The present invention relates to slag volume evaluation method of the molten metal surface.
　Priority is claimed on Japanese Patent Application No. 2016-236936 filed in Japan on December 6, 2016, which is incorporated herein by reference.
BACKGROUND
[0002]
　Hot metal has been removed from the blast furnace hot metal pot or from the converter, such as molten steel were retrieved ladle, the housing surface of the molten metal in the vessel slag has emerged. Slag has emerged in the accommodating surface of the hot metal in the hot metal in the pot, there is a risk of generating components out in a converter furnace process is a later step. Also, slag which floats on the surface of the molten steel contained in the ladle is also there is a risk of generating components out a secondary refining process is post-process. Thus, slag which has emerged on the surface of the molten metal contained in the container, there is a risk of a deleterious effect in a later step, before sending the molten metal in the subsequent step, the slug out of the container it is generally performed Haikasu work of removing the slag using a scraping waste slag machine.
[0003]
　Depending on the type of molten metal, leaving a slug and when it is necessary to Haikasu work (full Haikasu) to completely remove from the container, slag and partially removing a portion of the slag in the vessel and a case where Haikasu work (partial discharge slag) may be performed. When scraping the slag, since thereby raking only molten metal also partially not slag, The more the amount of scraping the slag, the also increases the amount of molten metal scraped out it is common. Therefore, part Haikasu has the advantage compared to fully Haikasu, it is possible to increase the yield by reducing the loss of the molten metal. However, when the partial discharge slag and remaining in the container more than necessary slag, residual as described above, there is a risk of a deleterious effect in the subsequent step, in a container and the like determine the example exhaust slag rate there is a need to accurately grasp the amount of slag.
[0004]
　Here, as a prior art, there is a method of determining the exhaust slag rate slag area when viewed container from above. However, when out scraping a part of the slag in the vessel, for example, left and top collapse of slag fall into the molten metal surface was sometimes a phenomenon that appears to slag spreads in molten metal surface occurs. In this case, when determining the discharge slag rate above prior art methods, despite scraping the slag, resulting in waste slag rate does not increase. That is, in many cases it is not possible to correlate the slag area and Haikasu ratio, it is difficult to accurately grasp the amount of slag remaining in the container in the above prior art methods.
[0005]
　Patent Document 1 obtains the luminance histogram from the image data obtained by imaging the molten metal surface in the molten metal container by picked-up device installed in a molten metal container near the scraping slag from the pattern of the luminance histogram how to identify year, metaphase, it determines whether it is late, seeking slag determination threshold than the brightness histogram peak position of each of these times, binarizing the brightness at a set threshold, and a slag and molten metal There has been disclosed.
　According to the method of Patent Document 1, as compared with the case of fixing the threshold value for identifying the slag and the molten metal is believed that the slag and the molten metal can be accurately identified. Therefore, according to the method of Patent Document 1, it considered some extent accurately calculate the amount of slag in the molten metal surface.
[0006]
　However, there is a thickness in the actual slag process in slag thickness Haikasu work slag is considered to gradually decrease. In particular, in the case of partial discharge slag, it is necessary to accurately grasp the amount of slag remaining in the container, in the above method of Patent Document 1, because it does not evaluate the thickness of the slag, remaining in the container slag it is difficult to grasp the amount of accurately. Further, in the above method of Patent Document 1, many processes for calculating the amount of the slag is required, it is difficult to quickly know the amount of the slag.
CITATION
Patent Document
[0007]
Patent Document 1: Japanese Patent 2003-19553 JP
Summary of the Invention
Problems that the Invention is to Solve
[0008]
　The present invention has been made in view of the above circumstances, more accurately and quickly evaluate slag volume evaluation of the molten metal surface capable of the volume of the slag emerged that the surface of the molten metal in the vessel the object of the present invention to provide a method.
Means for Solving the Problems
[0009]
　The present inventors, it has emerged on the surface of the molten metal in the vessel, slag which solidifies in cold and exposed to the air, absorbs the radiation emitted by the thermal radiation from the molten metal, and slag absorption degree of the emitted light is focused on vary depending on the thickness. Then, images the molten metal surface in a state where a plurality of slugs of different thicknesses are emerging on the surface of the molten metal, be previously calculated relationship between the thickness and density of the slag (brightness), it is evaluated water It found that it is possible to calculate the volume of slag on the basis of the captured image of the surface.
[0010]
　Based on the above findings, the present invention employs the following in order to solve the above problems.
　(1) slag volume evaluation method of the molten metal surface in accordance with one embodiment of the present invention, the volume of slag has emerged on the surface of the molten metal contained in the container, the captured image of the hot water surface in the container a method for evaluating on the basis of the has emerged on the surface of the molten metal, while measuring a plurality of thicknesses of slag of different thicknesses from each other, a state in which the plurality of slag has emerged on the surface of the molten metal in the captured image obtained by imaging the molten metal surface of the container in the values of a plurality of concentration parameter having a correlation to the concentration of the pixel area corresponding to the slag by calculating the said concentration parameters and thickness of the slag the value of the concentration parameter of the pixels constituting the captured image obtained by the imaging step; preparation step and that calculated in advance an approximate curve indicating the relationship between; imaging process and imaging the molten metal surface to be evaluated , Serial based on said approximation curve calculated by the preparation step, wherein calculating the thickness of the slag for each pixel constituting the captured image obtained by the imaging step, by integrating thickness of the slag for each pixel obtained by the calculation, having; a slag volume calculation step of calculating the volume of the slag.
　(2) In the aspect described in (1) above, may be configured as follows: the Haikasu step and that Haikasu slag in the vessel; slag remaining to calculate the residual ratio of slag in the vessel a rate calculating step; further comprising a, in the imaging step, the the molten metal surface of Haikasu previous step in the container, and imaging the molten metal surface in the container after the Haikasu step, the slag volume calculation in step, the volume of slag in the vessel prior to the Haikasu step, and calculates the volume of slag in the vessel after the Haikasu step, in the slag remaining ratio calculation step, after the Haikasu step the volume of slag in the vessel, is divided by the volume of slag in the vessel prior to the Haikasu step, to calculate the residual ratio of slag in the vessel.
Effect of the invention
[0011]
　According to the above aspect of the present invention, it is possible to evaluate the volume of the slag that floats on the surface of the molten metal in the vessel more accurately and quickly.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012]
FIG. 1 is a schematic diagram showing a schematic configuration of the slag volume evaluation apparatus for use in slag volume evaluation method according to an embodiment of the present invention.
FIG. 2 is a flow diagram illustrating the slag volume evaluation methods.
3 is a diagram showing an example of a captured image obtained by imaging the molten metal surface in the container by using the first imaging unit 1 shown in FIG.
[Figure 4] slug S1 ~ S3 shown in FIG. 3 is a view showing a state of floating on the molten metal surface in the container, a sectional view taken along line X-X of FIG.
5 is a diagram showing an example of approximation curve calculated in preparation step ST1 shown in FIG.
A diagram for explaining a procedure for calculating the thickness of the slag in the slag volume calculation step ST3 shown in FIG. 6A] FIG. 2 is a diagram illustrating an example of a captured image obtained by the imaging step ST2.
A diagram for explaining a procedure for calculating the thickness of the slag in the slag volume calculation step ST3 shown in FIG. 6B] FIG. 2 is an enlarged view of a pixel region surrounded by a broken line A in Figure 6A.
A diagram for explaining a procedure for calculating the thickness of the slag in the slag volume calculation step ST3 shown in FIG 6C] FIG. 2 is a diagram showing the thickness of the slag which is calculated in the pixel region shown in FIG. 6B.
7 is a diagram showing the above slag volume evaluation method, the test results were compared to the method described in Patent Document 1.
DESCRIPTION OF THE INVENTION
[0013]
　Hereinafter, with reference to the accompanying drawings, slag volume evaluation method of the molten metal surface according to an embodiment of the present invention (hereinafter, simply referred to as "slag volume evaluation method") will be described. Incidentally, omitted in the present specification and drawings, are denoted by the same reference numerals to constituent elements having substantially the same functional configurations, and their redundant description.
　First, the configuration of the slag volume evaluation apparatus for use in slag volume evaluation method according to the present embodiment.
[0014]
　Figure 1 is a schematic diagram showing a schematic configuration of the slag volume evaluation apparatus 100 for use in slag volume evaluation method according to the present embodiment. In FIG. 1, the container 4 for containing the molten metal M is shown in cross-section.
　As shown in FIG. 1, the slag volume evaluation apparatus 100, the slag S has emerged on the surface of the molten metal M, such as molten iron contained in the container 4, such as hot metal pot is tilted, scraper 51 and the arm used Haikasu work raking the outer container 4 with Haikasu machine 5 with 52.
[0015]
　Molten metal M contained in the container 4, for example, the temperature is the 1200 ° C. ~ 1400 ° C., it is emitted by thermal radiation (i.e., the molten metal M is in the self-emission by thermal radiation). On the other hand, the slag S is has emerged on the surface of the molten metal M contained in the container 4, near the surface cools by exposure to the air is solidified, substantially without self-luminous, the molten metal and blocking the light.
[0016]
　Slag volume evaluation apparatus 100 includes a first imaging unit 1 for imaging the molten metal surface in the container 4 from the upper side in the vertical direction, and the second imaging means 3 for capturing obliquely from above the molten metal surface in the container 4 with respect to the vertical direction and an image processing unit 2 connected to these first imaging unit 1 and the second imaging means 3.
　Incidentally, the "molten metal surface" as used herein does not mean only the surface of the molten metal M, if the slag has emerged on the surface of the molten metal means the surface of the slag. That means the outermost surface of the housing in the container 4 (the top surface).
[0017]
　The first imaging unit 1, for example, can be used as the thermal imaging camera having a CCD camera or the main sensitivity to the infrared region, having a main sensitivity in a visible light region (thermography). In the present embodiment uses a CCD camera as the first imaging unit 1.
　In the case of using a CCD camera as in the present embodiment, it is possible to calculate the value of density of a pixel area corresponding to the slag in the captured image. In the case of using a thermal imaging camera (thermography), it is possible to calculate the value of the temperature or concentration of the pixel region (concentration prior to conversion to the temperature).
[0018]
　Image processing means 2, for example, a general-purpose personal computer in which a predetermined program for executing the slag volume calculation step ST3 and slag remaining ratio calculation step ST7 described later is installed. The image processing unit 2 includes a monitor for displaying a captured image obtained by the first image pickup means 1 and the second imaging means 3.
[0019]
　As the second imaging means 3, like the first imaging unit 1, it is possible to use a thermal imaging camera (thermography) having a CCD camera or the main sensitivity to the infrared region, having a main sensitivity, for example the visible light region . In the present embodiment, the second imaging means 3 uses a CCD camera.
[0020]
　Slag volume evaluation method according to the present embodiment is performed using the slag volume evaluation apparatus 100. The following describes the slag volume evaluation method according to the present embodiment.
[0021]
　Figure 2 is a flow diagram illustrating the slag volume evaluation method according to the present embodiment. Slag volume evaluation method according to the present embodiment, based on the captured image obtained by capturing by the melt surface first imaging unit 1 in the container 4 for containing the molten metal M, has emerged on the surface of the molten metal M a method of assessing the volume of slag S, as shown in FIG. 2, the preparation step ST1, the imaging step ST2, the slag volume calculation step ST3, the Haikasu step ST4, the imaging step ST5, calculated slag volume a step ST6, the slag remaining ratio calculation step ST7, and a judgment step ST8 to determine whether to end the Haikasu work.
　Hereinafter, the contents of each process will be sequentially described.
[0022]
　(Preparation step ST1)
　in the preparation step ST1, firstly, a plurality of slag S having a different thickness of the molten metal surface in a state of simultaneously rise to the surface of the molten metal M to one another, to image using the first image capturing means 1. At this time, may be imaged the Haikasu work plurality of hot surface obtained at different times (partial discharge slag) with Haikasu machine 5, the imaging of a single molten metal surface at a point in time with Haikasu work it may be. As a specific example of a plurality of hot surface obtained at different times Haikasu work (partial discharge slag), for example, considered the largest thickness before the molten steel surface (slag S to start Haikasu work slag S is molten metal surface), it can be exemplified molten metal surface of Haikasu working medium term, and Haikasu work end after molten steel surface in the (molten metal surface the thickness of the slag S is considered the smallest).
　The resulting captured image is stored in the image processing unit 2.
[0023]
　Note that, as the concentration of the pixel area corresponding to the molten metal M in the captured image obtained by the first imaging means 1 is 255 (white) of the maximum value, the lens aperture of the first imaging unit 1 comprises, and gain of the video signal output from the first imaging unit 1 is adjusted. The same applies to the imaging step ST2 will be described later.
　Further, in the present embodiment, the first field of view of the imaging means 1 is not only the molten metal surface of the container 4, is set so as container 4 and the background B is also included in the field of view. It is also possible to set the first field of the imaging means 1 so that only hot water surface of the container 4 is included in the field of view.
[0024]
　Here, the "density" herein, for example, refers to the 256 gradations of the image brightness (i.e., luminance of the image). Then, a the concentration, the relationship between the thermal radiance of the molten metal surface in the container is in a linear relationship.
[0025]
　Figure 3 is a diagram schematically showing an example of a captured image obtained by imaging the molten metal surface in the container 4 by the first imaging unit 1. 3, the field of view of the first imaging means is set to a wide field of view also container 4 and the background B contained in the field of view, a plurality of slugs S1 ~ S3 having different thicknesses from each other in a single molten metal surface is emerged at the same time It shows the case. In Figure 3, the thickness of the slag S1 is the largest, slag S2, the thickness in the order of the slag S3 is smaller.
[0026]
　In the captured image shown in FIG. 3, among the pixel regions corresponding to the slag S, (small density) darkest pixel area corresponding to the largest slug S1 is the thickness becomes, the pixel area corresponding to the smallest S3 is the thickness and brightest become (a large concentration). Further, as described above, the concentration of the pixel area corresponding to the molten metal M has a 255 (white) of the maximum value.
　The pixel region corresponding to the pixel region and the background B corresponding to the container 4, the temperature of the container 4 and the background B is lower than the molten metal M and slag S, becomes actually dark (small density), for convenience of illustration, it is shown in white in the same manner as the pixel area corresponding to the molten metal M.
[0027]
　Here, with reference to FIG. 4, shown in FIG. 3, the brightness of each corresponding pixel area will be described different reasons each slug S1 ~ S3. Incidentally, FIG. 4 is a diagram showing a state where the slug S1 ~ S3 are emerging in the molten metal M in the vessel 4 is a sectional view taken along line X-X of FIG.
　As shown in FIG. 4, the emitted light SR emitted by thermal radiation from the molten metal M is partially absorbed in the slag S1 ~ S3. On the other hand, emitted light SR transmitted through the slag S1 ~ S3 is next transmitted light TI1 ~ TI3, they transmitted light TI1 ~ TI3 is incident on the first imaging unit 1.
　As the thickness of the slag is high, the absorption of the radiation SR by slag increases, the transmitted light TI1 transmitted through the slag S1, the transmitted light TI2 is transmitted through the slag S2, and the order of the transmitted light TI3 transmitted through the slag S3 of the light the intensity is increased. Thus, the captured image shown in FIG. 3, slag S1, slag S2, and the order of the slag S3, the pixel region is brighter.
[0028]
　Subsequently, in the step of preparing ST1, in the captured image shown in FIG. 3, to calculate the value of the density parameter having a correlation to the concentration of the pixel area corresponding to the slug S1 ~ S3. The concentration parameter, other concentrations themselves, can be exemplified a temperature, in the present embodiment uses the density itself as a density parameter.
　Specifically, to calculate the average density of the pixel region corresponding to each slug S1 ~ S3. Pixel region corresponding to each slug S1 ~ S3 is, for example, to display the captured image on the monitor of the image processing unit 2, operating person it is recognizable by visual observation. Then, for example, if installing the program for calculating the average density and the like in the contour specified by using a pointing device such as a mouse to the image processing unit 2, operation person while viewing the monitor of each slug S1 ~ S3 by specifying the contour can be calculated the average density of the pixel area corresponding to the image processing unit 2 is automatically each slug S1 ~ S3.
[0029]
　Then, in the step of preparing ST1, using the value of the average density of the pixel area corresponding to the slug S1 ~ S3, it calculates the approximate curve indicating the relationship between the thickness and density of the slag S. In other words, by using the thicknesses of plurality of different slag S (slag S1 ~ S3 in the example shown in FIG. 3), the value of the average density of the pixel region corresponding to each slug S to each other, for example, a least by applying the multiplicative, to calculate the approximate curve. In the present embodiment, as a preferred embodiment, not only the value of the density of a pixel area corresponding to the slag S, a pixel region thickness is zero slag S (i.e., a pixel region corresponding to the molten metal M) concentrations of value (in this embodiment 255) calculates the approximate curve may be used.
[0030]
　The thickness of each slug S is, for example, by comparing the slag S vertical dimension of the scraper 51 of Haikasu machine 5 can be measured. Specifically, in this embodiment, as shown in FIG. 1, drives the arm 52 of Haikasu machine 5 (by rotating) the lower end of the scraper 51 is buried in the slag S, scraper 51 substantially matching the lower surface of the lower surface of the slag S (upper surface of the molten metal M). The imaged obliquely from above the molten metal surface in the container 4 with respect to the vertical direction by the second imaging means 3. Thus, the captured image captured both the slag S and scraper 51 is obtained.
[0031]
　Incidentally, as shown in FIG. 1, in the state in which tilting the container 4, and the upper surface of the molten metal M, the position in the height direction is substantially coincident with the spout 4a of the container 4. Therefore, by the height position of the lower surface of the height position and scraper 51 of the spout 4a substantially match, be a lower face of the scraper 51 substantially coincide with the lower surface of the slag S (upper surface of the molten metal M) it can. Furthermore, from the volume of the molten metal M in the vessel 4, calculated in advance the melt surface position when tilting the container 4, so that the lower surface of the scraper 51 and the calculated melt surface position substantially coincides, the scraper 51 may be lowered.
[0032]
　Then, to display the captured image on the monitor of the image processing unit 2, operating person this is by visual inspection, and calculates the distance H1 between the upper surface of the lower surface and the slag S of the arm 52. Specifically, for example, shows the distance of a straight line passing through two points specifying the (actual size), the imaging magnification and the visual axis angle of the second imaging means 3 set in advance (in FIG. 1 using a pointing device such as a mouse if to install the program for calculating by geometric calculation using the theta) to the image processing unit 2, operation person by specifying two points and the upper surface of the lower surface and the slag S of the arm 52 while viewing the monitor , the image processing means 2 can be calculated automatically distance H1. Then, the distance H0 between the lower surface of the scraper 51 and the lower surface of the arm 52 is known in advance, the thickness K of the slag S in the portion where the lower end of the scraper 51 is buried, the relationship K = H0-H1 the equation can be calculated by subtracting the distance H1 from the distance H0.
　In the example shown in FIG. 3, the lower end portion of each scraper 51 of the slug S1 ~ S3 by sequentially buried following the above steps, measuring the thickness of each slug S1 ~ S3.
[0033]
　In the present embodiment, in order to accurately approximate the relationship between the thickness K and the concentration I the slag, indicative of the approximate curve to be calculated by the exponential function. Specifically, the thickness of the slag and K, the value of the concentration of I, (specifying the coefficient a by the least square method) approximate curve to calculate the represented by the following formula (1). I
　= I 0 × E　-AK · · · (1)
[0034]
　In the above formula (1), I 0 values of the density of the pixel area corresponding to the molten metal M in the captured image obtained by the preparation step ST1 is a (255 in the present embodiment), e is the base of natural logarithms, a is a positive coefficient, it means respectively.
[0035]
　Figure 5 is a diagram showing an example of approximation curve calculated in the preparation step ST1. Data plotted by a circle in FIG. 5, the concentration I in the thickness K of the slag S used for calculating the approximate curve, bar extending vertically indicates the concentration variation (standard deviation 1 [sigma) in the same thickness K . In Figure 5, prompts the coefficient a = 0.009 in the above equation (1), when the correlation coefficient between the thickness K and the concentration I the slag S and R, R 2 = .9413, and the relatively accurate It can be well approximated be seen.
[0036]
　Preparation step ST1 described above is performed before evaluating the volume of slag S in the molten metal surface which actually evaluated. Then, obtained in preparation step ST1, the correspondence relationship between the thickness K and the concentration I the slag S (approximate curve) is stored in the image processing unit 2, used in the slag volume calculation step ST3 will be described later. Specifically, equation (2) below is stored in the image processing unit 2.
[0037]
　(Imaging step ST2)
　Next, the imaging step ST2, the first imaging unit 1, to image the molten metal surface to be evaluated. At this time, the imaging condition of the gain or the like of the first aperture of the lens image pickup means 1 comprises, and the first video signal outputted from the imaging unit 1 are identical to the conditions set in preparation step ST1.
[0038]
　(Slag volume calculation step ST3)
　in slag volume calculation step ST3, the image processing means 2, the value of the concentration I of the pixels constituting the captured image obtained by the imaging step ST2, the approximation curve calculated by the preparation step ST1 based on, to calculate the thickness K of the slag S in each pixel constituting the captured image obtained by the imaging step ST2. In this case, the thickness K of the slag S, which is calculated for a function of the concentration I, using equation (2) below obtained by modifying the above equation (1). It should be noted that, "ln" of the following formula (2) refers to the natural logarithm.
　K (I) = (- 1 / a) × ln (I / I 0 ) · · · (2)
[0039]
　As mentioned above, (in the example shown in FIG. 5, a = 0.009) the coefficient a previously obtained by the preparation step ST1, the concentration I 0 is also set in advance by the preparation step ST1 (in the example shown in FIG. 5, I 0 = 255) is, the coefficients a and concentration I 0 is stored in the image processing unit 2. Therefore, the image processing means 2, the value of the concentration I of each pixel by substituting the above equation (2), the thickness K of the slag S corresponding to the concentration I can automatically calculated.
[0040]
　FIGS. 6A ~ 6C are views for explaining a procedure of calculating the thickness K of the slag S in the slag volume calculation step ST3. Note that FIG. 6A is a diagram schematically showing an example of a captured image obtained by the imaging step ST2. Figure 6B is an enlarged view of a pixel region surrounded by a broken line A in FIG. 6A (left), and a graph (right diagram for calculating the thickness of the slag from the density of the pixel area using an approximate curve shown in FIG. 5 ) it is. Figure 6C is a diagram showing the thickness K of the slag S calculated in the pixel region shown in FIG. 6B.
　During pixel area surrounded by a broken line A in FIG. 6A, if the concentration is present pixel region 50, 100, and 150, (based on the above equation (2)) based on the approximate curve shown in Figure 6B, the thickness 181mm, 104mm, 59mm is calculated.
　In slag volume calculation step ST3, the above processes described for pixel areas surrounded by the broken line A, is executed for the pixels constituting the captured image obtained by the imaging step ST2.
[0041]
　However, as shown in FIG. 6A, when the pixel regions corresponding to the containers 4 and the background B in the captured image is present, as described above, for the concentration of these pixel regions are small, the thickness calculated based on the approximate curve It increases. Therefore, the addition of the thickness of the pixel region on the integrated later, a large error in the volume of slag S to be calculated occurs.
　Thus, for example, in all the pixels constituting the captured image, only the pixels located inside the pixel region corresponding to the container 4, to subject to calculate the thickness. In general, often the position of the container 4 when performing Haikasu work is fixed, in this case, the position of the pixel regions corresponding to the containers 4 and the background B in the captured image will not fluctuate. Therefore, as previously set the coordinates of pixels located inside the pixel region corresponding to the container 4 in the captured image by storing the image processing unit 2, a pixel located inside the corresponding pixel region it can be calculated thickness only.
　Further, for example, for all the pixels constituting the captured image (including pixels corresponding to the container 4 and a background B) After calculating the thickness by the thickness of the pixels located inside the pixel region corresponding to the container 4 it may also be integrating the.
　Further, the pixel regions corresponding to the containers 4 and the background B concentration, since the smaller than the concentration of the pixel area corresponding to the molten metal M and slag S is common, for example, greater than or equal to a predetermined threshold value it may be directed to only the pixels having the density.
　Further, after calculating the thickness of all the pixels constituting the captured image, only it is integrated thickness for a pixel having a predetermined threshold value or more concentrations. The predetermined threshold value is the concentration and, identifying possible values of the density of a pixel area corresponding to the container 4 and the background B of the pixel region corresponding to the molten metal M and the slag S.
　Further, for example, so that only the hot water surface in the container 4 is imaged, it may be adjusted in advance a first field of view of the imaging unit 1. However, too small a field of view, part of the slag S is outside the field of view, because it may not be accurately calculate the volume of slag S, it can be adjusted as much as possible within a range in which the container 4 is not reflected in the large field of view preferable.
　The pixel area corresponding to the molten metal M may be in the calculation target, it may not be. Concentration of the pixel area corresponding to the molten metal M I 0 for a (255 in the present embodiment), the thickness is calculated by formula (2) K (I 0 ) is zero. Therefore, if calculating the thickness for the pixel area corresponding to the molten metal M, even added to the integration described later, the error in the volume of slag S to be calculated because no.
[0042]
　Subsequently, the slag volume calculation step ST3, by integrating the thickness calculated for each pixel, and calculates the volume of slag S.
　Specifically, the captured image captured at time t starting from the start time of Haikasu work, when the total number of pixels of density I and Ns (t, I), the image processing means 2, for example, the following based on the equation (3) to calculate the volume V (t) of the slag S at time t. In the following equation (3), I th is the molten metal M and the concentration of the pixel area corresponding to the slag S, a container 4 and a predetermined threshold described above can be identified and density of the pixel area corresponding to the background B It refers to a value. The unit of volume that is calculated by the following formula (3) is a pixel × pixels × thickness (mm), on the basis of the first imaging magnification and the like of the imaging device 1, the resolution per one pixel (actual size) be previously determined, it can be calculated the volume at actual size units.
[Number 1]

[0043]
　(Haikasu Step ST4)
　Next, in a state of tilting the container 4, scraping a part of the slag S to the container 4 out using Haikasu machine 5 (see FIG. 1). That is, in Haikasu step ST4, not raked all slag in the container 4, the Haikasu work as part of the slag S remains in the container 4 performed.
[0044]
　(Imaging step ST5)
　In the imaging step ST5, imaging the molten metal surface in the container 4 after Haikasu step ST4. The imaging conditions are the same as the imaging process ST2.
[0045]
　(Slag volume calculation step ST6)
　in slag volume calculation step ST6, based on the captured image obtained by the imaging step ST5, calculates the volume of slag in the vessel 4 after Haikasu step ST4. The calculation method is the same as the slag volume calculation step ST3 described above.
[0046]
　(Slag residual ratio calculating step ST7)
　in slag remaining ratio calculation step ST7, slag image processing means 2, which is calculated on the basis of the captured image captured after the volume (Haikasu step ST4 slag S calculated by the slag volume calculation step ST6 the S volume), is divided by the volume of slag S calculated by the slag volume calculation step ST3 (Haikasu step ST4 volume of slag S calculated on the basis of the captured image captured before), slag S in the container 4 to calculate the residual rate. That is, the image processing unit 2, based on the following equation (4) to calculate the residual ratio Ps (t) of the slag S at time t. Residual ratio of the calculated slag S Ps (t) is stored in the image processing unit 2 is displayed on the monitor.
　Ps (t) = V (t ) / V (0) ··· (4)
[0047]
　Incidentally, by using the residual ratio Ps (t) of the slag S, the slag S Haikasuritsu Qs (t) can be calculated by the following equation (5).
　　Qs (t) = 1-Ps (t) ··· (5)
[0048]
　Then visually residual ratio Ps slag S which operating person is displayed on the monitor (t), it is determined whether or not reach the desired residual ratio, or to end the Haikasu work slag S not or to determine the (ST8 in Fig. 2). To end the Haikasu work ( "Yes" in ST8 in FIG. 2), slag volume evaluation method according to the present embodiment is completed.
　On the other hand, (if in ST8 of FIG. 2 of "No") if it does not finish the Haikasu work, Haikasu step ST4, the imaging step ST5, slag volume calculation step ST6, and repeatedly executes the slag remaining ratio calculation step ST7.
[0049]
　According to the slag volume evaluation method according to the present embodiment described above, in the preparation step ST1, previously calculated approximation curve indicating a relationship between the thickness and density of the slag S, based on the approximate curve, obtained in the imaging step ST2, for calculating the thickness of the slag for each pixel constituting the captured image of the molten metal surface to be evaluated, it is possible to evaluate the volume of slag S more accurately and quickly. Therefore, in the course of Haikasu working slag S, to evaluate the volume of slag S remaining in the container 4 sequentially, so as not to remain in the container 4 is more than necessary slag S, optimize Haikasu work it is possible to.
[0050]
　Further, according to the slag volume evaluation method according to the present embodiment, to calculate the residual rate of slag S in the container 4 in the slag remaining ratio calculation step ST7. Using this residual ratio, when processing molten metal M in the container 4 in a subsequent step, it is possible to predict the amount of sulfur component contained in the molten metal M. This allows optimization of the component adjustment of the molten metal M in the subsequent step.
[0051]
　Here, desulfurized sulfur components in the molten metal in the vessel by the addition of desulfurizing agent (flux), taking as an example a refined to shift the slag generated the sulfur component in molten metal, the remaining slag in the vessel rate, it has a correlation to the amount of sulfur component in molten metal in a subsequent process is generally known.
　In the previous step Haikasu work, the use of the sample analysis, the content of the sulfur components in the molten metal prior to generating slag, the sulfur component in the molten metal after being generated slag (after desulfurization refining) can be measured and content, based on both measurement results, it is possible to calculate the content of the sulfur components in the slag before the vessel starts Haikasu work (content difference × molten metal weight = slag the content of the sulfur components).
　According to this embodiment, in the container 4 by the slag remaining ratio calculation step ST7 since it calculates the residual rate of the slag, and the residual ratio of the calculated slag in the vessel prior to Haikasu work start calculated as described above and a content of sulfur components in the slag, it is possible to calculate the content of the sulfur components in the slag in the vessel after Haikasu work start. Then, the content of the sulfur components in the slag in the vessel Haikasu work start after that the calculated and the content of sulfur components in the molten metal after the desulfurization refining calculated using the sample analysis as described above used, light of multiple硫率from the slag during processing in a later step into the molten metal, it is possible to predict the content of sulfur component in molten metal during processing in the subsequent step.
　Therefore, we determine the slag remaining rate (end of Haikasu work can be determined) in accordance with the content of the sulfur components required for the molten metal. Thus, with the advantage of optimization of the component adjustment of molten metal in a subsequent process.
Example
[0052]
　Next, a description will be given of an embodiment carried out for confirming the effect of the present invention.
[0053]
　And slag volume evaluation method according to the present embodiment was compared with the method described in Patent Document 1.
　Specifically, skilled operation person, while confirming the molten metal surface in the container 4 visually, as discharge slag ratio of slag S at Haikasu work end is 0.7-0.8 Haikasu work was done. During this Haikasu work, using the slag volume evaluation method according to the present embodiment, to calculate the residual ratio of the slag S at Haikasu work end Ps (t), discharge of slag S by the above formula (5) to determine the slag rate. Moreover, this Haikasu during work, was calculated using the method described in Patent Document 1 calculates a residual ratio of slag S from the area of the slag S at Haikasu work start before and Haikasu work end, the was determined discharge slag ratio of slag S by equation (5).
　The above test was repeated three times. The results are shown in Figure 7.
[0054]
　In Figure 7, with respect to the discharge slag ratio of slag S by operation's visual judgment, and discharge slag ratio of slag S obtained using the slag volume evaluation method according to the present embodiment, the method described in Patent Document 1 used indicates a value obtained by normalizing the discharge slag ratio of slag S found by. In FIG. 7, the average value of the values of bar graphs of three tests, extends from the bar in the vertical bars indicate the variation (standard deviation 1 [sigma).
　As shown in FIG. 7, it was determined using the method described in Patent Document 1, while the discharge slag ratio of slag S is 0.70 ± 0.08, the slag volume evaluation method according to this embodiment used was determined, Haikasuritsu slag S was 0.98 ± 0.06. In other words, towards the discharge slag ratio of slag S by slag volume evaluation method according to the present embodiment is close to the feeling of a skilled operation's than discharge slag rate according to the method described in Patent Document 1, is considered to be accurate.
[0055]
　Having described the embodiments of the present invention, the above embodiments have been presented by way of example, the scope of the present invention is not limited to the above embodiment. The embodiments described herein may be embodied in other various forms, without departing from the spirit of the invention, various omissions, substitutions, and changes can be made. The above embodiments and their modifications as would fall within the scope and spirit of the invention, and are included in the invention and the scope of their equivalents are claimed.
[0056]
　For example, in the above embodiment, in the preparation step ST1, it shows a case of calculating the approximate curve (see FIG. 5) represented by the above formula (1). In the step of preparing ST1, which is incident on the first imaging means 1, since the radiation light of the molten metal M that has passed through the slag S, seeking a relationship between the thickness K and density I of the slag, as shown in FIG. 5, If can be approximated by an exponential function of equation (1) is large. However, the approximate curve is not limited to Equation (1), it is sufficient fitting the measured data of the thickness and density of the slag. And it may calculate an approximate curve for example represented by the following formula (6) or (7). = I
　I 0 / (aK 2 + bK + 1) · · · 　(6) I = I 0 / (aK 3 + bK 2 + cK + 1) · · · (7)
[0057]
　Further, for example, in the above embodiment, prepared in step ST1, according to the second imaging means 3, based on the underside of the scraper 51 to the captured image of the bottom surface state of substantially aligned with the (upper surface of the molten metal M) of slag S It shows the case of measuring the thickness K of the slag S (see FIG. 1). However, instead of the second imaging means 3, for example, arranged in mutually the same height above the scraper 51 may be used a pair of laser distance meter is a distance meter contactless. In this case, the measuring the distance to the top surface of the slag S in one laser rangefinder, after measuring the distance to the upper surface of the arm 52 in the other laser rangefinder, from the measurement result of the one laser rangefinders, with subtracting the measurement result of the other laser rangefinder, by subtracting the vertical dimension of the arm 52, it is possible to calculate the distance H1 between the upper surface of the lower surface and the slag S of the arm 52. By subtracting this way the distance H1 which is calculated from H0, may be measured thickness K of the slag S.
　Further, for example, using a set of laser rangefinders above, with measures the distance to the top surface of the slag S in one laser rangefinder measures the distance to the surface of the molten metal M in other laser rangefinder, the thickness K of the measurement results of the slag from the difference S may be measured. Further, the measuring bar may be measured thickness K of the slag S using. In the case of these, it is not necessary to measure the distance H1.
[0058]
　Further, for example, in the above embodiment, the first imaging unit 1 to be used for the purpose of obtaining a captured image to assess the volume of slag S in the slag volume calculation step ST3, to calculate the thickness K of the slag S in the preparation step ST1 and second imaging means 3 used for the purpose are separately provided. However, for example, the second imaging means 3, and at the same time used for the purpose of calculating the thickness K of the slag S, may be used in order to obtain a captured image for evaluating the volume of slag S. However, the second imaging means 3, it is necessary to image the obliquely upward with respect to the vertical direction in order to calculate the distance H1 between the upper surface of the lower surface and the slag S of the arm 52, the larger the visual axis angle theta, of molten metal surface of the container 4, between the side portions and the far side of the portion close to the second imaging means 3, or the difference in resolution is increased per pixel, even thickness of the slag S is the same there is a possibility that a difference in concentration of the corresponding pixel region is caused. Thus, since this can adversely affect the calculation accuracy of the slag volume, as in the above embodiment, it is preferable to use the first image pickup means 1 and the second imaging means 3.
[0059]
　Further, for example, in the above embodiment, 255 (white) and so as to the first imaging means 1 is adjusted concentration maximum value of the pixel area corresponding to the molten metal M in the captured image obtained by the first imaging unit 1 It is. In the above embodiment, since the density of pixels constituting the captured image is converted to the thickness of the slag S, in enhancing the resolution of calculating the thickness of the slag S, a pixel region corresponding to the molten metal M other than slag S by limiting the concentration range of the maximum value, it is because it is possible to secure a wide concentration range of the pixel area corresponding to the slag S. However, for example, (as including the concentration of other than the maximum value) so that the concentration of the pixel region is 250 to 255 corresponding to the molten metal M, may be adjusted first image pickup means 1. In this case, the above equation (1), the concentration I in equation (2), and (3) 0 as, may be used (250 in the above example) the minimum value of the density of the pixel area corresponding to the molten metal M .
[0060]
　In the above embodiment, as shown in FIG. 5, and calculates an approximate curve represented by the above formula (1). Here relates coefficient a of formula (1), while changing the slag ingredients and the molten steel temperature was measured and the slag thickness and density, coefficient a, irrespective of the slag ingredients and the molten steel temperature, be approximately constant all right. Therefore, if once determined the approximate curve indicating the relationship between the slag thickness K and density I, even slag ingredients and the molten steel temperature is changed, it is possible to use the approximate curve. However, from the viewpoint of calculated more accurately slag volume, every time the slag ingredients and the molten steel temperature is changed, it is preferable to calculate the approximate curve indicating the relationship between the slag thickness K and density I.
DESCRIPTION OF SYMBOLS
[0061]
1: first imaging means
2: The image processing unit
3: second imaging means
4: container
5: Haikasu machine
100: slag volume evaluation apparatus
M: molten metal
S: Slag

WE claims

The volume of the slag that floats on the housing surface of the molten metal into the container, a method of assessing on the basis of the captured image of the hot water surface in the container,
　has emerged on the surface of the molten metal, with measuring a plurality of different thicknesses of slag thicknesses from each other, the molten metal surface in the captured image obtained by imaging of the vessel in a state where the plurality of slag has emerged on the surface of the molten metal, said plurality ; of by calculating the value of the density parameter having a correlation to the concentration of the pixel area corresponding to the slag, preparation process and to advance calculating an approximate curve indicating the relationship between the thickness of the slag and the concentration parameter
　is evaluated an imaging step of imaging the molten metal surface;
　based on the value of the concentration parameter of the pixels constituting the captured image obtained by the imaging step, and the approximate curve calculated by the preparation step, obtained by the image pickup step The thickness of the slag is calculated for each pixel constituting the captured image, by integrating the thickness of the slag for each pixel the calculated, and slag volume calculation step of calculating the volume of slag;
and characterized in that it has a slag volume evaluation method of the molten metal surface to be.
[Requested item 2]
　And Haikasu step of Haikasu slag in the vessel;
　and slag remaining ratio calculation step of calculating a residual ratio of slag in the vessel;
further comprising a,
　in the imaging step, the container before the Haikasu step and molten metal surface of the inner, the imaged and molten metal surface of Haikasu the vessel after the step
　in the slag volume calculation step, the volume of slag in the vessel prior to the Haikasu step, after the Haikasu step wherein calculating the volume of slag in the vessel,
　with the slug remaining ratio calculation step, the volume of slag in the vessel after the Haikasu step, a volume of the slag of the Haikasu step prior to said container division to, to calculate the residual ratio of slag in the vessel
slag volume evaluation method of the molten metal surface of claim 1, wherein the.