JP2023046166A - Method for determining charging of raw material into blast furnace, apparatus for determining charging method, and program for determining charging method - Google Patents

Abstract

To reduce variation in an amount of a raw material (coke and ore) to be charged into a blast furnace in a furnace circumferential direction.SOLUTION: A method for determining charging of a raw material into a blast furnace determines a method for charging a raw material into a bell-less type blast furnace. The method calculates a parameter relating to an occurrence frequency in a region in which the amount of the raw material to be charged is relatively large in a furnace circumferential direction for each position in the furnace circumferential direction, on the basis of a charging start position when the same kind of raw material is charged a plurality of times, and a turning direction and a turning number error of a turning chute. Then, the method determines a position in the furnace circumferential direction in which the parameter is the smallest, as a charging start position when the same kind of raw material is charged into the blast furnace again, on the basis of distribution of a parameter according to the position in the furnace circumferential direction. In addition, the method compares two integral values obtained by integrating each of the parameters toward two different furnace circumferential directions from the position in the furnace circumferential direction in which the parameter is the smallest, using the distribution of the parameter according to the position in the furnace circumferential direction. The furnace circumferential direction indicating a small integral value is determined as a turning direction of the turning chute when the same kind of raw material is charged into the blast furnace again.SELECTED DRAWING: Figure 2

Description

TECHNICAL FIELD The present invention relates to a charging determination method, a charging method determining device, and a charging method determining program for determining a method of charging blast furnace raw material into a bell-less blast furnace having a turning chute.

For stable operation of a blast furnace, it is necessary to stabilize the gas flow in the furnace. When the blast furnace raw material is charged into the blast furnace by turning the chute, if the charging amount of the blast furnace raw material varies in the circumferential direction of the furnace, the gas flow in the circumferential direction of the furnace will also vary. Therefore, in Patent Document 1, for each charging charge of blast furnace raw material, the position at which charging of blast furnace raw material is started (charging start position) is shifted by a predetermined amount in the circumferential direction (furnace circumferential direction). .

JP-A-2000-336411 JP 2018-48361 A JP-A-8-188806 JP-A-58-123808 JP-A-6-10018 Japanese Patent No. 3948162

However, simply shifting the charging start position in the circumferential direction of the furnace as in Patent Document 1 may not reduce variations in the charging amount of the blast furnace raw material in the circumferential direction of the furnace, as will be described later.

According to the invention described in Patent Document 1, if the number of turns of the chute is the same each time the blast furnace raw material is charged, the charge start position is shifted in the furnace circumferential direction, thereby charging in the furnace circumferential direction. Potentially reduce volume variability. However, in actual charging, the number of turns of the chute from the start to the end of charging the blast furnace raw material varies depending on the properties (particle size composition) of the blast furnace raw material.

For example, when charging blast furnace raw material into a blast furnace, a predetermined weight of blast furnace raw material is stored in the hopper, and then the blast furnace raw material is supplied from the hopper to the chute. Since the time for supplying the blast furnace raw material from the hopper to the chute is different, the time from the start to the end of charging the blast furnace raw material is also different. For example, the coarser the blast furnace raw material, the longer it takes to charge, and the finer the blast furnace raw material, the shorter the charging time. As a result, variation occurs in the number of revolutions of the chute from the start to the end of charging the blast furnace raw material.

As described above, if the number of turns of the chute varies, even if the charging start position is shifted in the circumferential direction of the furnace, the blast furnace raw material cannot be charged as expected. It becomes difficult to reduce variations in input amount.

A first invention of the present application is a blast furnace raw material charging determination method for determining a method of charging blast furnace raw material into a bell-less blast furnace by turning a turning chute. In this charging determination method, the charging amount of the blast furnace raw material in the furnace circumferential direction is determined based on the charging start position, the turning direction of the turning chute, and the turning number error when the same type of blast furnace raw material is charged multiple times. A parameter relating to the number of occurrences of relatively large regions is calculated for each position in the furnace circumferential direction. The turn number error indicates the deviation of the actual number of turns from the set number of turns of the turn chute, and includes cases where the actual number of turns is greater than the set number of turns and cases where the actual number of turns is less than the set number of turns. .

Next, based on the parameter distribution according to the positions in the furnace circumferential direction, the position in the furnace circumferential direction where the parameter is the smallest is determined as the charging start position when charging the same type of blast furnace raw material again. Also, using the distribution of parameters according to the positions in the circumferential direction of the furnace, two integrated values obtained by accumulating the parameters in two different circumferential directions from the position in the circumferential direction where the parameter is the smallest are compared. Then, the circumferential direction of the furnace showing a small integrated value is determined as the turning direction of the turning chute when charging the same type of blast furnace raw material again.

When the parameter is the smallest within a specified range of positions in the circumferential direction of the furnace, positions in the circumferential direction of the furnace corresponding to both ends of the specified range are determined as candidates for the charging start position when charging the same type of blast furnace raw material again. can do. As the parameter described above, the ratio of the number of occurrences to the predetermined number of times of charging the blast furnace raw material can be used. The above-mentioned turning number error includes cases where the actual turning number is greater than the set turning number, and the final turning exceeds one turn in the furnace circumferential direction and the blast furnace raw material is charged, and the actual turning number is greater than the set turning number. is reduced, and the blast furnace raw material is charged before the final swirl reaches one turn in the furnace circumferential direction.

A second invention of the present application is a blast-furnace raw material charging method determination device that determines a method of charging blast-furnace raw material into a bell-less blast furnace by turning a turning chute, and has a computing unit and a determining unit. Based on the charging start position when the same type of blast furnace raw material is charged multiple times, the turning direction of the turning chute, and the above-mentioned turning number error, the charging amount of the blast furnace raw material is calculated relative to the furnace circumferential direction. A parameter relating to the number of occurrences of the region with a large number of turbulence is calculated for each position in the circumferential direction of the furnace.

Based on the parameter distribution according to the positions in the furnace circumferential direction, the determination unit determines the position in the furnace circumferential direction where the parameter is the smallest as the charging start position when charging the same type of blast furnace raw material again. Further, the determination unit uses the parameter distribution according to the position in the furnace circumferential direction to obtain two integrated values obtained by integrating the parameters in two different furnace circumferential directions from the position in the furnace circumferential direction where the parameter is the smallest. compare. Then, the determination unit determines the circumferential direction of the furnace showing the small integrated value as the turning direction of the turning chute when charging the same type of blast furnace raw material again.

A third invention of the present application is a program for causing a computer to execute the following steps in order to determine a method of charging blast furnace materials into a bell-less blast furnace by turning a turning chute. In this process, the amount of blast furnace raw material charged in the furnace circumferential direction is determined based on the charging start position when the same type of blast furnace raw material is charged multiple times, the turning direction of the turning chute, and the above-mentioned turning number error. A parameter relating to the number of occurrences of the region with a large number of turbulence is calculated for each position in the circumferential direction of the furnace.

Next, based on the parameter distribution according to the positions in the furnace circumferential direction, the position in the furnace circumferential direction where the parameter is the smallest is determined as the charging start position when charging the same type of blast furnace raw material again. Also, using the distribution of parameters according to the positions in the circumferential direction of the furnace, two integrated values obtained by accumulating the parameters in two different circumferential directions from the position in the circumferential direction where the parameter is the smallest are compared. Then, the circumferential direction of the furnace showing a small integrated value is determined as the turning direction of the turning chute when charging the same type of blast furnace raw material again.

ADVANTAGE OF THE INVENTION According to this invention, the dispersion|variation in the charging amount of a blast furnace raw material in a furnace circumferential direction can be reduced.

It is a figure which shows a part of internal structure of a blast furnace. It is a flow chart which shows the processing which determines the method of charging blast furnace raw material. FIG. 10 is a diagram for explaining a charging state of final swirl of blast furnace raw material when the swirl number error is a negative value; FIG. 10 is a diagram for explaining a charging state of the final swirl of the blast furnace raw material when the swirl number error is a positive value; FIG. 5 is a diagram showing the distribution of the ratio R after charging coke (after 4 charges); FIG. 4 is a diagram showing the distribution of the ratio R after ore charging (after 4 charges); It is a block diagram which shows the structure of a charging method determination apparatus. FIG. 5 is a diagram showing the distribution of ratio R in Examples and Comparative Examples with respect to coke charging. FIG. 4 is a diagram showing the distribution of ratio R in Examples and Comparative Examples with respect to ore charging.

(Internal structure of blast furnace)
A bell-less type blast furnace (hereinafter simply referred to as "blast furnace") is used in the method of charging blast furnace raw material according to the present embodiment. The internal structure of a blast furnace will be described with reference to FIG. FIG. 1 shows the internal structure in a part (top) of a blast furnace.

A chute 2 (swivel chute) is provided at the top of the blast furnace 1, and the chute 2 swivels about a swivel axis RA as indicated by an arrow D1 or an arrow D2. The directions indicated by arrows D1 and D2 are opposite to each other. The pivot axis RA coincides with the furnace center. When the chute 2 is rotating, blast furnace raw materials (coke and ore) supplied from a hopper (not shown) to the chute 2 fall from the tip of the chute 2 and fall inside the blast furnace 1 (that is, the furnace wall 3). accumulate.

Since coke and ore are respectively charged from the chute 2, coke layers CL and ore layers OL are alternately formed inside the blast furnace 1 (that is, the furnace wall 3). A single charge of blast furnace raw material (supplying a predetermined weight of blast furnace raw material from the hopper to the chute 2 and charging it into the blast furnace 1) is called a dump, and the unit of repeated charging of the blast furnace raw material is called a charge. . When forming the coke layer CL, coke is charged by dumping once or multiple times, and when forming the ore layer OL, ore is charged by dumping once or multiple times.

When the blast furnace raw material is charged into the blast furnace 1, the chute 2 rotates about the rotation axis RA, and the angle θ at which the chute 2 is tilted with respect to the rotation axis RA is changed.

(Method of charging blast furnace raw material)
A method of charging the blast furnace raw material into the blast furnace 1 will be described with reference to the flowchart shown in FIG. According to the blast furnace raw material charging method described below, it is possible to reduce variations in charging amount in the furnace circumferential direction for each blast furnace raw material layer (coke layer CL or ore layer OL).

In step S<b>101 , blast furnace raw material is charged into the blast furnace 1 . In charging the blast furnace raw material, a position to start charging the blast furnace raw material (hereinafter referred to as "charging start position") and a direction to turn the chute 2 (hereinafter referred to as "turning direction") are determined. Therefore, in the processing of step S101, blast furnace raw material is charged based on the determined charging start position and turning direction.

The charging start position is a position in the furnace circumferential direction of the blast furnace 1, and is defined by an angle (0 to 360 [deg]) when one turn in the furnace circumferential direction is 360 [deg]. Here, the charging start position can be based on the position of the chute 2 in the furnace circumferential direction, or can be based on the position where the blast furnace raw material dropped from the chute 2 lands in the blast furnace 1. The position where the blast furnace raw material lands can be specified based on, for example, a simulation using the Discrete Element Method (publicly known document, ISIJ International, Vol. 57, pp. 272-278). Further, it is not necessary for the actual landing position and the landing position specified by the simulation to completely match the position at which the blast furnace raw material lands.

In this embodiment, the turning direction is the turning direction of the chute 2 when viewed from the top of the blast furnace 1 (the direction of the arrow D3 shown in FIG. 1). Here, when the chute 2 turns clockwise, the turning direction is defined as "rightward", and when the chute 2 turns counterclockwise, the turning direction is defined as "leftward". The turning direction of the chute 2 when viewed from the lower part of the blast furnace 1 can also be the turning direction determined in the process of step S101. The swirling direction at this time is in the opposite relationship to the swirling direction of the chute 2 when the chute 2 is viewed from the top of the blast furnace 1 .

In step S102, a turning number error Er is obtained based on the charging state of the blast furnace raw material in the process of step S101. The turning number error Er is the difference between the preset turning number (hereinafter referred to as the "set turning number") N and the turning number when the blast furnace raw material is actually charged (hereinafter referred to as the "actual turning number"). and is represented by the following formula (1).

[ sec], N is the set number of turns [turn], and tr is the time [sec] when the chute 2 makes one turn (360 [deg]). The value of "Nxtr" is the time (hereinafter referred to as "planned charging time") for charging the blast furnace raw material by rotating the chute 2 at the set number of rotations N.

According to the above formula (1), when the blast furnace raw material is charged in excess of the set turning number N, the actual charging time tm becomes longer than the scheduled charging time (N×tr), so the turning number error Er becomes a positive value [-]. On the other hand, when the blast furnace raw material is charged without reaching the set turning number N, the actual charging time tm becomes shorter than the scheduled charging time (N×tr), so the turning number error Er is a negative value [ -]become. Also, the absolute value of the turning number error Er may exceed one.

In the present embodiment, the actual charging time tm from the actual start of charging of the blast furnace raw material to the end of charging is measured, and the actual charging time tm is converted into the turning number error Er. there is Here, since the turning speed of the chute 2 is constant, the actual charging time tm can be converted into the turning number error Er based on the relationship between the time tr and the turning angle 360 [deg].

The time tr, which can be measured in advance or can be calculated from the set turning speed [rpm] of the chute 2, is a fixed time. As described above, the actual charging time tm is the time from the actual start of charging of blast furnace raw material to the end of charging, and there are various methods for measuring the actual charging time tm. be. Two examples of methods for measuring the actual charging time tm are given below.

In the first measurement method, first, a load cell is provided in a hopper (not shown) in which blast furnace raw materials are stored. The hopper referred to here is a hopper arranged at a position closest to the chute 2 in the blast furnace raw material supply route.

For example, when hoppers are arranged in two tiers, upper and lower, and the blast furnace raw material is supplied from the upper hopper to the lower hopper and from the lower hopper to the chute 2, the lower hopper is the closest hopper to the chute 2. Further, when the blast furnace raw material is supplied from a plurality of hoppers arranged in parallel in the horizontal direction to the collecting hopper and the blast furnace raw material is supplied from the collecting hopper to the chute 2, the collecting hopper is the closest hopper to the chute 2. Here, in a structure in which blast furnace raw materials simply pass through a collecting hopper, a load cell can be provided in the collecting hopper or parallel hoppers. Furthermore, when the blast furnace feedstock is supplied to the chute 2 from a plurality of hoppers arranged in parallel in the horizontal direction, each of the plurality of hoppers arranged in parallel is the hopper closest to the chute 2 .

At the timing when the gate of the hopper is opened (that is, the timing when charging of the blast furnace raw material is started), measurement of the actual charging time tm using a timer is started. Then, at the timing when the load cell detects that the blast furnace raw material in the hopper has run out (that is, the weight of the blast furnace raw material has reached zero [t]), the measurement of the actual charging time tm using the timer is terminated. . Thereby, the actual charging time tm can be measured. Note that the weight of the blast furnace raw material may not reach zero [t] because the blast furnace raw material continues to remain in the hopper. In this case, the fact that the weight of the blast-furnace raw material stops changing can be regarded as the fact that the blast-furnace raw material in the hopper has run out.

On the other hand, in a structure in which the blast furnace raw material simply passes through the collecting hopper, if a load cell is provided in the collecting hopper, the measured value of the load cell (the weight of the blast furnace raw material) will rise from zero [t] according to the movement of the blast furnace raw material. to return to zero [t]. Here, the timing to start measuring the actual charging time tm is the timing when the measured value of the load cell starts to rise from zero [t], and the timing to end the measurement of the actual charging time tm is the measured value of the load cell. becomes zero [t] again. Note that the weight of the blast furnace raw material may not reach zero [t] because the blast furnace raw material continues to remain in the hopper. In this case, the fact that the weight of the blast-furnace raw material stops changing can be regarded as the fact that the blast-furnace raw material in the hopper has run out.

In the second measurement method, first, acoustic sensors are provided in a hopper (not shown) in which blast furnace raw materials are stored and in a supply route after the hopper. The acoustic sensor detects the sound generated when the raw material for blast furnace moves from the hopper to the chute 2, and the location of the acoustic sensor can be appropriately determined as long as this purpose is achieved. The hopper referred to here is the hopper arranged at the position closest to the chute 2 in the supply route of the blast furnace raw material, as described above.

At the timing when the gate of the hopper is opened (that is, the timing when charging of the blast furnace raw material is started), measurement of the actual charging time tm using a timer is started. Here, while the blast furnace raw material is being supplied from the hopper to the chute 2, sound is generated as the blast furnace raw material moves, and this sound can be detected by the acoustic sensor. Then, when the sound accompanying the movement of the blast furnace raw material ceases to be generated, it can be grasped that the blast furnace raw material in the hopper has run out. Measurement of the actual charging time tm using a timer is terminated at the timing when the acoustic sensor detects that the blast furnace raw material in the hopper has run out. Thereby, the actual charging time tm can be measured.

Next, the turning number error Er will be described with reference to FIGS. 3 and 4. FIG. 3 and 4 show a plane perpendicular to the furnace height direction in the blast furnace 1, and the position where charging of the blast furnace raw material is started (charging start position) is 0 [deg].

FIG. 3 is a schematic diagram (one example) of the final swirling when the charging of the blast furnace raw material is completed when the number of swirling is less than the set number of swirls (-0.2 swirl). That is, FIG. 3 is a schematic diagram showing a state in which the blast furnace raw material is charged before the final turning reaches one turn in the circumferential direction of the furnace.

The arrow R1 shown in FIG. 3 indicates the turning direction of the chute 2 (here, the right direction) and the area where the blast furnace raw material is charged (the area from the position where charging is started to the position where charging is completed). show. In FIG. 3, area A1 is an area where charging in the final turning is not performed and the charging amount of blast furnace raw material is small (insufficient charging amount area). Therefore, the charging amount of the blast furnace raw material is larger in the region R1 than in the region A1. In the example shown in FIG. 3, since the actual charging time tm is shorter than the scheduled charging time (N×tr), the turning number error Er calculated from the above equation (1) shows a negative value. Note that when the actual charging time tm matches the scheduled charging time (N×tr), the rotation number error Er becomes 0 [-].

FIG. 4 is a schematic diagram (one example) of final swirling when the number of swirling times (+0.1 swirling) is greater than the set number of swirling times when charging of blast furnace raw material is completed. That is, FIG. 4 is a schematic diagram showing a state in which the blast furnace raw material is charged with the final turning exceeding one turn in the circumferential direction of the furnace.

The arrow R2 shown in FIG. 4 indicates the turning direction of the chute 2 (here, the right direction) and the area where the blast furnace raw material is charged (the area from the charging start position to the charging end position). show. In FIG. 4, area A2 is an area where the charging of blast furnace raw material is overlapped in the charging of blast furnace raw material in the final turning. ). In the example shown in FIG. 4, the actual charging time tm is longer than the scheduled charging time (N×tr), so the turning number error Er calculated from the above equation (1) shows a positive value.

In the above description, the turning number error Er is obtained based on the times tm, tr and the set turning number N, but the present invention is not limited to this. For example, the inside of the blast furnace 1 can be photographed using a camera, and the position where the blast furnace raw material first dropped and the position where the blast furnace raw material last dropped can be specified by image analysis. Based on these positions, it is also possible to determine the number of turns error Er.

In step S103, it is determined whether or not the blast furnace raw material has been charged a predetermined number of times Nd. The predetermined number of times Nd can be determined appropriately, and can be set to 1 to 10, for example. Also, the predetermined number of times Nd can be changed according to the number of times the distribution of the ratio R is obtained by the process of step S104, which will be described later. For example, when the distribution of the ratio R is first obtained by the process of step S104, which will be described later, in charging a predetermined number of times Nd, coke and ore are each charged based on a predetermined rule (charging start position and turning direction). can enter. Further, after obtaining the distribution of the ratio R, the process of step S104, which will be described later, can be performed in addition to the predetermined number of times Nd each time the blast furnace raw material is charged.

Regarding the above-described rules (charging start position and turning direction), for example, when the predetermined number of times Nd is 4, the charging start position and turning direction are set for coke and ore, respectively, as shown in Table 1 below. can decide.

In Table 1 above, coke and ore are alternately charged in this order, and each time the blast furnace raw materials (coke and ore) are changed, the charging start position is set in a predetermined furnace circumferential direction (for example, the clockwise direction shown in FIGS. 3 and 4 ) by 90 [deg]. Here, in the first and third charges, the coke charging start position is the same (0 [deg]). On the other hand, the turning direction is changed when the charging start position returns from 0 [deg] to 0 [deg]. Here, in the first and second charges, the turning direction when charging coke and ore is right, and in the third and fourth charging, the turning direction when charging coke and ore is left. changing direction.

In the process of step S103, if the charging of the predetermined number of times Nd has not been completed, the process returns to step S101, and the processes of steps S101 to S103 are repeated until the charging of the predetermined number of times Nd is completed. When charging of the predetermined number of times Nd is completed, the process proceeds to step S104.

In step S104, the position of the blast furnace 1 in the furnace circumferential direction is determined based on the charging start position and the turning direction in the process of step S101 (charging of the blast furnace raw material) and the turning number error Er obtained in the process of step S102. A ratio R is obtained for each (hereinafter referred to as "furnace circumferential position"). Here, the ratio R is the ratio [-] of the number of occurrences Nex to the total number of charging times Nt, and is expressed by the following formula (2). Ratio R is determined for each of coke and ore.

The total number of charging times Nt is a cumulative value of the number of times the blast furnace raw material has been charged a predetermined number of times Nd. That is, each time blast furnace raw material (coke or ore) is charged, the total number of charges Nt is counted up. Here, the total number of charging times Nt is interlocked with the predetermined number of times Nd.

The number of times of occurrence Nex is the number of times that a region where the charging amount is relatively large in the furnace circumferential direction occurs as described with reference to FIGS. As can be seen from FIGS. 3 and 4, the region where the charging amount is large (region R1 in FIG. 3 or region A2 in FIG. 4) can be specified by the furnace circumferential position, so the number of occurrences Nex can be counted. For example, if there is a region where the charging amount is relatively large at the furnace circumferential position of 36 [deg], the number of occurrences Nex at the furnace circumferential position of 36 [deg] is counted up. On the other hand, if there is no region where the charging amount is relatively large at the furnace circumferential position of 36 [deg], the number of occurrences Nex at the furnace circumferential position of 36 [deg] is not counted up. In addition, the interval of the furnace peripheral position when counting up can be set arbitrarily.

In this way, by counting the number of occurrences Nex for each furnace circumferential position, the ratio R can be obtained for each furnace circumferential position. As a result, a distribution of the ratio R according to the furnace circumferential position (hereinafter sometimes simply referred to as "the distribution of the ratio R") is obtained.

In one charge, the states shown in FIGS. 3 and 4 can be determined based on the turning number error Er in this charge. For example, when the turning number error Er is a positive value, it can be understood that the region (excessive charging amount) A2 shown in FIG. 4 has occurred. Considering the charging start position and the turning direction, the position of the region (excessive charging amount) A2 in the furnace circumferential direction can be grasped. The position of the area (excessive charging amount) A2 in the furnace circumferential direction can be defined by two furnace circumferential positions corresponding to both ends of the area (excessive charging amount) A2 in the furnace circumferential direction. At the furnace circumferential positions included between these two furnace circumferential positions (that is, the region (excessive charging amount) A2), the number of occurrences Nex is counted up as described above.

On the other hand, when the turning speed error Er is a negative value, the charging amount is relatively large in the region R1 shown in FIG. As described above, the number of occurrences Nex is counted up.

In step S105, based on the distribution of the ratio R obtained in the process of step S104, the charging start position and turning direction of the blast furnace raw material to be charged next time are determined. As described above, the distribution of the ratio R is obtained for each of coke and ore, so the charging start position and turning direction are determined for each of coke and ore. A method for determining the charging start position and the turning direction will be described below.

First, in the distribution of the ratio R, the furnace circumference position corresponding to the lowest ratio R is identified. Here, as can be seen from the above formula (2), the possible values of the ratio R are 0 to 1 [-], so the lowest ratio R may be 0 [-]. Also, depending on the charging state of the blast furnace raw material, the lowest ratio R may show a value higher than 0 [-].

If there is only one furnace circumferential position corresponding to the lowest ratio R, this furnace circumferential position is determined as the charging start position. On the other hand, when the ratio R is the lowest within the range of specific furnace circumferential positions, furnace circumferential positions corresponding to both ends of the furnace circumferential position range are determined as candidates for the charging start position.

If there are a plurality of furnace circumferential position ranges showing the lowest ratio R, the ratios R outside the furnace circumferential position range are compared, and the furnace circumferential position range with the lowest ratio R is specified. Here, when comparing the ratio R outside the range of the furnace circumferential position, the ratio R included in the predetermined range adjacent to the range of the furnace circumferential position on both sides in the furnace circumferential direction is integrated. The integrated value can be compared within a range of a plurality of furnace peripheral positions. Then, in the specified range of furnace circumferential positions, the furnace circumferential positions corresponding to both ends are determined as candidates for the charging start position.

Next, in the distribution of the ratio R, the integrated value of the ratio R (hereinafter referred to as (referred to as "first integrated value"). In addition, the integrated value of the ratio R between the charging start position and the furnace circumferential position shifted from the charging start position by a predetermined angle Ad in the furnace circumferential direction (left direction) (hereinafter referred to as "second integrated value") ). A smaller integrated value is identified by comparing the first integrated value and the second integrated value. The furnace circumferential direction (the right direction or the left direction) when the specified integrated value is obtained is determined as the turning direction of the chute 2 when charging the next blast furnace raw material.

As described above, when the candidates for the charging start position are determined, the above-described first integrated value and second integrated value are obtained for each charging start position (candidate). Then, the smallest integrated value is specified from among the first integrated values and the second integrated values of all charging start positions (candidates). The charging start position (candidate) when the smallest integrated value is obtained is determined as the charging start position when charging the next blast furnace raw material. Further, the circumferential direction of the furnace (the right direction or the left direction) when the smallest integrated value is obtained is determined as the turning direction of the chute 2 when charging the next blast furnace raw material.

The above-described predetermined angle Ad may be determined in advance, and can be set to 90 [deg], for example. Further, when the amount of the integrated value of the ratio R cannot be determined with the predetermined angle Ad, the predetermined angle Ad can be increased stepwise until the amount of the integrated value of the ratio R can be determined. For example, when the predetermined angle Ad is 90 [deg], if the amount of the integrated value of the ratio R cannot be determined, the predetermined angle Ad is set to 145 [deg] until the amount of the integrated value of the ratio R can be determined. , 180 [deg].

In the process of step S105, when the charging start position and turning direction are determined, the next blast furnace raw material is charged based on the determined charging start position and turning direction. As described above, when the charging start position is the position of the chute 2 in the furnace circumferential direction, considering variations in the movement trajectory of the blast furnace raw material falling from the chute 2 and variations in the position of the chute 2, The position to land the blast furnace raw material does not need to completely match the determined charging start position. The deviation (deviation in the furnace circumferential direction) between the landing position of the blast furnace raw material and the determined charging start position should be within an allowable range. This allowable range can be, for example, within a range of 20% or less (72 [deg] as an angle) of the total length in the furnace circumferential direction at the determined charging start position.

Next, a specific example of determining the charging start position and turning direction will be described with reference to FIGS. 5 and 6. FIG. FIG. 5 shows the ratio R distribution for coke after four charges and FIG. 6 shows the ratio R distribution for ore after four charges. 5 and 6, the horizontal axis is the furnace circumferential position [deg] of the blast furnace, and the vertical axis is the ratio R [-]. 5 and 6 show distributions of the ratio R obtained in Examples described later.

First, based on the distribution of the ratio R shown in FIG. 5, a method for determining the charging start position and the swirling direction for charging the next coke will be described.

In the distribution of the ratio R shown in FIG. There is a range of circumferential positions (approximately 153 to approximately 351 [deg]). The fact that the ratio R is 0.5 [-] means that the region R1 shown in FIG. 3 or the region (excessive charge) A2 shown in FIG. 4 occurs in two of the four charges. means that In addition, the fact that the ratio R is 0.25 [-] means that the region R1 shown in FIG. 3 and the region (excessive charge) A2 shown in FIG. 4 occur in one charge out of four charges. means that

In the distribution of the ratio R shown in FIG. 5, there is a range of furnace circumferential positions (approximately 117 to 135 [deg]) where the ratio R is 0 [-] (minimum value). A furnace circumferential position (117 [deg]) P1 and a furnace circumferential position (135 [deg]) P2 corresponding to both ends of the furnace circumferential position range are determined as candidates for the charging start position. After determining the candidates for the charging start position, each candidate is used as a reference to determine which of the rightward and leftward turning directions makes it possible to reduce the integrated value of the ratio R, thereby determining the charging start position. and the turning direction can be determined.

Assuming that the furnace circumferential position (117 [deg]) P1 is the charging start position, as can be seen from the distribution of the ratio R shown in FIG. ), the integrated value of the ratio R can be reduced by accumulating the ratio R on the positive side from the furnace circumferential position P1 (right side in FIG. 5, turning direction is right). On the other hand, when the furnace circumferential position (135 [deg]) P2 is assumed to be the charging start position, as can be seen from the distribution of the ratio R shown in FIG. It can be seen that the integrated value of the ratio R can be reduced by integrating the ratio R on the negative side (left side in FIG. 5, the turning direction is left) rather than on the right side).

Next, the case where the ratio R is integrated on the plus side (the right side in FIG. 5, the turning direction is the right direction) from the furnace circumferential position (117 [deg]) P1, and the minus side from the furnace circumferential position (135 [deg]) P2 (Left side in FIG. 5, the turning direction is the left side) and the case where the ratio R is integrated are judged which can reduce the integrated value of the ratio R. FIG. As can be seen from FIG. 5, the furnace circumferential position (117 [deg]) P1 Integrating the ratio R on the plus side (the right side in FIG. 5, the turning direction is the right direction) can reduce the integrated value of the ratio R. Specifically, when the ratio R is integrated within the range of 90 [deg] from the furnace circumferential position (135 [deg]) P2 to the negative side (left side in FIG. 5, the turning direction is left), the integrated value is 0. .75, when the ratio R is integrated within the range of 90 [deg] from the furnace peripheral position (117 [deg]) P1 to the plus side (right side in FIG. 5, the turning direction is rightward) The integrated value is 1.25.

Therefore, according to the distribution of the ratio R shown in FIG. 5, the charging start position can be determined as the furnace circumferential position (117 [deg]) P1, and the turning direction can be determined as the rightward direction. That is, in the next coke charging, the chute 2 starts turning at the furnace circumferential position (117 [deg]) P1, which is the charging start position, and turns rightward.

Next, based on the distribution of the ratio R shown in FIG. 6, a method for determining the charging start position and the turning direction for charging the next ore will be described.

In the distribution of the ratio R shown in FIG. There is a range of circumferential positions (about 9 to 45 [deg], 135 to about 189 [deg], about 243 to about 351 [deg]). The fact that the ratio R is 0.5 [-] means that the region R1 shown in FIG. 3 or the region (excessive charge) A2 shown in FIG. 4 occurs in two of the four charges. means that Further, the fact that the ratio R is 0.25 [-] means that in one charge out of four charges, the region R1 shown in FIG. 3 or the region (excessive charge) A2 shown in FIG. has occurred.

In the distribution of the ratio R shown in FIG. 6, there is a range of furnace circumferential positions (approximately 207 to 225 [deg]) where the ratio R is 0 [-] (minimum value). A furnace circumferential position (210 [deg]) P3 and a furnace circumferential position (225 [deg]) P4 corresponding to both ends of the furnace circumferential position range are determined as candidates for the charging start position. After determining the candidates for the charging start position, each candidate is used as a reference to determine which of the rightward and leftward turning directions makes it possible to reduce the integrated value of the ratio R, thereby determining the charging start position. and the turning direction can be determined.

Assuming that the furnace circumferential position (210 [deg]) P3 is the charging start position, as can be seen from the distribution of the ratio R shown in FIG. ), the integrated value of the ratio R can be reduced by accumulating the ratio R on the positive side from the furnace circumferential position P3 (right side in FIG. 6, turning direction is right). On the other hand, when the furnace circumferential position (225 [deg]) P4 is assumed to be the charging start position, as can be seen from the distribution of the ratio R shown in FIG. It can be seen that the integrated value of the ratio R can be reduced by accumulating the ratio R on the negative side (left side in FIG. 6, the turning direction is left) rather than accumulating the ratio R on the right side).

Next, the case where the ratio R is integrated on the positive side (the right side of FIG. 6, the turning direction is the right direction) from the furnace circumferential position (210 [deg]) P3, and the negative side from the furnace circumferential position (225 [deg]) P4 (Left side in FIG. 6, the turning direction is the left side) and the case where the ratio R is integrated, it is determined which one can reduce the integrated value of the ratio R. FIG. As can be seen from FIG. 6, the furnace circumferential position (210 [deg]) P3 Integrating the ratio R on the plus side (the right side in FIG. 6, the turning direction is the right direction) can reduce the integrated value of the ratio R.

Therefore, according to the distribution of the ratio R shown in FIG. 6, the charging start position can be determined as the furnace circumferential position (210 [deg]) P3, and the turning direction can be determined as the rightward direction. That is, in the next ore charging, the chute 2 starts turning at the furnace circumference position (210 [deg]) P3, which is the charging start position, and turns rightward.

According to the present embodiment, the blast furnace raw material is charged based on the charging start position and the turning direction of the chute 2 determined from the distribution of the ratio R, thereby reducing variations in the charging amount in the furnace circumferential direction. be able to. If the blast furnace raw material is charged as in the present embodiment, the blast furnace raw material is positively charged into the region where the ratio R is low (the region where the ratio R is 0 [-] shown in FIGS. 5 and 6). It is possible to reduce the variation in charging amount in the furnace circumferential direction. Then, every time such charging of blast furnace raw material is repeated, the charging amount in the furnace circumferential direction can be made uniform.

In this embodiment, the ratio R is obtained for each position in the furnace circumferential direction, but the present invention is not limited to this. As described above, since it is sufficient to grasp the region where the charging amount is relatively large, instead of the ratio R, for example, the above-described number of occurrences Nex can be used. That is, instead of the distribution of the ratio R, the distribution of the number of occurrences Nex according to the position in the furnace circumferential direction is used to determine the charging start position and the turning direction of the chute 2 when charging the next blast furnace raw material. can be done. Here, the ratio R and the number of occurrences Nex correspond to "parameters relating to the number of occurrences" in the present invention.

The processing shown in FIG. 2 can be realized by the operation of the charging method determination device 10 shown in FIG. The charging method determination device 10 only needs to have a portion that performs each process shown in FIG. Specifically, as shown in FIG. 7, the charging method determination device 10 may include an acquisition unit 11, a calculation unit 12, and a determination unit 13. FIG.

The acquisition unit 11 acquires information for calculating the distribution of the turning number error Er and the ratio R. The information for calculating the turning number error Er includes the times tm, tr and the set turning number N. The information for calculating the distribution of the ratio R is the charging start position, the turning direction, and the turning number error Er when the blast furnace raw material is charged.

The calculation unit 12 calculates the turning number error Er based on the above equation (1), and calculates the distribution of the ratio R based on the charging start position, turning direction, and turning number error Er. The determination unit 13 determines the charging start position and the turning direction of the chute 2 based on the ratio R distribution.

The operation of the charging method determination device 10 described above can be realized by a program (the charging method determination program according to the present invention). To implement this program, specifically, a computer program prepared in advance for realizing each function described above is stored in an auxiliary storage device, and a control unit such as a CPU is stored in the auxiliary storage device. is read into the main memory, and the control unit executes the program read into the main memory, so that each function can be operated. Each function can be operated by one controller or by multiple controllers connected to each other.

The program described above can be provided to the computer in a state recorded on a computer-readable recording medium. Recording media include optical discs such as CD-ROM, phase-change optical discs such as DVD-ROM, magneto-optical discs such as MO (Magnet Optical) and MD (Mini Disk), floppy (registered trademark) discs and removable hard disks. Examples include memory cards such as magnetic disks, compact flash (registered trademark), smart media, SD memory cards, and memory sticks. Also included as a recording medium is a hardware device such as an integrated circuit (IC chip, etc.) specially designed and configured for the purposes of the present invention.

Examples of the present invention will be described below. It should be noted that the present invention is not limited to the examples described below.

A charging test of blast furnace raw material was conducted using a test furnace that was 1/3 the size of an actual furnace. In order to evaluate variations in the charging amount of blast furnace raw materials according to the examples and comparative examples, the following pretreatment was performed. After the pretreatment, the blast furnace raw material was charged in Examples and Comparative Examples.

(Preprocessing)
As shown in Table 2 below, 4 charges of blast furnace raw materials (coke and ore) were charged while changing the charging start position and turning direction. Table 2 below also shows the swirl number error Er at the time of charging each blast furnace raw material. Table 2 below is the same as Table 1 above regarding the charging start position and turning direction.

After charging the blast furnace raw materials shown in Table 2 above, the distribution of the ratio R was calculated for each of coke and ore. The distribution of ratio R for coke was as shown in FIG. 5 and the distribution of ratio R for ore was as shown in FIG.

(Example)
After charging as the pretreatment described above, the charging start position and the turning direction of the chute 2 when charging coke were determined based on the distribution of the ratio R of coke (see FIG. 5). Also, the charging start position and the turning direction of the chute 2 when charging the ore were determined based on the distribution of the ratio R regarding the ore (see FIG. 6). As described above with reference to FIGS. 5 and 6, when the next coke is charged, the charging start position is the furnace circumferential position 117 [deg], and the turning direction of the chute 2 is rightward. Further, when the next ore is charged, the charging start position is the furnace circumferential position 207 [deg], and the turning direction of the chute 2 is the right direction. Table 3 below shows the charging start position and turning direction determined in the example. Table 3 below also shows the actual turning number error Er when charging the blast furnace raw material.

(Comparative example)
After the charging as the pretreatment described above, coke and ore were charged in order according to the rules shown in Table 2 above. According to the rules shown in Table 2 above, when the next coke was charged, the charging start position was set to 0 [deg] and the turning direction was set to the right. Moreover, when charging the ore, the charging start position was set to 90 [deg], and the turning direction was set to the right. Table 4 below shows the charging start position and turning direction in the comparative example. Table 4 below also shows the actual turning number error Er when charging the blast furnace raw material.

FIG. 8 shows the distribution of the ratio R in the above-described pretreatment, working example, and comparative example with respect to coke charging. The distribution of ratio R for pretreatment is the same as the distribution of ratio R shown in FIG. The distribution of the ratio R for the example is the distribution of the ratio R after the coke charging described in the above example. The distribution of the ratio R for the comparative example is the distribution of the ratio R after the charging of coke described in the above comparative example.

As can be seen from FIG. 8, in the comparative example, the variation in the ratio R increased compared to the pretreatment. On the other hand, in the example, the variation in the ratio R decreased compared to the pretreatment. Therefore, according to this example, it is possible to reduce the variation in the charging amount of coke in the furnace circumferential direction.

FIG. 9 shows the distribution of the ratio R in the above-described pretreatment, working example and comparative example with respect to ore charging. The distribution of ratio R for pretreatment is the same as the distribution of ratio R shown in FIG. The distribution of the ratio R for the example is the distribution of the ratio R after the ore charging described in the above example. The distribution of the ratio R relating to the comparative example is the distribution of the ratio R after the charging of the ore explained in the above comparative example.

As can be seen from FIG. 9, in the comparative example, the variation in the ratio R increased with respect to the pretreatment. On the other hand, in the example, the variation in the ratio R decreased compared to the pretreatment. Therefore, according to the present embodiment, it is possible to reduce the variation in the charging amount of ore in the circumferential direction of the furnace.

1: blast furnace, 2: chute, 3: furnace wall, RA: pivot shaft, CL: coke layer,
OL: ore layer, θ: tilt angle

Claims (6)

A blast furnace raw material charging determination method for determining a method of charging blast furnace raw material into a bell-less blast furnace by turning a turning chute, comprising:
Based on the charging start position when charging the same type of blast furnace raw material multiple times, the turning direction of the turning chute, and the turning number error indicating the deviation of the actual turning number from the set turning number of the turning chute, the blast furnace raw material Calculate a parameter related to the number of occurrences of a region where the charging amount of is relatively large in the furnace circumferential direction for each position in the furnace circumferential direction,
Based on the distribution of the parameters according to the position in the furnace circumferential direction, the position in the furnace circumferential direction where the parameter is the smallest is determined as the charging start position when charging the same type of blast furnace raw material again, Two integrated values obtained by integrating the parameters in two different circumferential directions from the position in the circumferential direction where the parameter is the smallest are compared, and the circumferential direction showing the smaller integrated value is selected as the blast furnace raw material of the same type. as the turning direction of the turning chute when charging again,
A method for determining charging of blast furnace raw materials, characterized by: When the parameter is the smallest within a specific range of positions in the furnace circumferential direction, positions in the furnace circumferential direction corresponding to both ends of the specific range are used as candidates for the charging start position when charging the same type of blast furnace raw material again. 2. The method for determining the charge of blast furnace raw material according to claim 1, wherein the determination is made as follows. 3. The method for determining charging of blast furnace raw material according to claim 1, wherein the parameter is a ratio of the number of occurrences to a predetermined number of charging of blast furnace raw material. The error in the number of turns is such that the actual number of turns is greater than the set number of turns, and the actual number of turns is less than the set number of turns when the blast furnace raw material is charged with the final turn exceeding one turn in the circumferential direction of the furnace. 4. The blast furnace raw material charging according to any one of claims 1 to 3, characterized in that the blast furnace raw material is charged without the final turning reaching one turn in the furnace circumferential direction. How to decide. A blast furnace raw material charging method determining device for determining a method of charging blast furnace raw material into a bell-less blast furnace by turning a turning chute,
Based on the charging start position when charging the same type of blast furnace raw material multiple times, the turning direction of the turning chute, and the turning number error indicating the deviation of the actual turning number from the set turning number of the turning chute, the blast furnace raw material A computing unit that calculates, for each position in the furnace circumferential direction, a parameter related to the number of occurrences of regions in which the charging amount of is relatively large in the furnace circumferential direction;
Based on the distribution of the parameters according to the position in the furnace circumferential direction, the position in the furnace circumferential direction where the parameter is the smallest is determined as the charging start position when charging the same type of blast furnace raw material again, Two integrated values obtained by integrating the parameters in two different circumferential directions from the position in the circumferential direction where the parameter is the smallest are compared, and the circumferential direction showing the smaller integrated value is selected as the blast furnace raw material of the same type. a determination unit that determines the turning direction of the turning chute when charging again;
A blast furnace raw material charging method determination device, comprising: A program for causing a computer to execute the following steps in order to determine a method of charging blast furnace materials into a bell-less blast furnace by turning a turning chute,
Based on the charging start position when charging the same type of blast furnace raw material multiple times, the turning direction of the turning chute, and the turning number error indicating the deviation of the actual turning number from the set turning number of the turning chute, the blast furnace raw material Calculate a parameter related to the number of occurrences of a region where the charging amount of is relatively large in the furnace circumferential direction for each position in the furnace circumferential direction,
Based on the distribution of the parameters according to the position in the furnace circumferential direction, the position in the furnace circumferential direction where the parameter is the smallest is determined as the charging start position when charging the same type of blast furnace raw material again, Two integrated values obtained by integrating the parameters in two different circumferential directions from the position in the circumferential direction where the parameter is the smallest are compared, and the circumferential direction showing the smaller integrated value is selected as the blast furnace raw material of the same type. as the turning direction of the turning chute when charging again,
A blast furnace raw material charging method determination program characterized by:

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