JPH046206A - Method for charging raw material into blast furnace - Google Patents

Abstract

PURPOSE:To execute highly efficient and stable operation so as to enable to charge coke into center part in a blast furnace by beforehand obtaining tilting angle of a swinging chute by a test. CONSTITUTION:Bottom face of the swinging chute 4 is fitted to a discharging hopper side to the blast furnace center, and by varying the tilting angle of the swinging chute 4 little by little so that dropped raw material hits against bottom face of the swinging chute, the tilting angle, by which the dropped position becomes the center, is obtd.

Description

[Detailed description of the invention] [Industrial application field 1 The present invention relates to a method for charging raw materials into a blast furnace.

[Prior Art] It is preferable for blast furnace operation to charge coke into the center of a blast furnace to increase the central flow of blast furnace gas.

Japanese Patent Publication No. 64-9373 discloses a technology in which a new centralized charging device to the center of the blast furnace is added to the existing equipment, and raw material is charged into the center of the blast furnace separately from the conventional blast furnace material charging system. ing.

Since such a device requires a separate device for central charging into the center of the furnace, it becomes necessary to separately provide a pressure seal device at the top of the furnace, which increases equipment costs and maintenance costs.

In addition, other charging materials collide with this charging device, causing the circumferential balance of the charging distribution to be disrupted, making unloading and gas distribution unstable, and worsening the furnace condition.

[Problems to be Solved by the Invention] Therefore, it is required to achieve the objective using a conventional blast furnace raw material charging device.

When charging raw materials into the center of a blast furnace using a pelletless charging device, a problem arises in that the raw materials are charged unevenly from the center of the blast furnace due to drifting of the raw materials in the vertical chute.

For example, the falling position of the raw material varies due to the difference in the stopping position of the rotating chute, and it deviates from the center of the blast furnace. Furthermore, the falling raw material may hit members such as reinforcing ribs of the rotating chute, causing trouble.

An object of the present invention is to provide a simple and practical method for charging coke into the center of a blast furnace in a pelletless blast furnace using a conventional raw material charging device.

[Means to solve the problem]

In the present invention, when charging coke into the center of a pelletless blast furnace, the rotating chute is stopped so that its bottom is located on the top hopper side of the discharge port with respect to the center of the blast furnace, and the rotating chute is stopped at the center of the blast furnace. This method of charging raw materials into a blast furnace is characterized in that the tilting angle of the rotating chute through which the raw material falls is determined in advance and the tilting angle is set to this tilting angle.

[Effect]

The raw material discharged from the furnace top hopper falls into the blast furnace following a trajectory determined by the characteristics of the raw material, the shape, arrangement, dimensions, etc. of the raw material falling channel.

Therefore, the object falls to a unique falling position depending on these characteristic values. According to various observations and analytical studies, coke discharged from the top hopper collides with the wall on the opposite side of the vertical chute, is reflected, and falls to the top hopper side where it is being discharged from the center of the blast furnace. It was approved to do so.

The present invention corrects this falling trajectory using a rotating chute and guides it to the center of the blast furnace. For this purpose, the stopping position of the rotating chute was set so that its bottom surface was on the discharge hopper side with respect to the center of the blast furnace, so that the falling raw material would hit the bottom surface of the rotating chute. In this state, the tilting angle of the rotating chute was changed little by little, and the falling position of the falling object was observed, and as a result, Figure 4 was obtained. From FIG. 4, it can be seen that in this blast furnace, the tilting angle should be set to 15 degrees. This tilting angle can be easily determined experimentally for a particular blast furnace for the charged raw material.

[Example] Fig. 1 is a system diagram showing a raw material charging system of a pelletless blast furnace, and shows an example of the present invention. Furnace top hopper 1
The coke discharged from the blast furnace passes through a collecting chute 2, falls down a vertical chute 3, hits a rotating chute 4, and is charged into a blast furnace 5. The rotating chute 4 has a range 12 shown in FIG.
It is stopped so that its bottom surface 41 is located inside. FIG. 3 corresponds to a plan view seen from above of the vertical chute 3, and shows the intersection 6 of the orthogonal center lines 9 and 10 of the blast furnace plane, that is, the angle of the top hopper with respect to the blast furnace central axis 6 shown in FIG. The rotating chute 4 is suspended and suspended so that the bottom surface 41 of the rotating chute 4 is located on the side where the discharge port 11 is located. In addition, when the rotating chute 4 is suspended in this state, the deviation of the peak position of the coke charged into the blast furnace from the center of the blast furnace is measured by changing the tilt angle, and the results shown in Fig. 4 are obtained. ing. Therefore, the tilting angle of the rotating chute was adjusted to the 4th angle.
Set to 15 degrees according to the diagram. This setting is for charge type 1
It varies depending on the particle size, the arrangement of the blast furnace charging system, dimensions, etc., so it must be determined in advance through experiments.

FIG. 2 shows a diagram in which coke is charged into the center of the blast furnace even when this tilt angle is zero, but in this case, the peak position of the accumulation of the centrally charged coke shifts from the central axis of the blast furnace.

Figure 5 shows a comparison of the measured values of the furnace top temperature in the radial direction between the case where the rotating chute is simply suspended at a tilting angle of zero and coke is charged into the center of the blast furnace, and the method of the present invention shown in Figure 1. It is something. As shown in FIG. 4, by setting the tilting angle to 15 degrees and charging, the symmetry of the furnace top temperature in the radial direction is improved compared to charging as shown in FIG. As shown in FIG. 6, by carrying out the present invention, the number of blast furnace slips and the variation in Si during tapping are reduced, making it possible to stabilize unloading in the blast furnace and stabilize the furnace condition.

[Effects of the Invention] According to the present invention, coke can be charged into the center of the blast furnace using a conventional blast furnace raw material charging device without adding any special charging device, and the blast furnace It greatly contributes to efficient and stable operation.

[Brief explanation of drawings]

1 and 2 are explanatory diagrams of blast furnace coke charging according to an embodiment of the present invention, FIG. 3 is a schematic plan view thereof, and FIG. 4 is a graph showing the relationship between changes in tilt angle and coke charging position, FIG. 5 is an example of the temperature distribution in the upper part of the blast furnace, and FIG. 6 is a graph showing the effects of the example. 1...Furnace top hopper 2...Collecting chute 3...Vertical chute 4...Swivel chute 5...Blast furnace 6...Blast furnace central axis 7...Blast furnace charge top surface 8... Center charging coke 9.10...Center line 11...Top hopper 12...Area application agent Kawasaki Steel Corporation

Claims (1)

[Claims] 1. Stop the rotating chute so that the bottom of the rotating chute of the pelletless blast furnace is located on the side of the top hopper during discharge with respect to the center of the blast furnace, and set the tilting angle of the rotating chute to a predetermined angle, A method for charging raw materials into a blast furnace characterized by charging coke into the center of the furnace.