JP2012172224A - Apparatus and method for charging raw material into blast furnace - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an apparatus and a method for charging raw materials into a blast furnace with which in the case of supplying a plurality of raw material kinds into the blast furnace, each raw material can be mixed while restraining the effects of the difference in the average granular diameter and outward density, etc., and as a result, in the blast furnace, the desirable raw material distribution can be obtained.SOLUTION: In the apparatus 1 for charging the plurality of the blast furnace raw materials M1, M2. M3 into the blast furnace 2, the apparatus 1 is provided with a main-hopper 15, a plurality of sub-hoppers 23, 33, a swinging chute 40, a supplying passage 16 for transporting the main raw material M1 from the main-hopper 15 into the swinging chute, and a raw material transporting means 24, 34 for transporting the sub-raw materials M2, M3 from each of sub-hoppers 23, 33. The raw material transporting means 24, 34 are peculiarly opened in the flowing speed controlling range for flowing each of sub-raw materials M2, M3 and the main raw material M1 with a prescribed ratio.

Description

  The present invention relates to a blast furnace raw material charging apparatus and a blast furnace raw material charging method for charging a plurality of types of raw materials into a blast furnace furnace.

As is well known, for example, a bellless charging device using a turning chute is known as means for charging raw fuel such as sintered ore and coke into a blast furnace furnace.
When the raw fuel is charged into the blast furnace using the bellless charging device, the furnace is considered from the viewpoint of ventilation in consideration of productivity of pig iron production, consumption of the blast furnace furnace wall, suppression of deposits on the furnace wall, etc. The distribution of the charge at the radial position is controlled.
When considering the distribution of charges in the radial direction in the blast furnace from the viewpoint of ventilation, for example, in the furnace center, the blown hot air is easy to vent through the gaps of the charges so that the reduction of the ore is promoted. However, it is important not to allow excess gas to flow in the vicinity of the furnace wall around the furnace so that the furnace wall is protected.

In general blast furnace operation, a plurality of kinds of raw materials such as sintered ore, pellets and lump ore are used. Further, even in the same type, the properties (physical properties such as average particle diameter and apparent density) may be different.
Therefore, even when mixing such a plurality of types of raw materials at a predetermined mixing ratio, in order to obtain the appropriate charge distribution as described above, the process until the raw materials are transported from the storage hopper to the swiveling chute Attempts have been made to provide means for simultaneously discharging and cutting out raw materials (for example, belt conveyors, relay hoppers, main hoppers, etc.).

However, when a large number of hoppers and dampers exist in the raw material transport process, there is a demerit that a variation in the mixing ratio per unit capacity (hereinafter referred to as segregation) is likely to occur.
Therefore, in order to suppress the segregation and mix the raw materials at a predetermined raw material mixing ratio, and to obtain the desired charge distribution in the blast furnace furnace, the timing of charging the raw materials from the main hopper and sub hopper is controlled. Have been devised (see, for example, Patent Documents 1 and 2).

Japanese Patent Application Laid-Open No. 2004-010980 Japanese Patent Laid-Open No. 05-339612

  However, even if the techniques disclosed in Patent Documents 1 and 2 are used, it is not easy to mix a plurality of types of raw materials having different properties stored in the main hopper and the sub hopper without causing segregation.

  In particular, when using raw materials with different properties even when the types are the same, or when the number of types of raw materials charged simultaneously (during one dump) is increased, In some cases, it may not be sufficient to properly load a predetermined position at a predetermined amount.

  The present invention was made in consideration of such circumstances, and when supplying multiple types of raw materials into the blast furnace, each raw material is suppressed from the influence of differences in properties such as average particle diameter and apparent density. A blast furnace raw material charging apparatus and a blast furnace raw material which can be mixed at a predetermined mixing ratio, and can be charged into a predetermined position in the blast furnace furnace to obtain a desired distribution of charges. The purpose is to provide a charging method.

In order to solve the above problems, the present invention proposes the following means.
The invention according to claim 1 is a blast furnace raw material charging device for charging a plurality of raw materials into a blast furnace, wherein a main hopper for storing a main raw material, a plurality of sub hoppers for storing a sub raw material, A turning chute for supplying the raw material into the blast furnace, a supply passage for transporting the main raw material from the main hopper to the turning chute, and a raw material for transporting the sub raw material from each sub hopper provided corresponding to the plurality of sub hoppers The plurality of raw material transport means, wherein the sub raw materials from the plurality of sub hoppers and the main raw material flow at a predetermined ratio in the main hopper or the supply passage. It is characterized by being open to a possible flow rate control region.

  The invention according to claim 5 includes a main hopper for storing a main raw material, a plurality of sub hoppers for storing sub raw materials, a turning chute for supplying the raw material into the blast furnace furnace, and the main hopper to the turning chute. A blast furnace raw material charging method of charging a main raw material and a sub raw material into a blast furnace furnace provided with a supply passage for transporting a main raw material, wherein the sub raw material from the sub hopper is supplied into the main hopper or the supply In the passage, the sub raw material from the sub hopper is transported to a flow rate control region where the sub raw material can flow at a predetermined ratio with the main raw material.

According to the blast furnace raw material charging apparatus and the blast furnace raw material charging method according to the present invention, the main raw material and the sub raw material supplied from the main hopper and the plurality of sub hoppers flow at a predetermined ratio.
As a result, the main raw material and the sub raw material are mixed at a predetermined mixing ratio per unit capacity, and a raw material having a predetermined raw material mixing ratio can be supplied to the swivel chute.

  Here, each sub raw material from the sub hopper and the main raw material flow at a predetermined ratio means that the sub raw material and the main raw material are moved when the sub raw material from the sub hopper is transferred into the main raw material. In addition to the case of flowing at a constant speed to a predetermined mixing ratio, the sub-raw material and the main raw material flow at a predetermined speed ratio to a predetermined raw material mixing ratio.

  A second aspect of the present invention is the blast furnace raw material charging apparatus according to the first aspect, wherein the plurality of raw material transporting means are open in the supply passage.

  A sixth aspect of the invention is the blast furnace raw material charging method according to the fifth aspect of the invention, wherein each of the sub raw materials in the plurality of sub hoppers is transported to the supply passage to flow. .

  According to the blast furnace raw material charging apparatus and the blast furnace raw material charging method according to the present invention, since the sub raw material is transported to the supply passage, the sub raw material is moved into the main raw material at a predetermined speed ratio while suppressing the influence of properties. Can be made. As a result, a plurality of raw materials can be easily and efficiently mixed with the main raw material at a predetermined mixing ratio and supplied to the turning chute.

Invention of Claim 3 is a blast furnace raw material charging apparatus of Claim 1 or Claim 2, Comprising: Each sub raw material of the said turning chute is based on the extent of the flow of each sub raw material to the said blast furnace center direction. Calculate the notch angle when charging
The turning chute is configured to start charging each sub raw material at a timing corresponding to the notch angle.

  The invention according to claim 7 is the blast furnace raw material charging method according to claim 5 or claim 6, wherein each sub raw material of the swirl chute is based on a degree of flow of each sub raw material toward the blast furnace center. The notch angle at the time of charging is calculated, and charging of each sub raw material is started at a timing corresponding to the notch angle of the turning chute.

  According to the blast furnace raw material charging apparatus and the blast furnace raw material charging method according to the present invention, each sub-raw material is estimated from the flow deviation in the blast furnace center direction from the particle size ratio and density ratio of each sub-raw material to the main raw material, In consideration of the above, it is charged into the blast furnace furnace through a turning chute. As a result, each sub-material can be deposited in a predetermined amount at a predetermined position in the blast furnace furnace to obtain a predetermined charge distribution.

  A fourth aspect of the present invention is the blast furnace raw material charging apparatus according to any one of the first to third aspects, wherein the sub raw material is transported from the sub hopper to the flow rate control region. Adjusts the inside of the sub hopper to the same pressure as the inside of the blast furnace, and when the sub raw material is supplied into the sub hopper, the pressure inside the sub hopper is shut off from the inside of the blast furnace in pressure. Means are provided.

  According to the blast furnace raw material charging apparatus and the blast furnace raw material charging method according to the present invention, the sub hopper is adjusted to a pressure corresponding to the blast furnace furnace and the sub raw material from the sub hopper is transported into the blast furnace furnace. The raw material can be stably transported into the main raw material without being affected by the pressure in the blast furnace furnace, and the sub raw material and the main raw material can be stably mixed.

  According to the blast furnace raw material charging apparatus and the blast furnace raw material charging method according to the present invention, when a plurality of types of raw materials are supplied into the blast furnace furnace, each raw material is affected by differences in properties such as average particle diameter and apparent density. Can be mixed at a predetermined mixing ratio, and a predetermined amount of raw material can be charged into a predetermined position in the blast furnace to obtain a desired distribution of charges. As a result, productivity of pig iron production is improved, and stable blast furnace operation can be achieved by suppressing consumption of the blast furnace wall and generation of deposits on the furnace wall.

It is a figure which shows schematic structure of the blast furnace raw material charging device which concerns on one Embodiment of this invention. It is a figure which shows an example of the raw material distribution in the blast furnace furnace which concerns on one Embodiment. It is a figure which shows the property and characteristic of a charging raw material. It is a figure explaining the behavior in the blast furnace of each raw material based on an average particle diameter and an apparent density, (A) is a behavior of a raw material with a large average particle diameter, (B) is an average particle diameter compared with (A). It is a figure which shows the behavior of a raw material with small. It is a figure explaining the segregation index of each raw material based on a particle diameter ratio and a segregation index. It is a figure explaining the relationship between the segregation index | exponent of each raw material, and a flow. It is a figure explaining the operating condition and base conditions of a blast furnace to which a blast furnace raw material charging apparatus is applied. It is a figure explaining an example of the operation schedule of a blast furnace raw material charging device. It is a figure explaining an example of the operation schedule of a blast furnace raw material charging device. It is a figure explaining an example of the operation schedule of a blast furnace raw material charging device. It is a figure explaining an example of the operation schedule of a blast furnace raw material charging device. It is a figure explaining the effect of the blast furnace raw material charging device concerning one embodiment.

Hereinafter, an embodiment of the present invention will be described with reference to FIGS.
FIG. 1 is a diagram showing a schematic configuration of a blast furnace raw material charging apparatus according to an embodiment of the present invention. Reference numeral 1 indicates a blast furnace raw material charging apparatus, and reference numeral 2 indicates a blast furnace main body. Moreover, FIG. 2 is a figure which shows an example of the distribution state of the raw material in a blast furnace furnace.

  The blast furnace raw material charging device 1 includes a main raw material charging device 10, for example, two (plural) sub raw material charging devices 20 and 30, and a turning chute 40.

The main raw material charging apparatus 10 includes, for example, a main conveyor 11 that conveys the raw material M1, a furnace top chute 12, a parallel hopper 13, a raw material passage 14, and a main hopper 15.
The raw material M <b> 1 conveyed by the main conveyor 11 is distributed by the furnace top chute 12, charged into the parallel hopper 13, and stored in the parallel hopper 13.
Further, for example, a shutoff valve 13S is provided in the raw material passage 14 between the parallel hopper 13 and the main hopper 15, and the flow of the raw material M1 from the parallel hopper 13 to the raw material passage 14 is controlled by opening and closing the shutoff valve 13S. It is supposed to be.

A cylindrical supply passage 16 is connected to the lower portion of the main hopper 15, and a flow rate adjusting valve 15C is provided between the main hopper 15 and the supply passage 16 to adjust the opening of the flow rate adjusting valve 15C. Thus, the flow rate of the raw material M1 from the main hopper 15 to the supply passage 16 is adjusted.
In addition, a shutoff valve 16S is provided at the lower opening of the supply passage 16, and a swiveling chute 40 is disposed below the supply passage 16, and the raw material from the supply passage 16 to the swiveling chute 40 is disposed by the shutoff valve 16S. The movement is controlled.

  The raw material M1 stored in the parallel hopper 13 moves to the main hopper 15 through the raw material passage 14 and is temporarily stored. The flow rate of the raw material M1 stored in the main hopper 15 is adjusted by, for example, the opening of the flow control valve 15C. Then, when it flows into the supply passage 16 and the shutoff valve 16S is opened, it moves to the turning chute 40 by gravity.

  The sub raw material charging device 20 includes a sub raw material charging conveyor 21 for conveying the raw material M2, a chute 22, a sub hopper 23, a raw material transport chute 24 for transporting the raw material M2 from the sub hopper 23 to the supply passage 16, and a flow rate. An adjustment valve 25, an upper cutoff valve 26, and a lower cutoff valve 27 are provided. Further, the upper shut-off valve 26 and the lower shut-off valve 27 constitute a uniform pressure exhausting means for the sub hopper 23.

  The material M2 is transported to the sub hopper 23 by the sub material charging conveyor 21, and when the material M2 is charged into the sub hopper 23, the upper shut-off valve 26 and the lower shut-off valve 27 are closed, The inside of the hopper 23 is shut off from the inside of the blast furnace by pressure.

  The raw material M2 in the sub hopper 23 closes the upper shutoff valve 26 and opens the lower shutoff valve 27 so that the sub hopper 23 is shut off from the atmosphere to a pressure corresponding to that in the blast furnace furnace. Then, the amount of movement of the raw material M2 is adjusted by the flow rate adjustment valve 25.

  The sub raw material charging device 30 includes a sub raw material charging conveyor 31 for conveying the raw material M3, a chute 32, a sub hopper 33, a raw material transport chute 34 for transporting the raw material M3 from the sub hopper 33 to the supply passage 16, and a flow rate. An adjustment valve 35, an upper cutoff valve 36, and a lower cutoff valve 37 are provided. Further, the upper shut-off valve 36 and the lower shut-off valve 37 constitute a uniform pressure exhausting means for the sub hopper 33.

  The transport of the raw material M3 to the sub hopper 33 is performed by the sub raw material charging conveyor 31, and when the raw material M3 is charged into the sub hopper 33, the upper shut-off valve 36 and the lower shut-off valve 37 are closed. The inside of the hopper 33 is cut off from the inside of the blast furnace by pressure.

  The raw material M3 in the sub hopper 33 closes the upper shut-off valve 36 and opens the lower shut-off valve 37 so that the sub hopper 33 is shut off from the atmosphere to a pressure corresponding to that in the blast furnace. Then, the amount of movement of the raw material M3 is adjusted by the flow rate adjustment valve 35.

  In this embodiment, the flow rate adjustment valve 15C and the flow rate adjustment valve 25 can be controlled in synchronization with the opening, and the flow rate can be adjusted while maintaining a predetermined ratio between the main material M1 and the sub material M2. . Further, for example, the mixing ratio of the main raw material M1 and the sub raw material M2 may be adjusted by independently controlling the opening degree of the flow regulating valve 15C and the flow regulating valve 25.

  Similarly, the flow rate adjustment valve 15C and the flow rate adjustment valve 35 are also capable of adjusting the flow rate while maintaining a predetermined ratio of the main raw material M1 and the sub raw material M3. Further, the flow rate adjustment valve 15C and the flow adjustment valve 35 may be configured to be able to adjust the mixing ratio of the main material M1 and the sub material M3.

  In this embodiment, the raw material transport chutes (transport means) 24 and 34 are opened in the supply passage 16 below the main hopper 15. And the opening part of the raw material transport chutes 24 and 34 in the supply passage 16 is made from the raw material M1 from the main hopper 15 and the raw materials M2 and M3 transported from the sub hoppers 23 and 33 via the raw material transport chutes 23 and 33. Is a flow velocity control region that flows at substantially the same speed (ratio 1: 1), for example. To control the flow rate equally, there is a method of measuring the weight change of each hopper 15, 23 and 33.

  As described above, as a result of the raw material M1 and the raw materials M2 and M3 flowing at substantially the same speed, a plurality of raw materials M1, M2 and M3 are easily and efficiently mixed at a predetermined mixing ratio to obtain a mixed raw material M4. The chute 40 is supplied. In addition, in the 1-dump mixed raw material M4, the sub raw materials M2 and M3 have a predetermined mixing ratio with respect to the main raw material M1, respectively.

The turning chute 40 has, for example, a bowl shape with a semicircular arc shape in cross section.
One dump of the mixed material M4 is usually performed in one step while reducing the angle of the turning chute. Thereby, the mixed raw material M4 is charged from the peripheral part (radially outward) of the blast furnace to the inner peripheral side (radially inward). At this time, the charging timing is controlled by a programmable controller (control unit) (not shown) so that the sub raw materials M2 and M3 come to predetermined positions in the blast furnace.

  For example, the programmable controller calculates, in the memory, based on the particle size ratio and density ratio (hereinafter referred to as segregation index) of each sub raw material with respect to the main raw material of each sub raw material M2 and M3 with respect to the main raw material M1, for example, each sub raw material. An index regarding the ease of flow of the raw materials M2 and M3 toward the center of the blast furnace, and the notch angle of the turning chute 40 when charging the sub-raw materials M2 and M3 calculated based on the ease of flow of the raw materials M2 and M3 (Θ) is stored. The programmable controller, for example, loads each sub-material into the blast furnace when the turning chute 40 has a notch angle (θ) corresponding to each sub-material M2, M3 based on these data stored in the memory. It is configured to enter. That is, the programmable controller opens the lower cutoff valves 27 and 37 of the sub hoppers 23 and 33 when the turning short 40 reaches the notch angle (θ) when the sub raw materials M2 and M3 are charged. At this time, the degree of inflow is considered for each sub-raw material.

A method for determining the charging start notch angle will be described below.
FIG. 2 shows a preferable charge distribution in the blast furnace furnace. The lower side of FIG. 2 is a diagram showing the radial distribution of the deposit pile height, and the upper side of FIG. 2 is (sintered ore with respect to (coke height LC + sinter ore height LO)). It is a figure which shows the ratio of (height LO).

In the vicinity of the central part of the blast furnace, it is preferable to lower the LO / (LC + LO) and lower the deposition height to increase the air permeability so as to promote efficient reduction of the sintered ore. .
Further, it is preferable that the intermediate portion has a high coke height / (coke + sinter ore height).
On the other hand, in the vicinity of the furnace wall on the outer periphery side of the blast furnace, it is preferable to suppress the gas flow so as not to increase the heat load, thereby suppressing the consumption of the furnace wall and the generation of deposits.

FIG. 3 is a diagram showing physical properties of raw materials charged in the blast furnace, suitable charging positions in the blast furnace, and characteristics of behavior in the blast furnace. An example of the input target position of each sub raw material is shown in the column of “preferred blast furnace charging position” in FIG. FIG. 4 is a diagram showing an average particle diameter (mm) and an apparent density (t / m ³ ) of each raw material.
In the present invention, if the raw material to be charged is large or light, it floats in the upper layer, and if it is small or heavy, it is applied to sink in the lower layer. The broken line in FIG. 4 shows the boundary of ups and downs, the raw material sinks on the upper side, and the raw material floats on the lower side.

Next, a method for determining the notch angle at which mixing of each sub raw material is started will be specifically described.
FIG. 5 is a graph showing the relationship between the raw material (particle size of the sub-raw material / sintered particle size), the density ratio, and the segregation index, and the representative values of each sub-raw material are also plotted. This segregation index is obtained by indexing the degree of ups and downs of each sub raw material with respect to sintered ore as the main raw material. When the segregation index is positive, the sub-raw material floats on the sintered ore, and when the segregation index is negative, the sub-material exhibits a behavior of sinking into the sintered ore.

  The raw material with a segregation index exceeding zero floats in the upper layer of the sintered ore and starts moving toward the furnace center. The raw material with a higher segregation index increases the relative flow index gradually and becomes easier to flow toward the furnace center. The raw material with index 1 flows into the furnace center.

  Therefore, when a raw material having a segregation index of zero or more is charged into the blast furnace, it is necessary to charge the peripheral portion of the furnace rather than the position where it is desired to deposit.

In FIG. 5, the relationship between the particle size ratio and the segregation index in each density ratio of the sub raw materials uses, for example, the following mathematical formula calculated by obtaining a correction value by experiment and correcting the simulation value.
Density ratio; 0.5: y = −0.23X ² + 0.99X−0.56
Density ratio; 1.0: y = −0.12X ² + 0.65X−0.53
Density ratio; 1.25: y = −0.07X ² + 0.44X−0.48
Density ratio; 1.5: y = −0.03X ² + 0.22X−0.43
Density ratio; 2.0: y = 0.06X ² + 0.01X−0.38
Density ^{ratio; 2.5: y = 0.06X 2 -0.03X} -0.39
When the second-order, first-order, and zero-order terms in the above expression are expressed in relation to the density ratio, A = −0.21 × ρr ⁴ + 1.46 × ρr ³ −3, which becomes the following expressions A, B, and C, respectively. .25 × ρr ² + 2.04 × ρr + 0.61
B = −0.04 × ρr ³ + 0.12 × ρr ² + 0.11 × ρr−0.31
C = −0.09 × ρr ³ + 0.35 × ρr ² −0.29 × ρr−0.49
From this, the segregation index can be expressed by the following formula.
Segregation index = A × Dpr + B × Dpr + C × Dpr
ρr: relative density ratio Dpr: relative particle size ratio

FIG. 6 is a diagram for determining the degree of inflow of each sub-material toward the center of the blast furnace (hereinafter referred to as a relative inflow index) from the segregation index of each sub-material to the sintered ore.
The relative inflow index indicates the ease of flow of each raw material toward the blast furnace center. When the segregation index is less than or equal to zero, the relative inflow index is zero, and the charged raw materials stay at the same position as the sintered ore and accumulate in the lower layer, so there is no inflow toward the blast furnace center. The raw material whose relative inflow index exceeds zero floats in the upper layer of the sintered ore and starts moving toward the furnace center. A raw material with a relative inflow index of 1 flows into the furnace center.

Therefore, when a raw material having a relative inflow index of zero or more is charged into the blast furnace, it is necessary to charge the periphery of the furnace rather than the position where it is desired to deposit.
In the following embodiment, the charging timing of the sub raw materials M2 and M3 from the sub hoppers 23 and 33 into the blast furnace is determined based on the above technical idea.

Next, the operation of the blast furnace raw material charging apparatus 1 will be described with reference to FIGS.
FIG. 7 shows base data relating to operation of a blast furnace to which the blast furnace raw material charging apparatus 1 is applied. FIG. 7 (A) shows base operating conditions, and FIG. 7 (B) shows base conditions of raw fuel charged into the blast furnace. ing.

  8 to 11 show an example of a specific schedule of the turning chute 40 when the blast furnace raw material charging apparatus 1 performs one dump charging. Is the control sequence order of the notch angle (°), and the notch angle (°) is a numerical value corresponding to the notch angle (θ) in FIG.

  The control unit of the blast furnace raw material charging apparatus 1 performs the main hopper 15, the sub hoppers 23, 33, the swivel based on the behavior of each sub raw material in the blast furnace furnace calculated according to FIGS. 3, 4, 5, and 6. The operation of the chute 40 is controlled. Note that the transportation of the raw material from the main hopper 15 and the sub raw material charging devices 20 and 30 is synchronized with the turning chute 40.

  That is, when the control unit mixes the main raw material M1 with the sub raw materials M2 and M3 to obtain the mixed raw material M4, the turning chute 40 has a notch angle (θ) taking into account the inflow toward the blast furnace center. In addition, the lower cutoff valves 27 and 37 of the sub hoppers 23 and 33 are controlled so that the sub raw materials M2 and M3 are charged into the blast furnace furnace, and the sub raw materials M2 and M3 are segregated to the mixed raw material M4. I am letting. In the following description, it is assumed that the sub raw materials M2 and M3 are appropriately segregated in one dump mixed raw material M4.

  In consideration of the inflow of each sub-material in the blast furnace, the control unit inserts a sub-material having a segregation index greater than 1 when the notch angle (θ) of the swivel chute 40 is large, thereby providing a blast furnace for each sub-material. Controls the radial position and deposition height inside.

FIG. 8 is a diagram showing an example of the schedule of the swivel chute 40 when charging the sintered ore from the main hopper 15 and the fine-grained sintered ore from the sub hopper 23.
In this case, as shown in FIG. 8 (A), the output ratio 2.25 ton / D / m ³ , lump coke ratio 353 kg / ton-p, pulverized coal ratio 142 kg / ton-p, sintered ore ratio 1396 kg / ton -P, fine grain sinter ratio is 220 kg / ton-p.
The operation schedule at this time is as shown in FIG. 2 to 11 (notch angle 48.5 to 40.5 °) for two turns each time, and from the sub hopper 23, fine-grained sintered ore is notched with a notch No. 1-4 (notch angle 48.5-47.3 °), notch No. When it is 1, notch no. The period between 2 and 4 is supplied for each two turns.
By carrying out such a schedule, a large amount of fine-grained sintered ore can be distributed in the vicinity of the furnace wall.

FIG. 9 is a diagram showing an example of the schedule of the turning chute 40 when charging the sintered ore from the main hopper 15, the small coke from the sub hopper 23, and the reduced iron from the sub hopper 33.
In this case, as shown in FIG. 9A, the output ratio is 2.34 ton / D / m ³ , the lump coke ratio is 291 kg / ton-p, the pulverized coal ratio is 135 kg / ton-p, and the sintered ore ratio is 1531 kg / ton. -P, small coke ratio 62 kg / ton-p, reduced iron ratio 45 kg / ton-p.
The operation schedule at this time is as shown in FIG. 2 to 11 (notch angle 48.5 to 40.5 °), from the sub hopper 23, a small coke is notch No. 1 to 6 (notch angle 48.5 to 45.5 °), reduced iron is supplied from the sub hopper 33 to the notch No. 2 to 10 (notch angle 48.5 to 42.3 °). In No. 1, one turn, no. 3, no. In No. 5, each 3 turns, other notch No. Then, it is supplied during each two turns.
By implementing such a schedule, a large amount of small coke can be distributed in the middle part of the furnace, and reduced iron can be uniformly distributed in the furnace inner diameter direction.

FIG. 10 is a diagram showing an example of the schedule of the turning chute 40 when charging the sintered ore from the main hopper 15, the carbon-containing agglomerated mineral from the sub hopper 23, and the reduced iron from the sub hopper 33.
In this case, as shown in FIG. 10 (A), the output ratio 2.41 ton / D / m ³ , lump coke ratio 288 kg / ton-p, pulverized coal ratio 133 kg / ton-p, sintered ore ratio 1499 kg / ton -P, carbon-containing agglomerated ratio 40 kg / ton-p, reduced iron ratio 45 kg / ton-p.
The operation schedule at this time is as shown in FIG. 2 to 11 (notch angle 48.5 to 40.5 °), the sub-hopper 23 gives a carbon-containing agglomerated notch no. 2-7 (notch angle 48.5-44.1 °), the reduced hopper 33 is supplied with reduced iron from the sub hopper 33. 2 to 10 (notch angle 48.5 to 42.3 °), 3, no. In No. 5, each 3 turns, other notch No. Then, it is supplied during each two turns.
By carrying out such a schedule, a large amount of carbon-containing agglomerated ore can be distributed in the middle part of the furnace, and reduced iron can be uniformly distributed in the furnace inner diameter direction.

FIG. 11 shows a case where sintered ore is charged from the main hopper 15, small coke from the sub hopper 23, carbon-containing agglomerated mineral from the sub hopper 33, and reduced iron from the third sub hopper (not shown). It is a figure which shows an example of the schedule of the turning chute 40 of.
In this case, as shown in FIG. 11 (A), the output ratio 2.53 ton / D / m ³ , lump coke ratio 230 kg / ton-p, pulverized coal ratio 134 kg / ton-p, sintered ore ratio 1499 kg / ton -P, small coke ratio 54 kg / ton-p, carbon-containing agglomerated ratio 40 kg / ton-p, reduced iron ratio 45 kg / ton-p.
The operation schedule at this time is as shown in FIG. 2 to 11 (notch angle 48.5 to 40.5 °), the sub-hopper 23 gives a carbon-containing agglomerated notch no. 1 to 6 (notch angle 48.5 to 45.5 °), from the sub hopper 33, the carbon-containing agglomerated mineral is notch No. 2 to 7 (notch angle 48.5 to 44.1 °), the reduced iron is supplied from the third sub-hopper to the notch No. 2-10 (notch angle 48.5-42.3 °), notch no. 1 turns 1 turn, notch no. For 3, 5, 7, and 9, 3 turns each, other notch No. Then, it is supplied during each two turns.
By carrying out such a schedule, a large amount of small coke and carbon-containing agglomerated ore can be distributed in the middle part of the furnace, and reduced iron can be uniformly distributed in the furnace inner diameter direction.

With reference to FIG. 12, the effect of the blast furnace raw material charging apparatus 1 is demonstrated based on a simulation result.
(Example A) According to the blast furnace raw material charging apparatus 1, the effect shown by (◯) in FIG. That is, there is almost no distribution of fine-grained sintered ore in the range up to 0.3 in the radial direction of the blast furnace, and the distribution greatly increases in the range of 0.3 to 0.5. Then, the amount of deposition decreases by about 20% around 0.6, and increases from about 0.4 to 0.8 in weight ratio from 0.6 to 1.0 (furnace wall).
In this way, the raw material distribution at the furnace center is greatly reduced compared to the raw material distribution in the control (コ ン ベ ア) on the conventional charging conveyor and the control (Δ) shown in Patent Documents 1 and 2, and the furnace wall This can be greatly improved in that the raw material distribution on the side greatly increases.

(Example B) According to the blast furnace raw material charging apparatus 1, with respect to the small coke, the small coke is about 0.5 to 0.9 in the radial direction of the blast furnace as shown by (O) in FIG. It was found that the distribution at the center of the furnace was greatly reduced.
As described above, the raw material distribution of the small coke by the control (◇) on the conventional charging conveyor and the control (Δ) shown in Patent Documents 1 and 2 is larger in the furnace center than in the furnace middle. The distributed inconvenience can be fundamentally improved.

(Example C) According to the blast furnace raw material charging apparatus 1, the effect shown by (O) in FIG. That is, the range of the blast furnace in the height direction of 0.4 increases from about 0.05 to about 0.45, there is almost no distribution of small coke, and it increases significantly in the range of 0.3 to 0.5. . When the height direction is 0.4 or more, the mass ratio gradually increases from 0.45 to about 0.7.
Thus, although there is no significant change compared to the raw material distribution in the control (Δ) shown in Patent Documents 1 and 2, the vertical segregation is significantly larger than that in the conventional control on the charging conveyor (◇). Can be improved.

(Example D) According to the blast furnace raw material charging apparatus 1, the effect as indicated by (O) in FIG. That is, the distribution of reduced iron is relatively small in the range up to about 0.3 in the radial direction of the blast furnace, and gradually increases in the range of 0.3 to 0.8 and gradually increases from about 0.8 to 1.0. Decrease.
In this way, the raw material distribution in the middle part of the furnace is stably ensured as compared with the raw material distribution in the conventional control on the charging conveyor (◇) and the control (△) shown in Patent Documents 1 and 2. it can.

  As described above, according to the blast furnace raw material charging apparatus 1, when charging a plurality of types of raw materials M1, M2, and M3 into the blast furnace furnace, the average particle diameters and apparent densities of the raw materials M1, M2, and M3 are as follows. The sub raw materials M2 and M3 can be mixed with the main raw material M1 at a predetermined ratio while suppressing the influence due to the difference in properties such as the above.

In addition, when charging a predetermined amount of the mixed raw material M4 into a predetermined position in the blast furnace, each sub raw material M2, M3 is taken into account by taking into account the inflow of the sub raw materials M2, M3 in the blast furnace. Can be deposited at a predetermined radial position in the blast furnace to have a predetermined material distribution.
As a result, productivity of pig iron manufacturing can be improved and consumption of the blast furnace furnace wall and suppression of deposits can be realized.

Note that the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the spirit of the invention.
For example, in the above-described embodiment, the case where the sub raw materials M2 and M3 are transported from the sub hoppers 23 and 33 to the flow rate control region in the supply passage 16 has been described. The sub-raw materials M2 and M3 may be transported to the flow rate control region formed inside the raw material M1 stored in 15.

  Moreover, in the said embodiment, although the case where the two sub hoppers 23 and 33 were provided was demonstrated, it cannot be overemphasized that the number of sub hoppers can be set according to the kind of target raw material, for example.

  Further, when the segregation indexes of the respective sub-materials M2 and M3 are different, the flow rates calculated by the material transport chutes 24 and 34 from the sub hoppers 23 and 33 according to the segregation indexes of the respective sub-materials M2 and M3 are different. It is good also as a structure opened to a control area | region.

  In the above embodiment, the case where the raw materials M2 and M3 from the sub hoppers 23 and 33 are formed in the supply passage 16 flowing at the same speed as the main raw material M1 as the flow velocity control region has been described. When some raw materials cannot flow at a constant speed due to frictional resistance with the wall surface or inclined portion of the main hopper 15, the sub raw materials M2 and M3 are changed to the main raw material M1 in consideration of the flow loss. On the other hand, a region that flows at a predetermined ratio may be set as a flow rate control region.

  Moreover, the driving schedule shown in the above embodiment is an example, and it goes without saying that other driving schedules can be applied.

  In the above embodiment, the case where the pressure equalizing / exhausting means is provided and the inside of the sub hoppers 23 and 33 is adjusted to the pressure corresponding to the inside of the blast furnace has been described. A pressure conveyor or another pressure adjusting mechanism may be used for supplying the raw materials to the hoppers 23 and 33. Moreover, when the raw material transport from the sub hoppers 23 and 33 to the main hopper 15 is not influenced by the pressure in the blast furnace, the pressure adjusting mechanism for the sub hoppers 23 and 33 may not be provided.

  Moreover, although the said embodiment demonstrated the case where the blast furnace raw material charging device 1 was controlled by the calculation result based on the average particle diameter and apparent density of each raw material stored in the programmable controller, it stored in the database of a computer. It is good also as a structure which calculates and controls in real time based on the numerical value data and the average particle diameter of the raw material supplied to the sub hoppers 23 and 33, and an apparent density.

  When a plurality of types of raw materials are supplied into the blast furnace, it is possible to suppress the influence of differences in properties such as the average particle diameter and the apparent density of the respective raw materials, and thus the present invention can be used industrially.

θ Notch angle M1 Main raw material M2, M3 Sub raw material M4 Mixed raw material 1 Blast furnace raw material insertion device 2 Blast furnace main body 10 Main raw material charging device 15 Main hopper 16 Supply passage (flow rate control region)
20, 30 Sub raw material charging device 23, 33 Sub hopper 24, 34 Raw material transport chute (raw material transport means)
26, 27 Shut-off valve (equal discharge pressure means)
36, 37 Shut-off valve (equal discharge pressure means)
40 Turning chute

Claims (7)

A blast furnace raw material charging apparatus for charging a plurality of raw materials into a blast furnace furnace,
A main hopper for storing main raw materials;
A plurality of sub hoppers for storing sub raw materials;
A swivel chute for supplying the raw material into the blast furnace;
A supply passage for transporting the main raw material from the main hopper to the turning chute;
A raw material transport means for transporting the sub raw material from each sub hopper provided corresponding to the plurality of sub hoppers,
The plurality of raw material transport means include
In the main hopper or the supply passage, each sub raw material from the plurality of sub hoppers and the main raw material are opened to a flow rate control region in which the main raw material can flow at a predetermined ratio. Blast furnace raw material charging equipment. The blast furnace raw material charging apparatus according to claim 1,
The blast furnace raw material charging apparatus, wherein the plurality of raw material transporting means are opened in the supply passage. A blast furnace raw material charging apparatus according to claim 1 or 2,
Based on the particle size ratio and density ratio of each sub raw material to the main raw material, the degree of inflow of each sub raw material in the blast furnace center direction is calculated,
Calculate the notch angle when charging each sub raw material of the swivel chute based on the degree of flow of each sub raw material in the blast furnace center direction,
A blast furnace raw material charging apparatus, wherein the turning chute is configured to start charging each sub raw material at a timing corresponding to the notch angle. The blast furnace raw material charging apparatus according to any one of claims 1 to 3,
When transporting the sub raw material from the sub hopper to the flow rate control region, the inside of the sub hopper is adjusted to a pressure equal to that in the blast furnace furnace,
A blast furnace raw material charging apparatus, comprising: a pressure equalizing / exhausting means for pressure-blocking the inside of the sub hopper from the inside of the blast furnace when supplying the sub raw material into the sub hopper. A main hopper for storing main raw materials;
A plurality of sub hoppers for storing sub raw materials;
A swivel chute for supplying the raw material into the blast furnace;
A blast furnace raw material charging method of charging a main raw material and a sub raw material into a blast furnace furnace provided with a supply passage for transporting a main raw material from the main hopper to the swivel chute,
Each sub-raw material from the plurality of sub-hoppers flows in the main hopper or the supply passage so that each sub-raw material from the plurality of sub-hoppers can flow at a predetermined ratio with the main raw material. A blast furnace raw material charging method, wherein the raw material is transported to a speed control region and fluidized. The blast furnace raw material charging method according to claim 5,
A blast furnace raw material charging method, wherein the sub raw materials in the plurality of sub hoppers are transported to the supply passage and flowed. The blast furnace raw material charging method according to claim 5 or 6,
Based on the particle size ratio and density ratio of each sub raw material to the main raw material, the degree of inflow of each sub raw material in the blast furnace center direction is calculated,
Calculate the notch angle when charging each sub raw material of the swivel chute based on the degree of flow of each sub raw material in the blast furnace center direction,
Blast furnace raw material charging method, wherein charging of each sub raw material is started at a timing when the turning chute corresponds to the notch angle.

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