JPS59166612A - Detection of abnormal reaction in converter - Google Patents

Abstract

PURPOSE:To quickly and accurately make the detection of abnormal reaction in converter possible, by a method wherein furnace light photometers are equipped at plural places of penetration holes provided at a nonimmersed parts of furnace wall and the furnace light in operation is detected and compared with a reference value for abnormality. CONSTITUTION:At plural places of penetration holes 4 are provided at the nonimmersed part of furnace wall 2 of a converter, furnace light photometers 5 equipped to at respective penetration holes 4 via protection tubes 11, the protection tubes 11 being cooled with cooling water (w) and purging gas is blown into from furnace openings 113. The intensity on wave length change of the furnace light detected with the photometer 5 is outputted to a signal processor 13, an operational processor 14 and a display device 15 via cable 12 as sensing signal. The operational processor is preliminarily inputted with the referance value for abnormality. Thus, The alarm is outputted and control commands are outputted to various kinds of control units.

Description

[Detailed description of the invention] The present invention relates to a method for detecting an abnormal reaction in a converter.

As is well known, in the so-called converter operation in which steel is refined from pig iron in a converter, slag becomes emulsion-like and forms during blowing. For example, if the forming becomes excessive, the slag flows out of the furnace. An overflowing abnormal reaction occurs. The abnormal reaction is usually called slopping, and when this slopping occurs, it not only causes a decrease in iron yield, but also makes it difficult to continue stable blowing.
This is a major obstacle to implementing efficient converter operations. If the above-mentioned slopping occurs, operational actions are taken, such as adjusting the oxygen supply rate during blowing or introducing oxidizing coolant.

By the way, conventional techniques for predicting the occurrence of the above-mentioned slopping etc. include, for example, measuring the sound inside the furnace,
Techniques have been proposed for estimating the occurrence of slopping by measuring the height of the slag from the furnace mouth using microwaves, or by measuring the vibration of the lance.

However, in the furnace during blowing, the molten metal, slag, gas, etc. move in an extremely complex manner, making it difficult to accurately detect or estimate abnormalities using the conventional method, and it is difficult to accurately detect or estimate abnormalities in signal processing. Advanced technology was required, and the costs were high.

The present invention aims to fundamentally solve the above-mentioned conventional problems, and its main purpose is to provide a method that can accurately detect abnormal reactions within a furnace during operation.

Hereinafter, the present invention will be explained in detail based on Examples.

Now, as a result of conducting various research studies on the occurrence of abnormal reactions in converters, the present inventors have found that the occurrence of abnormal reactions has a close relationship with the behavior of slag forming during operation. It has been found. As a result of further experimental research on the method for detecting the behavior of slag forming, it was found that there is a significant difference in the intensity and wavelength of the light itself between the gas atmosphere in the operating furnace and the slag. We found that it is possible to detect the above behavior by actively utilizing this property.

That is, as shown in FIG. 1, a through hole 4 is provided in the furnace wall 2 of the converter l, and the through hole 4 penetrates into the furnace interior 3, and the through hole 4 is used to measure the intensity and/or wavelength of the light inside the furnace. By installing a photometer (hereinafter referred to as photometer) 5 and measuring the intensity or wavelength of the light during operation, it is possible to determine whether slag forming is occurring at level X or not. It is possible to detect whether level X is under a gas atmosphere. By the way, in the converter 1, the side wall 20 to which the trunnion shaft 6 is fixed has a second a
As shown in the figure, a state in which the converter 1 is upright as in operation, and a state in which the converter l is tilted as in tapping steel (Fig. 2b);
and a state in which the converter 1 is tilted as during charging of hot metal (second c.
Also in FIG. 3, a portion that is not immersed in the molten metal 7, that is, a non-immersion portion 8 is formed. However, by providing one or two or more of the through holes 4 in this non-immersion portion 8 and attaching the photometer 5 to each of the through holes 4, a problem arises in which the molten metal 7 enters the through holes 4. Abnormal reactions, which will be described later, can be detected continuously.

Next, the basic principle of the present invention will be explained based on FIGS. 3a to 5. In FIGS. 3a to 3c, three photometers 5a to 5c are installed in the direction of the furnace height, and each of the photometers 58 to 5c is configured to measure the light in the furnace at the corresponding levels xa to Xc. ing.

Figure 4 shows the intensity of the light inside the furnace, for example, after signal processing using an appropriate transmission filter, on the vertical axis, and on the horizontal axis, the atmosphere inside the furnace during operation, and shows the correlation between them. .

As can be seen from Fig. 4, when the intensity of the light inside the furnace is measured by the photometers 5a to 5C, the level X of the photometer is the slag forming level (the level of the top surface of the slag forming).
It is possible to detect whether y has been reached.

When the light inside the furnace is continuously measured by each of the photometers 5a to 5c shown in FIGS. 3a to 3c, as shown in FIG. 5, for example, in the state shown in FIG. It can be seen that the slag forming level y is also under the gas atmosphere and the slag forming level y is below the level xc measured by the photometer 5c. Next, in the state shown in FIG. 3b, the photometers 5a and 5b are in a gas atmosphere, and slag forming occurs at level xc of the photometer 5c. Therefore, it can be seen that the slag forming level y is between h2 and h3 from the furnace mouth 9. Similarly, in the state shown in FIG. 3c, slag forming occurs at any level x a - x c of the measuring devices 5 a to 5 c, and the slag forming level y is the level xa of the photometer 5 a, that is, h1 from the furnace mouth 9. It can be seen below.

As described above, the photometers 5a to 5c are connected to the non-immersed part 8 of the converter wall.
By installing multiple units in the furnace height direction and furnace width direction and continuously measuring the light inside the furnace during operation, it is possible to accurately detect the complex behavior of slag forming inside the furnace.

Then, the relationship between the behavior of the slag forming and the abnormal reaction is determined in advance according to the operating conditions, the structure of the converter, the furnace volume, etc. for each type of abnormal reaction, and an abnormal reference value is obtained. It becomes possible to detect an abnormal reaction by comparing the values detected by 58 to 5c with the abnormality reference value.

For example, in the embodiment shown in FIG.
When slug forming level y reaches level Xa of a, slot 7. When the probability of occurrence of the slopping phenomenon is high, the level xa may be set as the slopping occurrence reference value.

On the other hand, in order to carry out a normal dephosphorization reaction in a converter, an appropriate amount of slag (T-Fe) and a predetermined amount of slag formation are required.

This slag formation can also be confirmed by detecting the slag forming level y. For example, in the embodiments shown in FIGS. 3a to 3c, an abnormality due to poor slug formation is detected at the level XC of the lowest photometer 5c. can.

Next, a method for mounting the photometer 5 and a method for measuring the photometer 5 will be explained.

FIG. 6 is a partial sectional view showing one embodiment of a method of mounting the photometer 5. FIG. In this embodiment, the protective tube 11 is fitted into the through hole 4 provided in the furnace wall 2, and the inner cylinder 1 of the protective tube 11 is
A photometer 5 is attached to 10. A cooling water @ ring path 111 is formed in the protection tube 110, and cooling water W is supplied through a water supply and drainage pipe 112 to cool the protection tube 11.

Further, an inert gas g such as N2, Ar, or CO2 is supplied from the rear of the inner cylinder 110 to which the photometer 5 is attached for purging. This purge gas g is ejected from the in-furnace opening 113, cools the photometer 5 (58 to 5c2 and below), and gases containing slag and dust to the inner cylinder 1.
10 is prevented from entering. The detection signal from the photometer 5 is transmitted via a cable 12 to a signal processing device 13 such as a transmission filter, an arithmetic processing device 142, and a display device 15.
etc. are input. In the arithmetic processing unit 14, for example, the abnormality reference value is inputted in advance, and an abnormal reaction is automatically detected by comparing the detection signal from the photometer 5 with the abnormality reference value, and an alarm is issued based on this. It is also possible to provide various control devices with the function of issuing control commands. Of course, it is also possible for the operator to monitor the detected value displayed on the display device 15, compare it with the preset abnormality reference value, detect an abnormal reaction, and take operational action to be described later.

FIG. 7 shows another embodiment of the photometer 5, in which an optical fiber 51 is attached to the inner tube 110 of the protective tube 1. This optical fiber 51 is connected to a photometer main body 52 installed at an appropriate location outside the furnace. In this embodiment, the light inside the furnace is input to the photometer main body 52 via the optical fiber 51 and measured by the photometer main body 52, which has a precise mechanism and the expensive photometer main body 52 is heated to a high temperature. It is extremely effective because it can be mounted away from the furnace wall 2. In the present invention, the photometer 5 attached to the through hole 4 may be attached via the protective tube 11, via the optical fiber 51, or may be attached directly to the through hole 4, although not shown. , including wearing. In addition, as the photometer 5,
There is no particular limitation as long as the intensity and/or wavelength of the light inside the furnace can be measured; for example, a device that combines a spectrometer and a photomultiplier to measure the intensity of light at various wavelengths, Alternatively, a CCD element combined with a filter and a lens, an ITV camera, etc. may be used.

Next, specific embodiments of the present invention will be described.

02 from the top blowing lance 16 and CO from the bottom blowing nozzle 17.
In a 170 ton top and bottom blowing converter that bottom blows
As shown in the figure, 1 and 5 m from the furnace mouth 9, respectively.
Through holes 4 are provided at the 2,5 m, 3,5 m level, and the protective tube 1 is inserted into the through holes 4 as shown in FIG.
1, and an optical fiber 51 with the same diameter of 12 mm was attached to the inner tube 110 of the protective tube 11. The optical fiber 51 is connected to the photometer body 52, but in this embodiment, the photometer 52 is connected to the photometer body 52.
In order to capture a clearer image of the difference in light intensity between the gas atmosphere and slag forming using an ITV camera combined with a single-wavelength transmission filter, the signal from the ITV camera described above is stored in a digital memory, and the signal from the ITV camera is stored in a digital memory. Image processing was performed using signals stored in digital memory.

FIG. 9 shows the detected values by the photometer 5 of this embodiment and the well-known
This is a time chart showing a comparison between the slag forming level and the values measured intermittently using a consumable thermometer attached to the tip of the sublance, which has been practiced in the past. As is clear from this figure, there is no difference between the measured values of the sublance, which has conventionally been considered the most reliable, and the detected values of the present invention, indicating that the slag forming level y can be measured with high accuracy. It could be confirmed. In particular, in the present invention, since continuous measurement is possible, it has become possible to accurately grasp the dynamic behavior of slag foaming in a furnace.

Table 11 shows the investigation results of the relationship between the slag forming level y reaching each level in Figure 8 and the slopping occurrence rate.
It can be seen that when the slag forming level y reaches a), the incidence of slopping increases rapidly.

In this embodiment, the time when the detection value of the photometer 5a detects slag forming is set as the slopping (abnormality) reference value. Therefore, the intensity of the light inside the furnace during operation is continuously measured by the photometer 5, and when the slopping reference value is reached and an abnormal reaction is detected, an abnormal reaction alarm is issued as shown by arrow 8 in Fig. 9. Ta. Based on this alarm, operational actions such as lowering the flow rate of 02 from the top blowing lance 16, adjusting the height of the top blowing lance 16, or introducing raw dolomite into the furnace can be used to reduce slopping. By implementing the present invention, it was possible to reduce the occurrence rate of slopping to 0.5% or less.

As described in detail above, by implementing the present invention, abnormal reactions within the furnace can be detected quickly and accurately.

As a result, it has become possible to take appropriate operational actions in response to abnormal reactions in a timely manner, enabling efficient and stable converter operation. The present invention is applicable not only to top-blown converters but also to top- and bottom-blown converters.

As described above, the practical effects of the present invention are extremely large.

[Brief explanation of drawings]

Each episode shows an example of the present invention; Fig. 1 is a cross-sectional structural diagram showing how a photometer is installed in a top-blowing converter;
Figures 2b and 2o are cross-sectional structural diagrams showing non-immersed parts, and Figures 3a, 3b, 3c, 4 and 5 are drawings for explaining the basic principle of the present invention. So, Figure 3a,
Figures 3b and 3c are structural diagrams showing how the photometers are installed, Figures 4 and 5 are time charts showing the level of detected optical signals, and Figures 6 and 7 are for different photometers. Sectional structural diagram showing an example of the mounting method, No. 8
The figure is a cross-sectional structural diagram showing how the photometer is installed in a top-bottom blowing converter, and Figure 9 is a time chart showing a comparison between the light signal detected by the photometer in Figure 8 and the slag level detected by the sublance. be. Converter 2: Furnace wall 20: Side wall 3: Furnace interior 4: Through hole 5a to 5c: Photometer 51: Optical fiber 52: Photometer body 6: Trunnion shaft 7: Molten metal 8: Non-immersed part 9: Furnace mouth
11: Protection tube 110: Inner cylinder 11
1: Cooling water circulation path 112 2 supply and drainage pipes 113: Furnace opening 12: Cable 13: Signal processing device 1
4: Arithmetic processing unit 15: Display device] 6: Top-blowing lance I7: Bottom-blowing nozzle patent applicant Nippon Steel Corporation Mitsuru 3 a'C? Kabuto 1 Shijuku 2c Tsukasa, 3b Kabuto 3c Shihaku 9 and procedural amendment band (voluntary) April 6, 1980 Commissioner of the Patent Office Kazuo Wakasugi 1, Indication of the case 1988 Patent Application No. 37872
No. 2, Title of the Invention Converter Abnormal Reaction Detection Method 3, Relationship with the Amendment Case Patent Applicant Address 2-6-3 Otemachi, Chiyoda-ku, Tokyo Name (665) Representative of Nippon Steel Corporation Take 1) Yutaka 4, Agent 103 Telephone 03-864-6052 Address 2-27-6-5 Higashi Nihonbashi, Chuo-ku, Tokyo Claims column of the specification to be amended and detailed description of the invention Column 6, Contents of amendment (1) The Claims column on page 1 of the specification is corrected as follows. ``2. Claims: One or more through holes are provided in the non-immersed part of the converter wall, and an in-furnace photometer is installed in the through hole, and the intensity of the in-furnace light during operation is measured. A converter characterized in that an abnormal reaction is detected by detecting a wavelength change or both, and comparing the detected value with an abnormal reference value of intensity and/or wavelength change that is determined in advance for each type of abnormal reaction in the furnace. Abnormal reaction detection method.
” (2) On page 6, line 11 of the specification, “...behaves,
``Abnormality degree'' should be corrected to ``behavior and abnormality degree J.''

Claims (1)

[Claims] One or more through holes are provided in the non-immersed part of the converter wall, and an in-furnace photometer is installed in the through-hole to detect the intensity or wavelength change or both of the in-furnace light during operation. A method for detecting an abnormal reaction in a converter, characterized in that the detected value is compared with an abnormal intensity and/or wavelength change reference value that has been certified in advance for each type of abnormal reaction in the reactor to detect an abnormal reaction.