A vacuum heat treatment furnace for processing super-large and super-heavy workpieces

Abstract

The present invention belongs to the field of vacuum heat treatment equipment, and particularly relates to a vacuum heat treatment furnace for processing super-large and super-heavy workpieces. Merely increasing the size of a traditional vacuum heat treatment furnace cannot meet the need for processing super-large and super-heavy materials. For this reason, the present invention provides a vacuum heat treatment furnace for processing super-large and super-heavy workpieces, which includes a furnace body shell. Inside the furnace body shell, a heating thermal field is provided. At the bottom of the furnace body shell, a lower furnace door is provided. On the lower furnace door, a bearing platform is provided. On the bearing platform, a material-bearing component made of tungsten alloy for bearing materials is provided; the heating thermal field includes a heating component and a heat preservation component. The heat preservation component includes an upper baffle, side baffles and a lower baffle. The heating component includes a side heating belt group and a lower heating belt group; it realizes a good bearing effect on super-large and super-heavy materials, and realizes ensuring the safety inside the equipment in the case of a super-large furnace body at high temperature, and reducing the possibility of situations such as heating belt deformation, fixing part fracture or equipment short circuit.

Description

Technical Field

[0001] The present invention belongs to the field of vacuum heat treatment equipment, and particularly relates to a vacuum heat treatment furnace for processing extra-large and extra-heavy workpieces. Background Art

[0002] A vacuum heat treatment furnace is a special heat treatment equipment that can enable workpieces to complete heat treatment processes such as annealing, tempering, quenching, and solution treatment in a vacuum environment or an inert gas protection atmosphere environment below standard atmospheric pressure. Compared with traditional atmospheric heat treatment furnaces, using a vacuum heat treatment furnace to perform heat treatment processing on workpieces can significantly eliminate surface contamination and oxidation of the workpieces and improve the quality of the processed products.

[0003] Existing technical solutions for vacuum heat treatment equipment for processing extra-large-sized or extra-heavy workpieces are not yet perfect, and generally have the following problems:

[0004] First, since most vacuum heat treatment furnaces use electric heating tapes as heating elements, a certain amount of thermal expansion will occur during their operation. As the furnace body size increases and the working temperature rises, the thermal deformation of the heating tapes will cause deformation or even fracture of themselves and the installation and fixing parts, seriously affecting the safety and stability of the equipment;

[0005] Second, during the operation of the vacuum heat treatment furnace, volatiles in the furnace body will deposit on the surface of the ceramic insulating parts used to install and fix the heating tapes and form a conductive layer, which is likely to cause a short circuit in the equipment;

[0006] Third, under high-temperature working conditions, the strength of the material-bearing system made of conventional structures and materials in the furnace cannot meet the processing requirements of extra-heavy parts. Summary of the Invention

[0007] To solve the above problems, the present invention proposes a new type of vacuum heat treatment furnace for processing extra-large and extra-heavy parts, which can achieve a good load-bearing effect on extra-large and extra-heavy materials, and ensure the safety inside the equipment under the condition of a high-temperature extra-large furnace body, reducing the possibility of situations such as heating tape deformation, fixing part fracture, or equipment short circuit.

[0008] To achieve the above object, the present invention adopts the following specific solutions, including a furnace body shell, a heating thermal field is arranged inside the furnace body shell, a lower furnace opening is arranged at the bottom of the furnace body shell, a lower furnace door is arranged through the lower furnace opening, a load-bearing platform is arranged on the side of the lower furnace door facing the inside of the furnace body shell, and a material-bearing component for bearing materials is arranged on the load-bearing platform;

[0009] The heating thermal field includes a heating component and a heat preservation component. The heat preservation component includes an upper baffle arranged above the interior of the furnace body shell, a plurality of side baffles arranged on the inner side wall of the furnace body shell, and a lower baffle arranged on the bearing platform. The heating component includes a side heating belt group arranged on the side of the side baffle facing the interior of the furnace body shell and a lower heating belt group arranged on the lower baffle.

[0010] As a preferred embodiment of the present invention, the material bearing component includes a plurality of load-bearing columns and a plurality of load-bearing cross beams. A material bearing tray for bearing materials is arranged through the load-bearing columns and the load-bearing cross beams. A plurality of column fixing sleeves are arranged on the bearing platform, and the load-bearing columns are fixed to the bearing platform through the column fixing sleeves.

[0011] As another preferred embodiment of the present invention, the lower heating belt group is spliced by a plurality of segments of lower heating belts. The lower heating belt group is wound in a star-shaped structure. The lower heating belt group is provided with three layers of star-shaped structures in sequence from the inside to the outside. The lower heating belt group is connected to the lower baffle through a ceramic fixing component arranged at the bending part of the star-shaped structure.

[0012] As a third preferred embodiment of the present invention, the plurality of side baffles are uniformly arranged along the vertical direction on the inner wall of the furnace body shell. There is a gap between adjacent side baffles. A first gap baffle and a second gap baffle are arranged at the gap between two adjacent side baffles. The first gap baffle and the second gap baffle are arranged alternately, and the shielding widths of the first gap baffle and the second gap baffle both exceed half of the gap width.

[0013] As a fourth preferred embodiment of the present invention, the side heating belts of the side heating belt group and the side baffles are provided with a plurality of corresponding mounting holes. The side heating belts of the side heating belt group and the side baffles are connected through a split ceramic part. The split ceramic part includes a first ceramic tube, a second ceramic tube and a connecting rod. The first ceramic tube includes a first large-diameter section and a first small-diameter section. A first annular groove is arranged on the side of the first large-diameter section facing the first small-diameter section. The inner and outer sides of the first annular groove are a first step and a second step. The outer diameter of the second step is larger than the diameter of the mounting hole of the side heating belt. The outer diameter of the first small-diameter section is smaller than the diameter of the mounting hole of the side heating belt. The second ceramic tube includes a second large-diameter section and a second small-diameter section. A second annular groove is arranged on the side of the second large-diameter section close to the second small-diameter section. The outer side of the second annular groove is a third step. A counterbore is arranged on the side of the second large-diameter section far from the second small-diameter section.

[0014] Both the first ceramic tube and the second ceramic tube are provided with through holes along the axial direction, and the diameter of the through holes is larger than the diameter of the connecting rod.

[0015] One end of the connecting rod is provided with fixing wires installed through a radially arranged through hole, and the other end is provided with an external thread.

[0016] As the fifth preferred embodiment of the present invention, the load-bearing columns, load-bearing crossbeams and material receiving trays are all made of tungsten alloy.

[0017] As the sixth preferred embodiment of the present invention, the side heating tapes of the side heating tape group and the lower heating tapes of the lower heating tape group are both made of molybdenum alloy.

[0018] As the seventh preferred embodiment of the present invention, the upper shielding screen, side shielding screen and lower shielding screen are all made of molybdenum alloy.

[0019] Advantages of the present invention:

[0020] In the present invention, shielding screens are provided above, on the side walls and below in the furnace body, and heating tape groups are provided at the side shielding screen and the lower shielding screen, achieving a good heating effect. Among them, the lower heating tape group is wound between the load-bearing columns of the bearing assembly in a three-layer star structure, making the workpiece heated more evenly;

[0021] The material receiving assembly for carrying materials in the present invention uses load-bearing columns, load-bearing crossbeams and material receiving trays made of tungsten alloy. The material receiving assembly with this structure and this material can maintain good strength and stiffness at high temperatures, meeting the heat treatment requirements of overweight workpieces;

[0022] In the present invention, the side heating tape and the side shielding screen are connected by a split ceramic part. The split ceramic part is designed with a gap structure in the thermal expansion direction of the heating tape, leaving a margin space for the expansion of the heating tape, which can effectively solve the possible deformation and fracture problems of the heating tape and its installation and fixing parts after heating and expansion; in addition, a ring groove structure is designed on the main structures of the split ceramic part, namely the first ceramic tube and the second ceramic tube, which can effectively prevent the short circuit and electric leakage phenomena caused by the deposition of volatile substances in the furnace on its surface, improving the stability and safety of processing. Description of the drawings

[0023] Figure 1 It is a schematic cross-sectional view of the furnace body structure of a vacuum heat treatment furnace for processing super-large and overweight workpieces proposed by the present invention.

[0024] Figure 2 It is a schematic view of the structure at the lower furnace door of a vacuum heat treatment furnace for processing super-large and overweight workpieces proposed by the present invention.

[0025] Figure 3 It is an exploded view of each part of the split ceramic part in a vacuum heat treatment furnace for processing super-large and overweight workpieces proposed by the present invention.

[0026] Figure 4 It is a schematic view of the structure of the split ceramic part in a vacuum heat treatment furnace for processing super-large and overweight workpieces proposed by the present invention.

[0027] Figure 5Schematic diagram of the assembly relationship between the split ceramic parts and the heating thermal field in a vacuum heat treatment furnace for processing super-large and super-heavy workpieces proposed by the present invention.

[0028] Figure 6 For Figure 1 Schematic diagram of the side baffle gap of the heating thermal field in area I marked in

[0029] In the attached drawings, 100 is the furnace body shell; 200 is the heating thermal field; 210 is the upper baffle; 220 is the side baffle; 230 is the side heating belt group; 300 is the lower furnace door; 310 is the material supporting structure; 311 is the load-bearing pillar; 312 is the load-bearing cross beam; 313 is the material supporting plate; 321 is the pillar fixing sleeve; 322 is the bearing platform; 330 is the lower heat insulation baffle; 340 is the lower heating belt group; 341 is the lower heating belt; 342 is the ceramic fixing component; 400 is the split ceramic part; 410 is the first ceramic tube; 411 is the first step; 412 is the second step; 413 is the first annular groove; 420 is the second ceramic tube; 421 is the third step; 422 is the second annular groove; 423 is the counterbore; 430 is the connecting rod; 431 is the radial through hole 431; 440 is the fixing wire; 450 is the nut; 510 is the first gap baffle; 520 is the second gap baffle. Specific embodiments

[0030] In order to make the purpose, technical solutions and advantages of the present invention clearer, the following will be described more clearly and completely in combination with specific embodiments and corresponding drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative work shall fall within the protection scope of the present invention.

[0031] It should be understood that in the description of this embodiment, the orientation or positional relationship indicated by the terms is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing this embodiment and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation of the present invention.

[0032] In the present invention, unless otherwise clearly specified and limited, terms such as "set", "connected", "fixed", etc. should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or integrated; it can be directly connected, or indirectly connected through an intermediate medium. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

[0033] Vacuum heat treatment equipment can be divided into types such as annealing, quenching, tempering, carburizing, nitriding, etc. according to specific processes and uses. The vacuum heat treatment furnace described in the embodiments of the present invention is not limited to specific types, and some of the structures and components described can be applied in various types of vacuum heat treatment equipment.

[0034] The furnace body structure is the core component of the vacuum heat treatment furnace equipment, and its main function is to provide the required process environment and conditions for the workpiece being processed; as Figure 1 shown, the outermost layer of the furnace body is the furnace body shell 100, and various interfaces that can be connected to the vacuum system, cooling system, gas system, electrical system, etc. are provided on the furnace body shell 100; a heating thermal field 200 is arranged inside the furnace body shell 100, and a lower furnace opening is arranged at the bottom of the furnace body shell 100. A lower furnace door 300 is arranged through the lower furnace opening. Loading and unloading workpieces into and out of the furnace through the lower furnace opening and facilitating the maintenance and repair of the equipment. The lower furnace door 300 and the furnace body shell 100 can be locked and sealed through a lock ring structure and a sealing structure; a bearing platform 322 is arranged on the side of the lower furnace door 300 facing the inside of the furnace body shell 100, and a material bearing component 310 for bearing materials is arranged on the bearing platform 322;

[0035] The heating thermal field 200 includes a heating component and a heat preservation component. The heat preservation component includes an upper baffle 210 arranged above the inside of the furnace body shell 100, a plurality of side baffles 220 arranged on the inner side wall of the furnace body shell 100, and a lower baffle 330 arranged on the bearing platform 322. Both the upper baffle 210 and the lower baffle 330 are composed of multiple parallel molybdenum plates. The side baffle 220 is assembled coaxially by a group of molybdenum plates curled into a cylindrical shape. There is a certain distance between adjacent layers of molybdenum plates, which is used to reflect the thermal radiation inside the thermal field and play a role in heat preservation and heat insulation;

[0036] The heating component includes a side heating belt group 230 arranged on the side of the side baffle 220 facing the inside of the furnace body shell 100 and a lower heating belt group 340 arranged on the lower baffle 330.

[0037] As Figure 2 shown, as a preferred solution of the present invention, the material bearing component 310 includes a plurality of load-bearing columns 311 and a plurality of load-bearing cross beams 312. A material bearing tray 313 for bearing materials is arranged through the load-bearing columns 311 and the load-bearing cross beams 312. A plurality of column fixing sleeves 321 are arranged on the bearing platform 322, and the load-bearing columns 311 are fixed to the bearing platform 322 through the column fixing sleeves 321; all the load-bearing cross beams 312 are arranged in a divergent manner in the form of angular equal division with the center of the bearing platform 322 as the center point, and jointly bear the upper circular material bearing tray 313, so as to achieve the purpose of dispersing local stress and further improving the overall strength and load-bearing capacity of the material bearing structure.

[0038] The load-bearing columns 311, load-bearing crossbeams 312, and material-bearing trays 313 are all made of tungsten alloy, which can maintain high strength and stiffness under high-temperature conditions and meet the requirements for high-temperature treatment of overweight parts.

[0039] As another preferred embodiment of the present invention, the lower heating belt group 340 is formed by splicing several sections of lower heating belts. The lower heating belt group 340 is coiled in a star-shaped structure in the gaps of the load-bearing columns 311. The lower heating belt group 340 is provided with three layers of star-shaped structures from the inside to the outside. The lower heating belt group 340 is connected to the lower baffle 330 through ceramic fixing components 342 provided at the bends of the star-shaped structure; to ensure the uniformity of the heating temperature below the material-bearing tray 313 during the operation of the thermal field.

[0040] As Figure 3 and Figure 4 As shown, as the third preferred embodiment of the present invention, a plurality of side heating belts are installed on the inner wall of the side baffle 220. The side heating belts are bent into a ring shape and arranged coaxially with the side baffle 220 at a certain interval; a number of corresponding mounting holes are provided on the side heating belts of the side heating belt group 230 and the side baffle 220. The side heating belts of the side heating belt group 230 are connected to the side baffle 220 through split ceramic parts 400. The split ceramic parts 400 include a first ceramic tube 410, a second ceramic tube 420, and a connecting rod 430. The first ceramic tube 410 includes a first large-diameter section and a first small-diameter section. A first ring groove 413 is provided on the side of the first large-diameter section facing the first small-diameter section. The inner and outer sides of the first ring groove 413 are a first step 411 and a second step 412. The outer diameter of the second step 412 is greater than the diameter of the side heating belt mounting hole, and the outer diameter of the first small-diameter section is smaller than the diameter of the side heating belt mounting hole; the second ceramic tube 420 includes a second large-diameter section and a second small-diameter section. A second ring groove 422 is provided on the side of the second large-diameter section close to the second small-diameter section. The outer side of the second ring groove 422 is a third step 421. A counterbore 423 is provided on the side of the second large-diameter section away from the second small-diameter section;

[0041] Both the first ceramic tube 410 and the second ceramic tube 420 are provided with through holes along the axial direction, and the diameter of the through holes is greater than the diameter of the connecting rod 430;

[0042] One end of the connecting rod 430 is provided with a fixing wire 440 installed through a radially through hole 431, and the other end is provided with an external thread.

[0043] As Figure 5As shown in the figure, during installation, the first small-diameter section is passed through the installation hole on the side heating belt and inserted into the counterbore 423 on the second large-diameter section, and the first small-diameter section abuts against the bottom of the counterbore 423; the through-hole of the first ceramic tube 410 is aligned with the installation hole on the side baffle 220, and the second small-diameter section abuts against the inner wall of the side baffle 220; the fixing wire 440 is passed through the radial through-hole 431 on the connecting rod 430 and fastened. Then, the connecting rod 430 is inserted into the through-hole of the first large-diameter section from the end with an external thread and passes through the installation hole of the side baffle 220 and out towards the outside of the furnace body. And until the fixing wire 440 is stuck on the end face of the first large-diameter section, a nut 450 is screwed onto the end of the connecting rod 430 with an external thread, and it is fixed by the nut 450.

[0044] The distance between the second step 412 on the first ceramic tube 410 and the second large-diameter section of the second ceramic tube 420 is greater than the thickness of the side heating belt. Therefore, the side heating belt can freely expand within this range under high-temperature conditions, thus avoiding problems such as deformation and cracking of the heating belt itself or ceramic parts caused by a large amount of thermal expansion of the long heating belt inside the large equipment under high-temperature working conditions; in addition, under high-temperature conditions, there are a certain amount of polluted gases and suspended particles in the thermal field. These pollutants are likely to form a conductive layer after long-term accumulation on insulating parts such as ceramic parts, resulting in equipment leakage and short circuit; the first annular groove 422 structure on the first ceramic tube 410 and the second annular groove 422 on the second ceramic tube 420 can effectively avoid such situations, thereby greatly improving the reliability and safety of the equipment.

[0045] As Figure 6 shown, as the fourth preferred solution of the present invention, the plurality of side baffles 220 are evenly arranged along the vertical direction on the inner wall of the furnace body shell 100, and there is a gap between adjacent side baffles 220. A first gap baffle 510 and a second gap baffle 520 are arranged at the gap between two adjacent side baffles 220. The first gap baffle 510 and the second gap baffle 520 are also assembled by a plurality of molybdenum plates. The number of molybdenum plates of the first gap baffle 510 and the second gap baffle 520 is the same as or close to the number of molybdenum plates of the side baffle 220, and the thickness of the first gap baffle 510 and the second gap baffle 520 is less than half of the thickness of the side baffle;

[0046] The first gap baffle 510 and the second gap baffle 520 are arranged in an interleaved manner. The first gap baffle 510 is connected to a section of the side baffle 220 above the gap and is installed closely outside the side baffle 220. The second gap baffle 520 is connected to a section of the side baffle 220 below the gap and is installed closely inside the side baffle 220. The metal plates of the two gap baffles are arranged in an interspersed manner with the metal plate of the side baffle 220 and are fixedly installed respectively through the connecting rod 430 adjacent to the gap. The shielding widths of the first gap baffle 510 and the second gap baffle 520 both exceed half of the gap width, so as to block the internal thermal radiation of the thermal field while being able to accommodate the large axial thermal expansion amount of the large-size baffle under high-temperature conditions, avoiding the resulting structural deformation and fracture.

[0047] It can be understood that the above specific description of the present invention is only for explaining the present invention and is not limited to the technical solutions described in the embodiments of the present invention. Those of ordinary skill in the art should understand that the present invention can still be modified or equivalently replaced to achieve the same technical effects; as long as the use requirements are met, they are all within the protection scope of the present invention.

Claims

1. A vacuum heat treatment furnace for processing an extra-large and extra-heavy workpiece, comprising a furnace shell (100), wherein a heating thermal field (200) is arranged inside the furnace shell (100), characterized in that: A lower furnace opening is provided at the bottom of the furnace shell (100), a lower furnace door (300) is provided through the lower furnace opening, a carrying platform (322) is provided on a side of the lower furnace door (300) facing the inside of the furnace shell (100), and a material bearing assembly (310) for bearing materials is provided on the carrying platform (322); The heating thermal field (200) comprises a heating component and a heat preservation component, the heat preservation component comprising an upper baffle (210) arranged above the interior of the furnace shell (100), a plurality of side baffles (220) arranged on the inner side walls of the furnace shell (100), and a lower baffle (330) arranged on the carrying platform (322), the heating component comprising a side heating belt group (230) arranged on the side of the side baffle (220) facing the interior of the furnace shell (100), and a lower heating belt group (340) arranged on the lower baffle (330); The plurality of side shields (220) are evenly arranged along the vertical direction on the inner wall of the furnace shell (100), a gap exists between adjacent side shields (220), a first gap shield (510) and a second gap shield (520) are arranged at the gap between two adjacent side shields (220), the first gap shield (510) and the second gap shield (520) are arranged alternately, and the shielding widths of the first gap shield (510) and the second gap shield (520) are both greater than half of the gap width; The material bearing assembly (310) comprises a plurality of load-bearing pillars (311) and a plurality of load-bearing beams (312); a material bearing tray (313) for bearing materials is arranged via the load-bearing pillars (311) and the load-bearing beams (312); a plurality of pillar fixing sleeves (321) are arranged on the bearing platform (322); and the load-bearing pillars (311) are fixed to the bearing platform (322) via the pillar fixing sleeves (321); The side heating belts of the side heating belt group (230) and the side baffle (220) are provided with a plurality of corresponding mounting holes. The side heating belts of the side heating belt group (230) and the side baffle (220) are connected via a split ceramic component (400). The split ceramic component (400) comprises a first ceramic tube (410), a second ceramic tube (420) and a connecting rod (430). The first ceramic tube (410) comprises a first large diameter section and a first small diameter section. A first annular groove (413) is provided on the side of the first large diameter section facing the first small diameter section. The inner and outer sides of the annular groove (413) are a first step (411) and a second step (412); the outer diameter of the second step (412) is larger than the diameter of the mounting hole of the side heating belt; the outer diameter of the first small diameter section is smaller than the diameter of the mounting hole of the side heating belt; the second ceramic tube (420) comprises a second large diameter section and a second small diameter section; a second annular groove (422) is provided on the side of the second large diameter section close to the second small diameter section; the outer side of the second annular groove (422) is a third step (421); and a countersunk hole (423) is provided on the side of the second large diameter section away from the second small diameter section; The first ceramic tube (410) and the second ceramic tube (420) are both provided with through holes along the axial direction, and the diameter of the through holes is greater than the diameter of the connecting rod (430); One end of the connecting rod (430) is provided with a fixing wire (440) installed through a radial through hole (431), and the other end is provided with an external thread; The material of the load-bearing pillar (311), the load-bearing crossbeam (312) and the material receiving tray (313) are all tungsten alloy.

2. A vacuum heat treatment furnace for processing super-large and super-heavy workpieces as claimed in claim 1, characterized in that: The lower heating belt group (340) is formed by splicing a plurality of lower heating belt sections, the lower heating belt group (340) is coiled in a star-shaped structure, the lower heating belt group (340) is provided with three layers of star-shaped structures in sequence from the inside to the outside, and the lower heating belt group (340) is connected to the lower baffle (330) via a ceramic fixing assembly (342) provided at a bend of the star-shaped structure.

3. A vacuum heat treatment furnace for processing super-large and super-heavy workpieces as claimed in claim 1, characterized in that: The side heating belts of the side heating belt group (230) and the lower heating belt of the lower heating belt group (340) are both made of molybdenum alloy.

4. A vacuum heat treatment furnace for processing super-large and super-heavy workpieces as claimed in claim 1, characterized in that: The upper shield (210), the side shield (220) and the lower shield (330) are all made of molybdenum alloy.

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