JPH02213405A - Method and apparatus for classifying and charging raw material in blast furnace - Google Patents

Abstract

PURPOSE:To improve raw material charging capacity by conveying the raw materials having different grain sizes at the same time, classifying them at lower part of head part in a charging belt conveyor and separately charging into top furnace hoppers in each grain size. CONSTITUTION:A classifying device 3-1 for raw material grain sizes is set at the lower part of the head part of the charging belt conveyor 1. The raw material 4 including two or more kinds of different grain sizes is conveyed with the charging belt conveyor 1 and divided into large grain diameter raw material 6 and small grain diameter raw material 5 with the classifying device 3-1 for raw material grain sizes. The small diameter raw material 5 is charged into the top furnace charging device hopper 10-1 or 10-2 and the large diameter raw material 6 is charged into the top furnace charging device hopper 11 or 12. By this method, change-over of the charging into the top furnace hopper is eliminated, and the productivity can be increased.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a method and apparatus for classifying and charging raw material particles in a blast furnace.

<Prior art> In general, raw materials are charged into the blast furnace using the top charging device of a blast furnace, since batch charging is performed using the equipment shown in Figures 6 and 7. The raw materials conveyed by the input belt conveyor are also supplied separately for each batch.

Traditionally, raw material distribution system at the furnace mouth? In order to control the gas flow on the furnace wall side and ensure the center flow in step 1, a method of controlling the raw material charging distribution to ensure a central flow is to thicken the ore layer and thin the coke layer on the furnace wall side. However, problems such as increased wind pressure inside the furnace, damage to the tuyeres, and deterioration of furnace conditions occur, so in recent years, ore and coke have been changed to larger particle sizes, in order to suppress the gas flow on the furnace wall without changing the layer thickness of ore and coke. A method has been adopted in which particles are divided into small particles and charged.

Therefore, when classifying and charging particles by particle size into a blast furnace, JP-A-55-
No. 62106, JP-A-55-28308, JP-A-56
As disclosed in Japanese Patent Publication No. 133405, the raw material is divided into large particles and small particles and is individually conveyed to a furnace top charging device by a charging belt conveyor, and then batch charged into a furnace top hopper.

If one charge of two batches of ore and coke is classified and charged in order to charge them according to particle size, the number of batches to be transported per 1 charge will increase depending on the number of divisions of ore and coke (4 to 6 Batch), the charging time for raw materials is extended, the charging capacity for raw materials is reduced, and the production volume is accordingly reduced.As a result, there are many cases in which charging classified by particle size is abandoned.

On the other hand, due to the raw material situation, there is no choice but to use raw materials that have smaller particle sizes, are cheaper, and are difficult to adjust the raw material distribution at the furnace mouth.

<Problems to be Solved by the Invention> The present invention solves the problem that the conventional blast furnace top charging technology has the problem that charging by particle size increases the material charging time and reduces the material charging capacity. , 2m to solve this problem!
A method for charging a blast furnace according to particle size without reducing the raw material charging capacity, rather than improving it, even when raw materials with different particle sizes of II or higher are simultaneously conveyed to the head of a charging belt conveyor, and the method thereof. This was done to provide a charging device.

Means for Solving the Problems> The present invention consists of: (1) When charging raw materials according to particle size into the top hoister of a blast furnace, two or more types of raw materials with different particle sizes are simultaneously conveyed by a charging belt conveyor; Classification and charging of raw materials in a blast furnace characterized by classifying raw materials into two or more types of different particle sizes using a raw material particle size classification device disposed below the head of a charging belt conveyor and charging the raw materials into a furnace top hopper according to particle size. method, and ■ A raw material particle size classification device is placed below the head of the charging belt conveyor, and further below the classified 2
This is a raw material classification and charging device for a blast furnace used in the method described in item 1 above, which is equipped with a furnace top hopper for receiving raw materials with different particle sizes.

Conventionally, when raw materials are classified and charged into a blast furnace by particle size, the raw materials are separated into large particle sizes and small particle sizes and are conveyed to the top of the furnace using a charging belt conveyor, and batches are transferred to the top hopper. However, in the present invention, raw materials of different particle sizes (large particle size, small particle size, etc.) are conveyed simultaneously on a charging heald conveyor, are classified under the charging belt conveyor head, and are continuously conveyed. Particles are charged to the furnace top hosiper according to particle size. Therefore, the operation time of the charging belt conveyor is increased, and since there is no need to switch charging to the furnace top hopper, the ability to charge raw materials to the blast furnace is improved.
In addition, raw materials can be classified and charged by particle size into the blast furnace.

The above-mentioned classification and charging of raw materials can be carried out by disposing a raw material particle size classification device below the head of the charging belt and a furnace top hopper that receives raw materials of different particle sizes below the device.

Also, when transporting raw materials on a charging belt conveyor,
On a conveyor, basically the upper layer has large particles of 1. Since small particles are distributed and conveyed to the lower layer, particle size classification can be performed by using a raw material particle size classification plate such as a tilting damper instead of a screen or the like as a raw material particle size classification device.

<Example> Fig. 1 is a cross-sectional view of a furnace top charging device showing the installation of the raw material particle size classification device of the present invention, in which the raw material particle size classification device 3-1 is installed below the head of the charging belt conveyor l. ing. A raw material 4 is conveyed by a charging belt conveyor 1, and is classified into large-particle raw materials 6 by a raw material particle size classification device 3-1 such as a sieve.
(For example, coke is 25-50ml, ore is 6-30m)
and smaller particle size raw materials 5. Small particle size raw materials 5
is the furnace top charging device hopper 1O-1 or 1O shown in Figure 2.
-2, the large particle diameter raw material 6 is charged into the furnace top charging device hopper 11 or 12.

Furthermore, in FIG. 3, instead of the raw material particle size classification device (screen or grizzly bar) 3-1 shown in FIG. It was shown that raw material particle size classification can be performed even if 3-2 is used. That is, the tilting damper 3-2 is used to classify large particles in the upper layer and small particles in the lower layer.

Furnace top hopper 10-1, 10-2, 11 of furnace top charging device
and 12 planar arrangements are shown in FIG.

FIG. 4 shows a raw material particle size classifier, whereas the raw material particle size classifier 3-1 in FIG. 1 and the raw material particle size classifier 3-2 in FIG. The state of the raw material particle size classifier 3-2 is shown in which the angle of the damper is adjusted to the right to classify large particles 6 from the main raw material 4 to a smaller number.

FIG. 5 is a plan layout diagram of the furnace top charging device hopper 10-3 into which a small number of large particles 6 of the grain size classified raw materials are placed and the furnace top charging device hopper 11.12 into which small particles 5 are placed. It was shown to.

More specific examples will be described below.

Blast furnace internal volume + 4,500 vol, tapped iron amount: 10,000 t
When charging 120 tons of ore and 34 L of coke in a /D blast furnace, conventionally, large particles and small particles were loaded separately on the furnace top charging conveyor, and then transported as is. For ore and coke, large particle size and small particle size were alternately charged into the top hopper of the furnace, so it took 520 hours from the start of charging into the furnace for one charge to the next charge. However, by applying the charging method of the present invention, there was no need to switch charging to the furnace top hopper, so charging into the furnace could be completed in 440 seconds.

Therefore, whereas conventionally only 166 charges could be charged per day, according to the present invention, up to 196 charges per day can be charged, as shown in Figure 10 (the production volume has also increased from the conventional 8880 7 days to toooo t 7 It is now possible to increase the number of days.

<Effects of the Invention> According to the present invention, as mentioned above, there is no need to switch charging to the top hopper, so the ability to charge raw materials to the blast furnace is improved rather than reduced, and the blast furnace can be charged separately by particle size. We were able to significantly increase production.

[Brief explanation of the drawing]

FIG. 1 is a schematic sectional view of a raw material classification and charging device according to the present invention, FIG. 2 is a cross-sectional view cut along the line A-A in FIG. 1, and FIGS. 3 and 4 are different embodiments of the present invention. A schematic sectional view showing an example, FIG.
Fig. 4 is a layout diagram of the furnace top hopper in the embodiment, Fig. 6 is a schematic sectional view of a conventional material classification and charging device, and Fig. 7 is a
The BB sectional view of FIG. 6 and FIG. 8 are characteristic diagrams showing the relationship between the amount of iron tapped and the number of times of charging. 14...Bellless gear unit, 15...Blast furnace, 16...Large particle diameter raw material chute, 17...Moving chute. DESCRIPTION OF SYMBOLS 1... Charging heald conveyor, 2... Charging B, C head pulley, 3-1... Raw material particle size classification device, 3-2... Raw material particle size classification plate, 4... Raw material, 5.
...Small particle size raw material, 6...Large particle size raw material, 7
...Particle size classifier lower chute, 8...Charging B, C head cover 9...Moving chute, 91...Moving chute, 9-2...Moving chute, 1O-1...Small particles Diameter raw material furnace top hopper 10-2...
Small particle diameter raw material furnace top hopper l0-3...Large particle diameter raw material furnace top hopper 11...Furnace top hopper, 12...
Furnace top hopper 13...lower collecting hopper

Claims (2)

[Claims] (1) When charging raw materials according to particle size into the top hopper of a blast furnace, two or more types of raw materials with different particle sizes are simultaneously conveyed by a charging belt conveyor and placed below the head of the charging belt conveyor. A method for classifying and charging raw materials in a blast furnace, characterized in that the raw materials are classified into two or more types of raw materials with different particle sizes using a raw material particle size classification device, and are charged into a furnace top hopper according to particle size. (2) Used in the method according to claim 1, further comprising a raw material particle size classification device below the head of the charging belt conveyor, and further below the furnace top hopper for receiving the classified raw materials with two or more different particle sizes. Blast furnace raw material classification and charging equipment.