JPS604409B2 - Method for measuring hot metal level in pig iron receiving container - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for measuring the level of hot metal in a container such as a ladle, a torpedo car, or a mold of continuous casting equipment when the hot metal is injected into the container. It is something.

Pig iron produced in a blast furnace is transported to the converter plant in receiving containers such as torpedo cars, and level monitoring is essential to inject the optimum amount of hot metal into these containers.

That is, overflowing molten iron is dangerous, and insufficient injection is uneconomical. Therefore, although various methods have been considered for measurement at this level, none of them have been satisfactory. For example, with the method of indirectly determining the hot metal level by measuring the weight of the torpedo car, there are too many variables, such as the state of the torpedo car's lining or the presence of slag in the hot metal. Equipment costs a lot of money.

In addition, with the method of attaching an electrode level meter to a torpedo car, the temperature of the molten iron is as high as 1,500 degrees Celsius or more, so the electrodes are damaged by the molten iron and have a short lifespan. However, the insulation deteriorates due to the high temperature, resulting in large measurement errors, making it impractical. Furthermore, a method is known in which the contact point between the liquid level and the electrode is determined by raising and lowering the electrode with a hoisting device, but this method also wears out the electrode, requires correction, and makes the device complicated. It will interfere with the work on the floor. Furthermore, the method of suspending pipes of different lengths from the top and blowing out nitrogen gas, and measuring the liquid level based on the discharge pressure, is not suitable because the pipes are subject to severe wear and tear. In the present invention, television cameras are installed at two points that can monitor the liquid level above the pig iron receiving container, the optical axes of each camera are made to intersect at a desired level, and the images captured by both cameras are combined into one.
The molten iron level is displayed on two color cathode ray tubes in different colors and superimposed, and the molten iron level is judged by the way the images of the tangent line between the molten gun and the container overlap, or the way the images of the poured hot metal column overlap, or both. An embodiment thereof will be described with reference to the drawings. In Fig. 1, 1 is a partially cutaway pig iron receiving container, 2 is molten iron poured into it,
3 is a column of hot metal being poured into the iron receiving vessel 1 from a hot metal trough (not shown), 4 and 4' are television cameras installed at positions almost symmetrical to the molten metal column 3, and 5 and 5' are 6 and 6' are the viewing angles of the camera and 4 and 4', 7 and 7' are the optical axes, 8 is the hot metal surface, 9 is the low level, 10 is the set level (desired level), 11 is the high level, 12 is an amplifier and a computing unit, 13 is a color cathode ray tube, and 14 is a bell indicator.

That is, when molten iron is poured into the iron receiving container 1, the surface tension of the molten pig iron causes the molten pig iron to become a tapered, substantially circular cylindrical column 3, and the twill iron surface 8 rises in accordance with the amount of the molten iron 2.

Above the iron receiving container 1, the entire molten iron surface 8 can be monitored.
Television cameras 4 and 4' are installed at two upper locations where the container 1 is within a viewing angle 6 even if it is slightly shifted and is approximately equidistant from the molten iron column 3. These television cameras 4 and 4' are
In order to reduce the influence of soot and smoke generated from the hot metal 2 and the container 1, a material with good long wavelength characteristics (red to infrared) is selected, and light rays from short wavelengths are removed by filters 5 and 5'. In addition, TV cameras 4 and 4' and filter 5
and 5' perform air purging and air cooling to reduce the effects of Korean radiation heat and high-temperature gas. Moreover, the television cameras 4 and 4' are installed so that their optical axes 7 and 7' both intersect at the desired level 10. The television cameras 4 and 4' are monochrome (black and white) having the same characteristics and are operated synchronously. The two television cameras 4 and 4
The video signal from ' is passed through an amplifier 12 to a suitable level and displayed on a single color cathode ray tube 13 in different colors, such as red and green, in a superimposed manner.

In addition, the same video signal is pattern-processed by the arithmetic unit 12, and 2
A level near the set level 10 is calculated from the degree of overlapping of the two images and displayed on the level indicator 14. Figure 2 shows the display on a color cathode ray tube and the method of level calculation.

That is, the image of the set level 10 in FIG. Further, the image captured by the right TV camera 4 in FIG. 1 is shown by a solid line, and the image captured by the left TV camera 4' is shown by a dotted line. Due to the characteristics of each camera and filter, the image is displayed with the high-temperature area emphasized, and the hot metal surface 8 in Figure 1 appears as a nearly circular inertia circle, and the hot metal column 3 in Figure 1 has a V-shape with a rounded tip. Photographed as. Here, if the image taken by the right TV camera 4 is red and the image taken by the left TV camera 4' is a line, then at set level 10, the hot metal surface 8 is yellow, and the hot metal column 3 is light, yellow-green, and yellow-green, respectively. Become. Further, the portion of the molten iron column 3 that is in contact with the liquid surface is particularly bright, and its shape is approximately circular. That is, x2≠y2. Also, the x direction and Y direction of the hot metal surface 8
The ratio of the directional dimensions is a constant value determined by the angle that the optical axes 7 and 7' of each camera 4 and 4' make with a vertical plane. Looking at low-level image 1, the images of the left and right cameras are shifted, and the molten iron column has x, > y, and the molten iron surface has a monochromatic part at the edge (red on the right, green on the left) appears, X, /Y.
>×2'Y2.

In the high-level image m, contrary to image 1, x3 x y3
. , The hot metal level can be calculated from the x/y value of how the images of the hot metal column overlap, or from the Calculate from the values of x'y and X/Y.

Note that the above calculation is a simple mathematical process, and detailed explanation will be omitted. Furthermore, many techniques have been announced for processing video signals and images, and since it is not the purpose of the present invention to discuss which technique to adopt, the description will be omitted. In addition, if the pig iron receiving container is a torpedo car, it is impossible to monitor the hot metal surface beyond the expected angle of the opening in the low level range.
The main focus is on determining the x and y values of how the images of the injected hot metal columns overlap. In the above embodiment, the axis of the molten iron 3, the optical axes 7 and 7' of the two television cameras 4 and 4', and the center of the pig iron receiving container 1 are arranged on one vertical plane. The position of the hot metal column may shift due to wear and tear, or the center may shift due to the way the pig iron receiving container is placed.

This deviation is generally slight and does not pose a particular problem in monitoring the molten iron surface. However, if these deviations become particularly large and, for example, the above-mentioned values of X and Y cannot be determined, it may be necessary to determine the x and y values of how the images of the injected hot metal column overlap, as in the case of a torpedo car. become. In addition, if the injected hot metal column does not form a straight line as an image on a cathode ray tube but becomes V-shaped (X-shaped at low levels),
It is necessary to take a special method for processing image data.
For example, as shown in Fig. 3, each center line is determined from the image of the molten iron column, and the dimension x' from the intersection of the two center lines to the tip of the image of the molten iron column is determined, and the direction from the intersection point to the center line is Find the dimension y' to the green part of the image, and calculate this ratio ×'
Measures such as calculating the mustard value of 'y' will be taken. In either case, it is easy to visually determine whether the level is high or low from the image on the cathode ray tube.

As described above, the present invention has television cameras attached to two points at which the level of molten iron in the pig iron receiving container can be monitored, and the optical axes of the television cameras intersect at a desired level, so that the molten iron level can be monitored by both cameras. This method measures the molten metal level by displaying images in different colors on a single color cathode ray tube, and measuring the molten metal level based on at least one phenomenon of how the molten iron and the container overlap. This makes it possible to perform long-distance monitoring, and color-based level monitoring makes it easy to monitor levels, and it also makes it possible to automate the switching of hot metal sluices.

In addition, since there is no material that comes into contact with the molten gun for measurement, there is nothing damaged by the molten iron, which is safe and does not interfere with the work of the treasury. big.

[Brief explanation of the drawing]

FIG. 1 is an elevational view showing an example of an apparatus for carrying out the method of the present invention, FIG. 2 is an explanatory diagram of one aspect of the display on a color cathode ray tube, and FIG. 3 is an explanatory diagram of another aspect. be. 1... Pig receiving container, 2... Molten iron, 3... Molten iron column, 4, 4'... Television camera, 5, 5'... Filter, 6, 6'...・TV camera viewing angle, 7,7′・
...TV camera optical axis, 8...Hot metal surface,
9...Low level, 10...Set level, 11
...High level, 12...Amplifier computing unit, 13...
・Color cathode ray tube, 14...Level indicator. Figure 1, figure 2, figure 3

Claims (1)

[Claims] 1. In a method for measuring the level of hot metal when pouring hot metal into a receiving container, television cameras are installed at two points where the level of hot metal in the container can be monitored, and the optical axes of the two cameras intersect at the desired level. The images captured by both cameras were superimposed and displayed in different colors on 11 color cathode ray tubes to determine how the images of the tangent between the hot metal and the container overlap, and how the images of the injected hot metal column overlap. A method for measuring a hot metal level in a pig iron receiving vessel, characterized in that the hot metal level is measured with at least one event.