JP3526108B2 - Blast furnace raw material charging equipment - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a blast furnace raw material charging apparatus, and more specifically, to a raw material specially treated in the central portion of a blast furnace (for example, large coke or sinter). It relates to the charging technology used for filling separately.

[0002]

2. Description of the Related Art In recent years, as the size of blast furnaces has increased, the amount of pig iron produced per blast furnace has increased dramatically. It is an important point to do it stably. Particularly, in a large blast furnace, the production amount is significantly reduced as the furnace condition deteriorates, and the influence on the next process is also great. Therefore, in operating the blast furnace, various operating conditions must be skillfully adjusted, and it is particularly important to properly control the distribution of the blast furnace raw material (hereinafter simply referred to as raw material) charged in the furnace. That is, the ore charged in the furnace is heated and reduced by the high-temperature reducing gas rising in the furnace. To efficiently perform this heating and reduction, raw materials (including coke) are used.
It is necessary to maintain a uniform distribution in the furnace and supply the reducing gas evenly to all ores. However, in the actual operation, it is difficult to always maintain a uniform distribution state due to factors such as the characteristics of the charging device and the characteristics of the deposition of the charging material. In particular, physical and chemical fluctuations that occur in the raw material adjustment process or disturbances in the distribution state due to deterioration of the furnace conditions are unavoidable in current operations. If the balance of the ascending gas in the circumferential direction of the furnace is lost due to this turbulence, the reducing gas locally drifts, and hanging of the charging, slipping, flooding and the like occur frequently. In particular, when hanging occurs, the blowing pressure temporarily rises, and a flooding phenomenon or a slugging phenomenon in which the charged raw material is blown up by this wind pressure appears, and the furnace condition deteriorates extremely. Therefore, even if there is an unavoidable change in the furnace conditions as described above, in order to maintain stable operation, the gas flow in the furnace is not simply evenly distributed, but a part of the gas flow is kept constant. It is a recent general judgment to concentrate in the region, especially in the core of the furnace (hereinafter referred to as the central flow), and to fulfill the function of a safety valve against the rise in the gas pressure in the furnace. These have been confirmed empirically. Has been done. Therefore, it is necessary to have a technology to continuously obtain the above-mentioned central flow,
Currently, it is most common to densely load coke, which has good air permeability in the blast furnace, toward the center of the furnace (Japanese Patent Publication 6).
4-9373).

By the way, as shown in FIG. 2, a method of charging coke into the center of the furnace in a blast furnace having a bell-type charging device is arranged in a group of storage tanks provided in the vicinity of the blast furnace. It begins by selecting the raw material storage tank 2 and storing the coke specially classified for central charging (hereinafter referred to as central charging coke). Then, the coke for central charging is charged to the top of the furnace by using a gap for winding other raw materials (usually, the coke and the ore are charged alternately in layers) on the charging belt conveyor 4 to the top of the furnace. It is wound up and stored in a separately provided storage hopper 24 for coke for center charging by switching the damper 8 of the branch chute 5 on the furnace top. The stored center charging coke is cut out and weighed in the center charging coke weighing hopper according to the raw material charging schedule, discharged to the pressure equalizing hopper 12, and equalized to the furnace pressure in the pressure equalizing hopper 12. Then, it is charged only in the center of the furnace by the charging chute 13 in the furnace.

However, the apparatus configuration shown in FIG. 2 requires improvement of the surroundings of the storage tank group 1, that is, a large-scale sieve for classifying coke for central charging is provided near the storage tank group 1. In addition, since it is processed through the gap of other raw material hoisting, it is necessary to significantly modify the control device that controls the operation of the blast furnace and the cutting of the raw material, and to adopt it in the operating blast furnace, There was a problem that the blast furnace had to be blown for a long time.

[0005]

SUMMARY OF THE INVENTION In view of such circumstances, the present invention has improved a raw material cutting control device or a large-scale sieve newly provided in the vicinity of a group of storage tanks in a blast furnace having a bell type charging device. Even without doing so, it is an object of the present invention to provide a blast furnace raw material charging device capable of simply charging coke or ore for central charging to the center of the furnace.

[0006]

Means for Solving the Problems The inventor has conducted diligent research in order to achieve the above-mentioned object, and classifies the raw material for central charging, which has been conventionally performed before storing in a storage tank or a storage tank. We focused on hoisting on the furnace top with a belt conveyor and then classifying.
Then, in order to embody it, the present invention has been achieved by making the classifying device light and simple, and adding a new idea to the conventional charging device. That is, the present invention is a storage tank and a storage tank for storing blast furnace raw materials, a charging belt conveyor for hoisting those raw materials to the top of the furnace, and a winding belt at the discharging portion of the charging belt conveyor. A branch chute that divides the raw material into two, a storage and transport means for the central charging raw material that feeds one of the divided raw materials to the central part of the furnace, and a fixed hopper that stores the other for feeding to the bell type charging device. In the charging device for blast furnace raw material consisting of, the branch chute, a fixed chute toward the fixed hopper, and a central charging chute in which an upper end portion can be freely inserted into and removed from an opening provided in a part of the fixed chute. A blast furnace raw material charging device characterized in that it is provided with a classifying means for returning the undersize of the raw material passing therethrough to a fixed chute at the bottom surface and the upper end side of the central charging chute. is there. Further, the present invention, on the upstream side near the tip of the central charging chute inserted in the fixed chute,
The blast furnace raw material charging device is characterized in that a grizzle for classifying a large lump of raw material is provided.

[0007]

In the present invention, a storage tank and a storage tank for storing blast furnace raw materials, a charging belt conveyor for hoisting those raw materials to the top of the furnace, and a discharging portion of the charging belt conveyor are wound up. A branch chute that divides the raw material into two parts, one of the divided raw materials for storing and conveying the raw material for central charging for sending to the central part of the furnace, and a fixed hopper for storing the other for sending to the bell type charging device. In the charging device for blast furnace raw material, the branch chute has a fixed chute directed to the fixed hopper, and a central charging chute in which an upper end portion of the fixed chute can be inserted into and removed from an opening provided in a part of the fixed chute. And a classifying means for returning the under-sieve of the raw material passing therethrough to the fixed chute on the bottom surface and the upper end side of the central charging chute, so that it is easy to use at the top of the blast furnace. Can be classified and installed in the vicinity of one group of slag tanks Sieve and a consuming, so also avoid having to improve the material cutout control unit. As a result, it became possible to install a central charging device for raw materials without prolonged blast furnace breeze, and to stabilize the operation. Further, in the present invention, since the grizzly for classifying a large lump of the raw material is arranged on the upstream side in the vicinity of the tip end position of the central charging chute inserted into the fixed chute, it is charged into the blast furnace. By dividing the raw material into three stages of particle size range, it becomes possible to appropriately adjust the particle size of the raw material to be subjected to central charging or normal charging.

In the following, the contents of the present invention will be specifically described with reference to FIGS.

[0009]

EXAMPLE FIG. 1 shows an overall view of a blast furnace raw material charging apparatus according to the present invention. As is clear from FIG. 1, first, in the present apparatus, large-scale classification equipment is not required in the vicinity of the group 1 of the storage tanks, and it is not necessary to prepare a special storage tank for the central charging raw material. Then, the coke wound up from the storage tank 1 in the usual manner is used as the charging belt conveyor 4 used for hoisting, the branch chute 5 provided at the discharge portion, the center charging coke and the furnace top charging coke. After classification, the coke for charging the top of the furnace is stored in the fixed hopper 6 at the top of the furnace as usual, and the coke for the central charging is stored in the hopper for central charging 24, and is charged into the blast furnace according to the charging sequence. .

Next, the branch chute 5, which is an important point of the present invention, is a fixed chute 9 heading to the fixed hopper 6.
And a central charging chute 11 whose tip is freely inserted into and removed from an opening provided in a part of the fixed chute (see FIGS. 3 to 6). The central charging chute 11 is retracted to the outside of the fixed chute 9 when the charging belt conveyor 4 is winding up the ore, and is also provided with a blinding means 23 for feeding the ore only to the fixed hopper 6. . As shown in FIG. 4, the central charging chute 11 has a structure in which the upper end side 12 and the lower end side are bisected, and the upper end side 12 is pushed into the fixed chute 9 by the moving cylinder 19. , They will be withdrawn. Further, a removable sieve screen 14 is attached to the bottom surface of the upper end side 12 of the central charging chute 11, and when a granular material passes therethrough in correspondence with the size of the sieve screen, It is designed to perform classification.

On the other hand, when the charging belt conveyor 4 is winding up the coke, the tip end side of the central charging chute 11 enters the fixed chute 9 and collects the necessary amount of falling coke. At that time, among the collected cokes, the one that passes over the sieve mesh is the large coke 20.
As a result, the small-diameter coke 22 that has passed through the sieve mesh toward the central charging hopper 24 is combined with the coke that has passed through the fixed chute 9 and is sent to the fixed hopper. The state is shown in FIG. 3, in which the coke falling from the charging belt conveyor 4 is classified into large lumps 20 and small lumps 22 by using a sieve mesh of 20 to 40 mm.

FIG. 5 shows a case where the coke falling from the charging belt conveyor 4 is classified into three stages of a large lump 20, a middle lump 21, and a small lump 22 by the same method as described above. However, the large block 20 is the upper end 12 of the center charging chute.
It is classified by the grizzly 15 provided on the upstream side. In addition,
FIG. 6 shows a state of the central charging chute 11 when the sieve screen plate 14 is replaced, and is independent of the fixed chute 9. Therefore, in the blast furnace raw material charging apparatus according to the present invention, it is easy to install the main part of the blast furnace raw material without blowing the blast furnace for a long time.

Finally, the blast furnace raw material charging apparatus according to the present invention was applied to a test blast furnace. In order to obtain the central flow, it is desirable to charge coke having a particle size as large as possible in the center of the furnace, but there is a concern that the coke may be clogged in the central charging hopper 24, the piping, and the chute 13. Therefore, the particle size of the coke collected in the central charging hopper 24 is, for example, 40.
It was possible to prevent clogging of the hopper, chute, and the like, and to perform stable operation by collecting only the coke of the medium block 21 into the central charging hopper 24 with a size of mm to 70 mm.

In the present specification, the blast furnace raw material charging apparatus according to the present invention has been described by way of an example in which coke having a large particle size is charged in the center of the furnace. However, the apparatus mainly focuses on raw materials other than coke. Needless to say, it can be used even when charging. Further, the present invention can be used even in a blast furnace having a bellless charging device.

[0015]

As described above, according to the present invention, in the blast furnace, a large-scale sieve can be newly provided in the vicinity of the group of storage tanks 1, and the raw material cutting control device can be simply and easily used for central charging. Coke and ore can be charged in the center of the furnace, and stable operation of the blast furnace can be achieved.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view showing the entire blast furnace raw material charging device according to the present invention.

FIG. 2 is an explanatory view of a device for charging a conventional large coke into the center of a blast furnace.

FIG. 3 is an explanatory diagram for classifying coke into large chunks and small chunks in the blast furnace raw material charging apparatus according to the present invention.

FIG. 4 is an explanatory diagram for charging ore in the charging device for raw material of blast furnace according to the present invention.

FIG. 5 is an explanatory diagram for classifying coke into three stages of large lumps, medium lumps, and small lumps in the blast furnace raw material charging device according to the present invention.

FIG. 6 is an explanatory diagram for performing maintenance on the blast furnace raw material charging device according to the present invention.

[Explanation of symbols]

1 storage tank 2 Central charging storage tank 3 Weighing hopper 4 Loading belt conveyor 5 branch shoots 6 Fixed hopper 7 Bell type furnace top charging device 8 damper 9 fixed chute 10 openings 11 Central charging chute 12 Upper end of the center charging chute 12 Pressure equalizing hopper 13 Furnace charging chute 14 Classification means (sieve screen) 15 Grizzly 16 Charges 17 Blast furnace 18 raw materials 19 Moving cylinder 20 large blocks 21 Medium 22 small pieces 23 Blind means 24 Center loading hopper

─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Katsumi Ino 1-chome, Mizushima Kawasaki-dori, Kurashiki-shi (no street number) Kawasaki Steel Co., Ltd. Mizushima Steel Works (72) In-house Taiko Furukawa, 1-chome, Mizushima Kawasaki-dori, Kurashiki-shi (no street number) (56) Reference JP-A-63-199810 (JP, A) JP-A-6-33120 (JP, A) JP-A-2-213405 (JP, A) JP-A-1- 123013 (JP, A) JP 61-149409 (JP, A) Actual development 61-120743 (JP, U) Actual development 59-57552 (JP, U) (58) Fields investigated (Int.Cl. ⁷ , DB name) C21B 7/20 302

Claims (2)

(57) [Claims] 1. A storage tank and a storage tank for storing blast furnace raw materials, a charging belt conveyor for hoisting the raw materials to the top of the furnace, and the raw material hoisted at the discharge portion of the charging belt conveyor. From a branch chute that divides the raw material into two, one of the two divided raw materials is stored and transported to the center of the furnace for feeding and the other is a fixed hopper that stores the other for feeding to a bell-type charging device. In the charging device for blast furnace raw material, the branch chute includes a fixed chute directed to the fixed hopper, and a central charging chute in which an upper end of the fixed chute is freely opened and closed. A blast furnace raw material charging device, characterized in that a classification means for returning the undersize of the raw material passing therethrough to a fixed chute is provided on the bottom surface and the upper end side of the central charging chute. 2. The blast furnace raw material according to claim 1, further comprising a grizzly for classifying a large lump of the raw material on the upstream side in the vicinity of the tip of the central charging chute inserted into the fixed chute. Charging device.