JP2018048361A - Blast furnace raw fuel charging device and blast furnace raw fuel charging method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a blast furnace raw fuel charging device and a blast furnace raw fuel charging method, capable of gradually reducing deviation of depositional surface height in a circumferential direction of a raw fuel and therefor conducting stable blast furnace operation.SOLUTION: There is provide a blast furnace top charging device, having a swing chute which capable of rotating around a vertical axis line O1, a raw fuel deposition surface height detector for detecting deposition surface height of the raw fuel in the circumferential direction in the blast furnace, a flow regulating valve for regulating flow of the raw fuel and control part, the control part controls opening degree of a flow regulating valve so that the raw fuel is charged with overlapping with correspondence to the circumferential direction position having lower deposition surface height of the raw fuel in the blast furnace based on the deposition surface height of the raw fuel detected by the raw fuel deposition surface height detector.SELECTED DRAWING: Figure 4A

Description

  The present invention relates to a blast furnace raw fuel charging apparatus and a blast furnace raw fuel charging method for charging raw fuel into a blast furnace.

As is well known, for example, a bellless charging device using a turning chute is known as means for charging raw fuel such as sintered ore and coke into a blast furnace.
When the raw fuel is charged into the blast furnace using the bell-less charging device, considering the productivity of pig iron production, the consumption of the blast furnace furnace wall, the suppression of deposits on the furnace wall, etc. The distribution of the charge is controlled.

  In blast furnace operation, the distribution of charge in the circumferential direction in the blast furnace greatly affects the productivity and stability of the blast furnace, so it is extremely difficult to reduce the deviation in the distribution of charge in the circumferential direction in the blast furnace. Is important to.

  However, due to fluctuations in gas flow and unloading fluctuations that flow through the gap between the charges, there is a deviation in the height of the deposition surface in the circumferential direction in the blast furnace (difference in height of the deposition surface). The lowest circumferential position changes with time. Therefore, techniques relating to correction of the height of the deposited surface in the circumferential direction are disclosed (for example, see Patent Documents 1 and 2).

Japanese Patent Laid-Open No. 08-188806 JP 2000-336411 A

  However, the technique disclosed in Patent Document 1 detects a depletion using the maximum value and the minimum value of a plurality of sounding data, and installs a necessary amount of raw fuel in the decrement part based on the result. To enter. According to this method, it is difficult to detect a decrease when the sounding device is at the maximum / minimum position where it cannot be detected. In addition, since the FCG gate is opened and closed in real time to increase the amount of charging at the one-reduction position in a concentrated manner, the accuracy of the opening and closing operation in a short period of time, the accompanying turn number error and local O / C (Ore) And the weight ratio of coke).

  Further, the technique disclosed in Patent Document 2 shifts the charging start position of the turning chute by the shift angle, for example, inserts the forced chute position at a frequency of once every predetermined number of times, and makes a deviation for each outlet. Is reduced. In this method, there is a problem that it is not easy to sufficiently correct the portion where the raw fuel deposition surface is low.

  On the other hand, the distribution of charges in the blast furnace from the viewpoint of ventilation, for example, the hot air blown so that the reduction of ore is promoted in the center of the furnace makes it easy to vent the gap between the charges, and the furnace around the furnace It is important not to let excess gas flow near the wall so that the furnace wall is protected.

  The present invention has been made in consideration of such circumstances, and it is possible to moderately reduce the unevenness of the height of the deposition surface of the raw fuel in the circumferential direction in the blast furnace, which in turn enables stable blast furnace operation. An object of the present invention is to provide a blast furnace raw fuel charging apparatus and a blast furnace raw fuel charging method.

In order to solve the above problems, the present invention proposes the following means.
The invention described in claim 1 is a blast furnace raw fuel charging device installed in an upper part of a blast furnace, wherein a swivel chute capable of swiveling around the vertical axis while changing an inclination angle with respect to the vertical axis, and the blast furnace A raw fuel accumulation surface height detector for detecting the height of the raw fuel accumulation surface in the inner circumferential direction, a flow rate adjusting valve for adjusting the flow rate of the raw fuel, and a control unit, the control unit, Based on the raw fuel accumulation surface height detected by the raw fuel accumulation surface height detector, the raw fuel is caused to correspond to a circumferential position in the blast furnace where the raw fuel accumulation surface height is low. The opening degree of the flow rate adjusting valve is controlled so as to be charged in an overlapping manner.

  According to a third aspect of the present invention, there is provided a turning chute that is installed in the upper part of the blast furnace and that can turn around the vertical axis while changing an inclination angle with respect to the vertical axis, and deposition of raw fuel in the circumferential direction in the furnace In a blast furnace raw fuel charging device comprising a raw fuel accumulation surface height detector for detecting a surface height and a flow rate adjusting valve for adjusting the flow rate of the raw fuel, the raw fuel is introduced into the blast furnace by the turning chute. The raw fuel deposition surface height is detected in the blast furnace based on the raw fuel deposition surface height detected by the raw fuel deposition surface height detector. The raw fuel is overlapped and charged in correspondence with a low circumferential position.

  According to the blast furnace raw fuel charging apparatus and the blast furnace raw fuel charging method according to the present invention, the deposition of the raw fuel in the blast furnace is based on the raw fuel deposition surface height detected by the raw fuel deposition surface height detector. Since the raw fuel is charged so as to overlap with the circumferential position where the surface height is low, the deviation of the height of the deposited surface in the circumferential direction of the raw fuel can be gradually reduced in the blast furnace. As a result, stable blast furnace operation can be performed.

  A second aspect of the present invention is the blast furnace raw fuel charging device according to the first aspect, wherein the raw fuel deposition surface height detector is a height of the raw fuel deposition surface in the radial direction in the blast furnace. The control unit determines whether the height of the raw fuel deposition surface in the blast furnace is based on the height of the raw fuel deposition surface detected by the raw fuel deposition surface height detector. Corresponding to low radial and circumferential positions, the opening of the flow rate adjusting valve is controlled so that the raw fuel is overlapped and charged.

  A fourth aspect of the present invention is the blast furnace raw fuel charging method according to the third aspect, wherein the raw fuel deposition surface height detector is a height of the raw fuel deposition surface in the radial direction in the blast furnace. In the radial direction and the circumferential direction where the raw fuel deposition surface height is low in the blast furnace based on the raw fuel deposition surface height detected by the raw fuel deposition surface height detector. The raw fuel is overlapped and charged in correspondence with the direction position.

According to the blast furnace raw fuel charging apparatus and the blast furnace raw fuel charging method according to the present invention, the height of the raw fuel deposition surface in the radial direction in the blast furnace can be detected. Based on the height of the raw fuel deposition surface detected by the height detector, the raw fuel is overlapped and charged in correspondence with the radial and circumferential positions where the height of the raw fuel deposition surface in the blast furnace is low. Therefore, the deviation of the height of the deposition surface in the circumferential direction and the radial direction of the raw fuel can be gradually reduced in the blast furnace.
As a result, more stable blast furnace operation can be performed.

  According to the blast furnace raw fuel charging apparatus and the blast furnace raw fuel charging method according to the present invention, it is possible to moderately reduce the deviation of the height of the raw fuel deposition surface in the blast furnace, and thus to perform stable blast furnace operation. Can do.

It is a figure explaining schematic structure of the blast furnace top charging device concerning a 1st embodiment of the present invention. It is a flowchart explaining an example of operation | movement of the blast furnace top charging apparatus which concerns on 1st Embodiment of this invention. It is a perspective view which explains notionally raw fuel distribution in the peripheral direction in a blast furnace concerning a 1st embodiment of the present invention. It is a figure explaining an example of raw fuel distribution in the peripheral direction in a blast furnace concerning a 1st embodiment of the present invention. It is a conceptual diagram explaining the outline of operation | movement of the turning chute in the case of carrying out overlap charging in 1st Embodiment of this invention. It is a conceptual diagram explaining the outline of the operation | movement of the turning chute | shoot in the case of not carrying over overlap in 1st Embodiment of this invention. It is a flowchart explaining an example of operation | movement of the blast furnace top charging apparatus which concerns on 2nd Embodiment of this invention. It is a perspective view explaining notionally the raw fuel distribution in the circumferential direction in the blast furnace concerning 2nd Embodiment of this invention. It is a figure explaining an example of the raw fuel distribution in the circumferential direction in the blast furnace concerning 2nd Embodiment of this invention. It is a conceptual diagram explaining the outline of operation | movement of the turning chute in the case of carrying out overlap charging in 2nd Embodiment of this invention. It is a conceptual diagram explaining the outline of the operation | movement of the turning chute | shoot in the case of not carrying over overlap in 2nd Embodiment of this invention. It is a figure explaining the Example of this invention, and is a figure which shows the change of a charge number and O / C. It is a figure explaining the Example of this invention, and is a figure which shows the influence which the predetermined value H has on the difference in the charge deposit surface height.

<First Embodiment>
Hereinafter, a first embodiment of the present invention will be described with reference to FIGS. 1 to 4B.
FIG. 1 is a diagram showing a schematic configuration of a blast furnace top charging apparatus according to an embodiment of the present invention. Reference numeral 1 denotes a blast furnace, reference numeral 10 denotes a blast furnace main body, and reference numeral 20 denotes a blast furnace top charging apparatus ( Blast furnace raw fuel charging device).

  As shown in FIG. 1, the blast furnace 1 includes, for example, a blast furnace main body 10 and a blast furnace top charging device 20, and the blast furnace top charging device 20 is installed in an upper part of the blast furnace 1.

The blast furnace main body 10 is formed in, for example, a substantially cylindrical shape whose lower diameter is enlarged, and a raw fuel inlet 11 is opened at the upper part.
Then, the blast furnace top charging device 20 charges the raw fuel in a layered manner from the raw fuel inlet 11 to a specific range of the blast furnace main body 10, and the charged raw fuel reacts in the blast furnace main body 10 to produce pig iron. It is to be generated.

  The blast furnace top charging device 20 includes, for example, a profile meter (raw fuel deposition surface height detector) 21, a turning chute 24, and a turning device (not shown) for turning the turning chute 24 around the vertical axis O1. An inclination device (not shown) for setting a notch angle (inclination angle) θ with respect to the vertical axis O1 of the turning chute 24, a plurality of furnace top hoppers (not shown), and a flow rate adjusting valve (not shown) provided below the furnace top hoppers (Not shown), a collective chute (not shown), a vertical chute 22, and a control unit (not shown).

  The blast furnace top charging device 20 is configured to charge the raw fuel stored in the plurality of furnace top hoppers into the blast furnace main body 10 via the collecting chute, the vertical chute 22 and the swiveling chute 24. .

The profile meter (raw fuel deposition surface height detector) 21 is disposed, for example, in an opening formed in an inclined wall portion at the top of the blast furnace body 10.
Moreover, the profile meter 21 emits electromagnetic waves such as microwaves from the antenna onto the deposition surface of the charge in the blast furnace and scans it, so that the unevenness of the deposition surface and the height of the deposition surface of the raw fuel are planar ( For example, it can be detected in a circumferential direction and a radial direction) or linearly (for example, in the circumferential direction).
As the profile meter 21, it is possible to use a known profile meter as described in, for example, Japanese Patent Application Laid-Open No. 2011-033619.
When the radial position is constant, for example, a sounding device (measurement bar) (not shown) as described in JP-A-8-188806 may be used.

  The furnace top hopper (not shown) is arranged side by side on the upper part of the blast furnace top charging apparatus 20, and each corresponding raw fuel is stored, and a flow rate adjusting valve (lower part of the furnace top hopper ( The flow rate of the raw fuel to be discharged can be adjusted by adjusting the opening amount of the raw fuel discharge port (not shown).

  The collecting chute (not shown) is disposed below the furnace top hopper and has a concave shape opening upward.

  The vertical chute 22 is connected to an opening formed in the lower part of the collective chute and is formed to extend downward in the vertical direction. A turning chute 24 is disposed below the vertical chute 22.

The turning chute 24 is formed in, for example, a bowl shape having a semicircular arc shape in cross section or a cylindrical shape.
Further, the turning chute 24 can be turned around the vertical axis O1 by a turning device (not shown), and tilted around the radial axis O2 by the tilting device to be notched (tilt angle) θ with respect to the vertical axis O1. (Deg) can be changed. Reference symbol L indicates a reference line for defining the notch angle θ of the turning chute 24.

  Based on the height of the raw fuel deposit surface detected by the profile meter 21, the control unit (not shown) associates the raw fuel with the circumferential position (concave portion) in which the height of the raw fuel deposit surface is low. Are configured to overlap with each other.

  Specifically, for example, based on the deposition surface height of the raw fuel detected by the profile meter 21, the maximum position of the deposition surface height in the circumferential direction (the circumferential position where the deposition surface becomes the top of the mountain) and the minimum position (The circumferential position where the deposition surface becomes the bottom of the valley) is determined, and when the difference D in the height of the deposition surface between the maximum position and the minimum position is greater than or equal to the reference value S (m), Is set to the charging start position P (deg) of the (bellless) blast furnace top charging device 20, and the deposition surface height is set to the predetermined value H (in the swirling direction). m) First, the circumferential position at which the predetermined value H is equal to or greater than the predetermined value H is set to the charging end position Q (deg) of the (bellless) blast furnace top charging device 20. Then, the flow rate adjusting valve is opened in accordance with the charging start position P (deg), and the opening of the flow rate adjusting valve is adjusted so that the charging of the raw fuel is completed at the charging end position Q (deg).

Hereinafter, with reference to FIG. 2, FIG. 3A, FIG. 3B, FIG. 4A, and FIG.
FIG. 2 is a flowchart for explaining an example of the operation of the blast furnace top charging apparatus according to the first embodiment. 3A is a perspective view conceptually illustrating the raw fuel distribution in the circumferential direction in the blast furnace 1 according to the first embodiment, and FIG. 3B illustrates an example of the raw fuel distribution in the circumferential direction in the blast furnace. It is a figure to do. 4A and 4B are conceptual diagrams for explaining the outline of the raw fuel charging operation. A symbol L11 (L) illustrated in FIG. 3A is a reference line that defines the notch angle θ11 when the turning chute 24 faces the circumferential locus C11.

(1) First, the height of the deposited surface of the raw fuel charge in the blast furnace is measured with a profile meter (S01).
The height of the deposition surface in the circumferential direction at a predetermined position in the furnace radial direction is measured by a profile meter or a sounding device (measurement bar) (not shown). For example, as shown in FIG. 3A, the deposition surface is measured linearly along a circumferential locus C11. Here, the predetermined position is the radial position where the measuring bar is installed when it is used. In the profile meter, it is possible to detect an arbitrary radial position, but it is preferable to identify a radial position where unevenness is most likely to occur in accordance with the charging pattern to be used and fix it to the radial position.
(2) Next, the maximum position and the minimum position of the deposition surface in the circumferential direction (turning direction) are detected (S02).
For example, as shown in FIG. 3B, the maximum position and the minimum position of the deposition surface in the circumferential direction (turning direction) are obtained based on the fluctuation of the height of the deposition surface at the circumferential position. Here, the symbol A11 indicates the maximum position, and the symbol B11 indicates the minimum position.
(3) Next, the difference D between the heights of the deposited surfaces at the maximum position and the minimum position is calculated (S03).
In FIG. 3B, the difference D11 is calculated from the height of the deposition surface at the maximum position A11 and the minimum position B11.
(4) Next, it is determined whether or not the difference D between the heights of the deposited surfaces at the maximum position and the minimum position calculated in S04 is greater than or equal to the reference value S (S04).
When there is a combination of the maximum position and the minimum position where the difference D in the deposition surface height is greater than or equal to the reference value S (S04: Yes), the process proceeds to S05, and the difference D in the deposition surface height is greater than or equal to the reference value S. When the combination of the maximum position and the minimum position does not exist (S04: No), the process proceeds to S07.
Here, the reference value S (m) is preferably 0.2 m, for example.
In FIG. 3B, since there exists a recess U11 whose difference D11 is equal to or greater than the reference value S from the height of the deposited surface at the maximum position A11 and the minimum position B11, the process proceeds to S05.
In addition, when there are a plurality of recesses in the blast furnace where the difference D in the height of the deposition surface between the maximum position and the minimum position is equal to or greater than the reference value S, for example, the recess having the lowest deposition surface height at the minimum position is targeted. It is preferred to overlap the raw fuel charges.
(5) When the raw fuel charging is overlapped, a circumferential position where the height of the deposition surface first becomes a predetermined value H or less is set as a charging start position (overlap start position) P (S05).
Here, the predetermined value H (m) is a range (H = −0.05 m to 0 m) from the average deposition surface (average value of the maximum height and the minimum height of the deposition surface) to (−0.05 m). Is preferred.
In FIG. 3B, a circumferential position (for example, 90 ° (deg)) P11 at which the height of the deposition surface first becomes a predetermined value H or less is set as a raw fuel charging start position (overlap start position).
(6) Next, after the raw fuel charging start position (overlap start position) P, a circumferential position where the height of the deposition surface first becomes a predetermined value H or more is set as an overlap end position Q (S06). .
In FIG. 3B, after the raw fuel charging start position (overlap start position) P11, the circumferential position (for example, 135 ° (deg)) Q11 at which the height of the deposition surface first becomes a predetermined value H or more overlaps. Set to end position.
(7) A predetermined raw fuel charging start position R (deg) when not overlapping is set (S07).
(8) The raw fuel charge flow rate is set (S08).
When the raw fuel charging overlaps, the raw fuel charging flow rate is set based on the overlap start position P and the overlapping end position Q. When the raw fuel charging does not overlap, the predetermined raw fuel charging is performed. Set to flow rate.
The charging end position adjustment may be performed by learning control of the gate opening.
(9) The raw fuel is charged (S09).
Each time the raw fuel to be charged is switched, S01 to S09 are repeated.

The turning chute usually turns at a constant angular velocity. As shown in FIG. 4A, the raw fuel charging is performed by opening the flow rate adjusting valve at the timing when the turning chute becomes the charging start position (overlap start position) P11 as shown in FIG. 4A. Start fuel charging. After the turning chute turns a preset number of times, the opening degree of the flow rate adjusting valve is adjusted so that the charging of the raw fuel is finished at the overlap end position Q11. In FIG. 4A, the symbol T10 indicates a turn on the turning trajectory C11, the symbol T11 indicates a one-turn turn starting from the charging start position (overlap start position) P11, and the symbol W11 indicates a charging start position ( It shows charging by overlap from overlap start position P11 to overlap end position Q11. The white circles shown in FIGS. 4A and 4B indicate the charging start position.
In one charge of the normal bell-less charging method, a plurality of turns are performed from the furnace periphery to the furnace center. In this case, it is preferable to overlap at the time of the first turn. This is because the flow of raw fuel from the periphery of the furnace to the center of the furnace occurs most strongly in the first turn, so that the concave portion of the deposition surface can be repaired efficiently.

  In addition, when the overlap turning is not performed, as shown in FIG. 4B, the raw fuel charging is started at a predetermined charging start position R (for example, 0 ° (deg)), and the number of times set in advance is set. The opening degree of the flow rate adjustment valve is adjusted so that the turning is finished and the charging is finished at the turning start position R at the same position. In FIG. 4B, symbol S10 indicates one round of charging starting from a charging start position (overlap start position) R on the turning trajectory C11.

  According to the blast furnace top charging apparatus 20 according to the first embodiment, the circumferential position of the raw fuel deposition surface height in the blast furnace 1 is low based on the raw fuel deposition surface height detected by the profile meter 21. Accordingly, the raw fuel is overlapped and charged in the blast furnace 1, so that the deviation of the height of the deposition surface in the circumferential direction of the raw fuel can be gradually reduced. As a result, stable blast furnace operation can be performed.

Second Embodiment
Hereinafter, a second embodiment of the present invention will be described with reference to FIGS. 1 and 5 to 7B.
The second embodiment is different from the first embodiment in that the control unit and the profile meter (raw fuel accumulation surface height detector) 24 are different from the first embodiment in that the accumulation surface is detected by the turning chute 24 also in the radial direction. Is different. Reference signs L21, L22, and L23 (L) shown in FIG. 6A are reference lines that define the notch angles θ21, θ22, and θ23 when the turning chute 24 faces the turning trajectories C21, C22, and C23. Others are the same as those in the first embodiment, and thus the description of the same parts is omitted.

Hereinafter, the control procedure of raw fuel charging will be described with reference to FIG.
FIG. 6 is a flowchart for explaining an example of the operation of the blast furnace top charging apparatus according to the second embodiment.
(1) First, the height of the deposition surface of the raw fuel charge in the blast furnace is measured with a profile meter (S11).
For example, as shown in FIG. 6A, the height of the deposited surface by the profile meter is measured by a turning locus C21 corresponding to a notch angle θ (for example, θ21, θ22, θ23) at which the turning chute changes in one charge. The deposition surfaces at C22 and C23 are measured in a planar shape (radial direction and circumferential direction).
(2) Next, for each radial position corresponding to the notch angle θ of the turning chute (inside the blast furnace), the maximum position and the minimum position of the deposition surface in the circumferential direction (turning direction) are detected (S12).
For example, as shown in FIGS. 6A and 6B, the maximum position and the minimum position of the deposition surface in the circumferential direction (swirl direction) correspond to the notch angles θ21, θ22, and θ23 of the swivel chute (inside the blast furnace). Further, it is obtained based on the fluctuation of the height of the deposition surface at the circumferential position. Here, reference symbols A21 and A22 indicate maximum positions, and reference symbols B21 and B22 indicate minimum positions.
(3) Next, a difference D between the heights of the deposited surfaces at the maximum position and the minimum position is calculated (S13).
In FIG. 6B, the differences D21 and D22 are calculated from the heights of the deposition surfaces at the maximum position A21 and the minimum position B21 at the notch angle θ21 and between the maximum position A22 and the minimum position B22 at the notch angle θ22.
(4) Next, it is determined whether or not the difference D between the heights of the deposited surfaces at the maximum position and the minimum position calculated in S14 is greater than or equal to the reference value S (S14).
When there is a combination of the maximum position and the minimum position where the difference D in the deposition surface height is equal to or greater than the reference value S (S14: Yes), the process proceeds to S15, and the difference D in the deposition surface height is equal to or greater than the reference value S. When the combination of the maximum position and the minimum position does not exist (S14: No), the process proceeds to S18.
Here, the reference value S (m) is preferably 0.2 m, for example.
In FIG. 6B, for example, the concave portion U21 which is the difference D21 (≧ reference value S) in the deposition surface height between the maximum position A21 and the minimum position B21, and the difference D22 in the deposition surface height between the maximum position A22 and the minimum position B22. There is a recess U22 where ≧ reference value S).
Here, when there are a plurality of recesses in the blast furnace in which the difference D in the height of the deposition surface at the maximum position and the minimum position is equal to or greater than the reference value S, for example, the recess having the lowest deposition surface height at the minimum position is targeted. It is preferable to overlap the raw fuel charging.
Therefore, comparing the height of the deposit surface at the minimum position B21 and the height of the deposit surface at the minimum position B22, the height of the deposit surface at the minimum position B22 is the lowest. Therefore, the concave portion U22 is the target for overlapping the raw fuel charging. Set to a recess (combination of turning start position (overlap start position) P and overlap end position Q). And since the recessed part U22 of object exists, it transfers to S15.
(5) The notch angle θ of the turning chute where the turning chute raw fuel charging overlaps is set in accordance with the combination of the target maximum position and minimum position (S15).
The notch angle θ at which the raw fuel charging overlaps is set to the notch angle θ22 corresponding to the target recess U22.
(6) When the raw fuel charging overlaps, the circumferential position where the deposition surface height first becomes equal to or less than the predetermined value H is set as the overlap start position P (deg) (S16).
Here, the predetermined value H (m) is a range (H = −0.05 m to 0 m) from the average deposition surface (average value of the maximum height and the minimum height of the deposition surface) to (−0.05 m). Is preferred.
In FIG. 6B, the circumferential position (for example, 270 ° (deg)) P22 at which the height of the deposition surface first becomes a predetermined value H or less at the notch angle θ22 is set as the overlap start position P.
(7) Next, after the overlap start position P, a circumferential position where the height of the deposition surface first becomes equal to or greater than a predetermined value H is set as an overlap end position Q (deg) (S17).
(8) A predetermined charging start position R (deg) when not overlapping is set (S8).
In FIG. 6B, after the overlap start position P22, a circumferential position (for example, 135 ° (deg)) Q11 at which the deposition surface height first becomes equal to or higher than a predetermined value H is set as the overlap end position.
(9) The raw fuel charging flow rate is set (S19).
When the raw fuel charging overlaps, the raw fuel charging flow rate is set based on the overlap start position P and the overlap end position Q, and the flow rate adjusting valve is adjusted to an opening corresponding to the flow rate. When the raw fuel charging does not overlap, a predetermined raw fuel charging flow rate is set, and the flow rate adjusting valve is adjusted to an opening corresponding to the flow rate.
The charging end position adjustment may be performed by learning control of the gate opening degree of the flow rate adjusting valve.
(10) The raw fuel is charged (S20).
Then, S11 to S19 are repeated every time the raw fuel to be charged is switched.

The raw fuel charging is continuously performed while tilting the turning chute in the order of the notch angles θ21, θ22, and θ23. In the case of overlapping charging, as shown in FIG. 7A, when turning at the notch angle θ21, the charging start position is adjusted to the position of the overlapping starting position P22 and the flow rate adjustment valve is opened to load the raw fuel. Be started. The turning chute turns a predetermined number of times at the notch angle θ21. Next, at the notch angle θ22, the turning chute turns for the overlap in addition to the preset number of times from the overlap start position and completes the turn at the overlap end position. Finally, at the notch angle θ23, the turning chute turns a preset number of times from the overlap end position. Then, the opening degree of the flow rate adjusting valve is adjusted so that the charging of the raw fuel is completed at the overlap end position.
In FIG. 7A, a symbol T20 indicates a turn T21 on the turn locus C21, a turn T22 on the turn locus C22, an overlap turn W22 on the turn locus C22, and a turn T23 on the turn locus C23. Here, the turn T21 and the turn T22 are turns starting from the overlap start position P22 and starting from the overlap start position P22. The overlap turn W22 is a turn from the overlap start position P22 to the overlap end position Q22, and the turn T23 is a turn from the overlap end position Q22 to the overlap end position Q22. . The white circles shown in FIGS. 7A and 7B indicate the charging start position. The raw fuel charging ends at the overlap end position Q11.

  Further, when the overlap turning is not performed, as shown in FIG. 7B, the raw fuel charging is started from a predetermined start position R (for example, 0 ° (deg)), and is charged a predetermined number of times. Then, the opening degree of the flow rate adjusting valve is adjusted so that the raw fuel charging is finished at the start position R. In FIG. 4B, symbol S10 indicates a one-turn turn starting from the charging start position (overlap start position) R on the turn locus C11.

According to the blast furnace top charging apparatus 20 according to the second embodiment, the height of the raw fuel deposition surface in the radial direction in the blast furnace 1 can be detected, and the control unit detects the raw fuel deposition surface height. Based on the radial and circumferential raw fuel deposition surface heights detected by the vessel, the swirl chutes overlap in the blast furnace 1 in correspondence with the radial and circumferential positions where the raw fuel deposition surface height is low. Therefore, the deviation of the height of the deposition surface in the circumferential direction and the radial direction of the raw fuel can be accurately reflected in the blast furnace 1, so that the operation fluctuation can be further reduced as compared with the first embodiment.
As a result, more stable blast furnace operation can be performed.

  Note that the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the spirit of the invention.

In the first embodiment, the height of the deposit surface of the charge in the blast furnace 1 is detected only at a predetermined radial position. Therefore, this is a method suitable for a measuring rod type charging device. In the second embodiment, the height of the deposit surface of the charge in the blast furnace 1 is detected in the radial direction and the circumferential direction. Therefore, this is a method suitable for a charging apparatus capable of three-dimensionally detecting a deposition surface using a profile meter using a microwave or the like.
In the second embodiment, the example in which the turning to perform the overlap is performed with the number of notches corresponding to the radial direction position having the deepest recess, but the notch angle to perform the first turning may be used as in the first embodiment. . This is because even if the recess is on the radial center side of the furnace, it is gently repaired by the inflow.

  When a sounding device is used, the overlap start and end positions may be estimated by approximating measured data at a plurality of points with a polynomial function of third order or higher.

  Moreover, in the said embodiment, although an example of the flowchart was shown in FIG. 2, FIG. 5, it cannot be overemphasized that methods (algorithms) other than a flowchart may be used.

The present embodiment aims to confirm the basic raw fuel charging behavior in which the concave portion is repaired by the overlapping charging, which is an operation common to both the first and second inventions.
In this example, a 1/3 size bell-less apparatus was used under the following experimental method and conditions. First, as shown by the point where the number of charges is zero in FIG. 8 regardless of the radial position, irregularities of the deposition surface of the raw fuel charge according to the circumferential position were formed. Next, the raw fuel was alternately charged up to 5 times by one turn + overlap turn. Each time of charging, the shape of the raw fuel surface is measured, and based on it, O / C (the average value in the radial direction by the ratio of the thickness of the ore layer and the coke layer) and D (the highest position of the deposition surface height) And the average value of the lowest position).
The predetermined value H was set to three levels of -0.05, -0.15, and +0.10 m with respect to the average value of the highest position and the lowest position of the deposition surface height when the number of charges was zero. At this time, the overlap start position and overlap end position were 45 and 230, 70 and 145, and 25 and 310 (deg), respectively.
The test results are shown in FIGS.
FIG. 8 is a diagram for explaining a change in O / C up to 5 charges. . In FIG. 8, the horizontal axis represents the number of charges, and the vertical axis represents O / C. As shown in FIG. 8, the O / C was improved moderately, and it was confirmed that the unevenness D on the deposit surface of the charge in the blast furnace was below the reference value S (= 0.2 m) at 5 charges. .

FIG. 9 shows the influence of the predetermined value H. The charge number and the charge accumulation surface in the blast furnace at the predetermined value H = −0.15 (m) and the predetermined value H = −0.05 (m). It is a figure which shows the difference D (maximum height-minimum height) of height. In the case of H = −0.15, as shown in FIG. 9, it is confirmed that the target range (circumferential length) (circumferential angle) is narrowed and it takes time to correct, but it is corrected moderately. did it.
On the other hand, when H = 0.10 (m) and the range to be corrected is enlarged, the overlapping turns are almost two turns (not shown). It can be said that the influence on the deposited shape is increased and the recess can be eliminated in a short time. Although there is no problem if there is no unknown variation factor as in this embodiment, it is necessary to be careful because there is a possibility that the variation does not converge due to overaction in actual operation.

    According to the blast furnace raw fuel charging apparatus and the blast furnace raw fuel charging method according to the present invention, stable blast furnace operation is performed by gradually reducing the deviation of the height of the deposition surface in the circumferential direction of the raw fuel in the blast furnace. It can be used industrially.

O1 swivel axis (vertical axis)
O2 Tilt axis θ11, θ21, θ22, θ23, θ Notch angle (tilt angle with respect to vertical axis)
1 Blast furnace 10 Blast furnace body 20 Blast furnace top charging device (Blast furnace raw fuel charging device)
21 Profile meter (raw fuel accumulation surface height detector)
22 Vertical chute 24 Turning chute

Claims (4)

A blast furnace raw fuel charging device installed at the top of the blast furnace,
A turning chute capable of turning around the vertical axis while changing an inclination angle with respect to the vertical axis;
Raw fuel deposition surface height detector for detecting the height of the raw fuel deposition surface in the circumferential direction in the blast furnace,
A flow rate adjusting valve for adjusting the flow rate of the raw fuel;
A control unit;
With
The controller is
Based on the raw fuel accumulation surface height detected by the raw fuel accumulation surface height detector, the raw fuel is caused to correspond to a circumferential position in the blast furnace where the raw fuel accumulation surface height is low. A blast furnace raw fuel charging device, wherein the opening degree of the flow rate adjusting valve is controlled so as to be charged in an overlapping manner. The blast furnace raw fuel charging device according to claim 1,
The raw fuel accumulation surface height detector is capable of detecting the accumulation surface height of the raw fuel in the radial direction in the blast furnace,
The controller is
Based on the raw fuel accumulation surface height detected by the raw fuel accumulation surface height detector, in the blast furnace, the raw fuel accumulation surface height is associated with a low radial and circumferential position, and A blast furnace raw fuel charging device, wherein raw fuel is overlapped and charged. A swivel chute installed at the top of the blast furnace and capable of swiveling around the vertical axis while changing an inclination angle with respect to the vertical axis, and raw fuel deposition for detecting the height of the raw fuel deposition surface in the circumferential direction in the blast furnace A surface height detector, a flow rate adjusting valve for adjusting the flow rate of the raw fuel,
In the blast furnace raw fuel charging apparatus comprising: a blast furnace raw fuel charging method of charging raw fuel into the blast furnace with the turning chute,
Based on the raw fuel accumulation surface height detected by the raw fuel accumulation surface height detector, the raw fuel is caused to correspond to a circumferential position in the blast furnace where the raw fuel accumulation surface height is low. Blast furnace raw fuel charging method characterized by overlapping charging. A blast furnace raw fuel charging method according to claim 3,
The raw fuel accumulation surface height detector is capable of detecting the accumulation surface height of the raw fuel in the radial direction in the blast furnace,
Based on the raw fuel accumulation surface height detected by the raw fuel accumulation surface height detector, in the blast furnace, the raw fuel accumulation surface height is associated with a low radial and circumferential position, and A blast furnace raw fuel charging method, wherein raw fuel is overlapped and charged.

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