A graphitization furnace device and a method for online compensation of heating element load

Abstract

The present invention relates to the technical field of high-temperature equipment, and discloses a graphitization furnace device and a method for online compensation of heating element load. A heating element feeding mechanism is arranged in the heat-insulating body of the induction furnace, wherein the heating element feeding mechanism includes a heating graphite tube and two compensation graphite tubes, and the two compensation graphite tubes are respectively sleeved on both ends of the heating graphite tube. A push rod enters the induction furnace through the air seals at the inlet and outlet ends of the induction furnace and presses against the outer end surface of the compensation graphite tube. When the heating graphite tube is ablated and thinned, resulting in a load change, the push rod can be used to push the compensation graphite tubes at both ends to the middle section to compensate for the load change of the middle section furnace, thereby extending the continuous and stable operation life of the tubular graphitization furnace under high-temperature conditions and facilitating continuous and stable operation of the heating element.

Description

Technical Field

[0001] The present invention relates to the technical field of high-temperature equipment, and in particular to a graphitization furnace device and a method for online compensation of heating element load. Background Art

[0002] Carbon fiber is a fibrous carbon material with a lower density than aluminum but higher strength than steel. It also exhibits corrosion resistance and a high modulus. Graphite fiber generally refers to carbon fiber with a carbon content of over 99%. Compared to carbon fiber, graphite fiber not only has a higher carbon content but also a higher tensile modulus. It also boasts excellent properties such as a low coefficient of thermal expansion, good thermal stability, and dimensional stability. Therefore, it is used to manufacture rigid, thin, and dimensionally stable composite components, which are widely used in spacecraft and aerospace.

[0003] Graphite fiber manufacturing requires the integration of high-temperature technology and equipment. Extending the service life of continuous graphitization at temperatures between 2200°C and 3200°C is crucial. "Carbon Fiber and Graphite Fiber" proposes an induction graphitization furnace for producing continuous carbon fiber. However, due to issues with maintaining the furnace atmosphere caused by fiber inlet and outlet, and the short service life of the heating element at high temperatures, this furnace type has never been widely used at ultra-high temperatures above 2800°C.

[0004] The CN210030982U utility model patent proposes a graphitization furnace that solves the problems of overall airtightness of the equipment and expansion damage of the heating element. However, as the heating element undergoes a certain degree of ablation during high-temperature operation, its resistance increases, the operating power of the equipment increases, and the current load on the surface of the heating element increases, which further accelerates the ablation damage of the heating element and limits its service life and reliability in high-temperature conditions. Summary of the Invention

[0005] In order to overcome the defects of the above-mentioned prior art, the purpose of the present invention is to provide a graphitization furnace device and a method for online compensation of the heating element load, so as to solve the technical problem that the heating element of the graphitization furnace device in the prior art suffers from ablation and thinning and changes in resistance, causing the thermal field and load state to deviate from the design state and fail to operate continuously and stably.

[0006] The present invention is achieved through the following technical solutions:

[0007] A graphitization furnace device comprises an induction furnace, a heat preservation body, a heating element feeding mechanism, an air seal, carbon fiber and two sets of push rods; the inlet and outlet of the induction furnace are coaxially arranged, and the air seal is respectively assembled at the inlet and outlet ends of the induction furnace through flange seals; the heat preservation body is assembled inside the induction furnace, and a through hole is provided in the heat preservation body, and the through hole is coaxially arranged with the inlet and outlet ends of the induction furnace; the heating element feeding mechanism is assembled in the through hole, and the carbon fiber passes through the heating element feeding mechanism along the air seal at the inlet end of the induction furnace to the air seal at the outlet end of the induction furnace; the heating element feeding mechanism comprises a heating graphite tube and two compensating graphite tubes; the two compensating graphite tubes are respectively sleeved at both ends of the heating graphite tube; the two sets of push rods respectively enter the induction furnace through the air seal and press against the outer end faces of the compensating graphite tubes.

[0008] Preferably, the heating graphite tube and the two compensating graphite tubes are hollow tubes, which are coaxially connected inside the tube bodies to form a fiber channel, and the carbon fibers are arranged throughout the fiber channel.

[0009] Preferably, there is a clearance fit between the two compensating graphite tubes and the heating graphite tube.

[0010] Preferably, the push rod is a ceramic rod; the material of the ceramic rod is aluminum oxide or boron nitride.

[0011] Preferably, a rubber sealing ring is provided on the push rod, and a dynamic seal is formed between the push rod and the flange end of the air seal through the rubber sealing ring.

[0012] Preferably, a length scale line is provided on the push rod.

[0013] Preferably, the insulation body includes two groups of end insulation bodies and a middle insulation body; the two groups of end insulation bodies are respectively assembled at the two ends of the middle insulation body and pressed against the inlet and outlet ends of the induction furnace; the two groups of end insulation bodies and the middle insulation body are both provided with through holes, and the through holes are coaxially arranged, and the heating body feeding mechanism is assembled in the through holes of the middle insulation body.

[0014] Preferably, an induction coil is sleeved on the middle heat-insulating body.

[0015] Preferably, heat insulation blocks are provided in the through holes of the two groups of end insulation bodies.

[0016] A method for online compensation of a heating element load of a graphitization furnace device, based on the graphitization furnace device described above, comprises the following steps:

[0017] The induction furnace operates at high temperature. When the heating graphite tube in the induction furnace burns and thins, causing load changes, the push rods on both sides of the induction furnace are pushed to press against the compensating graphite tubes at both ends of the heating graphite tube. The compensating graphite tubes are pushed toward the middle of the furnace at the same time, so that the compensating graphite tubes at both ends of the heating graphite tube are simultaneously superimposed on the heating graphite tube, thereby performing online compensation on the heating graphite tube.

[0018] Compared with the prior art, the present invention has the following beneficial technical effects:

[0019] The present invention provides a graphitization furnace device, in which a heating element feeding mechanism is arranged in the heat-insulating body of the induction furnace, wherein the heating element feeding mechanism includes a heating graphite tube and two compensating graphite tubes, and the two compensating graphite tubes are respectively sleeved on both ends of the heating graphite tube. A push rod enters the induction furnace through the air seals at the inlet and outlet ends of the induction furnace and presses against the outer end surface of the compensating graphite tube. When the heating graphite tube is ablated and thinned, resulting in a load change, the push rod can be used to push the compensating graphite tubes at both ends to the middle section to compensate for the load change of the middle section furnace, thereby extending the continuous and stable operation life of the tubular graphitization furnace under high-temperature conditions and facilitating continuous and stable operation of the heating element.

[0020] Furthermore, the heating graphite tube and the two compensating graphite tubes are hollow tubes, which are coaxially connected inside the tube bodies to form a fiber channel, thereby facilitating the circulation of carbon fibers in the limiting channel.

[0021] Furthermore, there is a gap fit between the two compensating graphite tubes and the heating graphite tube, so that the two compensating graphite tubes can be sleeved on the heating graphite tube and move on the tube body of the heating graphite tube. After the heating graphite tube is ablated and thinned, causing a load change, the compensating graphite tube is moved to compensate for the load change of the middle furnace, thereby extending the continuous and stable operation life of the tubular graphitization furnace under high-temperature conditions.

[0022] Furthermore, the push rod is a ceramic rod; the material of the ceramic rod is aluminum oxide or boron nitride, which effectively plays an insulating effect.

[0023] Furthermore, a rubber sealing ring is provided on the push rod, and a dynamic seal is formed between the push rod and the flange end of the gas seal through the rubber sealing ring, which greatly improves the sealing performance of the induction furnace.

[0024] Furthermore, a length scale line is provided on the push rod for controlling the axial movement distance of the compensation graphite tube.

[0025] A method for online compensation of the load of a heating element in a graphitization furnace device is disclosed. When the induction furnace is operating at high temperature, when the heating graphite tube in the induction furnace is burned and thinned, causing a load change, push rods on both sides of the induction furnace are pushed, and the push rods are pressed against the compensating graphite tubes at both ends of the heating graphite tube. The compensating graphite tubes are simultaneously pushed toward the middle of the furnace, so that the compensating graphite tubes at both ends of the heating graphite tube are simultaneously superimposed on the heating graphite tube, thereby compensating for the load change in the middle section of the furnace, extending the continuous and stable operation life of the tubular graphitization furnace under high-temperature conditions, and facilitating continuous and stable operation of the heating element. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 Schematic diagram of the structure of the graphitization furnace device of the present invention;

[0027] Figure 2 Schematic diagram of the push rod structure of the present invention.

[0028] In the figure: 1-end insulation body; 2-middle insulation body; 3-induction coil; 4-compensating graphite tube; 5-heating graphite tube; 6-insulation block; 7-push rod; 8-air seal; 9-induction furnace; 10-carbon fiber; 71-rubber sealing ring; 72-length scale line. DETAILED DESCRIPTION

[0029] In order to enable those skilled in the art to better understand the solutions of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts should fall within the scope of protection of the present invention.

[0030] It should be noted that the terms "first", "second", etc. in the description and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that the numbers used in this way can be interchanged where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0031] The present invention is described in further detail below with reference to the accompanying drawings:

[0032] The present invention provides a graphitization furnace device and a method for online compensation of heating element load, so as to solve the technical problem in the prior art that the heating element of the graphitization furnace device suffers from ablation, thinning and resistance change, causing the thermal field and load state to deviate from the designed state and thus failing to operate continuously and stably.

[0033] Specifically, according to Figure 1As shown, the graphitization furnace device includes an induction furnace 9, a heat preservation body, a heating body feeding mechanism, an air seal 8, carbon fibers 10 and two groups of push rods 7; the inlet and outlet of the induction furnace 9 are coaxially arranged, and the air seal 8 is respectively assembled at the inlet and outlet ends of the induction furnace 9 through flange seals; the heat preservation body is assembled inside the induction furnace 9, and a through hole is provided in the heat preservation body, and the through hole is coaxially arranged with the inlet and outlet ends of the induction furnace 9; the heating body feeding mechanism is assembled in the through hole, and the carbon fibers 10 pass through the heating body feeding mechanism along the air seal 8 at the inlet end of the induction furnace 9 to the air seal 8 at the outlet end of the induction furnace 9; the heating body feeding mechanism includes a heating graphite tube 5 and two compensating graphite tubes 4; the two compensating graphite tubes 4 are respectively sleeved at both ends of the heating graphite tube 5; the two groups of push rods 7 respectively enter the induction furnace 9 through the air seal 8 and press against the outer end surface of the compensating graphite tube 4.

[0034] Specifically, the heating graphite tube 5 and the two compensating graphite tubes 4 are hollow tubes, which are coaxially connected to form a fiber channel, and the carbon fibers 10 are arranged through the fiber channel.

[0035] Specifically, there is a clearance fit between the two compensating graphite tubes 4 and the heating graphite tube 5 .

[0036] Specifically, the push rod 7 is a ceramic rod; the material of the ceramic rod is aluminum oxide or boron nitride.

[0037] Specifically, a rubber sealing ring 71 is provided on the push rod 7 , and a dynamic seal is formed between the push rod 7 and the flange end of the air seal 8 through the rubber sealing ring 71 .

[0038] Specifically, according to Figure 2 As shown, a length scale line 73 is provided on the push rod 7 .

[0039] Specifically, the insulation body includes two groups of end insulation bodies 1 and a middle insulation body 2; the two groups of end insulation bodies 1 are respectively assembled at the two ends of the middle insulation body 2, and are pressed against the inlet and outlet ends of the induction furnace 9; the two groups of end insulation bodies 1 and the middle insulation body 2 are both provided with through holes, and the through holes are coaxially arranged, and the heating body feeding mechanism is assembled in the through holes of the middle insulation body 2.

[0040] The middle heat-insulating body 2 is provided with an induction coil 3 .

[0041] Specifically, heat insulation blocks 6 are provided in the through holes of the two groups of end heat-insulating bodies 1 .

[0042] The present invention also provides a method for online compensation of a heating element load of a graphitization furnace device, based on the graphitization furnace device described above, comprising the following steps:

[0043] The induction furnace 9 operates at high temperature. When the heating graphite tube 5 in the induction furnace 9 is burned and thinned, causing load changes, the push rods 7 on both sides of the induction furnace 9 are pushed, and the push rods 7 are pressed against the compensating graphite tubes 4 at both ends of the heating graphite tube 5. The compensating graphite tubes 4 are pushed toward the middle of the furnace at the same time, so that the compensating graphite tubes 4 at both ends of the heating graphite tube 5 are simultaneously superimposed on the heating graphite tube 5, and the heating graphite tube 5 is compensated online.

[0044] The graphitization furnace device provided in the present invention can achieve continuous operation of the induction furnace 9 at a temperature of 2800-3000° C. for more than 10 days by compensating for changes in the load of the heating element.

[0045] Example 1

[0046] After the induction furnace 9 has been running at 2800°C for 15 days, when the thickness of the heating graphite tube 5 in the induction furnace 9 has been reduced by 1 / 3, the push rods 7 on both sides of the induction furnace 9 are pushed, and the push rods 7 are pressed against the compensating graphite tubes 4 at both ends of the heating graphite tube 5, and the compensating graphite tubes 4 are pushed toward the middle of the furnace at the same time, so that the compensating graphite tubes 4 at both ends of the heating graphite tube 5 are simultaneously superimposed on the heating graphite tube 5, and are all pushed toward the middle of the furnace along the heating graphite tubes to compensate for the load changes in the middle section of the furnace, and then stably operate at 2800°C for 10 days.

[0047] Example 2

[0048] After the induction furnace 9 has been running at 2900°C for 10 days, when the thickness of the heating graphite tube 5 in the induction furnace 9 is reduced by 1 / 2, the push rods 7 on both sides of the induction furnace 9 are pushed, and the push rods 7 are pressed against the compensating graphite tubes 4 at both ends of the heating graphite tube 5, and the compensating graphite tubes 4 are pushed toward the middle of the furnace at the same time, so that the compensating graphite tubes 4 at both ends of the heating graphite tube 5 are simultaneously superimposed on the heating graphite tube 5, and are all pushed toward the middle of the furnace along the heating graphite tube to compensate for the load changes in the middle section of the furnace, and then stably run at 2900°C for 5 days.

[0049] Example 3

[0050] After the induction furnace 9 has been running at 3000°C for 7 days, when the thickness of the heating graphite tube 5 in the induction furnace 9 has been reduced by 2 / 3, the push rods 7 on both sides of the induction furnace 9 are pushed, and the push rods 7 are pressed against the compensating graphite tubes 4 at both ends of the heating graphite tube 5, and the compensating graphite tubes 4 are pushed toward the middle of the furnace at the same time, so that the compensating graphite tubes 4 at both ends of the heating graphite tube 5 are simultaneously superimposed on the heating graphite tube 5, and are all pushed toward the middle of the furnace along the heating graphite tubes to compensate for the load changes in the middle section of the furnace, and then stably run at 3000°C for 4 days.

[0051] Example 4

[0052] After the induction furnace 9 has been running at 3000°C for 7 days, when the thickness of the heating graphite tube 5 in the induction furnace 9 has been reduced by 2 / 3, the push rods 7 on both sides of the induction furnace 9 are pushed, and the push rods 7 are pressed against the compensating graphite tubes 4 at both ends of the heating graphite tube 5, and the compensating graphite tubes 4 are pushed toward the middle of the furnace at the same time, so that the compensating graphite tubes 4 at both ends of the heating graphite tube 5 are simultaneously superimposed on the heating graphite tube 5, and each is pushed 1 / 2 toward the middle of the furnace along the heating graphite tube to compensate for the load change in the middle section of the furnace, and then the induction furnace is stably operated at 3000°C for 4 days.

[0053] In summary, the long-term continuous and stable operation of the graphitization furnace of the present invention under high-temperature conditions is closely related to improving product stability and reducing production costs. The present invention adopts a heating body feeding mechanism, which includes a heating graphite tube 5 and two compensating graphite tubes 4; the two compensating graphite tubes 4 are respectively arranged at both ends of the heating graphite tube 5. When the thermal field and load state of the graphitization furnace deviate from the design state, the graphite tubes at both ends are used to realize online compensation of the load change of the middle graphite tube, thereby extending the high-temperature continuous operation service life of the graphitization furnace.

[0054] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to the above embodiments, ordinary technicians in the field should understand that the specific implementation methods of the present invention can still be modified or replaced by equivalents. Any modification or equivalent replacement that does not depart from the spirit and scope of the present invention should be covered by the scope of protection of the claims of the present invention.

Claims

1. A graphitization furnace device, characterized in that: The invention comprises an induction furnace (9), a heat preservation body, a heating element feeding mechanism, an air seal (8), carbon fibers (10) and two sets of push rods (7); the inlet and outlet of the induction furnace (9) are coaxially arranged, and the air seal (8) is respectively assembled at the inlet and outlet of the induction furnace (9) through flange sealing; the heat preservation body is assembled inside the induction furnace (9), and a through hole is provided in the heat preservation body, and the through hole is coaxially arranged with the inlet and outlet of the induction furnace (9); the heating element feeding mechanism is assembled in the through hole, and the carbon fibers (10) pass through the heating element feeding mechanism along the air seal (8) at the inlet end of the induction furnace (9) to the air seal (8) at the outlet end of the induction furnace (9); the heating element feeding mechanism comprises a heating graphite tube (5) and two compensating graphite tubes (4); the two compensating graphite tubes (4) are respectively sleeved at both ends of the heating graphite tube (5); the two sets of push rods (7) respectively enter the induction furnace (9) through the air seal (8) and press against the outer end surface of the compensating graphite tube (4); The heating graphite tube (5) and the two compensating graphite tubes (4) are hollow tubes, and the tube bodies are coaxially connected to form a fiber channel, and the carbon fiber (10) is arranged to penetrate the fiber channel; The push rod (7) is provided with a rubber sealing ring (71), and the push rod (7) and the flange end of the air seal (8) form a dynamic seal through the rubber sealing ring (71); The push rod (7) is provided with a length scale line (73); The heat-insulating body comprises two groups of end heat-insulating bodies (1) and a middle heat-insulating body (2); the two groups of end heat-insulating bodies (1) are respectively assembled at the two ends of the middle heat-insulating body (2) and pressed against the inlet and outlet ends of the induction furnace (9); the two groups of end heat-insulating bodies (1) and the middle heat-insulating body (2) are both provided with through holes, and the through holes are coaxially arranged, and the heating body feeding mechanism is assembled in the through hole of the middle heat-insulating body (2); The middle heat-insulating body (2) is provided with an induction coil (3); Heat insulation blocks (6) are provided in the through holes of the two groups of end heat-insulating bodies (1).

2. The graphitization furnace device according to claim 1, characterized in that: There is a clearance fit between the two compensating graphite tubes (4) and the heating graphite tube (5).

3. The graphitization furnace device according to claim 1, characterized in that: The push rod (7) is a ceramic rod; the material of the ceramic rod is aluminum oxide or boron nitride.

4. A method for online compensation of heating element load of a graphitization furnace device, based on the graphitization furnace device according to any one of claims 1 to 3, characterized in that: The steps include: The induction furnace (9) operates at a high temperature. When the heating graphite tube (5) in the induction furnace (9) is burned and thinned, causing a load change, the push rods (7) on both sides of the induction furnace (9) are pushed, and the push rods (7) are pressed against the compensating graphite tubes (4) at both ends of the heating graphite tube (5). The compensating graphite tubes (4) are simultaneously pushed toward the middle of the furnace, so that the compensating graphite tubes (4) at both ends of the heating graphite tube (5) are simultaneously superimposed on the heating graphite tube (5), and the heating graphite tube (5) is compensated online.

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