Graphite heater for high temperature vacuum furnace and its installation device and installation method

Abstract

The present application discloses a graphite heater for a high-temperature vacuum furnace, and its mounting device and method, relating to the technical field of high-temperature vacuum furnaces. The invention can solve the problem of sparking and ablation between heater connectors caused by threaded connections in the prior art. The graphite heater includes a first conductive ring plate, a second conductive ring plate, a plurality of graphite rods, a plurality of electrode members, and a plurality of first graphite sleeves. The first conductive ring plate is uniformly provided with a plurality of first conductive through-holes along its circumferential direction, the first graphite sleeves are embedded in the inner walls of the first conductive through-holes, the second conductive ring plate is uniformly provided with a plurality of second conductive through-holes along its circumferential direction, the second conductive ring plate is composed of three spaced conductive arc plates, the electrode members are connected to the conductive arc plates, and the outer wall of the first graphite sleeve is provided with a first through-groove that communicates with the inner wall of the first graphite sleeve, and the first through-groove penetrates the first graphite sleeve along the length direction of the first graphite sleeve.

Description

Technical Field

[0001] The present invention relates to the technical field of high-temperature vacuum furnaces, and in particular to a graphite heater of a high-temperature vacuum furnace and a mounting device and a mounting method thereof. Background Art

[0002] A vacuum furnace primarily consists of a furnace body, heating system, insulation and temperature measurement system, vacuum system, gas charging system, water cooling system, and control system. Vacuum furnaces generally operate in cycles. Common traditional vacuum furnaces include: vacuum quenching furnaces, vacuum brazing furnaces, vacuum annealing furnaces, vacuum tempering furnaces, vacuum diffusion welding furnaces, and vacuum carburizing furnaces.

[0003] In the existing technology, the temperature inside a vacuum furnace is generally lower than 1600°C. The expansion of the internal thermal field components and the resulting stress and deformation are relatively small compared to high-temperature vacuum furnaces. The main considerations in the thermal field design are process requirements, cost, maintenance, and installation convenience. Therefore, the heater design in traditional vacuum furnaces is mostly integrated (small and medium sizes) or threaded split type.

[0004] With the advancement of science and technology and industry, new demands have been placed on vacuum furnaces in recent years in numerous industries. Some of these furnaces require high temperatures and large effective spaces, such as graphitization furnaces, ceramic sintering furnaces, ceramic hot pressing furnaces, and specialty material synthesis furnaces, often reaching temperatures around 2000°C or higher. Due to the high temperatures and large effective spaces, modular graphite heaters are essentially the only choice. Currently, the most common combinations include threaded connections and tight-fitting bore-to-axis connections. Threaded connections are prone to loosening in these scenarios. At high temperatures, the two threaded components expand and squeeze against each other, causing wear and tear on the threaded connection. When the furnace temperature drops, the components contract and loosen the threaded connection. During operation, high-temperature furnaces are repeatedly heated and cooled, causing the threaded connection to loosen or develop gaps. This leads to poor electrical contact (small effective contact surface), resulting in sparking and ablation between the heater's connecting components. This can cause localized breakdown at these locations (poor contact points), leading to localized high temperatures. In severe cases, excessive temperatures can vaporize the graphite, causing ablation and premature heater failure. Among them, the simple hole-shaft tight fit design is often particularly difficult to install, requiring rich on-site installation experience and high-precision dimensional processing control of parts. Summary of the Invention

[0005] The present invention provides a graphite heater for a high-temperature vacuum furnace and an installation device and an installation method thereof, which are used to solve the problem of sparking and ablation between heater connectors caused by threaded connections in the prior art.

[0006] In order to achieve the above objectives, the embodiments of the present invention provide the following technical solutions:

[0007] The present invention discloses a graphite heater for a high-temperature vacuum furnace, comprising a first conductive structure, a second conductive structure, and a plurality of graphite rods, wherein one end of the plurality of graphite rods is respectively connected to the first conductive structure, and the other end of the plurality of graphite rods is respectively connected to the second conductive structure, and electric heating of the graphite rods is achieved by applying voltage to the first conductive structure and the second conductive structure. The graphite heater is characterized in that: the graphite heater further comprises a plurality of first graphite sleeves, the first conductive structure is provided with a plurality of first conductive through holes, the second conductive structure is provided with a plurality of second conductive through holes, and the plurality of first conductive through holes and the plurality of second conductive through holes correspond to each other one by one; The first graphite sleeve is embedded in the inner wall of the first conductive through-hole, and the first graphite sleeve and the first conductive through-hole are interference fit. The first graphite sleeve is embedded in the inner wall of the second conductive through-hole, and the first graphite sleeve and the second conductive through-hole are interference fit. One end of the graphite rod is embedded in the inner wall of the first graphite sleeve in the first conductive through-hole, and the other end is embedded in the inner wall of the first graphite sleeve in the second conductive through-hole. Both ends of the graphite rod are interference fit with the first graphite sleeve. Multiple graphite rods correspond one-to-one to multiple first conductive through-holes. The first graphite sleeve is provided with a first through groove along its length, which is connected to the inner wall of the first graphite sleeve.

[0008] Preferably, the width of the first through groove along the circumferential direction of the first graphite sleeve is 0.01-10 mm.

[0009] Preferably, both ends of the first graphite sleeve are provided with chamfers for facilitating insertion into the first conductive through-hole or the second conductive through-hole.

[0010] Preferably, the first conductive structural member is a first conductive ring plate, the second conductive structural member is a second conductive ring plate, the first conductive through-holes are evenly arranged along the circumferential direction of the first conductive ring plate, the second conductive through-holes are evenly arranged along the circumferential direction of the second conductive ring plate, the second conductive ring plate is composed of a plurality of conductive arc plates arranged at intervals, a plurality of second conductive through-holes are evenly arranged on a plurality of the conductive arc plates, the conductive arc plates are connected to electrode members, the central axes of the first conductive ring plate and the second conductive ring plate are collinear, the electrode members are electrically connected to an external power supply; the conductive arc plates are provided with a plurality of conductive arc plates for matching the electrode members. The third conductive through hole of the pole piece, the shape of the hole wall of the third conductive through hole is a first conical surface, the outer wall shape of one end of the pole piece is a second conical surface that matches the first conical surface, and the end of the pole piece close to the second conical surface is integrally connected to a limiting rod; when one end of the pole piece is embedded in the third conductive through hole, the second conical surface presses against the first conical surface, the limiting rod passes through the third conductive through hole, and the limiting rod is connected to the conductive arc plate through a limiting nut, the limiting rod is threadedly matched with the limiting nut, and the end of the pole piece away from the limiting rod is electrically connected to the external power supply.

[0011] Preferably, a second graphite sleeve is further embedded between the third conductive through hole and the electrode member, the outer side wall of the second graphite sleeve is formed with a tapered surface matching the first tapered surface, the inner side wall of the second graphite sleeve is formed with a tapered surface matching the second tapered surface, and the second graphite sleeve is provided with a second through groove communicating with the inner wall of the first graphite sleeve along its length.

[0012] Preferably, the width of the second through groove along the circumferential direction of the second graphite sleeve is 0.01-20 mm.

[0013] Preferably, the graphite rod is a hollow or solid cylindrical rod, and annular steps are formed on the outer walls of both ends of the graphite rod.

[0014] The present application also discloses a mounting device for a graphite heater, the mounting device comprising a first mounting ring plate and a second mounting ring plate; the first mounting ring plate is provided with a plurality of first mounting holes for matching graphite rods along its own circumferential direction, and the plurality of first mounting holes correspond to the plurality of graphite rods one-to-one; the second mounting ring plate comprises an inner circular plate and an outer circular plate, the inner circular plate is located on the inner ring of the outer circular plate, the inner circular plate comprises a plurality of inner circular arc plates arranged at intervals, the outer circular plate comprises a plurality of outer circular arc plates arranged at intervals, the plurality of inner circular arc plates correspond to the plurality of outer circular arc plates The arc plates are arranged in a staggered manner, and the inner side wall of the outer arc plate is formed with a first groove adapted to the outer wall of the graphite rod, and the outer side wall of the inner arc plate is formed with a second groove adapted to the outer wall of the graphite rod. The inner arc plate and the outer arc plate are connected by a plurality of distance adjusting members, and the distance adjusting members are used to adjust the distance between the inner arc plate and the outer arc plate; the upper and lower ends of the outer circular ring plate both exceed the upper and lower ends of the inner circular ring plate, and the inner sides of the upper and lower ends of the outer circular ring plate are formed with steps that match the first conductive ring plate or the second conductive ring plate.

[0015] Preferably, the distance adjusting member includes a connecting rod, a distance adjusting nut, and a limit block, the limit block is integrally connected to one end of the connecting rod, the inner arc plate is provided with a first distance adjusting hole, and the outer arc plate is provided with a second distance adjusting hole that matches the first distance adjusting hole. When the connecting rod is passed through the first distance adjusting hole and the second distance adjusting hole, the limit block abuts against the outer side wall of the outer arc plate, the distance adjusting nut is threadedly engaged with the end of the connecting rod away from the limit block, and the distance adjusting nut abuts against the inner side wall of the inner arc plate.

[0016] The present application also discloses a method for installing a graphite heater, comprising the following steps:

[0017] 1) Fixing the graphite rods, placing a first mounting ring plate horizontally and fixing it on a mounting platform, vertically inserting one end of a plurality of graphite rods into the first mounting holes of the first mounting ring plate in sequence, and passing the ends of the plurality of graphite rods through the first mounting holes and resting against the mounting platform;

[0018] 2) Installing a second mounting ring plate, installing the second mounting ring plate on one end of the plurality of graphite rods away from the first mounting ring plate, so that the first groove and the second groove are respectively located on two opposite side walls of the graphite rods, and rotating the spacing nut to gradually reduce the distance between the inner arc plate and the outer arc plate until the groove walls of the first groove and the groove walls of the second groove are tightly against the outer walls of the graphite rods and the annular step of the graphite rods abuts against the lower end of the second mounting ring plate;

[0019] 3) Installing the first conductive ring plate, placing the first conductive ring plate on the upper end of the second mounting ring plate, so that the first conductive ring plate abuts against the step of the outer circular ring plate and the upper end of the inner circular ring plate, and one end of the graphite rod is embedded in the first conductive through-hole of the first conductive ring plate, partially inserting one end of the first graphite sleeve into the gap between the graphite rod and the first conductive through-hole, and then using a soft wooden hammer or a rubber hammer to hammer the end surface of the first graphite sleeve until the first graphite sleeve is completely embedded in the gap between the graphite rod and the first conductive through-hole;

[0020] 4) Installing a second conductive ring plate. Remove the second mounting ring plate and the first mounting ring plate, invert the end where the first conductive ring plate is installed, and place the first conductive ring plate flat on the mounting platform. Repeat step 3) to reinstall the second mounting ring plate on the end of the graphite rod away from the first conductive ring plate, and then install the second conductive ring plate on the end of the graphite rod away from the first conductive ring plate.

[0021] 5) Install the electrode component, sleeve the second graphite sleeve on the second conical surface of the electrode component, insert one end of the electrode component into the third conductive through-hole of the second conductive ring plate, make the outer wall of the second graphite sleeve abut against the hole wall of the third conductive through-hole, and extend the limiting rod out of the third conductive through-hole, then thread the limiting rod onto the limiting rod through the limiting nut, rotate the limiting nut to fix the electrode component on the second conductive ring plate, and finally, connect the end of the electrode component away from the limiting nut to the external power supply.

[0022] This application has the following advantages:

[0023] The two ends of the graphite rod are connected to the first conductive through-hole and the second conductive through-hole through the first graphite sleeve. The two ends of the graphite rod are interference fit with the first graphite sleeve to prevent the graphite rod from loosening. When the graphite heater is powered on and heated, the graphite rod, the first conductive structure, the second conductive structure, and the first graphite sleeve expand due to heat. These components squeeze each other, causing the first graphite sleeve to be compressed and deformed. The first through-groove of the first graphite sleeve can allow the first graphite sleeve to deform to a certain extent, avoiding extrusion and wear of the various components, and solving the problem of sparking and ablation between the heater connectors caused by threaded connection in the prior art.

[0024] Compared with the simple hole-shaft combination, this application has the advantages of easy installation, lower processing precision requirements and low replacement cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] To more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for the embodiments or the description of the prior art. Obviously, the drawings described below are merely exemplary, and those skilled in the art can derive other implementation drawings based on the provided drawings without inventive effort.

[0026] The structures, proportions, sizes, etc. illustrated in this specification are intended only to complement the contents disclosed herein and to facilitate understanding and reading by persons familiar with the art. They are not intended to limit the conditions under which the present invention may be implemented and therefore have no substantive technical significance. Any structural modifications, changes in proportions, or adjustments in sizes, without affecting the efficacy and objectives of the present invention, shall still fall within the scope of the technical contents disclosed herein.

[0027] Figure 1 A schematic diagram of the overall structure of a graphite heater for a high-temperature vacuum furnace provided by an embodiment of the present invention;

[0028] Figure 2 A schematic structural diagram of a first conductive ring plate of a graphite heater of a high-temperature vacuum furnace provided by an embodiment of the present invention;

[0029] Figure 3 A schematic structural diagram of a first graphite sleeve of a graphite heater of a high-temperature vacuum furnace provided by an embodiment of the present invention;

[0030] Figure 4 A schematic structural diagram of a second conductive ring plate of a graphite heater of a high-temperature vacuum furnace provided by an embodiment of the present invention;

[0031] Figure 5 A schematic diagram of an explosion of a conductive arc plate of a graphite heater of a high-temperature vacuum furnace provided by an embodiment of the present invention;

[0032] Figure 6 A schematic structural diagram of a first mounting ring plate of a mounting device for a graphite heater provided in an embodiment of the present invention;

[0033] Figure 7 A schematic structural diagram of a second mounting ring plate of a mounting device for a graphite heater provided in an embodiment of the present invention;

[0034] Figure 8 A schematic diagram of step 2 of a method for installing a graphite heater provided in an embodiment of the present invention;

[0035] Figure 9 A schematic diagram of step 3 of a method for installing a graphite heater provided in an embodiment of the present invention;

[0036] Figure 10 A schematic diagram of step 4 of a method for installing a graphite heater provided in an embodiment of the present invention;

[0037] Figure 11 A schematic diagram of step 5 of a method for installing a graphite heater provided in an embodiment of the present invention;

[0038] Figure 12 It is a star connection mode of three-phase electric circuit in the prior art.

[0039] Description of reference numerals:

[0040] 1. First conductive structural member; 11. First conductive through-hole; 2. Second conductive structural member; 21. Conductive arc plate; 211. Second conductive through-hole; 3. Graphite rod; 4. Electrode member; 41. Second conical surface; 42. Limit rod; 43. Limit nut; 5. First graphite sleeve; 51. First through-groove; 6. Second graphite sleeve; 7. First mounting ring plate; 71. First mounting hole; 72. Weight reduction groove; 8. Second mounting ring plate; 81. Outer circular plate; 811. Outer circular plate; 8111. First groove; 82. Inner circular plate; 812. Inner circular plate; 8121. Second groove; 83. Adjustable distance member; 831. Connecting rod; 832. Adjustable distance nut; 833. Limit block; 9. Winding. DETAILED DESCRIPTION

[0041] In order to make the purpose, technical solutions and advantages of this application more clear, the following further describes this application in detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain this application and are not intended to limit this application.

[0042] In the description of the present application: the terms "inside" and "outside" refer to the inside and outside of the corresponding component contours; the terms "first" and "second" are intended to distinguish the objects referred to, "upper" and "lower" refer to the upper and lower parts of the graphite heater when it is normally placed, and the terms "including", "having" and any variations thereof are intended to cover non-exclusive inclusions. For example, a process, method, system, product or apparatus that includes a series of steps or units is not necessarily limited to those steps or units that have been explicitly listed, but may also include other steps or units that are not explicitly listed but are inherent to these processes, methods, products or apparatuses, or steps or units that are added based on further optimization schemes conceived in the present application.

[0043] A graphite heater for a high-temperature vacuum furnace, comprising a first conductive structure 1, a second conductive structure 2, and a plurality of graphite rods 3, wherein one end of the plurality of graphite rods 3 is respectively connected to the first conductive structure 1, and the other end of the plurality of graphite rods 3 is respectively connected to the second conductive structure 2, and the graphite rods 3 are electrically heated by applying voltage to the first conductive structure 1 and the second conductive structure 2. The graphite heater is characterized in that: the graphite heater further comprises a plurality of first graphite sleeves 5, the first conductive structure 1 is provided with a plurality of first conductive through-holes 11, the second conductive structure 2 is provided with a plurality of second conductive through-holes 211, and the plurality of first conductive through-holes 11 and the plurality of second conductive through-holes 211 correspond one to one; the first graphite sleeves 5 is embedded in the inner wall of the first conductive through-hole 11, and the first graphite sleeve 5 and the first conductive through-hole 11 are interference fit. The first graphite sleeve 5 is embedded in the inner wall of the second conductive through-hole 211, and the first graphite sleeve 5 and the second conductive through-hole 211 are interference fit; one end of the graphite rod 3 is embedded in the inner wall of the first graphite sleeve 5 in the first conductive through-hole 11, and the other end is embedded in the inner wall of the first graphite sleeve 5 in the second conductive through-hole 211, and both ends of the graphite rod 3 are interference fit with the first graphite sleeve 5. Multiple graphite rods 3 correspond to multiple first conductive through-holes 11 one by one; the first graphite sleeve 5 is provided with a first through groove 51 along its length direction, which is connected to the inner wall of the first graphite sleeve 5.

[0044] The two ends of the graphite rod 3 are connected to the first conductive through-hole 11 and the second conductive through-hole 211 through the first graphite sleeve 5. The two ends of the graphite rod 3 are interference fit with the first graphite sleeve 5 to prevent the graphite rod 3 from loosening. When the graphite heater is powered on and heated, the graphite rod 3, the first conductive structure 1, the second conductive structure 2, and the first graphite sleeve 5 expand due to heat. These components squeeze each other, causing the first graphite sleeve 5 to be compressed and deformed. The first through-groove 51 of the first graphite sleeve 5 can allow the first graphite sleeve 5 to deform to a certain extent, avoiding extrusion and wear of the various components, and solving the problem of sparking and ablation between the heater connectors caused by threaded connections in the prior art.

[0045] The width of the first through groove 51 along the circumferential direction of the first graphite sleeve 5 is 0.01-10 mm.

[0046] The number of graphite rods 3 can be 18. The outer cylindrical diameter of the first graphite sleeve 5 is preferably 35 mm, with a tolerance of preferably -0.01 to +0.005 mm. The inner cylindrical diameter of the first graphite sleeve 5 is preferably 28 mm, with a tolerance of preferably -0.005 to +0.01 mm. The height of the first graphite sleeve 5 is preferably 40 mm.

[0047] When the outer cylindrical surface of the first graphite sleeve 5 fits with the corresponding holes of the first conductive through-hole 11 and the second conductive through-hole 211, the designed fitting clearance is -0.1 to +0.08 mm (a negative clearance value indicates an interference fit design, and the clearance range indicates a preferred selection within the range based on different sizes, structures, operating conditions, etc.); when the inner cylindrical surface of the first graphite sleeve 5 fits with the two ends of the graphite rod 3, the designed fitting clearance is -0.1 to +0.08 mm; when the first graphite sleeve 5, the graphite rod 3, the first conductive structural member 1 and the second conductive structural member 2 are connected, the first graphite sleeve 5, the graphite rod 3 and the corresponding first conductive through-hole 11 and the second conductive through-hole 211 have an interference fit.

[0048] Both ends of the first graphite sleeve 5 are provided with chamfers for easy insertion into the first conductive through-hole 11 or the second conductive through-hole 211 .

[0049] The first conductive structural member 1 is a first conductive ring plate, the second conductive structural member 2 is a second conductive ring plate, the first conductive through-holes 11 are evenly arranged along the circumferential direction of the first conductive ring plate, the second conductive through-holes 211 are evenly arranged along the circumferential direction of the second conductive ring plate, the second conductive ring plate is composed of a plurality of conductive arc plates 21 arranged at intervals, the plurality of second conductive through-holes 211 are evenly arranged on the plurality of conductive arc plates 21, the conductive arc plates 21 are connected to the electrode member 4, the central axes of the first conductive ring plate and the second conductive ring plate are collinear, the electrode member 4 is electrically connected to an external power supply; the conductive arc plate 21 is provided with a mating electrode member 4 The third conductive through hole of the third conductive through hole has a hole wall shaped as a first conical surface, and the outer wall shape of one end of the electrode member 4 is a second conical surface 41 that matches the first conical surface. The end of the electrode member 4 close to the second conical surface 41 is integrally connected to a limiting rod 42. When one end of the electrode member 4 is embedded in the third conductive through hole, the second conical surface 41 presses against the first conical surface, the limiting rod 42 passes through the third conductive through hole, and the limiting rod 42 is connected to the conductive arc plate 21 via a limiting nut 43. The limiting rod 42 and the limiting nut 43 are threadedly engaged, and the end of the electrode member 4 away from the limiting rod 42 is electrically connected to the external power supply. The cooperation between the first conical surface and the second conical surface 41 is conducive to the installation of the electrode member 4, that is, the first conical surface serves as a guide for the second conical surface 41. The worker only needs to turn the limiting nut 43 to make the second conical surface 41 press against the first conical surface to complete the installation. It should be explained that the outer periphery of the limiting nut 43 is not restricted by other components. Therefore, the threaded connection here will not cause the limiting nut 43 or the limiting rod 42 to expand due to heat, resulting in extrusion damage.

[0050] The multiple electrode members 4 are connected to the external power supply respectively, and the heating rods on each conductive arc plate 21 are connected in parallel. The conductive connection mode of the graphite heater is the star connection mode of the three-phase circuit (such as Figure 12 As shown, the multiple heating rods on each conductive arc plate 21 are equivalent to Figure 12 windings in the ).

[0051] A plurality of graphite rods 3 are connected to the first conductive ring plate and the second conductive ring plate to form a cylindrical structure. The heating element to be heated is placed at the center of the cylindrical structure. The heat radiation generated by the power supply of the plurality of graphite rods 3 heats the heating element.

[0052] The outer diameter of the first conductive ring plate is preferably 1000 mm, the inner diameter is preferably 880 mm, and the height (thickness) is preferably 40 mm; the diameter of the first conductive through hole 11 is preferably 35 mm, and the tolerance is preferably -0.005 to +0.01 mm.

[0053] The outer diameter of the second conductive ring plate is preferably 1000 mm, the inner diameter is preferably 880 mm, and the height is preferably 40 mm; the number of second conductive through holes 211 on each conductive arc plate 21 is preferably 6, the central angle between two adjacent second conductive through holes 211 is 20°, the diameter of the second conductive through hole 211 is preferably 35 mm, and the tolerance is preferably -0.005 to +0.01 mm.

[0054] The shape of the first conductive ring plate can be a circular ring, a square ring, or other shapes; the shape of the second conductive ring plate can be a circular ring, or other shapes, and the conductive arc plate 21 constituting the second conductive ring plate can be an arc shape, or an "L" shape, and this application does not impose any restrictions on this.

[0055] A second graphite sleeve 6 is embedded between the third conductive through-hole and the electrode member 4. The outer wall of the second graphite sleeve 6 has a tapered surface that mates with the first tapered surface, and the inner wall of the second graphite sleeve 6 has a tapered surface that mates with the second tapered surface 41. A second through-slot is defined along the length of the second graphite sleeve 6, communicating with the inner wall of the first graphite sleeve 5. The circumferential width of the second through-slot in the second graphite sleeve 6 is 0.01 to 20 mm, preferably 3 mm. The second graphite sleeve 6 serves the same function as the first graphite sleeve 5.

[0056] The third conductive through hole is matched with the outer cylindrical surface of the second graphite sleeve 6, and the matching clearance is +0.01 to +1 mm.

[0057] The small end diameter of the third conductive through hole is 0.1 to 20 mm larger than the small end diameter of the conical surface of the second graphite sleeve 6 . The two conical surfaces have the same angle, with a taper of 0.1 to 30°. The conical surface height of the electrode member 4 is 1 to 100 mm larger than that of the second graphite sleeve 6 .

[0058] The limiting nut 43 is a hollow ring, the central internal thread is preferably M34*2, the outer diameter is preferably 70mm, and the outer cylindrical surface of the limiting nut 43 is designed with 4 flat edges for easy tightening. The height is preferably 20mm.

[0059] The graphite rod 3 is a hollow cylindrical rod with annular steps formed on the outer walls of both ends. The diameter of the graphite rod 3 ranges from 5 to 150 mm, and the length ranges from 50 to 5000 mm. Preferably, the inner diameter of the graphite rod 3 is 15 mm; the outer diameters at both ends are 28 mm, with a tolerance of -0.01 to +0.005 mm; and the lengths of both ends are 40 mm. The outer diameter of the center of the graphite rod 3 is 40 mm, and the total length of the graphite rod 3 is 1290 mm. The graphite rod 3 can also be a solid cylindrical rod or a variable diameter round rod.

[0060] The second graphite sleeve 6 is hollow barrel-shaped, the outer diameter of the outer cylindrical surface is preferably 50 mm, and the tolerance is preferably -0.01 to +0.02 mm; the small end diameter of the inner conical surface is preferably 36 mm, and the taper of the conical surface is preferably 8°; the height of the second graphite sleeve 6 is preferably 40 mm.

[0061] The end of the electrode part 4 away from the limiting rod 42 is connected to the copper electrode of the external power supply. The connection method is preferably: the electrode part 4 is designed with an internal thread, and the copper electrode is designed with a corresponding external thread. The threads are tightened to fit. The internal thread of the electrode part 4 is preferably M36*3, and the thread depth is preferably 45mm.

[0062] The present application also discloses a mounting device for a graphite heater, which includes a first mounting ring plate 7 and a second mounting ring plate 8; the first mounting ring plate 7 is provided with a plurality of first mounting holes for matching the graphite rods 3 along its circumferential direction, and the plurality of first mounting holes correspond to the plurality of graphite rods 3 one by one; the second mounting ring plate 8 includes an inner circular plate 82 and an outer circular plate 81, the inner circular plate 82 is located on the inner ring of the outer circular plate 81, the inner circular plate 82 includes a plurality of inner circular arc plates 812 arranged at intervals, the outer circular plate 81 includes a plurality of outer circular arc plates 811 arranged at intervals, and the plurality of inner circular arc plates are aligned with the outer circular plate 81. Multiple outer arc plates are arranged in a staggered manner, and the inner side wall of the outer arc plate is formed with a first groove 8111 that is adapted to the outer wall of the graphite rod 3, and the outer side wall of the inner arc plate is formed with a second groove 8121 that is adapted to the outer wall of the graphite rod 3. The inner arc plate and the outer arc plate are connected by multiple distance adjusting members 83, and the distance adjusting members 83 are used to adjust the distance between the inner arc plate and the outer arc plate; the upper and lower ends of the outer circular ring plate 81 both exceed the upper and lower ends of the inner circular ring plate 82, and the inner sides of the upper and lower ends of the outer circular ring plate 81 are formed with steps that match the first conductive ring plate or the second conductive ring plate.

[0063] The inner annular plate 82 and the outer annular plate 81 are respectively composed of a plurality of arc segments, and there are gaps between the plurality of arc segments. In this way, the distance between the inner annular plate 82 and the outer annular plate 81 can be adjusted, and the gaps provide space for making way.

[0064] The inner annular plate 82 and the outer annular plate 81 are each divided into three sections along their own radial direction and connected by six distance adjusting members 83 .

[0065] The mounting device is used for assembling the above-mentioned graphite heater. As mentioned in the background technology, the simple hole-shaft tight fitting installation in the prior art is difficult and requires relatively high technical quality and technical ability of the personnel. The present application discloses an mounting device that can facilitate workers to assemble the graphite heater. The specific installation and use methods can refer to the installation method of the graphite heater.

[0066] The distance-adjusting member 83 includes a connecting rod 831, a distance-adjusting nut 832, and a stopper 833. The stopper 833 is integrally connected to one end of the connecting rod 831. The inner circular plate has a first distance-adjusting hole, and the outer circular plate has a second distance-adjusting hole that matches the first distance-adjusting hole. When the connecting rod 831 is inserted into the first and second distance-adjusting holes, the stopper 833 abuts against the outer wall of the outer circular plate. The distance-adjusting nut 832 is threadedly engaged with the end of the connecting rod 831 away from the stopper 833, and the distance-adjusting nut 832 abuts against the inner wall of the inner circular plate. Rotating the distance-adjusting nut 832 adjusts the distance between the inner and outer circular plates 82 and 81.

[0067] The first mounting ring plate 7 and the second mounting ring plate 8 are preferably made of 304 steel.

[0068] The first mounting ring plate 7 is provided with a plurality of weight-reducing grooves 72 along its circumferential direction.

[0069] The present application also discloses a method for installing a graphite heater, comprising the following steps:

[0070] 1) Fix the graphite rods 3, place the first mounting ring plate 7 horizontally and fix it on the mounting platform, and vertically insert one end of multiple graphite rods 3 into the first mounting holes 71 of the first mounting ring plate 7 in sequence. The ends of the multiple graphite rods 3 pass through the first mounting holes and abut against the mounting platform;

[0071] 2) Install the second mounting ring plate 8. Install the second mounting ring plate 8 on one end of the graphite rods 3 away from the first mounting ring plate 7, so that the first groove and the second groove are respectively located on two opposite side walls of the graphite rods 3. Turn the spacing nut 832 to gradually reduce the distance between the inner arc plate and the outer arc plate until the groove walls of the first groove and the groove walls of the second groove are tightly against the outer walls of the graphite rods 3 and the annular step of the graphite rods 3 abuts against the lower end of the second mounting ring plate 8.

[0072] 3) Install the first conductive ring plate and place it on the upper end of the second mounting ring plate 8, so that the first conductive ring plate rests against the step of the outer circular ring plate 81 and the upper end of the inner circular ring plate 82, and one end of the graphite rod 3 is embedded in the first conductive through-hole 11 of the first conductive ring plate. Partially insert one end of the first graphite sleeve 5 into the gap between the graphite rod 3 and the first conductive through-hole 11 (the first graphite sleeve 5 has a chamfer and can be partially inserted). Then, use a soft hammer or a rubber hammer to hammer the end face of the first graphite sleeve 5 until the first graphite sleeve 5 is completely embedded in the gap between the graphite rod 3 and the first conductive through-hole 11. If the first graphite sleeve 5 cannot be installed, use fine sandpaper to evenly and lightly polish the inner and outer cylindrical surfaces of the first graphite sleeve 5. During trial installation, install the first graphite sleeve 5 to 1 / 4 of its height.

[0073] 4) Install the second conductive ring plate. Remove the second mounting ring plate 8 and the first mounting ring plate 7. Invert the end where the first conductive ring plate is installed so that the first conductive ring plate is placed flat on the mounting platform. Repeat step 3) to reinstall the second mounting ring plate 8 on the end of the graphite rod 3 away from the first conductive ring plate. Then, install the second conductive ring plate on the end of the graphite rod 3 away from the first conductive ring plate.

[0074] 5) Install the electrode member 4, sleeve the second graphite sleeve 6 on the second conical surface 41 of the electrode member 4, insert one end of the electrode member 4 into the third conductive through-hole of the second conductive ring plate, make the outer wall of the second graphite sleeve 6 abut against the hole wall of the third conductive through-hole, and extend the limiting rod 42 out of the third conductive through-hole, then thread the limiting nut 43 onto the limiting rod 42, rotate the limiting nut 43 to fix the electrode member 4 on the second conductive ring plate, and finally, connect the end of the electrode member 4 away from the limiting nut 43 to the external power supply.

[0075] After installation is complete, remove the mounting device and check the installation of each part. There should be no obvious looseness. The entire graphite heater is now installed. According to the installation requirements and sequence of the entire vacuum furnace equipment, the heater is installed into the high-temperature vacuum furnace at the appropriate stage using the appropriate method. The electrode 4 is connected to the copper electrode of the equipment power supply.

[0076] Although the present invention has been described in detail above using general descriptions and specific embodiments, it will be apparent to those skilled in the art that modifications and improvements may be made thereto. Therefore, such modifications and improvements, without departing from the spirit of the present invention, are intended to be within the scope of protection claimed herein.

Claims

1. A graphite heater for a high-temperature vacuum furnace, comprising a first conductive structure, a second conductive structure, and a plurality of graphite rods, wherein one end of the plurality of graphite rods is respectively connected to the first conductive structure, and the other ends of the plurality of graphite rods are respectively connected to the second conductive structure. Electrical heating of the graphite rods is achieved by applying a voltage to the first conductive structure and the second conductive structure. The invention is characterized in that: The graphite heater further comprises a plurality of first graphite sleeves, the first conductive structure is provided with a plurality of first conductive through holes, the second conductive structure is provided with a plurality of second conductive through holes, and the plurality of first conductive through holes corresponds to the plurality of second conductive through holes in a one-to-one manner; The first graphite sleeve is embedded in the inner wall of the first conductive through-hole, and the first graphite sleeve and the first conductive through-hole are interference fit; the first graphite sleeve is embedded in the inner wall of the second conductive through-hole, and the first graphite sleeve and the second conductive through-hole are interference fit; One end of the graphite rod is embedded in the inner wall of the first graphite sleeve in the first conductive through-hole, and the other end is embedded in the inner wall of the first graphite sleeve in the second conductive through-hole. Both ends of the graphite rod are interference fit with the first graphite sleeve, and the plurality of graphite rods correspond one to one with the plurality of first conductive through-holes. The first graphite sleeve is provided with a first through groove connected to the inner wall of the first graphite sleeve along its length direction; the width of the first through groove along the circumferential direction of the first graphite sleeve is 0.01 to 10 mm; The graphite heater further comprises a mounting device, wherein the mounting device comprises a first mounting ring plate and a second mounting ring plate; The first mounting ring plate is provided with a plurality of first mounting holes for matching the graphite rods along its circumferential direction, and the plurality of first mounting holes correspond to the plurality of graphite rods one-to-one; The second mounting ring plate includes an inner circular plate and an outer circular plate, the inner circular plate is located on the inner ring of the outer circular plate, the inner circular plate includes a plurality of inner circular arc plates arranged at intervals, the outer circular plate includes a plurality of outer circular arc plates arranged at intervals, the plurality of inner circular arc plates are arranged alternately with the plurality of outer circular arc plates, the inner side wall of the outer circular arc plate is formed with a first groove adapted to the outer wall of the graphite rod, the outer side wall of the inner circular arc plate is formed with a second groove adapted to the outer wall of the graphite rod, the inner circular arc plate and the outer circular arc plate are connected by a plurality of distance adjusting members, and the distance adjusting members are used to adjust the distance between the inner circular arc plate and the outer circular arc plate; The upper and lower ends of the outer annular plate are both beyond the upper and lower ends of the inner annular plate, and the inner sides of the upper and lower ends of the outer annular plate are both formed with steps matching the first conductive ring plate or the second conductive ring plate.

2. The graphite heater according to claim 1, characterized in that: Both ends of the first graphite sleeve are provided with chamfers for facilitating insertion into the first conductive through hole or the second conductive through hole.

3. The graphite heater according to claim 1 or 2, characterized in that: The first conductive structural member is a first conductive ring plate, the second conductive structural member is a second conductive ring plate, the first conductive through-holes are evenly arranged along the circumferential direction of the first conductive ring plate, the second conductive through-holes are evenly arranged along the circumferential direction of the second conductive ring plate, the second conductive ring plate is composed of a plurality of conductive arc plates arranged at intervals, a plurality of second conductive through-holes are evenly arranged on the plurality of conductive arc plates, the conductive arc plates are connected to electrode members, the central axes of the first conductive ring plate and the second conductive ring plate are collinear, and the electrode members are electrically connected to an external power supply; The conductive arc plate is provided with a third conductive through hole that matches the electrode member. The hole wall of the third conductive through hole is shaped as a first conical surface. The outer wall of one end of the electrode member is shaped as a second conical surface that matches the first conical surface. The end of the electrode member close to the second conical surface is integrally connected to a limit rod. When one end of the electrode member is embedded in the third conductive through hole, the second conical surface is pressed against the first conical surface, the limiting rod passes through the third conductive through hole, and the limiting rod is connected to the conductive arc plate through a limiting nut, the limiting rod is threadedly engaged with the limiting nut, and the end of the electrode member away from the limiting rod is electrically connected to the external power supply.

4. The graphite heater according to claim 3, characterized in that: A second graphite sleeve is further embedded between the third conductive through hole and the electrode member. The outer wall of the second graphite sleeve is formed with a tapered surface that matches the first tapered surface. The inner wall of the second graphite sleeve is formed with a tapered surface that matches the second tapered surface. The second graphite sleeve is provided with a second through groove along its length that communicates with the inner wall of the first graphite sleeve.

5. The graphite heater according to claim 4, characterized in that: The width of the second through groove along the circumferential direction of the second graphite sleeve is 0.01 to 20 mm.

6. The graphite heater according to claim 1, characterized in that: The graphite rod is a hollow or solid cylindrical rod, and annular steps are formed on the outer walls of both ends of the graphite rod.

7. The graphite heater according to claim 1, characterized in that: The distance adjusting member includes a connecting rod, a distance adjusting nut, and a limit block. The limit block is integrally connected to one end of the connecting rod. The inner arc plate is provided with a first distance adjusting hole, and the outer arc plate is provided with a second distance adjusting hole that matches the first distance adjusting hole. When the connecting rod is passed through the first distance adjusting hole and the second distance adjusting hole, the limit block abuts against the outer side wall of the outer arc plate, the distance adjusting nut is threadedly engaged with one end of the connecting rod away from the limit block, and the distance adjusting nut abuts against the inner side wall of the inner arc plate.

8. A method for installing a graphite heater according to any one of claims 1 to 7, characterized in that: The steps include: 1) Fixing the graphite rods, placing a first mounting ring plate horizontally and fixing it on a mounting platform, vertically inserting one end of a plurality of graphite rods into the first mounting holes of the first mounting ring plate in sequence, and passing the ends of the plurality of graphite rods through the first mounting holes and resting against the mounting platform; 2) Installing a second mounting ring plate, installing the second mounting ring plate on one end of the plurality of graphite rods away from the first mounting ring plate, so that the first groove and the second groove are respectively located on two opposite side walls of the graphite rods, and rotating the spacing nut to gradually reduce the distance between the inner arc plate and the outer arc plate until the groove walls of the first groove and the groove walls of the second groove are tightly against the outer walls of the graphite rods and the annular step of the graphite rods abuts against the lower end of the second mounting ring plate; 3) Installing the first conductive ring plate, placing the first conductive ring plate on the upper end of the second mounting ring plate, so that the first conductive ring plate abuts against the step of the outer circular ring plate and the upper end of the inner circular ring plate, and one end of the graphite rod is embedded in the first conductive through-hole of the first conductive ring plate, partially inserting one end of the first graphite sleeve into the gap between the graphite rod and the first conductive through-hole, and then using a soft wooden hammer or a rubber hammer to hammer the end surface of the first graphite sleeve until the first graphite sleeve is completely embedded in the gap between the graphite rod and the first conductive through-hole; 4) Installing a second conductive ring plate. Remove the second mounting ring plate and the first mounting ring plate, invert the end where the first conductive ring plate is installed, and place the first conductive ring plate flat on the mounting platform. Repeat step 3) to reinstall the second mounting ring plate on the end of the graphite rod away from the first conductive ring plate, and then install the second conductive ring plate on the end of the graphite rod away from the first conductive ring plate. 5) Install the electrode component, sleeve the second graphite sleeve on the second conical surface of the electrode component, insert one end of the electrode component into the third conductive through-hole of the second conductive ring plate, make the outer wall of the second graphite sleeve abut against the hole wall of the third conductive through-hole, and extend the limiting rod out of the third conductive through-hole, then thread the limiting rod onto the limiting rod through the limiting nut, rotate the limiting nut to fix the electrode component on the second conductive ring plate, and finally, connect the end of the electrode component away from the limiting nut to the external power supply.

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