JPH03180410A - Method for controlling bulky and powdery charging materials in vertical type furnace - Google Patents

Abstract

PURPOSE:To control powder ratio in charging material to a specific value and to make difficult to cause abnormal furnace condition by selecting number of frequency of a sieve for screening the charging material according to the analyzed result of grading grain size of the bulky and powdery charging materials. CONSTITUTION:By sintered ore sampling means arranged to the A point at outlet side of the quaternary screen 24 at outlet side of a grading apparatus and iron ore sampling means arranged to the B point at outlet side of the yard 25, the sintered ore, iron ore, etc., are sampled, respectively. For example, in the case of the sintered ore, the grain size in the sampled material is analyzed with the grain size analysis means, and based on this result, number of frequency of the sieve used for the sieve frequency selecting means is selected. This selected frequency signal is transmitted to frequency output means to control the number of revolution of a motor for screening means 27 through frequency control means. Then, these are screened and the charging material removed with these having grains size except of the prescribed grain size is conveyed to an ore vessel 10 at blast furnace 16 side. By this method, ratio of the charging material having grain size less then the prescribed grain size, is low and the abnormal furnace condition becomes difficult to cause.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a method for managing a lump powder charge for a vertical furnace.

[Prior art] Conventional management of lump powder charge in a vertical furnace involves, for example, sifting sintered ore sent from a sintering factory on an ore tank to separate coarse and fine sintered ore. They were placed in separate tanks, weighed, and cut out. At this time, the issue of balancing the amount of coarse grains and fine grains is A, but we have adopted the method of preparing two types of sieves with the same mesh but different opening areas, and switching them depending on the balance of ore stock. Was.

In addition to this method, there is also a method using a damper. This utilizes the classification effect at the conveyor transfer section, and has the advantage of low construction and running costs and easy balance control. There is no significant difference in classification accuracy compared to the sieving method.

・[Problem 8 to be solved by the invention] Both the conventional sieving method and the damper method described above cannot be switched freely depending on the quantity balance, and fine sintered ore that is below a predetermined standard inevitably falls into the vertical column. There are problems in that the deposition inclination angle becomes small when the particles are charged into the mold furnace, or that abnormal furnace conditions are likely to occur due to an increase in the number of small particles.

This invention was made to solve this problem, and by controlling the powder ratio of the burden material carried into the burden tank, the burden material having a particle size below a predetermined value is delivered to the vertical furnace. It is an object of the present invention to provide a method for managing bulk charges in a vertical furnace that prevents them from being charged and thereby makes it difficult to cause abnormal furnace conditions.

[Means for Solving the Problems] A method for managing a lump powder charge for a vertical furnace according to the present invention includes the steps of sampling the charge and analyzing its particle size, and sieving according to the analysis results. a step of selecting a frequency of vibration;
The method includes the step of sieving the charge at a selected frequency and transporting it to a tank on the side of the vertical furnace.

[Function] In this invention, the charge is sampled before the vertical furnace, its particle size is analyzed, and the charge is sieved at a frequency corresponding to the particle size to remove particles with a predetermined particle size or less. is eliminated to prevent the deposition inclination angle from becoming small when charged into a vertical furnace.

[Embodiment] FIG. 1 is a block diagram showing the configuration of an apparatus that implements a management method according to an embodiment of the present invention. In the figure, (1
), (2) is a charge sampling means, (3) is a particle size analysis means, (4> is a sieve frequency selection means, (5)
is a sieve frequency output means, and (6> is a sieve frequency control means).

FIG. 2 is an explanatory diagram showing a system for feeding charges to a blast furnace. In the figure, (10) is an ore tank, (13) is a coke tank, (14) is a coke measuring hopper (15) and a beam serving hopper, and (1B) is a blast furnace.

(20> is the sintering machine, (21> to (24) are the primary screen to 4th screen. (25> is the secondary crusher (26) is the yard, and (27) is the ore tank (10
The sieve placed in front of ) is the means.

The sintered ore sampling means (1) in FIG.
) are provided at eight points on the output side of the output side, and samples are taken at each point.

Next, the operation of the above-mentioned management device will be explained.

Sintered ore, iron ore, etc. are sampled at points A and B in FIG. 2 using the charge sampling means (1), (2), etc., respectively. Here, the case where sintered ore is sampled will be explained. The particle size analysis means (3) analyzes the particle size of the sampled material.

Next, the sieve frequency selection means <4> selects the frequency of the sieve to be used based on the analyzed particle size.

FIG. 3 is a diagram showing the relationship between the vibration frequency of the sieve and the particle size after sieving. As a result of analysis using particle size analysis means (3),
For example, if the amount of over 4■ is 31.1wt% and it is vibrated at the frequency shown, the proportion of over 4IIm on the output side will not change, but 4+
The one under am is 9.5 wt depending on its frequency.
, %, 8.9 wt, %, and 7.6 vt, %, and it can be seen that the proportions decreased to 4 hunders were eliminated. Therefore, by appropriately selecting the frequency according to the proportion of 41 m under, sintered ore under 41 m can be eliminated.

Therefore, for example, the frequency is set as follows depending on the ratio A of sintered ore of 4 cm or less in the particle size analysis means (3).

A < 10wt, %-1100rpI110v
t,%≦A<15vt,%-120Orpa
15vt,%≦A<201i1t,%-13
00 rpm The frequency signal selected by the sieve frequency selection means (4) is output to the sieve frequency output means (5), and the frequency output means (5) is outputted to the screen (27) via the sieve frequency control means (6). ) The vibration frequency of the screen is controlled by controlling the rotation of the vibration motor.

FIG. 4 is an external view of the screen (27). In the figure, (41) is the hopper, (42) is the screen part, and (4
3) is an undersized hopper. (44) is a belt conveyor that conveys the undersized sintered ore obtained through the undersized hopper (43) to the sintering factory. (45) is an oversize hopper (46) is a belt conveyor that conveys the oversized sintered ore obtained through the oversize hopper (45) to the ore tank (10) on the blast furnace side. (47) is a vibrator motor that vibrates the screen section.

The rotation speed of the motor (47) is controlled by the sieve frequency control means (6), the screen part (42) vibrates at the frequency selected by the sieve frequency selection means (4), and the screen part (42) vibrates at the frequency selected by the sieve frequency selection means (4). The sintered ore which has been put in has a particle size of less than a predetermined value depending on the mesh size and vibration frequency of the screen part (42), and falls into the undersize hopper (43>) through the mesh of the screen part (42>). The fine sintered ore that has fallen into the undersize hopper (43) is transported to the belt conveyor (4).
4) is returned to the sintering factory and reprocessed.

On the other hand, the sintered ore that did not fall at the screen section (42) reaches an overhopper (45), and is then transported by a belt conveyor (46) and stored in, for example, an ore tank (lO).

By appropriately selecting the vibration frequency of such a sieve according to its particle size, the sintered ore in the ore tank (lO) before the blast furnace is sintered to a predetermined particle size, in this example, fine particle size of 4 mm or less. The mine will be eliminated.

In addition, in the above embodiment, an example of sintered ore was explained, but the same applies to iron ore, and iron ore is stored in an ore tank (lO) by selecting the vibration frequency of the sieve depending on the particle size. , particles smaller than a predetermined particle size are excluded.

[Effects of the Invention] As described above, according to the present invention, sintered ore or iron ore is sampled before the vertical furnace, its particle size is analyzed, and the vibration frequency of the sieve is selected according to the particle size. Since particles with a particle size below a predetermined size are excluded, when the particles are charged into a vertical furnace, the proportion of particles with a particle size below a predetermined size is small, and the inclination angle of their accumulation becomes large. Therefore, abnormal reactor conditions are less likely to occur.

[Brief explanation of drawings]

Fig. 1 is a block diagram showing the configuration of a management device that implements a method according to an embodiment of the present invention, Fig. 2 is an explanatory diagram showing a system for feeding charge to a blast furnace, and Fig. 3 is a sieve FIG. 4 is a diagram showing the relationship between the frequency of vibration and the particle size after sieving, and FIG. 4 is an external view of the screen. In the figure, (1) and (2) are the charge sampling device, (3> is the particle size analysis means, (4> is the sieve frequency selection means, (5> is the sieve frequency output means, and (6) is the sieve. It is a frequency control means.

Claims (1)

[Claims] A step of sampling the charge and analyzing its particle size, a step of selecting a vibration frequency of the sieve according to the analysis result, and a step of sieving the charge at the selected vibration frequency. A method for managing a lump powder charge in a vertical furnace, comprising the step of transporting the lump powder charge to a tank on the side of the vertical furnace.