JPH08199209A - Method for charging raw material in bell-type blast furnace - Google Patents

Abstract

PURPOSE: To enable use of a large quantity of small block sintered ores in a bell type blast furnace which is incapable of multi-butch charging. CONSTITUTION: Grain size of the raw material colliding agaist an armor plate 11 is detected with a grain size detecting means 12 and it is detected that the kind of the raw material is charged when the detected value obtd. by the grain detecting means 12 changes by a prescribed quantity, and then, the armor plate 11 is displayed in the radial direction of the furnace 1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a raw material charging method for a bell type blast furnace.

[0002]

2. Description of the Related Art In recent years, a plurality of kinds of raw materials such as sinter or coke having different grain sizes have been charged into a blast furnace. In particular, since small sinter ore can be used in a large amount to significantly reduce the raw material cost of the blast furnace, efforts are being made to increase the charging amount. in this case,
Since the distribution of charging of each raw material in the blast furnace has a great influence on the air permeability in the blast furnace, it is required to accurately charge each raw material at a target position in the blast furnace. In the case of a bellless blast furnace, it is possible to charge each raw material to the target position in the furnace relatively easily by changing the charging angle of the bellless chute, and in the case of a multi-batch type blast furnace, It is possible to distribute raw materials of various types (for example, coke, ordinary sinter, and small sinter) into individual single batches and individually charge them at their respective target positions.

However, a bell-type blast furnace in which the number of batches cannot be increased has a charging position control device called a movable armor, but the controllability of the control device is such as that of a bellless blast furnace or multiple batches. Since it is considerably inferior to that of the type blast furnace, it was almost impossible to accurately charge a plurality of kinds of raw materials having different particle sizes at the target positions.

Therefore, in order to eliminate such inconvenience,
A method for charging a raw material for a bell type blast furnace described in JP-A-60-174808 has been proposed. This method detects the particle size distribution of a plurality of types of raw materials deposited on the large bell hopper in advance by a sampling test or the like, and based on the particle size distribution, the types of raw materials continuously falling from the large bell hopper for each type are detected. Grasping the temporal change of the particle size in advance, displacing the armor plate of the movable armor in the radial direction of the blast furnace according to the temporal change of the particle size, and reacting each raw material by the reaction when colliding with the armor plate. Each of them is designed to be dropped into a target furnace position.

[0005]

However, in such a bell-type blast furnace raw material charging method, the actual change over time in the particle size of the raw material falling from the large bell hopper does not match the change over time grasped in advance. There are cases. In such a case, the displacement of the moveable armor does not correspond to the time-dependent change of the particle size of the falling raw material, so even if a large amount of small lump sinter is used to reduce the raw material cost, the small lump sinter will be used. It will not be possible to accurately load the ore into the target position. As a result, in order to ensure air permeability in the blast furnace, it is necessary to mix and use the small lump sinter ore and the ordinary sinter, which is a factor that hinders the reduction of raw material costs.

The present invention has been made in order to eliminate such inconvenience, and in a bell-type blast furnace in which multi-batch charging is not possible, it is possible to accurately charge each raw material to a target position in the blast furnace. It is an object of the present invention to provide a raw material charging method for a bell-type blast furnace, which enables the use of a large amount of small sinter.

[0007]

In order to achieve such an object, the present invention continuously drops a plurality of types of raw materials having different particle sizes deposited in layers on a large bell hopper into a blast furnace for each type. Then, the falling raw materials are collided with the armor plate of the movable armor which is displaced in the radial direction of the blast furnace according to the particle size of the raw materials, and the reaction of the collision causes each raw material to drop into the target furnace position. In the method for charging the raw material of the bell-type blast furnace, the particle size of the raw material that collides with the armor plate is detected by the particle size detecting means, and when the detected value obtained by the particle size detecting means changes by a predetermined amount, It is characterized in that the armor plate is displaced by detecting that the type has changed.

[0008]

According to the present invention, the particle size of the raw material falling from the large bell hopper and colliding with the armor plate is detected by the particle size detecting means, and when the detected value obtained by the particle size detecting means changes by a predetermined amount, By displacing the armor plate by detecting that the type of raw material has changed, the displacement of the armor plate can be reliably matched to the type of raw material. It is possible to accurately load the position.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. FIG. 1 is an explanatory schematic diagram for explaining a raw material charging system of a bell type blast furnace, and FIG. 2 is an explanatory schematic diagram for explaining a raw material charging method of a bell type blast furnace which is an embodiment of the present invention. is there. As shown in FIG. 1, the raw material charging system of the bell-type blast furnace 1 is composed of a raw material mixing tank 2, a surge hopper 3 and a charging equipment 4 at the top of the furnace. A plurality of raw material mixing tanks 2 are installed, and a plurality of types of raw materials having different particle sizes are cut out from each tank 2. This cutting out is referred to as discharging, but a discharging method in which the raw materials are sequentially discharged from each mixing tank 2 onto the conveyor 5 that feeds the raw material from the raw material mixing tank 2 to the surge hopper 3 and not mixed on the conveyor 5 is called sequential discharge. Call. The raw material discharged onto the conveyor 5 is charged into the surge hopper 3, conveyed on the conveyor 6 to the furnace top, and charged into the furnace 1.

When the small sinter ore 7 and the ordinary sinter 8 are sequentially discharged, if the small sinter 7 is set to be the head of discharge, the small sinter 7 is discharged. And ordinary sinter 8
And are carried to the top of the furnace without mixing and are charged into the furnace 1 from the surge hopper 3, as shown in FIG.
It is deposited in layers on the large bell hopper 9. When the raw material deposited in layers on the large bell hopper 9 is charged into the furnace 1, the first part of the flow of the raw material that drops when the large bell hopper 9 is opened is the small sinter ore 7, Change to ordinary sinter 8. The raw material falling from the large bell hopper 9 collides with the armor plate 11 of the movable armor 10 and is dropped into the target position in the furnace 1 by its reaction. At this time, the movable armor 10 displaces the armor plate 11 in the radial direction of the furnace 1 in accordance with the type (grain size) of the falling material to target the small sinter ore 7 and the ordinary sinter 8 respectively. Drop into position.

Here, in the present embodiment, the armor plate 1
In order to reliably correspond the displacement of 1 to the type of the falling material, the particle size of the material colliding with the armor plate 11 is detected by the particle size detecting means 12, and when the detected value changes by a predetermined amount, the flow of the falling material is When the change from the small sinter 7 to the ordinary sinter 8 is detected, the armor plate 11 is displaced in the radial direction. Specifically, for example, the particle size detecting means 12 measures the vibration when the raw material collides with the armor plate 11, and when the change of the frequency component reaches a predetermined amount, the controller 13 drives the movable armor 10 (for example, hydraulic pressure). The armature plate 11 is displaced in the radial direction of the furnace 1 by controlling the forward / backward movement of the cylinder 14. The move-back armor 10 is moved back and forth in conjunction with the furnace top charging sequence control.

Then, as shown in FIG.
Tends to pull the armor plate 11 when it falls (on the furnace wall side)
Then, the small sinter 7 is dropped onto the coke terrace 15 as close to the furnace wall as possible, and when the flow of the falling raw material changes from the small sinter 7 to the ordinary sinter 8, the armor plate 1
1 is displaced to the furnace center side and the ordinary sinter 8 is dropped to the furnace center side. As a result, small sinter 7 and ordinary sinter 8
Can be charged into a target position in the furnace 1 accurately and in good balance, and as a result, a large amount of small sinter ore 7 can be used without deteriorating the air permeability in the blast furnace 1. The raw material cost can be significantly reduced.

In addition to the advance / retreat control of the movable armor 10 described above, the opening speed and the opening speed of the large bell hopper 9 are adjusted to control the falling speed of the small sinter ore 7 and the ordinary sinter 8. You may do it.

[0014]

As is apparent from the above description, according to the present invention, it is possible to do multi-batch charging by ensuring that the displacement of the armor plate corresponds to the type of raw material falling from the large bell hopper. Even in the blast furnace, each raw material can be accurately charged to the target position in the furnace, so that it is possible to use a large amount of small lump sinter without deteriorating the air permeability in the blast furnace. This has the effect of significantly reducing costs.

[Brief description of drawings]

FIG. 1 is an explanatory schematic diagram for explaining a raw material charging system of a bell-type blast furnace.

FIG. 2 is an explanatory schematic diagram for explaining a raw material charging method for a bell-type blast furnace that is an embodiment of the present invention.

[Explanation of symbols]

 1 ... Bell type blast furnace 7 ... Small sinter ore 8 ... Ordinary sinter 9 ... Large bell hopper 10 ... Movable armor 11 ... Armor plate 12 ... Particle size detection means 15 ... Coke

Claims (1)

[Claims] 1. A plurality of types of raw materials having different particle sizes deposited in layers on a large bell hopper are continuously dropped into the blast furnace for each type, and the falling raw materials are fed into the blast furnace according to the particle size of the raw material. In the raw material charging method for a bell-type blast furnace, the raw material is collided with an armor plate of a movable armor that is displaced in the radial direction, and each raw material is dropped into a target furnace position by a reaction at the time of the collision. The particle size of the raw material that collides with the plate is detected by the particle size detecting means, and when the detection value obtained by the particle size detecting means changes by a predetermined amount, it is detected that the type of the raw material has changed and the armor plate is displaced. A method of charging raw materials for a bell-type blast furnace, characterized in that