Test coke oven, method for measuring coal expansion pressure, and method for producing coke

Abstract

We provide a test coke oven that can measure coal expansion pressure with higher accuracy than conventional methods. [Solution] The device comprises a container for holding coal, having sides with holes or notches, a pressure receiving plate having a shape corresponding to the shape of the holes or notches, a heating furnace housing the container and the pressure receiving plate, a load cell installed outside the heating furnace, and a pressure receiving rod connecting the pressure receiving plate and the load cell. The pressure receiving plate is installed to cover the holes or notches, and the shape of the container side of the pressure receiving plate is such that it encloses a square with sides of 80 mm.

Description

Technical Field

[0001] The present invention relates to a test coke oven, a method for measuring the coal swelling pressure, and a method for producing coke.

Background Art

[0002] When coal is carbonized, the coal expands due to the pressure of the gas generated during the softening and melting process, and a load is applied to the furnace wall of the carbonization chamber in the coke oven. If the pressure applied to the furnace wall exceeds the durability of the furnace wall, the furnace wall will be damaged. Therefore, there is a need for a test coke oven that can measure the swelling pressure of coal during carbonization.

[0003] As a method for measuring the swelling pressure of coal, a method using a movable hearth furnace that can carbonize several hundred kilograms of coal and measure the coal swelling pressure at that time is known. By using a movable hearth furnace, the swelling pressure of coal can be measured under conditions similar to those of an actual machine, which can be useful for the coal blending of an actual machine. On the other hand, since the implementation of a test using a movable hearth furnace requires a large number of personnel and days, there is a problem that the number of test implementations is limited.

[0004] In response to such problems, Patent Document 1 discloses a coal swelling pressure measuring device that can simply measure the swelling pressure of coal on a smaller scale than an actual furnace, and a method for measuring the coal swelling pressure using the device. In the coal swelling pressure measuring device disclosed in Patent Document 1, a hole is formed in the side wall of a container for storing coal, and the swelling pressure of the coal is received by a pressure receiving plate facing the coal through this hole and transmitted to a load cell to measure the swelling pressure.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] In the coal expansion pressure measuring device disclosed in Patent Document 1, while it is stated that a circular shape is preferable for the holes in the side wall of the container and the pressure receiving plate from the viewpoint of the durability of the pressure receiving plate, the preferred shape and size from the viewpoint of measurement accuracy are not disclosed. In order to accurately measure the expansion pressure of coal, it is important to keep the contact state between the coal and the pressure receiving plate constant. However, cracks occur during the carbonization and coking process of coal, and since the location of these cracks cannot be controlled, the contact state between the coal and the pressure receiving plate changes from test to test, which has resulted in a problem of low measurement accuracy of coal expansion pressure.

[0007] This invention was made in view of the problems of the prior art, and its purpose is to provide a test coke oven and a method for measuring coal expansion pressure that can measure the expansion pressure of coal during carbonization with higher accuracy than conventional methods. Another object of this invention is to provide a method for producing coke using the method for measuring coal expansion pressure. [Means for solving the problem]

[0008] The means to solve the above problems are as follows: [1] A test coke oven comprising: a container for containing coal, having sides with holes or notches; a pressure receiving plate having a shape corresponding to the shape of the holes or notches; a heating furnace housing the container and the pressure receiving plate; a load cell installed outside the heating furnace; and a pressure receiving rod connecting the pressure receiving plate and the load cell, wherein the pressure receiving plate is installed to cover the holes or notches, and the shape of the pressure receiving plate on the container side is such that it encloses a square with sides of 80 mm. [2] The test coke oven according to [1], further comprising a flexible metal foil, the metal foil provided on the side so as to cover the holes or notches. [3] The test coke oven according to [1] or [2], further comprising a weight for applying a load to the coal contained in the container. [4] A method for measuring coal expansion pressure, comprising: a coal-charging step of loading coal into a container having holes or notches on its sides; a heating step of heating the coal in a heating furnace; and a measurement step of measuring the coal expansion pressure by bringing a pressure-receiving plate having a shape corresponding to the shape of the holes or notches into contact with the coal to receive the expansion pressure of the coal and transmitting the expansion pressure to a load cell installed outside the heating furnace, wherein the contact shape between the pressure-receiving plate and the coal before heating in the heating step is a shape that encloses a square with sides of 80 mm. [5] The method for measuring coal expansion pressure according to [4], wherein the hole or notch is sealed with a flexible metal foil. [6] The method for measuring coal expansion pressure according to [4] or [5], wherein the coal charging step involves loading coal into the container and then applying a load to the coal. A method for producing coke, comprising adjusting the coal blend so that the coal expansion pressure measured by the coal expansion pressure measurement method described in any of [4] to [6] is less than or equal to a predetermined target value, and producing coke using the blended coal with the adjusted blend. [Effects of the Invention]

[0009] By using the test coke oven according to the present invention, which has a pressure-receiving plate shaped to enclose a square with sides of 80 mm, the pressure-receiving plate and the coal can be brought into contact regardless of the location of crack occurrence. This makes it possible to maintain a constant contact state between the pressure-receiving plate and the coal, and to measure the expansion pressure of the coal during carbonization with higher accuracy than conventional methods. [Brief explanation of the drawing]

[0010] [Figure 1] Figure 1(a) is a schematic longitudinal cross-sectional view of the test coke oven according to this embodiment, and Figure 1(b) is an enlarged view of section A in Figure 1(a). [Figure 2] Figure 2 is a schematic cross-sectional view of the test coke oven according to this embodiment. [Figure 3] Figure 3 is a schematic diagram showing the configuration inside the heating furnace of the test coke oven according to this embodiment. [Figure 4] Figure 4 is a schematic diagram showing the configuration of a container with circular holes on its sides and a circular pressure-receiving plate. [Figure 5] Figure 5 is a schematic diagram showing the configuration of a container with a notch on the side and a pressure receiving plate. [Figure 6] Figure 6 is a schematic diagram showing the configuration of a container with reinforcing material and a pressure-receiving plate with guides. [Modes for carrying out the invention]

[0011] The present invention will be described in detail below through embodiments of the present invention. The following embodiments are preferred examples of the present invention, and the present invention is not limited in any way by these embodiments. Figure 1(a) is a schematic longitudinal section of the test coke oven 100 according to this embodiment, and Figure 1(b) is an enlarged view of part A in Figure 1(a). Figure 2 is a schematic cross-sectional view of the test coke oven 100 according to this embodiment. Figure 3 is a schematic diagram showing the configuration inside the heating furnace of the test coke oven 100 according to this embodiment. The configuration of the test coke oven 100 will be explained using Figures 1 to 3.

[0012] The test coke oven 100 is equipment used to simply measure the expansion pressure of coal during carbonization. The test coke oven 100 comprises a container 10, a pressure receiving plate 20, a heating furnace 30, a load cell 40, and a pressure receiving rod 50.

[0013] <Container 10> First, let's describe the container 10. The container 10 contains coal 60, which is the raw material for coke. The container 10 is a bottomed cylindrical container with a rectangular cross-section. A hole 14 is formed on one of the sides of the container 10.

[0014] In this embodiment, the dimensions of the container 10 are, for example, 273 mm in width, 261 mm in length, and 350 mm in height (internal volume 24938.6 cm³). 3) That is. In order to simply measure the swelling pressure of coal 60, the amount of coal 60 used in the measurement of the coal swelling pressure is preferably 100 kg or less, and more preferably 30 kg or less. On the other hand, if the amount of coal 60 used is too small, the conditions will deviate from the actual operation using a coke oven, and the measurement accuracy of the swelling pressure of coal 60 will decrease. Therefore, the amount of coal 60 used in the measurement of the coal swelling pressure is preferably 8 kg or more, and more preferably 10 kg or more.

[0015] If the coking density of coal 60 is 800 kg / m 3 Then, the internal volume of the container 10 is 10000 cm 3 or more and 125000 cm 3 or less is preferable, and 12500 cm 3 or more and 37500 cm 3 or less is more preferable. When measuring the coal swelling pressure at a coking density other than the above, a container with an internal volume such that the amount of coal used is 8 kg or more and 100 kg or less according to the coking density may be used, and it is preferable to use a container with an internal volume such that the amount of coal used is 10 kg or more and 30 kg or less.

[0016] The size of the hole 14 formed on the side surface may be a shape corresponding to the shape of the pressure receiving plate 20. Considering the thermal expansion of the container 10 and the pressure receiving plate 20 due to heating, the size of the hole 14 may be such that a gap of about 3 to 5 mm is formed when the container 10 and the pressure receiving plate 20 are assembled. The material of the container 10 has heat transfer properties and rigidity capable of transferring heat from the heating furnace 30, and any material may be used as long as it does not deform even when heated to 1000 °C or higher. As the material of the container 10, for example, metals such as SUS or ceramics can be used. In this embodiment, a container 10 of SUS304 was used.

[0017] Preferably, a flexible metal foil 16 is provided on the inner surface of the holes 14 formed on the side surface to seal the holes 14. This prevents coal 60 from spilling out of the container 10 through the holes 14. Furthermore, it prevents oxygen from entering through the gap between the container 10 and the pressure receiving plate 20 and causing the heated coal to burn. For example, SUS304 with a thickness of 0.02 mm can be used as the metal foil 16.

[0018] Furthermore, it is preferable to place the weight 12 on top of the coal 60 contained in the container 10. Since the height of the carbonization chamber in a coke oven is about 6.0m, for example, to simulate the coal loaded at the bottom of the carbonization chamber, it is necessary to apply a load of coal equivalent to a height of 5.7m from above the coal 60 loaded in the container 10. In order to apply this load to the coal 60, it is preferable to place the weight 12 corresponding to this load on top of the coal 60 contained in the container 10. Also, since the load differs depending on the height of the coal 60 in the coke oven, it is preferable to identify the load corresponding to that height and place the weight 12 corresponding to the identified load. This makes it possible to simulate the state of coal at any height in a coke oven and to measure the expansion pressure of coal 60 at any height in a coke oven.

[0019] <Pressure receiving plate 20> Next, the pressure receiving plate 20 will be described. The pressure receiving plate 20 is responsible for receiving the expansion pressure of the coal as it is heated and expands. For this reason, the pressure receiving plate 20 is installed so as to block the holes 14. As a result, the surface of the pressure receiving plate 20 facing the container 10 comes into contact with the coal 60, and the pressure receiving plate 20 can receive the expansion pressure of the coal 60 through the holes 14. In this embodiment, the pressure receiving plate 20 is a plate-shaped member made of SUS304, which is a square with sides of 80 mm.

[0020] To measure the expansion pressure of coal 60 with high accuracy, it is necessary to maintain a constant contact state between the coal and the pressure-receiving plate 20. However, cracks occur in the coke during the carbonization process of coal to coke production. Since the location of these cracks cannot be controlled, the contact state between the coal and the pressure-receiving plate 20 changes with each expansion pressure measurement, resulting in low accuracy in measuring the coal's expansion pressure.

[0021] In contrast, the test coke oven according to this embodiment uses a square plate-shaped member with a side length of 80 mm for the pressure receiving plate 20. The interval at which cracks occur in coal during the coking process is about 40 mm. Therefore, by making the shape of the pressure receiving plate 20 a square with a side length of 80 mm and increasing the contact shape that comes into contact with the coal 60 before heating, the contact state between the coal and the pressure receiving plate 20 can be kept constant regardless of the location of the cracks. As a result, the test coke oven 100 according to this embodiment can measure the expansion pressure of coal with higher accuracy than conventional ovens.

[0022] If the pressure receiving plate 20 is square or rectangular, the length in both the width and height directions should be 80 mm or more. Furthermore, to further improve the accuracy of measuring the expansion pressure of the coal 60, it is effective to increase the number of coke particles in contact with the pressure receiving plate 20. For this reason, it is preferable to make the length of one side of the pressure receiving plate 20 120 mm or more, and more preferable to make it 160 mm or more. This makes it possible to measure the expansion pressure of the coal 60 with even higher accuracy.

[0023] Figure 4 is a schematic diagram showing the configuration of a container 10 with a circular hole on its side and a circular pressure receiving plate 22. As shown in Figure 4, the shape of the pressure receiving plate is not limited to a square or rectangle, but may be circular, for example. In this case, the shape of the pressure receiving plate 22 must be such that it contains a square with sides of 80 mm. Here, a shape that contains a square with sides of 80 mm means that the shape of the surface of the pressure receiving plate 22 facing the container 10 contains a square with sides of 80 mm. To further improve the accuracy of measuring the expansion pressure of the coal 60, it is preferable to have a shape that contains a square with sides of 120 mm, and more preferable to have a shape that contains a square with sides of 160 mm.

[0024] <Heating furnace 30> Next, the heating furnace 30 will be described. Referring again to Figures 1 and 2, the heating furnace 30 heats the coal 60 contained in the container 10 from the direction of the load cell 40 in order to simulate the carbonization of coal in a coke oven. In the example shown in Figures 1 and 2, the heating furnace 30 has an electric heater 32 that is installed so as to heat the coal 60 from the direction of the load cell 40 and from the direction opposite to the load cell 40. However, the heating direction does not have to be both directions; the heating furnace 30 only needs to be able to heat from at least the direction of the load cell 40.

[0025] In the test coke oven 100, the coal 60 needs to be heated to a temperature of 350-500°C or higher, which is the softening and melting temperature of coal. For this reason, the electric heater 32 of the heating furnace 30 has a heating capacity that can heat the container 10 to 700°C or higher. Preferably, the heating furnace 30 has an electric heater 32 that can heat to 800°C or higher, and more preferably, an electric heater 32 that can heat to 1000°C or higher. Although the heating furnace 30 shown in Figures 1 and 2 is an example that has an electric heater 32, it is not limited to this. The heating means is not limited to the electric heater 32; heating means such as a gas heater may be used as long as they can heat to 700°C or higher. Also, for safety reasons, an exhaust port may be provided in the heating furnace 30.

[0026] <Load cell 40> Next, the load cell 40 will be described. The load cell 40 has a load cell using strain gauges or the like, and measures the expansion pressure of the coal 60. The load cell 40 is positioned in the same direction as the pressure receiving plate 20 relative to the coal 60, and is fixed to the fixing device 42 outside the heating furnace 30. However, the fixing method and fixing position of the load cell 40 are not particularly limited.

[0027] <Pressure-receiving rod 50> Next, the pressure-receiving rod 50 will be described. The pressure-receiving rod 50 is attached to the load-measuring surface of the load cell 40. One end of the pressure-receiving rod 50 is attached to the load cell 40, and the other end of the pressure-receiving rod 50 is connected perpendicularly to the pressure-receiving plate 20 inside the heating furnace 30. As a result, the expansion pressure of the coal 60 is transmitted to the load cell 40 via the metal foil 16, the pressure-receiving plate 20, and the pressure-receiving rod 50, and the expansion pressure of the coal 60 during heating can be continuously measured using the load cell 40.

[0028] In the example shown in Figures 1 and 2, a pressure receiving plate 52 is attached to one end of the pressure receiving rod 50. The pressure receiving plate 52 is attached so as to be perpendicular to the pressure receiving rod 50. By joining the plane of the pressure receiving plate 52 with the plane of the pressure receiving plate 20, the pressure receiving rod 50 can be brought into contact with the plane of the pressure receiving plate 20 perpendicularly. In this way, by providing the pressure receiving plate 52 at the other end of the pressure receiving rod 50, the contact between the pressure receiving plate 20 and the pressure receiving rod 50 is improved, and the accuracy of measuring the expansion pressure of the coal 60 is improved.

[0029] In this embodiment, the pressure receiving plate 52 is a rectangular plate-shaped member, for example, having a width of 40 mm and a height of 20 mm. The shape of the pressure receiving plate 52 is not particularly limited as long as it is smaller than the pressure receiving plate 20. Any material can be used for the pressure receiving rod 50 and the pressure receiving plate 52, as long as it has rigidity and heat resistance so as not to deform at the temperature inside the heating furnace 30. For example, stainless steel (SUS) or ceramic can be used for the pressure receiving rod 50 and the pressure receiving plate 52. In this embodiment, stainless steel (SUS304) was used for the pressure receiving rod 50 and the pressure receiving plate 52.

[0030] Next, the assembly method of the test coke oven 100 and the method for measuring the coal expansion pressure according to this embodiment will be described. First, the container 10 and the pressure receiving plate 20 are assembled as shown in Figure 3. In this embodiment, the container 10 and the pressure receiving plate 20 are fixed together using adhesive tape. Note that the method of fixing the container 10 and the pressure receiving plate 20 is not limited to adhesive tape; adhesive may also be used. However, the adhesive tape or adhesive used for fixing must melt with the heat in the heating furnace 30 or burn in the presence of oxygen. If the container 10 and the pressure receiving plate 20 remain fixed together, the expansion pressure of the coal 60 will not be transmitted to the load cell 40. For this reason, before the coal 60 is heated and begins to expand, the fixing between the container 10 and the pressure receiving plate 20 must be released by heating in the heating furnace 30.

[0031] After assembling the container 10 with the pressure receiving plate 20, a coal-charging step is performed in which coal 60 is loaded into the container 10. Since the container 10 is equipped with metal foil 16, coal 60 can be loaded into the container 10 without spilling any coal 60. The amount of coal 60 to be loaded may be set arbitrarily according to the purpose of the test.

[0032] Furthermore, it is preferable to increase the bulk density of the coal 60 in order to approximate the bulk density of the coal 60 in a coke oven. This makes it possible to bring the state of the coal 60 in the container 10 closer to the state inside a coke oven where the coal is carbonized. In addition, to simulate the coal loaded into the carbonization chamber of a coke oven, a weight 12 may be placed on top of the coal 60 contained in the container 10. This makes it possible to simulate the state of the coal in a coke oven and to measure the expansion pressure of the coal carbonized in a coke oven with even higher accuracy.

[0033] Next, the container 10 containing the coal 60 is placed inside the heating furnace 30. After the container 10 is placed inside the heating furnace 30, the pressure receiving rod 50 is pressed against the pressure receiving plate 20 and fixed in place while checking the load on the load cell 40 so that the load reaches a predetermined level. By pressing and fixing the pressure receiving rod 50 against the pressure receiving plate 20 in this way so that the load reaches a predetermined level, fluctuations in the state of the pressure receiving rod 50 during fixing can be suppressed, and the accuracy of measuring the expansion pressure of the coal 60 can be further improved.

[0034] After placing the container 10 in the heating furnace 30, a heating step is performed in which the coal 60 is heated to 1150°C using the electric heater 32. This allows the coal 60 to be coked. The heating temperature by the electric heater 32 should be 700°C or higher, preferably 800°C or higher, and more preferably 1000°C or higher. Furthermore, it is preferable that the heating temperature by the electric heater 32 be below the heat resistance temperature of the container 10, pressure receiving plate 20, pressure receiving rod 50, and metal foil 16.

[0035] The heating time for the coal 60 is preferably set to the time required to heat the coal 60 in the center of the container 10 to the temperature at which it cokes. Specifically, it should be set to the time required to heat the coal 60 to a temperature of 600°C or higher, which is the temperature at which the center of the coal 60 cokes. It is preferable to set the heating time for the coal 60 to a temperature of 700°C or higher, and more preferably to a temperature of 800°C or higher.

[0036] In this embodiment, the electric heater 32 was set to a temperature of 1150°C and a heating time of 8.5 hours. However, the electric heater 32 is not limited to these settings. The heating temperature and heating time can be determined by conducting a preliminary study in which a thermocouple is inserted into the center of the coal 60 and the temperature of the center is monitored, and setting the temperature and heating time to a level that can raise the temperature of the center of the coal 60 to 600°C or higher.

[0037] The heat from the electric heater 32 is transferred to the coal 60 through the container 10 and the pressure receiving plate 20. The expansion pressure generated by the expansion of the molten coal 60 due to this heating is transmitted to the load cell 40 via the metal foil 16, the pressure receiving plate 20, the pressure receiving plate 52, and the pressure receiving rod 50. This allows the expansion pressure of the coal 60 during heating to be continuously measured using the load cell 40. This is the measurement step in the coal expansion pressure measurement method according to this embodiment. The measured load can be converted to the expansion pressure of the coal 60 by dividing it by the contact area between the coal 60 and the pressure receiving plate 20 before heating. In this way, the test coke oven 100 according to this embodiment can be assembled and the expansion pressure of the coal 60 can be measured. After measuring the expansion pressure of the coal 60, the coke obtained by heating the coal 60 may be used for analysis.

[0038] As described above, the test coke oven 100 according to this embodiment has a pressure receiving plate 20 that is a square with sides of 80 mm, and the expansion pressure of the coal 60 is measured by bringing the pressure receiving plate 20 into contact with the coal. This makes it possible to keep the contact state between the pressure receiving plate 20 and the coal constant, and to measure the expansion pressure of the coal with higher accuracy than in the conventional method.

[0039] Furthermore, it is preferable to adjust the coal blend so that the coal expansion pressure measured in the test coke oven 100 according to this embodiment is below a predetermined target value, and then carry out a coke manufacturing method using the blended coal with the adjusted coal blend. As described above, if the expansion pressure due to the gas pressure generated during the coal softening and melting process exceeds the durability of the furnace wall, the furnace wall will be damaged. For this reason, it is preferable to pre-determine a target value for coal expansion pressure that will not damage the furnace wall of the carbonization chamber in the coke oven, and to adjust the coal blend so that the coal expansion pressure measured in the test coke oven 100 according to this embodiment is below that target value. By manufacturing coke using the blended coal with the adjusted coal blend in this way, it becomes possible to manufacture coke while suppressing damage to the furnace wall of the carbonization chamber in the coke oven.

[0040] It should be noted that the embodiments of the present invention are not limited to those described above, and various modifications can be made. In the examples shown in Figures 1 and 2, an example using a square-shaped pressure receiving plate 20 is shown, but the invention is not limited to this. As long as the shape of the container 10 that receives the expansion pressure of the coal 60 contains a square with sides of 80 mm, the pressure receiving plate 20 may have other shapes.

[0041] Furthermore, while the examples shown in Figures 1 and 2 show an example in which metal foil 16 is provided in the hole 14, the design is not limited to this. If the size of the hole 14 is such that there is a gap of about 3 to 5 mm when the pressure receiving plate 20 is assembled, the spillage of coal 60 can be reduced, so the test coke oven 100 does not necessarily have to have metal foil 16. However, since providing metal foil 16 prevents coal 60 from spilling out of the container 10, it is preferable for the test coke oven 100 to have metal foil 16.

[0042] Furthermore, while the examples shown in Figures 1 and 2 show an example where a weight 12 is placed on the coal 60, the invention is not limited to this. The test coke oven 100 does not need to have a weight 12. However, it is preferable for the test coke oven 100 to have a weight 12 because placing a weight 12 on the coal 60 allows for the simulation of the coal's state at any height inside the coke oven.

[0043] Furthermore, while Figures 1 to 3 show a container 10 with holes 14 on its side, the container is not limited to this. Instead of holes 14, notches may be provided on the side of the container 10. Figure 5 is a schematic diagram showing the configuration of a container 10 with a notch 18 on its side and a pressure receiving plate 24. As shown in Figure 5, a notch 18 may be provided on one side of the container 10, and a pressure receiving plate 24 with a shape corresponding to the shape of the notch 18 may be used. Even with such a notch 18 and a pressure receiving plate 24 with a shape corresponding to the shape of the notch 18, if the shape of the pressure receiving plate 24 contains a square with sides of 80 mm, the expansion pressure of coal can be measured with higher accuracy than conventional methods.

[0044] Figure 6 is a schematic diagram showing the configuration of a container 10 equipped with reinforcing members 19 and a pressure receiving plate 24 equipped with a guide 26. The container 10 and pressure receiving plate 24 shown in Figure 6 differ from the container 10 and pressure receiving plate 24 shown in Figure 5 in that the container 10 has two reinforcing members 19 and the pressure receiving plate 24 has a rod-shaped guide 26. The two reinforcing members 19 are provided at two different positions in the vertical direction on the side surface of the container 10, where a notch 18 is provided, so as to straddle the notch 18. The guide 26 is provided on the upper part of the pressure receiving plate 24.

[0045] In this way, by providing a rod-shaped guide 26 on the upper part of the pressure receiving plate 24, it is possible to prevent the pressure receiving plate 24 from falling from the container 10. Furthermore, if a continuous notch 18 is formed from the top surface to the side surface, the rigidity of the container 10 will decrease and its durability will be reduced. In contrast, by providing a reinforcing material 19 that straddles the notch 18, the container 10 is reinforced and the decrease in the durability of the container 10 can be suppressed. The guide 26 and the reinforcing material 19 may also be made of SUS304. [Examples]

[0046] Next, an example of measuring the expansion pressure of coal using a test coke oven according to this embodiment will be described. In this example, the electric heater of the heating furnace was set to a temperature of 1150°C, and the coal was heated for 8.5 hours. The maximum load generated by this heating was measured with a load cell, and the maximum load among the measured loads was identified. The value obtained by dividing this maximum load by the contact area between the pressure receiving plate and the coal was evaluated as the maximum expansion pressure of the coal. The measurement of the maximum expansion pressure of the coal was performed twice under the same conditions. The measurement conditions for the maximum expansion pressure are shown in Table 1 below, and the measurement results for the maximum expansion pressure are shown in Table 2 below.

[0047] [Table 1]

[0048] [Table 2]

[0049] As shown in Table 2, compared to the comparative example using a pressure-receiving plate that does not contain a square with sides of 80 mm, the difference in the maximum expansion pressure obtained in two measurements was smaller in Invention Examples 1 to 5, which used a pressure-receiving plate with a shape that contains a square with sides of 80 mm. From these results, it was confirmed that by contacting the coal with a pressure-receiving plate with a shape that contains a square with sides of 80 mm and measuring the expansion pressure of the coal, the variation between measurements can be reduced, and the expansion pressure of the coal can be measured with high reproducibility. Since large variation between measurements means low measurement accuracy, it can be said that by using the test coke oven according to this embodiment, the expansion pressure of coal can be measured with higher accuracy than conventional methods. [Explanation of Symbols]

[0050] 10 containers 12 weights 14 holes 16 Metal foil 18 Notches 19 Reinforcement material 20 Pressure-receiving plate 22 Pressure-receiving plate 24 Pressure-receiving plate 26 Guide 30 Furnace 32 Electric heaters 40 Load cell 42 Fixtures 50 Pressure-receiving rod 52 Pressure plate 60 Coal 100 Test coke ovens

Claims

1. A container for holding coal, having sides with holes or notches, A pressure receiving plate having a shape corresponding to the shape of the aforementioned hole or notch, A heating furnace housing the container and the pressure receiving plate, A load cell installed outside the aforementioned heating furnace, A pressure-receiving rod connecting the pressure-receiving plate and the load cell, It has, A test coke oven, wherein the pressure receiving plate is installed to cover the hole or notch, and the shape of the pressure receiving plate on the container side is such that it encloses a square with sides of 80 mm.

2. It further comprises a flexible metal foil, The test coke oven according to claim 1, wherein the metal foil is provided on the side surface so as to cover the hole or notch.

3. The test coke oven according to claim 1 or claim 2, further comprising a weight for applying a load to the coal contained in the container.

4. A coal-charging step in which coal is loaded into a container having holes or notches on its sides, A heating step of heating the coal in a heating furnace, A measurement step of measuring the expansion pressure of coal by bringing a pressure receiving plate having a shape corresponding to the shape of the hole or notch into contact with the coal to receive the expansion pressure of the coal, and transmitting the expansion pressure to a load cell installed outside the heating furnace, It has, A method for measuring coal expansion pressure, wherein the contact shape between the pressure receiving plate and the coal before heating in the heating step is a shape that encloses a square with sides of 80 mm.

5. The method for measuring coal expansion pressure according to claim 4, wherein the hole or notch is covered with a flexible metal foil.

6. The coal expansion pressure measurement method according to claim 4 or claim 5, wherein in the coal charging step, a load is applied to the coal after the coal has been loaded into the container.

7. A method for producing coke, comprising adjusting the coal blend so that the coal expansion pressure measured by the coal expansion pressure measurement method described in claim 4 or claim 5 is less than or equal to a predetermined target value, and producing coke using the blended coal with the adjusted blend.

8. A method for producing coke, comprising adjusting the coal blend so that the coal expansion pressure measured by the coal expansion pressure measurement method described in claim 6 is less than or equal to a predetermined target value, and producing coke using the blended coal with the adjusted blend.

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