Raw material crushing method, coke manufacturing method, and raw material crushing device

Abstract

Provided is a raw material crushing method performed by a raw material crushing device (14) in a crushing facility having: a plurality of crushers (2) for crushing a raw material; a conveyance line for collectively conveying the raw material crushed by the plurality of crushers; and one measuring device for measuring the particle size of the raw material conveyed. The raw material crushing method comprises: acquiring crushing facility information including information regarding the relative positions and operations of the plurality of crushers and the conveyance line; calculating, on the basis of the crushing facility information, a proportion according to position of the raw material crushed by each of the plurality of crushers using simulation, and determining a measurement position for measuring the particle size of the raw material crushed by each of the plurality of crushers; and outputting information about the determined measurement position as an instruction to the measuring device.

Description

Method for crushing raw materials, method for producing coke, and raw material crushing device

[0001] The present disclosure relates to a raw material pulverization method, a coke manufacturing method, and a raw material pulverization device.

[0002] For example, in the ironmaking process, the coke in the blast furnace must be high-strength and have small particle size variations (uniformity) to ensure good gas permeability within the furnace. To produce uniform high-strength coke, the raw material coal must be heated and carbonized in the coke oven, and the bulk density of the coal charged into the coke oven must be increased. Therefore, it is important to optimize the particle size of the coal charged into the coke oven.

[0003] Coarse coal with large particle size undergoes cracking at the contact interface due to differences in contraction rates between adjacent coal particles during heating in a coke oven, reducing its strength. Furthermore, fine coal with small particle size floats in the air when charged into the coke oven, reducing the bulk density of the coal charged. Therefore, in order to produce uniform high-strength coke, it is necessary to select crushing conditions when crushing coal in a crusher to achieve the target particle size and reduce the variation in particle size of the coal after crushing.

[0004] For example, Patent Document 1 discloses a method of measuring the particle size of coal after crushing processing, and changing the crushing strength for each crusher based on the particle size change calculated from the measurement results, so that the particle size of the coal after crushing processing becomes a target particle size.

[0005] Japanese Patent Application Laid-Open No. 2004-16983

[0006] In the method of Patent Document 1, the particle size of the coal pulverized by each pulverizer is measured using multiple CCD cameras installed on each belt conveyor at the outlet of each pulverizer. This method makes it possible to adjust the pulverization strength of each pulverizer based on the particle size of each pulverizer. However, the installation costs for multiple CCD cameras are high, and maintenance time is also long, increasing maintenance costs. Furthermore, installing CCD cameras at the outlet of the pulverizer makes stable measurement difficult due to the influence of dust generation.

[0007] In consideration of the above circumstances, the object of the present disclosure is to provide a raw material crushing method, a coke manufacturing method, and a raw material crushing device that can measure raw materials crushed by multiple crushers using a single measuring device.

[0008] (1) A method for crushing raw materials according to one embodiment of the present disclosure is a method for crushing raw materials performed by a raw material crushing device in a crushing facility having a plurality of crushers for crushing raw materials, a conveying line for collectively conveying the raw materials crushed by the plurality of crushers, and one measuring device for measuring the particle size of the conveyed raw materials, the method including: acquiring crushing facility information including information regarding the positional relationship and operation of the plurality of crushers and the conveying line; calculating, by simulation based on the crushing facility information, a proportion corresponding to the position of the raw materials crushed by each of the plurality of crushers, and determining measurement positions for measuring the particle size of the raw materials crushed by each of the plurality of crushers; and outputting information about the determined measurement positions as instructions to the measuring device.

[0009] (2) As one embodiment of the present disclosure, in (1), the conveying line includes a plurality of belt conveyors that convey the pulverized raw material in a conveying direction by transferring between them, and the measuring device includes a camera and photographs the pulverized raw material at a specific position in the conveying direction set on the belt conveyors where the transfer takes place.

[0010] (3) As one embodiment of the present disclosure, in (1) or (2), the conveying line includes a plurality of belt conveyors that convey the crushed raw material in the conveying direction by transferring, the crushing equipment information includes the speeds of the plurality of belt conveyors and the steps at the time of transfer, and the measurement position is determined as the widthwise position of the belt conveyors at a specific position in the conveying direction set on the belt conveyor where the transfer took place.

[0011] (4) A method for producing coke according to one embodiment of the present disclosure includes determining the measurement position using any one of the raw material crushing methods (1) to (3), changing the crushing strength of each of the multiple crushers based on the particle size measured at the measurement position, and producing coke by heating the coal crushed by the crushers in a coke oven, wherein the raw material is coal.

[0012] (5) A raw material crushing device according to one embodiment of the present disclosure is a raw material crushing device used in a crushing facility having a plurality of crushers for crushing raw materials, a conveying line for collectively transporting the raw materials crushed by the plurality of crushers, and one measuring device for measuring the particle size of the transported raw materials, and includes: an acquisition unit for acquiring crushing facility information including information regarding the positional relationship and operation of the plurality of crushers and the conveying line; a determination unit for calculating, by simulation based on the crushing facility information, a proportion corresponding to the position of the raw materials crushed by each of the plurality of crushers, and determining a measurement position for measuring the particle size of the raw materials crushed by each of the plurality of crushers; and an output unit for outputting information about the determined measurement position as an instruction to the measuring device.

[0013] According to the present disclosure, it is possible to provide a raw material crushing method, a coke manufacturing method, and a raw material crushing device that can measure raw materials crushed by multiple crushers using a single measuring device.

[0014] FIG. 1 is a diagram illustrating the overall configuration of a raw material crushing facility. FIG. 2 is a detailed diagram of a portion of the crushing facility of FIG. 1. FIG. 3 is a diagram illustrating an example configuration of a raw material crushing device according to an embodiment of the present disclosure. FIG. 4 is a flowchart illustrating a process of a raw material crushing method according to an embodiment of the present disclosure. FIG. 5 is a diagram illustrating an example of a mixture of raw materials crushed by multiple crushers on a belt conveyor before a transfer. FIG. 6 is a diagram illustrating an example of a mixture of raw materials crushed by multiple crushers on a belt conveyor after a transfer. FIG. 7 is a diagram illustrating the proportion of coal crushed by multiple crushers in a first region. FIG. 8 is a diagram illustrating the proportion of coal crushed by multiple crushers in a second region. FIG. 9 is a diagram illustrating the proportion of coal crushed by multiple crushers in a third region. FIG. 10 is a diagram illustrating an example of a measurement position determined on a belt conveyor after a transfer of raw materials.

[0015] A raw material pulverization method, a coke manufacturing method, and a raw material pulverization device 14 according to an embodiment of the present disclosure will be described below with reference to the drawings. FIG. 1 shows the overall configuration of the raw material pulverization facility. FIG. 2 is a detailed view of a portion 10 of the pulverization facility shown in FIG. 1 , including a measuring device 13 and the raw material pulverization device 14. FIG. 3 is a block diagram showing an example configuration of the raw material pulverization device 14. The raw material pulverization device 14 is used in a pulverization facility having multiple pulverizers 2 for pulverizing raw materials, a conveying line for collectively conveying the raw materials pulverized by the multiple pulverizers 2, and one measuring device 13 for measuring the particle size of the conveyed raw materials. As described below, the raw material pulverization device 14 simulates the mixing ratio of the raw materials pulverized by each of the multiple pulverizers 2 and determines measurement positions for the particle size of the raw materials pulverized by each of the multiple pulverizers 2 based on the mixing ratio. Furthermore, the raw material pulverization device 14 can set (change) the pulverization strength for each of the multiple pulverizers 2 based on the particle size of the raw material measured at the determined measurement position.

[0016] The raw material crushing equipment shown in FIG. 1 represents a coal crushing line for coke ovens. In this embodiment, the raw material is coal. The raw material is not limited to coal, as long as it can be crushed to minimize particle size variation. Coal stored in a yard 1 by brand is transported to a crusher 2 by brand, crushed to a target particle size range, and stored in a blending tank 4. Here, the particle size refers to the particle size ratio within a predetermined range (e.g., 6 mm or more). The target particle size range is the particle size range (particle size ratio range) that the crushed coal 12 must satisfy in order to uniformly produce high-strength coke, and is determined based on the quality required for the coke to be produced. For example, the target particle size range is determined as "4% to 12% of coal with a particle size of 6 mm or more." While three crushers 2 are shown in the example of FIG. 1, the number of crushers 2 is not limited to a specific number, as long as there are two or more (multiple) crushers. Here, when distinguishing between the three pulverizers 2, they may be referred to as pulverizers 2A, 2B, and 2C, as shown in FIG. 2 . In other words, when there is no need to distinguish between them, they will simply be referred to as pulverizers 2. Coal is transported to each pulverizer 2, and the pulverizers 2 pulverize the coal in accordance with a signal (control signal) from the raw material pulverizer 14. The control signal includes an instruction to change the pulverization strength of the pulverizer 2. Changing the pulverization strength of the pulverizer 2 includes changing the amount of coal transported to the pulverizer 2 and changing the rotation speed of the hammers of the pulverizer 2. In addition, a measuring device 13 that measures the particle size of the pulverized coal 12 is provided, for example, above the belt conveyor 11 to which the pulverized coal 12 is transferred from the belt conveyor 18 on the outlet side of the pulverizer 2. The measuring device 13 may continuously measure the particle size at a specific position 3 in the conveying direction set on the belt conveyor 11. The coal stored in the blending tank 4 is transported to the coke oven 5, heated, and carbonized to produce coke.

[0017] In this embodiment, the conveying line includes multiple belt conveyors that transfer the pulverized coal 12 in the conveying direction. In the example of FIG. 2 , the multiple belt conveyors include a belt conveyor 18 before the transfer of the pulverized coal 12 and a belt conveyor 11 after the transfer. Here, the multiple belt conveyors may also include another belt conveyor. The pulverized coal 12 is transported in the conveying direction to the blending tank 4 by the belt conveyor 11. The measuring device 13 measures the pulverized coal 12. The measuring device 13 outputs the measurement results to the raw material pulverizer 14. The measurement results are the particle size measured by the measuring device 13. In this embodiment, the measuring device 13 includes a camera and captures a two-dimensional image of the pulverized coal 12 stacked on the belt conveyor 11. The measuring device 13 identifies the two-dimensional shape of the pulverized coal 12 from the captured two-dimensional image and calculates the particle size using a known method (image processing). The image processing may include, for example, binarization, contour extraction, etc.

[0018] As shown in FIG. 3 , the raw material crushing device 14 includes an acquisition unit 15, a determination unit 16, and an output unit 17. The acquisition unit 15 acquires crushing equipment information, including information about the positional relationship and operation of the multiple crushers 2 and the conveying lines. The crushing equipment information preferably includes the speeds of the multiple belt conveyors and the steps (drops) at transfers so that the mixing ratio of the crushed raw materials can be accurately calculated in the simulation. The multiple belt conveyors may operate at a constant speed, such as 3 m / s. The simulation is not limited to a specific type as long as it can calculate the movement of the crushed raw materials. In this embodiment, a fluid simulation is used. The fluid simulation calculates the movement of the fluid (the collection of crushed raw materials) using equations of fluid dynamics. The determination unit 16 uses the fluid simulation to calculate the proportion of raw materials crushed by each of the multiple crushers 2 according to their positions based on the crushing equipment information. Here, the fluid simulation may be any type that can treat the crushed raw materials as particles and simulate the behavior of the particles, and any known simulator may be used. The determination unit 16 then determines measurement positions for measuring the particle size of the raw material pulverized by each of the multiple pulverizers 2. The determination of the measurement positions will be described in detail below. The output unit 17 outputs information about the measurement positions determined by the determination unit 16 as instructions to the measuring device 13. In this embodiment, the measurement positions are determined as positions in the width direction (direction perpendicular to the conveying direction) of the belt conveyor 11 at the specific position 3 (a predetermined position in the conveying direction). The determination unit 16 may also acquire the particle sizes of the raw material measured at the determined measurement positions and determine whether a change in the crushing strength is necessary for each of the multiple pulverizers 2. For example, when the crusher 2A is set so that all particle sizes are 3 to 5 mm, the determination unit 16 may determine that a change in the crushing strength is necessary if the proportion of particle sizes 6 mm or larger is equal to or greater than a predetermined value (e.g., 10%). The determination unit 16 then determines the setting to be changed (e.g., increasing the crushing strength), and the output unit 17 may output a signal to the crusher 2A to change the crushing strength.

[0019] Here, the raw material crushing device 14 may be, for example, a computer as a hardware configuration. The computer may be a server computer or a portable computer such as a laptop or tablet. In this embodiment, the raw material crushing device 14 is a computer used in the raw material crushing equipment. Furthermore, crushing equipment information, the target particle size range, etc. may be stored in the computer's storage device.

[0020] 4 is a flowchart illustrating the processing of the raw material crushing method executed by the raw material crushing device 14. The raw material crushing method is executed in a crushing facility having a plurality of crushers 2 that crush the raw material, a conveying line that collectively conveys the raw material crushed by the plurality of crushers 2, and one measuring device 13 that measures the particle size of the conveyed raw material.

[0021] The acquisition unit 15 acquires, for example, from a storage device, crushing equipment information including information on the positional relationship and operation of the plurality of crushers 2 and the conveying line (step S1).

[0022] The determination unit 16 calculates the ratio of the raw material pulverized by each of the plurality of pulverizers 2 according to the position by fluid simulation based on the pulverization equipment information (step S2). Then, the determination unit 16 determines the measurement positions for measuring the particle size of the raw material pulverized by each of the plurality of pulverizers 2 (step S3).

[0023] The output unit 17 outputs information about the measurement position determined by the determination unit 16 as an instruction to the measurement device 13 (step S4).

[0024] The acquisition unit 15 acquires the particle size of the raw material measured by the measuring device 13 (step S5).

[0025] The determination unit 16 determines whether or not the crushing strength of each of the plurality of crushers 2 needs to be changed based on the measured particle size acquired by the acquisition unit 15 and, for example, the target particle size range (step S6).

[0026] If the determination unit 16 determines that there is a crusher 2 that needs to be changed (Yes in step S6), the determination unit 16 determines further settings to be changed, and the output unit 17 outputs a signal to change the crushing strength to that crusher 2 (step S7), and the series of processes ends. Also, if the determination unit 16 determines that there is no crusher 2 that needs to be changed (No in step S6), the series of processes ends.

[0027] The effects of the present disclosure will be specifically described below based on examples, but the present disclosure is not limited to these examples. The raw material grinding equipment targeted in these examples is the raw material grinding equipment shown in Figures 1 and 2.

[0028] FIG. 5 is a diagram showing an example of mixing of raw materials pulverized by multiple pulverizers 2 on the belt conveyor 18 before transfer. FIG. 5 is a diagram showing the belt conveyor 18 as viewed from above. The pulverized raw materials are coal 12 pulverized by each of the pulverizers 2A, 2B, and 2C. Black indicates coal 12 pulverized by the pulverizer 2A, which is output from the pulverizer 2A to a drop position 202 on the belt conveyor 18 and transported in the conveyance direction. White (white sandwiched between black and gray) indicates coal 12 pulverized by the pulverizer 2B, which is output from the pulverizer 2B to a drop position 203 on the belt conveyor 18 and transported in the conveyance direction. Gray indicates coal 12 pulverized by the pulverizer 2C, which is output from the pulverizer 2C to a drop position 204 on the belt conveyor 18 and transported in the conveyance direction. The coal 12 pulverized by each of the pulverizers 2A, 2B, and 2C is transferred from the belt conveyor 18 to the belt conveyor 11.

[0029] FIG. 6 is a diagram showing an example of mixing of raw materials pulverized by multiple pulverizers 2 on the belt conveyor 11 after a transfer, and is the result of a fluid simulation. In this example, a fluid simulation based on the equation of motion of particles (pulverized raw materials) taking into account the collision and contact forces of particles in the discrete element method was used. FIG. 6 is a view of the belt conveyor 11 viewed from above. Particle group 302 (black) represents coal 12 pulverized by pulverizer 2A. Particle group 303 (white sandwiched between black and gray) represents coal 12 pulverized by pulverizer 2B. Particle group 304 (gray) represents coal 12 pulverized by pulverizer 2C.

[0030] In this embodiment, the determination unit 16 sets regions (first to third regions) in the width direction of the belt conveyor 11 based on the results of the fluid simulation in FIG. 6 , the same number of regions as the number of pulverizers 2. The first to third regions may be determined so that the proportion of coal 12 pulverized by a specific pulverizer 2 is higher than the proportion of coal 12 pulverized by other pulverizers 2 by a predetermined value or more (e.g., 20% or more). In other words, the first to third regions are regions biased toward coal 12 pulverized by a specific pulverizer 2. FIGS. 7, 8, and 9 show the proportions of pulverized coal 12 in the first region, second region, and third region of FIG. 6, respectively. In FIGS. 7, 8, and 9, the proportion of coal 12 pulverized by pulverizer 2A is indicated as "2A," the proportion of coal 12 pulverized by pulverizer 2B is indicated as "2B," and the proportion of coal 12 pulverized by pulverizer 2C is indicated as "2C."

[0031] FIG. 10 shows measurement positions on the belt conveyor 11 determined by the determination unit 16 in this embodiment after the raw material transfer. FIG. 10 is a diagram similar to FIG. 6 . As shown in FIG. 7 , the proportion of coal 12 pulverized by the pulverizer 2A is high in the first region. The determination unit 16 determines a measurement position (402) within the first region for measuring the particle size of the coal 12 pulverized by the pulverizer 2A. Also, as shown in FIG. 8 , the proportion of coal 12 pulverized by the pulverizer 2B is high in the second region. The determination unit 16 determines a measurement position (403) within the second region for measuring the particle size of the coal 12 pulverized by the pulverizer 2B. Also, as shown in FIG. 9 , the proportion of coal 12 pulverized by the pulverizer 2C is high in the third region. The determination unit 16 determines a measurement position (404) within the third region for measuring the particle size of the coal 12 pulverized by the pulverizer 2C.

[0032] The output unit 17 outputs information about the measurement positions (402 to 404) determined by the determination unit 16 as instructions to the measurement device 13. The information about the measurement positions may be coordinates of each measurement position in a two-dimensional image, or the like.

[0033] The measuring device 13 calculates the particle size of the pulverized coal 12 at measurement positions (402-404) in the captured two-dimensional image. That is, the measuring device 13 calculates the particle size of the coal 12 pulverized by the pulverizer 2A at measurement position (402). The measuring device 13 calculates the particle size of the coal 12 pulverized by the pulverizer 2B at measurement position (403). The measuring device 13 also calculates the particle size of the coal 12 pulverized by the pulverizer 2C at measurement position (404). In this way, a single measuring device 13 can calculate the particle size for each of the multiple pulverizers 2A, 2B, and 2C. These calculated particle sizes are used to set (change) the crushing strength of each of the multiple pulverizers 2A, 2B, and 2C.

[0034] As described above, the raw material crushing method, coke manufacturing method, and raw material crushing device 14 according to the present embodiment are configured as described above, allowing a single measuring device 13 to measure raw material crushed by multiple crushers 2. That is, the raw material crushing method, coke manufacturing method, and raw material crushing device 14 according to the present embodiment simulate the mixing ratio of raw material crushed by each of the multiple crushers 2. Then, the measurement position for the particle size of the raw material crushed by each of the multiple crushers 2 is determined based on the magnitude of the ratio in the width direction of the belt conveyor 11 in the simulation results. The method disclosed herein makes it possible to reduce the cost and maintenance time associated with the measuring device 13. Furthermore, the measuring device 13 can perform measurements on the belt conveyor 11 after the raw material has been transferred, thereby avoiding the influence of dust generation and enabling stable measurements.

[0035] Although the embodiments of the present disclosure have been described based on the drawings and examples, it should be noted that those skilled in the art would easily be able to make various modifications or alterations based on the present disclosure. Therefore, it should be noted that these modifications and alterations are included within the scope of the present disclosure. For example, functions included in each component or step can be rearranged so as not to cause logical inconsistencies, and multiple components or steps can be combined or divided into one. The embodiments of the present disclosure can also be realized as a program executed by a processor included in an apparatus or a storage medium on which a program is recorded. It should be understood that these are also included within the scope of the present disclosure.

[0036] In the above embodiment, the pulverized coal 12 is identified from a two-dimensional image captured by a camera. As another example, the measurement device 13 may be a laser rangefinder or the like. In this case, three-dimensional measurement may be performed on each of the raw materials pulverized by the multiple pulverizers 2 at the measurement positions determined by the above method, and the pulverized raw materials may be identified and their particle sizes may be calculated using the obtained three-dimensional data.

[0037] Furthermore, the raw material crushing device 14 may not be a single device, but may be composed of multiple devices located in multiple locations and capable of transmitting and receiving data to and from each other via a network. In other words, multiple devices connected via a network may function as the raw material crushing device 14 as a whole. Therefore, for example, the raw material crushing device 14 may be composed of a single computer as a hardware configuration, or multiple computers connected via a network. When composed of multiple computers, a shared memory accessible by each computer may be used to share data or programs. For example, some of the functions of the output unit 17 of the raw material crushing device 14 (for example, the function of outputting instructions regarding crushing strength to the crusher 2) may be realized by a single device (crushing strength instruction device). In this case, other functions of the raw material crushing device 14 may be realized by a separate device (crushing control device).

[0038] Furthermore, when the raw material crushing device 14 is configured as a computer, one or more programs used to control the operation of the raw material crushing device 14 may be stored in a storage device (e.g., memory) of the computer. When the program stored in the storage device is read by a processor included in the computer, the processor may function as the acquisition unit 15, the determination unit 16, and the output unit 17. Then, the processing of the raw material crushing method may be executed by the computer.

[0039] REFERENCE SIGNS LIST 1 Yard 2, 2A, 2B, 2C Crusher 3 Specific position 4 Blending tank 5 Coke oven 10 Part of crushing equipment 11 Belt conveyor 12 Crushed coal 13 Measuring device 14 Raw material crushing device 15 Acquisition unit 16 Determination unit 17 Output unit 18 Belt conveyor 202, 203, 204 Drop position 302, 303, 304 Particle group 402, 403, 404 Measurement position

Claims

1. A method for crushing raw materials in a crushing facility having a plurality of crushers for crushing raw materials, a conveying line for collectively transporting the raw materials crushed by the plurality of crushers, and one measuring device for measuring the particle size of the transported raw materials, the method comprising: acquiring crushing facility information including information relating to the positional relationship and operation of the plurality of crushers and the conveying line; calculating, by simulation based on the crushing facility information, a proportion of the raw materials crushed by each of the plurality of crushers according to their positions, and determining measurement positions for measuring the particle size of the raw materials crushed by each of the plurality of crushers; and outputting information on the determined measurement positions as instructions to the measuring device.

2. The method for grinding raw materials described in claim 1, wherein the conveying line includes a plurality of belt conveyors that transfer the ground raw material in the conveying direction, and the measuring device includes a camera that photographs the ground raw material at a specific position in the conveying direction set on the belt conveyor where the transfer takes place.

3. A method for crushing raw materials as described in claim 1 or 2, wherein the conveying line includes a plurality of belt conveyors that transfer the crushed raw material in the conveying direction, the crushing equipment information includes the speeds of the plurality of belt conveyors and steps at the time of transfer, and the measurement position is determined as a position in the width direction of the belt conveyors at a specific position in the conveying direction set on the belt conveyor where the transfer has taken place.

4. A method for producing coke, comprising determining the measurement position using the raw material crushing method described in any one of claims 1 to 3, changing the crushing strength of each of the plurality of crushers based on the particle size measured at the measurement position, the raw material being coal, and producing coke by heating the coal crushed by the crushers in a coke oven.

5. A raw material crushing device used in a crushing facility having a plurality of crushers for crushing raw materials, a conveying line for transporting the raw materials crushed by the plurality of crushers together, and one measuring device for measuring the particle size of the transported raw materials, comprising: an acquisition unit for acquiring crushing facility information including information on the positional relationship and operation of the plurality of crushers and the conveying line; a determination unit for calculating, by simulation based on the crushing facility information, a proportion according to the position of the raw materials crushed by each of the plurality of crushers, and determining a measurement position for measuring the particle size of the raw materials crushed by each of the plurality of crushers; and an output unit for outputting information on the determined measurement position as an instruction to the measuring device.

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