JPS58218610A - Measuring method of layer thickness distribution for charged material of vertical furnace - Google Patents

Abstract

PURPOSE:To detect distribution of the layer thickness and the layer thickness ratio of charged material with high accuracy, by detecting a surface sectional shape of a charged material charged successively in a vertical furnace batchwise and performing a prescribed operational processing. CONSTITUTION:A laser beam 7 of a laser apparatus 6 is irradiated to the inside of a blast furnace 1 with a reflex mirror 9 and a reflected light 7a from the surface of a charged material 2 is detected by a photodetector 8. A surface sectional shape of the material 2 is measured by a light projection angle alpha of the beam 7, a photodetecting angle beta of the light 7a and a distance L between a light projection window 4 and a photodetecting window 5. A sedimentation velocity distribution dn of n-th time's charged material is found by the difference of a curve A-A of the surface sectional shape immediately after charging n-th time's charged material and a curve B-B of the remeasured surface sectional shape immediately before charging (n+1)-th time's charge and each difference of the measuring time. Next, a curve C-C of the surface sectional shape immediately after (n+1)-th time's charge is measured and B'=B+(tB- tC)dn is computed from its measuring time tC and a measuring time tB of the curve B-B. The layer thickness distribution of (n+1)-th charged material is found from the difference of both curves. The layer thickness ratio distribution is found by repeating said process.

Description

[Detailed Description of the Invention] The present invention... This method relates to a method for measuring the layer thickness distribution and layer thickness ratio distribution of the charge when the charge is charged layered in batches into a vertical (μ) furnace such as a melting steel furnace.

In the blast furnace. Detecting the layer thickness distribution and layer thickness 111 distribution of the charges charged one after another in batches is an important detection element in Operation-L. This layer thickness distribution and layer 11JJ
If the I Jls distribution can be detected with high accuracy, the operators of blast furnaces, etc. can Ideal layer j1,1 distribution: 1. By charging the charge with the layer thickness ratio distribution, the operational performance can be highly stabilized.

However, in the conventional method, there was no way to detect with high precision the layer thickness distribution and layer thickness ratio distribution of the charge required by operators of blast furnaces, etc. The required accuracy is equivalent to 111 uniform diameter of particles in one charge, in a blast furnace.

It is equivalent to ±30 ho. In addition, the measurement pitch needs to be several times the 1' average diameter of the particles in the charge, and in a steel melting furnace. 10
0-2 Q O 11M pitch is required.

3- Therefore, in the past, operators of blast furnaces created layers of the charge,
The charge is actually charged in a simulator of a device called a PW rotating charging device or a movable armor, and the layer thickness distribution and layer thickness ratio of the charge are determined by simulator experiments. We have operated by calculating the distribution and assuming that the same thing is happening in an actual blast furnace. As a means of directly detecting the charge in an actual blast furnace, only sounding measurements using mechanical weights at several points have been performed.

The present invention has been made by paying attention to the above-mentioned circumstances.

The purpose of this is to determine the surface cross-sectional shape (profile) of the charges that are sequentially charged in batches into a vertical furnace such as a blast furnace.
The present invention provides a method for directly detecting the layer thickness distribution and layer thickness ratio distribution of the charged material using the directly detected surface cross-sectional shape using the method described below.

The present invention will be explained below with reference to an embodiment shown in the drawings. I will clarify.

In this example, the method for detecting the layer thickness distribution and layer thickness ratio distribution of the charge was applied to a blast furnace equipped with a so-called laser-type profile meter that uses a laser to detect the cross-sectional shape of the surface of the charge. This is what I did.

Figure 1 is a schematic diagram of a blast furnace equipped with a laser type profilometer as described in 2. In the figure, 1 is an internal wall with 30 walls.
1 is an inclined surface with a constriction 1 at the top, and a light emitting window 1 and a light receiving window 5 are provided on this slanted surface, for example, facing each other through the inside of the blast furnace. At this time, the distance L between the light emitting window 4 and the light receiving window 5 is determined in advance by h. Ru.

”The second floodlight window 4 is. This is for projecting laser light 7 from a laser device 6 provided outside the blast furnace main body l into the blast furnace. On the other hand, the light receiving window 5 is composed of a light receiving lens, and the laser beam 7 diffusely reflected on the surface of the charge 2 in the blast furnace main body l.
The light is focused and guided to the photodetector 8.

In a blast furnace equipped with such a laser type profile meter, the laser beam 7 from the laser device 6 passes through an optical system such as a collimator (not shown) 7, and then is reflected by a reflecting mirror 9 to enter the inside of the blast furnace body 1. Irradiate. The diffusely reflected light 7a of the laser beam 7 from the surface of the charge 2 is focused by the light receiving lens of the light receiving window 5 and detected by the photodetector 8. And the projection angle α of the laser beam 7.

The so-called triangulation method is calculated using the acceptance angle β of the reflected light 7a and the distance L between the light emitting window 4 and the light receiving window 5, and the height of each part of the surface of the charge 2, in other words, the charge For example, the surface cross-sectional shape (profile) of
It is possible to obtain it in seconds.

By the way, n (any positive integer) measured in this way
A schematic representation of the surface cross-sectional shape immediately after the first charging is the A-'A cross-sectional curve in FIG.

Next, just before the (n+1)th charging, when re-measuring the surface cross-sectional shape of the n-th charge, it appears that the surface cross-sectional shape of the charge is below the A-A cross-sectional curve like the B-B cross-sectional curve because the charge has settled. The cross-sectional curve is expressed as .

The A-A cross-sectional curve and the B-B cross-sectional curve are the results of sedimentation caused by the irregular sedimentation velocity distribution in each location caused by the operating conditions of the -ft'F ore, not by simple horizontal movement. It is something that occurs. The approximate distribution shape of this sedimentation velocity distribution is as shown in Fig. 3, in which the sedimentation velocity is high in the furnace wall portion, and the sedimentation velocity is small in the furnace core portion.

Therefore, - is written A, - the difference between the A cross-sectional curve and the B-B cross-sectional curve, and 1. The settling velocity distribution dn(γ) of the n-th charge can be determined from the difference in measurement times.

Here, the radial position is c, and the A-Δ cross-sectional curve is A(γ).

If the B-B cross-section curve is 80'), /1-, the measurement time of the A-section curve is tA, and the measurement time of the B-13 cross-section curve is tB, then 0 times [1 person's sedimentation velocity distribution d, n
(γ) can be expressed as follows.

Next, after the (n+1)th charging surface, the surface cross-sectional shape of the (n+1)th charging is determined by 1lllll, and then C
-C cross-section curve is found 1. Ru. The C-C cross section curve is.

The cross-sectional curve is expressed on the B-1311i plane curve. On the other hand, it is expressed by the a-01Qr surface curve (n+
1) B at the time when the surface cross-sectional shape of the charged material was measured for the 7th time.
- The estimated surface cross-sectional shape of the n-th charge expressed by the B cross-sectional curve is corrected by the settling velocity distribution an(γ) of the n-th charge, and the estimated surface cross-sectional shape is the B'-B' cross-section. Express with a curve. Here, −Bl −B/cross-sectional curve is B′(γ), C
The measurement time of the −C cross-sectional curve is t. If so.

Bl-B+cross-sectional curve B'(γ) is determined by the following equation.

B'(γ)-B(γ)+ (tBtc)an(γ)C
The difference between the -C cross-sectional curve and the B+ -B/ cross-sectional curve determined by the above equation becomes the layer thickness distribution of the (n+1)th charge.

Since the layer thickness distribution of this charge is corrected using actually measured sedimentation velocity distribution data, it is possible to detect the layer thickness distribution with extremely high accuracy, making it possible to achieve the above-mentioned required accuracy equivalent to ±30 fins. I can do it.

In addition, although the sedimentation velocity distribution changes only to a negligible extent within a few minutes, it varies considerably depending on the operating conditions over a period of several tens of minutes, and detailed correction of the sedimentation velocity distribution based on actual measurements is extremely important. The above is a method for determining the layer thickness distribution of the charge with high accuracy.

8- Next, layer 1’b of the charge I will explain.

In No. 4121, the AA cross-sectional curve, the B-B cross-sectional curve, and the cc cross-sectional curve 1-3'-B' cross-sectional curve have the same definitions as in FIG. This is the cross-sectional curve.

With the above method, one layer thickness distribution is obtained as the difference between the CC cross-sectional curve and the B'-B' cross-sectional curve.

Next, the O-0 cross-sectional curve in Figure 4 is the A-A cross-sectional curve in Figure 2, the 1', -D cross-sectional curve in Figure 4 is the B-B cross-sectional curve in Figure 2, and the la is in Figure 4. -p: The cross-sectional curve is 0- in Figure 2.
0 cross section curve, D'-D' cross section curve in Figure 4, and 1 in Figure 2.
1'-13' section curve, and use the above method to obtain the fourth
Another layer thickness ratio distribution is obtained as the difference between the F-In cross-sectional curve and the D'-D' cross-sectional curve in the figure. These two consecutive
The layer thickness ratio distribution of the layer charge can be calculated as the ratio of the respective layer thicknesses of the two layers. The above is the method for determining the layer thickness ratio distribution of the charge.

As described above, a blast furnace is operated by charging coke and ore one after another in a Zandertsch shape to fill the blast furnace. Charging 19 = The ratio of coke to ore is extremely important as it is directly connected to the fuel consumption of the blast furnace. Too much coke is not good because it increases fuel consumption. Conversely, if there is less coke, the melting ability of the blast furnace will decrease.

Operational conditions become poor. Therefore, the ratio of coke to ore is
This is important from an energy saving and operational perspective, and the conventional macro management method has been to control the ratio of coke to ore based on the weight of the charge charged at one time.

Recently, there has been a shift toward micromanagement. In other words, micromanagement is aimed at ideally controlling the ratio of coke to ore in each part of the blast furnace.

The layer thickness of the coke and ore charges in the blast furnace is usually about several hundred layers, and the average particle size is about 3 layers. Therefore, the ideal accuracy required for layer thickness distribution and layer thickness ratio distribution is about ±30 lines.

If the method for detecting the layer thickness distribution and layer thickness ratio distribution of a charge according to the present invention is applied to a blast furnace, it becomes possible to perform the micro-management required by blast furnace operators as described above, thereby reducing fuel consumption and stabilizing operations. It has a huge 10-degree effect on reduction.

It should be noted that the present invention is not limited to the soil n1: example, but can be applied to each type of push needle.

Figure 4 rI'Ii (1) Simple 111 fr, if), 4 sets 11-1 is a schematic configuration diagram of a blast furnace equipped with a laser type P1-1 fill and a meter, Figure 2 is the surface cross-sectional shape of the charge 3S diagram t1 is a schematic diagram showing an example of the sedimentation velocity distribution of the charge, Figure 4 t: J is a schematic diagram of the surface cross-sectional shape of the mounting body, 1 1... Blast furnace main body 2. ...Charging material 3...Furnace wall 4...Light emission window 5...Light receiving window
6... Laser device 7... Laser light 7a
...Diffuse reflected light 8...Light detection Z 9...
Reflector A-A, II-I (, C-C', , I) River'
*li knee lj;... Actual surface cross-sectional shape 13'-II', r+'-D'... Sedimentation velocity distribution (
, Estimated surface cross-sectional shape after correction by 2-"L- 1st 60-

Claims (1)

[Scope of Claims] ■ The profile of a charge consisting mainly of ore and coke charged for the nth time into a vertical furnace and immediately before the (n+1)th charging is measured, and A method of determining the settling velocity distribution in the furnace of the nth charge from the difference between both profiles and the measurement time difference, and (n+
1) A method of measuring the profile of the (n+1)th charge immediately after the (n+1)th charging, and a method of measuring the profile of the nth charge immediately after the (n+1)th charging.
) Based on the measurement value before the charging time a, a method of estimating the sedimentation velocity distribution from the difference in time of profile measurement immediately before and immediately after the (n+1)th charging is provided; The layer thickness of the charge in a vertical furnace characterized by determining the layer thickness of the charge in the furnace from the profile of the charge and the (n+1)th measured value of the profile of the charge. Distribution measurement method. 2. The method for measuring the layer thickness distribution of a charge in a vertical furnace according to claim 1, wherein the profile of the charge is measured in real time using a profile meter operated by laser light. 3. A method for measuring the layer thickness distribution of the charge in a vertical furnace according to claim 1 or 2, characterized in that the layer thickness distribution of the charge is determined in the radial direction of the furnace through the furnace core. 4. Measurement of charge layer thickness distribution in a vertical furnace as set forth in claim 1.2 or 3., wherein the layer thickness distribution of the charge is measured for each type of charge. Method. 5. The layer thickness distribution of the charge is obtained by determining the adjacent ore layer and coke layer as a pair, and further determining the layer thickness ratio distribution of the ore layer/coke layer.
．． The method for measuring charge layer thickness distribution in a vertical furnace according to item 3 or 4. 2-