JP2000309809A - Method for charging center coke in bell-less blast furnace - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for efficiently charging coke into the center of a furnace in a bell-less blast furnace having an exclusive chute for charging the center coke. SOLUTION: A swing chute 6 is swung surrounding the center axis of a furnace top zone, and in this way, raw material is uniformly spread in the circular direction of the furnace top part 7 to constitute a raw material layer 8. The chute 14 is extended to the tip end part of the furnace body 7 and the raw material charged from the chute 14 is naturally dropped after leaving from the chute 14 and heaped up as the projecting state upward and piled. In the case of bumping the center coke charged from the chute 14 against the raw material charged from a swing chute 6, the center coke is not charged into the center of the furnace body and the distribution of the raw material is not uniformized. Therefore, the coke charged from the chute 14 is divided into plural times of charges and charged at the timing when the swing chute 6 is not directed to the chute 14 side.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a bellless blast furnace having a device for intensively charging coke in the center of a furnace, separately from a rotating chute for charging a raw material. The present invention relates to a method for charging coke.

[0002]

2. Description of the Related Art In a blast furnace operation, ore is reduced stably.
In order to dissolve the gas, it is necessary to maintain the gas flow velocity distribution in the shaft portion in an appropriate state, and to efficiently use the sensible heat and the reducing ability of the gas. For this purpose, it is important to control the distribution of the furnace interior and obtain an appropriate gas flow rate. In the bellless blast furnace, a tiltable swiveling chute is provided for this purpose. The swing chute is swiveled while controlling the tilt angle, and the charge is dropped into the furnace from the swivel chute. You can enter.

However, even when such a swiveling chute is used, since the angle of repose of the ore in the charge is smaller than the angle of repose of coke, the ore after charging is less than the coke. The degree of flow into the central part of the furnace increases, and the ratio of ore increases in the central part of the furnace.

[0004] As a technique for preventing this, Japanese Patent Publication No.
In 28098, a special charging device for charging the raw material only at the center of the furnace is provided separately from the turning chute,
A method is described from which a raw material having a predetermined ore / coke ratio is charged. The method will be described with reference to FIG.

In FIG. 5, a raw material 33 in a raw material hopper 32 of a bell-less charging device 31 is discharged into a collecting hopper 35 when a discharge gate 34 is opened. The raw material hopper 32 is provided separately for ore and for coke, and the raw materials in the raw material hopper 32 are sequentially discharged to the collecting hopper 35 according to a predetermined charging sequence. The raw material in the collecting hopper is guided to a turning chute 36.
The revolving chute 36 is revolving around the central axis of the furnace body,
As a result, the raw material is evenly distributed in the circumferential direction of the furnace top portion 37 to form the raw material layer 38. The figure shows a situation in which coke and ore are charged in layers sequentially.
The turning chute 36 has a variable charging angle θ, so that the charging position of the raw material in the furnace radial direction can be changed.

Separately from this, a device 31 for charging a raw material into the center of the furnace is provided, and mainly coke is charged into the center of the furnace by this device. That is, the raw material in the hopper 42 is guided to the chute 44 when the discharge gate 43 is opened. The chute 44 extends to the center of the furnace body,
The raw material 45 introduced from the chute 44 is piled up at the center of the furnace body so as to protrude upward. In particular, by using this raw material charging device 41, coke is charged into the center of the furnace body, and then the ore is charged by the swirling chute 36, so that the ore is preliminarily deposited in the center of the furnace body. Is suppressed, and the ore / coke ratio can be prevented from becoming unnecessarily large in the central part of the furnace body.

[0007]

However, the method for charging raw materials using the equipment shown in FIG. 5 has the following problems. As shown in FIG. 5, since the chute 44 extends to the center of the furnace body, the raw material supplied from the revolving chute 36 hits the chute 44 and hinders charging with uniform distribution in the circumferential direction. In addition, the chute 44 is heavily worn and needs to be replaced frequently. In the case where the raw material flies through the furnace from the chute 44 and accumulates at the center of the furnace body, the timing of the raw material input by the revolving chute 36 and the chute 44 depend on the required input time of the raw material.
Therefore, when the timing of the input of the raw materials sometimes overlaps, both raw materials interfere (collide with each other), and a sufficient effect cannot be obtained.

The present invention has been made in view of such circumstances, and it is an object of the present invention to provide a method of efficiently charging coke into the center of a bellless blast furnace having a central coke charging dedicated chute. I do.

[0009]

A first means for solving the above-mentioned problems is a method of charging coke into the center of a furnace in a bellless blast furnace, which usually uses a rotating chute for charging raw materials. In the position where the raw material does not fall, a central coke charging chute for charging coke in the center of the furnace is provided, using this central coke charging chute,
A central coke charging method in a bellless blast furnace, wherein coke is charged into a central portion of the furnace (claim 1).

In this means, unlike the equipment shown in FIG. 5, a dedicated coke for charging the central coke is provided at a position where the raw material from the revolving chute does not fall, and coke is oblique from the tip of the dedicated chute. At the center of the furnace body. Therefore, the raw material supplied from the turning chute is not hindered by the dedicated chute, so that the raw material can be uniformly distributed in the circumferential direction in the furnace, and the dedicated chute does not wear.

A second means for solving the above-mentioned problem is as follows.
This is a method of charging coke into the center of the furnace in a bellless blast furnace.A dedicated coke charging chute for charging coke is provided in the center of the furnace. The method of charging central coke in a bellless blast furnace, wherein the method is performed a plurality of times so as not to interfere with the raw material charged from a revolving chute for charging.

This means is an effective method especially when applied to the first means. A chute dedicated to charging coke at the center of the furnace is provided at a position where the raw material falls from the revolving chute. This is an effective means in the case where the raw material supplied from the turning chute and the raw material supplied from the central coke charging dedicated chute interfere with each other (such as collision).

In other words, in this means, when the central coke for one charge is to be thrown in once from the chute dedicated for charging the central coke, there is a possibility that the coke may interfere with the raw material fed from the turning chute. Is divided into a plurality of times, and the central coke is charged at the timing when the turning chute is charging the raw material in a direction different from the direction of the central coke charging dedicated chute, and the rotating chute is directed to the central coke charging dedicated chute. When the raw material is being charged in a direction close to, do not charge the central coke.

Thus, the center coke can be charged while the normal raw material is being inserted from the revolving chute, and even in such a case, the interference between the normal raw material and the central coke is eliminated. , Both can be accurately placed at the target position. In addition, by separately charging the central coke a plurality of times, it is possible to separately charge cokes having different properties.

[0015] A third means for solving the above problems is as follows.
The second means is characterized in that the amount of central coke charged per one time is controlled by the time for opening a charging gate valve provided on a central coke charging dedicated chute (claim). Item 3).

When the central coke is charged in a plurality of times, it is ideal to determine the amount by charging each time. However, there are cases where such a weighing mechanism is not provided at the furnace top. is there. On the other hand, since there is a correlation between the opening time of the injection gate and the central coke injection amount, this means determines this correlation in advance and inputs the central coke by the time when the injection gate valve is opened. The amount is controlled. Therefore, it is not necessary to provide a special weighing mechanism, and the center coke can be quickly charged in the next time.

A fourth means for solving the above-mentioned problem is:
The second means or the third means, wherein the input amount of the central coke a plurality of times is substantially uniform (Claim 4).

If the amount of the central coke charged in each time is not uniform, the inflow of the ore may not be completely blocked by the central coke in the small amount of the charged amount, and the accumulation of the central coke may occur. In some cases, the shape becomes broad, and accumulation of coke at the pole center cannot be expected. In the present means, such a problem is solved because the amount of the central coke charged each time is made substantially uniform. Note that “almost” means that the uniformity is sufficient to solve such a problem, and that it is not necessary to be strictly uniform. How much is acceptable
It can be determined experimentally by furnace conditions.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a schematic diagram showing an example of an embodiment of the present invention. In FIG. 1, 1 is a bellless type charging apparatus, 2 is a raw material hopper, 3 is a raw material, 4 is a discharge gate, 5 is a collecting hopper, 6 is a rotating chute, 7 is a furnace top, 8 is a raw material layer, and 11 is a furnace center. A coke charging device, 12 is a coke hopper, 13 is a discharge gate, 14
Is a chute and 15 is a central coke. In the following drawings, the same components are denoted by the same reference numerals, and description thereof is omitted.

In FIG. 1, a raw material 3 in a raw material hopper 2 of a bellless type charging apparatus 1 is discharged into a collecting hopper 5 when a discharge gate 4 is opened. The raw material hopper 2 is provided separately for ore and coke, and the raw materials in the ore and the coke are sequentially discharged to the collecting hopper 5 according to a predetermined charging sequence. The raw material in the collecting hopper 5 is guided to a turning chute 6. The revolving chute 6 is revolving around the central axis of the furnace zone, whereby the raw material is evenly distributed in the circumferential direction of the furnace top 7, thereby forming the raw material layer 8. The figure shows a situation in which coke and ore are charged in a sequential layer. The turning chute 6 has a variable charging angle θ, so that the charging position of the raw material in the furnace radial direction can be changed.

Separately from this, a coke charging device 11 is provided to the center of the furnace, and coke is charged into the center of the furnace by this device. That is, coke hopper 1
When the discharge gate 13 is opened, the material in the chute 1
It is led to 4. The chute 14 extends to the end of the furnace body 7, and the raw material 35 introduced from the chute 14 falls naturally after leaving the chute 14, and rises to the center of the furnace body so as to protrude upward and accumulate. I do.

In this embodiment, unlike the prior art shown in FIG. 5, since the chute 14 does not extend to the center of the furnace body, the raw material introduced from the swirling chute 6 does not hit the chute and is dispersed. In addition, the raw materials can be charged in a uniform distribution, and the chute 14 is not worn by the falling normal raw materials.

However, when the central coke fed from the chute 14 and the raw material fed from the revolving chute 6 collide with each other, the central coke is not charged into the center of the furnace body and the distribution of the raw material is not uniform. Must be avoided. For that purpose, the turning chute 26
When the input direction of the raw material from the furnace is within a certain angle range with respect to the direction of the chute 14, it is necessary to determine the timing for opening the discharge gate 13 so as not to input the central coke.

However, in general, it is not possible to throw all the central coke charged at once from the chute 14 while the turning chute 6 makes one rotation. Therefore, in the present embodiment, the charging of the central coke is performed in a plurality of times. This will be described with reference to FIG. That is, as shown in (a), when the turning chute 6 is within the central coke charging range, the central coke is supplied from the chute 14. The charging of the central coke is performed a plurality of times (three times in the figure) as shown in FIG. That is, assuming that the turning chute has to turn n times in order to charge the raw material for one charge, the central coke is supplied at appropriate a1 times, a2 times, and a3 times.

As described above, by dividing the central coke, the central coke required for one charge can be charged while avoiding interference with the charging of the normal raw material from the turning chute. It is desirable to determine how many times the turning of the central coke is to be performed in order to block the flow of the ore with the central coke as much as possible, and it is determined by an experiment.

According to the results of experiments by the inventors, when charging the central coke in a plurality of times, if the amount of coke charged in each time is different, the amount of coke charged in each time is small.
It was found that the inflow of ore could not be completely blocked by the central coke, and that the shape of the central coke became broad, and that the coke could not be expected to be deposited at the pole center. Therefore,
In the present embodiment, the amount of coke supplied each time is made substantially uniform.

FIG. 3 is a detailed view of the coke hopper 12 for charging the central coke. In FIG. 3, 16 is a furnace top hopper, 17 is a metric conveyor weigher, 18 is an upper seal valve, 19 is a weighing hopper, 20 is a lower gate valve, and 21 is a lower seal valve.

The coke cut out from the furnace top hopper 16 is weighed by a metric conveyor weighing machine 17, and a predetermined amount of coke is stored in a weighing hopper 19. The upper seal valve 18 is opened when coke is charged into the weighing hopper 19 from the metric conveyor weighing machine 17, but is closed at other times. When charging the central coke into the blast furnace, the lower seal valve 21 is opened, and then the lower gate valve 20 is opened. When the coke in the weighing hopper 19 falls, the coke in the blast furnace is charged through the chute. Is entered.

When the central coke is dividedly charged in one charge, the meric conveyor weighing machine 1
If a predetermined amount of coke can be stored in the weighing hopper 19 and then charged in 7, the target amount of central coke can be accurately charged. However, in practice, the introduction of the central coke after such weighing is performed for each introduction is not enough in time.

Therefore, in the embodiment of the present invention, the central coke for each charge is stored by storing the central coke for one charge in the weighing hopper 19 and adjusting the time for opening the lower gate valve 20. Is almost constant.

According to our experiments, the lower gate valve 2
Between the time when 0 is open and the central coke input, FIG.
There is a relationship as shown in FIG. Therefore, this regression equation is determined in advance by experiments,
When the amount of central coke to be injected per one time is determined, the time for opening the lower gate valve may be determined by applying this regression equation. In order to make such control accurate, it is desirable that the opening and closing speed of the lower gate valve 20 be high, and it is preferable that the lower gate valve 20 be of a hydraulic drive type rather than an electric one.

[0032]

As described above, in the invention according to claim 1 of the present invention, the raw material introduced from the turning chute is not obstructed by the special chute.
The raw material can be evenly distributed in the circumferential direction in the furnace, and the dedicated chute does not wear.

According to the second aspect of the present invention, there is no interference between the ordinary raw material and the central coke, and both of them can be accurately introduced into the target position.

According to the third aspect of the present invention, it is not necessary to provide a special weighing mechanism, and the center coke can be charged the next time quickly.

According to the fourth aspect of the present invention, the inflow of ore can be completely blocked by the central coke, and the accumulation shape of the central coke is prevented from being broadened, and the coke is accumulated in the pole center. be able to.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing an example of an embodiment of the present invention.

FIG. 2 is a diagram illustrating an example of timing for charging a central coke.

FIG. 3 is a detailed view of a coke hopper for charging central coke.

FIG. 4 is a diagram showing a relationship between a lower gate valve opening time and a central coke injection amount.

FIG. 5 is a schematic view showing an example of a conventional central coke charging device.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Bell-less type charging device, 2 ... Raw material hopper, 3 ... Raw material, 4 ... Discharge gate, 5 ... Collecting hopper, 6 ... Swirling chute, 7 ... Furnace top, 8 ... Raw material layer, 11 ... Coke to furnace center Charging device, 12: coke hopper, 13: discharge gate, 14: chute, 15: central coke, 16:
Furnace top hopper, 17 ... Meric conveyor weighing machine, 1
8 upper seal valve, 19 weighing hopper, 20 lower gate valve, 21 lower seal valve

Continuing from the front page (72) Inventor Shoka Hayasaka 1-2-1, Marunouchi, Chiyoda-ku, Tokyo Nihon Kokan Co., Ltd. (72) Inventor Tomi Yamaguchi 1-2-1, Marunouchi, Chiyoda-ku, Tokyo Nihon Kokan Stock In-company (72) Inventor Kenichiro Tadokoro 1-2-1 Marunouchi, Chiyoda-ku, Tokyo F-term (reference) 4K012 BA04 BA08 4K015 GB03 GB10

Claims (4)

[Claims] 1. A method of charging coke into the center of a furnace in a bellless blast furnace, wherein coke is charged into the center of the furnace at a position where the raw material does not fall from a swing chute for charging the raw material. A method for charging central coke in a bellless blast furnace, comprising: providing a chute exclusively for charging central coke, and charging coke into the furnace center using the chute exclusively for charging central coke. 2. A method for charging coke into the center of a furnace in a bellless blast furnace, comprising providing a chute for charging central coke for charging coke in the center of the furnace, and removing coke from the chute dedicated for charging central coke. A center coke charging method in a bellless blast furnace, wherein charging is performed in a plurality of times so as not to interfere with a raw material charged from a revolving chute for charging a normal raw material. 3. The method for charging central coke in a bellless blast furnace according to claim 2, wherein a charging amount of the central coke per one time is adjusted by opening a charging gate valve provided on a dedicated chute for charging central coke. A method of charging central coke in a bellless blast furnace, characterized in that the method is controlled by the time taken. 4. The method of charging central coke in a bellless blast furnace according to claim 2 or 3, wherein the charging amount of the central coke a plurality of times is substantially uniform. Center coke charging method in Japan.