JPS6075505A - Device for detecting behaviour of raw material fed to blast furnace - Google Patents

Abstract

PURPOSE:To detect behaviour of raw material fed to a blast furnace exactly for a long period by protruding a top end of a receiving part of a microwave radiometer into a blast furnace and providing an operation means by catcying microwave energy radiated from the charged raw material. CONSTITUTION:Receiving parts 41, 42 are made to penetrate through attaching holes 31, 32 formed on a furnace wall 2, and their top ends are located to by >=ca.50-100mm. to the furnace core side than the mixing layer 10c. The opening at the top end of the receiving parts are closed by lids 7 made of a refractory which permits penetration of mu wave. The radiant energy of the mu wave emitted from the charged raw material 10 through waveguides 41a and 42a of the receiving parts 41, 42 are detected by antennas 41C, 42C and detection signals are given to the mu wave raiometer 51, 52. The behaviour of the charged raw material is detected by an operator 6 by measuring the mu wave energy in accordance with the lapse of time. For example, ratio of time measuring high energy to time measuring low energy is operated, and thus, ratio of thickness of sintered ore 10b to the thickness of coke layer 10a is detected.

Description

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

The raw materials charged into the blast furnace, such as coke, sintered ore, and other ores, are heated and melted in the furnace to form pig iron, and for this melting, the charged raw materials in the upper layer are sequentially heated under their own weight. This causes a so-called unloading phenomenon in which the load moves downward. This unloading phenomenon has a major impact on blast furnace operation. Therefore, coke and sintered ore affect the behavior of the charged raw material in the furnace, that is, the unloading speed of the charged raw material, as well as the unloading speed.

It is necessary to accurately detect the layer thickness ratio and mixing condition with the ore, as well as the particle size and temperature distribution of the charged raw material in the blast furnace circumferential direction, radial direction, and height direction.

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, these have the following drawbacks.

Figure 1 is a schematic diagram of the vicinity of the electrical resistance type sonde attachment part, Figure 2
The figure is a cross-sectional view of the sonde section taken along the line ■-■ in FIG. 1.

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 device that detects electrical resistance values at the same boundary surface of the sintered ore 10b by measuring time differences, and the temperature characteristics of electrical resistance are affected by poor insulation due to adhesion of charged raw material powder or deterioration of the insulator 14. Therefore, it is not always possible to make accurate measurements, and for measurement, the electrode 15 is
It is necessary to protrude toward the 0 side, which causes a problem of significant wear.

FIG. 3 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. This is a device designed to estimate the unloading speed, and the accuracy is not good due to the phenomenon of raw material flowing in. Note that instead of hanging the weight 16, there is also a device that transmits microwaves from the top of the furnace to the top of the charging material and measures the distance, but this device is similar in that the unloading speed is estimated. There is a problem with accuracy.

FIG. 4 is a schematic diagram showing the vicinity of a sensor mounting part of a magnetic sensor type. In the magnetic sensor method, a magnetic sensor 11 is installed inside the blast furnace wall 2, and coke 10a in the blast furnace charging material 10,
This is a device that measures sintered ore 10b using the difference in magnetic permeability of ore. 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, when measuring with this device, it is possible to detect in the relatively low-temperature area near the top of the blast furnace, but it is difficult to detect in the high-temperature area from the middle to the bottom of the shaft, which is directly involved in blast furnace operation, because the magnetic permeability decreases. Also, when the charging raw material IO is unloaded, coke 1 is generated near the furnace wall due to the wall effect.
Since 0a, sintered ore 10b, etc. are mixed, measurement errors are likely to occur.

Therefore, when such a detection device is used, it is difficult to accurately measure the unloading speed in a range extending from the top of the furnace to the lower middle of the high-temperature shaft, and it is hard to say that stable operation can be achieved.

The present invention has been made in order to eliminate the second drawback of "Measurement of unloading speed". When the incoming raw materials are unloaded, the tip of the receiver protrudes further inside the mixed layer near the furnace wall due to the wall effect, and the microwave energy radiated from the charged raw materials is captured. An object of the present invention is to provide a behavior detection device for raw material input into a blast furnace that accurately detects behavior.

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 coke and the broken line showing the case of sintered ore. 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 (1).

Therefore, the measured μ wave radiant energy value P is as follows (1
, by substituting into equation 1, the brightness temperature T of the surface of the charging material
B('K) is calculated.

P=to -TO・Δf...(1) However, K: Boltzmann's constant 1.38X10 (J/'K) Δf: In the micro frequency band (Hz) Also, the brightness temperature TB is calculated by the following formula (2) By substituting the calculated TB value into equation (2), the charging material temperature T is calculated.

TB = ε・T ... (2) However, ε: emissivity (=radiant energy from the surface of the charging material temperature T/radiant energy from the black body at the charging material temperature T) In other words, the charging material temperature T has a relationship with the μ-wave radiation 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. Figure 6 shows the relationship between

In Figure 6, the horizontal axis shows the charging material temperature (°K) and the vertical axis shows the brightness temperature (°K), marked with a circle.

The O mark, 0 mark, and ・ mark have particle diameters of 7 mm and 20 mm, respectively.
50mm, ・70mm coke, Δ mark, A mark, Mu mark have particle size of 7 mm, 20nun, 50+no respectively
+ indicates sintered ore, 0 mark indicates Hamasley, ■ mark indicates powder sintering, and l mark indicates mixed sintering. This figure shows that there is a sufficiently large difference in brightness temperature above about 800°. 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 apparatus of the present invention will be specifically explained below based on the drawings.

FIG. 7 is a schematic diagram showing an embodiment of the present invention, and 1 in the figure indicates a blast furnace. In the blast furnace 1, coke 10a and sintered ore 10b are alternately stacked and charged as charging materials 10, and the charging materials 10 are melted in the lower part of the blast furnace 1 (not shown in the figure). It is moving downward under its own weight. At this time, the charging raw material 10 is mixed by the wall effect of the furnace wall 2, and the coke 10a and the sintered ore 1 are about 200 to 300 mm from the furnace wall 2.
0b to form a mixed layer 10c.

A large number of mounting holes are arranged in the circumferential direction of the furnace wall 2 in the height direction, and two in the height direction are shown in the drawing. It is formed as follows. In the mounting holes 31 and 32, there is a receiving section 4 configured as follows.
1.42 is penetrated, and the receiving portion 41.42 can advance and retract in the radial direction of the furnace. The receiving sections 41 and 42 have a double tube structure, and the inner tubes thereof are waveguides 41a and 42a for guiding the μ-wave radiation energy from the charged raw material 10.

The tip thereof is located 50 to 100 mm or more closer to the core than the mixed layer 10c. The opening at the tip is closed with a lid 7 made of a refractory material (for example, 3i02 porous brick) through which μ waves can pass, so that the charging raw material 10 cannot enter. Cooling water is passed between the outer tubes 41b, 42b and the waveguides 41a, 42a to cool the receiving section 41.42, and the waveguides 41a, 42a
The inside of 42a is under positive pressure due to N2 gas. For this reason, the receiving parts 41 and 42 can be installed even in the high-temperature part inside the lower part of the blast furnace 1, and even if a part of the lid 7 is damaged, the N2 gas pressure inside the receiving part is higher than the pressure inside the furnace, so the N2 Geometer 51゜52 where gas blows out into the furnace wall and the reducing gas inside the furnace generates μ waves.
There is no inflow into the area.

Receiving sections 41 and 42 configured and arranged in this way
The μ wave radiant energy emitted by the charging raw material 10 passes through the waveguides 41a and 42a.
The detected signals are detected by the antennas 41c, 42c coupled to the outer ends of the μ-wave geometers 51.
52. Various types of μ wave geometers 51, 52 are known, such as a Dicksky type radiometer and a 1-tal power type radiometer. The μ-wave geometers 51 and 52 are connected to a calculator 6, and the calculator 6 calculates the temperature two-layer thickness ratio, unloading speed, and distribution as follows based on the signals sent from the radiometers 51 and 52. Detect it like this. 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 through the front surface of the receiving section 41, 42 of each radiometer 51, 52 are calculated using the above formula (1). By substituting the difference between the two brightness temperatures TB (brightness temperature difference) obtained by substituting into Calculate T.

The layer thickness ratio is calculated as follows by measuring the μ wave radiation energy over time using radiometers 51 and 52. 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, when the coke 10a N passes through the front surface of the receiver 41, 42, the energy level is low, and conversely, when the sintered ore 10b N passes, the energy level appears high, so the measurement time is low energy. By calculating the ratio of high energy measurement time ts to tc, coke 1
The ratio of the layer thickness of sintered ore 10b to the layer thickness of 0a, that is, the layer thickness ratio can be detected. 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 radiant energy changes from + flash to partial.

Regarding the unloading speed, the front surfaces of the receiving parts 41 and 42 whose separation distance (L) is known are the coke 10a and the sintered ore 10b.
The μ-wave radiation energy emitted by is measured for a predetermined period of time, and calculated as follows. FIG. 9 shows the measurement results with time (1) plotted on the horizontal axis and μ-wave radiation energy on the vertical axis. As a result, the upper side shows the measurement results in the receiving section 41, and the respective μ-wave radiation energies appear at the boundaries in the same manner as in FIG. 8, and are maximum or minimum at the center in the thickness direction of each raw material layer. Therefore coke 1
Measurement time difference Δ between the interface between 0a N and the sintered ore 10b layer or the center of one layer using the radiometers 51 and 52
t, the receiving section 41. of the μ-wave geometer 51.52.
42 distance I7 is used to calculate the unloading speed. This time difference Δt may be determined by a method similar to the above-mentioned method or from the peak value of the remeasurement result.

Regarding the temperature distribution, the distribution in the blast furnace height direction is based on the μ wave radiant energy P measured by radiometers 51 and 52 connected to receiving sections 41 and 42 of different mounting heights arranged on the furnace wall 2 of the blast furnace 1, respectively. It can be obtained by substituting the values into the above equation (3) and arranging them in the height direction. The temperature distribution in the radial direction is obtained based on the μ wave radiant energy value detected by protruding the tips of the receiving parts 41 and 42 from the furnace wall 2 by a required length, and the temperature distribution in the circumferential direction is obtained by It is obtained based on the μ wave radiant energy values obtained by a plurality of receivers arranged at regular intervals on the furnace wall 2.

As for the particle size distribution, since the brightness temperature changes depending on the particle size as shown in FIG. 6, this can be used to determine the particle size distribution.

In other words, as can be seen from this figure, the brightness temperature changes with the temperature of the charging material, and in the case of coke, the brightness temperature differs even at the same temperature due to the difference in particle size, and the temperature of the charging material T Since there is a certain relationship between the brightness temperature TB and the fit
The brightness temperature TB is determined by the formula, and the coke particle size distribution can be determined based on this brightness temperature and FIG.

Note that the receiving section 41. used in the present invention. , 42 are water-cooled and can withstand high temperatures and loads. Since the opening at the tip of the waveguide is closed with a refractory lid with high μ-wave transmittance, measurement errors due to clogging of the charging material can be avoided. There is no corrosion and stable detection is possible over a long period of time.

Next, another embodiment of the present invention will be described based on FIGS. 10 and 11.

FIG. 10 is a schematic diagram of a device having a plurality of waveguides, for example, five waveguides in one receiving section, and parts similar to those shown in FIG. 7 above are given the same numbers. be. The receiving section 43 of this device is water-cooled and is inserted into the furnace wall 2 so as to penetrate through the furnace wall 2.
are attached to the five waveguides 43a, 43a.
···have. The waveguides 43a, 43a-
Tip #43d, 43e, 43f, 43g
, 43h are provided on the lower side inside the furnace wall 2 of the receiving part 43 so that the tip 43d closer to the furnace wall 2 is inside the mixed layer 10c, and each tip opening is closed by a lid 7 that can transmit μ waves. has been done. The μ-waves transmitted through each image 7 are alternately sent to the μ-wave geometer 53 by the waveguide switch 8, and the output signal of the μ-wave geometer 53 is given to the arithmetic unit 61. The computing unit 61 detects the behavior of the charged raw material based on the input signal. The apparatus of the present invention configured in this manner can detect the behavior of the raw material 2 in the radial direction within the furnace, such as the gradient of the charged raw material in the radial direction of the furnace, as shown in FIG. 10, with one receiving section. Further, by arranging this in one circumferential direction in the height direction of the furnace, it is possible to obtain results similar to those detected by the apparatus shown in FIG.

FIG. 11 is a schematic diagram of an apparatus using a gas sampling sonde as a receiving section. In this device, a water-cooled sonde 44 for gas sampling inside the furnace is also used as a waveguide, and a three-way tube 92 is installed at the proximal end of the sonde 44 outside the furnace, and a geometer with μ waves on the straight direction side of the μ waves is installed. 54, a gas analyzer 91 is connected to one branch side, and the μ-wave transmitting geometer 54 side of the three-way tube 92 is closed with a μ-wave transparent lid 7.
The gas is made to flow only toward the gas analyzer 91, and the micro-waves can be measured by the micro-wave geometer 54, so that the behavior is detected by the computing unit 62. Therefore, this device allows gas analysis and raw material behavior detection at the same location.

As described in detail above, the apparatus for detecting the behavior of raw material charged in a blast furnace according to the present invention penetrates the furnace wall in order to receive the microwave band radiant energy emitted by the charged raw material, and its tip protrudes for a required length from the inner surface of the furnace wall. At the same time, the opening is closed with a microwave-transparent lid, and there is also a receiving section on the section equipped with a cooling means, a radiometer that measures the received radiant energy, and a radiometer that measures the behavior of the charged material based on the measurement results. The behavior of the charging material can be accurately detected without receiving microwaves from the mixed layer, and the lid that closes the opening prevents the inflow of reducing gas into the furnace. Moreover, since the receiving part is cooled, the receiving part is strong against the furnace atmosphere (stable detection can be performed for a long period of time, and furthermore, blast furnace operation can be performed stably based on the detection results, etc.). It has a great effect.

[Brief explanation of drawings]

Figures 1, 2, 3, and 4 are schematic diagrams showing the measurement contents of the unloading speed using conventional equipment, and Figure 5 is the relationship between the temperature of each blast furnace charging material and μ-wave radiant energy. FIG. 6 is a graph showing the relationship between the temperature and brightness temperature of each blast furnace charging material, FIG. 7 is a schematic diagram showing an example of the present invention, and FIG. Figure 9 is a graph showing the measured μ-wave radiation energy.
FIGS. 10 and 11 are schematic diagrams showing other embodiments of the present invention. 1... Blast furnace 2... Furnace wall 41.42.43.44
...Receiving section IO...Charging raw material patent Applicant: Sumitomo Metal Industries, Ltd. ゛Representative: Patent attorney Noboru Kono 5 Imo Ikuni'' /U Kaya? Concave v3 Fig. G /l Fig. 4 - Inseriji; ML degree (°) No. 1

Claims (1)

[Claims] 1. In a device that detects the behavior of raw materials stacked and charged in a blast furnace, the furnace wall is penetrated in order to receive the microwave band radiant energy emitted by the charged raw materials, and the tip is inserted for a required length from the inner surface of the furnace wall. It protrudes and the opening is closed with a microwave-transparent lid, and it also has a cylindrical receiver equipped with a cooling means, a radiometer that measures the received radiant energy, and a radiometer that measures the charging material based on the measurement results. A behavior detection device for raw material input into a blast furnace, characterized by comprising a computing unit for detecting behavior.