Heat treatment apparatus and heat treatment method

Abstract

To provide a heat treatment apparatus and a heat treatment method capable of improving the maintainability of a member to be heated more than heretofore available.SOLUTION: A heat treatment apparatus includes: a body to be conveyed including an object to be treated and provided with at least a heating element for heating the object to be treated; a conveying device for conveying the body to be conveyed; and an induction heating device provided with a heating coil moving freely to and from the body to be conveyed and generating heat in the heating element by applying a magnetic field to the body to be conveyed.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to a heat treatment apparatus and a heat treatment method. This application claims priority based on Japanese Patent Application No. 2022-051160, filed on March 28, 2022, the contents of which are incorporated herein by reference. [Background technology]

[0002] Patent Document 1 discloses a graphitization furnace and a method for producing graphite, which obtains graphite by continuously heat-treating a powder that is a carbon source. In this graphitization furnace and method for producing graphite, a conductive powder is placed in a crucible made of a conductive material that functions as a heating electrode, and the crucible is then put into a chamber, and a separately provided electrode is embedded in the powder in the chamber, and the crucible is transported from one end of the chamber to the other. In this way, the powder is electrically heated to obtain graphite continuously. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2014-210710 A Summary of the Invention [Problem to be solved by the invention]

[0004] In the background art, although graphite can be obtained continuously, there is still room for improvement in the maintainability of the equipment. In other words, in order to obtain graphite from carbon powder, the powder needs to be heated to a high temperature of nearly 3000°C in an air-tight state, which accelerates the deterioration of the components (heated components) that are heated together with the powder, such as the crucible, electrodes, and insulating materials provided around the crucible.

[0005] However, since the background art does not take into consideration the ease of maintenance of the heated member, it is necessary to stop the operation of the device in order to perform maintenance on the heated member. In other words, there is room for improvement in the ease of maintenance of the background art.

[0006] An object of the present disclosure is to provide a heat treatment apparatus and a heat treatment method that can improve the ease of maintenance of a heated member compared to conventional methods. [Means for solving the problem]

[0007] The heat treatment apparatus of the first aspect of the present disclosure employs a means comprising a transported body including an object to be treated and having at least a heating element for heating the object to be treated, a transport device for transporting the transported body, and an induction heating device having a heating coil that can move freely toward and away from the transported body and applies a magnetic field to the transported body to cause the heating element to generate heat.

[0008] In a second aspect of the present disclosure, in the above-mentioned first aspect, the transported object may further include a heat insulating material provided around the heating element.

[0009] In a third aspect of the present disclosure, in the first or second aspect, the transferred object may further include a cooling pipe through which a cooling gas flows.

[0010] In a fourth aspect of the present disclosure, in any one of the first to third aspects, the transported object may include a heat transfer plate that transfers heat from the heating element to an inside of the processing object.

[0011] In a fifth aspect of the present disclosure, in any one of the first to fourth aspects, the transported object may be configured to hold the heating element and the object to be treated in a degassed atmosphere or an inert gas atmosphere in advance.

[0012] A heat treatment method according to a sixth aspect of the present disclosure is a heat treatment method for heat treating an object to be treated, in which a member to be heated together with the object to be treated is transported together with the object to be treated.

[0013] In a seventh aspect of the present disclosure, in the sixth aspect, the treatment object may be held in a degassed atmosphere or an inert gas atmosphere in a pre-step of the heat treatment. Effect of the Invention

[0014] According to the present disclosure, it is possible to provide a heat treatment apparatus and a heat treatment method that can improve the ease of maintenance of a heated member compared to conventional methods. [Brief description of the drawings]

[0015] [Figure 1] FIG. 1 is a front view showing an overall configuration of a continuous graphitization apparatus according to a first embodiment of the present disclosure. [Figure 2A] 1 is a vertical cross-sectional view showing a configuration of a transport object in a first embodiment of the present disclosure. [Figure 2B] 1 is a cross-sectional view showing a configuration of a transport object in a first embodiment of the present disclosure. [Diagram 3] FIG. 4 is a front view showing an overall configuration of a continuous graphitization apparatus according to a second embodiment of the present disclosure. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0016] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. [First embodiment] First, a first embodiment of the present disclosure will be described with reference to Figures 1, 2A, and 2B. A continuous graphitization apparatus A according to the first embodiment is a graphite production apparatus that produces graphite (also called graphite or graphite) by heating a powder W to be treated, which is made of carbon, to a high temperature of about 2500 to 3000°C.

[0017] The powder W to be treated is an amorphous powder containing impurities, and the impurities are removed and the crystal structure becomes hexagonal graphite by heating to a high temperature of about 2500 to 3000° C. The powder W to be treated is the object to be treated in the first embodiment.

[0018] The continuous graphitization apparatus A performs a heating treatment and a cooling treatment while transporting a transport object M filled with a powder to be treated W. As shown in Fig. 1, the continuous graphitization apparatus A includes a transport device 1, a heating chamber 2, a first cooling chamber 3, a second cooling chamber 4, a first partition wall 5, a second partition wall 6, a third partition wall 7, a fourth partition wall 8, a heating coil 9, a power source 10, a gas replacement device 11, a first cooling device 12, and a second cooling device 13 as components.

[0019] Here, the heating chamber 2, the first partition wall 5, the second partition wall 6, the heating coil 9, the power source 10, and the gas replacement device 11 constitute a heating chamber R1 as shown in the figure. The first cooling chamber 3, the second partition wall 6, the third partition wall 7, and the first cooling device 12 constitute a first cooling chamber R2. The second cooling chamber 4, the third partition wall 7, the fourth partition wall 8, and the second cooling device 13 constitute a second cooling chamber R3.

[0020] The conveying device 1 includes a pair of rails 1a that extend linearly in the horizontal direction and face each other in parallel with a predetermined distance therebetween. The conveying device 1 is a facility that conveys an object M placed on the pair of rails 1a in the extension direction. Note that the conveying device 1 may have another structure as long as it can convey the object M in the horizontal direction, and may, for example, have a structure that does not include the pair of rails 1a.

[0021] The heating chamber 2 is a substantially sealed storage container provided midway along the pair of rails 1a. The heating chamber 2 has a pair of openings (an entrance and an exit) through which the pair of rails 1a pass and which face each other in the extending direction of the rails 1a. The heating chamber 2 accommodates, in a substantially sealed state, the transport object M that is carried in from the entrance along the pair of rails 1a. The transport object M accommodated in the heating chamber 2 is carried out from the exit to the first cooling chamber 3 by the transport device 1.

[0022] The first cooling chamber 3 is a substantially sealed storage container provided midway along the pair of rails 1a adjacent to the heating chamber 2. The first cooling chamber 3 has a pair of openings (an entrance and an exit) through which the pair of rails 1a pass and which face each other in the extending direction of the rails 1a. The first cooling chamber 3 accommodates, in a substantially sealed state, the object M to be transported that is carried in from the entrance along the pair of rails 1a. The object M to be transported that is accommodated in the first cooling chamber 3 is carried out from the exit to the second cooling chamber 4 by the transport device 1.

[0023] The second cooling chamber 4 is a substantially sealed storage container provided midway along the pair of rails 1a adjacent to the first cooling chamber 3. The second cooling chamber 4 has a pair of openings (an entrance and an exit) through which the pair of rails 1a pass and which face each other in the extending direction of the rails 1a. The second cooling chamber 4 accommodates, in a substantially sealed state, the transport object M that is carried in from the entrance along the pair of rails 1a. The transport object M accommodated in the second cooling chamber 4 is carried out from the exit to the outside by the transport device 1.

[0024] That is, in the first embodiment, the transport target M is transported linearly from the heating chamber 2 to the first cooling chamber 3 to the second cooling chamber 4 in this order by the transport device 1 equipped with a pair of rails 1a. The pair of rails 1a may be circular. That is, the pair of rails 1a may be composed of a first rail and a second rail that are circular and have different diameters. The first rail and the second rail are arranged concentrically. The transported object M is transported along the pair of circular rails 1a in the order of heating chamber 2 → first cooling chamber 3 → second cooling chamber 4, and then returned to heating chamber 2 again.

[0025] The first partition wall 5 is a wall provided on the entrance side of the heating chamber 2. The first partition wall 5 has an entrance door 5a that opens and closes the entrance of the heating chamber 2. The entrance door 5a is opened when the transport object M is accommodated in the heating chamber 2, and is closed when the accommodation of the transport object M is completed.

[0026] The second partition wall 6 is a wall provided between the heating chamber 2 and the first cooling chamber 3. The second partition wall 6 is equipped with a first intermediate door 6a that opens and closes the exit of the heating chamber 2, i.e., the entrance of the first cooling chamber 3. The first intermediate door 6a is opened when the transported object M is moved from the heating chamber 2 to the first cooling chamber 3, and is closed when the movement of the transported object M to the first cooling chamber 3 is completed.

[0027] The third partition wall 7 is a wall provided between the first cooling chamber 3 and the second cooling chamber 4. The third partition wall 7 is equipped with a second intermediate door 7a that opens and closes the exit of the first cooling chamber 3, i.e., the entrance of the second cooling chamber 4. The second intermediate door 7a is opened when the object M is moved from the first cooling chamber 3 to the second cooling chamber 4, and is closed when the movement of the object M to the second cooling chamber 4 is completed.

[0028] The fourth partition wall 8 is a wall provided on the exit side of the second cooling chamber 4. The fourth partition wall 8 has an exit door 8a that opens and closes the exit of the second cooling chamber 4. The exit door 8a is opened when the transport object M is discharged from the second cooling chamber 4 to the outside, and is closed when the transport object M has been completely carried out to the outside.

[0029] The heating coil 9 is a hollow cylindrical induction coil that is provided so as to be capable of being raised and lowered within the heating chamber 2. The heating coil 9 is provided in a position in which its axis is vertical and in a state in which it is suspended from the ceiling of the heating chamber 2. The heating coil 9 rises and falls by the operation of an additionally provided lifting device.

[0030] The heating coil 9 has an inner diameter set to be larger than the outer diameter of the object to be transported M so that the object to be transported M can be accommodated therein. When the object to be transported M is accommodated in the heating chamber 2, the lifting device is operated to set the heating coil 9 at a standby position (raised position), and when the object to be transported M is to be heated, the lifting device is operated to set the heating coil 9 at an operating position (lowered position) surrounding the object to be transported M.

[0031] That is, the heating coil 9 can move freely toward and away from the transported object M, and applies a magnetic field to the transported object M. The heating coil 9 is set at a standby position above the entrance door 5a, thereby enabling the transported object M to be accommodated in the heating chamber 2. The heating coil 9 is also set at an operating position surrounding the transported object M, and applies a high-frequency magnetic field to the transported object M based on the supply of electricity from the power source 10.

[0032] When energized from power source 10, heating coil 9 generates a high-frequency magnetic field around it and inevitably generates heat. In order to prevent heating coil 9 from becoming too hot due to heat generation, heating coil 9 is provided with a water-cooling mechanism.

[0033] The power source 10 generates high-frequency power for heating. The power source 10 supplies high-frequency power to the heating coil 9, thereby generating a heating magnetic field around the heating coil 9. The heating magnetic field acts on the inside of the transported body M, thereby heating a susceptor 17 (described below) and the powder W to be treated (raw material). The heating coil 9 and the power source 10 constitute an induction heating device.

[0034] The gas replacement device 11 is a device that creates an inert gas atmosphere inside the heating chamber 2. The gas replacement device 11 creates an inert gas atmosphere inside the heating chamber 2 by discharging the air inside the heating chamber 2 from the heating chamber 2 to the outside and supplying an inert gas such as nitrogen gas into the heating chamber 2.

[0035] For example, the heating chamber 2 is provided with an oxygen concentration meter that measures the oxygen concentration within the heating chamber 2. The gas replacement device 11 replaces the air within the heating chamber 2 with an inert gas so that the oxygen concentration indicated by the oxygen concentration meter becomes equal to or lower than a preset concentration threshold value.

[0036] The first cooling device 12 is a device that cools the transport object M in the first cooling chamber 3. The first cooling device 12 supplies a cooling gas to the transport object M via a pair of connection pipes additionally provided in the first cooling chamber 3, and collects the cooling gas from the transport object M.

[0037] That is, the first cooling device 12 supplies cooling gas to the object M through one connecting pipe provided at the bottom of the first cooling chamber 3. The first cooling device 12 also recovers the cooling gas from the object M through the other connecting pipe provided at the top of the first cooling chamber 3. The first cooling device 12 circulates the cooling gas from the bottom to the top inside the object M by supplying and recovering the cooling gas.

[0038] The second cooling device 13 is a device that cools the transport object M in the second cooling chamber 4. The second cooling device 13 supplies a cooling gas to the transport object M via a pair of connection pipes additionally provided in the second cooling chamber 4, and collects the cooling gas from the transport object M.

[0039] That is, the second cooling device 13 supplies cooling gas to the transported object M through one connecting pipe provided at the bottom inside the second cooling chamber 4. The second cooling device 13 also recovers the cooling gas from the transported object M through the other connecting pipe provided at the top inside the second cooling chamber 4. The second cooling device 13 circulates the cooling gas from the bottom to the top inside the transported object M by supplying and recovering the cooling gas.

[0040] 2A and 2B, the detailed configuration of the transport object M in the first embodiment will be described. The transport object M is a member that contains the powder W to be processed, and includes a furnace shell 15, a furnace lid 16, a susceptor 17, a heat transfer plate 18, a cooling pipe 19, a heat insulating layer 20, and a molded heat insulating material 21 as shown in the figure.

[0041] Of these components of the transported body M, the furnace shell 15, furnace lid 16, susceptor 17, heat transfer plate 18, cooling pipe 19, insulating layer 20 and molded insulation material 21, excluding the powder W to be treated, are heated members that are heated by the heating coil 9 together with the powder W to be treated (object to be treated).

[0042] The furnace shell 15 is a cylindrical container with a bottom. The cylindrical internal space of the furnace shell 15 is a space for accommodating the susceptor 17, the heat transfer plate 18, the cooling pipe 19, the heat insulating layer 20, the molded heat insulating material 21, and the powder W to be treated. The furnace shell 15 is made of a non-magnetic and non-conductive material such as silicon carbide (SiC) so as not to be affected by the high-frequency magnetic field generated by the heating coil 9. As shown in the figure, the furnace shell 15 is placed on a pair of rails 1a of the conveying device 1 with the bottom facing downward and the open part facing upward.

[0043] The lid 16 is a disk-shaped member whose diameter is approximately equal to that of the furnace shell 15. The lid 16 is formed of a non-magnetic and non-conductive material such as silicon carbide (SiC) like the furnace shell 15. The lid 16 is fixed to the upper opening of the furnace shell 15 and closes the upper opening. In other words, the lid 16 seals the inside of the furnace shell 15 from above the molded insulation material 21 arranged above the susceptor 17.

[0044] The susceptor 17 is a cylindrical container with a bottom and an outer shape smaller than the furnace shell 15. The powder W to be processed (raw material) is accommodated inside the susceptor 17. That is, the susceptor 17 has a circular peripheral portion, a bottom portion that closes the lower end of the peripheral portion, and a top portion that closes the upper end of the peripheral portion. The powder W to be processed is accommodated in the cylindrical internal space of the susceptor 17. The top portion is detachable from the peripheral portion. The powder W to be processed is accommodated inside the susceptor 17 with the top portion removed from the peripheral portion.

[0045] The susceptor 17 is made of a material having electrical conductivity and heat resistance, and is a heating element in which a high-frequency current (eddy current) is induced by the action of a high-frequency magnetic field generated by the heating coil 9. The susceptor 17 generates heat when a high-frequency current flows therethrough, and as a result, the powder W (raw material) to be processed is heated.

[0046] 2B, the heat transfer plate 18 is a plate-like member provided in a cross shape inside the susceptor 17. The heat transfer plate 18 is made of a material having excellent heat transfer and heat resistance. The four outer peripheral edges of the heat transfer plate 18 are in contact with the inner peripheral surface of the susceptor 17, and the heat of the susceptor 17 is transferred well.

[0047] 2B, the heat transfer plate 18 is provided over substantially the entire area in the axial direction (height direction) of the susceptor 17. That is, the length in the vertical direction of the heat transfer plate 18 is set so that the lower end of the heat transfer plate 18 abuts against the inner bottom surface of the susceptor 17 (i.e., the upper surface of the bottom part) and the upper end of the heat transfer plate 18 contacts the inner top surface of the susceptor 17 (i.e., the lower surface of the top part). The heat transfer plate 18 conducts the heat generated by the susceptor 17, that is, the heat generated on the outer periphery side of the powder W to be treated (raw material), to the inner side of the powder W to be treated.

[0048] The cooling pipes 19 are a plurality of pipes extending in the axial direction (height direction) of the transported object M and provided at predetermined intervals in the radial direction of the transported object M. That is, the cooling pipes 19 are provided so as to vertically penetrate the furnace shell 15, the furnace lid 16, the susceptor 17, the insulating layer 20, the molded insulating material 21, and the powder W to be treated.

[0049] 2B, a total of five cooling pipes 19 are provided. Of the total of five cooling pipes 19, one is provided at the axial center of the susceptor 17, i.e., the axial center of the transported object M. Of the total of five cooling pipes 19, the remaining four are provided at midpoints in the radial direction of the cross-shaped heat transfer plate 18.

[0050] The cooling pipe 19 is set at a reference position in the first cooling chamber 3, and thereby the lower end (one end) is connected to the first cooling device 12. The cooling pipe 19 is set at a reference position in the second cooling chamber 4, and thereby the lower end (one end) is connected to the second cooling device 13. The upper end (the other end) of the cooling pipe 19 is an open end. The cooling pipe 19 is configured to allow the circulation of cooling gas.

[0051] In the cooling step after heating of the powder W to be treated, a cooling gas supplied from the first cooling device 12 or the second cooling device 13 flows sequentially from bottom to top through the cooling pipe 19. The powder W to be treated, which has been heated to a high temperature of about 2500 to 3000°C in the heating step, which is a step prior to the cooling step, is cooled by heat exchange with the cooling gas via the cooling pipe 19.

[0052] The insulating layer 20 is a powder-like insulating material accommodated in the furnace shell 15. As shown in the figure, a cylindrical susceptor 17 is accommodated concentrically in the cylindrical furnace shell 15, and the insulating layer 20 is provided around the susceptor 17 so as to fill the space between the furnace shell 15 and the susceptor 17. That is, the insulating layer 20 is provided between the inner peripheral surface of the furnace shell 15 and the outer peripheral surface of the susceptor 17, and between the inner bottom surface of the furnace shell 15 and the outer bottom surface of the susceptor 17.

[0053] The molded insulating material 21 is a layered insulating material placed on the top of the susceptor 17. The molded insulating material 21 is formed by stacking a plurality of plate-shaped insulating materials. The molded insulating material 21 is set to a cylindrical shape with a diameter that matches the inner circumference of the furnace shell 15 so that it can be placed on the top of the susceptor 17, that is, stored in the furnace shell 15.

[0054] The transported object M includes a furnace shell 15, a furnace lid 16, a heat transfer plate 18, a cooling pipe 19, a heat insulating layer 20, and a molded heat insulating material 21, in addition to the powder W to be treated and the susceptor 17 to heat the powder W to be treated. That is, the transported object M includes the powder W to be treated and includes at least the susceptor 17 to heat the powder W to be treated.

[0055] Next, the operation of the continuous graphitization apparatus A thus configured will be described in detail. In the continuous graphitization apparatus A according to the first embodiment, a preparation step of the transport object M is first performed. In this preparation step, as shown in Figures 2A and 2B, the powder W to be treated is automatically or manually filled into the susceptor 17, and the furnace cover 16 is attached to the furnace shell 15 in a state in which the molded insulating material 21 is placed on the susceptor 17. Alternatively, a graphite crucible may be attached in the susceptor 17, and the powder W to be treated may be filled into the crucible.

[0056] The object M to be transported that has undergone the preparation process is transferred onto the transport device 1 as shown in Fig. 1, and a heating process is performed. That is, the object M to be transported is placed on the rail 1a of the transport device 1 in front of (outside) the entrance door 5a provided on the first partition wall 5. Then, the object M to be transported is transported from the entrance into the heating chamber 2 by the operation of the transport device 1.

[0057] Then, by operating the gas replacement device 11 while the entrance door 5a and the first intermediate door 6a are closed, the air in the heating chamber 2 is degassed and replaced with an inert gas, and an inert gas atmosphere is set in the heating chamber 2. That is, the inside of the heating chamber 2 is set to an environment with an extremely low oxygen concentration.

[0058] Then, an elevator device annexed to the heating coil 9 is operated, whereby the heating coil 9 is lowered from the standby position (raised position) to an operating position (lowered position) surrounding the transported object M. Then, the power source 10 is operated to supply a high-frequency current to the heating coil 9 in the operating position.

[0059] The heating coil 9 generates a high-frequency magnetic field (induced magnetic field) around it by supplying high-frequency current from a power source 10. This high-frequency magnetic field selectively acts on a susceptor 17 made of a conductive material in the transported body M, generating an induced current (eddy current).

[0060] The susceptor 17 generates heat due to this induced current (eddy current), heating the powder W (raw material) to be treated. The powder W to be treated is ultimately heated to a high temperature of about 2500 to 3000° C. as the heat generation by the susceptor 17 due to the induced current continues for a predetermined time.

[0061] When the susceptor 17 heats the powder W (raw material) to be treated, a cross-shaped heat transfer plate 18 is provided inside the susceptor 17, which is a heating element. The heat transfer plate 18 transfers the heat generated by the susceptor 17 not only to the outer periphery of the powder W to be treated, but also to the inside of the powder W to be treated. As a result, the powder W (raw material) to be treated is heated relatively evenly from the inside to the outside, reaching a high temperature of about 2500 to 3000°C, and becomes treated powder Wa (graphite).

[0062] When the heating step in the heating chamber R1 is thus completed, the power supply 10 stops operating. Then, the lifting device is operated to move the heating coil 9 from the operating position (lowered position) surrounding the transported object M to a standby position (raised position). In this state, the first intermediate door 6a is opened, and the transport device 1 is operated to transport the transported object M from the heating chamber R1 to the first cooling chamber R2, where the first cooling step is performed.

[0063] Then, the first intermediate door 6a and the second intermediate door 7a are closed, thereby setting the environment in the first cooling chamber 3 in a sealed state. In this state, the first cooling device 12 is operated to supply cooling gas from the lower end of the cooling pipe 19 of the transported object M, and collect the cooling gas exhausted into the first cooling chamber 3 from the upper end of the cooling pipe 19.

[0064] That is, the cooling gas is sequentially supplied in a circulating manner to the cooling pipe 19 of the transport object M. The treated powder Wa (graphite) in the transport object M is gradually cooled by heat exchange with the cooling gas flowing from below to above through the cooling pipe 19. Then, after a predetermined cooling time has elapsed, the operation of the first cooling device 12 is stopped, and the first cooling step is completed.

[0065] When the first cooling step is completed in this manner, the second intermediate door 7a is opened, and the transport device 1 is operated to transport the transported object M from the first cooling chamber R2 to the second cooling chamber R3, where the second cooling step is performed. In the second cooling step, the second intermediate door 7a and the exit door 8a are closed, so that the inside of the second cooling chamber 4 is set to an airtight environment.

[0066] In this state, the second cooling device 13 is operated to supply cooling gas from the lower end of the cooling pipe 19 of the transported object M, and the cooling gas exhausted into the second cooling chamber 4 is collected from the upper end of the cooling pipe 19. The processed powder Wa (graphite) in the transported object M is sequentially cooled over time by heat exchange with the cooling gas flowing through the cooling pipe 19 from the bottom to the top, as the cooling gas is sequentially supplied in a circulating manner to the cooling pipe 19 of the transported object M.

[0067] Then, when a predetermined cooling time has elapsed, the operation of the second cooling device 13 is stopped, and the second cooling step is completed. The treated powder Wa (graphite) in the transported object M is cooled to a desired temperature through the first and second cooling steps. When the second cooling step is completed in this manner, the exit door 8a is opened, and the transport device 1 is operated, so that the transported object M is automatically or manually discharged outside the continuous graphitization apparatus A.

[0068] According to this embodiment, the heated members (furnace shell 15, furnace lid 16, susceptor 17, heat transfer plate 18, cooling pipe 19, insulating layer 20 and molded insulating material 21) that are heated together with the powder W (raw material) to be treated are transported together with the powder W (raw material) to be treated, making it possible to provide a heat treatment apparatus A and a heat treatment method that enable improved maintainability of the heated members compared to conventional methods.

[0069] That is, the furnace shell 15, furnace lid 16, susceptor 17, heat transfer plate 18, cooling pipe 19, insulating layer 20, and molded insulating material 21 are consumables that deteriorate due to induction heating caused by the magnetic field generated by the heating coil 9. If such consumables were fixedly installed in the heating chamber 2, it would be necessary to stop operation and perform maintenance on the consumables. However, according to this embodiment, such consumables are transported together with the powder W to be treated, so that maintenance such as replacement and repair is easy, and it is possible to continue operation without interrupting the operation even while the transported body M is undergoing maintenance.

[0070] According to the present embodiment, since the heat transfer plate 18 is provided, it is possible to uniformly heat the powder W (raw material) to be treated. That is, according to the present embodiment, it is possible to suppress uneven heating of the powder W (raw material) to be treated, and it is possible to suppress the input of unnecessary energy in heating.

[0071] According to this embodiment, since the cooling pipe 19 is provided, it is possible to uniformly and effectively cool the treated powder Wa (graphite). That is, according to this embodiment, it is possible to reduce the time required to cool the treated powder Wa (graphite) and to suppress the input energy.

[0072] According to this embodiment, since the gas replacement device 11 is provided, it is possible to suppress the wear due to oxidation of the structures (furnace internal structures) in the heating chamber 2 and the generation of carbon dioxide (CO2). That is, according to this embodiment, it is possible to provide a heat treatment apparatus A and a heat treatment method with a small environmental load.

[0073] According to this embodiment, since the molded insulating material 21 is used instead of the insulating layer 20 as the insulating material to be placed on the susceptor 17, the working environment when removing the treated powder Wa (graphite) can be made clean. If the insulating layer 20 were used instead of the molded insulating material 21, it would be necessary to dig out the treated powder Wa (graphite) from the insulating layer 20, which may cause the insulating layer 20 to turn into dust and worsen the working environment. In this embodiment, since the work of digging out the treated powder Wa (graphite) is not necessary, the working environment can be made clean.

[0074] Second Embodiment Next, a second embodiment of the present disclosure will be described with reference to Fig. 3. In the second embodiment, in a pre-processing step of the heat treatment of the powder W (raw material), the powder W (raw material) is held in a degassed atmosphere or an inert gas atmosphere.

[0075] That is, the heat treatment apparatus B according to the second embodiment includes a heating chamber R1a obtained by removing the heating chamber 2 and the gas replacement device 11 from the heating chamber R1 of the first embodiment. The first cooling chamber R2 and the second cooling chamber R3 of the heat treatment apparatus B are similar to the first cooling chamber R2 and the second cooling chamber R3 of the first embodiment.

[0076] In the second embodiment, the transport object Ma is provided with an air supply port P1 and an exhaust port P2 communicating with the inside and outside of the furnace lid 16. The air supply port P1 and the exhaust port P2 are each provided with, for example, a check valve. The transport object Ma is accommodated in the preparation chamber C prior to the heating process in the heating chamber R1a, i.e., prior to the process of being carried into the heating chamber R1a.

[0077] A vacuum pump D is connected to the preparation chamber C, and a gas source E is connected to the air supply port P1 of the transport object Ma. When the vacuum pump D is operated, the remaining air in the transport object Ma and the air in the preparation chamber C are exhausted to the outside of the preparation chamber C, and when the gas source E is operated, an inert gas is supplied into the transport object Ma and an inert gas atmosphere is also set inside the preparation chamber C.

[0078] The transport object Ma is taken out of the preparation chamber C and is accommodated in a heating chamber R1a equipped with a heating coil 9 and a power source 10 by the operation of the transport device 1. Here, since valves are provided at the air supply port P1 and the exhaust port P2 of the transport object Ma, the inert gas atmosphere inside the transport object Ma is maintained even when the transport object Ma is taken out of the preparation chamber C.

[0079] The transport object Ma is transported from the heating chamber R1a to the first cooling chamber R2 by the operation of the transport device 1, where it is primarily cooled. Then, when the primary cooling in the first cooling chamber R2 is completed, it is transported from the first cooling chamber R2 to the second cooling chamber R3, where it is secondary cooled. Then, when the secondary cooling in the second cooling chamber R3 is completed, it is carried out to the outside through the exit door 8a.

[0080] According to the second embodiment, in addition to the various effects of the first embodiment described above, a relatively large-capacity chamber that takes into account local heat during induction heating, such as the heating chamber 2 of the first embodiment, is not required. Therefore, according to the second embodiment, it is possible to provide a heat treatment apparatus B having a simpler device configuration than the heat treatment apparatus A of the first embodiment.

[0081] The present disclosure is not limited to the above-described embodiment, and the following modifications are possible. (1) In the above embodiment, the present disclosure has been described as being applied to a graphite manufacturing apparatus, but the present disclosure is not limited thereto. The object to be processed in the present disclosure is not limited to powder, which is a raw material for graphite, but includes various powders and objects other than powders. For example, the object to be processed may be a sheet-like object or a granular object in addition to a powder.

[0082] (2) In the above embodiment, the transport object M, Ma is configured to include the furnace shell 15, the furnace lid 16, the susceptor 17 (heat generating element), the heat transfer plate 18, the cooling pipe 19, the insulating layer 20, and the molded insulating material 21. However, the configuration of the transport object M is not limited to this.

[0083] The objects to be transferred M, Ma include the powder to be treated W and at least include a susceptor 17 (heating element), and therefore components other than the susceptor 17 (heating element) and the powder to be treated W are provided as necessary. For example, the objects to be transferred M, Ma may be composed of only the susceptor 17 (heating element) and the insulating layer 20 and molded insulating material 21 attached to the susceptor 17.

[0084] (3) In the above embodiment, the continuous graphitization apparatuses A and B that inductively heat the powder W to be treated are described, but the present disclosure is not limited thereto. The present disclosure is also applicable to a continuous graphitization apparatus of an electric heating type and a continuous graphitization apparatus of a resistance heating type.

[0085] That is, in the case of an electric current heating type continuous graphitization apparatus, the powder W to be treated is contained in a conductive container instead of the susceptor 17 as a heating element, and a heating current is passed through the powder W to be treated by a counter electrode embedded in the powder W to be treated and the conductive container. In this case, the conductive container, the counter electrode, and insulating materials arranged around the conductive container are heated members that are heated together with the powder W to be treated.

[0086] In an electric current heating type continuous graphitization apparatus, heated members such as a conductive container, a counter electrode, and a heat insulating material are transported together with the powder W to be treated. This makes it possible to improve the ease of maintenance of the heated members compared to conventional methods.

[0087] (4) In the above embodiment, the layout of the rails 1a in the conveying device 1 was not described in detail. However, various layouts of the rails 1a, i.e., conveying paths for the objects M and Ma to be conveyed, can be considered taking into account the processing efficiency of the powder to be processed.

[0088] (5) In the above embodiment, the continuous graphitization apparatuses A and B are configured with three chambers consisting of the heating chamber R1, the first cooling chamber R2, and the second cooling chamber R3, or three chambers consisting of the heating chamber R1a, the first cooling chamber R2, and the second cooling chamber R3, but the present disclosure is not limited to this. That is, the number of chambers in the continuous graphitization apparatuses A and B, i.e., the number of stopping positions (number of positions) in the transportation of the transported objects M and Ma, may be other than three.

[0089] (6) In the heating step in the above embodiment, impurities contained in the powder W to be treated may volatilize. A gas exhaust pipe may be provided to exhaust the volatilized gas to the outside of the transfer object M, Ma and the outside of the heating chamber 2.

[0090] (7) In the above second embodiment, the processed powder Wa (graphite) is cooled using the first cooling chamber 3 and the second cooling chamber 4, but the present disclosure is not limited thereto. Since the transport object Ma in the second embodiment is provided with an air supply port P1 and an exhaust port P2, the processed powder Wa (graphite) in the transport object Ma may be cooled by directly connecting the first cooling device 12 or the second cooling device 13 to the air supply port P1 and the exhaust port P2.

[0091] That is, in this modification, cooling gas is supplied from the first cooling device 12 or the second cooling device 13 to the air supply port P1, and the cooling gas heated by heat exchange from the exhaust port P2 is collected in the first cooling device 12 or the second cooling device 13. As a result, the treated powder Wa (graphite) is circulated and cooled by the cooling gas. According to this cooling method, the first cooling chamber 3 and the second cooling chamber 4 are not necessary, so that the configuration of the heat treatment device can be further simplified. [Industrial Applicability]

[0092] According to the present disclosure, it is possible to provide a heat treatment apparatus and a heat treatment method that can improve the ease of maintenance of a heated member compared to conventional methods. [Explanation of symbols]

[0093] A, B Continuous graphitization equipment (heat treatment equipment) M, Ma Transported object W Powder to be treated (material to be treated) 1. Conveyor device 2 Heating chamber 3. First cooling chamber 4. Second Cooling Chamber 5. First Compartment Wall 6 Second Compartment Wall 7. Third Compartment Wall 8 4th Compartment Wall 9 Heating coil 10 Power supply 11 Gas replacement device 12 1st cooling device 13 Second cooling device 15 Furnace shell 16 Hearth cover 17 Susceptor (heating element) 18 Heat transfer plate 19 Cooling pipe 20 Thermal insulation layer 21 Molded insulation material

Claims

1. A transported object including a processing object and having at least a heating element for heating the processing object; a transport device for transporting the transported object; an induction heating device including a heating coil that can move freely toward and away from the transported object and that applies a magnetic field to the transported object to generate heat from the heating element; A powder-like heat insulating layer is provided on the sides and bottom of the heating element, The heat treatment device further comprises a molded heat insulating material provided on the upper portion of the heating element.

2. The heat treatment apparatus according to claim 1 , wherein the transported object comprises a furnace shell having an upper opening and accommodating the heating element, and a furnace lid for closing the upper opening.

3. 3. The heat treatment apparatus according to claim 1, wherein the transported body is configured to hold the heating element and the processing object in a degassed atmosphere or an inert gas atmosphere in advance.

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