Furnace for synthesizing graphite

Abstract

Provided is a furnace for synthesizing graphite. The furnace for synthesizing graphite according to the present invention comprises: a main body having a vertical main passage therein; first and second electrode heads provided on the upper and lower parts of the main passage, respectively; and a plurality of crucible heaters stacked in the main passage and directly heating, to a set temperature, raw material for synthesizing graphite inserted into the interior to produce synthetic graphite.

Description

With artificial graphite

[0001] The present invention relates to an artificial graphite furnace.

[0002] In general, graphite has excellent lubricity, conductivity, heat resistance, acid resistance, and alkali resistance, and is used in various applications such as mechanical seals, brake pads, linings, electrode pastes, foundry paints, batteries, refractories, steelmaking insulation, crucibles, and electric brushes, and its application range is very wide.

[0003] In particular, lithium ion batteries are used as electrode materials by utilizing the phenomenon in which lithium (Li) ions enter the layered structure of graphite crystals.

[0004] The heating process for making artificial graphite used in lithium-ion batteries accounts for a significant portion of the total energy cost, making the establishment of an efficient manufacturing method very important.

[0005] Typically, artificial graphite is made from green coke, a carbon material produced by separating and heating coal tar, a byproduct of coal and petroleum. To make it suitable for use in lithium-ion batteries, the crystallinity of the graphite molecules must be maximized.

[0006] A key requirement for increasing the crystallinity of graphite molecules is prolonged heating, for example, at temperatures exceeding 2800°C. Graphite is the most common material capable of withstanding temperatures exceeding 2800°C, and thus, the production of artificial graphite utilizes furnaces and components made of graphite.

[0007] In a vertical artificial graphitization furnace, the raw material to be graphitized from the coke drawn on the carbon material graphite wall descends inside the ultra-high temperature heater, and the gases generated by the sublimation of foreign substances contained inside the coke recombine with or damage the wall.

[0008] That is, impurities contained in the raw material, such as moisture, ash, volatile matter (VM), nitrogen, and sulfur, gasify and deteriorate or stick to the side of the furnace.

[0009] This gasification occurs, for example, mostly below 1500°C. Because of this characteristic, a calcination process is included in the graphitization process to remove unnecessary impurities in a relatively low temperature range, for example, below 1500°C.

[0010] In addition, the temperature required for the graphitization process is, for example, 2900℃ to 3000℃ or higher, and in most cases, the crucible is loaded at room temperature, the temperature is increased over a long period of time, and the temperature is maintained at the highest temperature for a short period of more than 1 hour and a long period of up to 20 hours, and then cooled to room temperature at which the crucible can be handled by the worker.

[0011] At this time, since the method of applying heat to the crucible is indirect heating by radiation from the heater, only a much smaller amount of heat than 100% of the amount of heat generated by the heater is transferred to the crucible, and a considerable amount of time is delayed for the coke that must receive the heat, which increases energy consumption and greatly increases the cost of the artificial graphitization process.

[0012] Therefore, there is an urgent need for a method that can be more efficient than the indirect method and significantly reduce the time delay in the artificial graphitization process by applying a direct heating method that directly heats the graphitization raw material using the crucible itself as a heat source.

[0013] The present invention aims to provide an artificial graphite furnace that is more efficient than an indirect heating method and can minimize the time delay in the artificial graphite process by applying a direct heating method that directly heats the graphitization raw material using the crucible itself as a heat source when manufacturing artificial graphite in a vertical artificial graphite furnace.

[0014] According to one embodiment of the present invention, an artificial graphite furnace is a vertical artificial graphite furnace for producing artificial graphite, which may include a main body having a main passage in a vertical direction therein, and a first electrode head and a second electrode head installed respectively above and below the main passage of the main body.

[0015] Additionally, the artificial graphite furnace may include a plurality of crucible heaters for directly heating the graphitization raw material stacked in the main passage and loaded inside to a set temperature to produce artificial graphite.

[0016] The first electrode head and the second electrode head may each have a first passage and a second passage, which are connected to the main moving passage and in which the crucible heater is stacked.

[0017] The first electrode head and the second electrode head can be connected to a first electrode connection portion and a second electrode connection portion, respectively, for connection to a power supply.

[0018] The first electrode connection portion and the second electrode connection portion can support the crucible heaters stacked in the first passage and the second passage, respectively.

[0019] The body may have a rectangular or cylindrical shape.

[0020] The crucible heater may have a square or cylindrical shape.

[0021] The outside of the crucible heater may be filled with an inert gas.

[0022] The crucible heater can be manufactured from graphite material.

[0023] The first electrode head and the second electrode head can be made of graphite material.

[0024] The first electrode head and the second electrode head may have a square or cylindrical shape.

[0025] The width or diameter of the first electrode head and the second electrode head may have a size that is at least 1.2 to 3 times larger than the width or diameter of the crucible heater.

[0026] The interior of the body may be filled with insulating material to insulate the body.

[0027] The insulation may be made of carbon black material.

[0028] The main body may be provided with a supply unit for supplying a crucible heater to the main passage of the main body from the outside.

[0029] The main body may be provided with an exhaust port for exhausting the crucible heater to the outside from the main passage of the main body.

[0030] The supply section may include a first transfer line arranged vertically with respect to the main body and for transferring the crucible heater from one side of the main body toward one end of the main body, and a first chamber arranged between the main body and the first transfer line and for supplying the crucible heater transferred by the first transfer line to the main passage.

[0031] The first transport line may be equipped with at least one first clean room filled with an inert gas and removing entrained air together with a crucible heater transported to the first chamber.

[0032] A vertical transport device may be installed in the first chamber to vertically transport the crucible heater transferred to the first chamber to the main passage.

[0033] The discharge unit may include a second transfer line arranged vertically with respect to the main body and for transferring the crucible heater from the other end of the main body to one side of the main body, and a second chamber arranged between the main body and the second transfer line and for discharging the crucible heater transferred to the other end of the main body to the second transfer line.

[0034] The second transfer line may be equipped with at least one second clean room filled with an inert gas and removing entrained air together with the crucible heater transferred from the second chamber.

[0035] A horizontal transfer device may be installed in the second chamber to horizontally transfer the crucible heater transferred to the second chamber to the second transfer line.

[0036] According to an embodiment of the present invention, when manufacturing artificial graphite in a vertical artificial graphitization furnace, a direct heating method is applied in which the crucible itself is used as a heat source to directly heat the graphitization raw material, which is more efficient than an indirect heating method and can also greatly reduce the time delay in the artificial graphitization process.

[0037] Figure 1 is a schematic diagram of an artificial graphite furnace according to one embodiment of the present invention.

[0038] Hereinafter, with reference to the attached drawings, embodiments of the present invention will be described so that those skilled in the art can easily implement them. As will be readily apparent to those skilled in the art, the embodiments described below may be modified in various ways without departing from the spirit and scope of the present invention. Wherever possible, identical or similar parts are indicated in the drawings using the same reference numerals.

[0039] The terminology used below is for the purpose of describing specific embodiments only and is not intended to limit the present invention. As used herein, the singular forms "singular" and "comprising" include plural forms as well, unless the context clearly dictates otherwise. The word "comprising" as used herein specifies a particular feature, region, integer, step, operation, element, and / or component, but does not exclude the presence or addition of other specific features, regions, integers, steps, operations, elements, components, and / or groups.

[0040] All terms, including technical and scientific terms, used below have the same meaning as commonly understood by those of ordinary skill in the technical field to which this invention pertains. Terms defined in the dictionary are further interpreted to have meanings consistent with the relevant technical literature and the present disclosure, and are not to be construed as ideal or overly formal unless otherwise defined.

[0041] Figure 1 is a schematic diagram of an artificial graphite furnace according to one embodiment of the present invention.

[0042] Referring to FIG. 1, an artificial graphite according to one embodiment of the present invention may include a main body (10), a first electrode head (20), a second electrode head (30), and a crucible heater (40).

[0043] The main body (10) may have a main passage (11) in a vertical direction (Y direction in Fig. 1) inside.

[0044] In addition, the first electrode head (20) and the second electrode head (30) are installed respectively at the upper and lower portions of the main passage (11) of the main body (10), and may have a first passage (21) and a second passage (31) that are connected to the main passage (11).

[0045] The crucible heater (40) may be stacked in the first passage (21), the main passage (11), and the second passage (31) and may be provided in multiple units to directly heat the graphitizing raw material loaded inside to a set temperature to produce artificial graphite.

[0046] The first electrode head (20) and the second electrode head (30) can be connected to the first electrode connection portion (23) and the second electrode connection portion (33), respectively, for connection to the power supply portion (50).

[0047] The first electrode connection portion (23) and the second electrode connection portion (33) can support the crucible heater (40) stacked on the first passage (21) and the second passage (31), respectively.

[0048] The main body (10) may have a rectangular or cylindrical shape, etc., and may have a main passage (11) through which a crucible heater (40) may be stacked in a vertical direction (Y direction in FIG. 1) and passed.

[0049] The crucible heater (40) may have a shape such as a square cylinder or a cylinder into which graphitization raw material can be loaded, and may be manufactured from a material such as graphite.

[0050] The outside of the crucible heater (40) may be filled with an inert gas such as nitrogen or argon gas so that the crucible heater (40) can maintain the set temperature.

[0051] The first electrode head (20) and the second electrode head (30) can be manufactured from the same material as the crucible heater (40), such as graphite.

[0052] Additionally, the first electrode head (20) and the second electrode head (30) may have the same shape as the crucible heater (40), such as a square cylinder or a cylindrical cylinder.

[0053] The width (or diameter) (W2) (length in the X direction in FIG. 1) of the first electrode head (20) and the second electrode head (30) may have a size at least 1.2 to 3 times larger than the width (or diameter) (W1) of the crucible heater (40).

[0054] Additionally, the interior of the main body (10) may be filled with an insulating material (60) for insulation and heat retention of the crucible heater (40), the first electrode head (20), and the second electrode head (30) within the main body (10).

[0055] The insulation material (60) can be made of a material such as carbon black that can sufficiently withstand high temperatures.

[0056] A supply part (100) for supplying a crucible heater (40) from the outside to the main passage (11) of the main body (10) and a discharge part (200) for discharging the crucible heater (40) from the main passage (11) of the main body (10) to the outside may be installed at the upper and lower parts of the main body (10).

[0057] Hereinafter, it is described that the supply part (100) is installed at the lower part of the main body (10) and the discharge part (200) is installed at the upper part of the main body (10) (in FIG. 1, the crucible heater moves as indicated by the solid arrow), but conversely, the discharge part may be installed at the lower part of the main body (10) and the supply part may be installed at the upper part of the main body (10) (in FIG. 1, the crucible heater moves as indicated by the dotted arrow).

[0058] An upper cooling device (not shown) and a lower cooling device (not shown) for cooling the crucible heater (40) to a set temperature may be installed on the upper and lower parts of the main body (10), respectively, and the upper cooling device and the lower cooling device may be formed of a water cooling jacket or the like for easy cooling of the crucible heater (40).

[0059] And, the supply unit (100) may include a first transfer line (110) and a first chamber (120).

[0060] The first transfer line (110) is arranged in a vertical direction (X direction in FIG. 1) with respect to the main body (10) at the lower part of the main body (10), and can horizontally transfer the crucible heater (40) from one side of the main body (10) to the lower part of the main body (10).

[0061] In addition, the first chamber (120) is arranged between the lower part of the main body (10) and the first transfer line (110), and can supply the crucible heater (40) transferred to the first transfer line (110) to the main passage (11) of the main body (10).

[0062] At least one first clean room (130, 131) filled with an inert gas and removing air, etc. that is introduced along the first transfer line (110) and transferred to the first chamber (120) along the first transfer line (110) may be installed.

[0063] In the first chamber (120), a vertical transfer device (not shown) may be installed to vertically transfer the crucible heater (40) transferred to the first chamber (120) to the main passage (11) of the main body (10) (Y direction in FIG. 1).

[0064] Additionally, the discharge unit (200) may include a second transfer line (210) and a second chamber (220).

[0065] The second transport line (210) is arranged vertically (X direction in FIG. 1) with respect to the main body (10) on the upper part of the main body (10), and can horizontally transport the crucible heater (40) from the upper part of the main body (10) to one side of the main body (10).

[0066] Additionally, the second chamber (220) is arranged between the upper part of the main body (10) and the second transfer line (210), and can discharge the crucible heater (40) transferred to the upper part of the main body (10) to the second transfer line (210).

[0067] At least one second clean room (230, 231) filled with an inert gas and removing air, etc. that is introduced together with the crucible heater (40) transferred from the second chamber (220) may be installed in the second transport line (210).

[0068] A horizontal transfer device (not shown) may be installed in the second chamber (220) to transfer the crucible heater (40) transferred to the second chamber (220) horizontally (X direction in FIG. 1) to the second clean room (230) of the second transfer line (210).

[0069] Hereinafter, with reference to FIG. 1, the operation of an artificial graphite according to one embodiment of the present invention will be described.

[0070] Hereinafter, it is described that a supply unit (100) is installed at the lower part of the main body (10) and a discharge unit (200) is installed at the upper part of the main body (10).

[0071] Here, the crucible heater (40) is a crucible in which graphitization raw material is loaded and acts as a heater.

[0072] That is, the crucible heater (40) is stacked on the first passage (21) of the first electrode head (20), the main passage (11) of the main body (10), and the second passage (31) of the second electrode head (30), and in this stacked state, the crucible heater (40) is in contact with the first electrode head (20) and the second electrode head (30) installed on the upper and lower portions of the main body (10), respectively.

[0073] Accordingly, since the first electrode head (20) and the second electrode head (30) are connected by the power supply (50) and the first electrode connection part (23) and the second electrode connection part (33), electricity is supplied to the crucible heater (40).

[0074] The width (W2) of the first electrode head (20) and the second electrode head (30) is set to be at least 1.2 to 2.5 times larger than the width (W1) of the crucible heater (40), so that the heat generation of the first electrode head (20) and the second electrode head (30) is relatively very small compared to the crucible heater (40).

[0075] Therefore, the crucible heater (40) generates a relatively large amount of heat compared to the first electrode head (20) and the second electrode head (30), so that it can be easily heated to a set temperature (e.g., 2900°C to 3100°C), and the graphitizing raw material loaded inside the crucible heater (40) can be efficiently heated to produce artificial graphite.

[0076] In addition, the outside of the crucible heater (40) is filled with an inert gas such as nitrogen or argon gas, and an insulating material (60) is installed, so that the crucible heater (40) can maintain the set temperature (2900°C to 3100°C).

[0077] And, the crucible heater (40) can be supplied from the outside to the main passage (11) through the supply unit (100) with the graphitization raw material loaded inside.

[0078] That is, the crucible heater (40) is transported along the first transport line (110) and passes through the first clean room (130, 131). At this time, the air mixed in with the crucible heater (40) is removed in the first clean room (130, 131).

[0079] In this way, when the air mixed in with the crucible heater (40) in the first clean room (130, 131) is removed, the crucible heater (40) is transferred to the first chamber (120) and then pushed vertically up into the main passage (11) of the main body (10) by a vertical transfer device (not shown).

[0080] Additionally, when the production of artificial graphite in the crucible heater (40) is completed, the crucible heater (40) is discharged to the outside by the discharge unit (200).

[0081] That is, the crucible heater (40) in which artificial graphite is generated is discharged to the second chamber (220), and is transported from the second chamber (220) along the second transport line (210) by a horizontal transport device (not shown) and discharged to the outside.

[0082] The crucible heater (40) discharged through the second transport line (210) passes through the second clean room (230, 231), and at this time, air mixed in with the crucible heater (40) is removed in the second clean room (230, 231).

[0083] Therefore, when manufacturing artificial graphite in a vertical artificial graphitization furnace, a direct heating method is applied in which the crucible heater (40) itself directly heats the graphitization raw material as a heat source, which is more efficient than the indirect heating method and also minimizes the time delay in the artificial graphitization process.

[0084] Although the present disclosure has been described through preferred embodiments as described above, it will be readily understood by those skilled in the art that the present invention is not limited thereto and that various modifications and variations are possible without departing from the scope of the claims set forth below.

[0085] (Explanation of symbols)

[0086] 10: Body

[0087] 11: Main passage

[0088] 20: First electrode head

[0089] 30: Second electrode head

[0090] 40: Crucible Heater

Claims

1. In a vertical artificial graphite furnace for manufacturing artificial graphite, A body having a main passage in a vertical direction inside, A first electrode head and a second electrode head each installed at the upper and lower portions of the main passage of the above body, and Multiple crucible heaters for directly heating the graphitized raw material loaded inside and stacked in the main passage above to a set temperature to produce artificial graphite With artificial graphite containing .

2. In paragraph 1, The first electrode head and the second electrode head are connected to the main moving passage and have first and second passages, respectively, in which the crucible heaters are stacked, in an artificial graphitization furnace.

3. In paragraph 2, The first electrode head and the second electrode head are artificial graphite, each connected to a first electrode connecting portion and a second electrode connecting portion for connecting to a power supply.

4. In paragraph 3, The first electrode connection portion and the second electrode connection portion are artificial graphitization devices that support the crucible heaters laminated in the first passage and the second passage, respectively.

5. In paragraph 1, The above body is made of artificial graphite and has a rectangular or cylindrical shape.

6. In paragraph 5, The above crucible heater is an artificial graphite furnace having a square or cylindrical shape.

7. In paragraph 6, An artificial graphite furnace, the outside of which is filled with an inert gas, is provided.

8. In paragraph 7, The above crucible heater is an artificial graphite made of graphite material.

9. In paragraph 8, The above first electrode head and the above second electrode head are made of artificial graphite, made of graphite material.

10. In paragraph 9, The above first electrode head and the above second electrode head are made of artificial graphite and have a square cylinder or cylindrical shape.

11. In paragraph 10, An artificial graphite furnace, wherein the width or diameter of the first electrode head and the second electrode head is at least 1.2 to 3 times larger than the width or diameter of the crucible heater.

12. In paragraph 1, The inside of the above body is filled with an insulating material for insulating the above body, which is an artificial graphite.

13. In paragraph 12, The above insulation material is made of carbon black, an artificial graphite.

14. In any one of paragraphs 1 to 13, An artificial graphite furnace, wherein a supply unit for supplying the crucible heater to the main passage of the main body from the outside is installed in the above body.

15. In paragraph 14, An artificial graphite furnace, wherein the main body is provided with a discharge port for discharging the crucible heater to the outside from the main passage of the main body.

16. In paragraph 15, The above supply unit, A first transfer line arranged vertically with respect to the main body and for transferring the crucible heater from one side of the main body to one end of the main body, and An artificial graphitization furnace, comprising a first chamber for supplying the crucible heater, which is disposed between the main body and the first transfer line and is transferred by the first transfer line, to the main passage.

17. In paragraph 16, An artificial graphitization furnace, wherein at least one first clean room is installed in the first transfer line to remove air introduced together with the crucible heater transferred to the first chamber and filled with an inert gas.

18. In paragraph 16, An artificial graphitization furnace, wherein a vertical transfer device is installed in the first chamber to vertically transfer the crucible heater transferred to the first chamber to the main passage.

19. In paragraph 15, The above discharge part, A second transfer line arranged vertically with respect to the main body and for transferring the crucible heater from the other end of the main body to one side of the main body, and An artificial graphitization furnace, comprising a second chamber disposed between the main body and the second transfer line and configured to discharge the crucible heater transferred to the other end of the main body to the second transfer line.

20. In paragraph 19, An artificial graphitization furnace, wherein at least one second clean room is installed in the second transfer line to remove air mixed with the crucible heater transferred from the second chamber and filled with an inert gas.

21. In paragraph 20, An artificial graphitization furnace, wherein a horizontal transfer device is installed in the second chamber to horizontally transfer the crucible heater transferred to the second chamber to the second transfer line.

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