JPS6059007A - Detection of behavior of raw material charged into blast furnace - Google Patents

Abstract

PURPOSE:To detect the behavior of the raw material charged into a blast furnace and to enable stable operation of the blast furnace by directing and disposing the receiving part of a radiometer to and in the blast furnace and measuring the radiation energy of the microwave band emitted by the raw material. CONSTITUTION:Mounting holes 3, 4, 5 are formed circumferentially at a specified interval to the circumferential wall 2 of a blast furnace 1 in the height direction. Probes 6a, 7a are inserted into the holes 3, 4 in such a way that the top ends thereof do not project into the furnace 1 and antennas 6b, 7b are coupled thereto to apply received mu waves to mu wave radiometers 6, 7. A probe 8a is freely attachable and detachable and loosely inserted into the hole 5 so as to advance into the furnace 1 and the antenna 8a is attached thereto to apply the received mu wave to a mu wave radiometer 8. A calculator 9 detects temp., layer thickness ratio, charge descending speed, temp. distribution and grain size distribution from the signals transmitted thereto from the radiometers 6, 7, 8.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for detecting the behavior of a charge in a blast furnace.

The raw materials charged into the blast furnace, namely coke 5 sintered ore and other ores, are heated and melted in the furnace to form °ζ pig iron, and due to this melting, the charged raw materials in the upper layer are released under their own weight. The load gradually moves downward, causing a phenomenon of unloading. This unloading phenomenon has a major impact on blast furnace operation. Therefore, the behavior of the charged raw material in the furnace, that is, the unloading speed of the charged raw material, the layer thickness ratio and mixing situation of coke, sinter, ore, and the particle size of the charged raw material, which affect the unloading speed, Accurately measure the distribution of temperature, etc. in the blast furnace circumferential direction, radial direction, and height direction.
need to be detected.

A magnetic sensor method is used to detect the unloading speed of this charged material.
The electrical resistance method and the profile measurement method on the surface of the raw material charged at the top of the furnace are used. However, they have the following nominal names:

FIG. 1 is a schematic diagram showing the vicinity of a magnetic sensor type sensor mounting section. In the magnetic sensor method, a magnetic sensor 11 is installed in the blast furnace wall 2, and coke 10a in the blast furnace charging material 10,
This is a measurement method that utilizes the difference in magnetic permeability between sintered ore and ore 10b. Generally, the temperature characteristic of magnetic permeability of materials is 400℃
Below this level, the permeability is approximately constant, but when the temperature exceeds about 400°C, the properties begin to change due to magnetic transformation of the material, and at even higher temperatures, that is, above about 700 to 800°C, the magnetic permeability becomes extremely small.

Therefore, with this method, detection is possible in a relatively low-temperature area near the top of the blast furnace, but detection is difficult in the high-temperature area in the middle of the shaft, which is directly involved in blast furnace operation, due to decreased magnetic permeability.

Figure 2 is a schematic diagram of the vicinity of the electrical resistance type sonde attachment part, Figure 3
The figure is a sectional view of the sonde section taken along the line ■-■ in FIG. 2.

In the electric resistance type, a pair of electrodes 15 consisting of two conductors 13 and 13 and an insulator 14 insulating them are attached to the top and bottom of the sonde 12 placed astride the blast furnace 1.
This is a method of detection based on the time difference in measuring the electrical resistance value at the same interface of the sintered ore 10b, and the temperature characteristics of the electrical resistance are affected by the adhesion of charging raw material powder or insulation failure due to deterioration of the insulator 14. It is not always possible to make accurate measurements during lightning, and for measurements the electrode 15 must be
It is necessary to protrude to the side, which causes a problem of significant wear.

FIG. 4 is a schematic diagram of a method for measuring the profile of the surface of the raw material charged at the top of the furnace. The method of measuring the profile of the surface of the raw material charged at the top of the furnace is to suspend the weight 16 from near the top of the furnace above the charged raw material 10, measure the descending distance, and calculate the time-series change by subtracting the thickness of the layer of raw material charged since then. It is a method of estimating the loading speed,
Accuracy is not good due to the phenomenon of raw material flowing in, etc. Furthermore, weight 16
There is also a method of emitting microwaves from the top of the furnace to the top of the charging material and measuring the distance instead of letting it hang down, but this method also has the same accuracy problem as it estimates the unloading speed. .

Therefore, when such a detection method is used, the unloading speed cannot be accurately measured in a range extending from the top of the furnace to the lower middle of the high-temperature shaft, and it is difficult to say that stable operation can be achieved.

The present invention has been made in order to eliminate such drawbacks in measuring the unloading speed, and the receiver of the microwave radiometer is directed into the blast furnace to capture the microwave energy radiated from the charged raw material. Detection of the behavior of raw materials in the blast furnace that accurately detects the layer thickness ratio and mixing status of coke and sintered ore, particle size of charged raw materials, and temperature distribution in the blast furnace without affecting the unloading speed and unloading speed. The purpose is to provide a method.

The method for detecting the behavior of raw materials charged in a blast furnace according to the present invention is a method for detecting the behavior of raw materials stacked and charged in a blast furnace, in which one or more radiomake receivers are arranged to face the inside of the blast furnace, and the raw materials are emitted. It is characterized by measuring radiant energy in the microwave band and detecting the behavior of the charged raw material based on the measurement results.

First, the measurement principle of the present invention will be explained. In Figure 5, the horizontal axis shows the charging material temperature (°K), and the vertical axis shows microwaves (μ waves).
This is a graph showing an example of the relationship between the energy of μ waves radiated from the charging material and the temperature of the charging material at that time, with the solid line showing the case of sintered ore and the broken line showing the case of coke. There is. This figure shows that the μ wave radiant energy increases as the temperature of the charged material increases. This μ-wave radiation energy P is expressed by the following fi1 formula.

Therefore, by substituting the measured μ-wave radiant energy value P into the fl1 formula below, the brightness temperature TB (
'K) is calculated.

P=to-TB・Δf...(1) However, K: Boltzmann's constant 1.38 X 10 (
J/”K) Δf: In the micro frequency band (1-1z) Also, since the brightness temperature TB is expressed by the following formula (2), by substituting the calculated TB value into (2), the charging material temperature T can be calculated as follows: Calculated.

TB-ε・T...(2) However, ε: Emissivity (-Radiant energy from the surface at charging material temperature T/Radiant energy from the black body at charging material temperature T) In other words, charging material temperature T has a relationship with the μ wave radiant energy P as shown in equation (3) below.

P=K・ε・T・Δf ...(3) Brightness temperature TB and charging material temperature when coke and sintered ore that emit μ-wave radiant energy having such a relationship are measured using a radiometer. The relationship with T is shown in FIG.

Figure 6 shows the charging material temperature (°K) on the horizontal axis and the brightness temperature difference (°K) between coke and sintered ore on the vertical axis. Shows temperature difference. Therefore, the coke layer and the sintered ore layer, which alternately descend in the furnace at approximately the same temperature, can be distinguished by the difference in radiant energy level or the difference in brightness temperature. The present invention utilizes this principle.

The present invention will be specifically explained below based on the drawings.

FIG. 7 is a schematic diagram showing the implementation state of the present invention, and in the figure l
is a blast furnace. A large number of mounting holes are arranged in the peripheral wall 2 of the blast furnace 1 in the height direction and in the circumferential direction at regular intervals, three of which are shown in FIG. 5 are formed in this order from the bottom, spaced apart by an appropriate length. Mounting hole 3,
4 has probes (waveguides) 6a and 7a have their tips connected to furnace 1
The outer ends of the probes 6a, 7a are coupled to antennas 6b, 7b, and the received μ-waves are applied to the μ-wave geometry 6.7. A probe 8a is provided in the attachment hole 5, which is loosely inserted so that it can enter the furnace through the peripheral wall 2 and exit outside the peripheral wall 2 when not in use, and an antenna 8b is attached to the outer end of the probe 8a. gives the received μ-wave to the μ-wave geomake 8. The μ wave geometer 6.7.8 is connected to the calculator 9. Note that the heat from the blast furnace body is transferred to the outside of the probes 6a, 7a, and 8a.

The probes 6a, 7a, 8a are water-cooled to prevent the μ-wave from being transmitted to the geometer 6.7.8.
Inside the tube is a geometer 6.7 where the high temperature atmosphere of the blast furnace generates μ waves.
．． N2 gas or the like is made to flow into the furnace so as not to flow into the furnace.

Various types of μ wave geometers 6.7.8 are known. For example, there are the Dietsky type radiomake and the total power type radiometer.

The calculator 9 detects the temperature, single layer thickness ratio, unloading speed and distribution in the following manner based on the signals sent from the radiometers 6.7.8. First, regarding the temperature, the two large and small μ-wave energy values P measured when the coke 10a and the sintered ore 10b alternately pass the front surface of the probe 6a, 7a, or 8a of the radiometer 6.7 or 8, respectively, are expressed as ( 3) Substitute into the equation and obtain the difference between the two brightness temperatures TBO (
brightness temperature difference) and the charging material temperature shown in Fig. 6 mentioned above.
The charging raw material temperature T is calculated using a predetermined formula based on the relationship with the brightness temperature difference.

The layer thickness ratio is calculated by measuring the μ wave radiant energy over time using a radiometer 6.7 or 8 as follows. FIG. 8 shows the measurement results, with time (1) plotted on the horizontal axis and μ-wave radiation energy plotted on the vertical axis. As shown in the figure, coke 10alti is connected to probes 6a and 7.
The energy level is low when passing through the front surface of a or 8a, and conversely, the energy level appears high when passing through the sintered ore 10b layer, so the low energy measurement time tc
By calculating the ratio of the high energy measurement time ts to the coke 10a layer thickness, it is possible to detect the ratio of the sintered ore 10b layer thickness to the coke 10a layer thickness, that is, the 1-reduction thickness ratio.

The boundary between both layers is determined by using the time at which the differential value or the amount of change over time of the μ-wave radiation energy changes from +■ to 1■.

The unloading speed is calculated as follows by measuring the μ wave radiant energy emitted by the coke 10a and the sintered ore 10b on the front surface of the probes 68 and 7a whose separation distance # (L') is known for a predetermined period of time. do. In Figure 9, the horizontal axis is time <L)
The measurement results are shown with the vertical axis representing the μ-wave radiation energy.
This is the measurement result shown in a, and the respective μ-wave radiant energies appear at the boundaries in the same way as in FIG. 8, and the center portion of each raw material layer in the thickness direction has a maximum or striped hull. Therefore, the measurement time difference Δt between the radiometers 6 and 7 at the interface between the coke 10a layer and the sintered ore 10b layer or at the center of one of the layers is taken into account, and the probe 6a of the μ-wave geometer 6°7 is calculated as follows. Calculate the unloading speed using the distance a. This time difference Δt may be determined by a method similar to the above-mentioned method or from the peak values of both measurement results.

Regarding the temperature distribution, the distribution in the blast furnace height direction is determined by a plurality of probes 6a, 7 arranged at different mounting heights on the peripheral wall 2 of the blast furnace 1.
radiometers 6.7.a and 8a connected respectively.
The μ wave radiant energy P value measured by 8 is expressed as (3
) and organize it in the height direction. The temperature distribution in the radial direction is determined by entering the probe 8a into the furnace, and is calculated based on the distance of the antenna 8b at its tip and the detected μ-wave radiation energy value. A plurality of probes 8a are evenly distributed on the peripheral wall 2 at regular intervals, and an antenna 8 is attached to the tip of the probes 8a.
(b) are made to enter the furnace so that the distance of entry into the furnace is the same, that is, it is obtained based on the μ-wave radiant energy value for one and a half flea.

Regarding the particle size distribution, the emissivity changes depending on the particle size as shown in FIG. 10, so this can be used to determine the particle size distribution. Figure 1O is a graph showing the relationship between the charged material temperature (°K) on the horizontal axis and the emissivity (ε) on the vertical axis, depending on the difference in coke particle size. '17mm
A white circle indicates a particle size of 20 mm, a triangle indicates a particle size of 50 mm or more, and a black circle indicates a case where the relationship between the two does not change depending on the particle size. From this figure, it can be seen that the emissivity changes with the temperature of the charged raw material, and in the case of coke, the emissivity differs even at the same temperature due to the difference in particle size. In addition, since there is a certain relationship between the charging material temperature T and the brightness temperature T'B, the charging material 6114 degrees T @ /ji'l was determined by a known method, and the μ-wave radiant energy value P was After measurement, the emissivity ε is calculated using equation (3), and the particle size distribution of the coke can be determined based on this emissivity ε and FIG.

Note that the probes 6a, 7a, and 8a used in the present invention and inserted into the holes in the peripheral wall 2 have extremely little wear due to the charged raw materials, and the microwave radiation energy from inside the furnace is transferred to the outside of the furnace using a waveguide. It can be guided to the installed radiometer body and detected, and since heat is not transmitted, it does not become high temperature and does not deteriorate due to temperature.

As detailed above, the method for detecting the behavior of the charging material in a blast furnace according to the present invention measures the radiant energy of μ waves emitted by the charging material by radiomaking, so it can be used not only in the low-temperature section at the top of the furnace but also in the high-temperature section inside the furnace. unloading speed, coke and sinter,
Layer thickness ratio and mixing situation with ore, particle size of charging raw material*, l, and particle size of charging raw material.

It is possible to accurately detect the temperature distribution within the blast furnace, and this provides excellent effects such as stably operating the blast furnace.

[Brief explanation of drawings]

Figures 1, 2, 3, and 4 are schematic diagrams showing the measurement contents of the unloading speed using the conventional method, and Figure 5 shows the relationship between the temperature of each blast furnace charging material and the microwave radiant energy. Graph shown, No. 6
The figure is a graph showing an example of the relationship between the temperature and the μ-wave radiation energy difference between the charged raw materials, Figure 7 is a schematic diagram showing the implementation state of the present invention, and Figures 8 and 9 are the measured μ-wave A graph showing radiant energy, FIG. 10 is a graph showing the relationship between charging material temperature and emissivity for different particle sizes. 1... Blast furnace 2... Surrounding wall 6, 7.8... Microwave radiometer 6a, 7a, 8a... Probe 10... Charging raw material patent applicant Sumitomo Metal Industries Co., Ltd. Agent Patent attorney Noboru Kono 1 (/ 1st Fig. 2 Σ *3 (branch) 4th time (t) Fig. 8 81 time (tl Charged raw materials, stems and skins) 10th box

Claims (1)

[Claims] 1. In a method for detecting the behavior of raw materials stacked and charged into a blast furnace, the receiving section of one or more radiometers is arranged to face the inside of the blast furnace, and the radiant energy in the microwave band emitted by the raw materials is measured, A method for detecting the behavior of raw material charged into a blast furnace, characterized by detecting the behavior of the charged raw material based on the measurement results.