Blast furnace raw material manufacturing device and blast furnace raw material manufacturing method

Abstract

To provide a blast furnace raw material manufacturing apparatus and a blast furnace raw material manufacturing method, that can enhance quality and productivity of a blast furnace raw material such as ferro-coke.SOLUTION: A blast furnace raw material manufacturing apparatus that manufactures a blast furnace raw material by distilling a molded article charged into a dry distillation furnace 1 has: a duct 90 that is connected to a side wall part 80 of the dry distillation furnace 1 so as to communicate with the dry distillation furnace 1, and collects powder from the molded product charged into the dry distillation furnace 1; and a lid part 92 that is provided so as to be rotatable with a lower end part as the center with respect to the side wall part 80, wherein the dry distillation furnace 1 and the duct are communicated by rotating around the lower end part to open toward an interior side of the dry distillation furnace 1.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present invention relates to an apparatus and a method for producing raw materials for a blast furnace, such as molded coke, particularly ferrocoke, used in a blast furnace. [Background technology]

[0002] In recent years, the steel industry has been required to reduce CO2 gas emissions in light of global warming. This has led to an urgent need to reduce the use of fossil fuels. In the steel industry, molten iron is produced in blast furnaces by reducing iron ore with carbon (coke produced by carbonizing coal in a coke oven). To reduce coke consumption, development is underway to use ferrocoke as a blast furnace feedstock. Ferrocoke is made by mixing a certain amount of iron ore with coal, forming it into agglomerates, and then carbonizing it to disperse fine metallic iron particles within the coke. This is a molded coke whose reactivity is enhanced by the catalytic action of the metallic iron.

[0003] A method using a vertical carbonization furnace has been proposed as a method for carbonizing ferro-coke. Patent Document 1 discloses a vertical carbonization furnace having a carbonization zone in the upper part and a cooling zone in the lower part. The method for producing ferro-coke in a vertical carbonization furnace includes a charging step of charging briquettes composed of a carbon-containing material and an iron-containing material into the vertical carbonization furnace using a charging device, a carbonization step of producing ferro-coke by carbonizing the briquettes while injecting a heated gas into the carbonization zone, a cooling step of cooling the ferro-coke by injecting a cooling gas into the cooling zone, an in-furnace gas discharge step of discharging in-furnace gas from an outlet at the top of the vertical carbonization furnace, and a ferro-coke discharge step of discharging the ferro-coke from the bottom of the cooling zone.

[0004] In the carbonization process, the shaped product is heated by injecting low-temperature gas into the furnace through a low-temperature gas inlet in the middle of the carbonization zone and high-temperature gas into the furnace through a high-temperature gas inlet in the lower part of the carbonization zone. In the cooling process, the ferro-coke is cooled by injecting cooling gas into the furnace through a cooling gas inlet in the lower part of the cooling zone.

[0005] In order to increase the production volume of ferro-coke, it is necessary to increase the volume of the vertical carbonization furnace. Generally, the charge material is charged at an angle using an inclined charging chute, but the heating gas and cooling gas are injected in the depth direction of the vertical carbonization furnace (parallel to the horizontal component of the charge material charging direction). Therefore, in order for the gas to penetrate to the center of the furnace, the internal dimension in the depth direction must be kept below a certain level. Therefore, vertical carbonization furnaces are configured with an internal dimension that is longer in the furnace width direction (the direction perpendicular to the depth direction in the cross section of the carbonization furnace) than in the depth direction, ensuring a large volume.

[0006] Furthermore, Patent Document 2 discloses a method for uniformly loading (transporting) materials, in which a dispersion guide section having an inclined surface that slopes radially downward from the center of the width direction of the transport path toward the exit side is provided to radially disperse the materials. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Japanese Patent Application Laid-Open No. 2011-57970 [Patent Document 2] Japanese Patent Application Laid-Open No. 2011-162271 Summary of the Invention [Problem to be solved by the invention]

[0008] The molded product is fed to a carbonization furnace through a chute. At this time, the molded product is broken up by colliding with the wall surface of the chute, and a part of it becomes powder. That is, the molded product contains granular material and powder having a smaller volume than the granular material.

[0009] The powder settles through the gaps between the granules. Therefore, the compact is supplied to the carbonization furnace in two separate layers: a granular layer (upper layer) and a powder layer (lower layer). Therefore, when the granules are supplied to the carbonization furnace from the chute, they are deposited farther away than the powder, and the powder is deposited on the chute side.

[0010] When the compacts are fed into the carbonization furnace, a slope of the pile is formed according to the angle of repose. Therefore, when the powder reaches the slope of the pile, it moves along the slope toward the opening of the chute and comes to rest. In particular, when the powder reaches the top of the slope of the pile, the slope becomes steeper, so the powder tends to move further toward the opening of the chute. In contrast, granular materials move farther than the powder, and most of them reach near the top of the pile. In other words, the granular materials are fed evenly onto the slope of the pile.

[0011] In this way, the granular material of the molded product and the powder tend to be deposited in uneven positions in the carbonization furnace. Therefore, when the powder is deposited in an uneven position, the air permeability of that area becomes worse than that of other areas. In the area where the powder is deposited in an uneven position, the amount of heated gas supplied decreases due to the deterioration of air permeability, and there is a possibility that defects such as poor carbonization will occur in the molded product supplied to that area.

[0012] Even if the dispersion guide unit described in Patent Document 2 is used when supplying the molded product to a dry distillation furnace, it is not possible to prevent the powder from being deposited in a biased position. Therefore, there is a need to improve the above problem.

[0013] The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide an apparatus and a method for producing blast furnace raw materials that can improve the quality and productivity of blast furnace raw materials such as ferro-coke. [Means for solving the problem]

[0014] In order to achieve the above object, the present invention provides: [1] A blast furnace raw material manufacturing device that produces blast furnace raw materials by carbonizing molded materials loaded into a carbonization furnace, the blast furnace raw material manufacturing device having a duct that is connected to a side wall of the carbonization furnace so as to be in communication with the inside of the carbonization furnace and that recovers powder from the molded materials loaded into the carbonization furnace, and a lid portion that is rotatable about its lower end relative to the side wall portion, and the lid portion rotates about its lower end and opens toward the inside of the carbonization furnace, thereby connecting the carbonization furnace and the duct. [2] The blast furnace raw material manufacturing apparatus described in [1] further includes a loading chute for loading the molded material into the carbonization furnace, the loading chute being located above the lid portion on the side wall of the carbonization furnace and overlapping at least a portion of the lid portion when viewed from the top to bottom of the carbonization furnace, and the lid portion is configured to receive the powder of the molded material being loaded into the carbonization furnace from the loading chute and to flow it toward the duct when the duct is open. [3] The duct has a sieve through which the powder passes, and is configured to recover the powder through the sieve. [1] The blast furnace raw material manufacturing apparatus described above in [1]. [4] The duct has a sieve through which the powder passes, and is configured to recover the powder through the sieve. [2] The blast furnace raw material manufacturing apparatus described above in [2]. [5] A blast furnace raw material manufacturing apparatus as described in [3] above, wherein a portion of the outer peripheral edge of the sieve is connected to the upper end of the lid, and another portion of the outer peripheral edge of the sieve, located on the opposite side of the center of the sieve from the portion of the outer peripheral edge, is connected to an upper inner wall surface of the duct so as to be movable along the longitudinal direction of the duct. [6] A blast furnace raw material manufacturing apparatus as described in [4] above, wherein a portion of the outer peripheral edge of the sieve is connected to the upper end of the lid, and another portion of the outer peripheral edge of the sieve, located on the opposite side of the center of the sieve from the portion of the outer peripheral edge, is connected to an upper inner wall surface of the duct so as to be movable along the longitudinal direction of the duct. [7] The blast furnace raw material manufacturing apparatus according to [1] above, wherein the opening angle of the lid portion from the closed state of the duct is 60° or less. [8] The blast furnace raw material manufacturing apparatus according to [3] above, wherein when the lid portion is open, the angle formed between the sieve and a horizontal plane is 30° or more. [9] A blast furnace raw material manufacturing apparatus as described in [2] above, in which, when the lid portion is in an open state, the distance d in the height direction of the carbonization furnace between the upper end of the lid portion and the lower end of the opening of the charging chute, and the distance w2 in the horizontal direction between the upper end of the lid portion and the lower end of the lid portion, satisfy the following equations relative to the internal dimension W1 in the depth direction of the carbonization furnace. 0.2≦d / W≦0.5, 0.35≦w / W≦0.55

[10] A method for producing raw materials for a blast furnace using the apparatus for producing raw materials for a blast furnace according to any one of [1] to [9] above. [Effects of the Invention]

[0015] According to the present invention, the powder of the shaped materials charged into the carbonization furnace can be recovered, which prevents the powder from being deposited in an uneven position. This prevents poor carbonization due to deterioration of permeability caused by powder segregation, and improves the quality and productivity of the raw material for the blast furnace. [Brief explanation of the drawings]

[0016] [Figure 1] FIG. 1 is a side view showing an example of a conventional vertical carbonization furnace. [Figure 2] 1 is a side cross-sectional view showing the top of a carbonization furnace as a blast furnace raw material manufacturing apparatus according to the present invention. FIG. [Figure 3] 3 is a diagram showing a state in which the cover shown in FIG. 2 is closed. FIG. [Figure 4] 10A and 10B are diagrams for explaining the opening angle of the lid portion. [Figure 5] FIG. 10 is a diagram illustrating a state in which powder is collected in a duct. [Figure 6] FIG. 10 is a graph showing the relationship between the lid portion and the powder removal rate in Example 1. [Figure 7] FIG. 10 is a graph showing the relationship between the lid portion and the powder removal rate in Example 2. DETAILED DESCRIPTION OF THE INVENTION

[0017] The present invention will be described below through embodiments of the present invention, taking as an example a case where ferro-coke, a type of molded coke, is produced by mixing a certain amount of iron ore with coal and agglomerating the mixture. The drawings are schematic and may differ from the actual product. The following embodiments are intended to exemplify devices and methods for embodying the technical concept of the present invention, and are not intended to limit the configuration to those described below. In other words, the technical concept of the present invention can be modified in various ways within the technical scope of the claims.

[0018] The configuration of a vertical carbonization furnace 100 as a conventional apparatus for producing raw materials for a blast furnace will be described with reference to FIG. 1. FIG. 1 shows a schematic side view of the vertical carbonization furnace 100. In the following description, the term "charge material" is not limited to "briquettes containing a carbon-containing material and an iron-containing material" for producing ferro-coke, but may also include "briquettes containing a carbon-containing material." In other words, it is sufficient if the briquettes contain at least a carbon-containing material. The term "charge material" includes "briquettes" and "powder" attached to or separated from the "briquettes." Furthermore, the term "raw material for a blast furnace" refers to "coke" including ferro-coke.

[0019] The vertical carbonization furnace 100 has a charging chute 10, a charging gate 20, a diffusion section 30, and a carbonization furnace body 70. First, a charge material including briquettes containing a carbon-containing material (coal) and an iron-containing material (iron ore) is supplied to the charging chute 10 provided above the carbonization furnace body. When the charging gate 20 is closed (see the dashed line in the figure), the charge material is temporarily accumulated inside the charging chute 10 (midway along the charging chute 10). When the charging gate 20 is opened (shown by the solid line in the figure), the charge material passes through the inside of the charging chute 10 toward the carbonization furnace body 70. The charge material is dispersed so as to spread throughout the inside of the charging chute 10 by passing through the diffusion section 30 of the charging chute 10. After passing through the inside of the charging chute 10, the charge material is deposited inside the carbonization furnace body 70. The charge material forms a mountain shape in accordance with the angle of repose inside the carbonization furnace body 70.

[0020] As described above, the charge material charged into the carbonization furnace body 70 is separated into two layers, a molded material layer (upper layer) and a powder layer (lower layer), inside the charging chute 10 before reaching the carbonization furnace body 70. Therefore, as shown in FIG. 1, the charge material charged into the carbonization furnace body 70 is separated into a molded material layer 40 and a powder layer 50, which then fall into the carbonization furnace body 70. For this reason, the charge material 60 accumulated inside the carbonization furnace body 70 has an uneven distribution of molded material and powder. Due to this uneven distribution, in the conventional vertical carbonization furnace 100, the gas flow inside the carbonization furnace body 70 becomes uneven, causing problems such as poor carbonization of the molded material.

[0021] Fig. 2 is a side cross-sectional view showing the furnace top of a carbonization furnace 1 as a blast furnace raw material manufacturing apparatus of the present invention. As shown in Fig. 2, side walls 80, 81 at the furnace top of the carbonization furnace 1 face each other in the depth direction S of the carbonization furnace 1. One of the side walls 80 has an opening formed therethrough in the thickness direction, and a charging chute 10 is connected to the opening. A duct 90 is connected to the side wall 80 below the charging chute 10 and above the top DMtop of the molded materials DM (hereinafter referred to as the deposit) deposited inside the carbonization furnace 1. The duct 90 recovers powder contained in the molded materials charged into the carbonization furnace 1 from the charging chute 10, and is connected to an opening 91 formed therethrough in the thickness direction of the side wall 80. In order to efficiently collect the powder, the opening 91 of the duct 90 is preferably provided at a position where, when viewed from the top and bottom of the carbonization furnace 1, at least a portion of the opening 91 of the duct 90 and the charging chute 10 overlap each other in the width direction (not shown) of the carbonization furnace 1. The powder contained in the molded product will be described later.

[0022] 2, duct 90 extends downward from opening 91 at an inclination, and the inclination angle of duct 90 is set to an angle greater than the angle of repose of the powder. Therefore, the powder charged into or collected in duct 90 slides downward along duct 90 due to its own weight.

[0023] The shape of the opening 91 of the duct 90 may be, for example, circular or rectangular. In this embodiment, it is rectangular. The cross-sectional shape of the duct 90 may be, for example, circular or rectangular. The inner dimensions or diameter of the inscribed circle of the opening 91 of the duct 90, and the inner dimensions or diameter of the inscribed circle of the duct 90, are larger than the particle size of the powder and are preferably set to about the particle size of the molded product, and more preferably about 1.5 times the particle size of the molded product. The sizes of the duct 90 and the opening 91 may be set to a size that allows the powder to move through them.

[0024] Of the inner wall surfaces of the duct 90 on the side of the carbonization furnace 1, the upper inner wall surface has a curved shape (hereinafter referred to as a curved surface) that is convex upward, as shown in Fig. 2. A rail (not shown) is provided on the curved surface, extending along the curved surface. A sieve (described later) is connected to the rail so as to be movable along the rail.

[0025] The opening 91 of the duct 90 is provided with a lid 92 that connects the duct 90 to the interior of the carbonization furnace 1 and blocks communication between the carbonization furnace 1 and the duct 90. FIG. 2 shows a state in which the lid 92 is open, thereby connecting the duct 90 to the carbonization furnace 1, and FIG. 3 shows a state in which the lid 92 is closed, thereby blocking communication between the duct 90 and the carbonization furnace 1. The shape of the lid 92 is not limited as long as it can open and close the opening 91, and it may be formed, for example, in a flat plate shape. In this embodiment, the lid 92 has a rectangular shape that is approximately the same as the outer shape of the opening 91 of the duct 90. The lid 92 may be formed to a size that covers the duct 90, or may be formed to a shape that fits into the opening 91 of the duct 90.

[0026] The lid portion 92 is rotatable around the lower end of the lid portion 92 on the side wall portion 80, and opens toward the inside of the dry distillation furnace 1, as shown in FIG.

[0027] FIG. 4 is a diagram illustrating the opening angle of the lid portion 92. The opening angle θ1 is the maximum angle formed between the side wall portion 80 and the lid portion 92 when the lid portion 92 is rotated toward the interior of the dry distillation furnace 1 around the lower end of the lid portion 92, and the maximum value of this opening angle is set in advance. The opening angle θ1 is set to satisfy the formulas (1) and (2) described below. When the opening angle of the lid portion 92 reaches θ1, a stopper (not shown) may be configured to prevent further rotation of the lid portion 92. Note that the means for rotatably connecting the lower end of the lid portion 92 to the side wall portion 80 is not limited, and a hinge may be used as an example.

[0028] The dry distillation furnace 1 is provided with an actuator that opens and closes the duct 90 relative to the interior of the dry distillation furnace 1 by rotating the lid portion 92 around the lower end of the lid portion 92, and a control device (not shown) that controls the operation of the actuator. The actuator is not limited to, but may be, for example, a hydraulic piston-type actuator configured to rotate the lid portion 92 a predetermined angle using hydraulic pressure from a hydraulic source (not shown). Alternatively, the lid portion 92 may be rotated a predetermined angle using torque output from a motor (not shown). The control device is primarily configured using a microcomputer and is configured to perform calculations based on input data, pre-stored data, etc., and output the calculation results as control command signals. The control device may be configured to control the operation of the hydraulic piston-type actuator or motor using preset timing or an input signal as a trigger. Instead of the control device, the operation of the hydraulic piston-type actuator or motor may be controlled by an operator.

[0029] FIG. 5 is a diagram illustrating the state in which powder is being collected in the duct. The lid portion 92 receives the powder contained in the molded products charged into the carbonization furnace 1 through the charging chute 10 and guides it to the duct 90. As described above, the molded products are supplied to the carbonization furnace 1 in a state in which they are separated into two layers, a molded product layer (upper layer) and a powder layer (lower layer). Therefore, as shown in FIG. 5, the size of the lid portion 92 and the opening angle θ1 of the lid portion 92 are set so that the position of the upper end of the lid portion 92 is the boundary between the powder charged through the charging chute 10 and the molded products. By setting the size of the lid portion 92 and the opening angle θ1 of the lid portion 92 in this way, the powder contained in the molded products can be received and guided to the duct 90 for collection. The position of the aforementioned boundary portion in the carbonization furnace 1 is determined in advance by experiment, and the size of the lid portion 92 and the opening angle θ1 of the lid portion 92 can be set based on the determined position of the boundary portion. Furthermore, since the lid portion 92 guides the received powder to the duct 90, it may be in the shape of a trough instead of a flat plate.

[0030] The removal of powder from the molded products by the lid 92 mainly depends on the contact area between the lid 92 and the powder. Therefore, when the lid 92 is in an open state, i.e., when the opening angle of the lid 92 is the maximum set angle θ1, the position of the upper end of the lid 92 is preferably set to a position that slightly interferes with the layer of molded products being charged through the charging chute 10. Specifically, as shown in FIG. 5 , the distance d (mm) in the height direction of the carbonization furnace 1 between the upper end of the lid 92 in the open state and the lower end of the opening of the charging chute 10, and the distance w2 (mm) in the horizontal direction between the upper end of the lid 92 in the open state and the lower end of the lid 92, preferably satisfy the following formulas (1) and (2), respectively, with respect to the internal dimension W1 (mm) of the carbonization furnace 1 in the depth direction S: 0.2≦d / W1≦0.5 (1) 0.35≦w2 / W1≦0.55 (2)

[0031] By setting the size of the lid portion 92, the opening angle θ1 of the lid portion 92, and the like so as to satisfy the relationship between equations (1) and (2), the upper end of the lid portion 92 in the open state can be made to slightly interfere with the layer of molded materials charged from the charging chute 10, and almost all of the powder charged from the charging chute 10 can be received and recovered by the lid portion 92. On the other hand, if the size of the lid portion 92 and the opening angle θ1 of the lid portion 92 are set as described above, the molded materials will also be received by the lid portion 92 along with the powder and guided to the duct 90, which is not preferable. Therefore, in this embodiment, a sieve, which will be described below, is installed in the lid portion 92 to prevent the molded materials from being recovered.

[0032] As shown in FIG. 3, the sieve 93 is stored inside the duct 90 when it is closed by the lid 92. As shown in FIG. 4, the sieve 93 is configured to be pulled out from inside the duct 90 by rotating the lid 92 toward the inside of the carbonization furnace 1. In this embodiment, the sieve 93 is configured to allow the powder to pass through, out of the molded material and the powder, so that the powder is collected in the duct 90 and the molded material that does not pass through the sieve 93 is loaded into the carbonization furnace 1. Therefore, the mesh size of the sieve 93 is set larger than the particle size of the powder and smaller than the particle size of the molded material. The sieve 93 is, for example, a wire mesh.

[0033] Next, a configuration for storing the sieve 93 inside the duct 90 and for withdrawing it from the duct 90 will be described. A portion of the outer peripheral edge of the sieve 93 is connected to the upper end of the lid 92 so as to be rotatable or at a predetermined angle. Another portion of the outer peripheral edge of the sieve 93 opposite the side connected to the lid 92 is connected to the rail so as to be movable along the rail. Therefore, as the opening angle of the lid 92 gradually increases, the other portion of the outer peripheral edge of the sieve 93 gradually moves along the rail toward the dry distillation furnace 1. Alternatively, instead of a rail, a groove may be formed in the curved surface, and the other portion of the outer peripheral edge of the sieve 93 may be engaged with the groove so as to be movable along the groove.

[0034] In the example shown in FIG. 5, the opening angle θ1 of the lid portion 92 is set to approximately 60°. This is determined by setting the size of the lid portion 92 and the installation height relative to the charging chute 10 so as to satisfy the above-mentioned formulas (1) and (2). Furthermore, when the lid portion 92 is opened at an opening angle of 60°, the angle θ2 formed between the horizontal plane and the sieve 93 is set to be equal to or greater than the angle of repose of the powder. This is to prevent the powder from remaining on the sieve 93. Specifically, the angle θ2 formed between the horizontal plane and the sieve 93 is preferably set to be equal to or greater than 30°.

[0035] Next, the operation and effect of the blast furnace raw material manufacturing apparatus configured as described above will be explained with reference to Figure 5. A batch of molded products is transported by a transport device to the charging chute 10 with the charging gate 20 closed. As described above, the transported molded products are partially converted into powder due to vibration during the transport process. The powder moves below the molded products through the gaps between the molded products, and therefore separates into two layers within the charging chute 10: a molded product layer 40 and a powder layer 50.

[0036] Subsequently, the charging gate 20 is opened, and the molded materials are charged into the carbonization furnace 1. The charging gate 20 may be opened by an operator, or may be opened by an actuator that opens and closes the charging gate 20 and a control device that controls the operation of the actuator (neither of which are shown).

[0037] Almost simultaneously with the opening of the charging gate 20, the lid 92 is rotated. The rotation of the lid 92 may be performed by the operator or the control device described above. As the opening angle of the lid 92 increases, the other part of the outer peripheral edge of the sieve 93 moves along the rail toward the carbonization furnace 1, and the sieve 93 is pulled out from the duct 90 into the carbonization furnace 1. When the opening angle of the lid 92 reaches the maximum angle θ1, the sieve 93 is stretched between the upper end of the duct 90 and the upper end of the lid 92.

[0038] The molded products that have passed through the charging gate 20 pass over the diffusion section 30, and are thereby dispersed so as to spread inside the charging chute 10 and charged into the carbonization furnace 1. Since the molded products are in the upper layer of the powder, they are charged from a higher position than the powder, and therefore fall toward the other of the side wall sections 80, 81, rather than the powder.

[0039] In contrast, the powder falls toward one side wall portion 80. Because the upper end of the lid portion 92 is positioned so as to slightly interfere with the falling molded product layer 40, the powder and some of the molded products fall onto the sieve 93, and the powder passes through the sieve 93. The powder that passes through the sieve 93 is guided by the lid portion 92 and collected in the duct 90. This prevents the powder from accumulating inside the carbonization furnace 1, and forms a deposit DM composed primarily of molded products. This makes it possible to prevent or suppress uneven accumulation of powder inside the carbonization furnace 1, and to suppress deterioration of air permeability inside the deposit DM due to uneven accumulation of powder.

[0040] When one batch of molded materials has been charged into the carbonization furnace 1, the charging gate 20 is closed to cut off communication between the charging chute 10 and the carbonization furnace 1, and the lid 92 is rotated to close the duct 90. These operations may be performed by an operator as described above, or may be performed by a control device that controls the opening and closing of the charging gate 20 and the lid 92. Alternatively, a timer (not shown) may be used to measure the elapsed time since the charging gate 20 was opened, and the charging gate 20 and the lid 92 may be closed when the elapsed time exceeds a preset time.

[0041] As described above, according to the blast furnace raw material manufacturing apparatus having the above-described configuration, the powder contained in the briquettes charged into the carbonization furnace 1 can be recovered by the duct 90, thereby preventing the powder from being deposited in an uneven position. This makes it possible to make the gas permeability throughout the carbonization furnace 1 almost uniform, thereby reducing variations in the degree of carbonization of the briquettes. As a result, high-quality ferro-coke with reduced quality variations can be manufactured, and the productivity of ferro-coke can be improved. [Example]

[0042] Next, examples conducted to confirm the operation and effects of the present invention will be described. In Example 1, a test device simulating the blast furnace raw material manufacturing apparatus shown in FIG. 2 was used. The powder removal rate of the powder was investigated when raw materials containing briquettes and powder (hereinafter referred to as briquettes) were charged into a collection box representing a carbonization furnace 1. A charging chute of the same shape as that installed in the blast furnace raw material manufacturing apparatus shown in FIG. 2 was used, and a collection box representing a carbonization furnace was installed on the outlet side of the charging chute. A duct, opening 91, lid 92, and sieve identical to the duct 90, opening 91, lid 92, and sieve 93 described above were installed on the lower side of the side wall of the collection box connected to the charging chute. The powder removal rate is calculated by dividing the mass of the powder collected in the duct by the mass of the briquettes charged into the collection box from the charging chute, and is expressed as a percentage (mass%).

[0043] 25 kg of molded products containing powder were charged into the collection box from the charging chute. During charging of the molded products, the lid was opened and the powder charged into the collection box from the charging chute was collected into a duct through a sieve. The proportion of powder in the molded products charged into the collection box was set to 10 mass %, and the proportion of molded products was set to 90 mass %. In this example, for convenience, particles with a diameter of 20 mm or more were defined as "molded products," and particles with a diameter of less than 20 mm were defined as "powder." The particle size of the molded products was 25 mm.

[0044] In Example 1, the powder removal rate was investigated when the distance w2 between the upper end of the lid portion 92 and the side wall portion 80 in the depth direction S was changed. A first ratio (d / W1) obtained by dividing the distance d between the upper end of the lid portion 92 in the open state and the lower end of the opening of the charging chute 10 by the inner dimension W1 of the carbonization furnace 1 was set to "0.4" (d / W1 = 0.4). In addition, the opening angle θ1 of the lid portion 92 was set to 60°.

[0045] In this state, the distance w2 between the upper end of the lid portion 92 in the open state and the side wall portion 80 was changed. The results are shown in FIG. 6. As shown in FIG. 6, when the second ratio (w2 / W1) obtained by dividing the distance w2 by the inner dimension W1 of the carbonization furnace 1 in the depth direction S was set smaller than 0.35, the powder removal rate was lower than when the second ratio (w2 / W1) was set to 0.35 or greater. This is thought to be because when the second ratio (w2 / W1) was set smaller than 0.35, contact between the lid portion 92 and the powder layer 50 became less likely, making it difficult to collect the powder. It was also confirmed that when the second ratio (w2 / W1) was set larger than 0.55, the powder removal rate remained almost constant. This is thought to be because the upper end of the lid portion 92 was located closer to the molded product layer 40 than the boundary portion described above, so that almost all of the powder charged into the collection box was received by the lid portion and collected in the duct. On the other hand, as the second ratio (w2 / W1) increases, the amount of molded material that collides with the lid portion 92 increases, which may shorten the service life of the lid portion 92. Therefore, it is preferable to adjust the distance w2 between the upper end of the lid portion 92 in the open state and the side wall portion 80 so that the second ratio (w2 / W1) is 0.35 or more and 0.55 or less (0.35≦w2 / W1≦0.55). In other words, it has been confirmed that it is preferable to adjust the distance w2 between the upper end of the lid portion 92 in the open state and the side wall portion 80 so as to satisfy the above-mentioned formula (2). [Example]

[0046] In Example 2, the powder removal rate when the distance d was changed was investigated. The second ratio (w2 / W1) was set to "0.45", and the opening angle θ1 of the lid portion 92 was set to 60°. In this state, the above-mentioned distance d was changed. The results are shown in FIG. 7. As shown in FIG. 7, as the first ratio (d / W1) increased, the powder removal rate decreased significantly. This is considered to be because as the first ratio (d / W1) increases, the area where the lid portion 92 contacts the powder layer 50 flowing down from the charging chute becomes narrower. In particular, it was confirmed that when the first ratio (d / W1) is greater than 0.5, the powder removal rate decreases significantly (0.5 < d / W1). Also, when the first ratio (d / W1) is less than 0.2, it was found that the powder removal rate becomes almost constant. This is considered to be because when the first ratio (d / W1) is less than 0.2, the lid portion 92 interferes with the molded product layer 40, and almost all of the powder is received by the lid portion and recovered in the duct. When the first ratio (d / W1) is less than 0.2, the amount of the molded product that collides with the lid portion 92 increases accordingly, and the service life of the lid portion 92 may decrease. Therefore, it is preferable to adjust the distance d between the upper end portion of the open lid portion 92 and the lower end portion of the opening of the charging chute so that the first ratio (d / W1) is 0.2 or more and 0.5 or less (0.2 ≦ d / W1 ≦ 0.5). That is, it was confirmed that it is preferable to adjust the distance d between the upper end portion of the lid portion 92 and the lower end portion of the opening of the charging chute 10 so as to satisfy the above-mentioned formula (1).

Explanation of Signs

[0047] 1 Carbonization furnace as a raw material manufacturing apparatus for blast furnace 10 Charging chute 20 Charging gate 30 Diffusion section 40 Molded product layer [[ID=1十七]]50 Powder layer 70 Carbonization furnace main body 80, 81 Side wall portions 90 Duct 91 Opening of the duct 92 Lid portion 93 Sieve DM Deposit DMtop Top of the deposit

Claims

1. A blast furnace raw material manufacturing apparatus for manufacturing blast furnace raw materials by carbonizing briquettes charged into a carbonization furnace, a duct connected to a side wall of the carbonization furnace so as to be able to communicate with the interior of the carbonization furnace, the duct recovering powder of the molded products charged into the carbonization furnace; a lid portion provided rotatably around a lower end portion of the side wall portion, the lid portion rotates about the lower end portion and opens toward the inside of the dry distillation furnace, thereby connecting the dry distillation furnace and the duct; The duct has a sieve through which the powder passes and is configured to collect the powder through the sieve. Blast furnace raw material production equipment.

2. The carbonization furnace further includes a charging chute that is provided above the lid portion on the side wall portion of the carbonization furnace and overlaps with at least a portion of the lid portion when viewed from the top-bottom direction of the carbonization furnace, and that charges the molded material into the carbonization furnace; The cover is configured to receive the powder of the molded products charged into the carbonization furnace from the charging chute and to cause it to flow toward the duct when the duct is open. The blast furnace raw material manufacturing apparatus according to claim 1.

3. a portion of the outer peripheral edge of the sieve is connected to the upper end of the lid; and Another part of the outer peripheral edge of the sieve, which is located on the opposite side of the center of the sieve from the part of the outer peripheral edge, is connected to an upper inner wall surface of the duct so as to be movable along the longitudinal direction of the duct. The blast furnace raw material manufacturing apparatus according to claim 1.

4. a portion of the outer peripheral edge of the sieve is connected to the upper end of the lid; and Another part of the outer peripheral edge of the sieve, which is located on the opposite side of the center of the sieve from the part of the outer peripheral edge, is connected to an upper inner wall surface of the duct so as to be movable along the longitudinal direction of the duct. The blast furnace raw material manufacturing apparatus according to claim 2.

5. The opening angle of the lid from the closed state of the duct is 60° or less. The blast furnace raw material manufacturing apparatus according to claim 1.

6. When the lid is open, the angle between the sieve and a horizontal plane is 30° or more. The blast furnace raw material manufacturing apparatus according to claim 1.

7. When the lid portion is open, a distance d between the upper end of the lid portion and the lower end of the opening of the charging chute in the height direction of the carbonization furnace; and The distance w2 between the upper end of the lid portion and the lower end of the lid portion in the horizontal direction satisfies the following formula with respect to the inner dimension W1 in the depth direction of the carbonization furnace. The blast furnace raw material manufacturing apparatus according to claim 2. 0.2≦d / W1≦0.5 0.35≦w2 / W1≦0.55

8. A method for producing blast furnace raw material using the blast furnace raw material producing apparatus according to any one of claims 1 to 7.

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