, showing a state where slag flows out of the refining vessel.

[0039] Fig. 20 This is a graph showing the average estimation error in estimating the slag discharge amount in Examples, Reference Examples, and Comparative Examples.

[0040] Fig.21 This is a graph showing the relationship between the actual slag discharge amount and the estimated slag discharge amount obtained by Examples, Reference Examples, and Comparative Examples.

[0041] Fig. 22 This is a flowchart for determining the width L of the equation (8) when the slag discharge amount estimation system uses the prediction method (2).

[0042] Fig.23 This is a diagram showing the change over time in the width of the slag flow in one test example among Examples 1 to 11.

[0043] Fig.24 This is a diagram showing the change over time in the width of the slag flow in one test example among Examples 12 and 13.

[0044] Fig.25 The results are those showing the relationship between the actual slag discharge amount and the estimated slag discharge amount obtained in the examples. DETAILED DESCRIPTION

[0045] Below, the method for implementing the technology disclosed in the present invention is described based on the drawings. The constituent elements represented by the same figure marks in each drawing refer to the same or identical constituent elements. In addition, in the embodiments described below, repeated descriptions and figure marks are sometimes omitted. In addition, the drawings used in the following description are all schematic, and the relationship between the sizes of the elements shown in the drawings, the ratio of the elements, etc. may not be consistent with reality. In addition, the relationship between the sizes of the elements, the ratio of the elements, etc. may not be consistent between multiple drawings.

[0046] <First Embodiment>

[0047] A method for estimating the amount of slag discharge according to the first embodiment of the present disclosure will be described.

[0048] First, a converter 20 as an example of a refining vessel used in the method for estimating the slag discharge amount and the refining method of the present embodiment will be described.

[0049] As shown in Figure 1~ Fig. 9 As shown, the converter 20 includes a bottom 20A, a furnace wall 20B, a furnace mouth 20C, and a steel tapping hole 20D provided in the furnace wall 20B. Fig. 9 ) and tilted movement.

[0050] When refining is performed using the converter 20, first, molten iron is charged into the converter 20, and a first refining material is added to the charged molten iron. The first refining material is a material (oxide) for removing phosphorus, silicon, and carbon from the molten iron charged into the converter 20, and includes, for example, calcium oxide (CaO)-based materials such as quicklime and limestone, magnesium oxide (MgO)-based materials, iron oxide (FeO)-based materials, and materials composed of one or more of these. Figure 3A As shown in FIG. 1 , a lance 30 is inserted into the converter 20 through the furnace port 20C. The lance 30 blows pressurized gas (e.g., oxygen) toward the molten iron in the converter 20. The blowing of the gas stirs the molten iron and the first refined material in the converter 20, and oxidizes and removes phosphorus, silicon, and carbon from the molten iron. Next, the lance 30 is withdrawn from the converter 20, as shown in FIG. Figure 3B As shown, the converter 20 is tilted and moved (at Figure 3B The converter 20 is tilted to the right). Due to the tilting movement of the converter 20, molten iron remains in the converter 20, and slag with high concentrations of phosphorus and silicon flows from the furnace opening 20C to the slag pot 22 arranged below the converter 20 to be discharged (intermediate slag discharge). After the intermediate slag discharge, Figure 4A As shown, the converter 20 becomes upright again. In addition, the upright state of the converter 20 mentioned here refers to a state in which the furnace mouth 20C is facing upward. Then, the second refined material is added to the molten iron in the converter 20. The second refined material is a material (oxide) used to remove phosphorus and carbon from the molten iron remaining in the converter 20 after the intermediate slag discharge, and as an example, includes the same material as the first refined material. Then, the lance 30 is inserted into the converter 20 through the furnace mouth 20C, and pressurized gas is blown from the lance 30 to the molten iron in the converter 20, so that the molten iron and the second refined material are stirred in the converter 20, and a small amount of phosphorus and carbon remaining in the molten iron is removed from the molten iron. Next, the lance 30 is withdrawn from the converter 20, as shown in FIG. Figure 4B As shown, the converter 20 is tilted and moved to the opposite side to the side during the intermediate slag discharge (at Figure 4B The converter 20 is tilted to the left). The molten steel flows out from the tapping hole 20D by the tilting movement of the converter 20. After the molten steel is taken out from the converter 20 (after tapping), the slag with low phosphorus and silicon concentrations and high CaO concentration remaining in the converter 20 is included in the first refined material in the next refining and reused. In addition, as a refining method using such a converter 20, for example, a MURC method, a double slag method, etc. can be listed.

[0051] Next, the method for estimating the slag discharge amount of the converter 20 using the present embodiment is described. In the method for estimating the slag discharge amount of the present embodiment, the slag discharge amount is estimated using image analysis. Specifically, the volume of the slag discharged is obtained from the image of the slag flow during the intermediate slag discharge, and the slag discharge amount (slag discharge mass) is estimated based on the volume.

[0052] [Method for estimating the amount of slag discharge]

[0053] The method for estimating the slag discharge amount according to the present embodiment includes an imaging step, a finding step, and an estimating step.

[0054] (Photography process)

[0055] First, the slag flow SF flowing out from the furnace port 20C of the converter 20 is photographed. Figure 6 As shown, the slag flow SF flowing out (flowing down) from the furnace port 20C of the converter 20 that moves obliquely during the intermediate slag discharge toward the slag discharge pot 22 is photographed by a photographing device 40. As the photographing device 40, for example, a CCD camera, a CMOS camera, etc. can also be used. In addition, the image information photographed by the photographing device 40 is sent to a computer 42 described later. In addition, the photographing device 40 is connected to the computer 42 by wire or wirelessly.

[0056] like Figure 5 As shown, the shooting direction SD of the shooting device 40 for shooting the slag flow SF may be tilted relative to the slag discharge direction of the converter 20 when viewed from above. Specifically, when the converter 20 in an upright state is viewed from above, the direction in which the converter 20 is tilted during the intermediate slag discharge, in other words, the direction in which the slag discharge pot 22 is arranged relative to the converter 20 is the slag discharge direction. Hereinafter, the slag discharge direction of the converter 20 is represented by the symbol DD. In addition, the shooting direction SD of the shooting device 40 is the optical axis direction of the shooting device 40. When the shooting device 40 is a camera, the shooting direction is the optical axis direction.

[0057] The shooting direction SD of the camera 40 may also be inclined at an angle θ relative to the slag discharge direction DD of the converter 20 when viewed from above. The angle θ is preferably set in the range of 0 to 70 degrees, and more preferably in the range of 20 to 50 degrees. In addition, in the present embodiment, the angle θ is set to 45 degrees, but the present disclosure is not limited to this configuration. In this way, by configuring the camera 40 so that the shooting direction SD of the camera 40 for shooting the slag flow SF is inclined relative to the slag discharge direction DD of the converter 20 when viewed from above, the camera 40 is not easily affected by the sedation flame described later.

[0058] In addition, if Figure 6 As shown, the shooting direction SD of the shooting device 40 for shooting the slag flow SF is inclined at an angle β relative to the vertical direction VD when viewed from the side. The angle β is preferably set in the range of 70 degrees to 110 degrees, and more preferably set in the range of 80 degrees to 100 degrees. In addition, in the present embodiment, the shooting direction SD is orthogonal to the vertical direction VD, that is, the angle β is 90 degrees. In addition, the angle β is more preferably set to 90 degrees. Here, when the angle β is 90 degrees, the shooting direction SD is along the horizontal direction.

[0059] In addition, if Figure 6 As shown, the installation height Y of the camera 40 is preferably set to a height that is not affected by the sedation flame. In addition, the "sedation flame" mentioned here refers to the flame generated by the reaction between the slag and the slag sedation material. For example, when the camera 40 is installed at a position lower than the sedation flame, the camera 40 can also be provided with an elevation angle and aimed at a position above the sedation flame to shoot the slag flow SF.

[0060] (Find the process)

[0061] Next, the volume flow rate or mass flow rate of the slag flow SF is obtained based on the captured image. In addition, in the present embodiment, the volume flow rate of the slag flow SF is obtained based on the captured image. Specifically, the computer 42 receives the image information obtained by the camera 40 capturing the slag flow SF, and the computer 42 performs image analysis to obtain the volume flow rate of the slag flow SF. In addition, the image information sent from the camera 40 may be image information of a still image captured at a predetermined interval (for example, at a interval of 1 second), or may be image information of a moving image. Here, in the case where the image information sent from the camera 40 is image information of a still image, image analysis is performed on each still image. On the other hand, in the case where the image information sent from the camera 40 is image information of a moving image, a still image is extracted from the moving image at a predetermined interval (for example, at a interval of 1 second), and image analysis is performed on each extracted still image.

[0062] In the image analysis of the still image performed by the computer 42, first, the still image is binarized. Then, the length of the high brightness portion of the slag flow SF in the preset analysis area is measured as the apparent length. Fig. 7A As shown, the length of the high brightness portion of the slag flow SF can also be referred to as the width of the slag flow SF. In addition, the analysis area based on the still image of the computer 42 is the middle of the furnace port 20C and the slag discharge pot 22, which are the outflow start positions of the slag flow SF, and needs to be set to a height that is not affected by the sedation flame rising from the slag discharge pot 22. Then, the computer 42 calculates the width L (m) of the slag flow SF at a predetermined height based on the still image captured by the camera 40, and the distance H (m) from the measurement position where the width L is calculated to the outflow start position of the slag flow SF from the furnace port 20C.

[0063] Next, the cross-sectional area S (m 2 ) as απL 2 Specifically, the cross-sectional area S is obtained by the computer 42. In addition, the parameter α is a shape correction coefficient of the slag flow SF. When the cross-sectional shape of the slag flow SF is a perfect circle, α=1 / 4 (see Figure 7B ).

[0064] Next, the flow velocity V (m / s) is calculated based on the captured image. Specifically, the computer 42 may assume that the flow velocity V (m / s) of the slag flow SF at the measurement position of the width L of the slag flow SF is the free fall of the slag flow SF (set to 2gH). 0.5 ), the moving distance of the slag flow SF can also be calculated by pattern matching based on at least two images, and the moving distance of the slag flow SF can be divided by the difference (s) between the shooting times of the images for which the moving distance is calculated, thereby calculating the flow velocity V (m / s).

[0065] Then, the volume flow rate Q (m 3 Specifically, the computer 42 uses the flow velocity V and the cross-sectional area S to calculate the volume flow rate Q.

[0066] Q=SV=απL 2 V = απL 2 (2gH) 0.5 … (1)

[0067] (Estimated process)

[0068] Next, the amount of slag discharged from the converter 20 (slag discharge mass) is estimated based on the volume flow rate or the mass flow rate. In the present embodiment, the amount of intermediate slag discharge from the converter 20 is estimated based on the volume flow rate obtained in the above-mentioned step.

[0069] First, the estimated value M based on at least the tilting angle of the converter 20 when the slag flow SF starts to flow out, the shape of the converter 20, the volume of the converter 20, and the mass of the slag in the furnace is used. S The slag bulk density ρ (kg / m 3 ), the volume flow rate Q is converted into the mass flow rate ρQ (kg / s). Specifically, in the computer 42, the accumulation flow rate Q is converted into the mass flow rate ρQ using at least the tilting movement angle of the converter 20, the shape of the converter 20, the volume of the converter 20, and the volume density ρ of the converter 20. In addition, the estimated value M S For example, it is determined from the mass (actual) of the first refined material charged into the converter 20, the mass (calculated) of oxides generated by oxidation of molten iron (for example, silicon dioxide (SiO2), phosphorus pentoxide (P2O5, manganese oxide (MnO) or a combination of one or more of these), and the mass (assumed value) of the previous slag that has been reused.

[0070] Method for calculating bulk density: Figure 1BAs shown, regarding the bulk density ρ of the slag, the effective furnace volume of the converter 20 at the time when the slag starts to flow out from the furnace opening 20C of the converter 20 that is moving obliquely may be represented by V. DS , let the volume of molten iron be V M , let the volume of slag be V S , use V S =V DS -V M Calculate the volume V of the slag S , the mass of slag is set as M S , through the bulk density ρ = M S / V S Come and ask for it.

[0071] In addition, if the tilting angle of the converter 20 is determined, V S +V M It can also be determined by CAD or geometric calculation based on the drawing of the converter 20 .

[0072] In addition, V M The mass of molten steel ≒ the mass of main raw materials (molten iron + scrap), so it can also be calculated by molten steel density × main raw material mass (actual).

[0073] The shape of the converter 20 is the shape of the furnace. Figure 1A In FIG. 1 , the shape is shown by the dotted line. That is, the shape inside the furnace is a shape including the inner surface shape of the furnace wall 20B and the inner surface shape of the bottom 20A.

[0074] In addition, regarding the bulk density ρ of the slag, the slag height (m) in the converter 20 at the start of refining can be set as h0, the slag height (m) when the width L of the slag flow is measured can be set as h, the gas phase ratio in the slag can be set as φ, and the gas phase ratio φ can be calculated by φ=(h0-h) / h0×100, and the density of the uniform liquid phase slag can be set as ρL (kg / m 3 ), calculated by bulk density ρ = ρL × (100-φ) / 100.

[0075] Then, the slag discharge mass (kg) is calculated based on the integrated value ΣρQ (kg) of the mass flow rate ρQ. In this way, in the method for estimating the slag discharge amount of the present embodiment, the volume flow rate Q of the discharged slag can be calculated based on the image of the slag flow SF during the intermediate slag discharge, and the slag discharge mass can be calculated based on the volume flow rate Q.

[0076] In addition, regarding the parameter α in the formula (1), when slag is discharged from the converter 20, α is obtained by parameter fitting so that the discharged slag mass (kg) obtained using a scale (not shown) and the integrated value ΣρQ (kg) of the mass flow rate ρQ (kg / s) agree.

[0077] Next, the refining method in the converter 20 of the present embodiment will be described.

[0078] In the refining method of this embodiment, the operating conditions of the subsequent steps are set based on the intermediate slag discharge amount estimated by the slag discharge amount estimation method. The operating conditions include the type and amount of the refined material added to the molten metal (hot metal) in the converter 20.

[0079] Next, the computer 42 for controlling the type and amount of refined material added to the converter 20 will be described. Figure 5 and Figure 6 As shown, the image information of the slag flow SF captured by the image capturing device 40 is sequentially transmitted to the computer 42. The computer 42 obtains the volume flow Q of the slag flow SF based on the received image information. Then, the computer 42 obtains the intermediate slag discharge quality based on the volume flow Q.

[0080] The computer 42 sets the operating conditions of the subsequent process based on the obtained intermediate slag discharge amount. Specifically, the computer 42 determines the type of refined material added to the molten iron in the converter 20 and the amount of the refined material added, operates the adding device (not shown) and adds the refined material to the molten iron in the converter 20. In addition, the computer 42 also controls the tilting movement mechanism 24 of the converter 20.

[0081] like Fig. 9 As shown, the computer 42 includes a CPU (Central Processing Unit) 43, a main storage device 44 providing a temporary storage area, an auxiliary storage device 45 providing a non-volatile storage area, and an input / output interface (I / F) 46. The CPU 43, the main storage device 44, the auxiliary storage device 45, and the input / output I / F 46 are connected to each other via a bus 47.

[0082] The auxiliary storage device 45 can be realized by a hard disk drive (HDD), a solid state drive (SSD), a flash memory, etc. The auxiliary storage device 45 stores an estimation program 48 for causing the computer 42 to function as an estimation device for the intermediate slag discharge amount in the converter 20. The CPU 43 reads the estimation program 48 from the auxiliary storage device 45 and expands it in the main storage device 44, and sequentially executes the processes described in the estimation program 48, thereby causing the computer 42 to function as an estimation device for the intermediate slag discharge amount in the converter 20.

[0083] The input / output I / F 46 is connected to the imaging device 40. Thus, the image information captured by the imaging device 40 is stored in the auxiliary storage device 45 via the input / output I / F 46, and the image analysis is performed by the CPU 43. In addition, the input / output I / F 46 is connected to the tilting movement mechanism 24 of the converter 20. Specifically, it is connected to the tilting movement control device of the tilting movement mechanism 24. The tilting movement control device is configured to control the tilting movement angle of the converter 20 by operating the tilting movement mechanism 24 based on the instruction from the computer 42.

[0084] Next, the effects of this embodiment will be described.

[0085] In the estimation method of the present embodiment, the intermediate slag discharge amount of the converter 20 is obtained using image analysis. Therefore, compared with the case where a weighing device is used to obtain the intermediate slag discharge amount, for example, the equipment cost becomes cheap. In addition, unlike the mechanical measurement method, it is easy to maintain the equipment because it is not affected by thermal deformation, deterioration over time, etc. In addition, in the mass measurement method using a weighing device, after the slag discharge is completed, an accurate measurement value cannot be obtained before the measurement value stabilizes. In contrast, in the estimation method of the present embodiment, since optical measurement is performed, the measurement value and the cumulative value can be obtained during the slag discharge, so the intermediate slag discharge amount can be stably obtained.

[0086] Moreover, in the estimation method of the present embodiment, the intermediate slag discharge amount from the converter 20 can be estimated with high accuracy compared to the case where the slag discharge amount is obtained geometrically. Specifically, in the case where the slag discharge amount is obtained geometrically, the estimation accuracy may be reduced due to large deviations between the shape of the furnace and the metal state of the slag. In contrast, in the estimation method of the present embodiment, by using the imaging device 40, the result reflecting the influence of the above deviation can be measured in the form of the volume of the slag flow, so the estimation accuracy is improved.

[0087] In addition, in the existing method for estimating the slag discharge amount, it is possible to accept the result of the intermediate slag discharge amount to optimize the subsequent processing. In contrast, in the estimation method of the present embodiment, in addition to the above-mentioned processing, the intermediate slag discharge amount can also be known. Therefore, the slag discharge amount itself can also be controlled. Specifically, in the existing method, when the slag discharge mass reaches a specified value, it is impossible to stop the slag discharge, and only the actual slag discharge mass can be obtained. In contrast, in the estimation method of the present embodiment, it is possible to stop the slag discharge when the slag discharge volume reaches a specified value. The existing method can stabilize and improve the subsequent process by quantifying the "result" of the intermediate slag discharge, but in the estimation method of the present embodiment, in addition to the above, the intermediate slag discharge can also be quantified, so the intermediate slag discharge itself can be stabilized and improved.

[0088] In the estimation method of the present embodiment, the imaging device 40 is arranged so that the imaging direction SD of the imaging device 40 for imaging the slag flow SF is inclined with respect to the slag discharge direction DD of the converter 20 in a plan view. Therefore, the imaging device 40 is not easily affected by the sedation flame.

[0089] Furthermore, in the estimation method of the present embodiment, when the imaging direction SD of the imaging device 40 that images the slag flow SF is orthogonal to the vertical direction VD when viewed from the side, high-precision image information can be obtained by the imaging device 40 .

[0090] In the above-mentioned embodiment, the imaging device 40 is connected to the computer 42 by wire or wirelessly, but the present disclosure is not limited to this configuration. For example, a removable image storage medium may be removed from the imaging device 40 and connected to the CPU 43 via the input / output I / F 46 .

[0091] In the above-mentioned embodiment, the shooting direction SD of the camera 40 is tilted relative to the slag discharge direction DD, but the present disclosure is not limited to this configuration. For example, if the camera 40 is arranged at the top and the slag flow SF flowing down from the furnace port 20C is photographed from the top, the shooting direction SD of the camera 40 and the slag discharge direction DD may also be the same direction.

[0092] In the above-mentioned embodiment, the volume flow rate of the slag flow SF is obtained by image analysis, and the slag discharge amount (slag discharge volume) is estimated based on the volume flow rate, but the present disclosure is not limited to this configuration. For example, the volume flow rate of the slag flow SF can also be obtained by image analysis, and the mass flow rate can be obtained, and the slag discharge amount can be estimated based on the mass flow rate.

[0093] In the refining method in the converter 20 of the above-mentioned embodiment, the volume flow rate of the slag flow SF is obtained by image analysis, the slag discharge amount (slag discharge volume) is estimated based on the volume flow rate, and the operation conditions of the subsequent process are set based on the estimated intermediate slag discharge amount, but the present disclosure is not limited to this configuration. For example, the slag flow SF flowing out from the furnace mouth of the converter 20 can also be photographed, the width L of the slag flow SF can be obtained based on the photographed image, and the operation conditions of the subsequent process can be set based on the obtained width L. That is, it can also be set as a configuration using the width L of the slag flow SF as the slag discharge parameter. In addition, the operating conditions include the type of refined material added to the molten metal (molten iron) in the converter 20 and the amount of the refined material added. Specifically, when the slag discharge parameter is within a preset range (level), the input amount of the auxiliary raw material (mainly CaO) is set to a preset amount. On the other hand, when the slag discharge parameter is less than the above range, the input amount of the auxiliary raw material (mainly CaO) is made larger than the above set amount. In addition, when the slag discharge parameter exceeds the above range, the input amount of the auxiliary raw material (mainly CaO) is made less than the above set amount, or the input amount of the auxiliary raw material (mainly CaO) is made the above set amount while the SiO2 source is also added. In addition, the SiO2 source mentioned here refers to SiO itself, a composite oxide containing SiO2, or an alloy containing Si (becoming oxidized SiO2). That is, in the case of less slag discharge, since there is more SiO2 in the furnace, more CaO is added, and in the case of more slag discharge, since CaO is excessive, CaO is reduced or SiO2 is added to achieve a balance. By controlling the CaO concentration / SiO2 concentration in the slag within a certain range in this way, the dephosphorization efficiency can be maximized. In addition, when the width L of the slag flow SF is used as a slag discharge parameter as described above, there is no need to calculate the slag bulk density, etc., and the use of data processing becomes simple. In particular, when performing operations with very little deviation in slag density, the relationship between the width L of the slag flow SF and the mass flow rate ρQ is close to 1:1, so by using the width L of the slag flow SF as a slag discharge parameter, data processing can be simplified.

[0094] Next, based on the following Table 1 and Figure 8 The relationship between the slag removal volume obtained by the image analysis according to the present embodiment and the slag removal volume obtained by the geometric calculation will be described.

[0095] Table 1 below shows the slag removal volume obtained by image analysis of Examples 1 to 10 using the estimation method of the present embodiment, the slag removal volume obtained by geometric calculation, and the actually measured slag removal mass. In addition, the slag removal start tilting movement angle in Table 1 refers to the tilt of the converter when the slag removal starts. In addition, the slag removal end tilting movement angle in Table 1 refers to the tilt of the converter when the slag removal ends.

[0096] [Table 1]

[0097]

[0098] Figure 8 The relationship between the slag removal volume obtained by image analysis and the slag removal volume obtained by geometric calculation is shown based on the slag removal volume obtained by image analysis of Examples 1 to 10 in Table 1. Figure 8 As shown, it can be seen that the slag removal volume obtained by image analysis and the slag removal volume obtained by geometric calculation have approximately similar values ​​although there is a slight deviation.

[0099] In the above embodiment, the converter 20 is used as an example of a refining vessel, but the present disclosure is not limited to this configuration. As an example of a refining vessel, for example, an electric furnace, a molten steel ladle, or a mixing car (torpedo car) may be used.

[0100] <Second Embodiment>

[0101] Next, a method for estimating the amount of slag discharge according to the second embodiment of the present disclosure will be described.

[0102] First, an electric furnace 101 as an example of a refining vessel used in a method for estimating the slag discharge amount and a system 110 for estimating the slag discharge amount (hereinafter sometimes referred to as “estimation system 110 ”) according to the present embodiment will be described.

[0103] Fig.10 1 is a schematic diagram showing an electric furnace 101 as an example. The electric furnace 101 is a device that uses a plurality of electrodes 102 to heat a high-temperature molten material 103 (for example, molten steel, molten iron, etc.) together with a refined material to perform refining. Fig.10 As shown, the electrode 102 is immersed in the high temperature melt 103, and the high temperature melt 103 is heated by passing an electric current through the electrode 102 to perform refining such as decarburization. At this time, slag 104 is generated as a by-product. The generated slag 104 flows out (discharged) to the outside through the slag door 105 as appropriate. The outflow of the slag 104 is implemented, for example, by slag flow, slag removal by scraping, slag removal by tilting, etc. Fig.11 The schematic diagram shows an electric furnace 101 performing tilting slag removal. In this way, in tilting slag removal, by tilting the electric furnace 101 to a predetermined angle θ, slag 104 can flow out from a slag door 105. The flowing slag 104 is recovered by a slag removal pot 106 or the like disposed at the bottom.

[0104] The estimation system 110 of the present embodiment senses the slag 104 flowing out from the slag door 105 in a non-contact manner, and estimates the outflow amount. Fig.122 shows a state in which the outflowing slag 104 (slag flow SF) is sensed by the estimation system 110 and the outflow amount thereof is estimated.

[0105] like Fig.12 As shown, the slag 104 flowing out from the slag door 105 of the electric furnace 101 is recovered in the slag pot 106 arranged at a lower side than the electric furnace 101. The slag pot 106 is placed on a slag collecting trolley 107, and the recovered slag 104 can be appropriately transferred to other places. The estimation system 110 of one embodiment senses the flowing slag 104 (slag flow SF) while the slag 104 flows down from the slag door 105 to the slag pot 106, and estimates the outflow amount of the slag 104.

[0106] The estimation system 110 includes an imaging device 111 and a computer 112. The imaging device 111 is a device having a function of imaging the slag flow SF. The computer 112 is a processing device having a sensor unit, which receives image information from the imaging device 111 and senses the slag flow SF flowing out of the electric furnace 101 by analyzing the received image information. In addition, the computer 112 includes a calculation unit for calculating the volume flow rate of the slag flow SF based on the image captured and an estimation unit for estimating the amount of slag flowing out of the electric furnace 101 based on the volume flow rate.

[0107] First, the imaging device 111 will be described. The imaging device 111 is not particularly limited as long as it can image the slag flow SF. The imaging device 111 is disposed on the front side of the slag door 105 and images the slag flow SF from the front.

[0108] (Sensing unit)

[0109] The sensor unit senses the slag flow SF flowing out of the electric furnace 101. The sensing of the slag flow SF can be implemented by monitoring at least the region (region X) where the slag 104 may flow out. In addition, the imaging device 111 may block light such as illumination using an optical filter when monitoring and imaging the slag flow SF.

[0110] The “area (area X) where the slag 104 may flow out” refers to an area where the sensing unit can sense the slag 104 when the slag 104 flows out from the electric furnace 101. The horizontal range of the area X includes the width of the slag 104 that may flow out, and the vertical range includes at least a portion between the slag door 105 as the slag discharge port and the upper end of the slag discharge pot 106. The “width of the slag 104 that may flow out” refers to the horizontal length of the slag flow SF estimated when the slag 104 flows out from the electric furnace 101. The estimated value of the width of the slag flow can be obtained by experiment or simulation.

[0111] From the perspective of preventing misdetection of the slag flow SF, the horizontal range of the region X may be set to be greater than the width of the slag flow SF, or less than 1500% of the width of the slag flow SF. Similarly, from the perspective of preventing misdetection of the slag flow SF, the vertical range of the region X may be set to be greater than 10% of the length from the slag door 105 to the upper end of the slag discharge pot 106, or less than 500%. Fig.12 An example of area X is shown.

[0112] The slag flow SF can be sensed by sensing a high brightness substance present in the region X. That is, the sensing unit measures the brightness value in the region X. The sensing unit uses a brightness value (0 to 255) expressed in 256 grayscales as the brightness value.

[0113] "High brightness value substance" refers to a substance whose brightness value is higher than the background by a predetermined value or more in the above-mentioned area X, specifically, the slag flow SF. For example, when the brightness value is greater than 30 and less than 255, the sensing unit can sense the high brightness value substance as the slag flow SF. "Background" refers to the part other than the high brightness value substance in the area X, for example, the part with a brightness value greater than 0 and less than 29. In this way, the brightness value in the area X is monitored by the camera 111, and the high brightness value substance (slag flow SF) with a brightness value higher than the background is sensed by the computer 112.

[0114] Here, the brightness value of the high brightness value substance only needs to be higher than the background, but when the difference in brightness value between the high brightness value substance and the background is small, the slag flow SF may not be properly sensed. Therefore, from the perspective of easy detection of the slag flow SF, the sensing unit may determine that the high brightness value substance with a brightness value higher than the background by 30 or more is the slag flow SF. From the perspective of further improving the sensing accuracy, the computer 112 may determine that the high brightness value substance with a brightness value higher than the background by 50 or more is the slag flow SF.

[0115] In addition, from the perspective of preventing false detection, the high-brightness substance may be determined to be the slag flow SF when the area of ​​the high-brightness substance is 0.1% or more relative to the total area of ​​the region X. Furthermore, from the perspective of preventing false detection, the high-brightness substance may be determined to be the slag flow SF when the area of ​​the high-brightness substance is 0.5% or more relative to the total area of ​​the region X.

[0116] (Photography Department)

[0117] The imaging unit images the slag flow SF. The captured images are sent to the computer 112 (calculation unit). Then, the imaging unit may continue to image the slag flow SF until the computer 112 cannot sense the slag flow SF. The number of images sent is not particularly limited, and may be at least 2.

[0118] The shooting form of the slag flow SF by the shooting unit may be a still image or a moving image. When shooting a still image, the image is shot at a rate of at least one image per second. From the viewpoint of improving the estimation accuracy of the outflow amount of the slag 104, more than 10 still images may be shot per second. When shooting a moving image, at least one still image is extracted from the captured moving image within 1 second. From the viewpoint of improving the estimation accuracy of the outflow amount of the slag 104, more than 10 still images may be extracted from the captured moving image within 1 second.

[0119] The computer 112 may have the same configuration as a general computer. The computer 112 is connected to the imaging device 111 by wire or wirelessly in order to obtain image data from the imaging device 111. As described above, the computer 112 includes a sensing unit, a computing unit, and an estimating unit.

[0120] (Calculation unit)

[0121] The computing unit calculates the volume flow rate of the slag flow SF based on the image captured by the imaging unit. The “image” captured by the imaging unit is the still image itself when the imaging unit captures a still image of the slag flow, and is a still image extracted from the moving image when the imaging unit captures a moving image of the slag flow.

[0122] The calculation unit may also use the above formula (1) to calculate the volume flow rate Q (m 3 / s).

[0123] The width L (m) is measured by the calculation unit from the image (still image) of the slag flow SF. Specifically, the width L is the width of the slag flow SF at any position in the vertical direction in the still image of the slag flow SF. The arbitrary position can be determined by the calculation unit or by the user of the estimation system 110. The measurement of the width L is based on the distance per 1 pixel of the still image geometrically calculated from the magnification of the shooting device 111 and the distance between the shooting device 111 and the slag flow SF, and is measured according to the number of pixels in the horizontal direction of the slag flow SF at any position.

[0124] The cross-sectional area S of the slag flow SF (m 2 ) is obtained by the same method as in the first embodiment.

[0125] The parameter α is obtained by the same method as in the first embodiment.

[0126] The flow velocity V (m / s) of the slag flow SF is obtained by the same method as in the first embodiment.

[0127] (Presumption Department)

[0128] The estimating unit estimates the amount of slag flowing out of the electric furnace 101 based on the volume flow rate determined in the calculating unit.

[0129] The estimation unit can also calculate the bulk density ρ (kg / m 3 ), the mass M (kg) of the slag flow is calculated by the following formula (3).

[0130] ρ=ρL·(100-φ) / 100…(2)

[0131] M=ρ·Σ(Δt·Q)…(3)

[0132] ρ: Bulk density of slag 104 (kg / m 3 )

[0133] ρL: Density of uniform liquid slag (kg / m 3 )

[0134] φ: Gas phase ratio in the slag calculated from the change in slag height from the start of power supply (processing start) to the time when the slag flows out in the electric furnace 101

[0135] Δt: The interval between the image capture times (s) (In the case of still image capture, it is the interval between the capture times of two still images; in the case of moving image capture, it is the interval between the capture times of two still images extracted from the moving image)

[0136] In addition, the gas phase ratio φ of the slag is calculated from the following formula (4).

[0137] φ=(h0-h) / h0·100…(4)

[0138] h0: Slag height at the beginning of power on (m)

[0139] h: Slag height when width L is measured (m)

[0140] Here, the density ρL of the uniform liquid slag can be obtained from the component composition of the slag 104. The slag height in the gas phase ratio φ can be obtained from the change in the energization condition caused by raising or lowering the electrode 102, or can be directly measured using a slag depth bar.

[0141] As described above, in the estimation system 110, the slag 104 flowing out of the electric furnace 101 is estimated by image analysis. In the past, the slag discharge amount (slag discharge amount) caused by installing a clamp on the slag discharge part and the slag discharge amount were estimated by geometric calculation taking into account the shape of the furnace. The problems of these methods are that continuous operation is difficult and the estimation error is caused by the great influence of changes in the shape of the furnace, slag, and molten metal. In addition, in the measurement using a weighing machine installed on a slag collecting trolley, etc., the weighing machine itself is expensive and the risk of failure caused by the contact between the weighing machine and the high-temperature molten material (molten slag, molten metal) becomes a problem.

[0142] On the other hand, the estimation system 110 according to one embodiment can solve all these problems.

[0143] That is, the estimation system 110 according to one embodiment is a method that can perform continuous operations compared to the case where a fixture is installed on the discharge nozzle, and can estimate the slag discharge amount from the electric furnace with higher accuracy than the case where the slag discharge amount is calculated by geometric or empirical measured values.

[0144] The estimation system of the present disclosure has been described above using the estimation system 110 as a preferred embodiment. However, the estimation system of the present disclosure is not limited to this example.

[0145] For example, the estimation system of the present disclosure can also be used to estimate the amount of slag discharge and splashing (sudden overflow of slag containing molten iron from the converter port) in a converter.

[0146] In addition, the estimation system disclosed in the present invention only needs to include a sensing unit, a photographing unit, a computing unit, and an estimation unit, and the configuration of the device implementing the sensing unit is not particularly limited. In one embodiment, the sensing unit, the computing unit, and the estimation unit are provided in the same device, but the estimation system disclosed in the present invention is not necessarily so. The computing unit and the estimation unit may also be provided in different devices (e.g., different computers). In addition, for example, the sensing unit may also be provided in the photographing device.

[0147] [Method for estimating the amount of slag discharged from an electric furnace]

[0148] The method for estimating the slag discharge amount of an electric furnace disclosed in the present invention comprises: a sensing step for sensing the slag flow flowing out of the electric furnace; a photographing step for photographing the slag flow when the slag flow is sensed; a calculation step for calculating the volume flow rate of the slag flow based on the photographed image; and an estimating step for estimating the amount of slag flowing out of the electric furnace based on the volume flow rate.

[0149] The estimation method of the present disclosure can be implemented by the estimation system of the present disclosure. As described above, the respective configurations of the estimation method of the present disclosure are omitted here.

[0150] [Refining method in electric furnace]

[0151] The refining method in the electric furnace of the present disclosure adjusts the type and amount of the refining material added to the electric furnace, and at least one of the voltage, current and electrode height based on the slag discharge amount estimated by the estimation system or estimation method of the present disclosure. The refining material is a component used for refining the high-temperature melt. The type of the refining material is not particularly limited. For example, a CaO source such as quicklime can be cited.

[0152] The estimation system or estimation method of the present disclosure can estimate the amount of slag discharged with high accuracy, and thus, as a result, can also estimate the amount of slag remaining in the electric furnace with high accuracy. Therefore, in the refining method in the electric furnace of the present disclosure, the type and amount of the refining material added to the electric furnace, and at least one of the voltage, current, and electrode height are adjusted based on the amount of slag discharged or the amount of slag remaining estimated with high accuracy, thereby making it possible to appropriately perform the refining of the high-temperature melt.

[0153] For example, when a CaO source is used as a refining material, there is a case where the estimated amount of slag flowing out of the electric furnace is less than expected, and the basicity of the high-temperature melt is lower than expected at the amount of CaO source prepared in advance. In this case, there is a concern of excessive bubbling and insufficient dephosphorization reaction, so additional CaO source needs to be added. In this way, by adjusting the amount of refining material added based on the slag discharge amount estimated with high accuracy, a slag composition suitable for the refining reaction can be obtained.

[0154] In addition, the voltage, current and electrode height used to generate the arc in the operation of the electric furnace are also important indicators. In order to carry out efficient power-on based on the reduction of power consumption rate, it is necessary to control the voltage, current and electrode height corresponding to the amount of slag. In the present disclosure, the amount of slag in the furnace can be grasped based on the slag discharge amount estimated with high accuracy, so the voltage, current and electrode height can be adjusted based on this information. As a result, power-on can be carried out efficiently, so the high-temperature molten material can be properly refined.

[0155] In the above-mentioned embodiment, the electric furnace 101 is used as an example of a refining vessel, but the present disclosure is not limited to this configuration. As an example of a refining vessel, for example, a converter, a molten steel ladle, or a mixing car (torpedo car) may be used.

[0156] <Test example>

[0157] Table 2 shows the conditions of the implemented test examples 1 to 10. α, H, and Δt in Table 2 are as described above. In addition, Table 3 shows the slag discharge amount estimated using the estimation system of the present disclosure as an example. As a comparative example, based on the prior art, the slag discharge amount estimated based on the furnace shape and tilting movement angle of the electric furnace is shown. The estimation error is calculated by the following formula (5).

[0158] Fig.13 This is the measurement result of one mass flow rate (slag outflow velocity) in Test Examples 1 to 10. Fig.14 This is the measurement result of the cumulative slag discharge amount of one of Test Examples 1 to 10. Fig.15 The results show the relationship between the actual amount of slag outflow and the estimated amount of slag outflow obtained through the examples.

[0159] [Table 2]

[0160]

[0161] [Table 3]

[0162] [Formula 1]

[0163]

[0164] As shown in Table 3, the embodiment estimates the slag discharge amount with higher accuracy than the comparative example. Fig.15 As shown, in the embodiment, the estimation error obtained from the estimated amount and the actual amount is small, and from this point of view, it can be confirmed that the slag discharge amount can be estimated with high accuracy.

[0165] <Third Embodiment>

[0166] Next, a method for estimating the amount of slag discharge according to the third embodiment will be described.

[0167] First, the estimation system of the slag discharge amount of the converter 20 using the present embodiment (hereinafter, appropriately abbreviated as "estimation system") is described. The estimation system of the present embodiment is a system that estimates the slag discharge amount using image analysis. Specifically, it is a system that estimates the slag discharge amount (slag discharge quality) by finding the width of the slag flow based on the image of the slag flow SF during the intermediate slag discharge. The estimation system includes a camera 40 and a computer 42 as an example of an estimation device. In the camera 40, the description of the same configuration as the first embodiment is omitted. In addition, in the computer 42, the description of the same configuration as the first embodiment is omitted.

[0168] The photographing device 40 is a device having a function of photographing the slag flow SF flowing out of the converter 20. Specifically, as shown in FIG1 , the photographing device 40 is disposed on the front side of the converter 20 to photograph the slag flow SF flowing out (flowing down) from the furnace mouth 20C of the converter 20 that is moving obliquely toward the slag pot 22 during intermediate slag discharge. Here, arranging the photographing device 40 on the front side of the converter 20 means arranging the photographing device 40 on the side opposite to the converter 20 across the slag pot 22 when viewed from above (when viewed from above). In addition, it is preferred to arrange the photographing device 40 in such a manner that a straight line passing through the center of the converter 20 and the center of the slag pot 22 when viewed from above overlaps with the optical axis OA. In addition, FIGS. 1 and 2 show that the photographing device 40 is disposed on the front side of the converter 20. Fig.16 The arrow UP shown indicates upward. In the present embodiment, one imaging device 40 is disposed on the front side of the converter 20 .

[0169] At least one of a bandpass filter that selectively transmits a wavelength range from the visible light region to the infrared light region and a dimming filter that reduces the amount of incident light may be installed in the imaging device 40. Thus, by installing at least one of a bandpass filter and a dimming filter that reduces the amount of incident light in the imaging device 40, it is possible to suppress the generation of a halo caused by the radiation light of the slag flow SF in the image captured by the imaging device 40.

[0170] As the bandpass filter mounted on the imaging device 40, it is preferable to use a bandpass filter that selects and transmits wavelengths of λ±10nm or less for a wavelength λ selected from the wavelength range of 380nm to 780nm as visible light. In addition, it is further preferable to use a bandpass filter that selects and transmits wavelengths of λ±10nm or less for a wavelength λ selected from the wavelength range of 450nm to 750nm.

[0171] In addition, it is preferable to use a light reduction filter that reduces the amount of incident light to 90% or less as the light reduction filter mounted on the imaging device 40. In addition, it is more preferable to use a light reduction filter that reduces the amount of incident light to 70% or less as the light reduction filter.

[0172] The computer 42 is a device that has the function of calculating the width of the slag flow SF based on the captured image to estimate the amount of slag discharge. The computer 42 of this embodiment has the following functions: in the image captured by the imaging device 40, when the slag flow SF is divided into multiple branches, calculate the width of each slag branch SF. i Width L i , using the width L obtained i The total value of L sum To estimate the slag discharge amount.

[0173] like Fig. 9As shown, the image information of the slag flow SF captured by the camera 40 is sequentially sent to the computer 42. The computer 42 performs image analysis on the received image information to obtain the width of the slag flow. Here, when the image information sent from the camera 40 is image information of a still image, the computer 42 performs image analysis on each still image. On the other hand, when the image information sent from the camera 40 is image information of a moving image, a still image is extracted from the moving image at a predetermined time interval (for example, every 1 second), and image analysis is performed on each extracted still image. In addition, from the viewpoint of improving the estimation accuracy of the slag flow SF, the computer 42 may, for example, cause the camera 40 to capture more than 10 still images per second and perform image analysis on each captured still image, or may extract more than 10 still images per second from the moving image captured by the camera 40 and perform image analysis on each extracted still image.

[0174] In the image analysis of the still image performed by the computer 42, first, the still image is binarized. Then, the length of the high brightness portion of the slag flow SF in the preset analysis area is measured as the apparent length. Fig.17 As shown, the length of the bright portion of the slag flow SF is equivalent to the width of the slag flow SF.

[0175] In addition, the computer 42 determines whether the slag flow SF is divided into multiple parts in the captured image. Specifically, in the captured image, when there are multiple high-brightness parts spaced apart in the horizontal direction, the computer 42 determines that the slag flow SF is divided into multiple parts. In addition, the determination of whether the slag flow SF is divided into multiple parts can be performed each time the image analysis of the still image is performed, or can be performed periodically.

[0176] In the captured image, when the slag flow SF is divided into a plurality of branches, the computer 42 obtains the value of each slag branch flow SF. i Width L i , according to the obtained width L i Find the total value L sum In addition, Fig.16 In the example shown, the slag flow SF is horizontally divided into two slag sub-flows SF i . The two slag streams SF i One slag flow is represented by SF1, and the other slag flow is represented by SF2. Fig.16 In the example shown, the total value L sum= width L1 + width L3. In addition, width L1 is the width of the first slag flow SF1, and width L3 is the width of the second slag flow SF2. In addition, width L2 is the width of the portion where the slag flow SF is cut off and does not flow through the slag discharge.

[0177] In addition, the computer 42 obtains the flow velocity V (m / s) based on the captured image. Regarding the flow velocity V (m / s), the flow velocity V (m / s) of the slag flow SF at the measurement positions of the width L1 and the width L2 can be assumed to be the free fall of the slag flow SF (set to 2gH). 0.5 ), the moving distance of the slag flow SF can also be obtained by pattern matching based on at least two images, and the moving distance of the slag flow SF is divided by the difference (s) between the shooting times of the images for which the moving distance is to be obtained. In addition, when the flow velocity V (m / s) is assumed to be the free fall of the slag flow SF, the computer 42 obtains the moving distance from the width L by image analysis based on the still images taken. i The distance H (m) from the measurement position to the outflow start position of the slag flow SF from the furnace port 20C. In addition, regarding the outflow position from the furnace port 20C, since the converter 20 rotates around the axis, the furnace port 20C (the outflow position of the slag) can be geometrically determined based on the tilting movement angle.

[0178] In addition, the computer 42 obtains the slag discharge amount M by the following equation (6).

[0179] [Formula 2]

[0180]

[0181] M: Slag discharge mass (kg)

[0182] ρ: Bulk density of slag (kg / m 3 )

[0183] Δt: image capture interval (s)

[0184] α: Parameter for correcting the cross-sectional shape of the slag flow

[0185] L i : Width of slag diversion (m)

[0186] V1: The average flow rate of each slag flow, the flow rate of any slag flow, or the flow rate of each slag flow

[0187] In addition, the method of obtaining the bulk density ρ of the slag is the same as that of the first embodiment.

[0188] exist Fig.16 In the example, the slag flow SF is split into two slag split flows SF1 and SF2, so (ΣLi ) 2 As (L1+L3) 2 Find out.

[0189] In addition, in the captured image, the computer 42 detects that the slag flow SF is not divided into multiple flows, such as Fig.17 As shown, the width L of the slag flow SF is obtained. In addition, the computer 42 obtains the flow velocity V (m / s) from the captured image. Then, the computer 42 obtains the slag discharge amount M by the following equation (8).

[0190] [Formula 3]

[0191]

[0192] M: Slag discharge mass (kg)

[0193] ρ: Bulk density of slag (kg / m 3 )

[0194] Δt: image capture interval (s)

[0195] α: Parameter for correcting the cross-sectional shape of the slag flow

[0196] L: Width of slag flow (m)

[0197] V: Flow velocity of slag flow (m / s)

[0198] Next, a method for estimating the slag discharge amount of the converter 20 using the present embodiment will be described. The method for estimating the slag discharge amount of the present embodiment is a method for estimating the slag discharge amount using image analysis. Specifically, it is a method for estimating the slag discharge amount (slag discharge mass) by finding the width of the slag flow SF based on an image of the slag flow during intermediate slag discharge. More specifically, the slag flow SF flowing out of the converter 20 is photographed, and the width of the slag flow SF is found based on the photographed image to estimate the slag discharge amount. In this method, when the slag flow SF is divided into multiple branches in the photographed image, the width L of each slag branch is found. i , using the obtained width L i The total value of L sum To estimate the slag discharge amount.

[0199] First, the slag flow SF flowing out of the furnace port 20C of the converter 20 is photographed. Specifically, as shown in FIG1 , the slag flow SF flowing out (flowing down) from the furnace port 20C of the converter 20 moving obliquely toward the slag tapping pot 22 during intermediate slag tapping is photographed by the imaging device 40 .

[0200] Next, in the captured image, it is determined whether the slag flow SF is bifurcated. In the case of bifurcation, the above formula (6) is used to estimate the slag discharge amount, and in the case of non-bifurcation, the above formula (8) is used to estimate the slag discharge amount. The determination of whether the slag flow SF is bifurcated is performed, for example, for each still image or periodically. That is, based on the repeated determination of whether the slag flow SF is bifurcated, the estimation of the slag discharge amount is also repeated. The following describes the case where the slag flow SF is determined to be bifurcated.

[0201] Next, the width of the slag flow SF is obtained based on the image captured by the camera 40. Specifically, the computer 42 receives the image information obtained by the camera 40 capturing the slag flow SF, and the computer 42 performs image analysis to obtain the width of the slag flow SF. Here, since it is determined that the slag flow SF is divided into multiple branches, the width Li of each slag branch SFi is obtained, and the total value L of the obtained widths Li is calculated. sum is used as the width of the slag flow SF. Fig. 9 In the example shown, the total value L is obtained based on the width L1 of the first slag flow SF1 and the width L3 of the second slag flow SF2. sum .

[0202] Next, the flow velocity V (m / s) is calculated based on the captured image. Specifically, the computer 42 may assume that the flow velocity V (m / s) of the slag flow SF at the measurement position of the width of the slag flow SF is the free fall of the slag flow SF (set to 2gH). 0.5 ), the moving distance of the slag flow SF can also be calculated by pattern matching based on at least two images, and the flow velocity V (m / s) can be calculated by dividing the moving distance of the slag flow SF by the difference (s) between the shooting times of the images for which the moving distance is calculated.

[0203] Next, the computer 42 calculates the slag discharge amount using the above-mentioned formula (6). Thus, the slag discharge amount from the converter 20 is estimated.

[0204] Next, the effects of this embodiment will be described.

[0205] In the present embodiment, when the slag flow SF is divided into a plurality of branches in the image captured by the imaging device 40, the flow rate of each slag branch SF is obtained. i Width L i , using the obtained width L i The total value of L sum Therefore, in this embodiment, for example, Fig.16As shown, compared with the configuration in which the width of the slag flow SF is calculated as width L1+width L2+width L3, the width L is calculated as width L1+width L3, so the slag discharge amount can be estimated with high accuracy. That is, according to this embodiment, even when the slag flow SF is divided into multiple flows, the slag discharge amount can be estimated with high accuracy.

[0206] In addition, when the imaging device 40 is equipped with at least one of a bandpass filter and a dimming filter that reduces the amount of incident light, it is possible to suppress the generation of a halo caused by the radiation light of the slag flow SF in the image captured by the imaging device 40. By suppressing the generation of the halo in this way, the width of the slag flow SF can be obtained with high accuracy from the image captured by the imaging device 40. In addition, it is also easy to detect the branching of the slag flow SF, and the slag discharge amount can be estimated with high accuracy.

[0207] In the above-mentioned embodiment, when the slag flow SF is divided into a plurality of branches in the image captured by the imaging device 40, the slag flow SF is obtained. i Width L i , using the obtained width L i The total value of L sum To estimate the slag discharge amount, the present disclosure is not limited to this configuration. In the image captured by the camera 40, as shown in FIG. Fig.16 As shown, when the slag flow SF is divided into multiple parts, the slag flow SF can also be obtained. i Width L i , using the width L i SF according to each slag i Estimated slag discharge volume M i , according to the estimated slag discharge amount M i Estimate the total slag discharge amount M. The total slag discharge amount M is calculated by the following formula (7).

[0208] [Number 4]

[0209]

[0210] M: Slag discharge mass (kg)

[0211] M i : Slag discharge mass of slag diversion (kg)

[0212] ρ: Bulk density of slag (kg / m 3 )

[0213] Δt: image capture interval (s)

[0214] α: Parameter for correcting the cross-sectional shape of the slag flow

[0215] L i: Width of slag diversion (m)

[0216] V2: The average flow rate of each slag flow, the flow rate of any slag flow, or the flow rate of each slag flow

[0217] exist Fig.16 In the example, the slag flow SF is split into two slag split flows SF1 and SF2, so L in equation (7) is replaced by i 2 As L1 2 +L3 2 Find out.

[0218] In addition, as the flow velocity V2, it is most preferable to obtain the flow velocity of each slag flow and apply it to equation (7), but it is also possible to obtain the flow velocity of any slag flow and use the flow velocity as the flow velocity of all slag flows and apply it to equation (7). This is because the position for measuring the width of the slag flow is the same in all slag flows, so the flow velocity is almost unchanged regardless of the slag discharge amount. In addition, in this case, the processing load for obtaining the flow velocity of the computer 42 can be reduced.

[0219] In addition, the camera 40 may monitor the shooting area, and when a substance with high brightness is sensed in the shooting area, the situation in the shooting area is recorded as an image, that is, shooting is started. The identification of substances with high brightness in the shooting area may be performed by the computer 42, or by an image processing unit mounted on the camera 40. In addition, the camera 40 may start shooting according to an instruction from the computer 42 when the inclination of the converter 20 reaches a predetermined angle.

[0220] In the above embodiment, the converter 20 is used as an example of a refining vessel, but the present disclosure is not limited to this configuration. As an example of a refining vessel, for example, an electric furnace, a molten steel ladle, or a mixing car (torpedo car) may be used.

[0221] (Test example)

[0222] Next, the effects obtained by the technology disclosed in the present invention were verified.

[0223] Table 4 shows the average estimation error of the example to which the technology of the present disclosure is applied and the average estimation error of the comparative example to which the technology of the present disclosure is not applied.

[0224] In the examples and comparative examples, 30 still images of the slag flow in the converter were captured every second using a camera (imaging device), and the slag discharge amount was estimated by analyzing the still images.

[0225] In addition, the embodiment uses the prediction method of the above-mentioned formula (6) and the prediction method of the above-mentioned formula (7) to calculate the slag discharge amount. The comparative example is based on the prior art and calculates the slag discharge amount under the condition that the slag flow split cannot be sensed. Other measurement conditions are the same in the embodiment and the comparative example. In addition, the estimated error is calculated by the above-mentioned formula (5).

[0226] Fig.18 The results are shown for the examples and comparative examples in relation to the actual slag discharge amount (measured by a weighing machine) and the estimated slag discharge amount obtained by the examples and comparative examples.

[0227] [Table 4]

[0228]

[0229] As shown in Table 4, the average estimation errors of the embodiment are 4.98% and 7.91%, while the average estimation error of the comparative example is 16.5%. That is, the embodiment has a smaller average estimation error than the comparative example, and thus the slag discharge amount of the slag is estimated with high accuracy. Moreover, in comparison between the embodiments, it can be confirmed that the result estimated using formula (7) can estimate the slag discharge amount with high accuracy compared with the result estimated using formula (6). In this way, it can be confirmed that either the technology of formula (6) of the present disclosure or the technology of formula (7) can estimate the slag discharge amount with high accuracy compared with the prior art.

[0230] <Fourth Embodiment>

[0231] Next, a method for estimating the amount of slag discharge according to the fourth embodiment will be described.

[0232] First, the estimation system of the slag discharge amount of the converter 20 using the present embodiment (hereinafter, appropriately abbreviated as "estimation system") is described. The estimation system of the present embodiment is a system that estimates the slag discharge amount using image analysis. Specifically, it is a system that estimates the slag discharge amount (slag discharge quality) by finding the width of the slag flow based on the image of the slag flow SF during the intermediate slag discharge. The estimation system includes a camera 40 and a computer 42 as an example of an estimation device. In the camera 40, the description of the same configuration as the first embodiment is omitted. In addition, in the computer 42, the description of the same configuration as the first embodiment is omitted.

[0233] The imaging device 40 limits the amount of incident light in such a manner that the brightness of the slag flow SF, which is a high-brightness substance, is not saturated in the captured image. In other words, in order to suppress the generation of a halo due to the radiation light of the slag flow SF in the captured image, the amount of incident light to the imaging device 40 is limited. In the present embodiment, a limiting filter 41 for limiting the amount of incident light is mounted on the imaging device 40. As the limiting filter 41, although it varies depending on the measurement conditions, it is preferred to use a limiting filter that reduces the amount of incident light to less than 90%, and it is more preferred to use a limiting filter that reduces the amount of incident light to less than 70%.

[0234] The computer 42 calculates the slag discharge amount M using the above equation (8).

[0235] Next, the method for estimating the slag discharge amount of the converter 20 using the present embodiment is described. The method for estimating the slag discharge amount of the present embodiment is a method for estimating the slag discharge amount using image analysis. Specifically, it is a method for estimating the slag discharge amount (slag discharge quality) by finding the width of the slag flow SF based on the image of the slag flow during intermediate slag discharge. More specifically, it is a method for estimating the slag discharge amount by photographing the slag flow SF flowing out of the converter 20 and finding the width of the slag flow SF based on the photographed image to estimate the slag discharge amount. In this method, the amount of incident light to the photographing device 40 that photographs the slag flow SF is limited, and in the photographed image, the slag flow SF and the flame are identified based on the brightness difference generated between the slag flow SF and the flame generated during the slag discharge (also called a sedation flame), and the width of the slag flow SF is found to estimate the slag discharge amount.

[0236] First, the slag flow SF flowing out from the furnace port 20C of the converter 20 is photographed. Fig.18 As shown, the slag flow SF flowing out (flowing down) from the furnace port 20C of the converter 20 that moves obliquely toward the slag discharge pot 22 during the intermediate slag discharge is photographed by using the photographing device 40. Here, the upstream side portion of the slag flow SF can also be photographed by using the photographing device 40. In addition, the upstream side portion of the slag flow SF refers to the portion above the position from the position where the slag flows out from the furnace port 20C to the half position in the height direction of the slag discharge pot 22. The photographing device 40 is arranged in such a manner that the optical axis OA of the photographing device 40 faces the upstream side portion of the slag flow SF, thereby photographing the upstream side portion of the slag flow SF.

[0237] Next, the width of the slag flow SF is obtained based on the image captured by the camera 40. Specifically, the computer 42 receives the image information obtained by the camera 40 capturing the slag flow SF, and the computer 42 performs image analysis to obtain the width L of the slag flow SF. In addition, the width L of the slag flow SF can also be obtained by using the upstream part of the slag flow SF in the image captured by the slag flow SF. In addition, the upstream part of the slag flow SF in the image captured by the slag flow SF refers to the part on the upper side than the center of the length of the slag flow SF in the vertical direction in the captured image.

[0238] Next, the flow velocity V (m / s) is calculated based on the captured image. Specifically, the computer 42 may assume that the flow velocity V (m / s) of the slag flow SF at the measurement position of the width of the slag flow SF is the free fall of the slag flow SF (set to 2gH). 0.5 ), the moving distance of the slag flow SF can also be calculated by pattern matching based on at least two images, and the flow velocity V (m / s) can be calculated by dividing the moving distance of the slag flow SF by the difference (s) between the shooting times of the images for which the moving distance is calculated.

[0239] Next, the computer 42 calculates the slag discharge amount using the above-mentioned formula (8). Thus, the slag discharge amount from the converter 20 is estimated.

[0240] Next, the operation of this embodiment will be described.

[0241] Regarding the sedation flame (flame) generated from the slag discharge pot 22 during slag discharge, in the image analysis of the image of the slag flow SF, a large error is caused in the measurement of the width L of the slag flow SF, so its influence needs to be considered. Here, the inventors believe that the luminous substances in the slag flow SF and the sedation flame are different, so there is a difference in the emissivity relative to the wavelength. Specifically, the slag flow SF is slag (molten oxide), while the sedation flame is composed of organic matter contained in the sedation material, and the spectral emissivity of each wavelength of the two is different. Therefore, it is believed that even at the same observation wavelength, there is a difference in the brightness of the slag flow SF and the sedation flame, and a specific wavelength at which only the slag flow SF can be clearly observed, and in-depth research has been conducted. As a result, it was found that in the wavelength range of visible light, by limiting the amount of incident light to the camera 40 to the extent that the brightness of the slag flow SF in the captured image is not saturated, the brightness of the slag flow SF in the captured image is significantly greater than the sedation flame. Therefore, it is considered that the width L of the slag flow SF can be continuously measured even when the sedation flame occurs during the slag discharge, and the present inventors have considered the following estimation method: by limiting the amount of incident light to the imaging device 40 that captures the slag flow SF, the slag flow SF and the sedation flame are distinguished from each other in the captured image based on the brightness difference between the slag flow SF and the sedation flame generated during the slag discharge, the width L of the slag flow SF is obtained, and the slag discharge amount is estimated using the obtained width L. In this estimation method, by limiting the amount of incident light to the imaging device 40 that captures the slag flow SF, for example, compared with a configuration in which the amount of incident light to the imaging device 40 is not limited, the slag flow SF and the sedation flame can be distinguished even when the sedation flame is generated from the slag discharge pot 22 due to the input of the sedation material. Therefore, even when the sedation flame is generated from the slag discharge pot 22, the width L of the slag flow SF can be obtained with high accuracy. By improving the measurement accuracy of the width L of the slag flow SF, the slag discharge amount can be estimated with high accuracy.

[0242] In the present embodiment, the slag flow SF is photographed by the photographing device 40 equipped with the limiting filter 41. That is, by preparing a plurality of limiting filters 41 with different amounts of limiting the incident light amount and replacing the limiting filter 41 used according to the photographing conditions, the slag flow SF and the sedation flame can be identified without changing the threshold setting of the computer 42.

[0243] In addition, when a limiting filter that reduces the amount of incident light to 90% or less is used as the limiting filter 41, it is possible to effectively suppress the generation of halo in the slag flow SF in the image captured by the imaging device 40. In addition, as the limiting filter 41, it is more preferable to use a limiting filter that reduces the amount of incident light to 70% or less.

[0244] In the present embodiment, since the upstream portion of the slag flow SF is photographed by the photographing device 40, the photographed image is less affected by the sedation flame than, for example, the downstream portion of the slag flow SF. Thus, even when the sedation flame is generated from the slag discharge pot 22, it is easy to identify the slag flow SF and the sedation flame, and the width L of the slag flow SF can be obtained with high accuracy.

[0245] In the present embodiment, the width L of the slag flow SF is obtained by using the upstream portion of the image in which the slag flow SF is captured, so that the image of the slag flow SF is less affected by the sedation flame than when the width L of the slag flow SF is obtained by using the downstream portion of the image in which the slag flow SF is captured. Thus, even when the sedation flame is generated from the slag discharge pot 22, it is easy to distinguish between the slag flow SF and the sedation flame, and the width L of the slag flow SF can be obtained with high accuracy.

[0246] In addition, the camera 40 may also record the situation in the shooting area as an image, i.e., start shooting, when a substance with high brightness is identified in the shooting area. The identification of the substance with high brightness in the shooting area may be performed by the computer 42, or by an image processing unit mounted on the camera 40. In addition, the camera 40 may also start shooting according to an instruction from the computer 42 when the inclination of the converter 20 reaches a predetermined angle.

[0247] In the above-mentioned embodiment, the amount of incident light to the camera 40 is limited, but the present disclosure is not limited to this configuration. For example, the wavelength of the incident light to the camera 40 may also be limited. Specifically, it is preferred to limit the light with a wavelength of 3.0 μm or more and 4.0 μm or more to be incident on the camera 40. This is because the slag flow SF is slag (molten oxide), and the sedation flame is composed of organic matter contained in the sedation material, and the spectral emissivity of each wavelength of the two is different. Therefore, it is believed that even at the same observation wavelength, there is a difference in brightness between the slag flow SF and the sedation flame, and a specific wavelength at which only the slag flow SF can be clearly observed. Therefore, the inventors of the present invention have considered a method of clearly photographing only the slag flow SF by limiting the wavelength of the incident light to the camera 40. Specifically, by setting the wavelength of the incident light incident on the camera 40 to a range of 3.0 μm or more and 4.0 μm or more, it is possible to clearly photograph only the slag flow SF. This is because the emission of the sedation flame is mainly caused by dust, which is fine iron powder, and the higher the wavelength, the lower the emissivity of iron. The absorption rate of moisture contained in the air and carbon dioxide generated when the flame is generated is relatively small, so the wavelength range of the incident light to the imaging device 40 is set as described above. By photographing the slag flow SF within this wavelength range, the sedation flame hardly appears in the photographed image, and only the slag flow SF can be photographed. Even if the sedation flame is generated during slag discharge, the width L of the slag flow SF can be continuously measured. In addition, the limitation of the wavelength of the incident light to the imaging device 40 can also be performed by installing a bandpass filter in the imaging device 40.

[0248] In addition, both the limiting filter 41 and the bandpass filter may be installed in the imaging device 40. Thereby, the width L of the slag flow SF can be obtained with higher accuracy.

[0249] In the above embodiment, the converter 20 is used as an example of a refining vessel, but the present disclosure is not limited to this configuration. As an example of a refining vessel, for example, an electric furnace, a molten steel ladle, or a mixing car (torpedo car) may be used.

[0250] (Test example)

[0251] Next, the effects obtained by the technology disclosed in the present invention were verified.

[0252] Table 5 shows the average estimation error of the example to which the technology of the present disclosure is applied, the average estimation error of the comparative example to which the technology of the present disclosure is not applied, and the average estimation error of the reference example.

[0253] In an embodiment, a camera (camera) is used to capture 30 still images of the slag flow in the converter every second under the condition that the amount of incident light to the camera is limited to 70%, and the still images are analyzed to estimate the amount of slag discharge. In a reference example, the slag discharge amount is estimated using the width of the slag flow obtained by simulation under the condition that the wavelength of the incident light to the camera is limited to 5.0 μm. In addition, regarding the estimation of the slag discharge amount, in the case of a sedated flame, the slag flow is manually identified and the width is measured, and the slag discharge amount is estimated according to formula (8). The comparative example is an example of applying the prior art, in which the slag discharge amount (slag discharge amount) is estimated in the converter based on the actual value of the slag discharge flow rate that is pre-measured with the change in the tilt movement angle of the furnace.

[0254] Fig. 20 : This is a graph showing a comparison of the average estimation error of 10 charges in the estimation of the slag discharge amount in the comparative example, the example and the reference example. The estimation error is obtained by the above-mentioned formula (5).

[0255] Fig.21 The results are the results showing the relationship between the actual slag discharge amount of the examples and comparative examples (measured by a weighing machine) and the estimated slag discharge amount obtained by the examples and comparative examples. In addition, the reference example is the result when the simulation is used.

[0256] [Table 5]

[0257]

[0258] As shown in Table 5, Fig. 20 and Fig.21 As shown in the figure, the average estimation error of the embodiment is 8.50%, while the average estimation error of the comparative example is 17.8%. In addition, the average estimation error of the reference example is 6.73%. Thus, it can be confirmed that when the technology disclosed in the present invention is used, the slag discharge amount can be estimated with high accuracy compared with the existing technology.

[0259] <Fifth Embodiment>

[0260] Next, a method for estimating the amount of slag discharge according to the fifth embodiment will be described.

[0261] The method for estimating the slag discharge amount of the fifth embodiment is a method for estimating the slag discharge amount of slag flowing out of a refining container by analyzing an image of the slag flow. A refining container refers to a container used for refining pig iron in a converter or an electric furnace. Slag is generated by the refining of pig iron and is appropriately discharged from the refining container. Usually, slag is discharged from a slag discharge port of the refining container and recovered into a slag recovery container such as a slag pan arranged at the bottom. In this specification, a slag discharge port refers to a component that has the function of discharging slag from a refining container, and includes a furnace mouth in addition to a typical slag discharge port. The method for estimating the slag discharge amount of the present embodiment is a method for estimating the slag discharge amount by photographing the slag flow discharged from the above-mentioned slag discharge port and analyzing the photographed image. The following is a description of the method for estimating the slag discharge amount of the present embodiment.

[0262] First, the slag discharge amount estimation system of the present embodiment is described. The estimation system comprises: a sensing unit that senses the slag flow of the slag flowing out of the refining container; a photographing unit that photographs the slag flow; a measuring unit that measures the width L1 of the slag flow based on the photographed still image; a recording unit that records the temporal change of the measured width L1 of the slag flow; and a judging unit that, in the temporal change of the width L1 of the slag flow, determines that the width L1 of the slag flow exceeds a predetermined threshold value L1. max The time at which at least one of flame and black smoke is generated is judged as the time at which flame or the like is generated, and the width L1 of the slag flow is set to a predetermined threshold value L max The following time is judged as a flame non-generation time during which neither flame nor black smoke is generated; a prediction unit, which uses the width L1 of the slag flow just before the flame generation time or just before the flame generation time and just after the flame generation time to predict the width L2 of the slag flow at the flame generation time; and an estimation unit, which estimates the slag discharge amount of the slag by the above-mentioned formula (8), the estimation unit uses the width L of the slag flow predicted by the prediction unit as the width L of the slag flow in the above-mentioned formula (8), when estimating the slag discharge amount of the slag at the flame generation time, and uses the width L2 of the slag flow predicted by the prediction unit when estimating the slag discharge amount of the slag at the flame non-generation time, and uses the width L1 of the slag flow calculated by the measurement unit or the moving average value L of the width L1 of the slag flow at the flame non-generation time when estimating the slag discharge amount of the slag at the flame non-generation time. ave .

[0263] The slag discharge amount estimation system having the above-mentioned structure can be realized, for example, by a system including a camera and a computer. The camera is not particularly limited as long as it can capture the slag flow. For example, a camera such as a CMOS camera can be cited. In order to properly capture the slag flow, the camera is preferably arranged in front of the slag discharge port of the refining container as much as possible. The computer only needs to have the same structure as a general computer. In order to obtain image data from the camera, the computer is connected to the camera via wired or wireless communication. The camera includes a camera unit, and the computer includes a sensing unit, a measuring unit, a recording unit, a judging unit, a predicting unit, and an estimating unit. The following describes the various structures of the slag discharge amount estimation system of one embodiment.

[0264] <Sensor>

[0265] The sensing unit senses the slag flow of the slag flowing out of the refining vessel. The sensing of the slag flow can be implemented by monitoring at least an area (area X) where the slag may flow out of the slag discharge port of the refining vessel. The sensing unit may also block light such as illumination using an optical filter or the like when sensing the slag flow.

[0266] The "area (area X) where slag may flow out" refers to an area where the slag flow can be sensed (an area that can be photographed by the camera) when the slag flows out from the slag discharge port of the refining container. The horizontal range of area X includes the width of the slag that may flow out from the slag discharge port, and the vertical range includes at least a portion from the lower end of the slag discharge port to the upper end of the slag recovery container. The "width of the slag that may flow out" refers to the horizontal length of the slag flow estimated when the slag flows out from the refining container. The estimated value of the width of the slag flow can be obtained by experiment or simulation.

[0267] From the perspective of preventing misdetection of the slag flow, the horizontal range of the region X may be set to be greater than the width of the slag flow (the width of the slag that may flow out), or less than 1500% of the width of the slag flow. Similarly, from the perspective of preventing misdetection of the slag flow, the vertical range of the region X may be set to be greater than 10% of the length from the slag discharge port to the upper end of the slag recovery container, or less than 500%.

[0268] The slag flow can be sensed by sensing a high brightness substance present in the region X. That is, the sensing unit measures the brightness value in the region X. As the brightness value, for example, a brightness value expressed in 256 grayscales (0 to 255) is used.

[0269] Here, the brightness value of the high brightness value substance only needs to be higher than the background, but when the difference between the brightness values ​​of the high brightness value substance and the background is small, the slag flow may not be properly sensed. Therefore, from the perspective of easy detection of the slag flow, the sensing unit may determine that the high brightness value substance is 30 or more higher than the background as the slag flow. From the perspective of further improving the sensing accuracy, the sensing unit may also determine that the high brightness value substance is 50 or more higher than the background as the slag flow.

[0270] In addition, from the perspective of preventing false detection, the high-brightness value substance may be determined to be a slag flow when the area of ​​the high-brightness value substance is 0.1% or more relative to the total area of ​​region X. Furthermore, from the perspective of preventing false detection, the high-brightness value substance may be determined to be a slag flow when the area of ​​the high-brightness value substance is 0.5% or more relative to the total area of ​​region X.

[0271] <Photography Department>

[0272] The photographing unit photographs the slag flow when the sensing unit senses the slag flow. The photographed image is sent to the computer (measurement unit). The number of images sent is not particularly limited, and may be at least 2.

[0273] The slag flow shooting form based on the shooting unit can be a still image or a moving image. In the case of shooting a still image, the image is shot at a rate of at least one image per second. From the viewpoint of improving the estimation accuracy of the slag discharge amount, more than 10 still images may be shot per second. In the case of shooting a moving image, at least one still image is extracted from the captured moving image within 1 second. From the viewpoint of improving the estimation accuracy of the slag discharge amount, more than 10 still images may be extracted from the captured moving image within 1 second.

[0274] <Measurement Section>

[0275] The measuring unit measures the width L1 of the slag flow based on the still image captured by the imaging unit. The "still image" refers to the still image itself when the imaging unit captures a still image of the slag flow, or refers to a still image extracted from the moving image when the imaging unit captures a moving image of the slag flow.

[0276] The width L1 (m) of the slag flow is obtained from a still image. Specifically, in a still image of the slag flow, the width L1 of the slag flow at any position in the vertical direction is measured. The arbitrary position can be determined by the measuring unit or by the user of the slag flow estimation system. The measurement of the width L1 of the slag flow is based on the distance per pixel of the still image geometrically calculated according to the magnification of the photographing device and the distance between the photographing device and the slag flow, and is measured according to the number of pixels in the horizontal direction of the slag flow. At this time, when the slag flow is cut off, the total value of the widths of the cut off slag flows is set as the width L1 of the slag flow.

[0277] <Records Department>

[0278] The recording unit records the temporal change in the width L1 of the slag flow measured by the measuring unit. Normally, the recording unit records the temporal change in the width of the slag flow until the sensing unit cannot sense the slag flow.

[0279] <Judgment Section>

[0280] The determination unit determines that the width L1 of the slag flow exceeds a predetermined threshold value L1 in the temporal change of the width L1 of the slag flow recorded in the recording unit. max The time at which at least one of flame and black smoke is generated is judged as the time at which flame or the like is generated, and the width L1 of the slag flow is set to a predetermined threshold value L max The following time is determined as a flame-free time when neither flame nor black smoke is generated.

[0281] Since a large number of bubbles (foaming) are generated in the slag recovered in the slag recovery container, a defoaming agent (sedative) is sometimes added to the slag, but if the defoaming agent is added, at least one of flame and black smoke will often be generated from the slag. When at least one of flame and black smoke is generated from the slag, there is a concern that at least one of the flame and black smoke will enter the still image captured by the shooting unit. Therefore, there is a concern that the measurement accuracy of the width of the slag flow in the measuring unit will be reduced. Specifically, both flame and black smoke are high-brightness value substances with high brightness values ​​(the brightness value of black smoke is lower than that of flame and slag flow, but higher than that of the background), so when at least one of flame and black smoke enters the still image, the width of the slag flow measured by the measuring unit is expected to be higher than the actual width of the slag flow.

[0282] Thus, if at least one of flame and black smoke is generated, the measurement accuracy of the slag flow width L1 by the measuring unit decreases, thereby reducing the estimation accuracy of the slag discharge amount. Therefore, in one embodiment, whether at least one of flame and black smoke is generated is determined based on the slag flow width L1.

[0283] Whether at least one of flame and black smoke is generated is determined by whether the width L1 of the slag flow exceeds a predetermined threshold value Lmax When the width L1 of the slag flow exceeds the specified threshold value L max When the width L1 exceeds the predetermined threshold value L max The time is treated as the flame generation time. When the width L1 of the slag flow is the predetermined threshold value L max In the following cases, the determination unit determines that at least one of flame and black smoke is not generated, and processes the time when the width L1 is equal to or smaller than a predetermined threshold value as a flame or the like non-generating time.

[0284] The specified threshold L max " can use a value obtained in advance through experiments, but can also use a value calculated by the following formulas (9) and (10). The predetermined threshold value L max Since the width is larger than the empirical maximum value of the width of the slag flow discharged from the slag discharge port, even if the values ​​calculated by the following equations (9) and (10) are used, it is possible to accurately determine whether at least one of flame and black smoke is generated.

[0285] [Formula 5]

[0286]

[0287] [Formula 6]

[0288]

[0289] D: Equivalent circle diameter of slag discharge port (m)

[0290] A: Area of ​​slag outlet (m 2 )

[0291] In addition, whether at least one of flame and black smoke is generated can also be determined based on the flow velocity value of the slag flow. This is because, although the slag flow falls vertically downward, the flame or black smoke rises vertically upward. Therefore, it is also possible to determine whether flame or black smoke is generated based on the vertical upward velocity component of the high-brightness material through image analysis.

[0292] <Forecasting Department>

[0293] The prediction unit predicts the width L2 of the slag flow at the time of the generation of the flame or the like using the width L1 of the slag flow before the start of the generation time of the flame or the like, or before the start of the generation time of the flame or the like and immediately after the end. As described above, the width L1 of the slag flow measured by the measurement unit at the time of the generation of the flame or the like can be measured to be higher than the actual width of the slag flow. Therefore, in order to appropriately estimate the slag discharge amount at the time of the generation of the flame or the like, it is also necessary to appropriately predict the width L2 of the slag flow at the time of the generation of the flame or the like. Therefore, in one embodiment, the width L1 of the slag flow before the start of the generation time of the flame or the like, or before the start of the generation time of the flame or the like and immediately after the end is used to predict the width L2 of the slag flow at the time of the generation of the flame or the like. Specifically, there are the following prediction methods (1) and (2).

[0294] (1) The prediction unit may predict the width L2 of the slag flow at the time of the generation of the flame or the like as the width L of the slag flow calculated by the following formula (11). est .

[0295] [Equation 7]

[0296]

[0297] L est : Width estimated at time t of the generation time of the flame or the like (m)

[0298] L i : Average value of N widths L1 of the slag flow immediately before the start of the generation time of the flame or the like (m) ref (m)

[0299] L f : Average value of N widths L1 of the slag flow immediately after the end of the generation time of the flame or the like (m) ref (m)

[0300] N ref : Number of samples of the width L1 of the slag flow used to obtain L i and L f (m)

[0301] t i : Start time of the generation time of the flame or the like

[0302] t f : End time of the generation time of the flame or the like

[0303] B: Set to a range of 0 < B < 1 when the generation time of the flame or the like is 8 seconds or more, and set to B = 1 when it is less than 8 seconds.

[0304] Number of samples N of the width L1 of the slag flow used to obtain L i and L f (m) refAt least 2 or more. To improve the estimation accuracy of the slag discharge amount, N ref can also be set to 10 or more. N ref The upper limit value of is not particularly limited. For example, it can be set to 30 or less. Thus, since N ref has a specified range, it is determined based on the number of samples N ref and the shooting interval of the still image immediately before and immediately after the start of the generation time of the flame or the like.

[0305] Alternatively, a specific time range can also be specified immediately before and immediately after the start of the generation time of the flame or the like. For example, immediately before and immediately after the start of the generation time of the flame or the like, it can be set to 5 seconds before the start time and after the end time of the generation time of the flame or the like, or it can be set to 3 seconds, or it can also be set to 1 second.

[0306] When the generation time of the flame or the like is 8 seconds or more, the constant B is in the range of 0 < B < 1. At this time, the constant B uses a value calculated in advance based on the true mass of the slag flow (the mass measured by the weighing machine). Specifically, first, in the charge without generating a flame, the parameter α for correcting the cross-sectional shape of the slag flow is determined. Then, under the same measurement conditions as the above charge, when the generation time of the flame or the like is 8 seconds or more, using the value of α, the value of B at which the true mass of the slag flow coincides with the slag discharge amount estimated by the estimation unit is obtained by fitting. If the measurement conditions are constant, the parameter α does not change, so the value of B can be obtained using it. When the constant B is in the range of 0 < B < 1, Equation (11) becomes a function connecting the widths L i and L f by an upwardly convex curve immediately before and immediately after the start of the generation time of the flame or the like. When the generation time of the flame or the like is less than 8 seconds, the constant B is B = 1. In this case, Equation (11) becomes a function connecting the widths L i and L f by a straight line immediately before and immediately after the start of the generation time of the flame or the like.

[0307] (2) Alternatively, the prediction unit can also calculate the slope T of the slag flow width L1 with respect to the time (s) immediately before the start of the generation time of the flame or the like based on the maximum value and the minimum value of the N ref widths L1 immediately before the start of the generation time of the flame or the like, or calculate it by the least squares method based on the N ref widths L1 immediately before the start of the generation time of the flame or the like, and determine whether the slope T exceeds the specified threshold T slope . When the slope T exceeds the threshold T slope , the width L2 of the slag flow at the generation time of the flame or the like is predicted as the average value L of the N ref slag flow widths L1 immediately before the start of the generation time of the flame or the likei , where the slope T is the threshold T slope In the following case, the width L2 of the slag flow at the time of flame generation is estimated as the width L2 of the slag flow calculated by equation (11): est .

[0308] The specified threshold T slope In order to improve the estimation accuracy of slag discharge quality, the threshold value T slope It can also be set to 0.2 or more. slope The upper limit of is not particularly limited, and can be set to 300 or less, for example. slope It can be appropriately set in consideration of the operating conditions and the estimation accuracy of the slag discharge quality.

[0309] Thus, the prediction method of (2) includes the prediction method of (1), and is based on whether the slope T of the width L1 of the slag flow exceeds a predetermined threshold value T slope , the width L2 of the slag flow at the time of flame generation is predicted using different methods.

[0310] Both prediction methods (1) and (2) improve the estimation accuracy of slag flow, and there is no superiority or inferiority here. The prediction methods (1) and (2) can be used according to the operating conditions of the converter and electric furnace.

[0311] <Estimation Department>

[0312] The estimating unit estimates the amount of slag discharged by the above-mentioned equation (8).

[0313] The estimation unit uses the slag flow width L2 predicted by the prediction unit when estimating the slag discharge amount during the flame generation time as the slag flow width L in the following formula (8), and uses the slag flow width L1 calculated by the measurement unit or the moving average value L1 of the slag flow width L1 during the flame generation time when estimating the slag discharge amount during the flame generation time. ave Moving average L ave The number of widths L1 used in the calculation of is not particularly limited, and is, for example, 5 to 30.

[0314] In this way, the estimating unit changes the width L used in the equation (8) according to whether at least one of flame and black smoke is generated. Therefore, the estimating unit can estimate the slag discharge amount with high accuracy regardless of whether at least one of flame and black smoke is generated.

[0315] (Flowchart for determining width L)

[0316] Here, Fig. 22 The flowchart for determining the width L of the equation (8) is shown when the slag discharge amount estimation system uses the prediction method (2).

[0317] As shown Fig. 22 firstly, it is judged whether the width L1 of the slag flow measured by the measuring unit exceeds a specified threshold value L max . When the width L1 is below the specified threshold value L max (L1 ≤ L max ), it is judged that at least one of flame and black smoke is not generated, and the width L1 or the moving average value L ave is adopted as the width L used in formula (8). In contrast, when the width L1 exceeds the specified threshold value L max (L1 > L max ), it is judged that flame or the like is generated.

[0318] When it is judged that flame or the like is generated, it is judged whether the slope T of the width L1 of the slag flow before the start of the flame generation time exceeds a specified threshold value T slope . When the slope T exceeds the threshold value T slope (T > T slope ), the width L i is adopted as the width L used in formula (8). When the slope T is below the threshold value T slope (T ≤ T slope ), it is judged whether the flame generation time is 8 seconds or more.

[0319] When T ≤ T slope and the flame generation time is 8 seconds or more, the width L est (0 < B < 1) is adopted as the width L used in formula (8). When T ≤ T slope and the flame generation time is less than 8 seconds, the width L est (B = 1) is adopted as the width L used in formula (8).

[0320] In the above-mentioned embodiment, a sensing unit and a photographing unit are provided in one photographing device, but the slag discharge amount estimation system of the present disclosure does not necessarily have to be like this. In one embodiment, a sensing unit, a measuring unit, a recording unit, a judging unit, a predicting unit, and an estimating unit are provided in one computer, but the slag discharge amount estimation system of the present disclosure does not necessarily have to be like this. The sensing unit, the measuring unit, the recording unit, the judging unit, the predicting unit, and the estimating unit may also be provided in different devices (for example, different computers). In addition, for example, the sensing unit may also be provided in the photographing device. The slag discharge amount estimation system of the present disclosure only needs to include a sensing unit, a photographing unit, a measuring unit, a recording unit, a judging unit, a predicting unit, and an estimating unit, and the configuration of the devices for realizing them is not particularly limited.

[0321] The above is a description of the slag discharge amount estimation system disclosed in the present invention using one embodiment. According to the slag discharge amount estimation system disclosed in the present invention, by performing image analysis on the slag flow discharged from the refining container in a prescribed method, the slag discharge amount can be estimated with high accuracy regardless of whether at least one of flame and black smoke is generated. In addition, since a non-contact method such as image analysis is adopted, it has high economic rationality compared with the method of directly weighing the slag discharge mass. That is, compared with the case of direct weighing, the maintainability and cost performance can be improved.

[0322] (Test example)

[0323] Table 1 shows the conditions of the implemented test examples 1 to 13. In addition, Table 2 shows, as an example, the amount of slag discharge estimated using the estimation system of the present invention. In Examples 1 to 13, in the converter, 30 still images of the slag flow were taken every second using a camera. In addition, in Examples 1 to 11, the above-mentioned prediction method (1) was used. In Examples 12 to 13, the above-mentioned prediction method (2) was used. As a comparative example, based on the prior art, the amount of slag discharge estimated based on the furnace shape and tilt movement angle of the electric furnace is shown. The estimated error is calculated by the above-mentioned formula (5).

[0324] Fig.23 This is a diagram showing the change over time in the width of the slag flow in one test example among Examples 1 to 11. Fig.24 This is a diagram showing the change over time in the width of the slag flow in one test example among Examples 12 and 13. Fig.25 The results show the relationship between the actual slag discharge amount (measured by a weighing machine) and the estimated slag discharge amount obtained by the example.

[0325] [Table 6]

[0326]

[0327] [Table 7]

[0328] As shown in Table 7, the embodiment estimates the slag discharge amount more accurately than the comparative example. In addition, the embodiment has a small estimation error between the estimated amount and the actual amount, and from this point of view, it can be confirmed that the slag discharge amount can be estimated with high accuracy.

[0329] As described above, Examples 1 to 11 used the prediction method (1), and Examples 12 to 13 used the prediction method (2). The average estimation error of the Examples was 4.71%, whereas the average estimation error of the Comparative Examples was 18.5%. Thus, regardless of which prediction method is used, the slag discharge amount can be predicted with high accuracy.

[0330] The preferred embodiments of the present disclosure are described in detail above with reference to the attached drawings, but the present disclosure is not limited to these examples. Personnel skilled in the art of the present disclosure can understand that various conceivable changes or modifications within the scope of the technical concept described in the claims also naturally fall within the technical scope of the present disclosure.

[0331] The following supplementary notes are further disclosed with respect to the above-mentioned embodiments.

[0332] <Additional Note 1> [1]

[0334] A method for estimating the amount of slag discharge from a converter has the following features:

[0335] Filming process: filming the slag flow from the furnace mouth of the converter;

[0336] a determination step of determining the volume flow rate or mass flow rate of the slag flow based on the captured image; and

[0337] The estimating step estimates the amount of slag discharged from the converter based on the volume flow rate or the mass flow rate. [2]

[0339] According to the method for estimating the amount of slag discharge from a converter described in [1], the imaging direction of the imaging device that images the slag flow is inclined with respect to the slag discharge direction of the converter when viewed from above. [3]

[0341] According to the method for estimating the converter slag discharge amount described in [2], the imaging direction of the imaging device that images the slag flow is orthogonal to the vertical direction when viewed from the side. [4]

[0343] According to the method for estimating the amount of slag discharged from a converter as described in any one of [1] to [3], in the step of determining, based on an image obtained by photographing the slag flow, a width L (m) of the slag flow at a predetermined height and a distance H (m) from a measurement position of the width L to a flow start position of the slag flow flowing out of the furnace port are determined, and a cross-sectional area S (m2) of the slag flow at the measurement position is determined. 2 ) as απL 2 , the flow velocity V (m / s) at the measurement position is assumed to be the free fall of the slag flow and is given as (2gH) 0.5 ) is used to calculate, and the volume flow rate Q (m 3 / s).

[0344] Q=SV=απL 2 V = απL 2 (2gH) 0.5 … (1) [5]

[0346] According to the method for estimating the amount of slag discharged from a converter described in [4], at least the inclination angle of the converter at the start of the outflow of the slag flow, the shape of the converter, the volume of the converter, and the bulk density ρ (kg / m 3 ), convert the volume flow rate into a mass flow rate ρQ (kg / s), and calculate the slag mass (kg) based on the cumulative value ΣρQ (kg). [6]

[0348] According to the method for estimating the converter slag discharge amount described in [4] or [5], when slag is discharged from the refining container, α is obtained by parameter fitting to obtain a correspondence between the slag discharge mass (kg) obtained using a scale and the integrated value ΣρQ (kg) of the mass flow rate ρQ (kg / s). [7]

[0350] A refining method for setting operating conditions of a subsequent step based on the slag discharge amount estimated by the method for estimating the converter slag discharge amount described in any one of [1] to [6]. [8]

[0352] A refining method includes photographing a slag flow flowing out of a furnace port of a converter, obtaining a width of the slag flow from the photographed image, and setting operating conditions for a subsequent process based on the obtained width. [9]

[0354] According to the refining method described in [7] or [8], the operating conditions include the type of refining material added to the molten metal in the converter and the amount of the refining material added.

[0355] <Note 2> [1]

[0357] A slag outflow estimation system for an electric furnace comprises:

[0358] a sensing portion that senses a slag flow from the electric furnace;

[0359] a photographing unit configured to photograph the slag flow when the slag flow is sensed;

[0360] a calculation unit for calculating a volume flow rate of the slag flow based on the captured image; and

[0361] An estimating unit estimates an amount of slag flowing out of the electric furnace based on the volume flow rate. [2]

[0363] According to the slag outflow estimation system of an electric furnace described in [1], the sensing unit measures the brightness value expressed in 256 grayscales and senses a high brightness value substance having a brightness value that is 30 or more higher than the background as the slag flow. [3]

[0365] According to the electric furnace slag outflow estimation system described in [1] or [2], the calculation unit calculates the volume flow rate Q (m 3 / s).

[0366] Q=SV=απL 2 V… (1)

[0367] Q: Volume flow rate of slag flow (m 3 / s)

[0368] S: Cross-sectional area of ​​the slag flow at the measurement position of the width L (m 2 )

[0369] V: Flow velocity V of the slag flow at the measurement position of the width L (m / s)

[0370] α: Parameter for correcting the cross-sectional shape of the slag flow

[0371] L: Width of the slag flow calculated from the image of the slag flow (m) [4]

[0373] According to the method for estimating the outflow amount of slag from an electric furnace described in [3], the estimating unit calculates the bulk density ρ (kg / m 3 ), the mass M (kg) of the slag flow is calculated by the following formula (3).

[0374] ρ=ρL·(100-φ) / 100 (2)

[0375] M = ρ·Σ(Δt·Q) (3)

[0376] ρ: Bulk density of slag (kg / m 3 )

[0377] ρL: Density of uniform liquid slag (kg / m 3 )

[0378] φ: Gas phase ratio in the slag calculated from the change in slag height from the start of power supply to the time when the slag flows out in the electric furnace

[0379] Δt: The interval between image capture times (s) [5]

[0381] According to the slag outflow estimation system for an electric furnace described in [3], the calculation unit calculates the vertical distance H (m) from the measurement position of the slag flow width L to the outflow start position of the slag flow in the electric furnace,

[0382] The flow velocity V (m / s) at the measurement position of the width L is assumed to be the free fall of the slag flow and is expressed as (2gH) 0.5 Find out. [6]

[0384] According to the electric furnace slag outflow estimation system described in [3], the calculation unit calculates the movement distance of the slag flow by pattern matching based on at least two images.

[0385] The flow velocity V (m / s) at the measurement position of the width L is obtained by dividing the movement distance of the slag flow by the difference (s) between the imaging times of the images for obtaining the movement distance. [7]

[0387] According to the slag outflow estimation system of an electric furnace described in [3], the calculation unit uses the theoretical outflow slag amount (kg) calculated based on the mass balance of the components constituting the slag or the outflow slag amount (kg) measured by a weighing device as the true value, and determines the parameter α through parameter fitting. [8]

[0389] A refining method in an electric furnace, which adjusts the type and amount of refined material added to the electric furnace, and at least one of the voltage, current and electrode height based on the slag outflow estimated by the slag outflow estimation system of the electric furnace described in [1] or [2].

[0390] <Addendum 3> [1]

[0392] A method for estimating the amount of slag discharge is provided, wherein a slag flow flowing out of a refining container is photographed, and the width of the slag flow is calculated based on the photographed image to estimate the amount of slag discharge, wherein:

[0393] In the captured image, when there are a plurality of slag flow branches, the width of each slag discharge branch is obtained, and the slag discharge amount is estimated using the total value of the obtained widths. [2]

[0395] According to the method for estimating the slag discharge amount described in [1], the slag discharge amount is calculated by the following formula (1).

[0396] [Formula 8]

[0397]

[0398] M: Slag discharge mass (kg)

[0399] ρ: Bulk density of slag (kg / m 3 )

[0400] Δt: image capture interval (s)

[0401] α: Parameter for correcting the cross-sectional shape of the slag flow

[0402] L i : Width of slag discharge diversion (m)

[0403] V1: The average flow rate of each slag discharge flow, the flow rate of any slag discharge flow, or the flow rate of each slag discharge flow [3]

[0405] A method for estimating the amount of slag discharge is provided, wherein a slag flow flowing out of a refining container is photographed, and the width of the slag flow is calculated based on the photographed image to estimate the amount of slag discharge, wherein:

[0406] In the captured image, when there are multiple slag flow branches, the width of each slag flow branch is calculated, the slag discharge amount is estimated for each slag flow branch using the calculated width, and the overall slag discharge amount is estimated based on the estimated slag discharge amounts. [4]

[0408] According to the method for estimating the slag discharge amount described in [3], the slag discharge amount is calculated by the following formula (2):

[0409] [Number 9]

[0410]

[0411] M: Slag discharge mass (kg)

[0412] M i : Slag discharge mass of slag discharge diversion (kg)

[0413] ρ: Bulk density of slag (kg / m 3 )

[0414] Δt: image capture interval (s)

[0415] α: Parameter for correcting the cross-sectional shape of the slag flow

[0416] L i : Width of slag discharge diversion (m)

[0417] V2: The average flow rate of each slag discharge flow, the flow rate of any slag discharge flow, or the flow rate of each slag discharge flow [5]

[0419] According to the method for estimating the slag discharge amount described in any one of [1] to [4], the slag flow is photographed using a photographing device equipped with at least one of a bandpass filter that selectively transmits a wavelength range from the visible light region to the infrared light region and a diopter filter that reduces the amount of incident light. [6]

[0421] A slag discharge amount estimation system comprising:

[0422] a camera for capturing the flow of slag from the refining vessel; and

[0423] An estimating device is used to estimate the slag discharge amount by calculating the width of the slag flow based on the captured image, wherein:

[0424] The estimating device, in the captured image, when the slag flow is divided into a plurality of flows,

[0425] Find the width of each slag diversion,

[0426] The slag discharge amount is estimated using the total value of each determined width, or the slag discharge amount is estimated for each slag discharge flow using the determined width, and the total slag discharge amount is estimated based on the estimated slag discharge amounts. [7]

[0428] According to the slag discharge amount estimation system described in [6], the imaging device is equipped with at least one of a bandpass filter that selectively transmits a wavelength range from a visible light region to an infrared light region and a dimming filter that reduces the amount of incident light.

[0429] <Note 4> [1]

[0431] A method for estimating the amount of slag discharge is provided, wherein a slag flow flowing out of a refining container is photographed, and the width of the slag flow is calculated based on the photographed image to estimate the amount of slag discharge, wherein:

[0432] limiting the amount of light incident on a camera that captures the slag flow,

[0433] In the captured image, the slag flow and the flame are identified based on the brightness difference generated between the slag flow and the flame generated during slag discharge, and the width of the slag flow is obtained. [2]

[0435] According to the method for estimating the slag discharge amount described in [1], the slag discharge amount is calculated by the following formula (1).

[0436] [Formula 10]

[0437]

[0438] M: Slag discharge mass (kg)

[0439] ρ: Bulk density of slag (kg / m 3 )

[0440] Δt: image capture interval (s)

[0441] α: Parameter for correcting the cross-sectional shape of the slag flow

[0442] L: Width of slag flow (m)

[0443] V: Flow velocity of slag flow (m / s) [3]

[0445] According to the method for estimating the slag discharge amount described in [1], the slag flow is imaged by the imaging device equipped with a limiting filter that limits the amount of incident light. [4]

[0447] According to the method for estimating the slag discharge amount described in any one of [1] to [3], when the slag flow in the captured image is divided into multiple branches, the width of each slag discharge branch is calculated, and the slag discharge amount is estimated using the total value of the calculated widths. [5]

[0449] According to the method for estimating the slag discharge amount described in any one of [1] to [3], in the captured image, when the slag flow is divided into multiple branches, the width of each slag discharge branch is calculated, and the slag discharge amount is estimated according to each slag discharge branch using the calculated width, and the overall slag discharge amount is estimated based on the estimated slag discharge amounts. [6]

[0451] According to the method for estimating the slag discharge amount described in any one of [1] to [3], the upstream side portion of the slag flow is photographed by the photographing device. [7]

[0453] According to the method for estimating the slag discharge amount described in any one of [1] to [3], the width of the slag flow is obtained using the upstream portion of the image obtained by photographing the slag flow. [8]

[0455] A slag discharge amount estimation system comprising:

[0456] a camera for capturing the flow of slag from the refining vessel; and

[0457] An estimating device is used to estimate the slag discharge amount by calculating the width of the slag flow based on the captured image, wherein:

[0458] The amount of incident light to the camera is limited.

[0459] The estimating device identifies the slag flow and the flame based on the brightness difference generated between the slag flow and the flame generated during slag discharge in the captured image, and obtains the width of the slag flow.

[0460] <Addendum 5> [1]

[0462] A slag discharge amount estimation system, comprising:

[0463] a sensing portion that senses a slag flow of the slag flowing out of the refining vessel;

[0464] a photographing unit configured to photograph the slag flow when the slag flow is sensed;

[0465] a measuring unit for measuring a width L1 of the slag flow based on the captured still image;

[0466] a recording unit for recording the measured change in the width L1 of the slag flow over time;

[0467] The determination unit determines that the width L1 of the slag flow exceeds a predetermined threshold value L1 when the width L1 of the slag flow changes with time. max The time at which flame or black smoke is generated is judged as the time at which flame or black smoke is generated, and the width L1 of the slag flow is set to a predetermined threshold value L max The following time is considered as non-generation time such as flame without flame or black smoke;

[0468] a prediction unit that predicts a width L2 of the slag flow at the flame etc. generation time using a width L1 of the slag flow immediately before the flame etc. generation time or immediately before and immediately after the flame etc. generation time; and

[0469] an estimating unit that estimates the amount of slag discharged from the slag using the following formula (1),

[0470] The estimating unit uses the width L2 of the slag flow predicted by the predicting unit when estimating the slag discharge amount of the slag during the flame etc. generation time as the width L of the slag flow in the following formula (1), and uses the width L1 of the slag flow calculated by the measuring unit or the moving average value L1 of the width L1 of the slag flow during the flame etc. generation time when estimating the slag discharge amount of the slag during the flame etc. generation time. ave .

[0471] [Formula 11]

[0472]

[0473] M: Slag discharge mass (kg)

[0474] ρ: Bulk density of slag (kg / m 3 )

[0475] Δt: Still image shooting interval (s)

[0476] α: Parameter for correcting the cross-sectional shape of the slag flow

[0477] L: Width of slag flow (m)

[0478] V: Flow velocity of slag flow (m / s) [2]

[0480] According to the slag discharge amount estimation system described in [1], in the judgment unit, the predetermined threshold value L max It is a value calculated by the following formulas (2) and (3).

[0481] [Formula 12]

[0482]

[0483] [Formula 13]

[0484]

[0485] D: Equivalent circle diameter of the slag discharge port set in the refining container (m)

[0486] A: Area of ​​slag outlet (m 2 ) [3]

[0488] According to the slag discharge amount estimation system described in [1] or [2], the prediction unit predicts the width L2 of the slag flow at the time of the flame generation as the width L2 of the slag flow calculated by the following formula (4): est ,

[0489] [Formula 14]

[0490]

[0491] L est : Width estimated at time t when flames etc. are generated (m)

[0492] L i : N before the flame generation time starts ref Average value of width L1 (m)

[0493] L f : N immediately after the flame generation time ends ref Average value of width L1 (m)

[0494] Nref : The number of samples for obtaining the width L1 of L i and Lf

[0495] t i : The start time of the generation time of the flame or the like

[0496] t f : The end time of the generation time of the flame or the like

[0497] B: When the generation time of the flame or the like is 8 seconds or more, it is set in the range of 0 < B < 1, and when it is less than 8 seconds, B = 1 is set. [4]

[0499] According to the slag discharge amount estimation system described in [3], the prediction unit calculates the slope T of the width L1 of the slag flow with respect to the time (s) immediately before the start of the generation time of the flame or the like based on the maximum value and the minimum value of N ref widths L1 immediately before the start of the generation time of the flame or the like, or calculates it by the least squares method based on the N ref widths L1 immediately before the start of the generation time of the flame or the like,

[0500] judges whether the slope T exceeds a specified threshold T slope ,

[0501] When the slope T exceeds the threshold T slope , the width L2 of the slag flow at the generation time of the flame or the like is predicted as the average value L ref of N i widths L1 of the slag flow immediately before the start of the generation time of the flame or the like,

[0502] When the slope T is below the threshold T slope , the width L2 of the slag flow at the generation time of the flame or the like is predicted as the width L of the slag flow calculated by the formula (4) est . [5]

[0504] According to the slag discharge amount estimation system described in [1] or [2], the sensing unit measures the luminance value expressed in 256 gray levels, and senses a high-luminance value substance with a luminance value 30 or more higher than the background as the slag flow. [6]

[0506] According to the slag discharge amount estimation system described in [1] or [2], the flow velocity V of the slag flow is calculated assuming free fall of the slag flow when the vertical distance from the measurement position of the width L1 of the slag flow in the measurement unit to the lower end of the slag discharge port is set to H (m) (2gH)0.5 . [7]

[0508] According to the slag discharge amount estimation system described in [1] or [2], the flow velocity V of the slag flow is the quotient obtained by dividing the movement distance of the slag flow obtained by pattern matching based on at least two or more of the still images by the difference (s) between the shooting times of the still images. [8]

[0510] According to the slag discharge amount estimation system described in [1] or [2], the parameter α is a value calculated by parameter fitting using the theoretical outflowing slag amount (kg) calculated based on the mass balance of the components constituting the slag, or the outflowing slag amount (kg) measured by a weighing machine as the true value.

[0511] In addition, the disclosures of Japanese Patent Application No. 2022-147356 filed on September 15, 2022 and Japanese Patent Application No. 2022-211373 filed on December 28, 2022 are incorporated herein by reference in their entirety. All documents, patent applications, and technical standards described in this specification are incorporated herein by reference as if each document, patent application, or technical standard was specifically and individually described as being incorporated by reference.

Claims

1. A method for estimating slag discharge amount, characterized in that: The steps include: A slag flow flowing out of a refining vessel's outflow port and becoming wider upstream than downstream is photographed by a photographing device. The width of the slag flow is calculated based on the captured image, and the volume flow rate or mass flow rate is calculated. The slag discharge amount is estimated based on the obtained volume flow rate or mass flow rate.

2. The method for estimating the slag discharge amount according to claim 1, characterized in that: Based on the image of the slag flow, the width L (m) of the slag flow at a predetermined height and the distance H (m) from the measurement position where the width L is obtained to the outflow start position of the slag flow from the outflow port are obtained, and the cross-sectional area S (m) of the slag flow at the measurement position is obtained. 2 ) as απL 2 , calculate the flow velocity V (m / s) at the measuring position, and calculate the volume flow rate Q (m 3 / s), Q=SV=απL 2 V…(1)。 3. The method for estimating the slag discharge amount according to claim 2, characterized in that: The flow velocity V is calculated as (2gH) assuming that the slag flow is in free fall. 0.5 , or by measuring the moving distance of the slag flow through pattern matching.

4. The method for estimating the slag discharge amount according to claim 3, characterized in that: Using the geometrically determined bulk density ρ (kg / m 3 ) The volume flow rate is converted into a mass flow rate ρQ (kg / s), and the slag discharge mass (kg) is calculated based on the cumulative value ΣρQ (kg).

5. The method for estimating the slag discharge amount according to claim 4, characterized in that: When slag is discharged from the refining vessel, α is obtained by parameter fitting so that the discharged slag mass (kg) obtained using a scale and the integrated value ΣρQ (kg) of the mass flow rate ρQ (kg / s) agree.

6. The method for estimating the slag discharge amount according to any one of claims 1 to 5, characterized in that: using the camera to monitor the outflow of slag from the outflow port of the refining container, When the outflow of the slag from the outflow port is sensed, the imaging device starts to image the slag flow.

7. The method for estimating the slag discharge amount according to claim 6, characterized in that: When a substance having a brightness value higher than that of the background by a predetermined value or more is recognized in the imaging area of ​​the imaging device, the substance is sensed as the slag flow.

8. The method for estimating the slag discharge amount according to any one of claims 1 to 7, characterized in that: In the image obtained by photographing the slag flow, when the slag flow has a plurality of branches, the width of each slag branch is obtained, and the slag discharge amount is estimated using the total value of the obtained widths.

9. The method for estimating the slag discharge amount according to any one of claims 1 to 7, characterized in that: In the image obtained by photographing the slag flow, when the slag flow is divided into multiple branches, the width of each slag branch is calculated, the slag discharge amount is estimated for each slag branch using the calculated width, and the overall slag discharge amount is estimated based on the estimated slag discharge amounts.

10. The method for estimating the slag discharge amount according to any one of claims 1 to 9, characterized in that: The slag flow is imaged by the imaging device equipped with a bandpass filter that selectively transmits a wavelength range from a visible light region to an infrared light region.

11. The method for estimating the slag discharge amount according to any one of claims 1 to 10, characterized in that: The slag flow is photographed by the photographing device equipped with a limiting filter for limiting the amount of incident light.

12. The method for estimating the slag discharge amount according to any one of claims 1 to 11, characterized in that: The imaging device captures an image of an upstream portion of the slag flow.

13. The method for estimating the slag discharge amount according to any one of claims 1 to 12, characterized in that: The width of the slag flow is determined using the upstream portion of the image obtained by photographing the slag flow.

14. The method for estimating the slag discharge amount according to any one of claims 1 to 13, characterized in that: In the case of estimating the slag discharge amount during the non-generation time when neither flame nor black smoke is presumed to be generated, as the width of the slag flow, use the measured value obtained by measuring the width of the slag flow at a specified position in the captured image or the moving average of the measured width.

15. The method for estimating the slag discharge amount according to any one of claims 1 to 9, characterized in that in the case of estimating the slag discharge amount during the generation time when at least one of flame and black smoke is generated, use the width of the slag flow obtained from the image captured immediately before the start of the generation time, or the width of the slag flow obtained from the images captured immediately before the start of the generation time and immediately after the end thereof, to predict the width of the slag flow.

16. The method for estimating the slag discharge amount according to claim 15, characterized in that the generation time is the time when the width of the slag flow exceeds a specified width in the temporal change of the width of the slag flow.

17. The method for estimating the slag discharge amount according to claim 16, characterized in that When the prescribed width is set to L max hour, L max From equation (2) and equation (3), we can get: L max =1 / 2D…(2) D = √4A / π…(3) D: Equivalent circle diameter (m) of the slag discharge port provided in the refining vessel A: Area of ​​slag outlet (m 2 ).

18. The method for estimating the slag discharge amount according to any one of claims 15 to 17, characterized in that As the width of the slag flow, the width L of the slag flow obtained by equation (4) is used. est , [Formula 1] ， L est : Width of the slag flow estimated at time t when the flame etc. is generated (m) L i : N before the flame generation time starts ref Average value of the width of the slag flow (m) L f : N immediately after the flame generation time ends ref Average value of the width of the slag flow (m) N ref :Used to find L i and L f Number of samples of the width of the slag flow t i : The start time of the flame generation time t f : The end time of the flame generation time B: In the case where the generation time of flame or the like is 8 seconds or more, it is in the range of 0 < B < 1, and in the case where it is less than 8 seconds, B = 1.

19. The method for estimating the slag discharge amount according to any one of claims 14 to 17, characterized in that Compare the slope T of the width of the slag flow with the threshold T slope , depending on whether the slope T exceeds the threshold T slope , changing the prediction of the width of the slag flow.

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