JPS60251208A - Method for charging raw material to blast furnace - Google Patents

Abstract

PURPOSE:To attain a satisfactory and stable furnace condition by storing separately or superposedly, for example, coarse grained raw material and fine- grained raw material in a hopper, discharging separately and successively the coarse-grained raw material and the fine-grained raw material from the hopper in one batch and charging the raw materials to the respective desired positions via a chute in the furnace. CONSTITUTION:The raw material from a charging belt conveyor 1 is classified by a classifying damper 14. The coarse-grained raw material 12 is charged into the inside cylindrical part 15 of the upper hopper 3 and is further charged into the inside cylindrical part 15' of the lower hopper 6 and is stored therein. The fine-grained raw material 13 is charged into the outside cylindrical part 16 of the upper hopper 3 and is further charged into the outside cylindrical part 16' of the lower hopper 6 and is stored therein. The pressure in the hopper 6 is equalized and thereafter a gate valve 7 and a lower seal valve 8 are opened to discharge first the material 12 in the part 15' into the chute 9 in the furnace. Said material is charged into the desired position in the furnace by the swiveling and tilting operation of the chute. The raw material 13 in the part 16' is similarly charged into the furnace in succession thereto.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Field of Application) The present invention relates to a method for charging raw materials into a blast furnace using a bellless charging device.

(Prior art) In a bell-less charging device for a blast furnace, raw materials such as iron-bearing ore and coke are charged into the furnace from a hopper via a chute.
By changing the falling position of the raw materials by tilting, the ore/coke ratio, gas flow distribution, etc. in the furnace are controlled to obtain desired furnace conditions.

In recent years, for example, as seen in the invention of JP-A No. 55-62106, for the purpose of particularly controlling the gas flow distribution in the furnace, the charging raw material is divided into coarse particles and fine particles in advance, and the coarse particles are placed in the center of the furnace. In recent years, a method of charging fine grains around the furnace wall is becoming popular.

FIG. 4 shows a typical example of conventional charging according to particle size. In this conventional raw material charging method, coarse grain raw material 12 is charged onto a belt conveyor 1. Rotating chute? After passing through the upper hopper 3 and storing it in the lower hopper 6, which is evacuated, the pressure is equalized, and then charged into the furnace from the lower hopper 6 through the furnace chute 9 by rotating and tilting the furnace.
Forms a raw material distribution like '.

Next, the exhaust pressure system 11 is operated to evacuate the lower hopper 6 and the charging belt conveyor 1. The fine raw material 13 stored in the upper hopper 3 via the rotating chute 2 is discharged and stored in the lower hopper 6, and after the pressure equalization system 10 is operated to equalize the pressure in the hopper 6, the gate valve at the bottom of the hopper 6 is activated. 7. Open the lower seal valve 8 and feed through the furnace chute 9.
By rotating and tilting the material, it is charged into the furnace and a raw material distribution as shown in 13' is formed.

In this conventional charging method, the coarse raw material 12 and the fine raw material 13 are each charged in one batch (meaning one cycle of hopper pressure equalization and pressure evacuation operation, hereinafter referred to as one batch). Therefore, the number of batches is doubled, and the pressure in the lower hopper 6 is equalized.
The increase in exhaust pressure operation reduces the time available for charging raw material from the furnace chute 9 into the furnace as rice feed, and the number of revolutions of the furnace chute must also be reduced. There are drawbacks such as difficulty in finely controlling the distribution.

In this case, increasing the number of revolutions will reduce the raw material charging capacity. This is particularly true for bellless charging systems with two-stage vertical hoppers.

(Problems to be Solved by the Invention) The present invention provides a blast furnace having a bellless charging device.
For example, by improving the drawbacks of the conventional method when charging raw materials separately into coarse particles and fine particles, increasing the number of rotations of the chute in the furnace, and ensuring the required charging capacity, it is possible to charge the raw material into the furnace. This enables fine control of the distribution of raw materials, improves raw material charging efficiency, creates good and stable furnace conditions, and improves blast furnace operation.

(Means for Solving the Problems) A feature of the present invention is that, for example, coarse grain raw materials and fine grain raw materials are stored separately or stacked in a hopper, and coarse grain raw materials and fine grain raw materials are separated in one batch. The materials are sequentially discharged from the hopper and charged to desired positions in the furnace through the in-furnace chutes 1 to 3, respectively.

Embodiments of the present invention will be described below along with an example of a bellless charging device for carrying out the present invention shown in FIG.

In this example of a bellless charging device for carrying out the present invention, a classification damper 14 is provided between the charging belt conveyor 1 and the rotating chute 2', and the rotating chute 2' is connected to the rotating part and the straight cylinder part. It has become.

Inner cylinder parts 15, 15' and outer cylinder parts 16, 16' are provided in the upper hopper 3 and lower hopper 6, respectively, and a movable ring 1' is provided at the lower part of the inner cylinder parts 15, 15', respectively.
i', 1 'i' is attached.

Thus, in the present invention: - Raw material from the charging belt conveyor l (hereinafter referred to as raw material, taking the case of iron-containing ore as an example);
is classified by the classification damper 14, and the coarse raw material 12 (for example, those with a particle size of 10wn or more) is fed into the inner surface 15 of the upper hopper 3 through the straight cylinder part 2'l of the rotating chute and stored. The raw material 13 (for example, those with a particle size of 5 to 10.m) is fed into the outer cylindrical portion 16 of the upper hopper 30 and stored in the rotating section. The raw material 13 is a unit charged into the furnace in one batch operation.

And the gate valve 4 at the bottom of the upper hopper 3. The upper seal valve 5 is opened, and first, the coarse raw material 12 in the inner cylinder part 15 is discharged into the inner cylinder part 15' of the lower hopper 6.

After or just before the completion of discharging the coarse raw material inside the inner cylinder part 15', the movable ring 1'7 at the lower part of the inner cylinder part 15 of the upper hopper 3 is moved upward to remove the fine particles in the outer cylinder part 16. Grain raw material 13
is discharged through the top of the coarse raw material 12 in the inner cylinder part ld of the lower hopper 6 into the outer cylinder part 16/.

Storage, upper hopper 3 lower gate valve 4. Close the upper seal valve 5.

Then, after equalizing the pressure inside the lower hopper 6, the lower hopper
6 Lower gate valve 7. The lower seal valve 8 is opened, and the coarse raw material 12 in the inner cylindrical part 15' of the lower hopper 60 is first discharged into the 1-yen chute 9, and then loaded into the desired position in the furnace by rotating and tilting the furnace chute 9. Input desired raw material distribution 12'-i
z Shadow formation. After or just before the completion of discharging the coarse raw material 12 from inside the inner cylinder part 15', move the inner cylinder part 15/lower movable ring 1'2' of the lower hopper 6 to the outer cylinder part 16.
' The fine raw material 13 in the furnace is discharged into the furnace chute 9, and charged at a desired position in the furnace by rotating and tilting the furnace chute 9 to form a desired raw material distribution 13'.
Lower gate valve7. Close the lower seal valve 8fc to complete one batch operation.

In this way, the coarse raw material 12 and the fine raw material 13 are transferred to the upper hopper 3. They are stored separately in the lower hopper 6, and during one batch operation, the coarse raw material 12 and the fine raw material 13 are separately charged from the lower hopper 6 to their respective desired positions in the furnace via the furnace chute. In this way, a desired raw material distribution 12', 13' is formed.

2 and 3 show another example of a bellless charging device for carrying out the present invention, which mainly includes an upper hopper 3. Coarse raw material 12 and fine raw material 1 in lower hopper 6
3 shows a modification of the storage section and discharge form of No. 3.

That is, in the case shown in FIG. 2, the inside of the upper hopper 3 is divided into a storage area for the coarse raw material 12 and a storage area for the fine raw material 13, and each is provided with a gate valve 4 and an upper seal valve 5. 1
Corresponding to the positions of these storage parts, a storage part for coarse grain raw material 12 and a storage part for fine grain raw material 13 are separately provided in the lower hopper 6, and an in-hopper gate valve 18 is interposed between these two storage parts. , further provided with a common gate valve 7 and lower seal valve 8.

Also, in the one shown in FIG. 3, the inside of the upper hopper 3 is divided into a coarse raw material storage section and a plurality of fine grain raw material storage sections, each of which is provided with a gate valve 4. An upper seal valve 5 is provided, and a coarse raw material storage area and a fine raw material storage area are separately provided in the lower hopper 6 corresponding to the positions of the respective storage areas. A movable ring 17' is provided between the granular raw material storage sections, and a common -margate valve and lower seal valve 8 are provided.

In the practical example, the coarse raw material 12 is a hora, +-3,
The raw materials are stored in the cylindrical portion 15.15' of the hopper 6, and the fine raw materials are stored in the outer cylindrical portion 16.16', and after the coarse raw materials are discharged, the fine raw materials are discharged. It is effective to allow the discharge order to be changed arbitrarily as needed. Further, although iron-containing ore is used as an example of the raw material, it goes without saying that the present invention can also be applied to coke and other raw materials. In addition, the raw material is conveyed to the top of the furnace by a belt conveyor 1, classified by a classification damper 14, and then fed into the hopper 3, but it is also possible to use a skip car, or other classification means can be used. You can also do it by setting up.

Further, in the above embodiments, charging by particle size is taken as an example, but it is also applicable to charging by brand, for example, and includes the case of charging by particle size, in which different polarity raw materials are simultaneously discharged from the hopper,
It is also possible to mix and charge the mixture into the furnace.

(Effects of the Invention) In the charging method according to the present invention, raw materials of different particle sizes or brands can be charged into the furnace within one cycle of evacuation and pressure equalization operations for coarse grain raw materials and fine grain raw materials. By increasing the number of revolutions of the chute, it is possible to finely control the distribution of raw materials in the blast furnaces, so that the gas flow distribution in the furnaces can be ideally formed. Therefore, the raw material efficiency is also good, the conditions in the milling furnace can be made good and stable, and the production capacity of the blast furnace can be greatly improved by 4 tons.

[Brief explanation of the drawing]

1, 2, and 3 are longitudinal cross-sectional explanatory views showing an example of a bellless type charging device for improving the method of charging materials into a blast furnace according to the present invention, and FIG. FIG. 2 is an explanatory longitudinal cross-sectional view showing an example of a bellless charging device for carrying out a raw material charging method. 1... Belt conveyor 2... Chute 3... Upper hopper 4... Gate valve 5... Upper seal valve 6... ...lower hopper? ...Gate valve 8...Lower seal valve 9...Furnace chute 1O...Pressure equalization system 11...Exhaust pressure system 12... ... Coarse grain raw material 13 ... Fine grain raw material 14 ... Classification damper 15 ... Inner cylinder part 15 of upper hopper ... Inner cylinder part 16 of lower hopper ... ... Upper hopper outer cylinder part 16' ... Lower hopper outer cylinder part 1'7.1'7
'...Movable ring -11- 18...Lower hopper internal gate valve Application person Shin Nippon Acupuncture Co., Ltd. 2 Figure 2 Figure 3

Claims (1)

[Claims] In a bell-less charging device that charges raw materials from a hopper into a furnace via a chute, raw materials are stored in the hopper by particle size, brand, etc., and these raw materials are used for pressure equalization and exhaust pressure operations in the hopper. A method for charging raw materials into a blast furnace, characterized in that raw materials are charged to respective desired positions in the furnace through a chute so that raw materials can be sequentially discharged from a hopper according to type in one cycle.