JPH06271915A - Bell-less charging device in blast furnace - Google Patents

Abstract

PURPOSE:To execute multi-divided charge of raw materials into a blast furnace with good controllability by arranging plural sets of respectively two kinds of hoppers of large and small sizes having different capacities at the furnace top in the blast furnace and executing the raw material charging by combining main raw material with a small quantity of raw material. CONSTITUTION:Two sets of the large hoppers 5 for receiving the main raw material to be charged and two sets of the small hoppers 6 for receiving a small quantity of raw material to be charged are arranged at symmetrical positions at the furnace top part in the furnace body 1 so as to be able to dividedly charge the raw materials into the furnace through a turning chute 3. By this method, at the time of dividedly charging the raw materials consisting of the main raw material and a small quantity of the other raw material, the max. charging quantity per one time of the main raw material to be charged is secured with the large capacity hoppers 5, and also, a pressure-equalizing time can be shortened with the small capacity hoppers 6 for a small quantity of the raw material to be charged.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a blast-furnace bellless charging apparatus suitable for carrying out divided charging of a main material and a small amount of raw material in combination.

[0002]

2. Description of the Related Art A blast furnace top charging device has been changed from a conventional bell type to a bellless type, which has excellent charge distribution controllability. A typical bellless charging device is shown in FIGS. 4, 5 and 6. FIG. 4 shows a system in which two hoppers 4a are installed in parallel, but the raw material discharged from the left and right hoppers 4a falls onto the swirling chute 3 and the circumferential balance is poor, and the distribution of the raw material 2 in the furnace becomes uneven. It has drawbacks. Note that FIG. 4A is a schematic explanatory view, and FIG. 4B shows the arrow a of FIG. 4A.

Therefore, as shown in FIG. 5, two hoppers 4 are provided.
There has been proposed a device in which b is coaxially arranged vertically and the raw material discharged from the hopper 4b falls on the swivel chute 3 to improve the circumferential balance controllability. Note that FIG. 5A is a schematic explanatory view, and FIG. 5B shows the arrow b of FIG. 5A.
Since all of these have two hoppers, it is difficult to arbitrarily charge a large number of brands of ore, coke, etc. Even if they are carried out, a waiting time for charging is required, which hinders the production capacity.

For the purpose of improving the above-mentioned drawbacks, Japanese Patent Laid-Open No.
No. 103804 and Japanese Patent Laid-Open No. 63-100113 propose a bellless device in which three hoppers 4c are arranged in parallel as shown in FIG. Note that FIG. 6A is a schematic explanatory view, and FIG. 6B shows the arrow c of FIG. 6A. Figure 7 shows an image of the state of charging raw materials into the furnace. FIG. 7 shows a mainstream charging situation by the swirling chute 3 when the bellless device is initially installed in the left half of the furnace body 1.
The right half shows the recent state of raw material charging by the raw material split charging method. That is, as shown in the left half, the different raw materials 2a and 2b were initially charged in layers and charged to one charge.
Fuel ratio improved by dividing the raw material as shown in the right half of low-grade material used up purposes, it has become _{2c 1, 2c 2, ... 2c} 5 in 1 charge. Moreover, in this case, the main charging material and the small amount charging material are combined and charged.

[0005]

By the way, since the top of the blast furnace operates at a pressure higher than atmospheric pressure, that is, so-called high pressure operation,
At the time of charging the raw materials, even if a small amount of raw material is charged, it is necessary to operate the uniform discharge pressure in the hopper. Therefore, the more the raw materials are dividedly charged, the longer the charging takes, and the number of charging charges decreases. Therefore, the merits of the three hoppers are canceled out every time, and a situation arises in which only the number of loadings of the two hoppers can be earned during the split charging.

The present invention has been made in view of the above circumstances, and when the raw material is dividedly charged in such a manner that the limited space at the top of the blast furnace is effectively used and a main charging material and a small charging material are combined. It is an object of the present invention to provide a bellless charging device for a blast furnace, which is capable of shortening the uniform discharge pressure time of a small amount of charged raw material while ensuring the hopper capacity of the main charged raw material.

[0007]

According to the present invention for achieving the above object, at least two hoppers of different sizes, each of which has a different capacity and is capable of arbitrarily supplying a raw material into the furnace of the blast furnace, are installed at the top of the blast furnace. However, the large capacity hopper secures the maximum amount of charge for each main charge material in the case of divided material charge in which the main charge material and the small amount charge material are combined, and the small capacity applied to the small amount charge material. A bellless charging device for a blast furnace, characterized in that it is constituted by a hopper so as to shorten the uniform discharge pressure time.

[0008]

FIG. 2 shows a time schedule when five, four and three hoppers are installed and the raw materials are charged in five parts. In the case of the 5 hopper shown in FIG. 2, the charging time and the discharging time of the main charging coke C to the No. 1 hopper are 120 seconds respectively, and the charging time and the discharging time of the small amount coke Co to the No. 2 hopper are 30 seconds respectively. Charge No. 3 hopper into the main ore O ₁ and discharge time 120
And second, to No4 hopper medium weight loading ore O _s a charging and discharging time of 60 seconds each, when further No5 hopper into a small amount charging ore O _ss the charging and discharging time was assumed to respectively 30 seconds The time required for one charge was calculated. In this case, the pressure equalization time of each hopper was 20 seconds and the pressure exhaustion time was 40 seconds.
It became 60 seconds / ch (= 240 ch / day).

Similarly, in the case of 4 hoppers as well, if the capacity of each hopper is increased, the time required for 1 charge by 5 divided charges can be 360 seconds, but if the 3 divided hoppers are used for 5 divided charges, the loss time is lost. Therefore, the time required for one charge is 450 seconds (192ch
/ Day). FIG. 3 is a plan view of what kind of hopper arrangement is possible in a limited square space at the top of the blast furnace. First, Fig. 3
Assuming that the diameter D of the circle passing through the respective center points of the three hoppers is constant with reference to the three hoppers shown in (1a) of (1a), as shown in (1b) to (1d) of FIG. Although the number is increased to 4 to 6, in this case, a hopper having the same size as the 3 hopper cannot be obtained.

Although (2a) of FIG. 3 is based on three hoppers, the diameter D of the circle passing through each center point of the hopper is made variable, as shown in (2b) to (2d) in the space. When the number of hoppers of the same size is increased to 4 to 6,
Only the four hopper (2b) can secure a larger hopper size than the three hopper (2a). (3 in FIG.
(a) to (3d) show how the maximum hopper becomes when two types of hoppers, large and small, are arranged and the diameter D of the circle passing through the center point of each hopper is made substantially constant. In the figures (3b) and (3d), the hoppers are arranged symmetrically, but (3
Since a) and (3c) are asymmetrical, as a furnace top charging device, a total of two different size hoppers are symmetrically combined as compared with (3a) and (3c) of FIG. Of (3
b) and (3d) are preferable.

From the results of the examination of the time schedule for the divided material charging to the hoppers shown in FIG. 2, the charging time is limited when the number of hoppers is 3, and the number of chargings cannot be earned. It is possible to increase the number of insertions and increase the size of the single hopper in (2b) and FIG.
As for (3b), it can be understood that not only is (3b) of FIG. 3 equipped with a small hopper advantageous in view of construction cost, considering the uniform discharge pressure time.

Further, as shown by the dotted line in (3b) of FIG. 3, both the large hopper and the small hopper may have a large capacity, and it is possible to install a large capacity hopper of a size comparable to the conventional one in a narrow space. It will be possible.

[0013]

Embodiments of the present invention will be described below with reference to the drawings. 1A is a schematic cross-sectional view of the device of the present invention, and FIG. 1B is a cross-sectional view taken along the line AA of FIG. 1A. As shown in FIGS. 1 (a) and 1 (b), two large hoppers 5 for receiving a main charging raw material and two small hoppers 6 for receiving a small charging raw material are provided at the top of the furnace body 1. The raw materials are arranged symmetrically one by one, and the raw materials are dividedly charged into the furnace through the swirling chute 3 according to a predetermined schedule.

The image of the raw material in the furnace dividedly charged into the furnace is as follows. For example, the divided charging such as the five-divided charging shown on the right side of FIG. A wide variety of charging patterns are performed depending on the characteristics of the blast furnace. According to the present invention, the large-capacity hopper 5 ensures the maximum charging amount per operation, and the small-capacity hopper 6 has a small capacity, so that the furnace inside the hopper 6 is performed every time raw material is received and paid. It is possible to shorten the time required for equalizing the exhaust pressure when the pressure is equalized with the internal pressure or when the exhaust pressure is returned to the atmospheric pressure.

Further, at the time of the conventional 2-batch 1-charge charging, it is possible to operate without using a small hopper,
It is also possible to mix and charge two or three specific raw materials at the same time. Table 1 shows the controllability and the number of times of charging at the time of charging the multi-divided raw materials according to the hopper type of the conventional example and the example of the present invention.

[0016]

[Table 1]

As shown in Table 1, according to the present invention, not only is the controllability of the raw material into the blast furnace better than in the prior art, but the number of times the raw material is divided and charged can be increased.

[0018]

As described above, according to the apparatus of the present invention, it is possible to charge the multi-divided raw material into the blast furnace with good controllability, so that the use ratio of low-grade raw material can be improved and the fuel ratio can be reduced Reduction of hot metal cost is achieved and great advantages are obtained.

[Brief description of drawings]

FIG. 1 is a schematic explanatory view showing an apparatus of the present invention.

FIG. 2 is a flow chart showing a schedule for each hopper type of the present invention.

FIG. 3 is a plan view showing an arrangement of hoppers.

FIG. 4 is a schematic explanatory view showing a conventional example of two juxtaposed hoppers.

FIG. 5 is a schematic explanatory view showing a conventional example of a double-stacked hopper.

FIG. 6 is a schematic explanatory view showing a conventional example of three juxtaposed hoppers.

FIG. 7 is an explanatory diagram showing a raw material charging pattern into the furnace.

[Explanation of symbols]

 1 Furnace body 2 Raw material 3 Revolving chute 4 Hopper 5 Large hopper 6 Small hopper

Continued Front Page (72) Inventor Masao Fujita 1-chome, Mizushima Kawasaki-dori, Kurashiki City, Okayama Prefecture (without street number) Kawasaki Steel Works Mizushima Works

Claims (1)

[Claims] 1. A raw material in which at least two hoppers of each of large and small sizes having different capacities capable of arbitrarily supplying raw materials into the blast furnace are installed at the top of the blast furnace, and a main charging material and a small charging material are combined. Main charging raw material in case of divided charging 1
A bellless charging device for a blast furnace, characterized in that the maximum charging amount per operation is ensured by a large capacity hopper, and the uniform discharging pressure time is shortened by a small capacity hopper that applies a small amount of raw material. .