JPH08193208A - Treatment of picture of charging material surface picked up with camera at furnace top opening part - Google Patents

Abstract

PURPOSE: To obtain picture information accurately reflecting the charged material condition in furnace. CONSTITUTION: The surface of the charged material 3 at the furnace top part of a blast furnace is picked up with a camera 1 at the furnace top opening part. At the time of developing a brightness dead zone deviated from the setting range of the brightness in the visual field in the picture obtd. with the camera 1, the picture is divided into the vertical and the horizontal gratings, the brightness in the brightness dead zone is estimated from each brightness of the grating surrounding the grate corresponding to the brightness dead zone. In the case of obtaining the picture, in which the brightness in the visual field in the camera 1 is lower than the reference value, the furnace temp. detected by a bridged sonde arranged at the furnace top is used as the reference value, and the brightness of the picture is corrected. By this method, the effect of flame 4 developed in the furnace and gauze for protecting the camera, etc., is cancelled, and the figure information needed for the operational control of the blast furnace is obtd. at high accuracy.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention processes the images obtained by an infrared camera or a night-vision camera for monitoring the distribution state and gas flow of the raw material feed at the top of the blast furnace to determine the condition inside the furnace. An image processing method for accurately grasping.

[0002]

2. Description of the Related Art In blast furnace operation, raw materials such as powdered ore, coke and lime are charged by a bucket or a belt conveyor.
The raw materials are layered in the furnace, but the hot air blown from the tuyere flows stably to the center of the furnace, so the amount of charge in the center is smaller than in the periphery. Controlled by. Therefore, the charge is inclined at a constant angle toward the central part of the furnace and is deposited in a dish shape having the lowest central part. The deposit shape, distribution, particle size, etc. of the furnace interior contents are determined by the gas flow in the furnace,
As a result, it has a great influence on the furnace condition and the hot metal composition of the blast furnace.
In this respect, the deposition status such as the deposition height of the raw material charge, the deposition shape, and the difference in the particle size distribution at a location becomes an important factor in controlling the blast furnace to a stable reactor condition.

Therefore, the state of deposit accumulation is measured by various methods, and the measurement results are used for operation management. For example, there is a method of measuring the level of the charged material with a measuring stick, a method of calculating the deposition shape using a mathematical formula, and the like. Also,
In order to observe and measure the inside of the furnace, it is equipped with an infrared TV camera, control equipment such as an optical fiber scope and sonde. Direct observation of the inside of the furnace reveals the particle size distribution, gas flow, etc. depending on the deposition status and deposition position, and provides a large amount of extremely effective information. It is known to install an infrared camera or a night-vision camera in the furnace for direct observation. Video signals obtained by infrared cameras and night-vision cameras are analyzed and used to determine the particle size distribution in the center, middle and peripheral parts of the coke containing furnace interior.

[0004]

An infrared camera or a night-vision camera installed in the furnace is effective as a means for directly observing the inside of the furnace, but it cannot capture the entire surface of the charge as an image. .. The camera 1 installed at the top of the blast furnace penetrates the furnace wall 2 (a) and observes the furnace interior container 3 at a predetermined dip angle (b), as shown in FIG. 1, for example.
In the center of the furnace, a flame rises from the surface of the furnace interior container 3. Therefore, the furnace interior container 3 on the opposite side of the installation location of the camera 1 is blocked by the flame 4 and cannot be captured by the camera 1. Even if observed, it is captured by the camera 1 as an image affected by the flame 4. Therefore, the image captured by the camera 1 is not an image of the entire charging surface as shown in FIG. In addition, the wire mesh and the grid provided to protect the lens of the camera 1
The image of the furnace interior container 3 is adversely affected.

When a video image as shown in FIG. 2 is image-processed and quantitatively analyzed, a brightness dead zone caused by a flame or a wire net appears as brightness of the surface of the charging material, and an error occurs in the analysis result. Cause to bring. Also, the lens of the camera 1 is regularly cleaned in a cycle of about 2 months, but dust and the like adhere to the lens until the next cleaning, so that the image obtained by the camera 1 is gradually clouded. come. The fogging of the image causes an erroneous analysis such that the brightness of the charging surface is lowered. The present invention has been devised to solve such a problem, and corrects a dead zone caused by a difference in brightness in an image captured by a camera,
The purpose is to estimate the luminance distribution over the entire surface of the charge.

[0006]

In order to achieve the object of the image processing method of the present invention, the surface of the charging material at the top of the blast furnace is photographed by a furnace mouth camera, and the brightness within the field of view of the camera is within a set range. When a brightness dead zone outside the range occurs in the image obtained by the furnace mouth camera, the image is divided into vertical and horizontal grids, and the brightness of the brightness dead zone is estimated from the brightness of each of the grids surrounding the grid corresponding to the brightness dead zone. It is characterized by doing. Further, when an image having a brightness lower than the reference value is obtained, the brightness of the image is corrected using the in-furnace temperature detected by the transfer sonde provided on the furnace top as the reference value. A factor that influences the brightness of the image captured by the camera is the flame 4 rising from the surface of the charging material 3 at the center of the furnace as described above. When the flame 4 is observed by the camera 1, the brightness of the image corresponding to that portion increases. Therefore, in this case, the upper limit is 500 ° C., and when the temperature exceeds this limit, it is treated as the occurrence of the brightness dead zone. On the other hand, in the portion where the luminance is reduced due to the wire mesh, the lattice, etc., the lower limit is set to 50 ° C. and the presence or absence of the luminance dead zone is determined. If the image brightness decreases due to lens fogging, etc., the temperature inside the furnace is detected by a transfer sonde installed at the furnace top and the detected value is used as a reference value to correct the image brightness. To do.

[0007]

[Example] Fig. 3 shows an image of the contents inside the furnace taken by a camera.
As shown in Fig. 5, the grid was divided into a plurality of grids in the vertical and horizontal directions. When the brightness was measured for each grid, the grids 1 to 33 were
It was in the selected range of 50 to 500 ° C. Lattice aj is 50
The brightness exceeded 0 ° C, and the lattices k to o showed brightness below 50 ° C. This is because the influence of the flame 4 appears in the brightness of the lattices a to j, and the influence of the camera protection mesh appears in the lattices k to o. Therefore, the luminances of the grids a to j and the grids k to o were corrected according to the present invention as follows. Luminance of lattice a = (luminance of lattice 3 + luminance of lattice 8 + luminance of lattice 9 + luminance of lattice 18) / 4 Luminance of lattice b = (luminance of lattice 4 + luminance of lattice 8 + luminance of lattice 9 + lattice 19 brightness) / 4. ． ． ． Luminance of lattice k = (luminance of lattice 21 + luminance of lattice 27) / 2 Luminance of lattice 1 = (luminance of lattice 22 + luminance of lattice 27) / 2

That is, the brightness of the grid that falls in the brightness dead zone is averaged over the brightness of the top, bottom, left, and right grids that are closest to the grid, and is corrected by the average value. Further, in the case where the upper, lower, left and right sides of the dead zone are not all aligned, the average value is taken and corrected only by the luminance of the closest grid. The luminances of the gratings a to j and the gratings k to o corrected in this manner accurately excluded the influence of the flame 4 and the wire netting, and accurately represented the surface state of the furnace interior container 3 as the entire image. In addition, when the inside of the furnace top of the blast furnace was observed using a camera, the brightness of the image tended to decrease with the lapse of observation time. When the temperature directly above the furnace interior container 3 was measured by a transfer sonde, the surface temperature of the charge obtained from the image was at a lower level as shown in Fig. 4 compared to the temperature inside the furnace measured by the sonde. It was In addition, a ₁ , a ₈ and a ₁₃ in FIG. 4 have a total of 13 thermocouples embedded in the transfer sonde along the radial direction, and the surface temperature of the charging material by the sonde and the image at each point. And the difference. Therefore, the average difference between the actually measured temperature distribution and the brightness distribution obtained by the image processing was obtained from FIG. 4, and correction was performed by adding the average difference to the estimated temperature analyzed from the image processing of the entire charging surface. The image corrected in this manner offsets the influence of lens deterioration and the like and accurately represents the surface state of the furnace interior container 3.

[0009]

As described above, in the image processing method of the present invention, the effects of the flame rising from the surface of the furnace interior container in the center of the furnace and the wire mesh protecting the camera are offset, From the images taken by the camera, it is possible to obtain information that accurately represents the charging status, including the surface temperature of the furnace interior container. This information is used as valuable control information for stable operation management of the furnace condition.

[Brief description of drawings]

FIG. 1 is a plan view (a) and a side sectional view (b) in which a camera is attached to a furnace wall at the top of a blast furnace.

[Figure 2] Camera image

FIG. 3 is a schematic diagram illustrating a method for correcting a brightness dead zone generated in an image.

FIG. 4 is a schematic diagram illustrating a method for correcting the brightness of an image based on the temperature inside the furnace actually measured by a delivery sonde.

[Explanation of symbols]

 1: Camera 2: Furnace wall 3: Furnace interior contents 4: Flame

Claims (2)

[Claims] 1. When the charging surface of the top of the blast furnace is photographed by a furnace mouth camera, and a brightness dead zone in which the brightness within the field of view of the camera is out of a set range occurs in the image obtained by the furnace mouth camera, A method of processing an image of a surface of a blast furnace charge taken by a furnace mouth camera, which divides an image into vertical and horizontal grids, and estimates the brightness of the brightness dead zone from each brightness of the grids surrounding the grid corresponding to the brightness dead zone. 2. When the surface of the charging material at the top of the blast furnace is photographed by a furnace mouth camera and an image in which the brightness in the field of view of the camera is lower than a reference value is obtained, a transfer sonde provided at the furnace top is used. A method of processing an image of a surface of a blast furnace charge, which is photographed by a furnace mouth camera, in which the detected furnace temperature is used as a reference value to correct the brightness of the image.