JPS58115351A - Measuring method of packing degree of sintered bed - Google Patents

Abstract

PURPOSE:To grasp a packing condition of a bed quickly by an on-line system extending nearly all over the area in a width direction continuously, by measuring a packing degree of the bed of powdered and granular raw materials by the intensity of radioactive rays of elements around the radioactive rays passing through said bed. CONSTITUTION:A bed 2 is formed on a pallet 1 of an icinearator and an RI 3 emitting radioactive rays is provided at its lower part and then, said RI 3 is housed in a housing closed vessel 4 serving both as shelter of the radioactive rays for each surroundings. The radioactive rays from the RI 3 are damped by the bed 2 passing through of a gap 7 of the bottom part of the pallet 1 and damped rays are reached at each measuring machine 8A, 8B, 8C, and 8D and then, the intensity of the radioactive rays is measured. The packing condition of the bed is grasped quickly by an on-line system extending over nearly all over the area in a width direction continuously by measuring a packing degree of the powdered and granular body bed 2.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for measuring the degree of filling of a sinter bed in a sintering operation.

Generally, in the Dwight Lloyd type completion method for producing sintered ore for blast furnaces, the coke in the bed is ignited by forced ventilation using the coke on the surface of a bed of granular material (hereinafter referred to as the bed) fed to a pallet as an ignition source. The combustion heat is used to sinter the fried powder granular raw material at high temperatures. The produced sintered ore has good or bad properties as a raw material for the furnace, and moths are also important in sintering work to stably produce sintered ore with good properties.

In order to produce sintered ore with good drawability, the raw materials to be used and their composition are important, but ultimately the filling state of the raw materials in the bed is important. In other words, in order to obtain sintered ore with good properties, the packing condition must be as uniform as possible in the length direction (the direction of bed movement) and the width direction of the pallet, or the overall packing density must be appropriate, that is, the porosity must be appropriate. These are conditions for stable production.

As mentioned above, the filling state of the bed is an essential requirement for producing good sintered ore, but conventionally it has been difficult to detect the filling state of the bed due to the following conditions, and there is no suitable method. Ta.

(a) The bed is moving along with the pallet.

(b) Since the maximum thickness of the bed is about 600 m, it is difficult to calculate the absolute value or comparative value of the filling state.

eC) Inserting a sensor into the bed disturbs the filling part of the bed and worsens the sintering problem, so the sensor cannot be used.

An object of the present invention is to solve the above-mentioned problems of the prior art, and to continuously check the filling state of the bed on-line without disturbing the filling state by continuously filling the filling area in the width direction. The object of the present invention is to provide a method for measuring the filling f of a sintering bed, which can quickly determine the filling f of a sintered bed.

The gist of the present invention is as follows.

That is, the powder and granule raw material is fed onto a pallet, ignited from the surface of the mosquito powder and granule raw material bed, and sintered by forced suction. This is a method for measuring the degree of filling of a sintering bed, characterized in that the degree of filling of the powder raw material bed is measured based on the radiation intensity of a radioactive isotope.

The radiation intensity of a radioisotope (hereinafter referred to as RI) is affected by attenuation due to the distance between the position of R1 and the radiation measuring device and attenuation due to shielding of a substance between the RI and the radiation measuring device. Attenuation due to distance is expressed by the following equation (r).

Dl='r:/4Kr,'
・(1) Here, DI: degree of attenuation due to distance (to) r: distance between the RI position and the radiation measuring device (an) r: radius of incidence of the radiation S measuring device (an) π: pi shielding Attenuation due to objects can be expressed using the following equation.

1) 1=6-DμtxI
...(2) Here, Dl: degree of attenuation due to shielding object (
c) 6 1718 μI: Linear absorption coefficient of material i (an-”) is expressed by the following equation (3).

D=D1 xD, ...0) Here, D: Total attenuation (to) Therefore, if the distance rl between the RI position and the radiation measuring device is kept constant, the change in the total attenuation will be due to the shielding object. Destruction 1
Since RritD* is determined by equation 0), the change in the absorption coefficient of material i in equation (2) and the thickness xl of material i It depends on K.

Current general sintering operations involve rounding to produce sintered ore with the same properties, using the same mixed raw materials for a certain period of time, and operating with the same bed thickness, that is, the layer thickness. . Therefore, within that period, if a radiation measuring device is installed above the bed and an RI is installed below the bed, the change in attenuation due to the shielding object, that is, the bed, will be affected by the material that makes up the linear absorption coefficient μt, that is, the powder. Since it depends on the change in the total thickness of the granular raw material, f-=D&i, it ultimately corresponds to a change in the true thickness of the granular raw material that accounts for the layer thickness of the bed, that is, a change in the degree of filling of the bed. .

The present invention measures the filling ft of a sintering bed by utilizing the fact that changes in the degree of attenuation of radiation are caused by changes in the degree of filling of the granular material in the bed as described above.

The details of the present invention will be explained by way of an II argument. First, the apparatus used in the present invention will be described. #! Figure 1 is a cross-sectional view showing four sets of measuring devices arranged in the width direction of the pallet, and Figure 2 is a longitudinal cross-sectional view taken along the line -1 in Figure 1. Pallet 1 of the sintering machine. A bed 2 is formed above, and an RI 3 that emits radiation is installed below it.
As shown in the enlarged view of the figure, each of them is housed in a containment container 4 which also serves as a radiation shield to the surrounding area. A transparent glass 5 is fixed to the upper part of the containment vessel 4 with screws 6.
The radiation of RIa is emitted only upward, and the structure is such that it is shielded from below and in the horizontal direction. There is a gap 7 at the bottom of the pallet 1 through which radiation can pass, and above the bed 2 there are radiation measuring machines 8 at positions corresponding to the lower RIs 3.
A, 8B, 8C.

8D is installed. Note that a cut 9 is installed above the bed 2 in FIG. 2 to level the surface of the bed 2.

Next, a method of measuring the degree of filling of the present invention using the above-mentioned device will be explained. The radiation from RI3 is between the bottom of pallet 1 P
J7 and is attenuated by bed 2, each measuring machine 8
A, 8B, 8C, 8DKB.

The intensity of the radiation is measured. Measuring machines 8A and 8B.

The nine radiations incident on 8C and 8D are directly below RI3, respectively.
Although it is possible that the incidence is from RI3 other than the one directly below,
The radiation from No. 13 is affected by the following three salt mountains: 0) Increase in attenuation due to increasing distance (b) Increase in attenuation due to tilted incident angle and apparent thickening of the enclosing material (c) It is thought that there is almost no influence of RIa other than directly below due to the decrease in incidence efficiency due to the incidence surface not facing directly, so the measured radiation intensity will affect the filling car of bed 2 between LI3 and measurement 118) It can be considered that it has been done. The nine RIBs used were 1@Co1mci in consideration of the relationship between the bed filling car and the measured radiation intensity, equipment maintenance, prevention of radiation damage, etc.

The filling car is obtained by determining the relationship between the filling car and the measured count number of radiation for the same layer thickness □ in an experimental sintering machine in advance, and converting it from the measured value. Figure 4 shows a layer thickness of 500m.
This is an example showing the relationship between the filling car and the measured count number in n.

Round can measuring machine 8A determined by the above method. 8B.

Filling cars of sC and 8D are pronated as shown in WX5, lc'1. 9 shown in ■. Figure 5 0 to measuring device 8
It can be seen from FIG. 5) that the filling car of the bed of C has little fluctuation, and the filling car of the bed of the measuring machine 8A has a lot of fluctuation. However, as a whole, the filling car of the bed is maintained within an appropriate range, so the shutter strength (8
, 1,) was 90-91 and #) D storm quality.

The following Figures 6 to 8 show the average values of the filling cars at four locations in the width direction of the bed, but in the case of Figure 6, the filling car decreases, the porosity increases, and the The difference also became relatively large, so the cut 9 was lowered to increase the amount of cut. As a result, the filling car rose and ventilation improved, and the production volume did not change, but the shutter strength (8, 1,) Fi 86-88 increased to 88-89 by taking measures. Figure 7 shows that the filling car of the bed rises, the production volume increases, and the shutter strength (8, 1,) decreases. increased and the production volume was within control.

In the case of Figure @8, the filling car of the bed rose similarly, but the production volume did not change, and the shutter strength (8, 1,) did not change either, so the cutting amount was reduced. As a result, ventilation is improved and shutter strength is further improved.

As is clear from the above embodiments, the present invention uses radioactive isotopes to measure and manage the filling car of the sintering machine bed, enables early implementation of countermeasures against abnormalities, and improves the quality and production of sintered ore. We were able to achieve the effect of stably achieving the amount.

[Brief explanation of drawings]

Figure WIJ1 is a cross-sectional view of a pallet showing the arrangement of the measuring device in the present invention, Figure 2 is a vertical cross-sectional view taken along the line I-1 of the llsl figure, and Figure 3 is an enlarged cross-sectional view showing the RI storage container in the present invention. Figure 4 is a diagram showing the relationship between the radiation measurement count number and the filling car of the present invention, Part 5, @, (C1
, ([) are diagrams showing temporal fluctuations of each filling car of the measurement mechanism in the example, and Figures 6, 7, and 8 are averages of four locations in the bed width direction in the example. FIG. 3 is a diagram showing temporal fluctuations in a filling car. 1... Pallet 2... Powder raw material pane 3... Radioactive isotope 8... Radiation measuring machine agent Takeo Nakaji Figure 1 ■ 1 ■ Figure 2, °# Chapter Figure 4: J'l constant count & (C, P, m,) Figure 5: Fll (h)

Claims (1)

[Claims] (1) On a pallet 4: In a method for sintering powder and granular material in which granular material is fed, ignited from the surface of the granular material bed, and sintered by forced suction, passing through the granular material bed. A method for measuring the degree of filling of a sintering bed in which the degree of filling of the granular raw material bed is measured as a percentage by the radiation intensity of a radioactive isotope.