JPS62218506A - Method for charging raw material to bell-less type blast furnace top hopper - Google Patents

Abstract

PURPOSE:To make the service life of two units of stationary hopper approximately equal and to assure the service life as a whole by alternately charging the ore and relatively soft coke to be carried in by two units of skip cars dividedly to the two stationary hopper according to a prescribed repetitive pattern. CONSTITUTION:The raw materials are charged from the skip cars 2-I, 2-II via a moving receiving chute 5 to two units of the right and left stationary hopper 6a, 6b by the method shown in the table. More specifically, the throwing of the coke and ore is executed in the sequence shown in A, B and the next throwing of the coke is executed by changing the place to be thrown with the coke from the hopper 6a to 6b and further changing the throwing sequence of the cars 2-I, 2-II as shown in figure E. The 1st throwing from the car 2-II to the hopper 6b is, therefore, executed in the route just slightly passing the chute 5 as shown in figure E. The 2nd throwing from the car 2-II to the hopper 6b is executed through the route long along the chute 5. On the other hand, the 1st throwing is executed in the long route and the 2nd throwing in the short route so as to correspond to the example of figure B as shown in figure F in the example of figure E for throwing the ore.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a method of charging raw materials into a blast furnace, and in particular, a method of charging coke and iron ore into a fixed hopper of a blast furnace using two skip cars. It is related to.

[Prior art] As a means of conveying coke and iron ore to the top of a blast furnace,
Methods such as skip type, packet type, and conveyor type are known. FIG. 1 shows an example of a skip-type raw material conveyance facility among these.

In order to carry the charged raw material to the top of the blast furnace 1, a slope base 3 is constructed between the ground and the top of the blast furnace, and a skip car 2 that moves up and down along the slope base 3 is provided. The skip car 2 receives raw materials discharged from the coke storage 8a or the ore layer 8b, is fully loaded with the raw materials, and is transported to the top of the furnace by the hoisting machine 4.

Figure 2 shows the skip car 2-I arriving at the top of the furnace.
It is a conceptual explanatory diagram of the distribution route showing the progress of dropping the charged raw material into the blast furnace from 2-1f. Skip car 2
The raw materials fully loaded in -I and 2-II are charged into either of the two fixed hoppers 6a, 6b via a movable receiving chute 5 (which reciprocates between the solid line position and the broken line position). Normally, a load equivalent to two skip cars is stored in one fixed hopper 68 or 6b, and the stored coke and ore are alternately charged into the blast furnace 1 via the rotating chute 9. Therefore, the coke layer C and the ore layer 0 are alternately formed in the furnace.

[Problems to be solved by the invention] Two left and right fixed hoppers 6a, 6 as shown in FIG.
Conventionally, in the raw material charging device having the above-mentioned hopper 6b, for example, the left side of the two units is used as a fixed hopper 68 exclusively for coke, and the right side fixed hopper 6b is used exclusively for ore. However, the shape and properties of coke and ore are very different, and ore in particular is often hard, so a fixed hopper used exclusively for ore suffers more wear and tear than a fixed hopper used exclusively for coke.
There was an inconvenience that the fixed hopper dedicated to ore would quickly reach the end of its lifespan, which could impede the continuous operation of the blast furnace.

Therefore, the present inventors have conducted various studies to develop a method that can extend the life of the fixed hopper without interfering with the operation of the blast furnace, and as a result, they have completed the present invention.

[Means for Solving the Problems] The method of the present invention that achieves the above object is summarized as follows. Namely two skip cars1.
In order to introduce the ore and coke conveyed by No. 11 into the fixed hopper, which is divided into two fixed hoppers on the left and right at the top of the blast furnace, through the moving receiving chute, the raw material charging process into the fixed hopper is carried out in the following two steps. (A),
In addition to dividing into (B), skip car 1. The process of charging from II to the fixed hopper via the moving receiving chute is divided into the following two steps ■ and ■. (A) Coke is introduced into the first fixed hopper, and ore is charged into the second fixed hopper. and (B) the step of introducing ore into the first fixed hopper and charging coke into the second fixed hopper according to an arbitrary repeating pattern, and the above-mentioned movement from the skip car. (A) either the ore or coke through the receiving chute;
(B) charging either ore or coke into any of the fixed hoppers selected in step (A) from the skip car II through the moving receiving chute;
The step of charging raw materials into one of the fixed hoppers selected in (B). If the raw materials are charged in the order of (1) and (2) in the above step (A), the step (2) in the above step (B) ), (1), and in the above step (A), the raw materials are charged in the order of (2), (1), in the above step (B), (1), (2).
) The gist of the present invention lies in charging the raw materials in the following order.

[Function] Since the fixed hopper on the side receiving the ore input wears unevenly, in order to prevent this, relatively soft coke and relatively hard ore are divided into both fixed hoppers alternately according to an arbitrary repeating pattern. We came up with the idea that it would be a good idea to adopt a method in which the hoppers are charged by using the same method, and as a result, the two fixed hoppers have approximately the same lifespan, ensuring longevity as a whole.

However, if the order in which skip cars are used and the order in which coke and ore are brought in is limited, the raw material charging procedure is
It has to look like the table below.

To describe the procedure in Table 1 in more detail, first, see Figure 3 (8).
When coke is charged into the fixed hopper 6a on the left side as shown in , the coke from the skip car 2-1 is dropped into the fixed hopper 6a as the first charge (solid line), and then the second
As input, coke from skip car 2-II is also input into the fixed hopper 6a (dashed line). Hereinafter, the first input will be shown by a solid line, and the second input will be shown by a broken line. After that, as shown in Figure 3 (B), move the mobile receiving chute to the right side and move the skip cars 2-I and 2-11.
The ores are charged into the fixed hopper 6b in this order. Up to this point, there is no difference from the conventional method. Next, it is necessary to change the left and right fixed hoppers into which coke and ore are fed, so for example, as shown in Figure 3 (D), coke is fed into the right fixed hopper 6b in the order of skip cars 2-I and 2-11. Then, as shown in FIG. 3(C), ore is charged into the left fixed hopper 6a in the order of skip cars 2-I and 2-H.

However, when comparing Fig. 3 (A) and (D) for coke charging and Fig. 3 (8) and (C) for ore charging, we find that the falling path from the skip car to the fixed hopper is If the first input is long and the second input is short [Fig. 3 CB), (D)], the first input is short and the second input is short.
When the input is long [Figure 3 (A).

(C)]. However, if the falling path is long or short, the falling trajectory of the raw material to the fixed hopper is different, resulting in a difference in the redistribution state of the raw material particle size within the hopper. For this reason, when the falling path changes between the first and second inputs, the stacked state of powder raw materials in the fixed hoppers 6a and 6b changes; In this case, the upper layer side is occupied by many small particles, resulting in an uneven layer balance. However, since these laminated raw materials are discharged from the lower layer to the upper layer in an orderly manner by the rotating chute, the unevenness of the layer balance described above may cause an imbalance in the layered state in the blast furnace.
It is conceivable that the stability of blast furnace operation will be significantly impaired.

Therefore, in the present invention, when the same raw material is alternately dumped into the two left and right fixed hoppers according to the example shown in Table 1, the raw material is fed from the skip car to the fixed hopper under almost the same conditions and under the same falling path. In order to guarantee the charging, we devised the method shown in the previous section and detailed in the Examples below. By doing this, even if the same raw material is alternately charged into different fixed hoppers, it is possible to charge the raw material into the fixed hopper with almost the same particle size distribution, which protects the stability of blast furnace operation. I was able to do that.

[Example] Table 2 shows a method of charging raw materials from the skip cars 2-I and 2-IT to the two left and right fixed hoppers 6a and 8b via the mobile receiving chute 5 according to the present invention.

First, the initial injection of coke and ore is shown in Figure 3 (A).
) and (B), and for the next coke injection, as shown in FIG.
-I, 2-Change the order in which JT is added. As a result, as shown in FIG. 3(E), the first feeding from the skip car to the fixed hopper 6b is performed through a short thread path (using skip car 2-II) that passes only a short distance through the movable receiving chute 5, and the skip The second charging from the car to the fixed hopper 6b is carried out via the long thread path running along the movable receiving chute 5 (using the skip car 2-I). On the other hand, in the example shown in Figure 3 (F) in which ore is introduced, the first input is carried out along a long thread path, and the second input is carried out along a short thread path, corresponding to the example shown in Figure 3 (B). ing. That is, as is clear from a comparison of FIG. 3(A) and FIG. 3(E), by reversing the order in which the skip cars 2-I and 2-11 are used, the order of the raw material input lines can be made the same. is ensured.

The order of charging coke and ore raw materials in the above explanation is the same even if it is reversed, and it can also be applied even when fixed hoppers are used alternately on the left and right sides, as in the example shown at the bottom of Table 2. Furthermore, it is also possible to use means of switching the arrival point of the skip car.

Figures 4 (A) to (C) are experimental results showing examples of particle size distribution in a fixed hopper, and Figure 4 (A) is the particle size distribution when ore is charged by the method shown in Figure 3 (B). FIG. 4(B) shows the particle size distribution state when ore is charged by the method of FIG. 3(C). In other words, when only the left and right fixed hoppers are used alternately without changing the loading order from the skip car, Figure 4 (A) and (B)
As shown, there is a large difference in particle size distribution between the two.

On the other hand, FIG. 4(C) shows the particle size distribution state when ore is charged by the method shown in FIG. 3(F), and a curve similar to that in FIG. 4(A) is drawn. In other words, Figure 3 (
Since the method B) and the method shown in FIG. 3(F) have similar raw material input routes from the skip car, the particle size distribution state is similar.

FIG. 5 is a graph comparing and observing changes in furnace conditions when raw materials were charged according to Table 1 and changes in furnace conditions when raw materials were charged according to Table 2. The solid line shows the case of raw material charging according to Table 1, the broken line shows the case of raw material charging according to Table 2, and 6a, 6b, etc. above the graph indicate the case of coke charging of the fixed hopper in Fig. 2. Indicates the entry side. As a result, it was found that charging raw materials according to Table 1 of the present invention caused considerable fluctuations in furnace conditions, whereas charging raw materials according to Table 2 of the present invention allowed stable blast furnace operation.

[Effects of the Invention] Since the fixed hopper is not used exclusively for coke or ore, uneven wear of the fixed hopper can be prevented. At this time, since the particle size distribution of the charged raw material does not change, stable blast furnace operation can be performed.

[Brief explanation of drawings]

Figure 1 is an explanatory diagram showing the equipment for charging raw materials into the blast furnace using a skip car, Figure 2 is an explanatory diagram showing the raw material charging system from the skip car to the inside of the furnace, and Figures 3 (A) to (F) is an explanatory diagram showing how to charge raw materials from a skip car to a fixed hopper,
Figures 4 (A) to (C) are graphs showing the state of particle size distribution when ore is charged into a fixed hopper, and Figure 5 is a graph showing the state of particle size distribution when charging ore into a fixed hopper. It is a graph showing changes in furnace conditions. 1...Blast furnace L2-t, 2-II...Skip car 3...
- Inclined base 4...Hoisting machine 5...Movable receiving chute 6a...Left fixed hopper 6b...Right fixed hopper 88...Coke storage 8b...Ore storage 9...
rotating chute

Claims (1)

[Claims] When ore and coke transported by two skip cars I and II are introduced into a fixed hopper fixedly installed in two groups on the left and right at the top of the blast furnace via a moving receiving chute, The raw material charging process to the fixed hopper is divided into the following two processes (A) and (B), and the skip car
The process of charging coke from I and II to the fixed hopper via the moving receiving chute is divided into the following two steps (1) and (2). (A) Introducing coke into the first fixed hopper and The process of charging ore into a fixed hopper (
B) The steps of introducing ore into the first fixed hopper and charging coke into the second fixed hopper are carried out alternately according to an arbitrary repeating pattern, and (1) the moving receiving chute is introduced from the skip car I. (A) through either ore or coke;
(2) charging either ore or coke from the skip car II through the mobile receiving chute in (A);
The step of charging raw materials into one of the fixed hoppers selected in (B). If the raw materials are charged in the order of (1) and (2) in the above step (A), the step (2) in the above step (B) ), (1), and in the above step (A), the raw materials are charged in the order of (2), (1), in the above step (B), (1), (2).
) A method for charging raw materials into a top hopper of a bellless blast furnace, which is characterized by charging raw materials in the following order.