JP2023046165A - 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 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, for all combinations of a plurality of prescribed charging start positions, and turning directions of a turning chute, when the same kind of raw materials are charged into a blast furnace a plurality of times and then the raw material is charged into the blast furnace again. The parameter is calculated from the charging start position, the turning direction and the turning number error. For all the combinations, variation in parameters is calculated on the basis of distribution of the parameter according to the position in the furnace circumferential direction. The charging start position when the minimum variation is obtained is determined as a charging start position when the same kind of raw material is charged into the blast furnace again. The turning direction when the minimum variation is obtained is determined as a turning direction of a turning chute when the same kind of raw material is charged into the blast furnace again.SELECTED DRAWING: Figure 5

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. First, when charging the blast furnace raw material again after charging the same type of blast furnace raw material a plurality of times, for all combinations of a plurality of predetermined charging start positions and turning directions of the turning chute, the amount of blast furnace raw material A parameter relating to the number of occurrences of regions where the charging amount is relatively large in the furnace circumferential direction is calculated for each position in the furnace circumferential direction. This parameter is calculated from the charging start position, the turning direction, and the turning number error that indicates the deviation of the actual turning number from the set turning number of the turning chute.

Next, for all combinations, the variation of the parameters is calculated based on the parameter distribution according to the position in the circumferential direction of the furnace. Then, the charging start position when the minimum variation is obtained is determined as the charging start position when charging the same type of blast furnace raw material again. Also, the turning direction when the minimum variation is obtained is determined as the turning direction of the turning chute when charging the same kind of blast furnace raw material again.

The standard deviation of parameters can be used as the variation described above. As a parameter, the ratio of the number of occurrences to the predetermined number of times of charging the blast furnace raw material can be used.

When calculating the parameter for each position in the circumferential direction of the furnace, the swirl number error can be determined from the swirl number error in past charging of blast furnace raw material. The error in the number of turns includes the case where the actual number of turns is greater than the set number of turns, and the final turning exceeds one turn in the circumferential direction of the furnace when the blast furnace raw materials are charged, and the actual number of turns is less than the set number of turns. This includes the case where the blast furnace raw material is charged before the final turning 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.

When charging the blast furnace raw material again after charging the same type of blast furnace raw material a plurality of times, the calculation unit calculates the blast furnace raw material for all combinations of a plurality of predetermined charging start positions and turning directions of the turning chute. A parameter relating to the number of occurrences of regions in which the charging amount of raw material is relatively large in the furnace circumferential direction is calculated for each position in the furnace circumferential direction. This parameter is calculated from the charging start position, the turning direction, and the turning number error that indicates the deviation of the actual turning number from the set turning number of the turning chute. Then, the calculation unit calculates the variation of the parameters based on the distribution of the parameters according to the positions in the circumferential direction of the furnace for all the combinations.

The determination unit determines the charging start position when the minimum variation is obtained as the charging start position when charging the same type of blast furnace raw material again. Further, the determination unit determines the turning direction when the minimum variation is obtained 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 step, when charging the blast furnace raw material again after charging the same type of blast furnace raw material a plurality of times, the blast furnace raw material is set for all combinations of a plurality of predetermined charging start positions and turning directions of the turning chute. A parameter relating to the number of occurrences of regions in which the charging amount of raw material is relatively large in the furnace circumferential direction is calculated for each position in the furnace circumferential direction. This parameter is calculated from the charging start position, the turning direction, and the turning number error that indicates the deviation of the actual turning number from the set turning number of the turning chute.

Next, for all combinations, the variation of the parameters is calculated based on the parameter distribution according to the position in the circumferential direction of the furnace. The charging start position when the minimum variation is obtained is determined as the charging start position when charging the same type of blast furnace raw material again. Also, the turning direction when the minimum variation is obtained is determined as the turning direction of the turning chute when charging the same kind 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 figure explaining the charging start position of a 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; It is a flow chart which shows the processing which determines the method of charging blast furnace raw material. It is a block diagram which shows the structure of a charging method determination apparatus. FIG. 5 is a diagram showing the distribution of the ratio R after charging coke (after 6 charges); FIG. 5 is a diagram showing the distribution of the ratio R after ore charging (after 6 charges); 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.

When charging the blast furnace raw material into the blast furnace 1, the position at which charging of the blast furnace raw material is started (hereinafter referred to as "charging start position") and the direction in which the chute 2 is turned (hereinafter referred to as "turning direction") are determined. be done.

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]. In this embodiment, the charging start position for charging the blast furnace raw material is determined from among a plurality of predetermined charging start positions. For example, as shown in FIG. 2, four positions of 0 [deg], 90 [deg], 270 [deg], and 360 [deg] can be determined in advance as the charging start position. FIG. 2 shows a plane perpendicular to the furnace height direction in the blast furnace 1 .

The charging start positions are not limited to the four positions shown in FIG. 2, and any number of charging start positions can be determined. Further, in FIG. 2, the charging start positions are set at equal intervals in the furnace circumferential direction, but the charging start positions may be determined at different intervals in the furnace circumferential direction.

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). In addition, it is not necessary for the actual landing position and the landing position specified by the simulation to completely match the position where 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". In addition, when the chute 2 is viewed from the lower part of the blast furnace 1, the turning direction of the chute 2 can also be defined. 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 .

(Turn number error Er)
When charging the blast furnace material into the blast furnace 1 by rotating the chute 2, the number of turns of the chute 2 is preset. There may be a deviation in the number of revolutions when the material is actually charged (hereinafter referred to as "actual number of revolutions"). This deviation is called a turning number error Er, and the turning number error Er is expressed by the following equation (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 "scheduled 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 [turn]. 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 [ turns].

In the present embodiment, the actual charging time tm is measured, and the turning number error Er is converted based on the actual charging time tm. 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 is a fixed time that can be measured in advance or calculated from the set turning speed [rpm] of the chute 2 . 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 become 0 [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 0 [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 the structure in which the blast furnace raw material simply passes through the collecting hopper, when a load cell is provided in the collecting hopper, the measured value of the load cell (the weight of the blast furnace raw material) rises from 0 [t] according to the movement of the blast furnace raw material. It returns to 0[t] later. 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 0 [t], and the timing to end the measurement of the actual charging time tm is the measured value of the load cell. becomes 0 [t] again. Note that the weight of the blast furnace raw material may not reach 0 [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 orthogonal to the furnace height direction in the blast furnace 1, and the charging start position is 0 [deg].

FIG. 3 is a schematic diagram (one example) of the final turning when the charging of the blast furnace raw material is completed when the turning number is less than the set turning number (when the turning number error Er is -0.2 [turning]). be. 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 rotation number error Er calculated from the above equation (1) is a negative value (here, − 0.2 [turn]). 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 the final turning when the charging of the blast furnace raw material is completed more than the set turning number (when the turning number error Er is +0.1 [turning]). . 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) is a positive value (here, +0 .1 [Turn]).

In the above description, the rotation number error Er is obtained based on the actual charging time tm, the time tr, and the set rotation 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.

(Distribution of ratio R)
In this embodiment, in order to determine the charging start position and the turning direction of the chute 2 when charging the blast furnace raw material, the ratio R described below is obtained.

As will be described later, the ratio R is the ratio [-] of the number of occurrences Nex to the total number of charging times Nt, and is obtained based on the charging start position and turning direction in charging the blast furnace raw material and the turning number error Er. be done. Here, the ratio R is represented 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 occurrences Nex is the number of occurrences of a region in which the amount of charge is relatively large in the furnace circumferential direction, 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) is the position in the furnace circumferential direction of the blast furnace 1 (hereinafter, “furnace circumferential position” ), the number of occurrences Nex can be counted for each furnace circumferential position.

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 circumference position (hereinafter sometimes simply referred to as "the distribution of the ratio R") is obtained. Here, as can be seen from the above formula (2), the possible values of the ratio R are 0.0 to 1.0 [-].

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.

(Method of charging blast furnace raw material)
A method for determining the conditions (the charging start position and the turning direction) for charging the blast furnace raw material into the blast furnace 1 will be described with reference to the flowchart shown in FIG. If the conditions for charging the blast furnace raw material are determined as in the present embodiment, and the blast furnace raw material is charged into the blast furnace 1 according to these conditions, each blast furnace raw material layer (coke layer CL or ore layer OL) is Variation in charging amount can be reduced.

In the present embodiment, after the blast furnace raw materials (coke and ore) have been charged a plurality of times, the conditions for charging the blast furnace raw materials from the next time onward are determined. For example, when charging the blast furnace raw material for the first time, charging conditions (charging start position and turning direction) can be determined according to a predetermined rule. An example of the predetermined rule is shown in Table 1 below.

In the rule shown in Table 1 above, the charging start position when charging the blast furnace raw material (here, coke) is set to 0 [deg], and each time the blast furnace raw material (coke and ore) is charged, the charging The on start position is shifted by 90 [deg]. Also, the chute 2 turns in the same direction (to the right or left) until the charging start position changes from 0 [deg] to 0 [deg] again. In Table 1 above, the turning direction is set to the right in the first and second charges, the turning direction is changed to the left in the third and fourth charges, and the turning direction is changed in the fifth and sixth charges. is changed again to the right.

In step S101, the turning number error Er for charging the next blast furnace raw material is set. The swirl number error Er can be set according to the type of blast furnace raw material (coke and ore), or a common swirl number error Er can be set regardless of the type of blast furnace raw material. The turning number error Er can be set in consideration of the turning number error Er when the blast furnace raw material has already been charged, or can be set to a predetermined value.

When considering the turning number error Er when the blast furnace raw material has already been charged, for example, the average value of the turning number error Er in charging the blast furnace raw material a predetermined number of times in the past (most recent) is obtained, and this average A value can be set as the revolution number error Er. Also, it is possible to set the swirl number error Er in charging the blast furnace raw material immediately before.

In step S102, the combination of the charging start position and the turning direction of the chute 2 when charging the next blast furnace raw material is provisionally set. In this provisional setting, the charging start position is selected from among the plurality of predetermined charging start positions described above. Also, the turning direction is either the right direction or the left direction. The total number of combinations of charging start positions and turning directions is determined according to the total number of selectable charging starting positions and the number of turning directions (two).

In step S103, the distribution of the ratio R is obtained based on the combination of the turning number error Er set in the process of step S101 and the charging start position and turning direction temporarily set in the process of step S102. The method of obtaining the distribution of the ratio R is as described above. The distribution of the ratio R obtained in the process of step S103 is based on the conditions when the blast furnace raw material has already been charged (the charging start position and the turning direction) and the conditions when the blast furnace raw material is charged next time (the charging start position and turning direction). Here, the conditions (the charging start position and turning direction) when the blast furnace raw material has already been charged may be the charging conditions of all past charging conditions, or the charging conditions of a predetermined number of times in the past (most recent). .

In step S104, the standard deviation of the ratio R is calculated based on the distribution of the ratio R obtained in the process of step S103, and the calculated standard deviation is stored. The standard deviation can be stored in the later-described storage unit 13 (see FIG. 6) while being associated with the combination of the charging start position and turning direction provisionally set in step S102.

In step S105, it is determined whether or not all combinations of the charging start position and turning direction have been provisionally set. Here, if temporary settings have not been made for all combinations, the process returns to step S102. Then, the standard deviation of the ratio R is obtained by performing the processing of steps S102 to S104 for the combination for which no provisional setting has been performed. On the other hand, if temporary settings have been made for all combinations, the process proceeds to step S106. If provisional settings are made for all combinations, the standard deviation of the ratio R is obtained for each combination.

In step S106, the minimum standard deviation is specified among the standard deviations of the ratio R in all combinations.

In step S107, the charging start position associated with the standard deviation (minimum value) specified in the process of step S106 is determined as the charging start position for charging the next blast furnace raw material. Also, the turning direction associated with the standard deviation (minimum value) specified in the process of step S106 is determined as the turning direction of the chute 2 when charging the next blast furnace raw material.

In the process of step S107, 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.

Although the standard deviation of the ratio R is obtained in the processing shown in FIG. As this parameter, for example, in the distribution of the ratio R, the difference between the ratio R (maximum value) and the ratio R (minimum value) can be used.

According to the present embodiment, the blast furnace raw material is charged based on the combination of the charging start position and the turning direction that minimizes the standard deviation 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 can be positively charged into the region where the ratio R is low, and the variation in charging amount in the furnace circumferential direction can be reduced. . 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 furnace circumferential position, but the present invention is not limited to this. As described above, it is only necessary to grasp that there is a region in which the charging amount is relatively large in the furnace circumferential direction. That is, instead of the distribution of the ratio R, the distribution of the number of occurrences Nex according to the furnace circumference position can be used. 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. 5 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. 6, the charging method determination device 10 may include an acquisition unit 11, a calculation unit 12, a storage unit 13, and a determination unit .

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 actual charging time tm, the time tr and the set turning number N. Information for calculating the distribution of the ratio R is the charging start position, the turning direction, and the turning number error Er.

The calculation unit 12 calculates the turning number error Er based on the above equation (1), calculates the distribution of the ratio R based on the charging start position, turning direction and turning number error Er, and calculates the standard of the ratio R Calculate the deviation. The storage unit 13 stores the standard deviation of the ratio R in the process of step 104 shown in FIG. Based on the standard deviation of the ratio R, the determination unit 14 determines the charging start position and the turning direction of the chute 2 when charging the next blast furnace raw material.

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, 6 charges of blast furnace raw material (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 is shown in FIG. 7 and the distribution of ratio R for ore is 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 in the seventh and eighth charges based on the standard deviation of the ratio R related to coke It was determined. Also, based on the standard deviation of the ratio R related to ore, the charging start position and the turning direction of the chute 2 when charging the ore in the seventh and eighth charging were determined. Here, in setting the combination of the charging start position and the turning direction, there are four options for the charging start position: 0 [deg], 90 [deg], 180 [deg], and 270 [deg]. Turn direction options are right and left. The total number of combinations in this case is 16. In this embodiment, as described above, four charging start positions are set, and charging of the blast furnace raw material four times is regarded as one unit. , the charging start position and the turning direction were determined. Here, the charging start position and turning direction can also be determined for each charge.

As the turning number error Er when charging coke in each of the 7th and 8th charges, in Table 2 above, the average value of the turning number error Er for charging 6 charges of coke (0.133 [turn] ) was used. Further, as the turning number error Er when ore is charged in each of the 7th and 8th charges, the average value of the turning number error Er (0.117 [ swirl]) was used.

For coke charging in each of the seventh and eighth charges, all combinations of charging start positions and turning directions are set, and the distribution of the ratio R when coke is charged in each combination is obtained. rice field. This distribution is the distribution of the ratio R when coke is charged in the 1st to 8th charges. Then, standard deviations were obtained from the obtained distributions of the ratios R, and the combination with the smallest standard deviation of the ratios R was determined from among the 16 combinations described above.

In this embodiment, when the coke charging start position in the seventh charge is 90 [deg] and the turning direction of the chute 2 is rightward, and the coke charging start position in the eighth charge is 270 [deg] and the turning direction of the chute 2 is rightward, the standard deviation of the ratio R is 0.104, which is the minimum value. Therefore, when charging coke in the seventh charge, coke charging is started at the charging start position of 90 [deg], the chute 2 is turned rightward, and coke is charged in the eighth charge. , coke charging was started at the charging start position of 270 [deg], and the chute 2 was turned rightward. Here, the charging start position was the position of the chute 2 in the furnace circumferential direction. Note that it is possible to exchange the seventh and eighth times.

Next, for charging the ore in each of the seventh and eighth charges, all combinations of the charging start position and the turning direction are set, and the ratio R when the ore is charged in each combination is set. distribution was obtained. This distribution is the distribution of the ratio R when the ore is charged in the 1st to 8th charges. Then, standard deviations were obtained from the obtained distributions of the ratios R, and the combination with the smallest standard deviation of the ratios R was determined from among the 16 combinations described above.

In this embodiment, when the ore charging start position in the seventh charge is 90 [deg] and the turning direction of the chute 2 is leftward, and the ore charging start position in the eighth charge is 90 [deg] and the turning direction of the chute 2 is leftward, the standard deviation of the ratio R is 0.094, which is the minimum value. Therefore, in the charging of the ore in the seventh charge, the charging of the ore is started at the charging start position of 90 [deg], the chute 2 is turned leftward, and the charging of the ore in the eighth charge is performed. , ore charging was started at the charging start position of 90 [deg], and the chute 2 was turned leftward. Here, the charging start position was the position of the chute 2 in the furnace circumferential direction. In this case, the conditions were the same for the 7th and 8th times, but if they are different, they can be exchanged.

The charging conditions for this example described above are summarized in Table 3 below. As described above, the swirl number error shown in Table 3 below is the average value (temporary set value) of the swirl number error Er for charging 6 charges of blast furnace raw material, not the actual value.

(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 rule shown in Table 2 above, when charging coke for the seventh charge, the charging start position is 0 [deg] and the turning direction is leftward. The turn number error Er in this charging was 0.1 [turn]. Also, when charging coke in the eighth charge, the charging start position is 180 [deg] and the turning direction is leftward. The turn number error Er in this charging was 0.2 [turn].

According to the rule shown in Table 2 above, when ore is charged in the seventh charge, the charging start position is 90 [deg] and the turning direction is leftward. The turn number error Er in this charging was 0.0 [turn]. Also, when ore is charged in the eighth charge, the charging start position is 270 [deg] and the turning direction is the left direction. The turn number error Er in this charging was 0.2 [turn].

The charging conditions for the comparative example described above are summarized in Table 4 below. The number of turns errors shown in Table 4 below are actual values.

FIG. 9 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 (8 charges) 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 (8 charges) described in the above comparative example. In the examples and comparative examples, the calculation of the distribution of the ratio R uses the turning number errors (actual values) shown in Table 4 above.

As can be seen from FIG. 9, in the example, the variation in the ratio R was reduced compared to the comparative example. Therefore, according to this example, it is possible to reduce the variation in the charging amount of coke in the furnace circumferential direction. The standard deviation was calculated based on the distribution of the ratio R shown in FIG.

FIG. 10 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 (8 charges) described in the above example. The distribution of the ratio R for the comparative example is the distribution of the ratio R after charging the ore (8 charges) described in the comparative example. In the examples and comparative examples, the calculation of the distribution of the ratio R uses the turning number errors (actual values) shown in Table 4 above.

As can be seen from FIG. 10, in the example, the variation in the ratio R was reduced compared to the comparative example. 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. The standard deviation was calculated based on the distribution of the ratio R shown in FIG.

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

Claims (7)

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:
When charging the blast furnace raw material again after charging the same type of blast furnace raw material multiple times, the charging start position for all combinations of a plurality of predetermined charging start positions and the turning direction of the turning chute And, based on the turning direction and the turning number error that indicates the deviation of the actual turning number from the set turning number of the turning chute, a parameter related to the number of occurrences of a region where the charging amount of blast furnace raw material is relatively large in the furnace circumferential direction is determined. Calculated for each position in the furnace circumferential direction,
For all the combinations, calculating the variation of the parameters based on the distribution of the parameters according to the position in the furnace circumferential direction,
The charging start position when the minimum variation is obtained is determined as the charging start position when charging the same type of blast furnace raw material again, and the turning direction when the minimum variation is obtained is determined. , determined as the turning direction of the turning chute when charging the same type of blast furnace raw material again,
A method for determining charging of blast furnace raw materials, characterized by: 2. The method for determining charging of blast furnace raw material according to claim 1, wherein said variation is a standard deviation of said parameter. 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. 4. Any one of claims 1 to 3, wherein when calculating the parameter for each position in the furnace circumferential direction, the swirl number error is determined from the swirl number error in past charging of blast furnace raw material. The method for determining the charging of blast furnace raw material according to . 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. 5. The blast furnace raw material charging according to any one of claims 1 to 4, 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 determination device for determining a method of charging blast furnace raw material into a bell-less blast furnace by turning a turning chute, the device comprising a computing unit and a determining unit,
The calculation unit is
When charging the blast furnace raw material again after charging the same type of blast furnace raw material multiple times, the charging start position for all combinations of a plurality of predetermined charging start positions and the turning direction of the turning chute And, based on the turning direction and the turning number error that indicates the deviation of the actual turning number from the set turning number of the turning chute, a parameter related to the number of occurrences of a region where the charging amount of blast furnace raw material is relatively large in the furnace circumferential direction is determined. Calculated for each position in the furnace circumferential direction,
For all the combinations, calculating the variation of the parameters based on the distribution of the parameters according to the position in the furnace circumferential direction,
The determining unit determines the charging start position when the minimum variation is obtained as the charging start position when charging the same type of blast furnace raw material again, and determines the charging start position when the minimum variation is obtained. the turning direction of the time is determined as the turning direction of the turning chute when charging the same type of blast furnace raw material again;
A blast furnace raw material charging method determination device characterized by: 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,
When charging the blast furnace raw material again after charging the same type of blast furnace raw material multiple times, the charging start position for all combinations of a plurality of predetermined charging start positions and the turning direction of the turning chute And, based on the turning direction and the turning number error that indicates the deviation of the actual turning number from the set turning number of the turning chute, a parameter related to the number of occurrences of a region where the charging amount of blast furnace raw material is relatively large in the furnace circumferential direction is determined. Calculated for each position in the furnace circumferential direction,
For all the combinations, calculating the variation of the parameters based on the distribution of the parameters according to the position in the furnace circumferential direction,
The charging start position when the minimum variation is obtained is determined as the charging start position when charging the same type of blast furnace raw material again, and the turning direction when the minimum variation is obtained is determined. , determined as the turning direction of the turning chute when charging the same type of blast furnace raw material again;
A blast furnace raw material charging method determination program characterized by:

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