Method for producing coke

Abstract

To provide a method for producing coke that enables adjustment of coke particle size by using a lump rate as an indicator.SOLUTION: A method for producing coke includes: a step of measuring, by a lump rate measuring apparatus 50 installed at a subsequent stage of a coke oven 30, a weight of coke produced by the coke oven 30 and a weight of lump coke, and calculating a lump rate; a step of determining a proportion of an inert material to be added to a blended coal raw material based on the measured lump rate; and a step of changing the proportion of the inert material to be added to the blended coal raw material based on the determined proportion of the inert material.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to a method for producing coke. [Background technology]

[0002] When coke is used as a reducing agent in a blast furnace, it is desirable for the coke particle size to be large in order to ensure ventilation in the blast furnace and to allow the reduction reaction to proceed sufficiently.

[0003] In general, the coke particle size can be adjusted by controlling the carbonization degree and thermoplasticity of coal and the operating rate of the coke oven.

[0004] However, the carbonization degree and thermoplasticity of coal are factors that determine the strength of coke, and therefore it is difficult to freely adjust them.In addition, the operating rate of coke ovens is determined based on the coke production plan, and therefore it is difficult to freely adjust them.

[0005] Another method for adjusting the coke particle size is known to be to control the coke particle size by adding inert materials such as coke breeze, petroleum coke, anthracite, etc. to the coal feedstock.

[0006] For example, Patent Document 1 discloses a method of adding fine coke to coal raw materials. For example, Patent Document 2 discloses a method of adding a low shrinkage carbonaceous material to the hearth of the carbonization chamber of a coke oven. For example, Patent Document 3 discloses a method of adding an additive that increases the coke particle size only to the coal charged on the wall side in the oven width direction of the coke oven. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Japanese Patent Application Laid-Open No. 62-190284 [Patent Document 2] JP 2014-91758 A [Patent Document 3] Japanese Patent Application Publication No. 10-273672 Summary of the Invention [Problem to be solved by the invention]

[0008] In the downstream process of the coke oven, such as the blast furnace, lump coke, which is a large particle of coke that is left on the sieve after passing through a sieving device, is mainly used, so the index of the lump ratio, which is the weight ratio of the lump coke, is important. However, Patent Documents 1 to 3 do not evaluate the lump ratio.

[0009] An object of the present disclosure is to provide a coke production method that enables adjustment of coke particle size using the lump ratio as an indicator. [Means for solving the problem]

[0010] [1] A method for producing coke by adding an inert material to a blended coal raw material, comprising the steps of: measuring the lumpiness of the coke produced by the coke oven using a lumpiness measuring device installed downstream of the coke oven; determining a proportion of the inert material to be added to the blended coal feedstock based on the measured lump ratio; Varying the proportion of the inert material added to the blended coal feedstock based on the determined proportion of the inert material; A method for producing coke, comprising:

[0011] [2] The method for producing coke described in [1] above, wherein the step of determining the proportion of inert material includes changing the proportion of inert material from its current proportion if the measured lump ratio is not within a predetermined range.

[0012] [3] further comprising a step of recording a relationship between the changed proportion of the inactive material and the change in the mass ratio; The method for producing coke described in [1] or [2] above, wherein the step of determining the proportion of inert material determines how much to change the proportion of inert material from its current proportion based on the relationship recorded in the past.

[0013] [4] A method for producing coke described in any one of [1] to [3] above, wherein the lump ratio measuring device includes a sieve device and a weight measuring device.

[0014] [5] The lump ratio measuring device includes a particle size measuring device, A method for producing coke described in any one of [1] to [4] above, wherein a cooling device for cooling the coke produced by the coke oven is installed between the coke oven and the particle size measuring device. Effect of the Invention

[0015] According to the coke manufacturing method of the present disclosure, the coke particle size can be adjusted using the lump ratio as an index. [Brief description of the drawings]

[0016] [Figure 1] FIG. 1 is a diagram illustrating an example of a coke production system to which a coke production method according to an embodiment of the present disclosure is applied. [Diagram 2] FIG. 1 is a diagram showing another example of a coke production system to which a coke production method according to an embodiment of the present disclosure is applied. [Diagram 3] FIG. 2 is a diagram illustrating a configuration example of a control device according to an embodiment of the present disclosure. [Figure 4] FIG. 13 is a diagram showing an example of a change in the lump ratio when the ratio of the inactive material is changed. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0017] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings.

[0018] FIG. 1 is a diagram illustrating an example of a coke production system to which a coke production method according to an embodiment of the present disclosure is applied.

[0019] The coke production system 1 includes a control device 10, a blending tank 20, a coke oven 30, a cooling device 40, and a lump ratio measuring device 50. The lump ratio is the weight percentage of particles having a particle size equal to or larger than a certain value.

[0020] The controller 10 is a general-purpose computer such as a workstation, a personal computer, etc. Alternatively, the controller 10 may be a dedicated computer configured to function as the controller 10 for the coke production system 1.

[0021] The configuration and functions of the control device 10 will be described in detail later.

[0022] The blending tank 20 is a device that blends a plurality of brands of raw coal materials and adds an inert substance to the blended plurality of brands of raw coal materials.

[0023] The blending tank 20 includes a coal storage tank 21 and an inert material tank 22 .

[0024] The coal storage bin 21 stores a blended mixture of multiple brands of raw coal. Hereinafter, the blended mixture of multiple brands of raw coal may be referred to as a "blend of raw coal." In the blend of raw coal, multiple brands of raw coal are blended in a predetermined ratio so that the coke produced by the coke oven 30 has a target quality.

[0025] The coal storage bin 21 can discharge the blended coal raw materials onto the conveyor at a predetermined discharge amount. The discharge amount of the blended coal raw materials discharged from the coal storage bin 21 can be controlled by the control device 10.

[0026] The inert material tank 22 stores an inert material. The inert material is preferably a carbonaceous material with a low shrinkage rate. Here, the carbonaceous material with a low shrinkage rate is a carbonaceous material with a low shrinkage coefficient during carbonization. The inert material may be, for example, coke powder, petroleum coke, anthracite, or the like.

[0027] In general, the coke particle size can be increased by adding an inert material, which is a carbonaceous material with a low shrinkage rate, to a blended coal raw material. For example, inert materials such as coke powder have a different amount of shrinkage from coke produced from coal. Therefore, a difference in shrinkage occurs at the interface between them, and microcracks occur at the interface. This relieves stress, suppresses the generation and growth of crack nuclei, and increases the coke particle size.

[0028] The inert substance tank 22 can discharge the inert substance onto the conveyor at a predetermined discharge amount. The discharge amount of the inert substance discharged from the inert substance tank 22 can be controlled by the control device 10.

[0029] The control device 10 can change the ratio of the inert material added to the blended coal raw materials by controlling the amount of the inert material discharged from the inert material tank 22. The control device 10 can adjust the coke particle size of the coke produced by the coke oven 30 by changing the ratio of the inert material added to the blended coal raw materials.

[0030] The coke particle size is the average diameter of the coke particles. The average diameter may be calculated, for example, by an arithmetic mean or a harmonic mean. The coke particle size may be calculated by any method as long as it can be managed as an index.

[0031] The blended coal raw material to which the inert material has been added discharged from the blending tank 20 is transported to a coke oven 30 by a conveyor.

[0032] The coke oven 30 produces coke by carbonizing the blended coal raw material to which the inert material has been added, which is transported from the blending tank 20. The coke produced by the coke oven 30 is transported to the lump ratio measuring device 50 via the cooling device 40.

[0033] The cooling device 40 is installed downstream of the coke oven 30. The cooling device 40 cools the coke transported from the coke oven 30.

[0034] The coke produced by the coke oven 30 is at a high temperature and is therefore difficult to handle as is. By cooling the coke using the cooling device 40, the coke produced by the coke oven 30 becomes easier to handle.

[0035] The lump ratio measuring device 50 is installed after the cooling device 40. The lump ratio measuring device 50 includes a sieving device 51 and a weight measuring device 52. The sieving device 51 sieves the coke transported from the coke oven 30 into coke particles having a particle size equal to or smaller than a predetermined size and lump coke.

[0036] The lump coke sieved by the sieving device 51 is transported to the next process, for example, the production of pig iron in a blast furnace.

[0037] The weight measuring devices 52 are installed in front of and behind the sieve device 51. The weight measuring devices 52 measure the weight of the produced coke.

[0038] The weight measuring device 52 measures the weights of the coke before sieving and the lump coke after sieving transported by the conveyor, and calculates the amount of coke transported per unit time for each. The weight measuring device 52 calculates the lump ratio from the calculated amounts of coke before sieving and the lump coke after sieving transported. The lump ratio is the ratio of the weight of the lump coke after sieving to the weight of the coke before sieving.

[0039] The lump ratio measuring device 50 may be, for example, a sieve analyzer. When the lump ratio measuring device 50 is a sieve analyzer, the lump ratio measuring device 50 automatically samples the coke transported by the conveyor and performs sieve analysis to create a coke particle size distribution and calculate the lump ratio.

[0040] FIG. 2 is a diagram showing another example of a coke production system to which the coke production method according to an embodiment of the present disclosure is applied.

[0041] The lump ratio measuring device 50 may include, for example, a particle size measuring device 53. The particle size measuring device 53 may be, for example, a three-dimensional measuring device. When the particle size measuring device 53 is a three-dimensional measuring device, the particle size measuring device 53 sequentially measures the three-dimensional shape of the coke being conveyed by the conveyor and calculates the particle size of each coke particle. The particle size measuring device 53 creates a coke particle size distribution from the calculated particle sizes, and calculates the lump ratio based on the distribution.

[0042] When the control device 10 acquires the information on the lump ratio from the lump ratio measuring device 50, it determines the ratio of the inert material to be added to the blended coal raw material based on the acquired lump ratio.

[0043] The control device 10 changes the ratio of the inert material to be added to the blended coal raw materials based on the determined ratio of the inert material. The control device 10 changes the ratio of the inert material to be added to the blended coal raw materials, for example, by controlling the amount of the inert material discharged from the inert material tank 22.

[0044] The ratio of the inert material to be added to the blended coal raw material may be automatically changed by the control device 10 as described above, or may be manually changed by an operator.

[0045] FIG. 3 is a diagram illustrating a schematic configuration example of the control device 10 according to an embodiment of the present disclosure.

[0046] The control device 10 includes a control unit 11, an input unit 12, an output unit 13, a storage unit 14, and a communication unit 15.

[0047] The control unit 11 includes at least one processor, at least one dedicated circuit, or a combination of these. The processor is a general-purpose processor such as a central processing unit (CPU) or a graphics processing unit (GPU), or a dedicated processor specialized for a specific process. The dedicated circuit is, for example, a field-programmable gate array (FPGA) or an application specific integrated circuit (ASIC).

[0048] The control unit 11 reads programs, data, etc. stored in the storage unit 14 and executes various functions.

[0049] The input unit 12 includes one or more input interfaces that detect a user input and acquire input information based on a user operation. The input unit 12 includes, for example, physical keys, capacitive keys, a touch screen that is integral with the display of the output unit 13, or a microphone that accepts voice input.

[0050] The output unit 13 includes one or more output interfaces that output information to notify a user. The output unit 13 includes, for example, a display that outputs information as an image, a speaker that outputs information as sound, etc. The display included in the output unit 13 may be, for example, an LCD (Liquid Crystal Display), a CRT (Cathode Ray Tube) display, etc.

[0051] The storage unit 14 is, for example, a flash memory, a hard disk, an optical memory, etc. A part of the storage unit 14 may be outside the control device 10. In this case, the part of the storage unit 14 may be a hard disk, a memory card, etc. connected to the control device 10 via an arbitrary interface.

[0052] The storage unit 14 stores programs for the control unit 11 to execute each function, data used by the programs, and the like.

[0053] The communication unit 15 includes at least one of a communication module corresponding to wired communication and a communication module corresponding to wireless communication. The control device 10 is capable of communicating with other devices via the communication unit 15.

[0054] Next, a process in which the control device 10 determines the ratio of the inert material to be added to the blended coal raw materials based on the lump ratio obtained from the lump ratio measuring device 50 will be described in more detail.

[0055] The control device 10 sets a predetermined range as the range of the lump ratio, and determines the ratio of the inert material to be added to the blended coal raw material so that the lump ratio falls within the predetermined range. For example, when the lump ratio is not within the predetermined range, the control device 10 may determine the ratio of the inert material to be added to the blended coal raw material so as to change the ratio of the inert material from the current ratio.

[0056] This allows the control device 10 to keep the lump ratio of the coke produced by the coke oven 30 within a range that does not deviate significantly from a predetermined range.

[0057] When the control device 10 changes the ratio of the inert material added to the blended coal raw materials, the control device 10 may record in the memory unit 14 the relationship between the changed ratio of the inert material and the change in the lump ratio of the coke.

[0058] FIG. 4 is a diagram showing an example of a change in the lump ratio of coke when the ratio of the inert material added to the blended coal material is changed.

[0059] In the example shown in Fig. 4, when the proportion of the inactive material is changed at date and time t1, the lump ratio changes by an amount of change 101. In this case, the control device 10 may record in the memory unit 14 the relationship between the proportion of the inactive material changed at date and time t1 and the change in the lump ratio of the coke.

[0060] When determining the ratio of the inert material to be added to the blended coal raw material, the control device 10 may determine how much to change the ratio of the inert material from the current ratio based on the relationship between the changed ratio of the inert material and the change in the lump ratio recorded in the past. At this time, the control device 10 may determine the ratio of the inert material based on the relationship between the changed ratio of the inert material and the change in the lump ratio recorded in the past, for example, by using a linear regression equation or by using case classification of conditions based on a decision tree structure.

[0061] The lump ratio does not depend only on the ratio of the inert material added to the blended coal raw materials. For example, the lump ratio also depends on the carbonization degree and thermoplasticity of the coal and the operating rate of the coke oven 30. For example, the lump ratio also depends on the components of the blended coal raw materials. Therefore, even if the ratio of the inert material added to the blended coal raw materials is constant, the lump ratio may change.

[0062] In such a case, the control device 10 may determine the ratio of the inert material to be added to the blended coal feedstock based on the relationship between the most recently changed ratio of the inert material and the change in the lump ratio. This allows the control device 10 to control the lump ratio in response to changes in the operating conditions over time.

[0063] In addition, it takes about 24 hours for the blended coal raw materials to turn into coke from the blending tank 20 and reach the lumpiness measuring device 50 because there is a time for carbonization in the coke oven 30 on the way. Therefore, while the blended coal raw materials discharged from the blending tank 20 turn into coke and reach the lumpiness measuring device 50, the components of the blended coal raw materials may change significantly due to a change in the type of coal used, etc.

[0064] In such a case, the control device 10 may record in advance the components of the blended coal raw material, the ratio of the inert material, and the lump ratio in the memory unit 14. The control device 10 may search and extract data of similar conditions from the memory unit 14 based on the components of the blended coal raw material that can be currently blended, and use the lump ratio at that time as a substitute for the measured lump ratio, and determine the ratio of the inert material based on the difference from the target lump ratio.

[0065] Furthermore, the control device 10 may track the state in which the blended coal raw materials are transported by a transport device such as a conveyor in order to accurately grasp the time difference of about 24 hours. In this case, the control device 10 calculates, from the tracking information, when the coke whose lump ratio is measured was blended. Coal tracking refers to managing coal in a unit of volume or weight set in advance, managing the movement of the unit of coal during transportation by a conveyor or storage in a hopper, and grasping the current location of the unit of coal.

[0066] The control device 10 calculates, from tracking information, when the coke whose lump ratio is measured was blended, and determines, based on the calculated time, whether the components of the current blended coal raw material are different from the components of the blended coal raw material when the measured coke is produced.

[0067] When the components of the two blended coal raw materials are different, the control device 10 searches for and extracts data of similar conditions from the memory unit 14 based on the components of the currently blendable blended coal raw materials, and uses the lump ratio of the extracted data instead of the measured lump ratio to determine the proportion of inactive material based on the difference from the target lump ratio.

[0068] If the components of both blended coal feedstocks are the same, the control device 10 may determine the proportion of inert material to be added to the blended coal feedstock based on the relationship between the most recently changed proportion of inert material and the change in lump ratio.

[0069] In addition, since coal is carbonized in the coke oven 30 to become coke, the control device 10 can also match the relevant coke with past blended coal raw materials by, for example, matching the above-mentioned units of coal on a kiln basis in the coke oven 30.

[0070] The control device 10 can adjust the coke particle size more precisely by taking into account operating conditions other than the components of the blended coal raw materials, such as the operating rate of the coke oven 30, the coal particle size, and moisture, in addition to the components of the blended coal raw materials.

[0071] As described above, the method for producing coke according to the present embodiment includes the steps of measuring the weight of the coke produced by the coke oven 30 and the weight of the lump coke by the lump ratio measuring device 50 installed downstream of the coke oven 30, and calculating the lump ratio, determining the ratio of the inert material to be added to the blended coal raw materials based on the measured lump ratio, and changing the ratio of the inert material to be added to the blended coal raw materials based on the determined ratio of the inert material. This allows the lump ratio to be within a target range, and as a result, the coke particle size to be within a certain range. Therefore, the method for producing coke according to the present embodiment allows the coke particle size to be adjusted using the lump ratio as an index.

[0072] The present disclosure is not limited to the above-described embodiments. For example, multiple blocks shown in the block diagram may be integrated, or one block may be divided. Instead of executing multiple steps shown in the flowchart in chronological order as described, each step may be executed in parallel or in a different order depending on the processing capacity of the device executing each step, or as necessary. Other modifications are possible without departing from the spirit of the present disclosure.

[0073] For example, in the above-described embodiment, a plurality of brands of raw coal materials are blended and an inert substance is added to the blended raw coal materials in the blending tank 20. However, without being limited thereto, a plurality of brands of raw coal materials may be blended and an inert substance may be added to the blended raw coal materials in a raw material yard.

[0074] For example, in the above embodiment, the cooling device 40 is installed downstream of the coke oven 30, but the cooling device 40 does not necessarily have to be installed. [Explanation of symbols]

[0075] 1 Coke manufacturing system 10 Control device 11 Control section 12 Input section 13 Output section 14 Storage section 15 Communications Department 20 Blending tank 21 Coal storage tank 22 Inert substance tank 30 Coke oven 40 Cooling device 50 Lump rate measuring device 51 Sieve device 52 Weight measuring device 53 Particle size measuring device

Claims

1. A coke manufacturing method comprising adding an inert material to a blended coal raw material to manufacture coke, measuring the lumpiness of the coke produced by the coke oven using a lumpiness measuring device installed downstream of the coke oven; determining a proportion of the inert material to be added to the blended coal feedstock based on the measured lump ratio; Varying the proportion of the inert material added to the blended coal feedstock based on the determined proportion of the inert material; A method for producing coke, comprising:

2. The method for producing coke as described in claim 1 , wherein the step of determining the proportion of the inert material includes changing the proportion of the inert material from a current proportion when the measured lump ratio is not within a predetermined range.

3. The method further includes recording a relationship between the changed proportion of the inactive material and the change in the mass ratio; The method for producing coke according to claim 2 , wherein the step of determining the proportion of the inert material determines how much to change the proportion of the inert material from a current proportion based on the relationship recorded in the past.

4. The method for producing coke according to claim 1 , wherein the lump ratio measuring device includes a sieve device and a weight measuring device.

5. The lump ratio measuring device includes a particle size measuring device, The method for producing coke according to claim 1 , further comprising: a cooling device for cooling the coke produced by the coke oven, which is disposed between the coke oven and the particle size measuring device.

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