JPS62174305A - Feeding and charging device for pig iron raw material - Google Patents

Abstract

PURPOSE:To stably feed reduced iron and dust and to permit the control of the mixing ratio of the reduced iron and coke by providing plural feeding ports provided with rotary feeders to the lower part of a reduction furnace, feeding the reduced iron and dust and mixing the same with the separately fed coke. CONSTITUTION:The reducing gas generated in the stage of refining pig iron in a melting and gasifying furnace 1 is fed from a take out port 3 via a hot dust remover 10 and a tuyere 9 to the reduction furnace 6 to reduce the iron ore. The plural feeding ports 12A, 12B having the rotary feeders 14A, 14B are provided to the lower part of th tuyere 9 of the reduction furnace 6 to feed the dust intruded into the reduction furnace 6 together with the reduced iron and to through the same through throwing pipes 13A, 13B and charging ports 2A, 2B into the gasifying furnace 1. The cake fed by a feeding device 16 is distributed and supplied to the throwing pipes 13A, 13B. The reduced iron is thereby stably fed together with the dust and is evenly charged into the gasifying furnace 1; in addition, the mixing ratio of the reduced iron and the coke is easily controlled.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a raw material cutting/charging device in a pig iron production facility that combines a coke packed bed type melting and gasification furnace and a shaft type packed reduction furnace.

[Prior Art] A melting and gasifying furnace that melts and refines lumpy reduced iron using sensible heat generated by gasifying coal-based solid fuel with oxygen-containing gas, and a melting and gasifying furnace that melts and refines lumpy reduced iron, and processes CO and H generated in this melting and gasifying furnace. The main component, reducing gas, is blown into the reduction furnace without cooling.
The iron manufacturing method in combination with a reducing furnace that reduces ore to produce lump reduced iron to be supplied to the melting and gasifying furnace is the KR method (Japanese Patent Publication No. 48607, 1982), the Kawatetsu method (Japanese Patent Publication No. 59, 1983).
18452), sc method (4'F Publication No. 184-184)
No. 43), which is known as the C0IN method.

However, in the KR method, the five-element iron is cut out from the reduction furnace using a paddle worm conveyor, and the reduced iron is removed by a melting and gasification furnace. In addition, in the Kawatetsu method, the Ω-based iron overflows on the fluidized bed of the reduction furnace, is guided through a reduced iron guide pipe, and is blown into the gasification furnace together with preheated air.

[Problems to be Solved by the Invention] By the way, in this type of equipment, reduced iron and coke exist in a predetermined ratio in the gasifier, and the manner in which they exist is as follows:
It is important that they are not unevenly distributed. Furthermore, it is important that the reduced iron be stably cut into the gasifier without being affected by dust in the dust-containing reducing gas.

However, although the KR method is superior in that it prevents dust from blowing through from the melting gasification furnace to the reduction furnace by capturing it in the paddle worm conveyor, the reduced iron and coal are mixed in advance. Since the raw materials are led to the melting and gasifier separately without being separated from each other, they are input from different input ports, which makes it difficult to maintain a uniform ratio over time even if the input ports are close to each other. , tend to be unevenly distributed.

In the iron production method, since the reduction furnace is a fluidized bed, there is no problem even if dust gets into the reduction furnace.

In order to blow powdered pre-reduced ore into the melting furnace through the tuyere, there is no concept of charging the ore and coke in a uniform mixture.

However, in the SC method targeted by the present invention, it is important to reliably achieve the above requirements.

[Means for Solving the Problems] The apparatus of the present invention for solving the above problems blows dust-containing reducing gas generated in a coke packed bed melting and gasification furnace into a shaft type packed bed reduction furnace. In a facility for manufacturing pig iron by melting reduced iron produced by reduction in the melting and gasifying furnace; a plurality of cutting ports provided in the lower part of the reducing furnace below the reducing gas inlet from the melting and gasifying furnace; , an input path that communicates each of these cutting ports with the melting and gasifying furnace, a rotary feeder disposed at each of the cutting ports, and a coke supply device that supplies coke into each of the input paths. It is characterized by the fact that it is equipped with

[Function] In the present invention, a plurality of cutting ports are formed in the lower part of the reduction furnace, preferably at the lower end, and each of the cutting ports is provided with a cutter using a rotary feeder.

On the other hand, in the gasifier, dust of about 10 to 50gr/Nrnj is generated together with the reducing gas, and the gas temperature is about 600g/Nrnj.
This dust-containing reducing gas, which has a high temperature of ~900″C, is removed by an inertial force dust collector such as a hot cyclone or a gravity settling dust collector, and then led to the reduction furnace. Sufficient dust removal cannot be carried out, and as a result, a considerable amount of dust is brought into the reduction furnace.When this dust accumulates, problems such as poor cutting of reduced iron from the main furnace and shelf hanging occur. In addition, since the reduction furnace is generally located directly above the gasification furnace, the original gas containing dust rises through the input pipe for the reduced iron gasification furnace, and dust is deposited at the bottom of the reduction furnace. .

However, according to the present invention, the dust that rises and accumulates in the lower part of the reduction furnace through the input pipe is captured together with the reduced iron by the blades of the rotary feeder and discharged to the gasification furnace. Further, in the present invention, dust and reduced iron fall in predetermined amounts between the blades as each blade rotates, so that the dust is reliably discharged. Further, the dust that enters through the reducing gas inlet eventually moves to the lower part of the reducing furnace as the reduced iron is unloaded, but it is also discharged together with the reduced iron.

On the other hand, since there are a plurality of cutting ports, dust can be discharged more favorably than in the case of one cutting port.

Further, when charging the reduced iron into the gasification furnace, the reduced iron is charged through a plurality of charging furnaces. Therefore, uneven distribution of reduced iron in the gasifier is prevented. Moreover, since coke is supplied to each input path, uneven distribution of coke is also prevented.

Furthermore, it is extremely easy to control the mixing ratio with reduced iron.

[Specific examples of the invention] The present invention will be explained below using specific examples shown in the drawings.

In FIGS. 1 and 2, the coke packed bed type melting and gasifying furnace 1 has reduced iron (including semi-element iron) charging ports 2A and 2B in its upper part. It has a J1 reducing gas extraction chamber 3, a tuyere 4 for blowing oxygen, steam and pulverized coal into the furnace wall near the middle stage of the furnace, and a tap iron slag port 5 in the lower furnace wall.

6 is a shaft-type packed reduction furnace, which is placed directly above the melting and gasifying furnace 1, and an iron ore input lower is provided above it.
Further, a reduced gas outlet 8 is formed in the upper furnace wall. A plurality of dust-containing reducing gas blowing tuyeres 9 (only one in the figure) are formed in the middle of the furnace wall, and the reducing gas outlet 3
After removing dust from the dust-containing reducing gas taken out from the hot dust remover 10, the gas is blown into each tuyere 9 through an annular pipe (not shown).

In the present invention, the cutting ports 12A and 1 are partitioned by a partition wall ll at the lower part of the reduction furnace 6, preferably at the lower end near the side wall.
2B is formed, and these cutting ports 12A and 12B are an input pipe (input path) 13A.

13B communicates with the charging ports 2A and 2B of the gasifier l. Moreover, rotary feeders 14A and 14B, a detailed example of which is shown in FIG. 3, are provided at the cutting ports 12A and 12B.

Here, the cutting ports 12A and 12B are connected to the tuyere 9 as shown in the figure.
It is desirable that the inner wall surface of the opening is continuous with the vertical surface. If the opening is inclined in a cone shape as shown in FIG. There is a possibility that the exits L2A and 12B may be blocked.

On the other hand, after the coke is cut out from the hopper 15 by a cutting device 16 consisting of, for example, a screw feeder,
After being distributed by the distribution pipes 17A and 17B, it is configured to be introduced into the corresponding input pipes 13A and 13B.

Next, to give an overview of the operation of such equipment, in the melting and gasification furnace 1, coke and pulverized coal are combusted and gasified with oxygen and steam to produce a reducing gas at approximately 2,500°C containing CO and H2 as main components. is generated in front of the tuyere 4, and the sensible heat is used to melt and refine the reduced iron charged from the top to produce pig iron, which is extracted from the tap slag opening, and the temperature is lowered to approximately 600-900℃. The gas is extracted from the outlet 3 and is blown into the reduction furnace 6 through the hot dust remover 10. In the reduction furnace 6, the gas is used to reduce iron ore charged from above to produce reduced iron. Rotary feeders 14A and 14B as cutting devices
through the reduced iron input pipes 13A and 13B,
The reduced iron is charged into the melting and gasifying furnace 1 together with fresh coke.

In the present invention, part of the dust in the reducing gas blown in from the blowing tuyere 9 adheres to the reduced iron, and the remaining part enters the reducing furnace 6 without being attached. This dust reaches the lower part of the reduction furnace 6 as the reduced iron is unloaded.

On the other hand, dust in the reducing gas blown up through the input pipes 13A and 13B accumulates at the lower part of the reducing furnace 6.

These dusts are eventually dispersed by the partition wall 11 together with the reduced iron and reach the respective cutting ports 12A and 12B. After that, the dust and reduced iron are transferred to the rotary feeder 14A,
14B at a predetermined cutting speed.
It is cut out.

As shown in FIG. 3, the rotary feeders 14A, 14B have a large number of blades 14b, 14b, . Due to this structure, reduced iron and dust are not separated by their own weight,
It falls between the blades 14b, 14b, and is cut out as it rotates.

On the other hand, the coke is transferred to the distribution pipe 17A by the cutting device 16.
, 17B are inserted into the input pipes 13A and 13B, and after being mixed with the dust-containing reduced iron, the input pipe 13
A and 13B are further dropped, and the iron is charged and dropped into the gasification furnace 1 together with the reduced iron from each charging port 2A and 2B.

In this case, since a plurality of charging ports 2A and 2B are formed, the reduced iron and coke are dropped into different positions in the gasifier l, so uneven distribution of the charging materials is prevented.

Incidentally, the cutting speed (fit) of each of the rotary feeders 14A, 14B is individually controlled, and the cutting speed of the cutting device 16 is also variable, and more preferably, the cutting speed (fit) of the cutting device 16 is made variable. is the distribution amount variable device 18
By desirably providing this, the overall mixing ratio of reduced iron and coke can be controlled, as well as the mixing ratio of reduced iron and coke per input pipe. As a result, it is possible to easily control the furnace heat of the gasifier and the molten iron production rate. Further, the ratio of reduced iron to coke at the falling position corresponding to each charging port 2A, 2B can be uniformly controlled.

In the above example, there are two cutting ports, an input pipe, a distribution pipe, and two charging ports, but of course there may be three or more, and it has been confirmed that the larger the number, the higher the dust discharge effect.

However, a value of 5 or more is not very preferable because it increases the amount of equipment.

In addition, a movable armor used in blast furnaces may be installed on the surface of the charge in the gasifier to equalize the charge, but this would be complicated in terms of maintenance, etc. It is preferable to achieve equalization using only the above example.

On the other hand, as shown in FIGS. 4 to 6, a 16° rotary feeder may be used as the coke cutting device instead of the screw feeder. As shown in Fig. 7, the input pipe 13
Depending on the number of screws A and 13B, the number of cutting devices such as screw feeders 16A and 16B may be provided.

[Effects of the Invention] As described above, according to the present invention, reduced iron can be stably cut out together with dust, can be charged into the gasifier without being unevenly distributed, and moreover, reduced iron and coke can be separated. Mixing ratio can be controlled.

[Brief explanation of drawings]

Figure 1 is an overall view of the bag of the present invention, Figure 2 is an enlarged view of its main parts, Figure 3 is a schematic diagram of the rotary feeder, and Figures 4 to 7.
The figure shows an example of coke charging in a different manner, and FIG. 8 shows an example of dust accumulation. 1... Coke packed bed melting and gasification furnace, 2A, 2B.
... Charging port, 3... Dust-containing reducing gas outlet, 6... Shaft type packed bed reduction furnace, 9... Dust-containing reducing gas blowing tuyere, 12A, 12B... Cutting port, 13A , 13B...
・Input pipe (input path), 14A, 14B... Rotary feeder (cutting device), 16, 16°... Cutting device,
17A, 17B...Distribution piping.

Claims (1)

[Claims] (1) Dust-containing reducing gas generated in a coke packed bed melting and gasifying furnace is blown into a shaft type packed bed reducing furnace and the resulting reduced iron is melted in the melting and gasifying furnace to produce pig iron. In the equipment; a plurality of cutting ports provided in the lower part of the reducing furnace below the reducing gas inlet from the melting and gasifying furnace, and an input passage that communicates each of these cutting ports with the melting and gasifying furnace; , comprising: a rotary feeder having a plurality of blades extending in a radial direction around a rotation axis disposed at each of the cutting opening portions; and a coke feeding device that supplies coke into each of the feeding passages. Pig iron raw material cutting and charging equipment.