JPH056654B2 - - Google Patents

Description

[Detailed description of the invention]

INDUSTRIAL APPLICATION FIELD The present invention relates to a device useful for the operation of a converter, and more particularly to a device for detecting slopping, which can be a major hindrance to the operation if it occurs during blowing. Prior Art The refining of hot metal and molten steel in a converter involves spraying pure oxygen gas onto the molten steel from a lance inserted into the furnace from the mouth of the converter, stirring the molten steel and decarburizing it. Dephosphorization and desulfurization are performed by the reaction of the molten slag that is formed into slag by the slag-forming agent introduced into the slag, and during this slag formation process, the slag composition,
Forming of slag occurs depending on various conditions such as viscosity and the amount of oxygen in slag, and if this progresses excessively, so-called slopping may occur in which slag and even molten steel overflow from the furnace mouth. When this slopping occurs, it has a major impact on the molten steel composition, steelmaking yield, etc., and also reduces work efficiency.
This causes various problems such as a decrease in calories in the recovered gas, deterioration of the working environment such as the generation of red smoke, and damage to equipment. Therefore, it is necessary to suppress the occurrence of sloping as much as possible. Therefore, it is possible to quickly predict the situation inside the converter furnace,
It is necessary to operate the converter appropriately, such as by preventing the occurrence of slopping, and various proposals have been made to understand the condition of the converter. Specifically, JP-A-52-101618 discloses a method for estimating the amount of oxides produced in the furnace, that is, slag, by calculating the oxygen balance based on exhaust gas information during blowing in the converter steel manufacturing process. ing. In this method, a time delay due to analysis is unavoidable, and since the cause of slopping is not only due to the amount of slag, the accuracy of predicting the occurrence of sloping is low. Various attempts have also been made to detect the slag level using physical measurement methods, including the acoustic measurement method (Japanese Patent Application Laid-Open No. 54-33790) and the vibration measurement method (Japanese Patent Application Laid-open No. 33790/1989).
No. 54-114414), Furnace Pressure Measurement Method (Unexamined Japanese Patent Publication No. 1983-
104417), microwave measurement method (Unexamined Japanese Patent Publication No. 104417),
140812), Furnace Surface Temperature Measuring Method (Unexamined Japanese Patent Publication No. 1983-
48615) have been proposed. The acoustic measurement method attempts to predict the occurrence of sloping by estimating the slag level by ascertaining changes in the frequency and intensity of the sound generated from inside the furnace during blowing, while the vibration measurement method attempts to predict the occurrence of slopping. This method attempts to predict the occurrence of slopping by estimating the slag level or state by understanding vibration changes and waveform transitions, while the furnace pressure measurement method attempts to predict the occurrence of slopping by understanding changes in the furnace exhaust gas injection pressure during blowing. This method attempts to predict the occurrence of slopping, and the microwave measurement method involves directly projecting microwaves into the furnace during blowing.
This method uses the principle of FM radar to directly measure the slag level and predict the occurrence of slopping.The furnace surface temperature measurement method captures the radiant energy at the top and bottom of the furnace body as temperature, and measures temperature changes and peaks. It attempts to detect the occurrence and amount of sloping from values etc. The acoustic measurement method, vibration measurement method, furnace pressure measurement method, and furnace body surface temperature measurement method described above are all indirect measurement methods, and cannot quantitatively grasp the slag level and slag condition, so they are difficult to detect due to slopping. Prediction accuracy is low. The microwave measurement method can directly measure the slag level, but since the molten metal, slag, gas, etc. move in an extremely complex manner inside the converter during blowing, it is difficult to detect or estimate abnormalities. This is not easy, and requires advanced technology for signal processing, etc., so it is inevitable that the equipment will be expensive. In response to these issues, the present applicant previously filed a patent application for a method for detecting abnormal reactions in a converter by detecting the intensity of light in the furnace, changes in wavelength, or both.
No. 37872). The present invention is a further improvement on that patent. OBJECTS OF THE INVENTION An object of the present invention is to provide an excellent converter slopping detection device, which can be utilized for highly accurate converter operation. Structure and operation of the invention The structure of the present invention includes a detection device that can insert and remove an optical probe into a through hole provided in a side wall of a converter furnace body, and a photoelectric conversion video signal from the detection device that is set in advance. a separation device that separates the images into a plurality of wavelength ranges, a device that uses a pulse counter to calculate the area occupied by the video of each of the separated wavelength regions in the total video, and an input signal from the calculation device that is determined in advance. This is a converter slopping detection device characterized by comprising a device that compares it with a sloping criterion and outputs a sloping detection signal. The present invention will be explained below using the drawings. FIG. 1 is an explanatory diagram schematically showing the overall appearance of the apparatus of the present invention. As shown in FIG. 1, a through hole 4 is provided in the side wall 2 of the converter 1 to penetrate into the furnace interior 3. This through hole may be a tapping hole, or may be provided separately from the tapping hole as shown in the figure. As an example, the detection device 6 includes a support frame 5 provided near the converter 1, and a moving device 8.
The optical probe 7, which is a component of the detection device, can be inserted into and removed from the through hole 4. The through hole can be selected from any location on the side wall of the furnace body that is not immersed in molten metal during blowing, tapping, charging of hot metal, etc. Furthermore, since the detection device 6 can be moved freely as described above, it is also possible to utilize the tapping hole. The detection device includes an optical probe 7 whose tip is inserted into and removed from a through hole, and a photoelectric conversion element 10 that is attached to the rear end of the probe via a connector 9, and the in-furnace light transmitted from the optical probe is It is photoelectrically converted and sent to the sorting device 11 as a photoelectrically converted video signal. In the separation device 11, the signal is separated into a plurality of predetermined wavelength ranges. The separated signals are processed by a calculation unit 12 that calculates the area occupied in the video signal for each wavelength range as the number of pulses of the video pulse signal using a pulse counter, and calculates the area amount for each wavelength range. Slopping is detected by a determining device 13 which compares the input signal from the device with a predetermined sloping criterion and outputs a sloping detection signal. Further, the main parts will be explained. In the present invention, an optical probe is a cylindrical object containing a light guide. A light guide is a conductor, such as a quartz optical fiber, that transmits radiation emitted from a high-temperature object with low loss. As described above, the optical probe is inserted into the through hole and faces the inside of the high-temperature furnace, so there is a risk of wear and tear, so at least its tip must be protected by some means of cooling. As an example, Figure 2 shows the simplest two optical probes.
Indicates heavy pipe type. The light guide 71 is a heat-resistant protective inner tube 7
2, and in the gap between it and the heat-resistant protection outer tube 73,
Cooling gas is introduced and flows in the direction of the tip of the optical probe 7 as shown by the arrow, cooling both protective tubes and preventing the front transparent body 74 that protects the front end of the optical guide from fogging up and dust from adhering to the furnace. released within. Regarding the device for moving the optical probe so that it is inserted into and removed from the through hole, FIG.
Although an example of a device in which an optical probe is mounted on the device 2 and a moving pedestal 82 is moved by the moving device 8 has been exemplified, the present invention is not limited to this. However, the optical probe was made to be able to be inserted into and removed from the through-hole at will.The optical probe was inserted only when it was actually necessary to input the furnace conditions to the detection device, and the optical probe was inserted into the through hole only when it was necessary to input the situation inside the furnace to the detection device. This is to avoid harmful effects such as unnecessary heat load and dust on the time or material charge time. The light image captured at the tip of the photoconductor is converted into a photoelectric conversion image signal by a photoelectric conversion element 10 attached via a connector 9. Here, a photoelectric conversion element has the function of converting light into electrical signals for each wavelength in proportion to its intensity. For example,
These include an ITV camera and a photomultiplier tube combined with a spectrometer. These are located at a sufficient distance from the light-receiving surface of the light guide, which is under severe conditions, and are therefore in a favorable environment to perform their functions. Figure 3 shows a typical example of the situation inside the furnace during blowing. Figure 3 assumes a situation inside the furnace where the amount of slag is relatively small, and the high-temperature gas atmosphere 18 inside the furnace appears white in the field of view of the circular light-receiving surface in front of the optical probe, as shown in Figure 3'. appear. As slag formation progresses further and the amount of slag 16 increases as shown in Figure 3,
The surface of the slag is shaken by the oxygen ejected from the lance and the CO gas generated by the blowing reaction.
The slag, which is in an emulsion state and whose temperature is lower than that of the upper gas atmosphere, is captured in the field of view of the light-receiving surface as a yellow wave shape, as shown in FIG. 3'. When the slag in the emulsion state causes so-called slopping and overflows out of the furnace as shown in FIG. 3, the field of view of the light-receiving surface takes on a yellowish color over the entire surface as shown in FIG. 3'. In other words, when slag formation in the furnace progresses to some extent during converter operation and the temperature of the gas 18 above the slag 16 becomes higher than the temperature of the slag, the wavelength and intensity of the light emitted by the gas atmosphere and the light emitted by the slag will change. The relationship is
A clear difference appears, and by extracting this difference to a specific enemy, we have completed a sloping detection device. The overall block diagram of the device of the present invention from receiving the light in the furnace to outputting the slopping detection signal is shown in Figure 4.
Shown in the figure. The relationship between the wavelength and intensity of the light emitted by the slag during blowing and the gas atmosphere above the slag is shown in FIG. The light inside the furnace during blowing is constantly fluctuating, but this is classified into B (blue), G (green), and R (red) by wavelength, and is exemplified as a short-time analog signal in Part 6. It is a diagram. In the figure, if the R signal shows a change like curve 21, the G signal shows a change like curve 22, and the B signal shows a change like curve 23, then the binarization circuit 51 in FIG. After being binarized based on the stochjold levels 24, 25, and 26 in the wavelength range, the R signal is expressed as 27 in FIG. 7, the G signal as 28, and the B signal as 29. , if we combine the three and express them in terms of color names, we get red, magenta, red, as shown in the subdivisions on the horizontal axis.
The colors are yellow and red, and the areas that do not receive light can be displayed as black. Therefore, considering all combinations of the binarized R signal, G signal, and B signal, signals corresponding to eight different colors can be obtained, including when no light is received. However, since the occurrence of slopping is considered to be correlated with the amount of slag and the magnitude of change in that amount, the area calculation device 12 is used to detect the proportion of area occupied in the video by color and its change. send a signal. The processing in the area calculation device 12 is shown as shown in FIG. The video signal 96 that has been binarized with respect to the three RGB components by the binarization circuit 51 is integrated by the eight integration pulse counters 90 in the area calculation device 12 for each of the eight colors based on the combination of the three RGB components. . The calculation is performed by converting 7MHz pulses generated by a count pulse generator 91 into a video signal 96 according to the combination of RGB representing each color.
This is done by counting and integrating only when the state is . One integration time is about 16.7 msec, and the color area amount signal 63 is reset by the reset pulse 94 generated from the control CPU 93 in response to the vertical synchronization signal 95.
commands to output, reset the integrated value, and start the next integration. In this way, from receiving the reset pulse 94 by the vertical synchronizing signal 95 until receiving the next reset pulse 94, that is, the area amount signal 63 of each of the eight colors occupying one video screen is controlled for 16.7 msec.
Can be output synchronously. The area amount signal 63 for each color, which is the output of the area calculating device 12 obtained in this way, is divided into two systems. One system inputs the area amount itself for each color to the determination device 13 as a binary signal of the area amount through the binarization circuit 55, and the other system inputs the area amount itself as a binary signal of the area amount, and a high-pass transmission filter is used to input it as a change in the area amount. 52, a positive value conversion circuit 53, and a binarization circuit 54, the signal is inputted to the determination device 13 as a color-specific area amount signal 65 in which the amount of change is emphasized. The slopping judgment criteria are as shown in Table 1, based on the combination of the color-based area amount binary signal and the color-based area amount binary signal that emphasizes the amount of change.

[Table] However, in reality, it is necessary to consider the operational status of the converter at the time of judgment. That is, in the early stage of blowing, slopping cannot occur and the gas temperature in the furnace is low, so the judgment in the previous table is not accurate. Furthermore, when the input of ore and auxiliary materials such as quicklime and dolomite have been incorporated into the operation sequence, there is no need to issue a warning, and if the amount of silicon in the hot metal is higher than a predetermined value, slopping occurs. There is a great possibility. In addition to this kind of decision logic,
Table 2 shows the cases in which slopping is likely to occur in Table 1. In any case, the basis of judgment is where to set the threshold level that serves as the standard for the area amount binary signal for each color and the area amount change amount binary signal for each color. It must be determined from a large number of operational records and the correlation of these signals by the device of the present invention. The above judgment criteria are determined in advance, and the sloping detection signal 67 is determined depending on whether the possibility of sloping occurring is high, low, or absent by comparing this standard with the two types of area amount binary signals described above. Judgment device 1
It can be output from 3. Example A through hole was provided in the side wall of a 170 t/CH top-bottom blowing converter at a height of approximately 4 m from the bottom of the furnace, and slopping was detected using the apparatus of the present invention. The hot metal conditions at this time are that the [Si] content is 0.30 to 0.50%. When a warning is issued by the sloping detection device, it is not realistic to continue operation until it is confirmed that sloping has actually occurred. This judgment was made by also performing actions. Example 1 The possibility of slopping occurring was detected by combining the yellow and red area amount binary signals and the area amount change amount binary signal, and the results shown in Table 3 were obtained. Example 2 The possibility of slopping occurring was detected by combining the area amount binary signals of yellow and white and the area amount change amount binary signal, and the results shown in Table 4 were obtained. Example 3 The possibility of sloping occurrence as in Examples 1 and 2 is received as a sloping prediction warning, and slopping suppression actions are actually taken, such as adding inhibitors such as coke powder or lime powder, increasing bottom blow flow rate, and reducing oxygen supply amount. Table 5 summarizes the results for a total of 95 cases with and without such a warning.The success rate of sloping prediction was 94.7%, and the overdetection rate was 5.3%. There were no occurrences.

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[Table] Effects of the Invention As detailed above, the converter slopping detection device of the present invention has a high slopping detection rate and can effectively suppress sloping, so it is extremely valuable for converter operation. be.

[Brief explanation of the drawing]

Fig. 1 is a schematic explanatory diagram of the present invention, Fig. 2 is a partial sectional view showing an example of an optical probe, Fig. 3 is an explanatory diagram showing the furnace condition and light receiving surface image, and Fig. 4 is an illustration of the signal system. Overall block diagram, Figure 5 is a diagram showing the relationship between the wavelength and intensity of light emitted by the slag and the gas above the slag, Figure 6 is an analog signal diagram of the light inside the furnace, and Figure 7 is the binary value of the light inside the furnace. FIG. 8 is a block diagram showing the processing of the arithmetic unit. 1...Converter, 2...Side wall, 3...Furnace interior, 4...
Through hole, 5... Support frame, 6... Detection device, 61
...Photoelectric conversion video signal, 62...Video signal for each wavelength range, 63...Area amount signal for each color, 64...Binarized area amount signal for each color, 65...Binarization of area amount change amount for each color Signal, 66...Input signal for ore, auxiliary materials, etc., 67...
...Sloping detection signal, 7...Optical probe, 7
1... Light guide, 72... Protective inner tube, 73... Protective outer tube, 74... Front transparent body, 8... Moving device, 8
1... Rail, 82... Moving frame, 9... Connector, 10... Photoelectric conversion element, 11... Sorting device,
12... Arithmetic device, 13... Judgment device, 16...
Slag, 17... Molten metal, 18... High temperature gas atmosphere, 19... Lance, 21... Analog R signal,
22...Analog G signal, 23...Analog B signal, 24...R signal threshold level, 25...
...G signal threshold level, 26...B signal threshold level, 27...Binarized R signal, 28
... Binarized G signal, 29 ... Binarized B signal, 51
... Binarization circuit, 52 ... High frequency transmission filter,
53... Positive value conversion circuit, 54... Binarization circuit, 55
...Binarization circuit, 56...Converter process, 90...
...Integration pulse counter, 91...Count pulse generator, 92...Count pulse, 93...Control
cpu, 94...Reset pulse, 95...Vertical synchronization signal, 96...RGB binary signal.

Claims (1)

[Claims] 1. A detection device that allows an optical probe to be inserted into and removed from a through hole provided in the side wall of the converter body, and a sorting device that separates the photoelectric conversion video signal from the detection device into a plurality of preset wavelength ranges. and a device that calculates the area occupied by the video of each of the separated wavelength ranges in the total video using a pulse counter, and a sloping detection signal that compares the input signal from the calculation device with a predetermined sloping criterion. 1. A converter slopping detection device comprising: a device for outputting output;