JP2001056183A - Vertical shaft cupola/blast furnace/melting furnace method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent emission of dust such as fine particles as much as possible by proving a gas extracting column in a lower part of a furnace and separately extracting a gas through the column. SOLUTION: Gas extracting columns 24 are installed in a several number of sites between a part 1 m downward from a raw material charge surface 15 and a part 1 m above a furnace bottom with an angle of 0 to 60 degrees by bending a halfway part. By this constitution, combustion gas, which has been allowed to ascend and discharged through a furnace top, is made to form a descending flow and discharged to a furnace bottom. The amount of dust to be emitted is largely reduced so that fine particle matters constituting the dust and pulverized ores called pellet feeds, incineration ash, dust and sludge can be used as they are, and inclusion of briquette, sintered ore matters and palletized matters can be used together with them. By this method, yield of various charged matters are raised drastically and resource conservation and energy saving are improved largely as compared with the prior arts.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a solid shaft cupola, a blast furnace, and a melting furnace method for extracting pig iron and slag by melting all substances such as iron ore, pig iron, sludge, industrial waste, and general waste. is there.

[0002]

2. Description of the Related Art As a conventional melting furnace such as a cupola, a shaft furnace, or a blast furnace, as shown in FIG. 1, a hearth 1 laid with refractory bricks is formed, and an upper portion of the hearth 1 is used to collect molten pig iron. A slag bed 3 for separating slag is provided at the upper part thereof, and a furnace belly 4 formed of refractory bricks is provided therearound, and a refractory brick is integrally formed on the upper part thereof. Stacked together to form shafts 5, the perimeter of which are surrounded and protected by an iron plate 6. Several dozens of tuyeres 7 for feeding hot air are opened in the furnace wall, and are formed so that heat can be completely transmitted through the raceway 8 in the furnace. The high-temperature hot air blown from here becomes a combustion gas passing between the iron ore raw material and the coke (for example, every 25 layers) in the multi-stage layer 9A, reduces the iron ore, dissolves and removes pig iron down. At the same time, the gas is collected from the furnace top 10 to the blast furnace gas riser 11. In addition, the slag is also taken out of the system. Raw materials 9 such as iron ore, coke, and limestone are charged by a belt conveyor 12.
Is carried to the upper furnace top 10 and put into the hopper 13,
The material is constantly replenished to the raw material charging surface 15 by the large bell 14 at a constant cycle by an external signal. The furnace temperature is higher in the lower part, and is as high as about 2,000 ° C. in the highest region. 16 is a blast furnace support, 17 is a hot blast tube, 18 is a gas ash dust settling device, 19 is a taphole, 20 is a torpedo car for carrying pig iron out there, 21 is a slag outlet, 22 is a slag wheel, and 23 is a hot air loop. Tube.

[0003]

In the conventional blast furnace, the shaft is filled with a multi-stage layer 9A of iron ore and coke inside the shaft, and the air supplied from the tuyere 7 burns coke at the raceway 8 to reduce the coke. It becomes a mixed gas of carbon monoxide and carbon dioxide at a high temperature of 2,000 ° C. Then, the gas in the furnace becomes an upward flow and becomes a countercurrent moving moving bed, and the furnace top 10
Had been discharged from. When this gas passes through the raw material packed bed 9A, the fine powder is suspended and transported together with the gas from the furnace top 10 to a gas ash dust sedimentation device (dust catcher) 18. Therefore, a gas ash dust sedimentation device is indispensable, and its accuracy must be high, so that there has been a problem that the equipment cost is high.

[0004] In addition, since raw materials floating from the furnace top 10, such as coke and iron ore, are discharged without becoming an effective resource in the furnace, there is a problem that the product yield is deteriorated.

The present invention has been made in view of the above problems, and has provided a smelting reduction furnace method in which dust such as fine powder is not discharged from the furnace as much as possible. By this method, the cost of equipment can be reduced without installing a separate dust catcher or increasing the size. The result is a reduction in the amount of industrial waste dust that is emitted.

[0006]

In order to solve the above-mentioned object, a gas venting tower 24 is provided at the lower part of the furnace, and the gas in the furnace becomes a downward downward flow by extracting gas alone therefrom. Dust is settled and collected in the downstream moving bed. One or more degassing towers may be provided, and all of them are effective at the bottom of the furnace. The shape of the degassing tower includes a leaning tower and a curved tower, and the angle of the leaning tower is preferably from 0 degree to about 60 degrees. The installation position is preferably between 1 m below the surface where the raw materials are charged and 1 m above the bottom of the furnace bottom. When installed within 1 m from the surface of the raw materials, fine powder and dust are easily scattered, and when installed within 1 m from the bottom of the furnace. In this case, there is a risk that the molten liquid flows out because the liquid is stored in the furnace bottom.

[0007] In addition, since almost no dust is emitted outside the system due to the downward flow caused by the installation of the degassing tower, it is necessary to form a briquette, sinter ore processing, or pellet processing even for a raw material having a large amount of fine powder before charging the furnace. Instead, fine powder is charged and used as it is.

[0008]

Embodiments of the present invention will be described with reference to the drawings. In FIG. 2, a hearth 1 is formed by placing a refractory brick thereon, and a furnace belly 4 is fired so that a hot metal bed 2 and a slag bed 3 where molten pig iron accumulates are formed at the upper part thereof. Above the belly 4, there is a shaft 5 having a structure in which refractory bricks are piled up. Iron ore, coke,
Limestone, sludge, dust, industrial waste, general refuse, and the like 9 are fed from a furnace top 10 of a blast furnace by a raw material charging belt conveyor 12. 13 is iron ore, coke,
It is a loading hopper that feeds limestone sequentially. 9A is a layer of raw iron ore and coke in the furnace, and the lowermost position is formed above the tuyere 7. The degassing tower 24 according to the present invention is disposed between 1 m below the raw material charging surface 15 and 1 m above the bottom of the furnace bottom, as shown in FIG.
An angle of about 0 degrees is provided, or the sheet is bent in the middle as shown in FIG.

When hot air is blown in from several tens of tuyeres 7 opened in the furnace wall, the heat is completely transmitted through the raceway 8 in the furnace. The high-temperature hot air blown from here reduces the iron ore through the multi-stage raw iron ore and the coke, and melts to drop pig iron down. Also, the accumulated slag is taken out of the system.

As shown in FIG. 5, in the present invention, by providing a degassing tower 24 in the lower part of the furnace, the combustion gas which has been raised and discharged from the furnace top in the past is discharged down the furnace as a downward flow. Is done. As a result, as shown in Table 1, the outflow of dust is greatly reduced, so that the fine powder constituting most of the dust or the fine iron ore called pellet feed, as well as incinerated ash, dust, and sludge can be used. It can be used as it is, or it can be used beforehand including briquette, sintered ore processing, and pellet processing.

[0011]

Since the present invention is configured as described above, the following effects can be obtained. Since the gas flow at the furnace top and shaft is a downward flow, the yield of charged materials such as coke and iron ore, as well as various charged materials such as industrial waste and general garbage, is significantly increased, and resource saving and
Energy savings will also be greatly improved.

[0012] A large-scale gas ash dust sedimentation device such as the conventional one is not required, and the equipment cost can be reduced. In addition, since it has a structure in which fine powder and the like are difficult to be discharged, there is an advantage that iron dust such as converter dust, electric furnace dust, and oil-containing rolling scale powder can be used in addition to fine iron ore. In the case of raw materials having a large amount of fine powder, such as garbage, general garbage, and other industrial wastes, the work of briquetting, sintering, or pellet processing can be omitted. Furthermore, industrial waste such as low-grade shredder waste and shredder dust can be used as recycled resources by using the smelting reduction furnace method of the present invention.

[0013]

[Brief description of the drawings]

FIG. 1 is a partial sectional view of a conventional general vertical shaft blast furnace.

FIG. 2 is a partial sectional view of a vertical shaft blast furnace according to one embodiment of the present invention.

FIG. 3 is a view of a leaning tower system according to the present invention.

FIG. 4 is a schematic view of a curved tower system according to the present invention.

FIG. 5 is an enlarged view of a furnace bottom according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Furnace floor 2 Hot metal bed 3 Slag bed 4 Furnace belly 5 Shaft 7 Tuyere 8 Raceway 15 Raw material charging surface 24 Degassing tower α 0 degree (horizontal) β 60 degree

Claims (2)

[Claims] In a vertical shaft cupola, blast furnace, or blast furnace having a shaft surrounding the upper part of a hearth to form a hot metal bed, a merle floor, a slag bed or a slag bed, A vertical shaft cupola, a blast furnace and a melting furnace method characterized by discharging gas generated during melting by a degassing tower. 2. A method of installing a plurality of degassing towers having a horizontal tower, a leaning tower, and a curved tower, wherein the degassing towers are installed between 1 m below the raw material charging surface and 1 m above the furnace bottom. The vertical shaft cupola, the blast furnace, and the vertical shaft according to claim 1,
Melting furnace reduction method.