Vacuum furnace thermal field structure for purification
Through the heater heating in a vacuum state through the vacuum furnace heat field structure, the problem of high thermal energy loss of high temperature purification furnace is solved, and efficient purification of carbon materials is achieved, meeting the requirements of high-purity graphite products for decomposition and purification.
Patent Information
- Application Number
- CN202421478235.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-06-26
- Publication Date
- 2025-07-08
- Estimated Expiration
- 2034-06-26
AI Technical Summary
The existing high-temperature purification furnaces have problems such as high electrical and thermal energy loss and low thermal utilization rate, making it difficult to meet the high impurity purification requirements of high-purity graphite products.
The vacuum furnace heat field structure is adopted, and the product is heated by heating the heater in a vacuum state, which eliminates internal stress, stabilizes the product structure and size, improves mechanical properties, and improves the degree of impurity removal and purification.
It realizes efficient purification of carbon materials, with a simple and reliable structure, easy to use, and can meet the requirements of decompression and purification of high-purity graphite products.
Smart Images
Figure CN223077394U_ABST
Abstract
Description
Technical Field
[0001] This application relates to the purification technology of graphite raw materials, and specifically to a thermal field structure of a vacuum furnace for purification. Background Art
[0002] A carbon material purification furnace is a purification device that uses a vacuum environment or halogen gas to directly evaporate the impurity elements in carbon materials such as graphite parts, carbon felt, cured felt, and graphite powder, or generate low-boiling halides and evaporate them outside the product itself to achieve purification. It is widely used in the development of single crystals in the photovoltaic industry, power fuel cells, positive and negative electrode materials, the semiconductor industry, silicon carbide, the sapphire industry, nuclear power plants, aerospace, and new materials.
[0003] The above-mentioned fields have very high requirements for the impurity content of the graphite products used, usually at the ppm level (one in a million) or ppb level (one in a billion). A high-temperature purification furnace is a device that passes halogen gas through processed graphite products, heat-insulating carbon felt, carbon powder, etc. at high temperatures to halogenate impurities, reduce their boiling points, and volatilize them in a timely manner to achieve the purification effect. The production of high-purity graphite in China is basically based on Acheson furnaces, and is equipped with a purification ventilation treatment system. Due to the large amount of power and heat loss in Acheson furnaces, the thermal utilization rate is very low. For chemical purification methods, the best reaction can only be carried out at high temperatures. Generally, the furnace temperature is required to be above 2800°C. The higher the furnace temperature, the more sufficient the reaction time, and the better the purification effect. It can be seen that the influence of temperature on the purification effect is significant. Although the gas distribution is uniform, if the relationship between the purification temperature and time is inappropriate, the purification effect cannot be improved either.
[0004] Therefore, how to provide a carbon material purification furnace with a higher degree of impurity removal and purification, a simple and reliable structure, and convenience and practicality is a technical problem that those skilled in the art need to solve urgently at present. Summary of the Utility Model
[0005] In order to overcome the above defects, this application provides a thermal field structure of a vacuum furnace for purification. The thermal field structure heats and purifies the product through a heater in a vacuum state, so as to achieve the effects of eliminating internal stress, stabilizing the product structure and size, and improving mechanical properties, and can improve the degree of impurity removal and purification of carbon material products.
[0006] The technical solution adopted by this application to solve its technical problems is:
[0007] A thermal field structure of a vacuum furnace for purification, comprising a furnace body, a heat insulation component and a crucible component. The heat insulation component is arranged inside the furnace body, and the crucible component is arranged inside the heat insulation component. The lower end of the furnace body is connected to a base, and the base can cover or be away from the lower end of the furnace body under the action of a driving mechanism. The base is fixedly connected to a bearing plate through a support column, and the bearing plate is located inside the crucible component. A heater is installed between the furnace body and the heat insulation component, and a ventilation pipe component is installed on the furnace body. The ventilation pipe component communicates with the inside of the crucible component.
[0008] Optionally, the heat insulation component includes an upper heat insulation layer, a side heat insulation layer component and a lower heat insulation layer component. The side heat insulation layer component is a cylindrical structure with upper and lower openings and a hollow interior. The upper heat insulation layer is sealed at the upper opening end of the side heat insulation layer component, and the lower heat insulation layer component is sealed at the lower opening end of the side heat insulation layer component.
[0009] Optionally, the side heat insulation layer component includes a first side heat insulation layer and a second side heat insulation layer. The first side heat insulation layer is installed at the upper end of the second side heat insulation layer. The lower heat insulation layer component includes a first lower heat insulation layer and a second lower heat insulation layer. The first lower heat insulation layer is installed at the upper end of the second lower heat insulation layer. The lower heat insulation layer component is installed on the inner side wall of the second side heat insulation layer.
[0010] Optionally, the ventilation pipe component includes an upper ventilation pipe and a lower ventilation pipe. The upper ventilation pipe penetrates through the upper heat insulation layer and the crucible component, and the lower ventilation pipe penetrates through the base, the lower heat insulation layer component and the crucible component.
[0011] Optionally, the upper heat insulation layer and the lower heat insulation layer component are both provided with feeding ports. The feeding port of the upper heat insulation layer is sealed by an upper furnace plug, and the feeding port of the lower heat insulation layer component is sealed by a lower furnace plug.
[0012] Optionally, the crucible component includes a crucible body, a crucible cover plate and a crucible bottom plate. The crucible body is a cylindrical structure with upper and lower openings and a hollow interior. The crucible cover plate is installed at the upper opening of the crucible body, and the crucible bottom plate is installed at the lower opening of the crucible body.
[0013] Optionally, a flow dividing plate is arranged inside the crucible component, and the flow dividing plate is fixedly installed on the crucible cover plate through a connecting piece.
[0014] Optionally, the connecting piece is a connecting piece made of carbon-carbon composite material, the crucible component is a crucible component made of isostatic pressing high-purity graphite, and the bearing plate is a bearing plate made of isostatic pressing high-purity graphite.
[0015] Optionally, the support column is a support column supported by isostatic pressing high-purity graphite, and the heat insulation component is a heat insulation component made of graphite hard felt.
[0016] Optionally, the heater includes an induction coil, and heat insulation cotton is provided between the heater and the heat insulation component.
[0017] The beneficial effects of this application are as follows: In this application, a vacuum state is formed inside the furnace body by using a vacuum device, and the product is heated and purified by the heater in the vacuum state, so as to eliminate internal stress, stabilize the structure and size of the product, and improve mechanical properties, which can improve the degree of impurity removal and purification of carbon material products, and has a simple and reliable structure, convenient use, and strong practicability. In this application, the base of the furnace body can be opened, and the product is placed on the carrier plate by opening the base, and the carrier plate runs synchronously during the operation of the base, so the feeding method is simple and convenient. Description of the Drawings
[0018] Figure 1 It is a structural schematic diagram of the thermal field structure of the vacuum furnace in this application;
[0019] In the figure: 10 - furnace body, 11 - base, 12 - support column, 13 - heater, 14 - heat insulation cotton, 20 - heat insulation component, 21 - upper heat insulation layer, 22 - first side heat insulation layer, 23 - second side heat insulation layer, 24 - first lower heat insulation layer, 25 - second lower heat insulation layer, 26 - upper furnace plug, 27 - lower furnace plug, 28 - upper ventilation pipe, 29 - lower ventilation pipe, 30 - crucible assembly, 31 - crucible body, 32 - crucible cover plate, 33 - crucible bottom plate, 34 - flow dividing plate, 35 - connecting piece, 36 - carrier plate. Detailed Embodiments
[0020] Next, the technical solutions in the embodiments of this application will be described clearly and completely in conjunction with the embodiments of this application. Obviously, the described embodiments of this application are only a part of the embodiments of this application, rather than all the embodiments. Based on the embodiments in this application, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of this application.
[0021] It should be noted that the terms "first", "second", etc. in the description, claims and the following drawings of this application are used to distinguish similar objects, and do not necessarily have to be used to describe a specific order or sequence. It should be understood that the objects so used can be interchanged under appropriate circumstances, so that the embodiments of the present application described here can be implemented in an order different from those illustrated or described here. In addition, the terms "include" and "have" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, system, product or device that includes a series of steps or units does not necessarily have to be limited to those steps or units clearly listed, but may include other steps or units not clearly listed or inherent to these processes, methods, products or devices.
[0022] For the sake of convenience in description, the space relative terms such as "above...", "over...", "on the upper surface of...", "upper" etc. can be used here to describe the spatial position relationship of a device or feature shown in the figure with other devices or features. It should be understood that the space relative terms are intended to include different orientations in use or operation in addition to the orientation of the device described in the figure. For example, if the device in the figure is inverted, the device described as "above other devices or structures" or "over other devices or structures" will then be positioned as "below other devices or structures" or "under other devices or structures". Thus, the exemplary term "above..." can include both the orientations of "above..." and "below...". The device can also be positioned in other different ways (rotated 90 degrees or in other orientations), and corresponding interpretations should be made for the space relative descriptions used here.
[0023] Embodiment: As Figure 1As shown in the figure, a thermal field structure of a vacuum furnace for purification includes a furnace body 10, a heat preservation component 20, and a crucible component 30. The heat preservation component 20 is arranged inside the furnace body 10, and the crucible component 30 is arranged inside the heat preservation component 20. The lower end of the furnace body 10 is connected to a base 11. Under the action of a driving mechanism, the base 11 can cover the lower end of the furnace body 10 or be away from the lower end of the furnace body 10. The base 11 is fixedly connected to a bearing plate 36 through a support column 12. The bearing plate 36 is located inside the crucible component 30. A heater 13 is installed between the furnace body 10 and the heat preservation component 20. A ventilation pipe component is installed on the furnace body 10, and the ventilation pipe component communicates with the inside of the crucible component 30. The ventilation pipe component is used to evacuate the inside of the furnace body 10 to form a negative pressure in the furnace or to introduce an inert gas into the furnace. This application includes a furnace body 10. The lower end of the furnace body 10 is connected to a base 11. The base 11 has an arc-shaped structure. The base 11 can move up and down relative to the furnace body 10 to seal or open the furnace body 10. A heat preservation component 20 is arranged inside the furnace body 10, and a crucible component 30 is arranged inside the heat preservation component 20. The inside of the crucible component 30 is the working area of the vacuum furnace. A bearing plate 36 is arranged inside the crucible component 30. The bearing plate 36 is used to support the graphite product to be purified. The crucible component 30 is connected to an external vacuum device or air inlet device through a ventilation pipe component. A heater 13 is arranged between the furnace body 10 and the heat preservation component 20. The heater 13 is used to heat the inside of the furnace body 10. The heat preservation component 20 is used to keep the inside of the crucible component 30 warm.
[0024] The vacuum device makes the inside of the furnace body form a vacuum through the ventilation pipe component, which is a vacuum furnace. A vacuum furnace refers to a device that uses a vacuum system to exhaust the air in the furnace chamber within a limited space, so that the pressure in the furnace chamber is less than one standard atmospheric pressure, and the space in the furnace chamber reaches a vacuum state, and then the product is heated.
[0025] In this application, a vacuum device is used to make the inside of the furnace body 10 in a vacuum state. In the vacuum state, the product is heated and purified by the heater 13, so as to achieve the effects of eliminating internal stress, stabilizing the product structure and size, and improving mechanical properties. It can improve the degree of impurity removal and purification of carbon material products, and has a simple and reliable structure, convenient use, and strong practicability. In this application, the base 11 of the furnace body 10 can be opened. The product is placed on the bearing plate 36 by opening the base 11. During the operation of the base 11, the bearing plate 36 runs synchronously. Therefore, the feeding method is simple and convenient.
[0026] During use, the driving mechanism drives the base 11 to move away from the lower end of the furnace body 10, that is, to open the furnace body 10. Place the product to be purified on the bearing plate 36, and drive the base 11 to move in the opposite direction to close the furnace body. Then, use a vacuum device to evacuate the air, water vapor, etc. inside the furnace body 10. Finally, heat the furnace body 10 through the heater 13 to raise the temperature inside the furnace body 10, achieving the purpose of purifying the product.
[0027] Optionally, the heat insulation assembly 20 includes an upper heat insulation layer 21, a side heat insulation layer assembly, and a lower heat insulation layer assembly. The side heat insulation layer assembly is a cylindrical structure with upper and lower openings and a hollow interior. The upper heat insulation layer 21 is sealed to the upper opening end of the side heat insulation layer assembly, and the lower heat insulation layer assembly is sealed to the lower opening end of the side heat insulation layer assembly.
[0028] As Figure 1 shown, the side heat insulation layer assembly includes a first side heat insulation layer 22 and a second side heat insulation layer 23. The first side heat insulation layer 22 is installed at the upper end of the second side heat insulation layer 23. The lower heat insulation layer assembly includes a first lower heat insulation layer 24 and a second lower heat insulation layer 25. The first lower heat insulation layer 24 is installed at the upper end of the second lower heat insulation layer 25. The lower heat insulation layer assembly is installed on the inner side wall of the second side heat insulation layer 23. Dividing the heat insulation assembly 20 into multiple heat insulation layers and forming it by splicing the multiple heat insulation layers facilitates the processing and transportation of the heat insulation assembly 20.
[0029] As Figure 1 shown, the ventilation pipe assembly includes an upper ventilation pipe 28 and a lower ventilation pipe 29. The upper ventilation pipe 28 passes through the upper heat insulation layer 21 and the crucible assembly 30 to communicate with the inside of the crucible assembly 30. The lower ventilation pipe 29 passes through the base 11, the lower heat insulation layer assembly, and the crucible assembly 30 to communicate with the inside of the crucible assembly 30. Optionally, the upper ventilation pipe 28 is connected to an inert gas tank for introducing inert gas into the inside of the crucible assembly 30, and the lower ventilation pipe 29 is connected to a vacuum device for evacuating the inside of the crucible assembly 30.
[0030] As Figure 1 shown, the upper heat insulation layer 21 and the lower heat insulation layer assembly are both provided with feeding ports. The feeding port of the upper heat insulation layer 21 is sealed by an upper furnace plug 26, and the feeding port of the lower heat insulation layer assembly is sealed by a lower furnace plug 27. The functions of the upper furnace plug 26 and the lower furnace plug 27 are to prevent heat loss inside the furnace body 10, maintain a specific atmosphere in the chamber of the furnace body, and ensure the safety of the furnace body.
[0031] As Figure 1As shown in the figure, the crucible assembly 30 includes a crucible body 31, a crucible cover plate 32, and a crucible bottom plate 33. The crucible body 31 is a cylindrical structure with openings at both the upper and lower ends and a hollow interior. The crucible cover plate 32 is installed at the upper opening of the crucible body 31, and the crucible bottom plate 33 is installed at the lower opening of the crucible body 31. The internal space formed by the crucible body 31, the crucible cover plate 32, and the crucible bottom plate 33 is the working area of the vacuum furnace. The upper gas pipe 28 passes through the upper insulation layer 21 and the crucible cover plate 32 to communicate with the interior of the furnace body, and the lower gas pipe 29 passes through the base 11, the lower insulation layer assembly, and the crucible bottom plate 33 to communicate with the interior of the furnace body.
[0032] As Figure 1 shown in the figure, a flow dividing plate 34 is provided inside the crucible assembly 30. The flow dividing plate 34 is fixedly installed on the crucible cover plate 32 through a connecting member 35. The function of the flow dividing plate 34 is to divide the gas flowing into the inside of the crucible assembly 30 so that the gas is quickly and evenly distributed.
[0033] Optionally, the connecting member 35 is a connecting member 35 made of carbon-carbon composite material. The crucible assembly 30 is a crucible assembly made of isostatic pressing high-purity graphite, and the bearing plate 36 is a bearing plate made of isostatic pressing high-purity graphite. Carbon-carbon composite material (c-c composite or carbon-carbon composite material) is a carbon matrix composite material reinforced by carbon fiber and its fabric. It has the advantages of low density (<2.0 g / cm 3 ), high strength, high specific modulus, high thermal conductivity, low expansion coefficient, good friction performance, good thermal shock resistance, high dimensional stability, etc. It is one of the few alternative materials applied above 1650 °C today, and the highest theoretical temperature can reach up to 2600 °C. Therefore, it is considered to be one of the most promising high-temperature materials; isostatic pressing graphite is pressed from high-purity graphite. Compared with ordinary graphite, its structure is fine and dense, and its uniformity is good. Optionally, the support column 12 is a support column supported by isostatic pressing high-purity graphite, and the insulation assembly 20 is an insulation assembly made of graphite hard felt.
[0034] The heater 13 includes an induction coil, and a heat insulating cotton 14 is provided between the heater 13 and the insulation assembly 20. The heat insulating cotton 14 is used to further improve the heat insulation effect of the furnace body 10. The induction coil is used to heat the furnace interior, and the heating effect is good and the heating is uniform.
[0035] The operation method of the present application includes the following steps:
[0036] Step 1: Use the driving mechanism to drive the base 11 to move away from the lower end of the furnace body 10, that is, open the furnace body 10. The driving mechanism can be a lifting cylinder or a lifting motor;
[0037] Step 2: Place the graphite product to be purified on the carrier plate 36, and the driving mechanism drives the base 11 to run in the opposite direction to close the furnace body 10;
[0038] Step 3: Use a vacuum device to evacuate the inside of the furnace body 10 to remove the air and water vapor inside the furnace and reduce the vacuum degree inside the furnace to below 0.1 mbar;
[0039] Step 4: Use the induction coil to heat up the inside of the furnace body 10 to 1000 °C and keep it warm for 1 h. Among them, the heating rate is 5 °C / min, and the vacuum inside the furnace is maintained below 0.2 mbar;
[0040] Step 5: Use the induction coil to continue heating up the inside of the furnace body 10 to 2000 °C and keep it warm for 1 h. Among them, the heating rate is 5 °C / min, and the vacuum inside the furnace is maintained below 0.2 mbar;
[0041] Step 6: Use a vacuum device to evacuate the inside of the furnace body 10, and use the induction coil to heat up the inside of the furnace body 10 to 2400 °C - 2600 °C and keep it warm for 1 h. During heating and heat preservation, introduce the purification process gas chlorine. Among them, the vacuum inside the furnace is maintained between 10 - 100 mbar;
[0042] Step 7: Cool the furnace body 10 to 1000 °C and keep it for 1 h. During heating and heat preservation, introduce high-purity argon gas with a purity of more than 99.999% into the furnace body 10. The vacuum degree inside the furnace is between 15 mbar - 90 mbar;
[0043] Step 8: Use a vacuum device to evacuate the inside of the furnace body 10 and cool the temperature inside the furnace to near room temperature. The cooling time is 48 - 60 h. During cooling, introduce high-purity argon gas with a purity of more than 99.999% to make the vacuum degree inside the furnace between 400 m - 700 mbar;
[0044] Step 9: Introduce high-purity argon gas with a purity of more than 99.999% into the furnace body 10 to make the pressure inside the furnace return to one atmosphere, open the furnace door and take out the graphite purified product to complete the purification process.
[0045] It should be noted that for those of ordinary skill in the art, without departing from the concept of this application, several modifications and improvements can still be made, and these all belong to the protection scope of this application. Therefore, the protection scope of this patent application shall be subject to the appended claims.
Claims
1. A thermal field structure of a vacuum furnace for purification, characterized in that: It includes a furnace body (10), a heat insulation component (20) and a crucible component (30). The heat insulation component (20) is arranged inside the furnace body (10), and the crucible component (30) is arranged inside the heat insulation component (20). The lower end of the furnace body (10) is connected to a base (11), and the base (11) can cover the lower end of the furnace body (10) or be away from the lower end of the furnace body (10) under the action of a driving mechanism. The base (11) is fixedly connected to a bearing plate (36) through a support column (12), and the bearing plate (36) is located inside the crucible component (30). A heater (13) is installed between the furnace body (10) and the heat insulation component (20), and a ventilation pipe component is installed on the furnace body (10), and the ventilation pipe component communicates with the inside of the crucible component (30).
2. The heat field structure of the vacuum furnace for purification according to claim 1, wherein: The heat insulation component (20) includes an upper heat insulation layer (21), a side heat insulation layer component and a lower heat insulation layer component. The side heat insulation layer component is a cylindrical structure with upper and lower openings and a hollow interior. The upper heat insulation layer (21) is sealed at the upper opening end of the side heat insulation layer component, and the lower heat insulation layer component is sealed at the lower opening end of the side heat insulation layer component.
3. The thermal field structure of the vacuum furnace for purification according to claim 2, characterized in that: The side heat insulation layer component includes a first side heat insulation layer (22) and a second side heat insulation layer (23). The first side heat insulation layer (22) is installed at the upper end of the second side heat insulation layer (23). The lower heat insulation layer component includes a first lower heat insulation layer (24) and a second lower heat insulation layer (25). The first lower heat insulation layer (24) is installed at the upper end of the second lower heat insulation layer (25). The lower heat insulation layer component is installed on the inner side wall of the second side heat insulation layer (23).
4. The heat field structure of the vacuum furnace for purification according to claim 2, characterized in that: The ventilation pipe component includes an upper ventilation pipe (28) and a lower ventilation pipe (29). The upper ventilation pipe (28) penetrates through the upper heat insulation layer (21) and the crucible component (30), and the lower ventilation pipe (29) penetrates through the base (11), the lower heat insulation layer component and the crucible component (30).
5. The thermal field structure of the vacuum furnace for purification according to claim 2, wherein: Both the upper heat insulation layer (21) and the lower heat insulation layer component are provided with feed openings. The feed opening of the upper heat insulation layer (21) is sealed by an upper furnace plug (26), and the feed opening of the lower heat insulation layer component is sealed by a lower furnace plug (27).
6. The thermal field structure of the vacuum furnace for purification according to claim 1, wherein: The crucible component (30) includes a crucible body (31), a crucible cover plate (32) and a crucible bottom plate (33). The crucible body (31) is a cylindrical structure with upper and lower openings and a hollow interior. The crucible cover plate (32) is installed at the upper opening of the crucible body (31), and the crucible bottom plate (33) is installed at the lower opening of the crucible body (31).
7. The thermal field structure of the vacuum furnace for purification according to claim 6, wherein: A flow dividing plate (34) is arranged inside the crucible component (30), and the flow dividing plate (34) is fixedly installed on the crucible cover plate (32) through a connecting piece (35).
8. The thermal field structure of the vacuum furnace for purification according to claim 7, wherein: The connecting piece (35) is a connecting piece (35) made of carbon-carbon composite material. The crucible component (30) is a crucible component made of isostatic pressing high-purity graphite, and the bearing plate (36) is a bearing plate made of isostatic pressing high-purity graphite.
9. The thermal field structure of the vacuum furnace for purification according to claim 1, wherein: The support column (12) is a support column supported by isostatic pressing high-purity graphite, and the heat insulation component (20) is a heat insulation component made of graphite hard felt.
10. The thermal field structure of the vacuum furnace for purification according to claim 1, characterized in that: The heater (13) includes an induction coil, and heat insulation cotton (14) is provided between the heater (13) and the heat insulation component (20).