JP3978105B2 - Raw material charging method for blast furnace - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a raw material charging method for a blast furnace capable of stabilizing a raw material falling trajectory by keeping a raw material accumulation level in a storage hopper below a fixed hopper constant.
[0002]
[Prior art]
[Patent Document 1]
Japanese Patent Publication No. 63-39642 [0003]
Conventionally, the raw materials from each fixed hopper of iron ore and coke are supplied to the furnace turning chute via the storage hopper, and alternately charged and distributed in the furnace by tilting and turning of the furnace turning chute. A raw material charging method for a bell-less blast furnace is widely known. On the other hand, in order to maintain stable operation of the blast furnace, the ratio of iron ore and coke at each location in the furnace and the coke amount ratio and the layer state are kept constant, and the gas flow distribution in the furnace and the furnace heat distribution are maintained. It is important to make it uniform.
[0004]
Therefore, the present applicant has developed a raw material charging method for a blast furnace in which the level of the raw material inside the furnace is flattened and the particle size in the furnace radial direction is changed stepwise in the furnace radial direction. Previously proposed as Japanese Patent Publication No. 63-39642 (Japanese Patent Application No. 60-67396).
However, as a result of research conducted by the present inventors, it has been found that the dropping trajectory of the raw material falling from the storage hopper to the in-furnace swivel chute has a great influence on uniformizing the iron ore and coke layer state. That is, it has been found that when the raw material deposition level in the storage hopper fluctuates, the falling trajectory of the raw material changes, and a uniform raw material layer cannot be formed in the furnace. Accordingly, it has been desired to develop a new technique for keeping the raw material accumulation level in the storage hopper constant.
In addition, since the initial opening of the upper flow control gate has been set to a predetermined value obtained empirically, the material accumulation level in the storage hopper changes when the material accumulation changes due to changes in the particle size of the material, etc. There was also a problem that the controllability of the system was adversely affected.
[0005]
[Problems to be solved by the invention]
The present invention solves the conventional problems as described above, and by keeping the raw material accumulation level in the storage hopper below the fixed hopper constant, it is possible to stabilize the raw material falling trajectory, and further, the raw material It was completed for the purpose of providing a raw material charging method for a blast furnace that can charge the raw material while keeping the raw material deposition level constant without being affected by the next raw material charging even if the particle size changes. Is.
[0006]
[Means for Solving the Problems]
The raw material charging method of the blast furnace of the present invention made to solve the above problems is to supply the raw materials of each fixed hopper of iron ore and coke alternately to the in-furnace swivel chute via the storage hopper, In the blast furnace raw material charging method in which the turning chute is tilted and swirled into the furnace, the upper flow adjustment gate at the lower part of the fixed hopper is set for each upper flow adjustment gate in each fixed hopper. (10a), when the base opening of the (10b), respectively (θ a), (θ b ), and the correction angle respectively set for each fixed hopper (β a), (β b ), The opening of the upper flow adjustment gate is set to (θ a −β a ) or (θ b −β b ) at a predetermined level, and the opening of the upper flow adjustment gate is set to (θ when the return to a) or (θ b), has become a high level The opening of the upper flow regulating gate and (θ a -2β a) or (θ b -2β b), back to when it reaches a predetermined level (θ a -β a) or (θ b -β b) The average of the upper flow control gate is calculated using data obtained by converting and quantifying the level to which the accumulation of each material belongs in the total time in one raw material charging process. The opening is calculated, and based on this value, the initial opening of the upper flow adjustment gate of each fixed hopper at the time of the next raw material charging is determined.
[0007]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.
In Figure 1, 1 a are each fixed hopper of iron ore, 1b coke fixed hopper, 2 a blast furnace body, said the stationary hopper iron ore and coke are charged interchanged at a constant period. These raw materials are charged into the fixed hoppers 1 a and 1 b through the belt conveyor 3 and the switching chute 4 at the top. The iron ore and the coke raw material stored in the fixed hoppers 1 a and 1 b are alternately supplied to the in-furnace turning chute 6 through the storage hopper 5, and the in-furnace turning chute 6 is tilted and swung in the furnace. The above raw material charging process is basically the same as the conventional bellless type blast furnace raw material charging method.
[0008]
In the present invention, the amount of the raw material is adjusted while adjusting the degree of opening of the upper flow control gate 10 at the lower portion of the fixed hopper so that the amount of the raw material is kept constant based on the level meter 7 installed in the storage hopper 5. At the same time, the average opening degree of the upper flow adjustment gate 10 at this time is calculated, and the initial opening degree of the upper flow adjustment gate 10 at the next raw material charging is determined based on this value. It has characteristics.
[0009]
More specifically, a level meter 7 for measuring the amount of raw material accumulated is installed in the storage hopper 5. Specifically, three level meters 7, 7, and 7 (from the top to H, M, and L) are installed in the vertical direction, and signals from each level meter when material accumulates beyond the level meter. Of the total time in one raw material charging process, it is determined whether the raw material accumulation level belongs to any of the four levels of less than level L, level L to M, level M to H, or level H or higher. It is configured to convert and quantify.
[0010]
Then, based on the numerical value quantified as described above, the opening degree of the upper flow adjustment gate 10 is adjusted, and fine adjustment is performed so that the accumulation state of the raw material is maintained in the vicinity of the level M.
That is, each upper flow regulating gate 10 a, 10 b of the base opening degree, respectively (θ a), (θ b ) and when, the upper flow regulating gate 10 a as they become level M, 10 b of the opening Is (θ a −β a ) or (θ b −β b ) . Here, β a and β b are correction angles set for the iron ore, the coke brand, and each fixed hopper. Then, returning the opening degree of the upper flow regulating gate 10 a, 10 b when it becomes level L in (theta a) or (θ b). Further, when the level H is reached, the opening degree of each upper flow control gate 10 a , 10 b is set to (θ a -2β a ) or (θ b -2β b ), and when the level M is reached (θ a Adjustment is made so as to return to −β a or (θ b −2β b ) .
Note that the levels M and H are detected, and the opening of the upper flow adjustment gate 10 is set to (θ a −β a ), (θ b −β b ), (θ a −2β a ), or (θ b −2β b ) . If the level does not return to L or M even after a lapse of a certain time, the opening degree of the upper flow adjustment gate 10 is returned to the base opening degree (θ) as an input value abnormality and is controlled again.
[0011]
In addition, the average opening of the upper flow adjustment gate is obtained by using the data obtained by converting and quantifying the level of the raw material accumulation level in the total time in one raw material charging process. Based on this value, the initial opening degree of the upper flow adjustment gate at the time of the next raw material charging is determined. As a result, even if there is a change in the amount of accumulation due to a change in the raw material particle size, etc., the initial opening of the upper flow control gate is an appropriate value, so there will be no adverse effects when the raw material is charged the next time, and smooth It is possible to carry out a raw material charging.
In addition, the determination of the initial opening of the upper flow adjustment gate at the time of the next raw material charging is, specifically, in the total time in one raw material charging process, the amount of raw material accumulation is less than level L, level L ~ Calculate the time ratio of each level based on the value obtained by converting the time of M, level M to H, or higher level H or higher to level H and converting it to time (calculated as the ratio when the total is 100) The average value obtained by multiplying this by the correction coefficient is taken as the average level. Then, the initial level of the upper flow adjustment gate is determined by adding a correction by ± in comparison with the average level.
[0012]
Thus, according to the present invention, the opening of the upper flow control gate 10 at the lower part of the fixed hopper is adjusted so that the amount of the material accumulated is constant based on the level meter 7 installed in the storage hopper 5. At the same time, the average opening of the upper flow adjustment gate 10 at this time was calculated, and the initial opening of the upper flow adjustment gate 10 at the time of the next raw material charging was determined based on this value. For example, even if there is a change in the particle size of the raw material, the raw material deposition level in the storage hopper is kept constant. As a result, since the raw material can always be dropped to the in-furnace swivel chute 6 under a certain condition, the ratio of the amount of iron ore and the amount of coke and the layer state at each position in the furnace are kept constant. A stable blast furnace operation can be secured with a constant reaction.
[0013]
【The invention's effect】
As is clear from the above description, the present invention can stabilize the material dropping trajectory by keeping the material accumulation level in the storage hopper below the fixed hopper constant, and further change the particle size of the material. Even if there is, etc., the raw material can be charged while keeping the raw material deposition level constant without being affected at the next raw material charging.
Therefore, the present invention greatly contributes to the development of industry as a raw material charging method for a blast furnace that eliminates conventional problems.
[Brief description of the drawings]
FIG. 1 is a front view showing an embodiment of the present invention.
[Explanation of symbols]
1 a iron ore fixed hopper
1 b Coke fixed hopper 2 Blast furnace body 5 Storage hopper 7 Level meter
10 a upper flow control gate
10 b upper flow regulating gate 11 lower flow regulating gate

Claims (1)

In a raw material charging method for a blast furnace in which raw materials of each fixed hopper of iron ore and coke are alternately supplied to a swivel chute in a furnace through a storage hopper, and charged and distributed in the furnace by tilting and swiveling of the swivel chute in the furnace , The opening of the upper flow adjustment gate below the fixed hopper, and the base opening of each upper flow adjustment gate ( 10a ), ( 10b ) set for each fixed hopper , respectively (θ a ), (θ b ), And the correction angles set for each fixed hopper are (β a ) and (β b ) , respectively , the opening of the upper flow adjustment gate is (θ a −β a ) or (θ b −β b ). When the level becomes low, the opening of the upper flow adjustment gate is returned to (θ a ) or (θ b ) , and when it becomes a high level, the upper flow adjustment gate the opening and (θ a -2β a) or (θ b -2β b) Adjusts back to (θ a -β a) or (θ b -β b) when it becomes a predetermined level, of the total time in one raw material charging step, reservoir of each raw material condition The average opening of the upper flow control gate is calculated using data that is converted to time and quantified to which level belongs, and based on this value, the upper flow of each fixed hopper at the next raw material charging is calculated. A raw material charging method for a blast furnace, characterized by determining an initial opening of the adjusting gate.

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