Slag discharge quantity estimation method and slag discharge quantity estimation system

Abstract

To provide a technique capable of highly accurately estimating a slag discharge quantity even if flame occurs in a discharged slag container.SOLUTION: A slag discharge quantity estimation method photographs a discharged slag stream flowing out from a refining vessel, and from a photographed image, obtains a width of the discharged slag stream so as to estimate a slag discharge quantity. The slag discharge quantity estimation method controls an incident light amount incident into the imaging apparatus that images the discharged slag stream, and in the photographed image, distinguishes the discharged slag flow and the flame by a difference in luminance between the discharged slag stream and the flame occurring in a slag discharge, and determine the width of the slag discharge stream.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to a method for estimating a quantity of discharged dregs and a system for estimating the quantity of discharged dregs. [Background technology]

[0002] The converter refining process is an important process for reducing impurities such as silicon, phosphorus, and carbon in the molten iron tapped from a blast furnace. Some of these impurities are oxidized and removed by blowing high-pressure oxygen gas onto the molten iron, resulting in slag whose basicity has been adjusted by adding quicklime. It is known that the progress of the refining reaction at that time varies depending on the amount of slag in the refining vessel, and accurate understanding of the amount of slag in the refining vessel is important for controlling the refining reaction, that is, for stabilizing the quality of the steel to be manufactured. However, the refining vessel is in a high-temperature and dusty environment, and it is not easy to measure the amount of slag in the refining vessel. Therefore, the amount of slag remaining in the refining vessel is estimated by grasping the amount of slag that has flowed out. Patent Document 1 is known as a method for quantitatively evaluating and estimating the amount of slag that has flowed out of a converter, which is a type of refining vessel.

[0003] Patent Document 1 discloses a method for estimating the amount of discharged slag in a converter by analyzing images of the discharged slag flow and the state inside the converter. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] International Publication No. 2022 / 195951 Summary of the Invention [Problem to be solved by the invention]

[0005] However, the slag discharged into the slag discharge pan is foamed and has a large volume. If the slag in this state is poured into the slag discharge pan, it may overflow from the slag discharge pan. Therefore, a foaming calming material for the slag is poured into the slag discharge pan. At this time, a flame is generated by the burning of the calming material. The generated flame is hot like the slag discharge flow, so in the image of the slag discharge flow, both the slag discharge flow and the flame are captured as high-brightness materials. Therefore, when such an image is analyzed and the amount of slag is estimated, the flame may be regarded as the slag discharge flow, and the occurrence of the flame may be a factor in the estimation error of the amount of slag. Patent Document 1 does not disclose a method for dealing with a flame that occurs during slag discharge.

[0006] An object of the present disclosure is to provide a technology that can estimate the amount of slag with high accuracy even when a flame is generating from the slag pan. [Means for solving the problem]

[0007] A first aspect of the present disclosure is a method for estimating the amount of discharged slag, which involves photographing a discharged slag flowing out of a refining vessel and estimating the amount of discharged slag by determining the width of the discharged slag flow from the photographed image, and which includes limiting the amount of light incident on an imaging device that photographs the discharged slag flow, distinguishing between the discharged slag flow and the flame that occurs in the discharged slag flow based on the brightness difference that occurs between the discharged slag flow and the flame in the photographed image, and determining the width of the discharged slag flow.

[0008] A method for estimating the amount of discharged slag in a second aspect of the present disclosure is the same as the method for estimating the amount of discharged slag in the first aspect, except that the amount of discharged slag is calculated by the following formula (1).

number

[0009] A third aspect of the present disclosure is a method for estimating the amount of discharged slag, in which the discharged slag flow is photographed by the photographing device equipped with a limiting filter that limits the amount of incident light, in the method for estimating the amount of discharged slag of the first aspect.

[0010] A method for estimating the amount of discharged slag in a fourth aspect of the present disclosure is a method for estimating the amount of discharged slag in any one of the first to third aspects, in which, when the discharged slag flow is branched into multiple flows in the captured image, the width of each discharged slag flow is calculated, and the amount of discharged slag is estimated using the sum of the calculated widths.

[0011] A method for estimating the amount of discharged slag in a fifth aspect of the present disclosure is a method for estimating the amount of discharged slag in any one of the first to third aspects, in which, when the discharged slag flow is branched into multiple flows in the captured image, the width of each discharged slag flow is determined, the amount of discharged slag is estimated for each discharged slag flow using the determined width, and the total amount of discharged slag is estimated from the estimated amounts of each discharged slag.

[0012] A sixth aspect of the present disclosure is a method for estimating the amount of discharged slag, comprising the steps of: capturing an image of an upstream portion of the discharged slag flow using the image capturing device;

[0013] A seventh aspect of the present disclosure is a method for estimating the amount of discharged slag, which is a method for estimating the amount of discharged slag in any one of the first to sixth aspects, in which the width of the discharged slag flow is determined using the upstream part of an image of the discharged slag flow.

[0014] An eighth aspect of the present disclosure is a system for estimating the amount of slag waste comprising an imaging device for photographing the slag waste flowing out of a refining vessel, and an estimation device for determining the width of the slag waste flow from the photographed image to estimate the amount of slag waste, wherein the imaging device has a limited amount of incident light, and the estimation device distinguishes between the slag waste flow and the flame occurring during the slag waste flow in the photographed image based on the brightness difference between the slag waste flow and the flame, and determines the width of the slag waste flow. Effect of the Invention

[0015] According to the present disclosure, it is possible to estimate the amount of slag with high accuracy even when a flame is emerging from the slag pan. [Brief description of the drawings]

[0016] [Figure 1] FIG. 2 is a cross-sectional side view of the refining vessel showing the tailings stream exiting the vessel. [Diagram 2] FIG. 2 is a diagram illustrating a configuration of a control device. [Diagram 3] FIG. 2 is a front view of the refining vessel showing the tailings stream exiting the refining vessel; [Figure 4] FIG. 2 is a front view of the refining vessel showing the state in which the tailings flow exiting the refining vessel is diverted. [Diagram 5] 1 is a graph showing the average estimation error in estimating the amount of discharged sludge in the examples, reference examples, and comparative examples. [Figure 6] 1 is a graph showing the relationship between the actual amount of discharged slag and the estimated amount of discharged slag obtained from the examples, reference examples, and comparative examples. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0017] Hereinafter, the embodiment for carrying out the technology of the present disclosure will be described with reference to the drawings. Components indicated by the same reference numerals in each drawing are the same or similar components. Note that duplicated explanations and reference numerals in the embodiments described below may be omitted. In addition, all drawings used in the following description are schematic, and the dimensional relationship of each element, the ratio of each element, etc. shown in the drawings do not necessarily match the actual ones. In addition, the dimensional relationship of each element, the ratio of each element, etc. between multiple drawings do not necessarily match.

[0018] First, a converter 20 used in the method for estimating the amount of discharged slag according to the present embodiment will be described. The converter 20 is an example of a refining vessel according to the present disclosure.

[0019] As shown in Fig. 1, the converter 20 includes a bottom 20A, a furnace wall 20B, a furnace throat 20C, and a tapping hole 20D provided in the furnace wall 20B. The converter 20 is configured to be tilted by a tilting mechanism 24 (see Fig. 2). When the converter 20 is tilted, a waste slag flow SF flows out from the furnace throat 20C. The flowed out waste slag flow SF is received in a waste slag ladle 22.

[0020] Next, a system for estimating the amount of discharged slag (hereinafter, appropriately abbreviated as "estimation system") using the converter 20 of this embodiment will be described. The estimation system of this embodiment is a system that estimates the amount of discharged slag using image analysis. Specifically, it is a system that obtains the width of the discharged slag flow from an image of the discharged slag flow SF during intermediate slag discharge to estimate the amount of discharged slag (discharged slag mass). This estimation system includes an imaging device 40 and a computer 42 as an example of an estimation device.

[0021] The photographing device 40 is a device having a function of photographing the slag flow flowing out from the refining vessel. Specifically, as shown in FIG. 1, the photographing device 40 is arranged in front of the converter 20, and photographs the slag flow SF flowing (flowing down) from the throat 20C of the converter 20 tilted during intermediate slag removal toward the slag ladle 22. Here, arranging the photographing device 40 in front of the converter 20 means arranging the photographing device 40 on the opposite side of the converter 20 across the slag ladle 22 in a plan view (from above). It is preferable to arrange the photographing device 40 so that the straight line passing through the center of the converter 20 in a plan view is the optical axis OA. The arrow UP shown in FIG. 1 and FIG. 3 points upward. In this embodiment, one photographing device 40 is arranged in front of the converter 20.

[0022] In addition, it is preferable that the camera 40 is placed at a height where it is not easily affected by the sedative frame. Note that the "sedative frame" here refers to the flame generated by the reaction between the slag in the slag ladle 22 and the slag sedative material.

[0023] The photographing device 40 may be, for example, a CCD camera or a CMOS camera.

[0024] The photographing device 40 is connected by wire or wirelessly to the computer 42. Image information photographed by the photographing device 40 is transmitted to the computer 42. The image information transmitted from the photographing device 40 may be image information of a still image photographed at predetermined time intervals (e.g., every second) or may be image information of a moving image.

[0025] In addition, the image capturing device 40 limits the amount of incident light so that the brightness of the waste slag flow SF, which is a high-brightness material, does not become saturated in the captured image. In other words, the amount of incident light to the image capturing device 40 is limited to suppress halation caused by the radiation light of the waste slag flow SF in the captured image. In this embodiment, a limiting filter 41 for limiting the amount of incident light is attached to the image capturing device 40. As the limiting filter 41, although it varies depending on the measurement conditions, it is preferable to use a limiting filter that reduces the amount of incident light to 90% or less, and it is more preferable to use a limiting filter that reduces the amount of incident light to 70% or less.

[0026] The computer 42 is a device having a function of estimating the amount of slag by obtaining the width of the slag flow SF from the captured image. The computer 42 of this embodiment has a function of obtaining the width L of the slag flow SF in the image captured by the imaging device 40, and estimating the amount of slag using the obtained width L.

[0027] As shown in FIG. 2, image information of the slag flow SF captured by the photographing device 40 is sequentially transmitted to the computer 42. The computer 42 performs image analysis on the received image information to determine the width of the slag flow. If the image information transmitted from the photographing device 40 is image information of a still image, the computer 42 performs image analysis on each still image. On the other hand, if the image information transmitted from the photographing device 40 is image information of a video, the computer 42 extracts a still image from the video at predetermined time intervals (e.g., every second) and performs image analysis on each extracted still image. Note that, from the viewpoint of improving the estimation accuracy of the slag flow SF, the computer 42 may, for example, cause the photographing device 40 to capture 10 or more still images per second and perform image analysis on each captured still image, or may extract 10 or more still images per second from the video captured by the photographing device 40 and perform image analysis on each extracted still image.

[0028] In the image analysis of the still image by the computer 42, the still image is first binarized. Specifically, since the luminance value of the slag flow SF is higher than that of the calming frame, a threshold value is set as the boundary value between the slag flow SF and the calming frame, and the still image is binarized based on the threshold value. Then, the length (horizontal length) of the high-luminance part of the slag flow SF within a predetermined analysis area is measured as the apparent length. As shown in FIG. 3, the length of the high-luminance part of the slag flow SF corresponds to the width of the slag flow SF.

[0029] The computer 42 also obtains the flow velocity V (m / s) from the captured image. The flow velocity V (m / s) is calculated by assuming that the flow velocity V (m / s) of the slag flow SF at the measurement position of the width L (position shown by the dashed line in FIG. 3) is a free fall of the slag flow SF (2 gH). 0.5 Alternatively, the moving distance of the slag flow SF may be calculated by pattern matching from at least two or more images, and the moving distance of the slag flow SF may be divided by the difference (s) between the photographing times of the images from which the moving distance was calculated. If the flow velocity V (m / s) is assumed to be the free fall of the slag flow SF, the computer 42 calculates the distance H (m) from the measurement position of the width L to the starting position of the slag flow SF from the throat 20C by image analysis of the captured still image. As for the outflow position from the throat 20C, the throat 20C (the outflow position of the slag) can be geometrically calculated from the tilt angle because the converter 20 rotates around its axis.

[0030] Further, the computer 42 calculates the amount of dregs M by the following formula (1).

[0031]

number

[0032] The bulk density ρ of the slag is expressed as V, which is the effective furnace volume of the converter 20 at the time when the slag starts to flow out of the throat 20C of the tilted converter 20. DS , the volume of the molten iron is V M , the volume of the slag is V S Let V be the volume of the slag. S V S =V DS -V M and the mass of the slag is M S Then, the bulk density ρ = M S / V S It may be found by: In addition, V S +V M Once the tilting angle of the converter 20 is determined, it may be obtained from a drawing of the converter 20 using CAD or geometric calculations. Also, V M Since the mass of molten steel is approximately equal to the mass of the main raw materials (molten iron + scrap), it can be calculated by multiplying the density of molten steel by the mass of the main raw materials (actual results). The shape of the converter 20 is the shape of the inside of the furnace. The shape of the inside of the furnace is a shape including the shape of the inner surface of the furnace wall 20B and the shape of the inner surface of the bottom 20A.

[0033] The bulk density ρ of the slag is calculated by taking the slag height (m) in the refining vessel at the start of refining as h0, the slag height (m) at the time of measuring the width L of the discharge slag flow as h, and the gas phase ratio in the slag as φ, and calculating the gas phase ratio φ from φ = (h0-h) / h0×100. The density of the uniform liquid slag is ρL (kg / m 3 ) and the bulk density ρ may be calculated as ρ=ρL×(100-φ) / 100.

[0034] The parameter α is a correction coefficient for the cross-sectional shape of the waste slag flow SF, and when the cross-sectional shape of the waste slag flow SF is a perfect circle, α is 1 / 4.

[0035] 2, the computer 42 includes a CPU (Central Processing Unit) 43, a main storage device 44 that provides a temporary storage area, an auxiliary storage device 45 that provides 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.

[0036] 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 amount of discharged slag in the converter 20. The CPU 43 reads out the estimation program 48 from the auxiliary storage device 45, loads it into the main storage device 44, and sequentially executes the processes described in the estimation program 48, whereby the computer 42 functions as an estimation device for the amount of intermediate discharged slag in the converter 20.

[0037] The input / output I / F 46 is connected to the photographing device 40. As a result, image information photographed by the photographing device 40 is stored in the auxiliary storage device 45 via the input / output I / F 46 and is configured to be subjected to image analysis by the CPU 43.

[0038] Next, a method for estimating the amount of discharged slag using the converter 20 of this embodiment will be described. The method for estimating the amount of discharged slag in this embodiment is a method for estimating the amount of discharged slag using image analysis. Specifically, this is a method for estimating the amount of discharged slag (discharged slag mass) by obtaining the width of the discharged slag flow SF from an image of the discharged slag flow during intermediate slag discharge. More specifically, this is a method for estimating the amount of discharged slag by photographing the discharged slag flow SF flowing out from the converter 20 and obtaining the width of the discharged slag flow SF from the photographed image to estimate the amount of discharged slag. The amount of incident light on the photographing device 40 that photographs the discharged slag flow SF is limited, and the discharged slag flow SF and the flame are distinguished from each other by the brightness difference between the discharged slag flow SF and the flame (also called the quenching frame) generated during the discharged slag in the photographed image, and the amount of discharged slag is estimated by obtaining the width of the discharged slag flow SF.

[0039] First, the slag flow SF flowing out from the throat 20C of the converter 20 is photographed. Specifically, as shown in FIG. 1, the slag flow SF flowing out (flowing down) from the throat 20C of the converter 20 tilted during intermediate slag removal toward the slag ladle 22 is photographed by the photographing device 40. Here, the photographing device 40 may be used to photograph the upstream part of the slag flow SF. The upstream part of the slag flow SF refers to the part above the halfway position in the height direction from the position where the slag flows out from the throat 20C to the slag ladle 22. The photographing device 40 is positioned so that the optical axis OA of the photographing device 40 faces the upstream part of the slag flow SF, whereby the upstream part of the slag flow SF is photographed.

[0040] Next, the width of the waste slag flow SF is obtained from the image captured by the photographing device 40. Specifically, image information of the waste slag flow SF captured by the photographing device 40 is received by the computer 42, which then performs image analysis to obtain the width L of the waste slag flow SF. The width L of the waste slag flow SF may be obtained using the upstream portion of the waste slag flow SF in the photographed image of the waste slag flow SF. The upstream portion of the waste slag flow SF in the photographed image of the waste slag flow SF refers to the portion above the center of the length of the waste slag flow SF in the photographed image in the vertical direction.

[0041] Next, the flow velocity V (m / s) is calculated from the captured image. Specifically, the computer 42 calculates the flow velocity V (m / s) of the waste slag flow SF at the measurement position of the width of the waste slag flow SF by assuming that the waste slag flow SF is in free fall (2 gH). 0.5 Alternatively, the travel distance of the tailings flow SF may be calculated by pattern matching from at least two or more images, and the flow velocity V (m / s) may be calculated by dividing the travel distance of the tailings flow SF by the difference (s) in the shooting times of the images from which the travel distance was calculated.

[0042] Next, the computer 42 calculates the amount of discharged slag using the above-mentioned formula (1), thereby estimating the amount of discharged slag from the converter 20.

[0043] Next, the effects of this embodiment will be described. The influence of the slag flow (flame) generated from the slag ladle 22 during slag discharge must be considered because it causes a large error in the measurement of the width L of the slag flow SF in the image analysis of the image of the slag flow SF. Here, the present inventors considered that the slag flow SF and the slag frame have different emissivities with respect to wavelengths because the emitting substances are different. Specifically, the slag flow SF is slag (molten oxide), while the slag frame is made of organic matter contained in the slag material, and the spectral emissivity of the two is different for each wavelength. Therefore, even at the same observation wavelength, the luminance of the slag flow SF and the slag frame differs, and there exists a unique wavelength at which only the slag flow SF can be clearly observed, and they conducted extensive research. As a result, they discovered that in the visible light wavelength range, the luminance of the slag flow SF is clearly greater than that of the slag frame in the captured image by limiting the amount of light incident on the imaging device 40 to a level where the luminance of the slag flow SF in the captured image is not saturated. As a result, even if a settling frame occurs during slag discharge, it is possible to continuously measure the width L of the discharged slag flow SF. The present inventors have devised an estimation method for identifying the discharged slag flow SF and the settling frame by the brightness difference occurring between the discharged slag flow SF and the settling frame occurring during slag discharge in the captured image by limiting the amount of light incident on the photographing device 40 that photographs the discharged slag flow SF, determining the width L of the discharged slag flow SF, and estimating the amount of discharged slag using the determined width L. In this estimation method, by limiting the amount of light incident on the photographing device 40 that photographs the discharged slag flow SF, it is possible to identify the discharged slag flow SF and the settling frame even when a settling frame occurs from the discharged slag pan 22 due to the introduction of a settling material, compared to a configuration in which the amount of light incident on the photographing device 40 is not limited. As a result, it is possible to accurately determine the width L of the discharged slag flow SF even when a settling frame occurs from the discharged slag pan 22. By improving the measurement accuracy of the width L of the discharged slag flow SF, it becomes possible to estimate the amount of discharged slag with high accuracy.

[0044] In this embodiment, the waste flow SF is photographed by the photographing device 40 equipped with the restriction filter 41. That is, by preparing a plurality of restriction filters 41 each having a different amount of restriction of the amount of incident light and replacing the restriction filter 41 to be used according to the photographing conditions, it becomes possible to distinguish the waste flow SF from the sedation frame without changing the threshold setting of the computer 42.

[0045] Furthermore, when a light-reducing 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 occurrence of halation in the waste sludge flow SF in the image captured by the imaging device 40. It is more preferable to use a limiting filter that reduces the amount of incident light to 70% or less as the limiting filter 41.

[0046] In this embodiment, the upstream portion of the slag flow SF is photographed by the photographing device 40, so that the photographed image is less affected by the settling frame than, for example, when the downstream portion of the slag flow SF is photographed. This makes it easier to distinguish between the slag flow SF and the settling frame even when the settling frame is generated from the slag pan 22, and makes it possible to accurately determine the width L of the slag flow SF.

[0047] In this embodiment, the width L of the discharged slag flow SF is obtained using the upstream part of the image of the discharged slag flow SF, so the image of the discharged slag flow SF is less affected by the settling frame than when the width L of the discharged slag flow SF is obtained using the downstream part of the image of the discharged slag flow SF. This makes it easier to distinguish between the discharged slag flow SF and the settling frame even when the settling frame is generated from the discharged slag ladle 22, and makes it possible to accurately obtain the width L of the discharged slag flow SF.

[0048] Also, as shown in FIG. 4, there are cases where the waste slag flow SF is divided into two or more in the horizontal direction, that is, the waste slag flow SF is branched into multiple flows. For this reason, the computer 42 may determine whether the waste slag flow SF is branched into multiple flows in the captured image. Specifically, the computer 42 may determine that the waste slag flow SF is branched into multiple flows when multiple high-brightness areas are present horizontally spaced apart in the captured image. The determination of whether the waste slag flow SF is branched into multiple flows may be performed each time a still image is analyzed, or may be performed periodically. When the computer 42 determines that the waste slag flow SF is branched into multiple flows in the captured image, the computer 42 may perform a process of calculating the amount of each of the branched waste slag flows SF. i Width L i Calculate the width L i The total value of L sum The amount of slag discharged may be estimated using the following formula (2) instead of formula (1).

[0049]

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[0050] In the example of Figure 4, the tailings flow SF is divided into two tailings flows SF1 and SF2, so (ΣL i ) 2 (L1+L3) 2 The width L1 is the width of the waste slag divided flow SF1, and the width L3 is the width of the waste slag divided flow SF2. The width L2 is the width of the portion where the waste slag flow SF is divided and no waste slag flows. The total value L sum isΣL i is the same value.

[0051] The computer 42 judges whether the slag flow SF is diverted or not. If it is diverted, the amount of slag is estimated using the above formula (1), and if it is not diverted, the amount of slag is estimated using the above formula (2). When the judgment of whether the slag flow SF is diverted or not is performed, for example, for each still image or periodically, the estimation of the amount of slag is repeatedly performed according to the repeated judgment of whether the slag flow SF is diverted or not.

[0052] In the image captured by the imaging device 40, when the tailings flow SF is divided into multiple flows, each tailings flow SF i Width L i Calculate the width L i The total value of L sum In other words, by determining whether the tailings flow SF is divided into multiple flows or not, and then calculating the tailings amount by switching between formula (1) and formula (2) depending on the result of the determination, the tailings amount can be estimated with high accuracy.

[0053] In addition, when the computer 42 determines that the waste slag flow SF is divided into a plurality of flows in the captured image, the computer 42 calculates the waste slag flow SF i Width L i Calculate the width L i Each tailings split flow SF i Alternatively, the amount of slag discharged may be estimated for each batch, and the total amount of slag discharged may be estimated from the estimated amounts of slag discharged. In this case, the following formula (3) may be used instead of formula (1).

[0054]

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[0055] In the example of Figure 4, the tailings flow SF is divided into two tailings flows SF1 and SF2, so L in equation (3) i 2 L1 2 +L3 2 is required.

[0056] As for the flow velocity V2, it is most preferable to obtain the flow velocity of each slag waste stream and apply it to formula (3), but it is also possible to obtain the flow velocity of one of the slag waste streams and apply that flow velocity to formula (3) as the flow velocity of all the slag waste streams. This is because the position where the width of the slag waste stream is measured is the same for all the slag waste streams, so the flow velocity is almost the same regardless of the slag waste stream. In this case, the processing load on the computer 42 for obtaining the flow velocity can be reduced.

[0057] The computer 42 judges whether the slag flow SF is diverted or not. If it is diverted, the amount of slag is estimated using the above formula (1), and if it is not diverted, the amount of slag is estimated using the above formula (3). When the judgment of whether the slag flow SF is diverted or not is performed, for example, for each still image or periodically, the estimation of the amount of slag is repeatedly performed according to the repeated judgment of whether the slag flow SF is diverted or not.

[0058] In the image captured by the imaging device 40, when the tailings flow SF is divided into multiple flows, each tailings flow SF i Width L i Calculate the width L i Each tailings split flow SF i The amount of slag can be estimated with high accuracy by estimating the amount of slag for each discharged slag and estimating the total amount of slag from the estimated amounts of each discharged slag. In other words, by determining whether the slag flow SF is branched into multiple flows and calculating the amount of slag by switching between equation (1) and equation (3) depending on the result of the determination, the amount of slag can be estimated with high accuracy.

[0059] The photographing device 40 may monitor the photographing area, and when a bright substance is detected in the photographing area, record the state of the photographing area as an image, i.e., start photographing. The recognition of the bright substance in the photographing area may be performed by the computer 42 or by an image processing unit mounted on the photographing device 40. The photographing device 40 may start photographing in response to a command from the computer 42 when the inclination of the converter 20 reaches a predetermined angle.

[0060] In the above embodiment, the amount of light incident on the photographing device 40 is limited, but the present disclosure is not limited to this configuration. For example, the wavelength of the light incident on the photographing device 40 may be limited. Specifically, it is preferable to limit the light incident on the photographing device 40 to a wavelength of 3.0 μm or more and 4.0 μm or less, or 5.0 μm or more. This is because the slag flow SF is slag (molten oxide), while the calming frame is made of organic matter contained in the calming material, and the spectral emissivity of each wavelength of the two is different. Therefore, even at the same observation wavelength, the luminance of the slag flow SF and the calming frame is different, and it is considered that there is a unique wavelength at which only the slag flow SF can be clearly observed. For this reason, the present inventors have devised a method of clearly photographing only the slag flow SF by limiting the wavelength of the light incident on the photographing device 40. Specifically, by setting the wavelength of the light incident on the photographing device 40 to a range of 3.0 μm or more and 4.0 μm or less, or 5.0 μm or more, it becomes possible to clearly photograph only the slag flow SF. This is because the light emitted by the sedative frame is mainly due to dust, which is fine iron powder, and the emissivity of iron decreases as the wavelength increases, and the absorption rate of moisture in the air and carbon dioxide generated when a flame occurs is relatively small, so the wavelength range of the light incident on the imaging device 40 is set as described above. By imaging the slag flow SF within this wavelength range, the sedative frame hardly appears in the captured image, and only the slag flow SF can be imaged, and even if a sedative frame occurs during slag removal, the width L of the slag flow SF can be continuously measured. The wavelength of the light incident on the imaging device 40 may be limited by attaching a bandpass filter to the imaging device 40. In addition, both the restriction filter 41 and the bandpass filter may be attached to the imaging device 40. This makes it possible to obtain the width L of the waste sludge flow SF with higher accuracy.

[0061] In the above embodiment, the converter 20 is an example of a refining vessel, but the present disclosure is not limited to this configuration. The refining vessel may be, for example, an electric furnace, a molten steel ladle, or a torpedo car.

[0062] (Test Example) Next, the effects obtained by the technique of the present disclosure were verified. Table 1 shows the average estimation error of the working 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.

[0063] In the example, the state of the slag flow in the converter was photographed with a camera (photographing device) at 30 still images per second under the condition that the amount of incident light to the photographing device was limited to 70%, and the amount of slag was estimated by analyzing the still images. In the reference example, the amount of slag was estimated using the width of the slag flow obtained by simulation under the condition that the wavelength of the incident light to the photographing device was limited to 5.0 μm. Note that, when a slag flame occurred, the amount of slag was estimated by manually identifying the slag flow and measuring its width, and then estimating the amount of slag from Equation (1). In the comparative example, a conventional technology was applied, and the discharge amount of slag (amount of slag) was estimated from the actual value of the discharge flow rate of slag accompanying the change in the tilt angle of the converter, which was measured in advance.

[0064] 5 is a graph showing a comparison of the average estimation error of 10 charges in estimating the amount of discharged slag according to the comparative example, the examples, and the reference example. The estimation error was calculated using the following formula (4).

[0065]

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[0066] 6 shows the results of the relationship between the actual amount of slag discharged (measured by a weighing machine) and the estimated amount of slag discharged obtained by the examples and comparative examples. Note that the reference examples are the results obtained by using a simulation.

[0067] [Table 1]

[0068] As shown in Table 1, Figures 5 and 6, the average estimation error of the working example was 8.50%, while the average estimation error of the comparative example was 17.8%. The average estimation error of the reference example was 6.73%. Thus, it can be confirmed that the use of the technology disclosed herein makes it possible to estimate the amount of discharged slag with a high degree of accuracy, compared to the conventional technology.

[0069] While one embodiment of the present disclosure has been described above, the present disclosure is not limited to the above, and it goes without saying that the present disclosure can be implemented in various other modified forms without departing from the spirit and scope of the present disclosure. [Explanation of symbols]

[0070] 20 Converter (an example of a refining vessel) 40 Imaging Equipment 41 Restriction Filter 42 Computer (an example of an estimation device) SF tailings flow science fiction i tailings diversion L i Width of tailings diversion

Claims

1. A method for estimating the amount of slag by photographing a slag flow flowing out of a refining vessel and obtaining a width of the slag flow from the photographed image, Limiting the amount of light incident on a photographing device for photographing the tailings flow; A method for estimating the amount of discharged slag, comprising: identifying the discharged slag flow and the flame occurring during the discharge of slag in the captured image based on a brightness difference between the discharged slag flow and the flame, and determining a width of the discharged slag flow.

2. The method for estimating the amount of discharged slag according to claim 1 , wherein the amount of discharged slag is calculated by the following formula (1): [0010] M: Mass of slag (kg) ρ: bulk density of slag (kg / m ３ ) Δt: Image capture interval (s) α: Parameter for correcting the cross-sectional shape of the tailings flow L: Width of tailings flow (m) V: Flow velocity of tailings (m / s)

3. The method for estimating the amount of discharged sludge according to claim 1 , wherein the discharged sludge flow is photographed by the photographing device to which a limiting filter for limiting an amount of incident light is attached.

4. The method for estimating the amount of discharged slag described in any one of claims 1 to 3, wherein, in the captured image, when the discharged slag flow is branched into multiple flows, the width of each discharged slag flow is calculated, and the amount of discharged slag is estimated using the sum of the calculated widths.

5. A method for estimating the amount of slag according to any one of claims 1 to 3, wherein, in the captured image, when the slag flow is branched into multiple flows, a width of each slag flow is calculated, the amount of slag is estimated for each slag flow using the calculated width, and the total amount of slag is estimated from the estimated amounts of each slag.

6. The method for estimating the amount of discharged tailings according to any one of claims 1 to 3, wherein the photographing device photographs an upstream portion of the discharged tailings flow.

7. The method for estimating the amount of discharged slag according to any one of claims 1 to 3, further comprising the step of determining a width of the discharged slag flow using an upstream portion of an image of the discharged slag flow.

8. A photographing device for photographing the tailings flowing out of the refining vessel; An estimation device that obtains a width of the tailings flow from the captured image and estimates the tailings amount; A system for estimating the amount of slag comprising: The imaging device has a limited amount of incident light, The estimation device distinguishes between the tailings flow and the flame generated during tailings in the captured image based on a brightness difference between the tailings flow and the flame, and obtains a width of the tailings flow. A system for estimating the amount of wastewater discharged.

Images